JP2016191917A - Method for manufacturing toner binder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent toner binder capable of obtaining low-temperature fixability, glossiness, hot offset resistance, and heat resistant storage stability and satisfying all of toner fluidity, charge stability, grindability, image intensity, bending resistance, and document offset properties.SOLUTION: Used is a toner binder obtained by a manufacturing method including the step of reacting the molten mixture of a polyester resin (A) obtained by polycondensing a diol component (x) including an ethylene oxide adduct (x1) of a bisphenol A and a dicarboxylic acid component (y) and having a peak molecular weight of 4,000 or more and 8,000 or less and a polyester resin (B) having a peak molecular weight of 8,000 or more and 30,000 or less with a polyvalent isocyanate compound (D) to obtain an urethane modified polyester resin (C).SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a toner binder for toner used for developing an electrostatic charge image or a magnetic latent image in electrophotography, electrostatic recording method, electrostatic printing method and the like.

  In recent years, with the development of electrophotographic systems, the demand for electrophotographic apparatuses such as copiers and laser printers is rapidly increasing, and the demands for their performance are also increasing. In general, in an electrophotographic system, an electrostatic charge image (latent image) is formed on a photoreceptor, and then the latent image is developed using toner to form a toner image. The toner image is transferred onto a recording medium such as paper and then fixed by a method such as heating.

From the viewpoint of energy saving, that is, reduction in energy consumption in the fixing process as well as promotion of miniaturization, high speed and high image quality of the electrophotographic apparatus, improvement of low temperature fixing property of toner is strongly demanded.
As a means for lowering the toner fixing temperature, a technique for lowering the glass transition point of the binder resin is generally used. However, if the glass transition point is too low, powder aggregation (blocking) is likely to occur and toner storage stability is lowered, so the lower limit of the glass transition point is practically 50 ° C. This glass transition point is a design point of the binder resin, and a toner that can be fixed at a lower temperature cannot be obtained by a method of lowering the glass transition point.
Another means is to reduce the molecular weight. However, if the molecular weight is too small, when the toner image is fixed by the hot roll fixing method, the hot roll and the molten toner are in direct contact at the time of fixing. There is a drawback that a so-called offset phenomenon is likely to occur which pollutes the transferred transfer paper or the like.

As a means for solving such a problem, for example, Patent Document 1 proposes a toner composed of a vinyl polymer that is appropriately crosslinked using a crosslinking agent and a molecular weight regulator. Document 2) proposes a toner having a wide molecular weight distribution so that the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 3.5 to 40. Certainly, although these toners expand the fixable range, that is, the temperature range between the offset generation temperature and the minimum fixing temperature, compared with the conventional uncrosslinked single resin having a narrow molecular weight distribution, it is still not sufficient.

On the other hand, toners using a reaction product of a mixture of a polymerizing resin and a polyester resin and an isocyanate have been proposed (Patent Documents 3 to 10).
However, even with this method, offset phenomenon at high temperature can be prevented to some extent, but at the same time, glossiness deteriorates and the lower limit fixing temperature increases, making it difficult to fix at low temperature. It is not answered enough.

Japanese Patent Publication No.51-2334 Japanese Patent Publication No.55-6805 JP-A 63-56659 Japanese Patent Laid-Open No. 1-154068 Japanese Patent Laid-Open No. 2-166464 JP-A-2-308175 JP-A-4-211272 JP 11-282203 A Japanese Patent Laid-Open No. 11-305481 JP 2004-258627 A

  The present invention is a toner having excellent toner fluidity, charging stability, pulverization property, image strength, folding resistance and document offset property while achieving both low-temperature fixability, glossiness, hot offset resistance and heat-resistant storage stability. It aims at providing the manufacturing method of a binder.

The inventors of the present invention have reached the present invention as a result of studies to achieve the above object.
That is, the present invention
In the method for producing a toner binder, a polyester resin having a peak molecular weight of 4,000 or more and less than 8,000 obtained by polycondensation of a diol component (x) containing an ethylene oxide adduct (x1) of bisphenol A and a dicarboxylic acid component (y) ( A step of reacting the polyisocyanate compound (D) with a molten mixture of A) and a polyester resin (B) having a peak molecular weight of 8,000 or more and 30,000 or less to obtain a urethane-modified polyester resin (C). A method for producing a toner binder characterized by the following.

  The production method of the present invention achieves both low-temperature fixability, glossiness, hot offset resistance, and heat-resistant storage stability, as well as toner fluidity, charge stability, grindability, image strength, folding resistance, and document offset. It has become possible to provide an excellent toner binder.

The urethane-modified polyester resin (C), which is an essential component contained in the toner binder of the present invention, reacts by mixing a polyvalent isocyanate compound (D) with a molten mixture of the polyester resin (A) and the polyester resin (B). Is obtained.
This polyester resin (A) is obtained by polycondensation of a diol component (x) containing an ethylene oxide adduct (x1) of bisphenol A and a dicarboxylic acid component (y), and its peak molecular weight is 4 8,000 or more and less than 8,000.
On the other hand, the peak molecular weight of the polyester resin (B) is 8,000 or more and 30,000 or less.
Below, it demonstrates sequentially.

The polyester resin (A) of the present invention is obtained by polycondensation of the diol component (x) and the dicarboxylic acid component (y). At least the bisphenol A ethylene oxide adduct (x1) is contained in the diol component (x). Including.
When the ethylene oxide adduct (x1) of bisphenol A is not used, the meltability of the obtained polyester resin (A) is deteriorated, and compared with the case where (x1) is used, low temperature fixability and heat resistant storage stability are obtained. Gets worse.

Among the ethylene oxide adducts of bisphenol A (hereinafter, “ethylene oxide” may be abbreviated as EO), the average added mole number of EO is preferably 2.0-4. 0 mol adduct, more preferably 2.0 to 3.0, and most preferably 2.0 to 2.5.

In the present invention, when the EO2 mol adduct of bisphenol A is used in the EO adduct (x1) of bisphenol A used in the polyester resin (A), the purity (content of 2 mol adduct, measurement by the following method) is From the viewpoint of heat-resistant storage stability, 85% or more is preferable, and 90% or more is more preferable.
Further, the content of the EO 1 mol adduct of bisphenol A in (x1) is preferably 1.5% or less, more preferably 1.2% or less from the viewpoint of storage stability.

The contents of bisphenol A EO 1 mol adduct, bisphenol A EO 2 mol adduct, bisphenol A EO 3 mol adduct and bisphenol A EO 4 mol adduct in the present invention are determined by the following gas chromatography method. It is a thing.

Add 1 ml of silylating agent [TMSI-H, manufactured by GL Sciences Co., Ltd.] to 30-50 mg of sample, dissolve in a hot water bath (50-70 ° C.), shake for 2 minutes to effect silylation, Separated by standing.
The supernatant liquid was analyzed by gas chromatography under the following conditions, and the unreacted product of bisphenol A, the EO 1, 2, 3, 4 mol or more of 1 mol of adduct in the peak area of adduct, 2 mol of adduct The area of the adduct, the area of the 3 mol adduct, and the area of the 4 mol adduct, expressed as a percentage, are the EO1 mol adduct content of bisphenol A, the EO2 mol adduct content, and the EO3 mol addition, respectively. The content of the product and the content of the EO 4 mol adduct.
In addition, in the EO molar adduct of bisphenol A used in Examples and Comparative Examples of the present invention, there were no unreacted bisphenol A and 5 mol or more adduct.

[Measurement conditions for gas chromatography]
Gas chromatography: GC-14B [manufactured by Shimadzu Corporation]
Carrier gas: Helium Flow rate: 5 mL / min Detector: Hydrogen flame ionization detector Hydrogen pressure: 0.6 kg / cm ²
Air pressure: 0.5 kg / cm ²
Column temperature: 200 to 300 ° C. (temperature increase rate: 15 ° C./min)

The content of the EO adduct (x1) of bisphenol A in the diol component (x) of the polyester resin (A) is usually 30 to 100 mol%, preferably 50 to 100 mol%, from the viewpoint of fixability. In addition, the amount removed outside the system under reduced pressure during the polycondensation reaction is excluded.

The polyester resin (A) and the polyester resin (B) of the present invention are distinguished by their peak molecular weight (hereinafter sometimes abbreviated as Mp), and the Mp of the polyester resin (A) is 4,000 or more and 8,000. On the other hand, the Mp of the polyester resin (B) is 8,000 or more and 30,000 or less. A polyester resin having an Mp of less than 4,000 and a polyester resin having an Mp of more than 30,000 do not correspond to (A) or (B) of the present invention.
Moreover, two or more types may be contained as (A), and two or more types may be contained as (B).

The peak molecular weight was calculated from the relationship between the logarithmic value of the calibration curve prepared from the standard polystyrene sample and the number of counts, and the peak molecular weight obtained from the peak maximum value in the obtained molecular weight distribution chart. Molecular weight.
Since the number of peaks in the chart is not limited to one, when there are a plurality of peaks, the peak molecular weight is obtained by adopting the peak having the maximum count number among the plurality of peaks.
In addition, it measures by gel permeation chromatography (GPC) and the measurement conditions are as follows.

In the present invention, the peak molecular weight, number average molecular weight (hereinafter sometimes abbreviated as Mn), and weight average molecular weight (hereinafter sometimes abbreviated as Mw) of a resin such as a polyester resin are measured using GPC. It can be measured under the following conditions.
Device (example): HLC-8120 manufactured by Tosoh Corporation
Column (example): TSK GEL GMH6 2 [Tosoh Corp.]
Measurement temperature: 40 ° C
Sample solution: 0.25 wt% THF solution Solution injection amount: 100 μl
Detection device: Refractive index detector Reference material: Tosoh Co., Ltd. standard polystyrene (TSK standard POLYSTYRENE) 12 points (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)
The molecular weight is measured by dissolving a polyester resin or the like in THF so as to be 0.25% by weight, and filtering the insoluble matter with a glass filter.

In producing the urethane-modified polyester resin (C) of the toner binder of the present invention, the Mp of the polyester resin (A) and the Mp of the polyester resin (B) are important from the viewpoint of achieving both low-temperature fixability and hot offset resistance. .

  Specifically, the Mp of the polyester resin (A) of the present invention is 4,000 or more and less than 8,000, preferably 4,250 to 8,000, more preferably 4,500 to 8,000. . When (A) less than 4,000 is used, the hot offset resistance deteriorates, and when (A) of 8,000 or more is used, low-temperature fixability deteriorates.

On the other hand, Mp of the polyester resin (B) of the present invention is 8,000 or more and 30,000 or less, preferably 8,000 to 25,000, and more preferably 8,000 to 20,000. When (B) less than 8,000 is used, hot offset resistance deteriorates, and when (B) exceeding 30,000 is used, low-temperature fixability deteriorates.

The hydroxyl value of the polyester resin (A) of the present invention is preferably 5 mgKOH / g or less, more preferably 3 mgKOH / g or less, particularly preferably 1 mgKOH / g or less.
When the hydroxyl value is 5 mgKOH / g or less, for example, the polyvalent isocyanate compound (D) is mixed and reacted with a molten mixture of the polyester resin (A) and the polyester resin (B) to react with the urethane-modified polyester resin (C). In the case of preparing the toner, the reaction points of the polyester resin (A) are reduced, the viscosity of the polyester resin (A) can be reduced, and the low-temperature fixability and glossiness when used as a toner are improved.

On the other hand, the hydroxyl value of the polyester resin (B) is preferably 10 KOHmg / g or more and 80 KOHmg / g or less, more preferably 25 to 55 KOHmg / g, and still more preferably 35, from the viewpoint of reactivity with the polyvalent isocyanate compound (D). ~ 45 KOH mg / g.
When the hydroxyl value is 80 mgKOH / g or less, the low-temperature fixability and glossiness when used as a toner are improved.

The hydroxyl value of the polyester resin can be measured by a method specified in JIS K0070 (1992 version).

The glass transition temperature (hereinafter sometimes abbreviated as Tg) of the polyester resin (A) of the present invention is preferably 50 to 80 ° C, more preferably 52 to 70 ° C, and further preferably 55 to 65 ° C. It is. When the Tg is 80 ° C. or lower, the low-temperature fixability is improved, and when it is 50 ° C. or higher, the heat resistant storage stability is improved.

On the other hand, the glass transition temperature (Tg) of the polyester resin (B) is preferably -35 ° C to 45 ° C. When the Tg is 45 ° C. or lower, the low-temperature fixability is good, and when it is −35 ° C. or higher, the heat resistant storage stability is good.
In addition, glass transition temperature (Tg) can be measured by the method (DSC method) prescribed | regulated to ASTM D3418-82, for example using Seiko Instruments Co., Ltd. DSC20 and SSC / 580.

The weight ratio (A) / (B) of the polyester resin (A) to the polyester resin (B) of the present invention is preferably 55/45 to 99 from the viewpoint of compatibility between low-temperature fixability, hot offset resistance and glossiness. / 1, more preferably 80/20 to 97/3, particularly preferably 90/10 to 95/5.

The polyester resin (A) and the polyester resin (B) in the present invention are obtained by polycondensing one or more diol components (x) and one or more dicarboxylic acid components (y). In addition to the diol component (x), a monoalcohol or a tri- to octa- or higher-valent polyol component may be used in combination as the alcohol component.

Examples of the diol component (x) include alkylene glycols having 2 to 36 carbon atoms (ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 3methyl-1,5-pentanediol. 1,6-hexanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, etc.);
C4-C36 alkylene ether glycol (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); C6-C36 alicyclic diol (1,4-cyclohexane) 2,2′-bis (4-hydroxycyclohexyl) propane of dimethanol and hydrogenated bisphenol A, etc.);
(Poly) oxyalkylene of the above alicyclic diol [polyoxyalkylene group having 2 to 4 carbon atoms (oxyethylene, oxypropylene, etc.) of the alkylene group is the same] ether [oxyalkylene unit (hereinafter abbreviated as AO unit) 1) to 30];
Bivalent phenol [monocyclic dihydric phenol (for example, hydroquinone), polyoxyalkylene ether of bisphenol excluding ethylene oxide adduct (X1) of bisphenol A (number of AO units: 2 to 30)], and the like.

Polyoxyalkylene ethers of bisphenols are usually obtained by adding alkylene oxide (hereinafter sometimes abbreviated as AO) to bisphenols. Examples of the bisphenol excluding the ethylene oxide adduct (X1) of bisphenol A include those represented by the following general formula (1).

OH-Ar-X-Ar-OH (1)
[Wherein X represents an alkylene group having 1 to 3 carbon atoms, —SO ₂ —, —O—, —S—, or a direct bond; Ar represents a halogen atom or an alkyl group having 1 to 30 carbon atoms; Represents an optionally substituted phenylene group. ]

  Specifically, for example, 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, and two or more of these may be used in combination.

The alkylene oxide added to these bisphenols is preferably an alkylene oxide having 2 to 4 carbon atoms, specifically, propylene oxide (hereinafter sometimes abbreviated as PO), 1,2-, 2, 3-, 1,3- or iso-butylene oxide, tetrahydrofuran and a combination of two or more thereof may be mentioned.

In addition to the dicarboxylic acid component (y), a monocarboxylic acid or a tri- or hexavalent or higher polycarboxylic acid component may be used in combination as the carboxylic acid component.

  Examples of the dicarboxylic acid (y) include alkane dicarboxylic acids having 2 to 50 carbon atoms (such as oxalic acid, malonic acid, succinic acid, adipic acid, repartic acid, and sebacic acid), and alkene dicarboxylic acids having 4 to 50 carbon atoms (dodecenyl succinic acid). Alkenyl succinic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, glutaconic acid, etc., C8-36 aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.) ), Vinyl polymer of unsaturated carboxylic acid [number average molecular weight (hereinafter referred to as Mn, according to gel permeation chromatography (GPC)): 450 to 10,000] (α-olefin / maleic acid copolymer, etc.), etc. Is mentioned.

  Examples of polycarboxylic acid components having 3 to 6 or more valences include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid), and aliphatic tricarboxylic acids having 6 to 36 carbon atoms. (Hexane tricarboxylic acid, etc.), vinyl polymer of unsaturated carboxylic acid [Mn: 450-10,000] (styrene / maleic acid copolymer, styrene / acrylic acid copolymer, styrene / fumaric acid copolymer, etc. ) And the like.

  As the carboxylic acid component, anhydrides and lower alkyl (carbon number 1 to 4) esters (methyl ester, ethyl ester, isopropyl ester, etc.) of these carboxylic acids may be used or used in combination with other carboxylic acid components. May be.

Among these carboxylic acid components, those preferable from the viewpoint of achieving both low-temperature fixability and hot offset resistance are alkane dicarboxylic acids having 2 to 50 carbon atoms, alkenedicarboxylic acids having 4 to 50 carbon atoms, and 7 to 20 carbon atoms. Aromatic carboxylic acids, aromatic dicarboxylic acids having 8 to 20 carbon atoms, and aromatic polycarboxylic acids having 9 to 20 carbon atoms.
More preferably from the viewpoint of storage stability, adipic acid, alkenyl succinic acid having 16 to 50 carbon atoms, terephthalic acid, isophthalic acid, maleic acid, fumaric acid, benzoic acid, trimellitic acid, pyromellitic acid, and combinations thereof It is.
Particularly preferred are adipic acid, terephthalic acid, benzoic acid, trimellitic acid, and combinations thereof. Likewise preferred are anhydrides and lower alkyl esters of these acids.

In the present invention, each polyester resin can be produced in the same manner as a normal polyester production method.
For example, the reaction can be performed in an inert gas (nitrogen gas or the like) atmosphere at a reaction temperature of preferably 150 to 280 ° C, more preferably 160 to 250 ° C, and particularly preferably 170 to 235 ° C. The reaction time is preferably 30 minutes or more, particularly preferably 2 to 40 hours, from the viewpoint of reliably performing the polycondensation reaction. It is also effective to reduce the pressure in order to improve the reaction rate at the end of the reaction.

As the polymerization catalyst, it is preferable to use a polymerization catalyst containing one or more metals selected from tin, titanium, antimony, zirconium, nickel, and aluminum. From the viewpoint of reactivity and environmental protection, a titanium-containing catalyst is used. Is more preferable.
Examples of the titanium-containing catalyst include titanium alkoxide, potassium oxalate titanate, titanium terephthalate, and catalysts described in JP-A-2006-243715 [titanium dihydroxybis (triethanolamate), titanium monohydroxytris (triethanolaminate). And their intramolecular polycondensates], and catalysts described in JP-A 2007-11307 (titanium tributoxy terephthalate, titanium triisopropoxy terephthalate, titanium diisopropoxy diterephthalate, etc.) and the like. .
Antimony trioxide etc. are mentioned as an antimony containing catalyst.
Zirconyl acetate etc. are mentioned as a zirconium containing catalyst.
Nickel acetylacetonate etc. are mentioned as a nickel containing catalyst.
Examples of the aluminum-containing catalyst include aluminum hydroxide and aluminum triisopropoxide.

The amount of the catalyst added is desirably determined as appropriate so as to maximize the reaction rate. The addition amount is preferably 10 ppm to 1.9%, more preferably 100 ppm to 1.7%, based on the total raw materials. The amount added is preferably 10 ppm or more, so that the reaction rate is increased.
In the above and the following, “%” means “% by weight” unless otherwise specified.

  The reaction ratio between the alcohol component and the carboxylic acid component is preferably 2/1 to 1/2, more preferably 1.5 / 1 to 1/1, as the equivalent ratio [OH] / [COOH] of the hydroxyl group to the carboxyl group. .3, particularly preferably 1.4 / 1 to 1 / 1.2.

  The toner binder of the present invention contains a urethane-modified polyester resin (C), and this urethane-modified polyester resin (C) is added to a polyisocyanate compound (A) and a polyester resin (B) in a molten mixture. D) is obtained by mixing and reacting.

In the urethane-modified polyester resin (C) obtained by the above-described method, the polyvalent isocyanate compound (D) as an extender reacts with the molten mixture to effectively cause a crosslinking reaction. It is preferable because the property is improved.

  Examples of the polyvalent isocyanate compound (D) used for this purpose include a divalent diisocyanate compound (D2) and a 3-8 valent polyisocyanate compound (D1).

Examples of the divalent diisocyanate compound (D2) include aliphatic diisocyanate compounds, alicyclic diisocyanates, and aromatic diisocyanate compounds.

Examples of the aliphatic diisocyanate compound include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4. Examples include 4-trimethylhexamethylene diisocyanate.

Examples of the alicyclic diisocyanate compound include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, Examples include hydrogenated tolylene diisocyanate and hydrogenated tetramethylxylylene diisocyanate.

Examples of the aromatic diisocyanate compound include phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate (TDI), 2,2′-didiphenylmethane diisocyanate (MDI), and 4,4′-diphenylmethane. Examples include diisocyanate, 4,4′-toluidine diisocyanate, 4,4′-diphenyl ether diisocyanate, 4,4′-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, and xylylene diisocyanate.

Of the divalent diisocyanate compounds (D2), preferred are aromatic diisocyanates having 6 to 15 carbon atoms, aliphatic diisocyanates having 4 to 12 carbon atoms, and alicyclic diisocyanates having 4 to 15 carbon atoms. TDI, MDI, HDI, hydrogenated MDI, and IPDI.

Although it will not specifically limit as a 3-8 valent polyisocyanate compound (D1) if it is a compound which has 3-8 isocyanate groups, The compound etc. which contain the chemical structure of a triisocyanate, tetraisocyanate, isocyanurate, biuret, etc. are mentioned. It is done.

Examples of the triisocyanate compound include a compound represented by the following chemical formula (1).

[Wherein, R ₁ represents an alkyl group, and R ₂ represents an alkylene group. ]

Examples of the tetraisocyanate compound include a compound represented by the following chemical formula (2).

[Wherein R ₂ represents an alkylene group. ]

Examples of the compound having an isocyanurate structure include an isocyanurate trimer and an isocyanurate pentamer, and also an isocyanurate heptamer and a multimer more than a 9-mer.
The isocyanurate trimer is a polyisocyanate composed of three diisocyanate monomers and having an isocyanurate group, and examples thereof include compounds represented by the following chemical formula (3).

  [Wherein R represents a diisocyanate monomer residue. ]

The isocyanurate pentamer is a polyisocyanate having an isocyanurate structure composed of 6 molecules of a diisocyanate monomer, and examples thereof include compounds represented by the following chemical formula (4).

  [Wherein R represents a diisocyanate monomer residue. ]

The compound having a biuret structure is formed from urea and an isocyanate group, and examples thereof include a compound represented by the following chemical formula (5).

[Wherein R represents a diisocyanate monomer residue. ]

Of the above polyisocyanate compounds (D), from the viewpoints of low-temperature fixability, offset resistance, and heat-resistant storage stability, 3 to 8 valent polyisocyanate compounds (D1) are preferable.
Furthermore, the polyisocyanate compound (D11) containing the chemical structure of isocyanurate and biuret is more preferable among the 3-8 valent polyisocyanate compounds (D1).

The urethane-modified polyester resin (C) of the present invention is obtained by a step of mixing and reacting a polyisocyanate compound (D) with a molten mixture of the polyester resin (A) and the polyester resin (B).

The method for carrying out the reaction by mixing the polyvalent isocyanate compound (D) is not particularly limited, and may be melt-mixed in a reaction vessel or heated and melted with a twin-screw extruder.
For example, a mixture of a polyester resin (A) and a polyester resin (B) is poured into a twin-screw extruder at a constant speed, and at the same time, a polyvalent isocyanate compound (D) is also poured at a constant speed and reacted while being kneaded and conveyed at 150 ° C. A method in which the polyester resin (A) and the polyester resin (B) are charged in a reaction vessel, heated to a temperature at which the solution is brought into a solution state, and mixed.

When using a twin-screw extruder, the polyester resin (A) and the polyester resin (B), which are reaction raw materials charged or injected into the twin-screw extruder, are directly fed directly to the extruder without cooling from the resin reaction solution. You may make it inject | pour, You may carry out by supplying what cooled and grind | pulverized resin once manufactured to a twin-screw extruder.

When the toner is prepared, the toner binder and the colorant of the present invention are contained.

As the colorant, all of dyes and pigments used as toner colorants can be used. Specifically, carbon black, iron black, Sudan Black SM, First Yellow G, Benzidine Yellow, Pigment Yellow, Indian First Orange, Irgasin Red, Paranitroaniline Red, Toluidine Red, Carmine FB, Pigment Orange R, Lake Red 2G, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lake, Phthalocyanine Blue, Pigment Blue, Brilliant Green, Phthalocyanine Green, Oil Yellow GG, Kayaset YG, Orazole Brown B, Oil Pink OP, etc. Or 2 or more types can be mixed and used. Further, if necessary, magnetic powder (a powder of a ferromagnetic metal such as iron, cobalt, or nickel or a compound such as magnetite, hematite, or ferrite) can also be included as a colorant.
The content of the colorant is preferably 1 to 40 parts by weight, more preferably 3 to 10 parts by weight with respect to 100 parts by weight of the toner binder of the present invention. In addition, when using magnetic powder, Preferably it is 20-150 weight part, More preferably, it is 40-120 weight part.

  When the toner is prepared, in addition to the toner binder and the colorant, if necessary, the toner contains one or more additives selected from a release agent, a charge control agent, a fluidizing agent, and the like.

  As the mold release agent, those having a softening point [Tm] of 50 to 170 ° C. by a flow tester are preferable, polyolefin wax, natural wax, aliphatic alcohol having 30 to 50 carbon atoms, fatty acid having 30 to 50 carbon atoms, and these A mixture etc. are mentioned.

  Polyolefin waxes include (co) polymers [obtained by (co) polymerization] of olefins (for example, ethylene, propylene, 1-butene, isobutylene, 1-hexene, 1-dodecene, 1-octadecene, and mixtures thereof). And olefin (co) polymer oxides with oxygen and / or ozone, maleic acid modifications of olefin (co) polymers [eg maleic acid and its derivatives (maleic anhydride, Modified products such as monomethyl maleate, monobutyl maleate and dimethyl maleate), olefins and unsaturated carboxylic acids [such as (meth) acrylic acid, itaconic acid and maleic anhydride] and / or unsaturated carboxylic acid alkyl esters [(meta ) Alkyl acrylate (alkyl 1 to 1 carbon atoms) 8) esters and maleic acid alkyl (C1-18 alkyl) copolymers of an ester, etc.] or the like, and Sasol wax.

  Examples of natural waxes include carnauba wax, montan wax, paraffin wax, and rice wax. Examples of the aliphatic alcohol having 30 to 50 carbon atoms include triacontanol. Examples of the fatty acid having 30 to 50 carbon atoms include triacontane carboxylic acid.

  As charge control agents, nigrosine dyes, triphenylmethane dyes containing tertiary amines as side chains, quaternary ammonium salts, polyamine resins, imidazole derivatives, quaternary ammonium base-containing polymers, metal-containing azo dyes, copper phthalocyanine dyes , Salicylic acid metal salts, boron complexes of benzylic acid, sulfonic acid group-containing polymers, fluorine-containing polymers, halogen-substituted aromatic ring-containing polymers, and the like.

Examples of the fluidizing agent include colloidal silica, alumina powder, titanium oxide powder, and calcium carbonate powder.

The release agent is 0 to 30% by weight, preferably 0.5 to 20% by weight, particularly preferably 1 to 10% by weight, based on the toner weight.
The charge control agent is 0 to 20% by weight, preferably 0.1 to 10% by weight, particularly preferably 0.5 to 7.5% by weight, based on the toner weight.
The fluidizing agent is 0 to 10% by weight, preferably 0 to 5% by weight, particularly preferably 0.1 to 4% by weight, based on the toner weight.
The total amount of additives is 3 to 70% by weight, preferably 4 to 58% by weight, particularly preferably 5 to 50% by weight, based on the toner weight. When the composition ratio of the toner is in the above range, a toner having good chargeability can be easily obtained.

When the toner is prepared, it may be obtained by any known method such as kneading and pulverizing method, emulsion phase inversion method, polymerization method and the like.
For example, when a toner is obtained by a kneading and pulverizing method, the components constituting the toner excluding the fluidizing agent are dry blended, and then melt-kneaded, then coarsely pulverized, and finally atomized using a jet mill pulverizer or the like. Further, by further classifying, the volume average particle diameter (D50) is preferably 5 to 20 μm and then mixed with a fluidizing agent.
The particle size (D50) is measured using a Coulter counter [for example, trade name: Multisizer III (manufactured by Coulter)].
When the toner is obtained by the emulsion phase inversion method, the components constituting the toner excluding the fluidizing agent are dissolved or dispersed in an organic solvent, and then emulsified by adding water, etc., and then separated and classified. it can. The volume average particle diameter of the toner is preferably 3 to 15 μm.

  The toner is mixed with carrier particles such as iron powder, glass beads, nickel powder, ferrite, magnetite, and ferrite whose surface is coated with resin (acrylic resin, silicone resin, etc.) as necessary to develop an electrical latent image. Used as an agent. The weight ratio of toner to carrier particles is usually 1/99 to 100/0. In addition, instead of carrier particles, it can be rubbed with a member such as a charging blade to form an electrical latent image.

  The toner is fixed on a support (paper, polyester film, etc.) by a copying machine, a printer or the like to be used as a recording material. As a method for fixing to the support, a known hot roll fixing method, flash fixing method, or the like can be applied.

  Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these. Hereinafter, unless otherwise specified, “%” represents “% by weight” and “parts” represents “parts by weight”.

<Production Example 1> [Production of bisphenol A EO adduct (X1-2)]
In a reaction vessel equipped with a stirrer and a nitrogen introduction tube, an average 2.2 mol adduct of bisphenol A EO (X1-1) (Sanyo Chemical Industries Newpol BPE-20: purity of EO2 mol adduct of about 81 %) 500 parts were charged and the temperature was raised to 120 ° C. After dissolving at 120 ° C., it was cooled to 100 ° C. Thereto, 500 parts of ion-exchanged water at 100 ° C. was charged and stirred at 100 ° C. for 1 hour, and then the upper aqueous phase was extracted. After repeating this three times, dehydration was performed at 130 ° C. under a reduced pressure of 0.5 to 2.5 kPa for 4 hours, the content of EO1 mol adduct of bisphenol A was 1.2%, and the EO2 mol adduct of bisphenol A. The average 2.0 mol adduct (X1-2) of EO of bisphenol A having a EO content of 93% and an EO content of bisphenol A of 4.8% was obtained.

<Production Example 2> [Production of bisphenol A EO adduct (X1-3)]
In a pressurized reaction vessel equipped with a stirrer and a nitrogen introducing tube, 277 parts of bisphenol A, 138.5 parts of ion-exchanged water, and 2 parts of triethylamine were charged, and nitrogen substitution was performed twice. Thereafter, the temperature was raised to 130 ° C., and 176 parts of EO was added dropwise over 2 hours under a pressure of 0.3 MPa. Then, it was made to react for 2 hours and took out. Thereafter, dehydration was performed at 130 ° C. under reduced pressure of 0.5 to 2.5 kPa for 4 hours, the content of EO1 mol adduct of bisphenol A was 0.1%, the content of EO2 mol adduct of bisphenol A was 18%, An average of 3.0 mol adduct (X1-3) of EO of bisphenol A having an EO3 mol adduct content of bisphenol A of 69% and an EO4 mol adduct content of bisphenol A of 13% was obtained.

<Production Example 3> [Production of polyester resin (A-1)]
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 678 parts (100.0 mol%) of bisphenol A · EO adduct (X1-2), 77 parts (25.3 mol%) of benzoic acid, As a condensation catalyst, 1.5 parts of dibutyltin oxide was added and reacted at 200 ° C. in a nitrogen stream for 4 hours while distilling off generated water. Next, 280 parts (67.6 mol%) of terephthalic acid and 1.5 parts of dibutyltin oxide as a condensation catalyst were added, and then the temperature was gradually raised to 230 ° C., and the pressure was reduced to 0.5 to 2.5 kPa. Reacted for hours. Next, the mixture was cooled to 180 ° C., 34 parts (7.1 mol%) of trimellitic anhydride was added, reacted for 2 hours under normal pressure sealing, and then reacted at 220 ° C. and normal pressure, when the hydroxyl value was less than 5. To obtain a polyester resin (A-1).
The polyester resin (A-1) had a peak average molecular weight of 6,500 and a hydroxyl value of 0.

<Production Examples 4 to 6> [Production of polyester resin (A-2), (A-3), (A-4)]
Into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, the alcohol component and carboxylic acid component described in Table 1 were charged, and the reaction was conducted in the same manner as in Production Example 3 except that the polyester resin (A-2 ), (A-3) and (A-4) were obtained.
Table 1 shows the peak molecular weight and the hydroxyl value.

<Comparative Production Examples 1 and 2> [Production of Polyester Resins (A′-1) and (A′-2)]
Into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, the alcohol component and the carboxylic acid component described in Table 1 were charged, and the reaction was conducted in the same manner as in Production Example 3 except that the polyester resin (A′- 1) and (A′-2) were obtained.
In Comparative Production Example 2, bisphenol A / PO 2.0 mol adduct (Hymer BP-2P manufactured by Sanyo Chemical Industries) was used as the alcohol component.
Since the polyester resin (A′-1) has a peak molecular weight of 1,900, it does not correspond to the polyester resin (A) of the present invention. Further, since the polyester resin (A′-2) does not use the EO adduct (X1) of bisphenol A, it does not correspond to the polyester resin (A) of the present invention.

<Production Example 7> [Production of polyester resin (B-1)]
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 204 parts (16.2 mol%) of Bisphenol A · PO 2.0 mol adduct (Sanyo Kasei Kogyo Himer BP-2P), 3-methyl 1 , 5-pentanediol 346 parts (81.0 mol%), trimethylolpropane 13 parts (2.8 mol%), terephthalic acid 557 parts (100.0 mol%) and tetrabutoxy titanate 1 part as a condensation catalyst The reaction was carried out for 4 hours at 220 ° C. while distilling off the water produced under a nitrogen stream. Furthermore, it was made to react under the reduced pressure of 0.5-2.5 kPa for 10 hours. The polyester resin (B-1) was obtained by taking out when the acid value became less than 1.
The peak molecular weight of the polyester resin (B-1) was 8,700, Tg was 16 ° C., and the hydroxyl value was 35.

<Production Example 8> [Production of polyester resin (B-2)]
Into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, the alcohol component and carboxylic acid component described in Table 2 were charged, and the reaction was carried out in the same manner as in Production Example 7 except that the polyester resin (B-2 ) Table 2 shows the peak molecular weight, Tg, and hydroxyl value.

<Comparative Production Example 3> [Production of polyester resin (B′-1)]
Into a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, the alcohol component and the carboxylic acid component described in Table 2 were charged, and the reaction was conducted in the same manner as in Production Example 7 except that the polyester resin (B′- 1) was obtained. Table 2 shows the peak molecular weight, Tg, and hydroxyl value.
Since this polyester resin (B′-1) has a peak molecular weight of 55,000, it does not correspond to the polyester resin (B) of the present invention.

<Example 1> [Production of urethane-modified polyester resin (C-1)]
After 90 parts of the polyester resin (A-1) and 10 parts of the polyester resin (B-1) are powder-mixed, they are supplied to a twin-screw kneader (Kurimoto Iron Works, S5KRC kneader) at 10 kg / hr. As the isocyanate compound (D), Duranate TPA-100 (isocyanurate compound, manufactured by Asahi Kasei Chemicals) (D-1) (3.4 parts) was supplied at 0.34 kg / hr, and a kneading extrusion reaction was performed at 150 ° C. for 30 minutes. What was obtained was cooled and resin (C-1) was obtained.

<Examples 2 to 5> [Production of urethane-modified polyester resins (C-2) to (C-5)]
According to Example 1, polyester resins (A-1) to (A-4) shown in Table 3, polyester resins (B-1) and (B-2), and an extender (D-1) were charged. Reaction was performed and resin (C-2)-(C-5) was obtained.

<Comparative Examples 1-5> [Production of Resins (C′-1) to (C′-5)]
Polyester resins (A-1), (A-2), (A′-1), (A′-2) and polyester resins (B-1), (B-2), (B ′) shown in Table 3 -1) and an extender (D-1) were charged and reacted according to Example 1 to obtain resins (C′-1) to (C′-5).

Example 6 [Production of Toner (T-1)]
Resin (C-1) 85 parts, pigment carbon black MA-100 [Mitsubishi Chemical Co., Ltd.] 6 parts, mold release carnauba wax 4 parts, charge control agent T-77 [Hodogaya Chemical ( Manufactured)] 4 parts were added, and toner was formed by the following method. First, after premixing using a Henschel mixer [FM10B manufactured by Mitsui Miike Chemical Co., Ltd.], the mixture was kneaded using a biaxial kneader [PCM-30 manufactured by Ikegai Co., Ltd.]. Next, the mixture was finely pulverized using a supersonic jet crusher lab jet [manufactured by Nippon Pneumatic Industry Co., Ltd.] and then classified by an airflow classifier [MDS-I made by Nippon Pneumatic Industry Co., Ltd.] Toner particles having a D50 of 8 μm were obtained.
Next, 100 parts of toner particles were mixed with 1 part of colloidal silica (Aerosil R972: manufactured by Nippon Aerosil Co., Ltd.) as a fluidizing agent in a sample mill to obtain toner (T1) of the present invention.

<Examples 7 to 10> [Production of Toners (T-2) to (T-5)]
Toners were produced in the same manner as in Example 6 with reference to Table 4, and toners (T-2) to (T-5) were obtained. Next, evaluation was made in the same manner as in Example 6, and the results are shown in Table 4.

<Comparative Examples 6 to 10> [Production of Toners (T′-1) to (T′-5)]
Toners were prepared in the same manner as in Example 6 with reference to Table 4, with reference to Table 4. Toners (T′-1) to (T′-5) were obtained. Next, evaluation was made in the same manner as in Example 6, and the results are shown in Table 4.

[Evaluation method]
Low-temperature fixability, glossiness, hot offset resistance, fluidity, heat-resistant storage stability, charge stability, grindability, image strength, folding resistance, document offset test measurement method, evaluation method, and toner obtained below The criteria will be described.

<Low temperature fixability>
The toner is uniformly placed on the paper so as to be 0.8 mg / cm ² . At this time, as a method of placing the powder on the paper surface, a printer from which the heat fixing machine is removed is used. Other methods may be used as long as the powder can be uniformly loaded with the above-described weight density.
The cold offset generation temperature (MFT) was measured when this paper was passed through a pressure roller under conditions of a fixing speed (heating roller peripheral speed) of 213 mm / sec and a fixing pressure (pressure roller pressure) of 10 kg / cm ² .
The lower the temperature at which cold offset occurs, the better the low-temperature fixability.

<Glossiness>
Fixation evaluation is performed in the same manner as low-temperature fixability. White cardboard was laid under the image, and the glossiness (%) of the printed image was measured at an incident angle of 60 degrees using a gloss meter (“IG-330” manufactured by Horiba, Ltd.). Higher gloss means better gloss.

<Hot offset resistance (hot offset temperature)>
Fixation was evaluated in the same manner as the low-temperature fixability, and the presence or absence of hot offset on the fixed image was visually evaluated.
The temperature at which hot offset occurred after passing through the pressure roller was defined as hot offset resistance (° C.).

<Fluidity>
The toner bulk density (g / 100 ml) was measured with a powder tester manufactured by Hosokawa Micron, and the fluidity was determined according to the following criteria.

[Criteria]
○: 30 or more Δ: 25 or more and less than 30
X: Less than 25

<Heat resistant storage stability>
The toner was allowed to stand in an atmosphere of 50 ° C. for 24 hours, the degree of blocking was judged visually, and the heat resistant storage stability was evaluated according to the following criteria.
[Criteria]
○: Blocking has not occurred.
Δ: Blocking occurs in part.
X: Blocking has occurred throughout.

<Charging stability>
(1) 0.5 g of toner and 20 g of a ferrite carrier (F-150, manufactured by Powdertech) are placed in a 50 ml glass bottle, and the humidity is adjusted at 23 ° C. and a relative humidity of 50% for 8 hours or more.
(2) Friction stirring was performed at 50 rpm × 20 minutes and 60 minutes with a tumbler shaker mixer, and the charge amount at each time was measured.
For the measurement, a blow-off charge measuring device [manufactured by Toshiba Chemical Co., Ltd.] was used.
“Charging amount of 60 minutes of friction time / charging amount of 20 minutes of friction time” was calculated and used as an index of charging stability.

[Criteria]
○: 0.7 or more Δ: 0.6 or more and less than 0.7 ×: less than 0.6

<Crushability>
A coarsely pulverized product (8.6 mesh pass to 30 mesh on) kneaded and cooled by a twin-screw kneader is finely pulverized under the following conditions by a supersonic jet pulverizer, Labo Jet (manufactured by Nippon Pneumatic Industry Co., Ltd.). Crushed.
Crushing pressure: 0.5 MPa
Grinding time: 10 minutes Adjuster ring: 15 mm
Size of louver: The volume average particle size (μm) was measured with Coulter Counter-TAII (manufactured by Coulter Electronics, USA) without classifying the louver, and the grindability was evaluated according to the following criteria.

[Criteria]
A: Less than 10 μm ○: 10 μm or more and less than 11 μm Δ: 11 μm or more and less than 12 μm X: 12 μm or more

<Image intensity>
The image fixed in the evaluation of the low temperature fixability was subjected to a scratch test by applying a load of 10 g from right above the pencil fixed at an angle of 45 degrees according to JIS K5600, and the image strength was evaluated from the pencil hardness without scratches. .
Higher pencil hardness means better image strength.

<Bending resistance>
The image fixed in the evaluation of the low-temperature fixability is folded so that the image surface is on the inside, and rubbed three times with a load of 30 g.
The presence or absence of white streaks after the paper was spread and folded on the image was visually judged.
[Criteria]
○: No white streak
Δ: Slight white streak ×: White streak

<Document offset property>
Two sheets of A4 paper on which an image obtained by evaluation of low-temperature fixability is fixed are overlapped with each other on a fixing surface, applied with a weight of 420 g (0.68 g / cm ² ), and left at 60 ° C. for 30 minutes. .
The document offset property was evaluated according to the following criteria for the state when the stacked papers were pulled apart.

[Criteria]
○: No resistance △: Crisp sound but image does not peel off from paper ×: Image peels off from paper

As is clear from the evaluation results in Table 4, all of the toners of Examples 6 to 10 of the present invention were excellent in performance evaluation.
On the other hand, the toner of Comparative Example 6 using (A′-1) having a peak molecular weight of 1,900 has poor hot offset property, heat resistant storage property, charging stability, image strength, bending resistance, and document offset property. The toner of Comparative Example 7 using (A′-2) which does not use the EO adduct (X1) of bisphenol A is low-temperature fixability, glossiness, fluidity, heat resistant storage stability, charging stability, image strength, document offset. The sex was poor.
The toner of Comparative Example 8 using (B′-1) having a peak molecular weight of 55,000 has poor low-temperature fixability, glossiness and grindability, and the toner of Comparative Example 9 not using the polyester resin (B) is hot. The offset property, image strength, and bending resistance are poor. Further, the toner of Comparative Example 10 which does not use the polyester resin (A) had poor low temperature fixability, glossiness, fluidity, heat resistant storage stability, charging stability, pulverization property, and document offset property.

The toner binder and toner of the present invention have both low-temperature fixability, glossiness, hot offset resistance and heat-resistant storage stability, and also have toner fluidity, charging stability, pulverization, image strength, folding resistance and document offset. It can be suitably used as an electrostatic charge image developing toner and toner binder used for electrophotography, electrostatic recording, electrostatic printing and the like.
Furthermore, it is suitable as a photosensitive resin composition for uses such as paint additives, adhesive additives, and electronic paper particles.

Claims (8)

A polyester resin (A) having a peak molecular weight of 4,000 or more and less than 8,000 obtained by polycondensation of a diol component (x) containing an ethylene oxide adduct (x1) of bisphenol A and a dicarboxylic acid component (y), and a peak molecular weight A toner binder comprising a step of reacting a polyisocyanate compound (D) with a molten mixture with a polyester resin (B) of 8,000 or more and 30,000 or less to obtain a urethane-modified polyester resin (C). Production method. The method for producing a toner binder according to claim 1, wherein the polyester resin (A) has a hydroxyl value of 5 KOHmg / g or less and the polyester resin (B) has a hydroxyl value of 10 to 80 KOHmg / g. The method for producing a toner binder according to claim 1 or 2, wherein the polyester resin (B) has a glass transition temperature of -35 to 45 ° C. The method for producing a toner binder according to claim 1, wherein the polyvalent isocyanate compound (D) is a tri- to octavalent polyisocyanate compound (D1). The method for producing a toner binder according to any one of claims 1 to 4, wherein the polyvalent isocyanate compound (D) is at least one polyisocyanate compound (D11) selected from the group consisting of isocyanurate and biuret. The method for producing a toner binder according to any one of claims 1 to 5, wherein the ethylene oxide adduct (x1) of bisphenol A has an average addition mole number of ethylene oxide of 2 to 4. The method for producing a toner binder according to any one of claims 1 to 6, wherein the ethylene oxide 2-mole adduct of bisphenol A in the ethylene oxide adduct (x1) of bisphenol A is 85% by weight or more. The method for producing a toner binder according to claim 1, wherein the weight ratio (A) / (B) of the polyester resin (A) to the polyester resin (B) is 55/45 to 99/1.