JPH06180513A - Toner composition - Google Patents

Abstract

PURPOSE:To provide a toner compsn. having a large max. amt. of electric charges, a high electrostatic charge speed and more satisfactory electrostatic chargeability, stable to an environmental change and a change with the lapse of time and not contaminating the inside of a copying machine even after use for a long time. CONSTITUTION:This toner compsn. consists of toner particles and an electrostatic charge controlling agent consisting of a cationic component and an anionic component. The electrostatic charge controlling agent exists at least on the surfaces of the toner particles or near the surfaces. The cationic component of the electrostatic charge controlling agent is represented by the general formula, the anionic component is an org. or inorg. anion and the size of the anionic component is smaller than that of the cationic component. In the formula, each of X and Y is N or P and each of R1-R6 is hydrophobic aliphatic hydrocarbon or hydrophobic arom. hydrocarbon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention directly corresponds to an electric signal or the like without visualizing an electrostatic latent image on a recording material such as paper, cloth, film or forming an electrostatic latent image. The present invention relates to a toner composition used for forming an image.

[0002]

2. Description of the Related Art A method for forming an electrostatic latent image is well known in the art. For example, in electrophotography, a photoconductor layer is usually charged, and then a photoimage based on an original is applied to the photoimage. An electrostatic latent image is formed by reducing or eliminating the electrostatic charge of a part. Next, the formed electrostatic latent image is developed with a developer called toner. As is well known, developers are roughly divided into wet developers and dry developers, but when the former is used, there are problems with odor, handleability, safety, etc., so in recent years development methods using dry developers have been used. Is the mainstream. Further, dry developers are classified into one-component developers and two-component developers based on their constitution. A two-component developer is often selected from the standpoint of stability of charging, easiness of charge control, and the like. On the other hand, for a one-component developer, a charge imparting member corresponding to a carrier of the two-component developer is used. In many cases, a one-component developer uses frictional charging or contact charging as in the toner charging process of a two-component developer. The largest performance required of these developers is the performance relating to the charging property. Therefore, many efforts have been made in the past to obtain an appropriate amount of charge as quickly and stably as possible. Further, in order to improve the charging property, various compounds have been proposed as charge control agents from the viewpoint of toner materials, and they are used by being mixed, adhered or chemically bonded to other toner constituent materials or the toner itself.

[0003]

However, conventionally known charge control agents include a wide variety of organic and inorganic materials ranging from low molecular weight to high molecular weight, and a toner constituent material and a specific combination are selected. However, it is not effective for all toner particles. Furthermore, if other additives are used in order to improve performance other than chargeability, problems may occur such that the charge polarity of the toner particles is reversed and an appropriate charge amount cannot be obtained. was there. Therefore, the present invention has been made in view of the above points in the prior art, and an object thereof is a toner composition having a high maximum charge amount, a high charging speed, and better chargeability. To provide. Another object of the present invention is to provide a toner composition that can provide stable image quality with respect to the environment and changes with time. Another object of the present invention is to provide a toner composition which does not contaminate the inside of the copying machine even after long-term use.

[0004]

As a result of intensive studies, the present inventor has found that the presence of a specific charge control agent on the surface of toner particles and in the vicinity thereof achieves the above object. The present invention has been completed.

The toner composition of the present invention comprises toner particles and
A charge control agent comprising a cation component and an anion component, wherein the charge control agent is present at least on or near the surface of the toner particles, and the cation component of the charge control agent is represented by the following general formula (I ), The anion component is an organic or inorganic anion, and the size of the anion component is smaller than the size of the cation component.

[Chemical 2] (X and Y are the same or different and each is an atom selected from a nitrogen atom and a phosphorus atom, and R _{1 to} R ₆ are the same or different and each is a hydrophobic aliphatic group or a hydrophobic group. In the present invention, the sizes of the anion component and the cation component mean sizes based on their respective ionic radii.

The present invention will be described in detail below. The toner particles used in the present invention may be any particles made of a colorant and a binder resin. Examples of the binder resin used for the toner particles include styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and isoprene, vinyl acetates such as vinyl acetate, vinyl propionate and vinyl benzoate, and acrylic acid. Α-Methylene aliphatic monocarboxylic acid ester such as methyl, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate, vinyl Homopolymers or copolymers of vinyl ether such as methyl ether, vinyl ethyl ether and vinyl butyl ether, vinyl ketone such as vinyl methyl ketone, vinyl hexyl ketone and vinyl isopropenyl ketone can be exemplified. Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. Polymers, polyethylene, polypropylene can be mentioned. Furthermore, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin and waxes can be mentioned.

As the toner colorant, carbon black, nigrosine dye, aniline blue, calcoil blue, chrome yellow, ultramarine blue, deupon oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, Lamp black, rose bengal,
C. I. Pigment Red 48, C.I. I. Pigment Red 122, C.I. I. Pigment Red 57:
1, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 12, C.I. I. Pigment Blue 1
5: 1, C.I. I. Pigment Blue 15: 3 and the like can be illustrated as typical ones. In the present invention, toner particles having an average particle size of less than about 30 μm, preferably 3 to 20 μm can be used.

In the present invention, a charge control agent is present at least on the surface of the toner particles or in the vicinity of the surface of the toner particles. The charge control agent is formed of a cation component and an anion component, and is a cation component. The component is an organic Cu complex represented by the general formula (I), the anion component is an organic or inorganic anion, and the size of the anion component, that is, the ionic radius is smaller than that of the cation component. Is characterized by. In the cation component represented by the general formula (I), X and Y are the same or different and each is an atom selected from a nitrogen atom and a phosphorus atom. Also, R
_{1 to} R ₆ are each a hydrophobic aliphatic or aromatic hydrocarbon group. _{Specifically, -C n H 2n + 1 (} n is 1 to 1
An integer of 0), —C ₆ H _{5 and the} like, and a bulky hydrophobic hydrocarbon group, particularly an aromatic hydrophobic hydrocarbon group is preferable. On the other hand, the anion component is an organic or inorganic anion and is selected to be smaller than the cation component. Specifically, hydroxide ion, F ⁻ , Cl ⁻ , Br ⁻ ,
Halogen ions such as I ⁻ , C ₁₅ H ₃₁ COO ⁻ , CH ₃ C
OO ^- organic acid ion such _{^{as, B - H 4, (C}} 6 H 5) 4 B
^- Although the like containing compound ions towards the like are exemplified, the relationship between the size of the cation, OH ^-, halogen ion or C
It is preferable that H ₃ COO ⁻ and B ⁻ H ₄ are relatively small and have negative charges concentrated on the ionic surface.

[0009] charging mechanisms of the charge control agent used in the toner of water molecules by the charge control agent H ⁺ ions and OH
^- an ion dissociation into ions, presumably is to charge to a particular polarity attracts the other. In the charge control agent of the present invention, the molecular structure of the cation component is such that large hydrophobic hydrocarbon groups are present on the left and right around the Cu atom where the positive charge is concentrated, and these hydrophobic hydrocarbon groups are present. However, in order to shield the positive charge of the Cu atom, the charge control agent has a molecular structure and charge distribution in which the anion component is close to the positive charge of the Cu atom from a specific direction. Therefore, even if the H ⁺ ion, which is considered to contribute to the charge of the charge control agent, can approach the anion component, the OH ⁻ ion is blocked by the large hydrophobic hydrocarbon group of the cation component and the strong negative charge of the anion component. It can be seen that the molecular structure makes it difficult to approach the charge control agent. From the combination of the anion component and the cation component described above, the charged active domain is considered to be a portion where a small anion component approaches the Cu atom.

On the other hand, the chargeability of the toner particles is also influenced by the surface condition of the toner particles, so in the present invention,
The charge control agent must be present on the surface of the toner particles and in the vicinity thereof. No special method is required as a method for allowing the charge control agent to exist on the surface of the toner particles and in the vicinity thereof. For example, after kneading the charge control agent together with the binder resin constituting the toner particles in a heated and molten state,
The presence of the charge control agent in the vicinity of the surface of the toner particles by a pulverization method or a method of granulating the binder resin and the charge control agent in a melt-kneaded state or by a spray method in the presence of an appropriate solvent. You can Of course, a method of adding and mixing the charge control agent to the outside of the toner particles may be adopted. The toner composition of the present invention does not necessarily need to use only one type of charge control agent, and may be a mixture of two or more types. In this case, it is also necessary to consider the interaction of the functional groups between the charge control agents. Further, a fluidizing agent such as silica, titania, or alumina, and an external additive such as a cleaning aid or a transfer aid such as polystyrene fine particles, polymethylmethacrylate fine particles, or polyvinylidene fluoride fine particles can be used. In particular, hydrophobic silica having a primary average particle diameter of 5 nm to 30 nm is preferably used.

The toner composition of the present invention may be used as a two-component developer in combination with a carrier, or may be used as a one-component developer in combination with a charge imparting member other than the carrier. When using a carrier,
There is no particular limitation as long as it is a known carrier, and iron powder-based carriers, ferrite-based carriers, surface-coated ferrite carriers, magnetic powder-dispersed carriers can be used. The present invention will be described below with reference to comparative examples and examples, but the present invention is not of course limited to these examples.

[0012]

【Example】

 Example 1 Styrene / n-butyl methacrylate copolymer (copolymerization ratio 60/40) 90 parts by weight Carbon black (manufactured by Cabot Corp., Black Pearls L) 10 parts by weight 1 part by weight of the charge control agent A in Table 1

Example 2 Styrene / n-butyl methacrylate copolymer (copolymerization ratio 60/40) 90 parts by weight Carbon black (manufactured by Cabot Corp., Black Pearls L) 10 parts by weight 1 part by weight of the charge control agent B in Table 1

Example 3 Styrene / n-butyl methacrylate copolymer (copolymerization ratio 60/40) 90 parts by weight Carbon black (manufactured by Cabot Corp., Black Pearls L) 10 parts by weight 1 part by weight of the charge control agent C in Table 1

Comparative Example 1 Styrene / n-butyl methacrylate copolymer (polymerization ratio 60/40) 90 parts by weight Carbon black (manufactured by Cabot Corp., Black Pearls L) 10 parts by weight 1 part by weight of the charge control agent D in Table 1

[0016] With the above composition, each of 100-120
The mixture was melt-kneaded at 7 ° C. for 7 minutes, cooled, pulverized, and classified to obtain a toner composition having an average particle diameter d _{50 of 10} to 12 μm. Further, this toner composition was mixed with spherical ferrite powder having an average particle size of 80 μm so that the toner concentration would be 3% by weight to obtain a developer. The presence of the charge control agent near the surface of the toner particles was confirmed by a scanning electron microscope (SEM). The charge amount (q _m ) of the toner and the rising speed (τ) of the charge were measured by the blow-off method. The rising speed of charging is the value of τ in the following equation (1). Further, using this developer, a copy image was produced by a copying machine (trade name: VIVACE120, manufactured by Fuji Xerox Co., Ltd.), and the image quality was evaluated. The results are shown in Table 1.

Q _m −q = (q _m −q ₀ ) · e (−t / τ) (1) q _m : Saturation charge amount (μc / g) q: Charge amount at time t (sec) (Μc / g) q ₀ : Virtual initial charge amount (μc / g)

[0018]

[Table 1]

[0019]

As described above, in the toner composition of the present invention, the cation component is the organic Cu complex having the molecular structure represented by the general formula (I), and the anion component is the organic or inorganic anion. Since the charge control agent in which the size of the anion component is smaller than the size of the cation component is present on or near the surface of the toner particles, the maximum charge amount of the toner particles is large and the charging speed is high. It has excellent chargeability, and can give excellent image quality with little change over time in both forward and reverse images and without fog. It is also stable against environmental changes and changes over time, and has the effect of not contaminating the interior of the copying machine even after long-term use.

Claims (1)

[Claims] 1. A toner composition comprising toner particles and a charge control agent comprising a cation component and an anion component, wherein the charge control agent is present at least on or near the surfaces of the toner particles, and the charge control agent is present. The cation component of the control agent is represented by the following general formula (I), the anion component is an organic or inorganic anion, and the size of the anion component is smaller than the size of the cation component. . [Chemical 1] (X and Y are the same or different and each is an atom selected from a nitrogen atom and a phosphorus atom, and R _{1 to} R ₆ are the same or different and each is a hydrophobic aliphatic group or a hydrophobic group. Aromatic hydrocarbon group.)