JPH11174727A - Electrophotographic toner composition and additive used in same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the quantity of electric charges, the environmental stability of electrostatic charge, the admixability and durability of toner, etc., and to obtain a high quality image free from image quality defects due to the internal contamination of a copying machine and the contamination of a photoreceptor with a free additive by incorporating fine additive particles treated with a treating agent contg. an isocyanatosilane compd. and silicone oil. SOLUTION: The electrophotographic toner compsn. contains toner particles contg. at least a colorant and a bonding resin and fine additive particles treated with a treating agent contg. an isocyanatosilane compd. and silicone oil. One or more selected from among modified silicone oil having a reactive group in the molecule, hydrogen silicone oil and fluorine-contg. silicone oil are preferably used as the silicone oil. The viscosity of the silicone oil is preferably 5-15,000 cP at a room temp. It is preferable that the treating agent further contains a releasing agent such as silicone resin or fluororesin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner composition for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, etc. It relates to the manufacturing method.

[0002]

2. Description of the Related Art Conventionally, in electrophotography, as a method for visualizing an electrostatic latent image with toner, for example, a magnetic brush method described in US Pat. No. 2,674,063 is known.
The cascade method described in U.S. Pat. No. 2,616,552 is known, and the dry developer used in these methods is a one-component developing method using a toner itself in which a colorant is dispersed in a binder resin. And a two-component developer in which a carrier is mixed with the toner. Since these developers by themselves do not have sufficient properties such as storability, transportability, developability, transferability, and chargeability, additives are externally added to the toner for the purpose of improving these properties. That is often done. As external additives, for example, hydrophobic silica fine powder (JP-A-56-128956), anatase-type titanium oxide (JP-A-60-112052), and aluminum oxide or titanium oxide fine particles added to silica fine particles (Japanese Patent Application Laid-Open No. 60-238847), and various types of the external additive fine particles having been subjected to a surface treatment, for example, those obtained by subjecting a vapor-phase titanium oxide to a hydrophobic treatment ( JP-A-59-52255), titanium oxide coated with aluminum oxide (JP-A-57-79961) and the like have been proposed. In addition, the surface of the untreated external additive generally has many polar groups such as a hydroxyl group and a carboxyl group,
It is considered that the surface activity of the toner is high, and the state of adsorption of water changes due to temperature and humidity, thereby changing the chargeability of the toner. For this reason, it has been studied to hydrophobize the surface of external additive fine particles such as titanium oxide by treating the surface of the external additive with a silane coupling agent or the like (Japanese Patent Application Laid-Open (JP-A) No)
Nos. 4-40467 and 4-348354).

On the other hand, it has been proposed to treat a toner or an external additive with a liquid lubricant such as silicone oil in order to improve the lubricity, releasability and releasability of the toner surface in order to improve the transferability of the toner. (JP-A-6-202461, 7-
Nos. 152199 and 8-328312). Further, inorganic additives used as external additives, such as those obtained by treating the surface of an external additive with a silane coupling agent such as alkoxysilane or silazane and silicone oil (Japanese Patent Application Laid-Open Nos. 8-15891 and 8-234479). Surface treatment of compounds has already been proposed. However, it is difficult to completely hydrophobize the surface polar group by the hydrophobic treatment of the surface of the external additive with the silane coupling agent. Therefore, it is necessary to ensure sufficient charging performance and to produce a toner with less environmental fluctuation. Not reached. This is because the silane coupling agent has low reactivity with the polar group on the surface of the external additive, and it is difficult to control this. Therefore, the amount of the silane coupling agent required to cover the surface of the external additive is required, and the excess silane coupling agent itself is polymerized and solidified other than on the surface of the external additive to generate a by-product. Furthermore, the excess silane coupling agent causes the external additives to agglomerate each other (free external additives), while an uneven surface coating layer is formed on the surface of the external additives. Further, the hydrophobization treatment using a silane coupling agent requires a high temperature and a long treatment time, and promotes a polymerization reaction of the silane coupling agent itself and aggregation of an external additive. These free external additives cannot be easily crushed by ordinary crushing means, and the non-uniform surface-treated external additives and the aggregated external additives remain.

On the other hand, the treatment of the external additive with the silicone oil merely involves the physical adsorption of the silicone oil on the surface of the external additive, and this silicone oil is transferred to the surface of the photoreceptor and the toner on the photoreceptor is separated. The moldability is improved, and the transferability of the toner is expected to be improved. However, this silicone oil simultaneously transfers to the developing device, the cleaning member, and other toners. If the amount of the silicone oil is excessive, the toner adheres to the members and the toner agglomerates. , Transferability, cleaning performance, and the like. The above problem cannot be solved by treating the silane coupling agent and the silicone oil simultaneously and in this order with an external additive.

In general, fine particles of several nm to several tens of nm are used as the external additive. Most of the fine particles exist as primary particles, but several to several hundreds of aggregates exist. The toner has the same particle size distribution as the toner, and the external additive itself has coarse particles of several μm. When the external additive and the toner are mixed using a mixer,
It is possible to loosen most of these aggregates,
There are agglomerates that remain without being loosened, and there are cases where there is an aggregate having a size larger than the toner particle size. In particular, when the external additive is subjected to a surface treatment with the above-described treating agent, the external additive is present as strong aggregates, which are released without adhering to the toner (free external additive). It is often recognized that these free external additives migrate to the photoconductor together with the toner when the toner is developed on the photoconductor surface, remain on the photoconductor surface even after transfer, and adhere to the photoconductor surface without being cleaned. Can be When these free external additives accumulate on the surface of the photoreceptor, they often cause image quality defects on copying (filming, comet) and scratches on the surface of the photoreceptor. Is causing it to be shorter. In addition, there is a problem that the toner is spilled from the developing machine during development and contaminates the inside of the copying machine. The addition of an additive or the treatment of an external additive as conventionally proposed above has not sufficiently solved the above-mentioned problems caused by a free external additive.

[0006] In recent years, with the demand for higher definition and higher image quality of copiers, attempts have been made to achieve higher image quality and color by further reducing the particle size of the toner. However, as the particle size becomes smaller, the surface area per unit weight increases, the charge amount of the toner increases, and there is a concern that the image density may be reduced and the durability may be deteriorated. Further, since the charge amount of the toner is large, the adhesive force between the toners is strong, the fluidity is reduced, and a problem occurs in toner supply and the like.
Further, in the case of a color toner, since it does not contain a conductive material such as a magnetic substance or carbon black, it is difficult to leak electric charges, and the charge amount is generally large. This remarkably appears when a polyester binder having high charging performance is used. Currently, transparency, color development,
Polyester resins are often used due to their fixability, but toners made of polyester resins are generally susceptible to temperature and humidity, causing problems such as excessive charge at low humidity and insufficient charge at high humidity. There is a demand for development of a color toner having a stable charge amount even in various environments. Further, when a toner having a small particle diameter is used for improving image quality, transferability when transferring from a photoconductor to a transfer material such as paper becomes important. If the transfer performance is not ensured, the image density decreases and the image becomes non-uniform, which causes problems of high definition and high image quality. Further, in the case of full-color toner, since toners of four colors are superimposed, fluctuations in transferability due to environmental fluctuations greatly affect image uniformity. Therefore, it is necessary to improve the transferability in addition to the chargeability and to stabilize the transferability in order to obtain good image quality.

Further, if the transferability is insufficient, the amount of toner (residual toner) remaining on the photoreceptor increases, which not only requires a cleaning process but also increases waste toner, resulting in cost reduction. It leads to up-sizing, system complexity, and upsizing. Further, a cleaning member such as a blade or a brush is used for cleaning. However, there is a problem that not only the residual toner adheres to these members, but also cleaning failure occurs, and the life of the cleaning member is shortened.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its objects the following: the charge amount, the environmental stability of charge; (Characteristics that indicate the rise of charging due to the addition of a suitable toner, the effect of charging on the environmental stability), excellent durability, etc., and no image defects due to free external additives in the copier and photoconductor contamination. An object of the present invention is to provide an electrophotographic toner capable of obtaining a high-quality image. It is a further object of the present invention to provide surface-treated external additive fine particles used as an external additive in the electrophotographic toner and a method for producing the same.

[0009]

An object of the present invention is to provide an electrophotographic toner composition containing at least toner particles containing a colorant and a binder resin and fine particles of external additives, wherein the fine particles of external additives are an isocyanate silane compound and a silicone. The problem is solved by providing an electrophotographic toner composition that is external additive fine particles treated with a treating agent containing oil. As the silicone oil, it is preferable to use at least one of a modified silicone oil having a reactive group in the molecule, a hydrogen silicone oil, and a fluorine-containing silicone oil. It is also possible to use unmodified silicone oil. Examples of the modified silicone oil having a reactive group in the molecule include a modified silicone oil containing one or more groups selected from the group consisting of a hydroxy group, a carboxyl group, an amino group, an epoxy group, an ether group, and a mercapto group in the molecule. One or more are preferred. The viscosity of the silicone oil is preferably 5 to 15,000 cp at room temperature. Further, the present invention provides an electrophotographic toner composition containing a modified silicone oil having a reactive group in a molecule, a hydrogen silicone oil or a fluorine-containing silicone oil in a treating agent and another silicone oil. . Further, the present invention provides an electrophotographic toner composition wherein the treating agent comprises a release agent such as a silicone resin, a fluororesin, a copolymer thereof, a low molecular weight synthetic wax, or a natural wax. Is preferably a curable silicone resin. In the present invention, the external additive fine particles are preferably at least one type of fine particles selected from the group consisting of metal oxides, nitrides, carbides, carbonates, sulfates, and sulfides. The present invention also provides external additive fine particles treated with a treating agent containing an isocyanate silane compound and silicone oil. Further, the present invention provides a method for producing the external additive fine particles, comprising a step of mechanically highly dispersing the external additive fine particles in a solvent and a step of performing a treatment with a treating agent containing an isocyanate silane compound and silicone oil. I will provide a.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The toner composition for electrophotography of the present invention and the method for producing the fine particles of the external additive used therein will be described in detail below. First, the colorant constituting the toner particles of the present invention will be described. As the colorant, a known colorant can be used without any particular limitation. For example, as a black toner, carbon black or the like, and as a color toner, CI Pigment Red 48: 1, CI Pigment Red 122, CI Pigment Red 57: 1, CI Pigment Yellow 97, CI Pigment Yellow 12, CI Pigment Yellow 17 and CI Pigment Blue 15: 3 can be exemplified as typical examples.

Further, as the binder resin constituting the toner particles, known resins can be used without any particular limitation. For example, styrenes such as styrene, vinyl styrene and chlorostyrene; monoolefins such as ethylene, propylene, butylene and isobutylene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate; methyl acrylate; Ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate,
Esters of α-unsaturated aliphatic monocarboxylic acids such as phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate and dodecyl methacrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether; vinyl Examples thereof include vinyl ketones such as methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone; and homopolymers or copolymers obtained by polymerizing one or more diene monomers such as isoprene and 2-chlorobutadiene. . Among these, styrenes, esters of α-unsaturated aliphatic monocarboxylic acids and the like are preferably used. Further, polyester, polyurethane, epoxy resin and the like can be used alone or in a mixed form.

Among the binder resins, it is particularly effective to use polyester. The polyester can be produced by reacting a polyhydroxy compound with a polybasic carboxylic acid or a reactive acid derivative thereof. Examples of the polyvalent hydroxy compound constituting the polyester include, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-
Diols such as propylene glycol and 1,4-butanediol; bisphenol A such as hydrogenated bisphenol A, polyoxyethylenated bisphenol A, and polyoxypropylene bisphenol A; alkylene oxide adducts; other dihydric alcohols and bisphenol A
And the like. As the polybasic carboxylic acid, for example, malonic acid, succinic acid, adipic acid, sebacic acid, alkyl succinic acid, maleic acid,
Fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, cyclohexanedicarboxylic acid, fumaric acid,
Examples include isophthalic acid, terephthalic acid, other divalent carboxylic acids, and reactive acid derivatives such as acid anhydrides, alkyl esters, and acid halides. In addition to these divalent hydroxy compounds and carboxylic acids,
To make the polymer non-linear to the extent that tetrahydrofuran insolubles do not occur, a trivalent or higher polyhydric hydroxy compound and / or a trivalent or higher polybasic carboxylic acid can be added. Among these polyesters, a linear polyester resin comprising a polycondensate containing bisphenol A and an aromatic polycarboxylic acid as main monomer components can be particularly preferably used. Regarding the physical properties of the polyester, the softening point is 90 to 150 ° C, the glass transition point is 50 to 70 ° C, the number average molecular weight is 2,000 to 6,000, the weight average molecular weight is 8,000 to 15,000, and the acid value is
Resins having a hydroxyl value of 5 to 30 and a hydroxyl value of 5 to 40 can be particularly preferably used.

In the present invention, the content of the colorant in the toner particles is preferably in the range of 1 to 8 parts by weight based on 100 parts by weight of the binder resin. When the content of the colorant is less than 1 part by weight, the coloring power is weakened, and when the content is more than 8 parts by weight, the transparency of the toner is deteriorated. If necessary, known additives such as a charge control agent and a fixing aid may be contained in the toner particles. In addition, toner particles having an average particle diameter of about 30 μm or less, preferably in the range of 5 to 20 μm can be used.

In the present invention, a table added as an external additive
Surface treatment external additive fine particles, at least Si, Ti, Al,
Mg, Zn, Sn, In, Mn, Pb, Ni, V, N
b, W, Ba, Fe, Ta, La, Cu, Ce, Ca,
Metal oxides such as Li, K, Na, Mo, Sr, and
And their composite metal oxides or nitrides thereof,
Consists of fine particles of carbides, sulfides, carbonates, sulfates, etc.
It is preferable to include one or more external additives. Oxide or
Specific examples of the composite oxide include SiO 2_Two, TiO_Two,
Al_TwoO_Three, ZnO_Two, MgO_Two, NiO, V_TwoO_Five,
Nb_TwoO_Five, WO _Two, MoO_Two, SnO_Two, BaO, F
e_TwoO_Three, CuO, CaSiO_Three, LaCrO_Three, Al
PO_Four, NbP_ThreeO_Four, LaFeO_Three, LiNbO_Three,
SrTiO _Three, BaTiO_Three, CaTiO_Three, PbTi
O_Three, FeTiO_Three, SrZrO_Three, BaZrO_Three, C
aZrO_Three, PbZrO_Three, MnSiO_Three, MgSiO
_Three, Nb_TwoO_Three-TiO_Two, Ta_TwoO_Five-TiO_Two, V
_TwoO_Five-ZnO_TwoAnd the like. Also, as nitride
Is silicon nitride, titanium nitride, aluminum nitride, and jill nitride
Conium etc. are used as carbides, such as silicon carbide and zirconium carbide.
As sulfides, as MoS, as carbonates
Is BaCO_Three, MgCO_ThreeEtc., but as sulfate, BaS
O_Four, MgSO_FourEtc. can be used. In this
Also preferred external additives are SiO 2_Two, TiO_TwoIn
You. The average particle size of the external additive is preferably 0.1 μm or less.
No. In the present invention, in addition to this, polymethacrylate is used.
Of polytetrafluoroethylene, melamine resin, etc.
Rimmer fine particles can also be used as an external additive.

These external additives may be produced by either a dry method or a wet method. Examples of the dry method include a steam oxidation method, and examples of the wet method include a hydrothermal synthesis method, a sulfuric acid method,
A hydrochloric acid method, an oxalic acid method, or the like is used. The amount of the external additive is preferably 0.01 to 5.0 parts by weight based on 100 parts by weight of the toner. It is more preferably 0.1 to 3 parts by weight or less. When the amount is less than 0.01 part by weight, the toner is easily embedded in the toner, resulting in insufficient charging performance or insufficient fluidity. Five.
When the amount is more than 0 parts by weight, the dispersibility becomes insufficient, so that the toner is easily released from the toner, and the free external additive adheres to the photoconductor, thereby causing image defects and toner scattering.

The external additive fine particles need to be mechanically highly dispersed in a medium before or during the surface treatment. The high dispersion treatment is preferably performed simultaneously with the step of subjecting the fine particles to a surface treatment with a treating agent. That is, in the process of dispersing the external additive and the surface treatment agent in the solvent,
By using a disperser called a medium stirring mill, aggregates of the external additive before the surface treatment can be effectively eliminated. As the solvent, aromatic solvents such as toluene and benzene, aliphatic solvents such as hexane, ethyl alcohol, butyl alcohol, alcohol solvents such as ethylene glycol, ethyl acetate, ester solvents such as butyl acetate, Organic solvents such as ketone solvents such as acetone, MEK and MIBK are used. In addition, as a medium stirring mill,
Ultra Visco Mill (made by Imex), Pure Mill
(Made by Asada Iron Works). By performing this high dispersion treatment, when the surface-treated product is crushed by a pin mill, aggregates can be significantly reduced. If the above-described high dispersion treatment is not performed, aggregates will be present in the external additive before the surface treatment, and as a result, the surface of the aggregates will be covered with the treatment agent and become strong aggregates. After the treatment, it is difficult to disintegrate the primary particles in the crushing, particularly when the treatment amount is large. In order to loosen these aggregates, there is a method of increasing the number of pin mills, but it is difficult to loosen the secondary or tertiary aggregates to the primary particles.

Next, the treating agent used for treating the external additive fine particles of the present invention will be described. The treatment agent according to the present invention is characterized by containing at least an isocyanate silane compound and silicone oil. The isocyanate silane compound found by the present inventors is generally higher in reactivity than a silane coupling agent such as an alkoxylane, and it alone reacts with a hydroxyl group or a carboxyl group present on the surface of the external additive fine particles to form a glass. To produce a similar silicon compound coating. When the external additive fine particles are treated with the treating agent containing the isocyanate silane compound and the silicone oil, a solid film is formed on the surface of the external additive fine particles. In the present invention, the composite solid film obtained from the isocyanate silane compound and the silicone oil immobilized on the surface of the external additive not only makes the surface of the external additive fine particles hydrophobic, but also simultaneously forms a solid lubricating release film. And has both lubricity and releasability to improve the transferability and cleaning properties of the toner. This solid lubricating release coating has a high affinity for silicone oil used as a liquid lubricant due to its chemical structure, and can be expected to have high silicone oil holding performance.

When a modified silicone oil having a reactive group in a molecule, a hydrogen silicone oil or a fluorine-containing silicone oil is used as the silicone oil in the treating agent of the present invention, the isocyanate silane compound has high reactivity as described above. Active hydrogen such as a hydroxyl group present on the surface of an external additive and a hydroxyl group, an alkoxy group, a carboxyl group, an amino group, an epoxy group, an acryloyl group, a methacryloyl group, or a mercapto group present in a modified silicone oil, or a hydrogen silicone oil. And can easily react with an active group such as a hydrogen atom or a fluorine atom in a fluorine-containing silicone oil even at room temperature, and quickly forms a solid lubricating release film. As a result, the surface of the external additive can be completely hydrophobized only by an amount necessary for coating the surface of the external additive. In the present invention, when a modified silicone oil, a hydrogen silicone oil, or a fluorine-containing silicone oil containing a reactive group in the molecule is used, the surface of the external additive as a solid lubricating release coating is further added. Has the advantage that the releasability, lubricity, and aggregation between external additives can be prevented, and the crushability (easy dispersibility) is improved. The modified silicone oil, hydrogen silicone oil, or fluorine-containing silicone oil may be partially unreacted. In such a case, these silicone oils are contained in the film in a free state. Therefore, it is considered that the silicone oil acts as a liquid lubricant and improves properties such as lubricity, releasability, releasability, and transferability (transfer to a photoreceptor) of the toner. Also, when using a silicone oil which does not have an active group as described above in the molecule, the silicone oil which is not incorporated in the solid coating may be released similarly. Will act as a liquid lubricant. In the present invention, a silicone oil having a high activity as described above and another unmodified silicone oil can be used in combination as the silicone oil.

The isocyanate silane compound of the present invention comprises
(R) _x Si (NCO) _y , wherein R represents an alkyl group having 1 to 20 carbon atoms, an aryl group, or a perfluoroalkyl group (including an alkyl group having a perfluoroalkyl group), and x Represents an integer of 0 to 3, and y represents 1 to 4
Indicates an integer. Further, as shown in the following specific example, -S
An isocyanate silane compound having a structure in which an i (NCO) _y group is linked by a divalent group can also be used. Specific isocyanate silane compounds include (CH ₃ ) ₃ SiNCO, (C
_{H 3) 2 Si (NCO)} 2, CH 3 Si (NCO) 3, vinyl _{triisocyanate, C 6 H 5 Si (NCO} ) 3, Si (NCO) 4, C 2 H 5 OSi (NCO) 3,
C ₈ H ₁₇ Si (NCO) ₃ , C ₁₈ H ₃₇ Si (NCO) ₃ , (NCO) ₃ SiC ₂ H ₄ Si (NC
_{O) 3, C 9 F 19} C 2 H 4 Si (NCO) 3, (NCO) 3 SiC 2 H 4 C 6 F 12 C 2 H 4 Si (N
CO) ₃ , etc. Among them, those having three or more isocyanate groups are particularly preferable. The isocyanate silane compound alone functions as a surface treatment material for an external additive, but is more preferably used in combination with a silicone oil. The isocyanate silane compound is used in an amount of 0.1 to 80% by weight, preferably
~ 30% by weight is added. If the amount is less than 0.1% by weight, it becomes difficult to achieve a desired treatment purpose. If the amount exceeds 80% by weight, by-products are easily generated due to a reaction between the surface treatment materials.

In addition, simultaneously with the isocyanate silane compound,
In addition, other silane compounds may be added. Silane compounds
For example, CF_Three(CH_Two)_TwoSi (OCH_Three)_Three, C₆F₁₃C_TwoH_FourSiC
l_Three, C₆F₁₃C_TwoH_FourSi (OCH_Three)_Three, C₇F_FifteenCONH (CH_Two)_ThreeSi (OC
_TwoH_Five)_Three, C₈F₁₇C_TwoH_FourSiCl_Three, C₈F₁₇C_TwoH _FourSi (OCH_Three)_Three, C₈F₁₇C
_TwoH_FourSiCH_ThreeCl_Two, C₈F₁₇C_TwoH_FourSiCH_Three(OCH_Three)_Two, C₈F₁₇C_TwoH_FourSi
(ON = C (CH_Three) (C_TwoH_Five))_Three, C₉F₁₉C_TwoH_FourSi (OCH_Three)_Three, C₉F₁₉C_TwoH_Four
Si (C_TwoH_Five) (OCH_Three)_Two, (CH_ThreeO)_ThreeSiC _TwoH_FourC₈F₁₆C_TwoH_FourSi (OC
H_Three)_Three, (CH_ThreeO)_Two(CH_Three) SiC₉F₁₈C_TwoH_FourSi (CH_Three) (CH_ThreeO)_Two,
Which fluorine-containing silane compounds and the addition of these compounds
Examples include hydrolysates and partial condensates.
More than 3 functional groups such as alkoxy groups and halogens
Those included above are preferred. Also, alkoxy sila
Si (OCH _Three)_Four, CH_ThreeSi (OCH_Three)_Three, (CH_Three)_TwoSi
(OCH_Three)_Two, C₆H_FiveSi (OCH_Three)_Three, Si (OC_TwoH_Five)_Four, CH_ThreeSi (OC_TwoH_Five)
_Three, (CH_Three)_TwoSi (OC_TwoH_Five)_Two, C₆H_FiveSi (OC_TwoH_Five)_Three, (CH_Three)_TwoCHCH_TwoS
i (OCH_Three)_Three, CH_Three(CH _Two)_FiveSi (OCH_Three)_Three, CH_Three(CH_Two)₇Si (OC
_TwoH_Five)_Three, CH_Three(CH_Two)₁₁Si (OC_TwoH_Five)_Three, CH_Three(CH_Two)_FifteenSi (OC
_TwoH_Five)_Three, CH_Three(CH_Two)₁₇Si (OC_TwoH_Five)_Three, Etc., and
As a silane compound having some SiH groups, HSi (OCH_Three)_Three, CH
_ThreeSiH (OCH_Three)_Two, H_TwoSi (OC_TwoH_Five)_Two, Such as silane compounds
Can be Furthermore, there are hydrolysates of these silane compounds.
Or a partial condensate. Among them, especially sensuality
Those having three or more functional groups are preferred.

As silane coupling agents, vinyl silanes such as vinyl tris (β-methoxyethoxy) silane, vinyl triethoxy silane, vinyl trimethoxy silane, acrylic silanes such as γ-methacryloxypropyl trimethoxy silane, β- (3 Epoxysilanes such as, 4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane ,
N-β (aminoethyl) γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane,
Examples include aminosilanes such as N-phenyl-γ-aminopropyltrimethoxysilane. In particular, the functional group
Those containing three or more functional groups are preferred. As other silane coupling agents, HSC ₃ H ₆ Si (OCH) ₃ , ClC ₃ H ₆ Si (O
Examples thereof include hydrolysates or partial condensates of silane compounds such as CH) ₃ . The silane compound is not limited to one kind of compound alone, and it is desirable to use a mixture of a plurality of compounds or a partial hydrolyzate thereof. The silane compound or the silane coupling agent is added in an amount of 0.1 to 50% by weight based on the treatment liquid.

As the silicone oil, a modified polysiloxane having a reactive group in the molecule, that is, a hydroxyl group (including a —SiOH, —CH ₂ —OH group, a phenolic hydroxyl group), an alkoxy group, a carboxyl group, Silicone oils having an amino group, an epoxy group, an acryloyl group, a methacryloyl group, a mercapto group, etc., hydrogen silicone oils such as methyl hydrogen silicone oils, fluorine-containing silicone oils, etc. are preferably used. Unmodified diorganopolysiloxanes having no groups can also be used as the silicone oil of the present invention. Specific examples of the unmodified diorganopolysiloxane oil include an alkyl group and an aryl group in a siloxane bond such as dimethyl silicone oil, diethyl silicone oil, methyl ethyl silicone oil, methyl phenyl silicone oil, and diphenyl silicone oil. Also,
It is also possible to use a modified silicone oil, a hydrogen silicone oil or a fluorine-containing silicone oil having a reactive group in the molecule together with an unmodified silicone oil. Further, a hetero-reactive group-modified silicone oil containing different reactive groups such as an amino group and an alkoxy group in one molecule is also preferable. Further, two or more of such silicone oils can be used in combination. These silicone oil addition ratios can be set arbitrarily according to the purpose. Generally, the addition ratio is preferably such that the amount of the silicone oil present in the isocyanate silane compound is 1 to 80% by weight. If the amount of silicone oil is too small, the effect as a surface treatment material is low.If the amount is too large, the amount of transfer to the photoconductor and other members increases, causing toner sticking and toner aggregation, causing toner fluidity and transport. This has an adverse effect on the properties, charging properties, transfer properties, cleaning properties, and the like. An unmodified silicone oil may be added simultaneously with the modified silicone oil. The viscosity of the silicone oil must be determined in consideration of the combination with the silane compound, and is 5 to 15000 cp.
Are preferred.

In addition to the above, the liquid composition for forming the surface treatment liquid of the external additive may contain an additive which does not impair its function, for example, an aluminum compound, a titanium compound, a zirconium compound, and a fluorine compound. Aluminum compounds, titanium compounds, and specific examples of zirconium compounds, aluminum isopropoxide,
Aluminum sec-butylate, Aluminum tert-butylate, Tetra iso-propyl titanate, Tetra n-butyl titanate, Tetra iso-butyl titanate, Tetra se
c-butyl titanate, tetra tert-butyl titanate,
Tetra n-pentyl titanate, tetra iso-pentyl titanate, tetra n-hexyl titanate, tetra n-heptyl titanate, tetra n-octyl titanate, tetra is
o-octyl titanate, tetra n-nonyl titanate, tetramethyl zirconate, tetraethyl zirconate,
Tetra iso-propyl zirconate, tetra n-propyl zirconate, tetra n-butyl zirconate, tetra iso-
Butyl zirconate, tetra tert-butyl zirconate, mono-sec-butoxyaluminum diisopropylate, ethyl acetoacetate aluminum diisopropylate, di-n-butoxyaluminum monoethylacetoacetate, aluminum di-n-butoxide methyl acetoacetate, aluminum Diisobutoxide monomethylacetoacetate, aluminum disec-butoxide monoethylacetoacetate, aluminum diiso-propoxide monoethylacetoacetate, aluminum trisacetylacetonate, aluminum diiso-propoxide monoacetylacetonate, aluminum Monoacetylacetonate bis (ethylacetoacetate), aluminum tris (ethylacetoacetate)
, Cyclic aluminum oxide acylate compound, di-
iso-propoxytitanium-bis (acetylacetonate)
, Di-n-butoxytitanium-bis (acetylacetonate)
, Tetraoctylene glycol titanate, tetrakisacetylacetone zirconate, and the like.

Examples of the fluorine compound include fluoroolefin resins, and specific examples thereof include polytetrafluoroethylene resin, polychlorotrifluoroethylene resin, polyhexafluoropropylene resin, and polyperfluoropropylvinyl ether resin. For example, these may be used in combination of two or more. Also,
The fluorine compound is a perfluoropolyether represented by X-CF ₂ (OC ₂ F ₄ ) p (OCH ₂ ) qOCF ₂ -X, and specifically, X is OC
NC ₆ H ₃ (CH ₃ ) NHCO- isocyanate-modified product, -C
Modified carboxyl group represented by OOH, -CH ₂ OH, -CF ₂ -C
Alcohol-modified product represented by H ₂ ((OCH ₂ CH ₂ ) _n ) OH or the like, -C
Examples include ester-modified products represented by OOR. The above-mentioned aluminum compound, titanium compound, zirconium compound, or fluorine compound is added to the external additive treatment solution by 3%.
It is preferable to add it in the range of 0% by weight or less.

In the present invention, a silicone resin, a fluorine resin, a copolymer thereof, an acrylic resin, a methacrylic resin, a vinyl resin, a polyester resin, a polyimide resin, an epoxy resin, etc. And at least one release agent such as a natural wax such as a low molecular weight synthetic wax such as a copolymer of polyethylene, polypropylene and the like, a carnauba wax, a bee wax, a montan wax, a paraffin wax and a microcrystalline wax. The addition amount of the release agent is preferably 0.1 to 30% by weight based on the external additive treatment liquid. If the release agent is low,
The effect of the release agent is not exhibited. On the other hand, if it exceeds 30% by weight, the reaction between the isocyanate silane compound and the silicone oil and the external additive is inhibited. By using a curable silicone resin as the silicone resin, not only the releasability can be improved, but also a strong reaction film can be formed on the surface of the external additive. Curable silicone resins synthesize polysiloxanes by condensing silanols obtained by hydrolyzing trifunctional or higher-functional chlorosilanes or mixtures of these with mono- or difunctional chlorosilanes, and use as catalysts organic metal salts or amines as catalysts. The compound can be synthesized by further promoting a condensation reaction (curing reaction) using, for example,

The curing reaction is a condensation type in which polydimethylsiloxane containing a silanol group at a terminal is used as a base polymer, polymethylhydrogensiloxane is blended as a crosslinking agent, and condensation is carried out by heating in the presence of an organotin catalyst. Addition type that cures in the presence of a platinum catalyst by blending polymethylhydrogensiloxane as a crosslinking agent with polydimethylsiloxane containing group as base polymer, curing type based on radical curing mechanism, photocationic curing There is a UV curing type that cures based on a mechanism. Curable silicone resins are classified into solvent type and solventless type in terms of coating form, and can be further classified into addition type, condensation type, UV type and the like depending on the type of reaction. The condensation type is morphologically divided into a solution type and an emulsion type,
The addition type is formally classified into a solvent type, an emulsion type, and a useless type. As the UV curing type, those using a photocationic catalyst and those using a radical curing mechanism are known. The UV-curing type is based on solventless coating, but for controlling the film thickness, it can be diluted with a solvent, coated, dried and irradiated with UV. The curable silicone resin used in the present invention is a silicone resin that is cured by energy rays such as humidity, heat, light, and an electron beam.

Next, in the present invention, a method for treating an external additive using the above-described treating agent containing a component containing an isocyanate silane compound, silicone oil and other components will be described. The surface-treated external additive fine particles of the present invention are, first, a step of mechanically highly dispersing the external additive fine particles in a medium, a step of subjecting the fine particles to a surface treatment with an external additive treating agent, and the obtained treated fine particles. Can be produced by the step of crushing. In addition, high dispersion treatment can be performed at the time of surface treatment, which is a preferable treatment method from the viewpoint of uniformizing external additive treatment. The high dispersion treatment of the external additive fine particles is as described above. The surface treatment does not react at least an isocyanate silane compound and an external additive treatment component containing a silicone oil with these components, i.e., active hydrogen such as hydroxyl group, thiol group, carboxyl group, amide group, amino group, imino group, etc. This is carried out by dissolving in a solvent not containing, and stirring the external additive fine particles in the treatment solution. Specific solvents include aromatic solvents such as toluene and benzene, aliphatic solvents such as hexane, ester solvents such as ethyl acetate and butyl acetate, ketone solvents such as acetone, MEK and MIBK,
Organic solvents such as halogen-based solvents such as monochlorobenzene and tetrachloroethylene are used. However,
A small amount of an alcohol solvent such as isopropyl alcohol may be added as long as the decomposition reaction of the isocyanate silane compound is not promoted. It is preferable that the isocyanate silane compound is added to the above-mentioned solvent so as to have a concentration of 1 to 30% by weight. It is preferable that the silicone oil is added so as to have a concentration of 1 to 30% by weight. Further, it is preferable that the treatment solution is used at a ratio of 5 to 30% by weight based on the external additive fine particles. The external additive treated with the isocyanate compound and the silicone oil of the present invention is a solid lubricating release film having a surface having a hydrophobic property and at the same time a releasability, lubricity, etc. And can be easily crushed into fine powder. However, when agglomeration of the external additive is observed, a general crushing means can be used. Specifically, a pin mill, a hammer mill, or the like is used.

In the present invention, a silicone resin, a fluorine resin, a vinyl resin, an acrylic resin, a methacrylic resin, a styrene resin, a urethane resin, an epoxy resin, an arylate resin, an imide resin, At least one kind of fine particles of amide resin, polysulfone resin, polyether resin, polyester resin, or a copolymer thereof, having a particle size of about 0.1 to 30 μm, for improving cleaning property, durability, fluidity, etc. May be added. Further, in the present invention,
Polyethylene, polypropylene, carnauba wax, amide wax, and the like are blended as a release agent as required to prevent offset.

The toner composition of the present invention can be used for either a one-component developer or a two-component developer. When used as a one-component developer, magnetic particles are further contained in the toner particles. As a magnetic material, metal powders such as iron, manganese, nickel, and cobalt and iron,
Ferrites such as manganese, nickel, cobalt, and zinc are available. Particularly preferred are oxide magnetic materials, and iron-based ferrite and magnetite are preferred. The average particle size of the magnetic powder is 1 μm or less, particularly preferably 0.6 μm or less.
When used as a two-component developer, a carrier is used. Examples of the carrier include magnetic carrier particles such as iron, ferrite, and magnetite, and a polymer carrier obtained by mixing a magnetic powder with a polymer.

[0030]

EXAMPLES <Toner Production Example 1 (Toner 1)> 100 parts of a polyester resin (condensation product of terephthalic acid with bisphenol A ethylene oxide adduct, Mn = 3000, Mw = 9000) and magenta coloring material (CI pigment Red 57: 1) 4 parts melted
The mixture was kneaded, pulverized, and classified to obtain a toner having an average particle size of 8 μm. <Production example of binder resin for toner> 100 parts of xylene, 100 parts of styrene monomer, 61.8 parts of n-butyl acrylate monomer
3.25 parts of di-t-butyl peroxide was placed in a 3 liter reaction tank and heated to 160 ° C. to perform solution polymerization to obtain a xylene solution of a low molecular weight styrene-acryl copolymer.
The weight average molecular weight of this copolymer was 5,500. To a xylene solution of the obtained copolymer, 350 parts of a styrene-n-butyl acrylate copolymer (composition ratio: 75/25) separately synthesized by suspension polymerization and having a weight average molecular weight of 800,000 was added and dissolved. Thereafter, xylene was removed at about 210 ° C. to obtain a resin composition for toner.

<Production Example 1 of External Additive> 10 parts of tetraisocyanate silane, amino-modified silicone oil (TSF4702:
10 parts of Toshiba Silicone Co., Ltd.) were stirred and mixed with 200 parts of ethyl acetate to obtain an external additive treatment liquid. Rutile-type titanium oxide with an average particle size of 15 nm (M
To 100 parts of T-150A (manufactured by Teica Co., Ltd.), 100 parts of the external additive treatment liquid was added, stirred for 10 minutes, filtered, dried with hot air at 100 ° C. for 10 minutes, and then pulverized once with a pin mill. The surface-treated titanium oxide fine particles were obtained. As a result of observing this surface-treated external additive with a scanning electron microscope (SEM), no aggregation of the external additive was observed. <Production example 2 of external additive> Methylsilyl triisocyanate
10 parts of silanol-modified silicone oil (YF3800: manufactured by Toshiba Silicone Co., Ltd.) and 10 parts were mixed with 300 parts of ethyl acetate to obtain an external additive treatment liquid. Silica fine particles were subjected to surface treatment in the same manner as in Production Example 1 of the external additive, except that 100 parts of the above-mentioned external additive treatment liquid was used for 100 parts of colloidal silica (R972, manufactured by Nippon Aerosil Co., Ltd.). As a result of observing this surface-treated external additive with a scanning electron microscope (SEM), no aggregation of the external additive was observed.

<Production Example 3 of External Additive> Barium titanate fine particles were surface-treated in the same manner as in Production Example 1 of the external additive except that barium titanate having an average particle diameter of 20 nm was used as the external additive. . Using this surface-treated external additive with a scanning electron microscope (SEM)
As a result, no aggregation of the external additive was observed. <Production Example 4 of External Additive> 20 parts of dimethyl silicone oil was treated with 300 parts of ethyl acetate using the external additive treatment liquid of Production Example 1 of the external additive.
In the same manner as in Production Example 1 of the external additive, except that the treating solution dissolved in the part was replaced, fine silica particles surface-treated with dimethyl silicone oil were obtained. As a result of observing the surface-treated external additive with a scanning electron microscope (SEM), aggregates of the external additive having an average particle size exceeding 10 μm were observed.

<Production Example 5 of External Additive> The same as Production Example 1 of the external additive except that the external additive treatment liquid of the external additive production example 1 was changed to 20 parts of γ-aminopropyltriethoxysilane. In this manner, rutile-type titanium oxide fine particles subjected to a surface treatment were obtained. As a result of observing this surface treatment external additive with a scanning electron microscope (SEM),
External additive aggregates having an average particle size of about 5 to 10 μm were observed. <External additive production example 6> Rutile-type titanium oxide fine particles surface-treated in the same manner as the external additive production example 1 except that the amino-modified silicone oil of the external additive production example 1 was replaced with dimethyl silicone oil. I got As a result of observing this surface-treated external additive with a scanning electron microscope (SEM), no aggregation of the external additive was observed. <Production Example 7 of External Additive> A rutile-type titanium oxide surface-treated in the same manner as in Production Example 1 of the external additive, except that the amino-modified silicone oil of the production example 1 of the external additive was replaced with hydrogen silicone oil. Fine particles were obtained. As a result of observing this surface-treated external additive with a scanning electron microscope (SEM), no aggregation of the external additive was observed.

Examples 1 to 3 and Comparative Examples 1 to 2 100 parts of toner particles (toner 1) were mixed with Production Examples 1 to 5 of external additives.
Was added and mixed with a Henschel mixer to obtain a toner composition. Iron powder coated with a fluorine-containing acrylic resin and having an average particle diameter of 50 μm was used as a carrier, and the toner composition was mixed to a toner concentration of 4% by weight to prepare a developer. Using these developers,
The image quality was evaluated at room temperature using a copier (A-Color935, manufactured by Fuji Xerox Co., Ltd.), and at 10 ° C / 15% RH and 28 ° C / 85% RH.
A 5,000 copy test was performed. The results are summarized in Table 1.

Example 4 An external additive treatment liquid prepared in Example 1 of the external additive was further added to a thermosetting silicone resin (TOSHIBA Silicone: Tosguard 510).
A rutile-type titanium oxide surface-treated in the same manner as in Production Example 1 of the external additive was obtained except that parts were added. Other than using this,
A developer was prepared in the same manner as in Example 1. Using these developers, image quality evaluation and copy test were performed in the same manner as in Example 1. The results are summarized in Table 1. In addition, while the new toner composition was charged into the developing device as needed, the image quality was evaluated, the charging stability at 10 ° C / 15% RH, the charging stability under 28 ° C / 85% RH, and the rise of charging were evaluated. The same performance as the stirred toner was exhibited, and the admix property was also good.

Example 5 A developer was prepared in the same manner as in Example 1 except that 1.5 parts of polyvinylidene fluoride fine particles were added together with the external additive for surface treatment. Using these developers, image quality evaluation and copy test were performed in the same manner as in Example 1. The results are summarized in Table 1.

Example 6, Comparative Example 3 48 parts of toner resin and 50 parts of amorphous magnetic material (saturation magnetization 80 emu / g, residual magnetization 10 emu / g) of Production Example 1 of toner resin Preparation agent (Spiron Black TRH) And 2 parts of a mixture (manufactured by Hodogaya Chemical Co., Ltd.) using an extruder, followed by pulverization and classification to obtain a toner composition (toner 2) having an average particle diameter of 9 μm and a residual magnetization of 3.8 emu / g. Production example of 100 parts of the above toner composition and external additives
One part of the surface-treated external additive obtained in 2 and 5 was stirred and mixed in a Henschel mixer to obtain a toner. Using a printer (4197; manufactured by Fuji Xerox Co., Ltd.), the obtained toner was subjected to image quality evaluation at room temperature and a copy test of 20,000 sheets at 10 ° C./15% RH and 28 ° C./85% RH.

Examples 7 and 8 Toner particles (produced in Production Example 1 of toner)
100 parts of the surface-treated external additive of Production Examples 6 and 7 of the external additive 1.5
Was added and mixed with a Henschel mixer to obtain a toner composition. Iron powder coated with a fluorine-containing acrylic resin and having an average particle diameter of 50 μm was used as a carrier, and the toner composition was mixed to a toner concentration of 4% by weight to obtain a developer. Using these developers, a copier (A-Color935, manufactured by Fuji Xerox Co., Ltd.) evaluated the image quality at room temperature,
A copy test was performed on 5000 sheets at 10 ° C./15% RH and 28 ° C./85% RH. The results are summarized in Table 1. Also,
While charging a new toner composition into the developing device as needed, its image quality evaluation, charge stability at 10 ° C / 15% RH, 28 ° C / 85% RH,
When the rise of charge was evaluated, the same performance as that of the toner sufficiently stirred in advance was exhibited, and the admix property was also good.

Table 1

[Table 1]

[0040]

According to the present invention, there is provided an electrophotographic toner composition comprising toner particles containing a colorant and a binder resin and an external additive, wherein the external additive is an isocyanate silane compound. The surface of the external additive is coated with an isocyanate silane compound and a silicone oil, whereby not only the surface of the external additive is sufficiently hydrophobicized, but also the surface of the external additive is coated with the silicone oil. Due to the properties such as lubricity, releasability, and releasability of the toner, the toner to which these external additives are added becomes a toner excellent in its storability, transportability, developability, transferability, chargeability, and the like. . Further, the surface-treated external additive of the present invention has excellent crushability, hardly any free external additive, and image quality defects on copying due to accumulation of these on the photoreceptor surface (filming, Comet) and scratches on the photoreceptor surface can be prevented. Further, it is possible to avoid the problem of spilling from the developing machine during development and contaminating the inside of the copying machine. Also, due to the demand for high definition and high image quality, stable charging performance and transfer performance can be obtained even if the particle size of the toner is made finer, and the transparency, color development, and fixing properties required for color toners are improved. The obtained high quality color toner can be obtained.
Further, the surface treatment method of the external additive of the present invention can treat the surface of the external additive in a short time with a simple device, and greatly contributes to shortening the toner production process and reducing the cost.

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Claims (16)

[Claims] 1. An electrophotographic toner composition comprising at least toner particles containing a colorant and a binder resin and fine particles of external additives, wherein the fine particles of external additives are treated with a treating agent containing an isocyanate silane compound and silicone oil. An electrophotographic toner composition comprising fine particles of external additives. 2. The electrophotographic toner according to claim 1, wherein the silicone oil contains at least one of a modified silicone oil having a reactive group in a molecule, a hydrogen silicone oil and a fluorine-containing silicone oil. Composition. 3. A modified silicone oil having a reactive group in a molecule, wherein a hydroxy group, an alkoxy group, a carboxyl group, an amino group, an epoxy group, an acryloyl group,
The electrophotographic toner composition according to claim 2, wherein the composition is at least one modified silicone oil containing at least one group selected from the group consisting of a methacryloyl group and a mercapto group. 4. The silicone oil has a viscosity of 5 to 1 at room temperature.
2. The electrophotographic toner composition according to claim 1, wherein the composition is 5000 cp. 5. The treatment agent contains a modified silicone oil having a reactive group in the molecule, a hydrogen silicone oil or a fluorine-containing silicone oil, and another silicone oil. 2. The electrophotographic toner composition according to item 1. 6. The electrophotographic toner composition according to claim 1, wherein the treating agent further contains a release agent. 7. The release agent is a silicone resin, a fluororesin,
The electrophotographic toner composition according to claim 6, wherein the composition is at least one member selected from the group consisting of a copolymer, a low-molecular-weight synthetic wax, and a natural wax. 8. The electrophotographic toner composition according to claim 7, wherein the silicone resin is a curable silicone resin. 9. The method according to claim 1, wherein the external additive fine particles are at least one type of fine particles selected from the group consisting of metal oxides, nitrides, carbides, carbonates, sulfates, and sulfides. The toner composition for electrophotography according to the above. 10. The binder resin is a polyester resin or at least one selected from the group consisting of styrene monomers, acrylic monomers, methacrylic monomers, vinyl ester monomers, vinyl ether monomers, vinyl ketone monomers, olefin monomers, and diene monomers. The electrophotographic toner composition according to claim 1, which is a resin comprising a copolymer of the following monomers. 11. The electrophotographic toner composition according to claim 1, wherein a magnetic material is contained in the toner particles. 12. The electrophotographic toner composition according to claim 1, wherein the toner composition further contains fine resin particles. 13. An electrostatic image developer containing a toner composition and a carrier, wherein the toner composition is a toner.
2. An electrostatic image developer, which is the toner composition according to any one of 1. 14. The electrostatic image developer according to claim 13, wherein the carrier has a resin coating layer. 15. An external additive fine particle used in an electrophotographic toner composition, wherein the external additive fine particle is an external additive treated with a treating agent containing an isocyanate silane compound and silicone oil. External additive fine particles for an electrophotographic toner composition. 16. The electrophotographic toner according to claim 15, comprising a step of mechanically highly dispersing the external additive fine particles in a solvent, and a step of performing a treatment with a treating agent containing an isocyanate silane compound and silicone oil. A method for producing external additive fine particles for a composition.