JPH0623866B2 - Image forming method - Google Patents
Image forming methodInfo
- Publication number
- JPH0623866B2 JPH0623866B2 JP63150878A JP15087888A JPH0623866B2 JP H0623866 B2 JPH0623866 B2 JP H0623866B2 JP 63150878 A JP63150878 A JP 63150878A JP 15087888 A JP15087888 A JP 15087888A JP H0623866 B2 JPH0623866 B2 JP H0623866B2
- Authority
- JP
- Japan
- Prior art keywords
- particles
- partial pressure
- oxygen partial
- firing
- starting material
- 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.)
- Expired - Lifetime
Links
- 238000000034 method Methods 0.000 title claims description 12
- 239000002245 particle Substances 0.000 claims description 50
- 239000000203 mixture Substances 0.000 claims description 26
- 238000010304 firing Methods 0.000 claims description 24
- 229910000859 α-Fe Inorganic materials 0.000 claims description 24
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 21
- 229910052760 oxygen Inorganic materials 0.000 claims description 21
- 239000001301 oxygen Substances 0.000 claims description 21
- 229910052749 magnesium Inorganic materials 0.000 claims description 18
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 12
- 239000007858 starting material Substances 0.000 claims description 12
- 239000012298 atmosphere Substances 0.000 claims description 11
- 239000012299 nitrogen atmosphere Substances 0.000 claims description 9
- 229910052748 manganese Inorganic materials 0.000 claims description 8
- 229910052725 zinc Inorganic materials 0.000 claims description 8
- 229910044991 metal oxide Inorganic materials 0.000 claims description 7
- 150000004706 metal oxides Chemical class 0.000 claims description 7
- 229910052802 copper Inorganic materials 0.000 claims description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims description 6
- 229910052799 carbon Inorganic materials 0.000 claims description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 9
- 230000005415 magnetization Effects 0.000 description 9
- 238000011161 development Methods 0.000 description 5
- 239000000969 carrier Substances 0.000 description 3
- 239000011230 binding agent Substances 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000002270 dispersing agent Substances 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 229910052596 spinel Inorganic materials 0.000 description 2
- 239000011029 spinel Substances 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- 229910001035 Soft ferrite Inorganic materials 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000012050 conventional carrier Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 239000011669 selenium Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G9/00—Developers
- G03G9/08—Developers with toner particles
- G03G9/10—Developers with toner particles characterised by carrier particles
- G03G9/107—Developers with toner particles characterised by carrier particles having magnetic components
- G03G9/108—Ferrite carrier, e.g. magnetite
- G03G9/1085—Ferrite carrier, e.g. magnetite with non-ferrous metal oxide, e.g. MgO-Fe2O3
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Developing Agents For Electrophotography (AREA)
- Compounds Of Iron (AREA)
Description
【発明の詳細な説明】 Ｉ 発明の背景 技術分野 本発明は、画像形成方法に関する。さらに詳しくは、特
に磁気ブラシ現像を用いる画像形成方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method. More specifically, it relates to an image forming method using magnetic brush development.
先行技術とその問題点 磁気ブラシ現像において、キャリヤ粒子として、いわゆ
るソフトフェライトを用いる旨の提案がなされている
（米国特許第３８３９０２９号、同３９１４１８１号、
同３９２９６５７号等）。Prior Art and Problems Thereof, it has been proposed to use so-called soft ferrite as carrier particles in magnetic brush development (US Pat. Nos. 3,839,029 and 3,914,181).
No. 3929657, etc.).
このようなフェライトからなるキャリヤ粒子は、従来の
鉄粉キャリヤと同等の磁気特性を示す他、鉄粉キャリヤ
のように、表面に樹脂等の被覆層を設ける必要がないの
で、耐久性もきわめて高いものである。Such carrier particles made of ferrite show magnetic characteristics equivalent to those of conventional iron powder carriers, and unlike iron powder carriers, there is no need to provide a coating layer of resin or the like on the surface, and therefore extremely high durability. It is a thing.
この場合、従来キャリヤ粒子として実際に、用いられて
いるフェライトの組成は、(MO)100-x(Fe2O3)x（ただし
Ｍは２価の金属の１種以上）とあらわしたとき、ｘが５
３モル％程度あるいはそれ以下である。In this case, when the composition of the ferrite actually used as the conventional carrier particles is expressed as (MO) 100-x (Fe 2 O 3 ) x (where M is one or more divalent metals), x is 5
It is about 3 mol% or less.
ところで、本発明者らの研究結果によれな、同一組成の
フェライト粒子でも、焼成の際の雰囲気を制御すると、
粒子の抵抗が変化することが判明している。そして、キ
ャリヤ粒子の抵抗を変えることにより、種々の階調をも
つ画像が得られ、画質を種々選定できる。また、抵抗を
変えることにより、種々の複写装置の機種に応じた最適
の画像特性とすることができる。By the way, according to the research results of the present inventors, even if ferrite particles having the same composition are controlled in the atmosphere during firing,
It has been found that the resistance of the particles changes. Then, by changing the resistance of the carrier particles, images having various gradations can be obtained, and various image quality can be selected. Further, by changing the resistance, it is possible to obtain the optimum image characteristics according to various types of copying machines.
このため、フェライト粒子としては、焼成雰囲気を変更
することによる抵抗値の変化巾が大きいものほど好まし
いといえる。Therefore, it can be said that as the ferrite particles, those having a large variation range of the resistance value by changing the firing atmosphere are preferable.
しかし、上記したような、Ｆｅ２Ｏ３量５３モル％程度
以下の組成のものでは、それ自体抵抗値が高く、得られ
る画像濃度が低い。また、焼成雰囲気を変更しても抵抗
値の変化巾は小さく、階調性の変化率が小さく、画質を
任意に選択できないことが判明している。However, in the case of the composition having the Fe 2 O 3 content of about 53 mol% or less as described above, the resistance value itself is high and the obtained image density is low. Further, it has been found that even if the firing atmosphere is changed, the range of change in resistance value is small, the rate of change in gradation is small, and the image quality cannot be arbitrarily selected.
II 発明の目的 本発明の主たる目的は、焼成雰囲気変化による抵抗値変
化巾が従来に比し格段と広いフェライトキャリヤ粒子を
用いることにより、抵抗値を大巾に変更でき、その結果
機種に応じ必要とする最適画質のトナー画像を得ること
のできる画像形成方法を提供することにある。II Aim of the invention The main object of the present invention is to change the resistance value to a large extent by using ferrite carrier particles in which the range of change in the resistance value due to changes in the firing atmosphere is significantly wider than in the past, and as a result, it is necessary depending on the model. An object of the present invention is to provide an image forming method capable of obtaining a toner image of optimum image quality.
本発明者らは、このような目的につき種々検討をくりか
えした結果、本発明をなすに至った。The present inventors have completed the present invention as a result of repeating various studies on such an object.
すなわち、本発明は、同一出発原料を用い、焼成雰囲気
として、空気中から窒素雰囲気までの範囲で空気と窒素
との混合比を変えることで酸素分圧を変化させたとき、
１０５以上の抵抗変化比をもつ焼結フェライト粒子組成
として、２価金属酸化物または３価金属酸化物に換算し
て下記式〔Ｉ〕で表わされる組成に対応する出発原料組
成比を選択し、 この出発原料を酸素分圧をかえて焼成して、粒子抵抗の
異なる複数のフェライト粒子を得、 この複数のフィライト粒子それぞれを、用いるトナーと
混合して現像剤とし、各現像剤を用いて用いる機種の静
電画像装置でトナー像を得、機種に応じて必要とされる
画像濃度と階調性とが得られる焼成時の酸素分圧を決定
し、 前記選択された組成の出発原料を、この決定された酸素
分圧で焼成して磁性キャリヤ粒子とし、 これをトナーと混合して現像剤とし、前記の機種の静電
画像装置でトナー画像を得る画像形成方法である。That is, the present invention, when using the same starting material, as the firing atmosphere, when the oxygen partial pressure is changed by changing the mixing ratio of air and nitrogen in the range from air to nitrogen atmosphere,
As a sintered ferrite particle composition having a resistance change ratio of 10 5 or more, a starting material composition ratio corresponding to the composition represented by the following formula [I] is selected by converting it into a divalent metal oxide or a trivalent metal oxide. The starting material is fired under different oxygen partial pressures to obtain a plurality of ferrite particles having different particle resistances. Each of the plurality of phyllite particles is mixed with a toner to be used as a developer, and each developer is used. Obtain a toner image with the electrostatic image device of the model used, determine the oxygen partial pressure at the time of firing to obtain the required image density and gradation according to the model, and use the starting material of the selected composition. This is an image forming method in which magnetic carrier particles are baked by the determined oxygen partial pressure and mixed with toner to be a developer, and a toner image is obtained by an electrostatic image device of the above model.
式〔Ｉ〕 (MO)100-x(Fe2O3)x ｛上記式において、Ｍは、ＭｇまたはＭｇとＺｎ、Ｃ
ｕ、ＭｎおよびＣｏのうちの１種〜４種との組合わせを
表わす。ただし、ＭがＭｇ＋Ｚｎ＋Ｃｕ、Ｍｇ＋Ｚｎ＋
Ｃｏ、Ｍｇ＋Ｚｎ＋Ｃｕ＋Ｃｏ、Ｍｇ＋Ｚｎ＋Ｃｏ＋Ｍ
ｎおよびＭｇ＋Ｚｎ＋Ｃｕ＋Ｃｏ＋Ｍｎのいずれかであ
る場合は除く、また、ＭがＭｇのほかに他の元素の１種
以上を含む場合は、Ｍ中のＭｇの原子比は０．０５以上
である。Formula [I] (MO) 100-x (Fe 2 O 3 ) x {In the above formula, M is Mg or Mg and Zn, C
Represents a combination with 1 to 4 types of u, Mn and Co. However, M is Mg + Zn + Cu, Mg + Zn +
Co, Mg + Zn + Cu + Co, Mg + Zn + Co + M
n and Mg + Zn + Cu + Co + Mn are excluded, and when M contains at least one other element in addition to Mg, the atomic ratio of Mg in M is 0.05 or more.
さらに、ｘは５３モル％より大である。｝ III 発明の具体的構成 以下、本発明の具体的構成について詳細に説明する。Furthermore, x is greater than 53 mol%. } III Specific Structure of the Invention Hereinafter, the specific structure of the present invention will be described in detail.
上記式において、Ｍは、Ｍｇのみからなるか、あるいは
ＭｇとＺｎ、Ｃｕ、ＭｎおよびＣｏのうちの１種以上と
の計２〜５種の組合せである。In the above formula, M is composed of only Mg or a combination of Mg and one or more of Zn, Cu, Mn and Co in a total of 2 to 5 types.
ただし、本出願の原出願である特公昭６２−３７７８２
号では、Ｍとして、Ｍｇ＋Ｚｎ＋Ｃｕ、Ｍｇ＋Ｚｎ＋Ｃ
ｏ、Ｍｇ＋Ｚｎ＋Ｃｕ＋Ｃｏ、Ｍｇ＋Ｚｎ＋Ｃｏ＋Ｍ
ｎ、およびＭｇ＋Ｚｎ＋Ｃｕ＋Ｃｏ＋Ｍｎをその対象と
しているので、本発明ではこれらを除外するものであ
る。However, Japanese Patent Publication No. 62-37782, which is the original application of this application
In the issue, M is Mg + Zn + Cu, Mg + Zn + C
o, Mg + Zn + Cu + Co, Mg + Zn + Co + M
Since n and Mg + Zn + Cu + Co + Mn are targeted, these are excluded in the present invention.
一方、Ｆｅ２Ｏ３に換算したＦｅ量ｘは５３モル％より
大である。ｘが５３モル％以下となると、抵抗値変化巾
が小さくなってしまう。そして、特に、ｘが５４モル％
以上となると、抵抗値変化巾がきわめて大きくなる。On the other hand, the Fe amount x converted to Fe 2 O 3 is larger than 53 mol%. When x is 53 mol% or less, the resistance value change width becomes small. And, in particular, x is 54 mol%
In the above case, the range of change in resistance becomes extremely large.
これに対し、ｘの上限については特に制限はなく、１０
０モル％未満でありさえすればよい。ただ、飽和磁化の
点では、ｘが９９モル％、より好ましくは９０モル％以
下であることが好ましい。このとき、飽和磁化はきわめ
て大きくなり、キャリヤが感光体に付着したり、キャリ
ヤが磁気ブラシから飛散してしまうことがほとんどなく
なるからである。On the other hand, the upper limit of x is not particularly limited, and 10
It need only be less than 0 mol%. However, in terms of saturation magnetization, x is preferably 99 mol%, more preferably 90 mol% or less. At this time, the saturation magnetization becomes extremely large, and the carrier hardly adheres to the photoconductor or scatters from the magnetic brush.
他方、Ｍは上記のとおりであり、Ｍは、Ｍｇのみからな
るものであっても、上記の制限内で、Ｍｇと他のＺｎ、
Ｃｕ、Ｍｎ、Ｃｏの１種以上からなるものであってもよ
い。ただ、ＭがＭｇのほかに他の元素の１種以上を含む
ときにはＭ中のＭｇの原子比は０．０５以上である。On the other hand, M is as described above, and even if M is composed only of Mg, Mg and other Zn,
It may be one or more of Cu, Mn, and Co. However, when M contains at least one other element in addition to Mg, the atomic ratio of Mg in M is 0.05 or more.
これは、Ｍｇの原子比が０．０５未満となると、飽和磁
化が減少し、前記のようなキャリヤ付着やキャリヤ飛散
が多くなるからである。This is because when the atomic ratio of Mg is less than 0.05, the saturation magnetization decreases, and the carrier adhesion and carrier scattering as described above increase.
このような上記式〔Ｉ〕で表わされる組成のうちでは、
式〔Ｉ〕におけるＭＯが下記式〔II〕で表わされるもの
であることが好ましい。Among the compositions represented by the above formula [I],
MO in the formula [I] is preferably represented by the following formula [II].
式〔II〕 (MgO)y (XO)1-y 上記式〔II〕において、Ｘは、Ｚｎ、またはＺｎとＣ
ｕ、ＭｎおよびＣｏのうちの１種以上との組合せを表わ
す。ただし、上記のとおり、Ｚｎ＋Ｃｕ、Ｚｎ＋Ｃｏ、
Ｚｎ＋Ｃｕ＋Ｃｏ、Ｚｎ＋Ｃｏ＋Ｍｎ、Ｚｎ＋Ｃｕ＋Ｃ
ｏ＋Ｍｎは除外する。Ｙは０．０５以上１未満である。Formula [II] (MgO) y (XO) 1-y In the above formula [II], X is Zn, or Zn and C.
Represents a combination with at least one of u, Mn and Co. However, as described above, Zn + Cu, Zn + Co,
Zn + Cu + Co, Zn + Co + Mn, Zn + Cu + C
O + Mn is excluded. Y is 0.05 or more and less than 1.
このような上記式〔II〕で示される組成のものは、きわ
めて高い飽和磁化を与える。The composition represented by the above formula [II] gives extremely high saturation magnetization.
この場合、ｙが０．０５〜０．９９、特に０．１〜０．
７となるとより好ましい結果を得る。In this case, y is 0.05 to 0.99, especially 0.1 to 0.
A more favorable result is obtained with 7.
さらに、Ｘ中におけるＺｎの原子比は、１または０．３
以上１未満であることが好ましい。このとき飽和磁化は
きわめて高いものとなる。Further, the atomic ratio of Zn in X is 1 or 0.3.
It is preferably 1 or more and less than 1. At this time, the saturation magnetization becomes extremely high.
なお、Ｘが、上記の制限内でＺｎとほかのＣｕ、Ｍｕ、
Ｃｏのうちの２種または３種との組合せであるとき、Ｃ
ｕ、ＭｎないしＣｏの組成比率は任意のものとすること
ができる。In addition, X is Zn and other Cu, Mu,
When it is a combination with 2 or 3 of Co, C
The composition ratio of u, Mn or Co may be arbitrary.
このようなフェライト粒子は、スピネル構造をもつ。Such ferrite particles have a spinel structure.
このような組成をもつフェライト粒子中には、一般に、
全体の５モル５以内の範囲内でＣａ、Ｂａ、Ｃｒ、Ｔ
ａ、Ｍｏ、Ｓｉ、Ｖ、Ｂ、Ｐｂ、Ｋ、Ｎａ等の元素が酸
化物等の形で含有されていてもよい。In ferrite particles having such a composition, in general,
Ca, Ba, Cr, T within 5 mol 5 of the total
Elements such as a, Mo, Si, V, B, Pb, K and Na may be contained in the form of oxides and the like.
このようなフェライト粒子は、通常、１０００μｍ以下
の平均粒子径をもつ。Such ferrite particles usually have an average particle size of 1000 μm or less.
また、粒子表面には、一般には被覆層を形成せず、その
まま磁性キャリヤ粒子とされる。Further, generally, a coating layer is not formed on the particle surface, and the magnetic carrier particles are used as they are.
上記したような磁性キャリヤを構成するフェライト粒子
の抵抗は、下記のような測定を行ったとき、１００Ｖ印
加時において、１０４〜１０14Ω、特に１０５〜１０12
Ωの範囲内の任意の値とされる。The resistance of the ferrite particles constituting the magnetic carrier as described above is 10 4 to 10 14 Ω, especially 10 5 to 10 12 when 100 V is applied when the following measurement is performed.
It is an arbitrary value within the range of Ω.
そして、このような抵抗値範囲内にて、本発明によれ
ば、後述の焼成条件の変更により、抵抗値が連続的に変
化し、その最大変化比は１０５以上、特に１０６〜１０
10にも及び、任意の画質の静電画像を適宜選定すること
ができる。フェライト粒子の抵抗測定は、磁気ブラシ現
像方式を模し、下記のようにして行う。And within such a resistance value range, according to the present invention, the resistance value is continuously changed by changing the firing condition described later, and the maximum change ratio thereof is 10 5 or more, particularly 10 6 to 10
It is possible to properly select an electrostatic image having an arbitrary image quality as many as 10 . The resistance measurement of the ferrite particles is performed as follows, simulating the magnetic brush development method.
すなわち、磁極間間隙８mmにて、Ｎ極およびＳ極を対向
させる。この場合、磁極の表面磁束密度は１５００Gaus
s、対向磁極面積は１０×３０mmとする。磁極間に、電
極間間隙８mmにて、非磁性の平行平板電極を配置し、電
極間に被検試料２００mgを入れ、磁力により電極間に試
料を保持する。このようにして抵抗を、絶縁抵抗計また
は電流計により測定すればよい。That is, the N pole and the S pole are opposed to each other with a gap between magnetic poles of 8 mm. In this case, the surface magnetic flux density of the magnetic pole is 1500 Gaus
The opposing magnetic pole area is 10 × 30 mm. A non-magnetic parallel plate electrode is arranged between the magnetic poles with an interelectrode gap of 8 mm, 200 mg of the test sample is put between the electrodes, and the sample is held between the electrodes by magnetic force. In this way, the resistance may be measured with an insulation resistance meter or an ammeter.
なお、このようにして測定した抵抗が、１０14Ωをこえ
ると、画像濃度が低下する。一方、１０４Ω未満となる
と、キャリヤの感光体への付着が多くなり、また、解像
力、階調性等が低下したり、画質が硬調となる傾向にあ
る。When the resistance measured in this way exceeds 10 14 Ω, the image density decreases. On the other hand, when it is less than 10 4 Ω, the carrier is often attached to the photoconductor, the resolution and gradation are deteriorated, and the image quality tends to be high.
さらに、本発明におけるフェライト粒子の飽和磁化σｍ
は、３５emu/ｇ以上であることが好ましい。このとき、
キャリヤが感光体に付着するいわゆるキャリヤ引きが解
消し、また、くりかえし現像に際してのキャリヤの飛散
がなくなるからである。この場合σｍは４０emu/ｇ以上
であると、より好ましい結果を得る。Furthermore, the saturation magnetization σ m of the ferrite particles in the present invention
Is preferably 35 emu / g or more. At this time,
This is because the so-called carrier pulling in which the carrier adheres to the photoconductor is eliminated, and the carrier does not scatter during repeated development. In this case, a more preferable result is obtained when σ m is 40 emu / g or more.
このようなフェライト粒子からなる磁性キャリヤ粒子
は、大略米国特許第３８３９０２９号、同３９１４１８
号、同３９２６６５７号等に記載されているような一般
的な手順によって製造される。Magnetic carrier particles composed of such ferrite particles are generally disclosed in U.S. Pat. Nos. 3,839,029 and 3,914,418.
No. 3,926,657, etc.
すなわち、まず、対応する金属の酸化物を調合する。That is, first, a corresponding metal oxide is prepared.
次いで、溶媒、通常水を加え、例えばボールミル等によ
りスラリー化し、必要に応じ、分散剤、結合剤等を添加
する。Next, a solvent, usually water, is added to form a slurry by, for example, a ball mill, and if necessary, a dispersant, a binder and the like are added.
そして、スプレードライヤーにて造粒乾燥する。Then, it is granulated and dried by a spray dryer.
この後、所定の焼成雰囲気および焼成温度プロフィール
にて焼成を行う。焼成は常法に従う。After that, firing is performed in a predetermined firing atmosphere and firing temperature profile. Firing follows a conventional method.
この場合、焼成の際の平衡酸素分圧を減少させれば、抵
抗値は減少する。そして、焼成雰囲気を空気中から窒素
雰囲気中まで連続的に酸素分圧を変化させたとき、粒子
の抵抗値は連続的に変化する。In this case, if the equilibrium oxygen partial pressure during firing is reduced, the resistance value is reduced. Then, when the oxygen partial pressure is continuously changed from the air to the nitrogen atmosphere in the firing atmosphere, the resistance value of the particles continuously changes.
焼成終了後、粒子を解砕ないし分散させ、次に所望の粒
度に分級して磁性キャリヤ粒子が製造される。After firing, the particles are crushed or dispersed, and then classified to a desired particle size to produce magnetic carrier particles.
本発明の画像形成方法の手順を示せば、以下のとおりで
ある。The procedure of the image forming method of the present invention is as follows.
まず、同一出発原料を用い、焼成雰囲気して、空気中か
ら窒素雰囲気までの範囲で空気と窒素との混合比を変え
ることで酸素分圧を変化させたとき、１０５以上の抵抗
変化比をもつ焼結フェライト粒子組成として、上記式
〔Ｉ〕で表わされる組成に対応する出発原料組成比を選
択する。First, when the oxygen partial pressure is changed by changing the mixing ratio of air and nitrogen in the range from air to nitrogen atmosphere using the same starting material and firing atmosphere, a resistance change ratio of 10 5 or more is obtained. As the composition of the sintered ferrite particles, a starting material composition ratio corresponding to the composition represented by the above formula [I] is selected.
次に、この出発原料を酸素分圧をかえて焼成して、粒子
抵抗の異なる複数のフェライト粒子を得る。そして、こ
の複数のフェライト粒子それぞれを、用いるトナーと混
合して現像剤とし、各現像剤を用いて用いる機種の静電
画像装置でトナー像を得、機種に応じて必要とされる画
像濃度と階調性とが得られる焼成時の酸素分圧を決定す
る。この後、前記選択された組成の出発原料を、この決
定された酸素分圧で組成して磁性キャリヤ粒子とする。Next, this starting material is fired while changing the oxygen partial pressure to obtain a plurality of ferrite particles having different particle resistances. Then, each of the plurality of ferrite particles is mixed with a toner to be used as a developer, and a toner image is obtained by an electrostatic image device of a model using each developer, and an image density required according to the model is obtained. It determines the oxygen partial pressure at the time of firing at which gradation is obtained. Then, the starting material having the selected composition is composed at the determined oxygen partial pressure to obtain magnetic carrier particles.
本発明によって製造される磁性キャリヤは、トナーと組
合せて現像剤とされる。この場合、用いるトナーの機種
およびトナー濃度については制限はない。The magnetic carrier produced according to the present invention is combined with toner to form a developer. In this case, there is no limitation on the type of toner used and the toner concentration.
また、静電複写画像を得るにあたり、用いる磁気ブラシ
現像方式および感光体等についても特に制限はなく、公
知の磁気ブラシ現像法に従い、静電複写画像が得られ
る。Further, in obtaining an electrostatically copied image, there is no particular limitation on the magnetic brush developing method and the photoconductor used, and the electrostatically copied image can be obtained according to a known magnetic brush developing method.
IV 発明の具体的作用効果 本発明では、その焼結雰囲気をかえて製造することによ
り、１０６〜１０10にも及ぶ広い抵抗値変化比をもつ磁
性キャリヤ粒子を得ることができる。このため、コピー
装置の機種に応じ、最適画像を与えるキャリヤを容易に
得ることができる。また、任意の画質を選定することが
できる。そして、表面に被膜形成する必要がないので、
キャリヤの耐久性も良好である。IV Specific Actions and Effects of the Invention In the present invention, magnetic carrier particles having a wide resistance change ratio of 10 6 to 10 10 can be obtained by changing the sintering atmosphere. Therefore, it is possible to easily obtain the carrier that gives the optimum image according to the model of the copying apparatus. Also, any image quality can be selected. And since it is not necessary to form a film on the surface,
The durability of the carrier is also good.
また、飽和磁化も３５emu/ｇ以上を得、キャリヤが感光
体に付着する、いわゆるキャリヤ引きや、キャリヤの飛
散の発生も少ない。Further, the saturation magnetization is 35 emu / g or more, so that the carrier adheres to the photosensitive member, so-called carrier pulling and carrier scattering are small.
Ｖ 発明の具体的実施例 以下、本発明を具体的実施例により、さらに詳細に説明
する。V Specific Examples of the Invention Hereinafter, the present invention will be described in more detail with reference to specific examples.
実施例１． ２価金属酸化物およびＦｅ２Ｏ３に換算して、モル比
で、下記表１に示される６種の組成にて（試料NO.１〜
６）、対応する金属酸化物を調合した。Example 1. Converted to a divalent metal oxide and Fe 2 O 3 , the molar ratio has six compositions shown in Table 1 below (Sample No. 1 to No. 1).
6), corresponding metal oxide was prepared.
次に、この調合組成物１重量部あたり、１重量部の水を
添加し、ボールミルにて５時間混合し、スラリー化し、
分散剤および結合剤を適量添加した。Next, 1 part by weight of water was added to 1 part by weight of the prepared composition, and the mixture was mixed in a ball mill for 5 hours to form a slurry,
An appropriate amount of dispersant and binder was added.
次いで、１５０℃以上の温度で、スプレードライヤーに
より造粒乾燥した。Then, it was granulated and dried with a spray dryer at a temperature of 150 ° C. or higher.
各造粒物を、トンネル炉中にて、それぞれ、酸素を含む
窒素雰囲気および窒素雰囲気下で、それぞれ最高温度１
３５０℃で焼成した。The maximum temperature of each granulated product was 1 in a tunnel furnace under a nitrogen atmosphere containing oxygen and a nitrogen atmosphere.
It was baked at 350 ° C.
この後、解砕、分級して、平均粒子径４５μｍの計１２
種のフェライト粒子を得た。After that, crushing and classification are performed to obtain a total of 12 particles having an average particle diameter of 45 μm.
Seed ferrite particles were obtained.
得られた各フェライト粒子のＸ線解析および定量化学分
析を行ったところ、各粒子ともスピネル構造をもち、上
記調合比と対応する金属組成をもつことが確認された。When X-ray analysis and quantitative chemical analysis were carried out on each of the obtained ferrite particles, it was confirmed that each particle had a spinel structure and had a metal composition corresponding to the above mixing ratio.
次いで、得られた各フェライト粒子の飽和磁化σｍ（em
u/ｇ）と１００Ｖ印加時の抵抗（Ω）を測定した。Then, the saturation magnetization σ m (em
u / g) and the resistance (Ω) at the time of applying 100 V were measured.
この場合、飽和磁化σｍは、振動試料型の磁力計で測定
した。In this case, the saturation magnetization σ m was measured by a vibrating sample type magnetometer.
また抵抗は、上記したようにして、２００mgの試料の１
００Ｖ印加時の抵抗を絶縁抵抗計で測定した。The resistance is the same as that of the 200 mg sample as described above.
The resistance when 00V was applied was measured with an insulation resistance meter.
各組成につき、測定された窒素中焼成での（σｍ）Ｎ、
酸素を含む窒素雰囲気中焼成での（σｍ）Ａ、酸素を含
む窒素雰囲気中焼成での抵抗ＲＡ、窒素中焼成での抵抗
ＲＮおよび抵抗変化比ＲＡ／ＲＮを下記表１に示す。For each composition, the measured (σ m ) N for firing in nitrogen,
In a nitrogen atmosphere firing containing oxygen (sigma m) A, the resistance R A in a nitrogen atmosphere firing containing oxygen, the resistance R N and the resistance change ratio R A / R N in a nitrogen firing in Table 1 Show.
さらに、以上のような各フェライト粒子をそのまま磁性
キャリヤとして、トナー濃度１１．５重量％にて、市販
の２成分トナー（平均粒子径１１．５±１．５μｍ）と
混合して、現像剤とした。Further, each ferrite particle as described above is used as a magnetic carrier as it is at a toner concentration of 11.5% by weight, and mixed with a commercially available two-component toner (average particle diameter 11.5 ± 1.5 μm) to obtain a developer. did.
各現像剤を用い、市販の静電複写機を用い、磁気ブラシ
現像を行った。Magnetic brush development was performed using a commercially available electrostatic copying machine using each developer.
この場合、磁気ブラシ用マグネットローラーの表面磁束
密度は１０００Gauss、回転数は９０rpmである。また、
マグネットローラー感光体間隙は４．０±０．３mmであ
る。さらに感光体としては、セレン感光体を用い、表面
最高電位は８００Ｖとした。In this case, the surface magnetic flux density of the magnet roller for the magnetic brush is 1000 Gauss, and the rotation speed is 90 rpm. Also,
The gap between the magnet roller photoconductors is 4.0 ± 0.3 mm. Further, a selenium photoconductor was used as the photoconductor, and the maximum surface potential was 800V.
イーストマン・コダック社製のグレースケールを用い、
上記の静電複写機により、普通紙上にトナー画像を得、
オリジナル濃度(OD)１．０における画像濃度(ID)を求
め、各組成における窒素雰囲気中焼成を行った粒子の(I
D)Ｎと、酸素を含む窒素雰囲気中焼成を行った粒子の(I
D)Ａとの差を求めた。Using a grayscale manufactured by Eastman Kodak Company,
Obtain a toner image on plain paper by the above electrostatic copying machine,
The image density (ID) at the original density (OD) of 1.0 was obtained, and the (I
(D) N and (I of the particles fired in a nitrogen atmosphere containing oxygen)
D) The difference from A was calculated.
結果を表１に併記する。The results are also shown in Table 1.
なお、ほとんどの磁性キャリヤは、キャリヤの感光体へ
の付着はほとんどなく、またキャリヤ飛散もほとんどな
かった。It should be noted that most of the magnetic carriers had almost no adhesion of the carrier to the photoconductor and almost no scattering of the carrier.
表１に示される結果から、Ｆｅ２Ｏ３量ｘが５３モル％
より大きい本発明の磁性キャリヤ粒子は、抵抗変化比が
きわめて大きく、画像の階調が大きく変化し、選択でき
る画質の自由度がきわめて大きいことがわかる。 From the results shown in Table 1, the Fe 2 O 3 amount x is 53 mol%
It can be seen that the larger magnetic carrier particles of the present invention have a very large resistance change ratio, a large change in image gradation, and a great degree of freedom in image quality that can be selected.
なお、上記において焼成雰囲気を、酸素と窒素の混合ガ
スとし、混合比を種々変更したところ、抵抗および画像
濃度が、上記の値の中間にて連続的に変化することが確
認された。In the above, when the firing atmosphere was a mixed gas of oxygen and nitrogen and the mixing ratio was variously changed, it was confirmed that the resistance and the image density continuously changed in the middle of the above values.
実施例２． 下記表２に示される組成にて、実施例１に準じて磁性キ
ャリヤを作成し、上記ＲＡ、ＲＮ、ＲＡ−ＲＮおよび(I
D)Ｎ−(ID)Ａを測定した。結果を表２および表３に示
す。Example 2. At compositions shown in Table 2, to create a magnetic carrier according to Example 1, the R A, R N, R A -R N and (I
D) N- (ID) A was measured. The results are shown in Tables 2 and 3.
表２および表３に示される結果から、本発明の効果があ
きらかである。 From the results shown in Table 2 and Table 3, the effect of the present invention is clear.
なお、試料NO.９〜２４では、４０emu/ｇ以上のσｍが
得られ、キャリヤ引きとキャリヤ飛散がほとんどなかっ
たが、試料NO.７、８では、σｍが２０emu/ｇ以下であ
り、キャリヤ引きとキャリヤ飛散が大きかった。In addition, in sample Nos. 9 to 24, σ m of 40 emu / g or more was obtained, and there was almost no carrier pulling and carrier scattering, but in sample Nos. 7 and 8, σ m was 20 emu / g or less, Carrier pulling and carrier scattering were large.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 柿崎 勝久 東京都中央区日本橋１丁目13番１号 ティ ーディーケイ株式会社内 (72)発明者 牧野 元彦 東京都中央区日本橋１丁目13番１号 ティ ーディーケイ株式会社内 (56)参考文献 特開 昭55−65406（ＪＰ，Ａ) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuhisa Kakizaki 1-13-1, Nihonbashi, Chuo-ku, Tokyo TDC Corporation (72) Inventor Motohiko Makino 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDC Within the corporation (56) References JP-A-55-65406 (JP, A)
Claims (2)
空気中から窒素雰囲気までの範囲で空気と窒素との混合
比を変えることで酸素分圧を変化させたとき、１０５以
上の抵抗変化比をもつ焼結フェライト粒子組成として、
２価金属酸化物または３価金属酸化物に換算して下記式
〔Ｉ〕で表わされる組成に対応する出発原料組成比を選
択し、 この出発原料を酸素分圧をかえて焼成して、粒子抵抗の
異なる複数のフェライト粒子を得、 この複数のフェライト粒子それぞれを、用いるトナーと
混合して現像剤とし、各現像剤を用いて用いる機種の静
電画像装置でトナー像を得、機種に応じて必要とされる
画像濃度と階調性とが得られる焼成時の酸素分圧を決定
し、 前記選択された組成の出発原料を、この決定された酸素
分圧で焼成して磁性キャリヤ粒子とし、 これをトナーと混合して現像剤とし、前記の機種の静電
画像装置でトナー画像を得る画像形成方法。 式〔Ｉ〕 (MO)100-x(Fe2O3)x ｛上記式において、Ｍは、ＭｇまたはＭｇとＺｎ、Ｃ
ｕ、ＭｎおよびＣｏのうちの少なくとも１種以上との組
合わせを表わす。ただし、ＭがＭｇ＋Ｚｎ＋Ｃｕ、Ｍｇ
＋Ｚｎ＋Ｃｏ、Ｍｇ＋Ｚｎ＋Ｃｕ＋Ｃｏ、Ｍｇ＋Ｚｎ＋
Ｃｏ＋ＭｎおよびＭｇ＋Ｚｎ＋Ｃｕ＋Ｃｏ＋Ｍｎのいず
れかである場合は除く。また、ＭがＭｇのほかに他の元
素の１種以上を含む場合は、Ｍ中のＭｇの原子比は０．
０５以上である。 さらに、ｘは５３モル％より大である。｝1. A firing atmosphere using the same starting material,
When the oxygen partial pressure is changed by changing the mixing ratio of air and nitrogen in the range from the air to the nitrogen atmosphere, a sintered ferrite particle composition having a resistance change ratio of 10 5 or more,
The starting material composition ratio corresponding to the composition represented by the following formula [I] is selected in terms of a divalent metal oxide or a trivalent metal oxide, and the starting material is fired while changing the oxygen partial pressure to obtain particles. Obtain a plurality of ferrite particles with different resistances, mix each of these ferrite particles with the toner to be used as a developer, and obtain a toner image with the electrostatic image device of the model used with each developer. Then, the oxygen partial pressure at the time of firing to obtain the required image density and gradation is determined, and the starting material having the selected composition is fired at the determined oxygen partial pressure to obtain magnetic carrier particles. An image forming method for obtaining a toner image with the electrostatic image device of the above model by mixing this with a toner to form a developer. Formula [I] (MO) 100-x (Fe 2 O 3 ) x {In the above formula, M is Mg or Mg and Zn, C
It represents a combination with at least one or more of u, Mn and Co. However, M is Mg + Zn + Cu, Mg
+ Zn + Co, Mg + Zn + Cu + Co, Mg + Zn +
Exclude any of Co + Mn and Mg + Zn + Cu + Co + Mn. When M contains one or more elements other than Mg, the atomic ratio of Mg in M is 0.
It is more than 05. Furthermore, x is greater than 53 mol%. }
を、粒子を構成するフェライトの平衡酸素分圧からはず
れたものとする特許請求の範囲第１項の画像形成方法。2. The image forming method according to claim 1, wherein the oxygen partial pressure for firing the magnetic carrier particles is deviated from the equilibrium oxygen partial pressure of ferrite constituting the particles.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63150878A JPH0623866B2 (en) | 1988-06-17 | 1988-06-17 | Image forming method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63150878A JPH0623866B2 (en) | 1988-06-17 | 1988-06-17 | Image forming method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6428233A JPS6428233A (en) | 1989-01-30 |
| JPH0623866B2 true JPH0623866B2 (en) | 1994-03-30 |
Family
ID=15506355
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63150878A Expired - Lifetime JPH0623866B2 (en) | 1988-06-17 | 1988-06-17 | Image forming method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0623866B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2518684B2 (en) * | 1989-04-10 | 1996-07-24 | 株式会社巴川製紙所 | Developer for reversal development |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6036082B2 (en) * | 1978-10-27 | 1985-08-19 | ティーディーケイ株式会社 | Ferrite powder for electrophotographic magnetic toner and method for producing the same |
-
1988
- 1988-06-17 JP JP63150878A patent/JPH0623866B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6428233A (en) | 1989-01-30 |
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