KR100291275B1 - Film for magnetic recording media - Google Patents

Film for magnetic recording media Download PDF

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Publication number
KR100291275B1
KR100291275B1 KR1019940035948A KR19940035948A KR100291275B1 KR 100291275 B1 KR100291275 B1 KR 100291275B1 KR 1019940035948 A KR1019940035948 A KR 1019940035948A KR 19940035948 A KR19940035948 A KR 19940035948A KR 100291275 B1 KR100291275 B1 KR 100291275B1
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South Korea
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weight
film
parts
alumina
magnetic recording
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KR1019940035948A
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Korean (ko)
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KR960022654A (en
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유득수
조현수
이경수
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구광시
주식회사코오롱
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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/62—Record carriers characterised by the selection of the material
    • G11B5/73—Base layers, i.e. all non-magnetic layers lying under a lowermost magnetic recording layer, e.g. including any non-magnetic layer in between a first magnetic recording layer and either an underlying substrate or a soft magnetic underlayer
    • G11B5/739—Magnetic recording media substrates
    • G11B5/73923—Organic polymer substrates
    • G11B5/73927—Polyester substrates, e.g. polyethylene terephthalate
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
    • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
    • B29C55/10—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial
    • B29C55/12—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets multiaxial biaxial
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
    • C08K3/20—Oxides; Hydroxides
    • C08K3/22—Oxides; Hydroxides of metals
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
    • C08K3/20—Oxides; Hydroxides
    • C08K3/22—Oxides; Hydroxides of metals
    • C08K2003/2227—Oxides; Hydroxides of metals of aluminium
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K2201/00—Specific properties of additives
    • C08K2201/002—Physical properties
    • C08K2201/005—Additives being defined by their particle size in general

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)

Abstract

PURPOSE: Provided is a biaxially oriented polyester film, suitable to produce a magnetic recording media of good quality which is excellent in traveling property, abrasion resistance and smoothness, as well as has a small quantity of coarse particles. CONSTITUTION: The film for magnetic recording media consists of the biaxially oriented polyester film containing alpha-alumina, of which an average diameter satisfy the formula, that is 0.01 T<R<0.1 T. In the formula, T represents thickness of biaxially oriented polyester film, and R represents an average diameter of alpha-alumina particles. The polyester comprises 0.1-5 wt.% of the alpha-alumina. The polyester film is prepared by pre-preparing a master polyester containing alpha-alumina particles in a high concentration and then mixing the master polyester with other polyester polymer to obtain a desired concentration.

Description

[발명의 명칭][Name of invention]

자기 기록 매체용 필름Film for magnetic recording media

[발명의 상세한 설명]Detailed description of the invention

[산업상 이용분야][Industrial use]

본 발명은 자기테이프의 기재 필름에 관한 것으로서, 더욱 상세하게는 주행성 및 내마모성이 우수함과 동시에 조대 입자가 적고 평활성이 매우 우수하여 전자 변환 특성 및 드롭 아웃 발생의 빈도가 적은 특성이 요구되어지는 고밀도 기록용 및 장시간 녹화재생용 자기테이프를 비롯한 고 품질의 자기 기록 매체의 제조에 이용하기에 적합한 용도를 갖는 2축 배향 폴리에스테르 필름에 관한 것이다.The present invention relates to a base film of magnetic tape, and more particularly, high density recording requiring excellent characteristics such as electron conversion characteristics and low frequency of dropout due to excellent coarse particles and excellent smoothness as well as excellent running and abrasion resistance. The present invention relates to a biaxially oriented polyester film having an application suitable for use in the production of high quality magnetic recording media, including magnetic tape for long time recording and reproduction.

[종래기술][Private Technology]

일반적으로 컴퓨터, 비디오, 또는 오디오등에 사용되고 있는 자기 기록 매체는 2축 배향 폴리에스테르 필름과 같은 비자성 포지 지체위에 강자성체 분말, 연마제, 대전방지제, 윤활제 및 그 밖의 첨가제를 결합제 용액에 혼합, 분산시켜 만든 자성 도료를 도포한 후, 배향, 건조, 카렌다링, 경화 및 슬릿팅하는 공정으로 제조되어 진다.In general, magnetic recording media used in computers, video, or audio are made by mixing and dispersing ferromagnetic powder, abrasive, antistatic agent, lubricant and other additives in a binder solution on a nonmagnetic substrate such as a biaxially oriented polyester film. After applying the magnetic paint, it is prepared by the process of orientation, drying, calendaring, curing and slitting.

자기 기록 매체는 정보의 저장 체이므로 전자 변환 특성이 매우 우수해야 하고 고속 주행이나 열악한 조건하에서의 주행시에도 변형이 일어나지 않는 우수한 주행성 및 내구성이 요구된다. 특히 이들 특성들은 최근 들어 급속하게 신장세를 보이고 있는 산업용 고속 복제에 사용되고 있는 자기 기록 매체에 있어서 더욱 요구되고 있다.Since the magnetic recording medium is a storage medium for information, it is required to have excellent electronic conversion characteristics and to have excellent driving performance and durability in which deformation does not occur even when traveling at high speeds or under severe conditions. In particular, these characteristics are increasingly required for magnetic recording media used for industrial high-speed copying, which is rapidly growing in recent years.

자기 기록 매체의 특성은 자성층의 조성 분산 기술, 도포 기술을 비롯한 자기 기록 매체의 제조 기술에 의하여서 결정되어 지지만, 특히 주행성 및 내구성등의 요소는 사용되어지는 비자성 지지체의 특성에 의하여서도 매우 크게 지배되어진다.The characteristics of the magnetic recording medium are determined by the manufacturing technique of the magnetic recording medium including the composition dispersion technique and the coating technique of the magnetic layer, but in particular, factors such as the runability and durability are very large depending on the characteristics of the nonmagnetic support used. Is dominated.

특히 평활성, 이활성, 자성층과 기재간의 접착성, 두께의 균일성 및 강인성은 자기 기록 매체의 비자성 지지체에 있어서 자기 기록 매체의 주행 특성 및 전자 변환 특성에 직접적인 영향을 주는 매우 중요하다.In particular, the smoothness, the active activity, the adhesion between the magnetic layer and the substrate, the uniformity of the thickness, and the toughness are very important in the nonmagnetic support of the magnetic recording medium, which directly affects the running characteristics and the electron conversion characteristics of the magnetic recording medium.

즉, 자기 기록 매체의 전자 변환 특성은 자기 기록 매체의 평활성과 주행 특성에 의하여 결정되는데 이들 특성들은 자기 기록 매체의 비자성 지지체의 이활성에 의하여 결정되어진다.That is, the electron conversion characteristics of the magnetic recording medium are determined by the smoothness and running characteristics of the magnetic recording medium, and these characteristics are determined by the deactivation of the nonmagnetic support of the magnetic recording medium.

이에 따라 자기 기록 매체의 비자성 지지체로 사용되어 지는 폴리에스테르 필름에 있어서 필름 표면의 평활성과 이활성은 우수한 특성의 자기 기록 매체의 제조에 있어서 무엇 보다 중요한 요소라 할 수 있다.Accordingly, in the polyester film used as the nonmagnetic support of the magnetic recording medium, the smoothness and deactivation of the surface of the film can be said to be an important factor in the production of the magnetic recording medium having excellent properties.

필름 표면에 높은 평활성과 우수한 이활성을 부여하기 위한 지금까지의 기술들을 살펴보면 주로 탄산 칼슘, 이산화 규소, 산화 알루미늄, 클레이, 이산화티탄과 같은 불활성 미립자들을 첨가하여 필름 표면에 미세한 돌기를 형성시키는 외부 입자법, 칼슘, 실리콘, 망간, 마그네슘, 안티모니, 게르마륨, 인, 라듐, 포타슘 또는 나트륨을 함유하는 촉매 잔류물 또는 착색 방지제의 일부가 중합 공정중에 모노머나 올리고머와 반응하여 불활성 입자를 형성하도록 하는 내부 입자법, 또는 상기 이들 양 방법을 병용하는 내외부 혼용법이 있다.In the past, techniques for giving high smoothness and good diactivity to the film surface have been examined. External particles are mainly formed by adding inert fine particles such as calcium carbonate, silicon dioxide, aluminum oxide, clay and titanium dioxide to form fine protrusions on the film surface. Method, which allows some of the catalyst residues or anti-colorants containing calcium, silicon, manganese, magnesium, antimony, germanium, phosphorus, radium, potassium or sodium to react with monomers or oligomers during the polymerization process to form inert particles. There is an internal and external mixing method, or an internal and external mixing method using both of these methods.

이러한 방법들은 모두 필름 표면에 첨가 입자에 의한 돌기를 형성시켜 필름과 접촉 대상물간의 접촉 면적을 감소시킴으로서 마찰 저항을 저하시켜 주는 것으로서, 이들 방법에 따라 제조된 필름은 그 표면에 돌기의 수가 많고 돌기의 높이가 높을 수록 우수한 이활성을 나타내어 자기 기록 매체의 주행 특성 및 내 마모성을 향상시키어 주는 효과를 기대하고 있다.All of these methods reduce the frictional resistance by reducing the contact area between the film and the contact object by forming projections by the particles added on the surface of the film. Films produced according to these methods have a large number of projections on the surface of the projections. It is expected that the higher the height, the better the activity and the improvement of the running characteristics and wear resistance of the magnetic recording medium.

그러나, 이와 같은 방법에 의하여 필름의 표면에 형성된 돌기의 형성은 필름의 주행 특성 및 내마모성과 같은 일부의 특성을 향상시키어 주는 효과가 있으나 필름의 평활성을 저해하는 요인이 되어 자기 기록 매체의 비데오 특성, 크로마 특성, 등의 전자 변환 특성이 불량하고며 동시에 드롭 아웃의 증대를 가져오는 바람직하지 못한 일면도 있게 된다.However, the formation of the projections formed on the surface of the film by such a method has the effect of improving some properties such as the running characteristics and the wear resistance of the film, but it is a factor that hinders the smoothness of the film, Electron conversion characteristics such as chroma characteristics and the like are poor, and at the same time, there is an undesirable aspect that leads to an increase in dropout.

또한, 필름의 평활성을 고려하여 돌기수를 적게 하고 돌기의 높이를 낮추게 되면 이활성이 악화되어 주행 특성 및 내마모성이 나빠지게 된다.In addition, when the number of the projections is reduced in consideration of the smoothness of the film and the height of the projections is lowered, this activity is deteriorated and the running characteristics and the wear resistance become worse.

이와 같이 자기 기록 매체의 비자성 지지체상에서의 평활성과 이활성은 서로 상반되는 특성으로서 이들의 특성을 동시에 만족시키는 것은 매우 어려운 일이다.As described above, smoothness and biactivity on the nonmagnetic support of the magnetic recording medium are mutually opposite characteristics, and it is very difficult to satisfy these characteristics simultaneously.

상기와 같은 자기 기록 매체의 비자성 지지체에 있어서의 평활성과 이활성에 관련된 문제점들을 해결하기 위하여 기본적으로 평활한 폴리에스테르 필름을 지지체로 하여 자성층을 형성시킨 다음, 자성층과의 반대면에 카본 블랙을 주성분으로 하는 무기 입제를 결합제 수지에 분산시킨 도료를 도포하여 소위 백코팅층을 형성하는 방법이 제안되고 있다. 이 방법에 의하여 자기 기록 매체에 있어서 평활성과 이활성에 관한 문제점은 어느 정도 해결되고 있으나 자기 기록 매체의 제조 공정에 있어서 별도의 백코팅용 도료 제조 설비 및 도포 설비가 필요하게 되어 공정이 복잡하여 지고 제조 비용이 상승하게 되는 문제점이 있으며, 더욱 평활한 필름 위에 백코팅층을 도포할 때까지의 보관이 용이하지 않는 문제점이 있다.In order to solve the problems related to the smoothness and deactivation in the nonmagnetic support of the magnetic recording medium as described above, a magnetic layer is formed by using a smooth polyester film as a support, and then carbon black is mainly formed on the opposite side of the magnetic layer. The method of apply | coating the coating material which disperse | distributed the inorganic granules to binder resin, and forming what is called a backcoat layer is proposed. This method solves the problem of smoothness and deactivation in magnetic recording media to some extent. However, in the manufacturing process of magnetic recording media, a separate back coating material manufacturing equipment and coating equipment are required, which makes the process complicated. There is a problem that the cost rises, there is a problem that storage is not easy until the back coating layer is applied on a smoother film.

한편, 자기 기록 매체의 기재 필름으로 사용되어지는 폴리에스테르 필름상에 이활성과 평활성을 동시에 부여하기 위한 방법도 일부 제안되어 지고 있다. 예를 들면, 일본국 특개소 제 51-52808 호에는 폴리에스테르 필름중에 카본 블랙을 첨가하는 방법이 개시되어 있다. 그러나 카본 블랙은 입자의 응집성이 강하여 분산시키기 어려울 뿐만 아니라 폴리에스테르 수지중에 균일하게 분산시키기 어려운 문제점이 있다.On the other hand, some methods for simultaneously imparting diactivation and smoothness on a polyester film used as a base film of a magnetic recording medium have also been proposed. For example, Japanese Patent Laid-Open No. 51-52808 discloses a method of adding carbon black in a polyester film. However, carbon black has a problem that it is difficult to disperse uniformly in the polyester resin as well as difficult to disperse due to the cohesiveness of particles.

자기 기록 매체의 내구성 및 내마모성의 향상에 대한 방법으로서는 일본국 특개소 제 63-230741호에 개시되어 있는 바와 같이 경도가 높은 단단한 입자를 함유한 2축 배향 폴리에스테르 필름을 기재로 사용하는 방법을 생각할 수 있지만, 이 방법으로 제조한 폴리에스테르 필름은 어느 정도의 내구성과 내마모성을 지니지만 자성층을 형성하는 경우 표면이 거칠어져 전자 변환 특성이 악화되는 문제점이 있다.As a method for improving the durability and abrasion resistance of a magnetic recording medium, a method of using a biaxially oriented polyester film containing hard particles having high hardness as a substrate, as disclosed in Japanese Patent Application Laid-Open No. 63-230741, can be considered. However, the polyester film produced by this method has a certain degree of durability and wear resistance, but when the magnetic layer is formed, there is a problem that the surface becomes rough and the electron conversion characteristics deteriorate.

[발명이 해결하려 하는 과제][Problems to Solve Invention]

본 발명은 상기한 바와 같은 자기 기록 매체 필름에 있어서의 제 문제 사함들을 해결하기 위하여 안출된 것으로서, 이활성과 평활성이 동시에 우수하고 또한 내마모성 및 내구성이 뛰어난 자기 기록 매체 비자성 지지체를 제공하려는 목적을 갖는다.The present invention has been made to solve the above-mentioned problems in the magnetic recording medium film, and has an object of providing a magnetic recording medium non-magnetic support having both excellent activity and smoothness, and excellent wear resistance and durability. .

[과제를 해결하기 위한 수단][Means for solving the problem]

상기한 목적을 달성하기 위하여, 본 발명은 하기의 관계식을 만족하는 평균 입경을 갖는 α-알루미나를 함유한 2축 배향 폴리에스테르 필름으로 구성되어지는 자기 기록 매체용 필름을 제공한다.In order to achieve the above object, the present invention provides a film for a magnetic recording medium composed of a biaxially oriented polyester film containing α-alumina having an average particle size satisfying the following relational formula.

0.01 T < R < 0.1 T0.01 T <R <0.1 T

(상기의 관계식에서 T는 2축 배향 폴리에스테르 필름의 두께이고, R은 α-알루미나 입자의 평균 입자이다.)(In the above relation, T is the thickness of the biaxially oriented polyester film, and R is the average particle of α-alumina particles.)

상기한 본 발명에 있어서 상기한 α-알루미나의 폴리에스테르에서의 함유량은 전체 중량에 대하여 0.1 내지 5중량%가 바람직하다.In the present invention described above, the content of the α-alumina in the polyester is preferably 0.1 to 5% by weight based on the total weight.

[작용][Action]

본 발명을 더욱 상세하게 설명하면 다음과 같다. 본 발명의 폴리에스테르 필름은 주요 디카르복실산 성분으로 테레프탈산 또는 그의 에스테르와, 주요 글리콜 성분으로 에틸렌 글리콜으로 하여 얻어진 폴리에틸렌테레프탈레이트 필름이다. 상기의 주요 성분에 부가하여 소량의 나프탈렌디카르복실산, 이소프탈산, 디페닐술폰디카르복실산, 숙신산, 아디프산, 세바신산 등의 디카르복실산 성분 및 소량의 1,3-프로판디올, 1,4-부탄디올, 1,4-시클로헥산디메탄올, 1,6-헥산디올, 네오펜틸글리콜 등과 같은 글리콜성분을 각각 10몰%이하로 부가하여도 무방하다. 폴리에틸렌테레프탈레이트는 공지된 방법에 의해 필요한 경우 촉매 및 산화방지제, 자외선 흡수제 또는 내열제 등을 첨가하여 제조된다.The present invention is described in more detail as follows. The polyester film of this invention is a polyethylene terephthalate film obtained by using terephthalic acid or its ester as a main dicarboxylic acid component, and ethylene glycol as a main glycol component. In addition to the above main components, a small amount of dicarboxylic acid components such as naphthalenedicarboxylic acid, isophthalic acid, diphenylsulfondicarboxylic acid, succinic acid, adipic acid, sebacic acid, and a small amount of 1,3-propanediol And glycol components such as 1,4-butanediol, 1,4-cyclohexanedimethanol, 1,6-hexanediol, and neopentylglycol may be added at 10 mol% or less, respectively. Polyethylene terephthalate is prepared by a known method by adding a catalyst and an antioxidant, a ultraviolet absorber or a heat-resistant agent, if necessary.

또한, 고농도의 α-알루미나 입자를 함유하는 마스터폴리에스테르를 미리 제조한 후 최종적으로 본 발명의 범위의 함량을 갖도록 다른 폴리에스테르중합체와 혼합하는 방법도 무방하다.In addition, a method of preparing a master polyester containing a high concentration of α-alumina particles in advance and finally mixing with other polyester polymers so as to have a content in the range of the present invention.

본 발명에 있어서 자기 기록 매체의 비자성 지지체로 사용되어지는 폴리에스테르 필름의 두께는 특별한 규정이 있는 것이 아니고 오디오, 비디오, 또는 컴퓨터 등의 일반적인 자기 기록 매체용도로서의 두께를 말한다.The thickness of the polyester film used as the nonmagnetic support of the magnetic recording medium in the present invention is not particularly specified, and refers to the thickness of a general magnetic recording medium such as audio, video, or computer.

α-알루미나의 평균 입경이 필름의 두께를 기준으로 하여 0.01 T 이상에서 0.1 T의 범위에 있는 것이 바람직하다.It is preferable that the average particle diameter of (alpha)-alumina exists in the range of 0.01T or more and 0.1T based on the thickness of a film.

α-알루미나의 평균 입경이 0.01 T보다 작을 경우에는 알루미나 입자가 필름의 내층에 분포하게 되어 본래 알루미나 입자를 첨가하여 표면이활성과 함께 내마모성을 부여하고자 하는 본 발명의 목적을 달성하기 어려우며, 0.1 T 이상이면 첨가되어지는 알루미나의 입자가 지나치게 커져 연신 공정을 거친 다음 필름 내부에 존재하는 알루미나의 입자에 의하여 필름 표면에 조대 돌기가 형성되어 자기 기록 매체의 제조시 전자 변환 특성을 저하시킴은 물론 드롭 아웃트의 요인이 되어 바람직하지 않게 된다.When the average particle diameter of α-alumina is less than 0.01 T, the alumina particles are distributed in the inner layer of the film, and it is difficult to achieve the object of the present invention to add alumina particles to provide surface activity and wear resistance, and 0.1 T If it is above, the particles of alumina to be added are too large to be subjected to the stretching process, and then coarse protrusions are formed on the surface of the film by the alumina particles present in the film, thereby degrading electron conversion characteristics in manufacturing the magnetic recording medium as well as dropping out. It becomes the factor of the net and becomes undesirable.

본 발명에 있어서 바람직한 α-알루미나의 함량은 폴리에스테르 필름의 총량에 대하여 0.1 내지 5중량%되도록 하는 것이다. α-알루미나의 함량이 0.1중량% 이하이면 필름의 단위 면적당 알루미나 입자가 차지하는 절대 갯수가 적어져 고속 복사시에는 물론 열악한 조건하에서 반복 사용하는 경우 충분한 주행성 및 내구성을 부여할 수 없게 되어 본 발명의 목적을 달성하기 어렵게 되며 5.0중량% 이상이 되면 주행성 및 내구성 측면에서는 우수한 성능을 보일 수 있으나 폴리에스테르 필름 내에 다량의 알루미나 입자를 균일하게 분산시키기가 어렵고, 2축 배향 폴리에스테르 필름을 제조한 다음의 필름 표면이 너무 거칠어져 자기 기록 매체의 전자 변환 특성을 악화시키고 드롭 아웃트의 발생 요인이 되어 바람직하지 못할 뿐만 아니라 2축 배향 필름을 형성하는 제막 공정의 여과율을 저해하고 연신성을 악화시켜 연신 공정에서의 파단이 발생하여 생산성이 좋지 못하게 되는 원인이되어 바람직하지 않다.In the present invention, the preferred content of α-alumina is 0.1 to 5% by weight based on the total amount of the polyester film. When the content of α-alumina is 0.1% by weight or less, the absolute number of alumina particles per unit area of the film becomes small, so that it is impossible to impart sufficient running property and durability in high-speed radiation and repeated use under poor conditions. When it is more than 5.0% by weight, it may be excellent in terms of runability and durability, but it is difficult to uniformly disperse a large amount of alumina particles in the polyester film, and the following film is made of a biaxially oriented polyester film. The surface is so rough that it deteriorates the electron conversion characteristics of the magnetic recording medium and is a cause of dropout, which is not desirable, but also inhibits the filtration rate of the film forming process of forming the biaxially oriented film and deteriorates the stretchability in the stretching process. That causes breakage of the product resulting in poor productivity This is undesirable.

α-알루미나 입자의 첨가 시점은 에스테르 교환 반응 또는 에스테르화 반응초기 또는 에스테르 교환반응 또는 에스테르화 반응직 후 중 축합 반응이 시작되기 전에 투입하는 것이 좋으며, 투입시에는 에틸렌글리콜에 미리 분산시킨 슬러리 상태로 투입하는 것이 바람직하다.The point of addition of the α-alumina particles is preferably added before the condensation reaction begins during the initial transesterification or esterification reaction or immediately after the transesterification reaction or esterification reaction. It is preferable to add.

본 발명의 자기 기록 매체용 비자성 지지체로 사용되어 지는 폴리에스테르 필름은 α-알루미나이외에도 필에 따라 탄산 칼슘, 이산화탄소, 이산화티탄등의 불활성 무기 입자를 함유하거나 또는 폴리에스테르 제조시 첨가되는 알칼리토금속화합물등의 금속 촉매와 반응에 의해 폴리에스테르 내부에 석출되는 내부 입자를 함유하여도 무방하다.The polyester film used as the nonmagnetic support for the magnetic recording medium of the present invention contains inert inorganic particles such as calcium carbonate, carbon dioxide, titanium dioxide or the like, in addition to α-alumina, or is added in the manufacture of polyester. It may contain the internal particles which precipitate inside the polyester by reaction with metal catalysts such as these.

필름제조 기술은 공지의 폴리에틸렌테레프탈레이트 필름제조 기술을 응용할 수 있고, 공지의 필름제조 기술들을 이해하기 쉽게 설명하면, 상기 방법으로 얻어진 중합체를 칩상으로 잘라 건조공정을 거쳐 압출다이를 통해 시이트상으로 급냉, 고화시켜 결정화도가 10% 이하인 무정형 시이트를 얻는다. 급냉 고화시킬 때 정전압 인가법이나, 알콜류를 이용한 밀착법을 이용할 수 있다. 이를 길이방향 및 폭방향으로 연신하되 길이-폭방향 축차연신 또는 동시연신법, 폭-길이방향 축차이축 연신법 또는 더욱 고탄성률을 얻기 위하여 길이방향 재연신이나, 폭방향재연신, 또는 길이-폭방향재연신법 중 어느 방법을 사용해도 무방하다. 필름제조 방법을 좀더 상세히 설명하면 축차이축 연신방법의 경우(유리전이 온도)-(유리전이 +60℃)의 온도에서 길이방향으로 1단 내지 2단이상에 걸쳐 3.5~5.0배 연신하고, (유리전이 온도)-(유리전이 온도 + 80℃)의 온도에서 3.5~5.0배 연신한 후 180-Tm(결정이 녹는 온도)이하에서 1~60초간 열처리하되 2~8% 이완하면서 열처리하는 것이 좋으며 최종 필름을 제조하여 이때의 필름두께는 20㎛이하가 되도록 한다.The film production technology can be applied to the known polyethylene terephthalate film production technology, and the known film production techniques to explain easily, the polymer obtained by the above method is cut into chips and subjected to a drying step through the extrusion process is quenched to the sheet through an extrusion die To solidify to obtain an amorphous sheet having a crystallinity of 10% or less. When quenching and solidifying, a constant voltage application method or an adhesion method using alcohols can be used. Stretch it in the longitudinal direction and the width direction, and extend longitudinally or laterally or simultaneously, longitudinally or laterally, or longitudinally or laterally to obtain higher modulus. Any of the aromatic re-stretching methods may be used. When explaining the film production method in more detail, in the case of the sequential biaxial stretching method, the film is stretched 3.5 to 5.0 times in the longitudinal direction at one to two or more stages at a temperature of (glass transition temperature)-(glass transition + 60 ° C.), ( After stretching at 3.5 ~ 5.0 times at the temperature of glass transition temperature)-(glass transition temperature + 80 ℃), heat-treat for 180 ~ Tm (crystal melting temperature) for 1 ~ 60 sec. The final film is prepared to have a film thickness of 20 μm or less.

[실시예]EXAMPLE

이하 본 발명의 바림직한 실시예 및 비교실시예를 기재한다. 그러나 하기한 실시예 및 비교실시예는 본 발명의 이해를 돕기 위한 본 발명의 바람직한 일실시예일 뿐 본 발명이 하기한 실시예에 한정되는 것은 아니다.Hereinafter, preferred and comparative examples of the present invention are described. However, the following examples and comparative examples are only preferred embodiments of the present invention to aid the understanding of the present invention, and the present invention is not limited to the following examples.

[실시예 1]Example 1

평균 입경 0.5㎛의 α-알루미나 100중량부를 에틸렌 글리콜 100중량부에 충분히 혼합시킨 후 여기에 에틸렌 글리콜 800중량부를 첨가하여 샌드 글라인딩하여 α-알루미나가 균일하게 분산된 에틸렌글리콜 슬러리를 제조하였다.100 parts by weight of α-alumina having an average particle diameter of 0.5 μm was sufficiently mixed with 100 parts by weight of ethylene glycol, and then 800 parts by weight of ethylene glycol was added thereto, followed by sand grinding to prepare an ethylene glycol slurry in which α-alumina was uniformly dispersed.

디메틸렌테레프탈레이트 100 중량부, 에틸렌글리콜 60중량부, 초산 마그네슘 4 수화물 0.1 중량부, 삼산화 안티몬 0.06중량부를 에스테르 교환 반응기에 투입하고 140℃부터 메탄올을 제거하면서 4시간에 걸쳐 에스테르 교환 반응을 종료하였다. 다음에 앞에서 제조한 에틸렌 글리콜 슬러리를 α-알루미나가 폴리에스테르 수지중에 0.5중량% 되도록 첨가하고 트리메틸포스페이트를 0.05중량부와 평균 입경이 0.3㎛인 탄산 칼슘을 0.2중량부 첨가한 후 중축합 잔응기로 이송하여 고진공으로 4시간 동안 중축합 반응을 실시하여 고유 점도 0.615인 폴리에틸렌테레프탈레이트를 제조하였다.100 parts by weight of dimethylene terephthalate, 60 parts by weight of ethylene glycol, 0.1 part by weight of magnesium acetate tetrahydrate, and 0.06 part by weight of antimony trioxide were added to a transesterification reactor, and the transesterification reaction was completed over 4 hours while removing methanol from 140 ° C. . Next, the ethylene glycol slurry prepared above was added so that α-alumina was 0.5% by weight in the polyester resin, 0.05 parts by weight of trimethyl phosphate and 0.2 parts by weight of calcium carbonate having an average particle diameter of 0.3 µm were added. Polycondensation reaction was carried out for 4 hours at high vacuum to prepare a polyethylene terephthalate having an intrinsic viscosity of 0.615.

이와 같이 제조한 폴리에틸렌테레프탈레이트를 150℃에서 건조시킨 후 290℃에서 용융압출시켜 무정형의 필름을 제조한 후 95℃에서 길이방향으로 4.0배 연신한 후 105℃에서 폭방향으로 3.8배되도록 이축 연신 한 후 220℃에서 3%의 완화율을 부여하면서 결정화시켜 14.5㎛ 두께의 2축 배향에틸렌테레프탈레이트 필름을 제조하였다.The polyethylene terephthalate thus prepared was dried at 150 ° C. and melt-extruded at 290 ° C. to prepare an amorphous film, followed by stretching at 4.0 times in the longitudinal direction at 95 ° C. and biaxially stretching at 105 ° C. in the width direction. After crystallization while giving a relaxation rate of 3% at 220 ℃ to prepare a biaxially orientated ethylene terephthalate film having a thickness of 14.5㎛.

[실시예 2]Example 2

평균 입경 0.5㎛의 α-알루미나 100중량부를 에틸렌 글리콜 100중량부에 충분히 혼합시킨 후 여기에 에틸렌 글리콜 800중량부를 첨가하여 샌드 글라인딩하여 α-알루미나가 균일하게 분산된 에틸렌글리콜 슬러리를 제조하였다.100 parts by weight of α-alumina having an average particle diameter of 0.5 μm was sufficiently mixed with 100 parts by weight of ethylene glycol, and then 800 parts by weight of ethylene glycol was added thereto, followed by sand grinding to prepare an ethylene glycol slurry in which α-alumina was uniformly dispersed.

디메틸렌테레프탈레이트 100 중량부, 에틸렌글리콜 60중량부, 초산 마그네슘 4 수화물 0.1 중량부, 삼산화 안티몬 0.06중량부를 에스테르 교환 반응기에 투입하고 140℃부터 메탄올을 제거하면서 4시간에 걸쳐 에스테르 교환 반응을 종료하였다. 다음에 앞에서 제조한 에틸렌 글리콜 슬러리를 α-알루미나가 폴리에스테르 수지중에 1.0중량% 되도록 첨가하고 트리메틸포스페이트를 0.05중량부와 평균 입경이 0.3㎛인 탄산 칼슘을 0.2중량부 첨가한 후 중축합 잔응기로 이송하여 고진공으로 4시간 동안 중축합 반응을 실시하여 고유 점도 0.615인 폴리에틸렌테레프탈레이트를 제조하였다.100 parts by weight of dimethylene terephthalate, 60 parts by weight of ethylene glycol, 0.1 part by weight of magnesium acetate tetrahydrate, and 0.06 part by weight of antimony trioxide were added to a transesterification reactor, and the transesterification reaction was completed over 4 hours while removing methanol from 140 ° C. . Next, the ethylene glycol slurry prepared above was added so that α-alumina was 1.0% by weight in the polyester resin, 0.05 parts by weight of trimethyl phosphate and 0.2 parts by weight of calcium carbonate having an average particle diameter of 0.3 µm were added. Polycondensation reaction was carried out for 4 hours at high vacuum to prepare a polyethylene terephthalate having an intrinsic viscosity of 0.615.

이와 같이 제조한 폴리에틸렌테레프탈레이트를 150℃에서 건조시킨 후 290℃에서 용융압출시켜 무정형의 필름을 제조한 후 95℃에서 길이방향으로 4.0배 연신한 후 105℃에서 폭방향으로 3.8배되도록 이축 연신 한 후 220℃에서 3%의 완화율을 부여하면서 결정화시켜 14.5㎛ 두께의 2축 배향에틸렌테레프탈레이트 필름을 제조하였다.The polyethylene terephthalate thus prepared was dried at 150 ° C. and melt-extruded at 290 ° C. to prepare an amorphous film, followed by stretching at 4.0 times in the longitudinal direction at 95 ° C. and biaxially stretching at 105 ° C. in the width direction. After crystallization while giving a relaxation rate of 3% at 220 ℃ to prepare a biaxially orientated ethylene terephthalate film having a thickness of 14.5㎛.

[실시예 3]Example 3

평균 입경 0.5㎛의 α-알루미나 100중량부를 에틸렌 글리콜 100중량부에 충분히 혼합시킨 후 여기에 에틸렌 글리콜 800중량부를 첨가하여 샌드 글라인딩하여 α-알루미나가 균일하게 분산된 에틸렌글리콜 슬러리를 제조하였다.100 parts by weight of α-alumina having an average particle diameter of 0.5 μm was sufficiently mixed with 100 parts by weight of ethylene glycol, and then 800 parts by weight of ethylene glycol was added thereto, followed by sand grinding to prepare an ethylene glycol slurry in which α-alumina was uniformly dispersed.

디메틸렌테레프탈레이트 100 중량부, 에틸렌글리콜 60중량부, 초산 마그네슘 4 수화물 0.1 중량부, 삼산화 안티몬 0.06중량부를 에스테르 교환 반응기에 투입하고 140℃부터 메탄올을 제거하면서 4시간에 걸쳐 에스테르 교환 반응을 종료하였다. 다음에 앞에서 제조한 에틸렌 글리콜 슬러리를 α-알루미나가 폴리에스테르 수지중에 3.0중량% 되도록 첨가하고 트리메틸포스페이트를 0.05중량부와 평균 입경이 0.3㎛인 탄산 칼슘을 0.2중량부 첨가 한 후 중축합 잔응기로 이송하여 고진공으로 4시간 동안 중축합 반응을 실시하여 고유 점도 0.615인 폴리에틸렌테레프탈레이트를 제조하였다.100 parts by weight of dimethylene terephthalate, 60 parts by weight of ethylene glycol, 0.1 part by weight of magnesium acetate tetrahydrate, and 0.06 part by weight of antimony trioxide were added to a transesterification reactor, and the transesterification reaction was completed over 4 hours while removing methanol from 140 ° C. . Next, the ethylene glycol slurry prepared above was added so that α-alumina was 3.0% by weight in the polyester resin, 0.05 parts by weight of trimethyl phosphate and 0.2 parts by weight of calcium carbonate having an average particle diameter of 0.3 µm were added. Polycondensation reaction was carried out for 4 hours at high vacuum to prepare a polyethylene terephthalate having an intrinsic viscosity of 0.615.

이와 같이 제조한 폴리에틸렌테레프탈레이트를 150℃에서 건조시킨 후 290℃에서 용융압출시켜 무정형의 필름을 제조한 후 95℃에서 길이방향으로 4.0배 연신한 후 105℃에서 폭방향으로 3.8배되도록 이축 연신 한 후 220℃에서 3%의 완화율을 부여하면서 결정화시켜 14.5㎛ 두께의 2축 배향에틸렌테레프탈레이트 필름을 제조하였다.The polyethylene terephthalate thus prepared was dried at 150 ° C. and melt-extruded at 290 ° C. to prepare an amorphous film, followed by stretching at 4.0 times in the longitudinal direction at 95 ° C. and biaxially stretching at 105 ° C. in the width direction. After crystallization while giving a relaxation rate of 3% at 220 ℃ to prepare a biaxially orientated ethylene terephthalate film having a thickness of 14.5㎛.

[실시예 4]Example 4

평균 입경 0.3㎛의 α-알루미나 100중량부를 에틸렌 글리콜 100중량부에 충분히 혼합시킨 후 여기에 에틸렌 글리콜 800중량부를 첨가하여 샌드 글라인딩하여 α-알루미나가 균일하게 분산된 에틸렌글리콜 슬러리를 제조하였다.100 parts by weight of α-alumina having an average particle diameter of 0.3 μm was sufficiently mixed with 100 parts by weight of ethylene glycol, and then 800 parts by weight of ethylene glycol was added thereto, followed by sand grinding to prepare an ethylene glycol slurry in which α-alumina was uniformly dispersed.

디메틸렌테레프탈레이트 100 중량부, 에틸렌글리콜 60중량부, 초산 마그네슘 4 수화물 0.1 중량부, 삼산화 안티몬 0.06중량부를 에스테르 교환 반응기에 투입하고 140℃부터 메탄올을 제거하면서 4시간에 걸쳐 에스테르 교환 반응을 종료하였다. 다음에 앞에서 제조한 에틸렌 글리콜 슬러리를 α-알루미나가 폴리에스테르 수지중에 1.0중량% 되도록 첨가하고 트리메틸포스페이트를 0.05중량부와 평균 입경이 0.3㎛인 탄산 칼슘을 0.2중량부 첨가 한 후 중축합 잔응기로 이송하여 고진공으로 4시간 동안 중축합 반응을 실시하여 고유 점도 0.615인 폴리에틸렌테레프탈레이트를 제조하였다.100 parts by weight of dimethylene terephthalate, 60 parts by weight of ethylene glycol, 0.1 part by weight of magnesium acetate tetrahydrate, and 0.06 part by weight of antimony trioxide were added to a transesterification reactor, and the transesterification reaction was completed over 4 hours while removing methanol from 140 ° C. . Next, the ethylene glycol slurry prepared above was added so that α-alumina was 1.0% by weight in the polyester resin, 0.05 parts by weight of trimethyl phosphate and 0.2 parts by weight of calcium carbonate having an average particle diameter of 0.3 μm were added. Polycondensation reaction was carried out for 4 hours at high vacuum to prepare a polyethylene terephthalate having an intrinsic viscosity of 0.615.

이와 같이 제조한 폴리에틸렌테레프탈레이트를 150℃에서 건조시킨 후 290℃에서 용융압출시켜 무정형의 필름을 제조한 후 95℃에서 길이방향으로 4.0배 연신한 후 105℃에서 폭방향으로 3.8배되도록 이축 연신 한 후 220℃에서 3%의 완화율을 부여하면서 결정화시켜 14.5㎛ 두께의 2축 배향에틸렌테레프탈레이트 필름을 제조하였다.The polyethylene terephthalate thus prepared was dried at 150 ° C. and melt-extruded at 290 ° C. to prepare an amorphous film, followed by stretching at 4.0 times in the longitudinal direction at 95 ° C. and biaxially stretching at 105 ° C. in the width direction. After crystallization while giving a relaxation rate of 3% at 220 ℃ to prepare a biaxially orientated ethylene terephthalate film having a thickness of 14.5㎛.

[실시예 5]Example 5

평균 입경 0.9㎛의 α-알루미나 100중량부를 에틸렌 글리콜 100중량부에 충분히 혼합시킨 후 여기에 에틸렌 글리콜 800중량부를 첨가하여 샌드 글라인딩하여 α-알루미나가 균일하게 분산된 에틸렌글리콜 슬러리를 제조하였다.100 parts by weight of α-alumina having an average particle diameter of 0.9 μm was sufficiently mixed with 100 parts by weight of ethylene glycol, and then 800 parts by weight of ethylene glycol was added thereto, followed by sand grinding to prepare an ethylene glycol slurry in which α-alumina was uniformly dispersed.

디메틸렌테레프탈레이트 100 중량부, 에틸렌글리콜 60중량부, 초산 마그네슘 4 수화물 0.1 중량부, 삼산화 안티몬 0.06중량부를 에스테르 교환 반응기에 투입하고 140℃부터 메탄올을 제거하면서 4시간에 걸쳐 에스테르 교환 반응을 종료하였다. 다음에 앞에서 제조한 에틸렌 글리콜 슬러리를 α-알루미나가 폴리에스테르 수지중에 1.0중량% 되도록 첨가하고 트리메틸포스페이트를 0.05중량부와 평균 입경이 0.3㎛인 탄산 칼슘을 0.2중량부 첨가한 후 중축합 잔응기로 이송하여 고진공으로 4시간 동안 중축합 반응을 실시하여 고유 점도 0.615인 폴리에틸렌테레프탈레이트를 제조하였다.100 parts by weight of dimethylene terephthalate, 60 parts by weight of ethylene glycol, 0.1 part by weight of magnesium acetate tetrahydrate, and 0.06 part by weight of antimony trioxide were added to a transesterification reactor, and the transesterification reaction was completed over 4 hours while removing methanol from 140 ° C. . Next, the ethylene glycol slurry prepared above was added so that α-alumina was 1.0% by weight in the polyester resin, 0.05 parts by weight of trimethyl phosphate and 0.2 parts by weight of calcium carbonate having an average particle diameter of 0.3 µm were added. Polycondensation reaction was carried out for 4 hours at high vacuum to prepare a polyethylene terephthalate having an intrinsic viscosity of 0.615.

이와 같이 제조한 폴리에틸렌테레프탈레이트를 150℃에서 건조시킨 후 290℃에서 용융압출시켜 무정형의 필름을 제조한 후 95℃에서 길이방향으로 4.0배 연신한 후 105℃에서 폭방향으로 3.8배되도록 이축 연신 한 후 220℃에서 3%의 완화율을 부여하면서 결정화시켜 14.5㎛ 두께의 2축 배향에틸렌테레프탈레이트 필름을 제조하였다.The polyethylene terephthalate thus prepared was dried at 150 ° C. and melt-extruded at 290 ° C. to prepare an amorphous film, followed by stretching at 4.0 times in the longitudinal direction at 95 ° C. and biaxially stretching at 105 ° C. in the width direction. After crystallization while giving a relaxation rate of 3% at 220 ℃ to prepare a biaxially orientated ethylene terephthalate film having a thickness of 14.5㎛.

[비교예 1]Comparative Example 1

디메틸렌테레프탈레이트 100 중량부, 에틸렌글리콜 60중량부, 초산 마그네슘 4 수화물 0.1 중량부, 삼산화 안티몬 0.06중량부를 에스테르 교환 반응기에 투입하고 140℃부터 메탄올을 제거하면서 4시간에 걸쳐 에스테르 교환 반응을 종료하였다. 트리메틸포스페이트를 0.05중량부와 평균 입경이 0.3㎛인 탄산 칼슘을 0.2중량부 첨가한 후 중축합 반응기로 이송하여 고진공으로 4시간 동안 중축합 반응을 실시하여 고유 점도 0.615인 폴리에틸렌테레프탈레이트를 제조하였다.100 parts by weight of dimethylene terephthalate, 60 parts by weight of ethylene glycol, 0.1 part by weight of magnesium acetate tetrahydrate, and 0.06 part by weight of antimony trioxide were added to a transesterification reactor, and the transesterification reaction was completed over 4 hours while removing methanol from 140 ° C. . After adding 0.05 parts by weight of trimethyl phosphate and 0.2 parts by weight of calcium carbonate having an average particle diameter of 0.3 μm, the polycondensation reactor was transferred to a polycondensation reactor to carry out polycondensation for 4 hours to prepare polyethylene terephthalate having an intrinsic viscosity of 0.615.

이와 같이 제조한 폴리에틸렌테레프탈레이트를 150℃에서 건조시킨 후 290℃에서 용융압출시켜 무정형의 필름을 제조한 후 95℃에서 길이방향으로 4.0배 연신한 후 105℃에서 폭방향으로 3.8배되도록 이축 연신 한 후 220℃에서 3%의 완화율을 부여하면서 결정화시켜 14.5㎛ 두께의 2축 배향에틸렌테레프탈레이트 필름을 제조하였다.The polyethylene terephthalate thus prepared was dried at 150 ° C. and melt-extruded at 290 ° C. to prepare an amorphous film, followed by stretching at 4.0 times in the longitudinal direction at 95 ° C. and biaxially stretching at 105 ° C. in the width direction. After crystallization while giving a relaxation rate of 3% at 220 ℃ to prepare a biaxially orientated ethylene terephthalate film having a thickness of 14.5㎛.

[비교예 2]Comparative Example 2

평균 입경 0.1㎛의 α-알루미나 100중량부를 에틸렌 글리콜 100중량부에 충분히 혼합시킨 후 여기에 에틸렌 글리콜 800중량부를 첨가하여 샌드 글라인딩하여 α-알루미나가 균일하게 분산된 에틸렌글리콜 슬러리를 제조하였다.100 parts by weight of α-alumina having an average particle diameter of 0.1 μm was sufficiently mixed with 100 parts by weight of ethylene glycol, and then 800 parts by weight of ethylene glycol was added thereto, followed by sand grinding to prepare an ethylene glycol slurry in which α-alumina was uniformly dispersed.

디메틸렌테레프탈레이트 100 중량부, 에틸렌글리콜 60중량부, 초산 마그네슘 4 수화물 0.1 중량부, 삼산화 안티몬 0.06중량부를 에스테르 교환 반응기에 투입하고 140℃부터 메탄올을 제거하면서 4시간에 걸쳐 에스테르 교환 반응을 종료하였다. 다음에 앞에서 제조한 에틸렌 글리콜 슬러리를 α-알루미나가 폴리 에스테르 수지중에 1.0중량% 되도록 첨가하고 트리메틸포스페이트를 0.05중량부와 평균 입경이 0.3㎛인 탄산 칼슘을 0.2중량부 첨가한 후 중축합 반응기로 이송하여 고진공으로 4시간 동안 중축합 반응을 실시하여 고유 점도 0.615인 폴리에틸렌테레프탈레이트를 제조하였다.100 parts by weight of dimethylene terephthalate, 60 parts by weight of ethylene glycol, 0.1 part by weight of magnesium acetate tetrahydrate, and 0.06 part by weight of antimony trioxide were added to a transesterification reactor, and the transesterification reaction was completed over 4 hours while removing methanol from 140 ° C. . Next, the ethylene glycol slurry prepared above was added so that α-alumina was 1.0% by weight in the polyester resin, 0.05 parts by weight of trimethyl phosphate and 0.2 parts by weight of calcium carbonate having an average particle diameter of 0.3 µm were transferred to the polycondensation reactor. Polycondensation reaction was carried out for 4 hours at high vacuum to prepare a polyethylene terephthalate having an intrinsic viscosity of 0.615.

이와 같이 제조한 폴리에틸렌테레프탈레이트를 150℃에서 건조시킨 후 290℃에서 용융압출시켜 무정형의 필름을 제조한 후 95℃에서 길이방향으로 4.0배 연신한 후 105℃에서 폭방향으로 3.8배되도록 이축 연신 한 후 220℃에서 3%의 완화율을 부여하면서 결정화시켜 14.5㎛ 두께의 2축 배향에틸렌테레프탈레이트 필름을 제조하였다.The polyethylene terephthalate thus prepared was dried at 150 ° C. and melt-extruded at 290 ° C. to prepare an amorphous film, followed by stretching at 4.0 times in the longitudinal direction at 95 ° C. and biaxially stretching at 105 ° C. in the width direction. After crystallization while giving a relaxation rate of 3% at 220 ℃ to prepare a biaxially orientated ethylene terephthalate film having a thickness of 14.5㎛.

[비교예 3]Comparative Example 3

평균 입경 2.0㎛의 α-알루미나 100중량부를 에틸렌 글리콜 100중량부에 충분히 혼합시킨 후 여기에 에틸렌 글리콜 800중량부를 첨가하여 샌드 글라인딩하여 α-알루미나가 균일하게 분산된 에틸렌글리콜 슬러리를 제조하였다.100 parts by weight of α-alumina having an average particle diameter of 2.0 μm was sufficiently mixed with 100 parts by weight of ethylene glycol, and then 800 parts by weight of ethylene glycol was added thereto, followed by sand grinding to prepare an ethylene glycol slurry in which α-alumina was uniformly dispersed.

디메틸렌테레프탈레이트 100 중량부, 에틸렌글리콜 60중량부, 초산 마그네슘 4 수화물 0.1 중량부, 삼산화 안티몬 0.06중량부를 에스테르 교환 반응기에 투입하고 140℃부터 메탄올을 제거하면서 4시간에 걸쳐 에스테르 교환 반응을 종료하였다. 다음에 앞에서 제조한 에틸렌 글리콜 슬러리를 α-알루미나가 폴리 에스테르 수지중에 1.0중량% 되도록 첨가하고 트리메틸포스페이트를 0.05중량부와 평균 입경이 0.3㎛인 탄산 칼슘을 0.2중량부 첨가한 후 중축합 반응기로 이송하여 고진공으로 4시간 동안 중축합 반응을 실시하여 고유 점도 0.615인 폴리에틸렌테레프탈레이트를 제조하였다.100 parts by weight of dimethylene terephthalate, 60 parts by weight of ethylene glycol, 0.1 part by weight of magnesium acetate tetrahydrate, and 0.06 part by weight of antimony trioxide were added to a transesterification reactor, and the transesterification reaction was completed over 4 hours while removing methanol from 140 ° C. . Next, the ethylene glycol slurry prepared above was added so that α-alumina was 1.0% by weight in the polyester resin, 0.05 parts by weight of trimethyl phosphate and 0.2 parts by weight of calcium carbonate having an average particle diameter of 0.3 µm were transferred to the polycondensation reactor. Polycondensation reaction was carried out for 4 hours at high vacuum to prepare a polyethylene terephthalate having an intrinsic viscosity of 0.615.

이와 같이 제조한 폴리에틸렌테레프탈레이트를 150℃에서 건조시킨 후 290℃에서 용융압출시켜 무정형의 필름을 제조한 후 95℃에서 길이방향으로 4.0배 연신한 후 105℃에서 폭방향으로 3.8배되도록 이축 연신 한 후 220℃에서 3%의 완화율을 부여하면서 결정화시켜 14.5㎛ 두께의 2축 배향에틸렌테레프탈레이트 필름을 제조하였다.The polyethylene terephthalate thus prepared was dried at 150 ° C. and melt-extruded at 290 ° C. to prepare an amorphous film, followed by stretching at 4.0 times in the longitudinal direction at 95 ° C. and biaxially stretching at 105 ° C. in the width direction. After crystallization while giving a relaxation rate of 3% at 220 ℃ to prepare a biaxially orientated ethylene terephthalate film having a thickness of 14.5㎛.

[비교예 4][Comparative Example 4]

평균 입경 0.5㎛의 α-알루미나 100중량부를 에틸렌 글리콜 100중량부에 충분히 혼합시킨 후 여기에 에틸렌 글리콜 800중량부를 첨가하여 샌드 글라인딩하여 α-알루미나가 균일하게 분산된 에틸렌글리콜 슬러리를 제조하였다.100 parts by weight of α-alumina having an average particle diameter of 0.5 μm was sufficiently mixed with 100 parts by weight of ethylene glycol, and then 800 parts by weight of ethylene glycol was added thereto, followed by sand grinding to prepare an ethylene glycol slurry in which α-alumina was uniformly dispersed.

디메틸렌테레프탈레이트 100 중량부, 에틸렌글리콜 60중량부, 초산 마그네슘 4 수화물 0.1 중량부, 삼산화 안티몬 0.06중량부를 에스테르 교환 반응기에 투입하고 140℃부터 메탄올을 제거하면서 4시간에 걸쳐 에스테르 교환 반응을 종료하였다. 다음에 앞에서 제조한 에틸렌 글리콜 슬러리를 α-알루미나가 폴리 에스테르 수지중에 0.05중량% 되도록 첨가하고 트리메틸포스페이트를 0.05중량부와 평균 입경이 0.3㎛인 탄산 칼슘을 0.2중량부 첨가한 후 중축합 반응기로 이송하여 고진공으로 4시간 동안 중축합 반응을 실시하여 고유 점도 0.615인 폴리에틸렌테레프탈레이트를 제조하였다.100 parts by weight of dimethylene terephthalate, 60 parts by weight of ethylene glycol, 0.1 part by weight of magnesium acetate tetrahydrate, and 0.06 part by weight of antimony trioxide were added to a transesterification reactor, and the transesterification reaction was completed over 4 hours while removing methanol from 140 ° C. . Next, the previously prepared ethylene glycol slurry was added so that the α-alumina was 0.05% by weight in the polyester resin, 0.05 parts by weight of trimethyl phosphate and 0.2 parts by weight of calcium carbonate having an average particle diameter of 0.3 μm were transferred to the polycondensation reactor. Polycondensation reaction was carried out for 4 hours at high vacuum to prepare a polyethylene terephthalate having an intrinsic viscosity of 0.615.

이와 같이 제조한 폴리에틸렌테레프탈레이트를 150℃에서 건조시킨 후 290℃에서 용융압출시켜 무정형의 필름을 제조한 후 95℃에서 길이방향으로 4.0배 연신한 후 105℃에서 폭방향으로 3.8배되도록 이축 연신 한 후 220℃에서 3%의 완화율을 부여하면서 결정화시켜 14.5㎛ 두께의 2축 배향에틸렌테레프탈레이트 필름을 제조하였다.The polyethylene terephthalate thus prepared was dried at 150 ° C. and melt-extruded at 290 ° C. to prepare an amorphous film, followed by stretching at 4.0 times in the longitudinal direction at 95 ° C. and biaxially stretching at 105 ° C. in the width direction. After crystallization while giving a relaxation rate of 3% at 220 ℃ to prepare a biaxially orientated ethylene terephthalate film having a thickness of 14.5㎛.

[비교예 5][Comparative Example 5]

평균 입경 0.5㎛의 α-알루미나 100중량부를 에틸렌 글리콜 100중량부에 충분히 혼합시킨 후 여기에 에틸렌 글리콜 800중량부를 첨가하여 샌드 글라인딩하여 α-알루미나가 균일하게 분산된 에틸렌글리콜 슬러리를 제조하였다.100 parts by weight of α-alumina having an average particle diameter of 0.5 μm was sufficiently mixed with 100 parts by weight of ethylene glycol, and then 800 parts by weight of ethylene glycol was added thereto, followed by sand grinding to prepare an ethylene glycol slurry in which α-alumina was uniformly dispersed.

디메틸렌테레프탈레이트 100 중량부, 에틸렌글리콜 60중량부, 초산 마그네슘 4 수화물 0.1 중량부, 삼산화 안티몬 0.06중량부를 에스테르 교환 반응기에 투입하고 140℃부터 메탄올을 제거하면서 4시간에 걸쳐 에스테르 교환 반응을 종료하였다. 다음에 앞에서 제조한 에틸렌 글리콜 슬러리를 α-알루미나가 폴리 에스테르 수지중에 7.0중량% 되도록 첨가하고 트리메틸포스페이트를 0.05중량부와 평균 입경이 0.3㎛인 탄산 칼슘을 0.2중량부 첨가한 후 중축합 반응기로 이송하여 고진공으로 4시간 동안 중축합 반응을 실시하여 고유 점도 0.615인 폴리에틸렌테레프탈레이트를 제조하였다.100 parts by weight of dimethylene terephthalate, 60 parts by weight of ethylene glycol, 0.1 part by weight of magnesium acetate tetrahydrate, and 0.06 part by weight of antimony trioxide were added to a transesterification reactor, and the transesterification reaction was completed over 4 hours while removing methanol from 140 ° C. . Next, the ethylene glycol slurry prepared above was added so that α-alumina was 7.0% by weight in the polyester resin, 0.05 parts by weight of trimethyl phosphate and 0.2 parts by weight of calcium carbonate having an average particle diameter of 0.3 µm were transferred to the polycondensation reactor. Polycondensation reaction was carried out for 4 hours at high vacuum to prepare a polyethylene terephthalate having an intrinsic viscosity of 0.615.

이와 같이 제조한 폴리에틸렌테레프탈레이트를 150℃에서 건조시킨 후 290℃에서 용융압출시켜 무정형의 필름을 제조한 후 95℃에서 길이방향으로 4.0배 연신한 후 105℃에서 폭방향으로 3.8배되도록 이축 연신 한 후 220℃에서 3%의 완화율을 부여하면서 결정화시켜 14.5㎛ 두께의 2축 배향에틸렌테레프탈레이트 필름을 제조하였다.The polyethylene terephthalate thus prepared was dried at 150 ° C. and melt-extruded at 290 ° C. to prepare an amorphous film, followed by stretching at 4.0 times in the longitudinal direction at 95 ° C. and biaxially stretching at 105 ° C. in the width direction. After crystallization while giving a relaxation rate of 3% at 220 ℃ to prepare a biaxially orientated ethylene terephthalate film having a thickness of 14.5㎛.

상기한 실시예 및 비교예에 따라 제조한 필름에 자성층을 하기한 방법으로 도포한 후 그들의 특성치를 다음과 같은 측정법에 의하여 특정하고 그 결과를 하기한 표에 나타내었다.After applying the magnetic layer to the films prepared according to the above Examples and Comparative Examples by the following method, their characteristic values were specified by the following measuring method and the results are shown in the table below.

[1.필름의 표면 조도(SRa)][1.Film Surface Roughness (SRa)]

비접촉식 3차원 표면 조도계(기기명 : WYKO사의 TOPO-3D)로 측정된 중심선 거칠기를 SRa로 하였다.The center line roughness measured by the non-contact three-dimensional surface roughness meter (the equipment name: TOPO-3D of WYKO Corporation) was made into SRa.

여기서here

, ,

z = f (x, y) = (x, y)위치에서의 표면 높이z = f (x, y) = surface height at position (x, y)

i = 측정숫자i = measurement number

N = 측정된 데이타 포인트의 갯수N = number of measured data points

[2. 이활성(마찰계수)][2. Activity (friction coefficient)]

ASTM D-1894에 의하여 25℃, 6.0±5% RH의 분위기에서 필름과 필름을 마찰시켜 동마찰계수를 측정하여 이활성을 평가하였다.According to ASTM D-1894, the activity was evaluated by rubbing the film and the film in a 25 ° C, 6.0 ± 5% RH atmosphere by measuring the coefficient of kinetic friction.

[3. RF 출력][3. RF output]

비디오 테이프를 일본 VICTOR사의 비디오 데크(BR-7000)에 장착하여 100% 백색신호를 기록한 뒤 재생시의 출력을 측정하고, 자사의 기준 테이프와 비교치를 나타내었다.A video tape was mounted on a video deck (BR-7000) from VICTOR, Japan, recorded a 100% white signal, measured the output during playback, and compared with its reference tape.

[4. 드롭아웃][4. Dropout]

비디오 테이프에 5단계 단차신호를 최적전류에서 기록하고 재생시 재생신호의 감쇄량이 20dB, 계속시간이 15usec이상인 것을 드롯아웃으로 간주하여 10분동안 측정하고 1분당 평균하여 나타냈다.A 5-step step signal was recorded on the video tape at the optimum current, and the attenuation of the playback signal during playback was 20 dB and the duration time was 15usec or more.

[5. 도포방법][5. Application method]

[자성층][Magnetic layer]

폴리에틸렌테레프탈레이트 필름에 다음과 같은 조성물을 혼합, 분산시킨뒤 3um 두께로 자성층을 도포하여 건조, 칼렌더링 하였다.The following composition was mixed and dispersed in a polyethylene terephthalate film, and then dried and calendered by applying a magnetic layer having a thickness of 3 μm.

강자성 분말 (Co-γ-Fe2O3: BET = 33 m2/g) … 100중량부Ferromagnetic powder (Co-γ-Fe 2 O 3 : BET = 33 m 2 / g). 100 parts by weight

염화비닐계 공중합체 수지(미국 UCC사 : 유카막 527) … 11중량부Vinyl chloride copolymer resin (UCC, USA) 527). 11 parts by weight

폴리우레탄 수지(미국 모톤사 : CA사 128) … 11중량부Polyurethane Resin (US Morton Corporation: CA Corporation 128)... 11 parts by weight

연마제(α-Al2O3) … 3중량부Abrasive (α-Al 2 O 3 ). 3 parts by weight

카본블랙(평균 입력 24nm) … 6중량부Carbon black (average input 24 nm)... 6 parts by weight

미리시틱산 … 1중량부Myristic acid… 1 part by weight

노말부틸스테아레이트 … 1중량부Normal Butyl Stearate 1 part by weight

사이클로헥사논 … 125중량부Cyclohexanone 125 parts by weight

메틸에틸케톤 … 125중량부Methyl ethyl ketone. 125 parts by weight

톨루엔 … 125중량부Toluene… 125 parts by weight

[표][table]

[효과][effect]

이렇게 하여 얻어진 이축배향 폴리에틸렌테레프탈레이트 필름은 0.3이하의 마찰계수를 갖는 이활성과 SRa(중심선 평균 거칠기)가 8~11nm의 고평활성을 만족한다.The biaxially oriented polyethylene terephthalate film obtained in this way satisfies the high activity of 8-11 nm with the diactivity and SRa (center line average roughness) which have a coefficient of friction of 0.3 or less.

상기 필름은 마찰특성이 좋음으로 인해 필름생산시 작업성, 권취성이 좋을 뿐 아니라, 공지에 도포기술을 이용하여 비디오 테이프를 만들고, 최종 평가를 한 결과 높은 평활성으로 인해 자성체 도포면이 매우 평활하여 자기헤드드럼과의 공간손실이 적음으로 전자 변환 특성이 우수하였고, 드롭 아웃도 매우 적었다.The film not only has good workability and winding property in film production due to its good friction characteristics, but also makes a video tape using a coating technique in advance, and as a result of the final evaluation, the magnetic coating surface is very smooth due to high smoothness. Due to the small space loss with the head drum, the electron conversion characteristics were excellent and the dropout was very small.

Claims (2)

하기의 관계식을 만족하는 평균 입경을 갖는 α-알루미나를 함유한 2축 배향 폴리에스테르 필름으로 구성되어지는 자기 기록 매체용 비자성 필름.A nonmagnetic film for a magnetic recording medium composed of a biaxially oriented polyester film containing α-alumina having an average particle diameter satisfying the following relational formula. 0.01 T < R < 0.1 T0.01 T <R <0.1 T 0.1㎛ ≤ R0.1 μm ≤ R (상기 관계식에서 T는 2축 배향 폴리에스테르 필름의 두께이고, R은 α-알루미나 입자의 평균 입경이다.(In the above relation, T is the thickness of the biaxially oriented polyester film, and R is the average particle diameter of the α-alumina particles. 제1항에 있어서, 상기 α-알루미나는 폴리에스테르 중에 0.1 내지 5중량% 함유됨을 특징으로 하는 필름.The film of claim 1, wherein the α-alumina is contained in an amount of 0.1 to 5 wt% in polyester.
KR1019940035948A 1994-12-22 1994-12-22 Film for magnetic recording media KR100291275B1 (en)

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Publication number Priority date Publication date Assignee Title
KR950001631A (en) * 1993-06-21 1995-01-03 다니모또 기요시 Magnetic recording media

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR950001631A (en) * 1993-06-21 1995-01-03 다니모또 기요시 Magnetic recording media

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