JP6776564B2 - Toner, developer, image forming equipment and process cartridge - Google Patents

Description

The present invention relates to toners, developing agents, image forming devices and process cartridges.

In recent years, toner is required to have low-temperature fixability for energy saving and heat-resistant storage property that can withstand high temperature and high humidity during storage and transportation after production. In particular, since the power consumption at the time of fixing occupies most of the power consumption in the image forming process, it is very important to improve the low temperature fixing property.

Patent Document 1 discloses a toner containing at least a colorant, a mold release agent, and a binder resin. Here, the binder resin includes a crystalline polyester resin and an amorphous polyester resin. Further, the amorphous polyester resin contains an amorphous polyester resin A having a urethane and / or urea bond and an amorphous polyester resin B having a urethane and / or urea bond. Further, the amorphous polyester resin A contains 0.5 mol of an isocyanate monomer for forming at least one of a urethane bond and a urea bond in all the monomers constituting the amorphous polyester resin A. % Or more. Further, the amorphous polyester resin B contains 0.5 mol of an isocyanate monomer for forming at least one of a urethane bond and a urea bond in all the monomers constituting the amorphous polyester resin B. % Or more. Further, the glass transition temperature of the amorphous polyester resin A is −60 ° C. or higher and lower than 10 ° C., and the glass transition temperature of the amorphous polyester resin B is 30 ° C. or higher and lower than 70 ° C.

However, it is desired to improve durability and cleanability.

One aspect of the present invention is to provide a toner having excellent heat-resistant storage property, low-temperature fixability, durability and cleaning property in view of the above-mentioned problems of the prior art.

One aspect of the present invention is a toner in which an amorphous polyester and a parent particle containing a crystalline polyester are coated with an external additive, and from the DSC curve of a component insoluble in THF at the second temperature rise. The required glass transition temperature is −50 ° C. or higher and 10 ° C. or lower, the average circularity is 0.98 or lower, and the component insoluble in THF includes an amorphous polyester having a urethane and / or urea bond. Assuming that the BET specific surface area of the toner is Bt [m ² / g] and the coverage of the toner covered with the external additive is Ct [%], the formula 0.80 ≦ Bt −0.025 × Ct ≦ 1 .20
Meet.

According to one aspect of the present invention, it is possible to provide a toner having excellent heat-resistant storage property, low-temperature fixability, durability and cleaning property.

It is a figure which shows an example of an image forming apparatus. It is a figure which shows another example of an image forming apparatus. It is a partially enlarged view of the image forming apparatus of FIG. It is a figure which shows an example of a process cartridge.

Next, a mode for carrying out the present invention will be described with reference to the drawings.

In the toner, the parent particles are coated with an external additive.

The glass transition temperature Tg _2nd determined from the DSC curve of the component insoluble in THF (tetrahydrofuran) of the toner at the time of the second temperature rise is -50 to 10 ° C, preferably -30 to 5 ° C. If Tg _2nd is less than −50 ° C., the heat-resistant storage stability of the toner is lowered, and if it exceeds 10 ° C., the low-temperature fixability of the toner is lowered.

The toner usually contains polyester, preferably containing non-linear amorphous polyester A and amorphous polyester B, and more preferably containing crystalline polyester C.

The component insoluble in THF usually contains a non-linear amorphous polyester A or a crystalline polyester C, and preferably contains a non-linear amorphous polyester A.

The content of the THF-insoluble component in the toner is usually 5 to 25% by mass. When the content of the component insoluble in THF in the toner is 5% by mass or more, the low-temperature fixability of the toner can be improved, and when it is 25% by mass or less, the heat-resistant storage stability of the toner is improved. be able to.

Amorphous polyester A is characterized in that the glass transition temperature is much lower than room temperature, has the property of deforming at low temperatures, deforms with heating and pressurization during fixing, and adheres to paper at lower temperatures. It has the property of being easy to use.

The amorphous polyester A preferably has a branched structure in the molecular skeleton, and more preferably has a urethane bond and / or a urea bond. As a result, the amorphous polyester A has high aggregation energy and therefore has excellent adhesiveness to paper. In addition, amorphous polyester A is a rubber in which the molecular chain has a three-dimensional network structure due to the branched structure in the skeleton and the pseudo-crosslinked points due to urethane bonds and / or urea bonds, and is deformed at low temperature but does not flow. Has a typical property. Therefore, the heat-resistant storage property and the high-temperature offset resistance of the toner can be improved.

Therefore, by combining amorphous polyester A, which has a glass transition temperature in the ultra-low temperature range but has high melt viscosity and is difficult to flow, with other binder resins in a compatible state, the toner has low-temperature fixability and heat resistance. Both storage stability can be achieved.

Amorphous polyester A is characterized by low solubility in an organic solvent, high melt viscosity, and low brittleness, and thus it is generally difficult to granulate by dispersing or pulverizing in an aqueous medium. Therefore, it is preferable to add it in the form of a prepolymer having a reactive group at the molecular terminal and react it together with granulation.

The amorphous polyester A contains a diol-derived structural unit and a dicarboxylic acid-derived structural unit, but preferably contains a trivalent or higher acid and / or a trivalent or higher alcohol-derived structural unit. As a result, rubber elasticity can be exhibited and blocking resistance can be improved.

The diol usually contains 50 mol% or more of an aliphatic diol having 3 to 10 carbon atoms.

The diol is not particularly limited, but is limited to ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 3-methyl-1,5-pentanediol, and 1,6-hexanediol. , 1,8-octanediol, 1,10-decanediol, 1,12-dodecanediol and other aliphatic diols; diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and other oxy Diols having an alkylene group; alicyclic diols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; alicyclic diols to which alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide are added; bisphenol A, Bisphenols such as bisphenol F and bisphenol S; alkylene oxide adducts of bisphenols such as those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide and butylene oxide to bisphenols, and the like, in combination of two or more. May be good. Of these, an aliphatic diol having 4 to 12 carbon atoms is preferable.

It is preferable that the portion of the diol that becomes the main chain has an odd number of carbon atoms and has an alkyl group in the side chain. As a result, rubber elasticity can be exhibited while having high thermal deformability of the resin in the fixing temperature region, and low temperature fixing property and blocking resistance of the toner can be improved.

The dicarboxylic acid is not particularly limited, and examples thereof include an aliphatic dicarboxylic acid and an aromatic dicarboxylic acid, and two or more kinds may be used in combination. Of these, an aliphatic dicarboxylic acid having 4 to 12 carbon atoms is preferable.

Instead of the dicarboxylic acid, an anhydride of the dicarboxylic acid, a lower alkyl ester having 1 to 3 carbon atoms or a halide may be used.

Examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic acid, fumaric acid and the like.

Examples of the aromatic dicarboxylic acid include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid and the like.

The trivalent or higher valent acid or alcohol is not particularly limited, but glycerin, trimethylolethane, trimethylolpropane (TMP), pentaerythritol, sorbitol, dipentaerythritol, trimellitic acid, (TMA), pyromellitic acid and the like can be used. Two or more of them may be used in combination. Among them, trivalent acid or trivalent acid or from the viewpoint that rubber elasticity can be exhibited while the resin has high thermal deformability in the fixing temperature range, and the low temperature fixability and blocking resistance of the toner can be improved. Alcohol is preferred.

Amorphous polyester A having a urethane bond and / or a urea bond can be synthesized by reacting an amorphous polyester prepolymer A having an isocyanate group with a compound having an active hydrogen group.

The amorphous polyester prepolymer A having an isocyanate group can be synthesized by reacting an amorphous polyester having an active hydrogen group with polyisocyanate.

The polyisocyanate is not particularly limited, and examples thereof include diisocyanates and isocyanates having a trivalence or higher, and two or more of them may be used in combination.

In addition, instead of polyisocyanate, polyisocyanate blocked with a phenol derivative, oxime, caprolactam or the like may be used.

Examples of the diisocyanate include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, aromatic aliphatic diisocyanates, and isocyanurates.

Aliphatic diisocyanates include tetramethylene diisocyanate, hexamethylene diisocyanate, methyl 2,6-diisocyanatocaproate, octamethylene diisocyanate, decametin diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, and tetramethylhexane diisocyanate. And so on.

Examples of the alicyclic diisocyanate include isophorone diisocyanate and cyclohexylmethane diisocyanate.

As aromatic diisocyanates, tolylene diisocyanate, diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4'-diisocyanatodiphenyl, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 4, Examples thereof include 4'-diisocyanato-3-methyldiphenylmethane and 4,4'-diisocyanato-diphenyl ether.

Examples of the aromatic aliphatic diisocyanate include α, α, α', α'-tetramethylxylylene diisocyanate and the like.

Examples of isocyanurates include tris (isocyanatoalkyl) isocyanurate and tris (isocyanatocycloalkyl) isocyanurate.

The active hydrogen group is not particularly limited, and examples thereof include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like, and two or more kinds may be used in combination.

The compound having an active hydrogen group is preferably an amine because it can form a urea bond.

The amine is not particularly limited, and examples thereof include diamines, trivalent or higher amines, amino alcohols, amino mercaptans, amino acids, and the like, and two or more kinds may be used in combination.

Instead of amine, ketimine, oxazoline or the like in which the amino group of amine is blocked with ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone may be used.

Among these, a mixture of diamine or diamine and a small amount of trivalent or higher valence amine is preferable.

Examples of the diamine include aromatic diamines, alicyclic diamines, and aliphatic diamines.

Examples of the aromatic diamine include phenylenediamine, diethyltoluenediamine, 4,4'-diaminodiphenylmethane and the like.

Examples of the alicyclic diamine include 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminocyclohexane, isophoronediamine and the like.

Examples of the aliphatic diamine include ethylenediamine, tetramethylenediamine, hexamethylenediamine and the like.

Examples of the trivalent or higher amine include diethylenetriamine and triethylenetetramine.

Examples of the amino alcohol include ethanolamine, hydroxyethylaniline and the like.

Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan.

Examples of amino acids include aminopropionic acid and aminocaproic acid.

The molecular structure of the amorphous polyester can be confirmed by NMR measurement using a solution or a solid, X-ray diffraction, GC / MS, LC / MS, IR measurement, or the like. Conveniently, in the infrared absorption spectrum, those having no absorption based on the olefin δCH (out-of-plane bending vibration) at 965 ± 10 cm ^-1 and 990 ± 10 cm ^-1 can be detected as amorphous polyester. ..

The glass transition temperature Tg _2nd obtained from the DSC curve of the amorphous polyester A at the time of the second temperature rise is usually −60 to 0 ° C. When the Tg _{2nd of the} amorphous polyester A is -60 ° C or higher, the heat-resistant storage property and filming resistance of the toner can be improved, and when the Tg _2nd is 0 ° C or lower, the low-temperature fixability of the toner can be improved. Can be improved.

The weight average molecular weight of the amorphous polyester A is usually 20,000 to 1,000,000, preferably 50,000 to 300,000, and preferably 100,000 to 200,000 or less. More preferred. When the weight average molecular weight of the amorphous polyester A is 20,000 or more, the heat-resistant storage property and the high-temperature offset resistance of the toner can be improved, and when it is 1,000,000 or less, the low temperature of the toner is low. Fixability can be improved.

The content of the amorphous polyester A in the toner is usually 5 to 20% by mass, preferably 5 to 15% by mass. When the content of amorphous polyester A in the toner is 5% by mass or more, the low temperature fixability and high temperature offset resistance of the toner can be improved, and when it is 25% by mass or less, the heat resistance of the toner is high. It is possible to improve the storage stability and the glossiness of the image.

The amorphous polyester B is preferably a linear amorphous polyester.

The amorphous polyester B is preferably an amorphous polyester that has not been modified.

The unmodified amorphous polyester B can be synthesized by reacting a polyhydric alcohol with a polyvalent carboxylic acid.

Instead of the polyvalent carboxylic acid, an anhydride of the polyvalent carboxylic acid, a lower alkyl ester having 1 to 3 carbon atoms or a halide may be used.

The polyhydric alcohol is not particularly limited, and examples thereof include diols and the like.

Examples of the diol include bisphenols such as polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl) propane. A alkylene (2 to 3 carbon atoms) oxide (average number of moles added 1 to 10) adduct; ethylene glycol, propylene glycol; hydrogenated bisphenol A, hydrogenated bisphenol A alkylene (2 to 3 carbon atoms) oxide (average) Number of additional moles 1 to 10) Additives and the like may be mentioned, and two or more kinds may be used in combination.

The polyvalent carboxylic acid is not particularly limited, and examples thereof include a dicarboxylic acid.

Examples of the dicarboxylic acid include adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, maleic acid; alkyl groups having 1 to 20 carbon atoms such as dodecenyl succinic acid and octyl succinic acid, or alkenyl groups having 2 to 20 carbon atoms. Examples thereof include succinic acid substituted with, and two or more kinds may be used in combination.

The dicarboxylic acid preferably contains 50 mol% or more of terephthalic acid. As a result, the heat-resistant storage stability of the toner can be improved.

Amorphous polyester B may have a structural unit derived from a trivalent or higher carboxylic acid and / or a trivalent or higher alcohol at the end. Thereby, the acid value and the hydroxyl value of the amorphous polyester B can be adjusted.

The carboxylic acid having a trivalent or higher valence is not particularly limited, and examples thereof include trimellitic acid and pyromellitic acid, and two or more kinds may be used in combination.

The trihydric or higher alcohol is not particularly limited, and examples thereof include glycerin, pentaerythritol, trimethylolpropane, and the like, and two or more kinds may be used in combination.

The weight average molecular weight of the amorphous polyester B is usually 3,000 to 10,000, preferably 4,000 to 7,000. When the weight average molecular weight of the amorphous polyester B is 3,000 or more, the heat-resistant storage stability and durability of the toner can be improved, and when it is 10,000 or less, the low-temperature fixability of the toner is improved. Can be made to.

The acid value of the amorphous polyester B is usually 1 to 50 mgKOH / g, preferably 5 to 30 mgKOH / g. When the acid value of the amorphous polyester B is 1 mgKOH / g or more, the toner tends to be negatively charged, the low temperature fixability of the toner can be improved, and when it is 50 mgKOH / g or less, the toner of the toner It is possible to improve the charge stability, particularly the charge stability against environmental changes.

The hydroxyl value of amorphous polyester B is usually 5 mgKOH / g or more.

The glass transition temperature of the amorphous polyester B is usually 40 to 80 ° C, preferably 50 to 70 ° C. When the glass transition temperature of the amorphous polyester B is 40 ° C. or higher, the heat-resistant storage stability, durability and filming resistance of the toner can be improved, and when the temperature is 80 ° C. or lower, the toner is fixed at a low temperature. The sex can be improved.

The content of the amorphous polyester B in the toner is usually 50 to 90% by mass, preferably 60 to 80% by mass. When the content of amorphous polyester B in the toner is 50% by mass or more, it is possible to suppress the occurrence of image fogging and distortion, and when it is 90% by mass or less, the low temperature fixability of the toner is improved. Can be improved.

Since the crystalline polyester C has high crystallinity, it exhibits a thermal melting property in which the viscosity sharply decreases in the vicinity of the fixing start temperature. Therefore, the toner containing the crystalline polyester C and the amorphous polyester B is excellent in heat-resistant storage stability because the crystalline polyester C does not melt until just before the melting start temperature. Further, at the melting start temperature, the crystalline polyester C melts and the viscosity sharply decreases, and the crystalline polyester C is compatible with the amorphous polyester B and fixed. Therefore, a toner having excellent heat-resistant storage stability and low-temperature fixability can be obtained. Further, a toner having a large release width, that is, a difference between the fixing lower limit temperature and the high temperature offset generation temperature can be obtained.

The crystalline polyester C is not modified and can be synthesized by reacting a polyhydric alcohol with a polyvalent carboxylic acid.

Instead of the polyvalent carboxylic acid, an anhydride of the polyvalent carboxylic acid, a lower alkyl ester having 1 to 3 carbon atoms or a halide may be used.

The polyhydric alcohol is not particularly limited, and examples thereof include diols, trihydric or higher alcohols, and two or more kinds may be used in combination.

Examples of the diol include saturated aliphatic diols.

Examples of the saturated aliphatic diol include a linear saturated aliphatic diol and a branched saturated aliphatic diol. Among them, the linear saturated aliphatic diol is preferable because the crystallinity of the crystalline polyester C is high, and the linear saturated aliphatic diol having 2 to 12 carbon atoms is more preferable because it is easily available.

Saturated aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, and 1,8-octane. Diol, 1,9-nonandiol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecane Diol, 1,14-eicosandecandiol and the like can be mentioned. Among them, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, and 1,10-decane are excellent because the crystalline polyester C has high crystallinity and excellent sharp meltability. Diol, 1,12-dodecanediol is preferred.

Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol and the like.

The polyvalent carboxylic acid is not particularly limited, and examples thereof include a divalent carboxylic acid and a trivalent or higher carboxylic acid.

Examples of the divalent carboxylic acid include oxalic acid, succinic acid, glutaric acid, adipic acid, speric acid, azelaic acid, sebacic acid, 1,9-nonandicarboxylic acid, 1,10-decandicarboxylic acid, and 1,12-dodecane. Saturated aliphatic dicarboxylic acids such as dicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid; phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, mesaconic acid, etc. Examples thereof include aromatic dicarboxylic acids such as dibasic acid.

Examples of the trivalent or higher valent carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid and the like.

The polyvalent carboxylic acid may contain a dicarboxylic acid having a sulfonic acid group.

Further, the polyvalent carboxylic acid may contain a dicarboxylic acid having a carbon-carbon double bond.

The crystalline polyester C preferably has a structural unit derived from a linear saturated aliphatic dicarboxylic acid having 4 to 12 carbon atoms and a structural unit derived from a linear saturated aliphatic diol having 2 to 12 carbon atoms. As a result, the crystalline polyester C has high crystallinity and is excellent in sharp meltability. As a result, the low temperature fixability of the toner can be improved.

The melting point of the crystalline polyester C is usually 60 to 90 ° C, preferably 60 to 80 ° C. When the melting point of the crystalline polyester C is 60 ° C. or higher, the heat-resistant storage stability of the toner can be improved, and when the melting point is 90 ° C. or lower, the low-temperature fixability of the toner can be improved.

The weight average molecular weight of the crystalline polyester C is usually 3,000 to 30,000, preferably 5,000 to 15,000. When the weight average molecular weight of the crystalline polyester C is 3,000 or more, the heat-resistant storage stability of the toner can be improved, and when it is 30,000 or less, the low-temperature fixability of the toner can be improved. ..

The acid value of the crystalline polyester C is usually 5 mgKOH / g or more, and preferably 10 mgKOH / g or more. Thereby, the low temperature fixability of the toner can be improved. On the other hand, the acid value of the crystalline polyester C is usually 45 mgKOH / g or less. Thereby, the high temperature offset resistance of the toner can be improved.

The hydroxyl value of the crystalline polyester C is usually 50 mgKOH / g or less, preferably 5 to 50 mgKOH / g. When the hydroxyl value of the crystalline polyester C is 50 mgKOH / g or less, the low temperature fixability and charging characteristics of the toner can be improved.

The molecular structure of crystalline polyester can be confirmed by NMR measurement using a solution or a solid, X-ray diffraction, GC / MS, LC / MS, IR measurement, or the like. Conveniently, in the infrared absorption spectrum, a polyester having absorption based on δCH (out-of-plane bending vibration) of an olefin at 965 ± 10 cm ^-1 or 990 ± 10 cm ^-1 can be detected as a crystalline polyester.

The content of the crystalline polyester C in the toner is usually 3 to 20% by mass, preferably 5 to 15% by mass. When the content of crystalline polyester C in the toner is 3% by mass or more, the low-temperature fixability of the toner can be improved, and when it is 20% by mass or less, the heat-resistant storage stability of the toner is improved. , The occurrence of image fog can be suppressed.

The external additive is not particularly limited, but is an oxide particle (for example, silica particle, titania particle, alumina particle, tin oxide particle, antimony oxide particle), a fatty acid metal salt (for example, zinc stearate, aluminum stearate), Fluoropolymer particles and the like can be mentioned. Of these, hydrophobized silica, titania, titanium oxide, and alumina are preferable.

Examples of commercially available silica particles include R972, R974, RX200, RY200, R202, R805, and R812 (all manufactured by Nippon Aerosil Co., Ltd.).

Commercially available titania particles include P-25 (manufactured by Aerosil Japan), STT-30, STT-65C-S (manufactured by Titanium Industry Co., Ltd.), TAF-140 (manufactured by Fuji Titanium Industry Co., Ltd.), MT-150W. , MT-500B, MT-600B, MT-150A (all manufactured by TAYCA) and the like.

The hydrophobized titanium oxide particles include T-805 (manufactured by Aerosil Japan), STT-30A, STT-65S-S (above, manufactured by Titanium Industry Co., Ltd.), TAF-500T, TAF-1500T (above, Fuji). (Titanium Industry Co., Ltd.), MT-100S, MT-100T (all manufactured by TAYCA Corporation), IT-S (manufactured by Ishihara Sangyo Co., Ltd.) and the like.

The method for hydrophobizing the oxide particles is not particularly limited, but a method for treating the oxide particles with a silane coupling agent, a method for heating the oxide particles as necessary, and treating with silicone oil, etc. Can be mentioned.

The silane coupling agent is not particularly limited, and examples thereof include methyltrimethoxysilane, methyltriethoxysilane, and octyltrimethoxysilane.

The silicone oil is not particularly limited, but dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methylhydrogen silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, Examples thereof include amino-modified silicone oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, phenol-modified silicone oil, carboxyl-modified silicone oil, mercapto-modified silicone oil, methacryl-modified silicone oil, and α-methylstyrene-modified silicone oil.

The content of the external additive in the toner is usually 0.1 to 5% by mass, preferably 0.3 to 3% by mass.

The average primary particle size of the oxide particles is usually 1 to 100 nm, preferably 3 to 70 nm. When the average primary particle size of the oxide particles is 1 nm or more, it is possible to suppress the embedding of the oxide particles in the parent particles, and when it is 100 nm or less, the uneven scratches on the surface of the photoconductor are damaged. Occurrence can be suppressed.

The toner may further contain a release agent, a colorant, a charge control agent, a cleaning property improver, a magnetic material, and the like.

The release agent is not particularly limited, but is limited to plant wax (for example, carnauba wax, cotton wax, wood wax, rice wax), animal wax (for example, honey wax, lanolin), mineral wax (for example, ozokelite, etc.). Sercin), petroleum wax (eg paraffin, microcrystallin, petrolatum), hydrocarbon wax (eg Fisher Tropsch wax, polyethylene wax, polypropylene wax), synthetic wax (eg ester, ketone, ether), fatty acid amide wax Compounds (for example, 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide and the like can be mentioned. Among them, hydrocarbon waxes such as paraffin wax, microcrystallin wax, Fisher Tropsch wax, polyethylene wax and polypropylene wax are used. preferable.

The melting point of the release agent is usually 60 to 80 ° C. When the melting point of the release agent is 60 ° C. or higher, the heat-resistant storage stability of the toner can be improved, and when the melting point is 80 ° C. or lower, the high-temperature offset resistance of the toner can be improved.

The content of the release agent in the toner is usually 2 to 10% by mass, preferably 3 to 8% by mass. When the content of the release agent in the toner is 2% by mass or more, the high temperature offset resistance and low temperature fixability of the toner can be improved, and when it is 10% by mass or less, the heat storage property of the toner is stored. Can be improved and the occurrence of image fogging can be suppressed.

The colorant is not particularly limited, but is carbon black, niglosin dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, yellow clay, yellow lead, titanium yellow, polyazo. Yellow, Oil Yellow, Hansa Yellow (GR, A, RN, R), Pigment Yellow L, Benzidine Yellow (G, GR), Permanent Yellow (NCG), Balkan Fast Yellow (5G, R), Tartragin Lake, Kinolin Yellow Lake, Anthracan Yellow BGL, Isoindolinon Yellow, Bengala, Lead Tan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Faise Red, Parachloro Ortho Nitroaniline Red, Resole Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resole Rubin GX, Permanent Red F5R, Brilliant Carmin 6B, Pigment Scarlet 3B, Bordeaux 5B, Truisin Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bonmaroon Light, Bonmaroon Medium, Eosin Lake, Rhodamin Lake B, Rhodamin Lake Y, Alizarin Lake, Thioinjigo Red B, Thioinjigo Maroon , Oil Red, Kinacridon Red, Pyrazolon Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinon Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phtalocyanin Blue, Phtalocyanin Blue, Fast Sky Blue, Indan Slen Blue (RS, BC), Indigo, Ultramarine, Navy Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zink Green , Chromium oxide, Pyridian, Emerald green, Pigment green B, Naftor green B, Green gold, Acid green lake, Malakite green lake, Phtalocyanin green, Anthracy Non-green, titanium oxide, zinc oxide, lithopone and the like can be mentioned, and two or more of them may be used in combination.

The content of the colorant in the toner is usually 1 to 15% by mass, preferably 3 to 10% by mass.

The pigment can also be combined with a resin and used as a masterbatch.

The resin is not particularly limited, but is a polymer of styrene such as amorphous polyester B, polystyrene, polyp-chlorostyrene, polyvinyltoluene or a substitute thereof; styrene-p-chlorostyrene copolymer and styrene-propylene. Styrene, styrene-vinyltoluene copolymer, styrene-vinylnaphthalin copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-acrylic acid Octyl copolymer, 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, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-inden copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, etc. Styrene-based copolymers; polymethylmethacrylate, polybutylmethacrylate, polyvinyl chloride, polyvinylacetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid, rosin, modified Examples thereof include rosin, sterene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin and the like, and two or more thereof may be used in combination.

A masterbatch can be produced by mixing and kneading the resin and the pigment. At this time, an organic solvent can be used in order to enhance the interaction between the pigment and the resin.

Further, a masterbatch is produced by using a so-called flushing method, in which an aqueous paste of a pigment is mixed and kneaded together with a resin and an organic solvent, the pigment is transferred to the resin side, and water and the organic solvent are removed. May be good. In this case, since the pigment wet cake can be used as it is, it is not necessary to dry the pigment.

The apparatus for mixing and kneading is not particularly limited, and examples thereof include a high shear dispersion apparatus such as a three-roll mill.

The cleaning property improving agent is not particularly limited, and examples thereof include fatty acid metal salts such as zinc stearate and calcium stearate, and polymer particles produced by soap-free emulsion polymerization such as polymethylmethacrylate particles and polystyrene particles.

The volume average particle size of the polymer particles is usually 0.01 to 1 μm.

The magnetic material is not particularly limited, and examples thereof include iron, magnetite, and ferrite. Of these, a white material is preferable in terms of color tone.

The average particle size of the number of toners is usually 3.0 to 8.0 μm. When the number average particle size of the toner is 3.0 μm or more, the non-electrostatic adhesive force between the toner and the intermediate transfer body is reduced, and the transfer efficiency can be improved. In addition, the toner and the carrier are easily mixed in the developing device. On the other hand, when the number average particle size of the toner is 8.0 μm or less, it is possible to develop faithfully to the electrostatic latent image, and a high-resolution and high-quality image can be obtained.

The average circularity of the toner is 0.98 or less, preferably 0.97 or less. When the average circularity of the toner exceeds 0.98, the cleanability of the toner deteriorates and the toner remains on the photoconductor. The average circularity of the toner is usually 0.92 or more.

The method for controlling the average circularity of the toner is not particularly limited, and examples thereof include heat treatment, adjustment of viscosity of oil droplets, adjustment of the number of associations of oil droplets, and the like.

Assuming that the BET specific surface area of the toner is Bt [m ² / g] and the coverage of the toner coated with the external additive is Ct [%], the formula Bt-0.025 × Ct ≦ 1.80
Bt-0.025 × Ct ≦ 1.20
It is preferable to satisfy. When Bt-0.025 × Ct exceeds 1.80, the durability of the toner is lowered and streaky color loss occurs in the image. Bt −0.025 × Ct is usually 0.80 or more.

The BET specific surface area of the toner is a value including the unevenness of the surface of the parent particles and the unevenness of the surface of the external additive. Here, when the coverage of the toner covered with an external additive having a BET specific surface area of about 20 to ²⁰⁰ m ² / g is Ct%, the amount of increase in the BET specific surface area of the toner with respect to the BET specific surface area of the parent particles is , Approximately 0.025 × Ctm ² / g. Therefore, the value of the BET specific surface area of the parent particles can be estimated from Bt-0.025 × Ct. Since the BET specific surface area is excellent in detecting fine irregularities on the surface according to the measurement principle, Bt-0.025 × Ct is an index of the surface smoothness of the parent particles.

By improving the surface smoothness of the matrix particles, the fluidity of the developer can be maintained and the durability of the toner can be improved. Although the reason for this has not been clarified, when the surface of the matrix particles has less fine irregularities, the contact area when other toners come into contact is reduced, and the non-electrostatic adhesive force can be reduced. It is considered that the rate of burial of the parent particles on the surface can be reduced.

The method for improving the surface smoothness of the matrix particles is not particularly limited, and examples thereof include heat treatment.

For example, when the matrix particles are not aggregated with each other, that is, when they are dispersed in an aqueous medium and heated at a temperature equal to or lower than the glass transition temperature of the binder resin, the fine irregularities on the surface of the matrix particles are reduced. The surface smoothness of the matrix particles can be improved.

In an environment of 32 ° C. and 40% RH, the load speed is 3.0 × 10 ^-5 N / sec, and the average value of the amount of toner deformation when the load reaches 3.00 × 10 ^-4 N is X [ μm], where the average particle size of the number of toners is Dn [μm], the formula X / Dn ≦ 0.14
It is preferable to satisfy. When X / Dn is 0.14 or less, the toner is less likely to be deformed due to the pressure stress in the developing unit, and the durability of the toner can be improved. X / Dn is usually 0.06 or more.

The method for producing the toner is not particularly limited, and examples thereof include a dissolution / suspension method.

The toner emulsifies or disperses an oil phase containing an amorphous polyester prepolymer A having an isocyanate group, an amorphous polyester B, and if necessary, a crystalline polyester C, a mold release agent, a colorant, and the like in an aqueous medium. It is preferable to produce by allowing.

It is preferable that the resin particles are dispersed in the aqueous medium.

The resin constituting the resin particles is not particularly limited as long as it can be dispersed in an aqueous medium, but is not particularly limited, but is vinyl-based resin, polyurethane, epoxy resin, polyester, polyamide, polyimide, silicon-based resin, phenol resin, and melamine. Examples thereof include resin, urea resin, aniline resin, ionomer resin, polycarbonate and the like, and two or more kinds may be used in combination. Of these, vinyl resins, polyurethanes, epoxy resins, and polyesters are preferable because fine spherical resin particles can be easily obtained.

The mass ratio of the resin particles to the aqueous medium is usually 0.005 to 0.1.

The aqueous medium is not particularly limited, and examples thereof include water and a solvent miscible with water, and two or more of them may be used in combination. Of these, water is preferable.

The solvent that can be miscible with water is not particularly limited, and examples thereof include alcohol, dimethylformamide, tetrahydrofuran, cellosolves, lower ketones and the like.

Examples of the alcohol include methanol, isopropanol, ethylene glycol and the like.

Examples of lower ketones include acetone, methyl ethyl ketone and the like.

The oil phase dissolves a toner material containing an amorphous polyester prepolymer A having an isocyanate group, an amorphous polyester B, and if necessary, a crystalline polyester C, a mold release agent, a colorant, and the like in an organic solvent. It can be produced by dispersing or dispersing.

The boiling point of the organic solvent is usually less than 150 ° C. Thereby, the organic solvent can be easily removed.

The organic solvent is not particularly limited, but toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichlorethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, etc. Ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone and the like can be mentioned, and two or more kinds may be used in combination. Among them, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride and the like are preferable, and ethyl acetate is more preferable.

Amorphous polyester A is produced by reacting an amorphous polyester prepolymer A having an isocyanate group with a compound having an active hydrogen group when the oil phase is emulsified or dispersed in an aqueous medium.

Amorphous polyester A can be produced by the following methods (1) to (3).
(1) An oil phase containing an amorphous polyester prepolymer A having an isocyanate group and a compound having an active hydrogen group is emulsified or dispersed in an aqueous medium to obtain a compound having an active hydrogen group and an isocyanate group in the aqueous medium. A method for producing an amorphous polyester A by subjecting the having amorphous polyester prepolymer A to an elongation reaction and / or a cross-linking reaction.
(2) An oil phase containing an amorphous polyester prepolymer A having an isocyanate group is emulsified or dispersed in an aqueous medium to which a compound having an active hydrogen group is added in advance, and a compound having an active hydrogen group is obtained in the aqueous medium. A method for producing an amorphous polyester A by subjecting an amorphous polyester prepolymer A having an isocyanate group to an elongation reaction and / or a cross-linking reaction.
(3) After the oil phase containing the amorphous polyester prepolymer A having an isocyanate group is emulsified or dispersed in an aqueous medium, a compound having an active hydrogen group is added to the aqueous medium, and particles are added to the aqueous medium. A method for producing an amorphous polyester A by subjecting a compound having an active hydrogen group and an amorphous polyester prepolymer A having an isocyanate group to an extension reaction and / or a cross-linking reaction.

When the compound having an active hydrogen group and the amorphous polyester prepolymer A having an isocyanate group are subjected to an elongation reaction and / or a cross-linking reaction from the interface of the particles, the amorphous polyester A is preferentially formed on the surface of the produced toner. It can also be produced to form a concentration gradient of amorphous polyester A in the toner.

The time for reacting the compound having an active hydrogen group with the amorphous polyester prepolymer A having an isocyanate group is usually 10 minutes to 40 hours, preferably 2 to 24 hours.

The temperature at which the compound having an active hydrogen group and the amorphous polyester prepolymer A having an isocyanate group are reacted is usually 0 to 150 ° C, preferably 40 to 98 ° C.

A catalyst can be used in reacting the compound having an active hydrogen group with the amorphous polyester prepolymer A having an isocyanate group.

The catalyst is not particularly limited, and examples thereof include dibutyltin laurate and dioctyltin laurate.

The method of emulsifying or dispersing the oil phase in the aqueous medium is not particularly limited, and examples thereof include a method of adding the oil phase to the aqueous medium and dispersing it by shearing force.

The disperser used to emulsify or disperse the oil phase in the aqueous medium is not particularly limited, but is a low-speed shear disperser, a high-speed shear disperser, a friction disperser, a high-pressure jet disperser, and an ultrasonic disperser. Machines, etc. can be mentioned. Among them, a high-speed shearing type disperser is preferable because the particle size of the dispersion (oil droplet) can be controlled to 2 to 20 μm.

When a high-speed shearing disperser is used, the rotation speed is usually 1,000 to 30,000 rpm, preferably 5,000 to 20,000 rpm. The dispersion time is usually 0.1 to 5 minutes in the case of the batch method. The dispersion temperature is usually 0 to 150 ° C., preferably 40 to 98 ° C. under pressure.

The mass ratio of the aqueous medium to the toner material is usually 0.5 to 20, preferably 1 to 10. When the mass ratio of the aqueous medium to the toner material is 0.5 or more, the oil phase can be dispersed well, and when it is 20 or less, it is economical.

The aqueous medium preferably contains a dispersant. Thereby, when the oil phase is emulsified or dispersed in the aqueous medium, the dispersion stability of the oil droplets can be improved, the base particles can be formed into a desired shape, and the particle size distribution can be narrowed.

The dispersant is not particularly limited, and examples thereof include a surfactant, a poorly water-soluble inorganic compound dispersant, a polymer-based protective colloid, and the like, and two or more kinds may be used in combination. Of these, surfactants are preferred.

Examples of the surfactant include anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants and the like. Of these, a surfactant having a fluoroalkyl group is preferable.

Examples of the anionic surfactant include alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters and the like.

After the oil phase is dispersed in the aqueous medium, it is preferable to remove the organic solvent to form the parent particles.

The method for removing the organic solvent is not particularly limited, but is a method of gradually raising the temperature of the aqueous medium in which the oil phase is dispersed to evaporate the organic solvent in the oil droplets, or an aqueous system in which the oil phase is dispersed. Examples thereof include a method of spraying the medium in a dry atmosphere to remove the organic solvent in the oil droplets.

It is preferable that the maternal particles are washed and then dried. At this time, the parent particles may be classified. Specifically, the particles may be classified by removing fine particles from the mother particles contained in the aqueous medium using a cyclone, a decanter, a centrifuge, or the like, or the dried mother particles may be classified.

Toner can be produced by mixing the matrix particles with an external additive and, if necessary, a charge control agent. At this time, by applying a mechanical impact force to the mixture, it is possible to suppress the desorption of the external additive from the surface of the parent particles.

The method of applying a mechanical impact force to the mixture is not particularly limited, but a method of applying an impact force to the mixture by rotating the blades at a high speed, or a method of throwing the mixture into a high-speed moving air stream and particles. Alternatively, a method of applying an impact force to the mixture by colliding the particles with the collision plate can be mentioned.

Commercially available devices that apply mechanical impact force to the mixture include ong mills (manufactured by Hosokawa Micron) and type I mills (manufactured by Nippon Pneumatic) to reduce the crushing air pressure, and hybridization systems. (Manufactured by Nara Machinery Co., Ltd.), Cryptron system (manufactured by Kawasaki Heavy Industries), etc.

The developer contains toner and, if necessary, further components such as carriers.

The developer may be a one-component developer or a two-component developer.

The carrier usually has a protective layer formed on the core material.

The material constituting the core material is not particularly limited, but is a manganese-strontium-based material having a mass magnetization of 50 to 90 emu / g, a manganese-magnesium-based material having a mass magnetization of 50 to 90 emu / g, and a mass magnetization of 100 emu / g. Examples of the above iron, high magnetization materials such as magnetite having a mass magnetization of 75 to 120 emu / g, and low magnetization materials such as copper-zinc type having a mass magnetization of 30 to 80 emu / g can be mentioned, and two or more kinds can be used in combination. May be good.

The volume average particle diameter of the core material is usually 10 to 150 μm, preferably 40 to 100 μm.

The content of the carrier in the two-component developer is usually 90 to 98% by mass, preferably 93 to 97% by mass.

The fluidity of the developer can be evaluated by measuring the total energy using a powder rheometer. Here, the powder rheometer will be described.

Conventional parameters such as particle size and shape are accurate because measuring the fluidity of particles is more affected by more factors than measuring the fluidity of liquids, solids, or gases. It is difficult to identify the fluidity of the particles. In addition, even if a factor to be measured (for example, particle size) for specifying fluidity is determined, in reality, the factor has little effect on liquidity, or only in combination with other factors. In some cases, it is meaningful to measure the factor, and even determining the measuring factor is difficult.

Furthermore, the fluidity of particles also varies significantly due to external environmental factors. For example, in the case of a liquid, the fluctuation range of fluidity is not so large even if the measurement environment fluctuates, but the fluidity of particles greatly fluctuates due to external environmental factors such as humidity and the state of the flowing gas. To do. Since it is not clear which measurement factor these external environmental factors affect, the actual measurement value is not reproducible even when measured under strict measurement conditions. is there.

The angle of repose, bulk density, etc. have been used as indicators for the fluidity of toner in the developing tank, but these physical property values are indirect with respect to the fluidity and are fluid. Was difficult to quantify and manage.

However, since the powder rheometer can measure the total energy applied to the rotor blades of the measuring machine from the developer, it is possible to obtain a total value of each factor due to fluidity. Therefore, in the powder rheometer, the items to be measured are determined for the developer obtained by adjusting the physical property values and particle size distribution of the surface as in the conventional case, and the optimum physical property values are found and measured for each item. The fluidity can be measured directly. As a result, it is possible to determine whether or not the developer is suitable for developing an electrostatic charge image simply by checking the total energy using a powder rheometer. Such manufacturing control of the developer is a method extremely practically suitable for keeping the fluidity of the developer constant, as compared with the conventional method of controlling with an indirect value. In addition, it is easy to keep the measurement conditions constant, and the reproducibility of the measured values is high. That is, the method of specifying the fluidity by the total energy is simpler, more accurate, and more reliable than the conventional method.

The powder rheometer is a fluidity measuring device that directly obtains fluidity by simultaneously measuring rotational torque and vertical load by rotating a rotary blade in a spiral shape in the filled particles. By measuring both the rotational torque and the vertical load, it is possible to detect the fluidity including the characteristics of the particles themselves and the influence of the external environment with high sensitivity. In addition, since the total energy is measured after keeping the state of particle filling constant, data with good reproducibility can be obtained.

The total energy measured using a powder leometer of the developer under the conditions of a container capacity of 25 mL, a propeller-type rotor tip speed of 10 mm / s, and a propeller-type rotor approach angle of -5 ° is usually 200. It is ~ 350 mJ, preferably 200 to 300 mJ. When the total energy of the developer is 200 mJ or more, it is possible to prevent the developer from ejecting from the vicinity of the developer carrier and contaminating the inside of the image forming apparatus. On the other hand, when the total energy of the developer is 350 mJ or less, the durability of the toner can be improved.

The total energy of the developer after stirring and mixing 30 g of the developer for 60 minutes under the condition of a frequency of 700 rpm using a locking mill is usually 200 to 350 mJ, preferably 200 to 300 mJ. When the total energy of the developer after stirring and mixing using the locking mill is 200 mJ or more, it is possible to further suppress the development agent from ejecting from the vicinity of the developer carrier and contaminating the inside of the image forming apparatus. .. On the other hand, when the total energy of the developer after stirring and mixing using a locking mill is 350 mJ or less, the durability of the toner can be improved.

The developer is usually used in a known container.

The container is not particularly limited, and examples thereof include a container having a container body and a cap.

The shape of the container body is not particularly limited, and examples thereof include a cylindrical shape.

The inner peripheral surface of the container body has spiral irregularities, and by rotating the container body, the developer can be transferred to the discharge port side, and a part or all of the spiral irregularities have a bellows function. Is preferable.

The material of the container body is not particularly limited, and examples thereof include resins such as polyester, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyacrylic acid, polycarbonate, ABS resin, and polyacetal.

Since the container containing the developing agent is easy to store, transport, etc. and has excellent handleability, it can be detachably attached to a process cartridge, an image forming apparatus, etc., which will be described later, and used for replenishing the developing agent. ..

The developer can be applied to a known image forming apparatus or process cartridge that forms an image by an electrophotographic method such as a magnetic one-component developing method, a non-magnetic one-component developing method, or a two-component developing method.

FIG. 1 shows an example of an image forming apparatus.

The image forming apparatus 100A includes a photoconductor drum 10, a charging roller 20, an exposure apparatus (not shown), a developing device 45 (K, Y, M, C), an intermediate transfer belt 50, and a cleaning blade. It has a device 60 and a static elimination lamp 70.

The intermediate transfer belt 50 is supported by three rollers 51 arranged inside, and can move in the direction of the arrow. A part of the three rollers 51 also functions as a transfer bias roller capable of applying a predetermined transfer bias to the intermediate transfer belt 50.

Further, a cleaning device 90 having a cleaning blade is arranged in the vicinity of the intermediate transfer belt 50. Further, a transfer roller 80 capable of applying a transfer bias for transferring the toner image to the recording paper P is arranged so as to face the intermediate transfer belt 50.

Further, around the intermediate transfer belt 50, a corona charger 52 that applies an electric charge to the toner image on the intermediate transfer belt 50 records the contact portion between the photoconductor drum 10 and the intermediate transfer belt 50 and the intermediate transfer belt 50. It is arranged between the contact portion of the paper P.

The developer 45 for each color of black (K), yellow (Y), magenta (M), and cyan (C) includes a developer accommodating portion 42 (K, Y, M, C), a developer supply roller 43, and a developer supply roller 43. A developing roller 44 is provided.

In the image forming apparatus 100A, the photoconductor drum 10 is uniformly charged by the charging roller 20, and then the exposure light L is irradiated onto the photoconductor drum 10 by the exposure apparatus (not shown) to form an electrostatic latent image. .. Next, the electrostatic latent image formed on the photoconductor drum 10 is developed by supplying a developer from the developer 45 to form a toner image, and then the toner image is formed by the transfer bias applied from the roller 51. Is transferred onto the intermediate transfer belt 50. Further, the toner image on the intermediate transfer belt 50 is charged by the corona charger 52 and then transferred onto the recording paper P. The toner remaining on the photoconductor drum 10 is removed by the cleaning device 60, and the photoconductor drum 10 is temporarily discharged by the static elimination lamp 70.

FIG. 2 shows another example of the image forming apparatus.

The image forming apparatus 100B is a tandem type color image forming apparatus, and includes a copying apparatus main body 150, a paper feed table 200, a scanner 300, and an automatic document transporting apparatus (ADF) 400.

An intermediate transfer belt 50 is installed in the central portion of the copying apparatus main body 150.

The intermediate transfer belt 50 is supported by rollers 14, 15 and 16 and can rotate in the direction of the arrow.

A cleaning device 17 for removing the toner remaining on the intermediate transfer belt 50 is arranged in the vicinity of the support roller 15. Further, on the intermediate transfer belt 50 supported by the roller 14 and the roller 15, four image forming units 120 of yellow, cyan, magenta, and black are arranged so as to face each other along the conveying direction.

As shown in FIG. 3, the image forming unit 120 of each color blackens the photoconductor drum 10, the charging roller 20 that uniformly charges the photoconductor drum 10, and the electrostatic latent image formed on the photoconductor drum 10. A developer 61 that develops with a developer of each color of (K), yellow (Y), magenta (M), and cyan (C) to form a toner image, and a toner image of each color are transferred onto an intermediate transfer belt 50. It includes a transfer roller 62, a cleaning device 63, and a static eliminator lamp 64.

An exposure apparatus (not shown) is arranged in the vicinity of the image forming unit 120. The exposure apparatus irradiates the photoconductor drum 10 with the exposure light L to form an electrostatic latent image.

Further, the transfer device 22 is arranged on the side of the intermediate transfer belt 50 opposite to the side on which the image forming unit 120 is arranged. The transfer device 22 is a transfer belt 24 supported by a pair of rollers 23, and the recording paper conveyed on the transfer belt 24 and the intermediate transfer belt 50 can come into contact with each other.

A fixing device 25 is installed in the vicinity of the transfer device 22. The fixing device 25 has a fixing belt 26 and a pressure roller 27 that is pressed and arranged by the fixing belt 26.

Further, in the vicinity of the transfer device 22 and the fixing device 25, a reversing device 28 for reversing the recording paper in order to form an image on both sides of the recording paper is installed.

Next, the formation of a full-color image in the image forming apparatus 100B will be described. First, the document is set on the platen 130 of the automatic document transfer device (ADF) 400, or the document is set on the contact glass 32 of the scanner 300 by opening the automatic document transfer device 400 and closing the automatic document transfer device 400. .. Next, when the start switch (not shown) is pressed, when the original is set in the automatic document conveying device 400, the original is conveyed and moved onto the contact glass 32, and then the original is placed on the contact glass 32. When set, the scanner 300 is immediately driven, and the first traveling body 33 and the second traveling body 34 travel. At this time, the light from the light source is irradiated by the first traveling body 33, the reflected light from the document surface is reflected by the mirror in the second traveling body 34, and is received by the reading sensor 36 through the imaging lens 35. .. As a result, the color original (color image) is read, and image information of each color of black, yellow, magenta, and cyan is obtained.

Further, after the electrostatic latent image of each color is formed on the photoconductor drum 10 based on the image information of each color obtained by the photofinishing apparatus, the electrostatic latent image of each color is supplied from the image forming unit 120 of each color. It is developed with the developed developer to form a toner image of each color. The toner images of each color are sequentially superimposed and transferred onto the intermediate transfer belt 50 rotated by the rollers 14, 15 and 16, and a composite toner image is formed on the intermediate transfer belt 50.

In the paper feed table 200, one of the paper feed rollers 142 is selectively rotated, and the recording paper is fed out from one of the paper feed cassettes 144 provided in the paper bank 143 in multiple stages, and one sheet is fed by the separation roller 145. They are separated from each other and sent out to the paper feed path 146, conveyed by the transfer roller 147, guided to the paper feed path 148 in the copying machine main body 150, and abutted against the registration roller 49 to stop. Alternatively, the recording paper on the manual feed tray 54 is fed out, separated one by one by the separation roller 58, put into the manual feed feed path 53, and abutted against the resist roller 49 to stop. Although the resist roller 49 is generally used on the ground, it may be used in a state where a bias is applied in order to remove paper dust from the recording paper.

Then, the resist roller 49 is rotated in time with the composite toner image formed on the intermediate transfer belt 50, the recording paper is sent out between the intermediate transfer belt 50 and the transfer device 22, and the composite toner image is transferred onto the recording paper. To do.

The recording paper on which the composite toner image is transferred is conveyed by the transfer device 22 and sent out to the fixing device 25. Then, in the fixing device 25, the composite toner image is fixed on the recording paper by being heated and pressed by the fixing belt 26 and the pressure roller 27. After that, the recording paper is switched by the switching claw 55, discharged by the discharge roller 56, and stacked on the paper discharge tray 57.

Alternatively, the image is switched by the switching claw 55, inverted by the reversing device 28, guided to the transfer position again, an image is formed on the back surface, and then the image is discharged by the discharge roller 56 and stacked on the paper discharge tray 57.

The toner remaining on the intermediate transfer belt 50 after the composite toner image is transferred is removed by the cleaning device 17.

FIG. 4 shows an example of the process cartridge.

The process cartridge 110 includes a photoconductor drum 10, a corona charger 52, a developing device 40, a transfer roller 80, and a cleaning device 90.

Hereinafter, examples of the present invention will be described, but the present invention is not limited to the examples. In addition, a part means a mass part, and% means a mass%.

(Synthesis of ketimin 1)
170 parts of isophorone diamine and 75 parts of methyl ethyl ketone were charged in a reaction vessel in which a stirring rod and a thermometer were set, and reacted at 50 ° C. for 5 hours to obtain ketimine 1. Ketimin 1 had an amine value of 418 mgKOH / g.

(Synthesis of Amorphous Polyester Prepolymer A-1)
3-Methyl-1,5-pentanediol, adipic acid and trimellitic anhydride were charged into a reaction vessel in which a cooling tube, a stirrer and a nitrogen introduction tube were set. At this time, the molar ratio of the hydroxyl group to the carboxyl group was 1.5, the content of trimellitic anhydride in all the monomers was set to 1 mol%, and 1000 ppm of titanium tetraisopropoxide was added to all the monomers. Next, the temperature is raised to 200 ° C. in about 4 hours, further raised to 230 ° C. in 2 hours, reacted until water does not flow out, and then reacted under reduced pressure of 10 to 15 mmHg for 5 hours to obtain a hydroxyl group. An amorphous polyester having the above was obtained.

Amorphous polyester A-1 having a hydroxyl group and isophorone diisocyanate were charged into a reaction vessel in which a cooling pipe, a stirrer and a nitrogen introduction pipe were set. At this time, the molar ratio of the isocyanate group to the hydroxyl group was set to 2.0. Next, after diluting with ethyl acetate, the reaction was carried out at 100 ° C. for 5 hours to obtain a 50% ethyl acetate solution of amorphous polyester prepolymer A-1.

A 50% ethyl acetate solution of amorphous polyester prepolymer A-1 was charged into a reaction vessel in which a heating device, a stirrer and a nitrogen introduction tube were set, and the mixture was stirred, and then ketimin 1 was added dropwise. At this time, the molar ratio of the amino group to the isocyanate group was set to 1. Next, after stirring at 45 ° C. for 10 hours, the mixture was dried under reduced pressure at 50 ° C. until the remaining amount of ethyl acetate became 100 ppm or less to obtain amorphous polyester A-1. The amorphous polyester A-1 had a glass transition temperature of −55 ° C. and a weight average molecular weight of 130000.

(Synthesis of Amorphous Polyester Prepolymer A-2)
(Non-) except that 1,6-hexanediol was used instead of 3-methyl-1,5-pentanediol and a mixture of isophthalic acid and adipic acid in a molar ratio of 8: 2 was used instead of adipic acid. Synthesis of crystalline polyester prepolymer A-1), a 50% ethyl acetate solution of amorphous polyester prepolymer A-2 and amorphous polyester A-2 were obtained. The amorphous polyester A-2 had a glass transition temperature of −5 ° C. and a weight average molecular weight of 120,000.

(Synthesis of Amorphous Polyester Prepolymer A-3)
A 50% ethyl acetate solution of amorphous polyester prepolymer A-3, non-amorphous polyester prepolymer A-3, except that decanedioic acid was used instead of adipic acid (synthesis of amorphous polyester prepolymer A-1). A crystalline polyester A-3 was obtained. The amorphous polyester A-3 had a glass transition temperature of −65 ° C. and a weight average molecular weight of 100,000.

(Synthesis of amorphous polyester prepolymer A-4)
50% ethyl acetate solution of amorphous polyester prepolymer A-4, amorphous, in the same manner as in (Synthesis of amorphous polyester prepolymer A-1) except that isophthalic acid was used instead of adipic acid. Quality polyester A-4 was obtained. The amorphous polyester A-4 had a glass transition temperature of 5 ° C. and a weight average molecular weight of 120,000.

Table 1 shows the characteristics of amorphous polyesters A-1 to A-4.

なお、後述する参考例１−１０、実施例１１−１３、及び比較例１−４において、母体粒子中に非晶質ポリエステルＡ−１〜Ａ−４が生成していると考えられる。

It is considered that amorphous polyesters A-1 to A-4 are formed in the parent particles in Reference Examples 1-10, Examples 11-13, and Comparative Examples 1-4 , which will be described later.

(Synthesis of amorphous polyester B)
Bisphenol A ethylene oxide 2 mol adduct (BisA-EO), bisphenol A propylene oxide 3 mol adduct (BisA-PO), terephthalic acid in a reaction vessel set with a nitrogen introduction tube, dehydration tube, stirrer and thermocouple. Acid and adipic acid were charged. At this time, the molar ratio of BisA-EO to BisA-PO was 40/60, the molar ratio of terephthalic acid to adipic acid was 93/7, the molar ratio of hydroxyl group to carboxyl group was 1.2, and the molar ratio of hydroxyl groups to carboxyl groups was 1.2. Then, 500 ppm of titanium tetraisopropoxide was added. Next, the reaction was carried out at 230 ° C. for 8 hours, and then the reaction was carried out under reduced pressure of 10 to 15 mmHg for 4 hours. Further, 1 mol% of trimellitic anhydride was added to all the monomers and then reacted at 180 ° C. for 3 hours to obtain an amorphous polyester B. The amorphous polyester B had a glass transition temperature of 67 ° C. and a weight average molecular weight of 10,000.

(Synthesis of crystalline polyester C-1)
Sebacic acid and 1,6-hexanediol were charged into a reaction vessel in which a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple were set. At this time, the molar ratio of the hydroxyl group to the carboxyl group was set to 0.9, and 500 ppm of titanium tetraisopropoxide was added to all the monomers. Next, after reacting at 180 ° C. for 10 hours, the temperature was raised to 200 ° C. and the reaction was carried out for 3 hours. Further, the reaction was carried out under a reduced pressure of 8.3 kPa for 2 hours to obtain crystalline polyester C-1. The crystalline polyester C-1 had a melting point of 67 ° C. and a weight average molecular weight of 25,000.

(Synthesis of crystalline polyester C-2)
Crystalline polyester C-2 was obtained in the same manner as in (Synthesis of crystalline polyester prepolymer C-1) except that ethylene glycol was used instead of 1,6-hexanediol. The crystalline polyester C-2 had a melting point of 78 ° C. and a weight average molecular weight of 20000.

<Melting point and glass transition temperature>
The melting point and the glass transition temperature were measured using a differential scanning calorimeter Q-200 (manufactured by TA Instruments). Specifically, after about 5.0 mg of the target sample was placed in a sample container made of aluminum, the sample container was placed on a holder unit and set in an electric furnace. Next, the temperature was raised from −80 ° C. to 150 ° C. at a heating rate of 10 ° C./min under a nitrogen atmosphere.

From the obtained DSC curve, the glass transition temperature of the target sample was determined using the analysis program in the differential scanning calorimeter.

Further, from the obtained DSC curve, the endothermic peak top temperature of the target sample was determined as the melting point by using the analysis program in the differential scanning calorimeter.

<Weight average molecular weight>
The weight average molecular weight was measured using a GPC measuring device HLC-8220 GPC (manufactured by Tosoh Corporation) and a column TSKgel SuperHZM-H 15 cm triplet (manufactured by Tosoh Corporation). Specifically, the column was stabilized in a heat chamber at 40 ° C. Next, tetrahydrofuran (THF) was flowed through the column at a flow rate of 1 mL / min, and 50 to 200 μL of a THF solution of 0.05 to 0.6% by mass of the sample was injected, and the weight average molecular weight of the sample was measured. At this time, the number average molecular weight of the sample was calculated from the relationship between the logarithmic value of the calibration curve prepared using several types of monodisperse polystyrene standard samples and the number of counts.

As standard polystyrene samples, the weight average molecular weights are 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , and so on. Samples of 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , and 4.48 × 10 ⁶ (manufactured by Polystyrene Chemical or Tosoh) were used.

Moreover, as a detector, an RI (refractive index) detector was used.

( Reference example 1)
<Making Masterbatch 1>
Using a Henschel mixer (manufactured by Nippon Coke Industries, Ltd.), 1200 parts of water, 500 parts of carbon black Printex35 (manufactured by Dexa) with a DBP oil absorption of 42 mL / 100 mg and a pH of 9.5, and 500 parts of amorphous polyester B Was mixed and then kneaded at 150 ° C. for 30 minutes using two rolls. Next, after rolling and cooling, it was pulverized using a pulperizer to obtain a master batch 1.

<Synthesis of wax dispersant 1>
In an autoclave reaction tank equipped with a thermometer and a stirrer, 100 parts of sun wax 151P (manufactured by Sanyo Chemical Industries, Ltd.) having 480 parts of xylene, a melting point of 108 ° C. and a weight average molecular weight of 1000 polyethylene was charged, and then the polyethylene was dissolved. , Nitrogen substitution. Next, a mixed solution of 805 parts of styrene, 50 parts of acrylonitrile, 45 parts of butyl acrylate, 36 parts of di-t-butyl peroxide and 100 parts of xylene was added dropwise over 3 hours, polymerized at 170 ° C., and held for 30 minutes. did. Further, the solvent was removed to obtain a wax dispersant 1. The wax dispersant 1 had a glass transition temperature of 65 ° C. and a weight average molecular weight of 18,000.

<Preparation of wax dispersion 1>
300 parts of paraffin wax HNP-9 (manufactured by Nippon Seiro Co., Ltd.) having a melting point of 75 ° C., 150 parts of wax dispersant 1 and 1800 parts of ethyl acetate were charged into a container in which a stirring rod and a thermometer were set. Next, the temperature was raised to 80 ° C. with stirring, held for 5 hours, and then cooled to 30 ° C. in 1 hour. Further, using a bead mill Ultra Viscomill (manufactured by Imex), 80% by volume of zirconia beads having a diameter of 0.5 mm was filled and dispersed under the condition of 3 passes to obtain a wax dispersion liquid 1. At this time, the liquid feeding speed was set to 1 kg / h, and the peripheral speed of the disc was set to 6 m / s.

<Preparation of crystalline polyester dispersion 1>
308 parts of crystalline polyester C-1 and 1900 parts of ethyl acetate were charged into a container in which a stirring rod and a thermometer were set. Next, the temperature was raised to 80 ° C. with stirring, held for 5 hours, and then cooled to 30 ° C. in 1 hour. Further, using a bead mill Ultra Viscomill (manufactured by IMEX), 80% by volume of zirconia beads having a diameter of 0.5 mm was filled and dispersed under the condition of 3 passes to obtain a crystalline polyester dispersion liquid 1. At this time, the liquid feeding speed was set to 1 kg / h, and the peripheral speed of the disc was set to 6 m / s.

<Preparation of oil phase 1>
225 parts of wax dispersion 1, 40 parts of 50% ethyl acetate solution of amorphous polyester prepolymer A-1, 390 parts of amorphous polyester B, 60 parts of masterbatch 1 and 285 parts of ethyl acetate are charged into a container. Then, using a TK homomixer (manufactured by Primix Co., Ltd.), the mixture was mixed at 7000 rpm for 60 minutes to obtain oil phase 1.

<Synthesis of vinyl resin dispersion 1>
In a reaction vessel with a stirring rod and a thermometer set, 683 parts of water, 11 parts of eleminol RS-30 (manufactured by Sanyo Kasei Kogyo Co., Ltd.), a sodium salt of sulfate ester of ethylene oxide adduct of methacrylic acid, 138 parts of styrene, 138 parts of methacrylic acid. After charging a part and 1 part of ammonium persulfate, the mixture was stirred at 400 rpm for 15 minutes to obtain a white emulsion. Next, the temperature in the system was raised to 75 ° C. and reacted for 5 hours, then 30 parts of a 1% ammonium persulfate aqueous solution was added and aged at 75 ° C. for 5 hours to obtain a vinyl resin dispersion liquid 1. It was. The vinyl-based resin dispersion liquid 1 had a volume average particle diameter of 0.14 μm.

The volume average particle size of the vinyl-based resin dispersion 1 was measured using a laser diffraction / scattering type particle size distribution measuring device LA-920 (manufactured by HORIBA).

<Preparation of aqueous phase 1>
990 parts of water, 83 parts of vinyl resin dispersion, 1 part of 48.5% aqueous solution of sodium dodecyldiphenyl ether disulfonate, 37 parts of eleminol MON-7 (manufactured by Sanyo Chemical Industries, Ltd.) and 90 parts of ethyl acetate are mixed and stirred to make a milky white color. Aqueous phase 1 was obtained.

<Emulsification / solvent removal>
0.2 parts of ketimine 1 and 1200 parts of aqueous phase 1 were added to the container containing the oil phase 1, and then mixed at 13000 rpm for 20 minutes using a TK homomixer to obtain [emulsified slurry 1].

The emulsified slurry 1 was charged into a container in which a stirrer and a thermometer were set, the solvent was removed at 30 ° C. for 8 hours, and then the mixture was aged at 45 ° C. for 4 hours to obtain a dispersed slurry 1.

<Washing / heat treatment / drying>
100 parts of the dispersed slurry 1 was filtered under reduced pressure. Next, 100 parts of ion-exchanged water was added to the filtered cake, mixed at 12000 rpm for 10 minutes using a TK homomixer, and then filtered (hereinafter referred to as washing step (1)). Further, 100 parts of a 10% aqueous sodium hydroxide solution was added to the filtered cake, mixed at 12000 rpm for 30 minutes using a TK homomixer, and then filtered under reduced pressure (hereinafter referred to as washing step (2)). Next, 100 parts of 10% hydrochloric acid was added to the filtered cake, mixed at 12000 rpm for 10 minutes using a TK homomixer, and then filtered (hereinafter referred to as washing step (3)). Further, 300 parts of ion-exchanged water was added to the filtered cake, mixed at 12000 rpm for 10 minutes using a TK homomixer, and then filtered (hereinafter referred to as washing step (4)). At this time, the operations of the cleaning steps (1) to (4) were repeated twice.

100 parts of ion-exchanged water was added to the filtered cake, mixed at 12000 rpm for 10 minutes using a TK homomixer, heat-treated at 50 ° C. for 4 hours, and then filtered.

The filtered cake was dried at 45 ° C. for 48 hours using a circulation dryer, and then sieved with a mesh having an opening of 75 μm to obtain mother particles.

Using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.), 100 parts of parent particles, 0.7 parts of hydrophobic silica HDK-2000 (manufactured by Asahi Kasei Wacker Silicone) with an average primary particle size of 20 nm, and hydrophobic with an average primary particle size of 20 nm. 0.5 parts of sex titanium oxide was mixed to obtain a toner.

( Reference example 2)
Toner was obtained in the same manner as in Reference Example 1 except that the addition amounts of hydrophobic silica and hydrophobic titanium oxide were changed to 1.2 parts and 1.0 parts, respectively.

( Reference example 3)
<Preparation of oil phase 2>
Same as oil phase 1 except that the addition amounts of amorphous polyester prepolymer A-1 in 50% ethyl acetate solution, amorphous polyester B and ethyl acetate were changed to 220 parts, 300 parts and 195 parts, respectively. The oil phase 2 was obtained.

Toner was obtained in the same manner as in Reference Example 2 except that the oil phase 2 was used instead of the oil phase 1.

( Reference example 4)
<Preparation of oil phase 3>
Same as oil phase 1 except that the addition amounts of the amorphous polyester prepolymer A-1 in 50% ethyl acetate solution, the amorphous polyester B and ethyl acetate were changed to 50 parts, 385 parts and 280 parts, respectively. The oil phase 3 was obtained.

Toner was obtained in the same manner as in Reference Example 2 except that the oil phase 3 was used instead of the oil phase 1.

( Reference example 5)
Toner was obtained in the same manner as in Reference Example 4 except that the amount of aqueous phase 1 added was changed to 1000 parts.

( Reference example 6)
<Preparation of oil phase 4>
Same as oil phase 1 except that the addition amounts of amorphous polyester prepolymer A-1 in 50% ethyl acetate solution, amorphous polyester B and ethyl acetate were changed to 190 parts, 315 parts and 210 parts, respectively. The oil phase 4 was obtained.

Toner was obtained in the same manner as in Reference Example 2 except that the oil phase 4 was used instead of the oil phase 1.

( Reference example 7)
<Preparation of oil phase 5>
The oil phase is the same as in oil phase 3, except that a 50% ethyl acetate solution of amorphous polyester prepolymer A-2 is used instead of the 50% ethyl acetate solution of amorphous polyester prepolymer A-1. I got 5.

Toner was obtained in the same manner as in Reference Example 2 except that the oil phase 5 was used instead of the oil phase 1.

( Reference example 8)
<Preparation of oil phase 6>
The same as in the oil phase 5, except that the addition amounts of the 50% ethyl acetate solution of the amorphous polyester A-2, the amorphous polyester B and the ethyl acetate were changed to 120 parts, 350 parts and 245 parts, respectively. Oil phase 6 was obtained.

Toner was obtained in the same manner as in Reference Example 2 except that the oil phase 6 was used instead of the oil phase 1.

( Reference example 9)
<Preparation of oil phase 7>
225 parts of wax dispersion 1, 120 parts of 50% ethyl acetate solution of amorphous polyester prepolymer A-2, 215 parts of crystalline polyester dispersion 1, 320 parts of amorphous polyester B, 60 parts masterbatch After charging 1 and 60 parts of ethyl acetate into a container, the mixture was mixed at 7000 rpm for 60 minutes using a TK homomixer (manufactured by Primix) to obtain an oil phase 7.

Toner was obtained in the same manner as in Reference Example 2 except that the oil phase 7 was used instead of the oil phase 1.

( Reference example 10)
Toner was obtained in the same manner as in Reference Example 9 except that the time for heat treatment was changed to 8 hours.

(Example 11)
Toner was obtained in the same manner as in Reference Example 9 except that the time for heat treatment was changed to 12 hours.

(Example 12)
Toner was obtained in the same manner as in Reference Example 9 except that the heat treatment time was changed to 24 hours.

(Example 13)
<Preparation of crystalline polyester dispersion 2>
A crystalline polyester dispersion 2 was obtained in the same manner as the crystalline polyester dispersion 1 except that the crystalline polyester C-2 was used instead of the crystalline polyester C-1.

A toner was obtained in the same manner as in Example 13 except that the crystalline polyester dispersion 2 was used instead of the crystalline polyester dispersion 1.

(Comparative Example 1)
<Preparation of oil phase 8>
The oil phase is the same as in oil phase 1, except that a 50% ethyl acetate solution of amorphous polyester prepolymer A-3 is used instead of the 50% ethyl acetate solution of amorphous polyester prepolymer A-1. I got 8.

Toner was obtained in the same manner as in Reference Example 2 except that the oil phase 8 was used instead of the oil phase 1 and the heat treatment time was changed to 3 hours.

(Comparative Example 2)
<Preparation of oil phase 9>
The oil phase is the same as in oil phase 1, except that a 50% ethyl acetate solution of amorphous polyester prepolymer A-4 is used instead of the 50% ethyl acetate solution of amorphous polyester prepolymer A-1. I got 9.

Toner was obtained in the same manner as in Reference Example 2 except that the oil phase 9 was used instead of the oil phase 1.

(Comparative Example 3)
Toner was obtained in the same manner as in Reference Example 4 except that the amount of aqueous phase 1 added was changed to 800 parts.

(Comparative Example 4)
Toner was obtained in the same manner as in Reference Example 2 except that the time for heat treatment was changed to 2 hours.

Next, the glass transition temperature Tg _2nd , the average circularity, the BET specific surface area Bt, and the coverage coated with the toner's external additive, which are obtained from the DSC curve of the component insoluble in THF of the toner at the time of the second temperature rise. Ct, the number average particle size Dn, and the average value X of the amount of deformation of the toner due to minute pressing were measured.

<Contents of components insoluble in THF>
After adding 1 part of toner to 40 parts of THF, the mixture was refluxed for 6 hours. Next, after sedimentation and separation using a centrifuge, the mixture was dried at 40 ° C. for 20 hours to obtain a component insoluble in THF.

The mass of the component insoluble in THF was measured, and the content of the component insoluble in THF was determined.

<Tg _2nd, a component insoluble in THF>
Using a differential scanning calorimeter Q-200 (manufactured by TA Instruments), Tg _2nd , a component insoluble in THF, was measured. Specifically, about 5.0 mg of a component insoluble in THF was placed in a sample container made of aluminum, and then the sample container was placed on a holder unit and set in an electric furnace. Next, in a nitrogen atmosphere, the temperature was raised from −80 ° C. to 150 ° C. at a temperature rising rate of 10 ° C./min, and then cooled from 150 ° C. to −80 ° C. at a temperature lowering rate of 10 ° C./min. Further, the temperature was raised from −80 ° C. to 150 ° C. at a heating rate of 10 ° C./min.

From the obtained DSC curve, the DSC curve at the time of the second temperature rise was selected by using the analysis program in the differential scanning calorimeter, and Tg _2nd of the component insoluble in THF was obtained.

<Average circularity>
The average circularity of the toner was measured using a wet flow type particle size / shape analyzer FPIA-2100 and analysis software FPIA-2100 Data Processing Program for FPIA version 00-10 (manufactured by Sysmex). Specifically, in a 100 mL beaker made of glass, 0.1 to 0.5 mL of a 10% aqueous solution of neogen SC-A (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 0.1 to 0.5 g of toner of alkylbenzene sulfonate were added. After the addition, the mixture was stirred using a microspartel, and 80 mL of ion-exchanged water was added. Next, using an ultrasonic disperser UH-50 (manufactured by STM), the mixture was dispersed for 1 minute under the conditions of 20 kHz and 50 W / 10 cm ³ , and then dispersed for a total of 5 minutes to obtain a measurement sample. Here, the average circularity of particles having a circle-equivalent diameter of 0.60 μm or more and less than 159.21 μm was measured using a measurement sample having a particle concentration of 4000 to 8000 particles / 10 ^-3 cm ³ .

<Bt>
Bt was measured using an automatic specific surface area / pore distribution measuring device TriStar3000 (manufactured by Shimadzu Corporation). Specifically, about 1.0 g of toner was weighed into a sample cell and then vacuum dried for 24 hours using a pretreatment smart prep (manufactured by Shimadzu Corporation) to remove impurities and moisture on the surface of the toner. Next, after the pretreated toner was set in the automatic specific surface area / pore distribution measuring device, the relationship between the amount of nitrogen gas adsorbed and the relative pressure was determined, and Bt was determined by the BET multipoint method.

<Ct>
Toner was observed using a field emission scanning electron microscope MERILIN (manufactured by SII Nanotechnology) to determine Ct. Specifically, the procedure was as follows. First, a secondary electron image of the toner was acquired. At this time, the substrate was made of a conductive tape so that the toner appeared brighter than the substrate, and the contrast was selected and acquired so that there were no black spots and white spots in the entire image. Next, the obtained image was read by GIMPforWindow (registered trademark), which is an image editing / processing software, and the part visually judged to be an external additive was painted in black (R: 0, G: 0, B: 0). .. Next, the area ratio A with respect to the entire image of the portion painted in black was obtained by the binarization process. Further, the original image read by GIMPforWindow (registered trademark) was binarized with an appropriate brightness threshold value to obtain an area ratio B of the toner projection image with respect to the entire image. Formula A / B
The ratio of the external additive region to the projected toner image was obtained, and the average value of 50 toners was defined as Ct. An example of SEM measurement conditions is shown below.

SEM measurement conditions Acceleration voltage: 3.0 kV
WD (Working Distance): 10.0mm
<Dn>
Toner Dn was measured using a Coulter Multi-Sizar II (manufactured by Beckman Coulter). First, 0.1 mL to 5 mL of polyoxyethylene alkyl ether was added as a dispersant to 100 mL to 150 mL of the aqueous electrolyte solution. Here, the electrolyte aqueous solution was prepared by preparing a 1% NaCl aqueous solution using primary sodium chloride, and ISOTON-II (manufactured by Coulter) was used. Further, 2 mg to 20 mg of toner was added. An aqueous electrolyte solution in which toner was suspended was dispersed for about 1 to 3 minutes using an ultrasonic disperser, and then the particle size and number of toners were measured using a 100 μm aperture to determine Dn.

The channels are 2.00 μm or more and less than 2.52 μm; 2.52 μm or more and less than 3.17 μm; 3.17 μm or more and less than 4.00 μm; 4.00 μm or more and less than 5.04 μm; 5.04 μm or more and less than 6.35 μm; 6 .35 μm or more and less than 8.00 μm; 8.00 μm or more and less than 10.08 μm; 10.08 μm or more and less than 12.70 μm; 12.70 μm or more and less than 16.00 μm; 16.00 μm or more and less than 20.20 μm; 20.20 μm or more and 25. Less than 40 μm; 25.40 μm or more and less than 32.00 μm; 13 channels of 32.00 μm or more and less than 40.30 μm were used, and particles having a particle size of 2.00 μm or more and less than 40.30 μm were targeted.

<X>
The amount of toner deformation due to minute indentation was measured using an ultra-fine indentation hardness tester ENT-2100 (manufactured by Elionix Inc.).

The measurement method will be described below.

In this device, a load-displacement curve can be obtained by measuring the load and displacement on the indenter when the indenter is pushed into the sample. From this curve, the amount of toner deformation can be measured. The flow of the indentation test is as follows. When the measurement was started, the indenter was pushed in at a constant load speed, and the maximum load was reached. A micro-indentation test was performed under the following measurement conditions.

Indenter: 20 μm × 20 μm planar indenter Measurement environment: 32 ° C, 40% RH
Load speed: 3.0 × ^10-5 N / sec
Maximum load: 3.0 x 10 ^-4 N
Number of toners to measure: 100
Specifically, toner was placed on a glass substrate, and by air blowing, a large amount of toner was present as one particle without aggregation. The toner to be measured was selected while confirming the existence of one particle by the microscope attached to the apparatus. At that time, the major axis and the minor axis of the toner were measured by the software attached to the apparatus, and only the toner having the major axis of Dn ± 0.3 μm was selected in order to prevent the particle size of the measured toner from being biased. If the toner adheres to the indenter after the micro-push test, wipe it off with a soft cloth, etc., and then confirm that the toner does not remain on the indenter from the load-displacement curve when the indenter is pressed against the substrate. Was measured.

Here, the average value of the amount of deformation of the toner when the maximum load is reached is defined as X.

(Creation of carrier)
To 100 parts of toluene, 100 parts of organostraight silicone, 5 parts of γ- (2-aminoethyl) aminopropyltrimethoxysilane and 10 parts of carbon black are added, and then dispersed for 20 minutes using a homomixer for a protective layer. A coating solution was obtained.

Using a fluidized bed coating device, a protective layer coating solution was applied to 1000 parts of spherical magnetite having an average particle size of 50 μm to form a protective layer, and carriers were obtained.

(Preparation of developer)
Using a ball mill, 5 parts of toner and 95 parts of carriers were mixed to obtain a developer.

Next, the initial state of the developer and the total energy after the deterioration test were measured.

Next, the initial state of the developer and the total energy after the deterioration test were measured.

<Total energy>
The total energy was measured using a powder rheometer FT4 (manufactured by freeman technology). Specifically, first, the split container was filled with a developer until the height exceeded 89 mm. Here, the split container is a 25 mL container having an inner diameter of 25 mm and a height of 54 mm, on which a cylinder having a height of 21 mm is placed so that it can be separated into upper and lower parts. Next, the tip speed of the rotor is 60 mm / s, the approach angle of the rotor is 5 °, and the propeller-type rotor is rotated to gently stir and homogenize the developer (hereinafter, conditioning). ) Was repeated 16 times. Further, the upper end of the split vessel was gently moved to scrape the developer at a height of 54 mm to obtain a developer that filled the 25 mL vessel.

In conditioning, the rotor is gently agitated in a direction of rotation (counterclockwise when viewed from above) that does not receive resistance from the developer so as not to stress the developer, resulting in excessive air or partial stress. Remove most of the stress to make it homogeneous. At this time, since the rotary blade moves downward at the same time as the rotation, the tip of the rotary blade draws a spiral. Here, the angle of the spiral path drawn by the tip of the rotor is called the approach angle. In order to obtain the total energy stably, it is important to always obtain a powder with a constant volume, so conditioning is performed.

Rotate the rotary blade by rotating the inside of the 25 mL container with a height from the bottom surface of 100 mm to 10 mm, a tip speed of the rotary blade of 100 mm / s, and an approach angle of the rotary blade of -5 ° without inflowing air. By measuring the torque and the vertical load, the total energy, which is the sum of the rotational torque and the vertical load, was obtained. At this time, the rotation direction of the rotary blade is opposite to that in the case of conditioning (clockwise when viewed from above). Next, the total energy was obtained in the same manner as above except that the tip speeds of the rotary blades were set to 70 mm / s, 40 mm / s, and 10 mm / s. Here, the total energy when the tip speed of the rotor is 100, 70, 40 mm / s is small even if the developer is severely deteriorated by stress because the tip speed of the rotor is too fast. Therefore, the degree of deterioration is not detected with high sensitivity. Therefore, the total energy when the tip speed of the rotary blade is 10 mm / s is used as an index of deterioration due to stress of the developer.

<Deterioration test>
Using a locking mill RM-05S (manufactured by Seiwa Giken Co., Ltd.), 30 g of a developer was stirred and mixed for 60 minutes at a frequency of 700 rpm for deterioration.

Tables 2 and 3 show the physical properties of the toner and the developer.

次に、トナーの低温定着性、耐熱保存性、耐久性及びクリーニング性を評価した。

Next, the low temperature fixability, heat storage resistance, durability and cleanability of the toner were evaluated.

<Low temperature fixability>
After filling a device with a modified fixing part of the copier Imageo MF2200 (manufactured by Ricoh) using a Teflon (registered trademark) roller as the fixing roller with a developer, the fixing temperature is changed to change the fixing temperature to type 6200 paper (Ricoh). The image was copied to (manufactured by) to determine the lower limit temperature for fixing, and the low temperature fixing property was evaluated. At this time, the linear velocity of the paper feed was 120 to 150 mm / s, the surface pressure was 1.2 kgf / cm ² , and the nip width was 3 mm. The lower limit of fixing temperature is ⊚ when it is less than 100 ° C., ◯ when it is 100 ° C. or higher and lower than 110 ° C., Δ when it is 110 ° C. or higher and lower than 120 ° C. did.

<Heat-resistant storage>
After storing the toner at 50 ° C. for 8 hours, the toner was sieved with a 42-mesh sieve for 2 minutes to determine the residual ratio on the wire mesh and evaluate the heat-resistant storage stability. The case where the residual rate on the wire mesh is less than 10% is ⊚, the case where it is 10% or more and less than 20% is ○, the case where it is 20% or more and less than 30% is Δ, and the case where it is 30% or more is ×. , Judged.

<Durability>
After filling the digital full-color multifunction device Imagio MP C5000 (manufactured by Ricoh Co., Ltd.) with a developer, 500,000 images having an image area ratio of 5% were copied. Next, after printing the entire solid image, the image was visually observed to evaluate the durability. In addition, when streak-like color loss does not occur, ◎, when streak-like light color loss occurs slightly (less than 5% of the solid image part), ○, when streak-like light color loss occurs (solid). 5% or more and less than 10% of the image part) was judged as Δ, and the case where many streaky light color loss occurred (10% or more of the solid image part) or the case where streak-like dark color loss occurred was judged as ×. ..

Durability was carried out in a low temperature and low humidity environment (10 ° C., 15% RH) and a high temperature and high humidity environment (27 ° C., 80% RH).

<Cleanability>
After filling the digital full-color multifunction device Imagio MP C5000 (manufactured by Ricoh Co., Ltd.) with a developer, a solid image of A4 size and a toner adhesion amount of 0.5 mg / cm ² was copied. Next, the toner remaining on the photoconductor that has passed the cleaning process is transferred to a blank sheet using Scotch tape (manufactured by Sumitomo 3M Ltd.) with the initial time when 1000 sheets are copied and the time when 100,000 sheets are copied. , The reflection density was measured using a reflection density meter RD514 (manufactured by Gretag Macbeth), and the cleanability was evaluated. The case where the difference between the time-lapse and the initial reflection density was less than 0.01 was evaluated as ◯, and the case where the difference was 0.01 or more was evaluated as x.

Table 4 shows the evaluation results of the low temperature fixability, heat storage resistance, durability and cleaning property of the toner.

表４から、参考例１〜１０、実施例１１〜１３のトナーは、低温定着性、耐熱保存性、耐久性及びクリーニング性に優れることがわかる。

From Table 4, it can be seen that the toners of Reference Examples 1 to 10 and Examples 11 to 13 are excellent in low temperature fixability, heat storage stability, durability and cleaning property.

On the other hand, in the toner of Comparative Example 1, the Tg _2nd of the component insoluble in THF is −52 ° C., so that the heat-resistant storage stability is lowered.

In the toner of Comparative Example 2, since Tg _{2nd, which} is a component insoluble in THF, is 13 ° C., the low temperature fixability is lowered.

Since the toner of Comparative Example 3 has an average circularity of 0.99, the cleanability is lowered.

Since the toner of Comparative Example 4 has a Bt-0.025 × Ct of 1.90, its durability is lowered.

10 Photoreceptor drum 20 Charging roller 22 Transfer device 23 Roller 24 Transfer belt 25 Fixing device 26 Fixing belt 27 Pressurizing roller 40, 45, 61 Developer 50 Intermediate transfer belt 51 Roller 52 Corona charger 62, 80 Transfer roller 100A, 100B Image forming device 110 Process cartridge P Recording paper

Japanese Unexamined Patent Publication No. 2013-145369

Claims (6)

A toner in which the base particles containing amorphous polyester and crystalline polyester are coated with an external additive.
The glass transition temperature obtained from the DSC curve at the time of the second temperature rise of the component insoluble in THF is -50 ° C or higher and 10 ° C or lower.
The average circularity is 0.98 or less,
The THF-insoluble component comprises urethane and / or amorphous polyester having a urea bond.
Assuming that the BET specific surface area of the toner is Bt [m ² / g] and the coverage of the toner covered with the external additive is Ct [%], the formula 0.80 ≦ Bt −0.025 × Ct ≦ 1 .20
Toner characterized by satisfying. The toner according to claim 1, wherein the content of the component insoluble in THF is 5% by mass or more and 25% by mass or less. In an environment of 32 ° C. and 40% RH, the load speed is 3.0 × ^10-5 N / sec, and the average value of the amount of deformation due to minute indentation when the load reaches 3.00 × 10 ^-4 N is X. Assuming [μm] and the number average particle size is Dn [μm], the formula X / Dn ≦ 0.14
The toner according to claim 1 or 2 , wherein the toner satisfies. A developer comprising the toner according to any one of claims 1 to 3 . Photoreceptor and
A charging means for charging the photoconductor and
An exposure means that exposes the charged photoconductor to form an electrostatic latent image,
A developing means for forming a toner image by developing an electrostatic latent image formed on the photoconductor using the developing agent according to claim 4 .
A transfer means for transferring the toner image formed on the photoconductor to a recording medium, and
An image forming apparatus comprising a fixing means for fixing a toner image transferred to the recording medium. Photoreceptor and
A process cartridge comprising a developing means for developing an electrostatic latent image formed on the photoconductor using the developing agent according to claim 4 to form a toner image.

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