JPH0613192B2 - Heat shrinkable film - Google Patents
Heat shrinkable filmInfo
- Publication number
- JPH0613192B2 JPH0613192B2 JP61044170A JP4417086A JPH0613192B2 JP H0613192 B2 JPH0613192 B2 JP H0613192B2 JP 61044170 A JP61044170 A JP 61044170A JP 4417086 A JP4417086 A JP 4417086A JP H0613192 B2 JPH0613192 B2 JP H0613192B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- stretching
- ethylene
- temperature
- copolymer
- 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 - Fee Related
Links
Landscapes
- Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
- Manufacture Of Macromolecular Shaped Articles (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は収縮包装材料に関するもので、より詳細には特
定のエチレン−α−オレフィン共重合体を主とする組成
物を原料とし、低温収縮性に優れ、厚みムラが小さいプ
ラスチック包装フィルムに関するものである。TECHNICAL FIELD The present invention relates to a shrink wrapping material, and more specifically, to a low temperature shrinkage using a composition mainly containing a specific ethylene-α-olefin copolymer as a raw material. The present invention relates to a plastic packaging film having excellent properties and having a small thickness unevenness.
（従来の技術） 従来熱収縮性フィルムとしてはポリ塩化ビニル、ポリプ
ロピレン２軸延伸フィルム、ポリエチレン系フィルムな
どが知られている。このうちポリエチレン系フィルムは
丸ダイより押出されたチューブおそのまま気体の圧力に
よってブローアップする謂ゆるインフレーション法によ
り製造されるものであり、安価であること、ヒートシー
ル部の強度が大きいことなどの特徴から収縮包装用途に
広く使用されている。(Prior Art) Conventionally, as the heat-shrinkable film, polyvinyl chloride, polypropylene biaxially stretched film, polyethylene film and the like are known. Among them, the polyethylene film is manufactured by a so-called loose inflation method in which a tube extruded from a round die is blown up by the pressure of gas as it is, and it is inexpensive, and the strength of the heat seal part is large. Widely used for shrink wrapping applications.
（発明が解決しようとする問題点） インフレ法により製造されるポリエチレン系熱収縮フィ
ルムはその製法から有効な分子配向が行なわれていない
為、フィルム強度が小さく伸びが大きく融点近い温度で
ないと高い収縮率を示さず、諸特性は必らずしも満足の
ゆくものではない。(Problems to be Solved by the Invention) The polyethylene heat-shrink film produced by the inflation method does not have effective molecular orientation due to the production method, so that the film strength is small and the elongation is high, and the shrinkage is high unless the temperature is close to the melting point. It does not show the rate and the characteristics are not always satisfactory.
かかる欠点を改良すべくポリエチレン系フィルムに電離
性放射線を照射して分子間架橋を生ぜしめた後加熱延伸
する方法によった謂ゆる照射ポリエチレンフィルムは、
延伸による配向効果が認められ強度は大きく伸度は小さ
くなるなどの改良はあるもののヒートシール性が悪いこ
と、屑の回収が出来ないこと、放射線処理によるコスト
アップが免れ難いなどの欠点を持つ。The so-called loose irradiation polyethylene film by a method of heating and stretching after irradiating the polyethylene film with ionizing radiation to cause intermolecular crosslinking in order to improve such a defect,
Although there are improvements in that the orientation effect due to stretching is recognized and the strength is large and the elongation is small, it has drawbacks such as poor heat sealability, inability to collect waste, and unavoidable increase in cost due to radiation treatment.
本発明者らは、ポリエチレン系収縮フィルムについて原
料面技術面より種々検討を加え、ヒートシール性や耐衝
撃性等のポリエチレン系フィルムの優れた特性を生かし
たまま、延伸配向により熱収縮性を改良したポリエチレ
ン系熱収縮フィルム及びその製法を見い出した。（特公
昭５７-36,142） この発明によって得られるフィルムは謂ゆるインフレー
ションフィルムと異なり融点以下でも収縮包装するに必
要な収縮率と収縮応力を発現し、被包装物に密着する良
好な収縮包装性をもつものであるが、延伸チューブの安
定性延伸の均一性が必らずしも満足ゆくものでなく、厚
みムラが大きい欠点を持つと共に、延伸配向効果が十分
に成り難くこの為低温での収縮特性に難を残していた。The present inventors have made various studies on the polyethylene-based shrinkable film from the viewpoint of raw material and technical aspects, and improved the heat-shrinkable property by stretching orientation while keeping the excellent properties of the polyethylene-based film such as heat sealability and impact resistance. The polyethylene-based heat-shrinkable film and its manufacturing method were found. (Japanese Patent Publication No. 57-36,142) Unlike the so-called blown film, the film obtained according to the present invention develops the shrinkage rate and shrinkage stress necessary for shrink-wrapping even at a melting point or lower, and has a good shrink-wrapping property that adheres well to the object to be packed. However, the stability of the stretched tube is not always satisfied evenly, and it has the drawback of large thickness unevenness, and the stretch orientation effect is difficult to achieve sufficiently. The characteristics were difficult.
（問題点を解決するための手段） 本発明者らは、延伸配向効果を大きくすると共に、延伸
の安定性均一性を向上させるべく鋭意検討した結果、エ
チレン系重合体を特定することによつて本発明に到達し
た。(Means for Solving Problems) As a result of intensive investigations by the present inventors to enhance the stretching orientation effect and to improve the stretching stability uniformity, the inventors have identified an ethylene-based polymer. The present invention has been reached.
即ち本発明は、エチレンとα−オレフィンとの線状共重
合体の１種又は２種以上を含み、この共重合体又は共重
合体混合物のDSCの測定による融解曲線について融点
（吸熱メインピーク温度）より１０℃低い温度以下の吸
熱面積が全吸熱面積の５５％以上であるエチレン系重合
体組成物を溶融押出しし、冷却固化して得られるフィル
ムを縦横それぞれ２倍以上延伸して得られる９０℃にお
ける面積収縮率が２０％以上であり厚みムラが２０％以
下である熱収縮性フィルムである。That is, the present invention contains one or more linear copolymers of ethylene and α-olefin, and the melting point (endothermic main peak temperature) of the melting curve of this copolymer or copolymer mixture measured by DSC. ) Is obtained by melt-extruding an ethylene-based polymer composition having an endothermic area at a temperature of 10 ° C. or less lower than 55% of the total endothermic area, and cooling and solidifying the resulting film to stretch it twice or more in the length and width directions. It is a heat-shrinkable film having an area shrinkage ratio of 20% or more at 0 ° C and a thickness unevenness of 20% or less.
本発明に用いられるエチレン系重合体組成物の主な樹脂
はエチレン−α−オレフィン線状共重合体であり、１種
単独であるか２種以上の混合物であることができる。エ
チレンと共重合されるα−オレフィンとしてはブテン−
１、ペンテン−１、ヘキセン−１、ヘプテン−１、オク
テン−１、４メチルペンテン−１、デセン−１、ウンデ
セン−１、ドデセン−１などがある。これらの共重合
は、いわゆるチーグラーナッタ型触媒を使った低中圧法
によって行なうことが出来、これらの製造法について
は、特公昭５０−32270、４９−35345、特開昭５５−78
004、特開昭５５−86804、特開昭５４−154488などに開
示される技術によることが出来る。α−オレフィンの含
量は０．５〜１０モル％の範囲が好ましい。The main resin of the ethylene-based polymer composition used in the present invention is an ethylene-α-olefin linear copolymer, which may be a single type or a mixture of two or more types. Butene is an α-olefin copolymerized with ethylene.
1, pentene-1, hexene-1, heptene-1, octene-1, 4 methylpentene-1, decene-1, undecene-1, dodecene-1 and the like. These copolymerizations can be carried out by a low-to-medium pressure method using a so-called Ziegler-Natta type catalyst, and the production methods thereof are described in JP-B-50-32270, 49-35345 and JP-A-55-78.
004, JP-A-55-86804, JP-A-54-154488 and the like. The α-olefin content is preferably in the range of 0.5 to 10 mol%.
更に本発明の目的に支障をきたさない範囲であれば高圧
法ポリエチレン、エチレン−酢酸ビニル共重合体アイオ
ノマー、エチレン−プロピレン共重合体等々を混合使用
することが出来る。Further, high-pressure polyethylene, ethylene-vinyl acetate copolymer ionomer, ethylene-propylene copolymer and the like can be mixed and used as long as the object of the present invention is not impaired.
又、滑剤、ブロッキング防止剤、帯電防止剤、防曇剤等
の添加剤が、それぞれの有効な作用を具備させる目的で
適宜使用されるのは当然である。Naturally, additives such as a lubricant, an antiblocking agent, an antistatic agent and an antifogging agent are appropriately used for the purpose of providing each effective action.
本発明に使用する樹脂は、前記のポリエチレン系重合体
組成物であって示差走査熱量計の測定による融解曲線に
ついて融点（吸熱メインピーク）より１０℃低い温度以
下の吸熱面積が全吸熱面積の５５％以上である必要があ
る。この条件を満たさないものは、延伸の均一性が容易
に得られず、均一性を得る為延伸温度を高くすると延伸
の持続安定性が損われるばかりでなく、延伸配向効果の
発現が少なく、低温での収縮性能が十分でなくなる。こ
の条件を満たすものは融点以下１０℃よりも低温で、特
別の狭い温度勾配の範囲に限定しなくても均一かつ安定
した延伸が可能であるばかりでなく、延伸配向効果が大
きく９０℃における面積収縮率が２０％以上であり厚み
ムラが２０％以下である実用性に優れた熱収縮性フィル
ムが得られる。The resin used in the present invention is the above-mentioned polyethylene-based polymer composition, and the endothermic area at a temperature lower than the melting point (endothermic main peak) by 10 ° C. in the melting curve measured by a differential scanning calorimeter is 55% of the total endothermic area. Must be at least%. Those that do not satisfy this condition cannot easily obtain the uniformity of stretching, and if the stretching temperature is increased to obtain the uniformity, not only the continuous stability of stretching is impaired, but also the stretching orientation effect is not sufficiently expressed and the temperature is low. The shrinkage performance at the time becomes insufficient. Those satisfying this condition are not more than the melting point and lower than 10 ° C, and not only the uniform and stable stretching is possible without being limited to a particular narrow temperature gradient range, but also the stretching orientation effect is large and the area at 90 ° C is large. A heat-shrinkable film having a shrinkage rate of 20% or more and a thickness unevenness of 20% or less, which is excellent in practicality, can be obtained.
ここで述べた示差走査熱量計による測定には、試料６〜
８mgをアルミパンに封入し、窒素気流下にて１９０℃ま
で昇温しこの温度で１時間保持し、次いで約１０℃／mi
nで室温まで冷却したのち昇温速度１０℃／min、感度２
５mg／secで得た融解曲線を用いるものである。For the measurement by the differential scanning calorimeter described here, Sample 6 to
Enclose 8 mg in an aluminum pan, raise the temperature to 190 ° C under nitrogen flow, hold at this temperature for 1 hour, and then about 10 ° C / mi
After cooling to room temperature with n, heating rate 10 ℃ / min, sensitivity 2
The melting curve obtained at 5 mg / sec is used.
本発明に用いられる延伸用原反フィルムの製造及び延伸
は公知の方法で行なうことができるが、以下管状製膜・
延伸の場合を例に挙げ、詳しく説明する。The production and stretching of the raw material film for stretching used in the present invention can be carried out by a known method.
The case of stretching will be described in detail as an example.
まず、前記の特定範囲の樹脂を加熱溶融し、混練し、チ
ューブ状に押出し、冷却固化して原反とする。First, the resin in the above-mentioned specific range is heated and melted, kneaded, extruded into a tube shape, and cooled and solidified to obtain an original fabric.
得られたチューブ状原反を例えば第１図で示すようなチ
ューブラー延伸装置に供給し、有効な高度の配向が起る
温度域、例えば樹脂の融点以下１０℃、更に好ましくは
２０℃よりも低い温度で、膨脹延伸して同時２軸配向を
行なわしめる。延伸倍率は縦横同一でなくとも良いが良
好な強度等の物性を得る為には縦横いずれの方向にも２
倍以上、好ましくは２．５倍以上である。The obtained tubular raw fabric is supplied to, for example, a tubular stretching apparatus as shown in FIG. 1, and a temperature range in which an effective high degree of orientation occurs, for example, 10 ° C. or lower than the melting point of the resin, more preferably 20 ° C. or lower. At low temperature, it is expanded and stretched to perform simultaneous biaxial orientation. The stretching ratio does not have to be the same in the length and width, but in order to obtain good physical properties such as strength, it is 2 in both the length and width directions.
It is 2 times or more, preferably 2.5 times or more.
延伸装置から取り出したフィルムは必要に応じてアニー
リングすることが出来る。The film taken out from the stretching device can be annealed if necessary.
以下本発明を実施例に基いて具体的に説明する。The present invention will be specifically described below based on examples.
なお実施例中に示した測定項目は次の方法によった。The measurement items shown in the examples are as follows.
1.面積収縮率 縦横共１０cmの正方形に切り取ったフィルムを所定温度
のグリセリン浴中に１秒間浸漬し、次式により算出し
た。1. Area shrinkage A film cut into a square having a length and width of 10 cm was immersed in a glycerin bath at a predetermined temperature for 1 second, and calculated by the following formula.
面積収縮率＝１００−Ａ×Ｂ 但し、Ａ，Ｂは浸漬後の縦横それぞれの長さ（単位はc
m）を示す。Area shrinkage rate = 100-A x B However, A and B are the vertical and horizontal lengths after immersion (unit is c
m) is shown.
2.厚みムラ 接触型電子マイクロメーター（安立電気（株）製Ｋ３０
６Ｃ型）を使用しフルスケール８μｍで測定したチュー
ブ円周方向のチャートについて最大値（Tmax）、最小値
（Tmin)及び平均値（Ｔ）を求め、次式より算出した。2. Thickness unevenness Contact type electronic micrometer (K30 manufactured by Anritsu Electric Co., Ltd.)
6C type), the maximum value (T max ), the minimum value (T min ), and the average value (T) of the chart in the circumferential direction of the tube measured with a full scale of 8 μm were determined and calculated from the following formula.
但し、Ｔは、測定フィルムの１０mm間隔に相当するチャ
ート位置から読み取った値の算術平均値。 However, T is the arithmetic mean value of the values read from the chart position corresponding to the 10 mm interval of the measurement film.
実施例1. ２５℃における密度０．９２２ｇ／cm3、メルトインデ
クス0.8g／１０分のエチレン−ブテン−１共重合体であ
ってDSCによる融解曲線について主ピーク温度が１２６
℃であり１１６℃以下の吸熱面積が全吸熱面積の６３．
８％であったエチレン糸重合体を１７０〜２３０℃で溶
融混練し２３０℃に保った環状ダイスより押出し、冷却
水を循環している円筒状マンドレルの外表面を摺動させ
ながら外側は水槽を通すことにより冷却して引取り、直
径約６６m/m厚み２５０μのチューブ状未延伸フィルム
を得た。この未延伸フィルムを原反とし、これを第１図
に示した２軸延伸装置に導き、９５〜１０５℃で縦横そ
れぞれ４倍に延伸した。延伸されたフィルムはチューブ
状アニーリング装置にて７５℃の熱風で１０秒間アニー
リングした後、室温に冷却し折り畳んで巻き取った。Example 1. An ethylene-butene-1 copolymer having a density of 0.922 g / cm 3 at 25 ° C. and a melt index of 0.8 g / 10 min and a main peak temperature of 126 as a melting curve by DSC.
C. and the endothermic area of 116.degree. C. or less is 63.
8% of the ethylene yarn polymer was melt-kneaded at 170 to 230 ° C. and extruded from an annular die kept at 230 ° C. While sliding the outer surface of a cylindrical mandrel circulating cooling water, a water tank was placed on the outside. It was cooled by passing through and taken off to obtain a tubular unstretched film having a diameter of about 66 m / m and a thickness of 250 μm. This unstretched film was used as an original fabric, which was introduced into the biaxial stretching device shown in FIG. The stretched film was annealed with hot air at 75 ° C. for 10 seconds in a tubular annealing device, cooled to room temperature, folded and wound up.
延伸チューブの安定性は良好で延伸点の上下動やチュー
ブの揺動もなく、又、ネッキングなどの不均一延伸状態
も観察されなかった。The stability of the stretched tube was good, neither vertical movement of the stretched point nor swing of the tube was observed, nor was non-uniform stretched state such as necking observed.
得られた延伸フィルムは厚み１６μで９０℃の面積収縮
率は３１．５％、厚みムラは１５％であった。このフィ
ルムを用い直径１５cm厚さ約１cmのピザパイを予備包装
し１１０℃の熱風が吹きつけている収縮トンネル中を約
３秒間通過させた。ぴったりと密着した良好な包装状態
となり、被包装物にも変化は認められなかった。The obtained stretched film had a thickness of 16 μm, an area shrinkage ratio at 90 ° C. of 31.5%, and a thickness unevenness of 15%. Using this film, a pizza pie having a diameter of 15 cm and a thickness of about 1 cm was prepackaged and passed through a shrinking tunnel blown with hot air at 110 ° C. for about 3 seconds. The product was in a good close-packed and good packaging condition, and no change was observed in the product to be packaged.
実施例2. ２５℃における密度０．９１７ｇ／cm3、メルトインデ
クス２．３ｇ／１０分のエチレン−オクテン−１共重合
体であってDSCによる融解曲線について主ピーク温度が
１２１℃であり、１１１℃以下の吸熱面積が全吸熱面積
の５７％であるエチレン系重合体を使用し、延伸温度を
９０〜１００℃とした他は実施例１と同様にして延伸し
た。Example 2. Ethylene-octene-1 copolymer having a density of 0.917 g / cm 3 at 25 ° C. and a melt index of 2.3 g / 10 min, the main peak temperature of which is 121 ° C. for the melting curve by DSC, 111 Stretching was carried out in the same manner as in Example 1 except that an ethylene-based polymer having an endothermic area of not more than ° C of 57% of the total endothermic area was used and the stretching temperature was 90 to 100 ° C.
延伸点の上下動やチューブの揺動もなく、延伸チューブ
の安定性は良好で、又、不均一な延伸状態も観察されな
かった。There was no vertical movement of the stretching point or swinging of the tube, the stability of the stretched tube was good, and a non-uniform stretched state was not observed.
得られた延伸フィルムは平均厚み１６μで厚みムラは８
％であり９０℃の面積収縮率は２７％であった。このフ
ィルムを用いて高さ７５mm最大径４０mmのポリスチレン
製容器に充填された乳酸菌飲料を５個ずつ集積し予備包
装し１００℃の熱風収縮トンネル中を３秒間通過させ
た。The obtained stretched film has an average thickness of 16μ and a thickness unevenness of 8
%, And the area shrinkage ratio at 90 ° C. was 27%. Using this film, five lactic acid bacteria beverages filled in a polystyrene container having a height of 75 mm and a maximum diameter of 40 mm were collected and pre-packaged, and passed through a hot air shrinkage tunnel at 100 ° C. for 3 seconds.
短い収縮時間にも拘らず良好な収縮包装状態となった。Despite the short shrinking time, it was in a good shrink-wrapped state.
実施例3. ２５℃における密度０．９２５ｇ／cm3、メルトインデ
クス１．０ｇ／１０分のエチレン−４−メチルペンテン
−１共重合体７０重量％と２５℃における密度が０．９
２３ｇ／cm3メルトインデクス０．８ｇ／１０分のエチ
レン−ブテン−１共重合体３０重量％との溶融混合物で
あってDSCによる融解曲線について主ピーク温度が１２
４℃であり、１１４℃以下の吸熱面積が全吸熱面積の５
８．８％であったエチレン系重合体組成物を１７０〜２
３０℃で溶融混練し、２３０℃に保った環状ダイスより
押出し、冷却水を循環している円筒状マンドレルの外表
面を摺動させながら外側は水槽を通すことにより冷却し
て引取り、直径約６６mm厚み３２０μのチューブ状未延
伸フィルムを得た。この未延伸フィルムを２軸延伸装置
に導き９５〜１０５℃で縦４．３倍横３．８倍に延伸し
た後７５℃で１０秒間アニーリングし折り畳んで巻き取
った。Example 3. Density at 25 ° C. 0.925 g / cm 3 , melt index 1.0 g / 10 min ethylene-4-methylpentene-1 copolymer 70% by weight and density at 25 ° C. 0.9
23 g / cm 3 melt index 0.8 g / 10 min melt mixture with 30% by weight of ethylene-butene-1 copolymer having a DSC melting curve with a main peak temperature of 12
4 ° C and the endothermic area of 114 ° C or less is 5 of the total endothermic area
The ethylene polymer composition, which was 8.8%, was added to 170 to 2
Melt and knead at 30 ° C, extrude from an annular die kept at 230 ° C, slide the outer surface of a cylindrical mandrel circulating cooling water, cool the outside by letting it pass through a water tank and take it out. A tubular unstretched film having a thickness of 66 mm and a thickness of 320 μ was obtained. This unstretched film was introduced into a biaxial stretching device and stretched at 95 to 105 ° C. in a length of 4.3 times and a width of 3.8 times, then annealed at 75 ° C. for 10 seconds, folded and wound.
延伸点の上下動やチューブの揺動もなく延伸チューブの
安定性は良好で、又、ネッキング、縦割れなどの不均一
延伸も観察されなかった。The stability of the stretched tube was good without vertical movement of the stretching point or swaying of the tube, and non-uniform stretching such as necking or longitudinal cracking was not observed.
得られたフィルムは平均厚み２０μで厚みムラは１０％
であり９０℃の面積収縮率は２５．８％であった。この
フィルムを用いて実施例１と同条件で収縮包装を行なっ
た。密着状態良好な包装となり、被包装物にも変化は認
められなかった。The obtained film has an average thickness of 20μ and an uneven thickness of 10%.
The area shrinkage ratio at 90 ° C. was 25.8%. This film was shrink-wrapped under the same conditions as in Example 1. The packaging was in a good adhesion state, and no change was observed in the packaged item.
比較例1. ２５℃における密度０．９１８ｇ／cm3メルトインデク
ス１．０ｇ／１０分のエチレン−ブデン−１共重合体で
あってDSCによる融解曲線について主ピーク温度が１２
０℃で、１１０℃以下の吸熱面積が全吸熱面積の４９％
であったエチレン系重合体を実施例１と同様な方法、条
件で製膜・延伸・アニーリングした。Comparative Example 1. An ethylene-buden-1 copolymer having a density of 0.918 g / cm 3 melt index of 1.0 g / 10 min at 25 ° C. and a main peak temperature of 12 in terms of a melting curve by DSC.
At 0 ° C, the endothermic area below 110 ° C is 49% of the total endothermic area
The ethylene-based polymer which was obtained was subjected to film formation / stretching / annealing under the same conditions and conditions as in Example 1.
このような低い延伸温度では延伸チューブは揺動し、延
伸部にはネッキング現象も見られた。延伸チューブの安
定性を増すべく延伸温度を下げるとネッキングは激しく
なり不均一さが増した。ネッキングを緩和すべく延伸温
度を１０３〜１０８℃に上げると延伸チューブの上下動
・揺動はひどくなり安静性が悪くなった。At such a low stretching temperature, the stretching tube shook, and a necking phenomenon was also observed in the stretching portion. When the stretching temperature was lowered to increase the stability of the stretched tube, necking became severe and nonuniformity increased. When the stretching temperature was raised to 103 to 108 ° C. in order to alleviate necking, the vertical movement / swing of the stretching tube became severe and the resting property deteriorated.
延伸温度１０３〜１０８℃で得られた延伸フィルムは平
均厚み１６μで厚みムラは２７％であり、９０℃での面
積収縮率は１５．４％であった。The stretched film obtained at a stretching temperature of 103 to 108 ° C. had an average thickness of 16 μ, a thickness unevenness of 27%, and an area shrinkage ratio at 90 ° C. of 15.4%.
このフィルムは平面性が悪く、自動包装機での連続包装
に適さなかった。又、実施例１と同条件での収縮工程に
おいても皺、凹凸が多く良好な包装状態とならかった。
熱風温度を上げたり、収縮トンネルの通過時間を長くす
ることにより良好な包装状態が得られたが、この条件で
は被包装物の一部が溶融変形し商品化値が著るしく低下
したものとなった。This film had poor flatness and was not suitable for continuous packaging in an automatic packaging machine. Further, even in the shrinking step under the same conditions as in Example 1, there were many wrinkles and irregularities, and a good packaging state was not obtained.
Good packaging was obtained by raising the hot air temperature and lengthening the passage time of the shrinking tunnel, but under these conditions, part of the packaged item melted and deformed, and the commercialized value was significantly reduced. became.
比較例2. ２５℃における密度０．９２１、メルトインデクス０．
７５ｇ／１０分のエチレン−ヘキセン−１共重合体６０
重量％と２５℃における密度０．９２０メルトインデク
ス１．０ｇ／１０分のエチレン−オクデン−１共重合体
４０重量％との溶融混合物であってDSCによる融解曲線
について主ピーク温度が１２７℃であり１１７℃以下の
吸熱面積が全吸熱面積の５０．４％であったエチレン系
重合体組成物を実施例３と同様な方法条件で製膜延伸ア
ニーリングした。Comparative Example 2. Density at 25 ° C. 0.921, melt index 0.
75 g / 10 min ethylene-hexene-1 copolymer 60
Wt% and a density of 0.920 melt index at 25 ° C. 1.0 g / 10 min of 40% by weight of ethylene-octene-1 copolymer, a melt mixture having a main peak temperature of 127 ° C. for the melting curve by DSC. The ethylene-based polymer composition whose endothermic area at 117 ° C. or less was 50.4% of the total endothermic area was subjected to film forming stretching annealing under the same method conditions as in Example 3.
延伸部のネッキング現象は顕著であり、ネッキングを緩
和すべく延伸温度を上げると延伸チューブの揺動がひど
く安定した延伸状態は得られなかった。The necking phenomenon in the stretched portion was remarkable, and when the stretching temperature was raised to alleviate necking, the stretched tube oscillated significantly and a stable stretched state could not be obtained.
延伸温度１０５〜１１２℃で得られた延伸フィルムは平
均厚み１６μで厚みムラは２３％であり９０℃での面積
収縮率は１６．４％であった。The stretched film obtained at a stretching temperature of 105 to 112 ° C. had an average thickness of 16 μ, a thickness unevenness of 23%, and an area shrinkage ratio at 90 ° C. of 16.4%.
（作用及び効果） 原料樹脂としてエチレンとα−オレフィンとの線状共重
合体、又はそれらの混合物の内、示差走査熱量計による
原料の融解時の融解曲線において、融点（吸熱メインピ
ーク）より１０℃低い温度以下の部分の吸熱面積が全吸
熱面積の５５％以上であるものを用いることにより、融
点以下比較的低い温度で安定して延伸可能であり、その
結果厚みムラは小さくなり、且配向効率が向上し、低温
における熱収縮率がすぐれた収縮性フィルムを安定して
製造することができた。(Operation and effect) Among the linear copolymers of ethylene and α-olefin as a raw material resin, or a mixture thereof, in the melting curve at the time of melting of the raw material by a differential scanning calorimeter, 10 from the melting point (endothermic main peak) By using a material whose endothermic area at a temperature lower than ℃ is 55% or more of the total endothermic area, it is possible to stably stretch at a relatively low temperature below the melting point, resulting in small thickness unevenness and orientation. A shrinkable film having improved efficiency and excellent heat shrinkage at low temperature could be stably manufactured.
第１図は本発明の実施例に用いた設備の説明用断面図で
ある。FIG. 1 is a sectional view for explaining equipment used in an embodiment of the present invention.
Claims (1)
チレンとα−オレフィンとの線状共重合体の１種又は２
種以上を含み、この共重合体又は共重合体混合物の示差
走査熱量計（ＤＳＣ）測定において、融点（吸熱メイン
ピーク）より１０℃低い温度以下の吸熱面積が全吸熱面
積の５５％以上であるエチレン系共重合体組成物、管状
ダイから溶融押出しし冷却固化して実質的に未延伸のチ
ューブ状未延伸フィルムを成形し、更にこのチューブ状
未延伸フィルムを融点より１０℃以下、縦横各々２倍以
上の条件下でチューブ状同時二軸延伸して得られる、９
０℃における面積収縮率が２０％以上であり厚みムラが
２０％以下である熱収縮性フィルム。1. A density 0.917~0.925g / cm 3 of ethylene and one linear copolymer of α- olefin or 2
In the differential scanning calorimeter (DSC) measurement of this copolymer or copolymer mixture containing at least one species, the endothermic area at a temperature 10 ° C lower than the melting point (endothermic main peak) is 55% or more of the total endothermic area. The ethylene-based copolymer composition is melt extruded from a tubular die, cooled and solidified to form a substantially unstretched tubular unstretched film, and the tubular unstretched film has a melting point of 10 ° C. or less and a length and a width of 2 each. Obtained by simultaneous tubular biaxial stretching under double or more conditions, 9
A heat-shrinkable film having an area shrinkage of 20% or more at 0 ° C and a thickness unevenness of 20% or less.
Priority Applications (9)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61044170A JPH0613192B2 (en) | 1986-03-03 | 1986-03-03 | Heat shrinkable film |
| CA000530633A CA1297651C (en) | 1986-03-03 | 1987-02-26 | Heat shrinkable film |
| DK102087A DK102087A (en) | 1986-03-03 | 1987-02-27 | shrink |
| AU69568/87A AU589498B2 (en) | 1986-03-03 | 1987-02-27 | Heat shrinkable film |
| EP87102895A EP0240705B1 (en) | 1986-03-03 | 1987-02-28 | Heat shrinkable film |
| DE3788970T DE3788970T2 (en) | 1986-03-03 | 1987-02-28 | Heat shrinkable film. |
| US07/020,980 US4801652A (en) | 1986-03-03 | 1987-03-02 | Heat shrinkable film |
| FI870891A FI87930C (en) | 1986-03-03 | 1987-03-02 | Heat shrinkable film |
| MX005449A MX168639B (en) | 1986-03-03 | 1987-03-03 | SHRINKABLE FILM WITH HEAT |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61044170A JPH0613192B2 (en) | 1986-03-03 | 1986-03-03 | Heat shrinkable film |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62201229A JPS62201229A (en) | 1987-09-04 |
| JPH0613192B2 true JPH0613192B2 (en) | 1994-02-23 |
Family
ID=12684114
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61044170A Expired - Fee Related JPH0613192B2 (en) | 1986-03-03 | 1986-03-03 | Heat shrinkable film |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0613192B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2623744B1 (en) * | 1987-11-30 | 1990-02-02 | Kaysersberg Sa | PROCESS FOR THE MANUFACTURE OF A THERMAL THERMAL TRACTABLE FILM BY SUCCESSIVE DRAWING |
| US20070122600A1 (en) * | 2003-11-21 | 2007-05-31 | Asahi Kasei Life & Living Corporation | Low-temperature shrinkable film |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5571529A (en) * | 1978-11-27 | 1980-05-29 | Mitsubishi Plastics Ind Ltd | Thermal contractive soft film |
| DE3018650A1 (en) * | 1980-05-16 | 1981-11-26 | Zahnradfabrik Friedrichshafen Ag, 7990 Friedrichshafen | HIGH PRESSURE PUMP WITH A FLOW CONTROL VALVE |
| CA1174423A (en) * | 1981-04-23 | 1984-09-18 | Ralph C. Golike | Shrink films of ethylene/alpha-olefin copolymers |
-
1986
- 1986-03-03 JP JP61044170A patent/JPH0613192B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62201229A (en) | 1987-09-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4801652A (en) | Heat shrinkable film | |
| EP0405916B1 (en) | Bioriented film | |
| JP2904903B2 (en) | Polyethylene film | |
| US5306549A (en) | Biaxially stretched polyethylene film | |
| JP4915749B2 (en) | Polyolefin multilayer shrink film | |
| JP3258830B2 (en) | Polyolefin-based heat-shrinkable laminated film | |
| JP3751965B2 (en) | Polyolefin multilayer shrink film | |
| JPH0613192B2 (en) | Heat shrinkable film | |
| US5635286A (en) | Heat shrinkable polyethylene laminate film | |
| JP3004314B2 (en) | Polyethylene heat-shrinkable laminated film | |
| JP3748639B2 (en) | Polyolefin resin composition | |
| JP2003145695A (en) | Method for manufacturing polyethylenic heat-shrinkable film | |
| KR100203444B1 (en) | Ldpe film and there manufacturing method | |
| CA2032272C (en) | Improved heat shrinkable polyolefin film | |
| WO1989001402A1 (en) | Process for producing heat-shrinkable polyethylene film | |
| JPH054276A (en) | Manufacture of polyethylene biaxially oriented film | |
| CA2118002C (en) | Heat shrinkable polyethylene laminate film | |
| JPH05131599A (en) | Heat shrinkable laminated polyethylene film | |
| JPH08151454A (en) | Thermally shrinkable polypropylene film | |
| JPS6244427A (en) | Heat-shrinkable film superior in transparency and its manufacture | |
| JPH09239926A (en) | Heat shrinkable laminated polyolefin film | |
| JPS6040229A (en) | Low temperature heat shrinkable film |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |