JPS62280757A - Developer composition - Google Patents

Abstract

PURPOSE:To enhance electrifiability to negative charges, developability, and transferability by incorporating a polymer having polar groups each formed by reacting an acid anhydride group or an acid group obtained by partially esterifying it with a cationic component. CONSTITUTION:The polymer having polar groups each formed by reacting an acid anhydride group or an acid group obtained by partially esterifying it with a cationic component is used as the constituent of a toner. Said polymer is obtained by reacting the polymer having acid anhydride groups or acid groups obtained by partially esterifying them with a cationic component, thus permitting negative electrifiability, developability, and transferability to be improved, and always good image quality to be ensured.

Description

Detailed Description of the Invention 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to a developer composition for visualizing electrical latent images and electrical signals formed in electrophotography, electrostatic recording, etc. The present invention relates to a developer composition with excellent negative chargeability, developability, and transferability.

Conventional technology Various methods are known for imparting charge to developer (toner), including friction, contact charging, ion irradiation, electrostatic induction using conductivity, and charge injection. However, the easiest and most widely used method is friction.
Alternatively, a contact charging method may be used.

In order to impart an electric charge to the toner, the developer used in this case is a two-component developer in which carrier particles that are charged to the opposite polarity to the toner are mixed with the toner, as well as a two-component developer that uses a charging blade, a charging roll, etc. and frictional charging of the toner. Also known is a one-component developer that uses frictional charging between toners.

When toner is charged by contact charging or frictional charging,
It is necessary to control chargeability by adding an electron-donating substance or an electron-attracting substance to the toner side or to the side of charge-imparting materials such as carriers and blades. Triboelectric development is complex, and its mechanism is not necessarily clear; however, in general, electron-donating substances and electron-withdrawing substances are positively charged.

Conventionally, in order to control the charge of toner, (i) dyes and pigments, surfactants, inorganic powders, etc. are added and mixed in the toner or on the surface of the toner particles, (ii) -COOH, - is used as a binder resin. CN, -(11
A method has been taken to use resin-like materials having functional groups such as halogens such as N 2 O 2 and NH 2 .

Problems to be Solved by the Invention However, these means have not succeeded in controlling the temporal stability and environmental stability of toner chargeability.
It has not reached a satisfactory level.

Furthermore, there are no known colorless or light-colored charge control agents that are sufficient for use in color applications.

Therefore, an object of the present invention is to provide a developer composition in which toner charge rises quickly, to provide a developer composition in which the amount of toner charge can be controlled and the charge distribution is sharp, and toner charge environment. It is an object of the present invention to provide a developer composition with excellent stability and stability over time, and therefore to provide a developer composition with improved developability and transferability to ensure good image quality at all times; It is an object of the present invention to provide a developer composition using a colorless or light-colored charge control agent that can be used for forming a charge control agent.

Means and Action for Solving the Problems The above object of the present invention is to provide a developer composition containing a colorant and a binder resin as main components, an acid anhydride group or an acid group resulting from partial esterification thereof, and a cationic acid group. This was achieved by using as a toner component a polymer having polar functional groups formed by reaction with a component.

'r! by the acid anhydride group used in the present invention or its partial esterification! A polymer having a polar functional group formed by the reaction of an i group with a cationic component can be obtained by reacting a polymer having an acid anhydride group or a partial ester structure thereof with a cationic component. It will be done.

Examples of polymers having an acid anhydride group include acrylic anhydride, methacrylic anhydride, acrylic propionic anhydride, acrylic methacrylic anhydride, itaconic anhydride, maleic anhydride, and citraconic anhydride. , dimethyl maleic anhydride, etc. as monomer components are required.

These polymers may be homopolymers of the above-mentioned heptamers having acid anhydride groups, or may be copolymers with other monomers such as styrenes, methacrylates, acrylates, dienes, etc. . In the case of copolymers, in addition to random copolymers, any form of copolymers such as alternating copolymers, block copolymers, graft copolymers, IPN, etc. can be used.

Among them, polymers containing maleic anhydride as a monomer component are
It is manufactured industrially in storage, so it is easy to obtain.

Acid anhydride decomposes in the presence of water, and for example, acrylic anhydride changes to acrylic acid, and maleic anhydride changes to maleic acid. In the present invention, the acid anhydride present in the polymer chain The group may be decomposed in the presence of water to become, for example, two adjacent carboxylic acid groups.

In the present invention, one type of monomer component forming the acid anhydride group may be used, or two or more types may be used.

In these polymers having acid anhydride groups, the acid anhydride groups may be partially esterified. Partial esterification is performed by an esterification reaction with alcohols, for example,
The reaction is carried out as shown below.

0f-10R1 (In the formula, the r°C convex is a polymer chain, and R1 represents an alcohol residue.) In the present invention, a polymer having an acid anhydride group or a partial esterified structure thereof is a cationic component. It is necessary to react with the acid anhydride group or its partially esterified structure to convert it into a polar functional group.

As a cationic component, an acid anhydride group or carboxyl M
Neutralizes with 1 to form Na, Li, AC7, Ca, Z
Gold a salts such as n, Ba, Au, Pb, Ni, etc., 5nR3
, GeR3 (R is an organic group), organic metal salts such as 5bPi (Ph is a phenyl group), or ammonium salts, alkylammonium salts, pyridinium salts, quinolinium salts,
Bases are used that form quaternary ammonium salts, such as imidazolium salts. .

The following is a typical schematic diagram of the polar functional groups formed by these neutralization reactions.

o-c c=o, o=c c=
.

0 0 0 0R1 Na Na+ NH4+ In the present invention, these neutralization reactions are carried out by r! It is not necessary to cover all of the i groups, and a partially neutralized form may be used.

In the present invention, the polar functional group is 0.0 acid group o1% to 1Qm01%, preferably Q, in molar concentration based on one monomer unit in the total toner binder resin of the developer composition.
It is preferable to adjust and use the acid group so that it contains about 1% to 5% of acid groups. Depending on the type of polar functional group, the method of adding it to the toner, the state of dispersion, and the combination with other materials, the optimal concentration of the polar functional group is difficult to determine, but it is less than 0.0 acid group o.
If it is less than 1%, it will have little effect on toner charge control, and if it is more than 10m01%, it will rather have an adverse effect on the charge retention properties and rheological properties of the toner.

When adjusting the polar functional group concentration in the total binder resin of the toner to the above range, the polar functional group of the present invention is introduced into the main binder resin itself of the toner, and the concentration of the polar functional group in the present invention is from about 0.0 acid group ○ 1% to about 1%. Q
The polar functional group concentration may be adjusted to about 1% mo, or the polar functional group concentration may be adjusted to about 1Qmo1%.
More preferably, the highly polar resin containing about 20m01% or more is diluted with another binder resin so that the polar functional group concentration in the entire toner binder resin is about 0.01 to 1%, preferably about 0. It may be adjusted to .1 to 5m01%. However, when adjusting using the latter method,
It is easy to control toner charging and fixing properties independently, and
It is preferable because the charge controllability itself is often excellent.

In addition, the polymer of the present invention has not only an acid anhydride group and a polar functional group formed by a reaction between an acid group and a cationic component by partial esterification thereof, but also an acid anhydride group,
When the toner contains a polar group that affects the chargeability of the toner, such as an acid group, -OH, halogen, -CN, or amine group, the total amount of the above-mentioned polar functional group and the above-mentioned other polar functional group is the toner pre-binding. Preferably, the resin width is about 1Qmo1% or less.

The polymer containing a polar functional group in the present invention may have any molecular weight depending on the purpose, but in order to prevent blocking, a polymer with a glass transition temperature TCI>50° C. is preferable.

In addition, when using other binder resins, styrene-based,
Acrylic, olefin, polyester, epoxy,
Any material such as polycarbonate, polyamide, polyurethane, silicone type, fluorine type, petroleum resin, etc. can be used.

The polar functional group-containing polymer in the present invention may be added externally to toner particles in the form of a fine powder, or may be used in the form of a capsule toner in which a layer containing it is provided on the surface of the toner particles. It's okay.

In the developer composition of the present invention, known colorants and other components can be used. For example, dyes and pigments such as carbon black, cyan, magenta, and yellow colors can be used as colorants, as well as magnetic materials such as ferrite, conductivity modifiers, inorganic materials such as metal oxides, reinforcing fillers, and antioxidants. Agents, etc. can be included. Further, a known charge control agent may be used in combination.

The developer composition of the present invention may contain external additives. As external additives, conventionally known additives such as anti-wrinkle, carbon, alumina, titanium oxide, zinc oxide, fine resin powder, and tin oxide are used.

In the developer composition of the present invention, the toner is produced by a kneading and pulverizing method.
It can be produced by any public method such as a spray drying method or a direct polymerization method.

The average particle size d50 of the toner measured by Coulter Counter method is preferably in the range of 1 to 20 μm, more preferably in the range of 5 μm to 15 μm.

Examples Next, the present invention will be explained by examples.
It is not limited to these.

Example 1 0 Styrene/butyl acrylate/85 parts 2-ethylhexyl acrylate copolymer (T!; 1=60°C, Hn=8.000.
Mw=27.000)○Styrene/maleic anhydride 1
:1 Co5-part polymer is partially esterified with alcohol to prepare a styrene/partially esterified maleic anhydride copolymer with an acid value of 170, and further reacted with potassium hydroxide to convert it into potassium salt. Combined Carbon Black 10 parts The above components were mixed and pulverized to obtain 50 parts of a toner having a particle size d of 12 μm. This was mixed with an iron powder carrier coated with methyl methacrylate resin, and the amount of charge was measured using the blow-off tribo method.
0'C, RH20%) and high temperature and high humidity (35°C, RH8
0%), the following results were obtained.

Normal temperature and humidity: about -21 μC/Q Low temperature and low humidity: about -20 μC/Cl High temperature and high humidity: about -18 μC/Cl As is clear from the results, the above-mentioned toner exhibited extremely good charging properties under all environments. In addition, charging started quickly, and there was no toner of opposite polarity.

To this toner, 0.7% by weight of hydrophobic silica fine powder and 0.6% by weight of higher fatty acid metal salt were added and mixed, and a ferrite carrier with a particle size of about 80 tin was coated with methyl methacrylate resin and silicone resin. A developer was obtained by mixing with Using this developer, we conducted a running test on a copying machine (FX-2830, manufactured by Fuji Xerox Co., Ltd.), and during a continuous copy test of 50,000 sheets, copies with extremely good image quality were obtained. .

Example 2 0 styrene/butyl acrylate 40 parts copolymer (T(1=60°C, )In=8.000. Mw=
27.000)○Styrene/butyl acrylate
40 parts copolymer (T (1=65°C, Hn=170.
000゜MW=480.000) Styrene/maleic anhydride from Example 1 1 10 parts Modified neutralized salt of copolymer O Low molecular weight polypropylene wax 3 parts O Carbon black 7 parts The above ingredients were mixed and pulverized. , 50 copies of toner having a particle size d of 12 μm were obtained. When this was mixed with an iron powder carrier coated with methyl methacrylate resin and the amount of charge was measured using the blow-off tribo method, the amount of charge was approximately It was extremely stable, ranging from -15 μC/CJ to about -19 μC/C1. In addition, charging started quickly, and there was no toner of opposite polarity.

This toner was further mixed with 0.7% by weight of hydrophobic silica fine powder and 0.6% by weight of methyl methacrylate resin powder, and further mixed with the carrier to obtain a developer. Using this developer, a running test was conducted on a copying machine (FX-2830■), and copies with extremely good image quality were obtained during a continuous copying test of 50,000 sheets.

Example 3 0.8% by weight of hydrophobic silica fine powder was added to the toner of Example 2.
A -component developer was prepared by adding and mixing 0.3% by weight of methyl methacrylate resin fine powder. Using this developer,
Copying machine (modified Fx) equipped with the one-component developing device shown in the drawing
-2s3o@>, a continuous copying test of 10,000 sheets was performed, and very good images were obtained.

Incidentally, in the one-component developing machine shown in the drawings, reference numeral 1 denotes a charging/metalling blade, which is made of modified silicone rubber and plays the role of imparting an electric charge to the toner through frictional charging. 2 is a developing roll whose surface layer has an electrical resistivity of approximately 1010Ω.
-cm hard resin roll. The charged toner is held on a roll and transported to a latent image area for development. Reference numeral 3 denotes an auxiliary roll, which is a rubber roll having an electrical resistivity of about 10 3 Ω·cm. The 19th step is to level out the charging history of the toner and mechanically supply the toner onto the developing roll.

Note that 4 is toner.

Example 4 0-styrene/butyl acrylate 93 parts copolymer (9=65°C, Hn=5,000.1 (w=40,
000)○Styrene/maleic anhydride copolymer 3
1 part ammonium chloride (acid value about 270) 4 parts disazo yellow pigment The above components were mixed and ground to obtain a yellow toner having a particle size d50=12μ. When this was mixed with an iron powder carrier coated with methyl methacrylate resin and the amount of charge was measured using the blow-off tribo method, the amount of charge was approximately -13μC/
The range was from Cl to about -17 μC/CI, which was extremely good. In addition, charging started quickly, and there was no toner of opposite polarity.

This toner was further mixed with 0.6% by weight of hydrophobic silica fine powder and 0.5% by weight of higher fatty acid metal salt to obtain a developer. When this developer was used in a running test on a copying machine (FX-28300), yellow images of extremely good quality were obtained during a continuous copying test of 10,000 sheets.

Example 5 0 Styrene/n-butyl acrylate/37 parts Sodium maleate copolymer (T (+=65°C, about 5 mo1% of sodium maleate)
○Styrene/butyl acrylate 60 parts copolymer (Tg=65°C,) in=7,000. )lv=1
8,000) ○Copper phthalocyanine pigment
3 parts The above ingredients are kneaded and pulverized by a conventional method to obtain particle size d.
A cyan toner of 50=8 μm was obtained. This was mixed with a ferrite carrier having a particle size of 60 μm coated with a methyl methacrylate resin. When the amount of charge was measured using a blow-off tribo in the same manner as in Example 1, the following results were obtained.

Normal temperature and humidity: Approximately -17μc/g Low temperature and low humidity: Approximately -16μC/F High temperature and high humidity: Approximately -11μc/q From these results, it was found that there was a tendency for the amount of frictional charging to be slightly lower at high temperature and high humidity, but this was practically a problem. It showed stable charging properties, and the rise of charging was quick. In addition, there was almost no toner of reverse polarity, even under high temperature and high humidity, and the performance was very good.

This toner was further mixed with 0.8% by weight of hydrophobic silica fine powder and 0.5% by weight of methyl methacrylate resin powder, and further mixed with the carrier to form a developer. Using this developer, use a copying machine (FX-28300) for 10,
When a continuous copying test of 1,000 copies was conducted, extremely good cyan images were obtained.

Comparative Example 1 0 styrene/butyl acrylate/90 parts 2-ethylhexyl acrylate copolymer (Tg=65°C, Mn=17,000J1w
=58,000)○Carbon black
10 parts of the above components were kneaded and pulverized by a conventional method to obtain a toner having a particle size d50=12 μm. This was mixed with a carrier and iron powder having a particle size of approximately 100 μm coated with a methyl methacrylate resin. When the amount of charge was measured using a blow-off tribo in the same manner as in Example 1, the following results were obtained.

Normal temperature and humidity: Approximately -13μC/c7 Low temperature, low humidity: Approximately -15μC/Cl High temperature, high humidity: Approximately -6μC/g Also, this toner has a slow charge rise, and when the charge distribution is measured using a charge spectrograph method, the amount of toner with opposite polarity It turns out that there are many.

Comparative Example 2 0 Styrene / Butyl acrylate / 90 parts Maleic anhydride copolymer (acid value 15) ○ Carbon black 10 parts Mix 1 cup of the above ingredients and grind to make 1 q of toner with an average particle size of about 12μ skin. . The above toner was mixed into an iron powder carrier having a particle size of about 100 .mu.m to a concentration of about 3%. Example 1
When the blow-off charge amount was measured in the same manner as in , it was approximately -12μC/Q at room temperature and humidity, but the rise of charge was slow, and even when measured by charge spectrograph, the charge distribution was wide, and the amount of toner with opposite polarity was low. There were many. In addition, under high temperature and high humidity conditions, the blow-off charge amount is approximately -6 μ
C/C1, the amount of reverse polarity toner further increased, and the environmental stability of charging was poor.

Effects of the Invention The developer composition of the present invention contains a polymer having a polar functional group formed by the reaction of an acid anhydride group or an acid group by partial esterification thereof with a cationic component. Excellent chargeability, developability, and transferability.

That is, the developer composition of the present invention has a quick rise in toner charge, allows control of the amount of charge on the toner, and has a sharp charge distribution, and has excellent environmental stability and stability over time in toner charge. There is. Therefore, the developability and transferability of conventional developer compositions are improved, and copies of good image quality can always be obtained. Furthermore, since the polymer is colorless or light-colored, the developer composition of the present invention is effective in forming color images.

The developer composition of the present invention can be applied to both a two-component developing method using a carrier and a one-component regular imaging method not using a carrier.

[Brief explanation of drawings]

The drawing is a sectional view of essential parts of a one-component developing machine for using the developer composition of the present invention. DESCRIPTION OF SYMBOLS 1... Charging/metalling blade, 2... Developing roll, 3... Auxiliary roll, 4... Toner.

Claims (1)

[Claims] In a developer composition containing a colorant and a binder resin as main components, a polymer having a polar functional group formed by a reaction between an acid anhydride group or an acid group resulting from partial esterification thereof and a cationic component. A developer composition comprising: