JP2020166206A - Electrostatic charge image developing toner - Google Patents

Abstract

To provide an electrostatic charge image developing toner excellent in low-temperature fixability, hot offset resistance and image robustness, and a method for manufacturing the same.SOLUTION: An electrostatic charge image developing toner includes a polyester based resin and a blocking isocyanate. The polyester based resin has a constitutional unit derived from polyol and a constitutional unit derived from polycarboxylic acid; the constitutional unit derived from the polycarboxylic acid includes a constitutional unit derived from the carboxylic acid having a valence of 3 or more; the hydroxyl value of the polyester based resin is 5 mgKOH/g or more; and the blocking isocyanate is an adduct type.SELECTED DRAWING: None

Description

The present invention relates to a toner for developing an electrostatic charge image.

In the field of electrophotographic, with the development of electrophotographic systems, the development of toners for electrophotographics corresponding to high image quality and high speed is required. As a method for obtaining toner having a narrow particle size distribution and a small particle size in response to higher image quality, a coagulation fusion method (emulsification) in which fine resin particles and the like are aggregated and fused in an aqueous medium to obtain toner. The so-called chemical toner is produced by the coagulation method and the coagulation union method).
Recently, the speed of copying machines, multifunction devices, and printers using electrophotographic systems has been remarkably increased. Therefore, toner is required to have hot offset resistance in addition to low temperature fixability. To cope with this, a toner using polyester having excellent low temperature fixability as a toner binder has been proposed.

Patent Document 1 describes a liquid developer having toner particles containing a polymer having an active hydrogen group and a polymer having a blocked isocyanate group and a carrier liquid, and has low-temperature fixability and fixing strength. It has been shown that a high toner image is obtained.
In Patent Document 2, at least 50% by weight or more and less than 100% by weight of the binder resin is a polyester resin, which is produced from a binder resin and a colorant in an aqueous medium, and the binder resin contains a blocked isocyanate compound. A toner for developing an electrostatic charge image, which is characterized by the above-mentioned effect, is described, and it is shown that the toner is excellent in low-temperature fixability and can suppress the toner leaching from the cleaning roller.

JP-A-2017-67861 Japanese Unexamined Patent Publication No. 2006-47898

However, although the toner using polyester has excellent low-temperature fixability, there are problems that the hot offset resistance is not sufficient and the fastness of the image after fixing is low. On the other hand, if the elasticity of the polyester is increased in advance by adding a cross-linking agent or the like, the low-temperature fixability deteriorates. Therefore, it has been required to have excellent low-temperature fixing property, excellent hot offset resistance, and to improve the fastness of the image after fixing.
The present invention relates to a toner having excellent low-temperature fixability, excellent hot offset resistance, and excellent fastness of an image after fixing, and a method for producing the same.

The present inventors have focused on a method for improving the elasticity of toner in a fixing step. As a result, it was found that it is effective to add a specific blocked isocyanate compound in which the isocyanate group is blocked in the toner.
The present invention relates to the following [1] and [2].
[1] Containing a polyester-based resin and a blocked isocyanate compound, the polyester-based resin has a constituent unit derived from a polyol and a constituent unit derived from a polycarboxylic acid, and is derived from the polycarboxylic acid. The unit contains a structural unit derived from a trivalent or higher carboxylic acid, the polyester resin has a hydroxyl value of 5 mgKOH / g or higher, and the blocked isocyanate compound is an adduct-type blocked isocyanate compound. Toner for static charge image development.
[2] The polyester resin comprises a step of aggregating resin particles containing a polyester resin and a blocked isocyanate compound to obtain agglomerated particles and a step of fusing the agglomerated particles, and the polyester resin has a constitution derived from a polyol. It has a unit and a structural unit derived from a polycarboxylic acid, and the structural unit derived from the polycarboxylic acid contains a structural unit derived from a carboxylic acid having a valence of 3 or more, and the hydroxyl value of the polyester resin is high. It is 5 mgKOH / g or more, and the blocked isocyanate compound is an adduct-type blocked isocyanate compound, and in all the steps thereafter after the addition of the blocked isocyanate compound, the temperature is below the dissociation temperature of the blocking agent of the blocked isocyanate compound. A method for producing a toner for developing an electrostatic charge image.

According to the present invention, it is possible to provide a toner having excellent low-temperature fixability, excellent hot offset resistance, and excellent fastness of an image after fixing, and a method for producing the same.

[Toner for static charge image development and its manufacturing method]
The toner for static charge image development of the present invention (hereinafter, also simply referred to as “toner”) contains a polyester resin and a blocked isocyanate compound, and the polyester resin contains a constituent unit derived from the polyol and a polycarboxylic acid. The constituent unit derived from the polycarboxylic acid contains a constituent unit derived from a carboxylic acid having a valence of 3 or more, and the hydroxyl value of the polyester resin is 5 mgKOH / g or more. , The blocked isocyanate compound is an adduct-type blocked isocyanate compound.
According to the present invention, it is possible to obtain a toner having excellent low-temperature fixability, excellent hot offset resistance, and excellent image fastness after fixing.

As described above, the toner using the polyester resin has excellent low temperature fixability, but has a problem that the hot offset resistance and the image fastness after fixing are not sufficient. In order to obtain image fastness after fixing, it is effective to add a cross-linking agent or the like to increase the cross-linking strength of the binder resin and increase the elasticity of the toner. However, when the elasticity of the toner is increased in advance, there is a problem that the image fastness after fixing is obtained, but the low temperature fixing property is deteriorated.
The present inventors have excellent low-temperature fixability, excellent hot offset resistance, and robustness of the obtained image by using a toner in which the polyester resin has a high molecular weight due to the heat received by the toner in the fixing step. It was found that the sex can be enhanced.
By adding a specific blocked isocyanate compound, the detailed mechanism for improving low temperature fixability, hot offset resistance, and image fastness after fixing is not clear, but it is as follows. Can be considered. The blocked isocyanate compound is a compound in which the blocking agent dissociates at a certain temperature or higher and the isocyanate groups react with each other. By producing the toner at a temperature at which the blocking agent of the blocked isocyanate compound does not dissociate, the toner containing the blocked isocyanate can be obtained. When this blocked isocyanate compound is present in the toner, it is heated at the time of fixing, and when the toner melts, the polyester resin which is the toner binder melts, and further, the blocking agent of the blocked isocyanate compound dissociates and the isocyanate group is formed. Be exposed. Then, the hydroxyl group (OH group) of the polyester resin, which is a molten toner binder, reacts with the isocyanate group to crosslink the polyester resin and increase the molecular weight. Therefore, after fixing, the elasticity is higher than that before fixing. It is considered that an image having excellent low-temperature fixability, excellent offset resistance, and high robustness can be obtained.
Further, as the blocked isocyanate compound, an adduct-type blocked isocyanate compound is particularly useful. The heat received when the toner is fixed is smaller as the toner has better low-temperature fixability. Therefore, with a polyisocyanate having a structure like a simple diisocyanate, the reaction with the hydroxyl group due to the heat received during fixing becomes insufficient. It is considered that sufficient high elasticity does not progress. Further, as a block type isocyanate, isocyanurate type and biuret type are known as trimers in addition to adduct type, but the adduct type is structurally more flexible than others, so that toner is fixed. It is considered that the useful reason is that the bond formation reaction with the polyester resin is likely to occur even with the short-time heat received during the process.
Further, when the polyester resin has a structural unit derived from a trivalent or higher carboxylic acid, a branched structure is introduced into the polyester resin, and when a crosslinked structure is formed, a structure having more excellent elasticity can be obtained. Conceivable.

Definitions of various terms in the present specification are shown below.
In the specification, the carboxylic acid component of the polyester resin includes not only the compound but also an anhydride that decomposes during the reaction to produce a carboxylic acid, and an alkyl ester of each carboxylic acid (alkyl group having 1 or more carbon atoms and 3 carbon atoms). The following) is also included.
The "volume medium particle size (D ₅₀ )" is a particle size in which the cumulative volume frequency calculated by the volume fraction is 50% calculated from the smaller particle size.
The coefficient of variation of the particle size distribution (hereinafter, also simply referred to as “CV value”) is a value represented by the following formula. The volume average particle size in the following formula is the particle size obtained by multiplying the particle size measured on a volume basis by the ratio of particles having that particle size value and dividing the value obtained by that by the number of particles. is there.
CV value (%) = [standard deviation of particle size distribution (μm) / volume average particle size (μm)] × 100

The method for producing a toner according to an embodiment of the present invention includes, for example, a step of aggregating resin particles containing a polyester resin and a blocked isocyanate compound to obtain agglomerated particles (hereinafter, also referred to as “step 1”), and the same. A step of fusing the agglomerated particles (hereinafter, also referred to as “step 2”) is provided in this order.
The polyester-based resin has a structural unit derived from a polyol and a structural unit derived from a polycarboxylic acid, and the structural unit derived from the polycarboxylic acid contains a structural unit derived from a trivalent or higher carboxylic acid. To do. Further, the hydroxyl value of the polyester resin is 5 mgKOH / g or more.
Further, the blocked isocyanate is an adduct-type blocked isocyanate, and is produced at a temperature equal to or lower than the dissociation temperature of the blocking agent of the blocked isocyanate in all subsequent steps after adding the blocked isocyanate.
That is, the toner for developing an electrostatic charge image of the present invention is preferably produced by the above method, and each component such as a polyester resin and a blocked isocyanate compound is common.
Hereinafter, the present invention will be described by taking the embodiment as an example.

<Step 1>
[Resin particle dispersion]
The resin particles used in step 1 (hereinafter, also referred to as “resin particles X”) contain a polyester resin and a blocked isocyanate compound.
The polyester resin contains a structural unit derived from a trivalent or higher carboxylic acid. Further, the hydroxyl value of the polyester resin is 5 mgKOH / g or more. Hereinafter, the polyester resin used for the toner of the present invention, which contains a structural unit derived from a trivalent or higher carboxylic acid and has a hydroxyl value of 5 mgKOH / g or more, is also referred to as "polyester resin A".
The polyester resin A is, for example, a polyester resin which is a polycondensate of an alcohol component and a carboxylic acid component.
Examples of the polyester resin A include a polyester resin and a modified polyester resin. Examples of the modified polyester resin include a urethane modified product of the polyester resin, an epoxy modified product of the polyester resin, and a composite resin containing a polyester resin segment and an addition polymerization resin segment. Among these, a polyester resin which is a polycondensate of an alcohol component and a carboxylic acid component is preferable.

Examples of the alcohol component include an alkylene oxide adduct of an aromatic diol, a linear or branched aliphatic diol, an alicyclic diol, and a trihydric or higher polyhydric alcohol. Among these, an alkylene oxide adduct of an aromatic diol is preferable from the viewpoint of obtaining a toner having excellent low temperature fixability.
The alkylene oxide adduct of the aromatic diol is preferably the alkylene oxide adduct of bisphenol A, more preferably of the formula (I) :.

(In the formula, OR ¹ and R ² O are oxyalkylene groups, R ¹ and R ² are independently ethylene or propylene groups, and x and y indicate the average number of moles of alkylene oxide added, respectively, which are positive. The value of the sum of x and y is 1 or more, preferably 1.5 or more, 16 or less, preferably 8 or less, and more preferably 4 or less) alkylene of bisphenol A. It is an oxide adduct.

Examples of the alkylene oxide adduct of bisphenol A include a propylene oxide adduct of bisphenol A (2,2-bis (4-hydroxyphenyl) propane) and an ethylene oxide adduct of bisphenol A. These may be used alone or in combination of two or more.
In the present invention, the ratio of the structural unit derived from the ethylene oxide adduct of bisphenol A to the total of the structural unit derived from the propylene oxide adduct of bisphenol A and the structural unit derived from the ethylene oxide adduct of bisphenol A is an isocyanate group. From the viewpoint of reactivity with and above, it is preferably 50 mol% or more, more preferably 70 mol% or more, further preferably 90 mol% or more, 100 mol% or less, still more preferably 100 mol%.
The content of the alkylene oxide adduct of bisphenol A is preferably 70 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more, and 100 mol% or less in the alcohol component. Even more preferably, it is 100 mol%.

Examples of the linear or branched aliphatic diol include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butanediol. , 2,3-Butanediol, 2,2-dimethyl-1,3-propanediol (also known as neopentyl glycol), 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1, , 10-decanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol.
Examples of the alicyclic diol include hydrogenated bisphenol A (2,2-bis (4-hydroxycyclohexyl) propane) and an alkylene oxide adduct having 2 or more and 4 or less carbon atoms of hydrogenated bisphenol A (average addition molar number 2). 12 or less).
Examples of other diol components include 1,2-propylene glycol.
Examples of the trihydric or higher polyhydric alcohol include glycerin, pentaerythritol, trimethylolpropane, and sorbitol.
As these alcohol components, one kind or two or more kinds may be used.

Examples of the carboxylic acid component include a dicarboxylic acid and a trivalent or higher valent carboxylic acid.
Examples of the dicarboxylic acid include aromatic dicarboxylic acid, linear or branched aliphatic dicarboxylic acid, and alicyclic dicarboxylic acid. Among these, at least one selected from aromatic dicarboxylic acids and linear or branched aliphatic dicarboxylic acids is preferable.
Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid and terephthalic acid are preferable, and terephthalic acid is more preferable.
The amount of the aromatic dicarboxylic acid is preferably 20 mol% or more, more preferably 30 mol% or more, still more preferably 40 mol% or more, still more preferably 50 mol% or more, and preferably 50 mol% or more in the carboxylic acid component. It is 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less.

The linear or branched aliphatic dicarboxylic acid preferably has 2 or more carbon atoms, more preferably 3 or more carbon atoms, and preferably 30 or less, more preferably 20 or less carbon atoms.
Examples of the linear or branched aliphatic dicarboxylic acid include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, and tetradecanedi. Examples thereof include acid, azelaic acid, and succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms. Examples of the succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms include dodecyl succinic acid, dodecenyl succinic acid, and octenyl succinic acid. Among these, fumaric acid, sebacic acid, and succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms are preferable.
The amount of the linear or branched aliphatic dicarboxylic acid is preferably 1 mol% or more, more preferably 3 mol% or more, still more preferably 5 mol% or more, and preferably 80 mol% or more in the carboxylic acid component. Below, it is more preferably 50 mol% or less, still more preferably 30 mol% or less.

The trivalent or higher valent carboxylic acid is preferably a trivalent carboxylic acid, and examples thereof include trimellitic acid. It is preferably trimellitic acid or an anhydride thereof.
In the present invention, the structural unit derived from a carboxylic acid has a structural unit derived from a trivalent or higher carboxylic acid. By having a structural unit derived from a trivalent or higher carboxylic acid, a branched chain can be introduced into the polyester resin, and when a crosslinked structure is formed by reaction with a blocked isocyanate compound, the elasticity is more excellent. A structure is obtained, and a more robust image is obtained.
The amount of the trivalent or higher polyvalent carboxylic acid is preferably 3 mol% or more, more preferably 5 mol% or more, still more preferably 8 mol% or more, and preferably 30 mol% or less in the carboxylic acid component. , More preferably 25 mol% or less, still more preferably 20 mol% or less, still more preferably 15 mol% or less.
One kind or two or more kinds of these carboxylic acid components may be used.

The equivalent ratio of the carboxy group of the carboxylic acid component to the hydroxyl group of the alcohol component [COOH group / OH group] is preferably 0.7 or more, more preferably 0.8 or more, and preferably 1.3 or less. It is preferably 1.2 or less.

The polyester resin A may be produced, for example, by a method including a step A of polycondensing an alcohol component and a carboxylic acid component.
In step A, if necessary, an esterification catalyst such as di (2-ethylhexanoic acid) tin (II), dibutyltin oxide, and titanium diisopropylate bistriethanolaminate is used as a total amount of 100 alcohol components and carboxylic acid components. 0.01 part by mass or more and 5 parts by mass or less with respect to parts by mass; an esterification cocatalyst such as gallic acid (same as 3,4,5-trihydroxybenzoic acid) is used as a total amount of 100 parts by mass of alcohol component and carboxylic acid component. Polycondensation may be carried out using 0.001 part by mass or more and 0.5 part by mass or less with respect to the parts.
When a monomer having an unsaturated bond such as fumaric acid is used for polycondensation, it is preferably 0.001 part by mass or more with respect to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component, if necessary. A radical polymerization inhibitor of 0.5 parts by mass or less may be used. Examples of the radical polymerization inhibitor include 4-tert-butylcatechol.
The temperature of the polycondensation reaction is preferably 120 ° C. or higher, more preferably 160 ° C. or higher, further preferably 180 ° C. or higher, and preferably 250 ° C. or lower, more preferably 240 ° C. or lower. The polycondensation may be carried out in an inert gas atmosphere.

≪Physical properties of polyester resin A≫
The softening point of the polyester resin A is preferably 70 ° C. or higher, more preferably 90 ° C. or higher, further preferably 100 ° C. or higher, and preferably 150 ° C. or lower from the viewpoint of further improving low temperature fixability. It is preferably 140 ° C. or lower, more preferably 125 ° C. or lower.
The glass transition temperature of the polyester resin A is preferably 30 ° C. or higher, more preferably 35 ° C. or higher, further preferably 40 ° C. or higher, and preferably 80 ° C. or lower from the viewpoint of further improving low temperature fixability. It is more preferably 70 ° C. or lower, still more preferably 65 ° C. or lower.

The hydroxyl value of the polyester resin A is preferably 5 mgKOH / or more, more preferably 10 mgKOH / g or more, still more preferably 15 mgKOH, from the viewpoint of reactivity with the blocked (deprotected) blocked isocyanate compound in which the blocking agent is dissociated. It is / g or more, and preferably 50 mgKOH / g, more preferably 45 mgKOH / g or less, still more preferably 40 mgKOH / g or less, still more preferably 35 mgKOH / g or less.
The acid value of the polyester resin A is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, still more preferably 15 mgKOH / g or more, and preferably 40 mgKOH / g or less, more preferably 35 mgKOH / g or less. , More preferably 30 mgKOH / g or less.
The softening point, glass transition temperature, hydroxyl value, and acid value of the polyester resin A can be appropriately adjusted depending on the type and amount of the raw material monomer used, and the production conditions such as reaction temperature, reaction time, and cooling rate. Moreover, those values are obtained by the method described in Examples.
When two or more kinds of polyester resins A are used in combination, it is preferable that the softening point, the glass transition temperature, the hydroxyl value and the acid value obtained as a mixture thereof are within the above ranges.

In the present invention, two or more kinds of polyester-based resins may be used in combination as the polyester-based resin, and in addition to the polyester-based resin A, for example, a constituent unit derived from a trivalent or higher carboxylic acid is provided. A polyester resin may be used in combination, and the present invention is not particularly limited. Further, as the binder resin, in addition to the polyester resin, another resin such as an addition polymerization resin may be contained.
The content of the polyester-based resin A is preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more, still more preferably, with respect to the total amount of the resin components of the resin particles X. Is 70% by mass or more, more preferably 90% by mass or more, and 100% by mass or less, and may be 100% by mass.

(Blocked isocyanate compound)
The blocked isocyanate compound is a polyisocyanate compound such as a diisocyanate compound in which the isocyanate group is protected by a heat-dissociable blocking agent. In the present invention, an adduct-type blocked isocyanate compound is used as the blocked isocyanate compound. There are various blocked isocyanates such as biuret type, isocyanurate type, adduct type, and bifunctional type as the blocked isocyanate, but by using the adduct type blocked isocyanate compound as the blocked isocyanate compound, it is resistant. A toner having excellent hot offset property and excellent image fastness can be obtained.

The adduct-type polyisocyanate compound can be obtained, for example, by reacting a diisocyanate compound with a polyhydric alcohol having three or more hydroxyl groups.
The diisocyanate compound is not particularly limited as long as it is a compound having two isocyanate groups (also referred to as isocyanato groups). For example, ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, and the carboxy group of dimer acid were converted into isocyanate groups. Aliper diisocyanates such as dimerge diisocyanate; 1,4-cyclohexanediisocyanate, isophorone diisocyanate, 1-methyl-2,4-cyclohexanediisocyanate, 1-methyl-2,6-cyclohexanediisocyanate, 4,4'-dicyclohexylmethane diisocyanate, And alicyclic diisocyanates such as 1,3-bis (isocyanatemethyl) cyclohexane; xylylene diisocyanate, 4,4'-diphenyl diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene. Diisocyanate, p-phenylenediocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyldiisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,5-naphthylene diisocyanate , 3,3'-dimethyl-4,4'-biphenylenediocyanate, polymethylenepolyphenylene polyisocyanate, phenylenediisocyanate, and aromatic diisocyanates such as m-tetramethylxylylene diisocyanate; aliphatic diisocyanates, alicyclic diisocyanates , And a diisocyanate compound having a uretdione structure, which is a dimer of at least one diisocyanate selected from the group consisting of aromatic diisocyanates; consisting of aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates. A diisocyanate compound having an allophanate structure using at least one diisocyanate selected from the group; and at least one diisocyanate selected from the group consisting of aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates. Examples thereof include diisocyanate compounds having a urea structure.
Among these, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate are preferably exemplified, and hexamethylene diisocyanate is more preferable, from the viewpoint of reactivity and availability.

Examples of polyhydric alcohols include glycerin, trimethylolpropane, pentaerythritol, diglycerin, dipentaerythritol, D-threitol, L-arabinitol, libitol, xylitol, sorbitol, mannitol, galactitol, ramnitol, arabinose, and ribose. Examples thereof include xylose, glucose, mannitol, galactose, fructose, sorbitol, lambnorth, fucose, ribodesose, trehalose, sucrose, maltose, cellobiose, gentiobiose, lactose, melibiose, raffinose, gentianose, meletitol and stachiose. These may be used alone or in combination of two or more.
Of these, trimethylolpropane is preferable from the viewpoint of availability and reactivity.
As the polyisocyanate compound having an adduct structure, a reaction product of trimethylolpropane and hexamethylene diisocyanate is particularly preferable.

The blocking agent is thermally dissociable and is not particularly limited as long as it is generally used. For example, an oxime type such as formaldehyde, acetoaldoxime, acetooxime, methylethylketone oxime, cyclohexanone oxime; methanol, Alcohol types such as ethanol, 2-propanol, n-butanol, sec-butanol, 2-ethyl-1-hexanol, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol; acetoanilide, acetate amide, ε-caprolactam, Acid amide type such as δ-valerolactam, γ-butyrolactam; Acid imide type such as succinateimide and maleateimide; Phenol, cresol, ethylphenol, butylphenol, nonylphenol, dinonylphenol, styrene phenol, hydroxybenzoic acid ester, etc. Phenol type; amine type such as diphenylamine, aniline, carbazole, di-n-propylamine, diisopropylamine, isopropylethylamine; active oxime type such as dimethyl malate, diethyl malonate, methyl acetoacetate, ethyl acetoacetate, acetylacetone; Examples thereof include imidazole types such as imidazole and 2-methylimidazole; pyrazole types such as pyrazole, 3-methylpyrazole and 3,5-dimethylpyrazole; and the like. These may be used alone or in combination of two or more.
Among these, in consideration of application to toner, a blocking agent that dissociates at a low temperature is preferable, pyrazole type and oxime type are more preferable, and 3,5-dimethylpyrazole (simply also referred to as dimethylpyrazole) and methylethylketone oxime are further preferable. ..

The dissociation temperature of the blocking agent in the blocked isocyanate compound is from the viewpoint of suppressing the dissociation of the blocking agent during the production of the toner, and promotes the dissociation of the blocking agent during the fixing of the toner, and reacts with the hydroxyl group of the polyester resin to crosslink. From the viewpoint of forming, it is preferably 100 ° C. or higher, more preferably 105 ° C. or higher, further preferably 110 ° C. or higher, and preferably 160 ° C. or lower, more preferably 150 ° C. or lower, still more preferably 140 ° C. or lower. ..

As the blocked isocyanate compound, a commercially available product may be used. Specifically, Tosoh Corporation, Coronate series; Showa Denko Corporation, Karenz series; Asahi Kasei Corporation, Duranate series; Examples include Baxenden, Trixene series; Meisei Kagaku Kogyo Co., Ltd., Meikanate series; Evonik, Vestagon series; Daiichi Kogyo Seiyaku Co., Ltd., Elastron series and the like.

The amount of the blocked isocyanate compound in the resin particles is such that the ratio of the isocyanate groups (NCO groups) in the blocked isocyanate compound to the hydroxyl groups (OH groups) of the polyester resin is preferably 0.4 or more. It is preferably 0.7 or more, more preferably 0.9 or more, and preferably 2.0 or less, more preferably 1.5 or less, still more preferably 1.2 or less.

(Manufacturing method of resin particle dispersion)
The resin particles X containing the polyester resin and the blocked isocyanate compound can be obtained by a known method such as a suspension method, a solvent inversion phase emulsification method, or a forced emulsification method. From the viewpoint of stably obtaining fine emulsified particles, it is preferable to obtain them by a solvent inversion phase emulsification method.
Further, in the step of obtaining the resin particles X, it is preferable to carry out the process at a temperature lower than the temperature at which the blocking agent of the blocked isocyanate is dissociated, preferably 95 ° C. or lower, more preferably 80 ° C. or lower, still more preferably 75 ° C. or lower. ..
Examples of the phase inversion emulsification method include a method in which an aqueous medium is added to an organic solvent solution of a resin for phase inversion emulsification.

The organic solvent used for phase inversion emulsification is not particularly limited as long as the resin is dissolved, but from the viewpoint of facilitating phase inversion, for example, alcohol solvents such as ethanol, isopropanol and isobutanol; acetone, methyl ethyl ketone and methyl isobutyl ketone. , Diethyl ketone and other ketone solvents; ether solvents such as dibutyl ether, tetrahydrofuran and dioxane; and acetate ester solvents such as ethyl acetate and isopropyl acetate. Among these, a ketone solvent and an acetate ester solvent are preferable, and methyl ethyl ketone, ethyl acetate, and isopropyl acetate are more preferable, from the viewpoint of easy removal from the mixed solution after the addition of the aqueous medium.
It is preferable to add a neutralizing agent to the organic solvent solution. Examples of the neutralizing agent include basic substances. Examples of the basic substance include hydroxides of alkali metals such as sodium hydroxide and potassium hydroxide; and nitrogen-containing basic substances such as ammonia, trimethylamine and diethanolamine.
The equivalent amount (mol%) of the neutralizing agent to the acid group of the polyester resin contained in the resin particles X is preferably 10 mol% or more from the viewpoint of obtaining fine resin particles and improving dispersion stability. , More preferably 30 mol% or more, further preferably 40 mol% or more, and preferably 90 mol% or less, more preferably 70 mol% or less.
The equivalent amount (mol%) of the neutralizing agent used can be calculated by the following formula. When the equivalent amount of the neutralizing agent is 100 mol% or less, it is synonymous with the degree of neutralization.
Equivalent to use of neutralizer (mol%) = [{Equivalent mass of neutralizer (g) / Equivalent of neutralizer} / [{Weighted average acid value of resin constituting resin particles X (mgKOH / g) × Mass of resin constituting resin particles X (g)} / (56 × 1000)]] × 100

In the present invention, it is preferable to dissolve the polyester resin in an organic solvent, neutralize it if necessary, and then add the blocked isocyanate compound.
From the viewpoint of suppressing the dissociation of the blocking agent from the blocked isocyanate compound, it is preferable to add the blocked isocyanate compound after neutralizing the polyester resin.
After the addition of the blocked isocyanate compound, it is preferable to stir sufficiently so that the blocked isocyanate is dissolved in the organic solvent.
In the present invention, in all the steps thereafter after adding the blocked isocyanate, the production is carried out at a temperature equal to or lower than the dissociation temperature of the blocking agent of the blocked isocyanate compound. As a result, isocyanate groups protected by the blocking agent are present in the toner, the blocking agent dissociates when the toner is fixed, and the toner functions as a cross-linking agent for the polyester resin contained in the toner, resulting in a more robust image. Is obtained.

Next, while stirring the organic solvent solution, an aqueous medium is gradually added to invert the phase.
The temperature of the organic solvent solution during stirring and mixing when the aqueous medium is added and the temperature in the system after the addition of the aqueous medium are determined from the viewpoint of improving dispersion stability and suppressing dissociation of the blocking agent from the blocked isocyanate compound. It is preferably 10 ° C. or higher, more preferably 15 ° C. or higher, still more preferably 20 ° C. or higher, and preferably 90 ° C. or lower, more preferably 85 ° C. or lower, still more preferably 80 ° C. or lower, still more preferably 75 ° C. or lower. Is.

After the phase inversion emulsification, if necessary, the organic solvent may be removed from the obtained dispersion by distillation or the like.
The temperature in the system during distillation is preferably 30 ° C. or higher, more preferably 50 ° C. or higher, still more preferably 60 ° C. or higher, from the viewpoint of efficiently removing the organic solvent and suppressing dissociation of the blocking agent. It is still more preferably 65 ° C. or higher, even more preferably 70 ° C. or higher, and preferably 90 ° C. or lower, more preferably 85 ° C. or lower, still more preferably 80 ° C. or lower, still more preferably 75 ° C. or lower.
In this case, the residual amount of the organic solvent is preferably 1% by mass or less, more preferably 0.5% by mass or less, and further preferably substantially 0% by mass in the dispersion liquid.

The volume median particle diameter (D ₅₀ ) of the resin particles X in the dispersion is preferably 0.05 μm or more, more preferably 0.08 μm or more, and more preferably 0.08 μm or more, from the viewpoint of obtaining a toner that can obtain a high-quality image. It is preferably 0.8 μm or less, more preferably 0.4 μm or less, still more preferably 0.3 μm or less.
The CV value of the resin particles X in the dispersion is preferably 10% or more, more preferably 20% or more, and preferably 40% or less, more preferably, from the viewpoint of obtaining a toner that can obtain a high-quality image. Is 35% or less, more preferably 30% or less.
The volume median particle diameter (D ₅₀ ) and CV value of the resin particles are determined by the method described in Examples described later.

In step 1, the colorant particles Z and the release agent particles W can be aggregated together with the resin particles X, if necessary.

[Colorant particle dispersion]
In step 1, the colorant particles Z containing the colorant may be aggregated together with the resin particles X.
As the colorant, all of the dyes, pigments and the like used as the colorant for toner can be used.
Examples of the colorants include carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, and disazoero. Be done. The toner may be either black toner or color toner other than black.

The content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 5 parts by mass or more with respect to 100 parts by mass of the polyester resin from the viewpoint of improving the image density of the toner. Yes, and preferably 40 parts by mass or less, more preferably 30 parts by mass or less, still more preferably 20 parts by mass or less, still more preferably 10 parts by mass or less.

(Manufacturing of dispersion of colorant particles)
The colorant is preferably contained in the agglomerated particles 1 by mixing with the resin particles X and aggregating the colorant as a dispersion liquid of the colorant particles Z.
The dispersion liquid of the colorant particles Z is preferably obtained by dispersing the colorant and an aqueous medium using a disperser such as a homogenizer or an ultrasonic disperser. The dispersion is preferably carried out in the presence of a surfactant from the viewpoint of improving the dispersion stability of the colorant. Examples of the surfactant include nonionic surfactants, anionic surfactants, and cationic surfactants, and from the viewpoint of improving the dispersion stability of the colorant particles Z, an anionic surfactant is preferable. It is an activator. Examples of the anionic surfactant include dodecylbenzene sulfonate, dodecyl sulfate, lauryl ether sulfate, and alkenyl succinate. Of these, dodecylbenzene sulfonate is preferred.

The content of the surfactant in the dispersion liquid of the colorant particles Z is preferably 1 part by mass or more, more preferably 5 parts by mass with respect to 100 parts by mass of the colorant from the viewpoint of improving the dispersion stability of the colorant. More than parts, more preferably 10 parts by mass or more, and preferably 40 parts by mass or less, more preferably 30 parts by mass or less.

The volume median particle diameter (D ₅₀ ) of the colorant particles Z is preferably 0.05 μm or more, more preferably 0.08 μm or more, still more preferably 0.1 μm or more, and preferably 0.3 μm or less. More preferably, it is 0.2 μm or less.
The method for measuring the volume median particle diameter (D ₅₀ ) of the colorant particles Z is as described in Examples.

[Release agent particle dispersion]
In step 1, the release agent particles W containing the release agent may be aggregated together with the resin particles X.
Examples of the release agent include hydrocarbon waxes such as polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax; microcrystalin wax, paraffin wax, Fishertropch wax, sazole wax and other hydrocarbon waxes or oxides thereof; carnauba wax. , Montan wax or ester waxes such as deoxidizing waxes and fatty acid ester waxes; fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts and the like. These may be used alone or in combination of two or more.

The melting point of the release agent is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and preferably 160 ° C. or lower, more preferably 150 ° C. or lower, still more preferably 140 ° C. or lower.
The content of the release agent in the toner is preferably 0.1% by mass or more, more preferably 1% by mass or more, further preferably 3% by mass or more, and preferably 20% by mass or less, more preferably 20% by mass or less. It is 15% by mass or less.

(Manufacturing method of release agent particle dispersion)
The release agent is preferably contained in the agglomerated particles by mixing with the resin particle dispersion and aggregating the release agent particles W as a dispersion.
The dispersion liquid of the release agent particles W can be obtained by using a surfactant, but it is preferably obtained by mixing the release agent and the resin particles P described later. By preparing the release agent particles W using the release agent and the resin particles P, the release agent particles W are stabilized by the resin particles P, and the release agent can be used as an aqueous medium without using a surfactant. It becomes possible to disperse in. It is considered that the dispersion liquid of the release agent particles W has a structure in which a large number of resin particles P are attached to the surface of the release agent particles W.
The type and amount of the release agent added are the same as those of the above-mentioned release agent.

The resin constituting the resin particles P in which the release agent is dispersed is preferably a polyester resin, and has a polyester resin segment and an addition polymerization resin segment from the viewpoint of improving the dispersibility of the release agent in an aqueous medium. It is more preferable to use the composite resin D.
Examples of the alcohol component and the carboxylic acid component used in the polyester resin segment of the composite resin D include the alcohol component and the carboxylic acid component exemplified in the polyester resin A.
Further, the addition polymerization resin segment of the composite resin D is, for example, an addition polymerization of a raw material monomer containing a styrene compound.
Examples of the styrene-based compound include unsubstituted or substituted styrene. Examples of the substituent substituted with styrene include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group having 1 to 5 carbon atoms, a sulfonic acid group or a salt thereof.
Examples of the styrene-based compound include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrenesulfonic acid or salts thereof. Of these, styrene is preferable.
The content of the styrene-based compound in the raw material monomer of the addition polymerization resin segment is preferably 50% by mass or more, more preferably 65% by mass or more, further preferably 75% by mass or more, and 100% by mass or less. It is preferably 95% by mass or less, more preferably 90% by mass or less, and further preferably 85% by mass or less.

Examples of the raw material monomer other than the styrene compound include (meth) acrylic acid esters such as alkyl (meth) acrylate, benzyl (meth) acrylate, and dimethylaminoethyl (meth) acrylate; ethylene, propylene, and butadiene. Olefins; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether; vinylidene halides such as vinylidene chloride; N-vinyl compounds such as N-vinylpyrrolidone. .. Among these, (meth) acrylic acid ester is preferable, and alkyl (meth) acrylic acid is more preferable.
The number of carbon atoms of the alkyl group in the alkyl (meth) acrylate is preferably 1 or more, more preferably 6 or more, still more preferably 10 or more, and preferably 24 or less, more preferably 22 or less, still more preferably 20. It is as follows.
Examples of the alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, (iso) propyl (meth) acrylate, (iso or tertiary) butyl (meth) acrylate, and (meth). ) Acrylic acid (iso) amyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid 2-ethylhexyl, (meth) acrylic acid (iso) octyl, (meth) acrylic acid (iso) decyl, (meth) acrylic acid ( Examples include iso) dodecyl, (meth) acrylic acid (iso) palmityl, (meth) acrylic acid (iso) stearyl, (meth) acrylic acid (iso) behenyl, and the like, 2-ethylhexyl (meth) acrylic acid or (meth). Stearyl acrylate is preferred, and stearyl (meth) acrylate is more preferred.
In addition, "(iso or tertiary)" and "(iso)" mean both the case where these prefixes exist and the case where these prefixes do not exist, and when these prefixes do not exist, it indicates a normal. Further, "(meth) acrylic acid" indicates acrylic acid or methacrylic acid.

The content of the (meth) acrylic acid ester in the raw material monomer of the addition polymerization resin segment is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 15% by mass or more, and preferably 50% by mass or more. It is mass% or less, more preferably 35 mass% or less, still more preferably 25 mass% or less.
The total amount of the styrene compound and the (meth) acrylic acid ester in the raw material monomer of the addition polymerization resin segment is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, still more. It is preferably 100% by mass.

The composite resin D preferably has a structural unit derived from a bireactive monomer bonded to the polyester resin segment and the addition polymerization resin segment via a covalent bond.
The “constituent unit derived from the bireactive monomer” means a unit in which the functional group and the addition polymerizable group of the bireactive monomer have reacted.
Examples of the addition-polymerizable group include a carbon-carbon unsaturated bond (ethylenically unsaturated bond).
Examples of the bireactive monomer include an addition-polymerizable monomer having at least one functional group selected from a hydroxyl group, a carboxy group, an epoxy group, a primary amino group and a secondary amino group in the molecule. .. Among these, from the viewpoint of reactivity, an addition-polymerizable monomer having at least one functional group selected from a hydroxyl group and a carboxy group is preferable, and an addition-polymerizable monomer having a carboxy group is more preferable.
Examples of the addition-polymerizable monomer having a carboxy group include acrylic acid, methacrylic acid, fumaric acid, and maleic acid. Among these, acrylic acid and methacrylic acid are preferable, and acrylic acid is more preferable, from the viewpoint of reactivity of both the polycondensation reaction and the addition polymerization reaction.
When both reactive monomers are addition polymerizable monomers having a carboxy group, the amount of the structural unit derived from both reactive monomers is preferably 1 mol with respect to 100 mol parts of the alcohol component of the polyester resin segment of the composite resin D. More than parts, more preferably 5 mol parts or more, still more preferably 8 mol parts or more, and preferably 30 mol parts or less, more preferably 25 mol parts or less, still more preferably 20 mol parts or less.

The content of the polyester resin segment in the composite resin D is preferably 35% by mass or more, more preferably 45% by mass or more, further preferably 50% by mass or more, and preferably 90% by mass or less, more preferably 90% by mass or less. It is 85% by mass or less, more preferably 75% by mass or less.

The content of the addition polymerized resin segment in the composite resin D is preferably 5% by mass or more, more preferably 15% by mass or more, further preferably 25% by mass or more, and preferably 60% by mass or less, more preferably. Is 55% by mass or less, more preferably 45% by mass or less.

The amount of the structural unit derived from the bireactive monomer in the composite resin D is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, still more preferably 0.8% by mass or more, and It is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 3% by mass or less.

The total amount of the constituent units derived from the polyester resin segment, the addition polymerization resin segment and the bireactive monomer in the composite resin D is preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more. Yes, and less than 100% by weight, and even more preferably 100% by weight.

The composite resin D may be produced by a method including a step A of polycondensing an alcohol component and a carboxylic acid component and a step B of addition polymerization of the raw material monomer and the bireactive monomer of the addition polymerization resin segment.
In the production of the composite resin D, step B may be performed after step A, step A may be performed after step B, or step A and step B may be performed at the same time.
In step A, a part of the carboxylic acid component is subjected to a polycondensation reaction, and then step B is carried out, and then the rest of the carboxylic acid component is added to the polymerization system, and the polycondensation reaction of step A and both reactions if necessary. A method of further advancing the reaction with the sex monomer is preferable.

The softening point of the composite resin D is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, and preferably 140 ° C. or lower, more preferably 120 ° C. or lower, still more preferably 100 ° C. or lower.
The preferred range of other resin properties of the composite resin D is the same as that shown in the polyester resin A. The dispersion liquid of the resin particles P can be obtained, for example, by the above-mentioned phase inversion emulsification method.
The volume median particle diameter D ₅₀ of the resin particles P is preferably 0.01 μm or more, more preferably 0.03 μm or more, and preferably 0.3 μm or less from the viewpoint of dispersion stability of the release agent particles. , More preferably 0.2 μm or less.
The CV value of the resin particles P is preferably 10% or more, more preferably 20% or more, and preferably 40% or less, more preferably 35% or less, from the viewpoint of dispersion stability of the release agent particles W. , More preferably 30% or less.

The release agent particle dispersion is, for example, a homogenizer, a high-pressure disperser, or an ultrasonic disperser in which a dispersion of a release agent and resin particles P and, if necessary, an aqueous medium are used at a temperature equal to or higher than the melting point of the release agent. It is obtained by dispersing using a disperser having a strong shearing force such as.
The heating temperature at the time of dispersion is preferably equal to or higher than the melting point of the release agent and 80 ° C. or higher, more preferably 85 ° C. or higher, further preferably 90 ° C. or higher, and preferably softening the resin contained in the resin particles P. The temperature is less than 10 ° C. higher than the point and 100 ° C. or lower, more preferably 98 ° C. or lower, still more preferably 95 ° C. or lower.

The amount of the resin particles P is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, further preferably 10 parts by mass or more, and preferably 70 parts by mass or less with respect to 100 parts by mass of the release agent. , More preferably 60 parts by mass or less, still more preferably 50 parts by mass or less.

The volume median particle diameter D ₅₀ of the release agent particles W is preferably 0.05 μm or more, more preferably 0.2 μm or more, still more preferably 0.3 μm or more, and from the viewpoint of obtaining uniform aggregated particles, and It is preferably 1 μm or less, more preferably 0.8 μm or less, and further preferably 0.6 μm or less.
The CV value of the release agent particles is preferably 10% or more, more preferably 20% or more, and preferably 40% or less, more preferably 35% or less, still more preferably 30% or less.
The method for measuring the volume median particle diameter D ₅₀ and the CV value of the release agent particles W is as described in Examples.

The aggregation of the resin particles X may be performed in the presence of other additives in addition to the colorant particles Z and the release agent particles W.
Examples of other additives include charge control agents, magnetic powders, fluidity improvers, conductivity modifiers, reinforcing fillers such as fibrous substances, antioxidants, antiaging agents, and cleanability improvers. ..

[Surfactant]
In step 1, when the dispersion liquid of each particle is mixed to prepare the mixed dispersion liquid, the dispersion stable of the resin particles X and any components such as the colorant particles Z and the release agent particles W added as needed. From the viewpoint of improving the properties, it may be carried out in the presence of a surfactant. Examples of the surfactant include anionic surfactants such as alkylbenzene sulfonates and alkyl ether sulfates; and nonionic surfactants such as polyoxyethylene alkyl ethers and polyoxyethylene alkenyl ethers.
When a surfactant is used, the amount used is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, and preferably 10 parts by mass with respect to 100 parts by mass of the resin particles X. Parts or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less.

The above-mentioned dispersion liquid of the resin particles X, the dispersion liquid of the colorant particles Z, the dispersion liquid of the release agent particles W, and the arbitrary component are mixed by a conventional method. From the viewpoint of efficient aggregation, it is preferable to add a flocculant to the mixed dispersion obtained by the mixing.

[Coagulant]
Examples of the flocculant include a cationic surfactant such as a quaternary salt, an organic flocculant such as polyethyleneimine, and an inorganic flocculant. Examples of the inorganic flocculant include inorganic metal salts such as sodium sulfate, sodium nitrate, sodium chloride, calcium chloride and calcium nitrate; inorganic ammonium salts such as ammonium sulfate, ammonium chloride and ammonium nitrate; and divalent or higher valent metal complexes. ..
From the viewpoint of improving the cohesiveness and obtaining uniform agglomerated particles, an inorganic flocculant of monovalent or higher and pentavalent or less is preferable, an inorganic metal salt of monovalent or higher and divalent or lower, an inorganic ammonium salt is more preferable, and an inorganic ammonium salt is preferable. More preferably, ammonium sulfate is even more preferable.

Using a flocculant, for example, in a mixed dispersion containing resin particles X at 0 ° C. or higher and 40 ° C. or lower and colorant particles Z, a flocculant of 5 parts by mass or more and 50 parts by mass or less is added to 100 parts by mass of the total amount of resin. Addition and agglomerate the resin particles X and the colorant particles Z in an aqueous medium to obtain agglomerated particles. Further, from the viewpoint of promoting aggregation, it is preferable to raise the temperature of the dispersion after adding the flocculant.

Aggregation may be stopped when the agglomerated particles have grown to an appropriate particle size as toner particles.
Examples of the method for stopping the aggregation include a method of cooling the dispersion, a method of adding an aggregation inhibitor, a method of diluting the dispersion, and the like. From the viewpoint of surely preventing unnecessary aggregation, a method of adding an aggregation terminator to stop aggregation is preferable.

[Coagulation terminator]
As the aggregation terminator, a surfactant is preferable, and an anionic surfactant is more preferable. Examples of the anionic surfactant include alkylbenzene sulfonate, alkyl sulfate, alkyl ether sulfate, polyoxyalkylene alkyl ether sulfate and the like. These may be used alone or in combination of two or more. The aggregation terminator may be added in an aqueous solution.
The amount of the aggregation terminator added is preferably 1 part by mass or more, more preferably 5 parts by mass or more, based on 100 parts by mass of the resin in the resin particles, from the viewpoint of surely preventing unnecessary aggregation. From the viewpoint of reducing the residue on the toner, it is preferably 60 parts by mass or less, more preferably 30 parts by mass or less, and further preferably 20 parts by mass or less.

Volume-median particle size _{D 50} of the aggregate particles is preferably 2μm or more, more preferably 3μm or more, more preferably 4μm or more, and, preferably 10μm or less, more preferably 8μm or less, more preferably at 6μm or less is there. Volume-median particle size D ₅₀ of the aggregate particles is obtained by the method described in Examples set forth below.

<Process 2>
In step 2, for example, the agglomerated particles are fused in an aqueous medium.
By fusion, each particle contained in the agglomerated particles is fused to obtain fused particles. Fusing is usually done in an aqueous medium.
The fusion temperature is preferably at least the glass transition temperature of the polyester resin A, more preferably at least 5 ° C. higher than the glass transition temperature of the polyester resin A, and even more preferably, from the viewpoint of efficiently promoting the fusion of the agglomerated particles. Is 10 ° C. or higher than the glass transition temperature of the polyester resin A, and preferably 30 ° C. or lower than the glass transition temperature of the polyester resin A, more preferably 25 ° C. higher than the glass transition temperature of the polyester resin A. It is as follows. However, from the viewpoint of suppressing the dissociation of the blocked isocyanate compound as described later, the fusion temperature is preferably equal to or lower than the dissociation temperature of the blocked isocyanate.
The volume median particle diameter D ₅₀ of the fused particles obtained by fusion is preferably 2 μm or more, more preferably 3 μm or more, further preferably 4 μm or more, and preferably 10 μm or less, more preferably 8 μm or less. , More preferably 6 μm or less.

The circularity of the fused particles obtained by fusion is preferably 0.955 or more, more preferably 0.960 or more, and preferably 0.990 or less, more preferably 0.985 or less, still more preferably. It is 0.980 or less.
The fusion is preferably completed after reaching the above-mentioned preferable circularity.

<Post-treatment process>
A post-treatment step may be performed after step 2, and toner particles are obtained by isolating the fused particles. Since the fused particles obtained in step 2 are present in the aqueous medium, it is preferable to first perform solid-liquid separation. A suction filtration method or the like is preferably used for solid-liquid separation.
It is preferable to perform cleaning after solid-liquid separation. At this time, since it is preferable to remove the added surfactant as well, it is preferable to wash with an aqueous medium below the cloud point of the surfactant. The washing is preferably performed a plurality of times.
Next, it is preferable to perform drying. Examples of the drying method include a vacuum low temperature drying method, a vibration type fluid drying method, a spray drying method, a freeze drying method, and a flash jet method.

In the present invention, it is preferable to produce the product at a dissociation temperature or lower of the blocked isocyanate in all subsequent steps after adding the blocked isocyanate compound, specifically, preferably 90 ° C. or lower, more preferably 85 ° C. or lower. , More preferably 80 ° C. or lower, and even more preferably 75 ° C. or lower.
By adding the blocked isocyanate compound to keep the subsequent production temperature within the above range, the dissociation of the blocked isocyanate compound during production can be suppressed, and the blocking agent is dissociated only at the time of fixing, and the isocyanate compound is dissociated. It is possible to cause a cross-linking reaction between the isocyanate group of the above and the hydroxyl group of the polyester resin. As a result, a toner having excellent low-temperature fixability, excellent hot offset resistance, and high image fastness can be obtained.

[Toner particles]
Volume-median particle size D ₅₀ of the toner particles, in view of obtaining a high quality image, from the viewpoint of improving the cleaning property of the toner, it is preferably 2μm or more, more preferably 3μm or more, more preferably 4μm or more, Then, it is preferably 10 μm or less, more preferably 8 μm or less, and further preferably 6 μm or less.
The circularity of the toner particles is preferably 0.955 or more, more preferably 0.960 or more, and preferably 0.990 or less, more preferably 0.985 or less, from the viewpoint of obtaining a high-quality image. More preferably, it is 0.980 or less.
Volume-median particle size D ₅₀ and circularity of the toner particles can be measured by the method described in Examples.

[toner]
The toner contains toner particles. The toner particles contain a polyester-based resin and a blocked isocyanate, and the polyester-based resin has a constituent unit derived from a polyol and a constituent unit derived from a polycarboxylic acid, and has a configuration derived from the polycarboxylic acid. The unit contains a structural unit derived from a trivalent or higher carboxylic acid, the polyester resin has a hydroxyl value of 5 mgKOH / g or higher, and the blocked isocyanate is an adduct-type blocked isocyanate.
Preferred embodiments of the polyester resin, blocked isocyanate compound and the like are as described above.

[External agent]
Although the toner particles can be used as they are as the toner, it is preferable to use the toner particles obtained by adding a fluidizing agent or the like as an external agent to the surface of the toner particles.
Examples of the external additive include fine particles of an inorganic material such as hydrophobic silica, titanium oxide, alumina, cerium oxide, and carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Of these, hydrophobic silica is preferred.
When the surface treatment of the toner particles is performed using an external additive, the amount of the external additive added is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and further preferably 2 parts by mass or more with respect to 100 parts by mass of the toner particles. It is 3 parts by mass or more, and preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less, and further preferably 4 parts by mass or less.

The fact that the electrostatic charge image developing toner of the present invention contains a blocked isocyanate can also be evaluated by improving the elasticity of the toner by heating. That is, at least a part of the blocked isocyanate is present in the toner in an undissociated state of the blocking agent, and the blocking agent is dissociated for the first time at the time of fixing to generate an isocyanate group, which reacts with the hydroxyl group of the polyester resin and crosslinks. Is formed to improve elasticity.
When the blocked isocyanate is dissociated before fixing and the reaction between the isocyanate group and the hydroxyl group of the polyester resin is in progress, such an improvement in toner elasticity is not observed by heating.
Specifically, it can be confirmed by DSC that the isocyanate group exists in the toner in a state where the blocking agent is bonded. When DSC measurement is performed on the blocked isocyanate compound, an exothermic peak associated with the dissociation of the blocking agent can be observed. By comparing the calorific value of the exothermic peak of the dissociation of the blocking agent with the calorific value of the exothermic peak when the toner containing the blocked isocyanate compound is measured, the amount of the isocyanate compound existing in the state where the blocking agent in the toner is bonded is compared. Can be obtained.
Furthermore, by measuring and comparing the molecular weight of the resin before toner conversion and the molecular weight of the resin after toner conversion, it is confirmed that there is no difference in the molecular weight before and after toner conversion, so that the isocyanate compound blocking agent can be used during toner conversion. It can also be confirmed that the cross-linking caused by the dissociation does not occur.

Toner is used for electrostatic charge image development in electrophotographic printing. The toner can be used, for example, as a one-component developer or mixed with a carrier as a two-component developer.

Hereinafter, the present invention will be described in more detail with reference to Examples and the like. In the following examples and the like, each physical property was measured by the following method.

[Measuring method]
[Acid value and hydroxyl value of resin]
The acid value and hydroxyl value of the resin were measured according to JIS K0070: 1992. However, the measurement solvent was a mixed solvent of acetone and toluene [acetone: toluene = 1: 1 (volume ratio)].

[Resin softening point, crystallinity index, melting point and glass transition temperature]
(1) Softening point Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), while heating 1 g of a sample at a heating rate of 6 ° C./min, a load of 1.96 MPa was applied by a plunger to give a diameter of 1.96 MPa. Extruded from a 1 mm, 1 mm long nozzle. The amount of plunger drop of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was used as the softening point.

(2) Glass transition temperature Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 g of a sample is weighed in an aluminum pan, and the temperature is raised to 200 ° C. The temperature was lowered to 0 ° C. at a temperature lowering rate of 10 ° C./min. Then, the temperature was raised at a temperature rising rate of 10 ° C./min, and the amount of heat was measured. Of the observed endothermic peaks, the peak temperature with the largest peak area was defined as the maximum endothermic peak temperature. The temperature at the intersection of the extension of the baseline below the maximum peak temperature of endothermic reaction and the tangent line indicating the maximum slope from the rising portion of the peak to the peak of the peak was defined as the glass transition temperature.

[Melting point of mold release agent]
Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 g of the sample is weighed in an aluminum pan, the temperature is raised to 200 ° C, and then the temperature is lowered from 200 ° C to 10 ° C. It was cooled to 0 ° C. at / min. Next, the sample was heated at a heating rate of 10 ° C./min, the amount of heat was measured, and the maximum peak temperature of endothermic reaction was taken as the melting point.

[Volume medium particle size (D ₅₀ ) and CV value of resin particles, mold release agent particles, and colorant particles]
(1) Measuring device: Laser diffraction type particle size measuring machine "LA-920" (manufactured by HORIBA, Ltd.)
(2) Measurement conditions: A sample dispersion was placed in a measurement cell, distilled water was added, and the volume median particle diameter (D ₅₀ ) and volume average particle diameter were measured at a concentration within an appropriate range of absorbance. The CV value was calculated according to the following formula.
CV value (%) = (standard deviation of particle size distribution / volume average particle size) x 100

[Solid concentration of resin particle dispersion, release agent particle dispersion, colorant particle dispersion]
Using an infrared moisture meter "FD-230" (manufactured by Ketsuto Scientific Research Institute Co., Ltd.), 5 g of the measurement sample was dried at a drying temperature of 150 ° C. and measured in measurement mode 96 (monitoring time 2.5 minutes, fluctuation range 0.05%). The water content (mass%) of the dispersion was measured. The solid content concentration was calculated according to the following formula.
Solid content concentration (mass%) = 100-moisture (mass%)

[Volume medium particle size of aggregated particles (D ₅₀ )]
The volume median particle size (D ₅₀ ) of the agglomerated particles was measured as follows.
-Measuring machine: "Coulter Multi-Sizar (registered trademark) III" (manufactured by Beckman Coulter Co., Ltd.)
・ Aperture diameter: 50 μm
-Analysis software: "Multisizer (registered trademark) III version 3.51" (manufactured by Beckman Coulter Co., Ltd.)
-Electrolytic solution: "Isoton (registered trademark) II" (manufactured by Beckman Coulter Co., Ltd.)
-Measurement conditions: By adding the sample dispersion to 100 mL of the electrolytic solution, the particle size of 30,000 particles is adjusted to a concentration that can be measured in 20 seconds, and then 30,000 particles are measured again and the particle size is measured. The volume median particle size (D ₅₀ ) was determined from the distribution.

[Circularity of toner particles]
The circularity of the toner particles was measured under the following conditions.
-Measuring device: Flow type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation)
-Preparation of dispersion: The dispersion of toner particles was prepared by diluting with deionized water so that the solid content concentration was 0.001 to 0.05% by mass.
-Measurement mode: HPF measurement mode

[Volume medium particle size of toner particles (D ₅₀ )]
The volume median particle diameter (D ₅₀ ) of the toner particles was measured as follows.
The measuring device, aperture diameter, analysis software, and electrolytic solution used were the same as those used in the above-mentioned measurement of the volume median particle diameter (D ₅₀ ) of the agglomerated particles.
Dispersion: Polyoxyethylene lauryl ether "Emargen (registered trademark) 109P" (manufactured by Kao Corporation, HLB (Hydrophile-Lipophile Balance) = 13.6) is dissolved in the electrolytic solution, and the concentration is 5% by mass. Got
-Dispersion conditions: 10 mg of a sample to be measured of dried toner particles is added to 5 mL of the dispersion liquid, dispersed for 1 minute with an ultrasonic disperser, then 25 mL of an electrolytic solution is added, and further, with an ultrasonic disperser. A sample dispersion was prepared by dispersing for 1 minute.
-Measurement conditions: By adding the sample dispersion to 100 mL of the electrolytic solution, the particle size of 30,000 particles is adjusted to a concentration that can be measured in 20 seconds, and then 30,000 particles are measured and the particle size is measured. The volume median particle size (D ₅₀ ) and volume average particle size were determined from the distribution.

[Evaluation method]
[Toner fixability (low temperature fixability) / hot offset resistance]
Using a commercially available printer "Microline (registered trademark) 5400" (manufactured by Oki Data Corporation) on high-quality paper "J paper A4 size" (manufactured by Fuji Xerox Co., Ltd.), the amount of toner adhered to the paper is 1.49 to 1. A solid image of .51 mg / cm ² was output with a length of 50 mm without fixing, leaving a margin of 5 mm from the upper end of the A4 paper. Next, the same printer in which the fuser was modified to have a variable temperature and a variable speed was prepared, the temperature of the fuser was set to 180 ° C., and the toner was fixed at a printing speed of 15 ppm in the A4 longitudinal direction to obtain a printed matter.
From the top margin of the printed matter to the solid image, lightly paste the mending tape "Scotch (registered trademark) Mending Tape 810" (manufactured by Sumitomo 3M Ltd., width 18 mm) cut to a length of 50 mm. After that, a weight of 500 g (contact area 1963 mm ² ) was placed and pressed once back and forth at a speed of 10 mm / s. Then, the attached tape was peeled off from the lower end side at a peeling angle of 180 ° and a speed of 10 mm / s to obtain a printed matter after the tape was peeled off. 30 sheets of high-quality paper "Excellent White Paper A4 size" (manufactured by Oki Data Co., Ltd.) are laid under the printed matter before and after the tape is applied, and the reflected image density of the fixed image part before and after the tape is applied to each printed matter is measured. , Colorimeter "SpectroEye" (manufactured by GretagMacbeth, light emission conditions; standard light source D50, observation field of view 2 °, density standard DINNB, absolute white standard), and the fixing rate from each reflected image density according to the following formula. Was calculated.
Fixing rate (%) = (Reflected image density after tape peeling / Reflected image density before tape application) x 100
When the fixing rate was 90% or more, it was judged that the fixing was possible.
In addition, the image of the printed matter was visually confirmed, and the presence or absence of an offset (hot offset) at 180 ° C. was also confirmed.

[Bending resistance]
The printed matter produced in the same manner as described above was bent so that the image was on the outside, a weight of 500 g was placed on the bent portion, and the printed matter was pressed back and forth once. After that, with the folded image opened and stretched, the mending tape "Scotch (registered trademark) mending tape 810" (manufactured by Sumitomo 3M Ltd., width 18 mm) was cut to a length of 50 mm with respect to the bent portion. After lightly pasting the object, a weight of 500 g (contact area 1963 mm ² ) was placed and pressed once back and forth at a speed of 10 mm / s. Then, the attached tape was peeled off from the lower end side at a peeling angle of 180 ° and a speed of 10 mm / s to obtain a printed matter after the tape was peeled off.
The bent portion after the tape was peeled off was visually confirmed and evaluated in the following five stages. The higher the score, the better the bending resistance.
<Evaluation criteria>
5 points No peeling is seen in the bent part.
There is a slight peeling on the bent line.
Along the three-point bent line, peeling with a width of less than 2 mm can be seen.
Along the two-point bent line, peeling with a width of 2 mm or more and less than 4 mm is observed.
Along the one-point bent line, peeling with a width of 4 mm or more can be seen.

[Manufacturing of resin]
Production Example A1 (Production of amorphous resin A1)
The inside of a four-necked flask with an internal volume of 10 L equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 5525 g of an ethylene oxide (2.2) adduct of bisphenol A, 1976 g of terephthalic acid, and di (di). Add 40 g of 2-ethylhexanoic acid) tin (II) and 4 g of gallic acid, raise the temperature to 235 ° C with stirring under a nitrogen atmosphere, hold at 235 ° C for 8 hours, and then lower the pressure in the flask. It was held at 8 kPa for 1 hour. Then, after returning to atmospheric pressure, the mixture was cooled to 180 ° C., 296 g of fumaric acid, 392 g of trimellitic anhydride, and 2.9 g of 4-tert-butylcatechol were added, and the temperature was raised to 220 ° C. at 10 ° C./hr. After that, the pressure in the flask was lowered, and the reaction was carried out at 10 kPa to a desired softening point to obtain an amorphous resin A1.

Production Example A2 (Production of amorphous resin A2)
The inside of a four-necked flask with an internal volume of 10 L equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple was replaced with nitrogen, and 3486 g of ethylene oxide (2.2) adduct of bisphenol A and propylene oxide of bisphenol A ( 2.2) Addition 2021 g, terephthalic acid 1917 g, di (2-ethylhexanoic acid) tin (II) 40 g, and gallic acid 4 g were added, and the temperature was raised to 235 ° C. with stirring under a nitrogen atmosphere at 235 ° C. After holding at 8 kPa for 8 hours, the pressure in the flask was lowered and held at 8 kPa for 1 hour. Then, after returning to atmospheric pressure, the mixture was cooled to 180 ° C., 287 g of fumaric acid, 317 g of trimellitic anhydride, and 2.9 g of 4-tert-butylcatechol were added, and the temperature was raised to 220 ° C. at 10 ° C./hr. After that, the pressure in the flask was lowered, and the reaction was carried out at 10 kPa to a desired softening point to obtain an amorphous resin A2.

Production Example A3 (Production of amorphous resin A3)
Nitrogen was substituted inside a four-necked flask with an internal volume of 10 L equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple, and 2034 g of a propylene oxide (2.2) adduct of bisphenol A and ethylene oxide of bisphenol A ( 2.2) Addition 3507 g, terephthalic acid 1929 g, di (2-ethylhexanoic acid) tin (II) 40 g, and gallic acid 4 g were added, and the temperature was raised to 235 ° C. with stirring under a nitrogen atmosphere at 235 ° C. After holding at 8 kPa for 8 hours, the pressure in the flask was lowered and held at 8 kPa for 1 hour. Then, after returning to atmospheric pressure, the mixture was cooled to 180 ° C., 578 g of fumaric acid and 5.8 g of 4-tert-butylcatechol were added, the temperature was raised to 220 ° C. at 10 ° C./hr, and then the pressure in the flask was increased. The reaction was carried out at 10 kPa to a desired softening point to obtain an amorphous resin A3.

Production Example D1 (Production of amorphous resin D1)
Nitrogen-substituted bisphenol A propylene oxide (2.2) adduct 4313 g, terephthalic acid 818 g, succinic acid inside a 10 L four-necked flask equipped with a nitrogen introduction tube, dehydration tube, stirrer, and thermocouple. 727 g of acid, 30 g of di (2-ethylhexanoic acid) tin (II), and 3 g of gallic acid were added, the temperature was raised to 235 ° C with stirring under a nitrogen atmosphere, and the temperature was maintained at 235 ° C for 5 hours, and then in the flask. The pressure was lowered and the mixture was held at 8 kPa for 1 hour. Then, after returning to atmospheric pressure, the mixture was cooled to 160 ° C. and kept at 160 ° C., and a mixture of 2755 g of styrene, 689 g of stearyl methacrylate, 142 g of acrylic acid, and 413 g of dibutyl peroxide was added dropwise over 1 hour. Then, after holding the temperature at 160 ° C. for 30 minutes, the temperature was raised to 200 ° C., the pressure in the flask was further lowered, and the reaction was carried out at 8 kPa to a desired softening point to obtain an amorphous resin D1. Various physical properties of the resin were measured and shown in Table 1.

[Manufacturing of resin particle dispersion]
Production Example X1 (Production of Resin Particle Dispersion Liquid X-1)
Amorphous resin A1 300 g and methyl ethyl ketone 300 g in a container with an internal volume of 3 L equipped with a stirrer "Three One Motor BL300" (manufactured by Shinto Kagaku Co., Ltd.), a reflux condenser, a dropping funnel, a thermometer and a nitrogen introduction tube. Was added, and the resin was dissolved at 30 ° C. for 2 hours. A 5 mass% sodium hydroxide aqueous solution was added to the obtained solution so as to have a neutralization degree of 65 mol% with respect to the acid value of the resin, and the mixture was stirred for 30 minutes.
Next, while maintaining the temperature at 30 ° C., a blocked isocyanate compound (Duranate SBF-70E: manufactured by Asahi Kasei Corporation, solid content 70%, effective NCO = 6.2 wt%, adduct) at a ratio of NCO / OH = 1/1. Mold) 72 g was added and stirred for 30 minutes. Next, 600 g of deionized water was added over 60 minutes while stirring at 200 r / min (peripheral speed 63 m / min) while maintaining 30 ° C. for phase inversion emulsification.
Then, the temperature was raised to 73 ° C. over 20 minutes, and after reaching 73 ° C., methyl ethyl ketone was distilled off under reduced pressure while maintaining the temperature at 73 ° C. to obtain an aqueous dispersion. Then, the aqueous dispersion is cooled to 30 ° C. while stirring, deionized water is added so that the solid content concentration becomes 30% by mass, and the mixture is filtered through a 150 mesh wire mesh to obtain a resin particle dispersion. I got X1. Volume-median particle size D ₅₀ and CV value of the obtained resin particles shown in Table 2.

Production Examples X2, X3, Y1 to Y5, P1 (Production of resin particle dispersions X-2, X-3, Y-1 to Y-5, P-1)
A resin particle dispersion was obtained in the same manner as in Production Example X1 except that the amorphous resin to be used and the blocked isocyanate were combined in Table 2. Volume-median particle size D ₅₀ and CV value of the obtained resin particles shown in Table 2.

[Manufacturing of mold release agent particle dispersion]
Production Example W1 (Production of release agent particle dispersion W-1)
120 g of deionized water, 53 g of resin particle dispersion liquid P-1, and 40 g of paraffin wax "HNP-9" (manufactured by Nippon Seiro Co., Ltd., melting point 75 ° C.) were added to a beaker having an internal volume of 1 L to 90 to 95 ° C. The temperature was maintained, the mixture was melted and stirred to obtain a molten mixture. While maintaining the temperature at 90 to 95 ° C., dispersion treatment was performed for 20 minutes using an ultrasonic homogenizer "US-600T" (manufactured by Nippon Seiki Seisakusho Co., Ltd.), and then the mixture was cooled to room temperature. Deionized water was added to the obtained dispersion to adjust the solid content concentration to 20% by mass to obtain a release agent particle dispersion W-1. The volume median particle size (D ₅₀ ) was 0.45 μm, and the CV value was 26%.

[Manufacturing of colorant particle dispersion]
Production Example Z1 (Production of colorant particle dispersion Z-1)
In a beaker with an internal volume of 1 L, 136.0 g of copper phthalocyanine pigment "ECB-301" (manufactured by Dainichiseika Kogyo Co., Ltd.) and anionic surfactant "Neoperex (registered trademark) G-15" (manufactured by Kao Co., Ltd.) 181.3 g of 15 mass% sodium dodecylbenzene sulfonate aqueous solution) and 340 g of deionized water were mixed and dispersed at room temperature for 3 hours using a homogenizer, and then deionized water so that the solid content concentration became 24 mass%. Was added to obtain a colorant particle dispersion liquid Z-1. The volume median particle diameter (D ₅₀ ) of the colorant particles in the dispersion was 0.12 μm.

[Manufacturing of toner]
Example 1 (Preparation of Toner 1)
300 g of aqueous dispersion of resin particles X1, 31.5 g of release agent particle dispersion W-1, and colorant particle dispersion in a 4-neck flask with an internal volume of 3 L equipped with a dehydration tube, agitator and thermocouple. 26.6 g of Z-1, 9 g of 10 mass% aqueous solution of nonionic surfactant "Emulgen (registered trademark) 150" (manufactured by Kao Co., Ltd., polyoxyethylene (average addition mole number 50) lauryl ether), anionic 6 g of the surfactant "Neoperex G15" (manufactured by Kao Co., Ltd., sodium dodecylbenzene sulfonate, effective concentration 15%) and 137.0 g of deionized water were mixed at a temperature of 25 ° C. Next, while stirring the mixture, 12.7 g of a 4.8 mass% potassium hydroxide aqueous solution was added to an aqueous solution prepared by dissolving 25.9 g of ammonium sulfate in 407 g of deionized water to adjust the pH to 8.1. The mixture was added dropwise at ° C over 15 minutes. Then, the temperature was raised to 60 ° C. over 2 hours, and the temperature was maintained at 60 ° C. until the volume median particle diameter (D ₅₀ ) of the agglomerated particles became 6.8 μm to obtain an agglomerated particle dispersion.
32.1 g of anionic surfactant "Emar (registered trademark) E-27C" (manufactured by Kao Corporation, sodium polyoxyethylene lauryl ether sulfate, effective concentration 27% by mass), 1896 g of deionized water in the aggregated particle dispersion. , Was added. Then, the temperature was raised to 75 ° C. over 1 hour. After reaching 75 ° C., 41 g of a 0.1 mol / L sulfuric acid aqueous solution was added. By holding at 75 ° C. for 30 minutes, a dispersion of fused particles in which aggregated particles were fused was obtained.
The obtained dispersion of fused particles was cooled to 30 ° C., suction filtered to separate solids, washed with deionized water at 25 ° C., and vacuum dried at 35 ° C. for 48 hours to obtain toner particles. Got 100 parts by mass of the toner particles, 2.5 parts by mass of hydrophobic silica "RY50" (manufactured by Nippon Aerosil Co., Ltd., number average particle size; 0.04 μm), and hydrophobic silica "Cabosil (registered trademark) TS720" (Cabot Japan) Manufactured by Co., Ltd., number average particle size; 0.012 μm) 1.0 part by mass was placed in a Henshell mixer and stirred, and passed through a 150 mesh sieve to obtain toner 1. When the viscoelasticity of the obtained toner 1 was measured under constant temperature conditions, the elasticity increased with the passage of time, and it was confirmed that the added blocked isocyanate compound was contained in the toner in an unreacted state.

Examples 2-3, Comparative Examples 1-5
Toners were obtained in the same manner as in Example 1 except that the resin particle dispersion liquid shown in Table 3 was used.

From the results of Examples and Comparative Examples, it can be seen that according to the present invention, a toner having excellent low temperature fixability, excellent hot offset resistance, and high fastness can be obtained.
Comparing Example 1 and Comparative Example 1, the toner of Comparative Example 1 containing no blocked isocyanate compound has a hot offset at 180 ° C., and the image fastness is not sufficient. Further, when comparing Example 1 and Comparative Example 2, in Comparative Example 2 in which the polyester resin does not contain a polyvalent carboxylic acid component having a trivalent or higher valence, the image fastness is slightly higher than that in Comparative Example 1. Although an increase was observed, the robustness of the image was not sufficient as compared with Example 1.
Further, when Example 1 is compared with Comparative Examples 3, 4 and 5, Comparative Examples 3 and 4 using an isocyanurate-type blocked isocyanate compound and a biuret-type blocked isocyanate compound are used as the blocked isocyanate. In Comparative Example 5 as well, a slight improvement in image fastness was observed as compared with Comparative Example 1, but it was not sufficient as compared with Example 1, and hot offset also occurred.

Claims (5)

Contains polyester resin and blocked isocyanate,
The polyester-based resin has a structural unit derived from a polyol and a structural unit derived from a polycarboxylic acid.
The structural unit derived from the polycarboxylic acid contains a structural unit derived from a trivalent or higher carboxylic acid.
The hydroxyl value of the polyester resin is 5 mgKOH / g or more, and
The blocked isocyanate is an adduct-type blocked isocyanate.
Toner for static charge image development. The toner for developing an electrostatic charge image according to claim 1, wherein the dissociation temperature of the blocking agent for the blocked isocyanate is 150 ° C. or lower. The toner for developing an electrostatic charge image according to claim 1 or 2, wherein the blocking agent for the blocked isocyanate is selected from an oxime type and a pyrazole type. It includes a step of aggregating resin particles containing a polyester resin and a blocked isocyanate to obtain agglomerated particles, and a step of fusing the agglomerated particles.
The polyester-based resin has a structural unit derived from a polyol and a structural unit derived from a polycarboxylic acid.
The structural unit derived from the polycarboxylic acid contains a structural unit derived from a trivalent or higher carboxylic acid.
The hydroxyl value of the polyester resin is 5 mgKOH / g or more, and
The blocked isocyanate is an adduct-type blocked isocyanate.
In all the subsequent steps after adding the blocked isocyanate, the product is produced at a temperature below the dissociation temperature of the blocking agent of the blocked isocyanate.
A method for manufacturing a toner for developing an electrostatic charge image. The method for producing an electrostatic charge image developing toner according to claim 4, wherein the blocked isocyanate is added and produced at 90 ° C. or lower in all subsequent steps.