JPS6354012B2 - - Google Patents
Info
- Publication number
- JPS6354012B2 JPS6354012B2 JP58007641A JP764183A JPS6354012B2 JP S6354012 B2 JPS6354012 B2 JP S6354012B2 JP 58007641 A JP58007641 A JP 58007641A JP 764183 A JP764183 A JP 764183A JP S6354012 B2 JPS6354012 B2 JP S6354012B2
- Authority
- JP
- Japan
- Prior art keywords
- particles
- particle size
- average particle
- barium sulfate
- film
- 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
Links
- 239000002245 particle Substances 0.000 claims description 88
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 claims description 34
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 claims description 28
- 229910000019 calcium carbonate Inorganic materials 0.000 claims description 14
- 229920006267 polyester film Polymers 0.000 claims description 13
- 229920000728 polyester Polymers 0.000 claims description 12
- LLLVZDVNHNWSDS-UHFFFAOYSA-N 4-methylidene-3,5-dioxabicyclo[5.2.2]undeca-1(9),7,10-triene-2,6-dione Chemical group C1(C2=CC=C(C(=O)OC(=C)O1)C=C2)=O LLLVZDVNHNWSDS-UHFFFAOYSA-N 0.000 claims description 3
- 238000005299 abrasion Methods 0.000 description 14
- 239000011362 coarse particle Substances 0.000 description 11
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 6
- 238000000034 method Methods 0.000 description 5
- 239000002002 slurry Substances 0.000 description 5
- -1 polyethylene terephthalate Polymers 0.000 description 4
- 229920000139 polyethylene terephthalate Polymers 0.000 description 4
- 239000005020 polyethylene terephthalate Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000010954 inorganic particle Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000005995 Aluminium silicate Substances 0.000 description 1
- 229910021532 Calcite Inorganic materials 0.000 description 1
- 235000019738 Limestone Nutrition 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 238000000576 coating method Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000006059 cover glass Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 150000001991 dicarboxylic acids Chemical class 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 150000002334 glycols Chemical class 0.000 description 1
- 238000010191 image analysis Methods 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 239000006028 limestone Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000012798 spherical particle Substances 0.000 description 1
- 239000004753 textile Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
- 230000037303 wrinkles Effects 0.000 description 1
Landscapes
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
Description
本発明は、滑り性および耐摩耗性に優れた配向
ポリエステルフイルムに関する。
一般にポリエチレンテレフタレートに代表され
るごときポリエステルは、その優れた物理的およ
び化学的諸特性の故に、繊維用、成型品用の他、
磁気テープ用、写真用、コンデンサー用、包装用
などのフイルム用としても多種の用途で広く用い
られている。これらフイルム用として用いられる
場合、その滑り性および耐摩耗特性はフイルムの
製造工程および各用途における加工工程の作業性
の良否、さらにはその製品品質の良否を左右する
大きな要因となつている。特に、ポリエステルフ
イルム表面に磁性層を塗布し磁気テープとして用
いる場合には、磁性層塗布時におけるコーテイン
グロールとフイルム表面との摩擦および摩耗が極
めて激しく、フイルム表面へのしわおよび擦り傷
が発生しやすい。また磁性層塗布後のフイルムを
スリツトしてオーデイオ、ビデオまたはコンピユ
ーター用テープ等に加工した後でも、リールやカ
セツト等からの引き出し巻き上げその他の操作の
際に、多くのガイド部、再生ヘツド等との間に摩
擦および摩耗が著しく生じ、擦り傷、歪の発生さ
らにはポリエステルフイルム表面の削れ等による
白粉状物質を析出させる結果、磁気記録信号の欠
落、即ちドロツプアウトの大きな原因となること
が多い。一般にフイルムの滑り性および耐摩耗性
の改良には、フイルム表面に凹凸を付与すること
によりガイドロール等との間の接触面積を減少せ
しめる方法が採用されており、フイルム原料に用
いる高分子の触媒残渣から不溶性の粒子を析出せ
しめる方法や、不活性の無機粒子を添加せしめる
方法等が用いられている。これら原料高分子中の
粒子は、その大きさが大きい程、滑り性の改良効
果が大であるのが一般的であるが、磁気テープ、
特にビデオ用のごとき精密用途にはその粒子が大
きいこと自体がドロツプアウト等の欠点発生の原
因ともなり得るため、フイルム表面の凹凸は出来
るだけ微細である必要があり、相反する特性を同
時に満足すべき要求がなされているのが現状であ
る。本発明者らは、特に近年磁気記録の高密度化
が一段と促進され、テープ用ベースフイルムの滑
り性および耐摩耗性の改良がより要求されつつあ
る状況下に鑑み、鋭意検討の結果、本発明に到達
したものである。
即ち本発明は、主たる繰り返し単位がエチレン
テレフタレートからなるポリエステル中に、平均
粒径が0.01μｍ以上1.2μｍ未満で体積形状係数が
0.08〜0.25である硫酸バリウム粒子を0.01〜1.0重
量％、および平均粒径が0.5〜5.0μｍかつ前記硫
酸バリウム粒子より大で体積形状係数が0.08〜
0.40である炭酸カルシウム粒子を0.005〜0.1重量
％を含有してなる配向ポリエステルフイルムであ
る。
〔ただし、体積形状係数ｆは次式で表わされる。
ｆ＝ｖ／D3
式中ｖは粒子体積（μm3）、Ｄは粒子の投影面
における最大径（μｍ）を示す。〕
本発明の配向ポリエステルフイルムは良好な滑
り性および耐摩耗性を有し、擦り傷および白粉発
生量が著しく少ない。
本発明における配向ポリエステルフイルムの特
徴は、２種類の特定成分粒子の特定粒径および体
積形状係数を有する粒子を特定量ずつ併用する点
にある。即ち特定粒径および体積形状係数を有す
る硫酸バリウム粒子の特定量と、特定粒径および
体積形状係数を有する炭酸カルシウム粒子の特定
量とがフイルム中に共存する場合においてのみ、
それぞれの粒子の単独使用や他の粒子類の添加に
よつては到底達し得ない優れた効果を発揮し得る
事実を見出したものである。
本発明において配向ポリエステルフイルムを構
成するポリエステルは、主たる繰り返し単位の80
モル％以上がエチレンテレフタレートからなるポ
リエステルであり、他の構成成分としてはこれと
共重合し得るジカルボン酸類、グリコール類、オ
キシカルボン酸類等の成分を20モル％未満共重合
させたものでもよい。なお配向フイルムとして
は、二軸配向フイルムが特に好適である。
本発明において、添加すべき不活性無機粒子の
第１成分である硫酸バリウム粒子の平均粒径は
0.01μｍ以上1.2μｍ未満である必要があり、0.1μｍ
以上1.2μｍ未満がより好ましく、0.2〜1.0μｍが特
に好ましい。また添加量は、該ポリエステルに対
し0.01〜1.0重量％とする必要があり、0.1〜0.6重
量％がより好ましい。第２成分である炭酸カルシ
ウム粒子の平均粒径は0.5〜5.0μｍの範囲が必要
であり、0.5〜1.5μｍがより好ましく、かつ第１
成分である硫酸バリウム粒子の平均粒径より大で
あることが必要である。添加量は該ポリエステル
に対し0.005〜0.1重量％とする必要があり、0.03
〜0.1重量％がより好ましい。
第１成分である硫酸バリウム粒子および第２成
分である炭酸カルシウム粒子のそれぞれがこれら
の適正範囲を逸脱する場合には、本発明の目的と
する良好な滑り性および耐摩耗性付与による擦り
傷発生防止効果を発揮し得ないか、または粒子自
体によるドロツプアウト発生の原因となる粗大粒
子混入を防ぎ得ない結果となる。
硫酸バリウム粒子と炭酸カルシウム粒子との添
加量の関係は、先に規定した条件を満足する範囲
であれば良いが、小粒径である硫酸バリウム粒子
の添加量が、大粒径である炭酸カルシウム粒子の
添加量より多い方がより好ましい結果を得ること
が出来る。
なお、ここに言う平均粒径とは、ストークスの
式に基づいて算出された等価球形粒度分布の積算
50％点における径をさす。
次に、本発明の粒子組成が好ましい理由につい
て述べる。
磁気テープベース用ポリエステルフイルムの滑
り性および耐摩耗性を改良する目的で、ポリエス
テル中に不活性粒子を添加する方法については従
来より多くの提案がなされて来ているが、近年の
高度化された要求を充分に満足し得るには至つて
いない。そこで本発明者らは、滑り性および耐摩
耗性の改良について多種にわたる粒子類の特性値
（粒径、形状および硬度）と添加量およびフイル
ム特性値との関係を詳細に検討した結果、粒子形
状としては球状または立方体状に近く異方性の少
ない粒子が好ましく、また平均粒径としては0.01
〜1.5μｍの小粒径と、0.5〜5.0μｍの範囲でかつ前
記粒子よりも大である大粒径の２種の粒子が共存
する状態が最も好ましいことを見出した。
これらの条件に適するものとしては、形状、硬
度等の点で体積形状係数0.08〜0.40の炭酸カルシ
ウム粒子、特にカルサイト結晶を主とする重質炭
酸カルシウム粒子が最も好ましいことが判明し
た。しかしこの重質炭酸カルシウムは石灰石を機
械的に粉砕することによつて得るという製法的理
由から、その平均粒径は0.5μｍが下限であり、必
要な２種の粒子のうち大粒径に相当するものしか
得られないという問題がある。
次に形状、硬度等の点で目的に適する粒子とし
ては、体積形状係数0.08〜0.25の硫酸バリウム粒
子が挙げられる。硫酸バリウム粒子は適当な分級
処理またはグレードの選択により、0.01μｍ以上
1.2μｍ未満程度の小粒径を得ることが可能であ
る。
以上の様な理由から滑り性および耐摩耗性が良
好なポリエステルフイルム用不活性粒子として
は、小粒径成分として体積形状係数0.08〜0.25の
硫酸バリウム、大粒径成分として体積形状係数
0.08〜0.40の炭酸カルシウムを本発明の粒子組成
のごとく併用することが最も好ましい。
本発明における不活性粒子のポリエステル中へ
の添加方法は、該ポリエステル製造過程における
任意の段階でスラリー状および粉末状いずれの状
態で添加しても良いが、粒子の飛散防止、均一性
向上の点からポリエステル構成成分の一種である
エチレングリコール中にスラリー状として分散さ
せて所定量添加する方法が望ましい。またスラリ
ー状に分散させる場合には、不活性粒子本来の一
次粒径を出来得る限り再現し、粗大凝集粒子の存
在を避けるように留意することが重要である。
特に10μｍ以上の粗大粒子の存在は、磁気テー
プとした場合のドロツプアウトの原因となるた
め、分級、分離等適当な手段をこうじて除去する
必要がある。
なお平均粒径測定は、島津製作所製遠心沈降式
粒度分布測定器によつて得た等価球径分布におけ
る積算50％点の値を採用した。またフイルム滑り
性および耐摩耗性の評価は、フイルムを細幅にス
リツトしたテープ状ロールを金属製ガイドロール
にこすりつけて高速、長時間走行させるとき、一
定の供給張力に対してガイドロール擦過後のテー
プ張力の大小およびガイドロール表面に発生する
白粉量の多少をそれぞれ５段階に評価し、次のラ
ンク付けで表わした。
The present invention relates to an oriented polyester film with excellent slip properties and abrasion resistance. In general, polyesters such as polyethylene terephthalate are used for textiles, molded products, and other applications due to their excellent physical and chemical properties.
It is also widely used in a variety of applications, including films for magnetic tape, photography, capacitors, and packaging. When used for these films, the slipperiness and abrasion resistance properties are major factors that determine the workability of the film manufacturing process and processing process in each application, as well as the quality of the product. In particular, when a magnetic layer is applied to the surface of a polyester film and used as a magnetic tape, the friction and abrasion between the coating roll and the film surface during application of the magnetic layer is extremely severe, and wrinkles and scratches are likely to occur on the film surface. Furthermore, even after the film coated with the magnetic layer is slit and processed into audio, video, or computer tapes, there are many guide parts, playback heads, etc. when pulling it out from a reel or cassette, winding it up, or performing other operations. Significant friction and wear occur between the two, causing scratches and distortion, as well as depositing white powdery substances due to scratches on the surface of the polyester film, which is often a major cause of missing magnetic recording signals, that is, dropouts. Generally, to improve the slipperiness and abrasion resistance of films, a method is adopted in which the surface of the film is made uneven to reduce the contact area with guide rolls, etc. A method of precipitating insoluble particles from the residue, a method of adding inert inorganic particles, etc. are used. Generally speaking, the larger the size of the particles in these raw polymers, the greater the effect of improving slipperiness.
Especially for precision applications such as video, the large particles themselves can cause defects such as dropouts, so the unevenness on the film surface must be as fine as possible, and contradictory characteristics must be satisfied at the same time. The current situation is that demands are being made. The inventors of the present invention have developed the present invention as a result of extensive studies, especially in view of the fact that the density of magnetic recording has been further promoted in recent years, and improvements in the slipperiness and abrasion resistance of base films for tapes have been increasingly required. has been reached. That is, the present invention provides polyester whose main repeating unit is ethylene terephthalate, which has an average particle size of 0.01 μm or more and less than 1.2 μm and a volume shape factor.
0.01 to 1.0% by weight of barium sulfate particles having a particle size of 0.08 to 0.25, an average particle size of 0.5 to 5.0 μm, larger than the barium sulfate particles, and a volume shape factor of 0.08 to 0.08.
This is an oriented polyester film containing 0.005 to 0.1% by weight of calcium carbonate particles of 0.40% by weight. [However, the volumetric shape factor f is expressed by the following equation. f=v/D In the formula, v is the particle volume (μm 3 ), and D is the maximum diameter (μm) of the particle in the projected plane. ] The oriented polyester film of the present invention has good slip properties and abrasion resistance, and produces significantly less scratches and white powder. The oriented polyester film of the present invention is characterized in that two types of specific component particles having specific particle diameters and volume shape coefficients are used together in specific amounts. That is, only when a specific amount of barium sulfate particles having a specific particle size and volume shape coefficient and a specific amount of calcium carbonate particles having a specific particle size and volume shape coefficient coexist in the film,
It has been discovered that these particles can exhibit excellent effects that cannot be achieved by using each particle alone or by adding other particles. In the present invention, the polyester constituting the oriented polyester film has a main repeating unit of 80
The polyester is composed of ethylene terephthalate in an amount of at least 20 mol %, and less than 20 mol % of other components such as dicarboxylic acids, glycols, and oxycarboxylic acids that can be copolymerized with the polyester may be used. Note that a biaxially oriented film is particularly suitable as the oriented film. In the present invention, the average particle size of barium sulfate particles, which is the first component of the inert inorganic particles to be added, is
Must be 0.01μm or more and less than 1.2μm, 0.1μm
More preferably, the thickness is less than 1.2 μm, and particularly preferably 0.2 to 1.0 μm. Further, the amount added needs to be 0.01 to 1.0% by weight, more preferably 0.1 to 0.6% by weight, based on the polyester. The average particle size of the calcium carbonate particles that is the second component must be in the range of 0.5 to 5.0 μm, more preferably 0.5 to 1.5 μm, and
It is necessary that the average particle size is larger than the average particle size of the barium sulfate particles that are the component. The amount added must be 0.005 to 0.1% by weight based on the polyester, and 0.03% by weight.
~0.1% by weight is more preferred. If the barium sulfate particles, which are the first component, and the calcium carbonate particles, which are the second component, each deviate from their appropriate ranges, the objective of the present invention is to prevent scratches by imparting good slipperiness and abrasion resistance. As a result, the effect may not be exhibited, or the contamination of coarse particles, which causes dropout due to the particles themselves, cannot be prevented. The relationship between the amounts of barium sulfate particles and calcium carbonate particles may be within a range that satisfies the conditions specified above; More favorable results can be obtained if the amount is greater than the amount of particles added. The average particle size referred to here is the sum of the equivalent spherical particle size distribution calculated based on the Stokes formula.
Refers to the diameter at the 50% point. Next, the reason why the particle composition of the present invention is preferable will be described. For the purpose of improving the slipperiness and abrasion resistance of polyester films for magnetic tape bases, there have been many proposals for adding inert particles to polyester. The requirements have not yet been fully met. Therefore, the present inventors investigated in detail the relationship between the characteristic values of various types of particles (particle size, shape, and hardness), the amount added, and the film characteristic values in order to improve slipperiness and abrasion resistance. Preferably, the particles are spherical or cubic and have little anisotropy, and the average particle size is 0.01
It has been found that the most preferable state is the coexistence of two types of particles: a small particle size of ~1.5 μm and a large particle size in the range of 0.5 to 5.0 μm and larger than the above particles. It has been found that calcium carbonate particles having a volumetric shape coefficient of 0.08 to 0.40, particularly heavy calcium carbonate particles mainly composed of calcite crystals, are most preferable in terms of shape, hardness, etc. as being suitable for these conditions. However, because this heavy calcium carbonate is produced by mechanically crushing limestone, the lower limit of its average particle size is 0.5 μm, which corresponds to the larger particle size of the two required particles. The problem is that you only get what you give. Next, examples of particles suitable for the purpose in terms of shape, hardness, etc. include barium sulfate particles having a volumetric shape coefficient of 0.08 to 0.25. Barium sulfate particles can be reduced to 0.01 μm or more by appropriate classification treatment or grade selection.
It is possible to obtain particle sizes as small as less than 1.2 μm. For the above reasons, as inert particles for polyester films with good slip properties and abrasion resistance, barium sulfate with a volume shape coefficient of 0.08 to 0.25 is used as a small particle size component, and barium sulfate with a volume shape coefficient of 0.08 to 0.25 is used as a large particle size component.
Most preferably, 0.08 to 0.40 calcium carbonate is used in combination as in the particle composition of the present invention. In the present invention, the inert particles may be added to the polyester in either a slurry or powder form at any stage in the polyester manufacturing process, but from the viewpoint of preventing particle scattering and improving uniformity. It is preferable to disperse it in the form of a slurry in ethylene glycol, which is a type of polyester component, and add it in a predetermined amount. Furthermore, when dispersing in a slurry form, it is important to reproduce the original primary particle size of the inert particles as much as possible and to avoid the presence of coarse agglomerated particles. In particular, the presence of coarse particles of 10 μm or more causes dropouts when used as a magnetic tape, so it is necessary to remove them by appropriate means such as classification or separation. For the average particle size measurement, the value at the cumulative 50% point of the equivalent spherical diameter distribution obtained using a centrifugal sedimentation type particle size distribution analyzer manufactured by Shimadzu Corporation was used. In addition, to evaluate film slipperiness and abrasion resistance, when a tape-like roll made by slitting the film into narrow widths is rubbed against a metal guide roll and run at high speed for a long period of time, the film after being rubbed by the guide roll under a constant supply tension is evaluated. The magnitude of the tape tension and the amount of white powder generated on the surface of the guide roll were each evaluated on a five-point scale and expressed in the following rankings.
【表】
フイルム中の粗大粒子量は、得られたフイルム
の少量を２枚のカバーグラス間にはさみ、溶融し
た後急冷、プレスし、得られたサンプルの位相差
顕微鏡像を画像解析処理装置ルーゼツクス500（日
本レギユレーター製）を用いて処理し、粒子像内
の最大長が10μｍ以上の２次凝集粒子の多少によ
つて次のようにランク付けした。
１級……粗大粒子多い
２級……粗大粒子やや多い
３級……粗大粒子普通
４級……粗大粒子少ない
５級……粗大粒子なし
以下、実施例によつて本発明を説明する。
実施例１〜６および比較例１〜４
平均粒径0.5μｍで体積形状係数0.21の沈降性硫
酸バリウム粒子および平均粒径1.0μｍで体積形状
係数0.24の重質炭酸カルシウム粒子をそれぞれエ
チレングリコール中に均一に分散させ、該スラリ
ーを常法によるポリエチレンテレフタレート製造
反応系にそれぞれ表１に記載した所要量で添加せ
しめた後、反応を完結し硫酸バリウム粒子および
炭酸カルシウム粒子を含有したポリエチレンテレ
フタレートを得た。次いで得られたポリエチレン
テレフタレートを285℃で押出成形し、90℃で延
伸倍率3.5倍の縦延伸、95℃で延伸倍率3.6倍の横
延伸、220℃の熱処理を行なつて厚さ15μｍの二
軸延伸ポリエステルフイルムを得た。
得られた各種フイルムの滑り性、耐摩耗性およ
び粗大粒子量を評価したところ、本発明を満足す
る条件下で得られたフイルムは、いずれも磁気テ
ープ用として非常に好ましい品質を有していた。
実施例７〜９および比較例５〜６
沈降性硫酸バリウム粒子および重質炭酸カルシ
ウム粒子の平均粒径をそれぞれ表２に記載したも
のを採用する以外は、実施例１〜６と同様の方法
で二軸延伸ポリエステルフイルムを得た。得られ
た各種フイルムの滑り性、耐摩耗性および粗大粒
子量を評価したところ、本発明を満足する条件下
で得られたフイルムは、いずれも磁気テープ用と
して非常に好ましい品質を有していた。
比較例 ７〜11
添加すべき不活性無機粒子として、平均粒径
0.5μｍで体積形状係数0.21の沈降性硫酸バリウム
粒子を0.25重量％、平均粒径1.0μｍで体積形状係
数0.24の重質炭酸カルシウム粒子を0.05重量％、
平均粒径0.5μｍで体積形状係数0.065のカオリン
粒子を0.25重量％、平均径1.5μｍのシリカ粒子を
0.05重量％および平均粒径0.04μｍのシリカ粒子
を0.50重量％をそれぞれ単独で添加する以外は、
実施例１〜６と同様の方法で二軸延伸ポリエステ
ルフイルムを得た。得られた各種フイルムの滑り
性、耐摩耗性および粗大粒子量を評価したところ
表３に示すごとき結果となり、いずれも磁気テー
プ用としては充分とはいえない品質であり、本発
明を満足する条件以外では磁気テープ用として好
ましい品質が得られないことがわかる。[Table] The amount of coarse particles in the film can be determined by sandwiching a small amount of the obtained film between two cover glasses, melting it, rapidly cooling it, and pressing it.The phase contrast microscope image of the obtained sample is then analyzed using an image analysis processing device. 500 (manufactured by Nippon Regulator) and ranked according to the number of secondary agglomerated particles with a maximum length of 10 μm or more in the particle image as follows. 1st grade...many coarse particles 2nd grade...slightly more coarse particles 3rd grade...normal coarse particles 4th grade...less coarse particles 5th grade...no coarse particles The present invention will be explained below with reference to Examples. Examples 1 to 6 and Comparative Examples 1 to 4 Precipitated barium sulfate particles with an average particle size of 0.5 μm and a volume shape coefficient of 0.21 and heavy calcium carbonate particles with an average particle size of 1.0 μm and a volume shape coefficient of 0.24 were respectively dissolved in ethylene glycol. After uniformly dispersing the slurry, the slurry was added to the polyethylene terephthalate production reaction system by a conventional method in the required amounts listed in Table 1, and the reaction was completed to obtain polyethylene terephthalate containing barium sulfate particles and calcium carbonate particles. . The obtained polyethylene terephthalate was then extruded at 285°C, longitudinally stretched at 90°C with a draw ratio of 3.5 times, transversely stretched at 95°C with a draw ratio of 3.6 times, and heat treated at 220°C to form a biaxial film with a thickness of 15 μm. A stretched polyester film was obtained. When the slipperiness, abrasion resistance, and amount of coarse particles of the various films obtained were evaluated, it was found that all films obtained under conditions satisfying the present invention had highly desirable qualities for use in magnetic tapes. . Examples 7 to 9 and Comparative Examples 5 to 6 The same methods as Examples 1 to 6 were used, except that the average particle diameters of precipitated barium sulfate particles and heavy calcium carbonate particles were those listed in Table 2. A biaxially stretched polyester film was obtained. When the slipperiness, abrasion resistance, and amount of coarse particles of the various films obtained were evaluated, it was found that all films obtained under conditions satisfying the present invention had highly desirable qualities for use in magnetic tapes. . Comparative Examples 7 to 11 As the inert inorganic particles to be added, the average particle size
0.25% by weight of precipitated barium sulfate particles with a volume shape coefficient of 0.21 and 0.5 μm, 0.05% by weight of heavy calcium carbonate particles with an average particle size of 1.0 μm and a volume shape coefficient of 0.24,
0.25% by weight of kaolin particles with an average particle diameter of 0.5 μm and a volume shape coefficient of 0.065, and silica particles with an average diameter of 1.5 μm.
Except for adding 0.05% by weight and 0.50% by weight of silica particles with an average particle size of 0.04 μm, respectively.
Biaxially stretched polyester films were obtained in the same manner as in Examples 1 to 6. When the slipperiness, abrasion resistance, and amount of coarse particles of the obtained various films were evaluated, the results shown in Table 3 were obtained, and all of them were of a quality that could not be said to be sufficient for use in magnetic tapes, which are conditions that satisfy the present invention. It can be seen that the preferred quality for magnetic tapes cannot be obtained in other cases.
【表】【table】
【表】【table】
Claims (1)
ートからなるポリエステル中に、平均粒径が
0.01μｍ以上1.2μｍ未満で体積形状係数が0.08〜
0.25である硫酸バリウム粒子を0.01〜1.0重量％、
および平均粒径が0.5〜5.0μｍかつ前記硫酸バリ
ウム粒子より大で体積形状係数が0.08〜0.40であ
る炭酸カルシウム粒子を0.005〜0.1重量％を含有
してなる配向ポリエステルフイルム。 〔ただし、体積形状係数ｆは次式で表わされる。 ｆ＝ｖ／D3 式中ｖは粒子体積（μm3）、Ｄは粒子の投影面
における最大径（μｍ）を示す。〕[Scope of Claims] 1. Polyester whose main repeating unit is ethylene terephthalate has an average particle size of
0.01μm or more and less than 1.2μm, volume shape factor 0.08~
0.01-1.0% by weight of barium sulfate particles, which is 0.25
and an oriented polyester film containing 0.005 to 0.1% by weight of calcium carbonate particles having an average particle size of 0.5 to 5.0 μm, larger than the barium sulfate particles, and a volume shape coefficient of 0.08 to 0.40. [However, the volumetric shape factor f is expressed by the following equation. f=v/D In the formula, v is the particle volume (μm 3 ), and D is the maximum diameter (μm) of the particle in the projected plane. ]
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP764183A JPS59133246A (en) | 1983-01-19 | 1983-01-19 | Orientated polyester film |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP764183A JPS59133246A (en) | 1983-01-19 | 1983-01-19 | Orientated polyester film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59133246A JPS59133246A (en) | 1984-07-31 |
| JPS6354012B2 true JPS6354012B2 (en) | 1988-10-26 |
Family
ID=11671450
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP764183A Granted JPS59133246A (en) | 1983-01-19 | 1983-01-19 | Orientated polyester film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59133246A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6257918A (en) * | 1985-09-04 | 1987-03-13 | Kuraray Co Ltd | High specific gravity yarn having rough surface |
| JPS6295338A (en) * | 1985-10-21 | 1987-05-01 | Diafoil Co Ltd | Polyester composition |
| JPS62172031A (en) * | 1986-01-24 | 1987-07-29 | Teijin Ltd | Biaxially oriented polyester film |
| JPS6339929A (en) * | 1986-08-05 | 1988-02-20 | Teijin Ltd | Release film for frp |
| JPH089669B2 (en) * | 1986-11-18 | 1996-01-31 | 東洋紡績株式会社 | Oriented polyester film |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3821156A (en) * | 1972-01-03 | 1974-06-28 | Celanese Corp | Polyethylene terephthalate film |
| JPS5134272A (en) * | 1974-07-15 | 1976-03-23 | Celanese Corp | |
| JPS55101136A (en) * | 1979-01-26 | 1980-08-01 | Teijin Ltd | Oriented polyester film for magnetic tape |
| JPS5734088A (en) * | 1980-06-18 | 1982-02-24 | Saint Gobain Isover | Removal of excess water in mixture of gypsum and water, device therefor and product thereof |
-
1983
- 1983-01-19 JP JP764183A patent/JPS59133246A/en active Granted
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3821156A (en) * | 1972-01-03 | 1974-06-28 | Celanese Corp | Polyethylene terephthalate film |
| JPS5134272A (en) * | 1974-07-15 | 1976-03-23 | Celanese Corp | |
| JPS55101136A (en) * | 1979-01-26 | 1980-08-01 | Teijin Ltd | Oriented polyester film for magnetic tape |
| JPS5734088A (en) * | 1980-06-18 | 1982-02-24 | Saint Gobain Isover | Removal of excess water in mixture of gypsum and water, device therefor and product thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59133246A (en) | 1984-07-31 |
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