JPS58216252A - Dry type toner - Google Patents

Abstract

PURPOSE:To obtain a dry type toner given a superior fluidity improving effect, and a superior stabilizing charging effect, by adding a metallic oxide fine powder surface treated with both amino silane and an agent for enhancing hydrophobic property to a toner. CONSTITUTION:The metallic oxide fine powder surface treated with both amino silane and an agent for enhancing hydrophobic property is added as a toner component. As said agent, hexamethyldisilazane, trimethyl-alkoxysilane, and dimethyl silicone oil are exemplified, and as said metallic oxide, silica, alumina, titania, and silicon and aluminum cooxide are used. Good amts. of them to be added are 5-20wt%, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrophotographic developer (hereinafter referred to as a toner), and more specifically, to provide a toner with improved fluidity and charging stability.

Copying machines using electrophotography have a method in which an electrostatic latent image is formed on a photosensitive medium, this electrostatic latent image is developed with toner, and the resulting toner image is transferred to another medium such as paper and then fixed. Widely adopted. .

The so-called dry toner used for this toner development has a problem in that if its powder fluidity decreases or the amount of charge changes9, toner development cannot be performed smoothly and the image quality will fluctuate. It is used in combination with a cooling agent that has a sex-improving function.

Examples of additives with such functions include 9, for example, Japanese Patent Publication No. 54-16219. Ill! j Kaisho 56-64351,
Powders of silica, alumina, magnesia, titania, etc., which have one surface made hydrophobic, as disclosed in JP-A-56-128956, have been suitably put into practical use.

However, since the above-mentioned additives are negatively chargeable, they are suitable for use as constituents of negatively chargeable toners used in copiers that use So or CdS as photosensitive media, but they have not been developed in recent years. When added as a component of the positive toner used in copying machines, etc., which is used for reversal development in advanced laser sol printers and organic photoreceptor media, the Q1 ratio changes. Since it has the disadvantage of being easily charged, the positively charged l/ri 7111
A drug was needed.

In order to meet this demand, the present inventor undertook development and discovered that a toner containing as a constituent component a fine metal oxide powder treated with aminosilane on its surface exhibits strong normal band retraceability.
"[Hint to the disclosure of Public IIN 53-22447] Table 11 + i In order to obtain fC Button 1 aqueous powder by applying both VCC aminosilane treatment and hydrophobizing agent treatment, IJ [
As a continuation of the research, a patent application was filed as Application No. 57-68618 at the time of r161. Furthermore, as a result of making and testing a toner containing gold I/i4 oxide fine powder f as a component that had been subjected to the 1ifJ i+l'4 square treatment, it was found that it had an excellent flowability improvement effect and (
3) The charging stabilizing effect was confirmed and the present invention was completed.

That is, the present invention provides a dry toner characterized in that it contains, as a component of the toner for developing an electrostatic image, a metal oxide fine powder surface-treated with both aminosilane and a hydrophobizing agent.

The present invention will be explained in detail below.

The metal oxide fine powder surface-treated with both aminosilane and a hydrophobizing agent used in the present invention is disclosed in detail in the inventor's earlier application No. 57-686181C, along with its manufacturing method. The base material of the fine powder is fumed silica, alumina, titania, or silicon-aluminum cooxide obtained by gas phase hydrolysis method, and has a specific surface area of at least Somy7y-, and the particle size is 50 nm or less. Aerosil 200 J manufactured by Aerosil, Aluminum Oxide C manufactured by West German Degussa, Titanium Oxide P25J
, r Aerosil MOX170J, etc. are suitable.

The preferred aminosilane coupling agent for treating the base metal oxide fine powder is a silane coupling agent that is highly reactive, easy to handle, is commercially available, and is easy to handle. Specifically, γ-aminopropyltriethoxysilane N
112 (12), 81 (QC2H5) 3 (Nihon Unicar A-11[1,0>, N-(β-Ryominoethyl)-
γ-Aminozo'1 pyrtrimethoxysilane NH2 (CH
2) 2NH (CH215St (OC11515 (Shin-Etsu Chemical KBM 603), r-(2=7minoethyl)-γ
-aminopropyl methoxysilane NH,2(C
H2) 2N) I (C11'2), 81 (CH5) (OC
H6)2 ()-Resilicone 5Z6D23),
γ-anilinosoropyltrimethoxysilane C6H3N
These include H(CH2158i (OCH5) 5 (Toray Silicone SZ 6083)), polyethyleneimine-containing silane (1·-Resilicone 5z6050), and the like.

Another substance, that is, a hydrophobizing agent for treating the parent metal oxide fine powder, is silazane such as hexamethyldisilazane, 1-lower argylalkoxysilane such as trimethylethoxysilane, and commonly commercially available dimethyl silicone oil (Shin-Etsu Chemical Co., Ltd.). KF96.)-Resilicone]H
2O0) etc.

The amounts of both processing agents used to treat the metal oxide fine powder are 5 to 2 each.
The 0-layer staff is good. Below 5% by weight, the effect of the treatment is not clear (2[This is because young fruits are saturated even if it exceeds 1% by weight.) Metal oxide fine powder treated with both aminosilane and hydrophobizing agent ±0 on a grounded aluminum plate
It has a charge of ~+450V (positive chargeability), completely floats in pure water, and has a hydrophobicity of 8 degrees that makes it wet only in a methanol aqueous solution of 35 to 50 volume.

As for the other constituent components of the toner to which the metal oxide fine powder is added, most of the resins used for fruits can be used for the binder resin powder, and for the N coloring agent, the metal oxide fine powder can be used. Since the fine powder is transparent or white, it can coexist widely with colorants other than black, such as carbon black.

There are also few cases in which coexistence is restricted with respect to other fillers. (Especially, the effect is remarkable in coexistence with a charge-controlling drug that imparts positive chargeability.) Furthermore, the content ratio of the metal oxide fine powder to other constituent components is [1, 1 to 5 11%].
The range is the most swampy, and in this range f
Positive charging property' (rMf
The fluidity of the toner is significantly improved while holding the toner.

A flow test was conducted using a glass funnel with a 5 mm orimeter at 11 and 17 to improve fluidity, and it was found that the toner mixed and dispersed with the metal oxide fine powder had much better fluidity than the toner without the addition. Indicated. Another indicator of liquidity is 1. Toner with the metal oxide fine powder separated and 1
Comparison of static bulk density with those without ~ is also an excellent criterion. In other words, if the static bulk density is increased by adding the fine powder, the fluidity tends to be improved. When the fine powder is added to a toner, the static bulk density is uniformly increased by about 10 to 15% compared to a toner without the addition.

In addition, the positive fluorescent wrinkles of the toner of the present invention show as little fluctuation under high temperature and high humidity conditions as they do under low temperature and low humidity conditions. is large.

(7) The drawback of instability was resolved. Although the metal oxide fine powder used in the present invention has a hydrophilic amino group on its surface, it has a hydrophobic effect that exceeds its water viewing effect. be.

The present invention will now be explained in detail with reference to Examples.

Example 1 Specification table... 20 parts by weight of fumed silica [Aerosil 200 J (manufactured by Nippon Aerosil Co., Ltd.) having a ratio table of u* 200 m21 It was placed in a high-speed rotating mixer, and the mixture was heated at 8000 rpm.
While stirring continuously at m, a bath solution prepared by diluting 2 parts by weight of γ-ami,/propyltriethoxysilane (rA-1100J, manufactured by Nippon Unicar Co., Ltd.) with 20 parts by weight of 90% ethanol was added face down to the resulting mixture. The powder liquid was transferred to a vat and dried by heating at 110° C. for 1 hour in a nitrogen gas atmosphere to remove ethanol. The obtained powder was put into a high-speed rotating mixer again, and hexamethyldisilazane ()IMDS) 2It
1 part by weight of a solution diluted with 16 parts by weight of hexane (8) in the same manner as above, and the resulting powder liquid was heated to 4 parts by weight at 150°C.
The mixture was heated and stirred for a period of time to obtain fumed silica which had been made hydrophobic and surface-modified with aminosilane. A toner was prepared by mixing 1 part by weight of the thus obtained humutonic acid with 100 parts by weight of the constituent components of the following formulation.

Styrene-butyl methacrylate copolymer 98 parts Phthalocyanine blue 1 part Cetyltrimethylammonium bromide 1 part The static bulk density of the obtained toner was measured and compared between cases containing and not containing the fumed silica as a component. CJ, 41j? /C- and [1,3
5) / CIJL' and vh values are obtained, and the static bulk density is 1
There was an increase of 7. In addition, when the toner containing the above-mentioned fumed silica was left in an environment of relative humidity 20% and temperature 0°C and relative humidity 90% and temperature 40°C for 24 hours, the impedance*m was measured by the flow-off method. → -26 μC/y- and 22 μC/y- values were obtained, and the measured value when the fumed silica was not included was +25 μC/? It was confirmed that the fluctuation was small with respect to +9 μC/no.

Examples 2 to 6 Various metal oxide fine powders were surface-modified and hydrophobized with aminosilane by the same method as in Example 1,
A certain amount of the mixture was mixed with 100 parts by weight of the constituent components of the following formulation to prepare a toner.

Polystyrene 150 parts Nicrosine stearate 18flS Carbon black 5 parts The results of measuring the static bulk density and charge amount of the obtained toner in the same manner as in Example 1 are listed in Table 1.

(a) Weight factor for electrolytic corrosion of other constituent acids (b)
Leave in an atmosphere with a relative humidity of 20 degrees and a temperature of 0°0 for 24 hours. (c) Leave in an atmosphere with a relative humidity of 90 degrees and a temperature of 40"0 for 24 hours. : Manufactured by Degussa [Aluminum Oxai].

EI T t O2: Degussa's "Getanium Oxide P25" S r 02 J205: Degussa's Aerosil MOX170J (e) A1100: Nippon Unicar's NI(,2(C)
H2) 5S i (OC2H5) 5(to) KBM
603: Shin-Etsu Chemical N)(2(CI(2) 2N)i(C)(2) 58
i (OCI(3) 3()l 5Z6023: )
-Resilicon NH2 (CH2>2NH(CH2)5
Si(CH3)(OCH3)2(e) HMDS:)-
Manufactured by Resilicone Co., Ltd. [(CH3), Si]2NH Example 7 4 parts of the toner of Example 2 and 95 parts of iron powder carrier were mixed to make a developer, and this developer was used to produce zinc oxide by a magnetic brush method. When the negative electrostatic charge I image on the resin-dispersed photoreceptor was developed, a clear black positive image without background smudge was obtained, and the transfer to plain paper was also good. Further, between the toners placed in the low-temperature, low-humidity and high-temperature, high-humidity conditions of Example 2, no tip with remarkable development characteristics was formed.

Patent applicant Hhon Aerosil Co., Ltd. Agent: Patent Attorney Masahiro Matsui

Claims (1)

[Claims] 1.! #Electronic - As a component of toner for developing images. A dry toner characterized in that it entirely contains metal oxide fine powder whose surface has been treated with both aminosilane and a hydrophobizing agent. 2. Claim 1 in which the hydrating agent is a substance selected from the group consisting of hexamethyldisilane, trimethylalkoxysilane, and dimethylsilicone oil.
Dry toner as described in section. 6. The dry toner according to claim 1, wherein the metal oxide fine powder is a substance selected from the group consisting of silica, alumina, titania, and fluoroxides of silicon and aluminum. (1)