JPH05119536A - Developer - Google Patents

Abstract

PURPOSE:To obtain a proper toner charge level and stability and to prevent splashing by using a toner containing a polyolefin resin coated carrier and calixarene compd. as a charge controlling agent. CONSTITUTION:The developer consists of a toner containing compd. as a charge controlling agent, and a carrier coated with polyolefin resin. Namely, this developer is a two-component developer comprising the toner and the carrier. The toner consists of calixarene compd. as at least a charge controlling agent. In this case, by using calixarene compd. as the negative charge controlling agent, proper charge level is obtd., stable electrification is maintained, and splashing of the toner, etc., is prevented even when the toner is used with carrier coated with polyolefin resin. Thereby, with combination of the polyolefin-coated resin carrier, such a developer can be obtd. that consists of the toner containing the charge controlling agent which can give proper, uniform, and stable negative charge level.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a two-component developer. More specifically, it relates to a developer comprising a polyolefin resin coated carrier and a toner containing a calixarene compound as a negative charge control agent.

[0002]

2. Description of the Related Art Conventionally, as an electrostatic latent image developing method for electrophotography, by mixing an insulating non-magnetic toner and carrier particles, the toner is triboelectrically charged, and a developer is conveyed to cause electrostatic latent image development. A two-component developing method is known in which the image is contacted with an image and developed. The granular carrier used in such a two-component developing method is used to prevent toner filming on the carrier surface, formation of a uniform carrier surface, prevention of surface oxidation, prevention of moisture sensitivity deterioration, extension of developer life, and exposure to light. It is usually coated with an appropriate material for the purpose of protection from scratches or abrasion by body carrier, control of charge polarity or adjustment of charge amount. As such a coating material, a carrier to which a polyolefin resin is applied is known. This resin has excellent environmental stability,
Further, since it can be coated with a relatively thin film, it is excellent in that the characteristics of the carrier core material itself can be utilized.

Generally, a toner, which is another element of the two-component type developer, is added with a charge control agent in order to adjust the charge level and ensure the charge stability, and the charge control agent is used for the toner. To be done. However, the polyolefin resin is
Uniform coatings are difficult and therefore difficult to stably charge the toner to a uniform charge level. Further, since the polyolefin resin itself has a strong negative charging property, it is difficult to negatively charge the toner by abrasion charging using the polyolefin resin coated carrier. There is also a problem that the rise of charging is slow. In addition to these problems, problems such as toner scattering occur.

As described above, the charging characteristics of the toner are greatly influenced by the combination with the carrier, and therefore it is necessary to examine the individual charging characteristics. For example, a technique of incorporating a titanium metal complex compound into a negatively chargeable toner used in combination with an iron powder carrier is disclosed in Japanese Patent Laid-Open Publication No.
It is described in JP-A-3-38960.

[0005]

The present invention has been made in view of the above circumstances, and contains a charge control agent capable of imparting a moderately and uniformly stable negative charge level in combination with a polyolefin resin-coated carrier. It is an object to provide a developer composed of toner. further,
It is an object of the present invention to provide a developer that is excellent in charging rise and does not cause toner scattering.

[0006]

The present invention relates to a negatively charged developer comprising a toner containing a calixarene compound as a charge control agent, and a polyolefin resin-coated carrier.

The developer of the present invention is a two-component developer comprising a toner and a carrier, and the toner comprises at least a calixarene compound as a negative charge control agent.

According to the present invention, by using a calixarene compound as a negative charge control agent, even when it is used in combination with a polyolefin resin-coated carrier described later, it is charged to an appropriate charge level and has stable chargeability. It is ensured and the prevention of toner scattering is achieved.

The calixarene compound contained in the toner of the present invention is represented by the following general formula [I];

[Chemical 1] It is represented by.

In the general formula [I], R is a hydrogen atom, C ₁ -C
_{12 represents} an alkyl group or an unsaturated alkyl group, a carboxyalkyl group such as carboxymethyl group or a salt thereof, an acyl group such as acetyl group, or an aromatic hydrocarbon group such as phenyl group; R ₁ , R ₂ and R ₃ Are each independently a hydrogen atom, a halogen atom such as a fluorine atom or a chlorine atom, a C _{1 to} C ₁₈ alkyl group, an alkoxy group such as a methoxy group, an aromatic hydrocarbon group such as an aryl group, a hydroxyl group, a carboxyl group. Selected from the group consisting of acyl groups such as an amino group optionally substituted with an alkyl group and / or an acyl group, a nitro group, a sulfone group, a sulfamido group, a carbamoyl group, a cyano group, a lower alkylcarboxylic acid ester, and an acetyl group. To be done. n is 4 to 1
Represents an integer of 0. ]

The calixarene compound of the present invention can be obtained, for example, from CD Gutsche (Accounts of Chemical Research, 1983).
(16) From page 161 to page 170), the following reaction formula:

[Chemical 2] Can be easily synthesized by reacting the phenol derivative represented by the general formula [II] with formaldehyde directly or in the presence of an inorganic strong alkaline catalyst using a suitable solvent. .. The calixarene compound represented by the general formula [III] represents a compound in which R is a hydrogen atom in the general formula [I].
II] can be obtained by carrying out a substitution reaction using an alkylating agent, a phenylating agent, a halogenated alkylcarboxylic acid or the like.

Specific examples of the calixarene compound represented by the general formula [I] obtained as described above are shown below, but the present invention is not limited to these compounds.

[0013]

[Chemical 3]

[0014]

[Chemical 4]

[0015]

[Chemical 5]

[0016]

[Chemical 6]

[0017]

[Chemical 7]

[0018]

[Chemical 8]

[0019]

[Chemical 9]

[0020]

[Chemical 10]

[0021]

[Chemical 11]

[0022]

[Chemical 12]

The toner of the present invention is a toner prepared by any known method, such as a suspension polymerization method, a pulverization method, a micro toner, as long as it has a mean particle size of 3 to 20 μm and is used in a two-component developing system. Capsule method, spray dry method,
A toner prepared by a mechanochemical method or the like can be used, and at least a thermoplastic resin, a colorant, a calixarene compound represented by the general formula [I] as a charge control agent, and optionally other additives, for example, It consists of an anti-offset agent.

The calixarene compound represented by the general formula [I] may be contained in the toner or may be attached and fixed on the surface of the toner. When included in the inside, in addition to the additives such as colorants, the calixarene compound of the present invention is further added to obtain a pulverized toner, suspension polymerization toner,
Capsule toner and the like may be prepared by a usual method. In the case of an encapsulated toner, it is desirable to prepare it so that the outer shell layer contains a calixarene compound.

In the embodiment in which the calixarene compound is attached to the surface of the outer shell layer, it is attached to the toner surface by the action of Van der Waals force and electrostatic force, and then fixed by mechanical impact force or the like. Good. Apparatuses that can be preferably used in such a method include a hybridization system using a high-speed air current impact method (manufactured by Nara Machinery Co., Ltd.), Ongmill (manufactured by Hosokawa Micron Co., Ltd.), Mechanomill (manufactured by Okada Seiko Co., Ltd.) and the like. .. However, of course, it is not limited to such a method.

The content of the calixarene compound represented by the general formula [I] should be appropriately selected depending on the kind of toner, the additive of toner, the kind of binder resin, etc., and the developing system of toner. However, when it is contained in the toner by a pulverization method or a suspension method, it is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight with respect to 100 parts by weight of the resin constituting the toner.
Parts by weight. If it is less than 0.1 parts by weight, the desired charge amount cannot be obtained, and if it is more than 20 parts by weight, the charge amount becomes unstable and the fixing property is deteriorated.

When the calixarene compound is used by adhering and fixing it to the toner surface, 0.001 to 10 parts by weight, preferably 0.0 to 100 parts by weight of the toner particles is used.
5 to 2 parts by weight, more preferably 0.1 to 1 part by weight is used. If the amount is less than 0.001 part by weight, the amount of the charge control agent present on the surface of the toner particles is small and the charge amount is insufficient.
When the amount is more than 10 parts by weight, the adhesion of the charge control agent to the toner surface becomes insufficient, and peeling of the charge control agent from the toner surface becomes a problem during use. When the charge control agent is adhered and fixed to the toner surface, it is possible to impart a stable charge amount by using a very small amount as described above, and the calixarene compound of the present invention is white. Therefore, it is possible to provide a color toner having excellent charging performance and capable of forming a clear color image.

When the calixarene compound represented by the general formula [I] is contained in the toner,
The particle size is 5 μm or less, preferably 3 μm or less, and more preferably 1 μm or less. If it is used with a particle size larger than 5 μm, the dispersed state becomes non-uniform and various characteristics of the charge amount become non-uniform. When the calixarene compound is attached to the toner surface, the particle size is 1 μm or less, more preferably 0.5 μm or less. If the particle size is larger than 1 μm, it is disadvantageous in that it is uniformly adhered and fixed on the toner surface.

As the thermoplastic resin constituting the toner,
Polystyrene, poly-p-chlorostyrene, homopolymers of styrene such as polyvinyltoluene and substitution products thereof, styrene-p-chlorostyrene copolymers, styrene-propylene copolymers, styrene-vinyltoluene copolymers,
Styrene-vinyl naphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate Copolymer, styrene- (methacrylic acid) ethyl copolymer, styrene-butyl methacrylate copolymer,
Styrene-d methyl chloromethacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer,
Styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, styrene-maleic acid ester copolymers and other styrene-based copolymers, polymethylmethacrylate , Polybutylmethacrylate,
Polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyamide, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon Resin, aromatic petroleum resin, chlorinated paraffin, paraffin wax and the like can be used alone or in combination.

The colorants contained in the toner include black pigments such as carbon black, acetylene black, lamp black and aniline black; red pigments such as red iron oxide, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R and resole red. , Pyrazolone Red, Watching Red, Calcium salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B, etc .; Chrome Green as green pigment,
Chromium oxide, Pigment Green B, Malachite Green Lake, Fanal Yellow Green, etc .; Blue pigments such as Navy Blue, Cobalt Blue, Alkali Blue Lake, Victoria Blue Lake, Phthalocyanine Blue, Metal-Free Phthalocyanine Blue, Phthalocyanine Blue Partial Chloride, Fast Sky Blue , Induslen Blue BC
Etc .; manganese purple as magenta pigment, fast violet B, methyl violet lake etc .; permanent brown, para brown etc. as sepia pigment; zinc white, titanium oxide, antimony white, zinc sulfide etc. as white pigment; yellow lead as yellow pigment; Zinc Yellow, Cadmium Yellow, Yellow Iron Oxide, Mineral Fast Yellow, Nickel Titanium Yellow, Navels Yellow, Naphthol Yellow S, Hansar Yellow G, Hansar Yellow 10
G, benzidine yellow G, benzidine yellow GR,
Quinoline yellow rake, permanent yellow, NC
G, tartrazine lake, etc .: reddish yellow lead as an orange pigment,
Examples thereof include molybdenum orange, permanent orange GTR, virazolone orange, vulcan orange, induslen brilliant orange RK, benzidine orange G and induslen brilliant orange GK.

The amount of these pigments (colorants) used is appropriately 1 to 20% by weight, more preferably 3 to 7% by weight, based on the total amount of the toner.

An offset preventing agent may be used in combination with the toner of the present invention in order to improve the fixing property. Examples of the anti-offset agent include wax, low molecular weight polypropylene, polyethylene, or oxidized polypropylene and polyethylene. A fluidizing agent may be externally added to and mixed with the toner of the present invention in order to improve fluidity. As a fluidizing agent, silica, aluminum oxide, titanium oxide,
Examples thereof include a silica / aluminum oxide mixture and a silica / titanium oxide mixture.

Next, the carrier to be combined with the toner of the present invention will be described. The carrier of the present invention has a structure in which a carrier core material is coated with a polyolefin resin. Here, polyolefin is an olefin monomer,
For example, it refers to a polymerized product of an olefin monomer such as ethylene, propylene, butene or butadiene.

As the carrier core material which is a constituent element of the carrier of the present invention, carrier adhesion (scattering) to the electrostatic latent image carrier
From the standpoint of prevention, a size of at least 20 μm (average particle size) is used, and from the viewpoint of prevention of deterioration of image quality such as occurrence of carrier stripes, a size of at least 100 μm is used.
Specific materials include those known as two-component carriers for electrophotography, for example, metals such as ferrite, magnetite, iron, nickel and cobalt, these metals and zinc, antimony, aluminum, lead, tin, bismuth, beryllium, manganese. , Selenium, tungsten, zirconium,
Alloys or mixtures with metals such as vanadium, iron oxide,
Metal oxides such as titanium oxide and magnesium oxide, nitrides such as chromium nitride and vanadium nitride, mixtures with carbides such as silicon carbide and tungsten carbide, ferromagnetic ferrites, and mixtures thereof can be applied.

The carrier surface of the present invention is preferably coated with a polyolefin resin in an amount of 70% or more, preferably 90% or more, more preferably 95% or more. Coverage is 7
When it is less than 0%, the characteristics of the carrier core material itself (instability in environmental resistance, decrease in electric resistance, instability in charging) appear strongly through the background, and the advantage of resin coating cannot be utilized.

The filling rate of the carrier core material is about 90 wt% or more,
It is preferably set to 95 wt% or more. The filling rate may be understood to indirectly define the resin coating layer thickness of the carrier. If the carrier filling rate is less than 90 wt%, the coating layer becomes too thick and even if it is actually applied to a developer. , The peeling of the coating layer, an increase in the amount of charge, etc., does not satisfy the durability and charge stability required for the developer, and the image quality is inferior in fine line reproducibility, and the image density is reduced. Occurs.

The polyolefin resin coating layer thickness is expressed by specific gravity,
It can also be expressed indirectly. The specific gravity of the carrier of the present invention is greatly influenced by the type of the carrier core material, but as long as the carrier core material is applied, it is 3.5 to 7.5, preferably 4.0 to 6.0, and more preferably. It shows a value within the range of about 4.0 to 5.5. If the value is out of the range, the same adverse effect as that of the carrier which is not covered with an appropriate filling rate occurs as described above.

The electric resistance of the polyolefin resin-coated carrier of the present invention is 1 × 10 ⁶ to 1 × 10 ¹⁴ Ω · cm, preferably 10 ⁸ to 10 ¹³ Ω · cm, more preferably 10 ⁹ to 1
0 ¹² Ω. Set to about cm. Electric resistance is 1 × 10 ⁶ Ω ・ c
When it is less than m, the carrier is developed and the image quality is deteriorated.
On the other hand, if it is larger than 1 × 10 ¹⁴ Ω · cm, the toner is excessively charged, and an appropriate image density cannot be obtained. It can be considered that the electric resistance indirectly represents the above-mentioned polyolefin resin coating rate and carrier filling rate.

Further, the carrier-coated polyolefin layer of the present invention may contain additives such as fine particles having charge imparting function or conductive fine particles.

The fine particles having a charge imparting function include Cr.
_{O 2, Fe 2 O 3,} Fe 3 O 4, IrO 2, MnO 2, MoO 2, Nb
O ₂ , PtO ₂ , TiO ₂ , Ti ₂ O ₃ , Ti ₃ O ₅ , WO ₂ , V ₂
Metal oxides such as O ₃ , Al ₂ O ₃ , MgO, SiO ₂ , ZrO ₂ and BeO, Nigrosine base, Spiron Black TRH
Specific examples thereof include dyes and the like.

The conductive fine particles include carbon black, carbon black such as acetylene black, and Si.
Carbides such as C, TiC, MoC, ZrC, BN, NbN,
Examples thereof include nitrides such as TiN and ZrN, magnetic powders such as ferrite and magnetite.

Addition of metal oxides, metal fluorides and metal nitrides is effective in further enhancing chargeability. It is considered that such an effect is brought about by the synergistic charging effect between each component and the toner due to the contact between the toner and the complicated interface formed of these compounds, the coating resin and the core material.

The addition of carbon black is effective in enhancing the developability and obtaining an image having a high image density and a high contrast. It is considered that the addition of conductive fine particles such as carbon black causes the electric resistance of the carrier to be appropriately reduced, and the leakage and accumulation of electric charges to be carried out in a well-balanced manner.

One of the characteristics of the conventional binder type carrier is that it is excellent in halftone reproducibility and gradation reproducibility. In the case of the resin-coated carrier of the present invention, the polyolefin-based resin coating layer is magnetic. By adding powder, a carrier excellent in gradation reproducibility can be obtained. It is considered that this is because the addition of magnetic powder to the resin coating layer gave a surface composition similar to that of the binder type carrier, and the chargeability and the specific gravity became closer to those of the binder type carrier. The addition of borides and metal carbides is effective in raising the charge.

The size and amount of the above additives are not particularly limited as long as they satisfy various characteristics such as coverage and electric resistance described in the present specification as various characteristics of the carrier of the present invention. As the size of the fine particles, in the relationship with the production method of the carrier of the present invention, which will be described later, for example, in the resin solution or in dehydrated hexane, the particle size can be uniformly dispersed to form a slurry without agglomeration. Well, specifically, an average particle diameter of 2 to 0.01 μm, preferably 1 to
It may be about 0.01 μm.

Further, the amount of both fine particles added cannot be unconditionally specified as described above, but is 0.1 wt% to 6 wt% with respect to the coated polyolefin resin.
0 wt%, preferably 1.0 wt% to 40 wt% is suitable. In particular, according to the present invention, when the filling rate is set in the range of 90 to 97 wt%, it is preferable to add an additive such as fine particles having a charge imparting function or conductive fine particles to the polyolefin resin coating. .. When the carrier filling rate is as low as about 90 wt% and the coating layer is relatively thick, continuous copying of fine lines using such a carrier causes a problem that the reproducibility thereof deteriorates. The problem is solved by the addition of the above additives.

To coat the carrier core material with the polyolefin resin, a known method may be applied. For example, polyolefin such as polypropylene is melted by heating in a suitable solvent, and the molten resin is spray-coated on the carrier core material. The surface may be coated with a polyolefin resin.
(For example, Japanese Patent Application Laid-Open No. 52-154639), coating may be performed by adhering a coating material powder on the surface of carrier particles and heating and fixing the coating material powder above the melting point of the coating material.
(For example, JP-A-54-35735). Besides,
The polyolefin resin coating layer may be formed by a surface polymerization coating method.

The surface polymerization coating method includes a product and an organoaluminum compound obtained by subjecting titanium and / or zirconium to a highly active catalyst component soluble in a hydrocarbon solvent and a carrier core material in advance. It can be formed by polymerizing an olefin monomer such as ethylene on the surface of the carrier core material. Further, in the case of adding fine particles having a charge imparting function or conductive fine particles, these additives may be added and made to exist when the coating layer is formed. Specifically, JP-A-60
The method described in JP-A-106808 is suitable. The publication is incorporated herein by reference. According to this method, a coating layer having excellent film strength and adhesion between the body core particles and the resin coating layer and having excellent durability is formed.

It is preferable to further provide pores on the surface of the polyolefin resin coated carrier applied to the present invention. By using a polymer containing calixarene as a charge control agent in combination with a polyolefin resin-coated carrier, it is possible to optimize the charge level, which has been a problem in the past, and to stabilize the charge level. There is a problem that the rise of charging is slow. Therefore, the higher the copying system speed, the more uneven the toner charging level is, and the more easily the toner is scattered. However, the presence of a large number of pores on the surface of the resin coating layer can improve the above problems.

A sectional view of the resin-coated carrier having pores is schematically shown in FIG. 1 for the sake of clarity, and a schematic sectional view of the resin-coated carrier having no pores is shown in FIG. The resin-coated carrier of the present invention comprises a carrier core material (1),
It comprises a resin coating layer (2) for coating the carrier core material (1) and pores (3) formed on the surface of the resin coating layer. As compared with the ordinary resin-coated carrier shown in FIG. 3, the presence of pores (3) is a great feature.

When the pores are present on the surface of the resin-coated carrier, the contact between the toner particles (4) and the carrier particles can be sufficiently secured, the charging of the toner can be rapidly started, and The toner particles can be charged sufficiently uniformly, and toner scattering due to poor charging can be prevented. In addition, since the pores on the surface of the carrier are excellent in trapping the toner particles, this is also effective in preventing toner scattering. Further, the presence of the pores frequently causes contact between the toner and the carrier, which is effective in preventing toner aggregation and crushing the aggregated toner. The problem is solved.

The pores on the surface of the resin-coated carrier of the present invention are
Specifically, it is defined by its pore size distribution, average pore size, and total pore volume. It is desirable that each pore size existing on the surface of the resin coating layer is distributed in the range of 0.001 to 3 μm, preferably 0.001 to 2 μm, and more preferably 0.005 to 2 μm. If the pore size is smaller than 0.001 μm, a sufficient effect cannot be expected from the viewpoint of the disintegration property of the toner, and if it is larger than 3 μm, the trapping property of the toner becomes too strong, which may impair the fluidity and developability. There is. The average pore size corresponds to the distribution range of the pore size described above,
It is preferably in the range of 0.1 to 0.5 μm. By setting the average pore diameter within the above range, the disintegration property of the toner and the charging property for the toner can be improved.

In the present invention, the total pore volume is expressed in two ways: total pore volume per 1 g of carrier (ml / g) and total pore volume per 1 ml of coating resin (ml / ml). The total pore volume (ml / g) per gram of carrier can be determined by mercury porosimetry. In the carrier of the present invention, it is desirable that the value has a value of 0.001 to 0.1 ml / g, preferably 0.01 to 0.05 ml / g. If the value is smaller than 0.001 (ml / g), the pores existing on the surface of the carrier are insufficient, and the effect of the pores may not be obtained. If it is more than 0.1 ml / g, the coating layer becomes brittle due to too many pores.

Total pore volume per ml of coating resin (ml /
ml) is the total pore volume (m) per 1 g of the above-mentioned carrier.
1 / g) can be obtained by converting the true specific gravity of the coating layer and the carrier core material filling rate. In the carrier of the present invention, the value is 0.1 to 2 ml / ml,
It is desirable to have a value of preferably 0.5 to 1.5 ml / ml. If the value is less than 0.1 ml / ml, the pores existing on the carrier surface are insufficient, and the effect of the pores may not be obtained. If it is larger than 2 ml / ml, there are too many pores and the coating layer becomes brittle.

In the carrier used in the present invention, it is preferable that the resin coating layer is further provided with irregularities. FIG. 2 shows a form in which the resin coating layer (2) has irregularities, and
(3) is present on the surface of the uneven resin coating layer (2). By imparting such irregularities to the surface of the carrier, it is possible to obtain a carrier having further improved toner charging rising characteristics, toner scattering, toner cohesive disintegration and the like.

The surface irregularities will be described in more detail. The surface irregularity structure of the surface coating layer is represented by the following formula [I];

[Equation 1] [In the formula, the outer circumference represents the outer circumference of the projected image of the carrier particles, and the area represents the average value of the projected areas of the carrier particles. ] When expressed by a shape factor S represented by
It is preferably within the range. The S value represents the degree of unevenness on the particle surface, and the greater the degree of unevenness of the surface state, the further away from 100. The shape factor S can be measured with, for example, an image analyzer (Luzex 5000; manufactured by Nippon Regulator Co., Ltd.). Generally, in measuring the shape factor S, a large difference is not recognized depending on the model. It does not mean that it will not happen.

As a method for forming a polyolefin resin coating layer having pores, for example, a fine particle component soluble in a suitable solvent is previously dispersed in a coating resin solution, and the fine particles can be dissolved after the coating layer is formed. There may be mentioned a method of immersing the soluble fine particle component in a different solvent and eluting the soluble fine particle component to form pores on the surface of the coating layer. In the case of this method, the pore size is determined by the particle size of the solvent-soluble fine particle component, the degree of dispersion, and the like. Further, the coating layer can be formed by a powder capsule method, a spray dry method or the like.

Examples of fine particle components that can be used in this method include fine particles of metal oxides such as ferrite, halides or hydroxides of alkali metals or alkaline earth metals, and transition metal complexes. Needless to say, it is necessary to use a solvent that does not dissolve the resin as the solvent to be eluted. More specifically, for example, by immersing a carrier having a resin coating layer containing ferrite in an acidic aqueous solution such as hydrochloric acid, a method of eluting the ferrite can be mentioned, and by doing so, pores are formed on the carrier surface. Can be formed. Furthermore, in the case of adding the above-mentioned fine particles having a charge imparting function or conductive fine particles, in the coating resin solution,
It suffices if these additives are added and allowed to exist, and it is also advantageous in terms of manufacturing process and characteristics to use fine particles such as ferrite that function as fine pore-forming particles and also as conductive fine particles. Is also useful.

According to the above method, the pores are sufficiently formed, but it may not be a method sufficient for imparting the above-mentioned unevenness. However, when the polyolefin resin coating layer is formed by the above-mentioned surface polymerization coating method, the pores and the surface irregularities are sufficiently satisfactory.

In the present invention, the carrier and toner obtained as described above are mixed to prepare a developer. The developer thus obtained stably charges the toner to an appropriate positive charge level, and the rising of the toner charge,
Excellent in preventing toner scattering and disintegrating toner aggregates.

The mixing ratio of the toner and the carrier is toner 2
-20 wt%, preferably 3-15 wt%, more preferably 4-12 wt%. Toner mixing ratio is 2wt
If it is less than 20% by weight, the toner charge amount becomes high and a sufficient image density cannot be obtained, and if it is more than 20% by weight, the inside of the copying machine is contaminated due to toner scattering and toner fogging occurs on the image. Hereinafter, the present invention will be described using examples. The term "parts" by weight means "parts by weight" unless otherwise specified.

Production Example 1 of Carrier (1) Preparation of Titanium-Containing Catalyst Component In a flask having an inner volume of 500 ml purged with argon, 200 ml of dehydrated n-heptane at room temperature and 15 g of magnesium stearate dehydrated in advance at 120 ° C. (2 mmHg).
(25 mmol) was added to make a slurry. 0.44 g (2.3 mmol) of titanium tetrachloride was added dropwise with stirring, and then the temperature was started and the reaction was carried out under reflux for 1 hour to obtain a viscous transparent titanium-containing catalyst component solution.

(2) Activity evaluation of titanium-containing catalyst component: 400 ml of dehydrated hexane, 0.8 mmol of triethylaluminum, 0.8 mmol of diethylaluminum chloride and the titanium obtained in the above (1) were placed in an autoclave having an internal volume of 1 l, which was purged with argon. The catalyst component contained was made into titanium atoms, and 0.004 mmol was sampled and charged, and the temperature was raised to 90 ° C. At this time, the system internal pressure was 1.5 kg / cm ² G. Then, hydrogen was supplied and the pressure was raised to 5.5 kg / cm ² G, then ethylene was continuously fed so that the total pressure was maintained at 9.5 kg / cm ² G, and polymerization was performed for 1 hour to obtain 70 g of ethylene. A polymer was obtained. The polymerization activity was 365 kg / g · Ti · Hr, and the MFR (190 ° C, load 2.16) of the obtained polymer.
Melt flow property in kg; JIS K7210) was 40.

(3) Reaction of Titanium-Containing Catalyst Component with Filler and Polymerization of Ethylene In an autoclave having an internal volume of 1 liter replaced with argon, 500 ml of dehydrated hexane at room temperature and a sintered ferrite dried under reduced pressure (2 mmHg) at 200 ° C. for 3 hours. Powder F-200
(Howard Tech Co., Ltd., average particle size 70 μm) 450 g was added and stirring was started. Then, raise the temperature to 40 ° C., and
The titanium-containing polymerization catalyst component of (1) is used as a titanium atom.
Addition of 02 mmol and reaction for about 1 hour. afterwards,
Triethylaluminum (2.0 mmol) and diethylaluminum chloride (2.0 mmol) were added, and the temperature was raised to 90 ° C. The internal pressure of the system at this time was 1.5 kg / cm ² G. Then, hydrogen was supplied to increase the pressure to ² kg / cm ² G, and then polymerization was carried out for 40 minutes while continuously supplying ethylene so as to maintain the total pressure at 6 kg / cm ² G to obtain a total amount of 473 g of the ferrite-containing polyethylene composition. Obtained. The dried powder was uniformly grayish white, and when observed by an electron microscope, the ferrite surface was thinly covered with polyethylene, and no aggregation of ferrite particles was observed in polyethylene. When this composition was measured by TGA (thermobalance), the core material filling rate was 95.2 wt%. Then, it was put into a hot air stream set at 120 ° C. and heat-treated for 2.0 hours. The obtained carrier was classified with a 106 μm sieve to remove aggregates.

Production Example 2 of Carrier In the same manner as in (3) of Production Example 1, the titanium-containing catalyst component prepared in (1) of Production Example 1 was added to 450 g of ferrite in an autoclave having an internal volume of 1 liter substituted with argon. 0.02 mmol of titanium atom was added and the reaction was carried out for 1 hour. Then, 0.47 g of carbon black (Ketchen black DJ-600, manufactured by Lion Akzo Co., Ltd.) was charged from the nozzle in the upper part of the autoclave. The carbon black used was one that had been dried under reduced pressure at 200 ° C. for 1 hour and then slurried with dehydrated hexane.
Then, 2.0 mmol of triethylaluminum and 2.0 mmol of diethylaluminum chloride were added, and 90
The temperature was raised to ° C. The system internal pressure at this time was 1.5 kg / cm ² G. Then, hydrogen was supplied to increase the pressure to ² kg / cm ² G, and then polymerization was carried out for 45 minutes while continuously supplying ethylene so as to keep the total pressure at 6 kg / cm ² , and the total amount was 469.3 g.
A polyethylene composition containing ferrite and carbon black was obtained. The dried powder was uniformly black, and it was observed by an electron microscope that the ferrite surface was thinly covered with polyethylene and the carbon black was uniformly dispersed in the polyethylene. In addition, this composition was
When measured by GA (thermal balance), the core material filling rate was 9
5.9 wt%, which is calculated from the charged amount of ferrite,
Polyethylene and carbon black are 24: 1: 0.025
Was the weight ratio. Then, it was put into a hot air stream set at 120 ° C. and heat-treated for 2.0 hours. The obtained carrier was classified with a 10.6 μm sieve to remove aggregates.

Production Example 3 of Carrier In an autoclave having an internal volume of 1 liter and having been replaced with argon, 450 g of ferrite was prepared in the same manner as in Production Example 1 of carrier.
On the other hand, 0.01 mmol of the titanium-containing catalyst component prepared in (1) of Production Example 1 was added as a titanium atom, and the reaction was carried out for 1 hour. Then, carbon black (Ketchen blac (Ketchen blac
k) EC, manufactured by Lion Akzo Co., Ltd.) (0.50 g) was added. The carbon black used was one that had been dried under reduced pressure at 200 ° C. for 1 hour and then slurried with dehydrated hexane. Then triethylaluminum 1.0
Mmol and 1.0 mmol of diethylaluminum chloride were added, and the temperature was raised to 90 ° C. The system pressure at this time was 1.5 kg / cm ² G. Next, 37.5 mmol (2.1 g) of 1-butene was introduced, and then hydrogen was supplied to the mixture to give 2 kg / cm ²
After the pressure was raised to G, polymerization was carried out for 28 minutes while continuously feeding ethylene so as to keep the total pressure at 6 kg / cm ² G to obtain a total amount of 467 g of a ferrite- and carbon black-containing polyethylene composition. The dried powder was uniformly black, and it was observed by electron microscopy that the ferrite surface was covered with a thin polymer and the carbon black was uniformly dispersed in the polymer. When this composition was measured by TGA (thermobalance), the weight ratio of ferrite, polymer and carbon black was 27: 1: 0.03. Furthermore, the polymer obtained by removing the ferrite and carbon black by Soxhlet extraction (solvent, xylene) was analyzed by IR, and it was confirmed to be a polyethylene-based copolymer containing 8 wt% butene. Then, put it in a hot air stream set at 120 ° C and 2.
Heat treatment was performed for 5 hours. 106 μ of the obtained carrier
The product was classified with a m sieve to remove aggregates.

Carrier Production Example 4 Low-density ethylene (High Wax 220P: manufactured by Mitsui Petrochemical Co., Ltd.) was dissolved in toluene by heating (0.5% solution), and ferrite fine powder having an average particle size of 0.2 μm was added to the above. 250 parts by weight was added to 100 parts by weight of the resin solid content of the solution, and the solution was uniformly dispersed by an ultrasonic homogenizer to obtain a coating liquid. Sintered ferrite powder (F-200: manufactured by Powder Tech Co., Ltd., average particle size: 70 μm) was used as a core material, and was repeatedly applied by a Spira coater (manufactured by Okada Seiko Co., Ltd.) so that 10 wt% of the core material could be coated. .. This carrier was immersed in 6N HCl for 2 hours, washed thoroughly with water, and then kept at 60 ° C for 5 hours.
Vacuum drying was carried out for an hour to obtain a resin-coated carrier having pores on the surface.

Carrier Production Example 5 A carrier was produced in the same manner as Carrier Production Example 4 except that ferrite fine powder was not added and no acid treatment was performed.

Carrier Carrier Preparation Examples 1 to 5 of the carrier core material filling rate (wt%), core specific gravity (g / cm ³ ), bulk specific gravity (g / cm ³ ).
³ ), electric resistance (Ω · cm), specific surface area (m ² / g), carrier 1 g
The total pore volume per unit (ml / g), the total pore volume per ml of the coating layer (ml / ml) and the average pore diameter are shown in "Table 1".
FIG. 4 shows the relationship between the penetration volume and the pore size. The relationship between the volume fraction and the pore size of the carrier obtained in Examples 1 to 4 is shown in FIGS.

[0070]

[Table 1]

Production Example of Toner Part by Weight Polyester Resin 100 (Softening Point: 130 ⁰ C, Glass Transition Point: 60 ⁰ C, AV25, OHV10) ・ Carbon Black 8 ・ Low Molecular Weight Polypropylene 5 ・ Calix Allene Compound [14] 5 after thoroughly mixing the above materials using a ball mill, and kneaded through three rolls heated to 140 ⁰ C. After leaving the kneaded mixture to cool,
Coarse pulverization was performed using a feather mill, and further fine pulverization was performed using a jet mill. Next, air classification was performed to obtain a negatively chargeable toner having an average particle size of 8.4 μm.

Toner Production Examples 2 to 4 Except for using [16], [26] and [31] in place of the calixarene compound [14] used in Production Example 1, exactly the same as Toner Production Example 1. To produce a toner.

Toner Production Example 5 A negatively charged toner having an average particle size of 8.7 μm was obtained in the same manner as in Toner Production Example 1 except that the calixarene compound was not used.

Evaluation of Developer Toner Charge Rate and Scatterability A developer was prepared from the carrier and toner obtained as described above, and the toner charge rate τ (sec) and scatterability were evaluated. The results are shown in "Table 2".

[0075]

[Table 2]

The toner charging rate was the same as that of the toner obtained in each of Toner Production Examples 1 to 5 using a developer prepared in a mixing ratio of 2 wt% shown in Table 2. Kenichi Karakida, Journal of Electrophotographic Society, 402,
27 (1988).

As for the scattering property, 450 ml of the developer prepared by mixing the toners obtained in Toner Production Examples 1 to 4 in the mixing ratio shown in "Table 2" was used as a copying machine (EP-8600; manufactured by Minolta Camera Co., Ltd.). ), Connect a motor to the drive system of the developing device, and externally drive this at a sleeve peripheral speed of 60 cm / sec for 1 hour, and at that time suck the scattered toner adhering to the sleeve opening of the developing device. Weighing was performed and ranked as follows. ◎: <10 mg ○: 10 to 30 mg △: 30 to 80 mg ×:> 80 mg

Further, the following examples were carried out. Carrier Production Example 6 40 g of methyl methacrylate resin (BR85: manufactured by Mitsubishi Rayon Co., Ltd.) was coated on the surface of 5 kg of iron oxide powder having a diameter of 100 μm using a fluidized bed type coating device to obtain a resin-coated carrier.

Example 6 The following evaluation was carried out using the toner obtained in Production Example 1 of Toner and the polyethylene-coated carrier obtained in Production Example 1 of carrier. The results are shown in "Table 3".

Comparative Example 2 Production Example 6 of Toner and Carrier Obtained in Production Example of Toner
The following evaluations were performed using the acrylic coating carrier obtained in. The results are shown in "Table 3".

Comparative Example 3 Production of Toner Toner obtained in Production Example 1 and iron powder carrier (T
The following evaluation was performed using EFV200 / 300: manufactured by Nippon Iron & Powder Co., Ltd.). The results are shown in "Table 3".

Evaluation of Evaluated Charge Amount The samples of Example 6 and Comparative Examples 2 and 3 were made to have a toner concentration of 10 wt%, and 60 g thereof was put in a 100 ml plastic bottle. The plastic bottle was placed on a pedestal so as to rotate at 120 rpm, and the charge amount (Qf) after 3 minutes, 10 minutes, and 30 minutes was obtained.

Amount of charge attenuation after aging of humidity resistance Amount of charge when mixed and stirred for 30 minutes: Qf (30 minutes), 35 ⁰ C,
Under 85% environment, the charge amount after leaving open the lid of the jar for 3 days: Qf measured ^{(35 0 C-85% -3days} ), following the "number 2":

[Equation 2] The decay rate of the charge amount was obtained by.

Image Evaluation The carrier and the toner were placed in a 1-liter plastic bottle so that the toner concentration was 7 wt%, placed on a ball mill stand and mixed at 120 rpm for 10 hours to prepare a developer. The obtained developer was put in a copying machine (EP80; manufactured by Minolta Camera Co., Ltd.), and a printing durability test of 10K sheets was performed, and the presence or absence of fog was evaluated and ranked as follows. 5: No fog at all 4: Slight fog was observed 3: Slight fog was observed, but practically no problem 2: Lots of fog 1: Very much fog

[0085]

[Table 3]

[0086]

INDUSTRIAL APPLICABILITY According to the present invention, a developer in which a toner containing a calixarene compound is combined with a carrier coated with a polyolefin resin can optimize the charge level of the toner, stabilize the toner, and prevent toner scattering.
Furthermore, by combining with a polyolefin-coated carrier having pores on the surface, rising of toner charging and scattering can be improved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a resin-coated carrier of the present invention.

FIG. 2 is a schematic sectional view of a resin-coated carrier of the present invention.

FIG. 3 is a schematic sectional view of a conventional resin-coated carrier.

FIG. 4 is a diagram showing the relationship between the pore size of carrier surface pores and the penetration volume.

FIG. 5 is a diagram showing a relationship between a pore diameter and a volume fraction of carrier surface pores obtained in Carrier Production Example 1.

FIG. 6 is a diagram showing a relationship between a pore diameter and a volume fraction of carrier surface pores obtained in Carrier Production Example 2.

FIG. 7 is a diagram showing a relationship between a pore diameter and a volume fraction of carrier surface pores obtained in Carrier Production Example 3.

FIG. 8 is a diagram showing a relationship between a pore diameter and a volume fraction of carrier surface pores obtained in Carrier Production Example 4.

[Explanation of symbols]

1: carrier core material, 2: resin coating layer, 3: pores, 4: toner particles

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Claims (1)

[Claims] 1. A developer comprising a toner containing a calixarene compound as a negative charge control agent, and a polyolefin resin-coated carrier.