KR20090072703A - Toner for electrostatic image development and its manufacturing method - Google Patents

Abstract

The present invention relates to a method of manufacturing a toner for electrostatic image development, wherein a toner manufacturing raw material comprising two kinds of polyester resins each having a softening point difference of 10 to 60 ° C. as a binder comprises two or more kneading parts or kneading parts. or separating and introducing the kneading unit or the kneading block into a melt kneading apparatus having a kneading block; And melt kneading the introduced toner raw material. The method minimizes agglomeration between fine particles of toner manufacturing materials during melt kneading, improves fluidity, stabilizes dispersibility and mixing ratio, and achieves significantly improved toner characteristics. Have

Description

Toner for electrostatic image development and its manufacturing method {Preparation Method of Toner for Developing Electrostatic Images}

The present invention relates to a method for producing a toner for developing electrostatic images. More specifically, the present invention provides a plurality of binder resins having different softening points in the melt kneading process for toner production by using a raw material inlet provided at a plurality of positions in the melt kneading apparatus, thereby providing a variety of residence time. The present invention relates to a manufacturing method of a toner for electrostatic image development, which is excellent in gloss, low temperature fixability, anti-offset and dispersibility, and exhibits improved fusion / deposition.

In general, the electrostatic charge image developing toner is melt-kneaded with an additive such as a colorant, a charge control agent, an inorganic filler, and the like together with a binder resin to obtain a mixed dough, pulverizing and classifying it, and toner particles obtained therefrom. It is manufactured through the external process which attaches a fluidity improver, a charge stabilizer, etc.

The toner obtained through the above process is subjected to the following process in the image developing apparatus.

(1) an exposure step of forming a latent electrostatic image by exposing a surface of a photosensitive drum charged with uniform charge through a charging step using static electricity;

(2) a developing step of obtaining a toner image by supplying toner to the electrostatic latent image,

(3) A fixing step of transferring and fixing a toner image fixed on the photosensitive drum surface by applying transfer heat and pressure on a transfer object.

On the other hand, the residual toner remaining on the surface of the photosensitive drum is removed and cleaned during the cleaning step.

In recent years, toners having improved anti-offset and charging stability along with low temperature fixing along with improvement of an image forming apparatus have been demanded. Furthermore, storage stability is required along with glossiness and durability of the toner after fixing to obtain a high quality image.

The toner is generally known to have the greatest influence on the physical properties of the binder resin, and therefore, a polyester resin is widely known as a binder resin material for toner. In addition, polyolefin resins such as styrene resins, acrylic resins, styrene-acrylic resins, polyethylene or polypropylene resins, polyamide resins, polyurethane resins, polycarbonate resins, and copolymers or condensates thereof are studied. Various proposals are made according to the conditions of use.

Among these, there is an increasing demand for resins having transparency for forming images of high quality, and for this purpose, various manufacturing techniques using polyester resins as binder resins suitable for the above-described needs have been examined.

In the prior art, the low softening point polyester resin according to the low molecular weight is advantageous to improve the gloss of the toner, but has a disadvantage in that offset resistance and durability are reduced. On the other hand, the polyester resin of the high softening point according to the large molecular weight can maintain the viscosity to suppress the offset phenomenon, but has a problem that the gross and low temperature fixability is lowered.

In order to overcome the above problems and to achieve improved fixability according to the fixing temperature of the toner and offset resistance in a wide temperature range, the use of two or more binder resins depending on molecular weight or softening point is used rather than one polyester resin alone. It is proposed.

For example, Korean Patent Publication No. 2006-74092 has an acid value of 25 KOH mg / g or less, a softening point of 140 to 215 ° C, and a glass transition temperature of 50 to 70 ° C in order to improve fixability and offset resistance. High softening point polyester and acid value 40KOH mg / g or less, softening point 100-150 ℃, and the glass transition temperature is 50 to 65 A toner composition comprising a polyester having a low softening point of ° C is disclosed.

Japanese Patent Publication No. 2007-148085 has a softening point of 145-190. Disclosed is a toner for electrostatic image development comprising a colorant, a releasing agent and the like using a polyester resin at 占 폚 and a polyester resin having a softening point of 85 to 130 占 폚 as a binder resin or a binder resin.

As in the prior art, even if two kinds of polyester resins having different softening points are used, there is still a problem that it is difficult to control for securing the compatibility between the resin and the viscosity characteristics according to the temperature during melt kneading.

Along with this, there are many difficulties in achieving instability of performance and various densities of images under various environments, along with problems of fine dispersion of additives used in toner production, compatibility and wettability between binder resins and additives, and the like.

In particular, uniform dispersion using the melt kneading apparatus of the toner material may be insufficient due to the limitation of the residence time due to the flow characteristics of the continuous kneading apparatus. Even if the residence time is increased as much as possible, the limitations of the inherent dispersion capacity are encountered, and efforts are being made to optimize various preliminary mixing techniques to overcome this. Furthermore, there are cases where fine materials are hindered by cohesion between fine particles and difficulty in mixing to an optimum ratio of toner materials, such as sticking to the inner wall of the mixer.

As a result of continuous research, the present inventors have used two kinds of polyester resins having relatively different softening points as binder resins, and melt kneading in consideration of the diversity of physical properties depending on the temperature of the binder resin and other toner materials. It has been found that by setting the conditions of the process, the above limitations of the prior art can be overcome. In particular, by considering the variety of physical properties depending on the temperature of the binder resin and other toner manufacturing materials, the toner characteristic (gross, low temperature) is significantly improved compared to the prior art by specifically designing the kneading part or the kneading block and the input of the raw material during the extrusion process. Fixation, offset resistance, dispersibility and fusion / deposition) can be achieved.

Accordingly, it is an object of the present invention to provide a method for producing a toner, in which melting and kneading minimizes agglomeration between fine particles of toner manufacturing materials, improves fluidity, and stabilizes dispersibility and mixing ratio.

According to one aspect of the invention,

The kneading unit or kneading in a melt kneading apparatus having two or more kneading parts or kneading blocks as raw materials for toner production, each containing two kinds of polyester resins having a softening point difference of 10 to 60 ° C as a binder. Separating and introducing the block as a center; And

Melt kneading the introduced toner manufacturing raw material;

Provided is a method of manufacturing an electrostatic charge toner comprising a.

According to another aspect of the invention,

Introducing a raw material for producing a toner including two kinds of polyester resins having a softening point difference of 10 to 60 ° C. into a twin screw extruder having the following configuration; And

Melt kneading the introduced toner manufacturing raw material;

Provided is a method for producing an electrostatic charge toner comprising a; twin screw extruder; And a plurality of raw material inlets provided before and after the kneading unit or the kneading block,

The raw material for toner production containing the polyester resin of high softening point and the raw material for production of the toner containing the polyester resin of low softening point are respectively introduced into the raw material inlets provided before and after the kneading portion.

The toner manufacturing method according to the present invention minimizes agglomeration between fine particles of toner materials during melt kneading, and improves fluidity to stabilize dispersibility and mixing ratio, thereby greatly improving toner properties (gross, low temperature fixability, and offset). Property, dispersibility, and fusion / deposition), and because it has the advantage of obtaining a good image, it is expected that a wide range of commercialization in the future.

The present invention can be achieved by the following description with reference to the accompanying drawings.

Binder resin

According to the present invention, two kinds of polyester resins having different softening point ranges are used as the binder for toner production. Such resins can typically be prepared from esterification and polycondensation reactions of aromatic dicarboxylic acids, aromatic diols and aliphatic diol components. At this time, the softening point difference between the two resins is in the range of about 10 to 60 ° C, more preferably about 15 to 40 ° C. Generally, polyester resins having high molecular weight and high softening point are suitable for enhancing the durability of toner and improving image shape after fixing to the transfer object, and polyester resins having low molecular weight and softening point are preferred for increasing fluidity and fixability. It is easy. Therefore, in order to obtain an improved toner by utilizing the properties between different softening points and resins having molecular weights accordingly, it is necessary to maintain the above-described ranges at which the softening point difference is required.

According to a preferred aspect of the present invention, the resin has a low glass transition point and softening point compared to other resins conventionally used as binders of toners, making it easy to form an image under a low fixing temperature, and thus the durability of the electrostatic charge developing apparatus and its Use something that increases your efficiency. For this purpose, it is preferable to select and use two kinds of binder resins having a difference in the softening point described above among polyester resins having a weight average molecular weight of about 40,000 to 200,000 and a softening point of about 100 to 160 ° C. Moreover, as long as it has the softening point difference mentioned above, 2 or more resin which belongs to the polyester resin of the high softening point, and the polyester resin of the low softening point may be used not only individually but also in combination.

In this regard, it is preferable that the resin having a relatively high softening point has a softening point of about 130 to 160 ° C. It is also desirable to have a weight average molecular weight of about 90,000 to 200,000 and a glass transition temperature (Tg) of about 60 to 75 ° C.

In the case of a resin having a relatively low softening point, it is preferable to have a softening point of about 100 to 130 ° C. It is also desirable to have a weight average molecular weight of about 8,500 to 90,000 and a glass transition temperature (Tg) of about 55 to 65 ° C.

As described above, in the present invention, it is possible to induce uniform mixing and dispersion between the binder resins in the toner particles by using two kinds of polyester resins having different molecular weight distributions and correspondingly having glass transition temperatures and softening points within different ranges. will be.

In the present invention, the weight ratio (A / B) of the high softening point polyester resin (A) to the low softening point polyester resin (B) may vary depending on the fixing temperature range of the toner particles and a relatively required function. And preferably in the range of about 0.1 to 9.0. The total content of the two kinds of polyester resins, that is, the total content of the binder resin, is preferably about 80 to 98.2% by weight based on the total weight of the toner.

 According to the present invention, a binder resin constituting a toner is a styrene resin in addition to a polyester resin; Acrylic resins; Styrene-acrylic resins; Polyolefin-based resins such as polyethylene-based and polypropylene-based resins; Polyamide-based resins; Polyurethane-based resins; Polycarbonate resins; And at least one selected from the group consisting of copolymers or condensates thereof.

Hereinafter, the additive component which is used together with the above-described binder and constitutes a component of the toner will be described. Each of these additives may be added to the binder alone, but it is preferable to use a suitable combination in view of the required properties of the toner.

coloring agent

According to the present invention, a colorant is used together with the binder resin during toner production, and the colorant is contained in a raw material containing each of the two types of polyester resins described above, or each of the two types of polyester resins. It may be contained only in any one of the raw materials to contain, and may be introduce | transduced into a melt kneading apparatus.

The kind of the colorant may be any one known in the art without particular limitation, and specifically, various pigments and dyes of inorganic or organic may be used. Black pigments include carbon blacks such as furnace black, acetylene black, thermal black, lamp black, copper oxide, various iron oxides, manganese dioxide and aniline black, etc. Can be mentioned. The content of the colorant is preferably about 1 to 7% by weight based on the total weight of the toner.

Release agent

According to the present invention, wax may be used as the release agent. Such wax components may be any known in the art without particular limitation.

Low melting waxes having a relatively low viscosity include carnauba wax, rice wax, natural plant ester waxes such as montan wax, paraffin wax, and the like. And synthetic hydrocarbon waxes such as polypropylene wax.

According to a preferred embodiment of the present invention, the cold offset (hot-offset) and hot offset (hot-offset) according to the temperature-specific viscosity characteristics of the wax to compensate for, and prevent the paper jam (wrap jam) in the fixing unit during image formation For this purpose, one kind or two or more kinds of waxes having different melting points (and thus different viscosities) may be used.

It is preferable that the melting point of the low melting wax wax having a low viscosity is 60 to 100 ° C, and the melting point of the high melting wax is 120 to 170 ° C.

On the other hand, the content of the release agent is preferably about 0.5 to 7% by weight based on the total weight of the toner. In addition, in order to prevent the problem of dispersion during melt kneading, it may be used by master batch with other additives such as binder resin and colorant.

Majesty Control agent

According to the present invention, a charge control agent can be added for the production of a toner capable of obtaining a high image by stabilizing charging characteristics of the toner for developing an electrostatic charge image and minimizing generation of residual amount during image formation.

The charge control agent is not particularly limited, but may include quaternary ammonium salts, resins containing quaternary ammonium salts or amino groups, azo metal compounds, acetyl acetone metal compounds and their complexes, benzyl acids and aromatic hydroxycarboxes. Main acid system, various black acid system, salicylic acid system, phthalocyanine, perylene, quinacridone, metal salt or complex of nitrogen compound, boron compound or complex thereof, sulfonic acid salt containing carboxyl group, sulfonyl group, Triphenyl methane type, trimethyl ethane type, nigrosine dye, etc. can be used. The content of the charge control agent is preferably about 0.3 to 6% by weight based on the total weight of the toner.

The charge control agent used in the present invention may impart improved compatibility and dispersibility by master batching with binder resin and wax and / or inorganic fine particles.

In addition, the charge control agent may be used in an external process for imparting charging stability of toner particles together with titanium dioxide, polymer powder, and the like.

According to the present invention, a kneaded product obtained by melt kneading a binder resin and other components such as a colorant is processed in the order of cooling, pulverization and classification to have a particle toner (eg, about 5 to 13 microns in particle size). ). Such a particulate toner can improve flow characteristics, antistatic characteristics, and the like by attaching various additive components to the surface thereof. Below, such an external component is demonstrated. However, in the present specification, the component is described as to adhere to the surface of the toner particles, but in some cases, may be contained by melt kneading in the binder resin together with the above-described components, that is, a colorant, a mold release agent, a charge control agent, and the like. It should be noted.

weapon Filler

As described above, according to the present invention, an inorganic filler may be used to improve the physical properties of the toner particles. Examples of such inorganic fillers include, but are not particularly limited to, dimethylchlorosilane, trimethylchlorosilane, methyltrichlorosilane, arylphenylchlorosilane, benzyldimethylchlorosilane, bromine methylchlorosilane, chrommethylchlorosilane, P-chlorophenylchlorosilane, Silane coupling agents such as 3-chloropromethyltrimethoxy, vinyltriethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, divinylchlorosilane, hexamethylenedisyragen, or Silicon dioxide, titanium oxide, aluminum oxide, cerium oxide, zinc oxide, tin oxide, copper oxide, iron oxide, zirconium oxide whose surface is hydrophobized by silicon oil, etc. Examples thereof include silicon carbide, boron carbide, titanium nitride, zirconium nitride, and magnesium fluoride.

In particular, in order to improve the durability and fluidity of the toner, at least one of inorganic particles having a small specific surface area (for example, specific surface area of about 20 to 100 m ² / g) and inorganic particles having a large specific surface area (for example, about At least one of 130 to 350 m ² / g specific surface area) may be mixed and adhered to the toner particle surface. The adhesion amount of the inorganic filler is preferably about 0.2 to 2.5 parts by weight based on 100 parts by weight of the toner particles.

Other additives

In addition to the above inorganic fillers, charge control agents, melamine formaldehyde-based, acrylic styrene-based resin powders (for example, particle sizes of about 0.1 to 2.0 microns), and the like, may be required to provide toners to impart the charging stability of the toner particles. It can be used as long as it can maintain its characteristics. The deposition amount of the other additive components is preferably about 0.05 to 1.0 parts by weight based on 100 parts by weight of the toner particles.

Melting Kneading  Device

Conventionally known toner production methods include the above-mentioned raw materials for toner production, which are sufficiently mixed with a mixer such as a Henschel mixer, a turbine type agitator, a super mixer, a ball mill, and the like, followed by melt kneading such as an open roll type kneader, a single screw or a twin screw extruder. The kneaded product obtained by kneading using a machine is cooled, then mechanically coarsely pulverized using an impact mill such as a hammer mill, finely pulverized by a jet mill or the like, and then classified.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematically the structure of the melt kneading apparatus which can be used by the preferable embodiment of this invention.

According to the figure, PART (A) refers to the inlet disposed before the first kneading portion or the kneading block. Through this, it is introduced through a supply device that can control the supply amount of additives such as binder resin, colorant, release agent (wax), charge control agent, and optionally inorganic filler.

The PART (B) is an inlet disposed between the first kneading portion or the kneading block and the second kneading portion or the kneading block so as to be close to the first kneading portion or the kneading block, and through this, a binder resin, a colorant, a mold release agent (wax) , Through a supply device that can control the supply of additives such as charge control agents, optionally inorganic fillers.

In addition, the toner fine powder obtained by sorting through a series of processes may be reused in the melt kneading process through the inlet.

The PART (C) is preferably disposed immediately after the second kneading portion or the kneading block to prevent excessive shearing of the kneaded material due to agglomeration and crushing due to a colorant such as carbon black. Can be configured in such a way.

The illustrated raw material kneading apparatus is supplied by using a free fall using an input amount adjusting device so that the mixing ratio in PART (A) and PART (B) can be constantly adjusted. In this case, the plurality of supply devices and the inlets are preferably coated so that the added particles do not adhere to the surface.

The plurality of inlets may remove the gas generated during the kneading to improve the compatibility and dispersibility of the kneaded material and to remove impurities. In order to double this effect, it is preferable to arrange a bent portion between the PART (C) and the die. Furthermore, the some vent part may be arrange | positioned before and after a kneading part.

As such, in consideration of the thermal and flow characteristics of polyester resins having two different softening point zones used as binder resins, the inner surface is coated to prevent adhesion of fine particles in a twin screw extruder having two or more kneading portions or kneading blocks. The treated one or more raw material supply devices and the plurality of raw material inlets can be arranged before and after around the kneading block to induce different residence times.

On the other hand, in the case of the melt kneading apparatus, the kneading unit or the kneading block is maintained at a temperature of about 100 to 220 ℃, preferably 120 to 200 ℃ to enable a smooth kneading.

The present invention can be more clearly understood by the following examples, which are only intended to illustrate the present invention and are not intended to limit the scope of the invention.

Example  One

This embodiment was carried out as follows using the melt kneading apparatus shown in FIG. As the binder resin, two kinds of polyester resins having different softening points were used. A relatively high melting point wax and charge control agent were added to the polyester resin (A1) having a relatively high softening point through the PART (A) of FIG. On the other hand, a relatively low melting point wax and a charge control agent were added to the relatively low softening point of the polyester resin (A2) through the PART (B) of FIG. In addition, a colorant was added through PART (C) of FIG. 1.

Based on the weight of the kneaded material, the binder resin was 93.5 wt%, 3 wt% carbon black (B1, Mogul-L, Cabot) as colorant, 1.0 wt% quaternary ammonium salt (C1, T-77, Hodogaya Chem.), Carr 0.5 wt% of Nauba wax (D1, Towax-143, Toa Kasei) and paraffin wax (D2, H1N1, Kato) and 1.5 wt% of low molecular weight polypropylene wax (D3, Viscol 660P, Sanyo Chem.) In this case, the weight ratio (A1 / A2) of the binder resins A1 and A2 was set to 5.7.

It was used through a plurality of inlets through one or more raw material feeder, through free fall at a feed rate of 15 kg / hr based on binder resin feed. This was melt kneaded and cooled at a temperature of 140 ° C. and 250 rpm using a twin screw extruder of L / D = 35, then coarsely pulverized using a hammer mill, followed by a jet mill type 100AFG (Hosokawa Alpine) grinder ( pulverizer) was used for pulverization and air flow was classified using a 50ATP (Hosokawa Alpine) classifier.

This gave toner particles having an average particle size of 6 to 10 microns. Hydrophobic silica (E1, RX300, Aerosil) having a specific surface area of 190 to 230m ² / g 1.0 parts by weight, hydrophobic silica (E2, H05TD) having a specific surface area of 30 to 70m ² / g based on 100 parts by weight of the toner particles , Wacker) at 1.0 parts by weight and 0.5 parts by weight of acrylic-styrene resin powder (E3, MP-1000, soken chemical co.) By high-speed mixing / adhesion by a Henschel mixer to obtain a toner.

Example  2

Example 2 was carried out in the same manner as in Example 1, except that the composition ratio between the high softening point polyester resin (A1) and the low softening point polyester resin (A2) was changed.

Example  3

Example 3 is a master batch obtained through the primary melt kneading and grinding process through the melt kneading apparatus of FIG. 1 using one polyester resin (A1) and a colorant, wax, charge control agent, and / or inorganic filler. Was prepared by secondary melt kneading of the polyester resin (A2) or other additives having a softening point different from that of the polyester resin (A1) using the melt kneading apparatus shown in FIG. 1 to prepare a toner having the same composition ratio as in Example 1. Except that it was carried out in the same manner as in Example 1.

Comparative example  One

In Comparative Example 1, according to the conventional toner production method, the same raw materials as those used in Example 1 before the melt kneading were premixed with a Henschel mixer, the mixture was introduced through one raw material inlet, and melt kneaded. The same procedure as in Example 1 was carried out except that a toner having the same composition ratio was produced.

Comparative example  2

Comparative Example 2 was carried out in the same manner as in Comparative Example 1 except that the composition ratio between the high softening point polyester resin (A1) and the low softening point polyester resin (A2) was changed.

Comparative example  3

Comparative Example 3 was carried out in the same manner as in Example 1 except that the polyester resin (A3) was used alone as the binder resin.

Toner particles obtained through the above Examples and Comparative Examples and binder resins used in the preparation thereof were evaluated through the following method, and the results are shown in Tables 1 and 2. In addition, Table 2 shows the final composition ratio of the toner obtained through Examples 1, 2 and 3, and Comparative Examples 1, 2 and 3.

(1) Glass transition temperature (Tg, ℃): The temperature increase rate was raised to 10 ℃ per minute using a differential scanning calorimeter (DSC Q100, TA Instrument), and then cooled and measured again.

(2) Softening temperature (° C.): Using a flow tester (CFT-500D, Shimadzu), a nozzle of 1 mm in diameter and 1 mm in height was measured at a temperature rising rate of 6 ° C. per minute at a load of 20 kgf.

(3) Molecular weight (Mw): A sample of 0.3-0.5% concentration was prepared using a THF solution in a 500 kPa column and measured under water at 40 ° C. using a Water Model 2690 at a flow rate of 1 ml / min.

(4) Gloss: To evaluate the density and gloss of the image quality, the image was adjusted by adjusting the toner concentration on the paper to about 1.0 g / cm 2 using a fixing unit having a printing speed of 100 mm / s and 140 ° C. It was fixed to the toner and expressed as a measurement value when the incident angle was 60 degrees using UGV-5D manufactured by Suga.

(4) Low temperature fixability: A fixing roller without silicone oil was set at a roller speed of 100 mm / s, and the fixing temperature was set to the minimum temperature at which the toner starts fixing on paper using a printer which can change the temperature. The visual observation was made by judging whether or not the aggregation of the settled images occurred.

◎ (very good): Fusing temperature is lower than 120 ° C

○ (good): The fixing temperature is 120 ° C or more and less than 130 ° C

△ (usable): Fusing temperature is 130 ° C or more and less than 160 ° C

× (defect): fixing temperature is 160 degreeC or more

(5) Offset resistance: When fixing the toner image using the above printer, it was visually observed whether or not toner contamination occurred on the transfer paper. At this time, the heat roller setting temperature of the said fixing roller device was repeatedly raised in the state which raised sequentially, and the minimum setting temperature which the contamination with toner generate | occur | produced was made into offset generation temperature.

◎ (very good): offset generation temperature is 240 ° C or higher

○ (good): The offset generation temperature is 220 ° C or more and less than 240 ° C

△ (usable): Offset temperature is 200 ° C or higher but less than 220 ° C

X (defect): Offset generation temperature is 200 degrees C or less

(6) Dispersibility: Toner particles are cut to a thickness of about 0.3 microns using a cutter such as a microdome, taken 1000 times with a transmission electron microscope, and the maximum diameter in the field of 200 microns x 200 microns. The distribution of the aggregates except for the particles having was observed and the number of particles was counted and evaluated.

◎ (very good): Dispersibility is quite good

○ (good): good dispersibility

△ (usually): moderate dispersibility

× (poor): poor dispersibility

(7) Fusion / Deposition: It was evaluated by the degree of deposition remaining on the wall and screw blades of the feeder and the extruder after melt kneading. In the case of the comparative examples 1 and 2, the stirring blade of the mixer and its wall surface were also observed.

○ (good): No welding or deposit is recognized on either the wall or the screw.

Δ (normal): A slight fusion / deposit on the wall and the screw is recognized.

X (poor): A large amount of fusion / deposit is recognized on the wall and the screw.

Binder resin A1 A2 A3 Tg (℃) 68 63 65 Molecular Weight 146,472 48,935 95,603 Softening point (℃) 140 120 130

Example Comparative example One 2 3 One 2 3 Binder Resin (Weight Ratio) A1 85 60 85 85 20 - A2 15 40 15 15 80 - A3 - - - - - 100 B1 (wt%) 3 3 3 3 3 3 C1 (wt%) 1.0 1.0 1.0 1.0 1.0 1.0 D1 (wt%) 0.5 0.5 0.5 0.5 0.5 0.5 D2 (wt%) 0.5 0.5 0.5 0.5 0.5 0.5 D3 (wt%) 1.5 1.5 1.5 1.5 1.5 1.5 E1 (part by weight) 1.0 1.0 1.0 1.0 1.0 1.0 E2 (part by weight) 1.0 1.0 1.0 1.0 1.0 1.0 E3 (part by weight) 0.3 0.3 0.3 0.3 0.3 0.3 Gross 26 25 23 14 21 18 Low temperature fixability ◎ ◎ ◎ △ ◎ ○ Offset resistance ◎ ◎ ◎ △ ○ × Dispersibility ◎ ◎ ◎ × ◎ ○ Fusion / Deposition ○ ○ ○ × △ △

As can be seen from Table 2, the toner prepared by using two kinds of polyester resins having different softening points in Examples 1 to 3 was excellent in gross, low temperature fixability, offset resistance and dispersibility, and were fused / deposited. It was also satisfactory.

However, the toner particles prepared by mixing the toner material through a mixer as in Comparative Example 1, and then melt-kneading the mixture through a single inlet, dispersibility and fusion / sedimentation It shows a marked drop in aptitude. It can be seen that the compatibility between the components during melt kneading is lowered due to the nonuniform mixing ratio and generation of aggregation between the fine particles from the mixing step of the raw material using the mixer. As a result, it can be seen that in Comparative Example 1, the low temperature fixability and the offset resistance of the toner particles were lowered, and the gloss of the formed image was also lowered.

In the case of a toner manufactured by using one polyester resin alone as a binder resin as in Comparative Example 3, as in Examples 1 to 3, by providing a variety of residence time through a plurality of feeders and inlets, The compatibility and dispersibility were good, and the gross according to the inherent physical properties of the binder resin was also good. However, it was confirmed that only a binder resin used alone could not obtain wide offset resistance and fusion / deposition.

As described above, the present invention uses two kinds of polyester resins having different softening points (due to different molecular weights) as binders, and at least one raw material supply device and a plurality of raw material inlets before and after the kneading block center during melt kneading. By using a melt kneading apparatus having an excellent compatibility and stable charging and durability between the binder resins or between the binder resin and other additives, a good image can be obtained under a wide anti-offset. Furthermore, a binder resin, a colorant, a charge control agent, a release agent, and the like are prepared through a primary melt kneading process to prepare a master batch, which is a binder resin having a softening point different from that used in the master batch according to the physical properties and composition ratio of the toner. Secondary melt kneading with (and other additives) can increase the efficiency of toner production and improve processability.

All simple modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of the present invention will be apparent from the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows schematically the structure of the melt kneading apparatus which can be used by the preferable embodiment of this invention.

Claims (16)

The kneading unit or kneading in a melt kneading apparatus having two or more kneading parts or kneading blocks as raw materials for toner production, each containing two kinds of polyester resins having a softening point difference of 10 to 60 ° C as a binder. Separating and introducing the block as a center; And Melt kneading the introduced toner manufacturing raw material; Method for producing an electrostatic charge toner comprising a. The method of claim 1, wherein the two kinds of polyester resins are selected from polyester resins having a weight average molecular weight of 40,000 to 200,000 and a softening point of about 100 to 160 ° C, respectively. The high softening point resin of the two kinds of polyester resins has a softening point of 130 to 160 ° C, a weight average molecular weight of 90,000 to 200,000, and a glass transition temperature (Tg) of 60 to 75 ° C. A method of producing an electrostatic charge toner. The low softening point resin of the two kinds of polyester resins has a softening point of 100 to 130 ° C, a weight average molecular weight of 8,500 to 90,000 and a glass transition temperature (Tg) of 55 to 65 ° C. A method of producing an electrostatic charge toner. The method for producing an electrostatic charged toner according to claim 1, wherein the weight ratio of the polyester resin of the high softening point to the polyester resin of the low softening point of the two kinds of polyester resins is 0.1 to 9.0. The method of claim 1, wherein the raw material for toner production further comprises an additive selected from the group consisting of colorants, mold release agents, charge control agents, or a combination thereof. 7. The toner according to claim 6, wherein the toner is 80 to 98.2 wt% polyester resin, 1 to 7 wt% colorant, 0.5 to 7 wt% release agent, and 0.3 to 6 wt% charge agent based on the total weight of the toner. A method for producing an electrostatic charge toner, comprising a yesterday. 7. The method of claim 6, wherein pre-melt kneading using any one of the two types of polyester resins and additives to prepare a master batch, and the master batch is melt kneaded with a polyester resin having a different softening point or an additive thereof. A method for producing an electrostatic charge toner, characterized by the above-mentioned. 7. The method for producing an electrostatically charged toner according to claim 6, wherein two types of waxes having different melting points are used as the release agent. 10. The method for producing an electrostatic charged toner according to claim 9, wherein the melting point of the low melting wax is 60 to 100 DEG C and the melting point of the high melting wax is 120 to 170 DEG C. of the two kinds of waxes. The method for producing an electrostatic charged toner according to any one of claims 1 to 10, wherein the molten kneaded product is further processed in the order of cooling, pulverization and classification to produce a particulate form. 12. The method of claim 11, wherein 0.2 to 2.5 parts by weight of the inorganic filler is attached to 100 parts by weight of the toner in the form of particles. 12. The method of claim 11, further comprising 0.05 to 1.0 parts by weight of a charge control agent based on 100 parts by weight of the toner in the form of particles; Or melamine formaldehyde-based or acrylic styrene-based resin powder. Introducing a raw material for producing a toner including two kinds of polyester resins having a softening point difference of 10 to 60 ° C. into a twin screw extruder having the following configuration; And Melt kneading the introduced toner manufacturing raw material; A method of manufacturing an electrostatic charge toner comprising: a twin screw extruder; And a plurality of raw material inlets provided before and after the kneading unit or the kneading block, The raw material for toner production containing the polyester resin of high softening point and the raw material for production of the toner containing the polyester resin of low softening point are separately introduced into raw material inlets provided before and after the kneading portion. 15. The method of claim 14, wherein one or more vent portions are provided before and after the kneading portion or the kneading block. 15. The method of claim 14, wherein the inner surface of the raw material inlet is coated.

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