JP5773764B2 - Toner production method - Google Patents

Description

  The present invention relates to a method for producing toner used in electrophotography, electrostatic recording, and toner jet recording. More specifically, the present invention is used for a copying machine, a printer, and a fax machine in which a toner image is formed on an electrostatic latent image carrier and then transferred onto a transfer material and fixed under a thermal pressure to obtain a fixed image. The present invention relates to a method for producing a toner.

In recent years, in electrophotographic apparatuses, energy saving has been considered as a major technical problem, and a great reduction in the amount of heat applied to the fixing apparatus is desired. Therefore, there is a growing need for so-called “low-temperature fixability” that enables fixing with lower energy.
As a general method for improving the low-temperature fixability of the toner, there is a method of lowering the glass transition temperature (Tg) of the binder resin to be used. However, simply reducing the Tg of the binder resin impairs the heat-resistant storage stability of the toner, and it is difficult to achieve both low-temperature fixability and heat-resistant storage stability.
Therefore, in order to achieve both low-temperature fixability and heat-resistant storage stability of the toner, a method of using a crystalline resin excellent in sharp melt property as a binder resin has been studied.
An amorphous resin generally used as a binder resin for toner does not show an endothermic peak as measured by a differential scanning calorimeter (DSC), but when a crystalline resin is contained in the binder resin, An endothermic peak in DSC measurement appears. The peak temperature of this endothermic peak means the melting point of the crystalline resin.
Crystalline polyester resin has a structure in which polymer chains are regularly arranged, and is difficult to soften in a temperature range below the melting point, and has a property of causing a sudden decrease in viscosity by melting at the melting point. Yes. Due to these characteristics, crystalline polyester resins have attracted particular attention in recent years, and toners using them as binder resins have been actively studied.
For example, Patent Document 1 is obtained by attaching amorphous (amorphous) resin fine particles to the surface of aggregated particles formed by agglomerating fine particles mainly composed of crystalline polyester resin, and further fusing them. Toner is proposed. However, as a result of studies by the present inventors based on this disclosure, the endothermic peak in the DSC measurement of the crystalline polyester resin in the toner is very broad, and the original sharp melt property can be effectively utilized. I found out. The reason is considered to be that the crystallinity is lowered by heating at a temperature equal to or higher than the melting point of the crystalline polyester resin in the fusion step.
Further, in Patent Document 2, a resin solvent solution composed of a crystalline part and an amorphous part containing aliphatic polyester as essential components is dispersed in carbon dioxide in a liquid or supercritical state to form particles, Toners obtained by removing the carbon dioxide have been proposed. However, when the present inventors examined based on this disclosure, the endothermic peak in the DSC measurement derived from the crystal part of the resin (that is, crystalline polyester) is also broad, and the sharp melt property inherent to this resin is also present. It has been found that is not necessarily effectively utilized. The reason is considered that the crystal part and the amorphous part in the resin are compatible with each other in the step of dissolving the resin in the organic solvent, and the crystallinity of the crystalline polyester component is impaired.
As described above, even when a crystalline polyester resin is used as a binder resin, it is not easy to be present in the toner while maintaining crystallinity. As a result, not only a sufficient low-temperature fixing effect is not exhibited, but also heat-resistant storage is achieved. It became clear that there was a case where the sex decreased.
In order to solve the problem of lowering the crystallinity in the toner using the crystalline polyester resin, an attempt has been made to reconstruct the crystal structure by performing a heat treatment at a temperature not exceeding the melting point of the crystalline polyester resin. For example, Patent Document 3 discloses that a toner composition containing a crystalline polyester resin and an amorphous polyester resin is at least 20 ° C. lower than the maximum endothermic peak temperature (Trm) in DSC measurement of the composition (Tra). A method of heating and holding at a temperature higher than (Tra) by 10 ° C. or more and lower than (Trm) is proposed.
When this method was applied to the toner produced by the present inventors based on the disclosure of Patent Document 2, the crystallinity of the resin could be improved relatively easily.
However, when the toner thus obtained was left to stand for a long time and then confirmed again, it was found that there was a change in the crystallinity of the resin. As a result of repeated studies on this phenomenon, it was found that the low molecular weight component of the wax encapsulated in the toner infiltrated into the crystal part of the resin due to the influence of environmental changes during standing, disturbing the crystal structure of the crystalline polyester component. It has been found that there is a possibility.
Further, when this toner was subjected to durability evaluation, it was found that the density of the fixed image may be lowered as the evaluation progresses. As a result of repeated studies on this phenomenon, in the case of a toner that has become a problem, it has been found that most of the wax contained therein tends to be distributed near the surface in the toner. From this, it is surmised that the wax in the vicinity of the toner surface oozes out from the durability evaluation and causes the member to be contaminated with the toner. Such uneven distribution of the wax in the toner is because the liquid or supercritical carbon dioxide that is the dispersion medium is hydrophobic, so that the wax having a small difference in solubility parameter (SP value) from the medium is used as the particle. This is thought to be due to the fact that it tends to diffuse and migrate to the medium side during the formation process.
As explained above, there are still problems in achieving the original performance of the crystalline polyester resin sufficiently and maintaining the low-temperature fixability and heat-resistant storage stability of the toner for a long period of time. The toner obtained by granulation in a hydrophobic medium such as carbon dioxide in a state has a problem in terms of dispersibility of the wax.

JP 2004-191927 A JP 2010-168529 A JP 2009-128653 A

The present invention provides a toner manufacturing method that solves the above-described conventional problems.
That is, the present invention is to provide a method for producing a toner that can stably maintain low-temperature fixability and heat-resistant storage stability for a long period of time, has little wax surface unevenness, and has excellent durability. .

The present invention includes a step of preparing a resin composition by dissolving or dispersing a binder resin containing a crystalline polyester, colorant particles, and wax particles in an organic solvent, and the obtained resin composition in a non-aqueous medium. A method for producing a toner comprising: a step of preparing a dispersion of a liquid particle of the resin composition by dispersing the resin composition; and a step of forming a toner particle by removing the organic solvent from the obtained dispersion of the liquid particle. The non-aqueous medium is a medium mainly composed of carbon dioxide in a liquid state or a supercritical state, the wax particles are particles obtained by coating a wax component with a resin, and the resin covering the wax component is crosslinked. a polyester resin a vinyl resin or a cross-linked structure the structure is introduced has been introduced, the wax component was dispersed the wax particles in the organic solvent and the non-aqueous medium Residual percentage of solids of the resin component to be covered is a method of manufacturing a toner, characterized in that at least 50 mass%.

  According to the present invention, it is possible to provide a toner production method that can stably maintain low-temperature fixability and heat-resistant storage stability for a long period of time, and that has less wax surface unevenness and excellent durability. .

Schematic showing an example of a manufacturing apparatus used for manufacturing the toner of the present invention

Hereinafter, the present invention will be described in more detail with reference to embodiments.
The present invention includes a step of preparing a resin composition by dissolving or dispersing a binder resin containing a crystalline polyester, colorant particles, and wax particles in an organic solvent, and the obtained resin composition in a non-aqueous medium. A method for producing a toner, comprising: preparing a dispersion of liquid particles of the resin composition by dispersing the resin composition; and forming toner particles by removing the organic solvent from the obtained dispersion of liquid particles. .
In the toner manufacturing method of the present invention (hereinafter also simply referred to as the method of the present invention), the toner particles are manufactured by a so-called “dissolution suspension method”.
In the dissolution suspension method, a resin composition is prepared by dissolving or dispersing a resin or the like in an organic solvent as described above, and the obtained resin composition is dispersed in a dispersion medium to obtain a liquid form of the resin composition. In this method, resin particles are obtained by forming a particle dispersion and then removing the organic solvent from the liquid particle dispersion.
In the present invention, the binder resin contains crystalline polyester, and toner particles are produced using the dissolution suspension method so as not to heat the crystalline polyester beyond its melting point. Thus, it is possible to produce a toner containing a crystalline polyester that maintains the crystallinity without destroying the crystallinity of the crystalline polyester contained in the toner particles.
In the present invention, examples of the organic solvent for dissolving the binder resin include the following. Ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and di-n-butyl ketone; ester solvents such as ethyl acetate, butyl acetate and methoxybutyl acetate; ether solvents such as tetrahydrofuran, diethyl ether, dioxane, ethyl cellosolve and butyl cellosolve An amide solvent such as dimethylformamide and dimethylacetamide; an aromatic hydrocarbon solvent such as toluene, xylene and ethylbenzene;
In the present invention, a resin composition is prepared by dissolving the binder resin in the organic solvent and dispersing the colorant particles and the wax particles. At this time, a charge control agent and other additives can be added to the resin composition as necessary.
In the present invention, the resin composition is dispersed in a dispersion medium to prepare liquid particles of the resin composition. As the dispersion medium, an aqueous medium is generally used, but in the present invention, granulation is performed using a non-aqueous medium.
Although the said non-aqueous medium is not specifically limited, The organic solvent which has a boiling point higher than the organic solvent used for preparation of the said resin composition, and is a poor solvent whose solubility of the said binder resin is about 20 mass% or less is used. It is preferable. In this case, toner particles can be obtained by first removing the organic solvent used in the resin composition from the dispersion of the liquid particles and then removing the organic solvent which is a poor solvent.
In the present invention, the non-aqueous medium is more preferably a medium mainly composed of carbon dioxide in a liquid state or a supercritical state. The above “main component” means that the ratio of carbon dioxide in the non-aqueous medium is 70% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more.
Here, carbon dioxide in a liquid state passes through a triple point (temperature = −57 ° C., pressure = 0.5 MPa) and a critical point (temperature = 31 ° C., pressure = 7.4 MPa) on the phase diagram of carbon dioxide. This represents carbon dioxide under the gas / liquid boundary line, the isotherm of the critical temperature, and the temperature and pressure conditions of the portion surrounded by the solid-liquid boundary line. Moreover, the carbon dioxide in a supercritical state represents carbon dioxide under temperature and pressure conditions above the critical point of the carbon dioxide.
When carbon dioxide is used as the non-aqueous medium in the method of the present invention, the resin composition is dispersed in carbon dioxide and granulated, and then the liquid particle dispersion obtained contains no organic solvent. Carbon is introduced and the organic solvent contained in the liquid particles is removed while being extracted into the carbon dioxide phase. After the removal of the organic solvent is completed, the toner particles can be obtained by releasing the pressure and separating the carbon dioxide. This method is particularly preferable because the toner particles can be collected very easily and the used organic solvent and carbon dioxide can be recycled.

The wax particles used in the method of the present invention are particles obtained by coating a wax component with a resin. As the resin for coating the wax component, a resin that does not completely dissolve in the organic solvent and the non-aqueous medium described above is used. Here, the “not completely dissolved” state means that when wax particles are dispersed in the organic solvent and the non-aqueous medium, the resin covering the wax component remains in a certain amount or more as a solid content. Means state. Therefore, even if it is in a swollen state or in a state where it is partially present as a soluble component, this is not regarded as complete dissolution.
In the present invention, whether or not the resin covering the wax component remains in a certain amount or more as a solid content depends on whether the resin of the resin covering the wax component after the wax particles are dispersed in an organic solvent and a non-aqueous medium. Judgment is made by quantitatively measuring and calculating the residual rate of the minute. Specifically, the following method is used.
First, in order to obtain wax particles after the dispersion treatment, the wax particles are dispersed in each of an organic solvent and a non-aqueous medium used in the actual production of toner particles, and stirred at a predetermined temperature and pressure for a predetermined time. Here, conditions such as a predetermined temperature, pressure, and stirring time are in accordance with conditions such as temperature, pressure, and stirring time when the toner particles are actually dispersed in an organic solvent or a non-aqueous medium. Usually, it is about 30 minutes to 2 hours in a temperature range from room temperature to 40 ° C. Moreover, the pressure in the case of using the above-described high-pressure carbon dioxide for the non-aqueous medium is in the range of 1 MPa to 20 MPa. Next, the organic solvent or the non-aqueous medium is separated and the residue remaining as a solid content is recovered. The residual ratio of the solid content of the resin covering the wax component in the collected residue is quantitatively grasped using an analysis method by 1H-NMR described later.
It is also possible to separately prepare a resin for coating the wax component as the material of the wax particles, perform the same dispersion treatment in an organic solvent and a non-aqueous medium, and obtain the residual ratio from the change in weight before and after the treatment.
In the present invention, the residual ratio of the solid content of the resin covering the wax component after the wax particles are dispersed in an organic solvent and a non-aqueous medium is 50% by mass or more. The residual rate is preferably 70% by mass or more.
Thus, by disperse | distributing the wax component in the liquid particle by the said resin composition by coat | covering the surface of a wax component with resin and controlling the residual rate of the solid content of resin which coat | covers a wax component to the said range. Even when granulation is performed in a non-aqueous medium, uneven distribution of the wax component in the toner particles can be prevented. Even when the toner is left for a long period of time, it is possible to suppress a decrease in the crystallinity of the binder resin due to environmental changes.
In the present invention, the method for coating the wax component with the resin is not particularly limited, and for example, the following method can be used.
In the case of coating with a vinyl resin, the wax component fine particles are dispersed in an aqueous medium in the presence of a suitable dispersant to form an emulsion, to which monomer and a polymerization initiator are sequentially added, and the wax component fine particles are added. It can be prepared by advancing a polymerization reaction using as a seed.
In addition, fine particles of the wax component are dispersed in an organic solvent in the presence of a suitable dispersant, a monomer capable of forming a polymer that is hardly soluble in the organic solvent is dissolved, and the wax is polymerized while the monomer is polymerized. It can be prepared by forming a polymer on the surface of the component fine particles.
When coating with a condensation resin such as polyester or polyurethane, the monomer, oligomer or solvent solution in which fine particles of the wax component are dispersed is dispersed in an aqueous medium in the presence of an appropriate dispersant, and heating or a curing agent is added. Then, it can be prepared by curing.
Also, by dissolving the resin prepared in advance in an organic solvent to prepare a resin solution, mixing the wax component fine particles therein, further dissolving an appropriate emulsifier, adding water to perform phase inversion emulsification. Can be prepared. Alternatively, the resin prepared in advance can be dissolved in an organic solvent to prepare a resin solution, and the wax component fine particles can be mixed therein and then sprayed in the form of a mist.
In the present invention, the resin for coating the wax component (hereinafter also simply referred to as a coating resin) is not particularly limited, and a resin used for a normal toner can be used. However, in order to suppress the solubility in the organic solvent and the non-aqueous medium and control the residual ratio, it is more preferable to use a coating resin into which a crosslinked structure is introduced. When a vinyl resin is selected as the coating resin, a crosslinked structure can be introduced by adding a polyfunctional monomer having two or more double bonds during polymerization. When a polyester resin is selected as the coating resin, a crosslinked structure can be introduced by using a compound having a trifunctional or higher functional group in either or both of the alcohol component and the carboxylic acid component during polymerization.

The wax component contained in the wax particles used in the present invention is not particularly limited, and the same wax components as those used in ordinary toners can be used. Specific examples include the following. Low molecular weight polyethylene, low molecular weight polypropylene, low molecular weight olefin copolymer, aliphatic hydrocarbon wax such as microcrystalline wax, paraffin wax, Fischer-Tropsch wax; oxide of aliphatic hydrocarbon wax such as oxidized polyethylene wax; fat Waxes based on fatty acid esters such as aliphatic hydrocarbon ester waxes; and partially or fully deoxidized fatty acid esters such as deacidified carnauba wax; partial esters of fatty acids and polyhydric alcohols such as behenic acid monoglyceride A methyl ester compound having a hydroxyl group obtained by hydrogenating vegetable oils and fats.
Among these waxes, aliphatic hydrocarbon waxes and ester waxes are particularly preferable from the viewpoints of bleeding from the toner during fixing and releasability.
The ester wax only needs to have at least one ester bond in one molecule, and either natural ester wax or synthetic ester wax may be used.
Examples of the synthetic ester wax include monoester wax synthesized from a long-chain linear saturated fatty acid and a long-chain linear saturated aliphatic alcohol. The long-chain linear saturated fatty acid is represented by the general formula C _n H _{2n + 1} COOH, and those having n = 5 or more and 28 or less are preferably used. The long-chain linear saturated aliphatic alcohol is represented by C _n H _{2n + 1} OH, and those having n = 5 or more and 28 or less are preferably used. Examples of natural ester waxes include candelilla wax, carnauba wax, rice wax, and derivatives thereof.
Among the above, more preferable waxes are synthetic ester waxes composed of long-chain linear saturated fatty acids and long-chain linear saturated aliphatic alcohols, or natural waxes based on the above esters. Furthermore, in addition to the linear structure described above, the ester is more preferably a monoester.
The wax component has sufficient stability with respect to an organic solvent and a non-aqueous medium that can be suitably used in the present invention, and the wax component is treated with an organic solvent and a non-aqueous solvent in the same manner as described above. The residual ratio of the solid content after being dispersed in the medium is 90% by mass or more.
Moreover, it is preferable that the said wax component has a peak temperature in the range of 60 degreeC or more and 85 degrees C or less in the maximum endothermic peak calculated | required by differential scanning calorimetry (DSC). Here, the peak temperature indicates the melting point of the wax component. If the peak temperature (that is, the melting point of the wax component) is lower than 60 ° C., the low molecular weight component of the wax component is likely to bleed out, and the effect on the decrease in the crystallinity of the binder resin due to the toner being left for a long time may not be sufficiently exhibited. . On the other hand, when the temperature is higher than 85 ° C., it is difficult to appropriately melt the wax component at the time of fixing, and low-temperature fixability and offset resistance tend to be lowered. More preferably, it is 65 degreeC or more and 80 degrees C or less.
In the present invention, the glass transition temperature (Tg) of the resin covering the wax component is preferably 50 ° C. or higher and 80 ° C. or lower. When the Tg of the coating resin is lower than 50 ° C., the shielding effect by the coating resin against the low molecular weight component of the wax component tends to be low, and the effect on the decrease in the crystallinity of the binder resin due to the toner being left for a long time may not be sufficiently exhibited. . On the other hand, when the Tg of the coating resin is higher than 80 ° C., it is difficult to properly exude the wax component at the time of fixing, and the low-temperature fixing property and the offset resistance tend to be lowered. More preferably, it is 55 degreeC or more and 75 degrees C or less.
In the present invention, the volume average particle diameter (Dv) of the wax particles is preferably 0.10 μm or more and 1.00 μm or less. As described above, in the preparation of the wax particles, the wax component is first made into a fine particle and then a coating layer is formed thereon. However, if the fine particle formation is excessive at this time, it becomes difficult to obtain particles having a uniform particle size distribution. Therefore, when the Dv of the wax particles is smaller than 0.10 μm, the coating effect by the resin tends to be reduced. On the other hand, if the Dv of the wax particles is larger than 1.00 μm, the dispersion of the wax particles tends to be insufficient, and it becomes difficult to properly exude the wax component at the time of fixing, and the low-temperature fixability and offset resistance tend to be lowered. is there. More preferably, it is 0.20 μm or more and 0.60 μm or less.
Further, in the present invention, the amount of wax particles added in the formation of toner particles is 2.0 parts by mass or more and 10.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin as a wax component. preferable. If the added amount of wax particles is less than 2.0 parts by mass, the releasability of the toner tends to be lowered, and the transfer paper is likely to be wound when the fixing member is at a low temperature. On the other hand, when the amount is more than 10.0 parts by mass, the particle size distribution of the toner particles obtained by reducing the granulation property tends to be broad, and the amount of the wax particles in the toner particles tends to decrease. More preferably, it is 3.0 parts by mass or more and 8.0 parts by mass or less with respect to 100.0 parts by mass of the binder resin.

The binder resin used in the method for producing a toner of the present invention is not particularly limited except that it contains a crystalline polyester, and other known amorphous resins known as binder resins for toner are used. can do. The binder resin used in the present invention preferably contains, as a main component, a copolymer in which a portion that can take a crystal structure and a portion that cannot take a crystal structure are chemically bonded. Here, “as the main component” means that the ratio of the copolymer in the binder resin is 50% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably. 90% by mass or more. In addition to the copolymer, the binder resin in the present invention may contain other known resins known as toner binder resins.
Furthermore, the site | part which can take the said crystal structure is a site | part which polymer chains regularly arrange | position by many gathering itself, and expresses crystallinity, and means a crystalline polymer. Moreover, the site | part which cannot take the said crystal structure is a site | part which takes a random structure without causing a regular arrangement | sequence, even if it collects itself, and means an amorphous polymer.
Examples of chemically bonded copolymers include block polymers, graft polymers, star polymers. Among these, a block polymer is particularly preferable. A block polymer is a copolymer in which polymers are linked by a covalent bond within one molecule. That is, the binder resin used in the present invention preferably contains, as a main component, a block polymer in which a portion that can take a crystal structure and a portion that cannot take a crystal structure are combined.
Examples of the block polymer include AB type diblock polymer, ABA type triblock polymer, BAB type triblock polymer, ABAB... Type multiblock polymer of crystalline polymer (A) and amorphous polymer (B). Such a form is mentioned. By using such a block polymer for the binder resin, the fine domains of the crystalline polymer (A) can be uniformly formed in the binder resin. As a result, the sharp melt property due to the crystalline polymer (A) is expressed in the entire toner, and the low-temperature fixing effect can be effectively exhibited.
Hereinafter, the crystalline polymer (A) in the block polymer will be described. In the present invention, the crystalline polymer (A) is preferably composed of a crystalline polyester. Here, the crystalline polyester means a polyester showing a clear melting point peak when differential heat is measured by differential scanning calorimetry (DSC).
The crystalline polyester used in the present invention preferably uses an aliphatic diol having 4 to 20 carbon atoms as an alcohol component and a polycarboxylic acid as a raw material as an acid component. The aliphatic diol is preferably linear. A polyester with higher crystallinity is obtained by being a linear type.
Examples of the aliphatic diol include the following compounds, but are not limited thereto. Depending on the case, it is also possible to use a mixture.
1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1 , 11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,20-eicosanediol.
Among these, from the viewpoint of melting point, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol are more preferable. These may be used alone or in combination of two or more.
An aliphatic diol having a double bond can also be used. Examples of the aliphatic diol having a double bond include the following compounds. 2-butene-1,4-diol, 3-hexene-1,6-diol, 4-octene-1,8-diol.
The polyvalent carboxylic acid is preferably an aromatic dicarboxylic acid or an aliphatic dicarboxylic acid, more preferably an aliphatic dicarboxylic acid, and particularly preferably a linear aliphatic dicarboxylic acid from the viewpoint of crystallinity.
Examples of the aliphatic dicarboxylic acid include the following compounds, but are not limited thereto. Depending on the case, it is also possible to use a mixture.
Succinic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, or a lower alkyl ester or acid anhydride thereof .
Of these, sebacic acid, adipic acid, 1,10-decanedicarboxylic acid or its lower alkyl ester and acid anhydride are preferred.
Examples of the aromatic dicarboxylic acid include, but are not limited to, the following compounds. Depending on the case, it is also possible to use a mixture.
Terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid.
Among these, terephthalic acid is preferable in terms of availability and easy formation of a low melting point polymer.
A dicarboxylic acid having a double bond can also be used. A dicarboxylic acid having a double bond can be suitably used in order to prevent hot offset at the time of fixing, because the entire resin can be crosslinked using the double bond.
Examples of such dicarboxylic acids include fumaric acid, maleic acid, 3-hexenedioic acid, and 3-octenedioic acid. Moreover, these lower alkyl esters and acid anhydrides are also included. Among these, fumaric acid and maleic acid are more preferable in terms of cost.
There is no restriction | limiting in particular as a manufacturing method of crystalline polyester, It can manufacture by the polymerization method of the general polyester resin which makes an acid component and an alcohol component react. For example, a direct polycondensation method or a transesterification method can be used, and production can be carried out using different types of monomers.
The production of the crystalline polyester is preferably carried out at a polymerization temperature of 180 ° C. or higher and 230 ° C. or lower, and the reaction system may be reacted while reducing the pressure inside the reaction system and removing water and alcohol generated during the condensation as necessary. preferable. When the monomer is not dissolved or compatible at the reaction temperature, a solvent having a high boiling point is preferably added as a solubilizer and dissolved. In the polycondensation reaction, the dissolution auxiliary solvent is distilled off. In the case where a monomer having poor compatibility exists in the polymerization reaction, it is preferable to condense the monomer having poor compatibility with the monomer and the acid or alcohol to be polycondensed in advance, and then polycondense together with the main component.
Examples of the catalyst that can be used in the production of the crystalline polyester include the following.
Titanium catalysts such as titanium tetraethoxide, titanium tetrapropoxide, titanium tetraisopropoxide, titanium tetrabutoxide. Tin catalysts such as dibutyltin dichloride, dibutyltin oxide, diphenyltin oxide.

Next, the amorphous polymer (B) in the block polymer will be described.
The amorphous polymer (B) is not particularly limited as long as it is amorphous, and the same amorphous resin as that generally used as a resin for toner can be used. However, the glass transition temperature (Tg) of the amorphous polymer (B) is preferably 50 ° C. or higher and 130 ° C. or lower, and more preferably 70 ° C. or higher and 130 ° C. or lower. By containing such an amorphous polymer (B), the elasticity of the toner in the fixing region after sharp melting is easily maintained.
Specific examples of the amorphous polymer (B) include polyurethane resin, amorphous polyester resin, styrene acrylic resin, polystyrene, and styrene butadiene resin. These resins may be modified with urethane, urea, or epoxy. Among these, from the viewpoint of maintaining elasticity, amorphous polyester resins and polyurethane resins can be preferably exemplified. Below, the amorphous polyester resin as an amorphous polymer (B) is described. Examples of the monomer that can be used for the production of the amorphous polyester resin include conventionally known divalent or trivalent monomers as described in “Polymer Data Handbook: Basic Edition” (Edited by Polymer Society: Bafukan). Examples thereof include the above carboxylic acids and divalent or trivalent or higher alcohols. Specific examples of these monomers are as follows.
Examples of the divalent carboxylic acid include the following. Dibasic acids such as succinic acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, terephthalic acid, malonic acid, dodecenyl succinic acid, and their anhydrides, their lower alkyl esters, maleic acid, fumaric acid, itaconic acid, Aliphatic unsaturated dicarboxylic acids such as citraconic acid.
Examples of the trivalent or higher carboxylic acid include the following. 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, and anhydrides thereof, lower alkyl esters thereof. These may be used individually by 1 type and may use 2 or more types together.
Examples of the divalent alcohol include the following. Bisphenol A, hydrogenated bisphenol A, ethylene oxide or propylene oxide adduct of bisphenol A, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, ethylene glycol, propylene glycol.
Examples of trihydric or higher alcohols include the following. Glycerin, trimethylol ethane, trimethylol propane, pentaerythritol. These may be used individually by 1 type and may use 2 or more types together.
For the purpose of adjusting the acid value and hydroxyl value, acetic acid, monovalent acid of benzoic acid, monovalent alcohol such as cyclohexanol and benzyl alcohol can be used as necessary.
Amorphous polyester resin is synthesized using the methods described in, for example, polycondensation (chemical doujin), polymer experiment (polycondensation and polyaddition: Kyoritsu Publishing), and polyester resin handbook (edited by Nikkan Kogyo Shimbun). The transesterification method and the direct polycondensation method can be used alone or in combination.
Next, the polyurethane resin as the amorphous polymer (B) will be described. The polyurethane resin is a reaction product of a diol and a substance containing a diisocyanate group, and a resin having various functions can be obtained by adjusting the diol and the diisocyanate.
Examples of the diisocyanate component include the following. Carbon number (excluding carbon in NCO group, the same shall apply hereinafter) 6 or more and 20 or less aromatic diisocyanate, C2 or more and 18 or less aliphatic diisocyanate, C4 or more and 15 or less alicyclic diisocyanate, carbon Aromatic hydrocarbon diisocyanates having a number of 8 or more and 15 or less, and modified products of these diisocyanates (urethane group, carbodiimide group, allophanate group, urea group, burette group, uretdione group, uretoimine group, isocyanurate group, oxazolidone group-containing modification) (Hereinafter also referred to as modified diisocyanate), and mixtures of two or more thereof.
Examples of the aromatic hydrocarbon diisocyanate include the following. m- and / or p-xylylene diisocyanate (XDI), α, α, α ′, α′-tetramethylxylylene diisocyanate.
Examples of the aliphatic diisocyanate include the following. Ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate.
Examples of the alicyclic diisocyanate include the following. Isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4′-diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate.
Among these, preferred are aromatic diisocyanates having 6 to 15 carbon atoms, aliphatic diisocyanates having 4 to 12 carbon atoms, and alicyclic diisocyanates having 4 to 15 carbon atoms, 8 or more carbon atoms, 15 or less aromatic hydrocarbon diisocyanates, particularly preferred are XDI, IPDI and HDI.
In addition to the diisocyanate component, a trifunctional or higher functional isocyanate compound can also be used as the polyurethane resin.
On the other hand, examples of the diol component that can be used for the polyurethane resin include the following.
Alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol); alkylene ether glycol (polyethylene glycol, polypropylene glycol); alicyclic diol (1,4-cyclohexanedimethanol); bisphenols (bisphenol) A); alkylene oxide (ethylene oxide, propylene oxide) adduct of the alicyclic diol.
The alkyl part of the alkylene glycol or alkylene ether glycol may be linear or branched. In the present invention, an alkylene glycol having a branched structure can also be preferably used.
In addition to the block polymer, as the binder resin, when using another amorphous resin, the same resin as the amorphous polymer (B) can be used.
In the block polymer in which the crystalline polymer (A) and the amorphous polymer (B) are bonded, examples of the bonding form connecting them include an ester bond, a urea bond, and a urethane bond. Among these, a block polymer bonded with a urethane bond is particularly preferable because moderate elasticity is easily maintained even in the fixing temperature region after sharp melting, and high temperature offset can be effectively suppressed.
As a method for preparing the block polymer, a crystalline polymer (A) and an amorphous polymer (B) are prepared separately, and both are combined (two-stage method), the crystalline polymer (A) and the amorphous polymer. A method (one-step method) in which the raw materials for the conductive polymer (B) are simultaneously charged and prepared at one time can be used.
The block polymer can be synthesized by selecting from various methods in consideration of the reactivity of the terminal functional group of each polymer. Below, the specific preparation example of a block polymer at the time of using crystalline polyester as a crystalline polymer (A) is shown.
In the case of a block polymer composed of a crystalline polyester and an amorphous polyester, each unit can be prepared separately and then combined using a binder. In particular, when the acid value of one polyester is high and the hydroxyl value of the other polyester is high, it is not necessary to use a binder, and the condensation reaction can proceed while heating and reducing pressure as it is. At this time, the reaction temperature is preferably about 200 ° C.
When the binder is used, the following binders are exemplified. Polyvalent carboxylic acid, polyhydric alcohol, polyvalent isocyanate, polyfunctional epoxy, polyanhydride. These binders can be used for synthesis by dehydration reaction or addition reaction.
In the case of a block polymer of crystalline polyester and polyurethane, each unit can be prepared separately, and then prepared by urethanating the alcohol terminal of the crystalline polyester and the isocyanate terminal of the polyurethane. Further, the synthesis can also be performed by mixing and heating a crystalline polyester having an alcohol terminal and a diol and diisocyanate constituting polyurethane. In this case, the diol and diisocyanate selectively react at the initial stage when the concentration of diol and diisocyanate is high to form polyurethane, and after the molecular weight increases to some extent, the urethanization reaction between the isocyanate terminal of polyurethane and the alcohol terminal of crystalline polyester occurs. Occurs and can be a block polymer.
In order to effectively express the effect of the block polymer, it is preferable that a homopolymer of a crystalline polymer or an amorphous polymer is not present in the binder resin as much as possible. That is, it is preferable that the blocking rate is high.
In the method of the present invention, the binder resin preferably contains, for example, 50% by mass or more and 85% by mass or less of the crystalline polyester as a resin component having a crystal structure, and is 60% by mass or more and 80% by mass or less. It is more preferable to contain. In the case where the binder resin is composed of a block polymer, it preferably contains 50% by mass or more and 85% by mass or less of a part that can take a crystal structure in the block polymer, for example, the above crystalline polyester part. 80% by mass or less is more preferable. In the case where the binder resin contains other amorphous resin in addition to the block polymer, a part capable of forming a crystal structure in the block polymer, for example, the above crystalline polyester part is 50 mass with respect to the total amount of the binder resin. % To 85% by mass, more preferably 60% to 80% by mass. When the content of the resin component having a crystal structure in the binder resin is 50% by mass or more, the sharp melt property is easily expressed effectively. When the content of the resin component having a crystal structure in the binder resin is less than 50% by mass, the sharp melt property is hardly expressed effectively, and the amorphous as a site that cannot take the crystal structure in the block polymer. It becomes easy to be influenced by the glass transition temperature (Tg) of the crystalline polymer or the amorphous resin added separately.
On the other hand, the binder resin preferably contains 15% by mass or more and 50% by mass or less of an amorphous resin component. In the case where the binder resin is composed of a block polymer, the content of the amorphous polymer as a site that cannot take a crystal structure in the block polymer is preferably 15% by mass or more and 50% by mass or less. When the binder resin contains other amorphous resin in addition to the block polymer, the total content of the amorphous polymer and the amorphous resin is 15% by mass with respect to the total amount of the binder resin. As mentioned above, it is preferable that it is 50 mass% or less. When the content of the amorphous resin component in the binder resin is 15% by mass or more, the maintenance of elasticity after the sharp melt is improved. If the content of the amorphous resin component in the binder resin is less than 15% by mass, it tends to be difficult to maintain elasticity after the toner is sharp melted, and high temperature offset may occur. More preferably, it is 20 mass% or more and 40 mass% or less.
The peak temperature of the maximum endothermic peak in the differential scanning calorimetry (DSC) of the block polymer used in the method of the present invention is preferably 50 ° C. or higher and 80 ° C. or lower. here,
The maximum endothermic peak is derived from a portion that can take a crystalline structure, for example, the crystalline polyester, and the peak temperature indicates a portion that can take a crystalline structure, for example, the melting point of the crystalline polyester.
When the peak temperature of the maximum endothermic peak is lower than 50 ° C., it is advantageous for low-temperature fixability of the obtained toner, but the heat-resistant storage stability of the toner tends to be lowered. Further, when the peak temperature of the maximum endothermic peak is higher than 80 ° C., excellent heat-resistant storage stability is exhibited, but low-temperature fixability tends to be lowered. That is, when the peak temperature of the maximum endothermic peak in the DSC measurement of the block polymer to be used is 50 ° C. or higher and 80 ° C. or lower, both low-temperature fixability and heat-resistant storage stability can be achieved. More preferably, it is 55 degreeC or more and 75 degrees C or less.
Furthermore, in the method of the present invention, the binder resin has a number average molecular weight (Mn) determined by gel permeation chromatography (GPC) measurement of a tetrahydrofuran (THF) soluble content from 8,000 to 30,000. The weight average molecular weight (Mw) is preferably 15,000 or more and 60,000 or less.
When the number average molecular weight (Mn) and the weight average molecular weight (Mw) are in the above ranges, it is possible to impart appropriate viscoelasticity to the toner. If Mn is less than 8,000 and Mw is less than 15,000, the toner becomes too soft and the heat-resistant storage stability tends to decrease. Further, the toner is easily peeled from the fixed image. On the other hand, if Mn is greater than 30,000 and Mw is greater than 60,000, the toner becomes too hard and the low-temperature fixability tends to decrease. A more preferable range of Mn is 10,000 or more and 20,000 or less, and a more preferable range of Mw is 20,000 or more and 50,000 or less.
Furthermore, the ratio of Mn to Mw (Mw / Mn) is preferably 6 or less. When the value of Mw / Mn exceeds 6, the crystalline polyester contained in the binder resin has low crystallinity, and the endothermic peak in DSC measurement is broad. A more preferable range of Mw / Mn is 3 or less.

In the method of the present invention, the toner particles contain a colorant in order to impart coloring power. Preferred examples of the colorant include organic pigments, organic dyes, inorganic pigments, carbon black as a black colorant, and magnetic powder. Colorants that are conventionally used in toners can be used.
Examples of the colorant for yellow include the following. Condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methine compounds, allylamide compounds. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 109, 110, 111, 128, 129, 147, 168, 180 are preferably used.
Examples of the magenta colorant include the following. Condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, perylene compounds. Specifically, C.I. I. Pigment Red 2, 3, 5, 6, 7, 23, 48: 2, 48: 3, 48: 4, 57: 1, 81: 1, 122, 144, 146, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254 are preferably used.
Examples of the colorant for cyan include the following. Copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 15: 3, 15: 4, 60, 62, 66 are preferably used.
These colorants can be used alone or in combination, and further in a solid solution state. The colorant to be used is selected from the viewpoints of hue angle, saturation, brightness, light resistance, OHP transparency, and dispersibility in the toner composition.
The colorant is preferably used by adding 1 part by mass or more and 20 parts by mass or less to 100 parts by mass of the binder resin in the toner composition. Similarly, when carbon black is used as the black colorant, it is preferably added and used in an amount of 1 to 20 parts by mass.
The colorant particles used in the present invention can be prepared by dispersing the colorant in an organic solvent for dissolving the binder resin by a known method.
When magnetic powder is used as the black colorant, the amount added is preferably 40 parts by mass or more and 150 parts by mass or less with respect to 100 parts by mass of the binder resin in the toner composition.

In the method of the present invention, a charge control agent can be added to the toner particles as necessary. By blending the charge control agent, the charge characteristics of the obtained toner are stabilized, and the optimum triboelectric charge amount can be controlled according to the development system.
As the charge control agent, a known one can be used, and a charge control agent that has a high charging speed and can stably maintain a constant charge amount is particularly preferable.
As the charge control agent for controlling the obtained toner to be negatively charged, organometallic compounds and chelate compounds are effective, and monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, and oxycarboxylic acids. And dicarboxylic acid-based metal compounds. These charge control agents can be used alone or in combination of two or more.
The preferred blending amount when using the charge control agent is 0.01 parts by mass or more and 10.0 parts by mass or less, more preferably 0.5 parts by mass or more, with respect to 100.0 parts by mass of the binder resin. 0 parts by mass or less.

Hereinafter, a method for producing toner particles using carbon dioxide in a liquid state or supercritical state as a dispersion medium, which is particularly suitable for obtaining toner particles used in the method of the present invention, will be described in detail by way of example. It is not limited to.
First, a binder resin containing crystalline polyester, colorant particles, and wax particles, and optionally other additives, together with an organic solvent capable of dissolving the binder resin containing crystalline polyester, a homogenizer, A resin composition is prepared by uniformly dissolving or dispersing using a dispersing machine such as a ball mill, a colloid mill, or an ultrasonic dispersing machine. Next, the obtained resin composition is dispersed in liquid or supercritical carbon dioxide filled in a container to prepare a dispersion of liquid particles of the resin composition.
At this time, it is preferable to perform granulation by dispersing a dispersant in the liquid or supercritical carbon dioxide. Examples of the dispersant include inorganic or organic fine particles, and may be used alone or in combination of two or more according to the purpose. That is, the dispersant may be any one of an inorganic fine particle dispersant, an organic fine particle dispersant, or a mixture thereof.
Examples of the inorganic fine particle dispersant include inorganic fine particles of silica, alumina, zinc oxide, titania, and calcium oxide.
Examples of the organic fine particle dispersant include vinyl resin, urethane resin, epoxy resin, ester resin, polyamide, polyimide, silicone resin, fluorine resin, phenol resin, melamine resin, benzoguanamine resin, urea resin, aniline resin, and ionomer resin. , Polycarbonate, cellulose fine particles, and mixtures thereof.
When resin fine particles are used as a dispersant, if amorphous resin fine particles are used, carbon dioxide in a liquid state or a supercritical state is dissolved in the resin to be plasticized, and the glass transition temperature (Tg) of the resin is increased. Therefore, the toner particles tend to aggregate. Therefore, it is preferable to use a resin having crystallinity as the fine particles of the resin, and when an amorphous resin is used, it is preferable to introduce a crosslinked structure. Moreover, the fine particle which coat | covered the amorphous resin fine particle with the crystalline resin may be sufficient.
The dispersant may be used as it is, but may be surface-modified by various treatments in order to give the resin composition an adsorptivity to the surface of the liquid particles. Specifically, for example, surface treatment with a silane-based, titanate-based, or aluminate-based coupling agent, surface treatment with various surfactants, and coating treatment with a polymer can be given.
Since the dispersant adsorbed on the surface of the liquid particles remains after the toner particles are formed,
When resin fine particles are used as the dispersant, toner particles whose surfaces are coated with resin fine particles can be formed. At this time, the particle diameter of the fine particles is preferably 0.03 μm or more and 0.30 μm or less in volume average particle diameter (Dv). More preferably, it is 0.05 μm or more and 0.10 μm or less. When the particle size of the fine particles is too small, the stability of the liquid particles at the time of granulation tends to decrease. When it is too large, it becomes difficult to control the particle size of the liquid particles to a desired size.
The blending amount of the fine particles is preferably 3.0 parts by weight or more and 15.0 parts by weight or less based on the solid content contained in the solution of the material constituting the toner particles. It can be appropriately adjusted according to the properties and desired particle size.
In the production of toner particles used in the method of the present invention, any method may be used as a method of dispersing the dispersant in carbon dioxide in a liquid state or a supercritical state. As a specific example, there is a method in which the dispersant and liquid or supercritical carbon dioxide are charged in a container and directly dispersed by stirring or ultrasonic irradiation. Another example is a method in which a dispersion liquid in which the dispersant is dispersed in an organic solvent is introduced into a container charged with liquid or supercritical carbon dioxide using a high-pressure pump.
Moreover, any method may be used as a method of dispersing the resin composition in a dispersion medium composed of carbon dioxide in a liquid state or a supercritical state. As a specific example, there is a method of introducing the resin composition into a container containing carbon dioxide in a liquid state or a supercritical state in which the dispersant is dispersed using a high-pressure pump. Further, carbon dioxide in a liquid state or a supercritical state in which the dispersant is dispersed may be introduced into a container charged with the resin composition.
The dispersion medium of carbon dioxide in the liquid state or supercritical state described above is preferably a single phase. When granulating by dispersing the resin composition in carbon dioxide in a liquid state or a supercritical state, a part of the organic solvent in the liquid particles moves into the dispersion. At this time, it is not preferable that the organic solvent phase is present in a separated state in addition to the phase containing carbon dioxide because the stability of the liquid particles is impaired. Therefore, the temperature and pressure of the dispersion medium, and the amount of the solution with respect to carbon dioxide in a liquid state or supercritical state are preferably adjusted within a range in which carbon dioxide and an organic solvent can form a homogeneous phase.
In addition, regarding the temperature and pressure of the dispersion medium, attention should be paid to granulation properties (ease of forming liquid particles) and solubility of the constituent components in the resin composition in the dispersion medium. For example, the resin, the wax component, and the resin for coating the wax component in the resin composition may be dissolved in the dispersion medium depending on temperature conditions and pressure conditions. In general, the lower the temperature and the lower the pressure, the more the solubility of the above components in the dispersion medium is suppressed, but the formed oil droplets are likely to agglomerate and coalesce, and the granulation property is lowered. On the other hand, although the granulation property is improved as the temperature and pressure are increased, the components tend to be easily dissolved in the dispersion medium.
Furthermore, the temperature of the dispersion medium is preferably lower than the melting point of the crystalline polyester so that the crystallinity of the crystalline polyester contained in the binder resin is not impaired. Therefore, in the production of the toner particles of the present invention, the temperature of the dispersion medium is preferably in the temperature range of 10 ° C. or higher and 40 ° C. or lower.
The pressure in the container forming the dispersion medium is preferably 1 MPa or more and 20 MPa or less, more preferably 2 MPa or more and 15 MPa or less. In addition, the pressure in this invention shows the total pressure, when components other than a carbon dioxide are contained in a dispersion medium.
The ratio of carbon dioxide in the dispersion medium in the present invention is usually 70% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more.
After the granulation is completed in this way, the organic solvent remaining in the liquid particles is removed through a dispersion medium of carbon dioxide in a liquid state or a supercritical state. Specifically, carbon dioxide in a liquid state or a supercritical state is further mixed with the dispersion medium in which liquid particles are dispersed, and the remaining organic solvent is extracted into a carbon dioxide phase. Is further replaced by liquid or supercritical carbon dioxide.
In the mixing of the dispersion medium and the liquid state or supercritical carbon dioxide, carbon dioxide in a liquid state or supercritical state having a higher pressure than this may be added to the dispersion medium. It may be added to carbon dioxide in a lower pressure liquid state or supercritical state.
As a method for further replacing carbon dioxide containing an organic solvent with carbon dioxide in a liquid state or supercritical state, there is a method of circulating liquid state or supercritical carbon dioxide while keeping the pressure in the container constant. Can be mentioned. At this time, the toner particles to be formed are performed while being supplemented by a filter.
When the liquid medium or the supercritical state is not sufficiently substituted with carbon dioxide, and the organic solvent remains in the dispersion medium, the dispersion medium is used when the container is decompressed in order to recover the obtained toner particles. In some cases, the organic solvent dissolved therein may condense and the toner particles may be redissolved or the toner particles may coalesce. Therefore, the substitution with carbon dioxide in the liquid state or supercritical state must be performed until the organic solvent is completely removed. The amount of carbon dioxide in the liquid state or supercritical state to be circulated is preferably 1 to 100 times, more preferably 1 to 50 times, most preferably 1 or more times the volume of the dispersion medium. 30 times or less.
When removing the toner particles from the dispersion containing carbon dioxide in a liquid state or supercritical state in which the toner particles are dispersed by decompressing the container, the pressure may be reduced to normal temperature and normal pressure at once, but the pressure is controlled independently. The pressure may be reduced stepwise by providing the container in multiple stages. The decompression speed is preferably set within a range where the toner particles do not foam.
Furthermore, in the present invention, it is preferable to heat-treat the toner particles taken out under a temperature condition lower than the melting point of the crystalline polyester. In the present invention, this heat treatment is hereinafter referred to as annealing treatment.
Generally, it is known that crystallinity of a crystalline resin increases when an annealing treatment is performed. The principle is considered as follows. That is, when annealing is performed on a crystalline material, the molecular mobility of the polymer chain is increased to some extent by the heat, so that the polymer chain is reoriented to a more stable structure, that is, a regular crystal structure. Thus, crystallization occurs. When treated at a temperature equal to or higher than the melting point of the crystalline material, the polymer chain obtains an energy higher than that required for reorientation, so recrystallization does not occur.
Therefore, it is important that the annealing treatment in the present invention is performed within a limited temperature range with respect to the melting point of the crystalline polyester in order to activate the molecular motion of the crystalline polyester in the toner as much as possible. Specifically, the obtained toner particles are subjected to DSC measurement at a temperature increase rate of 10.0 ° C./min to obtain an endothermic peak temperature derived from the crystalline polyester, and are equal to or higher than a temperature obtained by subtracting 15 ° C. from the peak temperature. It is preferable to perform the annealing process at a temperature less than 5 ° C. More preferably, it is a temperature range from a temperature obtained by subtracting 10 ° C from the peak temperature to a temperature obtained by subtracting 5 ° C.
The annealing treatment time can be appropriately adjusted depending on the ratio and type of crystalline polyester in the toner and the crystalline state, but it is usually preferable to perform the annealing treatment in the range of 1 hour to 50 hours. When the annealing time is less than 1 hour, it is difficult to obtain the effect of recrystallization. On the other hand, even if the annealing process is performed for more than 50 hours, no further effect can be expected. More preferably, it is the range of 2 hours or more and 24 hours or less.
In the present invention, the annealing treatment may be performed at any stage as long as it is after the toner particle forming step.

The method of the present invention may include a step of producing toner by externally adding inorganic fine particles to the toner particles. The inorganic fine powder has a function of improving the fluidity of the toner and a function of making the toner charge uniform.
Examples of the inorganic fine powder include fine powder such as silica fine powder, titanium oxide fine powder, alumina fine powder, and composite oxide fine powder thereof. Among these inorganic fine powders, silica fine powder and titanium oxide fine powder are preferable.
Examples of silica fine powder include dry silica or fumed silica produced by vapor phase oxidation of silicon halide, and wet silica produced from water glass. As the inorganic fine powder, dry silica having less silanol groups on the surface and inside of the silica fine powder and less Na ₂ O and SO ₃ ²⁻ is preferable. The dry silica may be a composite fine powder of silica and another metal oxide produced by using a metal halogen compound such as aluminum chloride or titanium chloride together with a silicon halogen compound in the production process.
In addition, as the inorganic fine powder, the inorganic fine powder itself is hydrophobized, so that adjustment of the charge amount of the toner, improvement of environmental stability, and improvement of characteristics under a high humidity environment can be achieved. More preferably, an inorganic fine powder subjected to a hydrophobic treatment is used. When the inorganic fine powder externally added to the toner absorbs moisture, the charge amount as the toner is reduced, and the developability and transferability are likely to be reduced.
Treatment agents for hydrophobizing inorganic fine powder include unmodified silicone varnish, various modified silicone varnishes, unmodified silicone oil, various modified silicone oils, silane compounds, silane coupling agents, other organosilicon compounds, and organic titanium. Compounds. These treatment agents may be used alone or in combination.
Among these, inorganic fine powder treated with silicone oil is preferable. More preferably, when the inorganic fine powder is hydrophobized with a coupling agent, or simultaneously with the treatment, the hydrophobized inorganic fine powder treated with silicone oil treated with silicone oil increases the charge amount of the toner even in a high humidity environment. It is good for maintaining and reducing selective developability.
The amount of the inorganic fine powder added is preferably 0.1 parts by mass or more and 4.0 parts by mass or less, more preferably 0.2 parts by mass or more and 3.5 parts by mass with respect to 100 parts by mass of the toner particles. It is below mass parts.
The toner produced using the method of the present invention preferably has a weight average particle diameter (D4) of 3.0 μm or more and 8.0 μm or less. More preferably, it is 5.0 μm or more and 7.0 μm or less. The use of the toner having such a weight average particle diameter (D4) is preferable from the viewpoint of sufficiently satisfying the dot reproducibility while improving the toner handling property.
Further, the ratio (D4 / D1) of the weight average particle diameter (D4) to the number average particle diameter (D1) of the obtained toner is preferably 1.25 or less. More preferably, it is 1.20 or less.

A method for measuring various physical properties in the method of the present invention will be described below.
<Measurement Method of Toner Weight Average Particle Size (D4) and Number Average Particle Size (D1)>
In the present invention, the weight average particle diameter (D4) and the number average particle diameter (D1) of the toner are calculated as follows.
As a measuring device, a precise particle size distribution measuring device “Coulter Counter Multisizer 3” (registered trademark, manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method equipped with a 100 μm aperture tube is used. For setting the measurement conditions and analyzing the measurement data, the attached dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) is used. The measurement is performed with 25,000 effective measurement channels.
As the electrolytic aqueous solution used for the measurement, special grade sodium chloride is dissolved in ion-exchanged water so as to have a concentration of about 1% by mass, for example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.
Prior to measurement and analysis, the dedicated software is set as follows.
On the “Change Standard Measurement Method (SOM)” screen of the dedicated software, set the total count in the control mode to 50,000 particles, set the number of measurements once, and set the Kd value to “standard particles 10.0 μm” (Beckman Coulter Set the value obtained using By pressing the “Threshold / Noise Level Measurement Button”, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte is set to ISOTON II, and the “aperture tube flush after measurement” is checked.
In the “Pulse to particle size conversion setting” screen of the dedicated software, the bin interval is set to logarithmic particle size, the particle size bin is set to 256 particle size bin, and the particle size range is set to 2 μm to 60 μm.
The specific measurement method is as follows.
(1) About 200 ml of the electrolytic solution is placed in a glass 250 ml round bottom beaker exclusively for Multisizer 3, set on a sample stand, and the stirrer rod is stirred counterclockwise at 24 rpm. Then, the dirt and bubbles in the aperture tube are removed by the “aperture flush” function of the dedicated software.
(2) About 30 ml of the electrolytic aqueous solution is put into a glass 100 ml flat bottom beaker. In this, "Contaminone N" (nonionic surfactant, anionic surfactant, 10% by weight aqueous solution of neutral detergent for pH7 precision measuring instrument cleaning, made by organic builder, manufactured by Wako Pure Chemical Industries, Ltd. About 0.3 ml of a diluted solution obtained by diluting 3) with ion-exchanged water is added.
(3) Two oscillators with an oscillation frequency of 50 kHz are incorporated with the phase shifted by 180 degrees, and an ultrasonic disperser “Ultrasonic Dispersion System Tetora 150” (manufactured by Nikka Ki Bios) having an electrical output of 120 W is prepared. About 3.3 l of ion-exchanged water is placed in the water tank of the ultrasonic disperser, and about 2 ml of Contaminone N is added to the water tank.
(4) The beaker of (2) is set in the beaker fixing hole of the ultrasonic disperser, and the ultrasonic disperser is operated. Then, the height position of the beaker is adjusted so that the resonance state of the liquid surface of the electrolytic aqueous solution in the beaker is maximized.
(5) In a state where the electrolytic aqueous solution in the beaker of (4) is irradiated with ultrasonic waves, about 10 mg of toner is added to the electrolytic aqueous solution little by little and dispersed. Then, the ultrasonic dispersion process is continued for another 60 seconds. In the ultrasonic dispersion, the temperature of the water tank is appropriately adjusted so as to be 10 ° C. or higher and 40 ° C. or lower.
(6) To the round bottom beaker of (1) installed in the sample stand, the electrolyte solution of (5) still dispersed using a pipette is dropped and adjusted so that the measured concentration is about 5%. . Measurement is performed until the number of measured particles reaches 50,000.
(7) The measurement data is analyzed with the dedicated software attached to the apparatus, and the weight average particle diameter (D4) and the number average particle diameter (D1) are calculated. The “average diameter” on the “analysis / volume statistic (arithmetic average)” screen when the graph / volume% is set in the dedicated software is the weight average particle size (D4). When the number% is set, the “average diameter” on the “analysis / number statistics (arithmetic average)” screen is the number average particle diameter (D1).

<Measurement method of peak temperature (Tp) of maximum endothermic peak>
In the present invention, the peak temperature (Tp) of the maximum endothermic peak of the toner, crystalline polyester, and block polymer is measured under the following conditions using an inspection scanning calorimeter DSC Q1000 (manufactured by TA Instruments).
Temperature increase rate: 10 ° C / min
Measurement start temperature: 20 ° C
Measurement end temperature: 180 ° C
The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium.
Specifically, about 5 mg of a sample is precisely weighed, placed in a silver pan, and measured once. A silver empty pan is used as a reference. The peak temperature of the maximum endothermic peak at that time is defined as Tp. Here, the maximum endothermic peak is a peak having the maximum endothermic amount when there are a plurality of peaks.

<Measurement method of content (mass basis) of a portion (for example, crystalline polyester) capable of taking a crystal structure>
In the present invention, the content (mass basis) of a portion (for example, crystalline polyester) that can have a crystal structure in the block polymer used is measured by 1H-NMR under the following conditions.
Measuring apparatus: FT NMR apparatus JNM-EX400 (manufactured by JEOL Ltd.)
Measurement frequency: 400MHz
Pulse condition: 5.0μs
Frequency range: 10500Hz
Integration count: 64 times Measurement temperature: 30 ° C
A sample (block polymer) 50 mg is put into a sample tube having an inner diameter of 5 mm, deuterated chloroform (CDCl ₃ ) is added as a solvent, and this is dissolved in a constant temperature bath at 40 ° C. to prepare a measurement sample. The measurement sample is measured under the above conditions to obtain a 1H-NMR chart. From the obtained 1H-NMR chart, a peak independent of the peaks attributed to other constituent elements was selected from the peaks attributed to the constituent elements of the crystalline polyester, and the integrated value S ₁ of this peak was determined. calculate. Similarly, among the peaks attributed to the components of the amorphous polymer, and select the independent peaks and peak attributable to other components, an integrated value S ₂ is calculated for this peak. The content of the crystalline polyester (mol%), using the integration value S ₁ and the integrated value S _2, obtained as follows. Note that n ₁ and n ₂ are the number of hydrogens in the constituent element to which the focused peak belongs.
Content (mol%) of crystalline polyester = {(S ₁ / n ₁ ) / ((S ₁ / n ₁ ) + (S ₂ / n ₂ ))} × 100
The value of the content (mol%) thus obtained is converted to “mass%” from the molecular weight of each component.

<Measuring method of glass transition temperature (Tg) of coating resin>
In the present invention, the glass transition temperature (Tg) of the resin used to coat the wax particles used is measured using an inspection scanning calorimeter DSC Q1000 (manufactured by TA Instruments) under the following conditions.
Measurement mode: Modulation mode Temperature increase rate: 2 ° C / min
Modulation temperature amplitude: ± 0.6 ° C / min
Frequency: 1 time / min
Measurement start temperature: 20 ° C
Measurement end temperature: 150 ° C
The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium.
Specifically, about 5 mg of a sample is precisely weighed, placed in a silver pan, and measured using an empty silver pan as a reference. The measurement is performed only once. From the obtained reversing heat flow curve at the time of temperature rise, draw the tangent line between the endothermic curve and the baseline before and after, and find the midpoint of the straight line connecting the intersection of each tangent line This is the glass transition temperature.

<Measuring method of melting point of wax component>
In the present invention, the melting point of the wax component in the wax particles used is measured under the following conditions using DSC Q1000 (manufactured by TA Instruments).
Temperature increase rate: 10 ° C / min
Measurement start temperature: 20 ° C
Measurement end temperature: 180 ° C
The temperature correction of the device detection unit uses the melting points of indium and zinc, and the correction of heat uses the heat of fusion of indium.
Specifically, about 2 mg of a sample is precisely weighed, placed in a silver pan, and measured using an empty silver pan as a reference. In the measurement, the temperature is once raised to 200 ° C., subsequently lowered to 30 ° C., and then heated again. In the second temperature raising process, the temperature showing the maximum endothermic peak of the DSC curve in the temperature range of 30 ° C. to 200 ° C. is defined as the melting point of the wax. The maximum endothermic peak means a peak having the largest endothermic amount when there are a plurality of peaks.

<Measurement method of residual ratio of solid content of resin covering wax component>
In the present invention, the residual ratio of the solid content of the resin that coats the wax component after dispersing the wax particles used in an organic solvent and a non-aqueous medium (hereinafter simply referred to as a coating resin) is as follows according to 1H-NMR. Measure under the following conditions.
Measuring apparatus: FT NMR apparatus JNM-EX400 (manufactured by JEOL Ltd.)
Measurement frequency: 400MHz
Pulse condition: 5.0μs
Frequency range: 10500Hz
Integration count: 64 times Measurement temperature: 30 ° C
As a sample, 50 mg of wax particles before dispersion treatment are put into a sample tube having an inner diameter of 5 mm, deuterated chloroform (CDCl ₃ ) is added as a solvent, and this is dissolved in a constant temperature bath at 40 ° C. to prepare a measurement sample. The measurement sample is measured under the above conditions to obtain a 1H-NMR chart. From the obtained 1H-NMR chart, a peak that does not receive the interference of the peak attributed to the wax component is selected from the peaks attributed to the coating resin. Then, the integrated value S _{P1 of the} peak attributed to the selected coating resin and the integrated value S _R1 of the peak of tetramethylsilane (TMS) added as an internal standard in CDCl ₃ are calculated.
Next, the same measurement is performed on the wax particles after the dispersion treatment. At this time, the amount of sample collected is determined by multiplying the residual ratio of the solid content of the wax particles obtained from the change in weight before and after the dispersion treatment in consideration of the amount eluted by the dispersion treatment. Then, from the obtained 1H-NMR chart, the peak integrated value S _P2 and the TMS peak integrated value S _R2 attributed to the coating resin are similarly calculated.
The solid content residual ratio of the coating resin is determined as follows using the integrated values S _P1 , S _R1 , S _P2 , and S _R2 .
Residual ratio of solid content of coating resin (mass%) = {( _SP2 / _SR2 ) / ( _SP1 / _SR1 )} × 100

<Method of measuring number average molecular weight (Mn) and weight average molecular weight (Mw)>
In the present invention, the number average molecular weight (Mn) and weight average molecular weight (Mw) of the resin in tetrahydrofuran (THF) are measured by gel permeation chromatography (GPC) as follows.
(1) Preparation of measurement sample Resin (sample) and THF were mixed at a concentration of about 0.5 to 5 mg / ml (for example, about 5 mg / ml) and allowed to stand at room temperature for several hours (for example, 5 to 6 hours). After that, the mixture was sufficiently shaken, and the THF and the sample were mixed well until there was no union of the sample. Furthermore, it left still at room temperature for 12 hours or more (for example, 24 hours). At this time, the time from the start of mixing the sample and THF to the end of standing was set to 24 hours or longer.
Thereafter, a sample processing filter (pore size 0.45 to 0.5 μm, Maisori Disc H-25-2 [manufactured by Tosoh Corp.], Excro Disc 25CR [manufactured by Gelman Science Japan Ltd.] can be preferably used) is passed. This was used as a GPC sample.
(2) Sample measurement The column was stabilized in a heat chamber at 40 ° C., and THF as a solvent was flowed through the column at this temperature at a flow rate of 1 ml / min, so that the sample concentration was 0.5 to 5 mg / ml. Measurement was made by injecting 50 to 200 μl of a THF sample solution of the prepared resin.
In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the calibration curve prepared from several monodisperse polystyrene standard samples and the number of counts.
As a standard polystyrene sample for creating a calibration curve, Pressure Chemical
Co. Made by Toyo Soda Kogyo Co., Ltd., molecular weight 6.0 × 10 ² , 2.1 × 10 ³ , 4.0 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2.0 × 10 ⁶ , 4.48 × 10 ⁶ were used. An RI (refractive index) detector was used as the detector.
As the column, in order to accurately measure the molecular weight region of 1 × 10 ^{3 to} 2 × 10 ⁶ , a plurality of commercially available polystyrene gel columns were used in combination as described below. The measurement conditions of GPC in the present invention are as follows.
[GPC measurement conditions]
Apparatus: LC-GPC 150C (manufactured by Waters)
Column: 7 series of Showdex KF801, 802, 803, 804, 805, 806, 807 (manufactured by Showa Denko KK) Column temperature: 40 ° C
Mobile phase: THF (tetrahydrofuran)

<Method for measuring volume average particle diameter (Dv) of wax particles and resin fine particles>
In the present invention, the volume average particle diameter (Dv) of the wax particles and the resin fine particles is measured with a microtrack particle size distribution measuring device HRA (X-100) (manufactured by Nikkiso Co., Ltd.) in a range setting of 0.001 μm to 10 μm. And measured as a volume average particle size (μm). In addition, water is selected as a dilution solvent.

EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this does not limit this invention at all. In addition, all the parts and% of an Example and a comparative example are mass references | standards unless there is particular notice.
<Synthesis of crystalline polyester 1>
The following raw materials were charged into a heat-dried two-necked flask while introducing nitrogen.
-Sebacic acid 136.2 parts by mass-1,4-butanediol 63.8 parts by mass-Dibutyltin oxide 0.1 part by mass The system was purged with nitrogen by depressurization, and then stirred at 180 ° C for 6 hours. Thereafter, the temperature was gradually raised to 230 ° C. under reduced pressure while continuing the stirring, and was further maintained for 2 hours. Crystalline polyester 1 was synthesize | combined by air-cooling when it became a viscous state and stopping reaction. The obtained crystalline polyester 1 had a number average molecular weight (Mn) of 5,100, a weight average molecular weight (Mw) of 11,500, and a peak temperature (Tp) of the maximum endothermic peak of 66 ° C.
<Synthesis of crystalline polyester 2>
In the synthesis of the crystalline polyester 1, the crystalline polyester 2 was synthesized in the same manner except that the raw materials were changed as follows. The obtained crystalline polyester 2 had Mn of 5,000, Mw of 11,600, and Tp of 61 ° C.
Sebacic acid 111.7 parts by mass Adipic acid 21.9 parts by mass 1,4-butanediol 66.4 parts by mass Dibutyltin oxide 0.1 part by mass <Synthesis of crystalline polyester 3>
In the synthesis of the crystalline polyester 1, the crystalline polyester 3 was synthesized in the same manner except that the raw material charge was changed as follows. The obtained crystalline polyester 3 had Mn of 4,600, Mw of 10,500, and Tp of 74 ° C.
-Tetradecanedioic acid 134.0 parts by mass-1,6-hexanediol 66.0 parts by mass-Dibutyltin oxide 0.1 parts by mass <Synthesis of crystalline polyester 4>
In the synthesis of the crystalline polyester 1, the crystalline polyester 4 was synthesized in the same manner except that the raw materials were changed as follows. The obtained crystalline polyester 4 had Mn of 5,100, Mw of 10,700, and Tp of 87 ° C.
-Dodecanedioic acid 116.5 parts by mass-1,10-decanediol 83.5 parts by mass-Dibutyltin oxide 0.1 parts by mass

<Synthesis of block polymer 1>
Crystalline polyester 1 210.0 parts by mass Xylylene diisocyanate (XDI) 56.0 parts by mass Cyclohexanedimethanol (CHDM) 34.0 parts by mass Tetrahydrofuran (THF) 300.0 parts by mass A stirrer and a thermometer The above materials were charged into a reaction vessel equipped with nitrogen substitution. The mixture was heated to 50 ° C. and subjected to urethanization reaction for 15 hours. Thereafter, 3.0 parts by mass of tertiary butyl alcohol was added to modify the isocyanate terminal. The solvent, THF, was distilled off to obtain block polymer 1. Table 2 shows the physical properties of the obtained block polymer 1.
<Synthesis of block polymers 2 to 8>
In the synthesis of block polymer 1, block polymers 2 to 8 were synthesized in the same manner except that the materials used and the blending amounts were changed to the conditions shown in Table 1. Table 2 shows the physical properties of the obtained block polymers 2 to 8.

<Preparation of block polymer resin solution 1>
In a beaker equipped with a stirrer, 500.0 parts by mass of acetone and 500.0 parts by mass of block polymer 1 are added, and stirring is continued until the polymer is completely dissolved to prepare a block polymer resin solution 1 having a solid content of 50% by mass. did.
<Preparation of block polymer resin solutions 2 to 8>
Block polymer resin solutions 2 to 8 were prepared in the same manner as in the preparation of the block polymer resin solution 1 except that the block polymer 1 was changed to the block polymers 2 to 8.

<Preparation of wax particle dispersion 1>
A reaction vessel equipped with a stirrer and a thermometer was charged with 200.0 parts by mass of paraffin wax 1 (HNP-11: melting point 67 ° C., manufactured by Nippon Seiwa) and 20.0 parts by mass of sodium dodecylbenzenesulfonate at 80 ° C. Then, 250.0 parts by mass of hot water at 95 to 100 ° C. was gradually added and emulsified while stirring at 200 rpm. Further, 197.0 parts by mass of hot water of 65 to 70 ° C. was added for dilution, and the mixture was cooled to room temperature to obtain a wax emulsion (solid content: 30.0% by mass) having a volume average particle size of 0.25 μm.
Next, the temperature of the emulsion of the wax was raised to 60 ° C., and 1.0 part by mass of ammonium persulfate was charged, and then 112.0 parts by mass of styrene and 21.0 butyl acrylate with stirring (rotation number: 200 rpm). A mixed solution of parts by mass and 1.3 parts by mass of divinylbenzene was added dropwise over 4 hours for polymerization. Further, 50.0 parts by mass of 1.0% ammonium persulfate aqueous solution was added, and after aging at 65 ° C. for 4 hours, the mixture was cooled to room temperature to obtain an aqueous dispersion of wax particles 1 having a vinyl resin coating layer on the surface. It was.
It was 0.30 micrometer when the volume average particle diameter of the obtained wax particle 1 was measured. Next, when a part of the wax particles 1 was taken out from the aqueous dispersion and subjected to a dispersion treatment in acetone at a temperature of 25 ° C. for 2 hours, the residual ratio of the solid content of the coating resin was determined by 1H-NMR. It was 88 mass%.
Further, after the wax particles 1 are put into an autoclave equipped with a stirring blade, carbon dioxide is introduced and a dispersion treatment is performed for 2 hours under the conditions of a temperature of 25 ° C. and a pressure of 5 MPa, the solid content of the coating resin is similarly applied. The residual ratio was 92% by mass.
The remaining aqueous dispersion of wax particles 1 was filtered to separate the wax particles 1, and then redispersed in acetone to prepare a wax particle dispersion 1 having a solid content of 40.0% by mass.
<Preparation of wax particle dispersions 2 to 4>
In the preparation of the wax particle dispersion 1, water dispersions of wax particles 2 to 4 were prepared in the same manner except that the wax used was changed to that shown in Table 3, and the solid content was 40.0% by mass in the same manner. Wax particle dispersions 2 to 4 were prepared. The volume average particle diameter of the obtained wax particles 2 to 4 and the solid content of the coating resin after the wax particles 2 to 4 are dispersed in acetone at a temperature of 25 ° C. and carbon dioxide at a temperature of 25 ° C. and a pressure of 5 MPa. Table 3 shows the residual ratio of each.
<Preparation of wax particle dispersion 5>
In the preparation of the wax particle dispersion 1, an aqueous dispersion of the wax particles 5 was prepared in the same manner except that the monomer composition used in the step of forming the coating layer with the vinyl resin was changed as follows. A wax particle dispersion 5 having a solid content of 40.0% by mass was prepared. The volume average particle diameter of the obtained wax particles 5, the residual ratio of the solid content of the coating resin after the wax particles 5 were dispersed in acetone at a temperature of 25 ° C. and carbon dioxide at a temperature of 25 ° C. and a pressure of 5 MPa. Table 3 shows.
-Styrene 105.0 parts by mass-Butyl acrylate 28.0 parts by mass-Divinylbenzene 1.3 parts by mass <Preparation of wax particle dispersion 6>
In the preparation of the wax particle dispersion 1, an aqueous dispersion of wax particles 6 was prepared in the same manner except that the monomer composition used in the step of forming the coating layer with the vinyl resin was changed as follows. A wax particle dispersion 6 having a solid content of 40.0% by mass was prepared. The volume average particle diameter of the obtained wax particles 6, the residual ratio of the solid content of the coating resin after the wax particles 6 were dispersed in acetone at a temperature of 25 ° C. and carbon dioxide at a temperature of 25 ° C. and a pressure of 5 MPa. Table 3 shows.
-Styrene 121.0 parts by mass-12.0 parts by mass of butyl acrylate-1.3 parts by mass of divinylbenzene <Preparation of wax particle dispersions 7 to 10>
In the preparation of the wax particle dispersion 1, the amount of sodium dodecylbenzenesulfonate was changed to 5.0 parts by weight, 10.0 parts by weight, 30.0 parts by weight, and 50.0 parts by weight, respectively. A water dispersion of wax particles 7 to 10 was prepared in the same manner except that the rotation speeds were changed to 1000 rpm, 500 rpm, 100 rpm, and 50 rpm, respectively. Similarly, wax particle dispersions 7 to 7 having a solid content of 40.0% by mass were prepared. 10 was prepared. The volume average particle diameter of the obtained wax particles 7 to 10, and the solid content of the coating resin after the wax particles 7 to 10 are dispersed in acetone at a temperature of 25 ° C. and carbon dioxide at a temperature of 25 ° C. and a pressure of 5 MPa. Table 3 shows the residual ratio of each.
<Preparation of wax particle dispersion 11>
Paraffin wax 1 (HNP-11: melting point 67 ° C., manufactured by Nippon Seiwa) 16.0 parts by mass Nitrile group-containing styrene acrylic resin (monomer mass ratio: styrene / n-butyl acrylate / acrylonitrile = 65.0 / 35. 0 / 10.0, peak molecular weight 8500)
8.0 parts by mass / acetone 76.0 parts by mass The above materials were put into a glass beaker (made by IWAKI glass) equipped with a stirring blade, and the system was heated to 70 ° C. to dissolve paraffin wax in acetone. .
Next, the system was gradually cooled while gently stirring at 50 rpm, and cooled to 25 ° C. over 3 hours to obtain a milky white liquid. This solution was put into a heat-resistant container together with 20.0 parts by weight of 1 mm glass beads, dispersed for 3 hours with a paint shaker, and a solid content of 20
. A 0 mass% wax particle dispersion 11 was prepared. The volume average particle size of the obtained wax particles 11 is shown in Table 3.
<Preparation of wax particle dispersions 12 and 13>
In the preparation of the wax particle dispersion 11, wax particle dispersions 12 and 13 having a solid content of 20.0% by mass were prepared in the same manner except that the wax used was changed to that shown in Table 3. Table 3 shows the volume average particle diameters of the obtained wax particles 12 and 13.
<Preparation of wax particle dispersion 14>
In the preparation of the wax particle dispersion 1, an aqueous dispersion of the wax particles 14 was prepared in the same manner except that divinylbenzene was not used in the step of forming the coating layer with the vinyl resin. A 0 mass% wax particle dispersion 14 was prepared. The volume average particle diameter of the obtained wax particles 14 and the residual ratio of the solid content of the coating resin after the wax particles 14 are dispersed in acetone at a temperature of 25 ° C. and carbon dioxide at a temperature of 25 ° C. and a pressure of 5 MPa. Table 3 shows.

<Preparation of Colorant Particle Dispersion 1>
・ C. I. Pigment Blue 15: 3 100.0 parts by mass, acetone 150.0 parts by mass, glass beads (1 mm) 300.0 parts by mass The above materials are put into a heat-resistant glass container, and a paint shaker (manufactured by Toyo Seiki) for 5 hours. Dispersion was performed, glass beads were removed with a nylon mesh, and a colorant particle dispersion 1 having a solid content of 40.0% by mass was obtained.

<Preparation of resin fine particle dispersion 1>
A two-necked flask equipped with a dropping funnel was dried by heating and charged with 870.0 parts by mass of normal hexane. In a separate beaker, 42.0 parts by mass of normal hexane, 52.0 parts by mass of behenyl acrylate (an acrylate of an alcohol having a linear alkyl group with 22 carbon atoms), and 0.3 parts by mass of azobismethoxydimethylvaleronitrile are charged. The monomer solution was prepared by stirring and mixing at 20 ° C. and introduced into the dropping funnel.
After the reaction vessel was purged with nitrogen, the monomer solution was added dropwise over one hour at 40 ° C. in a sealed state. Stirring was continued for 3 hours after the completion of dropping, and a mixture of 0.3 parts by mass of azobismethoxydimethylvaleronitrile and 42.0 parts by mass of normal hexane was added again, followed by stirring at 40 ° C. for 3 hours.
Then, it cooled to room temperature and obtained the resin fine particle dispersion 1 with the volume average particle diameter of 0.20 micrometer and the solid content of 20.0 mass%.

<Example 1>
(Manufacture of toner particles (before treatment))
In the experimental apparatus of FIG. 1, first, the valves V1 and V2 and the pressure adjusting valve V3 are closed, and the resin fine particle dispersion 1 is placed in a pressure resistant granulation tank T1 equipped with a filter and a stirring mechanism for capturing toner particles. The internal temperature was adjusted to 25 ° C. Next, the valve V1 was opened, carbon dioxide (purity 99.99%) was introduced into the granulation tank T1 from the cylinder B1 using the pump P1, and the valve V1 was closed when the internal pressure reached 4 MPa.
On the other hand, the block polymer resin solution 1, the wax particle dispersion 1, the colorant particle dispersion 1, and acetone were charged into the resin solution tank T2, and the internal temperature was adjusted to 25 ° C.
Next, the valve V2 is opened and the contents of the resin solution tank T2 are introduced into the granulation tank T1 using the pump P2 while stirring the inside of the granulation tank T1 at 2000 rpm. Valve V2 was closed.
After the introduction, the internal pressure of the granulation tank T1 was 5 MPa.
In addition, the preparation amount (mass ratio) of various materials is as follows.
Block polymer resin solution 1 200.0 parts by weight Wax particle dispersion 1 20.8 parts by weight Colorant particle dispersion 1 12.5 parts by weight Acetone 50.0 parts by weight Fine resin particle dispersion 1 37.5 Mass part / carbon dioxide 480.0 parts by mass The mass of introduced carbon dioxide is calculated from the temperature of carbon dioxide (25 ° C.) and the pressure (5 MPa), and the density of carbon dioxide is calculated from the state equation described in the following document: This was calculated by multiplying the volume of the granulation tank T1. (Journal of Physical and
Chemical Reference data, vol. 25, P.I. 1509-1596)
After the introduction of the contents of the resin solution tank T2 to the granulation tank T1, granulation was performed by further stirring for 10 minutes at 2000 rpm.
Next, the valve V1 was opened, and carbon dioxide was introduced into the granulation tank T1 from the cylinder B1 using the pump P1. At this time, the pressure regulating valve V3 was set to 10 MPa, and carbon dioxide was further circulated while maintaining the internal pressure of the granulation tank T1 at 10 MPa. By this operation, carbon dioxide containing the organic solvent (mainly acetone) extracted from the granulated droplets was discharged to the solvent recovery tank T3, and the organic solvent and carbon dioxide were separated.
The introduction of carbon dioxide into the granulation tank T1 was stopped when it reached 5 times the mass of carbon dioxide initially introduced into the granulation tank T1. At this point, the operation of replacing carbon dioxide containing an organic solvent with carbon dioxide not containing an organic solvent was completed.
Further, the pressure regulating valve V3 was opened little by little, and the internal pressure of the granulation tank T1 was reduced to atmospheric pressure to obtain toner particles (before treatment) 1 supplemented by the filter. The obtained toner particles (before treatment) 1 were subjected to DSC measurement, and the peak temperature of the maximum endothermic peak was determined to be 58 ° C.
(Annealing treatment)
The annealing treatment was performed using a constant temperature dryer (Satake Chemical 41-S5). First, the internal temperature of the constant temperature dryer was adjusted to 50 ° C. Next, the toner particles (before the treatment) 1 were spread and put evenly in a stainless steel vat, placed in the constant temperature dryer and allowed to stand for 2 hours, and then taken out. Thus, annealed toner particles (after treatment) 1 were obtained.
(Toner preparation)
1.8 parts by mass of hydrophobic silica fine powder treated with hexamethyldisilazane (number average primary particle size: 7 nm), rutile titanium oxide fine powder with respect to 100.0 parts by mass of the toner particles (after treatment) 1 The toner 1 of the present invention was obtained by dry-mixing 0.15 parts by mass (number average primary particle size: 30 nm) of the product with a Henschel mixer (Mitsui Mining Co., Ltd.) for 5 minutes.
<Example 2>
(Manufacture of toner particles (before treatment))
In Example 1, toner particles (before treatment) 2 were used in the same manner as in Example 1 except that the block polymer resin solution 2 was used instead of the block polymer resin solution 1 in the production process of toner particles (before treatment). Got. The obtained toner particles (before treatment) 2 were subjected to DSC measurement, and the peak temperature of the maximum endothermic peak was determined to be 53 ° C.
(Annealing treatment)
The toner particles 2 (before treatment) were annealed in the same manner as in Example 1 except that the internal temperature of the constant temperature dryer was changed to 45 ° C., and thus the toner 2 of the present invention was obtained.
<Example 3>
(Manufacture of toner particles (before treatment))
In Example 1, toner particles (before treatment) 3 were used in the same manner as in Example 1 except that the block polymer resin solution 3 was used instead of the block polymer resin solution 1 in the production process of toner particles (before treatment). Got. The obtained toner particles (before treatment) 3 were subjected to DSC measurement, and the peak temperature of the maximum endothermic peak was determined to be 66 ° C.
(Annealing treatment)
The toner particles (before treatment) 3 were annealed in the same manner as in Example 1 except that the internal temperature of the thermostatic dryer was changed to 58 ° C., and thus the toner 3 of the present invention was obtained.
<Example 4>
(Manufacture of toner particles (before treatment))
In Example 1, toner particles (before treatment) 4 were used in the same manner as in Example 1 except that the block polymer resin solution 4 was used instead of the block polymer resin solution 1 in the production process of toner particles (before treatment). Got. The obtained toner particles (before treatment) 4 were subjected to DSC measurement. The peak temperature of the maximum endothermic peak was determined to be 78 ° C.
(Annealing treatment)
The toner particles (before treatment) 4 were annealed in the same manner as in Example 1 except that the internal temperature of the constant temperature dryer was changed to 70 ° C., to obtain the toner 4 of the present invention.
<Examples 5 to 8>
(Manufacture of toner particles (before treatment))
In Example 1, toner particles (before treatment) 5 are the same as in Example 1 except that the block polymer resin solution 1 in the manufacturing process of toner particles (before treatment) is changed to block polymer resin solutions 5 to 8. Thru 8 were obtained. The obtained toner particles (before treatment) 5 to 8 were subjected to DSC measurement, and the peak temperature of the maximum endothermic peak was determined. (Annealing treatment)
The toner particles (before treatment) 5 to 8 were annealed in the same manner as in Example 1 to obtain toners 5 to 8 of the present invention.
<Examples 9 to 17>
(Manufacture of toner particles (before treatment))
In Example 1, toner particles (before treatment) 9 are the same as in Example 1 except that the wax particle dispersion 1 in the production process of toner particles (before treatment) is changed to wax particle dispersions 2 to 10. Thru 17 were obtained. The obtained toner particles (before treatment) 9 to 17 were subjected to DSC measurement, and the peak temperature of the maximum endothermic peak was determined.
(Annealing treatment)
The toner particles (before treatment) 9 to 17 were annealed in the same manner as in Example 1 to obtain toners 9 to 17 of the present invention.
<Examples 18 to 21>
(Manufacture of toner particles (before treatment))
In Example 1, the charged amount 20.8 parts by mass of the wax particle dispersion 1 in the production process of the toner particles (before treatment) is 6.3 parts by mass, 12.5 parts by mass, 33.3 parts by mass, 50. Toner particles (before treatment) 18 to 21 were obtained in the same manner as in Example 1 except that the amount was changed to 0 parts by mass. The obtained toner particles (before treatment) 18 to 21 were subjected to DSC measurement, and the peak temperature of the maximum endothermic peak was determined.
(Annealing treatment)
The toner particles (before treatment) 18 to 21 were annealed in the same manner as in Example 1 to obtain toners 18 to 21 of the present invention.

<Comparative Example 1>
(Manufacture of toner particles (before treatment))
In Example 1, the same procedure as in Example 1 was performed except that the wax particle dispersion 1 in the production process of the toner particles (before treatment) was changed to the wax particle dispersion 11 and the charge amount was 25.0 parts by mass. Toner particles (before treatment) 22 were obtained. The obtained toner particles (before treatment) 22 were subjected to DSC measurement. The peak temperature of the maximum endothermic peak was determined to be 56 ° C.
(Annealing treatment)
The toner particles (before treatment) 22 were annealed in the same manner as in Example 1 except that the internal temperature of the constant temperature dryer was changed to 48 ° C., and a comparative toner 22 was obtained.
<Comparative Example 2>
(Manufacture of toner particles (before treatment))
In Comparative Example 1, the same procedure as in Comparative Example 1 was performed except that 25.0 parts by mass of the charged amount of the wax particle dispersion 11 in the production process of the toner particles (before treatment) was changed to 15.0 parts by mass. Toner particles (before treatment) 23 were obtained. The obtained toner particles (before treatment) 23 were subjected to DSC measurement. The peak temperature of the maximum endothermic peak was determined to be 57 ° C.
(Annealing treatment)
The toner particles (before treatment) 23 were annealed in the same manner as in Comparative Example 1 except that the internal temperature of the constant temperature dryer was changed to 49 ° C., and a comparative toner 23 was obtained.
<Comparative Example 3>
(Manufacture of toner particles (before treatment))
In Comparative Example 1, the same procedure as in Comparative Example 1 was carried out except that the charged amount 25.0 parts by mass of the wax particle dispersion 11 in the production process of the toner particles (before treatment) was changed to 60.0 parts by mass. Toner particles (before treatment) 24 were obtained. The obtained toner particles (before treatment) 24 were subjected to DSC measurement, and the peak temperature of the maximum endothermic peak was determined to be 55 ° C.
(Annealing treatment)
The toner particles (before treatment) 24 were annealed in the same manner as in Comparative Example 1 except that the internal temperature of the constant temperature dryer was changed to 47 ° C., and a comparative toner 24 was obtained.
<Comparative Example 4>
(Manufacture of toner particles (before treatment))
In Comparative Example 1, toner particles (before treatment) 25 are obtained in the same manner as in Comparative Example 1 except that the wax particle dispersion 11 in the production process of toner particles (before treatment) is changed to the wax particle dispersion 12. It was. The obtained toner particles (before treatment) 25 were subjected to DSC measurement, and the peak temperature of the maximum endothermic peak was determined to be 55 ° C.
(Annealing treatment)
The toner particles (before treatment) 25 were annealed in the same manner as in Comparative Example 1 except that the internal temperature of the constant temperature dryer was changed to 47 ° C., and a comparative toner 25 was obtained.
<Comparative Example 5>
(Manufacture of toner particles (before treatment))
In Comparative Example 1, toner particles (before treatment) 26 are obtained in the same manner as in Comparative Example 1 except that the wax particle dispersion 11 in the manufacturing process of toner particles (before treatment) is changed to the wax particle dispersion 13. It was. The obtained toner particles (before treatment) 26 were subjected to DSC measurement, and the peak temperature of the maximum endothermic peak was determined to be 58 ° C.
(Annealing treatment)
The toner particles (before treatment) 26 were annealed in the same manner as in Example 1 to obtain a comparative toner 26.
<Comparative Example 6>
(Manufacture of toner particles (before treatment))
In Comparative Example 1, toner particles (before treatment) 27 are obtained in the same manner as in Comparative Example 1 except that the wax particle dispersion 11 in the production process of toner particles (before treatment) is changed to the wax particle dispersion 14. It was. The obtained toner particles (before treatment) 27 were subjected to DSC measurement, and the peak temperature of the maximum endothermic peak was determined to be 56 ° C.
(Annealing treatment)
The toner particles (before treatment) 27 were annealed in the same manner as in Comparative Example 1 except that the internal temperature of the constant temperature dryer was changed to 48 ° C., and a comparative toner 27 was obtained.

  Table 4 shows the physical properties of Toners 1 to 27 thus obtained. For toners 1 to 27, toners that were left in a normal temperature and normal humidity environment (23 ° C., 60% RH) for 24 hours were prepared and evaluated according to the following procedures. The results are shown in Table 5.

<Evaluation method>
(Heat resistant storage stability)
About 10 g of each toner left in a normal temperature and humidity environment (23 ° C., 60% RH) for 24 hours and about 10 g of each toner left in a harsh environment of 40 ° C. and 95% RH for 60 days are placed in a 100 ml polycup. After being allowed to stand in a thermostat adjusted to 10 days, it was visually evaluated.
Evaluation criteria for heat-resistant storage stability are as follows. The following A, B, C are no problem. The following D and E cause problems in practice.
A: No agglomerates are confirmed, and the state is almost the same as in the initial stage.
B: Although slightly agglomerated, it is in a state where it collapses by shaking the polycup lightly 5 times.
C: Although it is agglomerated, it is in a state where it can be easily loosened when loosened with a finger.
D: At a level where aggregation is severe and problems occur in actual use.
E: Solidified and cannot be used.

(Low temperature fixability)
A commercially available Canon printer LBP5300 was used to evaluate the low-temperature fixability.
The evaluation was performed for each toner left for 24 hours in a normal temperature and humidity environment (23 ° C., 60% RH) and for each toner left for 60 days in a severe environment of 40 ° C., 95% RH.
The LBP 5300 employs one-component contact development and regulates the amount of toner on the development carrier by a toner regulating member. As the evaluation cartridge, the toner contained in a commercially available cartridge was removed, the inside was cleaned by air blow, and the one filled with the toner was used. The cartridge was attached to the cyan station, and a dummy cartridge was attached to the other. Next, an unfixed toner image (toner applied amount per unit area of 0.6 mg / cm ² ) was formed on a thick A4 paper (“Prober Bond paper”: 105 g / m ² , manufactured by Fox River).
The fixing device of a commercially available Canon printer LBP5900 was modified so that the fixing temperature could be manually set, and the rotation speed of the fixing device was changed to 245 mm / s, and the pressure in the nip was changed to 98 kPa. Using this modified fixing device, the fixing temperature at each temperature of the unfixed image is increased while increasing the fixing temperature by 5 ° C. in the range of 80 ° C. to 180 ° C. in a normal temperature and humidity environment (23 ° C., 60% RH). I got an image.
The image area of the obtained fixed image was covered with a soft thin paper (for example, trade name “Dasper”, manufactured by Ozu Sangyo Co., Ltd.), and rubbed 5 times while applying a load of 4.9 kPa on the thin paper.
The image density before and after the rubbing was measured, the image density reduction rate ΔD (%) was calculated by the following formula, and the temperature at which this ΔD (%) was 10% or less was defined as the fixing start temperature.
The image density was measured with a color reflection densitometer (Color reflection densitometer X-Rite 404A: manufacturer X-Rite).
ΔD (%) = (image density before rubbing−image density after rubbing) / image density before rubbing × 100
Evaluation criteria for low-temperature fixability are as follows. The following A, B, C are no problem. The following D and E cause problems in practice.
A: Fixing start temperature is less than 100 ° C. (low temperature fixing performance is particularly excellent)
B: Fixing start temperature is 100 ° C. or higher and lower than 110 ° C. (low temperature fixing performance is excellent)
C: Fixing start temperature is 110 ° C. or higher and lower than 120 ° C. (low-temperature fixing performance is at a level where there is no problem)
D: Fixing start temperature is 120 ° C. or higher and lower than 130 ° C. (low temperature fixing performance is slightly inferior)
E: Fixing start temperature is 130 ° C. or higher (low temperature fixing performance is inferior)

(durability)
Using a commercially available Canon printer LBP5400, 150 g of each toner was charged in the developing unit of this apparatus. Under a high-temperature and high-humidity environment (30 ° C., 80% RH), A4 paper (“GF-R300”: 66 g / m ² , manufactured by Canon) was used as the transfer paper, and 20000 charts with a printing ratio of 1% were output. After the output, the developing container was disassembled and the surface of the toner carrier was visually observed.
The evaluation criteria for durability are as follows. The following A, B, C are no problem. The following D and E cause problems in practice.
A: No toner adhesion and no circumferential streaking B: Toner adhesion is inconspicuous, but one or two circumferential streaks occur at the end C: Toner sticking is slight, but circumferential streaks 3 to 5 lines are generated at the end D: Filming is observed and 6 or more circumferential streaks are generated on the front surface E: Filming is remarkable and toner leakage occurs due to scraping of the end of the toner carrier

  T1 granulation tank, T2 resin solution tank, T3 solvent recovery tank, B1 carbon dioxide cylinder, P1 and P2 pump, V1 and V2 valve, V3 pressure adjustment valve

Claims (8)

A step of preparing a resin composition by dissolving or dispersing a binder resin containing a crystalline polyester, colorant particles, and wax particles in an organic solvent;
A step of dispersing the obtained resin composition in a non-aqueous medium to prepare a dispersion of liquid particles of the resin composition;
A method for producing a toner comprising a step of forming toner particles by removing the organic solvent from the obtained dispersion of liquid particles,
The non-aqueous medium is a medium mainly composed of carbon dioxide in a liquid state or a supercritical state,
The wax particles are particles in which a wax component is coated with a resin,
The resin that coats the wax component is a vinyl resin having a crosslinked structure introduced therein or a polyester resin having a crosslinked structure introduced therein;
A method for producing a toner, characterized in that the residual ratio of the solid content of the resin covering the wax component after the wax particles are dispersed in the organic solvent and the non-aqueous medium is 50% by mass or more. The method for producing a toner according to claim 1, wherein the resin coating the wax component is a vinyl resin into which a cross-linked structure is introduced.   The method for producing a toner according to claim 1, wherein the wax component has a melting point of 60 ° C. or higher and 85 ° C. or lower.   4. The method for producing a toner according to claim 1, wherein a glass transition temperature (Tg) of the resin coating the wax component is 50 ° C. or more and 80 ° C. or less. 5.   The toner production method according to claim 1, wherein the wax particles have a volume average particle diameter (Dv) of 0.10 μm or more and 1.00 μm or less.   The addition amount of the wax particles is 2.0 parts by mass or more and 10.0 parts by mass or less as a wax component with respect to 100.0 parts by mass of the binder resin. The toner production method according to one item.   The binder resin contains, as a main component, a block polymer in which a portion that can take a crystal structure and a portion that cannot take a crystal structure are combined, and the portion where the binder resin can take a crystal structure is 50% by mass or more, 85 The toner production method according to claim 1, wherein the toner is contained in an amount of mass% or less.   The toner production method according to claim 7, wherein a peak temperature of a maximum endothermic peak in the differential scanning calorimetry (DSC) of the block polymer is 50 ° C. or more and 80 ° C. or less.

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