JPH0945516A - Magnetic particle powder, its manufacture and water-base magnetic paint using said magnetic particle powder as well as magnetic recording sheet using the water-base magnetic paint - Google Patents
Magnetic particle powder, its manufacture and water-base magnetic paint using said magnetic particle powder as well as magnetic recording sheet using the water-base magnetic paintInfo
- Publication number
- JPH0945516A JPH0945516A JP7211087A JP21108795A JPH0945516A JP H0945516 A JPH0945516 A JP H0945516A JP 7211087 A JP7211087 A JP 7211087A JP 21108795 A JP21108795 A JP 21108795A JP H0945516 A JPH0945516 A JP H0945516A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- particles
- particle powder
- water
- paint
- 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.)
- Pending
Links
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
- H01F41/14—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates
- H01F41/16—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates the magnetic material being applied in the form of particles, e.g. by serigraphy, to form thick magnetic films or precursors therefor
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Compounds Of Iron (AREA)
- Hard Magnetic Materials (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、磁気記録シートの磁性
層を形成する為の磁性塗料に使用する磁性粒子粉末及び
その製造法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic particle powder used in a magnetic paint for forming a magnetic layer of a magnetic recording sheet and a method for producing the same.
【0002】[0002]
【従来の技術】近年、事務や作業の省力化及び能率向上
を目的として磁気記録シートの使用が各分野で拡大して
いる。即ち、鉄道用磁気切符、磁気定期乗車券、高速道
路通行券、クレジットカード、ID(身分証明)カー
ド、テレフォンカード、オレンジカード等である。2. Description of the Related Art In recent years, the use of magnetic recording sheets has been expanding in various fields for the purpose of labor saving of office work and work and improvement of efficiency. That is, it is a magnetic ticket for railways, a magnetic commuter pass ticket, a highway pass ticket, a credit card, an ID (identification) card, a telephone card, an orange card, and the like.
【0003】これら磁気記録シートは、ポリ塩化ビニル
等のプラスチックや紙等の非磁性支持体の一面に磁性粒
子粉末をビヒクル中に分散させた磁性塗料を塗布したス
トライプ状の磁性層が設けられているか或いは支持体の
一面全体が磁性層であり、他面には絵や文字等の画像を
印刷した構造となっているのが一般的である。In these magnetic recording sheets, a stripe-shaped magnetic layer is provided on one surface of a non-magnetic support such as plastic such as polyvinyl chloride or paper, which is coated with a magnetic paint in which magnetic particle powder is dispersed in a vehicle. In general, one side of the support is a magnetic layer and the other side has a structure in which an image such as a picture or a character is printed.
【0004】磁性塗料は、溶剤の種類により有機溶剤を
主溶媒とする溶剤系磁性塗料、水を主溶媒とする水系磁
性塗料があるが、近年、大気を汚染することが少なく、
省資源、省エネルギーであり、しかも、火災の危険性が
少ない等、安全面、衛生面、環境面から水系磁性塗料が
有望視されている。Magnetic paints include solvent-based magnetic paints containing an organic solvent as a main solvent and water-based magnetic paints containing water as a main solvent, depending on the type of solvent.
Water-based magnetic paints are regarded as promising from the viewpoints of safety, hygiene, and environment because they save resources and energy, and have a low risk of fire.
【0005】しかし、水系磁性塗料中における磁性粒子
粉末の分散機構は、従来の溶剤系磁性塗料とは異なって
いるため、溶剤系磁性塗料と同様の分散技術によっては
磁性粒子粉末をビビクル中に十分分散させることができ
ない。即ち、水系磁性塗料の場合、水系樹脂(展色剤)
が用いられるが、この水系樹脂は溶剤系樹脂(展色剤)
が溶解状態で拡がりをもって存在しているのに対し、主
として乳化重合粒子又はコロイダル型粒子等の粒子状態
で存在するため、先ず、磁性粒子粉末をビヒクル中にい
かなる手段で分散させるのか、そしてどの位の時間を必
要とするのか、即ち、顔料の易分散性と分散均一性が問
題となり、次に、分散された磁性粒子と水系樹脂粒子と
の相互作用等により再凝集しやすいものであるため、分
散安定性が問題となる。殊に、水系塗料中に分散させる
粒子が磁性を有している場合には、磁気的凝集が生じる
為、これら分散性の問題は、殊に、深刻である。However, since the dispersion mechanism of the magnetic particle powder in the water-based magnetic paint is different from that of the conventional solvent-based magnetic paint, the magnetic particle powder is sufficiently dispersed in the vehicle by the same dispersion technique as the solvent-based magnetic paint. Cannot be dispersed. That is, in the case of water-based magnetic paint, water-based resin (color spreader)
The water-based resin is a solvent-based resin (color-developing agent).
Exists in a dissolved state with a spread, while it exists mainly in a particle state such as emulsion-polymerized particles or colloidal particles, first of all, by what means the magnetic particle powder is dispersed in the vehicle, and how much Is required, that is, the easy dispersibility and dispersion uniformity of the pigment become a problem, and then the re-aggregation is likely due to the interaction between the dispersed magnetic particles and the water-based resin particles. Dispersion stability becomes a problem. In particular, when the particles to be dispersed in the water-based coating material have magnetism, magnetic agglomeration occurs, so that these problems of dispersibility are particularly serious.
【0006】そして、水系磁性塗料における磁性粒子粉
末の分散性が不十分であると、磁性塗膜面の平滑性の低
下や角形比等の磁気特性の低下の原因となり、その結
果、磁気記録シートの出力変動、ドロップアウト等を引
き起こすことになる。If the dispersibility of the magnetic particle powder in the water-based magnetic paint is insufficient, it causes deterioration of the smoothness of the surface of the magnetic coating film and deterioration of magnetic characteristics such as squareness ratio, and as a result, the magnetic recording sheet. Output fluctuations, dropouts, etc.
【0007】そこで、水系磁性塗料中における磁性粒子
粉末の分散性を改良して易分散性、分散均一性及び分散
安定性に優れた磁性粒子粉末を得ることが強く要求され
る。Therefore, it is strongly required to improve the dispersibility of the magnetic particle powder in the water-based magnetic paint to obtain the magnetic particle powder having excellent dispersibility, dispersion uniformity and dispersion stability.
【0008】従来、ビヒクル中における磁性粒子粉末の
分散性を改良する為に磁性粒子粉末の粒子表面を各種無
機化合物や有機化合物で被着することが行われており、
例えば、磁性粒子粉末の粒子表面にオルガノポリシロキ
サンを被着する方法(特公昭58−13099号公報、
特公平5−4129号公報、特開昭63−113082
号公報、特開昭63−165461号公報、特開昭63
−168346号公報、特開平1−182368号公
報、特開平2−212561号公報、特開平3−163
172号公報等)、磁性粒子粉末の粒子表面に有機ケイ
素化合物を被着する方法(特開昭50−44498号公
報、特開昭51−40903号公報、特開昭62−87
237号公報等)及び磁性粒子粉末の粒子表面にシラン
カップリング剤を被着する方法(特開平49−5960
8号公報、特開昭51−134899号公報、特開昭5
2−44794号公報、特開昭54−7310号公報、
特開昭54−110999号公報、特開昭60−240
769号公報、特開平4−18930号公報、特開平5
−239446号公報等)等が試みられている。Conventionally, in order to improve the dispersibility of the magnetic particle powder in the vehicle, the particle surface of the magnetic particle powder has been coated with various inorganic compounds or organic compounds,
For example, a method of depositing organopolysiloxane on the particle surface of magnetic particle powder (Japanese Patent Publication No. 58-13099).
Japanese Examined Patent Publication No. 5-4129, Japanese Patent Laid-Open No. 63-113082.
JP, JP-A-63-165461, JP-A-63
-168346, JP-A-1-182368, JP-A-2-212561, JP-A-3-163
No. 172, etc.), a method of depositing an organosilicon compound on the particle surface of magnetic particle powder (JP-A-50-44498, JP-A-51-40903, JP-A-62-87).
No. 237, etc.) and a method of depositing a silane coupling agent on the particle surface of magnetic particle powder (JP-A-49-5960).
No. 8, JP 51-134899, and JP 5
2-44794, JP-A-54-7310,
JP-A-54-110999 and JP-A-60-240
769, JP-A-4-18930, JP-A-5
-239446 gazette) etc. are tried.
【0009】また、特開昭62−187772号公報に
は、ポリエステル変成ポリシロキサンが、粘着性を低下
させ、潤滑性を向上させる作用を有することから塗料中
に添加して使用することが開示されている。Further, Japanese Unexamined Patent Publication (Kokai) No. 62-187772 discloses that polyester-modified polysiloxane is used by adding it to a coating material because it has an action of lowering tackiness and improving lubricity. ing.
【0010】[0010]
【発明が解決しようとする課題】水系磁性塗料中におけ
る分散性を改良して易分散性、分散均一性及び分散安定
性に優れた磁性粒子粉末を得ることは現在最も要求され
ているところであるが、このような磁性粒子粉末は、未
だ得られていない。It is currently most demanded to improve the dispersibility in an aqueous magnetic coating composition to obtain a magnetic particle powder having excellent dispersibility, dispersion uniformity and dispersion stability. However, such magnetic particle powder has not been obtained yet.
【0011】即ち、粒子表面に前出公知のオルガノポリ
シロキサンや有機ケイ素化合物やシランカップリング剤
等が被着されている磁性粒子粉末は、後出比較例に示す
通り、ビヒクル中への易分散性、分散均一性及び分散安
定性のいずれも未だ十分なものとは言い難いものであ
る。That is, magnetic particle powders having the above-mentioned known organopolysiloxane, organosilicon compound, silane coupling agent, etc. deposited on the surface of the particles are easily dispersed in a vehicle as shown in Comparative Examples below. It is difficult to say that all of the properties, dispersion uniformity, and dispersion stability are sufficient.
【0012】また、前出特開昭62−187772号公
報に開示のポリエステル変成ポリシロキサンを塗料中に
添加する場合も同様に後出比較例に示す通り、磁性粒子
粉末のビヒクル中への分散性は、易分散性、分散均一性
及び分散安定性のいずれも十分ではない。Also, when the polyester-modified polysiloxane disclosed in the above-mentioned Japanese Patent Laid-Open No. 62-187772 is added to the paint, the dispersibility of the magnetic particle powder in the vehicle is also similarly shown in the comparative example. Is insufficient in easy dispersibility, dispersion uniformity, and dispersion stability.
【0013】そこで、本発明は、水系磁性塗料中におけ
る分散性を改良して易分散性、分散均一性及び分散安定
性に優れた磁性粒子粉末を得ることを技術的課題とす
る。Therefore, it is a technical object of the present invention to obtain a magnetic particle powder having improved dispersibility in a water-based magnetic coating material and excellent in dispersibility, dispersion uniformity and dispersion stability.
【0014】[0014]
【課題を解決するための手段】前記技術的課題は、次の
とおりの本発明によって達成できる。The above technical problems can be achieved by the present invention as described below.
【0015】即ち、本発明は、粒子表面に、ポリエーテ
ル、ポリエステル及びアラルキルから選ばれる1種又は
2種以上によって変成されているポリシロキサンが被着
されているマグネトプランバイト型フェライト粒子又は
磁性酸化鉄粒子からなる磁性粒子粉末、必要により、粒
子表面に、スクエア酸が被着されており、更に、該被着
スクエア酸の表面に、ポリエーテル、ポリエステル又は
アラルキルから選ばれる1種又は2種以上によって変成
されているポリシロキサンが被着されているマグネトプ
ランバイト型フェライト粒子又は磁性酸化鉄粒子からな
る磁性粒子粉末、マグネトプランバイト型フェライト粒
子又は磁性酸化鉄粒子、必要により、該マグネトプラン
バイト型フェライト粒子又は該磁性酸化鉄粒子とスクエ
ア酸とを含む水懸濁液を混合した後、濾別、乾燥するこ
とにより得られるスクエア酸が被着されているマグネト
プランバイト型フェライト粒子又は磁性酸化鉄粒子とポ
リエーテル、ポリエステル及びアラルキルから選ばれる
1種又は2種以上によって変成されているポリシロキサ
ンとを80℃以上の温度で混合することからなる磁性粒
子粉末の製造法、上記磁性粒子粉末を水系塗料構成基材
中に配合されてなる水系磁性塗料及び非磁性支持体上の
少なくとも一部に磁性層を設けてなる磁気記録シートに
おいて、前記磁性層が前記水系磁性塗料を塗布、乾燥す
ることにより形成されるものであって、磁性層の表面粗
度が0.35μm以下、角形比が0.87以上であるこ
とからなる磁気記録シートである。That is, according to the present invention, magnetoplumbite type ferrite particles or magnetic oxidization in which polysiloxane modified with one kind or two kinds or more selected from polyether, polyester and aralkyl are coated on the surface of particles. Magnetic particle powder consisting of iron particles, if necessary, the surface of the particles is coated with squaric acid, and further the surface of the deposited squaric acid is one or more selected from polyether, polyester or aralkyl. Magnetoplumbite-type ferrite particles coated with polysiloxane that has been modified by the above method, or magnetic particle powder consisting of magnetic iron oxide particles, magnetoplumbite-type ferrite particles or magnetic iron oxide particles, and if necessary, the magnetoplumbite-type Water suspension containing ferrite particles or magnetic iron oxide particles and squaric acid After mixing the liquids, the mixture is filtered and dried to obtain square plume-type magnetoplumbite-type ferrite particles or magnetic iron oxide particles, and one or more selected from polyether, polyester and aralkyl. A method for producing magnetic particle powder, which comprises mixing polysiloxane modified by the method at a temperature of 80 ° C. or higher, an aqueous magnetic coating material and a non-magnetic support obtained by mixing the magnetic particle powder in a water-based coating material. In a magnetic recording sheet having a magnetic layer provided on at least a part of a body, the magnetic layer is formed by applying the aqueous magnetic coating material and drying, and the surface roughness of the magnetic layer is 0. The magnetic recording sheet has a squareness ratio of 35 μm or less and a squareness ratio of 0.87 or more.
【0016】本発明の構成を詳しく説明すれば、次の通
りである。The structure of the present invention will be described in detail below.
【0017】先ず、本発明に係る磁性粒子粉末について
述べる。First, the magnetic particle powder according to the present invention will be described.
【0018】本発明に係る磁性粒子粉末は、マグネトプ
ランバイト型フェライト粒子粉末、磁性酸化鉄粒子粉末
である。The magnetic particle powder according to the present invention is a magnetoplumbite type ferrite particle powder or magnetic iron oxide particle powder.
【0019】マグネトプランバイト型フェライト粒子粉
末としては、バリウムフェライト粒子粉末、ストロンチ
ウムフェライト粒子粉末、バリウム−ストロンチウムフ
ェライト粒子粉末及びこれらのフェライト粒子粉末に、
Co、Ti、Zn、Sn、Al、Ni等の磁気特性を制
御するために添加される各種元素を含んだものであり、
粒子形状としては、板状、不定形等いずれの形状であっ
てもよい。塗料中における配向性を考慮すると板状粒子
が好ましい。Examples of the magnetoplumbite type ferrite particle powder include barium ferrite particle powder, strontium ferrite particle powder, barium-strontium ferrite particle powder and these ferrite particle powders.
It contains various elements such as Co, Ti, Zn, Sn, Al, and Ni that are added to control the magnetic characteristics.
The particle shape may be any shape such as a plate shape or an amorphous shape. Plate-like particles are preferable in consideration of the orientation in the paint.
【0020】マグネトプランバイト型フェライト粒子粉
末の粒子サイズは0.01〜10.0μmが好ましく、
より好ましくは0.1〜1.0μmである。BET比表
面積値は1.0〜15m2 /gが好ましく、より好まし
くは2.0〜10m2 /gである。板状比(板面径:厚
み)は1.5:1〜20:1が好ましく、より好ましく
は3:1〜10:1である。保磁力Hcは100〜60
00Oeが好ましく、より好ましくは200〜5000
Oeである。飽和磁化σsは50〜65emu/gが好
ましく、より好ましくは55〜65emu/gである。The particle size of the magnetoplumbite type ferrite particle powder is preferably 0.01 to 10.0 μm,
More preferably, it is 0.1 to 1.0 μm. The BET specific surface area value is preferably 1.0 to 15 m 2 / g, more preferably 2.0 to 10 m 2 / g. The plate ratio (plate surface diameter: thickness) is preferably 1.5: 1 to 20: 1, and more preferably 3: 1 to 10: 1. Coercive force Hc is 100-60
00 Oe is preferable, and more preferably 200 to 5000
Oe. The saturation magnetization σs is preferably 50 to 65 emu / g, and more preferably 55 to 65 emu / g.
【0021】粒子サイズが0.01μm未満の場合に
は、極めて微細であるため磁気的に凝集しやすくなり、
ビヒクル中における分散性が困難になりやすい。粒子サ
イズが10.0μmを越える場合には、得られる磁性層
表面の平滑性が悪いものとなり、スペーシングロスの関
係から磁気記録に不利となりやすい。When the particle size is less than 0.01 μm, the particles are extremely fine and magnetically aggregate easily,
Dispersibility in the vehicle tends to be difficult. When the particle size exceeds 10.0 μm, the surface of the magnetic layer to be obtained becomes poor in smoothness and is liable to be disadvantageous for magnetic recording due to the spacing loss.
【0022】BET比表面積値が1.0m2 /g未満の
場合には、粒子が粗大となり、磁性層表面の平滑性が悪
く、磁気記録にとって不利となりやすい。BET比表面
積値が15m2 /gを越える場合には、粒子が著しく微
細であるか又は粒子が多孔質となっており、良好な分散
を得るのが困難となる。If the BET specific surface area is less than 1.0 m 2 / g, the particles become coarse and the smoothness of the magnetic layer surface is poor, which is likely to be disadvantageous for magnetic recording. When the BET specific surface area value exceeds 15 m 2 / g, the particles are extremely fine or the particles are porous, and it becomes difficult to obtain good dispersion.
【0023】板状比が1.5:1未満の場合には、磁場
中における磁性粒子粉末の配向が不十分となりやすい。
板状比が20:1を越える場合には、磁場中における磁
性粒子粉末の配向はしやすくなるが、粒子相互間でスタ
ッキングが生じて粒子の凝集体を生じやすくなり、ノイ
ズが発生しやすくなる。When the plate ratio is less than 1.5: 1, the orientation of the magnetic particle powder in the magnetic field tends to be insufficient.
When the plate ratio exceeds 20: 1, the magnetic particle powders are easily oriented in the magnetic field, but stacking occurs between the particles and particle aggregates are easily generated, and noise is easily generated. .
【0024】保磁力Hcが100Oe未満の場合には、
保磁力が極めて低いため、外部磁場からの影響をうけや
すくなり、記録情報の保護が不十分となりやすい。保磁
力Hcが6000Oeを越える場合には、書き込まれた
情報を消去するため極めて強大な磁界を要するため、装
置の大型化が必要となり工業上、経済上好ましくない。When the coercive force Hc is less than 100 Oe,
Since the coercive force is extremely low, it tends to be affected by an external magnetic field, and the recorded information is likely to be insufficiently protected. If the coercive force Hc exceeds 6000 Oe, an extremely strong magnetic field is required for erasing written information, which necessitates enlargement of the device and is industrially and economically unfavorable.
【0025】磁性酸化鉄粒子粉末としては、マグネタイ
ト(FeO x ・Fe2 O3 )粒子粉末、マグヘマイト粒
子粉末、これら粒子にCoをドープさせたものやCo化
合物で粒子表面を被覆又は変成させたもの、更に、これ
らに磁気特性を改良させるために通常使用することがあ
るAl、Si、Zn、P、Sn等の元素を含有又は被着
させたもの等であり、粒子形状としては、粒状、針状、
紡錘状、板状等いずれの形状であってもよい。As the magnetic iron oxide particle powder, magnetite ( FeO x · Fe 2 O 3 ) particle powder, maghemite particle powder, those obtained by doping these particles with Co, or those obtained by coating or modifying the particle surface with a Co compound are used. Further, those containing or adhering elements such as Al, Si, Zn, P, Sn, etc., which are usually used for improving magnetic properties to these, etc. Shape,
It may have any shape such as a spindle shape or a plate shape.
【0026】磁性酸化鉄粒子粉末の粒子サイズは、粒状
粒子の場合、平均粒子径0.01〜10.0μmの粒子
が好ましく、分散性を考慮すれば0.1〜1.0μmが
より好ましい。また、針状粒子や紡錘状粒子の場合、長
軸径0.1〜20μm、軸比(長軸径:短軸径)2:1
〜20:1の粒子が好ましく、分散性、配向性を考慮す
れば、長軸径0.1〜1.0μm、軸比(長軸径:短軸
径)3:1〜10:1の粒子がより好ましい。また、板
状粒子の場合、平均粒子径(板面径)が0.01〜2
0.0μm、厚み0.005〜2.0μmの粒子が好ま
しく、分散性、配向性を考慮すれば,平均粒子径(板面
径)0.1〜10.0μm、厚み0.01〜1.0μm
の粒子がより好ましい。In the case of granular particles, the particle size of the magnetic iron oxide particles is preferably 0.01 to 10.0 μm in average particle diameter, and more preferably 0.1 to 1.0 μm in consideration of dispersibility. In the case of acicular particles or spindle-shaped particles, the major axis diameter is 0.1 to 20 μm and the axial ratio (major axis diameter: minor axis diameter) is 2: 1.
Particles having a major axis diameter of 0.1 to 1.0 μm and an axial ratio (major axis diameter: minor axis diameter) of 3: 1 to 10: 1 are preferable in view of dispersibility and orientation. Is more preferable. Further, in the case of plate-like particles, the average particle size (plate surface diameter) is 0.01 to 2
Particles having a thickness of 0.0 μm and a thickness of 0.005 to 2.0 μm are preferable. Considering dispersibility and orientation, an average particle diameter (plate surface diameter) of 0.1 to 10.0 μm and a thickness of 0.01 to 1. 0 μm
Are more preferable.
【0027】磁性酸化鉄粒子粉末の保磁力Hcは、マグ
ネタイト粒子の場合、100〜500Oeが好ましく、
より好ましくは250〜400Oe、マグヘマイト粒子
の場合、210〜400Oeが好ましく、より好ましく
は250〜380Oe、Coをドープさせるか又はCo
化合物で粒子表面を被覆又は変成させたマグネタイト粒
子やマグヘマイト粒子の場合、300〜1500Oeが
好ましく、より好ましくは400〜900Oeである。The coercive force Hc of the magnetic iron oxide particles is preferably 100 to 500 Oe in the case of magnetite particles.
More preferably 250 to 400 Oe, in the case of maghemite particles, 210 to 400 Oe is preferable, and more preferably 250 to 380 Oe, Co is doped, or Co is used.
In the case of magnetite particles or maghemite particles in which the surface of the particles is coated or modified with a compound, 300 to 1500 Oe is preferable, and 400 to 900 Oe is more preferable.
【0028】磁性粒子粉末の飽和磁化σsは、マグネタ
イト粒子の場合、75〜90emu/gが好ましく、よ
り好ましくは78〜90emu/g、マグヘマイト粒子
の場合、70〜85emu/gが好ましく、より好まし
くは75〜85emu/g、Coをドープさせるか又は
Co化合物で粒子表面を被着又は変成させたマグネタイ
ト粒子やマグヘマイト粒子の場合、70〜90emu/
gが好ましく、より好ましくは75〜90emu/gで
ある。The saturation magnetization σs of the magnetic particle powder is preferably 75 to 90 emu / g in the case of magnetite particles, more preferably 78 to 90 emu / g, and 70 to 85 emu / g in the case of maghemite particles, and more preferably 75 to 85 emu / g, 70 to 90 emu / g in the case of magnetite particles or maghemite particles which are Co-doped or whose particle surface is adhered or modified with a Co compound.
g is preferable, and more preferably 75 to 90 emu / g.
【0029】本発明に係る磁性粒子の粒子表面に被着さ
れる変成ポリシロキサンは、化1に示されるポリエーテ
ル変成ポリシロキサン、化2に示されるポリエステル変
成ポリシロキサン及び化3に示されるアラルキル変成ポ
リシロキサンから選ばれる1種又は2種以上(特定変成
ポリシロキサンという。)である。The modified polysiloxane deposited on the surface of the magnetic particles according to the present invention includes a polyether modified polysiloxane represented by Chemical formula 1, a polyester modified polysiloxane represented by Chemical formula 2, and an aralkyl modified polysiloxane represented by Chemical formula 3. One or more selected from polysiloxanes (referred to as a specific modified polysiloxane).
【0030】ポリエーテル変成ポリシロキサンの分子量
は、350〜500000の範囲であり、好ましくは1
000〜100000の範囲であり、より好ましくは2
000〜50000の範囲である。The molecular weight of the polyether modified polysiloxane is in the range of 350 to 500,000, preferably 1
000 to 100,000, more preferably 2
It is in the range of 000 to 50,000.
【0031】ポリエステル変成ポリシロキサンの分子量
は、400〜500000の範囲であり、好ましくは1
000〜100000の範囲であり、より好ましくは2
000〜50000の範囲である。The polyester-modified polysiloxane has a molecular weight in the range of 400 to 500,000, preferably 1.
000 to 100,000, more preferably 2
It is in the range of 000 to 50,000.
【0032】アラルキル変成ポリシロキサンの分子量
は、350〜500000の範囲であり、好ましくは1
000〜100000の範囲であり、より好ましくは2
000〜50000の範囲である。The molecular weight of the aralkyl-modified polysiloxane is in the range of 350 to 500,000, preferably 1.
000 to 100,000, more preferably 2
It is in the range of 000 to 50,000.
【0033】[0033]
【化1】 Embedded image
【0034】[0034]
【化2】 Embedded image
【0035】[0035]
【化3】 Embedded image
【0036】特定変成ポリシロキサンの被着量は、C換
算で磁性粒子に対し0.01〜10重量%が好ましい。
0.01重量%未満の場合には、本発明の目的とする分
散性に優れた磁性粒子粉末を得ることが困難となる。1
0重量%を越える場合にも、本発明の目的とする分散性
に優れた磁性粒子粉末が得られるが、その効果は飽和状
態にあり必要以上に添加する意味がない。The amount of the specific modified polysiloxane deposited is preferably 0.01 to 10% by weight based on the magnetic particles in terms of C.
When the amount is less than 0.01% by weight, it becomes difficult to obtain the magnetic particle powder excellent in dispersibility which is the object of the present invention. 1
Even if it exceeds 0% by weight, the magnetic particle powder excellent in dispersibility which is the object of the present invention can be obtained, but the effect is in a saturated state and it is meaningless to add more than necessary.
【0037】本発明に係る粒子表面に特定変成ポリシロ
キサンが被着されている磁性粒子粉末を溶剤系塗料に用
いた場合の分散性は、角形比が0.87以上、好ましく
は0.88以上、塗膜のRaが0.37μm以下、好ま
しくは0.35μm以下、RMSが0.44μm以下、
好ましくは0.42μm以下、分散安定性を示す塗料希
釈時のRaの変化率が8.9%以下、好ましくは8.5
%以下である。The dispersibility of the magnetic particle powder according to the present invention, in which the specific modified polysiloxane is adhered on the surface of the particle, is used in a solvent-based paint, has a squareness ratio of 0.87 or more, preferably 0.88 or more. Ra of the coating film is 0.37 μm or less, preferably 0.35 μm or less, RMS is 0.44 μm or less,
It is preferably 0.42 μm or less, and the change rate of Ra showing dispersion stability when the coating is diluted is 8.9% or less, preferably 8.5.
% Or less.
【0038】本発明に係る粒子表面に特定変成ポリシロ
キサンが被着されている磁性粒子粉末を水系塗料に用い
た場合の分散性は、角形比が0.86以上、好ましくは
0.88以上、塗膜のRaが0.35μm以下、好まし
くは0.30μm以下、RMSが0.41μm以下、好
ましくは0.36μm以下、分散安定性を示す塗料希釈
時のRaの変化率が15%以下、好ましくは10%以
下、貯蔵安定性を示す塗料保存後のRa値は0.45μ
m以下、好ましくは0.35μm以下である。When the magnetic particle powder according to the present invention, in which the specific modified polysiloxane is adhered to the surface of the particle, is used in the water-based paint, the dispersibility is such that the squareness ratio is 0.86 or more, preferably 0.88 or more, Ra of the coating film is 0.35 μm or less, preferably 0.30 μm or less, RMS is 0.41 μm or less, preferably 0.36 μm or less, and the rate of change of Ra upon dilution of the paint showing dispersion stability is 15% or less, preferably Is 10% or less, and the Ra value after storage showing the storage stability is 0.45μ
m or less, preferably 0.35 μm or less.
【0039】本発明に係る磁性粒子粉末のスクエア酸被
着量は、C換算で磁性粒子に対し0.01〜10重量%
が好ましい。0.01重量%未満の場合には、本発明の
目的とする分散性がより優れた磁性粒子粉末を得ること
が困難となる。10重量%を越える場合にも、本発明の
目的とする分散性がより優れた磁性粒子粉末が得られる
が、その効果は飽和状態にあり必要以上に添加する意味
がない。The amount of squaric acid deposited on the magnetic particle powder according to the present invention is 0.01 to 10% by weight based on C based on the magnetic particles.
Is preferred. If the amount is less than 0.01% by weight, it becomes difficult to obtain the magnetic particle powder having the better dispersibility, which is the object of the present invention. Even if the amount exceeds 10% by weight, the magnetic particle powder having a more excellent dispersibility, which is the object of the present invention, can be obtained, but the effect is in a saturated state and it is meaningless to add more than necessary.
【0040】本発明に係る磁性粒子粉末の特定変成ポリ
シロキサンの被着量とスクエア酸の被着量との割合は、
1:1000〜1000:1が好ましい。より好ましく
は1:100〜100:1である。The ratio of the amount of the specific modified polysiloxane deposited on the magnetic particle powder according to the present invention to the amount of squaric acid deposited is:
It is preferably 1: 1000 to 1000: 1. It is more preferably 1: 100 to 100: 1.
【0041】本発明に係る粒子表面にスクエア酸が被着
され、更に、該被着スクエア酸の表面に特定変成ポリシ
ロキサンが被着されている磁性粒子粉末を溶剤系塗料に
用いた場合の分散性は、角形比が0.88以上、好まし
くは0.89以上、塗膜のRaが0.35μm以下、好
ましくは0.33μm以下、RMSが0.43μm以
下、好ましくは0.42μm以下、Raの変化率が8.
0%以下、好ましくは7.5%以下である。Dispersion in the case where a magnetic particle powder according to the present invention in which squaric acid is adhered to the surface of a particle and further the specific modified polysiloxane is adhered to the surface of the adhered square acid is used in a solvent-based paint. As for the property, the squareness ratio is 0.88 or more, preferably 0.89 or more, Ra of the coating film is 0.35 μm or less, preferably 0.33 μm or less, RMS is 0.43 μm or less, preferably 0.42 μm or less, Ra Change rate of 8.
It is 0% or less, preferably 7.5% or less.
【0042】本発明に係る粒子表面にスクエア酸が被着
され、更に、該被着スクエア酸の表面に特定変成ポリシ
ロキサンが被着されている磁性粒子粉末を水系塗料に用
いた場合の分散性は、角形比が0.86以上、好ましく
は.088以上、塗膜のRaが0.35μm以下、好ま
しくは0.30μm以下,RMSが0.40μm以下、
好ましくは0.35μm以下、分散安定性を示す塗料希
釈時のRaの変化率が12.0%以下、好ましくは1
0.0%以下、貯蔵安定性を示す塗料保存後のRa値は
0.40μm以下、好ましくは0.30μm以下であ
る。The dispersibility of a magnetic particle powder according to the present invention, in which squaric acid is adhered to the surface of a particle, and further the specific modified polysiloxane is adhered to the surface of the adhered square acid, is used in an aqueous paint. Has a squareness ratio of 0.86 or more, preferably. 088 or more, Ra of the coating film is 0.35 μm or less, preferably 0.30 μm or less, RMS is 0.40 μm or less,
It is preferably 0.35 μm or less, and the rate of change of Ra upon dispersion of the coating showing dispersion stability is 12.0% or less, preferably 1
The Ra value after storage of the coating composition, which is 0.0% or less and has storage stability, is 0.40 μm or less, preferably 0.30 μm or less.
【0043】本発明における磁性粒子粉末の塗料への配
合割合は、塗料構成基材100重量部に対し10〜90
重量部の範囲で使用することができ、塗料のハンドリン
グを考慮すれば、好ましくは20〜60重量部、更に、
好ましくは30〜50重量部である。The mixing ratio of the magnetic particle powder to the coating material in the present invention is 10 to 90 relative to 100 parts by weight of the coating material base material.
It can be used in the range of parts by weight, and considering the handling of the paint, preferably 20 to 60 parts by weight,
It is preferably 30 to 50 parts by weight.
【0044】本発明に係る塗料構成基材としては、樹
脂、溶剤、及び必要に応じて体質顔料、乾燥促進剤、界
面活性剤、硬化促進剤、助剤、消泡剤等が配合される。A resin, a solvent, and if necessary, an extender pigment, a drying accelerator, a surfactant, a curing accelerator, an auxiliary agent, an antifoaming agent, etc. are mixed in the coating material base material according to the present invention.
【0045】本発明における塗料中の樹脂と溶剤の配合
割合は、樹脂100重量部に対し溶剤が50〜5000
重量部が好ましく、より好ましくは100〜2000重
量部である。50重量部未満の場合は、ビヒクルの粘度
が高くなりすぎ均一な混合分散が困難になる。5000
重量部を越える場合は、塗料中の溶剤組成分が多くなり
すぎる為、混合分散時において粒子への分散シェアーが
掛からなくなる為好ましくない。The blending ratio of the resin and the solvent in the coating material in the present invention is 50 to 5,000 with respect to 100 parts by weight of the resin.
Part by weight is preferred, and more preferably 100 to 2000 parts by weight. If the amount is less than 50 parts by weight, the viscosity of the vehicle becomes too high and it becomes difficult to uniformly mix and disperse. 5000
If the amount is more than parts by weight, the amount of the solvent composition in the coating material becomes too large, and the dispersion share to the particles is not applied during mixing and dispersion, which is not preferable.
【0046】樹脂としては、溶剤型塗料用として通常使
用される塩化ビニル・酢酸ビニル共重合樹脂、塩化ビニ
ル樹脂、酢酸ビニル樹脂、ニトロセルロース、ポリビニ
ルブチラール樹脂、アクリル樹脂、アルキッド樹脂、ポ
リエステル樹脂、ポリウレタン樹脂、エポキシ樹脂、フ
ェノール樹脂、メラミン樹脂、アミノ樹脂等を用いるこ
とができる。水系塗料用としては、通常使用される水溶
性アルキッド樹脂、水溶性メラミン樹脂、水溶性アクリ
ルエマルジョン樹脂、水溶性ウレタンエマルジョン樹脂
等を用いることができる。As the resin, vinyl chloride / vinyl acetate copolymer resin, vinyl chloride resin, vinyl acetate resin, nitrocellulose, polyvinyl butyral resin, acrylic resin, alkyd resin, polyester resin, polyurethane, which are usually used for solvent type paints, are used. Resins, epoxy resins, phenol resins, melamine resins, amino resins and the like can be used. For the water-based paint, a water-soluble alkyd resin, a water-soluble melamine resin, a water-soluble acrylic emulsion resin, a water-soluble urethane emulsion resin and the like which are commonly used can be used.
【0047】溶剤としては、溶剤系塗料用として通常使
用されるトルエン、キシレン、ブチルアセテート、メチ
ルアセテート、メチルイソブチルケトン、ブチルセロソ
ルブ、エチルセロソルブ、ブチルアルコール、メチルエ
チルケトン、シクロヘキサノン、脂肪族炭化水素等を用
いることができる。As the solvent, use may be made of toluene, xylene, butyl acetate, methyl acetate, methyl isobutyl ketone, butyl cellosolve, ethyl cellosolve, butyl alcohol, methyl ethyl ketone, cyclohexanone, and aliphatic hydrocarbon which are commonly used for solvent-based paints. You can
【0048】水系塗料用としては、通常使用されるブチ
ルセロソルブ、ブチルアルコール等を使用することがで
きる。For water-based paints, butyl cellosolve, butyl alcohol and the like which are commonly used can be used.
【0049】消泡剤としては、ノプコ8034(商品
名)、SNデフォーマー477(商品名)、SNデフォ
ーマー5013(商品名)、SNデフォーマー247
(商品名)、SNデフォーマー382(商品名)(以
上、いずれもサンノプコ(株)製)、アンチホーム08
(商品名)、エマルゲン903(商品名)(以上、いず
れも花王(株)製)等の市販品を使用することができ
る。As the defoaming agent, Nopco 8034 (trade name), SN deformer 477 (trade name), SN deformer 5013 (trade name), SN deformer 247.
(Brand name), SN Deformer 382 (Brand name) (all above are manufactured by San Nopco Ltd.), Anti Home 08
Commercial products such as (trade name) and Emulgen 903 (trade name) (all of which are manufactured by Kao Corporation) can be used.
【0050】本発明に係る磁気記録シートは、非磁性支
持体上の少なくとも一部に磁性層が設けられたものであ
り、必要により、更に、磁性層の色を覆い隠すための隠
蔽層や保護層等を設けたものである。The magnetic recording sheet according to the present invention is one in which a magnetic layer is provided on at least a part of a non-magnetic support, and if necessary, a concealing layer for protecting the color of the magnetic layer and a protective layer. Layers and the like are provided.
【0051】非磁性支持体は、塩化ビニル、ポリエステ
ル等のプラスチックスや紙とプラスチックスとを複合化
した複合紙(紙/ポリエステル/紙、ポリエステル/紙
/ポリエステル)、上質紙等の紙等である。The non-magnetic support is a plastic such as vinyl chloride or polyester, a composite paper obtained by compounding paper and plastics (paper / polyester / paper, polyester / paper / polyester), high-quality paper, or the like. is there.
【0052】バンクカード、クレジットカード、キャッ
シュカード、POSカード、キーカード等においては、
塩化ビニルが、シールレス型定期券、プログラムカー
ド、テレホンカード等においては、ポリエステルが、高
速道路回数券、郵便貯金台帳、シール型定期券は複合紙
が、高速道路通行券、工程管理カード、バス共通回数
券、一部のPOSカード、鉄道切符、勝馬投票券等は紙
が一般に使用されている。For bank cards, credit cards, cash cards, POS cards, key cards, etc.,
Polyvinyl chloride is used for sealless commuter passes, program cards, telephone cards, etc., and highway coupons, postal savings ledgers, composite paper for seal commuter passes, expressway pass tickets, process control cards, buses Paper is commonly used for common coupon tickets, some POS cards, railroad tickets, and horse voting tickets.
【0053】非磁性支持体の厚みは、塩化ビニルの場
合、100〜1000μmが好ましく、より好ましくは
500〜900μm、ポリエステルの場合、10〜50
0μmが好ましく、より好ましくは100〜300μ
m、複合紙の場合、50〜500μmが好ましく、より
好ましくは100〜300μm、上質紙の場合、50〜
1000μmが好ましく、より好ましくは100〜80
0μmである。The thickness of the non-magnetic support is preferably 100 to 1000 μm in the case of vinyl chloride, more preferably 500 to 900 μm, and 10 to 50 in the case of polyester.
0 μm is preferable, and more preferably 100 to 300 μm.
m, in the case of composite paper, 50 to 500 μm is preferable, more preferably 100 to 300 μm, and in the case of high-quality paper, 50 to 500 μm.
1000 μm is preferable, and more preferably 100-80
0 μm.
【0054】磁性層は、非磁性支持体の片面の一部、片
面の全面、片面の一部と他面の全面、両面の全面に設け
られ、その厚みは0.5〜20.0μmが好ましく、よ
り好ましくは1.0〜10.0μmである。The magnetic layer is provided on a part of one surface of the non-magnetic support, the entire surface of one surface, a part of the one surface and the entire surface of the other surface, and the entire surfaces of both surfaces, and the thickness thereof is preferably 0.5 to 20.0 μm. , And more preferably 1.0 to 10.0 μm.
【0055】次に、前記の通りの本発明に係る磁性粒子
粉末の製造法について述べる。Next, a method for producing the magnetic particle powder according to the present invention as described above will be described.
【0056】本発明における被処理粒子として用いるマ
グネトプランバイト型フェライト粒子粉末の形状、粒子
サイズ、BET比表面積値、保磁力Hc及び飽和磁化σ
sは、前述した特定変成ポリシロキサン被着後の磁性粒
子のそれら諸特性とほぼ同じである。The shape, particle size, BET specific surface area value, coercive force Hc and saturation magnetization σ of the magnetoplumbite type ferrite particle powder used as the particles to be treated in the present invention.
s is almost the same as those characteristics of the magnetic particles after the above-mentioned specific modified polysiloxane is adhered.
【0057】本発明における変成ポリシロキサンは、ポ
リエーテル、ポリエステル及びアラルキルから選ばれる
1種又は2種以上によって変成されていることが肝要で
あり、前出公知のポリジメチルシロキサン、メチルフェ
ニルポリシロキサン、メチルハイドロジエンポリシロキ
サン、ジメチルポリシロキシクロリド、アルコキシポリ
シロキサン、アミノ基末端修飾ポリシロキサン等のオル
ガノポリシロキサンやシランカップリング剤によって
は、後出比較例に示す通り、本発明の目的とする分散性
に優れた磁性粒子粉末を得ることができない。It is essential that the modified polysiloxane in the present invention is modified by one or more selected from polyether, polyester and aralkyl. Polydimethylsiloxane, methylphenylpolysiloxane, known in the above, Depending on the organopolysiloxane such as methylhydrogenpolysiloxane, dimethylpolysiloxycyclolide, alkoxypolysiloxane, amino group-end modified polysiloxane, or silane coupling agent, as shown in Comparative Examples below, the dispersibility of the present invention can be improved. It is impossible to obtain a magnetic particle powder having excellent properties.
【0058】本発明における特定変成ポリシロキサン
は、市販のものを使用すればよい。ポリエーテル変成ポ
リシロキサンとしては、BYK−320、BYK−32
5、BYK−080(商品名)(ビックケミー(株)
製)があり、ポリエステル変成ポリシロキサンとして
は、BYK−310(商品名)(ビックケミー(株)
製)があり、アラルキル変成ポリシロキサンとしては、
BYK−322(商品名)(ビックケミー(株)製)が
あり、これらはいずれも溶液状態をしており、そのまま
磁性粒子粉末に添加して使用すればよい。As the specific modified polysiloxane in the present invention, a commercially available product may be used. As the polyether-modified polysiloxane, BYK-320, BYK-32
5, BYK-080 (trade name) (Big Chemie Co., Ltd.)
Manufactured by BYK-310 (trade name) (by BIC Chemie Co., Ltd.).
Manufactured), and as the aralkyl modified polysiloxane,
There is BYK-322 (trade name) (manufactured by BYK Chemie Co., Ltd.), all of which are in a solution state, and may be used by adding them to the magnetic particle powder as they are.
【0059】特定変成ポリシロキサンの添加量は、磁性
粒子粉末に対して0.05〜20.0%が好ましい。
0.05%未満の場合には、本発明の目的とする分散性
に優れた磁性粒子粉末を得ることが困難となる。20.
0%を越える場合にも、本発明の目的とする分散性に優
れた磁性粒子粉末が得られるが、その効果は飽和状態に
あり必要以上に添加する意味がない。The addition amount of the specific modified polysiloxane is preferably 0.05 to 20.0% with respect to the magnetic particle powder.
If it is less than 0.05%, it becomes difficult to obtain the magnetic particle powder having excellent dispersibility, which is the object of the present invention. 20.
Even if it exceeds 0%, the magnetic particle powder excellent in dispersibility, which is the object of the present invention, can be obtained, but the effect is in a saturated state and it is meaningless to add more than necessary.
【0060】本発明における磁性粒子と特定変成ポリシ
ロキサンとの混合は、80℃以上の温度で行なう。80
℃未満の場合には、変成ポリシロキサンの粘性が非常に
高く、磁性粒子の粒子表面への均一な被着が困難とな
り、本発明の目的とする磁性粒子粉末を得ることができ
ない。The mixing of the magnetic particles and the specific modified polysiloxane in the present invention is carried out at a temperature of 80 ° C. or higher. 80
When the temperature is lower than 0 ° C, the viscosity of the modified polysiloxane is so high that it becomes difficult to uniformly deposit the magnetic particles on the particle surfaces, and the magnetic particle powder aimed at by the present invention cannot be obtained.
【0061】磁性粒子は、変成ポリシロキサンとの混合
にあたって、あらかじめ80℃以上で加熱して水分量を
低下し、殊に、0.2重量%以下に調整しておくことが
好ましい。磁性粒子の水分量が多いと、粒子間に液架橋
している水分が粒子同士の凝集を強固なものとするた
め、1個1個の粒子に均一に被着することが困難とな
る。When the magnetic particles are mixed with the modified polysiloxane, it is preferably heated in advance at 80 ° C. or higher to reduce the water content, and particularly adjusted to 0.2% by weight or less. If the magnetic particles have a large amount of water, the water that is liquid-crosslinked between the particles strengthens the agglomeration of the particles, making it difficult to uniformly apply the particles to each other.
【0062】混合するための機器としては、磁性粒子粉
末と表面処理剤とを混合するにあたって、通常使用され
る高速アジテート型ミキサー、具体的にはヘンシェルミ
キサー、スピードミキサー、ボールカッター、パワーミ
キサー、ハイブリッドミキサー等を使用すればよく、特
定変成ポリシロキサンの均一被着を考慮するとヘンシェ
ルミキサーを使用するのが好ましい。As a device for mixing, a high speed agitate mixer which is usually used in mixing the magnetic particle powder and the surface treatment agent, specifically, a Henschel mixer, a speed mixer, a ball cutter, a power mixer, a hybrid is used. A mixer or the like may be used, and a Henschel mixer is preferably used in consideration of uniform deposition of the specific modified polysiloxane.
【0063】攪拌時間は、高速アジテートミキサー内で
磁性粒子と特定変成ポリシロキサンとを充分に混合する
ことが肝要であり、少なくとも5分以上、好ましくは1
0分以上である。It is essential that the stirring time be sufficient to mix the magnetic particles and the specific modified polysiloxane in the high speed agitator mixer, and at least 5 minutes or more, preferably 1 minute.
0 minutes or more.
【0064】本発明におけるスクエア酸としては、市販
の3,4−ジヒドロキシ−3−シクロブテン−1,2−
ジオン(東京化成工業(株)製)を使用することができ
る。The squaric acid in the present invention is commercially available 3,4-dihydroxy-3-cyclobutene-1,2-
Zion (manufactured by Tokyo Chemical Industry Co., Ltd.) can be used.
【0065】スクエア酸は、粉末状態であり、これを被
着処理する水中に直接添加して使用しても、また、あら
かじめ水に溶解して溶液濃度0.1〜50g/l、好ま
しくは0.5〜10g/lにして使用してもよいが、後
者の方法が好ましい。Squaric acid is in a powder state and can be used by directly adding it to water to be coated, or by dissolving it in water in advance to obtain a solution concentration of 0.1 to 50 g / l, preferably 0. Although it may be used in an amount of 0.5 to 10 g / l, the latter method is preferable.
【0066】本発明におけるスクエア酸の被着処理は、
磁性粒子とスクエア酸とを含む水懸濁液を混合した後、
濾別、乾燥すればよい。The process for depositing squaric acid in the present invention is as follows.
After mixing an aqueous suspension containing magnetic particles and squaric acid,
It may be filtered and dried.
【0067】磁性粒子とスクエア酸の水中への添加順序
は、いずれが先でも、又は、同時でもよい。The magnetic particles and the squaric acid may be added to the water either first or simultaneously.
【0068】スクエア酸の添加量は、磁性粒子に対し
0.01〜30.0%、好ましくは0.02〜25.0
%である。0.01%未満の場合には、本発明の目的と
するより分散性に優れた磁性粒子粉末を得ることが困難
となる。30.0%を越える場合にも、本発明の目的と
するより分散性に優れた磁性粒子粉末が得られるが、そ
の効果は飽和状態にあり必要以上に添加する意味がな
い。The amount of squaric acid added is 0.01 to 30.0%, preferably 0.02 to 25.0%, based on the magnetic particles.
%. If it is less than 0.01%, it becomes difficult to obtain the magnetic particle powder having a better dispersibility than the object of the present invention. Even when the content exceeds 30.0%, magnetic particle powder having an excellent dispersibility, which is the object of the present invention, can be obtained, but the effect is in a saturated state and it is meaningless to add more than necessary.
【0069】水懸濁液の混合時間は、磁性粒子とスクエ
ア酸とを充分に混合攪拌することが肝要であり、少なく
とも5分、好ましくは10分以上である。It is essential that the mixing time of the aqueous suspension is such that the magnetic particles and the squaric acid are sufficiently mixed and stirred, and it is at least 5 minutes, preferably 10 minutes or more.
【0070】磁気記録シートの製造には、非磁性支持体
上に磁性塗料を直接塗布した後、乾燥する直接塗布法、
別に製造した磁気テープを非磁性支持体上に貼るテープ
貼り法、転写タイプ磁気テープを非磁性支持体上に接着
しベースを剥離する磁性層転写法等がある。For the production of a magnetic recording sheet, a direct coating method in which a magnetic coating is directly coated on a non-magnetic support and then dried,
There are a tape application method in which a separately manufactured magnetic tape is applied onto a non-magnetic support, and a magnetic layer transfer method in which a transfer type magnetic tape is adhered onto a non-magnetic support and the base is peeled off.
【0071】[0071]
【作用】本発明において最も重要な点は、粒子表面に特
定変成ポリシロキサンが被着されている磁性粒子は、溶
剤系塗料はもちろん、水系塗料中で優れた分散性を示す
という点である。The most important point in the present invention is that the magnetic particles coated with the specific modified polysiloxane on the surface of the particles exhibit excellent dispersibility not only in the solvent-based paint but also in the water-based paint.
【0072】本発明に係る特定変成ポリシロキサンが被
着されている磁性粒子が、殊に、水系塗料において優れ
た分散性を示す理由について、本発明者は、以下のよう
に考えている。The present inventor believes that the magnetic particles coated with the specific modified polysiloxane according to the present invention exhibit excellent dispersibility, particularly in an aqueous paint.
【0073】溶剤系塗料においては、樹脂が磁性粒子の
粒子表面に拡がりをもって吸着しているが、この吸着し
た樹脂によって磁性粒子が接近すると大きな交換反発力
が働く、所謂、立体障害が生じ磁性粒子相互の接近を妨
げ、磁性粒子が塗料中で安定して存在している。In the solvent-based paint, the resin is spread and adsorbed on the surface of the magnetic particles, and when the adsorbed resin brings the magnetic particles close to each other, a large exchange repulsive force is exerted, so-called steric hindrance occurs, and the magnetic particles They prevent them from approaching each other and the magnetic particles are stably present in the paint.
【0074】しかし、水系塗料においては、前述した通
り、樹脂が拡がりをもたず粒子状態で存在しているた
め、溶剤系塗料における磁性粉末に見られる立体障害効
果が発揮しにくいため、磁性粉末の分散が困難となる。However, in the water-based paint, as described above, the resin does not spread and exists in a particle state, so that the steric hindrance effect seen in the magnetic powder in the solvent-based paint is difficult to be exerted. Becomes difficult to disperse.
【0075】一般に、塗料中の懸濁粒子のゼータ電位
は、その絶対値が大きくなる程、静電気的反発によって
懸濁粒子の分散適性が優れることが知られているが、本
発明に係る粒子表面に特定変成ポリシロキサンが被着さ
れている磁性粒子は、水系塗料中でそのゼータ電位を測
定すると後出実施例に示す通り、−40〜−80mV程
度、殊に、−45〜−80mVとその絶対値が高いこと
から、水系塗料中において、その粒子表面が負に帯電し
やすくなっており、粒子相互間における電気的反発が大
きいものである。しかも、ポリエーテル、ポリエステル
及びアラルキル等の分子鎖が拡がりをもって粒子表面に
吸着しているので、その大きな電気的反発と立体障害効
果との相乗効果によって、凝集が解きほぐされ易く、か
つ、一次粒子に近い状態にまで分散させることが可能に
なり、その結果、易分散性、分散均一性に優れたものと
なる。It is generally known that the larger the absolute value of the zeta potential of the suspended particles in the paint, the better the dispersibility of the suspended particles due to electrostatic repulsion. When the zeta potential of the magnetic particles coated with the specific modified polysiloxane is measured in a water-based paint, as shown in the examples below, about -40 to -80 mV, and particularly -45 to -80 mV and the same. Since the absolute value is high, the surface of the particles in the water-based paint is likely to be negatively charged, and the electric repulsion between the particles is large. Moreover, since the molecular chains of polyether, polyester, aralkyl, etc. are spread and adsorbed on the particle surface, the synergistic effect of the large electric repulsion and steric hindrance effect makes it easy to loosen the aggregation, and the primary particles It becomes possible to disperse even to a state close to, and as a result, excellent dispersibility and dispersion uniformity are obtained.
【0076】そして、一旦、一次粒子に近い状態にまで
分散された後は、その電気的反発によって分散状態を長
時間保つことができ、その結果、分散安定性に優れたも
のとなる。After the particles are once dispersed in a state close to the primary particles, the electrical repulsion can maintain the dispersed state for a long time, resulting in excellent dispersion stability.
【0077】[0077]
【実施例】次に、実施例並びに比較例により本発明を説
明する。EXAMPLES Next, the present invention will be described with reference to Examples and Comparative Examples.
【0078】尚、以下の実施例並びに比較例における粒
子の平均粒子径は、電子顕微鏡写真から測定された数値
の平均値で示し、粒子の比表面積値はBET法により測
定した値で示した。板状粒子の厚み及び板状比は、BE
T法により測定した比表面積値と上記平均径(板面径)
から求めた数値で示した。The average particle diameter of the particles in the following Examples and Comparative Examples is shown by the average value of the numerical values measured from electron micrographs, and the specific surface area of the particles is shown by the value measured by the BET method. The thickness and plate ratio of the plate particles are BE
Specific surface area value measured by T method and the above average diameter (plate surface diameter)
It is shown by the numerical value obtained from.
【0079】粒子の形状は、透過型電子顕微鏡及び走査
型電子顕微鏡により観察したものである。The shape of the particles was observed with a transmission electron microscope and a scanning electron microscope.
【0080】変成ポリシロキサン及びスクエア酸の被着
量は、「堀場金属炭素・硫黄分析装置EMIA−220
0」((株)堀場製作所製)を用いて、炭素量を測定し
た値で示したThe amount of the modified polysiloxane and squaric acid deposited was determined by "Horiba Metal Carbon / Sulfur Analyzer EMIA-220".
0 ”(manufactured by Horiba, Ltd.) was used to show the amount of carbon measured.
【0081】磁性塗膜表面の平滑性は、後出の所定の組
成分を所定割合で配合し、ミルベースを分散させて得ら
れた塗料を紙製ベースフィルムに塗布、磁場配向、乾燥
した塗膜の表面平滑度を表面形状測定機サーフコム57
5A((株)東京精機製)を用いて測定した中心線平均
粗さ(Ra)及び平均二乗粗さ(RMS)を用いて示し
た。The smoothness of the surface of the magnetic coating film is obtained by coating the base film made of paper with the coating composition obtained by mixing the below-mentioned predetermined components in a predetermined ratio and dispersing the mill base, magnetic field orientation, and drying. Surface smoothness of the surface profile measuring device Surfcom 57
The center line average roughness (Ra) and the mean square roughness (RMS) measured using 5A (manufactured by Tokyo Seiki Co., Ltd.) are shown.
【0082】磁性粒子粉末の分散性は、易分散性、分散
安定性、貯蔵安定性、塗膜表面の平滑性及び磁性層中に
おける粒子の配向性で示した。The dispersibility of the magnetic particle powder is shown by the easy dispersibility, the dispersion stability, the storage stability, the smoothness of the coating film surface and the orientation of the particles in the magnetic layer.
【0083】易分散性は、ミルベースの分散時間を変え
て作製した2種類の磁性塗料を用いて作製した磁性層の
諸特性を比較することにより示した。その差が小さい
程、易分散性が優れていることを示す。The easy dispersibility was shown by comparing various characteristics of the magnetic layer prepared by using two kinds of magnetic coating materials prepared by changing the dispersion time of the mill base. The smaller the difference, the better the dispersibility.
【0084】分散安定性は、後出の所定の組成分を所定
割合で配合し、溶剤系塗料の場合はミルベース(2)を
120分間混合分散させた場合の溶剤系塗料に対し溶剤
(MEK/トルエン/シクロヘキサノン=5/3/2)
を40%加えて得られる希釈塗料を、水系塗料の場合は
ミルベースを60分間混合分散させた場合の水系塗料に
対し水を40%加えて得られる希釈塗料をベースフィル
ムに50μmの厚みで塗布、乾燥して作製した磁性層の
表面粗度Raを測定し、希釈前の塗料を用いて同様に作
製した磁性層の表面粗度Raに対する増加百分率で示し
た。値が小さいほど分散安定性が良好であることを示
す。Dispersion stability is determined by mixing the following predetermined components in a predetermined ratio, and in the case of a solvent-based paint, the mill base (2) is mixed and dispersed for 120 minutes, and the solvent-based paint is mixed with a solvent (MEK / Toluene / cyclohexanone = 5/3/2)
40% of the diluted paint, in the case of water-based paint, the diluted paint obtained by adding 40% of water to the water-based paint when the mill base is mixed and dispersed for 60 minutes is applied to the base film at a thickness of 50 μm, The surface roughness Ra of the magnetic layer produced by drying was measured, and shown as the percentage increase with respect to the surface roughness Ra of the magnetic layer similarly produced by using the coating material before dilution. The smaller the value, the better the dispersion stability.
【0085】最終磁性塗膜の平滑性の程度は、磁性粒子
粉末の均一分散性の程度を意味する。Ra、RMSの値
が小さい程、塗膜は表面平滑性に優れ、磁性粒子のビヒ
クル中における均一分散性が良好であることを示す。The degree of smoothness of the final magnetic coating film means the degree of uniform dispersion of the magnetic particle powder. The smaller the values of Ra and RMS, the better the surface smoothness of the coating film, and the better the uniform dispersibility of the magnetic particles in the vehicle.
【0086】水系塗料における貯蔵安定性は、後出の所
定の組成分を所定割合で配合し、ミルベースを60分間
分散させて得られた塗料を1日放置した後、紙製ベース
フィルムに50μmの厚みで塗布、乾燥して製造した塗
膜の表面粗度Raを測定した値で示した。値が小さいほ
ど貯蔵安定性が優れていることを示す。The storage stability of the water-based paint was determined by blending the following predetermined components in a predetermined ratio and dispersing the mill base for 60 minutes, and leaving the paint for 1 day. The surface roughness Ra of the coating film produced by applying and drying the thickness was shown by the measured value. The smaller the value, the better the storage stability.
【0087】配向性は、後出の所定の組成分を所定割合
で配合し、ミルベースを分散させて得られた塗料を基材
に塗布、磁場配向、乾燥した塗膜の角形比(RS)を測
定した値で示した。角形比が高い程、配向性に優れ磁気
記録シートとして好ましい方向である。The orientation is determined by blending the following predetermined components in a predetermined ratio and dispersing the mill base to obtain a coating, applying the coating on the substrate, magnetic field orientation, and the squareness ratio (RS) of the dried coating. The measured values are shown. The higher the squareness ratio, the better the orientation and the preferred direction for the magnetic recording sheet.
【0088】水系塗料における磁性粒子のゼータ電位の
値は、後出の所定の組成を所定割合で配合し、ミルベー
スを分散させて得られた塗料を純水100gに対して
0.5g加え、超音波分散器C−10(超音波工業社
(株)製)で1分間分散させて得られた懸濁液を用い
て、ゼータ電位計MODEL−501(PEN−KEM
社製)で測定した値で示した。The value of the zeta potential of the magnetic particles in the water-based paint is more than 0.5% with respect to 100 g of pure water by adding 0.5 g of the paint obtained by blending the below-mentioned predetermined composition in a predetermined ratio and dispersing the mill base. A zeta potentiometer MODEL-501 (PEN-KEM) was used by using a suspension obtained by dispersing with a sonic disperser C-10 (manufactured by Ultrasonic Industrial Co., Ltd.) for 1 minute.
It was shown by the value measured by the company.
【0089】<磁性粒子粉末の製造> 実施例1〜12、比較例1〜14;<Production of Magnetic Particle Powder> Examples 1-12, Comparative Examples 1-14;
【0090】実施例1 平均粒径0.65μm、BET比表面積値4.6m2 /
g、保磁力Hc2753Oe、飽和磁化σs55.6e
mu/g、pH値9.5、水分量0.17wt%の粒状
バリウムフェライト粒子3.0kgをあらかじめ85℃
に加熱したヘンシェルミキサー(10l)に投入し、回
転数1200rpmで10分間作動・混合させてバリウ
ムフェライト粒子の水分量を0.06wt%とした。Example 1 Average particle size 0.65 μm, BET specific surface area value 4.6 m 2 /
g, coercive force Hc2753Oe, saturation magnetization σs55.6e
3.0 kg of granular barium ferrite particles having a mu / g, a pH value of 9.5 and a water content of 0.17 wt% were preheated to 85 ° C.
The mixture was charged into a Henschel mixer (10 l) heated to 1, and operated and mixed at a rotation speed of 1200 rpm for 10 minutes to adjust the water content of barium ferrite particles to 0.06 wt%.
【0091】上記ヘンシェルミキサーを温度85℃に維
持しながらポリエーテル変成ポリシロキサンBYK−0
80(商品名)(ビックケミー(株)製)30g(有効
成分100%)(バリウムフェライト粒子に対し1.0
重量%に該当する。)を3.0g/分の添加速度で10
分間かけて添加し、引き続き20分間混合して、前記バ
リウムフェライト粒子の粒子表面にポリエーテル変成ポ
リシロキサンを被着させた。Maintaining the Henschel mixer at a temperature of 85 ° C., polyether modified polysiloxane BYK-0
80 (trade name) (manufactured by BYK Chemie Co., Ltd.) 30 g (100% active ingredient) (1.0 for barium ferrite particles)
Corresponds to% by weight. ) At a rate of 3.0 g / min.
The mixture was added over a period of 20 minutes, followed by mixing for 20 minutes to deposit the polyether-modified polysiloxane on the surface of the barium ferrite particles.
【0092】次いで、ヘンシェルミキサーを混合させな
がら室温まで冷却して粒子表面にポリエーテル変成ポリ
シロキサンが被着されているバリウムフェライト粒子を
得た。Then, the mixture was cooled to room temperature while mixing with a Henschel mixer to obtain barium ferrite particles having polyether modified polysiloxane deposited on the surface of the particles.
【0093】得られたバリウムフェライト粒子粉末は、
ポリエーテル変成ポリシロキサンの被着量がC換算で
0.52重量%であった。The obtained barium ferrite particle powder is
The deposited amount of the polyether modified polysiloxane was 0.52% by weight in terms of C.
【0094】実施例2〜6、比較例6〜14 磁性粒子粉末の種類、量及び加熱処理温度、スクエア酸
添加の有無及び量、変成ポリシロキサンの有無、種類、
量及び混合時温度を種々変化させた以外は、実施例1と
同様にして磁性粒子粉末を得た。Examples 2 to 6 and Comparative Examples 6 to 14 Type and amount of magnetic particle powder and heat treatment temperature, presence and amount of squaric acid addition, presence and type of modified polysiloxane,
Magnetic particle powders were obtained in the same manner as in Example 1 except that the amount and the temperature at the time of mixing were variously changed.
【0095】この時の諸条件を表1及び表2に示す。Various conditions at this time are shown in Tables 1 and 2.
【0096】比較例1〜5 比較の為、未処理の磁性粒子粉末を用意した。これら磁
性粒子粉末の諸特性を表2に示す。Comparative Examples 1 to 5 Untreated magnetic particle powders were prepared for comparison. Table 2 shows various characteristics of these magnetic particle powders.
【0097】[0097]
【表1】 [Table 1]
【0098】[0098]
【表2】 [Table 2]
【0099】実施例7 スクエア酸3,4−ジヒドロキシ−3−シクロブテン−
1,2−ジオン(東京化成工業(株)製)35gをあら
かじめ5lの純水に添加して作製したスクエア酸溶液に
水を加えて35lとし、攪拌機でよく攪拌した。この時
のスクエア酸の濃度は、1.0g/lであった。Example 7 Squaric acid 3,4-dihydroxy-3-cyclobutene-
35 g of 1,2-dione (manufactured by Tokyo Kasei Kogyo Co., Ltd.) was previously added to 5 l of pure water, and water was added to the squaric acid solution to make 35 l, which was well stirred with a stirrer. The concentration of squaric acid at this time was 1.0 g / l.
【0100】上記スクエア酸溶液中に平均粒径0.65
μm、BET比表面積値4.6m2/g、保磁力Hc2
753Oe、飽和磁化σs55.6emu/g、pH値
9.5、水分量0.17wt%の粒状バリウムフェライ
ト粒子3.5kgを徐々に添加し、ホモミキサーで30
分間混合攪拌した後、濾過、乾燥、粉砕して該バリウム
フェライト粒子の粒子表面にスクエア酸を被着させた。An average particle size of 0.65 was added to the square acid solution.
μm, BET specific surface area value 4.6 m 2 / g, coercive force Hc2
753 Oe, saturation magnetization σs 55.6 emu / g, pH value 9.5, 3.5 kg of granular barium ferrite particles having a water content of 0.17 wt% were gradually added, and 30 were added with a homomixer.
After mixing and stirring for a minute, filtration, drying and pulverization were carried out to apply squaric acid to the particle surface of the barium ferrite particles.
【0101】得られたバリウムフェライト粒子粉末は、
スクエア酸被着量がC換算で0.40重量%であった。The obtained barium ferrite particle powder is
The amount of deposited square acid was 0.40% by weight in terms of C.
【0102】上記粒子表面がスクエア酸で被着されてい
るバリウムフェライト粒子粉末3.0kgを、あらかじ
め85℃に加熱したヘンシェルミキサー(10l)に投
入し、回転数1200rpmで10分間作動・混合させ
て水分を除去してバリウムフェライト粒子の水分値を
0.03重量%とした。3.0 kg of barium ferrite particle powder having the surface of particles coated with squaric acid was put into a Henschel mixer (10 l) preheated to 85 ° C., and the mixture was operated and mixed at a rotation speed of 1200 rpm for 10 minutes. The water content was removed to make the water value of the barium ferrite particles 0.03% by weight.
【0103】上記ヘンシェルミキサーを温度を85℃に
維持しながらポリエーテル変成ポリシロキサンBYK−
080(商品名)(ビックケミー(株)製)60g(有
効成分100%)を3.0g/分の添加速度で20分間
かけて添加し、引き続き20分間混合して、前記バリウ
ムフェライト粒子の粒子表面にポリエーテル変成ポリシ
ロキサンを被着させた。While maintaining the temperature of the Henschel mixer at 85 ° C., polyether modified polysiloxane BYK-
080 (trade name) (manufactured by BYK Chemie Co., Ltd.) 60 g (100% active ingredient) was added at an addition rate of 3.0 g / min over 20 minutes, followed by mixing for 20 minutes, and the particle surface of the barium ferrite particles was added. Was coated with polyether modified polysiloxane.
【0104】次いで、ヘンシェルミキサーを混合させな
がら室温まで冷却してスクエア酸表面にポリエーテル変
成ポリシロキサンが被着されているバリウムフェライト
粒子を得た。Then, the mixture was cooled to room temperature while mixing with a Henschel mixer to obtain barium ferrite particles in which the polyether modified polysiloxane was adhered to the square acid surface.
【0105】得られたバリウムフェライト粒子粉末は、
ポリエーテル変成ポリシロキサン被着量がC換算で1.
05%であった。The obtained barium ferrite particle powder is
Polyether-modified polysiloxane deposited amount is 1.
It was 05%.
【0106】実施例8〜12 磁性粒子粉末の種類、量及び加熱処理、温度、変成ポリ
シロキサン処理の種類、量及び混合時温度を種々変化さ
せた以外は、実施例7と同様にして処理済磁性粒子粉末
を得た。Examples 8 to 12 Treated in the same manner as in Example 7 except that the type, amount and heat treatment of the magnetic particle powder, the temperature, the type and amount of the modified polysiloxane treatment, and the mixing temperature were variously changed. A magnetic particle powder was obtained.
【0107】この時の諸条件及び諸特性を表1に示す。Table 1 shows various conditions and various characteristics at this time.
【0108】<溶剤系塗料の製造> 実施例13〜24、比較例15〜28;<Production of Solvent-Based Paint> Examples 13 to 24, Comparative Examples 15 to 28;
【0109】実施例13 140mlのマヨネーズ容器に実施例1で得られた処理
済磁性粒子粉末18gを用い、下記塗料組成を下記割合
で配合して1.5mmφガラスビーズ100gとともに
ペイントシェーカーで15分間混合分散し、ミルベース
(1)を得た。Example 13 18 g of the treated magnetic particle powder obtained in Example 1 was used in a 140 ml mayonnaise container, and the following coating composition was blended in the following proportions and mixed with 100 g of 1.5 mmφ glass beads for 15 minutes on a paint shaker. Dispersion was performed to obtain a mill base (1).
【0110】 <ミルベース(1)の組成> 実施例1で得られた処理済磁性粒子粉末 37.5重量部 レシチン溶液(2.5wt%シクロヘキサノン溶液) 7.5重量部<Composition of Millbase (1)> Treated Magnetic Particle Powder Obtained in Example 3 37.5 parts by weight Lecithin solution (2.5 wt% cyclohexanone solution) 7.5 parts by weight
【0111】次に、得られたミルベース(1)を用い、
下記塗料組成物を下記割合で配合してペイントシェーカ
ーでさらに混合分散し、ミルベース(2)を得た。この
時、混合分散時間を60分間とした場合と120分間と
した場合の2種類のミルベース(2)を作製した。Next, using the obtained mill base (1),
The following coating composition was blended in the following proportions and further mixed and dispersed by a paint shaker to obtain a mill base (2). At this time, two types of mill bases (2) were prepared, with the mixing and dispersing time of 60 minutes and 120 minutes.
【0112】 <ミルベース(2)の組成> ミルベース(1) 45.0重量部 塩化ビニル酢酸ビニル共重合樹脂溶液 12.5重量部 (VAGF ユニオンカーバイド社製、30wt%シクロヘキサノン溶液) メチルエチルケトン 16.3重量部<Composition of Millbase (2)> Millbase (1) 45.0 parts by weight Vinyl chloride vinyl acetate copolymer resin solution 12.5 parts by weight (VAGF Union Carbide Co., 30 wt% cyclohexanone solution) Methyl ethyl ketone 16.3 parts by weight Department
【0113】さらに、得られたミルベース(2)を用
い、下記塗料組成物を下記割合で配合しペイントシェー
カーで30分間混合分散を行い溶剤系塗料を得た。Further, using the obtained mill base (2), the following coating compositions were blended in the following proportions and mixed and dispersed for 30 minutes with a paint shaker to obtain a solvent-based coating.
【0114】 <溶剤系塗料の組成> ミルベース(2) 73.8重量部 ポリウレタン樹脂溶液 12.5重量部 (ニッポラン2301 日本ポリウレタン工業(株)製、 メチルエチルケトン/トルエン=1/1の30wt%溶液) メチルエチルケトン 3.4重量部 シクロヘキサノン 10.3重量部<Composition of Solvent-Based Paint> Millbase (2) 73.8 parts by weight Polyurethane resin solution 12.5 parts by weight (Nipporan 2301 Nippon Polyurethane Industry Co., Ltd., methyl ethyl ketone / toluene = 1/1 30 wt% solution) Methyl ethyl ketone 3.4 parts by weight Cyclohexanone 10.3 parts by weight
【0115】得られた溶剤系塗料を目開き44μmのス
テンレスメッシュで濾過した後、PETベースフィルム
に厚み50μmで塗布し、2800Gの配向磁場で配向
した後、乾燥することにより塗膜を得た。得られた塗膜
の諸特性を表3及び表4に示した。The obtained solvent-based coating material was filtered through a stainless steel mesh having an opening of 44 μm, coated on a PET base film with a thickness of 50 μm, oriented with an orientation magnetic field of 2800 G, and dried to obtain a coating film. Various properties of the obtained coating film are shown in Tables 3 and 4.
【0116】尚、比較のため、ポリエーテル変成ポリシ
ロキサンBYK−080をバリウムフェライト粒子の粒
子表面に被着することなく溶剤系塗料の製造に際して塗
料中に添加した以外は、実施例13と同様にして塗料を
製造した(前出特開昭62−187772号公報記載の
方法に該当する。)この塗料を用いて製造した塗膜は、
分散時間が120分間のミルベース(2)を用いて作製
した塗膜の場合、保磁力Hcが2703Oe、Rsが
0.85、Raが0.47μm、RMSが0.56μm
であって、希釈時のRaの変化率は11.4%であっ
た。For comparison, the same procedure as in Example 13 was carried out except that the polyether-modified polysiloxane BYK-080 was added to the paint of the solvent-based paint without depositing it on the surface of the barium ferrite particles. The coating film produced by using this coating material is a coating material produced by applying the coating material (corresponding to the method described in JP-A-62-187772).
In the case of a coating film prepared by using a mill base (2) having a dispersion time of 120 minutes, coercive force Hc is 2703 Oe, Rs is 0.85, Ra is 0.47 μm, and RMS is 0.56 μm.
The rate of change of Ra upon dilution was 11.4%.
【011 【0117】実施例14〜24、比較例15〜28 磁性粒子粉末の種類を種々変化させた以外は、実施例1
3と同様にして溶剤系塗料を製造した。Examples 14 to 24, Comparative Examples 15 to 28 Example 1 except that the type of magnetic particle powder was variously changed.
A solvent-based paint was produced in the same manner as in 3.
【0118】得られた溶剤系塗料の諸特性を表3及び表
4に示す。Tables 3 and 4 show various properties of the obtained solvent-based paint.
【0119】[0119]
【表3】 [Table 3]
【0120】[0120]
【表4】 [Table 4]
【0121】<水系塗料の製造> 実施例25〜36、比較例29〜42;<Production of Water-based Paint> Examples 25-36, Comparative Examples 29-42;
【0122】実施例25 140mlのガラス容器に実施例1で得られたバリウム
フェライト粒子粉末20.0gを用い、塗料組成を下記
割合で配合して1.5mmφガラスビーズ100gとと
もにペイントシェーカーで混合分散し、ミルベースを作
製した。この時、混合分散時間を30分間とした場合と
60分間とした場合の2種類のミルベースを作製した。Example 25 Using 20.0 g of the barium ferrite particle powder obtained in Example 1 in a 140 ml glass container, the coating composition was blended in the following proportions and mixed and dispersed with 100 g of 1.5 mmφ glass beads in a paint shaker. , A mill base was produced. At this time, two types of mill bases were prepared, where the mixing and dispersing time was 30 minutes and the mixing and dispersing time was 60 minutes.
【0123】 <ミルベースの組成> 実施例1で得られたバリウムフェライト粒子粉末 44.4重量部 分散剤 0.5重量部 (商品名:ポイズ−521(40%水溶液):花王(株)製) 消泡剤 0.3重量部 (商品名:ノプコ8034:サンノプコ(株)製) イオン交換水 18.4重量部 ブチルセロソルブ 7.9重量部<Composition of Millbase> Barium ferrite particle powder obtained in Example 1 44.4 parts by weight Dispersant 0.5 parts by weight (trade name: Poise-521 (40% aqueous solution): manufactured by Kao Corporation) Defoamer 0.3 parts by weight (Brand name: Nopco 8034: manufactured by San Nopco Ltd.) Ion-exchanged water 18.4 parts by weight Butyl cellosolve 7.9 parts by weight
【0124】上記ミルベースを用いて、塗料組成を下記
割合で配合してペイントシェーカーでさらに15分間混
合分散し水系塗料を得た。Using the above mill base, the coating composition was blended in the following proportions and further mixed and dispersed for 15 minutes on a paint shaker to obtain an aqueous coating.
【0125】 <水系塗料の組成> ミルベース 71.5重量部 水溶性アクリルエマルジョン(35wt%) 28.5重量部 (商品名:SW−135:三洋化成(株)製)<Composition of water-based paint> Millbase 71.5 parts by weight Water-soluble acrylic emulsion (35 wt%) 28.5 parts by weight (Brand name: SW-135: Sanyo Kasei Co., Ltd.)
【0126】得られた水系塗料を目開き44μmのステ
ンレスメッシュで濾過した後、紙製ベースフィルムに厚
み50μmで塗布し、3200Gの配向磁場で配向した
後、乾燥することにより塗膜を得た。得られた塗膜の諸
特性を表5に示す。The obtained water-based paint was filtered through a stainless mesh having an opening of 44 μm, applied on a paper base film with a thickness of 50 μm, oriented with a 3200 G orientation magnetic field, and dried to obtain a coating film. Table 5 shows various properties of the obtained coating film.
【0127】尚、比較のため、ポリエーテル変成ポリシ
ロキサンBYK−080をバリウムフェライト粒子の粒
子表面に被着することなく水系塗料の製造に際して塗料
中に添加した以外は、実施例25と同様にして塗料を製
造した(前出特開昭62−187772号公報記載の方
法に該当する。)この塗料を用いて製造した塗膜は、分
散時間が60分間のミルベースを用いて作製した塗膜の
場合、保磁力Hcが2710Oe、Rsが0.83、R
aが0.42μm、RMSが0.50μmであって、希
釈時のRaの変化率は18.6%、保存時のRaは0.
56μm、塗料中の粒子のゼータ電位は−21.6mV
であった。For comparison, the same procedure as in Example 25 was carried out except that the polyether-modified polysiloxane BYK-080 was added to the coating material during the production of the water-based coating material without adhering to the surface of the barium ferrite particles. A paint was produced (corresponding to the method described in JP-A-62-187772). A coating film produced by using this coating material is a coating film produced by using a mill base having a dispersion time of 60 minutes. , Coercive force Hc is 2710 Oe, Rs is 0.83, R
a is 0.42 μm, RMS is 0.50 μm, the rate of change of Ra upon dilution is 18.6%, and the Ra upon storage is 0.
56 μm, zeta potential of particles in paint is -21.6 mV
Met.
【0128】実施例26〜36、比較例29〜42 磁性粒子粉末の種類を種々変化させた以外は、実施例2
5と同様にして得られた水系塗料を製造した。Examples 26 to 36, Comparative Examples 29 to 42 Example 2 except that the type of magnetic particle powder was variously changed.
A water-based paint obtained in the same manner as in No. 5 was produced.
【0129】得られた水系塗料の諸特性を表5及び表6
に示す。Table 5 and Table 6 show various properties of the obtained water-based paint.
Shown in
【0130】[0130]
【表5】 [Table 5]
【0131】[0131]
【表6】 [Table 6]
【0132】[0132]
【発明の効果】本発明に係る磁性粒子粉末は、前出実施
例に示した通り、塗料中、殊に、水系塗料中における分
散性及び配向性に優れた磁性粒子粉末であるので磁気記
録シート用磁性粒子粉末として好適である。INDUSTRIAL APPLICABILITY The magnetic particle powder according to the present invention is a magnetic particle powder having excellent dispersibility and orientation in paints, especially in water-based paints, as shown in the above-mentioned Examples, and therefore magnetic recording sheet. Suitable as magnetic particle powder for use.
【0133】本発明に係る磁性粒子粉末を用いて製造し
た水系塗料は、磁性粒子粉末の分散性及び配向性がよ
く、しかも、水系であることによって紙とのなじみがよ
いので、非磁性支持体として紙を用いる磁気記録シート
に使用する場合に、殊に、好ましいものである。The water-based coating material produced by using the magnetic particle powder according to the present invention has good dispersibility and orientation of the magnetic particle powder, and since it is water-based, it is well compatible with paper. It is particularly preferable when it is used for a magnetic recording sheet using paper as the sheet.
フロントページの続き (72)発明者 森井 弘子 広島県広島市中区舟入南4丁目1番2号戸 田工業株式会社創造センター内Continued Front Page (72) Inventor Hiroko Morii 4-1-2 Funairi Minami, Naka-ku, Hiroshima City, Hiroshima Prefecture Toda Industry Co., Ltd. Creative Center
Claims (6)
ル及びアラルキルから選ばれる1種又は2種以上によっ
て変成されているポリシロキサンが被着されているマグ
ネトプランバイト型フェライト粒子又は磁性酸化鉄粒子
からなる磁性粒子粉末。1. Magnetoplumbite-type ferrite particles or magnetic iron oxide particles, the surface of which is coated with a polysiloxane modified with one or more selected from polyether, polyester and aralkyl. Magnetic particle powder.
り、更に、該被着スクエア酸の表面に、ポリエーテル、
ポリエステル又はアラルキルから選ばれる1種又は2種
以上によって変成されているポリシロキサンが被着され
ているマグネトプランバイト型フェライト粒子又は磁性
酸化鉄粒子からなる磁性粒子粉末。2. The surface of the particles is coated with squaric acid, and the surface of the deposited square acid is polyether,
Magnetic particle powder consisting of magnetoplumbite type ferrite particles or magnetic iron oxide particles coated with a polysiloxane modified with one or more selected from polyester or aralkyl.
又は磁性酸化鉄粒子とポリエーテル、ポリエステル及び
アラルキルから選ばれる1種又は2種以上によって変成
されているポリシロキサンとを80℃以上の温度で混合
して前記マグネトプランバイト型フェライト粒子又は磁
性酸化鉄粒子の粒子表面に、前記変成ポリシロキサンを
被着させることを特徴とする請求項1記載の磁性粒子粉
末の製造法。3. Magnetoplumbite-type ferrite particles or magnetic iron oxide particles are mixed with a polysiloxane modified by one or more selected from polyether, polyester and aralkyl at a temperature of 80 ° C. or higher. 2. The method for producing magnetic particle powder according to claim 1, wherein the modified polysiloxane is deposited on the surface of the magnetoplumbite ferrite particles or magnetic iron oxide particles.
又は磁性酸化鉄粒子とスクエア酸とを含む水懸濁液を混
合した後、濾別、乾燥して前記マグネトプランバイト型
フェライト粒子又は磁性酸化鉄粒子の粒子表面にスクエ
ア酸を被着させ、次いで、該スクエア酸が被着されてい
るマグネトプランバイト型フェライト粒子又は磁性酸化
鉄粒子とポリエーテル、ポリエステル及びアラルキルか
ら選ばれる1種又は2種以上によって変成されているポ
リシロキサンとを80℃以上の温度で混合して前記被着
スクエア酸の表面に、ポリエーテル、ポリエステル又は
アラルキルから選ばれる1種又は2種以上によって変成
されているポリシロキサンを被着させることを特徴とす
る請求項2記載の磁性粒子粉末の製造法。4. A magnetoplumbite ferrite particle or magnetic iron oxide particle is mixed with an aqueous suspension containing squaric acid, and then filtered and dried to obtain the magnetoplumbite ferrite particle or magnetic iron oxide particle. Squaric acid is adhered to the particle surface, and then modified by magnetoplumbite type ferrite particles or magnetic iron oxide particles to which the square acid is adhered and one or more kinds selected from polyether, polyester and aralkyl. A polysiloxane which has been modified by one or more selected from polyether, polyester or aralkyl, and is mixed on the surface of the deposited square acid by mixing the polysiloxane with a polysiloxane having a temperature of 80 ° C. or higher. The method for producing the magnetic particle powder according to claim 2, wherein
粉末を水系塗料構成基材中に配合したことを特徴とする
水系磁性塗料。5. A water-based magnetic coating material, wherein the magnetic particle powder according to claim 1 or 2 is blended in a water-based coating material.
層を設けてなる磁気記録シートにおいて、前記磁性層が
請求項5に記載した水系磁性塗料を塗布、乾燥すること
により形成されたものであって、磁性層の表面粗度が
0.35μm以下、角形比が0.87以上であることを
特徴とする磁気記録シート。6. A magnetic recording sheet comprising a magnetic layer provided on at least a part of a non-magnetic support, wherein the magnetic layer is formed by applying the aqueous magnetic coating composition according to claim 5 and drying. The magnetic recording sheet is characterized in that the magnetic layer has a surface roughness of 0.35 μm or less and a squareness ratio of 0.87 or more.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7211087A JPH0945516A (en) | 1995-07-26 | 1995-07-26 | Magnetic particle powder, its manufacture and water-base magnetic paint using said magnetic particle powder as well as magnetic recording sheet using the water-base magnetic paint |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP7211087A JPH0945516A (en) | 1995-07-26 | 1995-07-26 | Magnetic particle powder, its manufacture and water-base magnetic paint using said magnetic particle powder as well as magnetic recording sheet using the water-base magnetic paint |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0945516A true JPH0945516A (en) | 1997-02-14 |
Family
ID=16600207
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP7211087A Pending JPH0945516A (en) | 1995-07-26 | 1995-07-26 | Magnetic particle powder, its manufacture and water-base magnetic paint using said magnetic particle powder as well as magnetic recording sheet using the water-base magnetic paint |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0945516A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001143243A (en) * | 1999-11-16 | 2001-05-25 | Toda Kogyo Corp | Magnetic recording medium |
JP2001143242A (en) * | 1999-11-15 | 2001-05-25 | Toda Kogyo Corp | Acicular magnetic particle powder for magnetic recording medium and magnetic recording medium using the same |
-
1995
- 1995-07-26 JP JP7211087A patent/JPH0945516A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001143242A (en) * | 1999-11-15 | 2001-05-25 | Toda Kogyo Corp | Acicular magnetic particle powder for magnetic recording medium and magnetic recording medium using the same |
JP2001143243A (en) * | 1999-11-16 | 2001-05-25 | Toda Kogyo Corp | Magnetic recording medium |
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