JPS63226665A - Toner composition - Google Patents

Abstract

PURPOSE:To enhance negative chargeability, developing performance, transferability, and fixability by incorporating in a toner composition an organic boron ammonium compound having a specified structure as an essential component. CONSTITUTION:The organic boron ammonium compound to be incorporated in the negatively chargeable toner composition is represented by formula I in which R is halogen, alkyl, haloalkyl, aralkyl, or aryl; n is an integer of >=1; the sum of the carbon atoms contained in R2, R3 and R4 is <=21; and when n is >=2, each of (R1)s may be independent of each other. The chargeability of the toner can be extremely enhanced by using, concretely for example, tetraphenyl-B-ammonium or tetraquis[3,5-bis(trifluoromethyl)phenyl-boron- ammonium.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a toner 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 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 to 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. Measures have been taken to use resinous materials having functional groups such as halogens such as COOHl-CN and -CI, -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 an adverse effect on the chargeability of toners, and controlling the 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, the particle size of toner has been reduced. In addition, when trying 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 method has the advantage that it is 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 (1) 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, and R4 each represent a hydrogen atom, an alkyl group, an arylalkyl group, or an aryl group. represents a group, and n represents an integer of 1 or more.However, the total of carbon atoms contained in the functional groups of R2, R3, and R4 is 21 or less, and n represents an integer of 2 or more. When expressed, each R1 may be the same or different.

Hereinafter, the toner composition of the present invention will be explained in detail.

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, When it represents an arylalkyl group or an aryl group and n is 2 or more, each R1 may be the same or different. Further, R2, R3 and R4 each represent 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, or an arylalkyl group such as a benzyl group. However, since the negative charging ability of the charge control compound used in the present invention depends on the strength and size balance of the ions of the anionic component and the cationic component, care must be taken in selecting the substituents R2, R3, and R4. It takes. That is, when the ion of the cationic component is large, the charge control compound loses its negative charging ability and instead begins to show positive charging ability, so special care is required. In addition, when using a 4-substituted cation component with no hydrogen atom bonded to the nitrogen atom, even when the substituent is small,
Although the compound exhibits negative chargeability, the rise in charge is slow.

Therefore, the charge control compound used in the present invention is
It is necessary that at least one hydrogen atom is bonded to a nitrogen atom, and that the total number of carbon atoms contained in the substituents R, R, and R4 of the cationic component is 21 or less. It has a quick rise and 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, R5 represents a hydrogen atom, a halogen atom, a lower alkyl group, or a halogenated methyl group, R6 represents a hydrogen atom or a trifluoromethyl group, and R, R, and R9 are a hydrogen atom and the number of carbon atoms, respectively. 1 to 21 alkyl groups or phenyl groups, provided that the total number of carbon atoms contained in R7, R8, and R9 is 21 or less.) Specific examples thereof are illustrated below.

Tetraphenyl is boronate ammoniumtetraphenyl is boronate cetyl ammoniumtetraphenyl is boronate trimethylammoniumtetraphenyl is boronate triethylammoniumtetraphenyl is boronate-N-phenylammoniumtetra (p-fluorophenyl) is boronate ammonium tetra( p-chlorophenyl) is boronate ammonium tetra(p-tolyl) boronate ammonium tetrakis [
3,5-bis(trifluoromethyl)phenyl]boronic ammonium These charge control compounds have a sufficient charge control effect by themselves, but may be used in combination with known charge control agents. Further, in the present invention, the charge control compound may be a single compound, or may be a mixture of two or more compounds or a solid solution.

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. When the charge control compound according to the present invention is added and mixed into the toner, it may be mixed mechanically with the binder resin by melt mixing, emulsion mixing, solution mixing, etc., or it may be mixed in the presence of the charge control compound. Alternatively, 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 occur between the charge control compound of the present invention 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 vinyl monomers such as maleic esters, maleic anhydride, vinyl chloride and 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.

Colorants used in the toner of the present invention include black dyes and pigments such as carbon black, oil black, and graphite:
C,1, Pigment Yellow 1, 3, 74, 97, 98 and other acetoacetate arylamide monoazo yellow pigments (fast yellow series); C,1, Pigment Yellow
Yellow dyes such as acetoacetate arylamide disazo yellow pigments such as Yellow 12, 13 and 14; C,1, Solvent Yellow 19, 77 and 79; C,1, yellow dyes such as Disperse Yellow 164; 1, Pigment・
Red 48, Red 49:1, Red 53:1, Red 57: Red or pink pigments such as L Red 81, Red 122, Red 5; C, 1,
Red dyes such as Solvent Red 52, Solvent Red 5B, and Solvent Red 8: C,1, Pigment Blue 15:3 Blue dyes and pigments such as copper fuclocyanine and its derivatives and modified products C,1, Pigment Green 7 , 36 (phthalocyanine green), colored or colorless sublimable dyes, and other dyes and pigments conventionally known for printing inks and other coloring applications can be used.

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 content is about 2% to 10%. 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 sufficient negative chargeability by itself, but if necessary, a magnetic material such as ferrite may be used.
Addition of conductivity modifiers, inorganic substances such as metal oxides such as tin oxide, silica, alumina, titanium oxide, and zinc oxide, reinforcing fillers such as extender pigments and fibrous substances, antioxidants, mold release agents, etc. can do.

Furthermore, it improves the powder fluidity and charging properties of the toner on the surface of the toner particles, prevents toner from filming on the surface of the photoconductor and carrier particles, and improves the cleaning performance of residual toner on the photoconductor. For this purpose, various external additives can be attached or fixed. 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 fluoride, silicon carbide, boron nitride, silica, alumina, titanium dioxide, and All conventionally known materials can be used, such as inorganic powders such as zinc, resin powders such as fluororesins, acrylic resins, and silicone resins, polycyclic aromatic compounds, and waxy substances.

The method for producing the toner composition of the present invention includes cross-wire pulverization 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; (ii) Neutralized salt type structure, (i) Stabilization of boron anion by resonance effect of phenyl group, (iv) Ionic strength and size of organic amine cation and tetraphenyl boron anion as counter method This is presumed to be due to the fact that the exchange and movement of electrons and/or ions in the compound itself and in the composite material in which the compound is dispersed or dissolved in a polymer or the like is promoted due to the effect of a good balance between the two.

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 steel represent "parts by weight" unless otherwise specified. Further, Tg represents the glass transition temperature, 811 represents the number average molecular weight 1, and Mw represents the weight average molecular weight. Furthermore,
Normal temperature and humidity is 22°C, 155% R, H, high temperature and humidity is 28
℃, 85% R0H0, low temperature and low humidity is 10℃, 15% R,H
, means the environment of .

Example 1 Styrene/n-butylmeth 100 parts acrylate copolymer (T!1J=65°C, Mn=23.000. Hw=
65.000 >Magenta pigment
5 parts (C, 1, Pigment Red 57:1) ammonium tetraphenylboron 1 part The above mixture was mixed, pulverized, and classified to obtain magenta toner particles having an average particle size d50=104 m.

This toner was mixed with a ferrite carrier having an average particle size of about 80 μm at a polymerization ratio of 3/100 to prepare a developer. 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 1 The same procedure was used as in Example 1, except that only tetraphenyl ammonium boron was removed from the toner of Example 1, and d50=10.
A μm toner was obtained.

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 cannot be used (Note)
× means that the level is not usable.

Comparative Example 2 Styrene/n-butyl meth 100 parts acrylate copolymer (at -65°C, ln=23,000. Hw=65
,000 >Magenta pigment 5
Part (C,1, Pigment Red 57:1)Tetraphenylboron
=10 μm magenta toner particles were obtained.

Using this toner, the charging property was evaluated in the same manner as in Example 1. As shown in the table below, the toner was resistant to electrification.Comparative Example 3: Styrene/n-butyl meth 100 parts =23.000.MW=6
5.000 >Magenta pigment
5 parts (C, 1, Pigment Red 57:1) Tetraphenyl 1 part Ammonium
=10 μm magenta toner particles were obtained.

Using this toner, the chargeability was evaluated in the same manner as in Example 1. As shown in the table below, although the toner exhibited negative chargeability, the rise of charge was slow and unsatisfactory.

Example 2 Styrene/n-butyl meth 100 parts acrylate copolymer (TO=65°C, Hn=23.000. Hw=65
．． 000) Magenta pigment 5
Part (C, 1, Pigment Red 57:1) Tetraphenyl Cetyl Boron 1 Part Ammonium The above mixture was kneaded, pulverized and classified to obtain an average particle size d50.
=10 μm magenta toner particles were obtained.

This toner was mixed with a ferrite carrier having an average particle size of about 80 μm at a polymerization ratio of 3/100 to prepare developer Preparation I. When the chargeability was evaluated using the charge spectrogram method, the results shown in the table below were obtained.

Example 3 Styrene/n-butyl acrylic 45 parts rate/2
-Ethylhexyl acrylate copolymer (Tg=60°C, Hn=150,000.) 1w=40
0,000) Styrene/n-butyl urethane 50
acrylate copolymer (Tg=60°C, Hn=4.000. Mw=50
．． 000) Low molecular weight polypropylene 5
5 parts cyan pigment (C, 1
, Pigment Blue 15:3) Tetraphenylborotrimethylammonium 1 part The above mixture was kneaded, pulverized, and classified to obtain a cyan toner having an average particle size d50 of 12 μm. This toner contains 0.7% by weight of hydrophobic silica fine powder and 0.8% by weight of polymethyl methacrylate fine powder.
FX-2830 copier (manufactured by Fuji Xerox) was used in combination with a ferrite carrier whose surface was treated with fluorosilane having a particle size of approximately 100 μm.
5 under each environment of high temperature and high humidity, normal temperature and humidity, and low temperature and low humidity.
000 sheets, a total of 15,000 sheets, and good images were always obtained.

Example 4

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, and R_4 are Each represents a hydrogen atom, an alkyl group, an arylalkyl group, or an aryl group, and n represents an integer of 1 or more.However, the total number of carbon atoms contained in R_2, R_3, and R_4 is 21 or less, and When n represents an integer of 2 or more, each R_1 may be the same or different.) (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_5 represents a hydrogen atom, a halogen atom, a lower alkyl group, or a halogenated methyl group, R_6 represents a hydrogen atom or a halogenated methyl group, and R_7 , R_8
and R_9 are each a hydrogen atom and a carbon atom number of 1 to 21
represents an alkyl group or a phenyl group. However, R_7,
The total number of carbon atoms contained in R_8 and R_9 is 21 or less. )