JPS6156244B2 - - Google Patents
Info
- Publication number
- JPS6156244B2 JPS6156244B2 JP16162979A JP16162979A JPS6156244B2 JP S6156244 B2 JPS6156244 B2 JP S6156244B2 JP 16162979 A JP16162979 A JP 16162979A JP 16162979 A JP16162979 A JP 16162979A JP S6156244 B2 JPS6156244 B2 JP S6156244B2
- Authority
- JP
- Japan
- Prior art keywords
- weight
- polymerization
- resin composition
- film
- ethylene
- 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.)
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Links
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 28
- 239000005977 Ethylene Substances 0.000 claims description 28
- 239000011342 resin composition Substances 0.000 claims description 23
- 238000000465 moulding Methods 0.000 claims description 17
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims description 9
- 229920001577 copolymer Polymers 0.000 claims description 7
- 239000000203 mixture Substances 0.000 claims description 5
- 239000000155 melt Substances 0.000 claims description 2
- 238000006116 polymerization reaction Methods 0.000 description 41
- -1 polypropylene Polymers 0.000 description 35
- 239000010408 film Substances 0.000 description 28
- 239000007789 gas Substances 0.000 description 26
- 239000004743 Polypropylene Substances 0.000 description 22
- 229920001155 polypropylene Polymers 0.000 description 22
- 239000001257 hydrogen Substances 0.000 description 20
- 229910052739 hydrogen Inorganic materials 0.000 description 20
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 19
- 238000000034 method Methods 0.000 description 16
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 12
- 238000004519 manufacturing process Methods 0.000 description 12
- 229920000642 polymer Polymers 0.000 description 10
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 7
- 239000000178 monomer Substances 0.000 description 6
- 239000003054 catalyst Substances 0.000 description 5
- 239000008188 pellet Substances 0.000 description 5
- 239000002002 slurry Substances 0.000 description 5
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 230000037303 wrinkles Effects 0.000 description 4
- 150000001336 alkenes Chemical class 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 238000005259 measurement Methods 0.000 description 3
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 3
- CXWXQJXEFPUFDZ-UHFFFAOYSA-N tetralin Chemical compound C1=CC=C2CCCCC2=C1 CXWXQJXEFPUFDZ-UHFFFAOYSA-N 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 239000003963 antioxidant agent Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000007334 copolymerization reaction Methods 0.000 description 2
- YNLAOSYQHBDIKW-UHFFFAOYSA-M diethylaluminium chloride Chemical compound CC[Al](Cl)CC YNLAOSYQHBDIKW-UHFFFAOYSA-M 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- YONPGGFAJWQGJC-UHFFFAOYSA-K titanium(iii) chloride Chemical class Cl[Ti](Cl)Cl YONPGGFAJWQGJC-UHFFFAOYSA-K 0.000 description 2
- NLZUEZXRPGMBCV-UHFFFAOYSA-N Butylhydroxytoluene Chemical compound CC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 NLZUEZXRPGMBCV-UHFFFAOYSA-N 0.000 description 1
- OWYWGLHRNBIFJP-UHFFFAOYSA-N Ipazine Chemical compound CCN(CC)C1=NC(Cl)=NC(NC(C)C)=N1 OWYWGLHRNBIFJP-UHFFFAOYSA-N 0.000 description 1
- XBDQKXXYIPTUBI-UHFFFAOYSA-M Propionate Chemical compound CCC([O-])=O XBDQKXXYIPTUBI-UHFFFAOYSA-M 0.000 description 1
- BGYHLZZASRKEJE-UHFFFAOYSA-N [3-[3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoyloxy]-2,2-bis[3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoyloxymethyl]propyl] 3-(3,5-ditert-butyl-4-hydroxyphenyl)propanoate Chemical compound CC(C)(C)C1=C(O)C(C(C)(C)C)=CC(CCC(=O)OCC(COC(=O)CCC=2C=C(C(O)=C(C=2)C(C)(C)C)C(C)(C)C)(COC(=O)CCC=2C=C(C(O)=C(C=2)C(C)(C)C)C(C)(C)C)COC(=O)CCC=2C=C(C(O)=C(C=2)C(C)(C)C)C(C)(C)C)=C1 BGYHLZZASRKEJE-UHFFFAOYSA-N 0.000 description 1
- 230000003078 antioxidant effect Effects 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- CJZGTCYPCWQAJB-UHFFFAOYSA-L calcium stearate Chemical compound [Ca+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O CJZGTCYPCWQAJB-UHFFFAOYSA-L 0.000 description 1
- 239000008116 calcium stearate Substances 0.000 description 1
- 235000013539 calcium stearate Nutrition 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 125000001570 methylene group Chemical group [H]C([H])([*:1])[*:2] 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 239000002667 nucleating agent Substances 0.000 description 1
- 239000005022 packaging material Substances 0.000 description 1
- NFHFRUOZVGFOOS-UHFFFAOYSA-N palladium;triphenylphosphane Chemical compound [Pd].C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1.C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1.C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1.C1=CC=CC=C1P(C=1C=CC=CC=1)C1=CC=CC=C1 NFHFRUOZVGFOOS-UHFFFAOYSA-N 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000000379 polymerizing effect Effects 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 229920001384 propylene homopolymer Polymers 0.000 description 1
- 238000010926 purge Methods 0.000 description 1
- 239000002516 radical scavenger Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 150000003608 titanium Chemical class 0.000 description 1
Landscapes
- Compositions Of Macromolecular Compounds (AREA)
- Graft Or Block Polymers (AREA)
Description
本発明は耐衝撃性並びに透明性に優れたフイル
ムの成形に適したポリプロピレン樹脂組成物に関
するものである。
従来、ポリプロピレンのフイルムとしてはキヤ
ステイング法によるものとインフレーシヨン成形
法によるものがあり、すでにそれぞれの成形法及
び用途に適したポリプロピレンが市販されてい
る。
しかしながらこれらのポリプロピレンには、特
に空冷インフレーシヨン成形法を使用して肉厚が
30ミクロン程度の極めて薄いフイルムを成形しよ
うとする場合に、フイルムの衝撃強さが弱くな
り、またフイルムの成形時のチユーブの安定性が
悪くなる(シワが多くなつたり肉厚のむら、折径
のばらつきを生じる。)などの欠点があり、その
改良が求められている。またこれらのフイルムは
製袋されて、一般規格袋等に使用されるのである
が袋の中に物を入れて運ぶ場合に、その内容物が
外側からよく見える透明性が必要である。
本発明の目的は、包装材料としてのフイルムに
必要とされる透明性を損なうことなく、衝撃強さ
およびフイルム成形時のチユーブの安定性を向上
させることである。
本発明者らは、これらの課題を達成するには、
ポリプロピレン樹脂組成物として、従来のものよ
りかなり分子量が大きく、かつ特定のエチレン含
有率を有するもののうち、特定のエチレン分布を
有し、かつ特定の極限粘度の関係を有しているも
のを用いることがよいことを見出し、遂に本発明
を完成した。
本発明に用いられるこの特殊なポリプロピレン
樹脂組成物は例えば次の様な方法で作られる。
即ちチーグラー・ナツタ型の活性化チタン触媒
を用いて、第1段階の重合においてプロピレン
100重量%の原料ガス、あるいはエチレン含有率
が共重合体中で20重量%未満になる様調整したプ
ロピレン−エチレン混合ガスを、全オレフイン重
合量の60〜95重量%の範囲で共重合させる。
この重合により生長した重合体分子の部分をA
部と称する。なお試料採取を行い、このA部が生
成した段階で触媒を破壊して重合を止めて得られ
るポリオレフインの極限粘度〔η〕(dl/g)を
〔η〕Aとする(〔η〕AをA部生成〔η〕と言うこと
にする。)なお〔η〕はテトラリン溶液の粘度
(135℃、50mg/50c.c.)より測定した。
ひき続き第2段階の重合で上記共重合体分子を
生長させるのであるが、第2段階ではエチレン含
有率が20重量%以上となる様に、プロピレン−エ
チレン混合ガスを全オレフイン重合量の40〜5重
量%の範囲で共重合させる。この段階で生長した
共重合体の部分をB部と称する。この時、第1段
階で生成したA部と第2段階で生成したB部とか
らなる樹脂組成物の全体としての平均(測定値)
の〔η〕を〔η〕ABとすれば、B部に生成した共
重合体の部分の〔η〕B(B部生成〔η〕と言う)
と測定値〔η〕Aとの間に次式の関係がある。
〔η〕AB=〔η〕A×a+〔η〕B×b/100
但し、a、bはそれぞれA部、B部で重合した
混合ガスの重量%である。
この場合、第1段重合及び第2段重合において
プロピレン−エチレンの混合比及び〔η〕を漸増
または漸減してもよく、あるいは断続的に変化さ
せて重合させてもよい。〔η〕を変化させるに
は、分子量調節剤を加減すればよい。また本発明
におけるポリプロピレン樹脂組成物の製造法とし
て第1段重合のA部及び第2段重合のB部を更に
各々2段階以上に例えばA部はA−1、A−1…
…、B部はB−1、B−2……と分けて重合して
も、A部、B部が本発明の特定組成及び特定生成
〔η〕を平均として有すればよい。
次いで本発明の樹脂組成物の各構成要件を説明
する。まず本発明で言うメルトインデツクス(以
下MIと略記)とはASTM D1238(JIS K−
7210)に記載する方法によるものであり、230℃
の温度、2160gの荷重により測定したものを示
す。本発明に用いられる樹脂組成物のMIは0.01
〜0.3g/10分であることが必要であり、特に
0.05〜0.2g/10分が好ましい。MIが0.3g/10分
を越えると成形時のチユーブの安定性が低下して
シワ、肉厚ムラを生じる。従来のフイルム成形用
ポリプロピレンは、そのMIが概ね8前後であ
り、本発明の樹脂組成物のMIとの大きな差がフ
イルムの性能に関係しているようである。
MI0.01g/10分未満のポリプロピレンは通常の
方法で製造することは極めて困難であり、また仮
に製造出来ても実際のフイルムを成形する際の成
形温度を異常な高温にするとかまた成形機内の溶
融した樹脂の圧力が異常に高くなるとかで成形の
装置が重装備となり実用的でない。MIはポリマ
ーの分子量が大きい程小さくなる。またポリマー
の分子量が大きい程ポリマーの〔η〕は大きくな
る。即ちMIは分子量及び〔η〕と逆の相関関係
を有する。また本発明に言うMIはポリプロピレ
ンのパウダーまたはペレツトの形で測定出来る
が、通常はポリプロピレンのパウダーに一定の酸
化防止剤、塩酸捕足剤を一定量添加して押出機に
てペレツトとしてから測定する。本発明でもこの
ようにして測定した。
本発明のポリプロピレン樹脂組成物では、エチ
レン含有率が1〜50重量%であることが必要であ
り、1重量%未満では以下に規定する条件を満足
することが困難となるばかりか、得られるフイル
ムでの衝撃強さが不足する。又、50重量%以上で
は非常に軟くなるだけでなく、フイルム成形時の
チユーブの安定性も著しく低下する。
本発明のポリプロピレン樹脂組成物のA部はプ
ロピレンのホモポリマーあるいはエチレン含有率
20重量%未満のコポリマーからなるが、エチレン
含有率は特に好ましくは3〜8重量%である。エ
チレン含有率が20重量%を越えると、第1段重合
によるA部の生成時にスラリーの性状が悪化し
て、スラリー移送の際に配管を閉塞する等のトラ
ブルが発生する。
実際にA部の平均組成としてエチレン含有率3
〜8重量%となるように重合させる場合にも、ス
ラリー性状の向上のために予めプロピレンを全オ
レフイン重合量の5〜20重量%程重合させ高結晶
性ホモポリマーを作り、次いでプロピレン−エチ
レン混合ガスによる共重合部を作る方法も行なわ
れている。本発明にはこのような場合も含まれ
る。
本発明のポリプロピレン樹脂組成物のB部のエ
チレン含有率は20重量%以上であることが必要で
ある。エチレン含有率が20重量%を下廻ると衝撃
強さが極度に低下して実用的なフイルムが得られ
ない。このB部は樹脂組成物全体に対して40〜5
重量%の範囲であることが必要である。5重量%
を下廻ると衝撃強度が低下する。また40重量%を
越えると非常に軟くなるだけでなく、フイルム成
形時のチユーブの安定性も著しく低下する。
本発明における〔η〕Aと〔η〕Bとの関係は
〔η〕A+0.5>〔η〕B≧〔η〕A−1.5
であることが必要である。好ましくは
〔η〕A≧〔η〕B≧〔η〕A−1.0
である。
〔η〕Bが〔η〕A+0.5以上になると透明性が悪
化し、本発明の対象とする用途に適さない。ま
た、〔η〕A−1.5を下廻るとチユーブの安定性が著
しく、低下し、本発明の目的を達成しない。
本発明において〔η〕Bを上記範囲にするために
はB部の重合において分子量調節剤の量を加減す
ればよい。
本発明の樹脂組成物を使用するフイルムの成形
法としては、通常、空冷インフレーシヨン法と言
われている公知の方法を使用できる。その際に通
常の場合と同様に、必要に応じて酸化防止剤、滑
剤、その他の添加物など、通常のポリプロピレン
に使用される各種添加剤を加えてもよい。
たとえば、透明性向上のため公知の核剤を添加
しても、なんら差支えない。
本発明において得られる極薄強化フイルムは肉
厚が薄くても衝撃強さが良好であるので、省資源
の観点からも広範な用途が期待される。また成形
時のチユーブの安定性が良く、シワや肉厚むらが
少いので実用上の価値が高い。また、このポリプ
ロピレン樹脂組成物でインフレーシヨン成形をす
る場合、前述の目的としたこと以外にも高速成形
が可能という技術上の効果がある。従つて、成形
速度を従来以上に速くしても良質のフイルムが得
られるので、フイルムの製造費を低減させること
ができる。
以下、実施例により本発明を説明する。
実施例 1
(1) ポリプロピレン樹脂組成物の製造
内容積20のSUS−27オートクレーブ中に窒
素雰囲気下でヘプタン10を装入し、触媒とし
て活性化三塩化チタン5g及びジエチルアルミ
ニウムクロライド8gを装入した。55℃に昇温
した時のオートクレーブ内圧がゲージ圧で4
Kg/cm2(以下、記号をKg/cm2Gと略記する)しか
も気相水素濃度が0.3容量%となるようにエチ
レン含有率3.4重量%のプロピレン−エチレン
混合ガスと水素とを装入し、55℃まで昇温し、
55℃にて内圧を4Kg/cm2・G、水素濃度を0.3容
量%に保つように上記プロピレン−エチレン混
合ガス及び水素を連続的に装入して、2、3時
間重合を継続した(第1段重合によるA部の生
成)。
次いで触媒の活性が保たれたままの状態で未
反応モノマーを完全にパージした後、気相水素
濃度が34容量%となる様に水素とエチレン含有
率35.4重量%のプロピレン−エチレン混合ガス
を0.5Kg/cm2・Gまで一括装入し、重合温度55℃
に維持すると再び重合が始まつた。そこで内圧
0.5Kg/cm2・G、気相水素濃度34容量%を保つよ
うにエチレン含有率86.2重量%のプロピレン−
エチレン混合ガス及び水素を連続的に装入し、
1.4時間重合を継続した(第2段重合によるB
部の生成)。
重合終了時メタノール2を装入して重合を
停止させ、通常の方法により精製乾燥して3.9
Kgのパウダー状重合体を得た。
各段階のモノマー分圧の測定値から物質収支
を求めて得たA部及びB部の重合量比率は
87.6:12.4であり、A部、B部各々のエチレン
含有率はそれぞれ4.2重量%、86.2重量%であ
つた。
このパウダー状重合体に2・6−ジ−t−ブ
チル−p−クレゾール0.5重量%、テトラキス
〔メチレン3−(3′・5′−ジ−t−ブチル−4′−
ヒドロキシフエニル)プロピオネート〕メタン
(チバガイギー社製イルガノツクス1010)0.05
重量%、ステアリン酸カルシウム0.15重量%を
均一に混合し、250℃にてペレツト化した。こ
のペレツトのMIは0.09g/10分であつた。
また〔η〕測定用試料としてA部重合終了時
点の重合スラリーをオートクレーブの底部の側
管より極く少量取り出して大過剰のメタノール
を装入し過、乾燥してパウダー状重合体(す
なわちA部のみからなる重合体)を得た。この
A部重合終了時の試料の〔η〕(〔η〕A)とB部
重合終了時のパウダーの〔η〕(〔η〕AB)を測
定すると、それぞれ4.01dl/g、3.99dl/gであ
つた。これよりB部の生成〔η〕(〔η〕B)は
〔η〕B=3.99−4.01×0.876/0.12
4
=3.85(dl/g)
と計算出来る。
また〔η〕B−〔η〕A=3.85−4.01=−0.16とな
る。これらの結果を表−1にまとめた。
(2) 極薄強化フイルムの成形及び物性評価
上記(1)で得たポリプロピレン樹脂組成物のペ
レツトをシリンダーの内径50mm、スクリユーの
L/D=28の押出機を用いて、スパイラル型環
状ダイから溶融、押出し、空冷インフレーシヨ
ン法により肉厚が30μと15μの管状フイルムを
成形した。空冷インフレーシヨン成形条件とし
ては、環状ダイの温度を220℃に、管状フイル
ムの引取り速度を肉厚30μの時に15m/分、肉
厚15μの時に30m/分に設定した。チユーブの
安定性は良く、シワ、肉厚むらは実用上問題な
く良好であつた。このようにして得られた管状
フイルムについて東洋精機(株)製インパクトテス
ターによりフイルムの衝撃強度を、また東洋精
機(株)製霞度計によりHaze(雰度)を測定し
た。結果は表−2に示したごとく、衝撃強度は
十分強く、また透明性も実用上十分であつた。
(Hazeが十分低い)。
実施例 2
ポリプロピレン樹脂組成物の製造方法について
はA部、B部のそれぞれの気相水素濃度を変え、
A部はプロピレン100重量%、B部はエチレン100
重量%で重合したこと、およびA、B部の重合量
比率を変えた以外は実施例1と全く同様に行い、
表−1の結果を得た。また極薄強化フイルムの成
形についても実施例1と全く同様に行い、得られ
たフイルムの性能を評価して表−2の結果を得
た。
比較例 1〜8
ポリプロピレン樹脂組成物の製造方法について
は、A部、B部それぞれの気相水素濃度、プロピ
レン−エチレン混合ガスのエチレン含有率、及び
A部、B部の重合量比率を変えた以外は実施例1
と全く同様に行い、表−1の結果を得た。また、
極薄強化フイルムの成形についても実施例1と全
く同様に行い、得られたフイルムの性能を評価し
て表−2の結果を得た。
実施例 3
(1) ポリプロピレン樹脂組成物の製造
内容積20のSUS−27オートクレーブ中に窒
素雰囲気下でヘプタン10を装入し、触媒とし
て活性化三塩化チタン5g及びジエチルアルミ
ニウムクロライド8gを装入した。オートクレ
ーブ内の窒素をプロピレンで置換し、50℃に昇
温した時のオートクレーブ内圧力が1Kg/cm2・
G、しかも気相水素濃度が0.3容量%となるよ
うにプロピレンと水素を装入した。
A部の形成はA−1とA−2の2段階に分け
る重合により実施した。
A−1段階は、オートクレーブ内容物を50℃
まで昇温し、50℃にて内圧1Kg/cm2・Gに保つよ
うにプロピレンを連続的に装入し、45分間重合
を継続し、次いで内温を55℃まで昇温して実施
した。
A−2段階は、55℃への昇温と同時にエチレ
ン含有率2.4重量%のプロピレン−エチレン混
合ガスを連続的に装入し、内圧を4Kg/cm2・G、
気相水素濃度を0.3容量%に保つて、2.2時間重
合を継続して実施した。
B部の形成はB−1とB−2の2段階に分け
る重合により実施した。
B−1段階は、A部重合終了後、残留モノマ
ーを速やかに常圧付近までパージし、次いで真
空ポンプで520mmHgまで更にモノマーを吸引除
去した。次に気相水素濃度が11容量%になるよ
うに水素とエチレンを0.5Kg/cm2・Gまで一括装
入し、重合温度55℃でエチレン含有率76.7重量
%のプロピレン−エチレン混合ガスを連続的に
装入し、オートクレーブ内圧を0.5Kg/cm2・Gに
保つて35分間重合を継続した。
B−2段階は、未反応モノマーを真空ポンプ
により完全に除去した後、気相水素濃度が25容
量%となる様に水素とエチレン含有率77.4重量
%のプロピレン−エチレン混合ガスを0.5Kg/
cm2・Gまで一括装入し、重合温度55℃、内圧0.5
Kg/cm2・G気相水素濃度25容量%を保つようにエ
チレン含有率97.5重量%のプロピレン−エチレ
ン混合ガスおよび水素を連続的に装入し、1.5
時間重合を継続した。
重合終了後、メタノール2を装入して重合
を停止させ、通常の方法により精製乾燥して
3.9Kgのパウダー状重合体を得た。
各段階のモノマー分圧の測定値から物質収支
を求めた結果、A−1、A−2、B−1、B−
2各部の重合比率は8.2:75.7:7.3:8.8であつ
た。またA−2、B−1、B−2各部のエチレ
ン含有率は、それぞれ2.8重量%、76.7重量
%、97.5重量%であつた。
また〔η〕測定用試料としてA−1、A−
2、B−1、B−2各部までの生成の終了時の
重合スラリーを極く少量取り出し、大過剰のメ
タノールに装入し、過、乾燥してパウダー状
重合体を得た。この各A−1、A−2、B−
1、B−2終了時のパウダーの〔η〕を測定し
たところ、それぞれ4.19dl/g、4.23dl/g、
4.22dl/g、4.24dl/gであつた。これよりA−
2部の生成〔η〕(〔η〕A-2)は
〔η〕A-2=4.23×(8.2+75.7)−4.19×(8.2)/75.7=4.23
B−1部の生成〔η〕(〔η〕B-1)は
〔η〕B-1=4.22×(8.2+75.7+7.3)−4.23×(8.2+75.7)/7.3=4.11
B−2部の生成〔η〕(〔η〕B-2)は
〔η〕B-2=4.24×100−4.22×(8.2+75.7+7.3)/8.8=4.45
と計算できる。
なおペレツトの製造方法及び極薄強化フイル
ムの成形方法については実施例1と全く同様で
ある。
結果は表−2および表−3にまとめた。
実施例 4
ポリプロピレン樹脂組成物の製造方法について
はA−1、A−2、B−1、B−2段階それぞれ
の気相水素濃度、プロピレン−エチレン混合ガス
のエチレン含有率、及びA−1、A−2、B−
1、B−2各段階の重合量比率を変えた以外は実
施例3と全く同様に行い、表−3に示す結果を得
た。また極薄強化フイルムの成形についても実施
例3と全く同様に行い、表−2の結果を得た。
The present invention relates to a polypropylene resin composition suitable for forming a film having excellent impact resistance and transparency. Conventionally, polypropylene films have been made using the casting method or the inflation molding method, and polypropylene suitable for each molding method and use is already commercially available. However, these polypropylenes can be made with increased wall thickness, especially using air-cooled inflation molding methods.
When trying to mold an extremely thin film of about 30 microns, the impact strength of the film becomes weaker, and the stability of the tube during film molding becomes worse (more wrinkles, uneven wall thickness, and bending diameter). There is a need for improvement. Furthermore, these films are made into bags and used for general standard bags, etc., but when carrying things inside the bags, the bags need to be transparent so that the contents can be clearly seen from the outside. The object of the present invention is to improve the impact strength and stability of the tube during film forming without compromising the transparency required for the film as a packaging material. In order to accomplish these tasks, the present inventors
As a polypropylene resin composition, use one that has a specific ethylene distribution and a specific intrinsic viscosity relationship among those that have a considerably larger molecular weight than conventional ones and a specific ethylene content. The present invention was finally completed. This special polypropylene resin composition used in the present invention is produced, for example, by the following method. That is, using a Ziegler-Natsuta type activated titanium catalyst, propylene is produced in the first stage of polymerization.
A 100% by weight raw material gas or a propylene-ethylene mixed gas adjusted so that the ethylene content in the copolymer is less than 20% by weight is copolymerized in a range of 60 to 95% by weight of the total amount of olefin polymerized. The part of the polymer molecule grown by this polymerization is A
It is called a department. The intrinsic viscosity [η] (dl/g) of the polyolefin obtained by taking a sample and stopping the polymerization by destroying the catalyst at the stage where this part A is produced is [η] A. (This will be referred to as part A formation [η].) Note that [η] was measured from the viscosity of the tetralin solution (135° C., 50 mg/50 c.c.). Subsequently, in the second stage of polymerization, the above-mentioned copolymer molecules are grown. In the second stage, a propylene-ethylene mixed gas is added in an amount of 40% to 40% of the total amount of olefin polymerized so that the ethylene content is 20% by weight or more. Copolymerization is carried out in a range of 5% by weight. The part of the copolymer grown at this stage is referred to as Part B. At this time, the overall average (measured value) of the resin composition consisting of part A produced in the first stage and part B produced in the second stage.
If [η] of [η] is [η] AB , then [η] B of the copolymer part formed in part B (referred to as part B formation [η])
There is a relationship between and the measured value [η] A as shown in the following equation. [η] AB = [η] A x a + [η] B x b/100 where a and b are weight percent of the mixed gas polymerized in parts A and B, respectively. In this case, the propylene-ethylene mixing ratio and [η] may be gradually increased or decreased in the first-stage polymerization and the second-stage polymerization, or may be changed intermittently during the polymerization. [η] can be changed by adjusting the amount of the molecular weight regulator. In addition, as a method for producing a polypropylene resin composition in the present invention, part A in the first stage polymerization and part B in the second stage polymerization are each further divided into two or more stages, for example, part A is A-1, A-1...
..., Part B may be polymerized separately from B-1, B-2, etc., as long as Part A and Part B have the specific composition and specific production [η] of the present invention as an average. Next, each component of the resin composition of the present invention will be explained. First of all, the melt index (hereinafter abbreviated as MI) referred to in the present invention is based on ASTM D1238 (JIS K-
7210) and at 230°C.
Measurements are shown at a temperature of 2160g and a load of 2160g. The MI of the resin composition used in the present invention is 0.01
~0.3g/10 minutes is required, especially
0.05 to 0.2 g/10 minutes is preferred. If MI exceeds 0.3 g/10 minutes, the stability of the tube during molding will decrease, causing wrinkles and uneven wall thickness. Conventional polypropylene for film molding has an MI of approximately 8, and the large difference in MI from the resin composition of the present invention seems to be related to the performance of the film.
It is extremely difficult to produce polypropylene with an MI of less than 0.01 g/10 minutes using normal methods, and even if it could be produced, the actual film forming temperature would be abnormally high, or the temperature inside the forming machine would be too high. Because the pressure of the molten resin becomes abnormally high, the molding equipment becomes heavily equipped and is not practical. MI becomes smaller as the molecular weight of the polymer increases. Furthermore, the larger the molecular weight of the polymer, the larger the [η] of the polymer. That is, MI has an inverse correlation with molecular weight and [η]. Furthermore, the MI referred to in the present invention can be measured in the form of polypropylene powder or pellets, but it is usually measured after adding a certain amount of antioxidant and hydrochloric acid scavenger to polypropylene powder and turning it into pellets using an extruder. . The present invention was also measured in this manner. In the polypropylene resin composition of the present invention, it is necessary that the ethylene content is 1 to 50% by weight; if it is less than 1% by weight, it will not only be difficult to satisfy the conditions specified below, but also the resulting film impact strength is insufficient. Moreover, if it exceeds 50% by weight, not only will the tube become extremely soft, but the stability of the tube during film molding will also be significantly reduced. Part A of the polypropylene resin composition of the present invention is a propylene homopolymer or ethylene content
It consists of less than 20% by weight of copolymer, but the ethylene content is particularly preferably between 3 and 8% by weight. If the ethylene content exceeds 20% by weight, the properties of the slurry will deteriorate during the production of part A in the first stage polymerization, causing problems such as clogging of pipes during slurry transfer. Actually, the average composition of part A is ethylene content 3
Even when polymerizing to 8% by weight, in order to improve the slurry properties, propylene is polymerized in advance by 5 to 20% by weight of the total amount of olefin polymerized to create a highly crystalline homopolymer, and then propylene-ethylene is mixed. A method of creating a copolymerization region using gas has also been used. The present invention also includes such cases. The ethylene content of Part B of the polypropylene resin composition of the present invention must be 20% by weight or more. If the ethylene content is less than 20% by weight, the impact strength will be extremely low, making it impossible to obtain a film of practical use. This part B is 40 to 5% of the total resin composition.
It is necessary that the amount is within the range of % by weight. 5% by weight
If it goes below , the impact strength will decrease. Moreover, if it exceeds 40% by weight, not only will the tube become extremely soft, but the stability of the tube during film molding will also be significantly reduced. In the present invention, the relationship between [η] A and [η] B needs to be as follows: [η] A +0.5>[η] B ≧ [η] A −1.5. Preferably, [η] A ≧ [η] B ≧ [η] A −1.0. When [η] B is [η] A +0.5 or more, transparency deteriorates and it is not suitable for the purpose of the present invention. On the other hand, when [η] A is less than -1.5, the stability of the tube decreases significantly and the object of the present invention is not achieved. In the present invention, in order to bring [η] B within the above range, the amount of the molecular weight regulator may be adjusted in the polymerization of the B part. As a method for forming a film using the resin composition of the present invention, a known method generally referred to as an air-cooled inflation method can be used. At this time, as in the usual case, various additives used in ordinary polypropylene, such as antioxidants, lubricants, and other additives, may be added as necessary. For example, there is no problem in adding a known nucleating agent to improve transparency. Since the ultra-thin reinforced film obtained in the present invention has good impact strength even if it has a small wall thickness, it is expected to have a wide range of uses from the viewpoint of resource saving. In addition, the stability of the tube during molding is good, and there are few wrinkles and uneven wall thickness, so it is of high practical value. Furthermore, when inflation molding is performed using this polypropylene resin composition, there is a technical effect that high-speed molding is possible in addition to the above-mentioned objective. Therefore, even if the molding speed is made faster than before, a film of good quality can be obtained, and the manufacturing cost of the film can be reduced. The present invention will be explained below with reference to Examples. Example 1 (1) Production of polypropylene resin composition In a SUS-27 autoclave with an internal volume of 20 mm, 10 g of heptane was charged under a nitrogen atmosphere, and 5 g of activated titanium trichloride and 8 g of diethylaluminium chloride were charged as catalysts. . The autoclave internal pressure when the temperature rose to 55℃ was 4 in gauge pressure.
Kg/cm 2 (hereinafter, the symbol will be abbreviated as Kg/cm 2 G), and hydrogen and a propylene-ethylene mixed gas with an ethylene content of 3.4% by weight were charged so that the gas phase hydrogen concentration was 0.3% by volume. , raise the temperature to 55℃,
Polymerization was continued for 2 to 3 hours at 55°C by continuously charging the propylene-ethylene mixed gas and hydrogen so as to maintain the internal pressure at 4 kg/cm 2 G and the hydrogen concentration at 0.3% by volume. Generation of part A by one-stage polymerization). Next, after completely purging unreacted monomer while maintaining the activity of the catalyst, 0.5% of a propylene-ethylene mixed gas containing hydrogen and ethylene with a content of 35.4% by weight was added so that the gas phase hydrogen concentration was 34% by volume. Bulk charging up to Kg/cm 2・G, polymerization temperature 55℃
When the temperature was maintained, polymerization started again. There the internal pressure
0.5Kg/cm 2・G, propylene with ethylene content of 86.2% by weight to maintain gas phase hydrogen concentration of 34% by volume.
Continuously charge ethylene mixed gas and hydrogen,
Polymerization was continued for 1.4 hours (B by second stage polymerization)
generation). At the end of the polymerization, methanol 2 was added to stop the polymerization, and the mixture was purified and dried using the usual method.
Kg of powdered polymer was obtained. The polymerization ratio of parts A and B obtained by calculating the mass balance from the measured values of monomer partial pressure at each stage is
87.6:12.4, and the ethylene contents of parts A and B were 4.2% by weight and 86.2% by weight, respectively. This powdery polymer was added with 0.5% by weight of 2,6-di-t-butyl-p-cresol, tetrakis[methylene 3-(3',5'-di-t-butyl-4'-
Hydroxyphenyl) propionate] methane (Irganox 1010 manufactured by Ciba Geigy) 0.05
% by weight and 0.15% by weight of calcium stearate were uniformly mixed and pelletized at 250°C. The MI of this pellet was 0.09 g/10 min. [η] As a sample for measurement, a very small amount of the polymerization slurry at the end of Part A polymerization was taken out from the side tube at the bottom of the autoclave, charged with a large excess of methanol, and dried to form a powdery polymer (i.e., Part A). A polymer consisting of only When we measured [η] ([η] A ) of the sample at the end of polymerization of part A and [η] ([η] AB ) of the powder at the end of polymerization of part B, they were 4.01 dl/g and 3.99 dl/g, respectively. It was hot. From this, the generation of part B [η] ([η] B ) is [η] B = 3.99-4.01×0.876/0.12
It can be calculated as 4 = 3.85 (dl/g). Also, [η] B − [η] A = 3.85 − 4.01 = −0.16. These results are summarized in Table-1. (2) Molding and physical property evaluation of ultra-thin reinforced film The pellets of the polypropylene resin composition obtained in (1) above were passed through a spiral-shaped annular die using an extruder with a cylinder inner diameter of 50 mm and a screw L/D = 28. Tubular films with wall thicknesses of 30μ and 15μ were formed by melting, extrusion, and air-cooled inflation. The air-cooled inflation molding conditions were as follows: the temperature of the annular die was set to 220° C., and the take-up speed of the tubular film was set to 15 m/min when the wall thickness was 30 μm, and 30 m/min when the wall thickness was 15 μm. The stability of the tube was good, and wrinkles and uneven wall thickness were good without any practical problems. The impact strength of the tubular film thus obtained was measured using an impact tester manufactured by Toyo Seiki Co., Ltd., and the haze (atmosphere) was measured using a haze meter manufactured by Toyo Seiki Co., Ltd. As shown in Table 2, the impact strength was sufficiently strong and the transparency was sufficient for practical use.
(Haze is low enough). Example 2 Regarding the manufacturing method of a polypropylene resin composition, the gas phase hydrogen concentration of each part A and B was changed,
Part A is 100% propylene by weight, part B is 100% ethylene.
The process was carried out in exactly the same manner as in Example 1, except that the polymerization was carried out in % by weight and the polymerization ratio of parts A and B was changed.
The results shown in Table 1 were obtained. Furthermore, the ultrathin reinforced film was molded in exactly the same manner as in Example 1, and the performance of the obtained film was evaluated and the results shown in Table 2 were obtained. Comparative Examples 1 to 8 Regarding the manufacturing method of polypropylene resin compositions, the gas phase hydrogen concentration of parts A and B, the ethylene content of the propylene-ethylene mixed gas, and the polymerization ratio of parts A and B were changed. Other than that, Example 1
The same procedure as above was carried out, and the results shown in Table 1 were obtained. Also,
The ultra-thin reinforced film was formed in exactly the same manner as in Example 1, and the performance of the obtained film was evaluated and the results shown in Table 2 were obtained. Example 3 (1) Production of polypropylene resin composition 10 g of heptane was charged under a nitrogen atmosphere into a SUS-27 autoclave having an internal volume of 20 g, and 5 g of activated titanium trichloride and 8 g of diethylaluminium chloride were charged as catalysts. . When the nitrogen in the autoclave was replaced with propylene and the temperature was raised to 50℃, the pressure inside the autoclave was 1Kg/cm 2 .
Propylene and hydrogen were charged so that the hydrogen concentration in the gas phase was 0.3% by volume. Part A was formed by polymerization divided into two stages, A-1 and A-2. In stage A-1, the contents of the autoclave were heated to 50°C.
Propylene was continuously charged to maintain the internal pressure at 1 Kg/cm 2 ·G at 50°C, polymerization was continued for 45 minutes, and then the internal temperature was raised to 55°C. In the A-2 stage, at the same time as the temperature was raised to 55℃, a propylene-ethylene mixed gas with an ethylene content of 2.4% by weight was continuously charged, and the internal pressure was raised to 4Kg/cm 2 G.
Polymerization was continued for 2.2 hours while keeping the gas phase hydrogen concentration at 0.3% by volume. Part B was formed by polymerization divided into two stages, B-1 and B-2. In the B-1 stage, after the polymerization of part A was completed, the residual monomer was immediately purged to around normal pressure, and then the monomer was further removed by suction to 520 mmHg using a vacuum pump. Next, hydrogen and ethylene were charged at once to 0.5Kg/cm 2 G so that the gas phase hydrogen concentration was 11% by volume, and a propylene-ethylene mixed gas with an ethylene content of 76.7% by weight was continuously added at a polymerization temperature of 55℃. The polymerization was continued for 35 minutes while maintaining the autoclave internal pressure at 0.5 Kg/cm 2 ·G. In the B-2 stage, after completely removing unreacted monomers using a vacuum pump, 0.5 kg of hydrogen and a propylene-ethylene mixed gas with an ethylene content of 77.4% by weight is added so that the gas phase hydrogen concentration is 25% by volume.
Charge up to cm 2・G at once, polymerization temperature 55℃, internal pressure 0.5
Kg/cm 2・G Propylene-ethylene mixed gas with an ethylene content of 97.5% by weight and hydrogen are continuously charged so as to maintain a gas phase hydrogen concentration of 25% by volume.
Polymerization was continued for hours. After the polymerization is completed, methanol 2 is charged to stop the polymerization, and the product is purified and dried using the usual method.
3.9Kg of powdered polymer was obtained. As a result of calculating the mass balance from the measured values of monomer partial pressure at each stage, A-1, A-2, B-1, B-
The polymerization ratio of the two parts was 8.2:75.7:7.3:8.8. Further, the ethylene content of parts A-2, B-1, and B-2 was 2.8% by weight, 76.7% by weight, and 97.5% by weight, respectively. [η] As measurement samples, A-1, A-
A very small amount of the polymerization slurry at the end of the production of parts 2, B-1, and B-2 was taken out, charged into a large excess of methanol, filtered, and dried to obtain a powdery polymer. Each of these A-1, A-2, B-
1. When we measured [η] of the powder at the end of B-2, it was 4.19 dl/g, 4.23 dl/g, respectively.
They were 4.22 dl/g and 4.24 dl/g. From this A-
The generation of the second part [η] ([η] A-2 ) is [η] A-2 = 4.23 x (8.2 + 75.7) - 4.19 x (8.2) / 75.7 = 4.23 The generation of part B-1 [η] ([η] B-1 ) is [η] B-1 = 4.22 x (8.2 + 75.7 + 7.3) - 4.23 x (8.2 + 75.7) /7.3=4.11 The production of part B-2 [η] ([η] B-2 ) is [η] B-2 = 4.24×100−4.22×(8.2+75.7+7.3) It can be calculated as /8.8=4.45. The method for producing pellets and the method for molding an ultra-thin reinforcing film are exactly the same as in Example 1. The results are summarized in Table-2 and Table-3. Example 4 Regarding the method for producing a polypropylene resin composition, the gas phase hydrogen concentration at each stage of A-1, A-2, B-1, and B-2, the ethylene content of the propylene-ethylene mixed gas, and the A-1, A-2, B-
1 and B-2 The same procedure as in Example 3 was carried out except that the polymerization ratio in each stage was changed, and the results shown in Table 3 were obtained. Furthermore, the ultra-thin reinforced film was molded in exactly the same manner as in Example 3, and the results shown in Table 2 were obtained.
【表】【table】
【表】【table】
Claims (1)
あり、かつ、エチレン含有率が1〜50重量%であ
るフイルム成形用プロピレン共重合体組成物であ
つて、該樹脂組成物が、 (a) エチレン含有率が20重量%未満(0重量%を
含む)であるA部が全樹脂組成物中60〜95重量
%であり、エチレン含有率が20重量%以上であ
るB部が全樹脂組成物中40〜5重量%であり、
かつ、 (b) A部の極限粘度数〔η〕AとB部の極限粘度数
〔η〕Bとの間に、次式 〔η〕A+0.5>〔η〕B≧〔η〕A−1.5 の関係を有する ことを特徴とするフイルム成形用プロピレン共重
合体組成物。[Scope of Claims] 1. A propylene copolymer composition for film molding having a melt index of 0.01 to 0.3 g/10 minutes and an ethylene content of 1 to 50% by weight, the resin composition comprising: (a) Part A having an ethylene content of less than 20% by weight (including 0% by weight) is 60 to 95% by weight of the total resin composition, and Part B having an ethylene content of 20% by weight or more; part is 40 to 5% by weight in the total resin composition,
and (b) between the limiting viscosity number of part A [η] A and the limiting viscosity number of part B [η] B , the following formula [η] A +0.5> [η] B ≧ [η] A A propylene copolymer composition for film forming, characterized in that it has a relationship of −1.5.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP16162979A JPS5684712A (en) | 1979-12-14 | 1979-12-14 | Propylene copolymer for molding film |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP16162979A JPS5684712A (en) | 1979-12-14 | 1979-12-14 | Propylene copolymer for molding film |
Publications (2)
Publication Number | Publication Date |
---|---|
JPS5684712A JPS5684712A (en) | 1981-07-10 |
JPS6156244B2 true JPS6156244B2 (en) | 1986-12-01 |
Family
ID=15738811
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP16162979A Granted JPS5684712A (en) | 1979-12-14 | 1979-12-14 | Propylene copolymer for molding film |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPS5684712A (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6244447A (en) * | 1985-08-23 | 1987-02-26 | 三菱油化株式会社 | Non-fogging propylene group resin film |
JP2598407B2 (en) * | 1987-05-11 | 1997-04-09 | 三井東圧化学株式会社 | Propylene-ethylene copolymer composition and method for producing the same |
JPS6431846A (en) * | 1987-07-29 | 1989-02-02 | Idemitsu Petrochemical Co | Propylene polymer film |
JP3358441B2 (en) | 1996-06-04 | 2002-12-16 | 住友化学工業株式会社 | Polypropylene block copolymer |
DE19833507A1 (en) * | 1997-07-28 | 1999-02-04 | Sumitomo Chemical Co | Propylene block copolymer for moulding |
-
1979
- 1979-12-14 JP JP16162979A patent/JPS5684712A/en active Granted
Also Published As
Publication number | Publication date |
---|---|
JPS5684712A (en) | 1981-07-10 |
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