JP5541026B2 - Toner and method for producing the same - Google Patents

Description

  The present invention relates to a toner, a toner manufacturing method, a developer, and an image forming method.

  In image formation by electrophotography, toner is fixed on an image support by a heat fixing method to obtain a permanent visible copy image. In this case, when a copied image is formed using a toner, particularly color toner, on the overhead projector transparency sheet, the surface of the image is smoothed in order to improve the light transmittance of the projected image of the overhead projector. Therefore, it is necessary to prevent the scattering, diffuse reflection, and the like of transmitted light on the image surface during projection.

  For this reason, it is designed to smooth the surface of an image by heating and pressurizing using a color toner that rapidly changes to a molten state having a lower viscoelasticity than black toner at the melting point.

  However, when the viscoelasticity of the toner is reduced, mechanical stress is applied when the toner is stirred in the developing device, so that the external additive existing on the surface of the toner is buried and the developability and transferability are lowered. There was a problem to do. In addition, there is a problem that so-called toner spent occurs in which the toner adheres to the carrier.

Therefore, Patent Document 1 contains a colorant, a binder resin, and a release agent, and the binder resin is represented by the general formula —OCOC—R—COO— (CH ₂ ) _n —.
(In the formula, R represents a linear unsaturated aliphatic group having 2 to 20 carbon atoms, and n represents an integer of 2 to 20).
A toner containing a crystalline polyester resin containing at least 60 mol% of the total ester bond in the entire resin is disclosed.

  However, further improvement in the heat resistant storage stability of the toner is required.

  An object of the present invention is to provide a toner having excellent low-temperature fixability and heat-resistant storage stability, and a method for producing the toner, in view of the above-described problems of the prior art. Another object of the present invention is to provide a developer having the toner and an image forming method using the developer.

  The invention according to claim 1 includes, in the toner, a polyester and / or a modified polyester and a lanolin wax, and the modified polyester includes a group having an active hydrogen group and a group capable of reacting with the active hydrogen group. The lanolin wax is an ester of an alcohol having an average carbon number of 18 or more and 24 or less and a fatty acid ester having an average carbon number of 22 or more and 28 or less.

  According to a second aspect of the present invention, in the toner according to the first aspect, the lanolin wax has a melt viscosity at 100 ° C. of 1 mPa · s to 50 mPa · s.

  The invention according to claim 3 is the toner according to claim 1 or 2, wherein the lanolin wax has a ratio of a weight average molecular weight to a number average molecular weight of 3.0 or more and 8.0 or less. .

  According to a fourth aspect of the present invention, in the toner according to any one of the first to third aspects, the lanolin wax has a melting point of 60 ° C. or higher and 90 ° C. or lower.

  According to a fifth aspect of the present invention, in the toner according to any one of the first to fourth aspects, the lanolin wax has a penetration of 7 mm or less at 25 ° C.

  According to a sixth aspect of the present invention, in the toner according to any one of the first to fifth aspects, the polyester has a glass transition point of 45 ° C. or higher and 60 ° C. or lower.

  According to a seventh aspect of the present invention, in the toner according to any one of the first to sixth aspects, the polyester has a weight average molecular weight of 4000 or more and 6000 or less.

  According to an eighth aspect of the present invention, in the toner according to any one of the first to seventh aspects, the content of the lanolin wax is 0.5% by mass or more and 15% by mass or less.

  The invention according to claim 9 is a method for preparing a first liquid by dissolving or dispersing a polyester and / or modified polyester precursor and a toner material containing lanolin wax in an organic solvent in a method for producing a toner. And a step of preparing a second liquid by emulsifying or dispersing the first liquid in an aqueous medium, and a step of removing the organic solvent from the second liquid. A polyester prepolymer having a compound having a hydrogen group and a group capable of reacting with the active hydrogen group, and the lanolin wax has a melt viscosity at 100 ° C. of 1 mPa · s to 50 mPa · s. Features.

  According to a tenth aspect of the present invention, the developer includes the toner according to any one of the first to eighth aspects.

  According to an eleventh aspect of the present invention, in the image forming method, the step of charging the photoconductor, the step of exposing the charged photoconductor to form an electrostatic latent image, and the electrostatic formed on the photoconductor A latent image is developed using the developer according to claim 10 to form a toner image, and the toner image formed on the photosensitive member is transferred to a recording material. .

  According to a twelfth aspect of the present invention, in the image forming method according to the eleventh aspect, after the toner image formed on the photosensitive member is transferred to the intermediate transfer member, the toner image transferred to the intermediate transfer member is transferred to the intermediate transfer member. It is characterized by being transferred to a recording material.

According to a thirteenth aspect of the present invention, in the image forming method according to the twelfth aspect, the linear velocity at which the toner image transferred to the intermediate transfer member is transferred to the recording material is 0.1 m / s or more and 1 m / second. The transfer time at the nip portion where the intermediate transfer member and the recording material are in contact is 5 × 10 ⁻⁴ s or more and 6 × 10 ⁻² s or less.

  According to a fourteenth aspect of the present invention, in the image forming method according to any one of the eleventh to thirteenth aspects, a tandem image forming apparatus is used.

  According to the present invention, a toner excellent in low-temperature fixability and heat-resistant storage stability and a method for producing the toner can be provided. In addition, according to the present invention, it is possible to provide a developer having the toner and an image forming method using the developer.

It is a figure which shows an example of the image forming apparatus used by this invention. FIG. 2 is a partially enlarged view of the image forming apparatus in FIG. 1. It is a figure which shows an example of the charging device of FIG. FIG. 4 is a diagram illustrating another example of the charging device in FIG. 2. FIG. 4 is a diagram illustrating another example of the charging device in FIG. 2. It is a figure which shows an example of the image development apparatus of FIG. It is a figure which shows an example of the fixing device of FIG. FIG. 8 is a cross-sectional view illustrating a layer configuration of the fixing belt in FIG. 7.

  Next, the form for implementing this invention is demonstrated with drawing.

  The toner of the present invention has base particles containing polyester and / or modified polyester and lanolin wax, and the modified polyester is a polyester having a compound having an active hydrogen group and a group capable of reacting with the active hydrogen group. It is obtained by reacting a prepolymer.

  Lanolin wax is an ester of higher alcohol and higher fatty acid extracted from wool, the higher alcohol is branched and saturated, the content of sterin is 70% by mass, the higher fatty acid is saturated fatty acid, and methyl branched The content of fatty acid is 60% by mass and the content of hydroxy fatty acid is 30% by mass. Since lanolin wax has a wide carbon number distribution, by controlling the average carbon number, low molecular weight components are compatible with polyester and / or modified polyester, and high molecular weight components are not compatible with polyester and / or modified polyester. Lanolin wax can be extracted. That is, since the low molecular weight component of the lanolin wax is compatible with the polyester and / or the modified polyester, the glass transition point of the toner can be lowered and the low-temperature fixability of the toner can be improved. On the other hand, the high molecular weight component of lanolin wax that is incompatible with polyester and / or modified polyester acts as a release agent, and can improve the heat-resistant storage stability of the toner.

  The average carbon number of the higher alcohol is 18 to 24, and 20 to 22 is preferable. The average carbon number of the higher fatty acid is 22 to 28, and preferably 24 to 26. When the average carbon number of the higher alcohol is less than 18 or when the average carbon number of the higher fatty acid is less than 22, the heat resistant storage stability of the toner is lowered, or the granulation property of the toner is lowered. On the other hand, when the average carbon number of the higher alcohol exceeds 24 or when the average carbon number of the higher fatty acid exceeds 28, the low-temperature fixability of the toner decreases.

  In addition, the average carbon number of a higher alcohol and a higher fatty acid can be measured using GC-MS.

  The melt viscosity of lanolin wax at 100 ° C. is preferably 1 to 50 mPa · s, and more preferably 1 to 30 mPa · s. When the melt viscosity of lanolin wax at 100 ° C. is less than 1 mPa · s, the heat-resistant storage stability of the toner may be lowered, and when it exceeds 50 mPa · s, the low-temperature fixability of the toner may be lowered.

  In addition, melt viscosity can be measured using a Brookfield type rotational viscometer.

  The ratio of the weight average molecular weight to the number average molecular weight of the lanolin wax is preferably 3.0 to 8.0, and more preferably 3 to 5. If the ratio of the weight average molecular weight to the number average molecular weight of the lanolin wax is less than 3.0, it may be difficult to achieve both low temperature fixability and heat resistant storage stability of the toner. May decrease.

  The number average molecular weight and the weight average molecular weight are polystyrene-equivalent molecular weights measured by GPC using tetrahydrofuran (THF) as a developing solvent.

  The melting point of lanolin wax is preferably 60 to 90 ° C, and more preferably 60 to 75 ° C. If the melting point of the lanolin wax is less than 60 ° C., the heat-resistant storage stability of the toner may be lowered, and if it exceeds 90 ° C., the low-temperature fixability of the toner may be lowered.

  The melting point can be measured using DSC.

  The penetration of lanolin wax at 25 ° C. is preferably 7 mm or less, more preferably 5 mm or less. If the penetration of lanolin wax at 25 ° C. exceeds 7 mm, the low-temperature fixability of the toner may deteriorate.

  The penetration can be measured using a penetration measuring device.

  The content of lanolin wax in the toner is preferably 0.5 to 15% by mass, and more preferably 3 to 8% by mass. When the content of lanolin wax in the toner is less than 0.5% by mass, the low-temperature fixability and heat-resistant storage stability of the toner may be reduced. May deteriorate or contaminate the carrier.

Polyester has the general formula A (OH) m
(In the formula, A is an aliphatic group having 1 to 20 carbon atoms, an aromatic group or a heteroaromatic group which may have a substituent, and m is an integer of 2 to 4.)
A polyalcohol represented by the general formula B (COOH) n
(In the formula, B is an aliphatic group having 1 to 20 carbon atoms, an aromatic group or a heteroaromatic group which may have a substituent, and n is an integer of 2 to 4).
It is obtained by polycondensation of a polycarboxylic acid represented by

  The polyalcohol is not particularly limited, but ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, 1,4-butenediol. 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, sorbitol, 1,2,3,6-hexanete Trol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpro Ntriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene, bisphenol A, bisphenol A ethylene oxide adduct, bisphenol A propylene oxide addition Products, hydrogenated bisphenol A, hydrogenated bisphenol A ethylene oxide adduct, hydrogenated bisphenol A propylene oxide adduct, etc., may be used in combination of two or more.

  Examples of polycarboxylic acids include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenyl succinic acid, Isooctyl succinic acid, isododecenyl succinic acid, n-dodecyl succinic acid, isododecyl succinic acid, n-octenyl succinic acid, n-octyl succinic acid, isooctenyl succinic acid, isooctyl succinic acid, 1,2,4-benzene Tricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl- 2-methyl-2-methylenecarboxypropane, 1,2,4-cyclohexane Carboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, etc., cyclohexanedicarboxylic acid, cyclohexenedicarboxylic acid, butanetetracarboxylic acid, diphenylsulfonetetra Examples thereof include carboxylic acid and ethylene glycol bis (trimellitic acid), and two or more kinds may be used in combination.

The weight average molecular weight of the polyester is preferably 4 × 10 ^{3 to} 6 × 10 ³ , and more preferably 4.5 × 10 ^{3 to} 5.5 × 10 ³ . If the weight average molecular weight of the polyester is less than 4 × 10 ³ , the heat-resistant storage stability of the toner may be lowered, and if it exceeds 6 × 10 ³ , the low-temperature fixability of the toner may be lowered.

  The glass transition point of the polyester is preferably 45 to 60 ° C, more preferably 45 to 50 ° C. When the glass transition point is less than 45 ° C., the heat resistant storage stability of the toner may be lowered, and when it exceeds 60 ° C., the low temperature fixability of the toner may be lowered.

  The glass transition point can be measured using DSC.

  Although it does not specifically limit as an active hydrogen group in the compound which has an active hydrogen group, A hydroxyl group (alcoholic hydroxyl group or phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group etc. are mentioned, You may use together 2 or more types. . Among these, an amino group is preferable because a urea-modified polyester is obtained by reacting with a polyester prepolymer having an isocyanate group.

  Although it does not specifically limit as a compound which has an amino group, A diamine, a trivalent or more polyamine, amino alcohol, an amino mercaptan, an amino acid, etc. are mentioned, You may use 2 or more types together. Of these, diamine and a mixture of diamine and a small amount of trivalent or higher polyamine are preferable.

  Examples of diamines include aromatic diamines such as phenylenediamine, diethyltoluenediamine, and 4,4′-diaminodiphenylmethane; alicyclic groups such as 4,4′-diamino-3,3′-dimethyldicyclohexylmethane, diaminecyclohexane, and isophoronediamine. Diamine; Aliphatic diamines such as ethylenediamine, tetramethylenediamine, hexamethylenediamine, and the like.

  Examples of trivalent or higher polyamines include diethylenetriamine and triethylenetetramine.

  Examples of amino alcohols include ethanolamine and hydroxyethylaniline.

  Examples of amino mercaptans include aminoethyl mercaptan and aminopropyl mercaptan.

  Examples of amino acids include aminopropionic acid and aminocaproic acid.

  In the compound having an amino group, the amino group may be blocked with a ketone such as acetone, methyl ethyl ketone, or methyl isobutyl ketone.

  The group capable of reacting with the active hydrogen group in the polyester prepolymer having a group capable of reacting with the active hydrogen group is not particularly limited, and examples thereof include an isocyanate group, an epoxy group, a carboxyl group, and a chlorocarbonyl group. 2 or more may be used in combination. Above all, it is easy to adjust the molecular weight of the polymer component, and the oil-less low-temperature fixability of the toner, especially urea modification that can ensure good release and fixability even without a release oil application mechanism to the fixing heating medium. Since polyester is obtained, an isocyanate group is preferable.

  The polyester prepolymer having an isocyanate group can be obtained by reacting a polyester having a hydroxyl group with a polyisocyanate. A polyester having a hydroxyl group can be obtained by polycondensation of a polyalcohol and a polycarboxylic acid.

  Although it does not specifically limit as polyalcohol, Dialcohol, trihydric or more alcohol, the mixture of dialcohol and trihydric or more alcohol, etc. are mentioned, You may use 2 or more types together. Among these, dialcohol or a mixture of dialcohol and a trihydric or higher alcohol is preferable.

  Examples of dialcohols include alkylene glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol; diethylene glycol, triethylene glycol, dipropylene glycol, Polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polybutylene glycol; alicyclic dialcohols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; alicyclic dialcohols, ethylene oxide, propylene oxide, butylene oxide Alkylene oxide adducts of alicyclic dialcohols such as those added with alkylene oxides such as bisphenol A, bisphenol F, bisphenol S, etc. Nord acids; the bisphenols include ethylene oxide, propylene oxide, alkylene oxide adducts of bisphenols such as those obtained by adding an alkylene oxide such as butylene oxide. Among them, alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols are preferable, and alkylene oxide adducts of bisphenols, mixtures of alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. Particularly preferred.

  Examples of trihydric or higher alcohols include trihydric or higher polyhydric aliphatic alcohols such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol; trisphenol compounds (Trisphenol PA (produced by Honshu Chemical Industry Co., Ltd.)) Polyphenols having a valence of 3 or more, such as phenol novolac and cresol novolac; alkylene oxides of a valence of 3 or more, such as ethylene oxide, propylene oxide, butylene oxide, etc. added to a triphenol or more polyphenol Examples include adducts.

  When a dialcohol and a trihydric or higher alcohol are mixed and used, the mass ratio of the trihydric or higher alcohol to the dialcohol is preferably 0.01 to 10, and more preferably 0.01 to 1.

  Although it does not specifically limit as polycarboxylic acid, Dicarboxylic acid, trivalent or more carboxylic acid, the mixture of dicarboxylic acid and trivalent or more carboxylic acid, etc. are mentioned, You may use 2 or more types together. Among these, dicarboxylic acid or a mixture of dicarboxylic acid and trivalent or higher carboxylic acid is preferable.

  Dicarboxylic acids include alkylene dicarboxylic acids such as succinic acid, adipic acid and sebacic acid; alkenylene dicarboxylic acids such as maleic acid and fumaric acid; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid and naphthalenedicarboxylic acid. Can be mentioned. Among these, alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms are preferable.

  Examples of the trivalent or higher carboxylic acid include trivalent or higher aromatic carboxylic acid such as trimellitic acid and pyromellitic acid. Among these, trivalent or higher aromatic carboxylic acids having 9 to 20 carbon atoms are preferable.

  In place of polycarboxylic acid, an anhydride or lower alkyl ester of polycarboxylic acid can also be used. Although it does not specifically limit as a lower alkyl ester, Methyl ester, ethyl ester, isopropyl ester etc. are mentioned.

  When a dicarboxylic acid and a trivalent or higher carboxylic acid are mixed and used, the mass ratio of the trivalent or higher carboxylic acid to the dicarboxylic acid is preferably 0.01 to 10, and more preferably 0.01 to 1.

  The equivalent ratio of the hydroxyl group of the polyalcohol to the carboxyl group of the polycarboxylic acid when the polyester having a hydroxyl group is synthesized is preferably 1 to 2, more preferably 1 to 1.5, and 1.02 to 1 .3 is particularly preferred.

  Polyisocyanate is not particularly limited, but tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethyl caproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, Aliphatic polyisocyanates such as tetramethylhexane diisocyanate; cycloaliphatic polyisocyanates such as isophorone diisocyanate and cyclohexylmethane diisocyanate; tolylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, diphenylene-4,4′-diisocyanate, 4 , 4'-Diisocyanato-3,3'-dimethyldipheny , Aromatic diisocyanates such as 3-methyldiphenylmethane-4,4′-diisocyanate, diphenyl ether-4,4′-diisocyanate; araliphatic diisocyanates such as α, α, α ′, α′-tetramethylxylylene diisocyanate; (Isocyanatoalkyl) isocyanurates such as isocyanurate, triisocyanatocycloalkyl isocyanurate and the like may be used, and two or more may be used in combination.

  In the polyisocyanate, the isocyanate group may be blocked by a phenol derivative, oxime, caprolactam, or the like.

  When the polyester prepolymer having an isocyanate group is synthesized, the equivalent ratio of the isocyanate group of the polyisocyanate to the hydroxyl group of the polyester having a hydroxyl group is preferably 1 to 5, more preferably 1.2 to 4. .5-3 are particularly preferred. When the equivalent ratio is less than 1, offset resistance may be lowered, and when it exceeds 5, the low-temperature fixability may be lowered.

  The content of the structural unit derived from polyisocyanate in the polyester prepolymer having an isocyanate group is preferably 0.5 to 40% by mass, more preferably 1 to 30% by mass, and particularly preferably 2 to 20% by mass. . When this content is less than 0.5% by mass, the hot offset resistance is lowered, and it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability. Fixability may be reduced.

  The content of the constituent unit derived from the polyalcohol in the polyester prepolymer having an isocyanate group is preferably 0.5 to 40% by mass, more preferably 1 to 30% by mass, and particularly preferably 2 to 20% by mass. . When this content is less than 0.5% by mass, the resistance to hot offset decreases, and it may be difficult to achieve both heat-resistant storage stability and low-temperature fixability of the toner. Low temperature fixability may be reduced.

  The number of isocyanate groups per molecule of the polyester prepolymer having an isocyanate group is preferably 1 or more, more preferably 1.2 to 5, and particularly preferably 1.5 to 4. When the number of isocyanate groups is less than 1, hot offset resistance may be lowered.

The polyester prepolymer having an isocyanate group preferably has a weight average molecular weight of 3 × 10 ³ to 4 × 10 ⁴ , and more preferably 4 × 10 ^{3 to} 3 × 10 ⁴ . When the weight average molecular weight is less than 3 × 10 ³ , the heat-resistant storage stability may be lowered, and when it exceeds 4 × 10 ⁴ , the low-temperature fixability may be lowered.

  When the polyester prepolymer having an isocyanate group and the compound having an amino group are reacted, the equivalent ratio of the isocyanate group of the polyester prepolymer to the amino group of the compound having an amino group is preferably 1/3 to 3, 5 to 2 is more preferable, and 2/3 to 1.5 is particularly preferable. When the equivalent ratio is less than 1/3, the low-temperature fixability may be lowered. When the equivalent ratio is more than 3, the molecular weight of the binder resin may be reduced, and the hot offset resistance may be lowered.

  In order to stop the reaction between the polyester prepolymer having an isocyanate group and the compound having an amino group, it is preferable to use a reaction terminator. Thereby, the molecular weight of the urea-modified polyester can be controlled.

  Examples of the reaction terminator include monoamines such as diethylamine, dibutylamine, butylamine, and laurylamine.

  The monoamine may have its amino group blocked by a ketone such as acetone, methyl ethyl ketone, or methyl isobutyl ketone.

  The urea-modified polyester may have a urethane bond. In this case, the equivalent ratio of the urethane bond to the urea bond is preferably 0 to 9, more preferably 0.25 to 4, and particularly preferably 2/3 to 7/3. When this equivalent ratio exceeds 9, the hot offset resistance may decrease.

Examples of the combination of the urea-modified polyester and the polyester include the following (1) to (10).
(1) A polycondensate of ethylene oxide 2 mol adduct of bisphenol A and isophthalic acid is reacted with isophorone diisocyanate and then reacted with isophorone diamine, and bisphenol A ethylene oxide 2 mol adduct and isophthalic acid. Mixture of polycondensate (2) 2 mol of bisphenol A ethylene oxide adduct and isophthalic acid polycondensate were reacted with isophorone diisocyanate and then reacted with isophorone diamine and 2 mol of bisphenol A ethylene oxide Mixture of adduct and terephthalic acid polycondensate (3) After reacting bisphenol A ethylene oxide 2 mol adduct and bisphenol A propylene oxide 2 mol adduct and terephthalic acid polycondensate with isophorone diisocyanate, Isoho Bisphenol A ethylene oxide 2-mole adduct and a mixture of bisphenol A propylene oxide 2-mole adduct and terephthalic acid polycondensate (4) bisphenol A ethylene oxide 2-mole adduct and bisphenol A polycondensate of propylene oxide 2 mol adduct of A and terephthalic acid is reacted with isophorone diisocyanate and then reacted with isophorone diamine, and a polycondensate of bisphenol A propylene oxide 2 mol adduct and terephthalic acid (5) A polycondensate of bisphenol A ethylene oxide 2 mol adduct and terephthalic acid was reacted with isophorone diisocyanate and then reacted with hexamethylenediamine, and bisphenol A ethylene oxide Mixture of a polycondensate of a mole adduct and terephthalic acid (6) An ethylene oxide 2 mol adduct of bisphenol A and a polycondensate of terephthalic acid are reacted with isophorone diisocyanate and then reacted with hexamethylenediamine A mixture of bisphenol A ethylene oxide 2 mol adduct and bisphenol A propylene oxide 2 mol adduct and terephthalic acid polycondensate (7) a bisphenol A ethylene oxide 2 mol adduct and terephthalic acid polycondensate, After reacting with isophorone diisocyanate, reaction with ethylenediamine and a mixture of bisphenol A ethylene oxide 2 mol adduct and terephthalic acid polycondensate (8) bisphenol A ethylene oxide 2 mol adduct and isophthalic acid Polycondensate A mixture of a reaction product with phenylmethane diisocyanate followed by a reaction with hexamethylene diamine, an ethylene oxide 2-mole adduct of bisphenol A and a polycondensation product of isophthalic acid (9) an ethylene oxide 2-mole adduct of bisphenol A, and A polycondensate of bisphenol A propylene oxide and terephthalic acid and dodecenyl succinic anhydride is reacted with diphenylmethane diisocyanate and then reacted with hexamethylene diamine, and bisphenol A ethylene oxide 2 mol adduct And a mixture of a polycondensate of bisphenol A with propylene oxide and terephthalic acid (10) a polycondensate of bisphenol A with ethylene oxide 2 mol and an isophthalic acid, and toluene diisocyanate A mixture of a product obtained by reacting with hexamethylenediamine and a polycondensate of bisphenol A with ethylene oxide and a polycondensate of isophthalic acid. The toner of the present invention comprises a colorant, a charge control agent, and a fluidity improver. Further, it may further contain a cleaning property improving agent, a magnetic material and the like.

  Although it does not specifically limit as a coloring agent, Carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher, yellow lead, titanium yellow, polyazo Yellow, Oil Yellow, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Vulcan Fast Yellow (5G, R), Tartrazine Lake, Quinoline Yellow Rake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Tan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimony Zhu, Permanent Red 4R, Para Red, Faise Red, Parachloro Ortho Nitroaniline Red, Risorf Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R, Brilliant Carmine 6B , Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B , Thioindigo maroon, oil red, quinacridone red, pyrazolone red, polyazo red, chrome bar Lion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC ), Indigo, Ultramarine Blue, Bituminous Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chrome Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Phthalocyanine Green, Anthraki Non-green, titanium oxide, zinc white, lithobon and the like can be mentioned, and two or more kinds may be used in combination.

  The content of the colorant in the toner is preferably 1 to 15% by mass, and more preferably 3 to 10% by mass. When the content of the colorant in the toner is less than 1% by mass, the coloring power of the toner may be reduced. When the content exceeds 15% by mass, poor dispersion of the pigment occurs in the base particles, and the toner is colored. The power may decrease, and the electrical characteristics of the toner may decrease.

  The colorant may be a master batch in which a pigment and a resin are combined.

  Although it does not specifically limit as resin, Polystyrene; Styrene, such as polystyrene, poly p-chlorostyrene, polyvinyl toluene, or its substituted polymer; Styrene-p-chlorostyrene copolymer, Styrene-propylene copolymer, Styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer Polymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene- Vinyl methyl ketone copolymer, steel Styrene copolymers such as styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethacrylic acid Methyl, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic hydrocarbon Resins, alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like may be used, and two or more kinds may be used in combination.

  The master batch is obtained by applying a high shear force to the pigment and the resin and mixing and kneading them. At this time, it is preferable to add an organic solvent in order to enhance the interaction between the pigment and the resin. Further, since a wet cake of pigment can be used as it is and does not need to be dried, it is preferable to produce a masterbatch using a flushing method. The flushing method is a method of mixing and kneading an aqueous pigment paste together with a resin and an organic solvent, transferring the pigment to the resin, and then removing water and the organic solvent. When mixing and kneading the pigment and the resin, it is preferable to use a high shear dispersion device such as a three-roll mill.

  The charge control agent is not particularly limited, but nigrosine dye, triphenylmethane dye, chromium-containing metal complex dye, molybdate chelate pigment, rhodamine dye, alkoxy amine, quaternary ammonium salt (fluorine-modified quaternary ammonium salt) Salt), alkylamide, phosphorus alone or compound thereof, tungsten alone or compound thereof, fluorosurfactant, metal salt of salicylic acid, metal salt of salicylic acid derivative, copper phthalocyanine, perylene, quinacridone, azo pigment, Examples thereof include polymer compounds having a functional group such as a sulfonic acid group, a carboxyl group, and a quaternary ammonium base, and two or more kinds may be used in combination.

  Commercially available charge control agents include Nigrosine dye Bontron 03, quaternary ammonium salt Bontron P-51, metal-containing azo dye Bontron S-34, oxynaphthoic acid metal complex E-82, salicylic acid metal E-84 of a complex, E-89 of a phenol-based condensate (above, manufactured by Orient Chemical Co., Ltd.), TP-302, TP-415 of a quaternary ammonium salt molybdenum complex (made of Hodogaya Chemical Co., Ltd.), Quaternary ammonium salt copy charge PSY VP2038, triphenylmethane derivative copy blue PR, quaternary ammonium salt copy charge NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR which is a boron complex -147 (made by Nippon Carlit Co., Ltd.).

  The fluidity improver is not particularly limited, but silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, silica sand, clay, mica, silica ash Stones, diatomaceous earth, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, etc., may be used in combination of two or more . Among these, surface treatment is performed with a treatment agent such as a silane coupling agent, a silylating agent, a silane coupling agent having an alkyl fluoride group, an organic titanate coupling agent, an aluminum coupling agent, silicone oil, or modified silicone oil. Hydrophobic silica and hydrophobic titanium oxide are preferred.

  The average primary particle size of the fluidity improver is preferably 5 to 50 nm, and more preferably 10 to 30 nm.

The fluidity improver preferably has a BET specific surface area of 20 to 500 m ² / g.

  The content of the fluidity improver in the toner is preferably 0.01 to 5% by mass, and more preferably 0.01 to 2% by mass.

  The cleaning improver is not particularly limited, and examples thereof include fatty acid metal salts such as zinc stearate and calcium stearate, resin particles synthesized by soap-free emulsion polymerization such as polymethyl methacrylate particles and polystyrene particles.

  The resin particles preferably have a volume average particle diameter of 0.01 to 1 μm.

  Although it does not specifically limit as a magnetic material, Iron powder, a magnetite, a ferrite, etc. are mentioned.

  The weight average particle diameter of the toner of the present invention is preferably 1 to 6 μm, and more preferably 2 to 5 μm. If the weight average particle size is less than 1 μm, toner dust may easily occur during transfer. If the weight average particle size exceeds 6 μm, dot reproducibility becomes insufficient, and the graininess of the halftone portion decreases. In some cases, a high-definition image cannot be formed.

  In the toner of the present invention, the ratio of the weight average particle diameter to the number average particle diameter is preferably 1.05 to 1.25. When the ratio of the weight average particle diameter to the number average particle diameter is less than 1.05, when used as a two-component developer, the toner is fused to the surface of the carrier during long-term agitation in the developing device, and the carrier is charged Capability may decrease and cleaning performance may decrease. Further, when used as a one-component developer, toner filming on the developing roller may occur, or toner may be fused to a member such as a blade in order to make the toner thinner. On the other hand, if the ratio of the weight average particle diameter to the number average particle diameter exceeds 1.25, a high-resolution and high-quality image may not be formed, and the balance of the toner in the developer is performed. The variation of the toner particle size may be increased. In addition, the toner charge amount distribution becomes wide, and a high-quality image may not be formed. Further, a toner having a ratio of the weight average particle diameter to the number average particle diameter of 1.05 to 1.25 tends to be a toner excellent in storage stability, low-temperature fixability, and hot offset resistance. In particular, when used in a full-color copying machine, an image having excellent gloss can be formed.

  The weight average particle size and number average particle size of the toner can be measured using a particle size measuring device Multisizer III (manufactured by Beckman Coulter, Inc.).

  The toner of the present invention preferably has an average circularity of 0.95 to 0.99. If the average circularity is less than 0.95, the image uniformity during development may decrease or the transfer efficiency of the toner may decrease, and if it exceeds 0.99, the cleaning property may decrease. is there.

  The average circularity of the toner can be measured using a flow type particle image analyzer FPIA-2100 (manufactured by Sysmex Corporation).

  The method for producing a toner of the present invention comprises a step of preparing a first liquid by dissolving or dispersing a precursor of polyester and / or modified polyester and a toner material containing lanolin wax in an organic solvent; Are emulsified or dispersed in an aqueous medium to prepare a second liquid, and an organic solvent is removed from the second liquid. At this time, the modified polyester includes a compound having an active hydrogen group and a polyester prepolymer having a group capable of reacting with the active hydrogen group. The toner material may further contain a colorant, a charge control agent, and the like.

  The organic solvent is not particularly limited, but toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, Examples thereof include ethyl acetate, methyl ethyl ketone, and methyl isobutyl ketone, and two or more kinds may be used in combination. Among these, ester solvents are preferable, and ethyl acetate is particularly preferable.

  The organic solvent preferably has a boiling point of less than 150 ° C. because it is easy to remove.

  The addition amount of the organic solvent is preferably 40 to 300 parts by mass, more preferably 60 to 140 parts by mass, and particularly preferably 80 to 120 parts by mass with respect to 100 parts by mass of the toner material.

  Before preparing the first liquid, it is preferable to disperse lanolin wax in an organic solvent containing polyester in advance.

  The mass ratio of lanolin wax to polyester is preferably 0.2-1. When the mass ratio of the lanolin wax to the polyester is less than 0.2, the dispersion diameter of the lanolin wax may increase, and when it exceeds 1, the lanolin wax may aggregate when preparing the first liquid. is there.

  The compound having an active hydrogen group may be added to the aqueous medium, or may be added when the first liquid is emulsified or dispersed in the aqueous medium. Moreover, after emulsifying or dispersing the first liquid in an aqueous medium, a compound having an active hydrogen group may be added. In this case, since the modified polyester is generated in the vicinity of the surface of the base particle, a concentration gradient of the modified polyester can be provided on the base particle.

  The toner material excluding the polyester and / or modified polyester precursor and the lanolin wax may be added to the aqueous medium instead of being added when the first liquid is prepared. It may be added when emulsified or dispersed in the aqueous medium, or may be added after the first liquid is emulsified or dispersed in the aqueous medium.

  When emulsifying or dispersing the first liquid in the aqueous medium, it is preferable to apply a shearing force using a dispersing machine such as a low speed shearing type dispersing machine or a high speed shearing type dispersing machine.

  Examples of the aqueous medium include, but are not limited to, water; alcohols such as methanol, isopropanol and ethylene glycol; dimethylformamide; tetrahydrofuran; cellosolves; lower ketones such as acetone and methyl ethyl ketone; Good. Of these, water is preferred.

  The amount of the aqueous medium used is preferably 50 to 2000 parts by mass, more preferably 100 to 1000 parts by mass with respect to 100 parts by mass of the toner material. If the amount of the aqueous medium used is less than 50 parts by mass, the dispersion state of the toner material may be deteriorated, and base particles having a predetermined particle size may not be obtained. If the amount exceeds 2000 parts by mass, the production cost increases. .

  The aqueous medium preferably contains particles containing an anionic resin and an anionic surfactant. Thereby, the particle size and particle size distribution of the base particles can be controlled. At this time, the particles containing the anionic resin adhere to the surface of the droplet obtained by emulsifying or dispersing the first liquid in the aqueous medium, and are fused and fused to form a relatively hard surface. . Moreover, the particle | grains containing anionic resin can suppress coalescence of droplets. Further, the particles containing an anionic resin can impart negative chargeability to the toner.

  The aqueous medium containing particles containing an anionic resin and an anionic surfactant can be obtained by dispersing particles containing an anionic resin in an aqueous medium in the presence of an anionic surfactant. The addition amount of the particles containing the anionic surfactant and the anionic resin is usually 0.5 to 10% by mass with respect to the aqueous medium.

  The resin contained in the particles containing an anionic resin is not particularly limited as long as it can be dispersed in an aqueous medium, but is not limited to vinyl resin, polyurethane, epoxy resin, polyester, polyamide, polyimide, silicon resin, phenol. Examples thereof include thermoplastic resins such as resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonates, or thermosetting resins, and two or more of them may be used in combination. Among these, vinyl resin, polyurethane, epoxy resin, and polyester are preferable because fine spherical resin particles are easily obtained.

  The vinyl resin is not particularly limited as long as it is a polymer obtained by homopolymerizing or copolymerizing a vinyl monomer, but styrene- (meth) acrylic acid ester copolymer, styrene-butadiene copolymer, (meth) acrylic acid-acrylic. Examples include acid ester copolymers, styrene-acrylonitrile copolymers, styrene-maleic anhydride copolymers, styrene- (meth) acrylic acid copolymers, and the like.

  The volume average particle diameter of the particles containing an anionic resin is usually 5 to 50 nm, and preferably 10 to 25 nm.

  The volume average particle diameter of the anionic resin particles can be measured using a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.).

  Particles containing an anionic resin can be obtained by polymerizing using an anionic surfactant or introducing an anionic group such as a carboxyl group or a sulfonic acid group into the resin.

Although it does not specifically limit as a manufacturing method of the particle | grains containing anionic resin, The following method is mentioned.
(1) Suspension polymerization, emulsion polymerization, seed polymerization or dispersion polymerization of vinyl monomers (2) Polyaddition or condensation resin precursors (monomers, oligomers, etc.) such as polyester, polyurethane, epoxy resins or solutions thereof (3) Polyaddition or condensation resin precursors (monomers, oligomers, etc.) such as polyesters, polyurethanes, and epoxy resins, or solutions thereof, after being dispersed in an aqueous medium in the presence of a dispersant and then polymerized or cured (4) Resin particles obtained by pulverizing and classifying a resin using a mechanical pulverizer or jet pulverizer after adding an emulsifier and then adding an aqueous medium. (5) The resin particles obtained by spraying the resin solution in the form of a mist are dispersed in the aqueous medium in the presence of the dispersant. (6) A method in which a resin solution obtained by adding or dissolving a poor solvent to a resin solution is cooled and the resin particles obtained by removing the solvent are dispersed in an aqueous medium in the presence of a dispersant ( 7) A method in which a resin solution is dispersed in an aqueous medium in the presence of a dispersant, and then the solvent is removed by heating, decompression, etc. (8) An emulsifier is added to the resin solution, and then an aqueous medium is added. Method of phase inversion emulsification The anionic surfactant is not particularly limited, and examples thereof include alkylbenzene sulfonate, α-olefin sulfonate, phosphate ester and the like, and two or more types may be used in combination. Among these, an anionic surfactant having a fluoroalkyl group is preferable.

  Examples of the anionic surfactant having a fluoroalkyl group include a fluoroalkyl carboxylic acid having 2 to 10 carbon atoms or a metal salt thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-11) oxy. ] -1-alkyl (C3-4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-20) carboxylic acid or Its metal salt, perfluoroalkyl carboxylic acid (C7-13) or its metal salt, perfluoroalkyl (C4-12) sulfonic acid or its metal salt, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- (2 -Hydroxyethyl) perfluorooctanesulfonami And perfluoroalkyl (C6-10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-16) ethyl phosphate, and the like.

  Commercially available anionic surfactants having a fluoroalkyl group include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.); Fluorard FC-93, FC-95, FC-98, FC-129 (Manufactured by Sumitomo 3M); Unidyne DS-101, DS-102 (manufactured by Daikin Industries); Megafac F-110, F-120, F-113, F-191, F-812, F-833 (DIC Corporation) Xttop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products); Footent F-100, F-150 (manufactured by Neos) Etc.

  The aqueous medium may further contain a poorly water-soluble inorganic dispersant.

  The inorganic dispersant is not particularly limited, and examples thereof include calcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite.

  In the case of using an inorganic dispersant that is soluble in acids or alkalis such as calcium phosphate, the base particles are dissolved by using an acid such as hydrochloric acid, then washed with water, or decomposed using an enzyme. The inorganic dispersant can be removed from

  The aqueous medium may further contain a polymeric protective colloid.

  The polymeric protective colloid is not particularly limited, but carboxyl groups such as acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid, maleic anhydride, etc. Or a derivative thereof: β-hydroxyethyl acrylate, β-hydroxyethyl methacrylate, β-hydroxypropyl acrylate, β-hydroxypropyl methacrylate, γ-hydroxypropyl acrylate, γ-hydroxy methacrylate Propyl, 3-chloro-2-hydroxypropyl acrylate, 3-chloro-2-hydroxypropyl methacrylate, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monometa (Meth) acrylic monomers having hydroxyl groups such as crylic acid ester, N-methylol acrylamide, N-methylol methacrylamide; vinyl alkyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether; vinyl acetate, propion Esters of vinyl alcohol and carboxylic acids such as vinyl acid and vinyl butyrate; amide compounds of acrylamide, methacrylamide, diacetone acrylamide, or methylolates thereof; single units having a carbonyl chloride group such as acrylates and methacrylates Examples thereof include homopolymers or copolymers such as monomers having a nitrogen atom such as vinyl pyridine, vinyl pyrrolidone, vinyl imidazole or ethylene imine or a heterocyclic ring thereof. Polymer protective colloids other than these include polyoxyethylene, polyoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, Examples include polyoxyethylenes such as polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, and polyoxyethylene nonyl phenyl ester; and celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose.

  In the present invention, after preparing the second liquid, it is preferable to react a polyester prepolymer having a group capable of reacting with an active hydrogen group and a compound having an active hydrogen group to produce a modified polyester. Thereby, the mechanical strength of the base particles is increased, and the burying of the particles containing the anionic resin can be suppressed. In addition, when the compound having an active hydrogen group is cationic, particles containing an anionic resin can be electrostatically attracted. Further, the fluidity of the toner during heat fixing can be adjusted, and the fixing temperature range can be widened.

  The reaction time for producing the modified polyester is preferably 10 minutes to 40 hours, and more preferably 2 to 24 hours.

  The method for removing the organic solvent from the second liquid is not particularly limited, but the second liquid is gradually heated to evaporate and remove the organic solvent in the oil droplets. And a method of evaporating and removing the organic solvent in the oil droplets while evaporating and removing the aqueous medium.

  If necessary, the second liquid from which the organic solvent has been removed is washed and then dried to obtain base particles. At this time, classification may be performed as necessary. In addition, you may classify | categorize by a cyclone, a decanter, centrifugation, etc. before drying, and you may classify after drying.

  The base particles may be mixed with particles such as a colorant, a charge control agent, a fluidity improver, and a cleaning property improver, and then mechanical impact force may be applied.

  The method of applying a mechanical impact force is not particularly limited, but a method of applying an impact force to the mixture with a blade rotating at high speed, and the mixture is injected into a high-speed air stream and accelerated to collide particles or composite particles. The method of making it collide with a board is mentioned.

  The device for applying the mechanical impact force is not particularly limited, but a device that reduces the pulverization air pressure by remodeling an ong mill (manufactured by Hosokawa Micron) or an I-type mill (manufactured by Nippon Pneumatic Co., Ltd.), hybridization. Examples include a system (manufactured by Nara Machinery Co., Ltd.), a kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), and an automatic mortar.

  The developer of the present invention has the toner of the present invention and may further have a carrier. At this time, the mass ratio of the toner to the carrier is preferably 1 to 10%.

  Although it does not specifically limit as a carrier, Iron powder, ferrite powder, magnetite powder, a magnetic resin carrier, etc. are mentioned.

  The carrier may be coated with a resin. Examples of such resins include, but are not limited to, urea-formaldehyde resins, melamine resins, benzoguanamine resins, urea resins, polyamides, epoxy resins and other amino resins; acrylic resins, polymethyl methacrylate, polyacrylonitrile, polyvinyl acetate, Polyvinyl alcohol, polyvinyl butyral, polystyrene resins, polystyrene resins such as styrene-acrylic resins, halogenated olefin resins such as polyvinyl chloride, polyethylene, polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, vinylidene fluoride Fluoroterpolymers such as acrylic copolymers, vinylidene fluoride-vinyl fluoride copolymers, terpolymers with tetrafluoroethylene-vinylidene fluoride-non-fluorinated monomers, etc. Ribiniru and polyvinylidene resins, polyethylene terephthalate, polyester resins such as polybutylene terephthalate; polycarbonate; and silicone resins.

  In addition, such a resin may contain conductive powder or the like as necessary. The conductive powder is not particularly limited, and examples thereof include metal powder, carbon black, titanium oxide, tin oxide, and zinc oxide.

  The conductive powder preferably has an average particle size of 1 μm or less. When the average particle size exceeds 1 μm, it may be difficult to control the electric resistance.

  The carrier preferably has a weight average particle diameter of 15 to 40 μm. When the weight average particle diameter is less than 15 μm, carrier adhesion may easily occur. On the other hand, if the weight average particle diameter exceeds 40 μm, scumming tends to occur when the concentration of toner in the developer is increased. In addition, when the dot diameter of the electrostatic latent image is small, the variation in dot reproducibility increases, and the graininess of the highlight portion may decrease.

  The weight average particle diameter of the carrier can be measured using a Microtrac particle size analyzer model HRA9320-X100 (manufactured by Honeywell).

  The image forming apparatus used in the present invention is not particularly limited as long as the image forming method of the present invention can be applied. As an example, an image forming apparatus 100 of a tandem type is shown in FIG.

  The image forming apparatus 100 includes a copying apparatus main body 110, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400.

  An intermediate transfer belt 50 supported by three rollers 14, 15 and 16 is provided at the center of the copying apparatus main body 110, and can be conveyed clockwise in the drawing. On the intermediate transfer belt 50 stretched between the rollers 14 and 15, four image forming units 18Bk, 18C, 18M and 18Y of black, cyan, magenta and yellow are laterally arranged along the conveying direction. Are arranged side by side. Further, an exposure device 21 is provided on the image forming unit 18 in the drawing. The exposure device 21 has four optical paths, and the photosensitive drum 10 of each color is exposed according to the image signal of each color. As the exposure device 21, a laser scanning optical system including a laser light source, a deflector such as a rotating polygon mirror, a scanning imaging optical system, and a mirror group is usually used. On the other hand, a secondary transfer device 22 is provided on the opposite side of the image forming unit 18 with the intermediate transfer belt 50 interposed therebetween. The secondary transfer device 22 is provided with a belt 24 supported by two rollers 23. The secondary transfer device 22 is disposed so as to be pressed against the roller 16 via the intermediate transfer belt 50, and transfers the full-color toner image on the intermediate transfer belt 50 to a sheet. Further, a fixing device 25 for fixing the full color toner image transferred to the sheet is provided on the left side of the secondary transfer device 22 in the drawing. The fixing device 25 is configured by pressing a pressure roller 27 against a heating belt 26 supported by two rollers. The sheet on which the full color toner image is transferred is conveyed to the fixing device 25 by the secondary transfer device 22. In the drawing, a sheet reversing device 28 for reversing the sheet to form images on both sides of the sheet is provided below the secondary transfer device 22 and the fixing device 25.

  When copying using the image forming apparatus 100, first, a document is set on the document table 130 of the automatic document feeder 400 or the automatic document feeder 400 is opened and placed on the contact glass 32 of the scanner 300. The document is set and the automatic document feeder 400 is closed. Next, when a start switch (not shown) is pressed, when the document is set on the document table 130, the document is transported and moved onto the contact glass 32, and then the document is set on the contact glass 32. In this case, the scanner 300 is immediately driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, the first traveling body 33 emits light from the light source and further reflects the reflected light from the document surface. This light is reflected by the mirror of the second traveling body 34 and then enters the reading sensor 36 through the imaging lens 35 to read the document content. Based on the image signal obtained in this way, image processing is performed by an image processing unit (not shown) and converted into an image signal of each color, and then the image signal of each color is transmitted to the exposure device 21.

  When a start switch (not shown) is pressed, one of the rollers 14, 15 and 16 is rotationally driven by a drive motor (not shown), the other two rollers are driven to rotate, and the intermediate transfer belt 50 is conveyed. To do. At the same time, in each color image forming unit 18, the photosensitive drum 10 is rotated to form a toner image of each color on the photosensitive drum 10. Then, the toner images of each color are sequentially superimposed and transferred onto the conveyed intermediate transfer belt 50 to form a full color toner image.

  On the other hand, when a start switch (not shown) is pressed, one of the paper feed rollers 142 of the paper feed table 200 rotates, and the sheet is fed out from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. Further, after the sheets are separated one by one by the separation roller 145 and put into the paper feed path 146, the sheet is transported by the transport roller 147, guided to the paper feed path 148 in the copying machine main body 100, and pushed against the registration roller 49. Stop it. Alternatively, after the sheet feeding roller 52 is rotated and the sheets are fed out from the manual feed tray 51, the sheets are separated one by one by the separation roller 58, put into the manual sheet feeding path 53, and abutted against the registration roller 49 and stopped.

Then, the registration roller 49 is rotated in synchronization with the full-color toner image on the intermediate transfer belt 50, and the sheet is fed between the intermediate transfer belt 50 and the secondary transfer device 22 to transfer the full-color toner image onto the sheet. At this time, the linear velocity of the secondary transfer is preferably 0.1 to 1 m / s. The transfer time for secondary transfer is preferably 5 × 10 ^{−4 to} 6 × 10 ⁻² s.

  The sheet onto which the full color toner image has been transferred is conveyed by the secondary transfer device 22 and sent to the fixing device 25, and then the fixing device 25 applies heat and pressure to fix the full color toner image. Further, the sheet is switched by the switching claw 55 and discharged onto the sheet discharge tray 57 by the discharge roller 56, or after the sheet is reversed by the sheet reversing device 28, the sheet is guided to the sheet feeding path 148 and stopped by being abutted against the registration roller 49. After the image is formed on the back surface of the sheet, the sheet is discharged onto the discharge tray 57 by the discharge roller 56. The registration roller 49 is generally grounded, but a bias may be applied to remove paper dust from the sheet.

  As shown in FIG. 2, the image forming units 18Bk, 18C, 18M, and 18Y for black, cyan, magenta, and yellow include a photoreceptor drum 10, and an OPC photoreceptor is usually used as the photoreceptor drum 10. . Around the photosensitive drum 10, there are provided a charging device 15, a developing device 20 that develops using the developer of the present invention, a primary transfer device 40, and a cleaning device 30, and a neutralizing device is provided if necessary. May be. Note that L is light emitted from the exposure device 21 to the photosensitive drums 10 of the respective colors. In addition, conductive rollers 41, 42, and 43 are provided between the primary transfer devices 40 of the respective colors. Further, the intermediate transfer belt 50 is interposed between the photosensitive drums 10 of the respective colors and the primary transfer device 40, and the toner images of the respective colors are sequentially transferred to the intermediate transfer belt 50 from the photosensitive drums 10 of the respective colors, thereby being full color. A toner image is formed. At this time, since the toner of the present invention is excellent in chargeability, durability and environmental stability, the amount of each color toner to be developed is stabilized, and a full color image excellent in color reproducibility can be formed.

  The full color toner image on the intermediate transfer belt 50 may include a halftone portion and a solid portion, or may include a portion in which the toner overlap amount is different, so that the charge amount may vary. In addition, in the full-color toner image on the intermediate transfer belt 50, variation in charge amount occurs due to peeling discharge generated in the downstream gap adjacent to the primary transfer device 40 with respect to the conveyance direction of the intermediate transfer belt 50. There is also. Such variation in the charge amount in the full-color toner image reduces the transfer margin in the secondary transfer device 22. For this reason, it is preferable to provide a pre-transfer charger at a position after the intermediate transfer belt 50 passes through the yellow primary transfer device 40Y and before passing through the secondary transfer device 22. The pre-transfer charger uniformly charges the full-color toner image with the same polarity as the full-color toner image before transferring the full-color toner image on the intermediate transfer belt 50 to the sheet. As a result, variations in the charge amount in the full-color toner image can be eliminated, a decrease in transfer margin in the secondary transfer device 22 can be suppressed, and the full-color toner image can be stably transferred.

  Note that the amount of charge charged by the pre-transfer charger varies depending on the conveyance speed of the intermediate transfer belt 50. Specifically, when the conveyance speed of the intermediate transfer belt 50 is low, the time for the full color toner image on the intermediate transfer belt 50 to pass through the charging region by the pre-transfer charger becomes long, and the charge amount increases. Therefore, when the conveyance speed of the intermediate transfer belt 50 changes while the full-color toner image on the intermediate transfer belt 50 is passing through the charging area by the pre-transfer charger, the intermediate transfer belt 50 depends on the conveyance speed of the intermediate transfer belt 50. Therefore, it is preferable to control the pre-transfer charger so that the charge amount for the full-color toner image does not change during the process.

  Since the full-color toner image on the intermediate transfer belt 50 before being transferred to the sheet by the secondary transfer device 22 has the same negative polarity as that at the time of development, a positive transfer bias voltage is applied to the roller 23, so that the full-color toner image is transferred. A toner image is transferred onto the sheet. At this time, the nip pressure affects the transferability and greatly affects the fixability. Further, the toner remaining on the intermediate transfer belt 50 is discharged and charged to a positive polarity at the moment when the sheet and the intermediate transfer belt 50 are separated. Note that the toner image formed when the sheet is jammed or in the non-image area is not affected by the secondary transfer, and therefore remains negative.

  The toner remaining on the intermediate transfer belt 50 is removed by the conductive fur brush 61 to which a positive voltage is applied and the conductive fur brush 62 to which a negative voltage is applied. When the toner remains without being removed by the conductive fur brush 62, the toner is negatively charged by the negative voltage of the conductive fur brush 62. For this reason, in the next primary transfer, the negatively charged toner is attracted to the intermediate transfer belt 50, so that the toner transfer to the photosensitive drum 10 can be suppressed.

  On the other hand, the developing device 20 for each color and the cleaning device 30 for each color are connected by a toner transfer tube 35 for each color. Screws (not shown) are contained in the toner transfer pipes 35 for the respective colors, and the toner collected by the cleaning devices 30 for the respective colors is transferred to the developing devices 20 for the respective colors.

  As described above, in the image forming apparatus 100, the intermediate transfer belt 50 is used, and the photosensitive drum 10 and the sheet do not come into contact with each other, so that paper dust is prevented from being mixed into the toner collected by the cleaning device 30. In addition, adhesion of paper dust to the intermediate transfer belt 50 during secondary transfer can be suppressed. As a result, image deterioration such as toner loss can be suppressed. In addition, since the image forming units 18 for the respective colors are provided, the color mixing of the toners can be suppressed when the toners for the respective colors are collected.

  The intermediate transfer belt 50 is usually a single resin layer, but an elastic layer or a surface layer may be formed as necessary.

  Although it does not specifically limit as resin which comprises a resin layer, Polycarbonate; Fluorine resin, such as ETFE and PVDF; Polystyrene, poly (α-chlorostyrene), poly (α-methylstyrene), styrene-butadiene copolymer, styrene -Vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer, styrene-methacrylic acid) Ethyl acid copolymer, styrene-phenyl methacrylate copolymer Styrene resins (styrene or styrene-substituted homopolymers or copolymers) such as styrene-α-chloroacrylic acid methyl copolymer, styrene-acrylonitrile-acrylic acid ester copolymer; methyl methacrylate Resins, acrylic resins such as butyl methacrylate resin, ethyl acrylate resin, butyl acrylate resin; modified acrylic resins such as silicone-modified acrylic resin, vinyl chloride resin-modified acrylic resin, acrylic / urethane resin; vinyl chloride resin, vinyl chloride Vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyester, polyester polyurethane, polyethylene, polypropylene, polybutadiene, polyvinylidene chloride, ionomer resin, polyurethane, silicone resin, ketone resin, Styrene - ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, polyamide, modified polyphenylene oxide and the like, may be used in combination.

  Further, the elastic material (elastic material rubber, elastomer) constituting the elastic layer is not particularly limited, but butyl rubber, fluorine-based rubber, acrylic rubber, EPDM, NBR, acrylonitrile-butadiene-styrene rubber, natural rubber, isoprene rubber, Styrene-butadiene rubber, butadiene rubber, ethylene-propylene rubber, ethylene-propylene terpolymer, chloroprene rubber, chlorosulfonated polyethylene, chlorinated polyethylene, urethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, Silicone rubber, fluoro rubber, polysulfide rubber, polynorbornene rubber, hydrogenated nitrile rubber; polystyrene, polyolefin, polyvinyl chloride, polyurethane, polyamide, polyurea, polyester, fluorine Thermoplastic elastomers fat based such as and the like, it may be used in combination.

  Further, the material constituting the surface layer is not particularly limited as long as it can reduce the adhesion of the toner to the intermediate transfer belt 50 and improve the secondary transfer property. What disperse | distributed the material which improves property to resin can be used. Examples of the resin include polyurethane, polyester, and epoxy resin, and two or more kinds may be used in combination. In addition, examples of the material for reducing the surface energy to improve the lubricity include fluororesin, fluorine compound, fluorocarbon, titanium dioxide, silicon carbide, and the like, and two or more kinds may be used in combination. At this time, materials having different particle sizes may be used as materials for reducing the surface energy and improving the lubricity. Further, as a material constituting the surface layer, a material in which a fluorine-rich layer is formed on the surface by heat treatment like a fluorine-based rubber material to reduce the surface energy may be used.

  Further, the resin layer and the elastic layer may include a resistance value adjusting conductive agent. The conductive material for adjusting the resistance value is not particularly limited, but carbon black, graphite; metal powder such as aluminum and nickel; tin oxide, titanium oxide, antimony oxide, indium oxide, potassium titanate, antimony oxide-tin oxide composite oxide And conductive metal oxides such as indium oxide (ATO), indium oxide-tin oxide composite oxide (ITO), etc., may be used in combination. At this time, the conductive metal oxide may be coated with insulating particles such as barium sulfate, magnesium silicate, and calcium carbonate.

  The charging device 15 is not particularly limited, but as an example, a roller charging device 15A which is a kind of contact charging device is shown in FIG. The photosensitive drum 10 is rotationally driven in the direction of the arrow at a predetermined speed (process speed). The charging roller 151 is brought into contact with the photosensitive drum 10 with a predetermined pressing force by a pressurizing unit (not shown). And rotates following the rotational drive of the photosensitive drum 10. The charging roller 151 basically includes a core bar 151a and a conductive rubber layer 151b formed concentrically and integrally on the outer periphery of the core bar 151a. Both ends of the core bar 151a are rotatably held by bearing members (not shown) or the like. Has been. The power source 152 is electrically connected to the core metal 151 a and applies a predetermined bias to the charging roller 151. As a result, the peripheral surface of the photosensitive drum 10 is uniformly charged to a predetermined polarity and potential.

  FIG. 4 shows a fur brush type charging device 15 </ b> B as another example of the charging device 15. The photosensitive drum 10 is rotationally driven in the direction of the arrow at a predetermined speed (process speed), but the fur brush roller 153 is in contact with the photosensitive drum 10 with a predetermined pressing force. It is rotationally driven at a predetermined speed in the direction opposite to the rotational direction. The fur brush roller 153 basically includes a cored bar 153a and a fur brush 153b formed concentrically on the outer periphery of the cored bar 153a. Both ends of the cored bar 153a are rotatably held by bearing members (not shown) or the like. ing. The power source 154 is electrically connected to the cored bar 153a and applies a predetermined bias to the fur brush roller 153. As a result, the peripheral surface of the photosensitive drum 10 is uniformly charged to a predetermined polarity and potential.

The fur brush 153b is obtained by winding or attaching a fur conductively treated with carbon, copper sulfide, metal, metal oxide or the like around a metal or another conductively treated core metal 153a. Although it does not specifically limit as fur, REC-B, REC-C, REC-M1, REC-M10 (above, the product made by Unitika), SA-7 (made by Toray Industries, Inc.), Thunderon (made by Nippon-Ishige) , Beltron (manufactured by Kanebo), Kurabobo (manufactured by Kuraray), Roval (manufactured by Mitsubishi Rayon), and the like. The fur preferably has a linear density of 3 to 10 denier and a hairy foot of 1 to 10 mm. Moreover, it is preferable that the fur brush 153b is 10-100 filaments / bundle and 80-600 pieces / mm < ² >.

  FIG. 5 shows a magnetic brush charging device 15 </ b> C as another example of the charging device 15. The photosensitive drum 10 is rotationally driven in the direction of the arrow at a predetermined speed (process speed), but the magnetic brush roller 155 is in contact with the photosensitive drum 10 with a predetermined pressing force. It is rotationally driven at a predetermined speed in the direction opposite to the rotational direction. The magnetic brush roller 155 basically includes a non-magnetic conductive sleeve 155a containing a magnet roll (not shown) and a magnetic brush 155b formed concentrically on the outer periphery of the conductive sleeve 155a. Both ends of the conductive sleeve 155a are bearings. A member (not shown) or the like is rotatably held. The power source 156 is electrically connected to the conductive sleeve 155a and applies a predetermined bias to the magnetic brush roller 155. As a result, the peripheral surface of the photosensitive drum 10 is uniformly charged to a predetermined polarity and potential.

  Examples of the magnetic particles constituting the magnetic brush 155b include ferrite such as Zn-Cu ferrite.

  Although it does not specifically limit as the developing device 20, The example is shown in FIG. In the developing device 20, during development, a vibration bias voltage obtained by superimposing an AC voltage on a DC voltage is applied from the power source 202 to the developing sleeve 201. Since the potentials of the non-image area and the image area of the photosensitive drum 10 are between the maximum value and the minimum value of the vibration bias voltage, an alternating electric field whose direction changes alternately in the development area A is formed. For this reason, in the developing area A, the toner and the carrier vibrate vigorously, and the toner that has shaken off the electrostatic binding force between the developing sleeve 201 and the carrier flies toward the photosensitive drum 10 and adheres to the electrostatic latent image. .

  The difference between the maximum value and the minimum value (peak-to-peak voltage) of the vibration bias voltage is preferably 0.5 to 5 kV, and the frequency is preferably 1 to 10 kHz. Examples of the waveform of the vibration bias voltage include a rectangular wave, a sine wave, and a triangular wave. The DC voltage component of the vibration bias voltage is a value between the potential of the non-image area of the photosensitive drum 10 and the potential of the image area, but is closer to the potential of the non-image area than the potential of the image area. preferable. Thereby, the adhesion of toner to the non-image area of the photosensitive drum 10 can be suppressed.

  When the vibration bias voltage waveform is a rectangular wave, the duty ratio is preferably 50% or less. The duty ratio is a ratio of time during which the toner is going to the photosensitive drum 10 in one cycle of the vibration bias voltage. As a result, the difference between the peak value at which the toner is directed to the photoconductor drum 10 and the time average value of the vibration bias voltage can be increased, so that the movement of the toner is further activated and the toner becomes an electrostatic latent image. It is possible to improve the rough feeling and resolution by adhering to the potential distribution. Further, since the difference between the peak value at which the carrier having the charge opposite to that of the toner is directed to the photosensitive drum 10 and the time average value of the vibration bias voltage can be reduced, the movement of the carrier is calmed down. Further, it is possible to suppress the carrier from adhering to the non-image area of the photosensitive drum 10.

  The fixing device 25 is not particularly limited. As an example, an oilless type fixing device 25 is shown in FIG. The fixing device 25 includes an induction heating unit 251, a heating roller 252 heated by electromagnetic induction of the induction heating unit 251, a fixing roller 253 disposed opposite to the heating roller 252, and the heating roller 252 and the fixing roller 253. The fixing belt 254 is stretched and heated by the heating roller 252, and the pressure roller 255 is pressed against the fixing roller 253 via the fixing belt 254. The fixing belt 254 is conveyed in the direction A in the drawing by the rotation of the heating roller 252 or the fixing roller 253, and the pressure roller 255 rotates in the forward direction with respect to the fixing belt 254.

  The heating roller 252 is a hollow cylindrical member made of magnetic metal, and preferably has an outer diameter of 20 to 40 mm and a wall thickness of 0.3 to 1.0 mm. As a result, the heat capacity is small and the rate of temperature increase can be increased. Although it does not specifically limit as a magnetic metal, Iron, cobalt, nickel, or the alloy of these metals etc. are mentioned.

  The fixing roller 253 includes a metal core 253a and an elastic layer 253b that covers the metal core 253a. The material of the cored bar 253a is not particularly limited, and examples thereof include metals such as stainless steel. The elastic layer 253b can be formed by forming a heat-resistant silicone rubber into a solid or foamed shape, and has a thickness of 4 to 6 mm. The fixing roller 253 has an outer diameter of 20 to 40 mm and is larger than the outer diameter of the heating roller 252 in order to form a contact portion having a predetermined width between the fixing roller 253 and the pressure roller 255.

  The fixing belt 254 is heated in a contact area W1 with the heating roller 252 heated by the induction heating unit 251. Then, due to the rotation of the heating roller 252 or the fixing roller 253, the inner surface of the fixing belt 254 is continuously heated and heated throughout.

  FIG. 8 shows a layer structure of the fixing belt 254. In the fixing belt 254, a heat generating layer 254b, an elastic layer 254c, and a release layer 254d are sequentially laminated on a base 254a. The material of the base 254a is not particularly limited, and examples thereof include heat-resistant resins such as fluororesin, polyimide, polyamide, polyamideimide, PEEK, PES, and PPS. The material of the heat generating layer 254b is not particularly limited, and examples thereof include conductive materials such as Ni, Ag, and SUS. The elastic layer 254c is not particularly limited as long as the full color toner image on the sheet can be fixed uniformly. The material of the release layer 254d is not particularly limited, and examples thereof include a resin such as a fluororesin. Note that the heat generating layer 254b may be used as the base without providing the base 254a.

  The release layer 254d preferably has a thickness of 10 to 300 μm. As a result, the full color toner image on the sheet is sufficiently wrapped by the surface layer portion of the fixing belt 254, so that the full color toner image can be uniformly heated and melted. When the thickness of the release layer 254d is less than 10 μm, the wear resistance with time may not be ensured. On the other hand, if the thickness of the release layer 254d exceeds 300 μm, the heat capacity of the fixing belt 254 may increase and the temperature increase rate may decrease. Further, the surface temperature of the fixing belt 254 is hardly lowered, and the toner aggregation effect cannot be obtained, and the toner may adhere to the fixing belt 254.

  The pressure roller 255 includes a metal core 255a and an elastic layer 255b that covers the metal core 255a. The material of the cored bar 255a is not particularly limited, and examples thereof include metals having high thermal conductivity such as copper and aluminum, SUS, and the like. The material of the elastic layer 255b is not particularly limited as long as it is an elastic material having high heat resistance and releasability. The pressure roller 255 has an outer diameter of 20 to 40 mm, is the same as the fixing roller 253, has a wall pressure of 0.5 to 2.0 mm, and is thinner than the fixing roller 253.

  The pressure roller 255 presses the fixing roller 253 via the fixing belt 254 to form the fixing nip region N. The pressure roller 255 is preferably harder than the fixing roller 253. Accordingly, the pressure roller 255 bites into the fixing roller 253, and the sheet follows the circumferential shape of the surface of the pressure roller 255, so that the sheet can be easily separated from the surface of the fixing belt 254.

  The induction heating means 251 for heating the heating roller 252 by electromagnetic induction has an exciting coil 251a formed on a semi-cylindrical coil guide plate 251a, and the coil guide plate 251a is disposed in the vicinity of the outer peripheral surface of the heating roller 252. Yes. Further, the exciting coil 251b is obtained by alternately winding a single wire in the axial direction of the heating roller 252 along the coil guide plate 251b. The exciting coil 251b is connected to a drive power source (not shown) whose frequency is variable. A semi-cylindrical excitation coil core 251c is disposed in proximity to the excitation coil 251b while being supported by the support member 251d. The material of the exciting coil core 251c is not particularly limited, and examples thereof include a ferromagnetic material such as ferrite.

  Hereinafter, the present invention will be described in more detail with reference to examples. In addition, this invention is not limited to an Example. Moreover, a part means a mass part.

(Synthesis of polyester)
In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 67 parts of ethylene oxide 2 mol adduct of bisphenol A, 84 parts of bisphenol A propion oxide 3 mol adduct, 274 parts of terephthalic acid and 2 parts of dibutyltin oxide The mixture was reacted at 230 ° C. for 8 hours under normal pressure. Furthermore, it was made to react under the reduced pressure of 10-15 mmHg for 5 hours, and the polyester 1 was obtained. Polyester 1 had a number average molecular weight of 2.1 × 10 ³ , a weight average molecular weight of 5.6 × 10 ³ , and a glass transition point of 55 ° C.

In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 43.5 parts of bisphenol A ethylene oxide 2 mol adduct, 6.5 parts of bisphenol A propion oxide 3 mol adduct, 30 parts terephthalic acid and dibutyltin oxide Two parts were added and reacted at 230 ° C. under normal pressure for 8 hours. Furthermore, it was made to react under the reduced pressure of 10-15 mmHg for 5 hours, and polyester 2 was obtained. Polyester 2 had a number average molecular weight of 4.8 × 10 ³ , a weight average molecular weight of 5.6 × 10 ³ , and a glass transition point of 45 ° C.

In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 43.5 parts of bisphenol A ethylene oxide 2 mol adduct, 6.5 parts of bisphenol A propion oxide 3 mol adduct, 45 parts terephthalic acid and dibutyltin oxide Two parts were added and reacted at 230 ° C. under normal pressure for 8 hours. Furthermore, it was made to react under the reduced pressure of 10-15 mmHg for 5 hours, and polyester 3 was obtained. Polyester 3 had a number average molecular weight of 5.4 × 10 ³ , a weight average molecular weight of 5.6 × 10 ³ , and a glass transition point of 60 ° C.

In a reaction vessel equipped with a condenser, a stirrer and a nitrogen introduction tube, 43.5 parts of bisphenol A ethylene oxide 2 mol adduct, 6.5 parts of bisphenol A propion oxide 3 mol adduct, 41 parts terephthalic acid and dibutyltin oxide Two parts were added and reacted at 230 ° C. under normal pressure for 8 hours. Furthermore, it was made to react under the reduced pressure of 10-15 mmHg for 5 hours, and the polyester 4 was obtained. Polyester 4 had a number average molecular weight of 5.3 × 10 ³ , a weight average molecular weight of 4 × 10 ³ , and a glass transition point of 55 ° C.

In a reaction vessel equipped with a cooling tube, a stirrer and a nitrogen introduction tube, 40 parts of bisphenol A ethylene oxide 2 mol adduct, 10 parts of bisphenol A propion oxide 3 mol adduct, 41 parts terephthalic acid and 2 parts dibutyltin oxide The mixture was reacted at 230 ° C. for 8 hours under normal pressure. Furthermore, it was made to react under the reduced pressure of 10-15 mmHg for 5 hours, and polyester 5 was obtained. Polyester 5 had a number average molecular weight of 5.2 × 10 ³ , a weight average molecular weight of 6 × 10 ³ , and a glass transition point of 55 ° C.

(Preparation of masterbatch)
1000 parts of water, 540 parts of carbon black Printex 35 (manufactured by Degussa) having a DBP oil absorption of 42 ml / 100 g and a pH of 9.5 and 1200 parts of polyester 1 were mixed using a Henschel mixer (manufactured by Mitsui Mining). The obtained mixture was kneaded at 150 ° C. for 30 minutes using a two-roll, then rolled and cooled, and pulverized using a pulverizer (manufactured by Hosokawa Micron) to obtain a master batch 1.

(Synthesis of polyester prepolymer)
In a reaction vessel equipped with a condenser, a stirrer and a nitrogen inlet tube, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 parts and 2 parts of dibutyltin oxide were added and reacted at 230 ° C. for 8 hours under normal pressure. Furthermore, it was made to react under reduced pressure of 10-15mHg for 5 hours, and polyester which has a hydroxyl group was obtained. The polyester having a hydroxyl group has a number average molecular weight of 2.1 × 10 ³ , a weight average molecular weight of 9.6 × 10 ³ , a glass transition point of 55 ° C., an acid value of 0.5 mgKOH / g, and a hydroxyl value of 49 mgKOH / g.

  Next, 411 parts of polyester having hydroxyl groups, 89 parts of isophorone diisocyanate and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. Prepolymer 1 was obtained. Polyester prepolymer 1 had a free isocyanate group content of 1.6% by mass, and had a solid content concentration of 50% by mass measured by standing at 150 ° C. for 45 minutes.

(Synthesis of ketimine)
In a reaction vessel equipped with a stir bar and a thermometer, 30 parts of isophoronediamine and 70 parts of methyl ethyl ketone were placed and reacted at 50 ° C. for 5 hours to obtain ketimine 1. Ketimine 1 had an amine value of 423 mg KOH / g.

(Preparation of resin particle dispersion)
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 16 parts of sodium salt Eleminol RS-30 (manufactured by Sanyo Chemical Industries) of ethylene oxide adduct of methacrylic acid, 83 parts of styrene, 83 parts of methacrylic acid Parts, 110 parts of butyl acrylate and 1 part of ammonium persulfate were added and stirred at 400 rpm for 15 minutes, then heated to 75 ° C. and reacted for 5 hours. Next, 30 parts of a 1% by mass ammonium persulfate aqueous solution was added and then aged at 75 ° C. for 5 hours to obtain a dispersion 1 of resin particles. Using a laser diffraction / scattering particle size distribution analyzer LA-920 (manufactured by Horiba, Ltd.), the volume average particle size of the dispersion 1 of resin particles was measured and found to be 42 nm.

(Preparation of aqueous medium)
660 parts of water, dispersion 1 of 25 parts of resin particles, 25 parts of 48.5% by weight aqueous solution of sodium dodecyldiphenyl ether disulfonate, Eleminol MON-7 (manufactured by Sanyo Chemical Industries) and 60 parts of ethyl acetate are stirred in a container. Thus, an aqueous medium 1 was obtained.

[Example 1]
In a beaker, 5 parts of an ester of an alcohol having an average carbon number of 21 and an fatty acid having an average carbon number of 25, a ratio of the weight average molecular weight to the number average molecular weight of 2.5, a melting point of 74 ° C., melting at 100 ° C. A lanolin wax 1 having a viscosity of 37 mPa · s and a penetration of 7 mm at 25 ° C., 15 parts of polyester 1 and 30 parts of ethyl acetate, and using a bead mill Ultra Visco Mill (manufactured by IMEX), liquid feeding speed Was 1 kg / h, the peripheral speed of the disk was 6 m / s, and 3 passes were performed under the condition that 80% by volume of zirconia beads having a particle diameter of 0.5 mm were filled, whereby a lanolin wax dispersion 1 was obtained.

  In a beaker, 100 parts of polyester 1 and 130 parts of ethyl acetate were stirred and dissolved. Next, 100 parts of lanolin wax dispersion 1 and 10 parts of masterbatch 1 were added, and using a bead mill Ultra Visco Mill (manufactured by IMEX), the liquid feeding speed was 1 kg / hour and the peripheral speed of the disk was 6 m. Per second, three passes were performed under the condition that 80% by volume of zirconia beads having a particle diameter of 0.5 mm were filled. Furthermore, 40 parts of polyester prepolymer 1 and 2.2 parts of ketimine 1 were added and stirred to obtain a first liquid 1.

  150 parts of the aqueous medium 1 is put in a container, and 100 parts of the first liquid 1 is added and mixed for 10 minutes while mixing at 12000 rpm using a TK homomixer (manufactured by Koki Kogyo Co., Ltd.). A second liquid 1 was obtained.

  100 parts of the second liquid 1 is put in a flask equipped with a degassing pipe, a stirrer and a thermometer, and the solvent is removed at 30 ° C. under reduced pressure for 12 hours while stirring at a stirring peripheral speed of 20 m / min. A slurry 1 was obtained.

  The resulting slurry 1 was filtered under reduced pressure. To the obtained filter cake, 300 parts of ion-exchanged water was added, mixed at 12000 rpm for 10 minutes using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), and then filtered under reduced pressure. The operation of adding 300 parts of ion exchange water to the obtained filter cake, mixing at 12000 rpm for 10 minutes using a TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.), and filtering under reduced pressure was repeated three times.

  The obtained filter cake was dried at 45 ° C. for 48 hours using a forward air dryer, and then sieved using a mesh having an opening of 75 μm to obtain base particles.

  100 parts of base particles, 0.6 parts of hydrophobic silica having an average particle diameter of 100 nm, 1.0 part of titanium oxide having an average particle diameter of 20 nm, and 0.8 parts of hydrophobic silica having an average particle diameter of 15 nm are added to a Henschel mixer. And mixed to obtain a toner. The toner had a glass transition point of 49 ° C.

[Example 2]
Lanolin wax is an ester of an alcohol having an average carbon number of 18 and a fatty acid having an average carbon number of 22, a ratio of the weight average molecular weight to the number average molecular weight of 2.0, a melting point of 60 ° C., and a melt viscosity at 100 ° C. of 16 mPa. A toner was obtained in the same manner as in Example 1 except that lanolin wax 2 having a penetration of 1 mm at 25 ° C. was used. The toner had a glass transition point of 47 ° C.

[Example 3]
The lanolin wax is an ester of an alcohol having an average carbon number of 24 and a fatty acid having an average carbon number of 28, a ratio of the weight average molecular weight to the number average molecular weight of 3.0, a melting point of 90 ° C., and a melt viscosity at 100 ° C. of 50 mPa. A toner was obtained in the same manner as in Example 1 except that lanolin wax 3 having a penetration of 5 mm at 25 ° C. was used. The toner had a glass transition point of 51 ° C.

[Example 4]
The lanolin wax is an ester of an alcohol having an average carbon number of 24 and a fatty acid having an average carbon number of 25, a ratio of the weight average molecular weight to the number average molecular weight of 2.0, a melting point of 77 ° C., and a melt viscosity at 100 ° C. of 46 mPa. A toner was obtained in the same manner as in Example 1 except that lanolin wax 4 having a penetration of 4 mm at 25 ° C. was used. The toner had a glass transition point of 50 ° C.

[Example 5]
The lanolin wax is an ester of an alcohol having an average carbon number of 24 and a fatty acid having an average carbon number of 28, a ratio of the weight average molecular weight to the number average molecular weight of 1.5, a melting point of 90 ° C., and a melt viscosity at 100 ° C. of 28 mPa. A toner was obtained in the same manner as in Example 1 except that lanolin wax 5 having a penetration of 7 mm at 25 ° C. was used. The toner had a glass transition point of 50 ° C.

[Example 6]
A toner was obtained in the same manner as in Example 1 except that the amount of lanolin wax dispersion 1 added was 5 parts. The toner had a glass transition point of 52 ° C.

[Example 7]
A toner was obtained in the same manner as in Example 1 except that the amount of lanolin wax dispersion 1 added was 150 parts. The toner had a glass transition point of 45 ° C.

[Example 8]
A toner was obtained in the same manner as in Example 1 except that polyester 2 was used instead of polyester 1. The toner had a glass transition point of 39 ° C.

[Example 9]
A toner was obtained in the same manner as in Example 1 except that polyester 3 was used instead of polyester 1. The toner had a glass transition point of 52 ° C.

[Example 10]
A toner was obtained in the same manner as in Example 1 except that polyester 4 was used instead of polyester 1. The toner had a glass transition point of 47 ° C.

[Example 11]
A toner was obtained in the same manner as in Example 1 except that polyester 5 was used instead of polyester 1. The toner had a glass transition point of 52 ° C.

[Comparative Example 1]
The lanolin wax is an ester of an alcohol having an average carbon number of 25 and a fatty acid having an average carbon number of 29, a ratio of the weight average molecular weight to the number average molecular weight of 1.5, a melting point of 92 ° C., and a melt viscosity at 100 ° C. of 52 mPa. A toner was obtained in the same manner as in Example 1 except that lanolin wax 6 having a penetration of 7 mm at 25 ° C. was used. The toner had a glass transition point of 53 ° C.

[Comparative Example 2]
Lanolin wax is an ester of an alcohol having an average carbon number of 17 and a fatty acid having an average carbon number of 21, a ratio of the weight average molecular weight to the number average molecular weight of 2.5, a melting point of 58 ° C., and a melt viscosity at 100 ° C. of 12 mPa. A toner was obtained in the same manner as in Example 1 except that lanolin wax 7 having a penetration of 6 mm at 25 ° C. was used. The toner had a glass transition point of 41 ° C.

[Comparative Example 3]
A toner was obtained in the same manner as in Example 1 except that paraffin wax having a melting point of 74 ° C., a melt viscosity of 32 mPa · s at 100 ° C., and a penetration of 4 mm at 25 ° C. was used instead of lanolin wax. It was. The toner had a glass transition point of 55 ° C.

[Comparative Example 4]
A toner was obtained in the same manner as in Example 1 except that dibutyl sebacate having a melting point of 205 ° C. was used instead of the lanolin wax. The toner had a glass transition point of 42 ° C.

(Glass transition point and melting point)
A glass transition point and a melting point were measured using a TG-DSC system TAS-100 (manufactured by Rigaku Corporation). Specifically, first, an aluminum container containing about 10 mg of a sample was placed on a holder unit and set in an electric furnace. Next, it heated from room temperature to 150 degreeC with the temperature increase rate of 10 degree-C / min, Then, it was left to stand at 150 degreeC for 10 minutes. Furthermore, after cooling to room temperature, it was left to stand for 10 minutes. Next, it heated to 150 degreeC by the temperature increase rate of 10 degree-C / min in nitrogen atmosphere, and obtained the DSC curve. From the DSC curve, the glass transition point and the melting point were determined using the analysis system in the TG-DSC system TAS-100 system.

  Table 1 shows the characteristics of the waxes used in the examples and comparative examples.

In addition, Mw and Mn represent a weight average molecular weight and a number average molecular weight, respectively.

(Creation of carrier)
Alumina particles 7 having 21 parts by weight of acrylic resin solution with a solid content of 50%, 6.4 parts of guanamine solution with a solid content of 70% by weight, an average particle size of 0.3 μm, and a volume resistivity of 1 × 10 ¹⁴ Ω · cm .6 parts, silicone resin solution SR2410 (made by Toray Dow Corning Silicone) having a solid content of 23% by weight, 1 part aminosilane SH6020 (made by Toray Dow Corning Silicone), 60 parts toluene, and 60 parts butyl cellosolve Was dispersed for 10 minutes using a homomixer to obtain a coating layer coating solution.

The coating liquid for the coating layer was prepared using a spira coater (manufactured by Okada Seiko Co., Ltd.) on sintered ferrite powder (MgO) _1.8 (MnO) _49.5 (Fe ₂ O ₃ ) _48.0 having an average particle size of 25 μm. After application, it was dried. Next, after baking for 1 hour at 150 ° C. using an electric furnace, it was cooled and crushed using a sieve having an opening of 106 μm to obtain a carrier. The obtained carrier had a weight average particle diameter of 35 μm and a coating layer thickness of 0.15 μm.

  In addition, the measuring method of the thickness of a coating layer and a weight average particle diameter is shown below.

(Thickness of coating layer)
The thickness of the coating layer was measured and averaged by observing the cross section of the carrier using a transmission electron microscope.

(Weight average particle size)
The weight average particle size was measured using a Microtrac particle size analyzer model HRA9320-X100 (Honewell). The particle size range was 8 to 100 μm, the channel length (channel width) was 2 μm, the number of channels was 46, and the refractive index was 2.42.

(Development of developer)
A developer was obtained by uniformly mixing 100 parts of the carrier and 7 parts of the toner using a type of tumbler mixer in which the container was rolled and stirred.

  Next, using a toner or a developer, low-temperature fixability, releasability, heat-resistant storage stability and carrier contamination were evaluated.

(Low temperature fixability)
Using an image Neo Neo450 (manufactured by Ricoh Co.), adjustment was made so that a solid image with a toner adhesion amount of 1.0 ± 0.1 mg / cm ² was developed on plain paper type 6200 (manufactured by Ricoh Company), and the fixing belt The lower limit temperature at which no offset occurs was measured by changing the temperature of the film, and the low temperature fixability was evaluated. When the toner of Comparative Example 3 is used, the lower limit of fixing temperature is decreased by 10 ° C. or more, Δ is decreased by 5 ° C. or more and less than 10 ° C. Judged as x.

(Releasability)
Take out only the fixing part of ipsio CX2500 (manufactured by Ricoh Co., Ltd.), and fix the fixing belt linear velocity to 125 mm / s using a fixing test device modified so that the temperature and linear velocity of the fixing belt can be adjusted. The belt temperature was fixed in the range of 140 to 190 ° C. in increments of 10 ° C., and fixing was performed from the 3 mm margin at the leading edge of the transfer paper, and the releasability was evaluated. If the number of sheets successfully fixed is 5 or more without wrapping around the fixing belt or clogging like a bellows at the exit of the fixing test apparatus, 3 or more 4 The case where the number was less than one was evaluated as Δ, and the case where the number was less than two as x.

(Heat resistant storage stability)
After leaving the toner in an environment of 40 ° C. and 70% RH for 2 weeks, the toner is passed through a 75-mesh sieve and vibrated, and then the amount of agglomerated toner remaining on the sieve is measured to evaluate heat-resistant storage stability. did. In addition, the case where the aggregated toner amount was less than 0.5 mg was evaluated as ◯, the case where it was 0.5 mg or more and less than 1.0 mg as Δ, and the case where it was 1.0 mg or more as ×.

(Carrier contamination)
A4 size solid image with a toner adhesion of 0.6 mg / cm ² using a modified evaluation machine modified from DocuColor 8000 Digital Press (manufactured by Fuji Xerox) to adjust the linear velocity and transfer time. A test of running 100,000 sheets was conducted. As a substitute index for carrier contamination, a part of the developer is sampled every 1000 sheets, the charge amount is measured by the blow-off method, and the decrease in the toner charge amount from the initial value is measured to evaluate the carrier contamination property. did. In addition, the case where the decrease from the initial value of the charge amount of the toner was less than 5 μC / g was judged as ◯, the case where it was 5 μC / g or more and less than 10 μC / g, and the case where it was 10 μC / g or more as x. .

  Table 2 shows the evaluation results of the toner or developer.

From Table 2, it can be seen that the toners of the examples are excellent in low-temperature fixability, releasability, heat resistant storage stability and carrier contamination.

  On the other hand, the toner of Comparative Example 1 had a low average fixing property due to the large average carbon number of alcohol and fatty acid in the lanolin wax.

  Since the toner of Comparative Example 2 has a small average carbon number of alcohol in the lanolin wax, the heat resistant storage stability was lowered.

  In the toner of Comparative Example 3, the low-temperature fixability was lowered because the paraffin wax was not compatible with the polyester.

  In the toner of Comparative Example 4, dibutyl sebacate did not act as a release agent but acted as a plasticizer, so that the release property, heat resistant storage property and carrier contamination were lowered.

DESCRIPTION OF SYMBOLS 10 Photosensitive drum 15 Charging apparatus 20 Developing apparatus 21 Exposure apparatus 22 Secondary transfer apparatus 30 Cleaning apparatus 40 Primary transfer apparatus 50 Intermediate transfer belt 100 Image forming apparatus

JP 2005-338814 A

Claims (14)

Including polyester and / or modified polyester and lanolin wax;
The modified polyester is obtained by reacting a compound having an active hydrogen group with a polyester prepolymer having a group capable of reacting with the active hydrogen group,
The toner according to claim 1, wherein the lanolin wax is an ester of an alcohol having an average carbon number of 18 to 24 and a fatty acid having an average carbon number of 22 to 28.   The toner according to claim 1, wherein the lanolin wax has a melt viscosity at 100 ° C. of 1 mPa · s to 50 mPa · s.   The toner according to claim 1, wherein the lanolin wax has a ratio of a weight average molecular weight to a number average molecular weight of 3.0 or more and 8.0 or less.   The toner according to claim 1, wherein the lanolin wax has a melting point of 60 ° C. or higher and 90 ° C. or lower.   5. The toner according to claim 1, wherein the lanolin wax has a penetration of 7 mm or less at 25 ° C. 5.   The toner according to claim 1, wherein the polyester has a glass transition point of 45 ° C. or more and 60 ° C. or less.   The toner according to claim 1, wherein the polyester has a weight average molecular weight of 4,000 to 6,000.   The toner according to claim 1, wherein a content of the lanolin wax is 0.5% by mass or more and 15% by mass or less. A step of preparing a first liquid by dissolving or dispersing a toner material containing a polyester and / or a modified polyester precursor and a lanolin wax in an organic solvent;
A step of preparing a second liquid by emulsifying or dispersing the first liquid in an aqueous medium;
Removing the organic solvent from the second liquid,
The modified polyester includes a compound having an active hydrogen group and a polyester prepolymer having a group capable of reacting with the active hydrogen group,
The lanolin wax has a melt viscosity at 100 ° C. of 1 mPa · s to 50 mPa · s.   A developer comprising the toner according to claim 1. Charging the photoreceptor,
Exposing the charged photoreceptor to form an electrostatic latent image;
Developing an electrostatic latent image formed on the photoreceptor using the developer according to claim 10 to form a toner image;
An image forming method comprising a step of transferring a toner image formed on the photoreceptor to a recording material.   12. The image forming method according to claim 11, wherein after the toner image formed on the photosensitive member is transferred to an intermediate transfer member, the toner image transferred to the intermediate transfer member is transferred to the recording material. . The linear velocity at which the toner image transferred to the intermediate transfer member is transferred to the recording material is 0.1 m / s or more and 1 m / s or less,
The image forming method according to claim 12, wherein a transfer time at a nip portion where the intermediate transfer member and the recording material are in contact is 5 × 10 ⁻⁴ s or more and 6 × 10 ⁻² s or less. .   The image forming method according to claim 11, wherein a tandem image forming apparatus is used.