JPH0770042B2 - Magnetic recording medium - Google Patents

Magnetic recording medium

Info

Publication number
JPH0770042B2
JPH0770042B2 JP62152222A JP15222287A JPH0770042B2 JP H0770042 B2 JPH0770042 B2 JP H0770042B2 JP 62152222 A JP62152222 A JP 62152222A JP 15222287 A JP15222287 A JP 15222287A JP H0770042 B2 JPH0770042 B2 JP H0770042B2
Authority
JP
Japan
Prior art keywords
particles
film
particle size
magnetic recording
polyester
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
Application number
JP62152222A
Other languages
Japanese (ja)
Other versions
JPS63316316A (en
Inventor
親和 川口
義男 目黒
昌司 稲垣
Original Assignee
ダイアホイルヘキスト株式会社
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by ダイアホイルヘキスト株式会社 filed Critical ダイアホイルヘキスト株式会社
Priority to JP62152222A priority Critical patent/JPH0770042B2/en
Priority to KR1019870006750A priority patent/KR960006092B1/en
Priority to EP87112252A priority patent/EP0257611B1/en
Priority to AT87112252T priority patent/ATE109493T1/en
Priority to DE3750319T priority patent/DE3750319T2/en
Priority to ES87112252T priority patent/ES2056802T3/en
Publication of JPS63316316A publication Critical patent/JPS63316316A/en
Priority to US07/420,740 priority patent/US4990400A/en
Priority to US07/420,474 priority patent/US5106681A/en
Publication of JPH0770042B2 publication Critical patent/JPH0770042B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明はポリエステルフイルム化工程や磁性層塗布工程
での取扱い作業性に優れ、再生出力が高くドロップアウ
トの少ないとりわけ磁気テープ化工程で生ずる摩耗粉の
発生が極めて少ない磁気記録媒体に関する。更に詳く
は、本発明はポリエステル中に特定の製法で作成した、
特定のシリカ粒子を特定量含有してなり、且つ表面粗さ
と表面破れ突起数とが特定の範囲を満たすフイルムの片
面に磁性層を設けた磁気記録媒体に関するものである。
DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention has excellent handling workability in the polyester film forming step and the magnetic layer coating step, has a high reproduction output and a small dropout, and particularly wear caused in the magnetic tape forming step. The present invention relates to a magnetic recording medium in which generation of powder is extremely small. More specifically, the present invention was made in polyester by a particular process,
The present invention relates to a magnetic recording medium containing a specific amount of specific silica particles and having a magnetic layer provided on one side of a film having surface roughness and the number of surface-breaking projections that satisfy specific ranges.

〔従来の技術と発明が解決しようとする問題点〕[Problems to be solved by conventional technology and invention]

磁気記録媒体、とりわけ磁気記録テープはその基材であ
るポリエステルフイルムの表面粗度を小さくし高画質、
高密度化したものが要望されている。しかしながら良く
知られているようにフイルム表面が平坦になると、フイ
ルムと基材との摩耗が激しくなり発生した摩耗粉により
種々の弊害を引き起こすようになる。例えばフイルム製
造工程を含む磁性層塗布工程以前の工程で摩耗粉が発生
すると、磁性層を塗布する際ヌケが生じ、ドロップアウ
トの原因となるし、又磁性層塗布、乾燥後行なわれる磁
性層表面処理工程いわゆるカレンダー処理工程で発生す
る摩耗粉はカレンダー処理ロールに付着し、磁性層表面
を粗面化し、磁気テープとしての特性を著しく低下させ
る。耐摩耗性の劣るベースフイルムを用いると、このカ
レンダー処理ロールへの付着が早期から見られ、その都
度ロールの洗浄を行なわねばならず、生産性に著しく支
障をきたす。
Magnetic recording media, especially magnetic recording tapes, have a high surface quality by reducing the surface roughness of the polyester film, which is the base material.
There is a demand for higher density. However, as is well known, when the film surface becomes flat, the film and the base material are abraded so much that abrasion powder generated causes various problems. For example, if abrasion powder is generated in the process before the magnetic layer coating process including the film manufacturing process, it may cause a dropout when coating the magnetic layer and cause dropout, and also the magnetic layer surface after coating and drying the magnetic layer. Abrasion powder generated in the so-called calendering step adheres to the calendering roll, roughens the surface of the magnetic layer, and significantly deteriorates the properties as a magnetic tape. When a base film having poor abrasion resistance is used, the adhesion to the calendered roll is observed from an early stage, and the roll must be washed each time, which seriously hinders productivity.

一方、フイルム製造工程、磁性層塗布工程等におけるフ
イルムの取り扱い作業性を改良するには、フイルムの摩
擦係数を低減させる必要があり、その手法としてはフイ
ルム中に不活性な無機或いは有機の微粒子を配合し、フ
イルム表面に適度の凹凸を付与せしめれば良いことが知
られている。フイルム表面の凹凸付与は、摩擦係数の低
減のみならず、耐摩耗性の向上にもある程度寄与し得る
が、これを改良する為にはこれら微粒子の配合量を増加
するか、大粒子を配合せしめる必要が生ずる。こうした
場合、フイルム表面の平均粗度が高くなると共に、粗大
粒子の混在や、粒子同志の凝集による粗大粒子の生成の
ため、往々にして粗大突起が増加してしまい、高性能化
のためのフイルム表面平坦化には相反してしまうことに
なる。
On the other hand, in order to improve the handling workability of the film in the film manufacturing process, the magnetic layer coating process, etc., it is necessary to reduce the friction coefficient of the film, and the method is to use inert inorganic or organic fine particles in the film. It is known that they may be blended to give appropriate irregularities to the film surface. The unevenness of the film surface can contribute not only to the reduction of the friction coefficient but also to the improvement of abrasion resistance to some extent, but in order to improve this, the compounding amount of these fine particles should be increased or large particles should be mixed. The need arises. In such a case, the average roughness of the film surface becomes high, and since coarse particles are mixed and coarse particles are generated by agglomeration of particles, coarse projections often increase, and the film for high performance is increased. It will be contrary to the surface flattening.

フイルム表面の凸乙付与の為、一般的に用いられる微粒
子として、タルク、カオリン、シリカ、炭酸カルシウ
ム、二酸化チタン、グラフアイト、カーボンブラックな
どのポリエステルに対し、不活性な無機化合物粒子を添
加することが知られている。しかしながらこれら無機粒
子は、通常天然鉱物を粉砕するか、又は合成することに
より得られるが、粗大粒子や凝集による粗大化粒子の混
在は避けることが困難である。この粗大粒子がポリエス
テル中に含まれると、フイルム化工程、或いは製品とし
た時の特性を著しく低下させることになる。例えば、フ
イルム化工程で、ポリエステルを押出機にて溶融押出し
する際、粗大異物を除去する為に設けられたフイルター
の閉塞が激しくなったり、フイルムを延伸する際、破断
が頻発するようになる。又、得られたフイルム中に単独
或いは凝集による、粗大粒子が含まれていると、いわゆ
るフィッシユアイとなり、磁気テーとなした時のドロッ
プアウトの原因となる。
To give the surface of the film a convex surface, add inactive inorganic compound particles to polyesters such as talc, kaolin, silica, calcium carbonate, titanium dioxide, graphite, and carbon black, which are commonly used. It has been known. However, although these inorganic particles are usually obtained by pulverizing or synthesizing natural minerals, it is difficult to avoid the inclusion of coarse particles or coarse particles due to aggregation. If the coarse particles are contained in the polyester, the properties in the film forming process or the product will be significantly deteriorated. For example, in the film forming process, when polyester is melt-extruded by an extruder, a filter provided for removing coarse foreign matters is severely clogged, or when the film is stretched, breakage frequently occurs. If the obtained film contains coarse particles, either alone or due to agglomeration, a so-called fisheye will be formed, which will cause dropout when a magnetic tape is formed.

フイルム表面を平坦化、均一化させるには粒子を微細化
させる必要がある。この目的に対し不活性無機粒子を予
め粉砕、分級し粗大粒子を除去する方法が提案されてい
る。例えば、天然原石を粉砕した粉末、或いは合成して
得られた粉末を、更に乾式又は湿式で粉砕、分級処理す
る方法が知られている。
In order to make the film surface flat and uniform, it is necessary to make the particles finer. For this purpose, a method has been proposed in which inert inorganic particles are previously crushed and classified to remove coarse particles. For example, a method is known in which a powder obtained by crushing natural ore or a powder obtained by synthesizing is further dry or wet crushed and classified.

しかしながら、かかる方法で、ある程度の粗大粒子の除
去、均一化は出来るが、十分ではない。
However, although such a method can remove and homogenize coarse particles to some extent, it is not sufficient.

一方、耐摩耗性に寄与する、今一つの要因として、フイ
ルム中に配合する粒子とポリエステルとの親和性があ
る。親和性の悪い粒子では、フイルムにした時、ポリエ
ステルと粒子との界面に空隙を生じ、フイルム化工程、
巻き上げ工程、磁気テープ化工程等の種々のロールとの
接触や、その他の外力によって粒子が脱落し、種々の弊
害を引き起こす。ポリエステルとの親和性を改良する目
的で粒子表面を有機シランやアクリル酸等の有機化合物
で処理する方法が用いられている。しかしながら、こう
して表面処理では十分な親和性が得られなかったり、又
粒子間での相互作用が強まり凝集、粗大粒子化を生じた
りして、十分な改良がなされていないのが現状である。
On the other hand, another factor that contributes to the abrasion resistance is the affinity between the particles blended in the film and the polyester. For particles with poor affinity, when formed into a film, voids are created at the interface between the polyester and the particles, and the film forming process,
The particles fall off due to contact with various rolls in the winding step, the magnetic tape forming step, and other external forces, causing various harmful effects. For the purpose of improving the affinity with polyester, a method of treating the particle surface with an organic compound such as organic silane or acrylic acid is used. However, in this situation, sufficient affinity cannot be obtained by the surface treatment, or the interaction between particles is strengthened, resulting in aggregation and coarsening of particles, so that sufficient improvement is not made at present.

ポリエステル中に配合する無機粒子の中でもシリカ粒子
は平均粒径の異なる種々の製品が市販されている。しか
しながらこうしたシリカ粒子をポリエステルに配合せし
めフイルムとなしても、前述した厳しい要求特性を十分
満足することが出来なかった。即ちシリカ粒子の如く粒
子表面の活性が比較的高く、微細な粒子は二次凝集粒子
を形成し易く、分散媒中に完全に分散させることが困難
である。又往々にしてポリエステル重合反応中凝集が増
加し結果的にポリエステル中の粗大粒子となり、フイル
ム表面に粗大突起を形成せしめ磁気記録媒体としての特
性を低下させ好ましくない状況であった。
Among the inorganic particles blended in polyester, silica particles are commercially available as various products having different average particle diameters. However, even if such silica particles are blended with polyester to form a film, the above-mentioned severely required properties cannot be sufficiently satisfied. That is, the activity of the particle surface such as silica particles is relatively high, and fine particles easily form secondary aggregated particles, and it is difficult to completely disperse them in a dispersion medium. Further, agglomeration is often increased during the polyester polymerization reaction, resulting in coarse particles in the polyester, resulting in formation of coarse protrusions on the film surface, which deteriorates the characteristics of the magnetic recording medium, which is not preferable.

〔問題点を解決するための手段〕[Means for solving problems]

本発明者らは、上記実情に鑑み、再生出力、出力変動等
の電磁変換特性に優れ、且つ、塗布工程、表面処理工程
等で生ずる摩耗粉の発生が少ない磁気記録媒体について
鋭意検討した結果、特定の製法で作成した特定のシリカ
粒子を特定量含有してなり、且つ表面粗さと表面破れ突
起数が特定の範囲を満たすベースフイルムの片面に磁性
層を設けた磁気記録媒体が優れた特性を有することを見
出し本発明に至った。
In view of the above circumstances, the present inventors have diligently studied a magnetic recording medium that is excellent in electromagnetic conversion characteristics such as reproduction output and output fluctuation, and has less abrasion powder generated in a coating step, a surface treatment step, and the like, A magnetic recording medium that contains a specific amount of specific silica particles created by a specific manufacturing method, and that has a magnetic layer on one side of a base film that has a surface roughness and a number of surface-breaking protrusions in a specific range has excellent characteristics. The present invention has been found to have the above and has led to the present invention.

即ち本発明の要旨はアルコキシシランの加水分解反応及
び縮合反応により得られる平均粒径0.01〜3μmの実質
的に非晶質の球状シリカ粒子を0.001〜5wt%含有してな
り、表面粗さRa及び最大突起高さRtとRaとの比が下記式
(1)及び(2)を満足し、且つ表面破れ突起数が20個
/mm2以下である配向ポリエステルフイルムの片面に磁性
層を設けてなることを特徴とする磁気記録媒体に存す
る。
That is, the gist of the present invention is to contain 0.001 to 5 wt% of substantially amorphous spherical silica particles having an average particle size of 0.01 to 3 μm obtained by the hydrolysis reaction and condensation reaction of alkoxysilane. The ratio of maximum protrusion height Rt to Ra satisfies the following formulas (1) and (2), and the number of surface break protrusions is 20
A magnetic recording medium is characterized in that a magnetic layer is provided on one surface of an oriented polyester film having a thickness of / mm 2 or less.

0.003≦Ra≦0.015 ……(1) 5≦Rt/Ra≦20 ……(2) 以下本発明を更に詳細に説明する。0.003 ≦ Ra ≦ 0.015 (1) 5 ≦ Rt / Ra ≦ 20 (2) The present invention will be described in more detail below.

本発明でいうポリエステルとは、テレフタル酸、2,6−
ナフタレンジカルボン酸の如き芳香族ジカルボン酸又は
そのエステルと、エチレングリコールを主たる出発原料
として得られるポリエステルを指すが他の第三成分を含
有していてもかまわない。この場合、ジカルボン酸成分
としては例えばイソフタル酸、フタル酸、2,6−ナフタ
レンジカルボン酸、テレフタル酸、アジピン酸、セバシ
ン酸、及びオキシカルボン酸成分、例えばp−オキシエ
トキシ安息香酸の一種又は二種以上を用いることが出来
る。グリコール成分としては、ジエチレングリコール、
プロピレングリコール、ブタンジオール、1,4−シクロ
ヘキサンジメタノール、ネオペンチルグリコール等の一
種又は二種以上を用いることが出来る。いずれにしても
本発明のポリエステルは反復構造単位の80%以上がエチ
レンテレフタレート単位又はエチレン−2,6−ナフタレ
ートン単位を有するポリエステルであることが好まし
い。本発明に於いては磁気記録媒体のベースフイルムで
あるポリエステルフイルムに配合する粒子及びフイルム
の表面状態に特徴を有する。即ち磁気記録媒体を製造す
る迄の段階、例えば塗布工程、カレンダー工程等で生ず
る摩耗粉の発生を少なくする為、又、これらの工程での
取扱い作業性を改良する為ベースフイルム中に不活性な
微粒子を存在せしめれば良いことが知られており本発明
者らはかかる微粒子としてアルコキシシランを加水分
解、縮合反応し得られた平均粒径が0.01〜3μmの極め
て微細な、非晶質で球形のシリカ粒子を用いればそれら
の特性が極めて顕著に改良されることを見出した。さら
に極めて高密度記録の要求される磁気記録媒体としての
電磁変換特性を同時に改良する為にベースフイルムの表
面粗さを0.003〜0.015μmと極めて微細に突起を付与
し、又それと共に最大突起と平均粗さとの比を5〜20
と、突起高さの分布をシャープにすることで達成される
ことを知見し本発明に至った。尚、本発明で用いるシリ
カ粒子の表面にエチレングリコール残基を付与せしめれ
ば、より優れた特性が得られることを見出した。
The polyester referred to in the present invention means terephthalic acid, 2,6-
An aromatic dicarboxylic acid such as naphthalenedicarboxylic acid or an ester thereof and a polyester obtained by using ethylene glycol as a main starting material are shown, but other third component may be contained. In this case, examples of the dicarboxylic acid component include isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, terephthalic acid, adipic acid, sebacic acid, and oxycarboxylic acid component such as p-oxyethoxybenzoic acid. The above can be used. As the glycol component, diethylene glycol,
One or more of propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol and the like can be used. In any case, the polyester of the present invention is preferably a polyester in which 80% or more of the repeating structural units have ethylene terephthalate units or ethylene-2,6-naphthalate units. The present invention is characterized by the surface state of the particles and the film to be added to the polyester film which is the base film of the magnetic recording medium. That is, in order to reduce the generation of abrasion powder generated in the steps up to the production of the magnetic recording medium, for example, the coating process and the calendering process, and to improve the handling workability in these processes, it is inert in the base film. It is known that fine particles should be allowed to exist, and the present inventors have found that the fine particles are extremely fine, amorphous and spherical with an average particle size of 0.01 to 3 μm obtained by hydrolysis and condensation reaction of alkoxysilane. It has been found that the use of the silica particles described in (1) and (2) significantly improves their properties. Furthermore, in order to simultaneously improve the electromagnetic conversion characteristics of a magnetic recording medium that requires extremely high density recording, the surface roughness of the base film is 0.003 to 0.015 μm, and the projections are extremely fine. Roughness ratio 5-20
Then, the inventors have found that this can be achieved by sharpening the distribution of the height of the protrusions, and have reached the present invention. It was found that more excellent characteristics can be obtained by adding an ethylene glycol residue to the surface of the silica particles used in the present invention.

本発明で用いるシリカ粒子はアルコキシシランを加水分
解、縮合反応し得られるが、粒径のコントロールは反応
温度、時間、アルコキシル基の鎖長、アルコキシシラン
の追添加等によって行なうことができ、粒子表面へのエ
チレングリコール残期の付与は粒子分散媒体をエチレン
グリコールに置換する際、100℃前後に加熱することで
達成出来る。
The silica particles used in the present invention can be obtained by hydrolyzing and condensing an alkoxysilane. The particle size can be controlled by the reaction temperature, time, chain length of alkoxyl group, additional addition of alkoxysilane, etc. The ethylene glycol residual period can be imparted to the particle dispersion medium by heating to about 100 ° C. when replacing the particle dispersion medium with ethylene glycol.

本発明のシリカ粒子は多くの特徴を有しているが、その
代表として粒径均一性に優れること、及び粒子形状が球
形であることが掲げられる。粒径均一性は粒度分布をも
って示されるが、その測定には電子顕微鏡を使用した。
粒子約1000個の粒径を投影写真像から測定し、各々の粒
径を体積換算し積算する。大粒子側から積算体積分率が
10%及び90%の所の粒径の比(d10/d90)をもって粒度
分布の尺度とする。本発明のシリカ粒子はこのd10/d90
の値が2.7以下であり、粒度分布がシャープであること
を示している。粒度分布が大であることは大粒子の存在
率が高いことを表わし、大粒子は大突起を形成し、電磁
変換特性低下の原因となり好ましくないものである。
The silica particles of the present invention have many characteristics, and representative examples thereof include excellent particle size uniformity and spherical particle shape. The particle size uniformity is shown by the particle size distribution, and the electron microscope was used for the measurement.
The particle size of about 1000 particles is measured from the projected photographic image, and each particle size is converted into volume and integrated. The cumulative volume fraction from the large particle side
The ratio of particle size at 10% and 90% (d10 / d90) is used as a measure of particle size distribution. The silica particles of the present invention have this d10 / d90
The value of is less than 2.7, indicating that the particle size distribution is sharp. A large particle size distribution means that the abundance of large particles is high, and large particles form large projections, which is a cause of deterioration of electromagnetic conversion characteristics and is not preferable.

粒子形状を表わす方法としては下記の体積形状係数をも
って表わした。粒子の投影面に於ける最大径(d)と粒
子体積(v)を用い下式にて体積形状係数を求めた。
As a method of expressing the particle shape, the following volume shape coefficient was used. The volume shape factor was calculated by the following formula using the maximum diameter (d) on the projection plane of the particles and the particle volume (v).

〔φ〕=v/d3 本発明のシリカ粒子は〔φ〕が0.4〜π/6の範囲であ
り真球に近いものであることを示す。
v ] = v / d 3 The silica particles of the present invention have [φ v ] in the range of 0.4 to π / 6, which indicates that they are close to a true sphere.

粒子形状が真球に近いとベースフイルムの表面粗さや、
滑性等に異方性を有しなくなったり、又、ベースフイル
ムの製造法に基づく製品幅方向の特性のムラ(ボーイン
グと称する)が少なくなり好ましい結果を生ずる。逆に
〔φ〕が0.4以下となり、例えば楕円状、角状となっ
てくると前述と反対に特性上のムラ、異方性が激しくな
り好ましくない。又同時にこうした形状の粒子を含有し
たベースフイルムのテープは応々にして取扱い作業性に
劣り、好ましくないものであった。
If the particle shape is close to a true sphere, the surface roughness of the base film,
Anisotropy in lubricity and the like is eliminated, and unevenness in characteristics in the product width direction (referred to as bowing) based on the manufacturing method of the base film is reduced, so that preferable results are obtained. On the other hand, if [φ v ] is 0.4 or less, for example, if it becomes elliptical or angular, the characteristic unevenness and anisotropy become severe contrary to the above, which is not preferable. At the same time, the tape of the base film containing particles having such a shape is unfavorable because the workability of handling is poor.

本発明で用いるシリカ粒子の平均粒径は0.01〜3μmで
あることが必要であり、好ましくは0.05〜0.7μm、更
に好ましくは0.1〜0.5μmである。0.01μm未満では取
扱い作業性、耐摩耗性効果が不充分であり、又粒子間で
の相互作用が高まり凝集体を生成するようになる。こう
した凝集体はフイルム表面の粗大突起となり、磁気記録
媒体のドロップアウト増加につながり好ましくない。粒
径が3μmを越えると、記録密度の高い用途では充分満
足する出録が得られず良くない。
The average particle size of the silica particles used in the present invention is required to be 0.01 to 3 μm, preferably 0.05 to 0.7 μm, and more preferably 0.1 to 0.5 μm. If it is less than 0.01 μm, the handling workability and abrasion resistance effect are insufficient, and the interaction between particles is increased to form aggregates. Such agglomerates form coarse protrusions on the film surface, which leads to an increase in dropout of the magnetic recording medium, which is not preferable. If the particle size exceeds 3 μm, satisfactory recording cannot be obtained in applications with high recording density, which is not good.

ベースフイルム中のシリカ粒子の含有量は0.001〜5wtで
あることが必要であり、好ましくは0.01〜1.0wt%、更
に好ましくは0.05〜0.6wt%である。含有量が0.001wt%
以下では取扱い作業性、耐摩耗性効果が不十分で、逆に
5wt%を越えるとフイルム表面の粗度が高まり出力の低
下を召いたり、凝集による粗大突起が生成しドロップア
ウトが多発したりして好ましくない。
The content of silica particles in the base film is required to be 0.001-5 wt%, preferably 0.01-1.0 wt%, more preferably 0.05-0.6 wt%. Content is 0.001wt%
In the following, handling workability and wear resistance are insufficient,
If it exceeds 5% by weight, the roughness of the film surface is increased and the output is lowered, or coarse projections are generated due to agglomeration, resulting in frequent dropouts, which is not preferable.

本発明の要件として更に、ベースフイルムの表面粗さ
(平均粗さRa)が0.003〜0.015μmの範囲にあり、最大
突起高さ(Rt)と平均粗さとの比(Rt/Ra)が5〜20で
且つベースフイルム表面の破れ突起数が20個/mm2以下で
あることが肝要である。Raが0.003μm未満では取扱い
作業性、耐摩耗性効果が不充分で、Raが0.015μmを越
えると高密度記録の媒体としての再生出力が充分得られ
ず好ましくない。又、Rt/Raは突起高さの均一性の尺度
となるもので、この値が小なる程均一性に優れるが、5
未満となると突起高さの均一性は良いものの形状がブロ
ードとなり、再生出力は逆に低下し好ましくない状態と
なる。Rt/Raが20を越えると突起高さ分布が不均一とな
り、やはり再生時の出力は低下してしまい好ましくない
ものとなる。Ra及びRt/Raの値は含有する粒子の平均粒
径、粒度分布、含有量にて概ね決定されるが、これら以
外にベースフイルムの製造条件、即ち二軸延伸法にて作
成されるポリエステルフイルムの延伸条件によっても変
えうる。何れにしても本発明の要件を満たすものであれ
ばその手法は限定されるものではない。
Further, as a requirement of the present invention, the surface roughness (average roughness Ra) of the base film is in the range of 0.003 to 0.015 μm, and the ratio (Rt / Ra) of the maximum protrusion height (Rt) to the average roughness is 5 to 5. It is important that the number is 20 and the number of torn protrusions on the surface of the base film is 20 / mm 2 or less. When Ra is less than 0.003 μm, handling workability and wear resistance are insufficient, and when Ra exceeds 0.015 μm, reproduction output as a medium for high density recording cannot be sufficiently obtained, which is not preferable. Also, Rt / Ra is a measure of the uniformity of the height of the protrusions. The smaller this value, the better the uniformity.
If it is less than the above range, the shape of the protrusions is good, but the shape is broad, and the reproduction output is decreased, which is not preferable. When Rt / Ra exceeds 20, the projection height distribution becomes non-uniform, and the output during reproduction also decreases, which is not preferable. The values of Ra and Rt / Ra are generally determined by the average particle size of the contained particles, the particle size distribution, and the content, but in addition to these, the manufacturing conditions of the base film, that is, the polyester film prepared by the biaxial stretching method. It can be changed depending on the stretching conditions. In any case, the method is not limited as long as it satisfies the requirements of the present invention.

一方、ベースフイルム表面の破れ突起数は粒子とベース
フイルムの親和性の指標となるものであるが、この値が
大なる程親和性に劣ることを示す。本発明においては該
表面破れ突起数が20個/mm2以下であることが必要であ
る。破れ突起数が20個/mm2を越えるとカレンダー工程で
のカレンダーロール汚れが多くなり再生出力が低下する
し、又、ドロップアウトも増加するようになり好ましく
ない。
On the other hand, the number of torn protrusions on the surface of the base film is an index of the affinity between the particles and the base film, and the larger this value is, the poorer the affinity is. In the present invention, it is necessary that the number of surface breaking protrusions is 20 / mm 2 or less. If the number of tear projections exceeds 20 pieces / mm 2 , the amount of stains on the calender roll in the calendering process increases, the reproduction output decreases, and the dropout increases, which is not preferable.

本発明に於けるシリカ粒子のベースフイルムであるポリ
エステル中への添加方法はポリエステル重縮合開始前、
重縮合中、重縮合後何れでも良いが特に好ましくは重縮
合前及び重縮合反応初期である。
The method for adding the silica particles in the present invention into the polyester, which is the base film, is as follows:
It may be during polycondensation or after polycondensation, but particularly preferably before polycondensation and at the beginning of polycondensation reaction.

尚、重縮合反応触媒としては通常アンチモン化合物、G
e,Ti,Su及びSi化合物の一種以上が使用される。
The polycondensation reaction catalyst is usually an antimony compound, G
One or more of e, Ti, Su and Si compounds are used.

以上詳述した如く、本発明は特に高密度記録の要求され
る磁気記録媒体として、再生出力が高く、出力変動の少
ない、優れた電磁変換特性及び塗布工程、カレンダー処
理工程等に於いて優れた取扱い作業性、耐摩耗性を得る
という目的を、ベースフイルムであるポリエステルフイ
ルム中に特定の製法で作成したシリカ粒子を含有せし
め、且つフイルム表面の粗さ、破れ突起数を特定の範囲
にすることにより成し遂げたものであって本発明の工業
的意義は大である。
As described in detail above, the present invention is particularly excellent as a magnetic recording medium for which high density recording is required, with high reproduction output and little output fluctuation, excellent electromagnetic conversion characteristics, coating process, calendering process and the like. The purpose of obtaining handling workability and abrasion resistance is to make the polyester film, which is the base film, contain silica particles produced by a specific manufacturing method, and to set the roughness of the film surface and the number of torn projections within a specific range. The present invention has been accomplished by the above, and the industrial significance of the present invention is great.

〔実施例〕〔Example〕

以下本発明を実施例により更に詳細に説明するが、本発
明はその要旨を越えない限り以下の実施例に限定される
ものではない。尚、本発明の諸物性、特性の測定は以下
の方法によって行なったものであり、実施例中の部又は
%は各々重量部、重量%を意味する。
Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist thereof is not exceeded. The physical properties and characteristics of the present invention were measured by the following methods, and parts or% in the examples mean parts by weight and% by weight, respectively.

(1) シリカ粒子の平均粒径及び粒径分布 粒子を電子顕微鏡にて撮影し、写真法で測定する。粒子
約1000個の粒径を測定し、各々の粒径を体積換算し積算
する。積算体積分率50%の所を平均粒径とし、粒径分布
は大粒子側からの積算体積分率10%、90%の所の粒径比
をもって表わす。
(1) Average particle size and particle size distribution of silica particles The particles are photographed with an electron microscope and measured by a photographic method. The particle size of about 1000 particles is measured, and each particle size is converted into volume and integrated. The average particle size is defined at the cumulative volume fraction of 50%, and the particle size distribution is expressed as the particle size ratio at the cumulative volume fractions of 10% and 90% from the large particle side.

(2) 表面粗さの測定 中心線平均粗さRa(μm)をもって表面粗さとする。(2) Measurement of surface roughness The center line average roughness Ra (μm) is defined as the surface roughness.

小坂研究所社製表面粗さ測定器(SE−3FK)によって、
次のようにして求めた。即ちフイルム断面曲線からその
中心線の方向に基準長さL(2.5mm)の部分を抜き取
り、この抜き取り部分の中心線をX線、縦倍率の方向を
Y軸として粗さ曲線Y=f(x)で表わした時、次の式
で与えられた値をμ(ミクロン)で表わす。但し触針の
先端半径は2(μm)、荷重は30mgとし、カットオフ値
は80μである。Raは縦方向に5点、横方向に5点の計10
点の平均値を求めた。
By the surface roughness measuring instrument (SE-3FK) manufactured by Kosaka Laboratory,
I asked for it as follows. That is, a portion having a reference length L (2.5 mm) is extracted from the film cross-section curve in the direction of the center line, the center line of the extracted portion is the X-ray, and the longitudinal magnification direction is the Y-axis, and the roughness curve Y = f (x ), The value given by the following equation is expressed in μ (micron). However, the tip radius of the stylus is 2 (μm), the load is 30 mg, and the cutoff value is 80 μ. Ra is 5 points in the vertical direction and 5 points in the horizontal direction, for a total of 10 points.
The average value of the points was calculated.

(3) 最大突起高さ(Rt)の測定 前項(2)の表面粗さで得た断面曲線の最大値と最小値
の差をもって表わす、測定点数はRa同様10点の平均値を
求め最大突起高さ(Rt)とした。
(3) Measurement of maximum protrusion height (Rt) Expressed by the difference between the maximum and minimum values of the cross-sectional curve obtained with the surface roughness of the previous item (2), the number of measurement points is the same as Ra, and the average value of 10 points is calculated. Height (Rt).

(4) 破れ突起数の測定 フイルム表面にAl蒸着を施こし、走査型電子顕微鏡に
て、2000倍の倍率で観察し、突起の先端が消失し陥没状
となった個数を1mm2に亘り測定する。
(4) Measurement of the number of torn protrusions The surface of the film was vapor-deposited with Al and observed with a scanning electron microscope at a magnification of 2000 times, and the number of protrusions disappeared and recessed was measured over 1 mm 2. To do.

(5) 取扱い作業性の評価 取扱い作業性は以下に示す動摩擦係数〔μd〕と良い相
関性を示し、〔μd〕値が高い程取扱い作業性は悪い。
(5) Evaluation of handling workability The handling workability shows a good correlation with the dynamic friction coefficient [μd] shown below, and the higher the [μd] value, the worse the handling workability.

第1図に示す走行系でフイルムを走行させ、第1図−
(I)の6mmφのSUS420−J2固定ピンにおける動摩擦係
数μdを測定する(温度23℃±2℃、湿度50%±10%R
H)。尚、フイルムの走行速度を1.0〜2m/分とし、θは1
35゜とした。
The film is run by the running system shown in FIG.
Measure the dynamic friction coefficient μd of (I) 6mmφ SUS420-J2 fixed pin (Temperature 23 ℃ ± 2 ℃, Humidity 50% ± 10% R
H). The traveling speed of the film is 1.0 to 2 m / min, and θ is 1
It was set to 35 °.

(6) カレンダー汚れの評価 ベースフイルムの接触するロール面の汚れ度を5段のミ
ニスーパーカレンダーを使って評価した。カレンダーロ
ールは鏡面仕上げの金属ロールとポリエステル系複合樹
脂ロールとから構成されている5段のカレンダーであ
る。各ロールの温度を85℃、線圧は250kg/cm、走行速度
を80m/分の条件にて行ない、磁気テープ10000mを走行さ
せ、樹脂ロールに付着する白粉量を目視で判定し下記の
3ランクに分け汚れの評価を行なった。
(6) Evaluation of Calendar Fouling The degree of fouling on the roll surface of the base film in contact with the base film was evaluated using a 5-stage mini super calendar. The calendar roll is a five-stage calendar composed of a mirror-finished metal roll and a polyester-based composite resin roll. The temperature of each roll is 85 ° C, the linear pressure is 250 kg / cm, the running speed is 80 m / min, the magnetic tape is run 10,000 m, and the amount of white powder adhering to the resin roll is visually judged and the following three ranks are given. The stain was evaluated by dividing into

○……樹脂ロールに白粉の付着は殆んど見られない。○: Almost no white powder adhered to the resin roll.

△……極くわずか白粉の付着が見られる。△: Very little white powder adhered.

X……明らかに白粉付着が見られる。X: Adhesion of white powder is clearly seen.

(7) 磁気テープ特性 松下電器(株)製NV−3700型ビデオデッキを用い下記の
要領で測定した。
(7) Magnetic tape characteristics It was measured in the following manner using an NV-3700 type video deck manufactured by Matsushita Electric Industrial Co., Ltd.

・VTRヘッド出力;シンクロスコープにより測定周波数
4メガヘルツに於けるVTRヘッド出力を測定し第1表実
施例−2のサンプルを0.0デシベル(dB)とし、その相
対値をデシベル(dB)表示した。
VTR head output: The VTR head output at a measurement frequency of 4 MHz was measured with a synchroscope, the sample of Example 2 in Table 1 was set to 0.0 decibel (dB), and its relative value was displayed in decibel (dB).

・ドロップアウト数;4.4メガヘルツの信号を記録したビ
デオテープを再生し、大倉インダストリー(株)製ドロ
ップアウトカウンターにて15μsec−20dBにおけるドロ
ップアウト数を約20分間測定し、1分間当りのドロップ
アウト数(ケ/分)に換算した。
・ Number of dropouts: A videotape recording a signal of 4.4 MHz was played back, and the number of dropouts at 15 μsec-20 dB was measured for about 20 minutes with a dropout counter manufactured by Okura Industry Co., Ltd., and the number of dropouts per minute It was converted to (ke / min).

実施例−1 (シリカ粒子の合成) テトラメチルシラン30.4gを400gのメタノールに溶解し2
0℃に保持した(A液)。一方、メタノール900gに水110
gを加え28%アンモニア水溶液243gを加え混合し、20℃
に保持した(B液)。次いでB液に撹拌装置を取り付
け、撹拌しながらA液を添加した。添加後直ちに加水分
解反応、縮合反応が起こり反応系内が白濁した。A液を
添加後更に2時間撹拌保持した後、エチレングリコール
103gを加え減圧下、加熱して過剰の水、メタノール、ア
ンモニアを留去せしめて、10%濃度の球状シリカ微粒子
を含有するエチレングリコールスラリーを得た。該エチ
レングリコールスラリーを乾燥後、電子顕微鏡法により
平均粒径、粒度分布(d10/d90)を求めた。平均粒径は
0.27μm、粒度分布(d10/d90)は1.5であり、極めて粒
径の揃った球形の粒子であった。該スラリーを3μカッ
トの過精度を有するフイルターを用いて過処理を行
なったがフイルターの通過性は非常に良好であった。
Example-1 (Synthesis of silica particles) Tetramethylsilane (30.4 g) was dissolved in 400 g of methanol to obtain 2
The temperature was maintained at 0 ° C (solution A). Meanwhile, 900 g of methanol and 110 parts of water
g, add 243 g of 28% aqueous ammonia solution, mix, and 20 ° C
(B liquid). Next, a stirring device was attached to the liquid B, and the liquid A was added while stirring. Immediately after the addition, a hydrolysis reaction and a condensation reaction occurred and the inside of the reaction system became cloudy. After adding Solution A and stirring for 2 hours, ethylene glycol
103 g was added and the mixture was heated under reduced pressure to distill off excess water, methanol and ammonia to obtain an ethylene glycol slurry containing 10% concentration of spherical silica fine particles. After drying the ethylene glycol slurry, the average particle size and particle size distribution (d10 / d90) were determined by electron microscopy. The average particle size is
The particle size was 0.27 μm and the particle size distribution (d10 / d90) was 1.5, and the particles were spherical particles having an extremely uniform particle size. The slurry was overtreated using a filter having an overprecision of 3 μ cut, but the filter passability was very good.

(ポリエステルの製造) ジメチルテレフタレート100部とエチレングリコール60
部及び酢酸マグネシウム四水塩0.09部を反応器にとり、
加熱昇温するとともにメタノールを留去し、エステル交
換反応を行ない、反応開始から4時間を要して230℃に
昇温し、実質的にエステル交換反応を終了した。
(Production of polyester) 100 parts of dimethyl terephthalate and 60 of ethylene glycol
Parts and 0.09 parts of magnesium acetate tetrahydrate in a reactor,
The temperature was increased by heating and the methanol was distilled off to carry out the transesterification reaction. It took 4 hours from the start of the reaction to raise the temperature to 230 ° C. to substantially end the transesterification reaction.

次いで、前述で得た平均粒径0.27μmのシリカ粒子含有
スラリー15部を添加し、更にエチルアシッドフオスフエ
ート0.04部、三酸化アンチモン0.04部を加えて4時間重
縮合反応を行ないポリエチレンテレフタレート樹脂を得
た。
Then, 15 parts of the silica particle-containing slurry having an average particle size of 0.27 μm obtained above was added, and 0.04 part of ethyl acid phosphate and 0.04 part of antimony trioxide were further added to carry out a polycondensation reaction for 4 hours to obtain a polyethylene terephthalate resin. Obtained.

(二軸延伸フイルムの製造) 上述で得たポリエステル樹脂を180℃で窒素雰囲気下加
熱乾燥後、押出機にてシート状に溶融里出しし、静電印
加冷却法にて200μmの無定形シートを作成した。次い
でこの無定形シートを多段縦延伸機にて3.7倍縦延伸し
た後、ステンターにて4.0倍横延伸し、更に200℃以上の
温度域で熱固定を行ない厚さ14μmの二軸延伸フイルム
を得た。
(Production of biaxially stretched film) After heating and drying the polyester resin obtained above at 180 ° C in a nitrogen atmosphere, it is melted and extruded in a sheet form by an extruder, and an amorphous sheet of 200 µm is formed by electrostatic cooling. Created. Next, this amorphous sheet was longitudinally stretched 3.7 times with a multi-stage longitudinal stretching machine, then laterally stretched 4.0 times with a stenter, and heat-set at a temperature range of 200 ° C or higher to obtain a biaxially stretched film with a thickness of 14 μm. It was

(磁気記録テープの作成) 強磁性合金微粉末(Fe−Co−B)200部、ポリウレタン
樹脂30部、ニトロセルロース10部、塩酢ビ共重合体10
部、レシチン5部、シクロヘキサノン100部、メチルイ
ソブチルケトン100部及びメチルエチルケトン300部をボ
ールミルにて48時間混合分散後ポリイソシアネート化合
物5部を加えて磁性塗料とし、これを前記二軸延伸フイ
ルムに塗布した後、塗料が充分乾燥固化する前に磁気配
向させその後乾燥した。更にこの塗布フイルムをスーパ
ーカレンダーにて表面処理を施こし、1/2インチ幅にス
リットしてビデオテープとした。
(Preparation of magnetic recording tape) 200 parts of ferromagnetic alloy fine powder (Fe-Co-B), 30 parts of polyurethane resin, 10 parts of nitrocellulose, 10 parts vinyl chloride copolymer
Parts, lecithin 5 parts, cyclohexanone 100 parts, methyl isobutyl ketone 100 parts and methyl ethyl ketone 300 parts were mixed and dispersed in a ball mill for 48 hours, and then 5 parts of a polyisocyanate compound was added to form a magnetic paint, which was applied to the biaxially stretched film. After that, the paint was magnetically oriented before being sufficiently dried and solidified, and then dried. Further, this coated film was surface-treated with a super calendar and slit into a 1/2 inch width to obtain a video tape.

以上のようにして得た、ベースフイルム及び磁気記録テ
ープの特性を第1表に示す。該ベースフイルムはRa、Rt
/Ra及び破れ突起数共、本発明の要件を満たし、磁気テ
ープとしての電磁変換特性及び、塗布工程、カレンダー
工程等での取扱い作業性、耐摩耗性に優れ、良好なもの
であった。
Table 1 shows the characteristics of the base film and the magnetic recording tape obtained as described above. The base film is Ra, Rt
Both / Ra and the number of broken projections satisfied the requirements of the present invention, and were excellent in electromagnetic conversion characteristics as a magnetic tape, handling workability in a coating process, a calendar process and the like, and abrasion resistance.

実施例2〜4 実施例−1に於いてシリカ粒子の製法を若干変更し、第
1表に掲げる平均粒径のものを作成し、これを用いた以
外実施例−1と全く同様にして磁気記録テープを得た。
該テープの特性を第1表に示す。実施例2〜4の磁気記
録テープの特性は何れも良好であった。
Examples 2 to 4 In the same manner as in Example-1, except that the production method of the silica particles in Example-1 was slightly changed, and those having the average particle size listed in Table 1 were prepared. I got a recording tape.
The characteristics of the tape are shown in Table 1. The characteristics of the magnetic recording tapes of Examples 2 to 4 were all good.

実施例−5 実施例−1に於いてジメチルテレフタレートをジメチル
ナフタレンに変え常法にてポリエチレンテレフタレート
樹脂を得、該樹脂を常法にて厚さ14μmの二軸延伸フイ
ルムを作成し、更に実施例−1と同様にして磁気記録テ
ープを得た。得られたテープの特性を第1表に示す。該
テープの取扱い作業性、耐摩耗性、電磁変換特性、何れ
も実施例−1で得た磁気記録テープと変わりなく良好な
ものであった。
Example-5 In Example-1, the dimethyl terephthalate was changed to dimethyl naphthalene to obtain a polyethylene terephthalate resin by a conventional method, and a biaxially stretched film having a thickness of 14 μm was prepared from the resin by a conventional method. A magnetic recording tape was obtained in the same manner as in -1. The characteristics of the obtained tape are shown in Table 1. The handling workability, abrasion resistance, and electromagnetic conversion characteristics of the tape were all the same as those of the magnetic recording tape obtained in Example-1.

比較例−1,2 実施例1〜4に於いてベースフイルムに含有するシリカ
粒子の平均粒径、及び含有量を第1表に記載したように
変更した以外全く同様にして磁気記録テープを得た。該
テープの特性を第1表に示す。
Comparative Examples-1 and 2 Magnetic recording tapes were obtained in the same manner as in Examples 1 to 4 except that the average particle size and the content of silica particles contained in the base film were changed as shown in Table 1. It was The characteristics of the tape are shown in Table 1.

比較例−1は含有するシリカ粒子の平均粒径が本発明の
範囲の上限を越えた場合の例であるが、取扱い作業性、
耐摩耗性は優れるものの、再生出力が低下し、又ドロッ
プアウトも多く満足のゆくものでなかった。
Comparative Example-1 is an example in which the average particle size of the silica particles contained exceeds the upper limit of the range of the present invention, but the handling workability,
Although the abrasion resistance was excellent, the reproduction output was reduced and the dropout was large, which was not satisfactory.

一方比較例−2は平均粒径が下限以下となり、同時に含
有量が上限を越えた例である。該テープはシリカ粒子の
凝集が見られ、ベースフイルムの突起高さが不均一とな
り、粗大突起も多いものであった。その影響がテープの
出力低下、ドロップアウトの増加に現われ好ましくない
ものであった。
On the other hand, Comparative Example-2 is an example in which the average particle size is below the lower limit and at the same time the content exceeds the upper limit. In the tape, agglomeration of silica particles was observed, the projection height of the base film was non-uniform, and there were many coarse projections. The effect was unfavorable because the output of the tape decreased and the dropout increased.

比較例−3、4 ポリエステル中の不活性粒子をCaCO3、TiO2にした以外
は実施例−1と同様にして磁気記録テープを得た。該テ
ープはカレンダーロールでの白粉発生量が多く見られ、
白粉による形状転写の影響と思われるが、出力の低下、
ドロップアウト数の増加が見られ好ましくないものであ
った。
Except that the inert particles in the comparative example 3,4 polyester was CaCO 3, TiO 2 was obtained a magnetic recording tape in the same manner as in Example -1. The tape shows a large amount of white powder generated on the calendar roll,
It seems to be the influence of the shape transfer due to white powder, but the output decreases,
The number of dropouts increased, which was not desirable.

比較例−5 実施例−5に於いてベースフイルム中に含有する不活性
粒子をCaCO3に変更した以外は全く同様にして磁気記録
テープを得た。該テープは比較例3、4と同様、出力低
下、ドロップアウト数増加が見られ好ましくないもので
あった。
To obtain a magnetic recording tape inert particles In Comparative Example -5 Example -5 contained in the base film in the same manner except for changing the CaCO 3. Similar to Comparative Examples 3 and 4, the tape was unfavorable because the output decreased and the number of dropouts increased.

〔発明の効果〕 以上説明した本発明によれば、フイルム化工程、磁性層
塗布工程での取扱い作業性に優れ、しかも、再生出力が
高くドロップアウトの少なくく、とりわけ、磁気テープ
化工程で生じる摩耗粉の発生が極めて少ない磁気記録媒
体が提供される。
[Effects of the Invention] According to the present invention described above, the handling workability in the film forming process and the magnetic layer coating process is excellent, the reproduction output is high and the dropout is small, and particularly, it occurs in the magnetic tape forming process. Provided is a magnetic recording medium in which generation of abrasion powder is extremely small.

【図面の簡単な説明】[Brief description of drawings]

第1図は摩擦係数を評価する走行系を示す図であり、
(I)は固定ピン、(II)は入り口テンシヨンメータ
ー、(III)は出口テンシヨンメーターを示し、θは135
゜である。
FIG. 1 is a diagram showing a traveling system for evaluating a friction coefficient,
(I) shows a fixed pin, (II) shows an entrance tension meter, (III) shows an exit tension meter, and θ is 135.
It is ゜.

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】アルコキシシランの加水分解反応及び縮合
反応により得られる平均粒径0.01〜3μmの実質的に非
晶質の球状シリカ粒子を0.001〜5wt%含有してなり、表
面平均粗さRa及び最大突起高さRtとRaとの比が下記式
(1)及び(2)を満足し、且つ表面破れ突起数が20個
/mm2以下である配向ポリエステルフイルムの片面に磁性
層を設けてなることを特徴とする磁気記録媒体。 0.003≦Ra≦0.015 ……(1) 5≦Rt/Ra≦20 ……(2)
1. A substantially amorphous spherical silica particle having an average particle size of 0.01 to 3 μm obtained by a hydrolysis reaction and a condensation reaction of an alkoxysilane is contained in an amount of 0.001 to 5 wt%, and the surface average roughness Ra and The ratio of maximum protrusion height Rt to Ra satisfies the following formulas (1) and (2), and the number of surface break protrusions is 20
A magnetic recording medium comprising a oriented polyester film having a thickness of / mm 2 or less and a magnetic layer provided on one side thereof. 0.003 ≦ Ra ≦ 0.015 …… (1) 5 ≦ Rt / Ra ≦ 20 …… (2)
JP62152222A 1986-08-29 1987-06-18 Magnetic recording medium Expired - Lifetime JPH0770042B2 (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
JP62152222A JPH0770042B2 (en) 1987-06-18 1987-06-18 Magnetic recording medium
KR1019870006750A KR960006092B1 (en) 1986-08-29 1987-07-01 Polyester films, magnetic recording media & film capacitors produced therefrom
ES87112252T ES2056802T3 (en) 1986-08-29 1987-08-24 POLYESTER COMPOSITIONS, PROCEDURE FOR PREPARING THEM, POLYESTER FILMS, POLYESTER FILMS FOR MAGNETIC RECORDING MEDIA AND FILMS FOR CAPACITORS PRODUCED FROM THEM.
AT87112252T ATE109493T1 (en) 1986-08-29 1987-08-24 POLYESTER COMPOSITIONS, PROCESS FOR THEIR PREPARATION, POLYESTER FILMS, POLYESTER FILMS FOR MAGNETIC TAPE AND FILMS THEREOF FOR CAPACITORS.
DE3750319T DE3750319T2 (en) 1986-08-29 1987-08-24 Polyester compositions, processes for their production, polyester films, polyester films for magnetic tapes and films made therefrom for capacitors.
EP87112252A EP0257611B1 (en) 1986-08-29 1987-08-24 Polyester compositions, process for preparing the same, polyester films, polyester films for magnetic recording media and films for capacitors produced therefrom
US07/420,740 US4990400A (en) 1987-02-12 1989-10-12 Polyester films, magnetic recording media and film capacitors produced therefrom
US07/420,474 US5106681A (en) 1987-02-12 1989-10-12 Polyester films, magnetic recording media and film capacitors produced therefrom

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62152222A JPH0770042B2 (en) 1987-06-18 1987-06-18 Magnetic recording medium

Publications (2)

Publication Number Publication Date
JPS63316316A JPS63316316A (en) 1988-12-23
JPH0770042B2 true JPH0770042B2 (en) 1995-07-31

Family

ID=15535753

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62152222A Expired - Lifetime JPH0770042B2 (en) 1986-08-29 1987-06-18 Magnetic recording medium

Country Status (1)

Country Link
JP (1) JPH0770042B2 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH089671B2 (en) * 1987-10-08 1996-01-31 東レ株式会社 Polyester film
JP7319816B2 (en) * 2019-04-24 2023-08-02 旭化成株式会社 molding

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0677308B2 (en) * 1984-06-19 1994-09-28 東レ株式会社 Polyester film for magnetic recording media

Also Published As

Publication number Publication date
JPS63316316A (en) 1988-12-23

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