JPH0740143B2 - Developer composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a developer composition for visualizing an electric latent image or an electric signal in electrophotography, electrostatic recording, etc., and particularly to negative charging property, developability and transfer property. The present invention relates to a developer composition having excellent properties.

BACKGROUND ART Various methods such as friction, contact charging method, ion irradiation method, electrostatic induction method utilizing conductivity, and charge injection method are known as methods for imparting electric charge to a developer (toner). But,
The most convenient and widely used method is the friction or contact charging method.

In order to give an electric charge to the toner as a developer used in this case, in addition to a two-component developer in which carrier particles charged with a polarity opposite to that of the toner are mixed with the toner, friction charging of the toner with a charging blade or a charging roll is used. Alternatively, a one-component developer that uses triboelectric charging between toners is known.

When charging the toner by such contact charging and friction charging,
It is necessary to add an electron-donating substance or an electron-withdrawing substance to the toner side or the charge-giving material side such as a carrier or a blade to control the charging property. Although triboelectrification development is complicated and its mechanism is not always clear, generally, an electron-donating substance is positively charged and an electron-withdrawing substance is negatively charged.

Conventionally, in order to control the charging of the toner, (i) a dye or pigment, a surfactant, an inorganic powder or the like is added and mixed in the toner or on the surface of the toner particles, (ii) as a binder resin, -COOH,- CN, halogen -Cl etc., -NO _2, a resin-like material having a functional group such as -NH _2, means have been taken that.

Problems to be Solved by the Invention However, these means have not succeeded in controlling the temporal stability of the toner charging property and the environmental stability.
Not at a satisfactory level.

Further, sufficient colorless or light-colored charge control agents usable for colors have not been known.

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

Means and Actions for Solving Problems The above object of the present invention is to provide a developer composition containing a colorant and a binder resin as main components, with an acid anhydride group or an acid group obtained by partial esterification thereof, and a monovalent group. A polymer having a polar functional group formed by the reaction with a cationic component of
It was achieved by using a specific amount as a toner constituent component, that is, by containing polar functional groups in a molar concentration of 0.01 mol% to 10 mol% based on a monomer unit.

The polymer having a polar functional group formed by the reaction of an acid anhydride group or an acid group obtained by partial esterification thereof used in the present invention with a monovalent cationic component is an acid anhydride group or a partial ester thereof. It is obtained by reacting a polymer having a compound structure with a monovalent cationic component.

As the polymer having an acid anhydride group, for example, acrylic acid anhydride, methacrylic acid anhydride, acrylic acid propionic acid anhydride, acrylic acid methacrylic acid anhydride, itaconic acid anhydride, maleic anhydride, citraconic acid anhydride. And a polymer containing dimethyl maleic anhydride as a monomer component.

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

Among them, a polymer containing maleic anhydride as a monomer component,
It is easy to obtain because it is manufactured industrially at low cost.

The acid anhydride is decomposed in the presence of water, for example, acrylic acid in the case of acrylic acid anhydride is changed to maleic acid in the case of maleic anhydride, but in the present invention, the acid anhydride present in the polymer chain is used. The group may be decomposed in the presence of water to be converted into, for example, two adjacent carboxylic acid groups.

In the present invention, the monomer component forming the acid anhydride group may be one kind or two or more kinds.

In the polymer having these acid anhydride groups, the acid anhydride group may be partially esterified. Partial esterification is carried out by an esterification reaction with alcohols, for example,
The reaction is performed according to the following formula.

(In the formula Is a polymer chain and R ₁ represents an alcohol residue. ) In the present invention, the polymer having an acid anhydride group or a partial esterified product structure thereof is reacted with a monovalent cationic component to convert the acid anhydride group or a partially esterified product structure thereof into a polar functional group. It is necessary.

Examples of the monovalent cationic component include a neutralization reaction with an acid anhydride group or a carboxylic acid group to form an alkali metal salt such as Na, K, Li, or an ammonium salt, an alkyl ammonium salt,
Bases are used which form quaternary ammonium salts such as pyridinium salts, quinolinium salts, imidazolium salts and the like.

The following are typical examples of polar functional groups formed by these neutralization reactions.

In the present invention, these neutralization reactions do not have to be performed over all of the acid anhydride groups in the polymer or the acid groups resulting from the esterification thereof, and may be in a partially neutralized form.

The polar functional group in the present invention is 0.01 mol% to 10 mol%, preferably 0.1 mol% to 5 mol in terms of molar concentration based on the monomer unit in the total toner binder resin of the developer composition.
Adjust it so that it is contained in about%. The optimum concentration of the polar functional group is difficult to determine depending on the type of the polar functional group, the method of addition into the toner, the dispersion state, and the combination with other materials. There is almost no effect on the charge control, and when it is more than 10 mol%, the charge retention and the rheological properties of the toner are rather adversely affected.

When the polar functional group concentration in the total binder resin of the toner is adjusted 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 polar functional group concentration of about 0.01 mol% to 10 mol% is added. May be adjusted so that the polar functional group is, for example, 10 mol% or more, and more preferably 20 mol%.
% Or more of the high-polarity resin may be diluted with another binder resin to adjust the polar functional group concentration of the entire toner binder resin to 0.01 to 10 mol%, preferably 0.1 to 5 mol%. However, the latter method is preferable because the chargeability and the fixability of the toner can be controlled independently and the charge controllability itself is often excellent.

Further, the polymer in the present invention, in addition to an acid anhydride group and a polar functional group formed by the reaction of an acid group by partial esterification thereof with a monovalent cationic component, further, an acid anhydride group, an acid group , -OH, halogen, -CN, an amino group, or other polar group that influences the charging property of the toner, the total amount of the polar functional group and the other polar functional group is in the binder resin before the toner. It is preferably about 10 mol% or less.

The polymer containing the polar functional group in the present invention may have any molecular weight depending on the purpose, but it is preferable that the glass transition temperature Tg> 50 ° C. is used for preventing blocking.

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

The polar functional group-containing polymer in the present invention may be externally added to the 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 the same is provided on the surface of the toner particles. May be.

In the developer composition of the present invention, known components can be used as the colorant and other components. For example, as the colorant, dyes and pigments such as carbon black, cyan, magenta, and yellow colors can be used, and other magnetic substances such as ferrite, conductivity adjusters, inorganic substances such as metal oxides, reinforcing fillers, and antioxidants. Agents and the like can be included. A known charge control agent may be used in combination.

An external additive may be used in the developer composition of the present invention. As the external additive, conventionally known ones such as silica, carbon, alumina, titanium oxide, zinc oxide, resin fine powder and tin oxide can be used.

In the developer composition of the present invention, the toner is kneaded and pulverized,
It can be produced by any known method such as a spray dry method or a direct polymerization method.

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

EXAMPLES Next, the present invention will be described by way of examples.
It is not limited to these.

Example 1 styrene / butyl acrylate / 85 parts 2-ethylhexyl acrylate copolymer (Tg = 60 ° C. Mn = 8,000.Mw = 27,000) 1: 1 styrene / maleic anhydride 5 parts copolymer with alcohol Polymer obtained by partially esterifying and preparing a styrene / partially esterified maleic anhydride copolymer having an acid value of about 170, further reacting it with potassium hydroxide, and potassium salting it. Carbon black 10 parts above Were mixed and pulverized to obtain a toner having a particle diameter d50 = 12 μm. This was mixed with an iron powder carrier coated with a methylmethacrylate resin, and the charge amount was measured by the blow-off tribo method.
The following results were obtained under all environments of high temperature and high humidity (35 ℃, RH80%).

Room temperature and normal humidity -21 μc / g Low temperature and low humidity -20 μc / g High temperature and high humidity -18 μc / g As is clear from these results, the above toners exhibited extremely good charging properties under all environments. In addition, the charge rises quickly and there is no reverse polarity toner.

This toner has a high hydrophobic silica fine powder content of 0.7% by weight.
Add 0.6% by weight of fatty acid metal salt, mix, and add methyl
Grains coated with methacrylate resin and silicone resin
A developer is obtained by mixing with a ferrite carrier with a diameter of about 80 μm.
It was Using this developer, copy machine (Fuji Xerox Co., Ltd.)
Made, FX-2830 ), The driving test was performed
Very good quality copy during continuous single copy test
was gotten.

Example 2 styrene / butyl acrylate 40 parts copolymer (Tg = 60 ° C. Mn = 8,000.Mw = 27,000) styrene / butyl acrylate 40 parts copolymer (Tg = 65 ° C. Mn = 170,000. Mw = 480,000 ) Styrene / maleic anhydride 10 parts of Example 1 Modified neutralization salt of copolymer ○ Low molecular weight polypropylene wax 3 parts ○ Carbon black 7 parts The above components are mixed and ground to a particle size d50 = 12 μm. Toner was obtained. This was mixed with an iron powder carrier coated with a methylmethacrylate resin, and the charge amount was measured by the blow-off tribo method.It was found that the charge amount was approximately room temperature and normal humidity, low temperature and low humidity, and high temperature and high humidity. The range was from -15 μc / g to about -19 μc / g, which was extremely stable. Also,
The charge started up quickly and there was no reverse polarity toner.

This toner further contains 0.7% by weight of hydrophobic silica fine powder and
Mixing 0.6% by weight of methylmethacrylate resin powder,
Further, it was mixed with the carrier to obtain a developer. This development
Copying agent (FX-2830 ) Was run test
However, during the continuous copying test of 50,000 sheets, extremely good
A good quality copy was obtained.

Example 3 The toner of Example 2 was prepared by adding 0.8% by weight of hydrophobic silica fine powder,
0.3% by weight of fine powder of chill methacrylate resin was added and mixed.
Then, a one-component developer was prepared. Drawing using this developer
Copier with the one-component developing device shown in (Modified FX-2830
), A continuous copy test of 10,000 sheets was performed.
A good image was obtained.

In the one-component developing machine shown in the drawings, numeral 1 is a charging / metalling blade made of modified silicone rubber, which plays a role of imparting an electric charge to the toner by frictional charging. 2 is a developing roll, which has an electric resistivity of the surface layer of about 10 ¹⁰ Ω · cm
Is a hard resin roll. The charged toner is held on the roll and is conveyed to the latent image portion for development. 3 is an auxiliary roll, which is a rubber-like roll having an electric resistivity of about 10 ³ Ω · cm. It serves to smooth the charge history of the toner and mechanically supply the toner onto the developing roll. In addition, 4 is a toner.

Example 4 ○ Styrene / butyl acrylate 93 parts Copolymer (Tg = 65 ° C. Mn = 5,000.Mw = 40,000) ○ Styrene / maleic anhydride copolymer 3 parts Ammonium chloride (acid value approx. 270) ○ Disazo Yellow pigment 4 parts The above components were mixed and pulverized to obtain a yellow toner having a particle diameter d50 = 12 μm. This is mixed with an iron powder carrier coated with methylmethacrylate resin and blow-off /
When the charge amount was measured by the tribo method, the charge amount was about -13 μc / g in all environments of normal temperature and normal humidity, low temperature and low humidity, and high temperature and high humidity.
To about −17 μc / g, which was extremely good. In addition, the charge rises quickly and there is no reverse polarity toner.

This toner was further mixed with 0.6% by weight of hydrophobic silica fine powder and
A developer was obtained by mixing 0.5% by weight of a higher fatty acid metal salt.
Using this developer, copy machine (FX-2830 ) Run test
During the continuous copying test of 10,000 sheets,
And a yellow image of good quality was obtained.

Example 5 Styrene / n-butyl acrylate / 37 parts Sodium maleate copolymer (Tg = 65 ° C., sodium maleate about 5 mol%) ○ Styrene / butyl acrylate 60 parts Copolymer (Tg = 65 ° C. Mn = 7,000.Mw = 18,000) ○ Copper phthalocyanine pigment 3 parts The above components are kneaded and pulverized by a conventional method to give a particle size d50 = 8.
A cyan toner of μm was obtained. This was mixed with a ferrite carrier coated with a methyl methacrylate resin and having a particle size of about 60 μm. When the charge amount was measured by the blow-off tribo in the same manner as in Example 1, the following results were obtained.

Room temperature and normal humidity Approx. -17 μc / g Low temperature and low humidity Approx. -16 μc / g High temperature and high humidity Approx. However, it showed stable chargeability, and the rise of charge was quick. In addition, there was almost no reverse polarity toner including high temperature and high humidity, which was very good.

This toner was further added with 0.8% by weight of hydrophobic silica fine powder and
Mix 0.5% by weight of methyl methacrylate resin powder,
Further, it was mixed with the carrier to obtain a developer. This development
Copying agent (FX-2830 ) With 10,000 copies
After testing, I got a very good cyan image
It was

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

Room temperature and normal humidity Approx. -13 μc / g Low temperature and low humidity Approx. -15 μc / g High temperature and high humidity Approx. It turns out that there are many.

Comparative Example 2 styrene / butyl acrylate / 90 parts maleic anhydride copolymer (acid value about 15) carbon black 10 parts The above components were kneaded and pulverized to obtain a toner having an average particle diameter of about 12 μm. The above toner was mixed with an iron powder carrier having a particle size of about 100 μm so that the toner concentration would be about 3%. When the blow-off charge amount was measured in the same manner as in Example 1, it was about −12 μc / g at room temperature and normal humidity, but the rise of charge was slow, and the charge distribution was wide even when measured by the charge spectrograph method. The amount of polar toner was large. Also, in the high temperature and high humidity state, the blow-off charge amount is about −6 μm.
It became c / g and 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 between an acid anhydride group or an acid group by partial esterification thereof and a monovalent cationic component. Therefore, it is excellent in negative charging property, developing property and transfer property.

That is, the developer composition of the present invention has a rapid rise in toner charge, can control the charge amount of toner, has a sharp charge distribution, has excellent environmental stability of toner charge, and has excellent stability over time. There is. Therefore, the developability and transferability of the conventional developer composition are improved, and a copy having 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 for forming a color image.

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

[Brief description of drawings]

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

Claims (1)

[Claims] 1. A developer composition comprising a colorant and a binder resin as main components, which is formed by reacting an acid anhydride group or an acid group resulting from partial esterification thereof with a monovalent cationic component. Polymers with polar functional groups, the polar functional group is 0.01mol% in molar concentration based on the monomer unit
To 10 mol% of the developer composition.