JP2020173351A - Binder resin composition for toner - Google Patents

Abstract

To provide a binder resin composition for toner that is excellent in all of low-temperature fixability and storage stability and durability under high temperature and high humidity, a method for manufacturing a polyester resin contained in the binder resin composition with good productivity, and a toner for electrophotography that contains the binder resin composition.SOLUTION: There is provided a binder resin composition for toner that contains an alcohol component containing an alkylene oxide adduct of bisphenol A represented by the formula (I), wherein OR and RO are an oxyalkylene group, R is an ethylene group and/or a propylene group, x and y represent the average number of additional moles of alkylene oxide and each a positive number, and the value of the sum of x and y is 1 or more and 5 or less, a carboxylic acid component, and a polyester resin A that is a polycondensate of polybutylene terephthalate. Also provided are a method for manufacturing a polyester resin contained in the binder resin composition, and a toner for electrophotography that contains the binder resin composition.SELECTED DRAWING: None

Description

The present invention manufactures a binder resin composition for toner used for developing latent images formed by electrophotographic methods, electrostatic recording methods, electrostatic printing methods, etc., and a polyester resin contained in the binder resin composition. The present invention relates to a method and an electrophotographic toner containing the binder resin composition.

Patent Document 1 describes a binder resin composition for toner containing amorphous polyester A and crystalline polyester C as a binder resin composition for toner having excellent low-temperature fixability, development stability, and storage property of printed matter. The amorphous polyester A is an amorphous polyester obtained by polycondensing an alcohol component containing an aromatic diol and an aliphatic diol having 3 or more and 6 or less carbon atoms and a carboxylic acid component. Disclosed is a binder resin composition for toner, wherein the crystalline polyester C is a crystalline polyester obtained by polycondensing an alcohol component containing an aliphatic diol having 2 or more and 9 or less carbon atoms and a carboxylic acid component. ing.

Patent Document 2 describes an electrophotographic toner composition having excellent pulverizability, wax dispersibility, mechanical durability, excellent blocking resistance and offset resistance, and an excellent balance between fixability after development and development durability. As a disclosure, a toner composition containing a binder resin component containing a crosslinked aromatic polyester resin component and a linear aromatic polyester resin component and a colorant component is disclosed.

Japanese Unexamined Patent Publication No. 2016-90628 JP-A-2009-288805

A polyester resin in which an alkylene oxide adduct of bisphenol A and 1,4-butanediol are used in combination as an alcohol component has excellent low-temperature fixability, while residual monomers and oligomers of 1,4-butanediol having high hydrophilicity. Because it contains, it has low storage stability and durability under high temperature and high humidity.

INDUSTRIAL APPLICABILITY The present invention is a method for producing a binder resin composition for toner, which is excellent in both low-temperature fixability, storage stability under high temperature and high humidity, and durability, and a polyester resin contained in the binder resin composition with high productivity. And an electrophotographic toner containing the binder resin composition.

The present invention
[1] Equation (I):

(In the formula, OR and RO are oxyalkylene groups, R is an ethylene group and / or a propylene group, x and y indicate the average number of moles of alkylene oxide added, which are positive numbers, respectively, and x and y. The value of the sum of is 1 or more and 5 or less)
A binder resin composition for toner, which contains an alcohol component containing an alkylene oxide adduct of bisphenol A represented by, a carboxylic acid component, and a polyester resin A which is a polycondensate of polybutylene terephthalate.
[2] In the presence of one or more esterification catalysts selected from tin (II) compounds and titanium compounds that do not have a Sn—C bond, formula (I):

(In the formula, OR and RO are oxyalkylene groups, R is an ethylene group and / or a propylene group, x and y indicate the average number of moles of alkylene oxide added, which are positive numbers, respectively, and x and y. The value of the sum of is 1 or more and 5 or less)
A method for producing a polyester resin A, which comprises a step of polycondensing an alcohol component containing an alkylene oxide adduct of bisphenol A represented by the above, a carboxylic acid component, and polybutylene terephthalate, and [2] the above-mentioned [1]. The present invention relates to an electrophotographic toner containing a binder resin composition for toner.

The electrophotographic toner containing the binder resin composition of the present invention exerts excellent effects in low temperature fixability, storage stability under high temperature and high humidity, and durability.

The binder resin composition for toner of the present invention is a polycondensate of an alcohol component containing an alkylene oxide adduct of bisphenol A, a carboxylic acid component, and polybutylene terephthalate (hereinafter, may be abbreviated as "PBT"). It contains polyester resin A and has one feature in that PBT is used. The present inventors have found that the residual monomers and oligomers of 1,4-butanediol can be reduced by using PBT, which is a polymer, as a raw material, and solve the deterioration of storage stability and durability under high temperature and high humidity. I was able to. Further, it has been found that by using PBT, the polycondensation reaction and the transesterification reaction having a high reaction rate are polymerized in parallel, so that the reaction time can be shortened and the productivity of the polyester resin is greatly improved.

As the alcohol component, from the viewpoint of low temperature fixability, the formula (I):

(In the formula, OR and RO are oxyalkylene groups, R is an ethylene group and / or a propylene group, x and y indicate the average number of moles of alkylene oxide added, which are positive numbers, respectively, and x and y. The value of the sum of is 1 or more, preferably 1.5 or more, 5 or less, preferably 4 or less)
Includes an alkylene oxide adduct of bisphenol A represented by. Examples of the alkylene oxide adduct of bisphenol A represented by the formula (I) include a polyoxypropylene adduct of 2,2-bis (4-hydroxyphenyl) propane and 2,2-bis (4-hydroxyphenyl) propane. Examples thereof include polyoxyethylene adducts. It is preferable to use one or more of these.

The alkylene oxide adduct of bisphenol A represented by the formula (I) contains an ethylene oxide adduct of bisphenol A represented by the formula (I) in which R is an ethylene group from the viewpoint of resin productivity. The content of the ethylene oxide adduct of the bisphenol A is preferably 1 mol% or more, more preferably 20 mol% or more, still more preferably 35 mol% or more, still more preferably 50 mol% or more in the alcohol component. And less than 100 mol%, preferably less than 95 mol%, more preferably less than 90 mol%.

The content of the alkylene oxide adduct of bisphenol A represented by the formula (I) is preferably 70 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, still more preferably 95 mol% or more in the alcohol component. It is 100 mol%.

Other alcohol components include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,4-butene. Examples thereof include aliphatic diols such as diols, 1,3-butanediol and neopentyl glycol, and trihydric or higher alcohols such as glycerin.

As the carboxylic acid component, at least one selected from the group consisting of aromatic dicarboxylic acid compounds, aliphatic dicarboxylic acid compounds, and carboxylic acid compounds having a valence of 3 or more is preferable, and the carboxylic acid component is storable at high temperature and high humidity. From the viewpoint, it is more preferable to contain an aromatic dicarboxylic acid compound.

Examples of the aromatic dicarboxylic acid compound include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters having 1 to 3 carbon atoms in the alkyl group. Among these, terephthalic acid or isophthalic acid is more preferable, and terephthalic acid is further preferable, from the viewpoint of low-temperature fixability.

The content of the aromatic dicarboxylic acid compound is preferably 50 mol% or more, more preferably 70 mol% or more, and 100 mol% or less, preferably 100 mol% or less, from the viewpoint of low-temperature fixability in the carboxylic acid component. Is 95 mol% or less, more preferably 90 mol% or less, still more preferably 85 mol% or less.

Aliphatic dicarboxylic acid compounds are substituted with oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, alkyl groups having 1 to 20 carbon atoms or alkenyl groups having 2 to 20 carbon atoms. Examples thereof include aliphatic dicarboxylic acids such as succinic acid and adipic acid, anhydrides of these acids, and alkyl esters having 1 to 3 carbon atoms in the alkyl groups, and alkyl groups having 1 to 20 carbon atoms or alkyl groups. It preferably contains succinic acid substituted with an alkyl group having 2 to 20 carbon atoms. The succinic acid is preferably succinic acid substituted with an alkyl group or alkenyl group having 6 to 14 carbon atoms, and more preferably succinic acid substituted with an alkyl group or alkenyl group having 8 to 12 carbon atoms. .. Specific examples thereof include octyl succinic acid and dodecenyl succinic acid (tetrapropenyl succinic acid).

Examples of trivalent or higher carboxylic acid compounds include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, anhydrides of these acids and alkyl groups. Examples thereof include alkyl esters having 1 to 3 carbon atoms, and among these, trimellitic acid-based compounds are preferable.

The content of the trivalent or higher carboxylic acid compound is preferably 5 mol% or more, more preferably 10 mol% or more, and low temperature in the carboxylic acid component from the viewpoint of durability under high temperature and high humidity. From the viewpoint of fixability, the carboxylic acid component is preferably 60 mol% or less, more preferably 40 mol% or less.

A monohydric alcohol may be appropriately contained in the alcohol component, and a monovalent carboxylic acid compound may be appropriately contained in the carboxylic acid component. However, in the present invention, the carboxylic acid component is stored at high temperature and high humidity. From the viewpoint of durability, it is preferable that the aromatic monocarboxylic acid compound is not substantially contained.

As the aromatic monocarboxylic acid compound, at least one selected from the group consisting of benzoic acid and an alkyl ester having 1 or more and 3 or less carbon atoms thereof is preferable.

The fact that the aromatic monocarboxylic acid compound is not substantially contained as the carboxylic acid component means that the aromatic monocarboxylic acid compound is not contained, or even if the aromatic monocarboxylic acid compound is contained, the content thereof is polybutylene terephthalate or carboxylic acid. It means that it is preferably 3% by mass or less, more preferably 2% by mass or less, and further preferably 1% by mass or less in the total amount of the component and the alcohol component.

Among the aromatic monocarboxylic acid compounds, reducing the content of benzoic acid is effective. Therefore, it is preferable that the carboxylic acid component does not substantially contain benzoic acid. That is, the carboxylic acid component does not contain benzoic acid, or even if it contains benzoic acid, the content thereof is preferably 3% by mass or less, more preferably 3% by mass or less, based on the total amount of the polybutylene terephthalate, the carboxylic acid component, and the alcohol component. Is 2% by mass or less, more preferably 1% by mass or less, still more preferably 0% by mass.

The PBT preferably has an IV value of 0.3 or more and 1.2 or less. The IV value of PBT is preferably 0.3 or more, more preferably 0.4 or more from the viewpoint of durability under high temperature and high humidity, and preferably 1.2 or less, more preferably 1.1 from the viewpoint of resin productivity. Below, it is more preferably 1.0 or less.

The content of PBT is preferably 5 mol% or more, more preferably 10 mol% or more, based on the total amount of the carboxylic acid component, the alcohol component and the PBT, from the viewpoint of durability under high temperature and high humidity and resin productivity. It is more preferably 15 mol% or more, and from the viewpoint of storage under high temperature and high humidity, it is preferably 70 mol% or less, more preferably 60 mol% or less, still more preferably 50 mol% or less. Incidentally, PBT but is a polymer, 1,4-butanediol - units of terephthalic acid _{(-O-CO-C 6 H} 4 -CO-O- (CH 2) 4 -) 1 mol (Mw: 220) Convert as.

The equivalent ratio of COOH groups to OH groups (COOH groups / OH groups) in the raw materials of the polyester resin (alcohol component, carboxylic acid component, and PBT) has an excess of COOH groups from the viewpoint of increasing the softening point of the obtained polyester resin. (COOH group / OH group is larger than 1) is preferable. Further, from the viewpoint of lowering the softening point of the obtained polyester resin, it is preferable that the OH group is excessive (COOH group / OH group is less than 1). Here, it is assumed that PBT, which is a polycondensate of 1,4-butanediol and terephthalic acid, has a COOH group and an OH group equivalently.

The polycondensation reaction of the alcohol component, the carboxylic acid component, and the PBT is carried out, for example, in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and if necessary, an esterification co-catalyst, a polymerization inhibitor, etc. In the presence, it can be carried out at a temperature of 180 ° C or higher and 250 ° C or lower.

Examples of the esterification catalyst include tin compounds and titanium compounds.

As the tin compound, for example, dibutyltin oxide is known, but in the present invention, a tin (II) compound having no Sn—C bond is preferable from the viewpoint of low-temperature fixability.

Examples of the tin (II) compound having no Sn—C bond include a tin (II) compound having no Sn—C bond and having a Sn—O bond, and Sn—X (X indicates a halogen atom). ) A tin (II) compound having a bond is preferable, and a tin (II) compound having a Sn—O bond is more preferable.

Examples of the tin (II) compound having a Sn—O bond include tin (II) oxalate, tin (II) acetate, tin (II) octanoate, tin (II) 2-ethylhexanoate, and tin (II) laurate. Tin carboxylate (II) having a carboxylic acid group having 2 to 28 carbon atoms such as tin stearate (II) and tin oleate (II); octyloxy tin (II), lauroxy tin (II), stearoxy tin (II) ), Oleyloxytin (II) and the like, alkoxytin (II) having an alkoxy group having 2 or more and 28 or less carbon atoms; tin oxide (II); tin sulfate (II) and the like are Sn-X (X indicates a halogen atom). Examples of the tin (II) compound having a) bond include tin (II) chloride, tin (II) halide such as tin (II) bromide, and the like, and among these, (R) from the viewpoint of catalytic ability. ¹ COO) ₂ Sn (where R ¹ represents an alkyl or alkenyl group having 5 or more and 19 or less carbon atoms) represented by the fatty acids tin (II), (R ² O) ₂ Sn (where R ² is carbon). Alkoxy tin (II) represented by number 6 to 20 (indicating an alkyl group or alkenyl group) or tin oxide (II) represented by SnO is preferable, and (R ¹ COO) ₂ Sn represented by fatty acid tin ( Tin (II) or tin (II) oxide is more preferred, and tin (II) octanoate, tin (II) 2-ethylhexanoate, tin (II) stearate or tin (II) oxide is even more preferred.

Titanium compounds include formula (IIa) or formula (IIb):
Ti (Y) _m (OH) _n (IIa)
O = Ti (Y) _p (OZ) _q (IIb)
(In the formula, Y is a residue obtained by removing a hydrogen atom from one hydroxyl group of mono or polyalkanolamine having 2 to 12 carbon atoms, and the other hydroxyl groups of polyalkanolamine are hydroxyl groups directly bonded to the same titanium atom. And may be polycondensed in the molecule to form a ring structure, or may be polycondensed between a hydroxyl group directly bonded to another titanium atom and a molecule to form a repeating structure. When forming a repeating structure The degree of polymerization is 2 to 5. Z is an alkyl group having 1 to 8 carbon atoms which may contain a hydrogen atom or 1 to 3 ether bonds. M is 1 to 4, preferably 2 to 4. An atom, n is 0 to 3, preferably an atom of 0 to 2, the sum of m and n is 4. p is an atom of 1 to 2, q is an integer of 0 to 1, and the sum of p and q is 2. Yes. When m or p is 2 or more, each Y may be the same or different.)
At least one titanium compound represented by is preferable.

As Y, residues of monoalkanolamine (particularly ethanolamine), residues of dialkanolamine (particularly diethanolamine), and residues of trialkanolamine (particularly triethanolamine) are preferable. Ethanolamine is preferable as the monoalkanolamine, diethanolamine is preferable as the dialkanolamine, triethanolamine is preferable as the trialkanolamine, and triethanolamine is more preferable.

In Z, the alkyl group having 1 to 8 carbon atoms which may contain 1 to 3 ether bonds includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group and an n-hexyl group. , N-octyl group, β-methoxyethyl group, β-ethoxyethyl group and the like.

As Z, an alkyl group having 1 to 4 carbon atoms which does not contain a hydrogen atom and an ether bond is preferable, and a hydrogen atom, an ethyl group, and an isopropyl group are more preferable.

Specific examples of the titanium compound represented by the formula (IIa) include titanium tetrakis (monoethanol aminate), titanium monohydroxytris (triethanol aminate), titanium dihydroxybis (triethanol aminate), and titanium trihydroxytri. Ethanol Aminate, Titanium Dihydroxybis (Diethanol Aminate), Titanium Dihydroxybis (Monoethanol Aminate), Titanium Dihydroxybis (Monopropanol Aminate), Titanium Dihydroxybis (N-Methyl Diethanol Aminate), Titanium Dihydroxybis (N-Butyl) Diethanol aminate), reaction products of tetrahydroxytitanium and N, N, N', N'-tetrahydroxyethylethylenediamine, intramolecular or intermolecular polycondensates of these, and the like.

Specific examples of the titanium compound represented by the formula (IIb) include titanylbis (triethanolamineate), titanylbis (diethanolaminetate), titanylbis (monoethanolaminetate), titanylhydroxyethanolaminetate, and titanylhydroxytriethanolamine. Examples thereof include aminate, titanylethoxytriethanolaminetate, titanylisopropoxytriethanolamineate, and intramolecular or intermolecular polycondensates thereof.

As the esterification catalyst, a tin (II) compound and a titanium compound having no Sn—C bond are preferable, and therefore, the polyester resin A is a tin (II) compound and a titanium compound having no Sn—C bond. In the presence of one or more esterification catalysts selected from the above, it comprises a step of polycondensing an alcohol component containing an alkylene oxide adduct of bisphenol A represented by the formula (I), a carboxylic acid component, and polybutylene terephthalate. It is preferably produced by the method.

The amount of the esterification catalyst used is preferably 0.1 part by mass or more, more preferably 0.2 part by mass or more, still more preferably 0.3 part by mass or more, based on 100 parts by mass of the total of the alcohol component, the carboxylic acid component, and the PBT. From the viewpoint of suppressing coloration derived from the catalyst, the amount is preferably 1 part by mass or less, more preferably 0.8 part by mass or less, and further preferably 0.6 part by mass or less.

Examples of the esterification co-catalyst that can be used together with the esterification catalyst include gallic acid and the like. The amount of the esterification catalyst used is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, and preferably 1 part by mass with respect to 100 parts by mass of the total amount of the PBT, alcohol component, and carboxylic acid component. Hereinafter, it is more preferably 0.6 parts by mass or less. The amount of the esterification cocatalyst used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass with respect to 100 parts by mass of the total amount of the PBT, alcohol component, and carboxylic acid component. Parts or less, more preferably 0.1 parts by mass or less.

The polyester resin A in the present invention may be, for example, a modified polyester resin such as a urethane-modified polyester resin obtained by urethane-extending the polyester resin with polyisocyanate, but is an unmodified polyester resin from the viewpoint of low-temperature fixability. Is preferable.

The softening point of the polyester resin A is preferably 90 ° C. or higher, more preferably 100 ° C. or higher from the viewpoint of storage stability, and preferably 150 ° C. or lower, more preferably 140 ° C. or higher from the viewpoint of low temperature fixability. It is as follows.

The polyester resin A is preferably an amorphous resin. The crystallinity of a resin is represented by the crystallinity index defined by the ratio of the softening point to the maximum endothermic temperature measured by the differential scanning calorimeter, that is, the value of [softening point / maximum endothermic temperature]. The crystalline resin is an amorphous resin having a crystallinity index of 0.6 or more, preferably 0.7 or more, more preferably 0.9 or more, and 1.4 or less, preferably 1.2 or less, more preferably 1.1 or less. Is a resin having a crystallinity index of more than 1.4, preferably more than 1.5, more preferably 1.6 or more, or less than 0.6, preferably 0.5 or less. The crystallinity of the resin can be adjusted by the type and ratio of the raw material monomers, the production conditions (for example, reaction temperature, reaction time, cooling rate) and the like. The maximum endothermic peak temperature refers to the temperature of the peak on the highest temperature side among the observed endothermic peaks. In the crystalline resin, the maximum peak temperature of endothermic reaction is defined as the melting point.

The glass transition temperature of the polyester resin A is preferably 40 ° C. or higher, more preferably 50 ° C. or higher from the viewpoint of storage stability, and preferably 80 ° C. or lower, more preferably 70 ° C. or higher from the viewpoint of low temperature fixability. ° C or lower, more preferably 65 ° C or lower.

The acid value of the polyester resin A is preferably 3 mgKOH / g or more, more preferably 6 mgKOH / g or more from the viewpoint of low temperature fixability, and preferably 20 mgKOH / g or less, more preferably from the viewpoint of hygroscopicity. It is 15 mgKOH / g or less.

The hydroxyl value of the polyester resin A is preferably 20 mgKOH / g or more, more preferably 30 mgKOH / g or more from the viewpoint of low temperature fixability, and preferably 50 mgKOH / g or less, more preferably 50 mgKOH / g or less from the viewpoint of hygroscopicity. It is 40 mgKOH / g or less.

Regarding the above physical properties of the polyester resin, when the polyester resin is composed of two or more kinds of polyester, it is preferable that the weighted average value thereof is within the above range.

The content of the polyester resin A is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and preferably 100% by mass or less, in the binder resin composition. It is preferably 95% by mass or less, more preferably 90% by mass or less.

The binder resin composition of the present invention may contain a resin other than the polyester resin A.

As the binder resin other than the polyester resin A, a crystalline polyester resin is preferable. Examples of the crystalline polyester resin include a polycondensate of an alcohol component containing an aliphatic diol having 2 to 16 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 4 to 14 carbon atoms. preferable.

Examples of the aliphatic diol containing 2 to 16 carbon atoms contained in the alcohol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1. , 6-hexanediol, 1,7-heptanediol, 1,8-octanediol, neopentyl glycol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecane Examples thereof include diols, and either one type or two or more types may be used in combination.

From the viewpoint of low-temperature fixability, the aliphatic diol having 2 to 16 carbon atoms is preferably an α, ω-aliphatic diol having a hydroxyl group at the end of the carbon chain, and is preferably an α, ω-linear alkane. It is more preferably a diol.

The carbon number of the aliphatic diol is 2 or more, preferably 4 or more, more preferably 6 or more from the viewpoint of low temperature fixability, and 16 or less, preferably 14 or less, more preferably from the viewpoint of storage stability. It is 12 or less, more preferably 8 or less.

The content of the aliphatic diol having 2 or more and 16 or less carbon atoms is 95 mol% or more, preferably 98 mol% or more, more preferably 100 mol% in the alcohol component of the crystalline polyester resin from the viewpoint of low temperature fixability. is there.

Examples of other alcohol components include aliphatic diols having 17 or more carbon atoms, aromatic diols such as alkylene oxide adducts of bisphenol A, and trihydric or higher alcohols such as sorbitol, pentaerythritol, glycerin, and trimethylpropane. ..

Examples of the aliphatic dicarboxylic acid compound having 4 to 14 carbon atoms contained in the carboxylic acid component include succinic acid (carbon number: 4), fumaric acid (carbon number: 4), adipic acid (carbon number: 6), and suberic acid. Acid (carbon number: 8), adipic acid (carbon number: 9), sebacic acid (carbon number: 10), dodecanedioic acid (carbon number: 12), tetradecanedioic acid (carbon number: 14), alkyl on the side chain Examples thereof include succinic acid having a group or an alkenyl group, anhydrides of these acids, and alkyl esters of these acids having 1 or more and 3 or less carbon atoms.

The carbon number of the aliphatic dicarboxylic acid compound is 4 or more, preferably 6 or more, more preferably 8 or more from the viewpoint of low temperature fixability, and 14 or less, preferably 12 or less from the viewpoint of storage stability. is there.

From the viewpoint of low-temperature fixability, the content of the aliphatic dicarboxylic acid compound having 4 to 14 carbon atoms is 95 mol% or more, preferably 98 mol% or more, more preferably 98 mol% or more in the carboxylic acid component of the crystalline polyester resin. It is 100 mol%.

Other carboxylic acid components include aromatic dicarboxylic acid compounds such as phthalic acid, isophthalic acid, and terephthalic acid, aliphatic dicarboxylic acid compounds having 15 or more carbon atoms, trimellitic acid, and pyromellitic acid having a trivalent value or higher. Examples thereof include carboxylic acid compounds, anhydrides of these acids, and alkyl esters having 1 to 3 carbon atoms.

The equivalent ratio (COOH group / OH group) of the carboxylic acid component and the alcohol component of the crystalline polyester resin is preferably 0.8 or more, more preferably 0.9 or more from the viewpoint of storage stability, and from the viewpoint of low temperature fixability. , Preferably 1.2 or less, more preferably 1.1 or less.

The polycondensation reaction conditions of the alcohol component and the carboxylic acid component are the same as the above-mentioned reaction conditions of the polyester resin except that the polycondensation reaction conditions are carried out at a temperature of 140 ° C. or higher and 250 ° C. or lower.

The softening point of the crystalline polyester resin is preferably 50 ° C. or higher, more preferably 65 ° C. or higher, still more preferably 70 ° C. or higher from the viewpoint of storage stability, and preferably 120 ° C. or higher from the viewpoint of low temperature fixability. Below, it is more preferably 110 ° C. or lower, further preferably 100 ° C. or lower, still more preferably 85 ° C. or lower.

The melting point of the crystalline polyester resin is preferably 40 ° C. or higher, more preferably 60 ° C. or higher from the viewpoint of storage stability, and preferably 110 ° C. or lower, more preferably 100 ° C. or lower from the viewpoint of low temperature fixability. , More preferably 80 ° C. or lower.

The acid value of the crystalline polyester resin is preferably 5 mgKOH / g or more, more preferably 8 mgKOH / g or more from the viewpoint of low-temperature fixability, and preferably 30 mgKOH / g or less, more preferably from the viewpoint of storage stability. Is 25 mgKOH / g or less.

The hydroxyl value of the crystalline polyester resin is preferably 5 mgKOH / g or more, more preferably 8 mgKOH / g or more, still more preferably 10 mgKOH / g or more from the viewpoint of low temperature fixability, and preferably from the viewpoint of storage stability. Is 30 mgKOH / g or less, more preferably 20 mgKOH / g or less.

The mass ratio of the polyester resin A to the crystalline polyester resin (polyester resin A / crystalline polyester resin) is preferably 75/25 or more, more preferably 80/20 or more, and further preferably 85/15 from the viewpoint of storage stability. From the viewpoint of low temperature fixability, it is preferably 99/1 or less, more preferably 95/5 or less.

When the binder resin composition of the present invention contains two or more kinds of resins, a mixture of these resins may be used as the binder resin, and these resins may be directly used as raw materials when producing toner. It may be mixed.

In addition to the binder resin (the binder resin composition of the present invention), the toner for electrophotographic of the present invention includes a colorant, a mold release agent, a charge control agent, a magnetic powder, a fluidity improver, a conductivity adjusting agent, and the like. Additives such as a reinforcing filler such as a fibrous substance, an antioxidant, and a cleaning property improver may be contained, and a colorant, a mold release agent, and a charge control agent are preferably contained.

As the colorant, all dyes, pigments, etc. used as colorants for toner can be used, and carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, Rhodamine-B base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, quinacridone, carmine 6B, disazoero and the like can be used, and the toner of the present invention may be either a black toner or a color toner.

The content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, with respect to 100 parts by mass of the binder resin, from the viewpoint of improving the image concentration and low temperature fixability of the toner. It is preferably 40 parts by mass or less, more preferably 10 parts by mass or less.

As the release agent, fatty acid hydrocarbon waxes such as polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax, microcrystallin wax, paraffin wax, Fishertropch wax, and sazole wax or their oxides; carnauba wax. , Montan wax or ester waxes such as deoxidizing waxes and fatty acid ester waxes; fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, etc., which may be used alone or in combination of two or more. it can.

The melting point of the release agent is preferably 60 ° C. or higher, more preferably 70 ° C. or higher from the viewpoint of toner transferability, and preferably 160 ° C. or lower, more preferably 140 ° C. or higher from the viewpoint of low temperature fixability. Below, it is more preferably 120 ° C. or lower, still more preferably 110 ° C. or lower.

The content of the release agent is preferably 0.5 parts by mass or more with respect to 100 parts by mass of the binder resin from the viewpoint of low temperature fixability and offset resistance of the toner and dispersibility in the binder resin. It is preferably 1.0 part by mass or more, more preferably 1.5 part by mass or more, and preferably 10 parts by mass or less, more preferably 8 parts by mass or less, still more preferably 7 parts by mass or less.

The charge control agent is not particularly limited, and may contain either a positive charge control agent or a negative charge control agent.

Positive charge control agents include niglosin dyes such as "niglosin base EX", "oil black BS", "oil black SO", "bontron N-01", "bontron N-04", and "bontron N-07". , "Bontron N-09", "Bontron N-11" (all manufactured by Orient Chemical Industries, Ltd.), etc .; Triphenylmethane dyes containing a tertiary amine as a side chain, a quaternary ammonium salt compound, for example. "Bontron P-51" (manufactured by Orient Chemical Industry Co., Ltd.), cetyltrimethylammonium bromide, "COPY CHARGE PX VP435" (manufactured by Clariant), etc .; polyamine resin, for example, "AFP-B" (manufactured by Orient Chemical Industry Co., Ltd.) (Manufactured), etc .; imidazole derivatives such as "PLZ-2001", "PLZ-8001" (all manufactured by Shikoku Kasei Kogyo Co., Ltd.), etc .; styrene-acrylic resin, for example "FCA-701PT" (Fujikura Kasei Co., Ltd.) Made) and the like.

As the negative charge control agent, metal-containing azo dyes such as "Varifast Black 3804", "Bontron S-31", "Bontron S-32", "Bontron S-34", and "Bontron S-36" (These are manufactured by Orient Chemical Industry Co., Ltd.), "Eisenspiron Black TRH", "T-77" (manufactured by Hodoya Chemical Industry Co., Ltd.), etc .; Metal compounds of benzylic acid compounds, for example, "LR-" 147 ”,“ LR-297 ”(above, manufactured by Nippon Carlit Co., Ltd.); metal compounds of salicylic acid compounds, for example,“ Bontron E-81 ”,“ Bontron E-84 ”,“ Bontron E-88 ”,“ Bontron E-304 "(above, manufactured by Orient Chemical Industry Co., Ltd.)," TN-105 "(manufactured by Hodoya Chemical Industry Co., Ltd.), etc .; copper phthalocyanine dye; quaternary ammonium salt, for example," COPY CHARGE NX VP434 " (Manufactured by Clariant), nitroimidazole derivatives and the like; organic metal compounds and the like can be mentioned.

The content of the charge control agent is preferably 0.01 part by mass or more, more preferably 0.2 part by mass or more, and preferably 10 parts by mass with respect to 100 parts by mass of the binder resin from the viewpoint of charge stability of the toner. Parts or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less, still more preferably 2 parts by mass or less.

The toner of the present invention may be a toner obtained by any known method such as a melt-kneading method, an emulsification phase inversion method, a polymerization method, etc., but from the viewpoint of productivity and dispersibility of the colorant, the toner is melt-kneaded. Grinded toner by the method is preferable. In the case of crushed toner by the melt-kneading method, for example, raw materials such as a binder resin, a colorant, a mold release agent, and a charge control agent are uniformly mixed with a mixer such as a Henschel mixer, and then a closed kneader, 1 shaft or 2 It can be manufactured by melt-kneading with a shaft extruder, an open roll type kneader, etc., cooling, crushing, and classifying.

It is preferable to use an external additive for the toner of the present invention in order to improve transferability. Examples of the external additive include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as resin particles such as melamine-based resin fine particles and polytetrafluoroethylene resin fine particles. The above may be used together. Among these, silica is preferable, and from the viewpoint of toner transferability, hydrophobicized silica is more preferable.

Examples of the hydrophobizing agent for hydrophobizing the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), silicone oil, octylliethoxysilane (OTES), and methyltriethoxysilane. Be done.

The average particle size of the external additive is preferably 10 nm or more, more preferably 15 nm or more, and preferably 250 nm or less, more preferably 200 nm or less, and further, from the viewpoint of toner chargeability, fluidity, and transferability. It is preferably 150 nm or less, more preferably 90 nm or less.

From the viewpoint of the chargeability, fluidity, and transferability of the toner, the content of the external additive is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass, based on 100 parts by mass of the toner before being treated with the external additive. More than parts, more preferably 0.3 parts by mass or more, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less.

The volume median particle diameter (D ₅₀ ) of the toner of the present invention is preferably 3 μm or more, more preferably 4 μm or more, and preferably 15 μm or less, more preferably 10 μm or less. In the present specification, the volume median particle size (D ₅₀ ) means a particle size in which the cumulative volume frequency calculated by the volume fraction is 50% calculated from the smaller particle size. When the toner is treated with an external additive, the volume median particle diameter of the toner particles before the toner is treated with the external additive is defined as the volume median particle diameter of the toner.

The toner of the present invention can be used as a one-component developer toner or as a two-component developer by mixing with a carrier.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. The physical properties of the resin and the like can be measured by the following methods.

[IV value of PBT]
It can be obtained by dissolving in a mixed solvent having a phenol / tetrachloroethane (mass ratio) of 60/40 at a concentration of 4 g / L, measuring with an Ubbelohde viscometer, and calculating according to the following formula.
IV = (-1 + √ (1 + 4kη)) / (2kC)
[In the formula, k = 0.33, C = 0.004 g / mL, and η = (t1 / t0) -1 (t0: number of seconds of solvent only falling, t1: number of seconds of sample solution falling). ]

[Resin softening point]
Using the flow tester "CFT-500D" (manufactured by Shimadzu Corporation), while heating a 1 g sample at a heating rate of 6 ° C / min, a load of 1.96 MPa was applied by a plunger, and the diameter was 1 mm and the length was 1 mm. Extrude from the nozzle of. The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is used as the softening point.

[Maximum endothermic temperature of resin]
Using the differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.01 to 0.02 g of the sample in an aluminum pan, and cool down from room temperature (25 ° C) to 10 ° C. Cool to 0 ° C at / min and maintain at 0 ° C for 1 minute. Then, the temperature is measured at a heating rate of 10 ° C./min. Among the observed endothermic peaks, the temperature of the peak on the highest temperature side is defined as the maximum endothermic temperature.

[Resin glass transition temperature]
Using the differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.01 to 0.02 g of the sample in an aluminum pan, raise the temperature to 200 ° C, and then use that temperature. Cool to 0 ° C at a temperature lowering rate of 10 ° C / min. Next, the sample is heated at a heating rate of 10 ° C./min, and the endothermic peak is measured. The temperature at the intersection of the extension of the baseline below the maximum endothermic peak temperature and the tangent line indicating the maximum slope from the rising portion of the peak to the peak of the peak is defined as the glass transition temperature.

[Acid value of resin]
Measure based on the method of JIS K 0070: 1992. However, only the measurement solvent is from the mixed solvent of ethanol and ether specified in JIS K 0070, the amorphous resin is the mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)), and the crystalline resin is chloroform. : Change to a mixed solvent of dimethylformamide (chloroform: dimethylformamide = 7: 3 (volume ratio)).

[Hydroxyl value of resin]
Measure based on the method of JIS K 0070: 1992. However, only the measurement solvent is changed from the mixed solvent of ethanol and ether specified in JIS K 0070 to tetrahydrofuran.

[Melting point of mold release agent]
Using the differential scanning calorimeter "DSC Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.01 to 0.02 g of the sample into an aluminum pan, and 200 at a heating rate of 10 ° C / min. The temperature is raised to ℃, and then cooled to -10 ℃ at a temperature lowering rate of 5 ℃ / min. Next, the sample is heated to 180 ° C. at a heating rate of 10 ° C./min and measured. The maximum peak temperature of heat absorption observed from the melt endothermic curve obtained there is taken as the melting point of the release agent.

[Average particle size of external additive]
The average particle size refers to the number average particle size, and the particle size (average value of major axis and minor axis) of 500 particles is measured from a scanning electron microscope (SEM) photograph and used as the average value of the number of particles.

[Medium particle size of toner]
Measuring machine: Coulter Multi-Sizar II (manufactured by Beckman Coulter Co., Ltd.)
Aperture diameter: 50 μm
Analysis software: Coulter Multi-Sizar AccuComp version 1.19 (manufactured by Beckman Coulter Co., Ltd.)
Electrolyte: Isoton II (manufactured by Beckman Coulter Co., Ltd.)
Dispersion: Emulgen 109P (manufactured by Kao Co., Ltd., polyoxyethylene lauryl ether, HLB (griffin): 13.6) was dissolved in an electrolytic solution to adjust the content to 5% by mass. Dispersion conditions: 10 mg of measurement sample in 5 mL of the dispersion Was added and dispersed with an ultrasonic disperser (machine name: US-1, manufactured by SND Co., Ltd., output: 80 W) for 1 minute, then 25 mL of the electrolytic solution was added, and the mixture was further added to the ultrasonic disperser. Disperse for 1 minute to prepare a sample dispersion.
Measurement conditions: Add the sample dispersion to 100 mL of the electrolytic solution so that the particle size of 30,000 particles can be measured in 20 seconds, measure 30,000 particles, and measure the volume from the particle size distribution. Determine the medium particle size (D ₅₀ ).

Resin production example 1
10 liters of alcohol component, polybutylene terephthalate (PBT), carboxylic acid component other than trimellitic anhydride and esterification catalyst shown in Table 1 equipped with a thermometer, a stainless steel stirring rod, a flow-down condenser and a nitrogen introduction tube. It was placed in a four-necked flask and heated in a mantle heater in a nitrogen atmosphere from room temperature to 200 ° C. over 8 hours, and then from 200 ° C. to 235 ° C. over 4 hours. Then, after cooling to 220 ° C., trimellitic anhydride was added, and the reaction was carried out at 220 ° C. at 8.0 kPa until the softening point shown in Table 1 was reached to obtain an amorphous polyester resin (resins A1 to A7). Obtained.

[Resin productivity]
The reaction time from the time when the temperature in the flask reached 235 ° C to the softening point of the produced resin reaching 90 ° C was used as an index of resin productivity. It can be said that the shorter the reaction time, the higher the productivity of the resin.
<Evaluation criteria>
A: Less than 2 hours B: 2 hours or more and less than 5 hours C: 5 hours or more

Resin production example 2
The alcohol and carboxylic acid components shown in Table 2 were placed in a 10-liter four-necked flask equipped with a thermometer, a stainless steel stir bar, a flow-down condenser and a nitrogen inlet tube, and placed in a mantle heater in a nitrogen atmosphere. The temperature was raised from room temperature to 200 ° C. over 8 hours. Then, the esterification catalyst shown in Table 2 was added at 200 ° C., and the reaction was carried out at 8.0 kPa until the softening point shown in Table 2 was reached to obtain a crystalline polyester resin (resin C1).

Examples 1-6 and Comparative Example 1
As the binder resin, 90 parts by mass of the amorphous polyester resin and 10 parts by mass of the crystalline polyester resin shown in Table 3, 5 parts by mass of the colorant "ECB-301" (phthalocyanine blue, manufactured by Dainichi Seika Co., Ltd.), and the charge control agent " After thoroughly stirring 1 part by mass of "LR-147" (manufactured by Nippon Carlit) and 2 parts by mass of the mold release agent shown in Table 3 with a Henschel mixer, the total length of the kneaded part is 1560 mm, the screw diameter is 42 mm, and the barrel inner diameter is 43 mm. It was melt-kneaded using a directional rotating twin-screw extruder. The rotation speed of the roll was 200 r / min, the set heating temperature in the roll was 90 ° C., the temperature of the kneaded product was 140 ° C., the supply speed of the kneaded product was 10 kg / h, and the average residence time was about 18 seconds. The obtained kneaded product is cooled from 140 ° C. to 50 ° C. for 1.5 hours, rolled and cooled at 50 ° C. with a cooling roller, allowed to stand at 45 ° C. for 4 hours, and then subjected to a medium volume particle size (D) with a jet mill. ₅₀ ) 5.5 μm toner particles were obtained.

For 100 parts by mass of the obtained toner particles, 1.5 parts by mass of the external additive "Aerosil R-972" (hydrophobic silica, manufactured by Nippon Aerosil Co., Ltd., hydrophobizing agent: DMDS, average particle size: 16 nm) and "RY-" 50 ”(manufactured by Nippon Aerosil Co., Ltd., hydrophobizing agent: silicone oil, average particle size 40 nm) Add 1.0 part by mass and mix at 3600 r / min for 5 minutes with a Henshell mixer to treat the toner. Obtained.

Test Example 1 [Low temperature fixability]
Toner was mounted on a device that was an improvement of the fixing machine of the copying machine "AR-505" (manufactured by Sharp Corporation) so that it could be fixed outside the device, and printed matter was obtained in an unfixed state (printed area: 2 cm x 12 cm, adhesion amount: 0.5 mg / cm ² ). After that, using a fixing machine (fixing speed 300 mm / sec) adjusted so that the total fixing pressure becomes 40 kgf, the temperature of the fixing roll is gradually increased from 100 ° C to 240 ° C by 5 ° C, and unfixed at each temperature. A fixing test was performed on the printed matter in the state. A cellophane adhesive tape "UNICEF cellophane" (manufactured by Mitsubishi Pencil Co., Ltd., width: 18 mm, JIS Z 1522) is attached to the image part of the obtained printed matter, passed through a fixing roller set at 30 ° C, and then the tape is applied. I peeled it off. The paper used for printing was "CopyBond SF-70NA" (manufactured by Sharp Corporation, 75 g / m ² ).
The optical reflection density before and after the tape was applied was measured using a reflection densitometer "RD-915" (manufactured by Gretag Macbeth), and the ratio of the two (after peeling / before applying x 100) was initially 90%. The temperature of the fixing roller exceeding the above was set as the minimum fixing temperature. The results are shown in Table 3. The lower the minimum fixing temperature, the better the low temperature fixing property.

Test Example 2 [Preservation under high temperature and high humidity]
4 g of toner was left for 72 hours in an environment of temperature 50 ° C. and humidity 85%. After being left to stand, the degree of toner aggregation was visually observed, and the storage stability was evaluated according to the following evaluation criteria. The results are shown in Table 3.
<Evaluation criteria>
A: No aggregation was observed after 48 hours and 72 hours.
B: No aggregation is observed after 48 hours, but slight aggregation is observed after 72 hours.
C: No aggregation is observed after 48 hours, but apparent aggregation is observed after 72 hours.
D: Aggregation is already observed within 48 hours.

Test Example 3 [Durability under high temperature and high humidity]
Toner is mounted on the laser printer "Page Presto N-4" (manufactured by Casio Computer Co., Ltd., fixing: contact fixing method, development: non-magnetic one-component development method, development roll diameter: 2.3 cm), and the temperature is 40 ° C and relative humidity. Continuous printing was performed under a condition of 85% with a diagonal stripe pattern having a blackening rate of 5.5%. On the way, a solid black image was printed every 500 sheets, and streaks on the image were confirmed. Durability was evaluated by using the number of printed sheets up to the time when the streaks were visually observed on the image as the number of sheets in which the streaks were generated due to the toner being fused and adhered to the developing roll. The results are shown in Table 3. The greater the number of streaks, the better the durability of the toner. The number of sheets is preferably 3,000 or more, more preferably 4,000 or more, and even more preferably 5,000 or more.

From the above results, it can be seen that the toners of Examples 1 to 6 are excellent in all of low temperature fixability, storage stability under high temperature and high humidity, and durability. Further, the amorphous polyester resin used in the examples can be produced with high productivity.
On the other hand, the toner of Comparative Example 1 containing a polyester resin using 1,4-butanediol without using PBT has all of low temperature fixability, storage stability under high temperature and high humidity, and durability. It is inadequate.

The binder resin composition for toner of the present invention is suitably used for an electrophotographic toner used for developing a latent image formed in an electrostatic charge image developing method, an electrostatic recording method, an electrostatic printing method, or the like. Is.

Claims (7)

Equation (I):

(In the formula, OR and RO are oxyalkylene groups, R is an ethylene group and / or a propylene group, x and y indicate the average number of moles of alkylene oxide added, which are positive numbers, respectively, and x and y. The value of the sum of is 1 or more and 5 or less)
A binder resin composition for toner, which contains an alcohol component containing an alkylene oxide adduct of bisphenol A represented by the above, a carboxylic acid component, and a polyester resin A which is a polycondensate of polybutylene terephthalate. The alkylene oxide adduct of bisphenol A represented by the formula (I) contains the ethylene oxide adduct of bisphenol A represented by the formula (I) in which R is an ethylene group, and the ethylene oxide adduct of the bisphenol A. The binder resin composition for toner according to claim 1, wherein the content of the adduct is 20 mol% or more and 100 mol% or less in the alcohol component. The binder resin composition for a toner according to claim 1 or 2, which does not substantially contain benzoic acid as a carboxylic acid component. The binder resin composition for a toner according to any one of claims 1 to 3, wherein the content of polybutylene terephthalate is 5 mol% or more and 70 mol% or less in the total amount of the carboxylic acid component, the alcohol component and the polybutylene terephthalate. .. The binder resin composition for toner according to any one of claims 1 to 4, further comprising a crystalline polyester resin. In the presence of one or more esterification catalysts selected from tin (II) compounds and titanium compounds that do not have a Sn—C bond, formula (I):

(In the formula, OR and RO are oxyalkylene groups, R is an ethylene group and / or a propylene group, x and y indicate the average number of moles of alkylene oxide added, which are positive numbers, respectively, and x and y. The value of the sum of is 1 or more and 5 or less)
A method for producing a polyester resin A, which comprises a step of polycondensing an alcohol component, a carboxylic acid component, and polybutylene terephthalate containing an alkylene oxide adduct of bisphenol A represented by. An electrophotographic toner containing the binder resin composition for toner according to any one of claims 1 to 5.