KR102171244B1 - Toner and method of preparing the same - Google Patents

Abstract

A toner and a method of manufacturing the same are disclosed. The disclosed toner includes a core portion including a first binder resin having a weight average molecular weight of Mw ₁ , a second binder resin having a weight average molecular weight of Mw ₂ and surrounding the core portion, and a weight average of Mw ₃ . It includes a third binder resin having a molecular weight and includes a second shell portion surrounding the first shell portion, and the Mw ₁ , Mw ₂ and Mw ₃ satisfy the formula (Mw ₂ <Mw ₁ <Mw ₃ ).

Description

Toner and method of preparing the same {Toner and method of preparing the same}

A toner and a method of manufacturing the same are disclosed. More specifically, a toner having a triple structure excellent in fixing properties, strength, and durability, and a method of manufacturing the same are disclosed.

In general, toners are prepared by adding a colorant and a wax to a thermoplastic resin serving as a binder resin. In addition, a charge control agent that imparts chargeability to the toner and maintains it, a release agent such as wax for a release action with the fixing unit of an image forming apparatus, and imparts fluidity and developability to the toner or improves physical properties such as drum cleaning properties. External additives for can be added to the toner. Methods for producing such toners include physical methods such as pulverization and chemical methods such as suspension polymerization, emulsion agglomeration, chemical milling, and dispersion polymerization.

Among them, the emulsion coagulation method (see U.S. Patent Nos. 5,916,725, 6,268,103, etc.) includes the step of preparing a fine emulsion resin particle composition through an emulsion polymerization reaction, and coagulating the composition with a colorant in a separate dispersion do. This method has the advantage of improving the problems such as high cost and wide particle size distribution in the pulverization method, and making the toner particles spherical by adjusting the aggregation conditions.

However, there is a problem that the toner particles manufactured by the conventional emulsion agglomeration method do not have excellent fixing properties, strength, and durability at the same time.

One embodiment of the present invention provides a toner having a triple structure having excellent fixing properties, strength, and durability.

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

One aspect of the present invention,

A core portion including a first binder resin having a weight average molecular weight of Mw ₁ ;

A first shell portion including a second binder resin having a weight average molecular weight of Mw ₂ and surrounding the core portion; And

It includes a third binder resin having a weight average molecular weight of Mw ₃ , and includes a second shell portion surrounding the first shell portion,

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 a wax,

The Mw ₁ , Mw ₂ and Mw ₃ provide a toner satisfying the formula (Mw ₂ <Mw ₁ <Mw ₃ ).

The weight average molecular weight (Mw ₁ ) of the first binder resin is 42,000 to 55,000, the weight average molecular weight (Mw ₂ ) of the second binder resin is 24,000 to 45,000, and the weight average molecular weight (Mw ₃ ) of the third binder resin ) Can be 55,000-79,000.

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.

Another aspect of the invention,

Adding a first binder resin dispersion and a coagulant to the reactor, and then first heating the reactor contents to form a toner core (S10);

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

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

Including a step (S40) of obtaining unified toner particles by secondarily raising the temperature of the contents of the reactor that has undergone the second shell portion forming step,

In at least one of the steps (S10) and (S20), at least one dispersion of a colorant dispersion and a wax dispersion is further added to the reactor,

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

In the method of manufacturing the toner, in the step (S10), instead of the first binder resin dispersion, the second binder resin dispersion and the second binder resin dispersion are added together in the reactor, and in this case, Mw ₁ is It may be a value obtained by a weighted average of the Mw ₂ and the Mw ₃ according to the ratio of the input amount of the second binder resin in the second binder resin dispersion and the third binder resin in the third binder resin dispersion.

The first temperature may be increased to a temperature of 2 to 20° C. lower than the glass transition temperature of the first binder resin introduced in the core part forming step.

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

The content of the first binder resin added to the core part forming step (S10), the content of the second binder resin added to the first shell part forming step (S20), and the second shell part 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 of manufacturing a toner according to an exemplary embodiment of the present invention, a toner having excellent fixing properties, strength, and durability can be obtained.

1 is a schematic diagram of a toner according to an embodiment of the present invention.
2 is a graph showing the change in storage modulus according to the temperature of the toners prepared in Example 1 and Comparative Example 1. FIG.
3 is a graph showing a change in loss modulus according to the temperature of the toners prepared in Example 1 and Comparative Example 1. FIG.
4 is a graph showing the change in storage modulus according to the frequency of the toners prepared in Example 1 and Comparative Example 1;
5 is a graph showing a change in loss modulus according to the frequency of the toners 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.

Hereinafter, a toner according to an embodiment of the present invention and a method of manufacturing 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 , a second binder resin having a weight average molecular weight of Mw ₂ and surrounds the core 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. In the present specification, "toner" may refer to one toner particle or a collection of toner particles (ie, toner powder) depending on the context.

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

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

Mw ₂ <Mw ₁ <Mw ₃ .

Since Mw ₁ is greater than Mw ₂ and less than Mw ₃ in the core portion occupying the largest amount of the toner, the toner may have an appropriate level of glass transition temperature.

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

Since the Mw ₃ is large in the second shell portion, the toner may have excellent thermal strength, mechanical strength, and durability. Accordingly, even if the toner is stored under a high temperature environment for a long period of time, the toner can be melted and fused together, preventing a caking phenomenon, thereby improving storage stability of the toner.

The second shell portion may have a thin film shape to prevent deterioration of the fixing property of the toner.

The Mw ₁ , Mw ₂ and Mw ₃ satisfy the formula (Mw ₂ <Mw ₁ <Mw ₃ ), thereby maintaining the glass transition temperature of the entire toner at an appropriate level, while maintaining the thermal strength, mechanical strength and durability of the toner. Can increase. Accordingly, it is possible to improve both the fixing characteristics and strength of toners in a trade-off relationship with each other.

The weight average molecular weight (Mw ₁ ) of the first binder resin may be 42,000 to 55,000, the weight average molecular weight (Mw ₂ ) of the second binder resin may be 24,000 to 45,000, and the weight average of the third binder resin The molecular weight (Mw ₃ ) may be 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 binder resins is within the above ranges, the strength and durability of the toner may be improved while maintaining high fixing characteristics of the toner.

Hereinafter, the configuration of the toner will be described in more detail with reference to FIG. 1.

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

Referring to FIG. 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 first binding resin (not shown) is distributed in the core portion 11, the second binding resin (not shown) is distributed in the first shell portion 12, and the third binding resin is distributed in the second shell portion 13. Resin (not shown) is distributed.

At least one of a colorant (not shown) and a wax (not shown) may be further distributed in 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 the toner includes the steps of forming a toner core part by adding a first binder resin dispersion and a coagulant to a reactor, and then raising the reactor contents to first temperature (S10), and a second binder resin in the reactor contents containing the toner core part. The step of forming a first shell part surrounding the toner core part by adding a dispersion liquid (S20), and a second shell surrounding the first shell part by adding a third binder resin dispersion to the reactor contents containing the first shell part Forming a portion (S30), and a step (S40) of obtaining unified toner particles by secondarily raising the temperature of the contents of the reactor after the second shell portion forming step. Each of the steps may be performed in one reactor, but the present invention is not limited thereto, and one or more steps and two or more steps of the four steps may be divided into two or more reactors.

In at least one of the steps (S10) and (S20), at least one dispersion of a colorant dispersion and a wax dispersion may be further added to the reactor.

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

Mw ₂ <Mw ₁ <Mw ₃ .

In the step (S10), instead of the first binder resin dispersion, the second binder resin dispersion and the second binder resin dispersion are added together in a predetermined ratio in the reactor, and in this case, Mw ₁ is the second binder. It may be a value obtained by a weighted average of the Mw ₂ and the Mw ₃ according to the ratio of the input amount of the second binder resin in the resin dispersion and the third binder resin in the third binder resin dispersion.

The reactor may be provided with a stirrer, heating means (eg, heater), pressurizing means and/or pressure reducing means (eg, vacuum pipe and vacuum pump).

In one embodiment, the binder resin dispersion, the colorant dispersion, and the wax dispersion may be prepared by the same or similar method as the latex dispersion, colorant dispersion, and wax dispersion disclosed in Korean Patent Publication No. 2010-0048071, respectively. Korean Patent Application Publication No. 2010-0048071 is incorporated herein in its entirety by reference.

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

The glass transition temperature of the first binder resin may be 54 to 60?, the glass transition temperature of the second binder resin may be 54 to 58?, and the glass transition temperature of the third binder resin may be 56 to 65? Can be When the glass transition temperature of each of the binder resins is within the above ranges, the toner formed using each of the binder resin particles has excellent fixing properties.

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

The total content 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 added amount of the first, second and third binder resins.

The wax used to prepare the wax dispersion may be a known wax. Natural waxes, such as carnauba wax and rice wax, for example; Synthetic waxes such as polypropylene wax and polyethylene wax; Petroleum waxes such as montan wax; Alcohol-based wax; And ester-based waxes, etc. may be used. One type of wax may be used alone, or two or more types may be used in combination.

In addition, the wax may include at least one of a paraffin wax and a polyester wax. The paraffin-based wax mainly includes a straight chain saturated hydrocarbon of C ₂₀ ~ C ₃₆ , 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 paraffinic 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 added amount of the first, second and third binder resins.

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

The total content of the coagulant added in the step (S10), the step (S20) and the step (S30) is based on 100 parts by weight of the total added amount of the first binder resin, the second binder resin, and the third binder resin. It may be 5 to 40 parts by weight.

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

The step (S10) (that is, the coagulation process by the first heating) may be performed until the toner has a particle diameter of 5.0 to 6.0 μm.

The secondary temperature may be increased to a temperature of 10 to 40° C. higher than the glass transition temperature (Tg ₃ ) of the third binder resin added to the second shell part forming step. If the temperature at the second temperature rise is within the above range (Tg ₃ + 10 to 40°C), the wax components can be aggregated to form a wax lump and then the wax lump protrudes to the toner surface can be prevented.

The step (S40) (ie, a coalescence process by the second temperature increase) may be performed until the particle diameter of the toner becomes 6.6 to 7.2 μm, thereby obtaining toner particles having a substantially uniform particle diameter and shape.

Each of the binder resins used in each step may be the same kind of binder resin.

The content of the first binder resin added to the core part forming step (S10), the content of the second binder resin added to the first shell part forming step (S20), and the second shell part 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 step is within the above ranges, a toner having excellent fixing properties and excellent strength and durability of the toner can be obtained.

The method of manufacturing the toner may further include washing and drying the toner particles obtained in the coalescence process with water. First, the reactor contents including toner particles are cooled to room temperature, filtered, and the filtrate is removed, and then 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 performed until the conductivity of the filtrate after washing the toner becomes 50 uS/cm or less. Washing of the toner using pure water may be performed in a batch manner or may be performed continuously. Washing of the toner using pure water can be performed to remove unnecessary components other than the toner component, such as impurities that may affect the charging properties of the toner and unnecessary coagulants not involved in agglomeration.

The toner obtained after the washing step may be dried using a fluid bed dryer or a flash jet dryer. In addition, desired external additives can be added to the toner obtained by drying. The external additive is for improving the fluidity of the toner or controlling the charging characteristics, and such external additives include large particle diameter silica (particle diameter≥40 nm), small particle diameter silica (7 nm ≤ particle diameter ≤ 30 nm), polymer beads, or two or more of them. Mixtures can 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 examples.

Example

Manufacturing example 1-1: Settlement balance Preparation of dispersion (A)

A reactor having a volume of 30 liters equipped with a stirrer, thermometer and condenser was installed in an oil tank. Distilled water and a surfactant (Dowfax 2A1) were added to each of 6,600 g and 32 g, respectively, in the reactor thus installed, and the temperature of the reactor was increased to 70° C. and stirred at a stirring speed of 100 rpm. Thereafter, monomers, i.e. 8,380 g of styrene, 3,220 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 surfactant (Dowfax 2A1), as a macromonomer An emulsion mixture of 530 g of polyethylene glycol ethyl ether methacrylate and 188 g of 1-dodecanethiol as a chain transfer agent was stirred for 30 minutes at 450 rpm with a disk type impeller, 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 the reaction was completed, the glass transition temperature (Tg) of the binder resin obtained above was measured using a differential scanning calorimeter (DSC), and the temperature was 57°C. In addition, the weight average molecular weight of the binder resin was measured by gel permeation chromatography (GPC) using a polystyrene reference sample, and as a result, the weight average molecular weight was 45,000.

Manufacturing example 1-2: Settlement balance Preparation of dispersion (B)

Styrene 9,700 g, butyl acrylate 1,916 g, 2-carboxyethyl acrylate 370 g and 1,10-decanediol diacrylate 226 g, distilled water 5,075 g, surfactant (Dowfax 2A1) 226 g, polyethylene glycol ethyl ether meta as a macromonomer A binder resin dispersion (B) was prepared in the same manner as in Preparation Example 1-1, except that 530 g of acrylate and 188 g of 1-dodecanethiol were used as a chain transfer agent. In addition, the glass transition temperature (Tg) and the weight average molecular weight of the binder resin measured in the same manner as in Preparation 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 Daeil Purification Co., Ltd.), 27 g of surfactant (Dowfax 2A1) and 2,450 g of distilled water were added to a 5 liter reactor equipped with a stirrer, thermometer, and condenser, and then pre-dispersion while slowly stirring for 10 hours. Was performed. After performing the pre-dispersion for 10 hours, it was dispersed for 4 hours using a beads mill (Germany Netzsch, Zeta RS). As a result, a colorant dispersion was obtained.

After completion of the dispersion, the particle size of the cyan pigment particles was measured using a Multisizer 2000 (manufactured by Malvern), and the D50(v) was 170 nm. Here, D50(v) means a particle diameter corresponding to 50% of the volume average particle diameter, that is, a particle diameter corresponding to 50% of the total volume when the volume is accumulated 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 5-liter reactor equipped with a stirrer, thermometer and condenser, the mixture was slowly stirred at 95° C. for about 2 hours while waxing (Chongqing Oil Corporation, P- 778) 1,000 g was added to the reactor. The mixture was dispersed for 30 minutes using a pressure discharge type homogenizer (Homogenizer, Japan 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 a Multisizer 2000 (manufactured by Malvern), and the D50(v) was 200 nm.

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

(Core part formation step)

In a 70-liter reactor, the binder resin dispersion (A) prepared in Preparation Example 1-1, the binder resin dispersion (B) prepared in Preparation Example 1-2, the colorant dispersion prepared in Preparation Example 2, and Preparation Example 3 The wax dispersion prepared in was added, followed by stirring at 25° C. for about 15 minutes at a stirring speed of 1.21 m/sec, followed by mixing. Here, as a coagulant, a mixed solution of PSI (Poly Silcato Iron) and nitric acid aqueous solution (concentration = 1.88 wt%) (PSI/nitric acid aqueous solution = 1/2 (weight ratio)) was added, and a homogenizer (IKA company, T- 50) was used to agitate the reactor contents for 30 minutes at 25°C at a stirring speed of 10,000 rpm. At this time, the pH of the reactor contents was 1.6. Thereafter, the temperature of the reactor was first heated to 53° C., and then stirred at 140 rpm, and aggregation was continued until the D50(v) of the toner particles became 5.3 μm.

(First cell part formation step)

After the step of forming the core part, the binder resin dispersion (A) prepared in Preparation Example 1-1 was added to the reactor over 30 minutes. Thereafter, while maintaining the temperature of the reactor at 53° C., aggregation was continued by stirring at a stirring speed of 120 rpm until the D50(v) of the toner particles reached 6.3 μm.

(Second shell part formation 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 20 minutes. Subsequently, stirring was continued until the D50(v) of the toner particles reached 6.8 mu m while the temperature of the reactor was maintained at 53 DEG C.

(Subsequent step)

After the step of forming the second shell portion, a 4% by weight aqueous sodium hydroxide solution was added to the reactor and stirred at 115 rpm until the pH reached 4, and stirred at 100 rpm until the pH reached 7. Thereafter, while maintaining the stirring speed, the temperature of the reactor was secondarily raised to 96° C. so that the toner particles were united. Thereafter, when measuring circularity using FPIA-3000 (manufactured by sysmex, made in Japan), when the measured circularity is 0.980, the temperature of the reactor is cooled to 40°C, and the pH of the reactor contents is adjusted to 9.0. Then, toner particles were separated using nylon mesh (pore size: 16㎛), and the separated toner particles were washed 4 times with distilled water, and then a pH of 1.5 prepared by mixing 1.88% by weight of nitric acid aqueous solution with distilled water. Re-washed with a phosphorus mixture, and then re-washed four times with distilled water to remove all surfactants and the like. Thereafter, the washed toner particles were dried in a fluid bed dryer at a temperature of 40° C. for 5 hours to obtain dried toner particles.

Comparative example 1: Preparation of core-shell structured toner particles

(Core part formation step)

In a 70-liter reactor, the binder resin dispersion (A) prepared in Preparation Example 1-1, the binder resin dispersion (B) prepared in Preparation Example 1-2, the colorant dispersion prepared in Preparation Example 2, and Preparation Example 3 The wax dispersion prepared in was added, followed by stirring at 25° C. for about 15 minutes at a stirring speed of 1.21 m/sec, followed by mixing. Here, as a coagulant, a mixed solution of PSI (Poly Silcato Iron) and nitric acid aqueous solution (concentration = 1.88 wt%) (PSI/nitric acid aqueous solution = 1/2 (weight ratio)) was added, and a homogenizer (IKA company, T- 50) was used to agitate the reactor contents for 30 minutes at 25°C at a stirring speed of 10,000 rpm. At this time, the pH of the reactor contents was 1.6. Thereafter, the temperature of the reactor was first heated to 53° C., and then stirred at 140 rpm, and aggregation was continued until the D50(v) of the toner particles became 5.3 μm.

(Cell part formation step)

After the step of forming the core part, the binder resin dispersion (A) prepared in Preparation Example 1-1 and the binder resin dispersion (B) prepared in Preparation 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 μm while the temperature of the reactor was maintained at 53°C.

(Subsequent step)

After the step of forming the shell portion, a 4% by weight aqueous sodium hydroxide solution was added to the reactor and stirred at 115 rpm until the pH reached 4, and stirred at 100 rpm until the pH reached 7. Thereafter, while maintaining the stirring speed, the temperature of the reactor was secondarily raised to 96° C. so that the toner particles were united. Thereafter, when measuring circularity using FPIA-3000 (manufactured by sysmex, made in Japan), when the measured circularity is 0.980, the temperature of the reactor is cooled to 40°C, and the pH of the reactor contents is adjusted to 9.0. Then, toner particles were separated using nylon mesh (pore size: 16㎛), and the separated toner particles were washed 4 times with distilled water, and then a pH of 1.5 prepared by mixing 1.88% by weight of nitric acid aqueous solution with distilled water. Re-washed with a phosphorus mixture, and then re-washed four times with distilled water to remove all surfactants and the like. Thereafter, the washed toner particles were dried in a fluid bed dryer at a temperature of 40° C. 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 ionicity 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 in a ratio used in each of the 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 Examples and Comparative Examples. After mixing in the ratio to prepare a mixed binder resin dispersion, drying the mixed binder resin dispersion to obtain a dried mixed binder resin, and then measuring the glass transition temperature of the dried mixed binder resin to measure the glass transition temperature of the final binder resin. It was recorded as the 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 is determined according to 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 obtained by weighting average.

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

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

The volume average particle diameter (D50(v)) of the toner particles was measured using a Multisizer™ 3 Coulter Counter ^® of Beckman Coulter Inc. The aperture in the multisizer was 100. ㎛, add an appropriate amount of surfactant (Dowfax 2A1) to 50 to 100 ml of ISOTON-II (Beckman Coulter), an electrolyte, add 10 to 15 mg of the measurement sample, and disperse the sample for 5 minutes in an ultrasonic disperser. Was prepared.

Toner particle circularity measurement

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

The circularity is automatically obtained from FPIA-3000 by Equation 1 below.

[Equation 1]

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

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

Evaluation example

The fixing properties and mechanical strength of the toners 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 properties)

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

2 and 3, it was found that the change in storage modulus and loss modulus according to temperature of the toner prepared in Example 1 substantially coincided with the toner prepared in Comparative Example 1, from which Example It can be seen that the toner prepared in 1 has almost the same level of fixing properties as the toner prepared in Comparative Example 1.

(Mechanical strength evaluation)

Changes in storage modulus and loss modulus according to the frequency of each toner were measured using a dynamics measuring device (Hysitron, nanoDMA ^® ), and the results are shown in FIGS. 4 and 5, respectively. Here, one toner particle was used as a measurement sample.

Referring to FIG. 4, it was found that the toner prepared in Example 1 had a greater increase in storage modulus according to frequency compared to the toner prepared in Comparative Example 1, and had a greater or equal storage modulus at the same frequency.

Referring to FIG. 5, compared to the toner prepared in Comparative Example 1, the toner prepared in Example 1 has a greater or equal loss modulus at the same frequency up to about 80 Hz, but at about 80 Hz or more, it has a small loss modulus at the same frequency. appear.

In addition, using a dynamic measuring device (Hysitron, nanoDMA ^®) to measure the stress-strain curve (stress-strain curve) of each toner, were respectively shown in Figs. 6 and 7 the results. Here, one strain curve per toner particle was obtained. FIG. 6 is a diagram showing a strain curve of each of two toner particles selected from the toner produced in Example 1, and FIG. 7 is a diagram showing a strain curve of each of three toner particles selected from the toner produced 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 was found to have 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 has superior mechanical strength compared to the toner prepared in Comparative Example 1.

The present invention has been described with reference to the drawings and embodiments, but these are merely exemplary, and those of ordinary skill in the art will appreciate that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical scope of the present invention should be determined by the technical spirit of the appended claims.

10: toner 11: core portion
12: first shell portion 13: second shell portion

Claims (8)

A core portion including a first binder resin having a weight average molecular weight of Mw ₁ ;
A first shell portion including a second binder resin having a weight average molecular weight of Mw ₂ and surrounding the core portion; And
It includes a third binder resin having a weight average molecular weight of Mw ₃ , and includes a second shell portion surrounding the first shell portion,
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 a wax,
The Mw ₁ , Mw ₂ and Mw ₃ are toners satisfying the following formula:
Mw ₂ <Mw ₁ <Mw ₃ . delete The method of claim 1,
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. Adding a first binder resin dispersion and a coagulant to the reactor, and then first heating the reactor contents to form a toner core (S10);
Forming a first shell portion surrounding the toner core portion by further adding a second binder resin dispersion to the contents of the reactor containing the toner core portion (S20);
Forming a second shell portion surrounding the first shell portion by further adding a third binder resin dispersion to the contents of the reactor containing the first shell portion (S30); And
Including a step (S40) of obtaining unified toner particles by secondarily raising the temperature of the contents of the reactor that has passed through the second shell portion forming step
In at least one of the steps (S10) and (S20), at least one dispersion of a colorant dispersion and a wax dispersion is further added to the reactor,
The weight average molecular weight of the first binder resin contained in the first binder resin dispersion (Mw ₁ ), the weight average molecular weight of the second binder resin contained in the second binder resin dispersion (Mw ₂ ), the third binder resin dispersion The weight average molecular weight (Mw ₃ ) of the third binder resin contained in is a method for producing a toner satisfying the following formula:
Mw ₂ <Mw ₁ <Mw ₃ . The method of claim 4,
In the step (S10), instead of the first binder resin dispersion, the second binder resin dispersion and the second binder resin dispersion are added together in the reactor, and in this case, Mw ₁ is in the second binder resin dispersion. A method for producing a toner, which is a value obtained by a weighted average of the Mw ₂ and the Mw ₃ according to the ratio of the input amount of the third binder resin in the second binder resin and the third binder resin dispersion. The method of claim 4,
The first temperature rise is 2 to 20 ℃ lower than the glass transition temperature of the first binder resin in the core part forming step. The method of claim 4,
The second temperature rise is 10 to 40 ℃ higher than the glass transition temperature of the third binder resin added to the second shell portion forming step. The method of claim 4,
The content of the first binder resin added to the core part forming step (S10), the content of the second binder resin added to the first shell part forming step (S20), and the second shell part forming step (S30) The amount of the third binder resin to be added is 70 to 90 parts by weight, 5 to 25 parts by weight, and 1 to 6 parts by weight, respectively.

Images