JPH0452203B2 - - Google Patents

Info

Publication number
JPH0452203B2
JPH0452203B2 JP59229651A JP22965184A JPH0452203B2 JP H0452203 B2 JPH0452203 B2 JP H0452203B2 JP 59229651 A JP59229651 A JP 59229651A JP 22965184 A JP22965184 A JP 22965184A JP H0452203 B2 JPH0452203 B2 JP H0452203B2
Authority
JP
Japan
Prior art keywords
film
die
mandrel
expansion ratio
bags
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
JP59229651A
Other languages
Japanese (ja)
Other versions
JPS61108530A (en
Inventor
Terumitsu Kotani
Toshio Taka
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Resonac Holdings Corp
Original Assignee
Showa Denko KK
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 Showa Denko KK filed Critical Showa Denko KK
Priority to JP59229651A priority Critical patent/JPS61108530A/en
Publication of JPS61108530A publication Critical patent/JPS61108530A/en
Publication of JPH0452203B2 publication Critical patent/JPH0452203B2/ja
Granted legal-status Critical Current

Links

Classifications

    • 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
    • B29C55/28—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of blown tubular films, e.g. by inflation
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/03—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor characterised by the shape of the extruded material at extrusion
    • B29C48/09—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
    • B29C48/10—Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels flexible, e.g. blown foils
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/25—Component parts, details or accessories; Auxiliary operations
    • B29C48/88—Thermal treatment of the stream of extruded material, e.g. cooling
    • B29C48/90—Thermal treatment of the stream of extruded material, e.g. cooling with calibration or sizing, i.e. combined with fixing or setting of the final dimensions of the extruded article
    • B29C48/901—Thermal treatment of the stream of extruded material, e.g. cooling with calibration or sizing, i.e. combined with fixing or setting of the final dimensions of the extruded article of hollow bodies
    • B29C48/902—Thermal treatment of the stream of extruded material, e.g. cooling with calibration or sizing, i.e. combined with fixing or setting of the final dimensions of the extruded article of hollow bodies internally
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/001—Combinations of extrusion moulding with other shaping operations
    • B29C48/0018—Combinations of extrusion moulding with other shaping operations combined with shaping by orienting, stretching or shrinking, e.g. film blowing
    • 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
    • B29C48/00—Extrusion moulding, i.e. expressing the moulding material through a die or nozzle which imparts the desired form; Apparatus therefor
    • B29C48/001—Combinations of extrusion moulding with other shaping operations
    • B29C48/0019—Combinations of extrusion moulding with other shaping operations combined with shaping by flattening, folding or bending

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Shaping By String And By Release Of Stress In Plastics And The Like (AREA)

Description

【発明の詳細な説明】[Detailed description of the invention]

〔産業上の利用分野〕 本発明はポリエチレン系樹脂の薄いインフレー
シヨンフイルムからなり、縦方向、横方向の強度
が共に強い袋用に好適なフイルムの製造方法に関
する。 〔従来技術〕 一般にフイルムをインフレーシヨン法で製造す
るには、樹脂の押出し速度に対して、高速で引取
るとともに、押出される管状フイルム内に気体を
封入して膨張させている。この場合膨張比が小さ
いと引取方向（縦方向又はＭ方向）への分子配向
が大きくなり、縦方向の引裂強度が極端に低下す
る。このため通常膨張比を３以上と大きくして引
取方向に対して直角方向（横方向又はＴ方向）の
分子配向も加え縦方向の分子配向とバランスさせ
ることが行なわれている。なお膨張比を大きくす
ると、形成されるバブルが不安定化し、これを高
速で引取ると、成形されるフイルムに厚みむら
や、しわ、たるみなどが発生するが、本発明者等
は、ダイスに安定体を突出させてフイルム内面の
一部の全周を接触させることによりこの問題を解
決した（特公昭55−2180）。 〔発明が解決しようとする課題〕 しかし、膨張比を大きくしてフイルムの厚みが
薄くなると、製袋後の使用時の荷重によつては横
方向に裂ける、いわば輪切れ現象が発生する。通
常、インフレーシヨンフイルムを袋にするには、
引取方向に直角にヒートシールを行ない製袋する
が、輪切れ現象は中に物を入れると、その荷重に
よつて発生するため袋として致命的欠陥となる。 本発明はポリエチレン系樹脂を用い、なかでも
好適には高密度ポリエチレン系樹脂を用いて、イ
ンフレーシヨン法によつて縦および横方向の強度
が共に高い特に薄い厚みの袋用として優れたフイ
ルムを製造する方法を提供することを目的とす
る。 〔課題を解決するための手段〕 本発明は上記の目的を達成するためになされた
もので、その要旨は、密度0.940ｇ／cm3以上、メ
ルトインデツクス１ｇ／10min以下のポリエチレ
ン系樹脂を環状ダイスから押し出して膨張比３以
上でインフレーシヨンフイルム成形をするにあた
り、環状ダイスのスリツトを構成するマンドレル
外側面に複数の凹溝を形成してインフレーシヨン
フイルム内面に押出方向に延在する複数の凸条を
形成する方法において、マンドレルにバブル安定
体を固定し、その長さ方向の少なくとも一部分の
全周域にわたり、インフレーシヨン内面に存在す
る凸条を強く接触させ、平坦にならず袋用フイル
ムの製造方法にある。 以下、本発明の内容を詳説する。 本発明に用いられるポリエチレン系樹脂とは、
ポリエチレンホモポリマー、ポリエチレンと異種
オレフイン、例えばプロピレン、１−ブテン、ヘ
キセン等のαオレフインとのコポリマー或いはこ
れらを主体とするブレンド物などで、該重合物の
密度が0.940ｇ／cm3以上、メルトインデツクスが
１ｇ／10min以下のものである。これには、必要
に応じて安定剤、紫外線吸収剤、滑剤、着色剤、
耐ブロツキング剤等を添加してもよい。 上記重合物の密度が0.940ｇ／cm3未満では、成
形したフイルムの強度が不足し、かつ腰が弱くな
り、また、メルトインデツクスが１ｇ／10minを
越えるとフイルムの強度が弱くなる。 本発明の袋用フイルム製造法の一例を次に示
す。 第１図および第２図は、装置の一例を示すもの
で、第１図は、ダイスの一部平面図、第２図はイ
ンフレーシヨンフイルムを製造している装置の側
面図である。ダイスリツト２を形成するマンドレ
ル３の外周面には、所定の間隔で流れ方向の凹溝
４が設けられ、またダイス１の面にはバブル安定
体５が突出されている。 上記ダイスリツト２より溶融して押出されたポ
リエチレン系樹脂管状体は内面に凸条が形成さ
れ、安定体５にくびれ部分６ａが密接し、バブル
６は安定するとともに、凸条はある程度ならされ
るが残存し、従来の成形法で得られるフイルムに
比して輪切れのないＴ方向の耐引裂性の改良され
たフイルムが得られる。すなわち、ダイスリツト
２より押出され凹溝４…によつて多数の凸条が内
面に形成された範囲７の管状樹脂は、くびれ部分
６ａにおいてバブル安定体５に密接してまだ固化
していない凸条は或る程度ならされ、安定体５を
貫通（図示せず）する空気により範囲８で所定の
比率で膨張され、フロストライン６ｂ以降の範囲
９において固化し、第３図に示すように縦方向の
平坦部１１とならされた凸条１２とよりなる薄い
フイルム１３となり、ニツプロールに巻取られ
る。なお、図中符号１４は空気を噴出するエアー
リングである。 上記フイルム１３は、ならされた凸条１２を有
するため横方向の引裂強度が強く、輪切れ現象の
発生が防止される。凸条１２の密度は平坦部１１
の厚みによつて異るが、特に平坦部の厚みが15μ
ｍ以下の場合に好適には幅方向で７mmに対して１
本以上、好ましくは3.5mmに対して１本以上であ
る、７mmに対して１本未満では、平坦部１１が引
裂かれ易くなる。 なお、本発明の製造方法によればならされた凸
条はインフレーシヨンフイルムの内側に形成され
るが、これは成形された凸部を、接触という簡単
な方法により達成されならすのに便利である。 実施例、比較例 次に実施例、比較例を示して本発明を説明す
る。 実施例 １ 密度（JIS K6760）；0.958ｇ／cm3、メルトイン
デツクス（JIS K6760）；0.5ｇ／10minのエチレ
ンホモポリマーを200℃で溶融し、これを、マン
ドレル外周面に深さ；0.5mm、幅；0.5mmのＶ字形
の流れ方向の凹溝240本が設けられたマンドレル
外径（非溝部）；59mmφ、ダイ内径；60mmφのダ
イスリツトを有し、面中央に外径；55mmφ、高
さ；700mmの円筒状の安定体が突出されているダ
イスが取付けられた65mmφの押出機を使用して、
膨張比；４、引取速度；80ｍ；minでインフレー
シヨンフイルムを作成し、これを試料として衝撃
強さ、エルメンドルフ引裂強度、高速衝撃強さを
測定した。 実施例 ２ 膨張比を３とし押出量を変えた外は実施例１と
同じにしてフイルムをつくり各物性を測定した。 比較例 １ 凹凸のないダイスリツトのダイスを用いた外は
実施例１と同じにしてフイルムをつくり、各物性
を測定した。 比較例 ２ 凹凸のないダイスリツトのダイスを用いた外は
実施例２と同じにしてフイルムをつくり、各物性
を測定した。 比較例 ３ 原料樹脂を変え、190℃で溶融し、膨張比を２
とした外は実施例１と同じにしてフイルムをつく
り、各物性を測定した。 比較例 ４ 原料樹脂を変え190℃で溶融した外は実施例１
と同じにしてフイルムをつくり、各物性を測定し
た。 実施例１、２、比較例１〜４の結果を第１表に
示す。 なお、衝撃強さはASTM Ｄ 781、エルメン
ドルフ引裂強度はJIS Ｚ 1702、による。また、
高速衝撃強さは、試料フイルムをダンベル状に打
ち抜き、もつとも細い部分を3.18mm幅×12μｍ厚
にして3.29ｍ／minの速度で引張り、試料の破断
した時のエネルギーをもとの断面積で除して求め
た。 [Industrial Field of Application] The present invention relates to a method for producing a thin inflation film made of polyethylene resin, which has strong strength in both the longitudinal and lateral directions and is suitable for use in bags. [Prior Art] Generally, to manufacture a film by the inflation method, the film is taken off at a high speed relative to the extrusion speed of the resin, and the extruded tubular film is filled with gas to expand it. In this case, if the expansion ratio is small, the molecular orientation in the pulling direction (longitudinal direction or M direction) becomes large, and the tear strength in the longitudinal direction is extremely reduced. For this reason, the expansion ratio is usually increased to 3 or more, and molecular orientation in the direction perpendicular to the drawing direction (transverse direction or T direction) is also added to balance the molecular orientation in the longitudinal direction. Note that when the expansion ratio is increased, the bubbles formed become unstable, and when these bubbles are taken off at high speed, uneven thickness, wrinkles, and sag occur in the formed film. This problem was solved by making the stabilizer protrude and contact the entire circumference of a part of the inner surface of the film (Japanese Patent Publication No. 55-2180). [Problems to be Solved by the Invention] However, when the expansion ratio is increased and the film thickness is reduced, depending on the load applied during use after bag making, the bag may tear laterally, a so-called tearing phenomenon. Normally, to make bags from inflation film,
Bags are made by heat-sealing them at right angles to the take-up direction, but the phenomenon of ring breakage occurs due to the load when something is placed inside, which is a fatal defect in the bag. The present invention uses a polyethylene resin, particularly a high-density polyethylene resin, to produce a film that has high strength in both the longitudinal and lateral directions and is particularly suitable for thin bags by an inflation method. The purpose is to provide a method for manufacturing. [Means for Solving the Problems] The present invention has been made to achieve the above object, and its gist is to form a polyethylene resin having a density of 0.940 g/cm 3 or more and a melt index of 1 g/10 min or less into a cyclic form. When extruding from a die to form a blown film at an expansion ratio of 3 or more, a plurality of concave grooves are formed on the outer surface of the mandrel constituting the slit of the annular die, and a plurality of grooves are formed on the inner surface of the blown film extending in the extrusion direction. In this method, a bubble stabilizer is fixed to a mandrel, and the protrusions existing on the inner surface of the inflation are brought into strong contact over the entire circumference of at least a portion of its length, so that the bag does not become flat. In the method of manufacturing film for use in Hereinafter, the content of the present invention will be explained in detail. The polyethylene resin used in the present invention is
Polyethylene homopolymers, copolymers of polyethylene and different olefins such as α-olefins such as propylene, 1-butene, hexene, etc., or blends mainly composed of these; Tux is 1g/10min or less. This includes stabilizers, UV absorbers, lubricants, colorants,
An anti-blocking agent or the like may be added. If the density of the polymer is less than 0.940 g/cm 3 , the strength of the formed film will be insufficient and it will be weak, and if the melt index exceeds 1 g/10 min, the strength of the film will be weak. An example of the method for producing a film for bags according to the present invention is shown below. 1 and 2 show an example of the apparatus, with FIG. 1 being a partial plan view of a die, and FIG. 2 being a side view of the apparatus for manufacturing blown film. The outer peripheral surface of the mandrel 3 forming the die slit 2 is provided with concave grooves 4 extending in the flow direction at predetermined intervals, and a bubble stabilizer 5 is protruded from the surface of the die 1. The polyethylene resin tubular body melted and extruded from the die slit 2 has ridges formed on its inner surface, and the constricted portion 6a is in close contact with the stabilizer 5, making the bubble 6 stable and the ridges smoothed out to some extent. Thus, a film with improved tear resistance in the T-direction without any ring breakage can be obtained compared to films obtained by conventional molding methods. That is, the tubular resin in the range 7, which has been extruded from the die slit 2 and has a large number of convex lines formed on the inner surface by the grooves 4, is in close contact with the bubble stabilizer 5 at the constricted part 6a, and has not yet solidified convex lines. is leveled to a certain extent, expanded at a predetermined ratio in a range 8 by air passing through the stabilizer 5 (not shown), solidified in a range 9 after the frost line 6b, and expanded in the vertical direction as shown in FIG. A thin film 13 consisting of flat portions 11 and smoothed protrusions 12 is formed and wound onto a nip roll. Note that the reference numeral 14 in the figure is an air ring that blows out air. Since the film 13 has the smoothed protrusions 12, it has high tear strength in the lateral direction, and the occurrence of the phenomenon of tearing is prevented. The density of the protrusions 12 is the same as that of the flat part 11
It varies depending on the thickness of the flat part, but especially the thickness of the flat part is 15μ.
If the width is less than m, preferably 1 for 7 mm in the width direction.
If the number is more than one per 3.5 mm, preferably one per 3.5 mm, but less than one per 7 mm, the flat portion 11 will be easily torn. Incidentally, according to the manufacturing method of the present invention, the smoothed protrusions are formed on the inside of the inflation film, but this is convenient for smoothing the formed protrusions by a simple method of contact. be. EXAMPLES AND COMPARATIVE EXAMPLES Next, the present invention will be described with reference to Examples and Comparative Examples. Example 1 An ethylene homopolymer having a density (JIS K6760) of 0.958 g/cm 3 and a melt index (JIS K6760) of 0.5 g/10 min was melted at 200°C and applied to the outer circumferential surface of a mandrel to a depth of 0.5 mm. Mandrel with 240 V-shaped concave grooves in the flow direction with a width of 0.5 mm.Outer diameter (non-grooved part): 59 mmφ, die inner diameter: 60 mmφ die slit, outer diameter: 55 mmφ in the center of the surface, height ; Using a 65mmφ extruder equipped with a die with a 700mm cylindrical stabilizer protruding,
An inflation film was prepared with an expansion ratio of 4 and a take-up speed of 80 m/min, and was used as a sample to measure impact strength, Elmendorf tear strength, and high-speed impact strength. Example 2 A film was prepared in the same manner as in Example 1 except that the expansion ratio was 3 and the extrusion amount was changed, and the various physical properties were measured. Comparative Example 1 A film was prepared in the same manner as in Example 1 except that a die with a die slit without unevenness was used, and each physical property was measured. Comparative Example 2 A film was prepared in the same manner as in Example 2 except that a die with a die slit without unevenness was used, and each physical property was measured. Comparative example 3 The raw material resin was changed, melted at 190℃, and the expansion ratio was changed to 2.
A film was prepared in the same manner as in Example 1 except that the film was prepared and its physical properties were measured. Comparative Example 4 Example 1 except that the raw resin was changed and melted at 190℃
A film was made in the same manner as above, and its physical properties were measured. The results of Examples 1 and 2 and Comparative Examples 1 to 4 are shown in Table 1. Note that the impact strength is based on ASTM D 781, and the Elmendorf tear strength is based on JIS Z 1702. Also,
High-speed impact strength was determined by punching a sample film into a dumbbell shape, making the thinnest part 3.18 mm wide x 12 μm thick, and pulling it at a speed of 3.29 m/min, and dividing the energy when the sample broke by the original cross-sectional area. I asked.

〔発明の効果〕〔Effect of the invention〕

以上述べたように本発明の製造方法に係る袋用
フイルムは多数の凸条が設けられているので、縦
方向および横方向の切断強度が共に高く、荷重に
よる輪切れ現象が発生せず、特に薄い厚みの袋用
フイルムとして極めて優れたものである。 As described above, since the bag film according to the manufacturing method of the present invention is provided with a large number of protrusions, it has high cutting strength in both the longitudinal and lateral directions, and does not suffer from ring breakage due to load, especially It is extremely excellent as a film for thin bags.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図および第２図は、本発明に係る製造法に
より袋用フイルムを製造する装置の一例を示すも
ので、第１図はダイスの一部拡大平面図、第２図
は第１図のダイスを用いてインフレーシヨンフイ
ルムをつくる状態を示す側面図、第３図は、第２
図のフイルムの−線矢視断面図である。 １１……平坦部、１２……ならされた凸条、１
３……フイルム。 FIGS. 1 and 2 show an example of an apparatus for producing film for bags by the manufacturing method according to the present invention. FIG. 1 is a partially enlarged plan view of a die, and FIG. Figure 3 is a side view showing how a blown film is made using a die.
FIG. 2 is a cross-sectional view taken along the line -- of the film shown in the figure. 11...Flat portion, 12...Smoothed protrusion, 1
3...Film.

Claims (1)

【特許請求の範囲】[Claims] １ 密度、0.940ｇ／cm3以上、メルトインデツク
ス１ｇ／10min以下のポリエチレン樹脂を環状ダ
イスから押し出して膨張比３以上でインフレーシ
ヨンフイルム成形をするにあたり、環状ダイスの
スリツトを構成するマンドレル外側面に複数の凹
溝を形成してインフレーシヨンフイルム内面に押
出方向に延在する複数の凸条を形成する方法にお
いて、マンドレルにバブル安定体を固定し、その
長さ方向の少なくとも一部分の全周域にわたり、
インフレーシヨンフイルム内面に存在する凸条を
強く接触させ平坦にならすことを特徴とする袋用
フイルムの製造方法。1 When extruding polyethylene resin with a density of 0.940 g/cm 3 or more and a melt index of 1 g/10 min or less from an annular die to form an inflation film at an expansion ratio of 3 or more, the outer surface of the mandrel that forms the slit of the annular die In this method, a bubble stabilizer is fixed to a mandrel, and the entire circumference of at least a portion of the lengthwise direction of the bubble stabilizer is fixed to a mandrel. Over the area,
A method for manufacturing a film for bags, characterized by strongly contacting the protrusions existing on the inner surface of the inflation film to make it flat.
JP59229651A 1984-10-31 1984-10-31 Film for bag Granted JPS61108530A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP59229651A JPS61108530A (en) 1984-10-31 1984-10-31 Film for bag

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP59229651A JPS61108530A (en) 1984-10-31 1984-10-31 Film for bag

Publications (2)

Publication Number Publication Date
JPS61108530A JPS61108530A (en) 1986-05-27
JPH0452203B2 true JPH0452203B2 (en) 1992-08-21

Family

ID=16895535

Family Applications (1)

Application Number Title Priority Date Filing Date
JP59229651A Granted JPS61108530A (en) 1984-10-31 1984-10-31 Film for bag

Country Status (1)

Country Link
JP (1) JPS61108530A (en)

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5933138B2 (en) * 1977-09-22 1984-08-14 旭化成株式会社 Film containing inorganic filler
JPS565172A (en) * 1979-06-25 1981-01-20 Snow Brand Milk Products Co Ltd Washing device
JPS5617226A (en) * 1979-07-24 1981-02-19 Mitsubishi Petrochem Co Ltd Production for stretchable inflated film of polyethylene
JPS5854014A (en) * 1981-09-25 1983-03-30 Sumitomo Chem Co Ltd Production of drawn yarn having bosses

Also Published As

Publication number Publication date
JPS61108530A (en) 1986-05-27

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