JPH0571622B2 - - Google Patents
Info
- Publication number
- JPH0571622B2 JPH0571622B2 JP1059514A JP5951489A JPH0571622B2 JP H0571622 B2 JPH0571622 B2 JP H0571622B2 JP 1059514 A JP1059514 A JP 1059514A JP 5951489 A JP5951489 A JP 5951489A JP H0571622 B2 JPH0571622 B2 JP H0571622B2
- Authority
- JP
- Japan
- Prior art keywords
- foam
- resin
- polyolefin resin
- weight
- polyorganosiloxane
- 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
- 239000006260 foam Substances 0.000 claims description 50
- 229920005672 polyolefin resin Polymers 0.000 claims description 31
- 229920005989 resin Polymers 0.000 claims description 16
- 239000011347 resin Substances 0.000 claims description 16
- 239000000203 mixture Substances 0.000 claims description 9
- 238000004519 manufacturing process Methods 0.000 claims description 8
- 229920001296 polysiloxane Polymers 0.000 claims description 8
- 229920006026 co-polymeric resin Polymers 0.000 claims description 7
- 239000004088 foaming agent Substances 0.000 claims description 7
- 239000011342 resin composition Substances 0.000 claims description 6
- 239000002667 nucleating agent Substances 0.000 claims description 5
- 238000000034 method Methods 0.000 description 19
- -1 polyethylene Polymers 0.000 description 17
- 230000000694 effects Effects 0.000 description 16
- 239000004604 Blowing Agent Substances 0.000 description 10
- 229920000098 polyolefin Polymers 0.000 description 10
- 229920001577 copolymer Polymers 0.000 description 9
- 238000001125 extrusion Methods 0.000 description 9
- 238000005187 foaming Methods 0.000 description 9
- 229920000578 graft copolymer Polymers 0.000 description 8
- 238000002156 mixing Methods 0.000 description 8
- 239000005022 packaging material Substances 0.000 description 8
- 230000000379 polymerizing effect Effects 0.000 description 7
- 239000004698 Polyethylene Substances 0.000 description 5
- 239000004743 Polypropylene Substances 0.000 description 5
- 238000010924 continuous production Methods 0.000 description 5
- 229920001684 low density polyethylene Polymers 0.000 description 5
- 239000004702 low-density polyethylene Substances 0.000 description 5
- 239000000463 material Substances 0.000 description 5
- 229920000573 polyethylene Polymers 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 238000010559 graft polymerization reaction Methods 0.000 description 4
- 150000008282 halocarbons Chemical class 0.000 description 4
- 238000004898 kneading Methods 0.000 description 4
- 229920001155 polypropylene Polymers 0.000 description 4
- 229920002545 silicone oil Polymers 0.000 description 4
- YMWUJEATGCHHMB-UHFFFAOYSA-N Dichloromethane Chemical compound ClCCl YMWUJEATGCHHMB-UHFFFAOYSA-N 0.000 description 3
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 3
- 238000004132 cross linking Methods 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- 239000012528 membrane Substances 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- 229920000642 polymer Polymers 0.000 description 3
- 230000003405 preventing effect Effects 0.000 description 3
- DDMOUSALMHHKOS-UHFFFAOYSA-N 1,2-dichloro-1,1,2,2-tetrafluoroethane Chemical compound FC(F)(Cl)C(F)(F)Cl DDMOUSALMHHKOS-UHFFFAOYSA-N 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000001273 butane Substances 0.000 description 2
- 229940087091 dichlorotetrafluoroethane Drugs 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 229920001519 homopolymer Polymers 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 2
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 239000000454 talc Substances 0.000 description 2
- 229910052623 talc Inorganic materials 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- LVGUZGTVOIAKKC-UHFFFAOYSA-N 1,1,1,2-tetrafluoroethane Chemical compound FCC(F)(F)F LVGUZGTVOIAKKC-UHFFFAOYSA-N 0.000 description 1
- BOSAWIQFTJIYIS-UHFFFAOYSA-N 1,1,1-trichloro-2,2,2-trifluoroethane Chemical compound FC(F)(F)C(Cl)(Cl)Cl BOSAWIQFTJIYIS-UHFFFAOYSA-N 0.000 description 1
- UJPMYEOUBPIPHQ-UHFFFAOYSA-N 1,1,1-trifluoroethane Chemical compound CC(F)(F)F UJPMYEOUBPIPHQ-UHFFFAOYSA-N 0.000 description 1
- NPNPZTNLOVBDOC-UHFFFAOYSA-N 1,1-difluoroethane Chemical compound CC(F)F NPNPZTNLOVBDOC-UHFFFAOYSA-N 0.000 description 1
- RFCAUADVODFSLZ-UHFFFAOYSA-N 1-Chloro-1,1,2,2,2-pentafluoroethane Chemical compound FC(F)(F)C(F)(F)Cl RFCAUADVODFSLZ-UHFFFAOYSA-N 0.000 description 1
- JQZFYIGAYWLRCC-UHFFFAOYSA-N 1-chloro-1,1,2,2-tetrafluoroethane Chemical compound FC(F)C(F)(F)Cl JQZFYIGAYWLRCC-UHFFFAOYSA-N 0.000 description 1
- BHNZEZWIUMJCGF-UHFFFAOYSA-N 1-chloro-1,1-difluoroethane Chemical compound CC(F)(F)Cl BHNZEZWIUMJCGF-UHFFFAOYSA-N 0.000 description 1
- CYXIKYKBLDZZNW-UHFFFAOYSA-N 2-Chloro-1,1,1-trifluoroethane Chemical compound FC(F)(F)CCl CYXIKYKBLDZZNW-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- VOPWNXZWBYDODV-UHFFFAOYSA-N Chlorodifluoromethane Chemical compound FC(F)Cl VOPWNXZWBYDODV-UHFFFAOYSA-N 0.000 description 1
- XWCDCDSDNJVCLO-UHFFFAOYSA-N Chlorofluoromethane Chemical compound FCCl XWCDCDSDNJVCLO-UHFFFAOYSA-N 0.000 description 1
- 239000004338 Dichlorodifluoromethane Substances 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 230000003078 antioxidant effect Effects 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- 230000003796 beauty Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 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
- 238000006243 chemical reaction Methods 0.000 description 1
- NEHMKBQYUWJMIP-NJFSPNSNSA-N chloro(114C)methane Chemical compound [14CH3]Cl NEHMKBQYUWJMIP-NJFSPNSNSA-N 0.000 description 1
- 235000019406 chloropentafluoroethane Nutrition 0.000 description 1
- AFYPFACVUDMOHA-UHFFFAOYSA-N chlorotrifluoromethane Chemical compound FC(F)(F)Cl AFYPFACVUDMOHA-UHFFFAOYSA-N 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 125000003963 dichloro group Chemical group Cl* 0.000 description 1
- PXBRQCKWGAHEHS-UHFFFAOYSA-N dichlorodifluoromethane Chemical compound FC(F)(Cl)Cl PXBRQCKWGAHEHS-UHFFFAOYSA-N 0.000 description 1
- 235000019404 dichlorodifluoromethane Nutrition 0.000 description 1
- 229940042935 dichlorodifluoromethane Drugs 0.000 description 1
- UMNKXPULIDJLSU-UHFFFAOYSA-N dichlorofluoromethane Chemical compound FC(Cl)Cl UMNKXPULIDJLSU-UHFFFAOYSA-N 0.000 description 1
- 229940099364 dichlorofluoromethane Drugs 0.000 description 1
- 235000014113 dietary fatty acids Nutrition 0.000 description 1
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical class [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 239000005038 ethylene vinyl acetate Substances 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000000194 fatty acid Substances 0.000 description 1
- 229930195729 fatty acid Natural products 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000012774 insulation material Substances 0.000 description 1
- 230000005865 ionizing radiation Effects 0.000 description 1
- 229940073584 methylene chloride Drugs 0.000 description 1
- 238000013508 migration Methods 0.000 description 1
- 230000005012 migration Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 231100000989 no adverse effect Toxicity 0.000 description 1
- 238000004806 packaging method and process Methods 0.000 description 1
- 150000002978 peroxides Chemical class 0.000 description 1
- 125000001997 phenyl group Chemical group [H]C1=C([H])C([H])=C(*)C([H])=C1[H] 0.000 description 1
- 229920013716 polyethylene resin Polymers 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000003892 spreading Methods 0.000 description 1
- 230000007480 spreading Effects 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 150000005846 sugar alcohols Polymers 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- CYRMSUTZVYGINF-UHFFFAOYSA-N trichlorofluoromethane Chemical compound FC(Cl)(Cl)Cl CYRMSUTZVYGINF-UHFFFAOYSA-N 0.000 description 1
- 229940029284 trichlorofluoromethane Drugs 0.000 description 1
- 239000006097 ultraviolet radiation absorber Substances 0.000 description 1
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical compound [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 1
Landscapes
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Extrusion Moulding Of Plastics Or The Like (AREA)
- Molding Of Porous Articles (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Description
（産業上の利用分野）
本発明はポリエチレン、ポリプロピレン等のポ
リオレフイン樹脂発泡体、特に均一微細な独立気
泡を有する表面が平滑で美麗なポリオレフイン樹
脂発泡体の製造方法に関する。
（従来の技術）
ポリオレフイン樹脂発泡体は、近年利用が様々
な分野に広がつてきているが、一般的に、微細な
気泡を好まれ、特に緩衝材、断熱材、装飾材等に
は均一微細な気泡を有する発泡体が強く望まれて
いる。その理由としては、まず、緩衝材としては
気泡が微細なものほど柔軟でクツシヨン性の良好
なものとなること、断熱材としては微細気泡のも
のほど熱伝導率が小さく断熱性能に優れること、
装飾材としては、微細気泡のものほど表面、カツ
ト面の外観が美麗であること等が挙げられる。
均一で微細な気泡を有するポリオレフイン樹脂
発泡体を連続的に得る方法として、ポリオレフイ
ン樹脂に過酸化物を混合したり、或は電子線を照
射してポリオレフイン樹脂に架橋反応を行なわせ
た後、発泡させる架橋発泡法がある。この方法に
よると確かに微細気泡を有した発泡体が得られる
が、発泡プロセスが複雑且つ設備コストが高いと
いう欠点を有している。
これとは別に、簡単なプロセスで薄いシート状
のものから厚い板状体まで得られる方法として、
ポリオレフイン樹脂と発泡剤を押出機で溶融混合
して流動性のゲルとなした後、低圧域に押出して
発泡させる。いわゆる押出発泡法がある。しかし
ながら、この方法は、発泡体が効率良く得られる
反面、気泡サイズが架橋発泡したものに比べて粗
大なものに成つてしまう欠点があつた。更に、重
梱包材として使用する発泡体密度0.5ｇ／cm3以上
であるポリオレフイン発泡体のような比較的低倍
率体では、発泡剤量を減らしているため、押出機
内での摩擦熱が大きく発泡不良、独立気泡率の低
下を起こしやすくなつてしまうという欠点を有し
ていた。
この問題を解決するために、メルトインデツク
スの更に高いポリオレフイン樹脂を使用すると、
摩擦熱防止効果は有るものの、製造した発泡体の
気泡粗化、そして重梱包材として致命的欠点であ
る発泡体強度不足を生じてしまうので、高いメル
トインデツクスのポリオレフインを使用すること
ができない。
また、上記問題点を解決するためにポリオレフ
イン系樹脂にシリコーン油、または変性ポリシロ
キサン系オイルを用いて気泡均一微細化する方法
が、特開昭62−89738号、特開昭62−89741号、特
開昭62−285930号等により開示されている。しか
し、これらシリコーン油または変性シロキサン系
オイルを用いると、特に押出発泡法において、オ
レフイン系樹脂と発泡剤（低級脂肪族炭化水素ま
たはハロゲン化炭化水素）との混練を妨げるよう
な作用を生じやすく、安定的な連続生産が難しい
欠点があつた。
また、製造した発泡体を梱包材として使用した
場合、発泡体表面へブリードしたシリコーン油ま
たは変性ポリシロキサンオイル等が梱包された製
品に移行し曇りを生じ、著しくその価値を失うと
いう梱包材として致命的欠点や熱接着性の低下、
表面印刷性の低下等の問題をもたらす。
（発明が解決しようとする課題）
このような現状に鑑み、本発明者等は、均一に
微細な気泡を有する独立気泡率の高い発泡体で且
つ該発泡体を梱包材として使用した場合に梱包さ
れる製品に曇り等の問題を生じないポリオレフイ
ン発泡体を安定に連続生産する方法について鋭意
検討した結果、ポリオルガノシロシキンをポリオ
レフイン樹脂にグラフト重合させた共重合体とポ
リオレフイン樹脂とを調合し、気泡核剤を加え、
押出機に供給し、これに発泡剤を混合融和させた
後、押出機先端より押し出すことにより、前述の
特徴を満足させる本発明を完成させるに至つたも
のである。
（課題を解決するための手段）
本発明によれば、ポリオレフイン樹脂と、ポリ
オレフイン樹脂にポリオルガノシロキサンをグラ
フト重合させた共重合樹脂とを混合し、全樹脂中
へのシリコーン含有量が0.1〜５重量部、好まし
くは0.2〜２重量部となる樹脂組成物を調合し、
気泡核剤0.1〜２重量部を加え、該樹脂組成物を
押出機に供給し、これに発泡剤として易揮発性炭
化水素またはハロゲン化炭化水素を混合融和させ
た後、押出機先端より押出して発泡体を得ること
を特徴とするポリオレフイン樹脂発泡体の製造方
法を提供することにある。
本発明においては、ポリオルガノシロキサンを
グラフト重合させたポリオレフイン共重合樹脂を
ポリオレフイン樹脂と混合し、気泡核剤を加え、
押出機に供給し、これに発泡剤を混合融和させた
後、押出機先端より押出して発泡体を得る方法を
採用したことにより、均一微細な独立気泡を有す
る表面が平滑で美麗なポリオレフイン発泡体を工
業的に有利に製造することができる。
次に、本発明について更に詳しく説明する。
本発明において用いるポリオルガノシロキサン
をグラフト重合させたポリオレフイン共重合樹脂
とは、一般式
R3−SiO（R2SiO）ｎ−SiR3
（但し、Ｒはアルキル基、フエニル基、及び水素
から選ばれた基であり、すべてＲが同一基であつ
ても、一部のＲが別の基であつても良く、ｎは１
〜10000の整数である。）
であるポリオルガノシロキサンを反応性変性又は
電離放射線等によりポリオレフイン樹脂にグラフ
ト重合したものである。グラフト重合は任意の割
合で良いが、好ましくは、シリコーン含有量で30
〜70重量％の割合が効率良く一般的に用いられ
る。
ポリオルガノシロキサンをグラフト重合させる
ポリオレフイン樹脂としては、エチレン、プロピ
レン、ブテン等の単独重合体、又は、これらの共
重合体、或は、これらオレフイン樹脂を主体とす
る他のビニル単量体との共重合体、又は、これら
重合物の混合体を意味する。特にポリエチレン、
エチレン−酢ビ共重合体樹脂等が好適に使用され
る。
更に、前記ポリオルガノシロキサンをグラフト
重合したポリオレフイン共重合樹脂は、製造時の
加工温度において安定なものであることが必要で
ある。
本発明において、特にポリエチレンにポリオル
ガノシロキサンをグラフト重合した共重合体を用
いた場合、ポリエチレン及びポリプロピレン発泡
体の気泡均一微細な独立気泡を有し、且つ表面平
滑で美麗な発泡体が得られる。この理由は、必ず
しも定かではないが、例えば、ポリオルガノシロ
キサングラフトポリオレフイン共重合体には、界
面活性作用があり、発泡時に生成する発泡膜の柔
軟性が増し、その表面張力が低下すること、更に
該気泡膜が早期に安定すること等に起因し、気泡
膜の破壊が防止され、気泡融合による気泡の成長
を抑制できるために気泡が微細化するものと考え
られる。更にポリオルガノシロキサンをグラフト
重合してあるために、発泡剤として易揮発性炭化
水素又はハロゲン化炭化水素を用いて押出発泡し
た場合にも、樹脂と該発泡剤との混練不良、押出
変動等はなく、良好に押出発泡することが可能に
なり、また製造した発泡体を梱包材として用いた
場合にも梱包された製品へポリシロキサンの移行
による曇り等の悪影響のない均一微細気泡を有す
る発泡体を得ることができるものと考えられる。
本発明においてポリオレフイン樹脂にポリオル
ガノシロキサンをグラフト重合した共重合樹脂
は、ポリオレフイン樹脂と混合し、全樹脂中のシ
リコーン含有量が0.1〜５重量部、好ましくは0.2
〜２重量部とするのが適当である。これは、0.1
重量部未満であるとポリオレフイン樹脂にポルオ
ルガノシロキサンをグラフト重合させた共重合体
の有する摩擦熱抑制効果、メルトフラクチヤー防
止効果、気泡均一微細化効果および表面平滑・美
麗化効果が充分に発揮されないためである。ま
た、５重量部を超えると、過剰のスリツプ効果の
ため樹脂と該発泡剤との混練不良が著しく、押出
変動、発泡体の連続気泡化を起こしやすく、その
生産性・品質を著しく低下させるので好ましくな
い。
本発明において用いるポリオレフイン樹脂と
は、エチレン、プロピレン、ブテン等の単独重合
体、又はこれらの共重合体、或は、これらのオレ
フイン樹脂を主体とする他のビニル単量体との共
重合体、又はこれら重合物の２種以上の混合体を
意味する。特に低密度ポリエチレン、ポリプロピ
レンが好ましく使用される。
本発明において用いる易揮発性発泡剤とは、例
えばプロパン、ブタン、ベンタン、塩化メチル、
塩化メチレン、トリクロロモノフルオロメタン、
ジクロロジフルオロメタン、モノクロロトリフル
オロメタン、ジクロロモノフルオロメタン、モノ
クロロジフルオロメタン、モノクロロモノフルオ
ロメタン、トリクロロトリフルオロエタン、ジク
ロロテトラフルオロエタン、モノクロロペンタフ
ルオロエタン、モノクロロテトラフルオロエタ
ン、テトラフルオロエタン、モノクロロジフルオ
ロエタン、ジクロロトリフルオロエタン、モノク
ロロトリフルオロエタン、ジフルオロエタン等の
易揮発性炭化水素又はハロゲン化炭化水素を意味
するもので、これらを単独もしくは必要に応じて
２種以上混合して用いることができ、上記発泡剤
は、樹脂100重量部に対して、通常１〜30重量部
の添加で用いられるが、特に、発泡剤量15重量部
以下である重梱包材として使用するポリオレフイ
ン発泡体に於いては、押出機内における摩擦熱の
増大により、製造した発泡体の独立気泡率の低
下、気泡不均一化が起こりやすく、本発明におけ
るポリオレフイン樹脂にポリオルガノシロキサン
をグラフト重合した共重合物の混合樹脂は、前述
の摩擦熱防止効果、気泡均一微細化効果等により
非常に有効な効果を発揮すると考えられる。
また、発泡体の気泡核剤としてタルク、炭酸カ
ルシウム、シリカ等の無機質微粉末やステアリン
酸カルシウム、ステアリン酸亜鉛等の有機質微粉
末を使用することができる。更に、寸法安定剤と
して多価アルコールの高級脂肪酸エステル等を
各々少量添加しても良い。
更に、本発明組成物には目的に応じて紫外線吸
収剤、酸化防止剤、帯電防止剤、着色剤等を含ま
せることができる。
（実施例）
次に実施例をもつて、更に本発明を具体的に説
明する。
なお、第１表における発泡体の性状評価は、そ
れぞれ下記を意味する。
見掛け密度：JIS Ｋ−6767に準ずる方法とす
る。
平均気泡径：ASTM Ｄ−3576 〃
独立気泡率：ASTM Ｄ−2856 〃
気泡の均一性：拡大鏡にて目視
◎：非常によい ○：良い
×：悪い
外観の均一性：表面の平滑性・美麗性を評価し
たもので
◎：非常によい ○：良い
△：普通 ×：悪い
実施例 １
密度0.921ｇ／cm3、メルトインデツクス0.3の低
密度ポリエチレン（以下LDPEと略す）100重量
部とポリエチレン樹脂に反応性ポリオルガノシロ
キサンをシリコーン含有量で40％グラフト重合し
たポリオレフイン樹脂（商品名：SP−300、ダ
ウ・コーニング社製、以下ポリオルガノシロキサ
ングラフト重合体と称す。）３重量部に微粉末タ
ルク0.3重量部を混合し、口径40ｍ／ｍのものが
２機連結された押出機に時間当り約８Kgの割合で
供給した。発泡剤としては、ジクロロテトラフル
オロエタンを樹脂100重量部に対して、10重量部
の割合で、第１押出機の先端付近から樹脂中に圧
入混合した。ダイとしては、口径４ｍ／ｍの樹脂
排出開口を有するロツドダイを使用した。第１の
押出機に供給された樹脂組成物は最高200℃に加
熱溶融混合され、続く第２の押出機で樹脂温度約
110℃に調整され、やはり110℃に設定されたダイ
に供給された。
口金から排出された樹脂は、発泡し、直径約15
ｍ／ｍのロツド状発泡体で均一微細な気泡を有
し、外観平滑な美麗なものであつた。
得られた発泡体の性状を、その配合割合と共に
第１表に示す。そして、その得られた発泡体は、
クツシヨン性に優れた良好なものであつた。
実施例 ２〜３
実施例１におけるLDPEとポリオルガノシロキ
サングラフト重合体の混合比率、発泡剤と樹脂と
の混合比率を第１表に示したように変えた以外
は、実施例１と同様の装置・方法で行なつた。但
し、実施例３について、顕著な摩擦熱防止効果が
認められ、押出機より吐出量を約20％上げても、
安定に連続製造することができたのは、ポリオル
ガノシロキサングラフト重合体混合により特記す
べき長所の１つである。また、得られた発泡体は
実施例１と同様に均一微細気泡を有する外観美麗
は優れたものであつた。
実施例 ４
実施例１におけるLDPEの代わりに密度0.910、
メルトインデツクス0.5であるポリプロピレン
（以下PPと略す）を用い、発泡剤をブタンに替
え、樹脂100重量部に対して５重量部を用いて第
２押出機で樹脂の温度160℃に調整し、160℃にダ
イ温度を設定した以外は実施例１と同様の装置・
方法で行なつた。得られた発泡体は、外観及び気
泡微細な優れたものであつた。
比較例 １
ポリオルガノシロキサングラフト重合体の効果
を明確にするため、ポリオルガノシロキサングラ
フト重合体を全く加えなかつた以外は、実施例１
と同様の装置・方法で行なつたが、条件的には第
２の押出機で充分に樹脂温度調整ができず（これ
は摩擦熱による発熱が大きすぎると考えられる）
に、樹脂温度115℃となり、測定評価できる発泡
体を得られなかつた。
比較例 ２
ポリオルガノシロキサングラフト重合体の効果
を明確にするために、比較としてシリコーンオイ
ル（動粘度：400cs）を１重量部用いた以外は、
実施例１と同様の装置・方法で行なつた。得られ
た発泡体は、気泡不均一で粗大、独立気泡率の低
い且つ外観の粗悪なものであつた。
比較例 ３
ポリオルガノシロキサングラフト重合体の効果
を明確にするため、ポリオルガノシロキサングラ
フト重合体を全く加えなかつた以外は、実施例４
と同様の装置・方法で行なつたが、気泡不均一で
粗大、独立気泡率の低い且つ外観の粗悪なもので
あつた。
更に、実施例１〜４及び比較列１〜３で得られ
た発泡体の性状を第１表に示し、本発明の作用効
果を明確にする。
(Field of Industrial Application) The present invention relates to a polyolefin resin foam such as polyethylene or polypropylene, and particularly to a method for producing a polyolefin resin foam having uniform fine closed cells and a smooth and beautiful surface. (Prior art) The use of polyolefin resin foams has been spreading to various fields in recent years, but fine bubbles are generally preferred, and uniform foams are particularly preferred for cushioning materials, insulation materials, decorative materials, etc. Foams with fine cells are highly desired. The reasons for this are: first, as a cushioning material, the finer the bubbles are, the softer and better the cushioning properties are; and as a heat insulating material, the finer the bubbles are, the lower the thermal conductivity and the better the insulation performance.
As a decorative material, the finer the cells, the more beautiful the appearance of the surface and cut surface. As a method for continuously obtaining a polyolefin resin foam having uniform and fine cells, the polyolefin resin is mixed with peroxide or irradiated with an electron beam to cause a crosslinking reaction in the polyolefin resin, and then foamed. There is a cross-linking foaming method that allows Although this method does yield a foam having fine cells, it has the drawbacks of a complicated foaming process and high equipment costs. Apart from this, there is a method to obtain everything from thin sheets to thick plates with a simple process.
Polyolefin resin and foaming agent are melt-mixed in an extruder to form a fluid gel, which is then extruded to a low pressure area to foam. There is a so-called extrusion foaming method. However, although this method can efficiently obtain a foam, it has the disadvantage that the cells are larger in size than those obtained by crosslinking and foaming. Furthermore, in the case of relatively low-density materials such as polyolefin foams with a foam density of 0.5 g/cm 3 or higher used as heavy packaging materials, the amount of blowing agent is reduced, so the frictional heat inside the extruder is large and causes foaming. It has the disadvantage that it tends to cause defects and a decrease in the closed cell ratio. To solve this problem, using a polyolefin resin with a higher melt index,
Although it has the effect of preventing frictional heat, polyolefin with a high melt index cannot be used because it causes coarsening of the cells in the produced foam and insufficient strength of the foam, which is a fatal drawback as a heavy packaging material. In order to solve the above problems, a method of uniformly making the bubbles finer by using silicone oil or modified polysiloxane oil in a polyolefin resin is disclosed in JP-A-62-89738 and JP-A-62-89741. It is disclosed in Japanese Patent Application Laid-Open No. 62-285930. However, when these silicone oils or modified siloxane oils are used, they tend to have an effect that hinders the kneading of the olefin resin and the blowing agent (lower aliphatic hydrocarbon or halogenated hydrocarbon), especially in the extrusion foaming method. The drawback was that stable continuous production was difficult. In addition, when the manufactured foam is used as a packaging material, silicone oil or modified polysiloxane oil that bleeds onto the surface of the foam transfers to the packaged product, causing cloudiness and significantly losing its value, which is fatal as a packaging material. defects, poor thermal adhesion,
This brings about problems such as a decrease in surface printability. (Problems to be Solved by the Invention) In view of the current situation, the present inventors have developed a foam with a high closed cell ratio that has uniformly fine cells, and which is suitable for packaging when used as a packaging material. As a result of intensive study on a method for stable and continuous production of polyolefin foam that does not cause problems such as cloudiness in the products to be manufactured, we formulated a copolymer obtained by graft polymerizing polyorganosiloshikin to polyolefin resin and polyolefin resin. Add bubble nucleating agent,
The present invention, which satisfies the above-mentioned characteristics, has been completed by supplying the foam to an extruder, mixing and blending the foaming agent therein, and then extruding it from the tip of the extruder. (Means for Solving the Problems) According to the present invention, a polyolefin resin and a copolymer resin obtained by graft polymerizing polyorganosiloxane to the polyolefin resin are mixed, and the silicone content in the total resin is 0.1 to 5. Prepare a resin composition in parts by weight, preferably 0.2 to 2 parts by weight,
Add 0.1 to 2 parts by weight of a cell nucleating agent, feed the resin composition to an extruder, mix and blend with it a readily volatile hydrocarbon or halogenated hydrocarbon as a foaming agent, and then extrude from the tip of the extruder. An object of the present invention is to provide a method for producing a polyolefin resin foam, which is characterized by obtaining a foam. In the present invention, a polyolefin copolymer resin obtained by graft polymerization of polyorganosiloxane is mixed with a polyolefin resin, a cell nucleating agent is added,
By adopting a method of supplying the foam to an extruder, mixing and blending it with a foaming agent, and then extruding it from the tip of the extruder to obtain a foam, we are able to produce a polyolefin foam with a smooth and beautiful surface that has uniform, fine closed cells. can be produced industrially advantageously. Next, the present invention will be explained in more detail. The polyolefin copolymer resin obtained by graft polymerization of polyorganosiloxane used in the present invention has the general formula R 3 -SiO(R 2 SiO)n-SiR 3 (wherein R is selected from an alkyl group, a phenyl group, and hydrogen). All R's may be the same group, or some R's may be different groups, and n is 1
It is an integer between ~10000. ) is graft-polymerized onto a polyolefin resin by reactive modification or ionizing radiation. Graft polymerization may be carried out at any ratio, but preferably the silicone content is 30
A proportion of ~70% by weight is commonly used with good efficiency. The polyolefin resin to be graft-polymerized with polyorganosiloxane may be a homopolymer of ethylene, propylene, butene, etc., a copolymer thereof, or a copolymer mainly composed of these olefin resins with other vinyl monomers. It means a polymer or a mixture of these polymers. Especially polyethylene,
Ethylene-vinyl acetate copolymer resin and the like are preferably used. Furthermore, the polyolefin copolymer resin obtained by graft polymerization of the polyorganosiloxane needs to be stable at the processing temperature during production. In the present invention, in particular, when a copolymer obtained by graft polymerizing polyorganosiloxane to polyethylene is used, a polyethylene and polypropylene foam having uniform, fine closed cells and a beautiful foam with a smooth surface can be obtained. The reason for this is not necessarily clear, but for example, the polyorganosiloxane graft polyolefin copolymer has a surfactant effect, which increases the flexibility of the foamed membrane produced during foaming and reduces its surface tension. It is thought that this is due to the early stabilization of the bubble membrane, which prevents the bubble membrane from being destroyed and suppresses the growth of bubbles due to bubble fusion, thereby making the bubbles smaller. Furthermore, since the polyorganosiloxane is graft-polymerized, even when extrusion foaming is performed using easily volatile hydrocarbons or halogenated hydrocarbons as a blowing agent, there will be no kneading failure between the resin and the blowing agent, extrusion fluctuations, etc. A foam with uniform fine cells that can be extruded and foamed without any problems, and even when the produced foam is used as a packaging material, there is no adverse effect such as clouding due to migration of polysiloxane to the packaged product. It is thought that it is possible to obtain the following. In the present invention, the copolymer resin obtained by graft polymerizing polyorganosiloxane to polyolefin resin is mixed with polyolefin resin and has a silicone content of 0.1 to 5 parts by weight, preferably 0.2 parts by weight in the total resin.
A suitable amount is 2 parts by weight. This is 0.1
If the amount is less than 1 part by weight, the frictional heat suppressing effect, melt fracture preventing effect, bubble uniformity and fineness effect, and surface smoothing and beautifying effect of the copolymer obtained by graft polymerizing polyorganosiloxane to polyolefin resin will not be sufficiently exhibited. It's for a reason. In addition, if the amount exceeds 5 parts by weight, the excessive slip effect will cause significant kneading failure of the resin and the foaming agent, which will easily cause extrusion fluctuations and open cell formation of the foam, which will significantly reduce its productivity and quality. Undesirable. The polyolefin resin used in the present invention is a homopolymer of ethylene, propylene, butene, etc., or a copolymer thereof, or a copolymer mainly composed of these olefin resins with other vinyl monomers. Or it means a mixture of two or more of these polymers. In particular, low density polyethylene and polypropylene are preferably used. Easily volatile blowing agents used in the present invention include, for example, propane, butane, bentane, methyl chloride,
methylene chloride, trichloromonofluoromethane,
Dichlorodifluoromethane, monochlorotrifluoromethane, dichloromonofluoromethane, monochlorodifluoromethane, monochloromonofluoromethane, trichlorotrifluoroethane, dichlorotetrafluoroethane, monochloropentafluoroethane, monochlorotetrafluoroethane, tetrafluoroethane, monochlorodifluoroethane, dichloro It means easily volatile hydrocarbons or halogenated hydrocarbons such as trifluoroethane, monochlorotrifluoroethane, difluoroethane, etc., and these can be used alone or as a mixture of two or more types as necessary. is usually added in an amount of 1 to 30 parts by weight per 100 parts by weight of resin, but especially in polyolefin foams used as heavy packaging materials where the blowing agent amount is 15 parts by weight or less, Due to the increase in frictional heat, the closed cell ratio of the produced foam tends to decrease and the cells become non-uniform. It is thought that it exhibits very effective effects such as heat prevention effect and bubble uniformity miniaturization effect. Furthermore, fine inorganic powders such as talc, calcium carbonate, and silica, and fine organic powders such as calcium stearate and zinc stearate can be used as cell nucleating agents for the foam. Furthermore, a small amount of higher fatty acid ester of polyhydric alcohol may be added as a dimensional stabilizer. Furthermore, the composition of the present invention may contain an ultraviolet absorber, an antioxidant, an antistatic agent, a coloring agent, etc. depending on the purpose. (Example) Next, the present invention will be explained in more detail with reference to Examples. In addition, the property evaluation of the foam in Table 1 means the following. Apparent density: Method according to JIS K-6767. Average cell diameter: ASTM D-3576 〃 Closed cell ratio: ASTM D-2856 〃 Cell uniformity: Visually inspected with a magnifying glass ◎: Very good ○: Good ×: Bad Appearance uniformity: Surface smoothness and beauty ◎: Very good ○: Good △: Average ×: Bad Example 1 100 parts by weight of low-density polyethylene (hereinafter abbreviated as LDPE) with a density of 0.921 g/cm 3 and a melt index of 0.3 and polyethylene resin. 3 parts by weight of polyolefin resin (product name: SP-300, manufactured by Dow Corning, hereinafter referred to as polyorganosiloxane graft polymer), which is obtained by graft polymerizing reactive polyorganosiloxane with a silicone content of 40%, to 3 parts by weight of finely powdered talc. 0.3 parts by weight were mixed and fed at a rate of about 8 kg per hour to two extruders with a diameter of 40 m/m connected together. As a blowing agent, dichlorotetrafluoroethane was injected into the resin from near the tip of the first extruder at a ratio of 10 parts by weight to 100 parts by weight of the resin. As the die, a rod die having a resin discharge opening with a diameter of 4 m/m was used. The resin composition supplied to the first extruder is heated and melted to a maximum of 200°C, and the resin composition is then heated to a temperature of about 200°C in the second extruder.
It was adjusted to 110°C and fed into a die which was also set at 110°C. The resin discharged from the nozzle foams and has a diameter of approximately 15 mm.
It was a rod-shaped foam with a size of m/m, had uniform fine bubbles, and had a smooth and beautiful appearance. The properties of the obtained foams are shown in Table 1 along with their blending ratios. And the obtained foam is
It was a good product with excellent cushioning properties. Examples 2 to 3 The same equipment as in Example 1 except that the mixing ratio of LDPE and polyorganosiloxane graft polymer and the mixing ratio of blowing agent and resin in Example 1 were changed as shown in Table 1.・It was done in a method. However, in Example 3, a remarkable effect of preventing frictional heat was observed, and even if the discharge rate was increased by about 20% from the extruder,
One of the notable advantages of mixing polyorganosiloxane graft polymers is that stable continuous production was possible. Further, the obtained foam had uniform fine cells and had an excellent appearance as in Example 1. Example 4 Density 0.910 instead of LDPE in Example 1,
Using polypropylene (hereinafter abbreviated as PP) with a melt index of 0.5, the blowing agent was replaced with butane, 5 parts by weight was used for 100 parts by weight of the resin, and the temperature of the resin was adjusted to 160°C in a second extruder. The same equipment as in Example 1 was used except that the die temperature was set at 160°C.
I did it by method. The obtained foam had an excellent appearance and fine bubbles. Comparative Example 1 Example 1 except that no polyorganosiloxane graft polymer was added in order to clarify the effect of the polyorganosiloxane graft polymer.
The experiment was carried out using the same equipment and method as above, but due to the conditions, the resin temperature could not be adjusted sufficiently in the second extruder (this is thought to be due to too much heat generation due to frictional heat).
However, the resin temperature reached 115°C, making it impossible to obtain a foam that could be measured and evaluated. Comparative Example 2 In order to clarify the effect of the polyorganosiloxane graft polymer, 1 part by weight of silicone oil (kinetic viscosity: 400 cs) was used as a comparison.
The experiment was carried out using the same apparatus and method as in Example 1. The obtained foam had non-uniform cells, was coarse, had a low closed cell ratio, and had a poor appearance. Comparative Example 3 Example 4 except that no polyorganosiloxane graft polymer was added in order to clarify the effect of the polyorganosiloxane graft polymer.
It was carried out using the same equipment and method as above, but the bubbles were uneven and coarse, the closed cell ratio was low, and the appearance was poor. Furthermore, the properties of the foams obtained in Examples 1 to 4 and Comparative Rows 1 to 3 are shown in Table 1 to clarify the effects of the present invention.
【表】
（効果）
本発明の均一微細気泡を有するポリオレフイン
樹脂発泡体の製造方法は、前記した構成からな
り、ポリオレフイン樹脂にポリオレフイン樹脂と
グラフト重合させたポリオルガノシロキサン共重
合体、特にポリエチレンとグラフト重合させたポ
リオルガノシロキサン共重合物を調合し、押出機
に供給し、これに発泡剤を混合融和させたのち、
押出発泡させる方法を採用したことにより、先に
述べた従来公知の製造方法に比べて次のような利
点を有するものであり、工業的に極めて有利な製
造方法ということができる。
(1) 樹脂と発泡剤との混練不良を起こすことな
く、また製造した発泡体を梱包材として使用し
た場合、梱包した製品を曇らせることなく、均
一微細気泡を有する発泡体を安定して連続生産
することができる。
(2) 密度0.05ｇ／cm3以上のポリオレフイン発泡体
の製造に於いて、押出中の摩擦熱により製造し
た発泡体の独立気泡率の低下を起こすことな
く、高い独立気泡率（80％以上）を有する均一
微細気泡発泡体を得られる。
(3) 密度0.05ｇ／cm3以下のポリエチレン発泡体の
連続生産において、押出中の摩擦熱の低下によ
り、安定押出量を約20％向上させることができ
る。[Table] (Effects) The method for producing a polyolefin resin foam having uniform microcells of the present invention has the above-described structure, and includes a polyorganosiloxane copolymer obtained by graft polymerizing a polyolefin resin with a polyolefin resin, especially a polyethylene copolymer. The polymerized polyorganosiloxane copolymer is prepared and fed to an extruder, and a blowing agent is mixed and blended with the extruder.
By employing the extrusion foaming method, it has the following advantages compared to the conventionally known manufacturing method described above, and can be said to be an extremely advantageous manufacturing method industrially. (1) Stable and continuous production of foams with uniform microcells without causing defects in kneading the resin and foaming agent, and without clouding the packaged products when the produced foams are used as packaging materials. can do. (2) In the production of polyolefin foams with a density of 0.05 g/cm 3 or more, a high closed cell ratio (80% or more) is achieved without reducing the closed cell ratio of the manufactured foam due to frictional heat during extrusion. A uniform fine-celled foam having the following characteristics can be obtained. (3) In the continuous production of polyethylene foams with a density of 0.05 g/cm 3 or less, the stable extrusion rate can be improved by about 20% by reducing the frictional heat during extrusion.
Claims (1)
脂にポリオルガノシロキサンをグラフト重合させ
た共重合樹脂とを混合し、全樹脂中のシリコーン
含有量が0.1〜５重量部となる樹脂組成物を調合
し、気泡核剤0.1〜２重量部を加え該樹脂組成物
を押出機に供給し、更に、これに易揮発性発泡剤
を混合融和させた後、押出機先端より押出して発
泡体を得ることを特徴とするポリオレフイン樹脂
発泡体の製造方法。1. Mix (A) a polyolefin resin and (B) a copolymer resin obtained by graft-polymerizing a polyolefin resin with a polyorganosiloxane to prepare a resin composition in which the silicone content in the total resin is 0.1 to 5 parts by weight. , add 0.1 to 2 parts by weight of a cell nucleating agent, feed the resin composition to an extruder, further mix and blend an easily volatile foaming agent therein, and then extrude from the tip of the extruder to obtain a foam. A method for producing a characteristic polyolefin resin foam.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1059514A JPH02240145A (en) | 1989-03-14 | 1989-03-14 | Preparation of polyolefin resin foam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1059514A JPH02240145A (en) | 1989-03-14 | 1989-03-14 | Preparation of polyolefin resin foam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02240145A JPH02240145A (en) | 1990-09-25 |
| JPH0571622B2 true JPH0571622B2 (en) | 1993-10-07 |
Family
ID=13115448
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1059514A Granted JPH02240145A (en) | 1989-03-14 | 1989-03-14 | Preparation of polyolefin resin foam |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH02240145A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5476901A (en) * | 1993-06-24 | 1995-12-19 | The Procter & Gamble Company | Siloxane modified polyolefin copolymers |
| US5670552A (en) * | 1995-12-18 | 1997-09-23 | W. R. Grace & Co.-Conn. | Foam and process for producing foam using a carbon dioxide blowing agent |
| KR100365380B1 (en) * | 1999-11-23 | 2002-12-26 | 삼성종합화학주식회사 | Polyolefin Resin Composition |
| EP1362080B1 (en) * | 2000-12-22 | 2005-09-28 | Samsung General Chemicals Co., Ltd. | Polyolefin resin composition |
| JP2023552049A (en) * | 2020-10-30 | 2023-12-14 | ダウ グローバル テクノロジーズ エルエルシー | Foam containing a blend of silicone-functionalized polyethylene and low-density polyethylene |
-
1989
- 1989-03-14 JP JP1059514A patent/JPH02240145A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02240145A (en) | 1990-09-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |