Toner, toner storage unit, and image forming apparatus

Abstract

To provide a resin particle that has reduced the load on the environment and is excellent in low temperature fixability and filming resistance despite the use of a biomass-derived resin.SOLUTION: A resin particle contains at least a binder resin. The binder resin contains a biomass-derived resin and polyethylene terephthalate or polybutylene terephthalate. The content A of a biomass-derived component and the content B of the polyethylene terephthalate or polybutylene terephthalate in the biomass-derived resin satisfy A>B. The resin particle has a core-shell structure composed of a shell layer and a core layer. The average thickness of the shell layer is 100nm-500nm.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to resin particles and a method for producing the same, a toner, a toner storage unit, and an image forming apparatus. [Background technology]

[0002] In recent years, there has been a demand for toners that reduce their environmental impact. To address this demand, for example, efforts are being made to reduce power consumption by improving the toner's low-temperature fixability, reduce energy consumption during production, and use biomass (plant-derived) resins as binder resins. Furthermore, with the recent increase in energy use due to population growth and resource depletion, the need for resource conservation, energy conservation, and resource recycling has become increasingly important. Local governments are implementing recycling programs for polyethylene terephthalate (PET) and polybutylene terephthalate (PBT) bottles, which are beginning to be used in various clothing and containers. Therefore, there is a strong demand for the development of new applications that enable the reuse of recycled PET and PBT.

[0003] From this perspective, a toner binder resin is produced using recycled PET or recycled PBT as a raw material, and a toner containing this binder resin (recycled toner) is known. For example, a toner resin has been proposed that contains bio-based polyester, which is bio-based and contains at least about 70% sustainable content that has been reused from other previous intended products and recycled for toner, a polyol containing depolymerized recycled plastic, an optional wax, and an optional colorant (see Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide resin particles that have a low environmental impact and are excellent in low-temperature fixability and filming resistance even when a biomass-derived resin is used. [Means for solving the problem]

[0005] The resin particles of the present invention, as a means for solving the above-mentioned problems, are resin particles containing at least a binder resin, wherein the binder resin contains a biomass-derived resin and polyethylene terephthalate or polybutylene terephthalate, wherein the content A of the biomass-derived component in the biomass-derived resin and the content B of the polyethylene terephthalate or polybutylene terephthalate satisfy A>B, the resin particles have a core-shell structure consisting of a shell layer and a core layer, and the shell layer has an average thickness of 100 nm to 500 nm. [Effects of the Invention]

[0006] According to the present invention, it is possible to provide resin particles that have a low environmental impact and are excellent in low-temperature fixability and filming resistance even when a biomass-derived resin is used. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic diagram showing an example of a process cartridge as a toner storage unit of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing an example of the image forming apparatus of the present invention. [Figure 3] FIG. 3 is a schematic diagram showing another example of the image forming apparatus of the present invention. [Figure 4] FIG. 4 is a schematic diagram showing another example of the image forming apparatus of the present invention. [Figure 5] FIG. 5 is a partially enlarged view of FIG. [Figure 6] FIG. 6 is a diagram showing an example of a TEM image of a cross section of a resin particle of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0008] (resin particles) The resin particles of the present invention contain at least a binder resin, and further contain other components as required. The binder resin contains a biomass-derived resin and polyethylene terephthalate or polybutylene terephthalate, and the content A of the biomass-derived component in the biomass-derived resin and the content B of the polyethylene terephthalate or polybutylene terephthalate satisfy A>B. The resin particles have a core-shell structure consisting of a shell layer and a core layer (also referred to as a "core portion"), and the shell layer has an average thickness of 100 nm to 500 nm.

[0009] In this specification, the term "shell layer" refers to the layer present on the outermost layer of the resin particle, the term "core layer" refers to the region within the resin particle excluding the shell layer, and the term "having a core-shell structure" refers to a structure having the core layer and the shell layer. The core layer and the shell layer are not completely compatible with each other and are formed heterogeneously. In the core-shell structure, the surface of the core layer is preferably covered with the shell layer. In the core-shell structure, the surface of the core layer may be completely covered with the shell layer, or may not be completely covered with the shell layer. Examples of a form in which the surface of the core layer is not completely covered with the shell layer include a form in which the core layer is covered with the shell layer in a mesh-like pattern, and a form in which the core layer is partially exposed from the shell layer. Among these, from the viewpoint of filming resistance, it is preferable that the surface of the core layer is completely covered with the shell layer.

[0010] In recent years, there has been a strong demand for improving the functionality of toners while enhancing environmental friendliness, including for biomass-derived resins. However, increasing the biomass content of toners by components other than release agents, such as binder resins, can lead to a decrease in compatibility and poor low-temperature fixability due to an increase in the absolute value ΔSP (the difference between the solubility parameter of the amorphous resin and the solubility parameter of the crystalline resin). Furthermore, while petroleum-based resins often have aromatic ring structures in their constituent monomers and thus easily achieve mechanical strength, biomass-derived resins lack aromatic ring structures in their constituent monomers, making it difficult to achieve the desired mechanical strength. When these resin particles are used in toners, they can cause photoreceptor filming. Therefore, it has been difficult to simultaneously achieve environmental friendliness through the use of renewable resources and the required toner properties of low-temperature fixability and filming resistance.

[0011] In order to solve the above problems, the inventors conducted extensive research and discovered that by incorporating polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) having an aromatic ring skeleton into the resin particles in addition to the biomass-derived resin, it is possible to reinforce the mechanical strength of the biomass-derived resin. Therefore, the resin particles can reduce the environmental impact and, because the resin particles also have excellent mechanical strength, they also have excellent filming resistance. This led to the invention of resin particles that combine environmental impact reduction with practicality.

[0012] The resin particles according to the present invention will be described below. The present invention is not limited to the following embodiments, and may be modified, added, modified, or deleted within the scope of what a person skilled in the art can conceive. Any embodiment is within the scope of the present invention as long as it exhibits the functions and effects of the present invention.

[0013] <<Radiocarbon isotopes 14 C concentration>> Radioactive carbon isotopes of the resin particles 14 C concentration (hereinafter referred to as “ 14The carbon concentration of the resin particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10.8 pMC or more, more preferably 20.0 pMC or more, and even more preferably 30.0 pMC or more. 14 If the carbon concentration is 10.8 pMC or more, it is generally recognized as having a high biomass level, which will be described later, and this can reduce the burden on the environment.

[0014] The aforementioned 14 C concentration exists in nature (in the atmosphere), and while plants are active, it is taken up by photosynthesis and exists in the atmosphere. 14 However, once the organism ceases to function, the carbon dioxide absorbed by photosynthesis ceases, and the carbon dioxide is released from the atmosphere. 14 According to the half-life of C, 5,730 years, 14 The carbon concentration decreases. Fossil resources derived from living organisms have been around for tens of thousands to hundreds of millions of years, so the carbon concentration decreases. 14 C concentration is barely detectable.

[0015] Here, "pMC" stands for percent modern carbon, which is the carbon content of biomass in 1950. 14 C and 12 Ratio to C ( 14 C / 12 C) is defined as 100pMC.

[0016] The aforementioned 14 The C concentration can also be expressed as the biomass degree calculated by the following formula (1). Biomass ratio (%) = 14 C concentration (pMC) / 107.5×100 Equation (1)

[0017] The aforementioned 14 A carbon concentration of 10.8 pMC or more means that the biomass ratio is 10% or more, which is a concentration desired from the standpoint of carbon neutrality.

[0018] In toners and the like, plant-derived waxes are sometimes used, but the above-mentioned resin particles 14 In order to achieve a carbon concentration of 10.8 pMC or more, i.e., a biomass ratio of 10% or more, it is not possible to achieve this by simply incorporating wax into the resin particles; it is also necessary to consider biomassification of the binder resin, and this is an important point in constituting the present invention.

[0019] The aforementioned 14 There are no particular limitations on the method for measuring the C concentration, and it can be selected appropriately depending on the purpose, but radiocarbon dating is particularly preferred. The radiocarbon dating method involves burning the resin particles, reducing the CO2 (carbon dioxide) and obtaining C (graphite). 14 The carbon concentration is measured by an accelerator mass spectroscopy (AMS). Measurement by AMS is disclosed in, for example, Japanese Patent No. 4050051.

[0020] <Binder resin> The binder resin contains a biomass-derived resin and polyethylene terephthalate or polybutylene terephthalate.

[0021] <<Polyethylene terephthalate or polybutylene terephthalate>> The polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) is contained mainly to improve filming resistance by improving mechanical strength, and is preferably contained in the core layer of the resin particles.

[0022] Both PET and PBT are semi-aromatic polyesters formed by the reaction of an aromatic diacid with an aliphatic diol. Specifically, PET has an aromatic ring structure and is a C2 compound derived from the aliphatic diol. PBT has an aromatic ring structure and is a C4 compound derived from the aliphatic diol. Because PET and PBT have similar chemical properties, it is commonly known in the art that what can be done with PET can generally also be done with PBT. In the resin particles of the present invention, PET and PBT are interchangeable, and the aromatic ring structures of PET and PBT are particularly effective in improving the mechanical strength of the resin particles. Among these, those having a smaller number of carbon atoms derived from the aliphatic diol are more preferred in terms of improving the mechanical strength of the resin particles, and PET is particularly preferred.

[0023] The PET or PBT is not particularly limited and can be appropriately selected depending on the purpose. For example, recycled products, off-spec fiber waste, or pellets of the PET or PBT can be used. However, from the viewpoint of reducing the environmental load, recycled products (hereinafter sometimes referred to as "recycled resin") processed into flakes are preferred. In this specification, the biomass-derived resin and the recycled resin may be collectively referred to as "environmentally friendly resin."

[0024] There are no particular limitations on the molecular weight distribution, composition, production method, and form when used of the PET or PBT, and they can be appropriately selected depending on the purpose. The weight average molecular weight (Mw) of the PET or PBT is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 30,000 to 100,000.

[0025] The analytical and calculation methods for the PET or PBT content in the resin particles are not particularly limited and can be appropriately selected from known methods. For example, the mass ratio of the constituent components of the resin particles can be calculated by separating the resin particles using GPC or the like and then analyzing each separated component using the analytical method described below. Quantitative analysis can also be performed by estimating the main constituent components from soft decomposition of the ester bonds in the resin structure by methylation using GC / MS at 300°C using a reaction reagent (10% tetramethylammonium hydroxide (TMAH) / methanol solution) and drawing a calibration curve of the total ion current chromatogram (TICC) intensity.

[0026] By adjusting the ratio of the PET or PBT introduced during synthesis of the binder resin, it is possible to adjust the environmental compatibility ratio (to be described later) and the toner quality when the resin particles are applied to a toner.

[0027] The content B of the PET or PBT is not particularly limited as long as the content A of the biomass-derived component of the biomass-derived resin and the content B of the PET or PBT satisfy the relationship A>B, and can be appropriately selected depending on the purpose. From the viewpoint of reducing the burden on the environment, however, the content B is preferably 5% by mass to 50% by mass, and more preferably 5% by mass to 20% by mass, relative to the total mass of the resin particles.

[0028] <<Biomass-derived resin>> The biomass-derived resin is a resin containing a plant-derived compound as a raw material. The biomass-derived resin is not particularly limited and can be appropriately selected depending on the purpose. It may be contained in a crystalline resin or an amorphous resin. These may be used alone or in combination of two or more. The biomass-derived resin is contained in the core layer of the resin particle. In the resin particles, by adjusting the ratio of the petroleum-derived component and the plant-derived component (biomass-derived component) in the alcohol component and acid component constituting the crystalline resin and the amorphous resin, the environmental compatibility resin ratio described later and the toner quality when the resin particles are applied to the toner can be adjusted.

[0029] As the content A of the biomass-derived component of the biomass-derived resin, there is no particular limitation as long as the content A of the biomass-derived component of the biomass-derived resin and the content B of the polyethylene terephthalate or polybutylene terephthalate satisfy A > B, and it can be appropriately selected according to the purpose. However, from the viewpoint of reducing the environmental load, 20% by mass to 70% by mass is preferable, and 25% by mass to 35% by mass is more preferable with respect to the total mass of the resin particles.

[0030] - Content of biomass-derived resin and PET or PBT - The content A of the biomass-derived component of the biomass-derived resin and the content B of the PET or PBT satisfy A > B (that is, the content of the biomass-derived component of the biomass-derived resin is more than the content of the PET or PBT). When the content A of the biomass-derived component of the biomass-derived resin and the content B of the PET or PBT are A = B or A < B, the desired low-temperature fixing property cannot be obtained.

[0031] There is no particular limitation on the total content [A + B] of the content A of the biomass-derived component of the biomass-derived resin and the content B of the PET or PBT with respect to the total mass of the resin particles, and it can be appropriately selected according to the purpose. However, from the viewpoint of reducing the environmental load, it is preferably 10% by mass or more, and more preferably 35% by mass or more. Also, there is no particular limitation on the upper limit value of the total content [A + B] of the content A of the biomass-derived component of the biomass-derived resin and the content B of the PET or PBT with respect to the total mass of the resin particles, and it can be appropriately selected according to the purpose, but it is preferably 80% by mass or less.

[0032] Here, when the PET or PBT is a recycled PET or PBT resin, the total content [A+B] of the content A of the biomass-derived component of the biomass-derived resin and the content B of the PET or PBT can be the content of the environmentally friendly resin (also referred to as the "environmentally friendly resin ratio").

[0033] The environmentally friendly resin ratio (mass %) is a value calculated by the following formula (2). Environmentally friendly resin ratio (mass%) = content of biomass-derived components in biomass-derived resin (A) + content of PET or PBT (B) = biomass degree + content of PET or PBT (B) Formula (2) In the formula (2), the "biomass degree" is a value calculated based on the formula (1). In addition, when the composition and blending ratio of the biomass-derived resin are known, the "biomass degree" can also be calculated from the blending amounts of the constituent components of the biomass-derived resin.

[0034] <<<Crystalline resin>>> The resin particles preferably contain a crystalline resin to improve low-temperature fixability, the crystalline resin is preferably contained in the core layer of the resin particles, and the crystalline resin preferably contains the biomass-derived resin to reduce environmental impact. The crystalline resin is not particularly limited as long as it has crystallinity and can be appropriately selected depending on the purpose. For example, polyester resin, polyurethane resin, polyurea resin, polyamide resin, polyether resin, vinyl resin, or modified crystalline resin can be mentioned. These can be used alone or in combination of two or more. Among these, crystalline polyester resin is preferred as the crystalline resin.

[0035] -Crystalline polyester resin- The crystalline polyester resin has high crystallinity and therefore exhibits a thermal melting property in which the viscosity changes rapidly near the fixing start temperature. By using the crystalline polyester resin having such properties together with an amorphous resin, resin particles having both good heat-resistant storage stability and low-temperature fixability can be obtained. For example, by using the crystalline polyester resin and the amorphous resin together, the heat-resistant storage stability is good due to the crystallinity up to just before the melting start temperature, and at the melting start temperature, the crystalline polyester resin melts, causing a sudden viscosity drop (sharp melt property), which leads to compatibility with the amorphous polyester resin B described below, and both of them rapidly drop in viscosity, allowing for good fixation.

[0036] The crystalline polyester resin can be obtained from a polyol and a polycarboxylic acid or a derivative thereof. These may be used alone or in combination of two or more. By using a plant-derived compound in at least one of the polyol and the polycarboxylic acid, the crystalline polyester resin can be made into a biomass-derived resin.

[0037] The derivative of the polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include polycarboxylic acid anhydrides and polycarboxylic acid esters.

[0038] In this specification, the crystalline polyester resin refers to a resin obtained by using the polyhydric alcohol and the polycarboxylic acid or a derivative thereof, and does not include modified polyester resins, such as prepolymers, and resins obtained by subjecting the prepolymers to at least one of a crosslinking reaction and an elongation reaction.

[0039] --Polyhydric alcohols-- The polyhydric alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diols and trihydric or higher alcohols. Examples of the diol include saturated aliphatic diols. Examples of the saturated aliphatic diol include linear saturated aliphatic diols and branched saturated aliphatic diols. Among these, linear saturated aliphatic diols are preferred as the saturated aliphatic diol, and linear saturated aliphatic diols having 2 to 12 carbon atoms are more preferred. If the saturated aliphatic diol is linear, the crystalline polyester resin will have high crystallinity and a high melting point, which is preferable. If the saturated aliphatic diol has more than 12 carbon atoms, it will be difficult to obtain a practical material.

[0040] Specific examples of the saturated aliphatic diol include ethylene glycol, 1,3-propanediol, 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, and 1,14-eicosanedecanediol. These may be used alone or in combination of two or more. Among these, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol are preferred in terms of high crystallinity of the crystalline polyester resin and excellent sharp melting properties.

[0041] Examples of the trihydric or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These may be used alone or in combination of two or more.

[0042] --Polycarboxylic Acids-- The polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include dicarboxylic acids and tricarboxylic or higher carboxylic acids. Examples of the dicarboxylic acid include saturated aliphatic dicarboxylic acids or aromatic dicarboxylic acids, or anhydrides thereof, or lower (C1 to C3) alkyl esters thereof. Examples of the saturated aliphatic dicarboxylic acid include oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, and 1,18-octadecanedicarboxylic acid. Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, and mesaconic acid. These may be used alone or in combination of two or more. Among these, from the viewpoint of carbon neutrality, the polycarboxylic acid is preferably a plant-derived saturated aliphatic dicarboxylic acid having 12 or less carbon atoms, more preferably a plant-derived saturated aliphatic dicarboxylic acid having 4 to 12 carbon atoms.

[0043] Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, anhydrides thereof, and lower (C1 to C3) alkyl esters thereof. These may be used alone or in combination of two or more.

[0044] Among these, the crystalline polyester resin is preferably composed of a linear saturated aliphatic dicarboxylic acid having 4 to 12 carbon atoms and a linear saturated aliphatic diol having 2 to 12 carbon atoms, which results in high crystallinity and excellent sharp melting properties, and therefore excellent low-temperature fixability.

[0045] Furthermore, the method for controlling the crystallinity and softening point of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose. For example, a method may be used in which a non-linear polyester is designed and used by adding a trivalent or higher polyhydric alcohol such as glycerin to the alcohol component or a trivalent or higher polycarboxylic acid such as trimellitic anhydride to the acid component during polyester synthesis and then subjecting the resulting polyester to condensation polymerization.

[0046] The molecular structure of the crystalline resin can be confirmed by measurement using nuclear magnetic resonance spectroscopy (NMR) in a solution or solid, as well as by measurement methods using X-ray diffraction, gas chromatography / mass spectrometry (GC / MS), liquid chromatography / mass spectrometry (LC / MS), or infrared absorption spectroscopy (IR). Among these, in the infrared absorption spectrum obtained by IR, the molecular structure of the crystalline resin can be confirmed by measurement methods using a peak at 965±10 cm -1 and 990±10cm -1 A simple method is to detect as a crystalline resin those that have absorption due to δCH (out-of-plane bending vibration) of olefin.

[0047] The molecular weight of the crystalline resin is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint that a resin with a sharp molecular weight distribution and a low molecular weight has excellent low-temperature fixability, and a resin with a high content of high molecular weight components has good heat-resistant storage stability, as a result of extensive research, it has been found that the molecular weight distribution of the o-dichlorobenzene soluble fraction measured by gel permeation chromatography (GPC) has a peak position in the range of 3.5 to 4.0 in a molecular weight distribution diagram with the horizontal axis representing log(M) and the vertical axis representing weight % and the half-width of the peak being 1.5 or less, and is preferably in the range shown below. The weight average molecular weight (Mw) of the crystalline resin is preferably from 3,000 to 30,000, and more preferably from 5,000 to 15,000. The number average molecular weight (Mn) of the crystalline resin is preferably from 1,000 to 10,000, and more preferably from 2,000 to 10,000. The molecular weight ratio (Mw / Mn) of the crystalline resin is preferably 1-10, and more preferably 1-5.

[0048] The acid value of the crystalline resin is not particularly limited and can be appropriately selected depending on the purpose, but the lower limit of the acid value is preferably 5 mgKOH / g or more in order to achieve the desired low-temperature fixability from the viewpoint of affinity between the recording medium and the resin particles, and more preferably 7 mgKOH / g or more from the viewpoint of preparing resin particles by a phase inversion emulsification method. Also, the upper limit of the acid value of the crystalline resin is preferably 45 mgKOH / g or less in order to improve hot offset resistance. The acid value of the crystalline resin can be measured in accordance with the measurement method described in JIS K0070-1992.

[0049] The hydroxyl value of the crystalline resin is not particularly limited and can be appropriately selected depending on the purpose. From the viewpoint of achieving a predetermined low-temperature fixability and good charging characteristics, the hydroxyl value is preferably 0 mgKOH / g to 50 mgKOH / g, and more preferably 5 mgKOH / g to 50 mgKOH / g. The hydroxyl value of the crystalline resin can be measured in accordance with the measurement method described in JIS K0070-1966.

[0050] The content of the crystalline resin in the resin particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 to 20 parts by mass, more preferably 5 to 10 parts by mass, per 100 parts by mass of the resin particles. When the content of the crystalline resin is 3 parts by mass or more per 100 parts by mass of the resin particles, the resin particles are easily softened to a non-crystalline resin, which is advantageous for low-temperature fixability. When the content of the crystalline resin is 20 parts by mass or less per 100 parts by mass of the resin particles, it is advantageous for filming resistance. When the content of the crystalline resin is in the above more preferred range, it is advantageous in terms of achieving both low-temperature fixability and filming resistance.

[0051] <<<Amorphous resin>>> The amorphous resin is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a modified polyester resin (hereinafter sometimes referred to as "amorphous polyester resin A") and an unmodified polyester resin (hereinafter sometimes referred to as "amorphous polyester resin B"). These may be used alone or in combination of two or more. Among these, it is preferable that the resin particles contain both the modified polyester resin and the unmodified polyester resin. The amorphous resin preferably contains the biomass-derived resin, since this can reduce the environmental load. In this specification, the amorphous resin refers to a resin other than the PET or PBT.

[0052] -Amorphous polyester resin A- The amorphous polyester resin A (modified polyester resin) is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a reaction product of the active hydrogen group-containing compound and a reactive precursor (hereinafter sometimes referred to as "prepolymer") containing a group capable of reacting with the active hydrogen group-containing compound. The amorphous polyester resin A is preferably contained in the core layer of the resin particles.

[0053] The amorphous polyester resin A is a polyester resin insoluble in tetrahydrofuran (THF). The polyester resin component insoluble in tetrahydrofuran (THF) lowers the glass transition temperature (Tg) and melt viscosity, ensuring low-temperature fixability, and has a branched structure in the molecular skeleton, forming a three-dimensional network structure in the molecular chain, resulting in rubber-like properties in that it deforms but does not flow at low temperatures.

[0054] --Compounds containing active hydrogen groups-- The active hydrogen group-containing compound is a compound that reacts with a polyester resin having a site capable of reacting with the active hydrogen group-containing compound.

[0055] The active hydrogen group is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), an amino group, a carboxyl group, or a mercapto group. These may be used alone or in combination of two or more.

[0056] The active hydrogen group-containing compound is not particularly limited and can be appropriately selected depending on the purpose. However, when the polyester resin having a site capable of reacting with the active hydrogen group-containing compound is a polyester resin containing an isocyanate group, amines are preferred in that they can increase the molecular weight of the polyester resin by an elongation reaction or crosslinking reaction with the polyester resin.

[0057] The amines are not particularly limited and can be appropriately selected depending on the purpose. Examples include diamines, trivalent or higher amines, amino alcohols, amino mercaptans, amino acids, and compounds in which the amino groups of these are blocked. These may be used alone or in combination of two or more. Among these, diamines or mixtures of diamines with a small amount of trivalent or higher amines are preferred as the amines.

[0058] The diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include aromatic diamines, alicyclic diamines, and aliphatic diamines. These may be used alone or in combination of two or more. The aromatic diamine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include phenylenediamine, diethyltoluenediamine, and 4,4'-diaminodiphenylmethane. The alicyclic diamine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminocyclohexane, and isophoronediamine. The aliphatic diamine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include ethylenediamine, tetramethylenediamine, and hexamethylenediamine.

[0059] The trivalent or higher amine is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diethylenetriamine and triethylenetetramine.

[0060] The amino alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include ethanolamine and hydroxyethylaniline.

[0061] The amino mercaptan is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aminoethyl mercaptan and aminopropyl mercaptan.

[0062] The amino acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aminopropionic acid and aminocaproic acid.

[0063] The blocked amino group is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include ketimine compounds and oxazolizone compounds obtained by blocking the amino group with ketones. Examples of the ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0064] --Reactive precursor containing a group capable of reacting with an active hydrogen group-containing compound-- The reactive precursor containing a group capable of reacting with the active hydrogen group-containing compound is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a polyester resin containing a group capable of reacting with the active hydrogen group-containing compound (hereinafter, sometimes referred to as a "polyester prepolymer").

[0065] The group capable of reacting with the active hydrogen group-containing compound is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include an isocyanate group, an epoxy group, a carboxylic acid, or an acid chloride group. Among these, the group capable of reacting with the active hydrogen group-containing compound is preferably an isocyanate group, since it can introduce a urethane bond or a urea bond into the amorphous polyester resin A.

[0066] The reactive precursor may have a branched structure imparted by at least one of a trivalent or higher alcohol and a trivalent or higher carboxylic acid.

[0067] The polyester resin containing an isocyanate group is not particularly limited and can be appropriately selected depending on the purpose. For example, a reaction product of a polyester resin having an active hydrogen group and a polyisocyanate can be mentioned.

[0068] ---Polyester resin with active hydrogen groups--- The polyester resin having an active hydrogen group is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include those obtained by polycondensation of a polyhydric alcohol and a polycarboxylic acid. By using a plant-derived compound in at least one of the polyhydric alcohol and the polycarboxylic acid, the amorphous polyester resin A can be made into the biomass-derived resin.

[0069] The polyhydric alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples include diols, trihydric or higher alcohols, and mixtures of diols and trihydric or higher alcohols. These may be used alone or in combination of two or more. Among these, diols or mixtures of diols and a small amount of trihydric or higher alcohols are preferred. The trihydric or higher alcohols impart a branched structure to the polyester resin containing isocyanate groups.

[0070] The diol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aliphatic diols, diols having an oxyalkylene group, alicyclic diols, alkylene oxide adducts of alicyclic diols, bisphenols, and alkylene oxide adducts of bisphenols. Examples of the aliphatic diol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol. Examples of the diol having an oxyalkylene group include diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Examples of the alicyclic diol include 1,4-cyclohexanedimethanol and hydrogenated bisphenol A. Examples of the alkylene oxide adduct of the alicyclic diol include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, or butylene oxide to the alicyclic diol. Examples of the bisphenols include bisphenol A, bisphenol F, and bisphenol S. Examples of the alkylene oxide adducts of the bisphenols include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, or butylene oxide to the bisphenols. These may be used alone or in combination of two or more.

[0071] Among these, from the viewpoint of controlling the glass transition temperature (Tg) of the amorphous polyester resin A to 20°C or less, it is preferable to use an aliphatic diol having 3 to 10 carbon atoms, such as 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, or 3-methyl-1,5-pentanediol, as the diol.

[0072] The amount of the aliphatic diol having 3 to 10 carbon atoms used is not particularly limited and can be appropriately selected depending on the purpose, but it is more preferable to use 50 mol % or more of the alcohol component in the amorphous polyester resin A.

[0073] The amorphous polyester resin A has a lower melt viscosity during fixing due to the steric hindrance of the resin chain, and is more likely to exhibit low-temperature fixability. For this reason, the main chain of the aliphatic diol preferably has a structure represented by the following general formula (1): [ka] (In the general formula (1), R1 and R2 each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and n represents an odd number from 3 to 9. However, in the n repeating units, R1 and R2 may be the same or different.)

[0074] In this specification, the main chain of the aliphatic diol means the carbon chain that connects two hydroxyl groups of the aliphatic diol with the shortest number of carbon atoms. The aliphatic diol preferably has an odd number of carbon atoms in its main chain because the odd-even ratio reduces crystallinity. Furthermore, the aliphatic diol preferably has at least one alkyl group having 1 to 3 carbon atoms in its side chain because the interaction energy between the main chain molecules is reduced due to stericity.

[0075] The trihydric or higher alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aliphatic alcohols, trihydric or higher polyphenols, and alkylene oxide adducts of trihydric or higher polyphenols. Examples of the aliphatic alcohol include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol. Examples of the trivalent or higher polyphenols include trisphenol PA, phenol novolac, and cresol novolac. Examples of the alkylene oxide adducts of the trivalent or higher polyphenols include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, or butylene oxide to the trivalent or higher polyphenols. These may be used alone or in combination of two or more.

[0076] The polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples include dicarboxylic acids, tricarboxylic or higher carboxylic acids, and mixtures of dicarboxylic acids and tricarboxylic or higher carboxylic acids. These may be used alone or in combination. Among these, the polycarboxylic acid is preferably a mixture of a carboxylic acid or a dicarboxylic acid with a small amount of tricarboxylic or higher carboxylic acid. The tricarboxylic or higher carboxylic acid imparts a branched structure to the polyester resin containing isocyanate groups.

[0077] The dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include aliphatic dicarboxylic acids, aromatic dicarboxylic acids, anhydrides thereof, lower (carbon number 1 to 3) alkyl esters thereof, and halides thereof. Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic acid, and fumaric acid. Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. These may be used alone or in combination of two or more.

[0078] Among these, from the viewpoint of controlling the glass transition temperature (Tg) of the amorphous polyester resin A to 20°C or less, it is preferable to use an aliphatic dicarboxylic acid having from 4 to 12 carbon atoms as the dicarboxylic acid, and from the viewpoint of carbon neutrality, it is more preferable to use plant-derived sebacic acid.

[0079] The amount of the aliphatic dicarboxylic acid having 4 to 12 carbon atoms used is not particularly limited and can be appropriately selected depending on the purpose, but it is more preferable to use 50 mol % or more of the carboxylic acid component in the amorphous polyester resin A.

[0080] The trivalent or higher carboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include trivalent or higher aromatic carboxylic acids. The trivalent or higher aromatic carboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include trivalent or higher aromatic carboxylic acids having from 9 to 20 carbon atoms, or anhydrides, lower (1 to 3 carbon atoms) alkyl esters, or halides of the trivalent or higher aromatic carboxylic acids having from 9 to 20 carbon atoms. These may be used alone or in combination of two or more. Examples of the trivalent or higher aromatic carboxylic acid having 9 to 20 carbon atoms include trimellitic acid and pyromellitic acid.

[0081] ---Polyisocyanate--- The polyisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples include aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, araliphatic diisocyanates, and trivalent or higher polyisocyanates. The polyisocyanate may also be a modified product thereof. These may be used alone or in combination of two or more.

[0082] Examples of the aromatic diisocyanate include 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4'-diphenylmethane diisocyanate (MDI), 4,4'-diphenylmethane diisocyanate (MDI), crude MDI [crude diaminophenylmethane [formaldehyde and aromatic amine (aniline)]], phosgenates of] condensation products of diaminodiphenylmethane with a small amount (for example, 5% by mass to 20% by mass) of a trifunctional or higher polyamine, polyallyl polyisocyanate (PAPI), 1,5-naphthylene diisocyanate, 4,4',4''-triphenylmethane triisocyanate, m-isocyanatophenylsulfonyl isocyanate, or p-isocyanatophenylsulfonyl isocyanate.

[0083] Examples of the aliphatic diisocyanate include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, and 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

[0084] Examples of the alicyclic diisocyanate include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, and 2,6-norbornane diisocyanate.

[0085] Examples of the araliphatic diisocyanate include m-xylylene diisocyanate (XDI), p-xylylene diisocyanate (XDI), and α,α,α',α'-tetramethylxylylene diisocyanate (TMXDI).

[0086] Examples of the tri- or higher hydric polyisocyanate include lysine triisocyanate and diisocyanate-modified products of tri- or higher hydric alcohols.

[0087] The modified polyisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include modified polyisocyanates containing a urethane group, a carbodiimide group, an allophanate group, a urea group, a biuret group, a uretdione group, a uretoimine group, an isocyanurate group, or an oxazolidone group.

[0088] The content of the amorphous polyester resin A is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 to 20 parts by mass, more preferably 5 to 15 parts by mass, per 100 parts by mass of the resin particles. When the content of the amorphous polyester resin A is 3 parts by mass or more per 100 parts by mass of the resin particles, an effect on low-temperature fixability can be achieved. Furthermore, when the content of the amorphous polyester resin A is 20 parts by mass or less per 100 parts by mass of the resin particles, an effect on hot offset resistance can be achieved. When the content of the amorphous polyester resin A is in the above more preferred range, it is advantageous in terms of achieving both low-temperature fixability, hot offset resistance, and heat-resistant storage stability.

[0089] -Amorphous polyester resin B- The amorphous polyester resin B means a polyester resin that does not substantially have a crosslinked structure, and is preferably a linear polyester resin. The amorphous polyester resin B may be contained in the core layer or the shell layer of the resin particles, but is preferably contained in both the core layer and the shell layer.

[0090] The amorphous polyester resin B is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include those obtained by polycondensation of a polyhydric alcohol and a polycarboxylic acid. The amorphous polyester resin B preferably does not have a urethane bond or a urea bond. By using a plant-derived compound for at least one of the polyhydric alcohol and the polycarboxylic acid or derivative thereof, the amorphous polyester resin B can be made into the biomass-derived resin.

[0091] --Polyhydric alcohols-- The polyhydric alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diols. Examples of the diol include an alkylene (having 2 to 3 carbon atoms) oxide (average number of moles added: 1 to 10) adduct of bisphenol A, ethylene glycol, propylene glycol, hydrogenated bisphenol A, and an alkylene (having 2 to 3 carbon atoms) oxide (average number of moles added: 1 to 10) adduct of hydrogenated bisphenol A. Examples of the alkylene (having 2 to 3 carbon atoms) oxide (average number of moles added: 1 to 10) adduct of bisphenol A include polyoxypropylene(2.2)-2,2-bis(4-hydroxyphenyl)propane and polyoxyethylene(2.2)-2,2-bis(4-hydroxyphenyl)propane. These may be used alone or in combination of two or more. Among these, it is preferable to use plant-derived propylene glycol as the polyhydric alcohol from the viewpoint of carbon neutrality.

[0092] --Polycarboxylic Acids-- The polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include dicarboxylic acids. Examples of the dicarboxylic acid include adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, maleic acid, and succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms. Examples of the succinic acid substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms include dodecenyl succinic acid and octylsuccinic acid. The derivative of the polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include polycarboxylic acid anhydrides and polycarboxylic acid esters. These may be used alone or in combination of two or more.

[0093] Among these, it is preferable to use at least one of succinic acid and terephthalic acid as the polycarboxylic acid, and from the viewpoint of carbon neutrality, it is more preferable to use succinic acid, which is a saturated aliphatic acid derived from plants. The saturated aliphatic acid has the effect of increasing the recrystallization property of the crystalline resin, increasing the aspect ratio of the crystalline resin, and improving low-temperature fixability.

[0094] The amount of the polycarboxylic acid used in the amorphous polyester resin B is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint of heat-resistant storage stability, it is preferable to use 50 mol % or more of terephthalic acid as the polycarboxylic acid.

[0095] Furthermore, for the purpose of adjusting the acid value and hydroxyl value, the amorphous polyester resin B may contain at least one of a trivalent or higher carboxylic acid and a trivalent or higher alcohol at the end of the resin chain. Examples of the trivalent or higher carboxylic acid include trimellitic acid, pyromellitic acid, and acid anhydrides thereof. Examples of the trihydric or higher alcohol include glycerin, pentaerythritol, and trimethylolpropane.

[0096] The molecular weight of the amorphous polyester resin B is not particularly limited and can be appropriately selected depending on the purpose, but is preferably in the following range. The weight average molecular weight (Mw) of the amorphous polyester resin B is preferably from 3,000 to 10,000, and more preferably from 4,000 to 7,000. The number average molecular weight (Mn) of the amorphous polyester resin B is preferably from 1,000 to 4,000, and more preferably from 1,500 to 3,000. The molecular weight ratio (Mw / Mn) of the amorphous polyester resin B is preferably from 1.0 to 4.0, more preferably from 1.0 to 3.5. The weight average molecular weight (Mw) and the number average molecular weight (Mn) of the amorphous polyester resin B can be measured by GPC. When the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the amorphous polyester resin B are equal to or greater than the lower limit, the resin particles can be prevented from having a deterioration in heat-resistant storage stability and durability against stress such as stirring in a developing machine. When the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the amorphous polyester resin B are equal to or less than the upper limit, the resin particles can be prevented from having an increase in viscoelasticity when melted, and the low-temperature fixability can be prevented from being reduced.

[0097] The acid value of the amorphous polyester resin B is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 mgKOH / g to 50 mgKOH / g, and more preferably 5 mgKOH / g to 30 mgKOH / g. When the acid value of the amorphous polyester resin B is 1 mgKOH / g or more, a toner containing the resin particles tends to be negatively charged. Furthermore, when the toner is fixed to a recording medium, the affinity between the recording medium and the toner is improved, thereby improving low-temperature fixability. Furthermore, when the acid value of the amorphous polyester resin B is 50 mgKOH / g or less, a decrease in charging stability, particularly charging stability against environmental fluctuations, can be suppressed. The acid value of the amorphous polyester resin B can be measured in accordance with the measurement method described in JIS K0070-1992.

[0098] The hydroxyl value of the amorphous polyester resin B is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 mgKOH / g or more. The hydroxyl value of the amorphous polyester resin B can be measured in accordance with the measurement method described in JIS K0070-1966.

[0099] The glass transition temperature (Tg) of the amorphous polyester resin B is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 40°C or higher and 80°C or lower, and more preferably 50°C or higher and 70°C or lower. When the glass transition temperature (Tg) of the amorphous polyester resin B is 40°C or higher, the toner containing the resin particles has sufficient heat-resistant storage stability and durability against stress such as stirring in a developing machine, and also has good filming resistance. Furthermore, when the glass transition temperature (Tg) of the amorphous polyester resin B is 80°C or lower, the toner containing the resin particles is sufficiently resistant to deformation due to heat and pressure during fixing, and has good low-temperature fixability.

[0100] The content of the amorphous polyester resin B is not particularly limited and can be appropriately selected depending on the purpose. However, it is preferably 50 to 90 parts by weight, more preferably 60 to 80 parts by weight, per 100 parts by weight of the resin particles. When the content of the amorphous polyester resin B is 50 parts by weight or more per 100 parts by weight of the resin particles, deterioration of the dispersibility of the pigment or release agent in the resin particles can be suppressed, and the occurrence of image fogging and distortion can be suppressed. Furthermore, when the content of the amorphous polyester resin B is 90 parts by weight or less per 100 parts by weight of the resin particles, a decrease in the contents of the crystalline resin and amorphous polyester resin A can be prevented, and a decrease in low-temperature fixability can be suppressed. The content of the amorphous polyester resin B within the above more preferred range is advantageous in that both high image quality and low-temperature fixability are excellent.

[0101] The molecular structures of the amorphous polyester resin A and the amorphous polyester resin B can be confirmed by NMR measurement using a solution or a solid, as well as by X-ray diffraction, GC / MS, LC / MS, or IR measurement. -1 and 990±10cm -1 A simple method is to detect a resin that does not have absorption due to δCH (out-of-plane bending vibration) of olefin as the amorphous polyester resin A or B.

[0102] <<Shell resin>> The resin particles have a core-shell structure. The resin constituting the shell layer (hereinafter, sometimes referred to as "shell resin") is preferably a binder resin that does not contain the biomass-derived resin.

[0103] The present inventors have found that when the biomass-derived resin is exposed on the surface of resin particles, the filming resistance may be insufficient. In contrast, they have found that by using a resin having a core-shell structure and not containing a biomass-derived component in the shell layer, even resin particles using the biomass-derived resin can have significantly improved filming resistance compared to conventional resin particles.

[0104] The shell resin constituting the shell layer is not particularly limited and can be appropriately selected depending on the purpose, but the amorphous resin not containing a biomass-derived resin is preferred, and the amorphous polyester resin B not containing a biomass-derived resin is more preferred.

[0105] As described above, the amorphous resin used as the shell resin may be one obtained by polycondensing a polyhydric alcohol and a polycarboxylic acid. However, by not using a biomass-derived compound in the polyhydric alcohol or the polycarboxylic acid, an amorphous resin that does not contain the biomass-derived resin can be obtained.

[0106] -Analysis of the resin composition of the shell layer- There are no particular limitations on the indicators used to confirm that the shell layer does not contain the biomass-derived resin, and they can be selected appropriately depending on the purpose. For example, confirmation can be achieved by surface layer (shell layer) composition analysis using nanoIR (also referred to as "AMF-IR"). Using an analytical technique that combines nano-IR atomic force microscopy (AFM) and IR to achieve nanoscale resolution, the composition can be obtained by obtaining the IR spectrum of the surface layer (shell layer) of the resin particles.

[0107] Specifically, the resin particles are embedded in an epoxy resin and cured, then cut with a knife and an ultramicrotome (Leica ULTRACUT UCT, manufactured by Leica, using a diamond knife) is used to cut the resin particles to a thickness of 50 nm to prepare ultrathin sections. The prepared ultrathin sections of the toner are collected on a substrate (ZnS), and the measurement area (shell layer) is measured by AFM-IR using a nanoscale infrared spectroscopy analysis system (e.g., nanoIR2, manufactured by Anasys Instruments). The measurement range is 1,900 cm. -1 From 910cm -1 The resolution is 2cm -1 The chemical structure of the measurement point (shell layer) can be analyzed from the obtained AFM-IR absorption spectrum. Therefore, this analysis can identify whether or not a biomass-derived composition is present in the surface layer (shell layer). By using the core layer as the measurement location, the chemical structure of the core layer can also be analyzed.

[0108] The average thickness of the shell layer is 100 nm to 560 nm, preferably 100 nm to 500 nm, and more preferably 200 nm to 300 nm. If the average thickness of the shell layer is less than 100 nm, the core layer inside the resin particle cannot be protected, resulting in poor mechanical strength and filming resistance. If the average thickness of the shell layer is more than 560 nm, low-temperature fixability is impaired, and sufficient mechanical strength and filming resistance cannot be obtained. In this specification, the "average shell layer thickness" refers to the thickness obtained by measuring the shell layer thickness of each of 10 arbitrarily selected resin particles using the method described below and averaging the shell layer thicknesses of these 10 resin particles.

[0109] The coverage of the core layer surface with the shell layer is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 70% to 100%, more preferably 90% to 100%. Note that a coverage of 100% means that the entire surface of the core layer in the resin particle is covered with the shell layer. The coverage (%) of the core layer surface with the shell layer is a value calculated by the following formula (3). Coverage (%) = (area of ​​the covered region) / (total surface area of ​​the resin particles) × 100 Equation (3) In the formula (3), the "total surface area of ​​the resin particle" means the sum of the area of ​​the coated region and the exposed area of ​​the core layer, the "area of ​​the coated region" means the area of ​​the region where the core layer is coated with the shell layer out of the total surface area of ​​the resin particle, and the "exposed area of ​​the core layer" means the area of ​​the region where the core layer is not coated with the shell layer out of the total surface area of ​​the resin particle.

[0110] -How to confirm the core-shell structure- The method for confirming that the resin particles have a core-shell structure is not particularly limited and can be appropriately selected depending on the purpose. For example, the resin particles are embedded in an epoxy resin and cured, then cross-sectioned with a knife and cut to a thickness of 80 nm using an ultramicrotome (Leica ULTRACUT UCT, manufactured by Leica, using a diamond knife) to prepare ultrathin sections of the resin particles. The prepared ultrathin sections of the toner are exposed to ruthenium tetroxide gas to differentiate the shell and core (hereinafter referred to as "ruthenium staining"). The gas exposure time can be adjusted appropriately depending on the contrast during observation. The presence of a core-shell structure can then be confirmed by observation using a transmission electron microscope (TEM) (H-7000, manufactured by Hitachi High-Technologies Corporation) at an accelerating voltage of 100 kV and a magnification of 15k.

[0111] Furthermore, in a TEM image observed by the above-described method, the core layer-coated region (the region of the resin particle where the core layer is coated with the shell layer) on the surface of the resin particle and the exposed region of the core layer (the region of the resin particle where the core layer is not coated with the shell layer) can be distinguished by the difference in brightness value. Therefore, the shell layer can be identified from the TEM image observed by the above-described method. Furthermore, the TEM image can be binarized using image processing software, and the shell layer can be identified based on the contrast ratio. Therefore, the thickness of the shell layer can be measured from the TEM image. An example of a TEM image of the cross section of the resin particle is shown in Figure 6. As shown in Figure 6, the shell layer appears to have a darker contrast than the core layer.

[0112] Image-J can be used as the image processing software. Image-J is open source, and by extending part of the code, processing variations and additional functions can be developed as plug-ins. The method for calculating the average thickness of the shell layer using Image-J is as follows. (1) Draw a straight line along the scale with Straight Line. Set its actual length and units with Set Scale in Analyze. (2) The periphery of one resin particle in the cross-sectional image is surrounded by freehand sections to create "area 1." (3) The outer periphery of the region excluding the shell layer in the cross-sectional image of one of the resin particles (i.e., the boundary between the shell layer and the core layer) is surrounded by freehand sections to create "region 2." (4) Determine the center of gravity of the "Area 1" by Analyze. (5) Using a proprietary plug-in, a straight line is drawn from the coordinates of the periphery of the "Area 1," i.e., the line drawn by freehand sections around the periphery of one resin particle in (2) above, divided into 100 equal intervals, toward the center of gravity of the resin particle determined in (4) above. (6) The length of each of the 100 straight lines created in (5) passing through "Area 1" minus the length passing through "Area 2" is calculated using the straight lines tracing the scale created in (1), and the average of the 100 straight lines is taken as the thickness of the shell layer of one of the resin particles. (7) The operations (2) to (6) above are carried out for 10 resin particles, and the average thickness of the shell layer of the 10 resin particles is calculated. This average value is defined as the average shell layer thickness in the present invention.

[0113] The method for calculating the coverage rate of the shell layer using Image-J is as follows. (1) In the cross-sectional image of one resin particle, trace the outer shell layer of the resin particle with a freehand line, and measure the length of the traced line using Analyze. This length is designated as "Length 1." (2) The periphery of one of the resin particles in the cross-sectional image is traced freehand, and the length of the traced line is measured using Analyze. This length is designated as “Length 2.” (3) Calculate length 1 / length 2×100, and use this as the coverage rate of one resin particle by the shell layer. (4) The operations (1) to (3) are carried out for 10 resin particles, and the average value of the coverage ratios of the 10 resin particles with the shell layer is calculated. This average value is defined as the coverage ratio with the shell layer in the present invention.

[0114] <Other ingredients> The other components in the resin particles are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a colorant, a release agent, a charge control agent, and a cleaning improver. These may be used alone or in combination of two or more.

[0115] <<Coloring agent>> The colorant is not particularly limited and can be appropriately selected from known dyes and pigments, and examples thereof include carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ochre, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Balkan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, and anthracene. Lazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Lead, Cinnabar, Cadmium Red, Cadmium Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Faise Red, Parachlor Orthonitroaniline Red, Lithol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Kanmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Lithol Rubin GX, Permanent Tread F5R, Brilliant Carmine 6B, Pogment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulia Blue, Alkali Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine, Prussian Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chromium Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold,Examples of the pigments include acid green lake, malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc oxide, lithopone, and mixtures thereof. These pigments may be used alone or in combination of two or more.

[0116] The content of the colorant is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1% by mass to 15% by mass, and more preferably 3% by mass to 10% by mass, based on the total amount of the resin particles.

[0117] The colorant can also be used as a masterbatch in which it is combined with a resin. The resin used to produce the masterbatch or to be kneaded with the masterbatch is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include, in addition to the amorphous resins, polymers of styrene or its substitution products, styrene copolymers, polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resins, epoxy polyol resins, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resins, rosin, modified rosin, terpene resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffin, and paraffin wax. These may be used alone or in combination of two or more. Examples of the polymer of styrene or a substituted styrene include polystyrene, poly-p-chlorostyrene, and polyvinyltoluene. Examples of the styrene copolymer include styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, and styrene-maleic acid ester copolymer.

[0118] The method for producing the masterbatch is not particularly limited and can be appropriately selected depending on the purpose. For example, a method can be used in which the resin for the masterbatch and the colorant are mixed and kneaded under high shear force. In this case, an organic solvent can be used to enhance the interaction between the colorant and the resin. A method known as the flushing method, in which an aqueous paste containing the colorant and water is mixed and kneaded with a resin and an organic solvent to transfer the colorant to the resin and then remove the water and organic solvent components, is also preferred because the wet cake of the colorant can be used as is, eliminating the need for drying. A high-shear dispersing device such as a three-roll mill is preferably used for mixing and kneading.

[0119] <<Release Agent>> The release agent is not particularly limited and can be appropriately selected depending on the purpose, but a low-melting release agent having a melting point of 50° C. to 120° C. is preferred. The low-melting release agent, when dispersed in the crystalline resin or the amorphous resin, effectively acts as a release agent between the fixing roller and the toner interface, thereby improving hot offset resistance even in an oil-less system (wherein a release agent such as oil is not applied to the fixing roller).

[0120] Specific examples of the release agent include waxes, fatty acid amides, homopolymers or copolymers of polyacrylate, and crystalline polymers having long alkyl groups on the side chains. These may be used alone or in combination of two or more.

[0121] Examples of the waxes include natural waxes, synthetic hydrocarbon waxes, and synthetic waxes. Examples of the natural wax include vegetable wax, animal wax, mineral wax, and petroleum wax. Examples of the vegetable wax include carnauba wax, cotton wax, Japan wax, and rice wax. Examples of the animal wax include beeswax and lanolin. Examples of the mineral wax include ozokerite and cerusine. The petroleum waxes include, for example, paraffin, microcrystalline, or petrolatum. Examples of the synthetic hydrocarbon wax include Fischer-Tropsch wax and polyethylene wax. The synthetic waxes include, for example, esters, ketones, or ethers.

[0122] Examples of the fatty acid amide include 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, and chlorinated hydrocarbons.

[0123] Examples of the polyacrylate include poly-n-stearyl methacrylate and poly-n-lauryl methacrylate, which are low-molecular-weight crystalline polymer resins. Examples of the polyacrylate homopolymer or copolymer include an n-stearyl acrylate-ethyl methacrylate copolymer.

[0124] Among these, the release agent is preferably a plant-based wax or a synthetic wax made from a plant-derived monomer from the viewpoint of reducing the environmental load.

[0125] The melting point of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50° C. to 120° C., more preferably 60° C. to 90° C. If the melting point is 50° C. or higher, the release agent can be prevented from adversely affecting heat-resistant storage stability, and if the melting point is 120° C. or lower, the problem of cold offset occurring during fixation at low temperatures can be effectively prevented.

[0126] The melt viscosity of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 cps to 1,000 cps, and more preferably 10 cps to 100 cps, as measured at a temperature 20° C. higher than the melting point of the release agent. When the melt viscosity of the release agent is 5 cps or more, the release property can be prevented from decreasing, and when it is 1,000 cps or less, the effects of hot offset resistance and low-temperature fixability can be sufficiently exhibited.

[0127] The content of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0% by mass to 40% by mass, and more preferably 3% by mass to 30% by mass, based on the total amount of the resin particles.

[0128] <<Charge control agent>> The charge control agent is not particularly limited, and any known agent can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substances or compounds, tungsten simple substances or compounds, fluorine-based surfactants, salicylic acid metal salts, metal salts of salicylic acid derivatives, oxynaphthoic acid metal salts, phenolic condensates, azo pigments, boron complexes, or polymeric compounds having functional groups (e.g., sulfonic acid groups, carboxyl groups, or quaternary ammonium salts). These agents may be used alone or in combination of two or more.

[0129] Specific examples of the charge control agent include the nigrosine dye Bontron 03, the quaternary ammonium salt Bontron P-51, the metal-containing azo dye Bontron S-34, the oxynaphthoic acid metal complex E-82, the salicylic acid metal complex E-84, and the phenol condensate E-89 (all manufactured by Orient Chemical Industry Co., Ltd.), the quaternary ammonium salt molybdenum complexes TP-302 and TP-415 (both manufactured by Hodogaya Chemical Co., Ltd.), the quaternary ammonium salt Copy Charge PSY VP2038, the triphenylmethane derivative Copy Blue PR, the quaternary ammonium salt Copy Charge NEG VP2036, and the quaternary ammonium salt Copy Charge NX VP434 (all manufactured by Hoechst), LRA-901, the boron complex LR-147 (manufactured by Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, or quinacridone.

[0130] The content of the charge control agent is not particularly limited as long as it is used in an amount that allows the agent to exhibit its performance and does not impair fixation properties, etc., and can be appropriately selected depending on the purpose. However, the content is preferably 0.5% by mass to 5% by mass, and more preferably 0.8% by mass to 3% by mass, based on the total amount of the resin particles.

[0131] <<Cleaning improver>> The cleaning property improver is used to remove the developer remaining on the photosensitive member or primary transfer medium after transfer. The cleaning property improver is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include fatty acid metal salts and polymer fine particles. These may be used alone or in combination of two or more.

[0132] Examples of the fatty acid metal salt include zinc stearate, calcium stearate, and stearic acid.

[0133] Examples of the polymer fine particles include polymethyl methacrylate fine particles and polystyrene fine particles, which can be produced by, for example, soap-free emulsion polymerization.

[0134] The volume average particle size of the polymer particles is not particularly limited and can be appropriately selected depending on the purpose, but it is preferable that the particle size distribution is relatively narrow and the volume average particle size is 0.01 μm to 1 μm.

[0135] The content of the cleaning property improver is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01% by mass to 5% by mass with respect to the total amount of the resin particles.

[0136] The volume average particle size of the resin particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 μm to 10 μm, more preferably 4 μm to 6 μm. When the volume average particle size of the resin particles is 3 μm or more, cleaning properties can be maintained and stable image quality can be obtained, and when it is 10 μm or less, developability and transferability are good, and improved image quality can be expected.

[0137] <<Measurement of the volume average particle size of resin particles>> The volume average particle size of the resin particles can be measured using a particle size distribution measuring device (for example, Coulter Multisizer III, manufactured by Coulter). Specifically, a mixture is prepared by adding 2 mL of a surfactant, preferably sodium dodecylbenzenesulfonate, as a dispersant to 100 mL of electrolyte. 10 mg of the measurement sample (solid content) is then added to this mixture to obtain an electrolyte in which the measurement sample is suspended. The electrolyte in which the measurement sample is suspended is subjected to a dispersion treatment using an ultrasonic disperser for approximately 1 to 3 minutes, and the volume and number of the resin particles are measured using a Coulter Multisizer III with a 100 μm aperture, and the volume distribution and number distribution are calculated. The volume average particle size (Dv) of the resin particles can be determined from the distribution obtained. The electrolyte is prepared by using first-grade sodium chloride to prepare an approximately 1% by mass aqueous sodium chloride solution, and for example, ISOTON-II (manufactured by Coulter) can be used.

[0138] <<Means for separating the constituent components of resin particles>> An example of a means for separating each component when analyzing the molecular weight, monomer composition, and constituent ratio of each resin, such as the biomass-derived resin, the PET or PBT, the crystalline resin, and the amorphous resin in the resin particles, will be described in detail.

[0139] First, 1 g of the resin particles is placed in 100 mL of chloroform and stirred at 25°C for 30 minutes to obtain a solution in which the soluble components are dissolved. This solution is then filtered through a membrane filter with a 0.2 μm mesh size to obtain the chloroform-soluble components of the resin particles. This can then be dissolved in chloroform to prepare a sample for gel permeation chromatography (GPC) measurement.

[0140] A fraction collector is placed at the GPC eluate outlet, and the eluate is collected at predetermined intervals (fractions corresponding to desired molecular weights from the full-area integral of the elution curve are collected together). The eluate is collected at 5% area ratios from the onset of elution (the rise of the curve). Each eluate is then concentrated and dried using an evaporator or similar. The solids are dissolved in 1 mL of a heavy solvent, such as deuterated chloroform or deuterated THF, and 0.05 vol% tetramethylsilane (TMS) is added as a reference material. The resulting solution is filled into a 5 mm diameter glass tube for nuclear magnetic resonance spectroscopy (NMR). A nuclear magnetic resonance spectrometer (e.g., JNM-AL400, manufactured by JEOL Ltd.) is used to obtain a spectrum by performing 128 integrations at 23°C to 25°C. The peak integral ratios of the obtained spectrum allow the monomer composition and composition ratio of each resin contained in the resin particles in the eluted component to be determined.

[0141] Alternatively, the eluate may be concentrated, hydrolyzed with sodium hydroxide or the like, and the decomposition products may be subjected to qualitative and quantitative analysis by high performance liquid chromatography (HPLC) or the like to calculate the proportion of constituent monomers.

[0142] <<Molecular weight measurement>> The molecular weight of each component of the resin particles can be measured, for example, by the following method using a gel permeation chromatograph (GPC) measuring device. The measurement sample can be a GPC measurement sample separated by the above-mentioned method. When measuring the molecular weight of the measurement sample, the molecular weight distribution of the measurement sample is calculated from the relationship between the logarithm of the calibration curve prepared using several monodisperse polystyrene standard samples and the count number. Examples of standard polystyrene samples used for preparing the calibration curve include Showdex (registered trademark) STANDARD (manufactured by Showa Denko K.K.) Std. Nos. S-6550, S-2330, S-1700, S-740, S-10, S-662, S-2.9, and S-0.6. [Analysis conditions] Equipment: GPC-8220GPC (Tosoh Corporation) Column: TSKgel (registered trademark) SuperHZM-H 15 cm, triple column (Tosoh Corporation) ·Temperature: 40℃ Detector: RI (refractive index) detector Solvent: tetrahydrofuran (THF) or chloroform Flow rate: 0.35 mL / min Sample: 100 μL of 0.1% by mass sample is injected Sample pretreatment: The resin particles are dissolved in THF (e.g., tetrahydrofuran (containing a stabilizer), manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) or chloroform at 0.1% by mass, and then filtered through a 0.2 μm filter, and the filtrate is used as the sample.

[0143] <<Measuring method of melting point (Tm) and glass transition temperature (Tg)>> In this specification, the melting point (Tm) and glass transition temperature (Tg) of each component can be measured, for example, using a DSC system (differential scanning calorimeter) (Q-200, manufactured by TA Instruments). Specifically, the melting point and glass transition temperature of a sample can be measured by the following procedure. First, approximately 5.0 mg of the measurement sample was placed in an aluminum sample container, which was then placed on a holder unit and placed in an electric furnace. Next, under a nitrogen atmosphere, the sample was heated from -80°C to 150°C at a heating rate of 10°C / min (first heating). The sample was then cooled from 150°C to -80°C at a cooling rate of 10°C / min, and further heated to 150°C at a heating rate of 10°C / min (second heating). During both the first and second heating, DSC curves were measured using a differential scanning calorimeter (Q-200, manufactured by TA Instruments). From the obtained DSC curves, the DSC curve during the first temperature rise can be selected using the analysis program in the Q-200 system, and the glass transition temperature of the measurement sample during the first temperature rise can be determined. Similarly, the DSC curve during the second temperature rise can be selected, and the glass transition temperature of the measurement sample during the second temperature rise can be determined. Furthermore, the DSC curve obtained during the first temperature rise can be selected using the analysis program in the Q-200 system, and the endothermic peak top temperature during the first temperature rise of the measurement sample can be determined as the melting point. Similarly, the DSC curve during the second temperature rise can be selected, and the endothermic peak top temperature during the second temperature rise of the measurement sample can be determined as the melting point. In this specification, unless otherwise specified, the glass transition temperatures and melting points of the amorphous polyester resin A, the amorphous polyester resin B, the crystalline polyester resin, and other components such as the release agent are defined as the endothermic peak top temperature during the second heating run and the Tg during the second heating run, respectively.

[0144] The use of the resin particles is not particularly limited and can be appropriately selected depending on the purpose, but they are preferably used in toners because they have low environmental impact, low-temperature fixability, and excellent filming resistance. Therefore, resin particles for toners are also included in the scope of the present invention.

[0145] The method for producing the resin particles is not particularly limited and can be appropriately selected depending on the purpose, but it is preferable that the resin particles are produced by the method for producing resin particles of the present invention described below.

[0146] (Method of producing resin particles) The method for producing resin particles of the present invention is the method for producing resin particles of the present invention described above, and includes the steps of: preparing an oil phase by dissolving or dispersing a binder resin containing a biomass-derived resin and polyethylene terephthalate or polybutylene terephthalate in an organic solvent so that the content A of the biomass-derived component in the biomass-derived resin and the content B of polyethylene terephthalate or polybutylene terephthalate satisfy the relationship A>B (hereinafter, this may be referred to as an "oil phase preparation step"); and adding an aqueous phase to the oil phase to invert and emulsify the water-in-oil dispersion into an oil-in-water dispersion. The method includes a step of preparing aggregated particles by aggregating fine particles in the oil-in-water dispersion (hereinafter, this step may be referred to as an "aggregation step"), and a step of forming a shell layer on the aggregated particles so that the aggregated particles have a core-shell structure consisting of a shell layer and a core layer, and so that the average thickness of the shell layer is 100 nm to 500 nm (hereinafter, this step may be referred to as a "shelling step"), and may further include other steps such as an aqueous phase preparation step, a desolvation step, a fusion step, a washing step, a drying step, an annealing step, and an external addition step, as necessary.

[0147] <Oil phase preparation process> The oil phase preparation step is a step of preparing an oil phase by dissolving or dispersing at least a binder resin in an organic solvent.

[0148] The method for preparing the oil phase is not particularly limited and can be appropriately selected depending on the purpose. For example, a method in which raw materials for resin particles are gradually added to an organic solvent while stirring to dissolve or disperse the raw materials is exemplified.

[0149] The raw material of the resin particles is at least a binder resin, but if necessary, other components such as a colorant, a release agent, an active hydrogen group-containing compound, a charge control agent, a cleaning property improver, etc. The release agent may be added in the aggregation step described below.

[0150] For the dispersion, known dispersing machines such as a bead mill or a disk mill can be used.

[0151] The raw materials used in the oil phase preparation step can be those described in the section (Resin particles) above. The binder resin used in the oil phase preparation step may be an amorphous resin or prepolymer, or PET or PBT, as described above in the section (Resin Particles). These may be used alone or in combination of two or more. The amorphous resin or prepolymer is preferably a biomass-derived resin. In addition, in the resin particles, the crystalline resin is localized in the core, and from the viewpoint of good heat-resistant storage stability and low-temperature fixability, the crystalline resin may be added in the oil phase preparation process, but is preferably added in the aggregation process.

[0152] The organic solvent is not particularly limited and can be appropriately selected depending on the purpose, but a volatile solvent having a boiling point of less than 100° C. is preferred because it makes it easier to remove the organic solvent later. Examples of such organic solvents include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, and isopropyl alcohol. These may be used alone or in combination of two or more.

[0153] When the resin to be dissolved or dispersed in the organic solvent is a resin having a polyester skeleton, the organic solvent is preferably an ester-based solvent or a ketone-based solvent because of its high solubility. Examples of the ester solvent include methyl acetate, ethyl acetate, and butyl acetate. Examples of the ketone solvent include methyl ethyl ketone and methyl isobutyl ketone. Among these, the organic solvent is preferably methyl acetate, ethyl acetate, or methyl ethyl ketone, which has high solvent removability.

[0154] The amount of the organic solvent used is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 40 to 300 parts by mass, more preferably 60 to 140 parts by mass, and even more preferably 80 to 120 parts by mass, per 100 parts by mass of the raw material for the resin particles.

[0155] <Aqueous phase preparation process> The aqueous phase preparation step is a step of preparing an aqueous phase (aqueous medium). The aqueous medium is not particularly limited and can be appropriately selected from known aqueous media, and examples thereof include water, a solvent miscible with water, and a mixture thereof. The water-miscible solvent is not particularly limited and can be appropriately selected from known solvents, and examples thereof include alcohol, dimethylformamide, tetrahydrofuran, cellosolves, lower ketones, and esters. Examples of the alcohol include methanol, isopropanol, and ethylene glycol. Examples of the lower ketones include acetone and methyl ethyl ketone. These may be used alone or in combination of two or more.

[0156] <Phase inversion emulsification process> The phase inversion emulsification step is a step of adding an aqueous phase to the oil phase to invert the phase emulsification from a water-in-oil dispersion to an oil-in-water dispersion, thereby obtaining a microparticle dispersion in which the oil phase is microparticulated.

[0157] In the phase inversion emulsification step, the oil phase is preferably neutralized with an alkali such as sodium hydroxide or aqueous ammonia before the aqueous phase is added. By gradually adding the aqueous phase to the neutralized oil phase, phase inversion emulsification from a water-in-oil dispersion to an oil-in-water dispersion can be achieved, thereby obtaining a microparticle dispersion containing the raw material for the resin particles.

[0158] The volume average particle size of the dispersed particles (oil droplets) in the fine particle dispersion is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 100 nm to 2,000 nm, more preferably 300 nm to 800 nm. The volume average particle size of the dispersed particles (oil droplets) in the fine particle dispersion can be measured, for example, by a particle size distribution measuring device (Coulter Multisizer III, manufactured by Coulter).

[0159] The amount of the aqueous phase used relative to 100 parts by mass of the oil phase is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 50 parts by mass to 2,000 parts by mass, more preferably 100 parts by mass to 1,000 parts by mass.

[0160] The phase inversion emulsification can be carried out using a stirring blade. The stirring blade is not particularly limited and can be appropriately selected depending on the viscosity of the solution, and examples thereof include low-viscosity stirring blades such as paddles and propellers, medium-viscosity stirring blades such as anchors and Maxblends, and high-viscosity stirring blades such as helical ribbons. Among these, paddles and anchors are preferred because they can control the volume-average particle size of the dispersion (oil droplets) within the preferred range.

[0161] When the stirring blade is used, the conditions such as the peripheral speed, dispersion time, and dispersion temperature are not particularly limited and can be appropriately selected depending on the purpose. When the stirring blade is used, the peripheral speed is not particularly limited, but is preferably 0.4 m / sec to 2.0 m / sec, and more preferably 0.7 m / sec to 1.5 m / sec. The stirring time and the stirring temperature are not particularly limited.

[0162] <Solvent removal process> The solvent removal step is a step of removing the organic solvent from the fine particle dispersion obtained in the phase inversion emulsification step to obtain base particles.

[0163] The method for removing the organic solvent from the microparticle dispersion is not particularly limited and can be appropriately selected depending on the purpose. Examples include a method in which the temperature is gradually increased while stirring the entire reaction system to completely evaporate and remove the organic solvent in the droplets, a method in which the microparticle dispersion is sprayed into a dry atmosphere while stirring to completely remove the organic solvent in the droplets, and a method in which the pressure is reduced while stirring the microparticle dispersion to evaporate and remove the organic solvent. These methods may be used alone or in combination of two or more. Among these, the method in which the temperature is gradually increased while stirring the entire reaction system to completely evaporate and remove the organic solvent in the droplets is preferred.

[0164] The drying atmosphere into which the microparticle dispersion is sprayed is not particularly limited and can be appropriately selected depending on the purpose. Examples include gases obtained by heating air, nitrogen, carbon dioxide, combustion gas, etc., and various air streams heated to a temperature equal to or higher than the boiling point of the highest boiling point solvent used are generally used.

[0165] The solvent removal step can be carried out using an apparatus such as a spray dryer, a belt dryer, or a rotary kiln, and the desired quality can be obtained sufficiently in a short period of time.

[0166] <Agglomeration process> The aggregation step is a step of preparing aggregated particles by aggregating fine particles in the oil-in-water dispersion. When the method for producing resin particles includes the solvent removal step, the aggregation step may be a step of preparing aggregated particles by aggregating base particles after the solvent removal.

[0167] In the aggregation step, it is preferable to further add a crystalline resin, since the crystalline resin can be finely dispersed within the base particles. The crystalline resin may be the same as that described above in the section (Resin Particles). In the aggregation step, the crystalline resin is preferably mixed with the aggregated particles or the base particles in the form of a dispersion.

[0168] The dispersion of the crystalline resin is not particularly limited and can be selected appropriately depending on the purpose, but it is preferably a dispersion of the crystalline resin in the aqueous medium, and more preferably a dispersion neutralized with an alkali such as sodium hydroxide or aqueous ammonia.

[0169] The volume average particle size of the crystalline resin dispersion is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 100 nm to 1,000 nm, more preferably 100 nm to 300 nm. The volume average particle size of the crystalline resin can be measured, for example, using a particle size distribution measuring device (Coulter Multisizer III, manufactured by Coulter).

[0170] The method for aggregating the microparticles or the base particles, or the mixture of the microparticles or the base particles and the crystalline resin until a desired particle size is reached is not particularly limited and can be appropriately selected depending on the purpose. Examples of the method include a method of adding an aggregating agent while stirring the aggregated particles or the base particles, or the mixture of the microparticles or the base particles and the crystalline resin, and a method of adjusting the pH while stirring the aggregated particles or the base particles, or the mixture of the aggregated particles or the base particles and the crystalline resin. In the method of adding the flocculant, the flocculant may be added as is, but it is preferable to add the flocculant in the form of an aqueous solution, since this can avoid localized high concentrations. In addition, it is preferable to add the flocculant gradually while monitoring the particle size of the flocculated particles.

[0171] The flocculant is not particularly limited and can be appropriately selected from known ones, and examples thereof include metal salts of monovalent metals, metal salts of divalent metals, and metal salts of trivalent metals. Examples of the metal salts of the monovalent metals include sodium and potassium. Examples of the metal salts of the divalent metals include calcium and magnesium. Examples of the metal salts of trivalent metals include iron and aluminum.

[0172] The temperature at which the aggregation step is carried out (the temperature of the reaction system) is not particularly limited and can be appropriately selected depending on the purpose, but it is preferably near the glass transition temperature (Tg) of the resin used. If the temperature is too low, aggregation may not proceed very well, resulting in poor efficiency, while if the temperature is too high, the aggregation rate may increase, resulting in the generation of coarse particles and a deterioration in particle size distribution.

[0173] In the aggregating step, the aggregating is stopped after the agglomerated particles reach a target particle size. The method for stopping the aggregation is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a method of adding a salt or a chelating agent with a low ionic valence, a method of adjusting the pH, a method of lowering the temperature of the system, a method of adding a large amount of an aqueous medium to dilute the concentration, etc. These methods may be used alone or in combination of two or more.

[0174] The volume average particle size of the aggregated particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 2 μm to 10 μm, more preferably 3 μm to 6 μm.

[0175] In the aggregation step, a release agent may be added, and the release agent may be any of those described above in the section (Resin Particles). When the release agent is added in the aggregation step, a method of using a dispersion in which the release agent is dispersed in an aqueous medium, or a method of mixing the release agent with the base particles and the crystalline resin and then aggregating the mixture, can be used to obtain aggregated particles in which the release agent and the crystalline resin are uniformly dispersed.

[0176] <Shelling process> The shelling step is a step of forming a shell layer on the aggregated particles so that the aggregated particles have a core-shell structure consisting of a shell layer and a core layer, and the shell layer has an average thickness of 100 nm to 500 nm. When the method for producing resin particles includes a fusion step described later, the shelling step may be a step of forming a shell layer on the spheroidized particles obtained in the fusion step.

[0177] The method for forming the shell layer is not particularly limited and can be appropriately selected depending on the purpose. Examples include a method in which a dispersion liquid containing a shell resin is added to the aggregated particles obtained in the aggregation step and heated; and a method in which a dispersion liquid containing a shell resin is added to the spherical particles having the desired particle size in the fusion step and heated. The heating may be carried out during the heating in the fusion step, or may be carried out as a separate step.

[0178] The shell resin is preferably a binder resin that does not contain the biomass-derived resin, and the same resins as those described in the <<Shell Resin>> section of the (Resin Particles) above can be used, with the amorphous polyester resin B being particularly preferred.

[0179] The volume average particle size of the shell resin in the dispersion is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 10 nm or more and 150 nm or less, and more preferably 30 nm or more and 100 nm or less. The volume average particle size of the shell resin in the dispersion can be measured, for example, by a particle size distribution measuring device (Coulter Multisizer III, manufactured by Coulter).

[0180] <Fusing process> The fusion step is a step in which the particles obtained in the shell forming step are fused to reduce irregularities and are made spherical, thereby obtaining resin particles.

[0181] The method for fusing the particles obtained in the shell-forming step is not particularly limited and can be appropriately selected depending on the purpose. For example, a method of heating a dispersion of the particles obtained in the shell-forming step while stirring can be mentioned.

[0182] The heating temperature is not particularly limited and can be appropriately selected depending on the purpose, but is preferably near a temperature exceeding the glass transition temperature (Tg) of the amorphous polyester resin B, more preferably from Tg to Tg + 20° C., and even more preferably from Tg to Tg + 10° C. When the heating temperature is Tg to 20° C., the amorphous polyester resin and the crystalline resin are suitably compatible with each other, and the major axis of the domains of the crystalline resin upon recrystallization does not become too large, making it less likely to be exposed on the resin particle surface.

[0183] The average circularity of the resin particles is not particularly limited and can be appropriately selected depending on the purpose. However, the higher the average circularity of the resin particles, the smoother they rotate in the development nip when used as a toner, and therefore, more resin particles can be transferred to an electrostatic latent image carrier. Therefore, the average circularity is preferably 0.930 or more, and more preferably 0.950 or more.

[0184] -Measurement of average circularity- In this embodiment, the average circularity can be measured using, for example, a flow particle image analyzer (FPIA-3000, manufactured by Sysmex Corporation). Specifically, 0.1 to 0.5 mL of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 mL of water from which solid impurities have been removed, and then approximately 0.1 to 0.5 g of the sample to be measured is added. The suspension containing the dispersed sample is subjected to a dispersion treatment for approximately 1 to 3 minutes using an ultrasonic disperser, and the dispersion concentration is adjusted to 3,000 particles / μL to 10,000 particles / μL, and the average particle size, average circularity, and standard deviation (SD) of the circularity are measured using the same device. However, the particle diameter is the equivalent circle diameter, the average particle diameter is determined from the equivalent circle diameter (number basis), and the analysis conditions for the flow type particle image analyzer are as follows: [Analysis conditions] Particle size limit: 0.5 μm≦circle equivalent diameter (number basis)≦200.0 μm Particle shape limit: 0.93<circularity≦1.00 In the present embodiment, the definition of the average circularity is as follows. (Average circularity) = (perimeter of a circle equal to the projected area of ​​a particle) / (perimeter of the projected image of a particle)

[0185] <Cleaning process> The washing step is a step of washing the resin particles obtained in the shell forming step or the fusion step. The resin particle dispersion obtained by the above-mentioned method may contain, in addition to the resin particles, secondary materials such as a flocculant, so it is preferable to perform washing in order to extract only the resin particles from the resin particle dispersion.

[0186] The method for washing the resin particles is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include centrifugation, vacuum filtration, and filter press. Any of the washing methods can produce a cake of the resin particles. However, if the resin particles cannot be sufficiently washed in one operation, the cake may be dispersed again in an aqueous solvent to form a slurry, and the resin particles may be extracted by at least one of the washing methods. When washing is carried out by the vacuum filtration method or the filter press method, a method may be used in which an aqueous solvent is passed through the cake body to wash away the secondary materials that are engulfed in the resin particles.

[0187] The aqueous solvent used in the washing step is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include water and a mixed solvent of water and alcohol. The alcohol includes, for example, methanol or ethanol. Among these, the aqueous solvent is preferably water from the viewpoint of cost and environmental load due to wastewater treatment.

[0188] <Drying process> The drying step is a step of washing the resin particles obtained in the washing step. The resin particles washed in the washing step contain a large amount of the aqueous medium, and therefore, by drying in the drying step and removing the aqueous medium, only the resin particles can be obtained.

[0189] The drying method is not particularly limited and can be appropriately selected depending on the purpose. Examples include methods using a dryer such as a spray dryer, a vacuum freeze dryer, a reduced pressure dryer, a stationary shelf dryer, a mobile shelf dryer, a fluidized bed dryer, a rotary dryer, or an agitator dryer.

[0190] The final moisture content of the dried resin particles is not particularly limited and can be selected appropriately depending on the purpose, but it is preferable that the moisture content is less than 1% by mass.

[0191] The resin particles dried in the drying step are in the form of soft agglomerates. If this causes inconvenience during use, the resin particles may be crushed to break up the agglomerates. The method for the crushing is not particularly limited and can be appropriately selected depending on the purpose. Examples include methods using devices such as a jet mill, a Henschel mixer, a super mixer, a coffee mill, an Oster blender, or a food processor.

[0192] <Annealing process> The annealing step is a step that is carried out after the drying step when a crystalline resin is added, and is a step that causes phase separation between the crystalline resin and the amorphous resin.

[0193] The method for performing the annealing treatment is not particularly limited and can be selected appropriately depending on the purpose, but examples include a method in which the crystalline resin is stored at a temperature near the glass transition temperature (Tg) of the crystalline resin for 10 hours or more.

[0194] In the fusion step, if the toner is heated to a temperature near the glass transition temperature (Tg) of the resin used, the crystalline resin and the amorphous resin may become compatible with each other, making it impossible to achieve both heat-resistant storage stability and low-temperature fixability. However, if the toner is annealed, phase separation between the crystalline resin and the amorphous resin proceeds, which is advantageous in that the toner is no longer in a compatible state.

[0195] <External addition process> The external addition process is a process of mixing the resin particles obtained in the drying process or the annealing process with a charge control agent or a cleaning performance improver to apply the charge control agent or the cleaning performance improver to the surfaces of the resin particles. This makes it possible to impart properties such as fluidity, chargeability, or cleaning properties to the resin particles.

[0196] As the charge control agent or cleaning property improver, those described above in the section (resin particles) can be used.

[0197] The method for mixing the resin particles with the charge control agent or the cleaning property improver is not particularly limited and can be appropriately selected depending on the purpose. Examples of the method include a method in which an impact force is applied to the mixture using a blade rotating at high speed, and a method in which the mixture is introduced into a high-speed airflow, accelerated, and the particles collide with each other or the composite particles with an appropriate collision plate.

[0198] The device used for the mixing is not particularly limited and can be appropriately selected depending on the purpose. Examples include Ang Mill (manufactured by Hosokawa Micron Corporation), I-type Mill (manufactured by Nippon Pneumatic Mfg. Co., Ltd.), or a device obtained by modifying these devices to reduce the grinding air pressure, Hybridization System (manufactured by Nara Machinery Works), Kryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), or an automatic mortar.

[0199] The resin particles have a low environmental impact and are excellent in low-temperature fixability, heat-resistant storage stability, and filming resistance, and are therefore suitable for use in toner. Therefore, the present invention includes "resin particles for toner," which are the resin particles used in toner.

[0200] (toner) The toner of the present invention contains the resin particles of the present invention, and preferably further contains an external additive, and further contains other components as required.

[0201] <Resin particles> The resin particles are as described in the above section (Resin particles), and details thereof will be omitted. In the toner, the resin particles become toner base particles.

[0202] The content of the resin particles in the toner is not particularly limited and can be appropriately selected depending on the purpose. The toner may be the resin particles themselves.

[0203] <External additives> The external additive is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include inorganic particles and polymeric fine particles. These may be used alone or in combination of two or more.

[0204] Examples of the inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, penguin, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride.

[0205] The primary particle diameter of the inorganic fine particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 nm to 2 μm, more preferably 5 nm to 500 nm.

[0206] The specific surface area of ​​the inorganic particles as measured by the BET method is not particularly limited and can be appropriately selected depending on the purpose. 2 / g~500m 2 / g is preferred.

[0207] Examples of the polymeric fine particles include polymer particles of polycondensation systems such as polystyrene, methacrylate copolymers, acrylate copolymers, silicone, benzoguanamine, or nylon obtained by soap-free emulsion polymerization, suspension polymerization, or dispersion polymerization, or polymer particles of thermosetting resins.

[0208] The external additives can be surface-treated to increase their hydrophobicity, thereby preventing deterioration of flowability and charging properties even under high humidity conditions. The surface treatment agent used for the surface treatment is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils.

[0209] The content of the external additive is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01% by mass to 5% by mass with respect to the total amount of the resin particles.

[0210] <Other ingredients> The other components in the toner are not particularly limited as long as they can be used in toner, and can be appropriately selected depending on the purpose. The content of the other components is not particularly limited and can be appropriately selected depending on the purpose.

[0211] The toner contains the resin particles, and therefore has a low environmental impact and is excellent in low-temperature fixability, heat-resistant storage stability, and filming resistance.

[0212] The method for producing the toner is not particularly limited and can be appropriately selected from known methods, and examples thereof include a method of mixing resin particles as the toner base particles with the external additive. In this case, applying a mechanical impact force is preferred in that it can prevent the external additive particles from being detached from the surfaces of the toner base particles.

[0213] The method for applying the mechanical impact force is not particularly limited and can be selected appropriately depending on the purpose. Examples include a method in which an impact force is applied to the mixture of the resin particles and the external additive by a blade rotating at high speed; and a method in which the mixture of the resin particles and the external additive is introduced into a high-speed airflow and accelerated to cause the particles to collide with each other or with an appropriate collision plate.

[0214] (developer) The developer of the present invention contains at least the toner of the present invention, and further contains other components such as a carrier that are appropriately selected as necessary. Since the toner contained in the developer of the present invention contains the resin particles of the present invention, the developer has a low environmental impact and is excellent in low-temperature fixability, heat-resistant storage stability, and filming resistance. The developer may be a one-component developer or a two-component developer, but when used in a high-speed printer or the like that corresponds to the recent improvement in information processing speed, a two-component developer is preferred because it has an improved lifespan.

[0215] When the developer is used as a one-component developer, even if the toner is balanced, there is little fluctuation in the particle size of the toner, there is little toner filming on the developing roller, and there is little toner fusion to components such as blades that thin the toner layer, and good and stable developability and images can be obtained even with long-term stirring in the developing device.

[0216] When the developer is used as a two-component developer, fluctuations in the particle size of the toner are small even when the toner is balanced over a long period of time, and good and stable developability and images can be obtained even when the developer is stirred for a long period of time in a developing device.

[0217] <Career> The carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably one having a core material and a resin layer covering the core material.

[0218] <<Core material>> The material for the core is not particularly limited and can be appropriately selected depending on the purpose. Examples include manganese-strontium-based materials with a density of 50 emu / g to 90 emu / g, or manganese-magnesium-based materials with a density of 50 emu / g to 90 emu / g. To ensure image density, it is preferable to use high-magnetization materials such as iron powder with a density of 100 emu / g or magnetite with a density of 75 emu / g to 120 emu / g. It is also preferable to use low-magnetization materials such as copper-zinc-based materials with a density of 30 emu / g to 80 emu / g, as this can reduce the impact of the developer in a standing state on the photoreceptor and is advantageous for achieving high image quality. These materials may be used alone or in combination of two or more.

[0219] The volume average particle diameter of the core material is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 10 μm to 150 μm, and more preferably 40 μm to 100 μm. A volume average particle diameter of the core material of 10 μm or more can prevent the carrier from containing a large amount of fine powder, thereby reducing the magnetization per particle and preventing carrier scattering. Furthermore, a volume average particle diameter of the core material of 150 μm or less can prevent a decrease in specific surface area and prevent toner scattering, and can prevent poor reproduction of solid areas, especially in full-color printers with many solid areas.

[0220] When the toner is used in a two-component developer, it may be mixed with the carrier. The content of the carrier in the two-component developer is not particularly limited and can be selected appropriately depending on the purpose. However, the content of the carrier is preferably 90 parts by mass or more and 98 parts by mass or less, and more preferably 93 parts by mass or more and 97 parts by mass or less, relative to 100 parts by mass of the two-component developer.

[0221] The developer can be suitably used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, or a two-component development method.

[0222] (Toner storage unit) The toner storage unit of the present invention stores toner in a unit having a function of storing toner. The toner contained in the toner storage unit is the toner of the present invention, and therefore the toner storage unit of the present invention has a low environmental impact.

[0223] The form of the toner storage unit is not particularly limited as long as it can store the toner, and can be appropriately selected depending on the purpose. For example, the toner storage unit may be a toner storage container, a developing unit, or a process cartridge.

[0224] <Toner storage container> The toner storage container refers to a container that stores the toner. The toner storage container is not particularly limited and can be appropriately selected from known containers, and examples thereof include a container having a container body and a cap.

[0225] The size of the container body is not particularly limited and can be changed as appropriate.

[0226] The shape of the container body is not particularly limited and can be changed as appropriate, but is preferably cylindrical.

[0227] The structure of the container body is not particularly limited and can be changed as appropriate, but a preferred structure is one in which spiral irregularities are formed on the inner surface, and by rotating the container, the toner content can be moved to the discharge outlet side, and part or all of the spiral irregularities have a bellows function.

[0228] The material of the container body is not particularly limited and can be changed as appropriate, but is preferably one with good dimensional accuracy, and examples thereof include resin materials such as polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyacrylic acid, polycarbonate resin, ABS resin, polyacetal resin, etc. These may be used alone or in combination of two or more.

[0229] The toner storage container is easy to store and transport, and has excellent handling properties, and therefore can be detachably attached to a process cartridge or an image forming apparatus and used to replenish the toner.

[0230] <Developer> The developing device is a device that contains the toner and has a developing means. The developing means is not particularly limited and can be appropriately selected depending on the purpose. For example, it has at least the toner storage container and a toner carrier that carries and transports the toner stored in the toner storage container. The developing means may further include a regulating member for regulating the thickness of the toner carried thereon.

[0231] <Process cartridge> The process cartridge is a device that integrates at least an electrostatic latent image carrier and a developing unit, contains the toner, and is detachably mountable to an image forming apparatus. The process cartridge may further include at least one selected from a charging unit, an exposing unit, a cleaning unit, and a discharging unit, as necessary.

[0232] An example of the process cartridge is one that is molded to be detachable from various image forming apparatuses and has at least an electrostatic latent image carrier that carries an electrostatic latent image, and a developing means that develops the electrostatic latent image carried on the electrostatic latent image carrier with the toner to form a toner image, and may further have other means, if necessary.

[0233] Next, one embodiment of the process cartridge is shown in Figure 1. As shown in Figure 1, the process cartridge 110 of this embodiment incorporates an electrostatic latent image carrier 10, and has a charger 58 as charging means, a developing device 40 as developing means, and a cleaning device 90 as cleaning means, and may further have other means as necessary. In Figure 1, the symbol L indicates exposure from an exposure means (not shown), and the symbol 95 indicates recording paper. The electrostatic latent image carrier 10 may be the same as the electrostatic latent image carrier in the image forming apparatus described later. The charger 58 may be any charging member. In the image forming process using the process cartridge shown in FIG. 1, the electrostatic latent image carrier 10 rotates in the direction of the arrow, and an electrostatic latent image corresponding to the exposed image is formed on its surface by charging with the charger 58 and exposure L by the exposure means. This electrostatic latent image is developed with toner by the developing device 40, and the toner development is transferred to recording paper 95 by the transfer roller 80 and printed out. Next, the surface of the electrostatic latent image carrier 10 after the image transfer is cleaned by the cleaning device 90, and further discharged by a discharge means (not shown), and the above operations are repeated again.

[0234] (Image forming apparatus and image forming method) The image forming apparatus of the present invention comprises an electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, a developing unit that has a toner that develops the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image, and may further comprise other units as necessary. The toner in the developing unit is the toner of the present invention.

[0235] The image forming method of the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and a developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with a toner to form a visible image, and may further include other steps as necessary. The toner in the developing step is the toner of the present invention.

[0236] The image forming method is carried out by the image forming apparatus. The image forming method of the present invention will be described below together with the image forming apparatus of the present invention.

[0237] <Electrostatic latent image carrier> The material, structure, and size of the electrostatic latent image carrier (hereinafter sometimes referred to as "photoreceptor") are not particularly limited, and can be appropriately selected from known materials. Examples of the material for the electrostatic latent image bearing member include an inorganic photoreceptor and an organic photoreceptor. The inorganic photoreceptor may be, for example, amorphous silicon or selenium. The organic photoreceptor may be, for example, polysilane or phthalopolymethine. Of these, amorphous silicon is preferred as the electrostatic latent image bearing member in terms of its long life.

[0238] The amorphous silicon photoreceptor may be, for example, a photoreceptor having a photoconductive layer made of a-Si formed on a substrate by heating the substrate to 50°C to 400°C and depositing the photoconductive layer on the substrate by a film-forming method such as vacuum deposition, sputtering, ion plating, thermal CVD (chemical vapor deposition), photo-CVD, or plasma CVD. Among these, plasma CVD, i.e., a method in which a source gas is decomposed by direct current, high frequency, or microwave glow discharge to form an a-Si deposited film on the substrate, is preferred.

[0239] The shape of the electrostatic latent image bearing member is not particularly limited and can be appropriately selected depending on the purpose, but a cylindrical shape is preferred. The outer diameter of the cylindrical electrostatic latent image carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 mm or more and 100 mm or less, more preferably 5 mm or more and 50 mm or less, and particularly preferably 10 mm or more and 30 mm or less.

[0240] <Electrostatic latent image forming means and electrostatic latent image forming process> The electrostatic latent image forming unit is a unit that forms an electrostatic latent image on the electrostatic latent image carrier. The electrostatic latent image forming step is a step of forming an electrostatic latent image on the electrostatic latent image bearing member. The electrostatic latent image forming step is preferably carried out by the electrostatic latent image forming means.

[0241] The electrostatic latent image forming means is not particularly limited and can be appropriately selected depending on the purpose. For example, it may be a means having at least a charging member that charges the surface of the electrostatic latent image carrier and an exposure member that exposes the surface of the electrostatic latent image carrier to light in an imagewise manner.

[0242] The electrostatic latent image forming step is not particularly limited and can be appropriately selected depending on the purpose. For example, the electrostatic latent image forming step can be performed by charging the surface of the electrostatic latent image bearing member and then exposing it to light in an imagewise manner.

[0243] <<Charging materials and charging>> The charging member is not particularly limited and can be appropriately selected from known ones depending on the purpose. Examples include a contact charger, a non-contact charger that utilizes corona discharge such as a corotron or a scorotron. The non-contact charger preferably includes a conductive or semi-conductive roller, brush, film, rubber blade, or the like.

[0244] The charging can be carried out, for example, by applying a voltage to the surface of the electrostatic latent image bearing member using the charging member.

[0245] The shape of the charging member may be a roller, a magnetic brush, a fur brush, or any other shape, and can be selected according to the specifications and shape of the image forming apparatus. The charging member is not limited to the contact-type charging member, but it is preferable to use a contact-type charging member because it allows an image forming apparatus in which the amount of ozone generated from the charging member is reduced.

[0246] <<Exposure member and exposure>> The exposure member is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charging member in the shape of an image to be formed, and can be appropriately selected depending on the purpose. Examples of the exposure member include various exposure members such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.

[0247] The light source used in the exposure member is not particularly limited and can be appropriately selected depending on the purpose. Examples include general light-emitting materials such as fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light-emitting diodes (LEDs), semiconductor lasers (LDs), and electroluminescence (EL).

[0248] In order to irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, or a color temperature conversion filter can be used.

[0249] The exposure can be carried out, for example, by exposing the surface of the electrostatic latent image bearing member to light in an imagewise manner using the exposure member. In the present invention, a backlight system may be employed in which exposure is performed imagewise from the back side of the electrostatic latent image bearing member.

[0250] <Developing means and developing process> The developing unit is a unit that includes toner for developing the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image. The developing step is a step of developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a visible image. The developing step is preferably carried out by the developing means.

[0251] The developing means is not particularly limited and can be appropriately selected depending on the purpose, and may be a dry developing type or a wet developing type. The developing means may be a monochromatic developing means or a multicolor developing means. Among these, the developing means is preferably a developing device having an agitator that frictionally agitates the toner to charge it, a magnetic field generating means fixed therein, and a rotatable developer carrier that carries a developer containing the toner on its surface.

[0252] In the developing unit, for example, the toner and carrier are mixed and stirred, and the toner is charged by friction during this process and held in a standing state on the surface of a rotating magnet roller, forming a magnetic brush. The magnet roller is disposed near the electrostatic latent image carrier. Therefore, a portion of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the electrostatic latent image carrier by electrical attraction. As a result, the electrostatic latent image is developed with the toner, and a visible toner image is formed on the surface of the electrostatic latent image carrier.

[0253] Here, the carrier is not particularly limited and can be appropriately selected depending on the purpose. For example, the carriers described in the above section (Developer) can be used.

[0254] <Other means and other steps> The other means is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a transfer means, a fixing means, a cleaning means, a discharging means, a recycling means, and a control means. The other steps are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a transfer step, a fixing step, a cleaning step, a discharging step, a recycling step, and a control step. The transfer step is preferably performed by the transfer means, the fixing step is preferably performed by the fixing means, the cleaning step is preferably performed by the cleaning means, the de-electrification step is preferably performed by the de-electrification means, the recycling step is preferably performed by the recycling means, and the control step is preferably performed by the control means.

[0255] <<Transfer means and transfer process>> The transfer means is a means for transferring the visible image formed by the developing means onto a recording medium. The transfer step is a step of transferring the visible image formed in the development step onto a recording medium.

[0256] The transfer means is not particularly limited and can be selected appropriately depending on the purpose, but a preferred embodiment has a primary transfer means that transfers the visible image onto an intermediate transfer body to form a composite transfer image, and a secondary transfer means that transfers the composite transfer image onto a recording medium.

[0257] The transfer step is not particularly limited and can be appropriately selected depending on the purpose. However, a preferred embodiment is one in which an intermediate transfer member is used, the visible image is primarily transferred onto the intermediate transfer member, and then the visible image is secondarily transferred onto the recording medium.

[0258] Here, when the image to be secondarily transferred onto the recording medium is a color image made up of toners of multiple colors, the transfer means can be configured to sequentially overlay toners of each color on the intermediate transfer body to form an image on the intermediate transfer body, and the intermediate transfer means can secondarily transfer the image on the intermediate transfer body onto the recording medium all at once. The intermediate transfer body is not particularly limited and can be appropriately selected from known transfer bodies depending on the purpose, and a suitable example is a transfer belt.

[0259] The transfer means (the primary transfer means, the secondary transfer means) preferably has at least a transfer device that peels and charges the visible image formed on the photosensitive member onto the recording medium. The transfer device is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.

[0260] The recording medium is typically plain paper, but is not particularly limited as long as it can be used to transfer the unfixed image after development, and can be selected appropriately depending on the purpose. PET base for overhead projectors can also be used.

[0261] <<Fixing means and fixing process>> The fixing unit is a unit for fixing the transferred image onto the recording medium. The fixing step is a step of fixing the transferred image onto the recording medium.

[0262] The fixing means is not particularly limited and can be appropriately selected depending on the purpose, but known heating and pressing members are preferred. The heating and pressing member is not particularly limited and can be appropriately selected depending on the purpose. For example, it may be a combination of a heating roller and a pressure roller, or a combination of a heating roller, a pressure roller and an endless belt. In the present invention, depending on the purpose, a known optical fixing device may be used together with or instead of the fixing means.

[0263] The fixing step is not particularly limited and can be appropriately selected depending on the purpose. For example, the fixing step may be performed for each color toner each time it is transferred to the recording medium, or may be performed simultaneously for each color toner in a stacked state.

[0264] The heating temperature of the heating and pressing member is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 80° C. or higher and 200° C. or lower.

[0265] The surface pressure in the fixing step is not particularly limited and can be appropriately selected depending on the purpose. 2More than 80N / cm 2 It is preferable that:

[0266] <<Cleaning means and cleaning process>> The cleaning means is a means for removing the toner remaining on the photosensitive member. The cleaning step is a step of removing the toner remaining on the photosensitive member.

[0267] The cleaning means is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.

[0268] <<Static removal means and static removal process>> The charge eliminating means is a means for applying a charge eliminating bias to the photosensitive member to eliminate the charge therefrom. The charge removal step is a step of removing electricity by applying a charge removal bias to the photosensitive member.

[0269] The static elimination means is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a static elimination lamp.

[0270] <<Recycling methods and processes>> The recycling unit is a unit that transports the toner removed by the cleaning unit to the developing unit and recycles the toner. The recycling step is a step of transporting the toner removed in the cleaning step to the developing step and recycling it.

[0271] The recycling means is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include known transport means.

[0272] <<Control means and control process>> The control means is a means capable of controlling the operation of each of the means. The control step is a step that can control the movement of each of the means.

[0273] The control means is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include devices such as a sequencer or a computer.

[0274] Next, an embodiment of the image forming apparatus of the present invention and the image forming method of the present invention will be described with reference to FIGS. The color image forming apparatus 100A shown in FIG. 2 includes a photosensitive drum 10 (hereinafter sometimes referred to as "photosensitive drum 10") as the electrostatic latent image carrier, a charging roller 20 as the charging means, an exposure device 30 as the exposure means, a developing device 40 as the developing means, an intermediate transfer body 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a discharging lamp 70 as the discharging means.

[0275] The intermediate transfer body 50 is an endless belt that is designed to move in the direction of the arrow by three rollers 51 arranged inside and tensioning it. Some of the three rollers 51 also function as transfer bias rollers that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer body 50. A cleaning device 90 having a cleaning blade is arranged near the intermediate transfer body 50. Also, a transfer roller 80 serving as the transfer means that can apply a transfer bias for transferring (secondary transfer) the developed image (toner image) to transfer paper 95 as a recording medium is arranged near the intermediate transfer body 50, facing the intermediate transfer body 50. A corona charger 58 for applying an electric charge to the toner image on the intermediate transfer body 50 is arranged around the intermediate transfer body 50, between the contact point between the photoreceptor 10 and the intermediate transfer body 50 and the contact point between the intermediate transfer body 50 and the transfer paper 95, in the direction of rotation of the intermediate transfer body 50.

[0276] The developing device 40 is composed of a developing belt 41 as the developer carrier, and a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C arranged around the developing belt 41. The black developing unit 45K includes a developer container 42K, a developer supply roller 43K, and a developing roller 44K. The yellow developing unit 45Y includes a developer container 42Y, a developer supply roller 43Y, and a developing roller 44Y. The magenta developing unit 45M includes a developer container 42M, a developer supply roller 43M, and a developing roller 44M. The cyan developing unit 45C includes a developer container 42C, a developer supply roller 43C, and a developing roller 44C. The developing belt 41 is an endless belt that is rotatably stretched around multiple belt rollers, and a portion of the belt is in contact with the electrostatic latent image carrier 10.

[0277] In the color image forming apparatus 100A shown in FIG. 2, for example, a charging roller 20 uniformly charges the photosensitive drum 10. An exposure device 30 exposes the photosensitive drum 10 to light in an imagewise manner to form an electrostatic latent image. The electrostatic latent image formed on the photosensitive drum 10 is developed by supplying toner from a developing device 40 to form a toner image. The toner image is transferred (primary transfer) onto an intermediate transfer body 50 by a voltage applied from a roller 51, and is further transferred (secondary transfer) onto a transfer paper 95. As a result, a transfer image is formed on the transfer paper 95. Any remaining toner on the photosensitive drum 10 is removed by a cleaning device 60, and the charge on the photosensitive drum 10 is temporarily removed by a discharging lamp 70.

[0278] Another example of the image forming apparatus of the present invention is shown in Figure 3. Image forming apparatus 100B has the same configuration as image forming apparatus 100A shown in Figure 2, except that it does not have developing belt 41 and has black developing unit 45K, yellow developing unit 45Y, magenta developing unit 45M, and cyan developing unit 45C arranged directly opposite each other around photosensitive drum 10.

[0279] Another example of the image forming apparatus of the present invention is shown in Fig. 4. The image forming apparatus 100C shown in Fig. 4 includes a copying machine main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400. An endless belt-like intermediate transfer body 50 is provided in the center of the copying machine main body 150. The intermediate transfer body 50 is stretched around support rollers 14, 15, and 16 and is rotatable clockwise in FIG. 4. An intermediate transfer body cleaning device 17 for removing residual toner from the intermediate transfer body 50 is located near the support roller 15. A tandem developing device 120 is located around the intermediate transfer body 50, stretched around the support rollers 14 and 15, along the transport direction of the intermediate transfer body 50. The tandem developing device 120 includes four image forming means 18 for yellow, cyan, magenta, and black, which are arranged side by side and face each other. An exposure device 21, which is the exposure member, is located near the tandem developing device 120. A secondary transfer device 22 is located on the side of the intermediate transfer body 50 opposite the side where the tandem developing device 120 is located. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched over a pair of rollers 23, and the transfer paper transported on the secondary transfer belt 24 and the intermediate transfer body 50 can come into contact with each other. A fixing device 25, which is the fixing means, is disposed near the secondary transfer device 22. The fixing device 25 includes a fixing belt 26, which is an endless belt, and a pressure roller 27 disposed so as to be pressed against the fixing belt 26. In the tandem image forming apparatus, a sheet reversing device 28 is disposed near the secondary transfer device 22 and the fixing device 25 for reversing the transfer paper in order to form images on both sides of the transfer paper.

[0280] Next, we will explain how to form a full-color image (color copy) using the tandem developing device 120. That is, first, an original is set on the platen 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and the original is set on the contact glass 32 of the scanner 300, and then the automatic document feeder 400 is closed.

[0281] When the start switch is pressed, the scanner 300 is driven after the document is transported and moved onto the contact glass 32 when the document is set on the automatic document feeder 400, or immediately when the document is set on the contact glass 32. Then, the first travelling body 33 and the second travelling body 34 travel. At this time, light from a light source is irradiated by the first travelling body 33, and the light reflected from the document surface is reflected by a mirror on the second travelling body 34 and received by the reading sensor 36 through the imaging lens 35, and the color document (color image) is read, and image information of black, yellow, magenta, and cyan is generated.

[0282] The image information for black, yellow, magenta, and cyan is then transmitted to the image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem developing device 120. Then, the toner images for black, yellow, magenta, and cyan are formed in the image forming means.

[0283] That is, as shown in FIG. 5, each image forming means 18 (black image forming means, yellow image forming means, magenta image forming means, and cyan image forming means) in the tandem developing device 120 includes an electrostatic latent image carrier 10 (black electrostatic latent image carrier 10K, yellow electrostatic latent image carrier 10Y, magenta electrostatic latent image carrier 10M, and cyan electrostatic latent image carrier 10C), a charging device 160 which is the charging means for uniformly charging the electrostatic latent image carrier 10, and a charging unit 160 which is a charging unit for charging the electrostatic latent image carrier 10 based on each color image information. The device is equipped with an exposure device that exposes the electrostatic latent image carrier to light (L in FIG. 5) in the form of an image corresponding to each color image, thereby forming an electrostatic latent image corresponding to each color image on the electrostatic latent image carrier, a developing device 61 that is the developing means that develops the electrostatic latent image using each color toner (black toner, yellow toner, magenta toner, and cyan toner) to form a toner image using each color toner, a transfer charger 62 that transfers the toner image onto the intermediate transfer body 50, a cleaning device 63, and a static eliminator 64.

[0284] Each image forming unit 18 can form a single-color image (black image, yellow image, magenta image, and cyan image) based on the image information of the corresponding color. The black, yellow, magenta, and cyan images thus formed are sequentially transferred (primary transfer) onto an intermediate transfer body 50, which is rotated by support rollers 14, 15, and 16: the black image formed on the black electrostatic latent image carrier 10K, the yellow image formed on the yellow electrostatic latent image carrier 10Y, the magenta image formed on the magenta electrostatic latent image carrier 10M, and the cyan image formed on the cyan electrostatic latent image carrier 10C. The black, yellow, magenta, and cyan images are then superimposed on the intermediate transfer body 50 to form a composite color image (color transfer image).

[0285] Meanwhile, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed out a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in a paper bank 143. The sheets are separated one by one by a separation roller 145 and sent out to a paper feed path 146, then transported by a transport roller 147 and guided to a paper feed path 148 inside the copier main body 150, where they are stopped by striking against a registration roller 49. Alternatively, the paper feed roller 142 is rotated to feed out sheets (recording paper) from a manual feed tray 54, and the sheets are separated one by one by a separation roller 52 and placed in a manual feed path 53, where they are also stopped by striking against a registration roller 49. Note that the registration roller 49 is generally grounded when used, but may be used with a bias applied to remove paper dust from the sheets.

[0286] Then, the registration rollers 49 are rotated in time with the composite color image (color transfer image) formed on the intermediate transfer body 50, and a sheet (recording paper) is sent between the intermediate transfer body 50 and the secondary transfer device 22, and the composite color image (color transfer image) is transferred (secondary transfer) onto the sheet (recording paper) by the secondary transfer device 22. In this way, a color image is transferred and formed on the sheet (recording paper). After the image transfer, any remaining toner on the intermediate transfer body 50 is cleaned by the intermediate transfer body cleaning device 17.

[0287] The sheet (recording paper) onto which the color image has been transferred is transported by secondary transfer device 22 and sent to fixing device 25, where the composite color image (color transfer image) is fixed onto the sheet (recording paper) by heat and pressure. Thereafter, the sheet (recording paper) is switched by switching claw 55, discharged by discharge rollers 56, and stacked on paper output tray 57. Alternatively, the sheet can be switched by switching claw 55, inverted by sheet inverting device 28, and guided to the transfer position again, where an image is also recorded on the back side, and then discharged by discharge rollers 56 and stacked on paper output tray 57. [Example]

[0288] The present invention will be specifically explained below with reference to Production Examples, Preparation Examples, Examples, and Comparative Examples, but the present invention is not limited to these Production Examples, Preparation Examples, and Examples. In the Production Examples, Preparation Examples, Examples, and Comparative Examples, unless otherwise specified, "%" indicates "% by mass" and "parts" indicates "parts by mass." Furthermore, the blending amounts in the Examples and Comparative Examples indicate the blending amounts of solids in each raw material.

[0289] <<Amine value measurement>> In the following production examples, the amine value of the ketimine compound was measured by the method described in JIS K7237.

[0290] <<Molecular weight measurement>> In the following synthesis examples, the molecular weights of amorphous polyester resin A, amorphous polyester resin B, and crystalline polyester resin C were measured using a gel permeation chromatograph (GPC) under the following analytical conditions. [Analysis conditions] Equipment: GPC-8220GPC (Tosoh Corporation) Column: TSKgel (registered trademark) SuperHZM-H 15 cm, triple column (Tosoh Corporation) ·Temperature: 40℃ Detector: RI (refractive index) detector Solvent: tetrahydrofuran (THF) or chloroform Flow rate: 0.35 mL / min Sample: 100 μL of 0.15% by mass sample injected Sample pretreatment: Amorphous polyester resin A, amorphous polyester resin B, or crystalline polyester resin C was dissolved in THF (tetrahydrofuran (containing stabilizer), Fujifilm Wako Pure Chemical Industries, Ltd.) or chloroform at 0.15% by mass, and then filtered through a 0.2 μm filter, and the filtrate was used as the sample. The molecular weight distribution of the sample was calculated from the relationship between the logarithm of the calibration curve and the count number, which was prepared using several monodisperse polystyrene standard samples. The standard polystyrene samples used for preparing the calibration curve were Showdex (registered trademark) STANDARD (manufactured by Showa Denko K.K.), Std. Nos. S-6550, S-2330, S-1700, S-740, S-10, S-662, S-2.9, and S-0.6.

[0291] <<Melting point (Tm) and glass transition temperature (Tg) measurement>> In the following synthesis examples, the glass transition temperatures (Tg) of amorphous polyester resin A and amorphous polyester resin B, and the melting point (Tm) of crystalline polyester resin C were measured using a DSC system (differential scanning calorimeter) (Q-200, manufactured by TA Instruments). First, approximately 5.0 mg of the measurement sample was placed in an aluminum sample container, which was then placed on a holder unit and set in an electric furnace. Next, under a nitrogen atmosphere, the sample was heated from -80°C to 150°C at a heating rate of 10°C / min (first heating). The sample was then cooled from 150°C to -80°C at a cooling rate of 10°C / min, and further heated to 150°C at a heating rate of 10°C / min (second heating). DSC curves were measured during each of the first and second heating periods using a differential scanning calorimeter (Q-200, manufactured by TA Instruments). From the obtained DSC curves, the DSC curve at the second temperature rise was selected using the analysis program in the Q-200 system, and the glass transition temperature of the measurement sample at the second temperature rise was determined. In addition, the DSC curve obtained during the second heating was selected using the analysis program in the Q-200 system, and the endothermic peak top temperature during the second heating of the measurement sample was determined as the melting point. The endothermic peak top temperature during this second temperature increase was taken as the melting point of each sample, and the Tg during the second temperature increase was taken as the Tg of each sample.

[0292] <<Volume average particle size measurement>> In the following Preparation Examples, Examples, and Comparative Examples, the volume average particle size of the crystalline polyester resin particles in the crystalline polyester resin C dispersion, the volume average particle size of the wax particles, and the volume average particle size of the emulsified slurry were measured using a particle size distribution measuring device (Coulter Multisizer III, manufactured by Coulter). Specifically, 2 mL of a surfactant (sodium dodecylbenzenesulfonate, manufactured by Tokyo Chemical Industry Co., Ltd.) was added as a dispersant to 100 mL of an electrolyte (ISOTON-II, manufactured by Coulter Corporation) to obtain a mixture. 10 mg of the measurement sample (solid content) was further added to this mixture to obtain an electrolyte in which the measurement sample was suspended. The electrolyte in which the measurement sample was suspended was subjected to a dispersion treatment using an ultrasonic disperser for approximately 1 to 3 minutes, and the volume and number of the measurement sample were measured using a Coulter Multisizer III with a 100 μm aperture, and the volume distribution and number distribution were calculated. The volume average particle size (Dv) of the measurement sample was determined from the obtained distribution.

[0293] <<Measurement of average circularity>> In the following examples and comparative examples, the average circularity of the dispersed slurry is defined by the following formula and was measured using a flow particle image analyzer (FPIA-3000, manufactured by Sysmex Corporation). (Average circularity) = (perimeter of a circle equal to the projected area of ​​a particle) / (perimeter of the projected image of a particle)

[0294] Specifically, 0.1 mL of a surfactant (sodium dodecylbenzenesulfonate, manufactured by Tokyo Chemical Industry Co., Ltd.) was added as a dispersant to 100 mL of water from which impurities had been removed in advance in a container, and approximately 0.1 g of the measurement sample was then added. The suspension in which the measurement sample was dispersed was subjected to a dispersion treatment for approximately 1 minute using an ultrasonic disperser, and the dispersion concentration was set to 3,000 particles / μL to 10,000 particles / μL, and the average particle size, average circularity, and standard deviation (SD) of the circularity were measured using the same device. However, the particle diameter was the equivalent circle diameter, the average particle diameter was determined from the equivalent circle diameter (number basis), and the analysis conditions for the flow type particle image analyzer were as follows: [Analysis conditions] Particle size limit: 0.5 μm≦circle equivalent diameter (number basis)≦200.0 μm Particle shape limit: 0.93<circularity≦1.00

[0295] (Production Example 1: Synthesis of Ketimine) A reaction vessel equipped with a stirrer and a thermometer was charged with 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone, and the mixture was reacted at 50°C for 5 hours to obtain [Ketimine Compound 1]. The amine value of [Ketimine Compound 1] was 418 mgKOH / g.

[0296] (Production Example A-1: ​​Synthesis of amorphous polyester resin A-1) <Synthesis of Prepolymer A-1> 3-methyl-1,5-pentanediol, isophthalic acid, and plant-derived sebacic acid (manufactured by Toyokuni Oil Mills Co., Ltd.) were added to a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet tube, along with titanium tetraisopropoxide (1,000 ppm relative to the resin component) so that the hydroxyl to carboxyl molar ratio [OH / COOH] was 1.1, the diol component was 100 mol% 3-methyl-1,5-pentanediol, the dicarboxylic acid component was 73 mol% isophthalic acid and 23 mol% sebacic acid, and the amount of trimethylolpropane in the total monomers was 1.5 mol%. The mixture was then heated to 200°C over approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The mixture was then further reacted for 5 hours under reduced pressure of 10 to 15 mmHg to obtain [Intermediate Polyester A-1].

[0297] Next, the obtained [Intermediate Polyester A-1] and isophorone diisocyanate (IPDI) were added to a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet tube in a molar ratio (isocyanate groups of IPDI / hydroxyl groups of intermediate polyester) of 2.0, diluted with ethyl acetate to make a 50% ethyl acetate solution, and reacted at 150°C for 4 hours to obtain [Prepolymer A-1].

[0298] <Synthesis of amorphous polyester resin A-1> The resulting [Prepolymer A-1] was stirred in a reaction vessel equipped with a heater, stirrer, and nitrogen inlet tube. Further, [Ketimine Compound 1] was added dropwise to the reaction vessel in an amount such that the amine content of [Ketimine Compound 1] was equimolar to the isocyanate content of [Prepolymer A-1]. After stirring at 45°C for 10 hours, the prepolymer elongation product was removed. The resulting prepolymer elongation product was dried under reduced pressure at 50°C until the residual ethyl acetate content was 100 ppm or less, yielding [Amorphous Polyester Resin A-1]. The Tg of this resin was -51°C and the molecular weight (Mw) was 17,000.

[0299] (Production Example B-1: Synthesis of Amorphous Polyester Resin B-1) A four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was charged with plant-derived propylene glycol (manufactured by DuPont), terephthalic acid, and plant-derived succinic acid (manufactured by Bioamber) so that the diol component was 100 mol % propylene glycol, the dicarboxylic acid component was 86 mol % terephthalic acid and 14 mol % succinic acid, and the molar ratio of hydroxyl groups to carboxyl groups, [OH / COOH], was 1.3. This mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin components) at normal pressure and 230°C for 8 hours, and then further reacted at a reduced pressure of 10 to 15 mmHg for 4 hours. After this, trimellitic anhydride was added to the reaction vessel in an amount of 1 mol % relative to the total resin components, and the mixture was reacted at 180°C, normal pressure, and for 4 hours to obtain [Amorphous Polyester Resin B-1]. The resin had a Tg of 57°C and a molecular weight (Mw) of 10,000.

[0300] (Production Example B-2: Synthesis of Amorphous Polyester Resin B-2) A four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was charged with bisphenol A 2-mol ethylene oxide adduct, bisphenol A 2-mol propylene oxide adduct, terephthalic acid, and adipic acid so that the diol component was 60 mol% bisphenol A 2-mol propylene oxide adduct and 40 mol% bisphenol A 2-mol ethylene oxide adduct, the carboxylic acid component was 97 mol% terephthalic acid and 3 mol% adipic acid, and the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 1.3. The mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin components) at normal pressure and 230°C for 8 hours, and then reacted for a further 4 hours at a reduced pressure of 10 to 15 mmHg. After that, trimellitic anhydride was added to the reaction vessel in an amount of 1 mol% relative to the total resin components, and the mixture was reacted at 180°C, normal pressure, and for 4 hours to obtain [Amorphous Polyester Resin B-2]. The resin had a Tg of 65°C and a molecular weight (Mw) of 9,000.

[0301] The amorphous polyester resin A obtained in Production Example A-1 and the amorphous polyester resin B obtained in Production Examples B-1 and B-2 are shown in Table 1 below.

[0302] [Table 1]

[0303] (Production Example C-1: Synthesis of Crystalline Polyester Resin C-1) A 5L four-neck flask equipped with a nitrogen inlet, dehydration tube, stirrer, and thermocouple was charged with plant-derived sebacic acid and 1,6-hexanediol at a molar ratio of 0.9 (OH / COOH). The mixture was then reacted with titanium tetraisopropoxide (500 ppm relative to the resin component) at 180°C for 10 hours, then heated to 200°C for 3 hours, and then further reacted at 8.3 kPa for 2 hours to obtain [Crystalline Polyester Resin C-1]. The melting point of this resin was 67°C and the molecular weight (Mw) was 25,000.

[0304] (Preparation Example 1-1: Preparation of Crystalline Polyester Resin Dispersion 1) 350 parts of [Crystalline Polyester Resin C-1], 210 parts of methyl ethyl ketone, and 61.8 parts of isopropyl alcohol were placed in a separable flask and thoroughly mixed and dissolved at 50°C. After this, 16.24 parts of 10% aqueous ammonia solution was added dropwise. The heating temperature was lowered to 65°C, and ion-exchanged water was added dropwise at a rate of 8 g / min using a liquid pump while stirring. After the liquid became uniformly cloudy, the rate was increased to 12 g / min. When the total liquid volume reached 1,400 parts, the addition of ion-exchanged water was stopped. The solvent was then removed under reduced pressure to obtain [Crystalline Polyester Resin Dispersion 1]. The volume average particle size of the resulting crystalline polyester resin particles was 150 nm, and the solids concentration of the resin particles was 30%.

[0305] (Preparation Example 2-1: Preparation of Wax Dispersion W-1) To 720 parts of ion-exchanged water, 180 parts of ester wax (WE-11, manufactured by NOF Corporation, synthetic wax made from plant-derived monomers, melting point 67°C) and 17 parts of an anionic surfactant (Neogen (registered trademark) SC, sodium dodecylbenzenesulfonate, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) were added. The mixture was dispersed using a homogenizer while heated to 90°C, yielding [Wax Dispersion W-1]. The volume-average particle size of the resulting wax particles was 300 nm, and the solids concentration of the resin particles was 25%.

[0306] (Preparation Example 3-1: Preparation of Masterbatch (MB)-1) To 1,200 parts of water, 500 parts of carbon black (Printex (registered trademark) 35, manufactured by Dexa) [DBP oil absorption = 42 mL / 100 mg, pH = 9.5] and 500 parts of [amorphous polyester resin B-1] were added and mixed in a Henschel mixer (manufactured by Nippon Coke and Engineering Co., Ltd.). The mixture was kneaded using two rolls at 150°C for 30 minutes, then rolled and cooled, and pulverized in a pulverizer to obtain masterbatch [MB-1].

[0307] Example 1 <Preparation of oil phase> 80 parts of [amorphous polyester resin A-1], 50 parts (solids) of [wax dispersion W-1], 450 parts of [amorphous polyester resin B-1], 150 parts of flake-shaped recycled PET resin [P-1], and 100 parts of [MB-1] were placed in a container and mixed at 5,000 rpm for 60 minutes using a TK Homomixer (manufactured by Primix Corporation) to obtain [oil phase 1].

[0308] <Preparation of aqueous phase> 990 parts of water, 20 parts of sodium dodecyl sulfate, and 90 parts of ethyl acetate were mixed and stirred to obtain a milky white liquid, which was designated as [aqueous phase 1].

[0309] <Phase inversion emulsification> While stirring 700 parts of [Oil Phase 1] with a TK Homomixer at 8,000 rpm, 20 parts of 28% aqueous ammonia was added and mixed for 10 minutes, after which 1,200 parts of [Aqueous Phase 1] was gradually added dropwise to obtain [Emulsified Slurry 1]. The volume average particle size of the obtained [Emulsified Slurry 1] was 560 nm.

[0310] <Solvent removal> [Emulsified slurry 1] was placed in a container equipped with a stirrer and a thermometer, and the solvent was removed at 30° C. for 180 minutes, yielding [solvent-removed slurry 1].

[0311] <Agglutination> 70 parts (solid content) of [Crystalline polyester resin dispersion 1] was added to [Desolvated slurry 1], and then 100 parts of a 3% magnesium chloride solution was added dropwise and stirred for 5 minutes. The temperature was then raised to 60°C, and when the particle size reached 5.0 μm, 50 parts of sodium chloride was added to terminate the aggregation process, thereby obtaining [Aggregated slurry 1].

[0312] <Preparation of fine particle dispersion> 100 parts of [amorphous polyester resin B-2] and 300 parts of methyl ethyl ketone were placed in a container and mixed and dissolved using a TK Homomixer (manufactured by Primix Corporation) to obtain [resin solution 1]. Separately, 990 parts of water, 20 parts of sodium dodecyl sulfate, and 90 parts of methyl ethyl ketone were mixed and stirred to obtain a milky white liquid, which was designated as [aqueous phase 2]. While stirring [Resin Solution 1] with a TK Homomixer at 8,000 rpm, 20 parts of 20% aqueous sodium hydroxide solution was added and mixed for 10 minutes, after which 1,200 parts of [Aqueous Phase 2] was gradually added dropwise to obtain [Fine Particle Dispersion Slurry 1]. [Fine Particle Dispersion Slurry 1] was placed in a container equipped with a stirrer and thermometer, and the solvent was removed at 30°C for 180 minutes, yielding [Fine Particle Dispersion 1]. The volume average particle diameter of the obtained [Fine Particle Dispersion 1] was 75 nm.

[0313] <Shelling and fusion> While stirring [Aggregated Slurry 1], 200 parts (solid content) of [Microparticle Dispersion 1] was added, and then 100 parts of a 3% magnesium chloride solution was added dropwise and stirred for 5 minutes. The mixture was then heated to 70°C, and when the desired average circularity of 0.957 was reached, 50 parts of sodium chloride was added and the mixture was cooled to obtain [Dispersed Slurry 1].

[0314] <Washing and drying> 100 parts of [Dispersion Slurry 1] was filtered under reduced pressure, and then the following operations (1) to (4) were carried out twice to obtain [Filter Cake 1]. (1) 100 parts of ion-exchanged water was added to the filter cake, and the mixture was mixed with a TK homomixer (at 12,000 rpm for 10 minutes), followed by filtration. (2): 100 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of (1) above, and the mixture was mixed with a TK homomixer (at 12,000 rpm for 30 minutes), followed by filtration under reduced pressure. (3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2) above, and the mixture was mixed with a TK homomixer (at 12,000 rpm for 10 minutes), followed by filtration. (4): 300 parts of ion-exchanged water was added to the filter cake of (3) above, and the mixture was mixed in a TK homomixer (at 12,000 rpm for 10 minutes), followed by filtration. The obtained [filter cake 1] was dried in a circulating air dryer at 45° C. for 48 hours and sieved through a mesh with 75 μm openings to obtain [resin particle base 1].

[0315] <External additive processing process> 100 parts of [Resin particle base 1] and 2.0 parts of hydrophobic silica (HDK (registered trademark) H2000, manufactured by Clariant Co., Ltd.) as an external additive were mixed in a Henschel mixer, and the mixture was passed through a 500 mesh sieve to obtain [Toner 1].

[0316] Example 2 [Toner 2] of Example 2 was obtained in the same manner as in Example 1, except that the number of parts of PET resin [P-1] added in the step of <Preparation of oil phase> and the number of parts of [Amorphous polyester resin B-2] added in the step of <Preparation of fine particle dispersion> (the number of parts of [Amorphous polyester resin B-2] added in [Fine particle dispersion 1] used in the step of <Shelling and fusing>) were changed as shown in Table 2 below.

[0317] Example 3 [Toner 3] of Example 3 was obtained in the same manner as in Example 1, except that the number of parts of [amorphous polyester resin B-1] added and the number of parts of PET resin [P-1] added in the <Preparation of oil phase> step in Example 1 were changed as shown in Table 2 below.

[0318] Example 4 [Toner 4] of Example 4 was obtained in the same manner as in Example 1, except that the number of parts of [amorphous polyester resin B-1] and the number of parts of PET resin [P-1] added in the step of <Preparation of oil phase> in Example 1, and the number of parts of [amorphous polyester resin B-2] added in the step of <Preparation of fine particle dispersion> (the number of parts of [amorphous polyester resin B-2] added in [fine particle dispersion 1] used in the step of <Shelling and fusing>) were changed as shown in Table 2 below.

[0319] Example 5 [Toner 5] of Example 5 was obtained in the same manner as in Example 1, except that in Example 1, the number of parts of [amorphous polyester resin B-1] added in the step of <Preparation of oil phase> was changed as shown in Table 2 below, 150 parts of PET resin [P-1] was changed to 50 parts of flaky recycled PBT resin [P-2], and the number of parts of [amorphous polyester resin B-2] added in the step of <Preparation of fine particle dispersion> (the number of parts of [amorphous polyester resin B-2] added in [fine particle dispersion 1] used in the step of <Shelling and fusing>) was changed as shown in Table 2 below.

[0320] (Comparative Example 1) [Toner 6] of Comparative Example 1 was obtained in the same manner as in Example 1, except that the amount of added [amorphous polyester resin B-1] used in the step of <preparation of oil phase> in Example 1 was changed as shown in Table 2 below, and the PET resin [P-1] was not added in the step of <preparation of oil phase>.

[0321] (Comparative Example 2) In Example 1, the number of parts of [amorphous polyester resin B-1] added and the number of parts of PET resin [P-1] added used in the step of <Preparation of oil phase>, and the number of parts of [amorphous polyester resin B-2] added used in the step of <Preparation of fine particle dispersion> (the number of parts of [amorphous polyester resin B-2] added in [fine particle dispersion 1] used in the step of <Shelling and fusing>) were changed as shown in Table 2 below, and the same procedure was repeated to obtain [Toner 7] of Comparative Example 2.

[0322] (Comparative Example 3) [Toner 8] of Comparative Example 3 was obtained in the same manner as in Example 1, except that the amount of [Amorphous Polyester Resin B-1] added in the step of <Preparation of Oil Phase> was changed as shown in Table 2 below, and [Fine Particle Dispersion 1] was not added in the step of <Shell Formation and Fusion>.

[0323] Comparative Example 4 [Toner 9] of Comparative Example 4 was obtained in the same manner as in Example 1, except that the number of parts of [amorphous polyester resin B-1] added in the step of <preparation of oil phase> in Example 1 was changed as shown in Table 2 below, PET resin [P-1] was not added in the step of <preparation of oil phase>, and [fine particle dispersion 1] was not added in the step of <shell formation and fusion>.

[0324] (Comparative Example 5) [Toner 10] of Comparative Example 5 was obtained in the same manner as in Example 1, except that in Example 1, 450 parts of [Amorphous Polyester Resin B-1] was changed to 700 parts of [Amorphous Polyester Resin B-2] in the step of <Preparation of Oil Phase>, PET resin [P-1] was not added, and [Fine Particle Dispersion 1] was not added in the step of <Shell Formation and Fusion>. (Comparative Example 6) [Toner 11] of Comparative Example 6 was obtained in the same manner as in Example 1, except that the number of parts of [amorphous polyester resin B-1] added and the number of parts of PET resin [P-1] added in the <Preparation of oil phase> step in Example 1 were changed as shown in Table 2 below.

[0325] [Table 2]

[0326] For each of the toners obtained in Examples 1 to 5 and Comparative Examples 1 to 6, the core-shell structure was confirmed, the average thickness of the shell layer was measured, the resin composition of the shell layer was analyzed, and radioisotopes indicating plant content were analyzed by the following methods. 14 The C concentration was measured, and the ratio of environmentally friendly resin (mass %) was calculated. The results are shown in Table 3-1 below. Table 3-1 also shows the content A (mass %) of the biomass-derived component of the biomass-derived resin and the content B (mass %) of PET or PBT in each of the toners obtained in Examples 1 to 5 and Comparative Examples 1 to 6.

[0327] <<Confirmation of core-shell structure and measurement of average shell layer thickness>> Each of the obtained toner particles was embedded in an epoxy resin (Devcon S-31, manufactured by ITW Performance Polymers & Fluids Japan Co., Ltd.) and cured. The toner particles were then cross-sectioned with a knife and cut to a thickness of 80 nm using an ultramicrotome (Leica ULTRACUT UCT, manufactured by Leica, using a diamond knife) to prepare ultrathin sections of the toner particles. The prepared ultrathin sections were exposed to ruthenium tetroxide gas for 5 minutes to differentiate the shell and core. The sections were then observed using a transmission electron microscope (TEM) (H-7000, manufactured by Hitachi High-Tech Corporation) at an accelerating voltage of 100 kV and a magnification of 15k. Ten toner particles were randomly selected for observation and photographed. As an example of the TEM image, a cross-sectional image of the toner particles of Example 1 is shown in FIG. 6.

[0328] The average thickness of the shell layer was calculated using image processing software (Image-J) as follows. (1) I drew a straight line along the scale using Straight Line. I set its actual length and units using Set Scale in Analyze. (2) The periphery of one resin particle in the cross-sectional image was surrounded by freehand sections to create "area 1." (3) The outer periphery of the region excluding the shell layer in the cross-sectional image of one of the resin particles (i.e., the boundary between the shell layer and the core layer) was surrounded by freehand sections to create "region 2." (4) The center of gravity of the "Area 1" was determined by Analyze. (5) Using a proprietary plug-in, a straight line was drawn from the periphery of the “Area 1,” i.e., the coordinates obtained by dividing the periphery of one resin particle into 100 equal sections in (2) above, toward the center of gravity of the resin particle determined in (4) above. (6) The length of each of the 100 straight lines created in (5) passing through "Area 1" minus the length passing through "Area 2" was calculated using the straight lines tracing the scale created in (1), and the average of the 100 straight lines was taken as the thickness of the shell layer of one of the resin particles. (7) The above steps (2) to (6) were carried out for 10 resin particles, and the average thickness of the shell layer of the 10 resin particles was calculated. The results are shown in Table 3-1 below. In Table 3 below, those having a core-shell structure are indicated by "◯" and those not having a core-shell structure are indicated by "X".

[0329] <<Analysis of Shell Layer Resin Composition>> Each of the obtained toner particles was embedded in an epoxy resin (Devcon S-31, manufactured by ITW Performance Polymers & Fluids Japan Co., Ltd.) and cured. Then, the cross section was cut with a knife and cut to a thickness of 50 nm using an ultramicrotome (Leica ULTRACUT UCT, manufactured by Leica, using a diamond knife) to prepare ultrathin sections of the resin particles. The prepared ultrathin sections of the toner were collected on a substrate (ZnS), and the shell layer was measured by AFM-IR using a nanoscale infrared spectroscopy analysis system (nanoIR2, manufactured by Anasys Instruments). The measurement range was 1,900 cm. -1 From 910cm -1 The resolution is 2cm -1 The chemical structure of the shell layer was analyzed from the obtained AFM-IR absorption spectrum. In Table 3-1 below, those in which the shell layer does not contain a biomass-derived resin are indicated by "◯", those in which the shell layer contains a biomass-derived resin are indicated by "X", and those without a core-shell structure are indicated by "-".

[0330] <<Radioisotope 14 How to measure C concentration>> Radioactive carbon isotopes of each toner 14 The C concentration was measured by radiocarbon dating. The toner was burned, and the CO2 (carbon dioxide) was reduced to obtain C (graphite). 14 The C concentration was measured using an accelerator mass spectrometer (AMS, manufactured by Beta Analytic). The standard used was an oxalic acid standard (HOxII, manufactured by NIST).

[0331] <<Calculation of environmentally friendly resin ratio (mass%)>> To calculate the ratio of environmentally friendly resin, the content (A) of biomass-derived components of the biomass-derived resin relative to the total mass of each toner, i.e., the biomass degree, was calculated using the following formula (1). The content (B) of PET or PBT was also calculated from the blending amount of each component. Next, the ratio of environmentally friendly resin was calculated using the following formula (2). Biomass ratio (%) = 14 C concentration (pMC) / 107.5×100 Equation (1) Environmentally friendly resin ratio (mass%) = content of biomass-derived components in biomass-derived resin (A) + content of PET or PBT (B) Formula (2)

[0332] The toners obtained in Examples 1 to 5 and Comparative Examples 1 to 6 were evaluated for environmental compatibility, low-temperature fixability, and filming resistance by the following methods. The results are shown in Table 3-2 below.

[0333] <Evaluation method> <<Environmental friendliness>> The "environmental compatibility" was evaluated based on the ratio of the environmentally compatible resin in the toners obtained in Examples 1 to 5 and Comparative Examples 1 to 6, according to the following evaluation criteria. -Evaluation criteria for "environmental friendliness"- ○: Environmentally friendly resin ratio is 35% or more by mass △: Eco-resin ratio is 10% by mass or more and less than 35% by mass ×: The ratio of environmentally friendly resin is less than 10% by mass

[0334] <<Low temperature fixability>> The carrier used in imageo MP C5503 (manufactured by Ricoh Co., Ltd.) and the toners obtained in Examples 1 to 5 and Comparative Examples 1 to 6 were mixed so that the toner concentration was 5%, to obtain developers. After putting the developer into the unit of Imageo MP C5503 (manufactured by Ricoh Co., Ltd.), a rectangular solid image of 2 cm x 15 cm was printed on PPC paper type 6000<70W>A4 T (manufactured by Ricoh Co., Ltd.) with a toner adhesion amount of 0.40 mg / cm 2At this time, the surface temperature of the fixing roller was changed, and it was observed whether cold offset, in which a residual image of a solid image is fixed in a location other than the desired location, occurred, and the cold offset temperature (lower limit temperature for fixing) was determined, and the "low temperature fixability" was evaluated based on the following evaluation criteria. -Evaluation criteria for "low temperature fixability"- 〇: Cold offset temperature is less than 110℃ △: Cold offset temperature is 110℃ or higher but less than 125℃ ×: Cold offset temperature is 125°C or higher

[0335] <<Filming resistance>> The carrier used in imageo MP C5503 (manufactured by Ricoh Co., Ltd.) and the toners obtained in Examples 1 to 5 and Comparative Examples 1 to 6 were mixed so that the toner concentration was 5%, to obtain a developer. After the developer was placed in the unit of an imageo MP C5503 (manufactured by Ricoh Co., Ltd.), a print pattern with a print rate of 2% was printed on PPC paper type 6000<70W>A4 T (manufactured by Ricoh Co., Ltd.) in a high-temperature, high-humidity environment (temperature 27°C, humidity 80%), one sheet per job. Every 10,000 sheets, the photoreceptor portion was visually inspected while printing, and the "filming resistance" was evaluated based on the following evaluation criteria. -Evaluation criteria for "filming resistance"- ○: No photoconductor filming occurred after 200,000 sheets △: Photoconductor filming occurred between 80,000 and 200,000 sheets ×: Photoconductor filming occurred within 70,000 sheets

[0336] [Table 3-1]

[0337] [Table 3-2]

[0338] The present invention includes, for example, the following aspects. <1> Resin particles containing at least a binder resin, the binder resin contains a biomass-derived resin and polyethylene terephthalate or polybutylene terephthalate, a content A of the biomass-derived component of the biomass-derived resin and a content B of the polyethylene terephthalate or polybutylene terephthalate satisfy A>B, the resin particles have a core-shell structure consisting of a shell layer and a core layer, The resin particles are characterized in that the average thickness of the shell layer is 100 nm to 500 nm. <2> the shell layer is made of a binder resin that does not contain the biomass-derived resin, <1> The resin particles are as described above. <3> The average thickness of the shell layer is 200 nm to 300 nm. <1> from <2> The resin particles are any of the above. <4> the total content [A+B] of the content A of the biomass-derived component of the biomass-derived resin and the content B of the polyethylene terephthalate or polybutylene terephthalate relative to the total mass of the resin particles is 35 mass% or more; <1> from <3> The resin particles are any of the above. <5> The content A of the biomass-derived component of the biomass-derived resin relative to the total mass of the resin particles is 25% by mass to 35% by mass. <4> The resin particles are as described in <6> Radioactive carbon isotopes of the resin particles 14 C concentration is 10.8 pMC or more, <1> from <5> The resin particles are any of the above. <7> The aforementioned <1> from <6> The method for producing resin particles according to any one of the above, a step of preparing an oil phase in which a binder resin containing a biomass-derived resin and polyethylene terephthalate or polybutylene terephthalate is dissolved or dispersed in an organic solvent so that a content A of a biomass-derived component in the biomass-derived resin and a content B of polyethylene terephthalate or polybutylene terephthalate satisfy the relationship A>B; adding an aqueous phase to the oil phase to invert and emulsify the water-in-oil dispersion into an oil-in-water dispersion; a step of preparing aggregated particles by aggregating the fine particles in the oil-in-water dispersion; forming a shell layer on the aggregated particles so that the aggregated particles have a core-shell structure consisting of a shell layer and a core layer, and so that the shell layer has an average thickness of 100 nm to 500 nm; The method for producing resin particles is characterized by comprising: <8> The aforementioned <1> from <6> 1. A toner comprising the resin particles according to any one of the above items. <9> The aforementioned <8> 10. A developer comprising the toner described in 1. <10> The aforementioned <8> 10. A toner storage unit characterized by storing the toner described above. <11> an electrostatic latent image carrier; an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier; a developing unit having a toner for developing the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image; and The toner is <8> 10. An image forming apparatus comprising the toner according to claim 9. <12> an electrostatic latent image forming step of forming an electrostatic latent image on the electrostatic latent image carrier; a developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a visible image; Including, The toner is <8> 2. An image forming method, characterized in that the toner is the toner described in 1.

[0339] The aforementioned <1> from <6> The resin particles according to any one of <7> The method for producing resin particles according to the <8> The toner according to <9> The developer according to <10> The toner storage unit according to <11> and the image forming apparatus described in <12> The image forming method described in the above can solve the above-mentioned problems in the prior art and achieve the object of the present invention. [Explanation of symbols]

[0340] 10 Photoconductor (photoconductor drum, electrostatic latent image carrier) 10K black electrostatic latent image carrier 10Y Yellow electrostatic latent image carrier 10M Magenta electrostatic latent image carrier 10C Cyan electrostatic latent image carrier 14 Support roller 15 Support roller 16 Support roller 17 Intermediate transfer body cleaning device 18 Image forming means 20 Charging device (charging roller) 21 Exposure equipment 22 Secondary transfer device 23 Laura 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet inverting device 30 Exposure equipment 32 Contact Glass 33 First running body 34 Second running body 35 Imaging lens 36 reading sensor 40 Developer 41 Developing belt 42K Developer compartment 42Y Developer storage unit 42M Developer compartment 42C Developer storage unit 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K developing roller 44Y developing roller 44M developing roller 44C Developing roller 45K Black Development Unit 45Y Yellow Development Unit 45M Magenta Development Unit 45C Cyan Development Unit 49 Registration roller 50 Intermediate transfer body 51 Laura 52 Separation roller 53 Manual feed path 54 Manual feed tray 55 Switching claw 56 Discharge roller 57 Paper output tray 58 Corona charger 60 Cleaning Device 61 Developing device 62 Transfer charger 63 Photoconductor cleaning device 64 Static eliminator 70 Static elimination lamp 80 Transfer roller 90 Cleaning Device 95 Transfer paper 100A, 100B, 100C image forming device 110 Process cartridge 120 Tandem developing unit 130 manuscript table 142 Paper feed roller 143 Paper Bank 144 Paper cassette 145 Separation roller 146 Paper feed path 147 Conveyor roller 148 Paper feed path 150 Copying device body 160 Charging device 200 Paper feed table 300 scanner 400 Automatic Document Feeder (ADF) L exposure [Prior art documents] [Patent documents]

[0341] [Patent Document 1] Patent No. 6138021

Claims

1. Contains resin particles containing at least a binder resin, the binder resin contains a biomass-derived resin and polyethylene terephthalate or polybutylene terephthalate, a content A of the biomass-derived component of the biomass-derived resin and a content B of the polyethylene terephthalate or polybutylene terephthalate satisfy A>B, the resin particles have a core-shell structure consisting of a shell layer and a core layer, The toner is characterized in that the average thickness of the shell layer is 100 nm to 500 nm.

2. The toner according to claim 1 , wherein the shell layer is made of a binder resin that does not contain the biomass-derived resin.

3. 3. The toner according to claim 1, wherein the shell layer has an average thickness of 200 nm to 300 nm.

4. 4. The toner according to claim 1, wherein a total content [A+B] of a content A of the biomass-derived component of the biomass-derived resin and a content B of the polyethylene terephthalate or polybutylene terephthalate relative to the total mass of the resin particles is 35% by mass or more.

5. 5. The toner according to claim 4, wherein a content A of the biomass-derived component of the biomass-derived resin relative to the total mass of the resin particles is 25% by mass to 35% by mass.

6. Radioactive carbon isotopes of the resin particles １４ 6. The toner according to claim 1, wherein the C concentration is 10.8 pMC or more.

7. 7. A method for producing the toner according to claim 1, a step of preparing an oil phase in which a binder resin containing a biomass-derived resin and polyethylene terephthalate or polybutylene terephthalate is dissolved or dispersed in an organic solvent so that a content A of a biomass-derived component in the biomass-derived resin and a content B of polyethylene terephthalate or polybutylene terephthalate satisfy the relationship A>B; adding an aqueous phase to the oil phase to invert and emulsify the water-in-oil dispersion into an oil-in-water dispersion; a step of preparing aggregated particles by aggregating the fine particles in the oil-in-water dispersion; forming a shell layer on the aggregated particles so that the aggregated particles have a core-shell structure consisting of a shell layer and a core layer, and so that the shell layer has an average thickness of 100 nm to 500 nm; A method for producing a toner, comprising:

8. A toner storage unit characterized by storing the toner described in any one of claims 1 to 6.

9. An electrostatic latent image carrier; an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier; a developing unit having a toner for developing the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image; and 7. An image forming apparatus, wherein the toner is the toner according to claim 1.

Images