JPS63231358A - Toner composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to toner compositions for developing electrostatic images used in electrophotography, electrostatic recording, etc. to visualize electrical latent images and other electrical signals. In particular, the present invention relates to a toner composition for developing electrostatic images that has excellent negative chargeability, developability, transferability, and fixability.

Conventional techniques Known methods for imparting charge to toner include the friction/contact charging method, ion irradiation method, electrostatic induction method using conductivity, and charge injection method. Friction and contact charging methods are widely used. in this case,
In addition to two-component developers that mix toner with carrier particles that are charged to the opposite polarity to the toner in order to impart an electric charge to the toner, we also use frictional charging between the toner and a charging blade or roll, and we also use frictional charging between the toner and the toner. One-component developers using charging are also known.

When toner is charged by such friction/contact charging,
Charge control is performed by adding an electron donating substance or an electron attracting substance to the toner side or the charge imparting material side such as a carrier or a blade.

Conventionally, in order to control the charge of toner, dyes and pigments, surfactants, inorganic powders, etc. have been added and mixed into toner, or adhered to the toner surface, or - as a binder resin. COOH.

Measures have been taken to use resin-like materials having halogens such as -CN and -CI, and functional groups such as -NO2 and -NH2.

Problems to be Solved by the Invention However, even with the use of the above-mentioned additives or binder resins that have been known in the past, there has not been sufficient success in controlling the temporal stability and environmental stability of toner chargeability. , has not reached a satisfactory level.

In particular, in the case of color toners, the substances used for charge control may change the color tone and reduce transparency, so the substances that can be used for charge control are limited, and the dyes used as colorants Pigments often have a negative effect on the chargeability of toners, and controlling their chargeability has been more difficult than in the case of black toners. In addition, in recent years, in order to obtain high-quality copy images with good reproducibility of fine lines and halftone images, efforts have been made to reduce the particle size of toner. When attempting to obtain a color image using the subtractive color method, by reducing the toner particle size, it is possible to prevent excessive bulging of the image and excessive gloss caused by the accumulation of one layer of toner.
This has the advantage of making it easy to obtain high-quality color images. However, in this case, since the toner particle size is small, the content of dye and pigment must be increased in order to obtain the same coloring power as a toner with a normal particle size, and as a result, the toner charge control becomes rough. The problem is that it becomes difficult.

Accordingly, an object of the present invention is to provide a negatively chargeable toner composition that has a rapid charge rise, has an appropriate charge amount and charge distribution, and is excellent in environmental stability and stability over time.

Furthermore, another object is to provide a toner composition that can consistently produce clear and high-quality color images.

Means for Solving the Problems The objects of the present invention are achieved by incorporating a compound represented by the following general formula (I>) into a toner composition as a charge control agent.

The toner composition of the present invention is characterized by containing a compound represented by the following general formula (I>) as an essential component.

(In the formula, R1 represents a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group, an arylalkyl group, or an aryl group, and R2, R3, R4, and R5 each represent a hydrogen atom, an alkyl group, an aryl group, and represents an arylalkyl group, and n represents an integer of 1 or more.) The toner composition of the present invention will be described in detail below.

In the present invention, in the compound represented by the above general formula (I) used as a charge control agent (hereinafter referred to as "charge control compound"), R1 is a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group, represents an arylalkyl group or an aryl group, and when n is 2 or more, each R may be the same or different. Furthermore, R2, R3, R4 and R5 are each a hydrogen atom, an alkyl group such as a methyl group, an ethyl group or a butyl group, an aryl group such as a phenyl group or a tolyl group,
Represents an arylalkyl group such as a benzyl group.

In general, a counterion type structure (such as that used in the present invention) (
Since the negative charging ability of a charge control agent that takes A″・D) depends on the strength and size balance of the ions of the anionic component and the cationic component, the substituents R2, R3, R4 and R5
When the ion of the cationic component becomes large, that is, when the ions of the cationic component are large, the charge control agent loses its negative charging ability and rather starts to show positive chargeability. This may be due to the excellent ionic balance between the ionic strength of the phonium cation and the ionic concentration of the tetraphenyl filament anion.
Even when the cationic component is relatively large, such as when 3 to 4 of R5 and R5 are phenyl groups or benzyl groups, it can be conveniently used as a negatively chargeable charge control agent.

Among the charge control compounds used in the present invention, a typical one is a compound represented by the following general formula (II>).

(In the formula, R6 represents a hydrogen atom, a halogen atom, a lower alkyl group, or a halogenated methyl group, R7 represents a hydrogen atom or a halogenated methyl group, and R8, R9, Rlo
and R11 each represent a lower alkyl group or a phenyl group. ) Specific examples of these are shown below.

Tetraphenyl is boronatetetramethylphosphoniumtetraphenyl is boronatetetraethylphosphoniumtetraphenyl is boronatetetrabutylphosphoniumtetraphenyl is boronatetributylmethylphosphoniumtetraphenyl is boronatetriphenylmethylphosphonium Tetraphenyl is phenyltrimethylphosphoniumtetra(p-fluorophenyl) is boronatetetramethylphosphoniumtetra(p-fluorophenyl) is boronatetetraethylphosphoniumtetra(p-fluorophenyl) is boronate Tetrabutylphosphoniumtetra(p-fluorophenyl) boronotributylmethylphosphoniumtetra(p-fluorophenyl) boronotriphenylmethylphosphoniumtetra(p-fluorophenyl) Methylphosphoniumtetra(p-chlorophenyl) boronatetetramethylphosphoniumtetra(p-chlorophenyl) boronatetetraethylphosphoniumtetra(p-chlorophenyl) boronatetetrabutylphosphoniumtetra(p-chlorophenyl) 〉Boronine tributylmethylphosphonium tetra (p-chlorophenyl) Boronine triphenylmethylphosphonium tetra (p-chlorophenyl) Boronine phenyltrimethylphosphonium tetra (p-tolyl) Boronine tetramethylphos Phoniumtetra(p-tolyl) is boronatete1-laethylphosphoniumtetra(p-tolyl) is boronatetetrabutylmethylphosphoniumtetra(p-tolyl) is boronatetributylmethylphosphoniumtetra(p-tolyl) -tolyl) boronate triphenylmethylphosphonium tetra(p-tolyl) boronate phenyltrimethylphosphonium tetrakis [3,5'-bis(trifluoromethyl)phenyl] boronate tetramethylphosphonium tetrakis [3,5-bis(trifluoromethyl)phenyl]boronatetetraethylphosphoniumtetrakis[3,5-bis(trifluoromethyl)phenyl]boronatetetrabutylphtsulfoniumtetrakis[3,5-bis(trifluoromethyl)phenyl] [fluoromethyl)phenyl] fluorine tributylmethylphosphonium tetrakis [3,5-bis(trifluoromethyl)phenyl] fluorine triphenylmethylphosphonium tetrakis [3,5-bis(trifluoromethyl)phenyl] Boron phenyltrimethylphosphonium These charge control compounds have a sufficient charge control effect by themselves, but may be used in combination with other known charge control agents. Further, in the present invention, the charge control compound may be a single compound, or may be a mixture or solid solution of two or more kinds of compounds.

The charge control compound in the present invention is contained in the developer at about 0.0%.
By adding about 0.1% to 10% by weight, preferably about 0.1% to 5% by weight, the charging properties of the toner can be improved very well. The charge control compound is not only dispersed or dissolved inside the toner, but also
It may be selectively added only to the surface layer of the toner, or may be added and mixed outside the toner. Further, when the charge control compound in the present invention is added and mixed into the toner, in addition to mechanically mixing with the binder resin by a method such as melt mixing, emulsion mixing, solution mixing, etc., in the presence of the charge control compound, The binder resin monomer may be polymerized and the charge control compound in the binder resin may be mixed or melted. In this case, a chemical bond may be formed between the charge control compound and the binder resin or other additives in the toner.

As the binder resin that can be used in the present invention, all conventionally known binder resins can be used. For example, styrene, vinyltoluene, methylstyrene, chlorstyrene,
Styrene derivatives such as aminostyrene and substituted products thereof, nistyl methacrylates such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate, and acrylic acid esters such as methacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. and dienes such as acrylic acid, butadiene, and isoprene, acrylonitrile, vinyl ethers, maleic acid, and maleic acid esters, maleic anhydride, vinyl monopolymers such as vinyl chloride, vinyl acetate, etc. alone or copolymers; Olefin polymers such as polyethylene and polypropylene, natural and synthetic waxes, polyesters, polyamides, epoxy resins, polycarbonates, polyurethanes, silicone resins, fluororesins, petroleum resins, etc. can be used alone or in combination.

The colorant used in the toner of the present invention includes black dyes and pigments such as carbon black, oil black, and graphite: C
, 1, Pigment Yellow 1, 3, 74, 9
7. Acetoacetate arylamide monoazo yellow pigment (fast yellow type) such as 98; c, 1. Pigment Yellow 12, 13, 14 and other acetoacetate arylamide disazo yellow pigments; C,1, Solvent Yellow 19, 77, 79, C,1, Disperse.
Yellow dye such as Yellow 164, C,1, Pigment Red 48, Pigment Red 49:L 53:1, 57:1, 81
, 122, 5 etc. Red or pink pigments: C1■, Solvent Red 52, 58, 8 etc. red dyes;
C,1, Pigment Blue 15=3 Blue dyes and pigments such as copper phthalocyanine and its derivatives and modified products C,1,
Pigment Green 7, 36 (phthalocyanine)
Conventionally known dyes and pigments for printing inks and other coloring applications can be used, such as green pigments such as (green), colored or colorless sublimable dyes, etc.

These dyes and pigments may be used alone or in combination of two or more. Of course, the color tone may be adjusted by mixing with an extender pigment or a white pigment. In addition, in order to improve the dispersibility of the binder component, the surface of the colorant may be treated with a surfactant, a coupling agent such as a silane coupling agent, or a polymer material, or a polymer dye or polymer graft pigment may be used. It's okay.

The concentration of dyes and pigments in toner depends on the specific gravity of toner constituent materials such as toner binding resin and dyes and pigments, the coloring power of dyes and pigments, the particle size distribution of toner particles, etc., and also depends on the amount of developed toner and the toner particle layer thickness. Although it is difficult to determine generally, if the layer thickness of the developed toner particles is controlled to about one or two layers, for example, in the case of a toner with an average particle size d50 of about 10 μm, the dye and pigment The appropriate amount of content is about 2% to 10% by weight. If the average particle size of the toner is larger,
Naturally, the dye and pigment concentration is lower, and conversely, when the average particle size of the toner is small, the dye and pigment concentration is adjusted to be higher.

Note that the binder resin and colorant that can be used in the present invention are not limited to those exemplified above.

The toner composition of the present invention exhibits sufficiently excellent negative chargeability by itself, but if necessary, it may be made of a magnetic material such as ferrite, etc.
Conductivity modifiers, inorganic substances such as tin oxide, silica, alumina, titanium oxide, zinc oxide, etc., reinforcing fillers such as extender pigments, fibrous substances, antioxidants, mold release agents, etc. Can be added.

Furthermore, on the surface of the toner particles, it is possible to improve the powder fluidity and charging properties of l-toner, to prevent toner from filming on the surface of the photoreceptor and carrier particles, and to improve the cleaning performance of residual toner on the photoreceptor. Various external additives can be attached or fixed for the purpose of improving the quality. These external additives include higher fatty acids such as stearic acid and derivatives such as their metal salts, esters, and amides, carbon black, tin oxide, graphite carbide, silicon carbide, boron nitride, silica, alumina, and titanium dioxide. , inorganic powder such as zinc oxide,
All conventionally known materials can be used, such as resin powders such as fluorine thread resin, acrylic resin, and silicone resin, polycyclic aromatic compounds, and waxy substances.

The method for producing the toner composition of the present invention includes a kneading and pulverizing method,
All conventionally known methods such as spray drying and direct polymerization can be used.

The particle size of the toner particles in the toner composition of the present invention is an average particle size d50 measured by Coulter counter method.
is 1 to 20 μm, preferably d50 is 5 to 15 μm
It is desirable to adjust the distance to m.

As a method for converting an electrical latent image or other electrical signals into a visible image using the toner composition of the present invention, all known developing methods can be applied, such as ordinary two-component developing method, microtoning method, etc. In addition, without using a carrier,
- It can also be applied to component development methods.

Effect The reason why the charge control compound represented by the above general formula used in the present invention has excellent negative charge control properties is not necessarily clear, but (i) electron acceptability of boron; (1) Dark blue image of neutralized salt type, (iii) Stabilization of boron anion due to resonance effect of phenyl group, (iv) Ion of cationic component phosphonium cation and tetraphenyl boron anion This is presumed to be due to the effect of a good balance between strength and size, which promotes the exchange and movement of electrons and/or ions in the compound itself and in a composite material in which the compound is dispersed or dissolved in a polymer or the like.

EXAMPLES Hereinafter, the present invention will be explained by examples, but of course the content of the present invention is not limited only to these examples.

Note that "parts" in the examples represent "parts by weight" unless otherwise specified. Further, Tg represents a glass transition temperature, Hn represents a number average molecular weight, and Hw represents a weight average molecular group. Furthermore,
Normal temperature and humidity is 22°C, 155% R, H, high temperature and humidity is 28
°C, 85% R0H9, low temperature and low humidity 10'C115%R,
H, means the environment.

Example 1 Styrene/n-butyl meth 100 parts acrylate copolymer (To=65°C, )In=23.000. t(w=
85,000) magenta pigment)
5 parts (C, 1, Pigment Red 57:1) 2 parts of tetraphenylboron triphenylmethylphosphonium By kneading, crushing and classifying the above ingredients, the average particle size d 50 = 10μ
A magenta toner of m was obtained. This toner has an average particle size of 8
A developer was prepared by mixing with a 0 μm ferrite carrier at a polymerization ratio of 3/100. When the chargeability was evaluated using the charge spectrogram method, the results shown in the table below were obtained.

(Note) The average charge amount and the amount of reverse polarity toner indicate the values after 1 minute of mixing with a high-speed mixer. The rise of charging is from 1=0 to t=
Means behavior up to 1 minute. Stability over time is the behavior for t>1 minute. Moreover, O means good.

Comparative Example A toner having a d50 of 10 .mu.m was obtained in the same manner as in Example 1 except that only tetraphenylboron triphenylmethylphosphonium was removed from the toner of Example 1. Using this toner, the chargeability was evaluated in the same manner as in Example 1, and the results shown in the table below were obtained. As is clear from this table, this toner was not at a usable level.

Note: × means that the level is not usable.

Example 2 Styrene/n-butyl acrylic 45 parts rate/
2-Ethylhexyl acrylate copolymer (Tg=60°C, )In=150.000. Hw=
400.000) Styrene/n-butyl acrylate 50 parts copolymer (9=60°C,) fn=4,000. )1w=5
0,000>Low molecular weight polypropylene 5
5 parts cyan pigment (C, 1
, Pigment Blue 15:3) Tetraphenylboron Tetramethyl 1 part Phosphonium The above mixture was mixed, crushed and classified to obtain an average particle size d50.
= 12 μm cyan toner was obtained. To this toner, 0.7% by weight of hydrophobic silica fine powder and 0.8% by weight of polymethyl methacrylate fine powder were externally added and mixed, and the particle size was 10% by weight.
It is used in combination with a ferrite carrier surface-treated with 0 μm perfluorosilane, and is used in the FX-2830 copier (
When a copy running test was conducted using a copying machine (manufactured by Fuji Xerox ■) for a total of 15,000 copies (5,000 copies in each environment of high temperature and high humidity, normal temperature and humidity, and low temperature and low humidity), good images were always obtained.

Example 3 Styrene/n-butyl meth 100 parts acrylate copolymer (T(J=65°C,)In=23,000.Mw=65
,000) Yellow pigment) 5 parts (C, 1, Pigment Yellow 97> Tetraphenyl boronate Tetrabutyl 2 parts Phosphonium
= 10 μm yellow toner was obtained. In this toner,
A developer was prepared by externally adding and mixing 0.7 mm% of hydrophobic silica fine powder and 0.8% Shigenobu of polymethyl methacrylate fine powder, and further mixing with a ferrite carrier having a particle size of 80 μm at a polymerization ratio of 3/100. . When the chargeability was evaluated using the charge spectrogram method, it was found that
It exhibited good chargeability of around -12 μc/q under all environments of low temperature and low humidity.

Furthermore, when a 5,000-sheet copying test was carried out using an FX-2300 copying machine (manufactured by Fuji Xerox (!1)), good images were always obtained.

Example 4 Hydrophobic silica fine powder was added to the yellow toner of Example 3 by 0.00%.
8% by weight and 0.8% by weight of remethyl methacrylate resin fine powder.
A developer was prepared by externally adding and mixing 5% by weight. Modification F using this developer and incorporating a one-component developing device with the following configuration
When a continuous copying test of 5,000 sheets was performed using an X-2300 copying machine, good images were always obtained.

The one-component developing device consists of (1) a developing roll with a diameter of 20 m and having a surface layer with an electrical resistivity of approximately 1080 am made of thermosetting resin, a reinforcing agent, and graphite, and (2) supplying toner onto the developing roll. a toner supply roll made of conductive rubber; and (3) a surface made of silicone rubber, a reinforcing agent, and a charge control agent that regulates the layer thickness of the toner supplied onto the developing roll by the toner supply roll and imparts an electric charge to the toner. It consists of a blade having layers. The distance between the developing roll and the photoreceptor is 150 μm, and the developing bias is 300 V for DC component and 2.5 KVp for AC component.
-p, 2.5kHz is applied.

In this developing device, the toner is supplied to a mainly mechanical developing roll by a toner supply roll, and then charged by a blade pressed against the developing roll, and forms a substantially single layer of toner on the developing roll, The image is transported to the electrostatic latent image area by mirror image force and van der Waals force, and development is performed.

Example 5 Partially crosslinked polyester resin 100 parts (Tj;
] = 65°C, Hn = 4.700. Mw=5(),
000° acid value = 1.5, hydroxyl value = 20.0, gel fraction -5%) Low molecular weight polypropylene 4 parts Carbon black 10 parts Tetraphenylboron Triphenylmethylphosphonium 2 parts Mixture of the above mixture , by crushing and classifying, the average particle size d 50 = 8 μm
Magnetic powder was obtained. Add hydrophobic silica fine powder (
A toner was obtained by externally adding and mixing 0.7% by weight of Aerosil R-972 and 0.6% by weight of methyl methacrylate resin fine powder. When this toner was used in combination with a ferrite carrier having a particle size of 100 μm and its charging properties were evaluated, it was found that the chargeability was 15 μm under all environments of high temperature and high humidity, normal temperature and humidity, and low temperature and low humidity.
It showed good charging properties of around C/g. Furthermore, FX-38
When the printer was installed in a 00 copying machine and a 5,000 copy test was performed, good images were always obtained.

Effects of the Invention The charge control compound in the present invention is colorless or light-colored and has excellent negative charge control properties, so it is difficult to be colored by other materials such as a black developer or a color developer. It can be used extremely effectively to control the electrification of materials that are disliked. Furthermore, many of the charge control compounds in the present invention are solid substances at room temperature, and most of them are thermally stable, and decompose during toner production, resulting in loss of charge control properties. It also does not melt at low temperatures and impair the toner's storage stability and stability over time.

Therefore, the toner composition of the present invention containing such a charge control compound as a charge control agent has a rapid charge rise, an appropriate amount of negative charge and charge distribution, and has good environmental stability and stability over time. It will be excellent. The toner composition of the present invention is also suitable as a color developer.

Claims (2)

[Claims] (1) A negatively chargeable toner composition containing a compound represented by the following general formula (I) as an essential component. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (In the formula, R_1 represents a hydrogen atom, a halogen atom, an alkyl group, a halogenated alkyl group, an arylalkyl group, or an aryl group, and R_2, R_3, R_4, and R_5
represent a hydrogen atom, an alkyl group, an aryl group and an arylalkyl group, respectively, and n represents an integer of 1 or more. ) (2) The negatively chargeable toner composition according to claim 1, which contains a compound represented by the following general formula (II) as an essential component. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (II) (In the formula, R_6 represents a hydrogen atom, a halogen atom, a lower alkyl group, or a halogenated methyl group, R_7 represents a hydrogen atom or a halogenated methyl group, and R_8 , R_9
, R_1_0 and R_1_1 each represent a lower alkyl group or a phenyl group. )