JP3248042B2 - Developer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer for visualizing a latent electrostatic image in an image forming method such as electrophotography and electrostatic recording.

[0002]

2. Description of the Related Art Toner must have a positive or negative charge, depending on the polarity of the electrostatic latent image to be developed. In order to retain the electric charge in the toner, it is possible to use the frictional charging property of the binder resin which is a component of the toner.However, in this method, since the charging property of the toner is small, an image obtained by development is easily fogged, It becomes unclear. Therefore,
In order to impart a desired frictional charging property to the toner, a dye, a pigment for imparting the charging property, and a charge control agent are added.

[0003] Charge control agents known in the art today include metal complexes of monoazo dyes, metal complexes of salicylic acid, naphthoic acid, dicarboxylic acids, copper phthalocyanine pigments, and acid components as negative triboelectrification. Resins and the like are known.

[0004] However, these compounds have respective disadvantages, and improvement is desired. For example, they are colored and cannot be applied to color toners, have insufficient charging stability, contain heavy metals such as chromium, and are desired to be improved in terms of environmental stability.

[0005] Toners containing a calix (n) arene compound as a charge control agent are known from JP-A-2-201378 and JP-A-4-346360. Calix (n) allene compounds do not contain heavy metals,
It is characterized by being substantially colorless.

However, it is difficult to stably obtain an appropriate charge amount under a wide range of environment only by using the calix (n) allene compound. For example, when titanium oxide having good environmental dependency is externally added as a fluidity imparting agent, the charge amount tends to be insufficient. Further, even if an appropriate charge amount can be once obtained, an appropriate charge amount cannot be maintained as copying proceeds further. In addition, some resins have a disadvantage that the dispersibility in the resin becomes insufficient.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a developer having good color reproducibility by using a colorless or light-colored charge control agent.

It is another object of the present invention to provide a developer which is charged very quickly and has little fluctuation in charge even during long-term durability.

Another object of the present invention is to provide a developer in which the durability of a copied image is less deteriorated.

[0010]

The present invention comprises at least a binder resin, a colorant and a calix (n) arene compound represented by the following general formula (I), the surface of which is coated with an inorganic oxide powder. A developer containing the obtained non-magnetic toner and a carrier, wherein the non-magnetic toner has an acid value of 5 to 40 mgKOH / g, and the electronegativity (金属 i) of a metal ion as a component of the inorganic oxide powder. Is 10-15
Wherein the current value of the carrier is 30 to 180 μA.

[0011]

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(Wherein n represents an integer of 4 to 8, R ₁ represents a hydrogen atom, an alkyl group optionally substituted by a fluorine atom, an alicyclic group, an aralkyl group, a sulfonic acid group, ₂ represents a hydrogen atom, an alkyl group or an aryl group.)

Hereinafter, the present invention will be described in detail.

In general, in order to reduce the size of a copying machine, it is necessary to reduce the size and simplification of the developing device and to reduce the amount of developer. At that time, the developer is required to be "quickly charged". A simple effect of the calix (n) allene compound as a charge control agent cannot provide a sufficient effect against such severe requirements. On the other hand, according to the constitution of the present invention, it is possible to obtain a developer which is charged very quickly and has little variation in charging even in long-term durability.

In the usual method, it is difficult to achieve both quick charging and a long life of the developer. The following can be considered to be the reason why this trade-off can be solved by the present invention.

The electronegativity (χi) of the metal ion is 10
It is considered that the inorganic oxide in the range of 15 is not so charged to the iron powder, and saturates rather quickly. Examples of such an inorganic oxide having a small charge amount include TiO.
₂ , Al ₂ O ₃ and the like. These are considered to have a very fast rise of toner charge due to the fact that they have weaker insulating properties than SiO ₂ , and have a low attractive force with the toner surface and are easily moved physically. However,
It shows a long-term change in charge (decrease tendency), which is solved by the acid of the binder resin and the calix (n) allene compound. That is, both the acid of the binder resin of the toner base and the calix (n) arene compound are negatively charged, but the charge by the acid causes the polymer to undergo molecular motion due to stress on the toner, and a new charging site appears. It tends to rise slowly. This tendency has the effect of counteracting the change in the charging of the long-term range exhibited by the inorganic oxide, resulting in long-term stability of charging. In addition, by using the calix (n) allene compound, carrier contamination is less likely to occur, and the tendency of the inorganic oxide to decrease in charge can be prevented. Further, it is possible to stabilize the change of the charge in a long-term range exhibited by the binder resin having an acid value.

In this way, by employing the constitution of the present invention, it is possible to obtain a developer which is charged very quickly and has little fluctuation in charge even in long-term durability.

The calix (n) arene compound used in the present invention is described in J. Am. Am. Chem. Soc. 103 3772-3
792 (1981) Pure & Appl. Chem, Vol. 58,
No. 1123-1528 (1985) Tetrahedron Letters, Vol.
26, No. 28 3343-3344 (1985) Hyundai Kagaku, 18214-23 (1986), etc., and can be easily synthesized.

When the calix (n) arene compound is synthesized according to a usual synthesis method, a mixture of a cyclic n-mer and an acyclic compound is formed. By isolating the target cyclic substance by recrystallization or the like, the calix (n) allene compound of the present invention can be obtained.

Examples of the calix (n) allene compound of the present invention are shown below, but are not limited thereto.

[0021]

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[0022]

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[0023]

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The calix (n) allene compound is preferably used in an amount of 0.1 to 10 parts by weight based on 100 parts by weight of the binder resin.
0.1 to 5 parts by weight is more preferred. When the amount is less than 0.1 part by weight, the dispersibility of the calix (n) arene compound is insufficient, and when the amount is more than 10 parts by weight, it is difficult to stably maintain an appropriate charge amount.

As the inorganic oxide powder, known ones can be used as long as the electronegativity (度 i) of the metal ion is in the range of 10 to 15, specifically, titanium oxide and strontium titanate. , Alumina, cerium oxide and the like. It is preferable that these inorganic oxide powders are further subjected to a hydrophobic treatment with a silane coupling agent, silicone oil or the like.

The amount of the inorganic oxide coated on the toner surface is 0.1 to 10%, more preferably 0.3 to 3%, based on the weight of the toner. The reason is that if it is less than 0.1%, the rise of toner charge becomes insufficient, and
%, The charge in the long-term range is significantly reduced,
Even if the calix (n) allene compound is added in excess of an appropriate amount, the calix (n) allene compound cannot be covered completely.

Examples of the binder resin include an acid value of 5 to 4
If it is in the range of 0 mgKOH / g, known ones can be used, and as a result, the acid value of the toner is preferably in the range of 5 to 40 mgKOH / g. Preferably, the acid value of the binder resin is 7-4.
The range of 0 mgKOH / g is good. The acid value is determined by the following method.

[0028] 200 to 300 ml of sample 2 to 10 g
Weighed in an Erlenmeyer flask, and methanol: toluene = 3
About 50 ml of a 0:70 mixed solvent is added to dissolve the resin.
If the solubility is poor, a small amount of acetone may be added. Using a mixed indicator of 0.1% bromthymol blue and phenol red, a standardized N / 10
Titration is performed with a potassium hydroxide-alcohol solution, and the acid value is determined from the consumption amount of the alcohol potassium solution by the following formula (III).

Acid value = KOH (ml) × N × 56.1 / sample weight (III) (where N is a factor of N / 10 KOH)

Examples of the binder resin used in the present invention include homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene and their substituted products; styrene-p-chlorostyrene copolymer; Styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylate copolymer,
Styrene-methacrylate copolymer, styrene-
α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer Styrene-based copolymers such as styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer; polyvinyl chloride, phenolic resin, naturally modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polystyrene Vinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, coumarone indene resin, petroleum resin and the like can be used.

A crosslinked styrene copolymer is also a preferred binder resin.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and the like.
Such as dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. A monocarboxylic acid having a heavy bond or a substituted product thereof;
For example, dicarboxylic acids having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like, and substituted products thereof; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate;
For example, ethylene olefins such as ethylene, propylene, butylene, etc .; vinyl ketones, such as vinyl methyl ketone, vinyl hexyl ketone, etc .; vinyl ethers, such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, etc .; Are used alone or in combination of two or more.

As the cross-linking agent, compounds having two or more polymerizable double bonds are mainly used, for example, aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, etc .; ethylene glycol diacrylate, Ethylene glycol dimethacrylate,
Carboxylic acid esters having two double bonds such as 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups; Are used alone or as a mixture. In particular, in the molecular weight distribution measured by GPC, 3
Styrene copolymers having at least one peak in the region of × 10 ^{3 to} 5 × 10 ⁴ and having at least one peak or shoulder in the region of 10 ⁵ or more are preferred.

The molecular weight distribution by GPC is measured under the following conditions.

The column was stabilized in a heat chamber at 40 ° C., and tetrahydrofuran (THF) was passed through the column at this temperature as a solvent at a flow rate of 1 ml / min.
100 μl of a sample solution dissolved in HF is injected and measured. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of a calibration curve prepared from several types of monodisperse polystyrene standard samples and the count number. As a standard polystyrene sample for preparing a calibration curve, for example, Tosoh Corporation or Showa Denko
^It is appropriate to use about ² to 10 ^{7 and} to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector. It is preferable to combine a plurality of commercially available polystyrene gel columns. For example, Shodex G manufactured by Showa Denko KK
PC KF-801,802,803,804,80
5,806,807,800P, TSKgel G1000H (H _XL ), G200 manufactured by Tosoh Corporation
0H (H _XL ), G3000H (H _XL ), G4000H
(H _XL ), G5000H (H _XL ), G6000H
(H _XL ), G7000H (H _XL ), TSKguardc
column can be mentioned.

A sample is prepared as follows.

After placing the sample in THF and leaving it to stand for several hours, shake it sufficiently,
Mix well with F and let sit for at least 12 hours. At this time, the time of being left in THF is set to be 24 hours or more. Thereafter, the sample processing filter (pore size 0.
45 to 0.5 μm, for example, Myshoridisk H-2
5-5 Tosoh Co., Ltd., and Exclo Disk 25CR manufactured by Germanic Science Japan can be used as a GPC sample. The sample concentration is
The resin component is adjusted to be 0.5 to 5 mg / ml.

As the magnetic particles (carrier) used in the developer of the present invention, known particles can be used as long as the current value is in the range of 30 to 180 μA. Specific examples include powders having magnetic properties such as iron powder, ferrite powder and nickel powder, glass beads, and the like, and those obtained by treating the surfaces of these with a resin or the like. Further, as the resin for coating the carrier surface, styrene-acrylate copolymer, styrene-methacrylate copolymer, acrylate copolymer, methacrylate copolymer, silicone resin, fluorine-containing resin, A polyamide resin, an ionomer resin, a polyphenylene sulfide resin, or a mixture thereof can be used.

In measuring the current value, the following method was used.

An electrode is provided at a distance of 1 mm opposite to a conductive sleeve having a built-in magnet roll and a spike regulating blade. A magnetic brush of a carrier is formed between the electrodes, and rotated while applying a DC voltage of 500 V between the sleeve and the counter electrode (110 rpm). A resistance of 1 MΩ and 10 KΩ is arranged in series between the DC power supply and the electrode, and a voltage drop at both ends of the resistance of 10 KΩ is measured. A current flowing through the circuit is obtained from this voltage, and the obtained current is used as a carrier current value.

[0041]

EXAMPLES The present invention will be described below in more detail with reference to Examples, which should not be construed as limiting the present invention. All parts in the following formulations are parts by weight.

Example 1 100 parts of polyester resin Compound Example (1) 2 parts Copper phthalocyanine pigment (CI Pigment Blue 15) 5 parts

After thoroughly mixing the above materials in a blender,
The mixture was kneaded by a twin-screw kneading extruder set at 120 ° C. After cooling the obtained kneaded material and coarsely pulverizing with a cutter mill,
Fine pulverization was performed using a fine pulverizer using a jet stream, and the obtained finely pulverized powder was classified with a fixed wall type air classifier.

Further, the obtained classified powder was strictly classified and removed simultaneously by a multi-division classifier utilizing a Coanda effect (an elbow jet classifier manufactured by Nippon Steel Mining Co., Ltd.) to obtain a powder having a volume average particle size of 8.3 μm. A fine powder was obtained. What was classified and removed in this process is referred to as fine powder A.

To 100 parts of the obtained fine powder A, 1.0 part of a hydrophobicized titanium oxide powder (＝ i = 14) was added, and mixed with a Henschel mixer.
Was coated on the surface of the toner.

Next, 100 parts of a silicon-coated ferrite carrier having an average particle size of 59 μm (current value: 55 μA) was mixed with 5 parts of the toner to prepare a developer.

This developer was subjected to a copy test using a commercially available color electrophotographic copying machine CLC-500 (manufactured by Canon Inc.).

As a result, a bright blue image having an image density of 1.45 was obtained from the beginning under the environmental conditions of 23 ° C./60%, and no deterioration was observed after copying 10,000 sheets. Also, the charge level was maintained at the initial level.

Next, a copy test was conducted under an environmental condition of 15 ° C./10%. As a result, a high-density image of 1.41 was obtained from the beginning, and no deterioration was observed after copying 10,000 sheets.

Example 2 Example 1 was repeated except that Compound Example (1) was replaced with Compound Example (2).
Fine powder B was prepared in the same manner as described above, and 1.0 part of titanium oxide powder was added to 100 parts of fine powder B, and mixed with a Henschel mixer to obtain a toner in which titanium oxide was coated on the surface of fine powder B. Next, 5 parts of the toner was mixed with 100 parts of an acrylic-coated ferrite carrier (current value: 55 μA) having an average particle size of 65 μm to prepare a developer. When this was subjected to a copying test in the same manner as in Example 1, good results shown in Table 1 were obtained.

Example 3 0.5 part of alumina powder, 0.1 part of silica powder, and 2.0 parts of strontium titanate powder were added to 100 parts of the fine powder A obtained in Example 1, and mixed with a Henschel mixer to obtain alumina. , Silica, and strontium titanate powder were coated on the surface of the fine powder A. Next, 5 parts of the toner was mixed with 100 parts of an acrylic-coated ferrite carrier (current value: 55 μA) having an average particle size of 65 μm to prepare a developer. When this was subjected to a copying test in the same manner as in Example 1, good results shown in Table 1 were obtained.

Example 4 A developer was prepared in the same manner as in Example 1 except that the carrier was an acryl-coated ferrite carrier having an average particle diameter of 65 μm (current value: 170 μA). When this developer was subjected to a copy test in the same manner as in Example 1, good results shown in Table 1 were obtained.

Comparative Example 1 In Example 1, the fine powder B was used as the toner, and the average particle size was 6
5 μm acrylic coated ferrite carrier (current value 5
5 μA) 100 parts of the toner was mixed with 5 parts of the toner to prepare a developer. This was subjected to a copy test in the same manner as in Example 1. As shown in Table 1, the image was blurred in continuous copying.

Comparative Example 2 In Example 1, 100 parts of the fine powder A was mixed with silica powder (χ
i = 17) 1.0 part was added and mixed with a Henschel mixer to obtain a toner in which silica powder was coated on the surface of fine powder A.

Next, 5 parts of the toner was mixed with 100 parts of an acrylic-coated ferrite carrier (current value: 55 μA) having an average particle size of 65 μm to prepare a developer.

When a copy test was performed on this product in the same manner as in Example 1, the rise of charging was slow.

Comparative Example 3 Fine powder D was prepared in the same manner as in Example 1 except that styrene-n-butyl acrylate resin (acid value 0) was used instead of the polyester resin.
1. Add titanium oxide powder (χi = 14) to 100 parts of fine powder D.
A toner was prepared in the same manner as in Example 1 except that 0 part was added.
Next, 5 parts of the toner was mixed with 100 parts of an acrylic-coated ferrite carrier (current value: 55 μA) having an average particle diameter of 65 μm to prepare a developer.

When a copy test was performed on this product in the same manner as in Example 1, the rise of charging was slow.

Example 5 Styrene / butyl acrylate / divinylbenzene copolymer 100 parts (copolymer weight ratio 80 / 19.5 / 0.5, weight average molecular weight 320,000) Compound example (8) 2 parts Low molecular weight propylene -Ethylene copolymer 3 parts Copper phthalocyanine 4 parts

After thoroughly mixing the above materials in a blender,
The mixture was kneaded with a twin-screw kneading extruder set at 150 ° C. Thereafter, pulverization and classification were performed in the same manner as in Example 1 to obtain a blue fine powder having a volume average particle size of 6.1 μm.

To 100 parts of the obtained blue fine powder, 1.0 part of titanium oxide was added and mixed with a Henschel mixer to obtain a toner having the blue fine powder.

This toner was applied to a reversing machine of FC-320 (manufactured by Canon Inc.) equipped with an amorphous silicon photosensitive drum, and an image output test of 5,000 sheets was performed. The good results shown in Table 1 were obtained. Was.

[0063]

[Table 1]

[0064]

As described above, the toner containing the calix (n) allene compound of the present invention as a charge control agent provides a color toner having good color reproducibility, and further, the electronegativity of metal ions is reduced. The toner coated with the inorganic oxide powder in the range of 10 to 15 has a current value of 30 to
The developer obtained by mixing with magnetic particles of 150 μA is charged very quickly, and has a small fluctuation of charging even in long-term durability, and therefore provides a good image without blurring of the image and toner scattering. Can be.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-341577 (JP, A) JP-A-2-201378 (JP, A) JP-A-7-64319 (JP, A) JP-A 7-64319 287418 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 9/08-9/10

Claims (2)

(57) [Claims] 1. A non-magnetic material comprising at least a binder resin, a colorant and a calix (n) allene compound represented by the following general formula (I), the surface of which is coated with an inorganic oxide powder.
A developer containing the sex toner and a carrier, the acid value of the non-magnetic toner is 5~40mgKOH / g, the inorganic oxide powder component of the electronegativity of the metal ion (χi) is 10 is 15, the developer current value of the carrier is characterized in that it is a 30～180Myuei. Embedded image (In the formula, n represents an integer of 4 to 8, R ₁ represents a hydrogen atom, an alkyl group optionally substituted with a fluorine atom, an alicyclic group, an aralkyl group, a sulfonic acid group, and R ₂
Represents a hydrogen atom, an alkyl group, or an aryl group. ) 2. The method according to claim 1, wherein the inorganic oxide powder is titanium oxide, titanium oxide or titanium oxide.
Strontium phosphate, alumina and cerium oxide
Specially selected from the group consisting of inorganic oxide powders
The developer according to claim 1, which is characterized by the following.