JPH08152736A - Hydrophobic metal oxide powder and electrophotographic developer containing the same - Google Patents
Hydrophobic metal oxide powder and electrophotographic developer containing the sameInfo
- Publication number
- JPH08152736A JPH08152736A JP6317777A JP31777794A JPH08152736A JP H08152736 A JPH08152736 A JP H08152736A JP 6317777 A JP6317777 A JP 6317777A JP 31777794 A JP31777794 A JP 31777794A JP H08152736 A JPH08152736 A JP H08152736A
- Authority
- JP
- Japan
- Prior art keywords
- metal oxide
- oxide powder
- organopolysiloxane
- powder
- acid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Developing Agents For Electrophotography (AREA)
- Oxygen, Ozone, And Oxides In General (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Silicon Compounds (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は疎水性金属酸化物粉体及
び該粉体を使用する電子写真用現像剤に関し、更に詳し
くは粉体の流動性を改良した疎水性金属酸化物粉体を含
有する電子写真用現像剤に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrophobic metal oxide powder and an electrophotographic developer using the powder, and more specifically to a hydrophobic metal oxide powder having improved fluidity. The present invention relates to a contained electrophotographic developer.
【０００２】[0002]
【従来の技術】金属酸化物粉体の表面を有機物によって
疎水化した、いわゆる疎水性金属酸化物粉体は、主に電
子写真、静電記録等において用いられる現像剤中のトナ
ーの流動性、クリーニング性等を改良する処理剤として
広く用いられている。これらの用途においては、キャリ
アである鉄あるいは酸化鉄に対する金属酸化物粉体自体
の疎水性と流動性が重要な性質の一つとなっており、種
々の処理剤によってその疎水性と流動性が同時に制御さ
れている。この中にあって、高い流動性を金属酸化物粉
体に付与する方法としては、ヘキサメチルジシラザンに
代表される低分子化合物が、金属酸化物粉体と高い反応
性を持つ性質を利用して、該粉体の表面を処理する方法
が一般的に行われている。しかし、このような低分子化
合物で処理した場合は、高い流動性は得られるものの十
分な疎水性が得られないという問題がある。一方、この
疎水性を満足するように、高い疎水性を金属酸化物粉体
に付与する方法として、オルガノポリシロキサンに代表
される高分子化合物によって粉体の表面を処理する方法
が開示されている。2. Description of the Related Art A so-called hydrophobic metal oxide powder, which is obtained by hydrophobizing the surface of a metal oxide powder with an organic substance, is a fluidity of toner in a developer mainly used in electrophotography, electrostatic recording, etc. It is widely used as a treatment agent for improving the cleaning property. In these applications, the hydrophobicity and fluidity of the metal oxide powder itself with respect to iron or iron oxide as a carrier are one of the important properties. Controlled. Among these, as a method of imparting high fluidity to the metal oxide powder, a low molecular weight compound represented by hexamethyldisilazane has a property of having high reactivity with the metal oxide powder. Then, a method of treating the surface of the powder is generally performed. However, when treated with such a low molecular weight compound, there is a problem that sufficient fluidity cannot be obtained although high fluidity is obtained. On the other hand, as a method of imparting high hydrophobicity to a metal oxide powder so as to satisfy this hydrophobicity, a method of treating the surface of the powder with a polymer compound represented by organopolysiloxane is disclosed. .
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、流動性
と共に高い疎水性を金属酸化物粉体に付与するために、
オルガノポリシロキサンに代表される高分子化合物によ
って粉体の表面を処理する場合には、疎水性は高いもの
が得られるが、その反面流動性が極端に低下するという
問題が起こった。更にこのような高い流動性と高い疎水
性とを有する金属酸化物粉体を得る試みとして、前述の
如きヘキサメチルジシラザンとオルガノポリシロキサン
を組み合わせる方法も検討されたが、オルガノポリシロ
キサンを用いた場合には同様に流動性が極端に低下する
という問題があり、上記の問題は必ずしも解決されてい
ない。However, in order to impart high hydrophobicity to the metal oxide powder along with fluidity,
When the surface of the powder is treated with a polymer compound represented by organopolysiloxane, the one having high hydrophobicity can be obtained, but on the other hand, there is a problem that the fluidity is extremely lowered. Further, as an attempt to obtain a metal oxide powder having such high fluidity and high hydrophobicity, a method of combining hexamethyldisilazane and an organopolysiloxane as described above was also examined, but an organopolysiloxane was used. In such a case, there is also a problem that the liquidity is extremely lowered, and the above problem is not always solved.
【０００４】そこで、本発明者等は、これらの問題点、
即ち良好な流動性と高い疎水性とを有する金属酸化物粉
体を得るために鋭意研究を行った結果、金属酸化物粉体
をオルガノポリシロキサンで表面処理する場合、その粘
度（又は分子量でもよい。）と疎水性、および流動性が
密接な関係にあることを見出した。即ち、金属酸化物粉
体が良好な流動性を得るためには、オルガノポリシロキ
サンの粘度が低い方が好ましいが、オルガノポリシロキ
サンの粘度が低くなりすぎると、揮発性が高まり、酸化
物粉末との表面処理中にこのオルガノポリシロキサンが
揮発してしまい、十分に酸化物表面を覆うことができな
くなって、逆に流動性が低下する。一方、高い疎水性を
得るには、ある一定以上の粘度を有するオルガノポリシ
ロキサンを用いる必要があり、低粘度のオルガノポリシ
ロキサンを用いると、流動性と同様の原因により、酸化
物粉末の表面処理中にオルガノポリシロキサンの揮発が
生じて十分な疎水性のものが得られず、したがって、金
属酸化物粉体が良好な流動性を得るためには、オルガノ
ポリシロキサンの粘度を低くする必要があるが、十分な
流動性を得るために低粘度のオルガノポリシロキサンを
使用すると、その酸化物粉体との処理中にオルガノポリ
シロキサンが揮発してしまい、実際上は表面処理が無理
であり、一方高い疎水性を得るためには、オルガノポリ
シロキサンの粘度は高い方が好ましいので、これらの相
反する特性を満足する必要があるという知見に到達し
た。Therefore, the present inventors have found these problems,
That is, as a result of intensive research to obtain a metal oxide powder having good fluidity and high hydrophobicity, when the metal oxide powder is surface-treated with an organopolysiloxane, its viscosity (or molecular weight may be sufficient). ,), And hydrophobicity and fluidity are closely related. That is, in order for the metal oxide powder to have good fluidity, it is preferable that the viscosity of the organopolysiloxane is low, but if the viscosity of the organopolysiloxane is too low, the volatility increases and The organopolysiloxane volatilizes during the surface treatment, and the oxide surface cannot be sufficiently covered, and conversely the fluidity is lowered. On the other hand, in order to obtain high hydrophobicity, it is necessary to use an organopolysiloxane having a certain viscosity or more. When an organopolysiloxane having a low viscosity is used, the surface treatment of the oxide powder is caused by the same cause as the fluidity. The organopolysiloxane volatilizes into the inside and a sufficiently hydrophobic one is not obtained. Therefore, in order to obtain good fluidity of the metal oxide powder, it is necessary to lower the viscosity of the organopolysiloxane. However, when a low-viscosity organopolysiloxane is used to obtain sufficient fluidity, the organopolysiloxane volatilizes during the treatment with the oxide powder, which makes surface treatment practically impossible. In order to obtain high hydrophobicity, it is preferable that the viscosity of the organopolysiloxane is high, and it has been found that it is necessary to satisfy these contradictory properties. .
【０００５】本発明者等は、このような知見に基づい
て、更に研究を続けた結果、オルガノポリシロキサンに
酸性化合物を添加することにより得られた混合物で金属
酸化物粉体を処理すると意外にも流動性と疎水性が共に
高い金属酸化物粉体が得られ、かつ帯電安定性にも優れ
たものが得られることを見出し、ここに本発明をなすに
至った。したがって、本発明が解決しようとする課題の
一つは、高い疎水性と良好な流動性とを同時に満足する
金属酸化物粉体を提供することにある。また本発明が解
決しようとする課題の第二番目は、疎水性と流動性とを
同時に満足する金属酸化物粉体を含有することによっ
て、高い疎水性と優れた流動性を持ち、かつ帯電安定性
を有する電子写真用現像剤を提供することにある。As a result of further research based on such findings, the present inventors have surprisingly found that a metal oxide powder is treated with a mixture obtained by adding an acidic compound to an organopolysiloxane. Furthermore, they have found that a metal oxide powder having both high fluidity and high hydrophobicity can be obtained, and also that having excellent charge stability can be obtained, and the present invention has been completed here. Therefore, one of the problems to be solved by the present invention is to provide a metal oxide powder that simultaneously satisfies high hydrophobicity and good fluidity. The second problem to be solved by the present invention is that it contains a metal oxide powder satisfying both hydrophobicity and fluidity at the same time, so that it has high hydrophobicity and excellent fluidity, and has stable charge stability. To provide a developer for electrophotography having properties.
【０００６】[0006]
【課題を解決するための手段】前述の本発明が解決しよ
うとする課題は、以下の各発明によってそれぞれ達成さ
れる。The above-mentioned problems to be solved by the present invention are achieved by the following respective inventions.
【０００７】（１）酸性化合物及びオルガノポリシロキ
サンの混合物の被覆を有することを特徴とする金属酸化
物粉体。 （２）透過率法によって測定された金属酸化物粉体の疎
水化率が８０％以上の値を示すことを特徴とする前記第
１項に記載の金属酸化物粉体。 （３）金属酸化物が、シリカ、アルミナまたはチタニア
から選択されたものであることを特徴とする前記第１項
又は第２項に記載の金属酸化物粉体。 （４）オルガノポリシロキサンが官能基としてヒドロ
基、アルキル基、ヒドロキシル基、エーテル基、カルボ
キシル基から選択された１つを有することを特徴とする
前記第１項乃至第３項のいずれかに記載の金属酸化物粉
体。 （５）前記第１項乃至第４項のいずれかに記載の金属酸
化物粉体を含有する電子写真用現像剤。(1) A metal oxide powder having a coating of a mixture of an acidic compound and an organopolysiloxane. (2) The metal oxide powder as described in the above item 1, wherein the hydrophobicity of the metal oxide powder measured by the transmittance method is 80% or more. (3) The metal oxide powder as described in the above item 1 or 2, wherein the metal oxide is selected from silica, alumina, and titania. (4) The organopolysiloxane has, as a functional group, one selected from a hydro group, an alkyl group, a hydroxyl group, an ether group and a carboxyl group, in any one of the above items 1 to 3. Metal oxide powder. (5) An electrophotographic developer containing the metal oxide powder according to any one of items 1 to 4.
【０００８】以下、本発明を更に詳しく説明すると、本
発明は、オルガノポリシロキサンと酸性化合物との混合
物（以下処理剤ともいう。）を用いて、金属酸化物粉体
を処理することによって、混合物の被覆を有する金属酸
化物粉体が得られる。ここで混合物の被覆を有する金属
酸化物粉体とは、金属酸化物粉体の表面にオルガノポリ
シロキサンや酸で切断された低分子量のオルガノポリシ
ロキサンが物理的又は化学的に吸着又は反応して存在し
ていることをいい、これにより高い疎水性と優れた流動
性を同時に有する金属酸化物粉体が得られる。例えば、
酸性化合物を添加することによってオルガノポリシロキ
サンが、その珪素−酸素間あるいは珪素−炭素間の結合
の一部が切断され、その切断部分の活性が極めて高いた
めに、該活性部分が金属酸化物粉末と強固に密着するの
で、その表面は高い流動性が得られ、したがって、高分
子量のオルガノポリシロキサンは、疎水性が高いので、
このようなオルガノポリシロキサンを使用した場合、そ
の結合が切断されることにより、実質上金属酸化物粉末
上でオルガノポリシロキサンは、その一部が低分子化合
物として作用し、優れた流動性が得られ、その結果高い
疎水性と優れた流動性を同時に有する金属酸化物粉体が
得られる。The present invention will be described in more detail below. In the present invention, a mixture of an organopolysiloxane and an acidic compound (hereinafter also referred to as a treating agent) is used to treat a metal oxide powder to obtain a mixture. A metal oxide powder having a coating of 1 is obtained. Here, the metal oxide powder having a mixture coating means that the surface of the metal oxide powder is physically or chemically adsorbed or reacted with an organopolysiloxane or a low molecular weight organopolysiloxane cut with an acid. It means that the metal oxide powder has high hydrophobicity and excellent fluidity at the same time. For example,
When an organopolysiloxane is added with an acidic compound, a part of its silicon-oxygen bond or silicon-carbon bond is cleaved, and the activity of the cleaved part is extremely high. Since it firmly adheres to the surface, high fluidity is obtained on the surface, and therefore, the high molecular weight organopolysiloxane has high hydrophobicity,
When such an organopolysiloxane is used, the bond is cleaved, so that the organopolysiloxane substantially acts on the metal oxide powder as a low molecular weight compound, resulting in excellent fluidity. As a result, a metal oxide powder having both high hydrophobicity and excellent fluidity can be obtained.
【０００９】また比較的低分子量のオルガノポリシロキ
サンでも、酸性化合物の作用によって結合の切断が生
じ、その活性が強く粉末表面で効果的に吸着して金属酸
化物粉末に優れた流動性を与える。本発明に用いられる
金属酸化物粉体は、用途に応じて選択することが可能で
あるが、特にシリカ、アルミナまたはチタニアが流動性
改良などの用途に好ましい。これらの金属酸化物粉体の
粒径も用途に応じて選択することが可能であるが、特に
比表面積が５０ｍ2 ／ｇ以上のものが電子写真乃至静電
記録等の現像剤の用途には好ましい。なお、金属酸化物
は複合酸化物、これらの混合物であってもよい。Even in the case of organopolysiloxane having a relatively low molecular weight, the action of an acidic compound causes the breaking of the bond, the activity is strong and the powder is effectively adsorbed on the surface of the powder to give the metal oxide powder excellent fluidity. The metal oxide powder used in the present invention can be selected according to the use, but silica, alumina or titania is particularly preferable for use in improving fluidity. The particle size of these metal oxide powders can also be selected according to the application, but those having a specific surface area of 50 m 2 / g or more are particularly suitable for use in developers such as electrophotography and electrostatic recording. preferable. The metal oxide may be a composite oxide or a mixture thereof.
【００１０】本発明に用いられる処理された金属酸化物
粉体は、好適な態様においては、透過率法によって測定
された金属酸化物粉体の疎水化率が８０％以上の値を示
すことが好ましい。また本発明では、オルガノポリシロ
キサンと酸性化合物を混合した溶液によって処理するこ
とによって、高い流動性と疎水性を有する金属酸化物粉
体が得られるので、これを電子写真用現像剤の流動性改
善剤として用いることができる。本発明に用いられるオ
ルガノポリシロキサンは、その分子中にヒドロ基、アル
キル基、ヒドロキシル基、エーテル基、カルボキシル基
から選択された少なくとも１つを有するものであればよ
く、その構造、分子量などは特に限定されないが、実用
上は粘度が２０ｃｓ〜２０００ｃｓのものが好ましく、
更に処理操作の面からは５０ｃｓ〜５００ｃｓの粘度の
ものを用いることが好ましい。オルガノポリシロキサン
に有する置換基として、アルキル基はメチル基、エチル
基、プロピル基、フェニル基、ヒドロ基、水酸基、アル
コキシ基、ポリエーテル基あるいは、炭素数１０〜２０
等の長鎖アルキル基を有するものが好ましい。本発明に
用いられるオルガノポリシロキサンは、現在市販の材料
として、信越シリコーン社製のＫＦ−９６、ＫＦ−５
６；東レダウコーニング社製のＳＨ２００、ＳＨ５１
０、ＳＨ１１０７等が例示される。In a preferred embodiment, the treated metal oxide powder used in the present invention has a hydrophobization ratio of 80% or more as measured by the transmittance method. preferable. Further, according to the present invention, a metal oxide powder having high fluidity and hydrophobicity can be obtained by treating with a solution obtained by mixing an organopolysiloxane and an acidic compound. It can be used as an agent. The organopolysiloxane used in the present invention may have at least one selected from a hydro group, an alkyl group, a hydroxyl group, an ether group and a carboxyl group in its molecule, and its structure, molecular weight and the like are particularly preferable. Although not limited, in practice, a viscosity of 20 cs to 2000 cs is preferable,
Further, from the viewpoint of processing operation, it is preferable to use one having a viscosity of 50 cs to 500 cs. As a substituent which the organopolysiloxane has, an alkyl group is a methyl group, an ethyl group, a propyl group, a phenyl group, a hydro group, a hydroxyl group, an alkoxy group, a polyether group or a carbon number of 10 to 20.
Those having a long-chain alkyl group such as The organopolysiloxane used in the present invention is commercially available as a commercially available material, KF-96 and KF-5 manufactured by Shin-Etsu Silicone Co., Ltd.
6; SH200, SH51 manufactured by Toray Dow Corning
0, SH1107, etc. are illustrated.
【００１１】本発明に用いられる酸性化合物は、無機酸
又は有機酸があり、オルガノポリシロキサンの結合を切
断することが可能であればよく、その酸の種類、構造は
特に限定されないが、具体的な例としては、無機酸は、
硫酸、塩酸、硝酸、燐酸、フッ酸、臭酸、フルオロスル
ホン酸、過塩素酸およびこれらの混合酸等が挙げられ
る。また有機酸としては、メタンスルホン酸、ベンゼン
スルホン酸、パラトルエンスルホン酸、トリフルオロ酢
酸、トリフルオロスルホン酸、ペルフルオロブチルスル
ホン酸、ペルフルオロオクチルスルホン酸、ペルフルオ
ロヘプチルカルボン酸等が挙げられる。有機酸の中でも
酸性度が低いと効果的にオルガノポリシロキサンの結合
を切断することができないので、一般には酸性が強い酸
を用いることが好ましく、特にスルホン酸系化合物又は
ペルフルオロアルキル基を有する化合物が好ましい。更
に有機酸と無機酸の混合液を用いることもできる。一
方、オルガノポリシロキサンの結合を切断する試みとし
て、強塩基を用いることも考えられるが、これは酸の使
用に比べて、結合を効果的に切断できず、また処理後の
粉末の疎水性が十分ではないので好ましくない。The acidic compound used in the present invention may be an inorganic acid or an organic acid, as long as it can cleave the bond of the organopolysiloxane, and the kind and structure of the acid are not particularly limited. As an example, the inorganic acid is
Examples thereof include sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, hydrofluoric acid, hydrobromic acid, fluorosulfonic acid, perchloric acid and mixed acids thereof. Examples of the organic acid include methanesulfonic acid, benzenesulfonic acid, paratoluenesulfonic acid, trifluoroacetic acid, trifluorosulfonic acid, perfluorobutylsulfonic acid, perfluorooctylsulfonic acid, perfluoroheptylcarboxylic acid and the like. Of the organic acids, if the acidity is low, the bond of the organopolysiloxane cannot be effectively cleaved, so it is generally preferable to use an acid having a strong acidity, particularly a sulfonic acid compound or a compound having a perfluoroalkyl group. preferable. Further, a mixed solution of an organic acid and an inorganic acid can be used. On the other hand, as an attempt to break the bond of the organopolysiloxane, it is possible to use a strong base, but this cannot cut the bond effectively as compared with the use of an acid, and the hydrophobicity of the powder after treatment is It is not preferable because it is not sufficient.
【００１２】本発明において、オルガノポリシロキサン
と混合する酸性化合物の量は、特に限定されないが、一
般にオルガノポリシロキサンに対して０．０１％〜１０
％であり、特に好ましくは０．１〜３％の間で用いるこ
とができる。この酸性化合物の添加量が０．０１％より
少ないと、それを用いない場合と比較して、得られる金
属酸化物粉体の疎水性及び流動性に大きな効果が見られ
ず、一方、その添加量が１０％を越えると疎水性の低
下、金属酸化物粉体の酸性の増大、またさらに帯電性も
変化しやすい等の問題が生じる。本発明を構成する疎水
性かつ流動性のある金属酸化物粉体を得るために使用さ
れる処理剤の使用量は、被処理金属酸化物粉体の種類、
比表面積や処理剤の種類に依存しており、特に規定され
ないが、好ましくはオルガノポリシロキサンの使用量
は、被処理金属酸化物粉体に対して、５〜３０重量％で
あり、特に好ましくは１０〜２５重量％を用いることが
好ましい。一般に、オルガノポリシロキサンの使用量が
５重量％未満のときは、被金属酸化物粉体の表面を十分
に覆うことができず、３０％を越えると流動性の低下の
原因となる。以上のような処理の結果として得られる金
属酸化物粉体の疎水性は、その程度が高いほど、その金
属酸化物粉体の吸湿性が減少して湿度に対するトナーの
帯電量の変化を小さくし、かつ凝集を防ぐ効果が高ま
り、利用価値が高いが、実用上は後述する透過率法によ
って測定される疎水化率の値が８０％以上の値を持つこ
とが望ましい。In the present invention, the amount of the acidic compound to be mixed with the organopolysiloxane is not particularly limited, but generally 0.01% to 10% with respect to the organopolysiloxane.
%, And particularly preferably 0.1 to 3% can be used. If the addition amount of this acidic compound is less than 0.01%, no significant effect is observed on the hydrophobicity and fluidity of the obtained metal oxide powder, as compared with the case where it is not used. When the amount exceeds 10%, there arise problems that the hydrophobicity is lowered, the acidity of the metal oxide powder is increased, and the chargeability is easily changed. The amount of the treating agent used to obtain the hydrophobic and fluid metal oxide powder constituting the present invention is the type of the metal oxide powder to be treated,
It depends on the specific surface area and the type of the treating agent and is not particularly specified, but the amount of the organopolysiloxane used is preferably 5 to 30% by weight, and particularly preferably, the amount of the metal oxide powder to be treated. It is preferable to use 10 to 25% by weight. Generally, when the amount of the organopolysiloxane used is less than 5% by weight, the surface of the metal oxide powder cannot be sufficiently covered, and when it exceeds 30%, the fluidity is deteriorated. The higher the degree of hydrophobicity of the metal oxide powder obtained as a result of the above treatment, the lower the hygroscopicity of the metal oxide powder and the smaller the change in the amount of charge of the toner with respect to humidity. In addition, the effect of preventing aggregation is enhanced and the utility value is high, but in practice, it is desirable that the value of the hydrophobization rate measured by the below-mentioned transmittance method has a value of 80% or more.
【００１３】本発明に用いられる金属酸化物粉体の処理
には、従来公知の方法が適用される。すなわち、被処理
金属酸化物粉体を機械的に十分攪拌をしながら、これに
酸性化合物を添加したオルガノポリシロキサンを滴下あ
るいは噴霧等の方法で加えるか、あるいはオルガノポリ
シロキサンを最初に金属酸化物粉体に噴霧しておき、そ
の後酸性化合物をさらに噴霧してもよい。また、この順
序を逆に行ってもよい。またここで、用いるオルガノポ
リシロキサンの粘度に応じて、アルコールあるいは炭化
水素等の溶剤を希釈剤として用いることも可能である。
処理剤の添加後、不活性ガス気流下で１００〜３００℃
の範囲の温度、特に好ましくは２００℃〜２５０℃の範
囲の温度で加熱して反応を完結させるとともに、溶剤を
除去する。ここで反応を完結させ溶剤を除去するのに要
する時間は、２時間〜５時間である。この範囲内で溶剤
の除去が完結する。また、金属酸化物粉体の種類によっ
て、上記のような乾式の処理が困難な場合には溶剤を相
当量用いた湿式条件で処理することも可能である。ここ
で用いる不活性ガスは、オルガノポリシロキサンの酸化
を防ぐために用いられるもので、一般的な例として窒
素、ヘリウム、アルゴン等が挙げられる。このような方
法によって得られた疎水性かつ流動性の金属酸化物粉体
は、従来公知である方法によってトナーに添加される。
その添加量はトナーに対して０．１〜２０重量％の範囲
であり、特に０．１〜３重量％の範囲にあることが実用
上望ましい。このようにして調整されたトナーを、さら
に鉄粉あるいは酸化鉄粉と混合することによって現像剤
が調製される。A conventionally known method is applied to the treatment of the metal oxide powder used in the present invention. That is, while mechanically stirring the metal oxide powder to be treated, an organopolysiloxane added with an acidic compound is added thereto by a method such as dropping or spraying, or the organopolysiloxane is first added to the metal oxide. The powder may be sprayed and then the acidic compound may be further sprayed. Also, this order may be reversed. A solvent such as alcohol or hydrocarbon may be used as a diluent depending on the viscosity of the organopolysiloxane used.
After adding the treating agent, 100 to 300 ° C under an inert gas flow.
In order to complete the reaction and to remove the solvent, heating is performed at a temperature in the range of, particularly preferably in the range of 200 ° C to 250 ° C. Here, the time required to complete the reaction and remove the solvent is 2 hours to 5 hours. Removal of the solvent is completed within this range. In addition, depending on the type of the metal oxide powder, when the dry treatment as described above is difficult, it is possible to perform the treatment under wet conditions using a considerable amount of a solvent. The inert gas used here is used to prevent the oxidation of the organopolysiloxane, and typical examples thereof include nitrogen, helium and argon. The hydrophobic and fluid metal oxide powder obtained by such a method is added to the toner by a conventionally known method.
The amount added is in the range of 0.1 to 20% by weight, and particularly preferably in the range of 0.1 to 3% by weight with respect to the toner. The toner prepared in this manner is further mixed with iron powder or iron oxide powder to prepare a developer.
【００１４】[0014]
【作用】本発明を構成する金属酸化物粉体は、酸性化合
物とオルガノポリシロキサンとの混合物で処理すること
によって、オルガノポリシロキサンがより強固に金属酸
化物粉体表面に固定されると共に、前記のオルガノポリ
シロキサンの結合の一部が切断されて低分子量のオルガ
ノポリシロキサンとなり、これが実際上金属酸化物粉体
上に低分子量の化合物として作用して流動性を与える。
その結果、前記混合物で処理された金属酸化物粉体を含
有する現像剤は、優れた疎水性、流動性を有すると共
に、経時的変化が少なく、かつまた湿気等の環境の影響
を受けにくい安定した帯電性を示すという効果を奏す
る。The metal oxide powder constituting the present invention is treated with a mixture of an acidic compound and an organopolysiloxane so that the organopolysiloxane is more firmly fixed on the surface of the metal oxide powder, and A part of the bond of the organopolysiloxane is cleaved to form a low molecular weight organopolysiloxane, which actually acts as a low molecular weight compound on the metal oxide powder to provide fluidity.
As a result, the developer containing the metal oxide powder treated with the mixture has excellent hydrophobicity and fluidity, has little change with time, and is stable and is not easily affected by the environment such as humidity. The effect of exhibiting the charged property is exhibited.
【００１５】[0015]
【実施例】本発明に対する理解を助ける目的で以下に実
施例および比較例を示すが、これらは本発明を何ら限定
するものではない。EXAMPLES Examples and comparative examples are shown below for the purpose of facilitating the understanding of the present invention, but these do not limit the present invention in any way.
【００１６】実施例１ ５０ｍｌガラス製ビーカーに、ジメチルポリシロキサン
（信越化学社製「ＫＦ−９６」、粘度１００ｃｓ）４．
０ｇを入れ、ヘキサン１０ｍｌを加えて溶解した。つい
で、この中に濃硫酸０．０４ｇを入れ、温室で２分間攪
拌し、処理液を作製した。一方、加熱乾燥したシリカ粉
体（日本アエロジル社製「アエロジル＃２００」、比表
面積２００ｍ2 ／ｇ）２０ｇをステンレス鋼製の容器に
仕込み、室温で窒素雰囲気下で攪拌しながら、上記の処
理液を噴霧した。噴霧終了後、さらに温室で５分間攪拌
した後、窒素気流下で外部加熱を行った。２０分かけて
２５０℃まで昇温させ、この温度で３時間保持した後、
室温まで放冷した。このようにして得られた金属酸化物
粉体１．０ｇと水１００ｍｌを抽出用分液ロートに入
れ、５分間激しく振とう攪拌し、その後１分間静置し、
分液ロートの底から少量の懸濁液を抜き出した。つい
で、この液の波長５５０ｎｍの光に対する透過率を、純
水の透過率を１００％として表した値を測定し、その金
属酸化物の疎水化率とした。また、具体的には、スチレ
ン−アクリル樹脂材料中にカーボン１８％を分散、粉砕
後、１０〜２０μｍに分級して得られた樹脂粉１０ｇ中
に、上記金属酸化物粉末０．１ｇを混合することによっ
てトナーを調製し、さらにこのトナーを１００メッシュ
篩と３００メッシュ篩いを二段重ねた上から添加し、１
分間振とうした後の３００メッシュ篩通過率を測定し
て、これを流動性とした。得られた結果を表１に示す。Example 1 A 50 ml glass beaker was charged with dimethylpolysiloxane ("KF-96" manufactured by Shin-Etsu Chemical Co., Ltd., viscosity 100 cs).
0 g was added, and 10 ml of hexane was added and dissolved. Then, 0.04 g of concentrated sulfuric acid was added to this, and the mixture was stirred in a greenhouse for 2 minutes to prepare a treatment liquid. On the other hand, 20 g of heat-dried silica powder (“Aerosil # 200” manufactured by Nippon Aerosil Co., Ltd., specific surface area 200 m 2 / g) was charged into a stainless steel container and stirred at room temperature under a nitrogen atmosphere while treating the above treatment liquid. Was sprayed. After the spraying was completed, the mixture was further stirred in a greenhouse for 5 minutes, and then externally heated under a nitrogen stream. After raising the temperature to 250 ° C. over 20 minutes and maintaining this temperature for 3 hours,
It was left to cool to room temperature. 1.0 g of the metal oxide powder thus obtained and 100 ml of water were placed in a separating funnel for extraction, vigorously shaken and stirred for 5 minutes, and then allowed to stand for 1 minute,
A small amount of suspension was withdrawn from the bottom of the separating funnel. Then, the transmittance of this liquid for light having a wavelength of 550 nm was measured by taking the transmittance of pure water as 100%, and the value was defined as the hydrophobicity of the metal oxide. Further, specifically, 18% of carbon is dispersed in a styrene-acrylic resin material, pulverized, and then classified to 10 to 20 μm, and 0.1 g of the metal oxide powder is mixed with 10 g of the obtained resin powder. To prepare a toner, and further add this toner from the top of a 100-mesh sieve and a 300-mesh sieve in two layers,
The 300 mesh sieve passing rate after shaking for 1 minute was measured, and this was made fluid. The results obtained are shown in Table 1.
【００１７】実施例２ オルガノポリシロキサンとしてメチルハイドロジエンポ
リシロキサン（信越化学社製、ＫＦ−９９、粘度２０ｃ
ｓ）３．０ｇをメタノール１０ｍｌに溶解し、無機酸と
して濃塩酸０．１０ｇを添加した以外は実施例１と同様
の操作を行った。得られた結果を表１に示す。Example 2 Methylhydrogenpolysiloxane as an organopolysiloxane (KF-99 manufactured by Shin-Etsu Chemical Co., viscosity 20c)
s) 3.0 g was dissolved in 10 ml of methanol, and the same operation as in Example 1 was performed except that 0.10 g of concentrated hydrochloric acid was added as an inorganic acid. The results obtained are shown in Table 1.
【００１８】実施例３ オルガノポリシロキサンとしてフェニル変性シリコーン
（信越化学社製、ＫＦ−５４、粘度４００ｃｓ）５．０
ｇをメタノール１０ｍｌに溶解し、無機酸として濃硫酸
０．１５ｇを添加し、酸化物粉末として加熱乾燥したア
ルミナ粉末（日本アエロジル社製「アルミニウム・オキ
サイドＣ」、比表面積９０ｍ2 ／ｇ）を用いた以外は実
施例１と同様の操作を行った。得られた結果を表１に示
す。Example 3 Phenyl-modified silicone (KF-54, viscosity 400 cs, manufactured by Shin-Etsu Chemical Co., Ltd.) 5.0 as an organopolysiloxane
g was dissolved in 10 ml of methanol, 0.15 g of concentrated sulfuric acid was added as an inorganic acid, and heat-dried alumina powder (“aluminum oxide C” manufactured by Nippon Aerosil Co., Ltd., specific surface area 90 m 2 / g) was used as an oxide powder. The same operation as in Example 1 was performed except that the above was performed. The results obtained are shown in Table 1.
【００１９】実施例４ オルガノポリシロキサンとしてアルキル変性シリコーン
（信越化学社製、ＫＦ−４１２、粘度５００ｃｓ）６．
０ｇをメタノール１０ｍｌに溶解し、有機酸としてメタ
ンスルホン酸０．３０ｇを添加し、酸化物粉末として加
熱乾燥したチタニア粉末（日本アエロジル社製「チタニ
ウム・オキサイドＰ２５」、比表面積８０ｍ2 ／ｇ）を
用いた以外は実施例１と同様の操作を行った。得られた
結果を表１に示す。Example 4 Alkyl-modified silicone as organopolysiloxane (KF-412, manufactured by Shin-Etsu Chemical Co., Ltd., viscosity 500 cs) 6.
0 g was dissolved in 10 ml of methanol, 0.30 g of methanesulfonic acid was added as an organic acid, and heat-dried titania powder (“Titanium oxide P25” manufactured by Nippon Aerosil Co., Ltd., specific surface area 80 m 2 / g) was added as an oxide powder. The same operation as in Example 1 was performed except that it was used. The results obtained are shown in Table 1.
【００２０】実施例５ オルガノポリシロキサンとしてヒドロキシ変性シリコー
ン（信越化学社製、ＫＦ−６００１、粘度４２ｃｓ）
２．０ｇをメタノール１０ｍｌに溶解し、有機酸として
トリフルオロ酢酸０．０２ｇを添加し、酸化物粉末とし
て加熱乾燥したシリカ粉末（日本アエロジル社製、アロ
エジル＃１３０、比表面積１３０ｍ2 ／ｇ）を用いた以
外は実施例１と同様の操作を行った。得られた結果を表
１に示す。Example 5 Hydroxy-modified silicone as organopolysiloxane (KF-6001 manufactured by Shin-Etsu Chemical Co., Ltd., viscosity 42 cs)
2.0 g of methanol was dissolved in 10 ml of methanol, 0.02 g of trifluoroacetic acid was added as an organic acid, and heat-dried silica powder (Aloesil # 130, specific surface area 130 m 2 / g manufactured by Nippon Aerosil Co., Ltd.) was used as an oxide powder. The same operation as in Example 1 was performed except that it was used. The results obtained are shown in Table 1.
【００２１】比較例１ 無機酸として濃硫酸を用いない以外は、実施例１と同様
の操作を行った。得られた結果を表１に示す。Comparative Example 1 The same operation as in Example 1 was carried out except that concentrated sulfuric acid was not used as the inorganic acid. The results obtained are shown in Table 1.
【００２２】比較例２ 無機酸として濃塩酸を用いない以外は、実施例２と同様
の操作を行った。得られた結果を表１に示す。Comparative Example 2 The same operation as in Example 2 was carried out except that concentrated hydrochloric acid was not used as the inorganic acid. The results obtained are shown in Table 1.
【００２３】比較例３ 無機酸として濃硫酸を用いない以外は、実施例３と同様
の操作を行った。得られた結果を表１に示す。Comparative Example 3 The same operation as in Example 3 was carried out except that concentrated sulfuric acid was not used as the inorganic acid. The results obtained are shown in Table 1.
【００２４】比較例４ 有機酸としてメタンスルホン酸を用いない以外は、実施
例４と同様の操作を行った。得られた結果を表１に示
す。Comparative Example 4 The same operation as in Example 4 was carried out except that methanesulfonic acid was not used as the organic acid. The results obtained are shown in Table 1.
【００２５】比較例５ 有機酸としてトリフルオロ酢酸を用いない以外は、実施
例５と同様の操作を行った。得られた結果を表１に示
す。Comparative Example 5 The same operation as in Example 5 was carried out except that trifluoroacetic acid was not used as the organic acid. The results obtained are shown in Table 1.
【００２６】[0026]
【表１】 [Table 1]
【００２７】実施例６ スチレン−ブタジエン樹脂材料中にカーボンブラック２
０％を分散し、粉砕後、７〜１５ｍに分級して得られた
樹脂粉末１００ｇ中に、実施例１で得られた酸化物粉体
１ｇを混合することによってトナーを調製した。さら
に、このトナー３０ｇを酸化鉄粉１，０００ｇに加え、
電子写真用現像剤とした。この現像剤の摩擦帯電量を文
献「色材」５５（９）６３０−６３６，１９８２等に規
定されている方法によって測定した。帯電量は−５４１
μＣ／ｇであった。本現像剤を市販の電子写真複写機に
入れ、寿命テストを行ったところ、約２０，０００枚以
上の複写においても画像にカブリは生じなかった。さら
に高温多湿（３０℃、８５％ＲＨ）の環境下においても
良好な画像を示した。Example 6 Carbon black 2 in styrene-butadiene resin material
A toner was prepared by mixing 1 g of the oxide powder obtained in Example 1 with 100 g of the resin powder obtained by dispersing 0%, pulverizing, and classifying to 7 to 15 m. Furthermore, 30 g of this toner is added to 1,000 g of iron oxide powder,
It was used as a developer for electrophotography. The triboelectric charge amount of this developer was measured by the method specified in the literature "Coloring Material" 55 (9) 630-636, 1982 and the like. The charge amount is -541
It was μC / g. When this developer was put into a commercially available electrophotographic copying machine and subjected to a life test, no fog occurred on the image even after copying about 20,000 sheets or more. Further, a good image was shown even in an environment of high temperature and high humidity (30 ° C., 85% RH).
【００２８】実施例７ 実施例２で得られた酸化物粉体１ｇを用いて実施例６と
同様の操作を行った。摩擦帯電量は−４７８μＣ／ｇで
本現像剤を市販の電子写真複写機に入れ、寿命テストを
行ったところ、約２０，０００枚以上の複写においても
画像にカブリは生じなかった。更に高温多湿（３０℃／
８５％ＲＨ）の環境下においても良好な画像を示した。Example 7 The same operation as in Example 6 was carried out using 1 g of the oxide powder obtained in Example 2. The amount of triboelectrification was -478 μC / g, and this developer was put into a commercially available electrophotographic copying machine and subjected to a life test. No fog occurred on the image even after copying about 20,000 sheets or more. Higher temperature and humidity (30 ° C /
A good image was shown even under the environment of 85% RH.
【００２９】比較例６ 比較例１で得られた酸化物粉体１ｇを用いて実施例６と
同様の操作を行った。本現像剤を市販の電子写真複写機
にいれ、寿命テストを行ったところ、約１６，０００枚
で画像にカブリが生じた。Comparative Example 6 The same operation as in Example 6 was carried out using 1 g of the oxide powder obtained in Comparative Example 1. When this developer was put into a commercially available electrophotographic copying machine and a life test was conducted, fog occurred on the image after about 16,000 sheets.
【００３０】[0030]
【発明の効果】本発明の金属酸化物粉体は、金属酸化物
粉体をオルガノポリシロキサンと酸性化合物との混合物
で処理することによって、オルガノポリシロキサンがよ
り強固に金属酸化物表面に固定され、またその結合が切
断されることにより、実際上金属酸化物粉末上で低分子
量の化合物として作用し流動性が良好となり、その結
果、この金属酸化物粉体を含有する現像剤は、優れた疎
水性、流動性を有すると共に、経時的変化が少なく、か
つまた湿気等の環境の影響を受けにくい安定した帯電性
を示すという優れた効果を奏する。The metal oxide powder of the present invention is treated with a mixture of the organopolysiloxane and the acidic compound so that the organopolysiloxane is more firmly fixed on the surface of the metal oxide. Moreover, by breaking the bond, it actually acts as a low molecular weight compound on the metal oxide powder to improve the fluidity, and as a result, the developer containing this metal oxide powder is excellent. It has an excellent effect that it has hydrophobicity and fluidity, has little change with time, and shows stable chargeability that is not easily influenced by environment such as humidity.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 桜井 英章 埼玉県大宮市北袋町一丁目297番地 三菱 マテリアル株式会社中央研究所内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hideaki Sakurai 1-297, Kitabukuro-cho, Omiya City, Saitama Prefecture Central Research Laboratory, Mitsubishi Materials Corporation
Claims (5)
の混合物の被覆を有することを特徴とする金属酸化物粉
体。1. A metal oxide powder having a coating of a mixture of an acidic compound and an organopolysiloxane.
粉体の疎水化率が８０％以上の値を示すことを特徴とす
る請求項１に記載の金属酸化物粉体。2. The metal oxide powder according to claim 1, wherein the hydrophobicity of the metal oxide powder measured by the transmittance method is 80% or more.
チタニアから選択されたものであることを特徴とする請
求項１又は請求項２に記載の金属酸化物粉体。3. The metal oxide powder according to claim 1 or 2, wherein the metal oxide is selected from silica, alumina, and titania.
ヒドロ基、アルキル基、ヒドロキシル基、エーテル基、
カルボキシル基から選択された１つを有することを特徴
とする請求項１乃至請求項３のいずれかに記載の金属酸
化物粉体。4. An organopolysiloxane having a functional group as a hydro group, an alkyl group, a hydroxyl group, an ether group,
The metal oxide powder according to claim 1, which has one selected from a carboxyl group.
の金属酸化物粉体を含有する電子写真用現像剤。5. An electrophotographic developer containing the metal oxide powder according to claim 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31777794A JP3344133B2 (en) | 1994-11-29 | 1994-11-29 | Hydrophobic metal oxide powder and electrophotographic developer containing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31777794A JP3344133B2 (en) | 1994-11-29 | 1994-11-29 | Hydrophobic metal oxide powder and electrophotographic developer containing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH08152736A true JPH08152736A (en) | 1996-06-11 |
| JP3344133B2 JP3344133B2 (en) | 2002-11-11 |
Family
ID=18091941
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31777794A Expired - Lifetime JP3344133B2 (en) | 1994-11-29 | 1994-11-29 | Hydrophobic metal oxide powder and electrophotographic developer containing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3344133B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001139815A (en) * | 1999-11-15 | 2001-05-22 | Dow Corning Toray Silicone Co Ltd | Thermally conductive silicone rubber composition |
| WO2008007649A1 (en) * | 2006-07-14 | 2008-01-17 | Jsr Corporation | Oxide particle-containing resin composition and method for producing the same |
| JP2011213921A (en) * | 2010-03-31 | 2011-10-27 | Jsr Corp | Composition for forming silicon-containing film, silicon-containing film, and pattern forming method |
-
1994
- 1994-11-29 JP JP31777794A patent/JP3344133B2/en not_active Expired - Lifetime
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001139815A (en) * | 1999-11-15 | 2001-05-22 | Dow Corning Toray Silicone Co Ltd | Thermally conductive silicone rubber composition |
| WO2008007649A1 (en) * | 2006-07-14 | 2008-01-17 | Jsr Corporation | Oxide particle-containing resin composition and method for producing the same |
| JP2008019403A (en) * | 2006-07-14 | 2008-01-31 | Jsr Corp | Oxide fine particle-containing resin composition and method for producing the same |
| JP2011213921A (en) * | 2010-03-31 | 2011-10-27 | Jsr Corp | Composition for forming silicon-containing film, silicon-containing film, and pattern forming method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3344133B2 (en) | 2002-11-11 |
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