JP7518121B2 - Polyester and resin particles for toner, and method for producing polyester for toner - Google Patents

Description

The present invention relates to polyester and resin particles for toner, and a method for producing polyester for toner.

2. Description of the Related Art In recent years, with the development of electrophotographic systems, the demand for electrophotographic apparatuses such as copying machines and laser printers has increased rapidly, and the requirements for their performance have also become more sophisticated.
Conventionally, in electrophotography, there have been known methods and apparatuses in which a latent image based on color image information is formed on a latent image carrier such as an electrophotographic photosensitive member, the latent image is developed with a toner of a corresponding color, and then the toner image is transferred onto a transfer material. After repeating such image forming steps, the toner image on the transfer material is heated and fixed to obtain a multi-color image.
To pass through these processes without any problems, the toner must first be able to maintain a stable charge (chargeability), and must also fulfill the functions of being able to fix the toner even at low heat roll temperatures (low-temperature fixability), and not fusing to the heat roll even at high fixation temperatures (hot offset resistance).
In order to realize low-temperature fixing properties, polyester-based toner binders are used, and a toner binder that can improve low-temperature fixing properties by introducing crystalline polyester into the binder has been proposed (Patent Document 1). However, such toners are prone to the problem of the toner fusing to a heated roll (hot offset).
In addition, for the purpose of hot offset resistance, there have been proposed (1) a toner binder using a polyester partially crosslinked with a polyfunctional monomer (Patent Document 2), (2) a toner using a modified polyester prepolymer having a crosslinked polyester resin as a backbone and further having a reactive functional group at an end (Patent Document 3), and (3) a toner using a modified resin obtained by introducing an unsaturated group into a polyester resin with an unsaturated carboxylic acid and subjecting the carbon-carbon double bonds to a crosslinking reaction while dispersed in an aqueous solvent (Patent Document 4).
However, these toners have problems such as (1) poor solubility in the oil phase and poor emulsification, resulting in poor particle size distribution, (2) poor charging characteristics due to the positive charging properties of the urethane and urea groups induced in the toner, and (3) a part of the double bonds reacts due to the reaction temperature during polyester synthesis, making it impossible to achieve both hot offset resistance and good particle size distribution.

JP 2002-287426 A Japanese Unexamined Patent Publication No. 57-109825 JP 2008-233360 A JP 2018-87320 A

The present invention aims to provide polyester and resin particles for toner that have excellent hot offset resistance, particle size distribution, and charging properties.

The present inventors have made extensive investigations and have arrived at the present invention. That is, the present invention relates to a polyester for a toner which is an addition reaction product of a polyester having a hydroxyl group and an acid anhydride (Z) having a polymerizable unsaturated group, the amount of the polymerizable unsaturated group being 2×10 ⁻⁶ to 4×10 ⁻³ mol/g , the polyester having a hydroxyl group being a polycondensate of a polyol and a polycarboxylic acid, the polyol being a polyester containing an alkylene oxide adduct of bisphenol A ; and resin particles containing a crosslinked reaction product of the polyester for a toner.

The present invention makes it possible to provide polyester and resin particles for toners that have excellent hot offset resistance, particle size distribution, and charging properties.

The toner polyester of the present invention is an addition reaction product of a polyester having a hydroxyl group and an acid anhydride (Z) having a polymerizable unsaturated group. By subjecting a polyester having a hydroxyl group to an acid anhydride (Z) having a polymerizable unsaturated group addition reaction, the reaction can be carried out under milder conditions than in the case of subjecting a carboxylic acid having a polymerizable unsaturated group to a condensation reaction, and a highly reactive polymerizable unsaturated group can be easily introduced to the end of the polyester while suppressing the reaction of the polymerizable unsaturated group, so that a toner polyester having high solubility in organic solvents and excellent hot offset resistance and charging characteristics can be obtained. Note that, from the viewpoint of charging properties, it is preferable that the toner polyester is a polyester that does not contain a urethane bond or a urea bond.

The polyester having a hydroxyl group in the present invention is not particularly limited as long as it is a polyester having a hydroxyl group, and examples thereof include condensation type polyester polyols and polylactone polyols. The polyester having a hydroxyl group may be used alone or in combination of two or more kinds.

The condensation type polyester polyol is not particularly limited, but examples thereof include polycondensates of polyols and polycarboxylic acids.

Examples of polyols include diols (g) and trihydric or higher polyols (h).

Examples of diols (g) include alkylene glycols having 2 to 36 carbon atoms, alkylene ether glycols having 4 to 36 carbon atoms, alicyclic diols having 4 to 36 carbon atoms, and aromatic diols.

Specific examples of alkylene glycols having 2 to 36 carbon atoms include ethylene glycol, 1,2-propanediol (propylene glycol), 1,3-propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, octanediol, decanediol, dodecanediol, tetradecanediol, neopentyl glycol, and 2,2-diethyl-1,3-propanediol.

Specific examples of alkylene ether glycols having 4 to 36 carbon atoms include diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene ether glycol.

Specific examples of alicyclic diols having 4 to 36 carbon atoms include 1,2-cyclohexanediol, 1,4-cyclohexanediol, 1,1-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 5-norbornene-2,3-dimethanol, hydrogenated bisphenol A, spiroglycol, isosorbide, and alkylene oxide (hereinafter, "alkylene oxide" may be abbreviated as AO) adducts of the above alicyclic diols.

Examples of the alkylene oxide adducts of the alicyclic diols include ethylene oxide (hereinafter, "ethylene oxide" may be abbreviated as EO) adducts, propylene oxide (hereinafter, "propylene oxide" may be abbreviated as PO) adducts, and butylene oxide (hereinafter, "butylene oxide" may be abbreviated as BO) adducts of the alicyclic diols. The average number of moles of the alkylene oxide added is preferably 1 to 15, and more preferably 2 to 5.

Examples of aromatic diols include 1,3-benzenedimethanol, 1,4-benzenedimethanol, bisphenol A, bisphenol F, bisphenol B, bisphenol AD, bisphenol S, trichlorobisphenol A, tetrachlorobisphenol A, dibromobisphenol F, 2-methylbisphenol A, 2,6-dimethylbisphenol A, and 2,2'-diethylbisphenol F, as well as alkylene oxide adducts of the above aromatic diols.

Examples of the alkylene oxide adducts of the aromatic diols include EO adducts, PO adducts, and BO adducts of the aromatic diols. The average number of moles of the alkylene oxide added is preferably 1 to 15, and more preferably 2 to 5.

As the diol (g), in addition to the above diols having no functional groups other than hydroxyl groups, diols (g1) having other functional groups may be used.
Examples of (g1) include diols having a carboxyl group, diols having a sulfonic acid group or a sulfamic acid group, and salts thereof.
The diol having a carboxyl group may be a dialkylolalkanoic acid having 6 to 24 carbon atoms, specifically 2,2-dimethylolpropionic acid (DMPA), 2,2-dimethylolbutanoic acid, 2,2-dimethylolheptanoic acid, 2,2-dimethyloloctanoic acid, etc.
Examples of diols having a sulfonic acid group or a sulfamic acid group include 3-(2,3-dihydroxypropoxy)-1-propanesulfonic acid, sulfoisophthalic acid di(ethylene glycol) ester, sulfamic acid diol, and bis(2-hydroxyethyl)phosphate.

Preferred diols (g) are alkylene glycols having 2 to 36 carbon atoms, aromatic diols, and diols having other functional groups (g1), more preferably alkylene glycols having 2 to 12 carbon atoms, diols having a carboxyl group, and AO adducts of bisphenol A, and even more preferably alkylene glycols having 2 to 12 carbon atoms, AO adducts of bisphenol A, and combinations of these.

Examples of the tri- or higher hydric polyol (h) include tri- or higher hydric polyhydric aliphatic alcohols having 3 to 36 carbon atoms, AO adducts of polyhydric aliphatic alcohols (number of moles added: 2 to 120), AO adducts of trisphenols (e.g., trisphenol PA) (number of moles added: 2 to 30), AO adducts of novolak resins (e.g., phenol novolak, cresol novolak) (number of moles added: 2 to 30), and acrylic polyols [e.g., copolymers of hydroxyethyl (meth)acrylate and other vinyl monomers].
Examples of the polyhydric aliphatic alcohol having 3 to 36 carbon atoms and having a valence of 3 or more include alkane polyols and their intramolecular or intermolecular dehydration products, as well as sugars (such as sucrose) and their methyl glucosides.
Specific examples of alkane polyols and their intramolecular or intermolecular dehydration products include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, sorbitan, and polyglycerin.

Preferred as the trihydric or higher polyol (h) are trihydric or higher polyhydric aliphatic alcohols having 3 to 36 carbon atoms and AO adducts of novolac resins, and more preferred are trihydric or higher polyhydric aliphatic alcohols having 3 to 36 carbon atoms.

Examples of polycarboxylic acids include dicarboxylic acids (i) and trivalent or higher polycarboxylic acids (j).

Examples of the dicarboxylic acid (i) include alkanedicarboxylic acids having 4 to 36 carbon atoms, alicyclic dicarboxylic acids having 6 to 40 carbon atoms, and aromatic dicarboxylic acids having 8 to 36 carbon atoms.
Examples of the alkanedicarboxylic acid having 4 to 36 carbon atoms include succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedicarboxylic acid, octadecanedicarboxylic acid, and decylsuccinic acid.
Examples of the alicyclic dicarboxylic acid having 6 to 40 carbon atoms include dimer acid (dimerized linoleic acid).
Examples of the aromatic dicarboxylic acid having 8 to 36 carbon atoms include phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid.
Of these, preferred are alkanedicarboxylic acids having 4 to 36 carbon atoms, aromatic dicarboxylic acids having 8 to 36 carbon atoms, and combinations of these.

Examples of trivalent or higher polycarboxylic acids (j) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (e.g., trimellitic acid, pyromellitic acid), anhydrides of these carboxylic acids, and lower alkyl (having 1 to 4 carbon atoms) esters (e.g., methyl esters, ethyl esters, and isopropyl esters).

The reaction ratio of polyol to polycarboxylic acid, expressed as the molar ratio [OH]/[COOH] of hydroxyl groups [OH] to carboxyl groups [COOH], is preferably 2/1 to 1.01/1, more preferably 1.5/1 to 1.01/1, and particularly preferably 1.2/1 to 1.01/1.

The polylactone polyol is not particularly limited, but examples thereof include polyaddition products of lactones with diols (g).

Examples of lactones include lactones having 4 to 12 carbon atoms (e.g., γ-butyrolactone, γ-valerolactone, and ε-caprolactone). Specific examples of polylactone polyols include polycaprolactone diol, polyvalerolactone diol, and polycaprolactone triol.

The polyester having a hydroxyl group can be produced by a known production method.
For example, the reaction can be carried out by reacting a polyol with a polycarboxylic acid in an inert gas (such as nitrogen gas) atmosphere. The reaction temperature is preferably 150 to 280° C., and the reaction time is preferably 30 minutes or more. It is also effective to reduce the pressure in order to improve the reaction rate at the end of the reaction.
In this case, an esterification catalyst can be used as necessary.
Esterification catalysts include tin-containing catalysts, antimony trioxide, titanium-containing catalysts, zirconium-containing catalysts, zinc acetate, and the like.
Specifically, the tin-containing catalyst may be dibutyltin oxide.
Examples of the titanium-containing catalyst include titanium alkoxides, potassium oxalate titanate, titanium terephthalate, the catalysts described in JP-A-2006-243715 (titanium dihydroxybis(triethanolaminate), titanium diisopropoxybistriethanolaminate, titanium monohydroxytris(triethanolaminate), and intramolecular polycondensates thereof, etc.), and the catalysts described in JP-A-2007-11307 (titanium tributoxyterephthalate, titanium triisopropoxyterephthalate, titanium diisopropoxyditerephthalate, etc.).
Zirconium-containing catalysts include zirconyl acetate.

Among the esterification catalysts, titanium-containing catalysts are preferred from the viewpoint of charging characteristics, and the catalysts described in JP-A-2006-243715 and JP-A-2007-11307 are even more preferred.

The acid anhydride (Z) having a polymerizable unsaturated group in the present invention is not particularly limited as long as it is an anhydride of an acid having a polymerizable unsaturated group, and one type may be used alone, or two or more types may be used in combination.
The polymerizable unsaturated group contained in the acid anhydride (Z) is not particularly limited as long as it is an unsaturated group that exhibits polymerizability in a general radical polymerization method, and examples thereof include alkenyl groups (vinyl groups, allyl groups, isopropenyl groups, 1-propenyl groups, dodecenyl groups), acryloyl groups, and methacryloyl groups, etc. Acryloyl groups and methacryloyl groups are preferred because they exhibit good polymerizability in the radical polymerization method.

Specific examples of acid anhydrides (Z) having a polymerizable unsaturated group include acrylic anhydride, methacrylic anhydride, crotonic anhydride, tiglic anhydride, pentadecenylsuccinic anhydride, hexadecenylsuccinic anhydride, octadecenylsuccinic anhydride, dodecenylsuccinic anhydride, citraconic anhydride, and 1,2,3,6-tetrahydrophthalic anhydride.

Among these, from the viewpoint of hot offset properties, it is preferable that the acid anhydride (Z) having a polymerizable unsaturated group is one or more compounds selected from the group consisting of acrylic anhydride, methacrylic anhydride, crotonic anhydride, and tiglic anhydride.

The amount of polymerizable unsaturated groups in the toner polyester of the present invention is 2×10 ⁻⁶ to 4×10 ⁻³ mol/g. By using the toner polyester within the above range, a toner having excellent hot offset resistance and charging properties can be obtained.
The amount of polymerizable unsaturated groups is preferably 5×10 ⁻⁶ to 4×10 ⁻³ mol/g, and more preferably 2×10 ⁻⁵ to 2×10 ⁻³ mol/g.
The amount of polymerizable unsaturated groups can be calculated by measuring the iodine value and using the following formula.
<Method of measuring iodine value>
Weigh out 1 g of sample into an Erlenmeyer flask, add 10 mL of chloroform to dissolve, add 25 mL of Wiess solution (0.10 mol/L iodine chloride solution), and leave in a dark place at 20-30°C for 1 hour, shaking occasionally. Add 20 mL of 10% potassium iodide solution and 100 mL of water, and shake. Next, titrate with 0.1 mol/L sodium thiosulfate standard solution. When the solution turns slightly yellow, add about 1 mL of starch indicator. Titrate with 0.1 mol/L sodium thiosulfate standard solution while shaking the Erlenmeyer flask well. The end point is when the blue color of starch disappears due to iodine. The above operations are carried out for the sample, and a blank test is also carried out.
The iodine value (IV) is calculated according to the following formula:
IV=((B-A)×f×1.269)/S
A: mL of 0.1 mol/L sodium thiosulfate standard solution required for this test, B: mL of 0.1 mol/L sodium thiosulfate standard solution required for the blank test, f: titer of 0.1 mol/L sodium thiosulfate standard solution, S: sample amount (g)
<Polymerizable unsaturated group amount>
The amount of polymerizable unsaturated groups can be calculated from the following formula.
Polymerizable unsaturated group amount = IV/25400

The glass transition temperature (Tg) of the polyester for toner is preferably from -70 to 80°C, more preferably from -70 to 50°C, and further preferably from -65 to 45°C.
In the present invention, Tg can be measured by the method (DSC) specified in ASTM D3418-82 using "DSC20, SSC/580" [manufactured by Seiko Denshi Kogyo Co., Ltd.].

The number average molecular weight (Mn) of the polyester for toner is preferably 1,000 to 500,000, and more preferably 1,500 to 50,000.

The weight average molecular weight (Mw) of the toner polyester is preferably 2,000 to 1,000,000, and more preferably 3,000 to 120,000.

In the present invention, Mn and Mw can be measured by gel permeation chromatography (GPC) under the following conditions.
Apparatus: "HLC-8120" [manufactured by Tosoh Corporation]
Column: 2 "TSK GEL GMH6" [manufactured by Tosoh Corporation] Measurement temperature: 40°C
Sample solution: 0.25% by weight tetrahydrofuran solution (undissolved matter was removed by filtration using a glass filter)
Solution injection volume: 100μl
Detector: Refractive index detector Reference material: 12 types of standard polystyrene (TSKstandard POLYSTYRENE) (molecular weight: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000, 355,000, 1,090,000, 2,890,000) [manufactured by Tosoh Corporation]

From the viewpoint of hot offset properties, the total chlorine content of the polyester for toner is preferably 1000 ppm or less. The total chlorine content can be measured by an ion chromatography method in which a sample is burned in a mixed gas flow of argon gas and oxygen gas, and then the generated chlorine ions are quantified by ion chromatography.

The tetrahydrofuran (hereinafter sometimes abbreviated as THF) insoluble content of the toner polyester is preferably 1% by weight or less, more preferably 0.1% by weight or less, from the viewpoints of hot offset resistance and particle size distribution.
The THF insoluble content of the polyester for toner can be easily achieved within the above range by setting the temperature in the addition reaction step to 110 to 150°C, for example.
The THF insoluble matter was determined by the following method.
50 ml of THF is added to 0.5 g of the sample, and the mixture is refluxed with stirring for 3 hours. After cooling, the insoluble matter is filtered off using a glass filter, and the resin matter on the glass filter is dried under reduced pressure at 80° C. for 3 hours. The weight of the dried resin matter on the glass filter is taken as the weight of the THF insoluble matter, and the weight ratio of the THF insoluble matter to the weight of the sample is taken as the THF insoluble matter.

The polyester for toner of the present invention is obtained by an addition reaction between a polyester having a hydroxyl group and an acid anhydride (Z) having a polymerizable unsaturated group.
Therefore, the method for producing a polyester for a toner includes an addition reaction step between a polyester having a hydroxyl group and an acid anhydride (Z) having a polymerizable unsaturated group.

As shown in the manufacturing method described above, by subjecting a polyester having a hydroxyl group to an addition reaction with an acid anhydride (Z) having a polymerizable unsaturated group, it is possible to easily introduce a highly reactive polymerizable unsaturated group to the end of the polyester while suppressing the reaction of the polymerizable unsaturated group, thereby making it possible to obtain a polyester for toner that is highly soluble in organic solvents and has excellent hot offset resistance and charging characteristics.

If necessary, a polymerization inhibitor such as tert-butylcatechol may be used in the above addition reaction process.

From the viewpoints of particle size distribution and hot offset resistance, the weight ratio of the polyester having a hydroxyl group used in the above addition reaction step is preferably 50 to 99% by weight, and more preferably 75 to 98% by weight, based on the total weight of the polyester having a hydroxyl group and the acid anhydride (Z) having a polymerizable unsaturated group.

The weight ratio of the acid anhydride (Z) having a polymerizable unsaturated group used in the above addition reaction step is preferably 1 to 50% by weight, more preferably 2 to 25% by weight, based on the total weight of the polyester having a hydroxyl group and the acid anhydride (Z) having a polymerizable unsaturated group, from the viewpoints of particle size distribution and hot offset resistance.

The hydroxyl value of the polyester having hydroxyl groups used in the above addition reaction step is preferably 0.75 mgKOH/g or more, more preferably 4.4 to 75 mgKOH/g, from the viewpoint of reactivity. The hydroxyl value can be measured by the method specified in JIS K0070.

From the viewpoint of reactivity, the acid value of the polyester having hydroxyl groups used in the above addition reaction step is preferably 5 mgKOH/g or less, more preferably 1 mgKOH/g or less. The acid value can be measured by the method specified in JIS K0070.

The temperature of the above addition reaction step is preferably 100 to 180°C, more preferably 110 to 150°C, from the viewpoints of reactivity and solubility in organic solvents, etc.

The pressure in the above addition reaction step is preferably 100 to 110 kPa, more preferably normal pressure (101.33 kPa), from the viewpoints of reactivity and solubility in organic solvents, etc.

The duration of the above addition reaction step is preferably 1 to 3.5 hours, more preferably 2 to 3 hours, from the viewpoints of reactivity and solubility in organic solvents, etc.

In addition to the above-mentioned addition reaction step, if necessary, a step of removing unreacted unsaturated carboxylic acid produced during the addition reaction by a method such as reducing pressure may be included.

The resin particles of the present invention are resin particles containing a crosslinked reaction product of a polyester for toner. The crosslinked reaction product of a polyester for toner is a modified resin obtained by a crosslinking reaction between carbon-carbon double bonds derived from polymerizable unsaturated groups in the polyester for toner, and the modified resin is, for example, a modified resin in which a crosslinking reaction occurs between carbon-carbon double bonds derived from polymerizable unsaturated groups in the polyester for toner, using radicals generated from a radical reaction initiator (c), resulting in chemical bonding.
The resin particles may contain other resins in addition to the crosslinked product of the polyester for toner. Any resin may be used as the other resin as long as it is a known resin, and specific examples of the other resin include polyester resins other than the polyester for toner, vinyl resins, polyurethane resins, epoxy resins, polyamide resins, polyimide resins, silicon resins, phenol resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins.
Preferable examples of the other resin include polyester resins other than the polyesters for toner, vinyl resins, polyurethane resins, epoxy resins, and combinations of these resins, and more preferable examples are combinations of polyester resins other than the polyesters for toner, and vinyl resins.

When the other resin is a polyester resin other than the polyester for the toner of the present invention, the polyester resin may be a crystalline polyester resin or an amorphous polyester resin, and a polycondensation product using the same polyols and polycarboxylic acids as those exemplified as the condensation type polyester polyols can be used, and the preferred polyols and polycarboxylic acids are the same as those of the above-mentioned condensation type polyester polyols.
In the present invention, "crystalline" refers to a state in which a differential scanning calorimetry (DSC) curve has a maximum and an endothermic peak during the temperature rise process of the differential scanning calorimetry curve obtained by DSC measurement, whereas "amorphous" refers to a state in which the DSC curve does not have an endothermic peak.

When the other resin is a vinyl resin, the vinyl resin is a polymer obtained by homopolymerizing or copolymerizing a vinyl monomer. Examples of the vinyl monomer include the following (1) to (10).
(1) Vinyl Hydrocarbons Examples of the vinyl hydrocarbons include (1-1) aliphatic vinyl hydrocarbons, (1-2) alicyclic vinyl hydrocarbons, and (1-3) aromatic vinyl hydrocarbons.
(1-1) Aliphatic Vinyl Hydrocarbons Examples of the aliphatic vinyl hydrocarbons include alkenes and alkadienes.
Specific examples of alkenes include ethylene, propylene, and α-olefins.
Specific examples of alkadienes include butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene, and 1,7-octadiene.
(1-2) Alicyclic Vinyl Hydrocarbons Alicyclic vinyl hydrocarbons include mono- or di-cycloalkenes and alkadienes, and specific examples thereof include (di)cyclopentadiene and terpene.
(1-3) Aromatic Vinyl Hydrocarbons Examples of aromatic vinyl hydrocarbons include styrene and its hydrocarbyl (alkyl, cycloalkyl, aralkyl and/or alkenyl) substituted products, and specific examples thereof include α-methylstyrene, 2,4-dimethylstyrene, and vinylnaphthalene.

(2) Carboxylic Group-Containing Vinyl Monomer and Salts Thereof Examples of the carboxyl group-containing vinyl monomer and salts thereof include unsaturated monocarboxylic acids (salts), unsaturated dicarboxylic acids (salts), and anhydrides (salts), and monoalkyl (C1-24) esters or salts thereof, each having 3 to 30 carbon atoms.
Specific examples thereof include carboxyl group-containing vinyl monomers such as (meth)acrylic acid, (anhydride) maleic acid, maleic acid monoalkyl esters, fumaric acid, fumaric acid monoalkyl esters, crotonic acid, itaconic acid, itaconic acid monoalkyl esters, itaconic acid glycol monoether, citraconic acid, citraconic acid monoalkyl esters, and cinnamic acid, and metal salts thereof.

In the present invention, the term "(salt)" means an acid or a salt thereof.
For example, an unsaturated monocarboxylic acid (salt) having 3 to 30 carbon atoms means an unsaturated monocarboxylic acid or a salt thereof.

In the present invention, "(meth)acrylic" means methacrylic acid or acrylic acid.
In the present invention, "(meth)acryloyl" means methacryloyl or acryloyl.
In the present invention, "(meth)acrylate" means methacrylate or acrylate.

(3) Sulfone Group-Containing Vinyl Monomers, Vinyl Sulfate Monoesters, and Salts Thereof Examples of the sulfone group-containing vinyl monomers, vinyl sulfate monoesters, and salts thereof include alkene sulfonic acids (salts) having 2 to 14 carbon atoms, alkyl sulfonic acids (salts) having 2 to 24 carbon atoms, sulfo(hydroxy)alkyl-(meth)acrylates (salts) or (meth)acrylamides (salts), and alkylarylsulfosuccinic acids (salts).
Specifically, an example of an alkene sulfonic acid having 2 to 14 carbon atoms is vinyl sulfonic acid (salt), etc., an example of an alkyl sulfonic acid (salt) having 2 to 24 carbon atoms is α-methylstyrene sulfonic acid (salt), etc., and an example of a sulfo(hydroxy)alkyl-(meth)acrylate (salt) or (meth)acrylamide (salt) is sulfopropyl(meth)acrylate (salt), sulfuric acid ester (salt), or a sulfonic acid group-containing vinyl monomer (salt), etc.

(4) Phosphate-containing vinyl monomers and their salts:
Examples of the phosphoric acid group-containing vinyl monomer and its salt include (meth)acryloyloxyalkyl (C1 to C24) phosphoric acid monoester (salt) and (meth)acryloyloxyalkyl (C1 to C24) phosphonic acid (salt).
Specific examples of the (meth)acryloyloxyalkyl (C1 to C24) phosphate monoester (salt) include 2-hydroxyethyl (meth)acryloyl phosphate (salt) and phenyl-2-acryloyloxyethyl phosphate (salt).
Specific examples of the (meth)acryloyloxyalkyl (C1 to C24)phosphonic acid (salt) include 2-acryloyloxyethylphosphonic acid (salt).

Examples of the salts (2) to (4) above include alkali metal salts (sodium salts, potassium salts, etc.), alkaline earth metal salts (calcium salts, magnesium salts, etc.), ammonium salts, amine salts, and quaternary ammonium salts.

(5) Hydroxyl Group-Containing Vinyl Monomers Examples of hydroxyl group-containing vinyl monomers include hydroxystyrene, N-methylol (meth)acrylamide, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, (meth)allyl alcohol, crotyl alcohol, isocrotyl alcohol, 1-buten-3-ol, 2-buten-1-ol, 2-butene-1,4-diol, propargyl alcohol, 2-hydroxyethyl propenyl ether, and sucrose allyl ether.

(6) Nitrogen-Containing Vinyl Monomers Examples of the nitrogen-containing vinyl monomers include (6-1) amino group-containing vinyl monomers, (6-2) amide group-containing vinyl monomers, (6-3) nitrile group-containing vinyl monomers, (6-4) quaternary ammonium cation group-containing vinyl monomers, and (6-5) nitro group-containing vinyl monomers.
(6-1) Examples of amino group-containing vinyl monomers include aminoethyl (meth)acrylate.
(6-2) Examples of the amide group-containing vinyl monomer include (meth)acrylamide and N-methyl(meth)acrylamide.
(6-3) Examples of nitrile group-containing vinyl monomers include (meth)acrylonitrile, cyanostyrene, and cyanoacrylate.
(6-4) Examples of the quaternary ammonium cation group-containing vinyl monomer include quaternized products of tertiary amine group-containing vinyl monomers such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, and diallylamine (which are quaternized with a quaternizing agent such as methyl chloride, dimethyl sulfate, benzyl chloride, or dimethyl carbonate).
(6-5) Nitro group-containing vinyl monomers include nitrostyrene and the like.

(7) Epoxy Group-Containing Vinyl Monomers Examples of epoxy group-containing vinyl monomers include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and p-vinylphenyl phenyl oxide.

(8) Halogen-Containing Vinyl Monomers Examples of halogen-containing vinyl monomers include vinyl chloride, vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluorostyrene, and chloroprene.

(9) Vinyl esters, vinyl (thio)ethers, vinyl ketones (9-1) Examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl propionate, vinyl butyrate, diallyl phthalate, diallyl adipate, isopropenyl acetate, vinyl methacrylate, methyl 4-vinyl benzoate, cyclohexyl methacrylate, benzyl methacrylate, phenyl (meth)acrylate, vinyl methoxyacetate, vinyl benzoate, ethyl α-ethoxyacrylate, and alkyl groups having 1 to 50 carbon atoms. alkyl(meth)acrylates having the formula (methyl(meth)acrylate, ethyl(meth)acrylate, propyl(meth)acrylate, butyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, dodecyl(meth)acrylate, hexadecyl(meth)acrylate, heptadecyl(meth)acrylate, octadecyl(meth)acrylate, eicosyl(meth)acrylate, behenyl(meth)acrylate, etc.), dialkyl fumarate (wherein the two alkyl groups have 2 to 8 carbon atoms and may be linear, branched or dialkyl maleates (wherein the two alkyl groups are straight, branched or alicyclic groups having 2 to 8 carbon atoms); poly(meth)allyloxyalkanes [diallyloxyethane, triallyloxyethane, tetraallyloxyethane, tetraallyloxypropane, tetraallyloxybutane, tetramethallyloxyethane, etc.]; vinyl monomers having polyalkylene glycol chains [polyethylene glycol (molecular weight 300) mono(meth)acrylate, polypropylene glycol (molecular weight 500) monoacrylate, acrylate, methyl alcohol ethylene oxide 10 mol adduct (meth)acrylate, lauryl alcohol ethylene oxide 30 mol adduct (meth)acrylate, etc.], poly(meth)acrylates [poly(meth)acrylates of polyhydric alcohols: ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, polyethylene glycol di(meth)acrylate, etc.].
(9-2) Examples of vinyl (thio)ethers include vinyl methyl ether.
(9-3) Examples of vinyl ketones include vinyl methyl ketone.

(10) Other Vinyl Monomers Examples of other vinyl monomers include tetrafluoroethylene, fluoroacrylate, isocyanatoethyl (meth)acrylate, and m-isopropenyl-α,α-dimethylbenzyl isocyanate.

In the synthesis of the vinyl resin, the above vinyl monomers (1) to (10) may be used alone or in combination of two or more.
As the vinyl resin, from the viewpoints of particle size distribution and chargeability, styrene-(meth)acrylic acid ester copolymers and (meth)acrylic acid ester copolymers are preferred, and styrene-(meth)acrylic acid ester copolymers are more preferred.

The resin particles of the present invention may contain various known additives such as colorants, release agents, charge control agents, and flow agents, if necessary.

The colorant preferably contains at least one selected from the group consisting of a black colorant, a blue colorant, a red colorant and a yellow colorant. As the colorant, any dye, pigment or the like that is used as a toner colorant can be used.
Specific examples thereof include carbon black, iron black, Sudan Black SM, Fast Yellow G, Benzidine Yellow, Solvent Yellow (21, 77, 114, etc.), Pigment Yellow (12, 14, 17, 83, etc.), India Fast Orange, Irgasin Red, Paranitoaniline Red, Toluidine Red, Solvent Red (17, 49, 128, 5, 13, 22, 48.2, etc.), Disperse Red, Carmine FB, Pigment Orange R, Lake Red 2G, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine Blue, Solvent Blue (25, 94, 60, 15.3, etc.), Pigment Blue, Brilliant Green, Phthalocyanine Green, Oil Yellow GG, Kayaset YG, Orasol Brown B, and Oil Pink OP. If necessary, magnetic powder (powders of ferromagnetic metals such as iron, cobalt and nickel, and compounds such as magnetite, hematite and ferrite) may be contained to function as a colorant.
The content of the colorant is preferably 1 to 40 parts by weight, more preferably 2 to 15 parts by weight, based on 100 parts by weight of the total of the polyester of the present invention and the other resin. When a magnetic powder is used, the content of the magnetic powder is preferably 20 to 150 parts by weight, more preferably 30 to 120 parts by weight, based on 100 parts by weight of the total of the polyester of the present invention and the other resin.

Examples of release agents include natural waxes (beeswax, carnauba wax, montan wax, etc.), petroleum waxes (paraffin wax, microcrystalline wax, petrolatum, etc.), synthetic waxes (Fischer-Tropsch wax, polyethylene wax, polypropylene wax, oxidized polyethylene wax, oxidized polypropylene wax, etc.), and synthetic ester waxes (fatty acid esters synthesized from fatty acids having 10 to 30 carbon atoms and alcohols having 10 to 30 carbon atoms, etc.), and it is preferable to contain one or more types selected from the group consisting of these release agents. The content of the release agent is preferably 0 to 30% by weight, more preferably 0.5 to 20% by weight, and even more preferably 1 to 10% by weight, based on 100 parts by weight of the total of the polyester of the present invention and other resins.

When using the above-mentioned release agent, modified wax may be used in combination, if necessary. The modified wax is a release agent to which a vinyl polymer chain has been grafted. The release agents used in the modified wax include the same as those described above, and the preferred ones are also the same. Examples of the vinyl monomers constituting the vinyl polymer chain of the modified wax include styrene and methacrylic acid esters. The vinyl polymer chain may be a homopolymer or copolymer of a vinyl monomer. The content of the modified wax is preferably 0 to 15% by weight, more preferably 0.5 to 10% by weight, and even more preferably 1 to 5% by weight, based on 100 parts by weight of the polyester of the present invention and other resins combined.

The charge control agent may be either a positively charged charge control agent or a negatively charged charge control agent, and examples thereof include nigrosine dyes, triphenylmethane dyes containing a tertiary amine as a side chain, quaternary ammonium salts, polyamine resins, imidazole derivatives, polymers containing a quaternary ammonium base, metal-containing azo dyes, copper phthalocyanine dyes, metal salicylic acid salts, boron complexes of benzilic acid, polymers containing sulfonic acid groups, fluorine-containing polymers, and halogen-substituted aromatic ring-containing polymers. The content of the charge control agent may be 0 to 20% by weight, preferably 0.1 to 10% by weight, and more preferably 0.5 to 7.5% by weight, based on 100 parts by weight of the total of the polyester of the present invention and other resins.

Examples of the fluidizing agent include silica, titania, alumina, fatty acid metal salts, silicone resin particles, and fluororesin particles, and two or more of them may be used in combination. From the viewpoint of the chargeability of the toner, silica is preferred. From the viewpoint of the transferability of the toner, the silica is preferably hydrophobic. The content of the fluidizing agent may be 0 to 10% by weight, preferably 0 to 5% by weight, and more preferably 0.1 to 4% by weight, based on 100 parts by weight of the total of the resin particles of the present invention.

The total weight of additives such as colorants, release agents, charge control agents, and flow agents may be 3 to 70% by weight, preferably 4 to 58% by weight, and more preferably 5 to 50% by weight, based on the weight of the resin particles.

The volume average particle size (D50) of the resin particles is preferably 1 to 15 μm, more preferably 2 to 10 μm, and particularly preferably 3 to 7 μm. The number average particle size is preferably 1 to 15 μm, more preferably 2 to 10 μm, and particularly preferably 3 to 7 μm. From the viewpoint of fluidity, a spherical shape is preferable.

The method for producing the resin particles is not particularly limited, and the resin particles may be obtained by a known kneading and grinding method, a suspension polymerization method described in JP-B-36-10231, JP-A-59-53856, and JP-A-59-61842, an emulsion polymerization method represented by a soap-free polymerization method in which a toner is produced by directly polymerizing a monomer in the presence of a water-soluble polymerization initiator that is soluble in the monomer, an interfacial polymerization method such as a microcapsule production method, an in site polymerization method, a coacervation method, an emulsion aggregation method in which at least one type of fine particles are aggregated to obtain particles of a desired particle size as disclosed in JP-A-62-106473 and JP-A-63-186253, a dispersion polymerization method characterized by monodispersion, a dissolution suspension method in which a necessary resin is dissolved in a water-insoluble organic solvent and then turned into resin particles in water, or an ester elongation polymerization method, or a method in which the resin particles are dispersed in carbon dioxide in a supercritical state.
From the viewpoint of achieving both hot offset resistance, particle size distribution, and chargeability, the method for producing resin particles preferably includes a step of dispersing a toner polyester or a solvent solution thereof in an aqueous medium and crosslinking carbon-carbon double bonds derived from polymerizable unsaturated groups in the polyester to obtain a modified resin, and more preferably includes a step of using fine particles of a resin, dispersing a toner polyester or a solvent solution thereof in an aqueous solvent containing fine particles of a resin, and crosslinking carbon-carbon double bonds derived from polymerizable unsaturated groups in the polyester to obtain a modified resin.

The method for producing a modified resin by crosslinking carbon-carbon double bonds derived from polymerizable unsaturated groups in the polyester for toner of the present invention in an aqueous medium is a method for producing a modified resin formed by crosslinking carbon-carbon double bonds derived from polymerizable unsaturated groups in the polyester in a dispersion containing the polyester for toner of the present invention, if necessary using radical polymerization.

As the aqueous solvent in the present invention, any liquid containing water as an essential component can be used without limitation, and examples of the aqueous solvent that can be used include water, an aqueous solution of an organic solvent, an aqueous solution of a surfactant (s), an aqueous solution of a water-soluble polymer (t), and mixtures thereof, as described below.
As a method for stably forming a dispersion containing the polyester for toner of the present invention in an aqueous solvent, there may be mentioned a method in which the polyester is added to an aqueous solvent and dispersed by shear force.
When the other resin is used, the polyester and the other resin can be mixed in advance and dispersed in an aqueous medium. Furthermore, the polyester can be crosslinked in the presence of the other resin by crosslinking the carbon-carbon double bonds derived from the polymerizable unsaturated groups in the polyester.
When other resins are used as fine particles, the fine particles of the resin are not particularly limited as long as they can form fine particles in an aqueous solvent and are adsorbed to the polyester for toner of the present invention.

The method for dispersing the resin particles is not particularly limited, but the following methods [1] and [2] can be mentioned.
[1] In the case of vinyl resins, a method of directly producing a fine particle dispersion of the resin by a polymerization reaction such as suspension polymerization, emulsion polymerization, seed polymerization or dispersion polymerization using a monomer as a starting material.
[2] In the case of polyaddition or condensation resins such as polyester resins, polyurethane resins, and epoxy resins, a precursor (monomer, oligomer, etc.) or a solvent solution thereof is dispersed in a medium in the presence of a suitable dispersant, and then heated or cured by adding a curing agent to produce a fine particle dispersion of the resin.

In the above method [1] or [2], the emulsifier or dispersant used in combination may be a known surfactant (s) or a water-soluble polymer (t) as described below. In addition, an organic solvent or the like as described below may be used in combination as an emulsifying or dispersing aid.

Furthermore, when using raw materials other than the polyester for toner of the present invention and other resins (such as colorants, release agents, modified waxes, and charge control agents), the polyester and other resins can be mixed in advance and dispersed in an aqueous medium. Furthermore, by crosslinking the carbon-carbon double bonds derived from the polymerizable unsaturated groups in the polyester, crosslinking can be performed in a state in which the polyester and other resins are mixed in advance with other raw materials. Mixing other toner raw materials in the resin in advance and crosslinking the materials makes it easier to disperse and fix the other raw materials in the resin, which is preferable from the viewpoints of particle size distribution and chargeability.
In the present invention, other raw materials such as a colorant, a release agent, a modified wax, and a charge control agent do not necessarily need to be mixed when forming particles in an aqueous solvent, but may be added after forming the particles. For example, after forming particles not containing a colorant, a colorant may be added by a known dyeing method.

The dispersion method is not particularly limited, but known equipment such as low-speed shear type, high-speed shear type, friction type, high-pressure jet type, and ultrasonic type can be applied. A high-speed shear type is preferred in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shear type dispersing machine is used, the rotation speed is not particularly limited, but is generally 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is generally 0.1 to 5 minutes.
Examples of the dispersion device include batch-type emulsifiers such as Homogenizer (manufactured by IKA Corporation), Polytron (manufactured by Kinematica Corporation), and TK Auto Homo Mixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), Ebara Milder (manufactured by Ebara Corporation), TK Filmix, TK Pipeline Homo Mixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), Colloid Mill (manufactured by Kobe Steel Pantech Co., Ltd.), Ultra Visco Mill (manufactured by Imex Co., Ltd.), Slasher, and Trigonal Wet Fine Grinding Mill (manufactured by Mitsui Miike Kakoki Co., Ltd.), etc. Examples of such emulsifiers include continuous emulsifiers such as Ebara Microfluidizer (manufactured by Ebara Microfluidizer Co., Ltd.), Capitron (manufactured by Eurotech Co., Ltd.), Fine Flow Mill (manufactured by Pacific Machinery Co., Ltd.), high pressure emulsifiers such as Microfluidizer (manufactured by Mizuho Kogyo Co., Ltd.), Nanomizer (manufactured by Nanomizer Co., Ltd.), APV Gaulin (manufactured by Gaulin Co., Ltd.), membrane emulsifiers such as Membrane Emulsifier (manufactured by Reika Kogyo Co., Ltd.), vibration type emulsifiers such as Vibro Mixer (manufactured by Reika Kogyo Co., Ltd.), ultrasonic emulsifiers such as Ultrasonic Homogenizer (manufactured by Branson Co., Ltd.), etc. Among these, preferred from the viewpoint of particle size uniformity are APV Gaulin, homogenizer, TK Auto Homo Mixer, Ebara Milder, TK Filmix, and TK Pipeline Homo Mixer.

Radical polymerization can be carried out by known methods, but the polymerization temperature is selected depending on the polymerization initiator used and the molecular weight of the polyester for toner of the present invention. It is preferably 5 to 200°C, more preferably 10 to 100°C, and even more preferably 15 to 60°C. The polymerization time is preferably 1 to 48 hours, and even more preferably 2 to 24 hours. Polymerization is generally carried out by heating after dispersion, but it may be partially carried out before dispersion.

The radical reaction initiator (c) used for the crosslinking reaction of the polyester for toner of the present invention is not particularly limited, and examples thereof include inorganic peroxides (c1), organic peroxides (c2), and azo compounds (c3). Two or more of them may be used in combination.

Inorganic peroxides (c1) are not particularly limited, but examples include hydrogen peroxide, ammonium persulfate, potassium persulfate, and sodium persulfate.

The organic peroxide (c2) is not particularly limited, but examples thereof include benzoyl peroxide, di-t-butyl peroxide, t-butylcumyl peroxide, dicumyl peroxide, α,α-bis(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane, di-t-hexyl peroxide, 2,5-dimethyl-2,5-di-t-butylperoxyhexyne-3, acetyl peroxide, isobutyryl peroxide, octanyl peroxide, decanolyl peroxide, Examples include lauroyl peroxide, 3,3,5-trimethylhexanoyl peroxide, m-toluyl peroxide, t-butyl peroxy isobutyrate, t-butyl peroxy neodecanoate, cumyl peroxy neodecanoate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxy 3,5,5-trimethylhexanoate, t-butyl peroxy laurate, t-butyl peroxy benzoate, t-butyl peroxy isopropyl monocarbonate, and t-butyl peroxy acetate.

The azo compound (c3) is not particularly limited, but examples thereof include 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, 2,2'-azobis(2-methylbutyronitrile), and azobisisobutyronitrile.

In the crosslinking reaction of the polyester for toner of the present invention, a reducing agent may be used, and it is preferable to use a radical reaction initiator (c) in combination with a reducing agent.
The reducing agent is not particularly limited as long as it is a known reducing agent, and examples of the reducing agent include reducing organic compounds such as ascorbic acid, tartaric acid, citric acid, glucose, and formaldehyde sulfoxylate metal salts, and reducing inorganic compounds such as sodium thiosulfate, sodium sulfite, sodium bisulfite, sodium metabisulfite, ferric chloride, ferric sulfate (ferric sulfate (II) heptahydrate, etc.), and diphosphates.

When dispersing the toner polyester of the present invention in an aqueous solvent, the polyester is preferably liquid. If the polyester is solid at room temperature, it may be dispersed in a liquid state at a high temperature equal to or higher than the melting point, or an organic solvent solution of the polyester may be used. Using an organic solvent is preferable in that the particle size distribution is sharper.

Examples of the organic solvent include aromatic hydrocarbon solvents, aliphatic or alicyclic hydrocarbon solvents, halogenated solvents, ester or ester ether solvents, ether solvents, ketone solvents, alcohol solvents, amide solvents, sulfoxide solvents, heterocyclic compound solvents, and mixed solvents of two or more of these.
Specific examples of organic solvents include aromatic hydrocarbon solvents (toluene, xylene, ethylbenzene, tetralin, etc.); aliphatic or alicyclic hydrocarbon solvents (n-hexane, n-heptane, mineral spirits, cyclohexane, etc.); halogenated solvents such as methyl chloride, methyl bromide, methyl iodide, methylene dichloride, carbon tetrachloride, trichloroethylene, and perchloroethylene; ester or ester ether solvents such as ethyl acetate, butyl acetate, methoxybutyl acetate, methyl cellosolve acetate, and ethyl cellosolve acetate; diethyl ether, tetrahydrofuran, dioxane, ethyl cellosolve, butyl ether ... Examples of the organic solvent include ether solvents such as Rosolve and propylene glycol monomethyl ether; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, di-n-butyl ketone and cyclohexanone; alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 2-ethylhexyl alcohol and benzyl alcohol; amide solvents such as dimethylformamide and dimethylacetamide; sulfoxide solvents such as dimethylsulfoxide, heterocyclic compound solvents such as N-methylpyrrolidone, and mixed solvents of two or more of these. Among the above organic solvents, volatile ones having a boiling point of less than 100° C. are preferred. Preferred organic solvents include ethyl acetate, acetone, and methyl ethyl ketone.

When dispersing the toner polyester of the present invention in an aqueous solvent, a known surfactant (s) can be used as an emulsifier or dispersant to be used in combination. The use of surfactant (s) is preferred in that it tends to reduce the volume average particle size of the resin particles.

The surfactant (s) is not particularly limited, and examples thereof include anionic surfactants (s-1), cationic surfactants (s-2), amphoteric surfactants (s-3), and nonionic surfactants (s-4). The surfactant (s) may be a combination of two or more surfactants.

Examples of the anionic surfactant (s-1) include carboxylic acids or their salts, sulfate salts, salts of carboxymethyl compounds, sulfonates, and phosphate salts.
Examples of the cationic surfactant (s-2) include quaternary ammonium salt type surfactants and amine salt type surfactants.
Examples of the amphoteric surfactant (s-3) include carboxylate-type amphoteric surfactants, sulfate-type amphoteric surfactants, sulfonate-type amphoteric surfactants, and phosphate-type amphoteric surfactants.
Examples of the nonionic surfactant (s-4) include AO-addition type nonionic surfactants and polyhydric alcohol type nonionic surfactants.
Specific examples of these surfactants (s) include those described in JP-A No. 2002-284881.

The amount of surfactant (s) used per 100 parts by weight of water as the aqueous solvent is preferably 0 to 300 parts by weight, more preferably 0.001 to 10 parts by weight, and particularly preferably 0.01 to 5 parts by weight.

When dispersing the toner polyester of the present invention in an aqueous solvent, a known water-soluble polymer (t) can be used as an emulsifier or dispersant to be used in combination. The use of a water-soluble polymer (t) is preferable because it reduces the volume average particle size of the resin particles and tends to reduce the particle size distribution (volume average particle size/number average particle size).

Examples of the water-soluble polymer (t) include cellulose compounds (e.g., methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, ethylhydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, and saponified products thereof, etc.), gelatin, starch, dextrin, gum arabic, chitin, chitosan, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polyethyleneimine, polyacrylamide, acrylic acid (salt)-containing polymers (sodium polyacrylate, potassium polyacrylate, ammonium polyacrylate, polyacrylic acid partially neutralized with sodium hydroxide, and sodium acrylate-acrylic acid ester copolymers, etc.), styrene-maleic anhydride copolymers partially neutralized with sodium hydroxide, and water-soluble polyurethanes (polyethylene glycol, and reaction products of polycaprolactone diol, etc., with polyisocyanates, etc.).

The amount of water-soluble polymer (t) used per 100 parts by weight of water as the aqueous solvent is preferably 0 to 5 parts by weight.

The toner polyester and resin particles of the present invention are toner raw materials that are fixed to a support (paper, polyester film, etc.) by a copier, printer, etc. to become a recording material. As a method for fixing to a support, a known heat roll fixing method, flash fixing method, etc. can be used.

The resin particles of the present invention are used in toners for developing electrostatic images or magnetic latent images in electrophotography, electrostatic recording, electrostatic printing, etc. More specifically, the present invention relates to toners used for developing electrostatic images or magnetic latent images that are particularly suitable for full color applications.

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these. In the following, "parts" means "parts by weight."
In the following, Examples 5 to 12 and 17 to 24 refer to Reference Examples 1 to 8 and 9 to 16.

Example 1: Production of polyester (A-1) for toner
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 446 parts of bisphenol A PO 2-mol adduct, 335 parts of bisphenol A PO 3-mol adduct, 198 parts of terephthalic acid, 83 parts of adipic acid and 0.6 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed, and the mixture was reacted for 10 hours under a reduced pressure of 0.5 to 2.5 kPa while gradually increasing the temperature to 230°C. The acid value was confirmed to be less than 1 mgKOH/g, and a polyester having a hydroxyl group was obtained. Then, 114 parts of methacrylic anhydride was added, and the mixture was reacted at 150°C for 3 hours, and then the by-products were distilled off under a reduced pressure of 0.5 to 2.5 kPa to obtain a polyester for toner (A-1).

<Examples 2 to 11> [Production of toner polyesters (A-2) to (A-11)]
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, the polyol, polycarboxylic acid, and acid anhydride shown in Table 1 were charged, and the reaction was carried out in the same manner as in Example 1, thereby obtaining polyesters (A-2) to (A-11) for toners.

Example 12: Production of polyester for toner (A-12)
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, 508 parts of 3-methyl-1,5-pentanediol, 283 parts of terephthalic acid, 249 parts of adipic acid, and 0.6 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed, and while gradually increasing the temperature to 230°C, a reaction was carried out for 10 hours under a reduced pressure of 0.5 to 2.5 kPa. It was confirmed that the acid value was less than 1 mgKOH/g, and a polyester having hydroxyl groups was obtained. Thereafter, 81 parts of methacrylic anhydride was added, and the reaction was carried out for 3 hours at 150°C, to obtain a toner polyester (A-12).

Comparative Example 1 [Production of Polyester (A'-1) for Toner]
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, 517 parts of bisphenol A·PO 2-mol adduct, 261 parts of bisphenol A·EO 2-mol adduct, 131 parts of terephthalic acid, 24 parts of trimellitic anhydride, 145 parts of fumaric acid, and 0.6 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed, and the temperature was gradually increased and the mixture was reacted for 4 hours at 180° C. while distilling off the water generated under a nitrogen stream. The mixture was further reacted for 10 hours under a reduced pressure of 0.5 to 2.5 kPa to obtain a toner polyester (A'-1).

Comparative Example 2 [Production of Polyester (A'-2) for Toner]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 508 parts of 3-methyl-1,5-pentanediol, 283 parts of terephthalic acid, 249 parts of adipic acid and 0.5 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed, and then the temperature was gradually raised to 220°C, and the reaction was carried out for 4 hours at 220°C under a nitrogen stream while distilling off the water produced. The reaction was further carried out for 10 hours under a reduced pressure of 0.5 to 2.5 kPa. When the acid value became less than 1 mgKOH/g, the mixture was removed to obtain polyester (a'-2). Further, 1000 parts of polyester (a'-2), 2.7 parts of trimethylolpropane, 116.3 parts of isophorone diisocyanate (IPDI) and 746 parts of ethyl acetate were placed in an autoclave, and the reaction was carried out at 80°C for 10 hours in a sealed state, to obtain a solution of polyester (A'-2) for toner containing an isocyanate group at the molecular end.

Comparative Example 3 [Production of Polyester (A'-3) for Toner]
In a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, 739 parts of bisphenol A·EO 2-mol adduct, 19 parts of trimethylolpropane, 225 parts of terephthalic acid, 33 parts of adipic acid, 73 parts of acrylic acid, and 0.6 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst were placed, and the temperature was gradually increased and the mixture was reacted for 4 hours at 180° C. while distilling off the water generated under a nitrogen stream. The mixture was further reacted for 10 hours under a reduced pressure of 0.5 to 2.5 kPa to obtain a toner polyester (A'-3).

Table 1 shows the composition, glass transition temperature (Tg), weight average molecular weight (Mw), amount of polymerizable unsaturated groups, and THF insoluble content of the toner polyesters (A-1) to (A-12) and (A'-1) to (A'-3).

<Production Example 1> [Production of Polyester (B-1)]
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen inlet tube, 260 parts of bisphenol A·PO 2-mol adduct, 195 parts of bisphenol A·PO 3-mol adduct, 260 parts of bisphenol A·EO 2-mol adduct, 10 parts of trimethylolpropane, 255 parts of terephthalic acid, 45 parts of adipic acid, 0.6 parts of titanium diisopropoxy bistriethanolamine as a condensation catalyst, and reacted at 220°C under a nitrogen stream while distilling off the water generated until the acid value was 20 mgKOH/g or less, and then reacted for 10 hours under a reduced pressure of 0.5 to 2.5 kPa. Next, 30 parts by weight of trimellitic anhydride was added and held at 175°C for 1 hour to obtain an amorphous polyester (B-1).

<Production Example 2> [Production of fine particle dispersion]
In a reaction vessel equipped with a stirring rod and a thermometer, 690.0 parts of water, 9.0 parts of sodium salt of polyoxyethylene monomethacrylate sulfate "Eleminol RS-30" [manufactured by Sanyo Chemical Industries, Ltd.], 90.0 parts of styrene, 90.0 parts of methacrylic acid, 110.0 parts of butyl acrylate, and 1.0 parts of ammonium persulfate were added and stirred at 350 rpm for 15 minutes, resulting in a white emulsion. The mixture was then heated to 75°C and reacted at the same temperature for 5 hours. Furthermore, 30 parts of a 1% by weight aqueous solution of ammonium persulfate was added, and the mixture was aged at 75°C for 5 hours to obtain a fine particle dispersion of a vinyl resin (a copolymer of styrene-methacrylic acid-butyl acrylate-methacrylic acid ethylene oxide adduct sulfate sodium salt).
The volume average particle size of the particles dispersed in the fine particle dispersion was measured using a laser diffraction/scattering type particle size distribution measuring device "LA-920" (manufactured by Horiba, Ltd.) and was found to be 0.1 μm.

<Production Example 3> [Production of colorant dispersion]
A reaction vessel equipped with a stirrer, a heating/cooling device, a thermometer, a cooling tube, and a nitrogen inlet tube was charged with 557 parts of propylene glycol, 569 parts of dimethyl terephthalate, 184 parts of adipic acid, and 3 parts of tetrabutoxy titanate as a condensation catalyst, and reacted for 8 hours under a nitrogen stream at 180 ° C. while distilling off the methanol produced. Then, while gradually increasing the temperature to 230 ° C., the reaction was carried out for 4 hours under a nitrogen stream while distilling off the propylene glycol and water produced, and further reacted for 1 hour under a reduced pressure of 0.007 to 0.026 MPa. The amount of propylene glycol recovered was 175 parts. Then, the mixture was cooled to 180 ° C., 121 parts of trimellitic anhydride was added, and the mixture was reacted for 2 hours under a sealed normal pressure, and then reacted at 220 ° C. and normal pressure until the softening point reached 180 ° C. to obtain a polyester (Mn = 8,500). 20 parts of copper phthalocyanine, 4 parts by weight of a colorant dispersant "Solsperse 28000" [manufactured by Avecia Corporation], 20 parts of the obtained polyester, and 56 parts of ethyl acetate were put into a beaker and stirred to uniformly disperse the mixture. The copper phthalocyanine was then finely dispersed using a bead mill to obtain a colorant dispersion.

<Production Example 4> [Production of modified wax]
Into a pressure-resistant reaction vessel equipped with a stirrer, a heating/cooling device, a thermometer, and a dropping cylinder, 454 parts of xylene and 150 parts of low molecular weight polyethylene wax "Sanwax LEL-400" [softening point: 128°C, manufactured by Sanyo Chemical Industries, Ltd.] were charged, and after nitrogen replacement, the temperature was raised to 170°C with stirring, and a mixed solution of 595 parts of styrene, 255 parts of methyl methacrylate, 34 parts of di-t-butylperoxyhexahydroterephthalate, and 119 parts of xylene was dropped at the same temperature over 3 hours, and the mixture was further maintained at the same temperature for 30 minutes. Next, xylene was distilled off under a reduced pressure of 0.039 MPa to obtain a modified wax.

<Production Example 5> [Production of release agent dispersion]
Into a reaction vessel equipped with a stirrer, a heating/cooling device, a cooling tube, and a thermometer, 10 parts of paraffin wax "HNP-9" [maximum peak temperature of heat of fusion: 73°C, manufactured by Nippon Seiro Co., Ltd.], 1 part of the modified wax obtained in Production Example 4, and 33 parts of ethyl acetate were charged, and the temperature was raised to 78°C while stirring. After stirring at the same temperature for 30 minutes, the mixture was cooled to 30°C over one hour to crystallize the paraffin wax into fine particles. The mixture was then wet-pulverized with Ultraviscomill (manufactured by Imex) to obtain a release agent dispersion.

<Production Example 6> [Production of polyester mixed solution (AB-1)]
In a reaction vessel equipped with a stirrer, 6.8 parts of toner polyester (A-1), 53.2 parts of polyester (B-1), and 40 parts of ethyl acetate were charged and dissolved by stirring to obtain a polyester mixed solution (AB-1).

<Production Examples 7 to 17> [Production of Polyester Mixture Solutions (AB-2) to (AB-12)]
Polyester mixed solutions (AB-2) to (AB-12) were obtained in the same manner as in Production Example 6, except that the toner polyester (A-1) was replaced with toner polyesters (A-2) to (A-12).

Comparative Production Example 1 Production of Polyester Mixture Solution (A'B-1)
A polyester mixed solution (A'B-1) was obtained in the same manner as in Production Example 6, except that the toner polyester (A-1) was replaced with the toner polyester (A'-1).

Comparative Production Example 2 Production of Polyester Mixture Solution (A'B-2)
In a reaction vessel equipped with a stirrer, 11.2 parts of the toner polyester (A'-2) solution, 53.2 parts of polyester (B-1), and 35.5 parts of ethyl acetate were added and dissolved by stirring under a nitrogen stream to obtain a polyester mixed solution (A'B-2).

Comparative Production Example 3 Production of Polyester Mixture Solution (A'B-3)
A polyester mixed solution (A'B-3) was obtained in the same manner as in Production Example 6, except that the toner polyester (A-1) was replaced with the toner polyester (A'-3).

Example 13: Production of resin particles (D-1)
Into a beaker, 135 parts of ion-exchanged water, 0.5 parts of the [fine particle dispersion], 5 parts by weight of sodium carboxymethylcellulose, 34 parts of a 48.5 wt % aqueous solution of sodium dodecyl diphenyl ether disulfonate “Eleminol MON-7” [manufactured by Sanyo Chemical Industries, Ltd.], and 15 parts of ethyl acetate were placed, and the mixture was stirred to dissolve uniformly.
Next, 67 parts of the polyester mixed solution (AB-1), 20 parts of the colorant dispersion, 20 parts of the release agent dispersion, and 5 parts of ethyl acetate were added and stirred for 2 minutes at 10,000 rpm with a TK Auto Homomixer. Then, 1 part of a 30% aqueous solution of hydrogen peroxide, 1.5 parts of ascorbic acid, and 0.1 parts of iron (II) sulfate heptahydrate were added and stirred for 3 hours at 40 ° C. Then, this mixed solution was transferred to a reaction vessel equipped with a stirrer and a thermometer, and ethyl acetate was distilled off at 50 ° C. until the concentration was 0.5 wt % or less, and an aqueous resin dispersion of resin particles was obtained, followed by washing, filtration, and drying at 40 ° C. for 18 hours to reduce the volatile content to 0.5 wt % or less, and the resin particles (D-1) of the present invention were obtained.

<Examples 14 to 24> [Production of resin particles (D-2) to (D-12)]
Resin particles (D-2) to (D-12) were obtained in the same manner as in Example 13, except that the polyester mixed solution (AB-1) in Example 13 was changed to the polyester mixed solutions (AB-2) to (AB-12).

Comparative Example 4 Production of Resin Particles (D'-1)
Into a beaker, 135 parts of ion-exchanged water, 0.5 parts of the [fine particle dispersion], 5 parts by weight of sodium carboxymethylcellulose, 34 parts of a 48.5 wt % aqueous solution of sodium dodecyl diphenyl ether disulfonate “Eleminol MON-7” [manufactured by Sanyo Chemical Industries, Ltd.], and 15 parts of ethyl acetate were placed, and the mixture was stirred to dissolve uniformly.
Next, 67 parts of polyester solution (A'B-1), 20 parts of [colorant dispersion], 20 parts of [release agent dispersion], 5 parts of ethyl acetate, and 1 part of 2,2'-azobis-(2,4-dimethylvaleronitrile) were added and stirred for 2 minutes at 10,000 rpm with a TK Auto Homomixer. Next, this mixed solution was transferred to a reaction vessel equipped with a stirrer and a thermometer, and ethyl acetate was distilled off at 65°C until the concentration was 0.5% by weight or less, to obtain an aqueous resin dispersion of resin particles, which was then washed, filtered, and dried at 40°C for 18 hours to reduce the volatile content to 0.5% by weight or less, to obtain resin particles (D'-1).

Comparative Example 5 Production of Resin Particles (D'-2)
Into a beaker, 135 parts of ion-exchanged water, 0.5 parts of the fine particle dispersion, 5 parts of sodium carboxymethylcellulose, 34 parts of a 48.5 wt % aqueous solution of sodium dodecyl diphenyl ether disulfonate "Eleminol MON-7" [manufactured by Sanyo Chemical Industries, Ltd.], and 15 parts of ethyl acetate were placed and stirred to dissolve uniformly.
Next, 67 parts of polyester solution (A'B-2), 20 parts of [colorant dispersion], 20 parts of [release agent dispersion], 5 parts of ethyl acetate, and 0.13 parts of isophorone diamine were added and stirred for 2 minutes at 10,000 rpm with a TK Auto Homomixer. Next, this mixed solution was transferred to a reaction vessel equipped with a stirrer and a thermometer, and ethyl acetate was distilled off until the concentration was 0.5% by weight or less at 50°C to obtain an aqueous resin dispersion of resin particles, which was then washed, filtered, and dried at 40°C for 18 hours to reduce the volatile content to 0.5% by weight or less, thereby obtaining resin particles (D'-2).

Comparative Example 6 Production of Resin Particles (D'-3)
Into a beaker, 135 parts of ion-exchanged water, 0.5 parts of the [fine particle dispersion], 5 parts by weight of sodium carboxymethylcellulose, 34 parts of a 48.5 wt % aqueous solution of sodium dodecyl diphenyl ether disulfonate “Eleminol MON-7” [manufactured by Sanyo Chemical Industries, Ltd.], and 15 parts of ethyl acetate were placed, and the mixture was stirred to dissolve uniformly.
Next, 67 parts of polyester solution (A'B-3), 20 parts of [colorant dispersion], 20 parts of [release agent dispersion], 5 parts of ethyl acetate, and 1 part of 2,2'-azobis-(2,4-dimethylvaleronitrile) were added and stirred for 2 minutes at 10,000 rpm with a TK Auto Homomixer. Next, this mixed solution was transferred to a reaction vessel equipped with a stirrer and a thermometer, and ethyl acetate was distilled off at 65°C until the concentration was 0.5% by weight or less, to obtain an aqueous resin dispersion of resin particles, which was then washed, filtered, and dried at 40°C for 18 hours to reduce the volatile content to 0.5% by weight or less, to obtain resin particles (D'-3).

100 parts of resin particles (D-1) to (D-12) and (D'-1) to (D'-3) were mixed with 1 part of hydrophobic silica "Aerosil R972" [manufactured by Nippon Aerosil] as a flow agent in a sample mill, and the granulation properties, low-temperature fixability, heat-resistant storage stability, and charging properties were evaluated using the following methods. The evaluation results are shown in Table 2.

[Evaluation method]
The methods for measuring and evaluating the hot offset resistance, particle size distribution and electrostatic chargeability will be described below, including the criteria for evaluation.

<Hot offset resistance (hot offset occurrence temperature)>
The resin particles after the external additive treatment are uniformly placed on the paper surface to a density of 0.8 mg/ ^cm2 . The method for placing the powder on the paper surface at this time is to use a printer without a heat fixing device. Other methods may be used as long as they can uniformly place the powder at the above weight density.
The paper was passed through a pressure roller at a fixing speed (heat roller peripheral speed) of 213 mm/sec and a fixing pressure (pressure roller pressure) of 10 kg/cm ² , and the temperature at which hot offset occurred was measured to evaluate hot offset resistance.
Generally, a temperature of 170° C. or higher is considered to be preferable under these evaluation conditions.
○: Hot offset occurs at a temperature of 170° C. or higher. ×: Hot offset occurs at a temperature of less than 170° C.

<Particle size distribution>
The resin particles after the external additive treatment were each dispersed in water, and the volume average particle size and particle size distribution were measured using a Coulter counter "Multisizer III" (manufactured by Beckman Coulter, Inc.) to evaluate the granulation properties.
Regarding the granulation property, it is considered preferable that the particle size distribution is 1.20 or less when the volume average particle size is 5.0 to 5.9 μm.
◯: Particle size distribution is 1.20 or less. ×: Particle size distribution is greater than 1.20.

<Electrostatic property>
0.5 g of the resin particles after the external additive treatment and 10 g of ferrite carrier (F-150, manufactured by Powder Tech Co., Ltd.) were placed in a 50 ml glass bottle, and the bottle was conditioned at 23°C and 50% relative humidity for 8 hours or more, and then friction-stirred with a Turbula shaker mixer at 90 rpm for 2 minutes. 0.2 g of the mixed powder after stirring was loaded into a blow-off powder charge amount measuring device equipped with a stainless steel mesh with a mesh size of 20 μm, and the charge amount of the remaining ferrite carrier was measured under conditions of a blow pressure of 10 KPa and a suction pressure of 5 KPa, and the charge amount (μC/g) of the resin particles was calculated by a standard method. Note that for toner, the higher the negative charge amount, the better the charging characteristics.
For the measurement, a blow-off charge amount measuring device (manufactured by Toshiba Chemica Co., Ltd.) was used.
[Judgment criteria]
○: Less than -20 △: -20 or more and less than -15 ×: -15 or more

The resin particles of Examples 13 to 24 of the present invention exhibited excellent performance in all of hot offset resistance, particle size distribution and electrostatic chargeability.
On the other hand, in the resin particles (D'-1) using the toner polyester (A'-1) not using the acid anhydride (Z) having a polymerizable unsaturated group, the toner polyester (A'-1) has a polymerizable unsaturated group, but the reactivity of the polymerizable unsaturated group is low, and the particle size distribution and chargeability are good, but the hot offset resistance is poor. In addition, in the resin particles (D'-2) using the toner polyester (A'-2) containing an isocyanate group at the molecular end, the hot offset property and particle size distribution are good, but the chargeability is poor. Furthermore, in the resin particles (D'-3) using the toner polyester (A'-3) not using the acid anhydride (Z) having a polymerizable unsaturated group, although the toner polyester (A'-3) has a polymerizable unsaturated group, there is a large amount of insoluble matter due to a side reaction, and the hot offset property and chargeability are good, but the particle size distribution is poor.

The polyester and resin particles for toner of the present invention have good hot offset properties, particle size distribution and chargeability, and are therefore extremely useful as a toner material for developing electrostatic images used in electrophotography, electrostatic recording, electrostatic printing and the like.

Claims (6)

A polyester for a toner, which is an addition reaction product of a polyester having a hydroxyl group and an acid anhydride (Z) having a polymerizable unsaturated group, and has a polymerizable unsaturated group amount of 2×10 ⁻⁶ to 4×10 ⁻³ mol/g , wherein the polyester having a hydroxyl group is a polycondensate of a polyol and a polycarboxylic acid, and the polyol is a polyester containing an alkylene oxide adduct of bisphenol A. The polyester for toner according to claim 1, wherein the tetrahydrofuran insoluble content of the polyester for toner is 1% by weight or less. The polyester for toner according to claim 1, wherein the acid anhydride (Z) having a polymerizable unsaturated group is one or more compounds selected from the group consisting of acrylic anhydride, methacrylic anhydride, crotonic anhydride, and tiglic anhydride. Resin particles containing a crosslinked reaction product of the polyester for toner according to any one of claims 1 to 3. A method for producing ^a polyester for a toner, the method comprising an addition reaction step of a polyester having a ^hydroxyl group and an acid anhydride (Z) having a polymerizable unsaturated group, the polyester having a hydroxyl group being a polycondensate of a polyol and a polycarboxylic acid, the polyol being a polyester containing an alkylene oxide adduct of bisphenol A. The method for producing a polyester for toner according to claim 5, wherein the acid anhydride (Z) having a polymerizable unsaturated group is one or more compounds selected from the group consisting of acrylic anhydride, methacrylic anhydride, crotonic anhydride, and tiglic anhydride.