JPH0417221B2 - - Google Patents
Info
- Publication number
- JPH0417221B2 JPH0417221B2 JP7551284A JP7551284A JPH0417221B2 JP H0417221 B2 JPH0417221 B2 JP H0417221B2 JP 7551284 A JP7551284 A JP 7551284A JP 7551284 A JP7551284 A JP 7551284A JP H0417221 B2 JPH0417221 B2 JP H0417221B2
- Authority
- JP
- Japan
- Prior art keywords
- foam
- polyethylene
- weight
- parts
- pressure
- 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
Links
- -1 polyethylene Polymers 0.000 claims description 100
- 239000004698 Polyethylene Substances 0.000 claims description 93
- 229920000573 polyethylene Polymers 0.000 claims description 93
- 239000006260 foam Substances 0.000 claims description 85
- 239000000203 mixture Substances 0.000 claims description 26
- 229920001083 polybutene Polymers 0.000 claims description 24
- 239000011347 resin Substances 0.000 claims description 23
- 229920005989 resin Polymers 0.000 claims description 23
- 238000000034 method Methods 0.000 claims description 17
- 238000002844 melting Methods 0.000 claims description 14
- 230000008018 melting Effects 0.000 claims description 12
- 125000003808 silyl group Chemical group [H][Si]([H])([H])[*] 0.000 claims description 11
- 238000004519 manufacturing process Methods 0.000 claims description 9
- 239000004604 Blowing Agent Substances 0.000 claims description 8
- 239000003054 catalyst Substances 0.000 claims description 7
- 238000009833 condensation Methods 0.000 claims description 6
- 230000005494 condensation Effects 0.000 claims description 6
- SCPYDCQAZCOKTP-UHFFFAOYSA-N silanol Chemical compound [SiH3]O SCPYDCQAZCOKTP-UHFFFAOYSA-N 0.000 claims description 6
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 claims description 5
- 229920001748 polybutylene Polymers 0.000 claims description 5
- 150000001336 alkenes Chemical class 0.000 claims description 3
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 claims description 3
- 229920013716 polyethylene resin Polymers 0.000 claims description 3
- 229920001577 copolymer Polymers 0.000 claims description 2
- 238000002360 preparation method Methods 0.000 description 25
- 238000001125 extrusion Methods 0.000 description 16
- 238000011156 evaluation Methods 0.000 description 13
- 238000005187 foaming Methods 0.000 description 12
- 229910000077 silane Inorganic materials 0.000 description 10
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 9
- 150000004756 silanes Chemical class 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- NKSJNEHGWDZZQF-UHFFFAOYSA-N ethenyl(trimethoxy)silane Chemical compound CO[Si](OC)(OC)C=C NKSJNEHGWDZZQF-UHFFFAOYSA-N 0.000 description 5
- 239000008188 pellet Substances 0.000 description 5
- XMNIXWIUMCBBBL-UHFFFAOYSA-N 2-(2-phenylpropan-2-ylperoxy)propan-2-ylbenzene Chemical compound C=1C=CC=CC=1C(C)(C)OOC(C)(C)C1=CC=CC=C1 XMNIXWIUMCBBBL-UHFFFAOYSA-N 0.000 description 4
- 125000000962 organic group Chemical group 0.000 description 4
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 3
- 239000004743 Polypropylene Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229920001155 polypropylene Polymers 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
- 239000004594 Masterbatch (MB) Substances 0.000 description 2
- UKLDJPRMSDWDSL-UHFFFAOYSA-L [dibutyl(dodecanoyloxy)stannyl] dodecanoate Chemical compound CCCCCCCCCCCC(=O)O[Sn](CCCC)(CCCC)OC(=O)CCCCCCCCCCC UKLDJPRMSDWDSL-UHFFFAOYSA-L 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 238000004132 cross linking Methods 0.000 description 2
- 239000012975 dibutyltin dilaurate Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 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
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 1
- XDLMVUHYZWKMMD-UHFFFAOYSA-N 3-trimethoxysilylpropyl 2-methylprop-2-enoate Chemical compound CO[Si](OC)(OC)CCCOC(=O)C(C)=C XDLMVUHYZWKMMD-UHFFFAOYSA-N 0.000 description 1
- 229920000089 Cyclic olefin copolymer Polymers 0.000 description 1
- 239000004338 Dichlorodifluoromethane Substances 0.000 description 1
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical group C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 1
- 239000005977 Ethylene Substances 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- XQBCVRSTVUHIGH-UHFFFAOYSA-L [dodecanoyloxy(dioctyl)stannyl] dodecanoate Chemical compound CCCCCCCCCCCC(=O)O[Sn](CCCCCCCC)(CCCCCCCC)OC(=O)CCCCCCCCCCC XQBCVRSTVUHIGH-UHFFFAOYSA-L 0.000 description 1
- 125000004423 acyloxy group Chemical group 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 125000003277 amino 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
- 238000009835 boiling Methods 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- IAQRGUVFOMOMEM-UHFFFAOYSA-N butene Natural products CC=CC IAQRGUVFOMOMEM-UHFFFAOYSA-N 0.000 description 1
- 125000004106 butoxy group Chemical group [*]OC([H])([H])C([H])([H])C(C([H])([H])[H])([H])[H] 0.000 description 1
- 150000008280 chlorinated hydrocarbons Chemical class 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 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
- 229940087091 dichlorotetrafluoroethane Drugs 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 239000000806 elastomer Substances 0.000 description 1
- FWDBOZPQNFPOLF-UHFFFAOYSA-N ethenyl(triethoxy)silane Chemical compound CCO[Si](OCC)(OCC)C=C FWDBOZPQNFPOLF-UHFFFAOYSA-N 0.000 description 1
- 125000001301 ethoxy group Chemical group [H]C([H])([H])C([H])([H])O* 0.000 description 1
- 239000003063 flame retardant Substances 0.000 description 1
- 238000010097 foam moulding Methods 0.000 description 1
- 239000004088 foaming agent Substances 0.000 description 1
- 229920001903 high density polyethylene Polymers 0.000 description 1
- 239000004700 high-density polyethylene Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000004611 light stabiliser Substances 0.000 description 1
- 229920000092 linear low density polyethylene Polymers 0.000 description 1
- 239000004707 linear low-density polyethylene Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 125000000956 methoxy group Chemical group [H]C([H])([H])O* 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- 239000002667 nucleating agent Substances 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 125000003544 oxime group Chemical group 0.000 description 1
- 239000002530 phenolic antioxidant Substances 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000006884 silylation reaction Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 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
- 239000008096 xylene Substances 0.000 description 1
Description
（技術分野）
本発明は耐熱性および独立気泡性に優れたポリ
エチレン系樹脂発泡体を押出発泡法により製造す
る方法に関する。
（従来技術）
揮発性発泡剤を用い、押出発泡法により発泡さ
れて得られるポリエチレン系発泡体は断熱材や緩
衝材として広く利用されている。ポリエチレン系
発泡体の原料となるポリエチレンとしては押出発
泡成形の容易な高圧法ポリエチレンが用いられ
る。その理由はこの高圧法ポリエチレンは溶融状
態において比較的広い温度範囲にわたつて安定で
ありしかも特有の流動特性と結晶化特性を有する
からである。この高圧法ポリエチレンを用いた発
泡体の製造においては、プロセスが簡単で複雑な
設備が必要とされない。しかし、得られた発泡体
は、原料の高圧法ポリエチレンの融点が低く架橋
構造を有していないため、耐熱性において充分で
はなく、そのため、発泡体の用途は著しく限定さ
れる。このようなポリエチレン系発泡体の耐熱性
を向上させるべく、例えば特公昭53−34226号公
報、特公昭58−47408号公報、特開昭54−161671
号公報および特開昭55−40739号公報には中低圧
法線状ポリエチレンや中低圧法線状ポリプロピレ
ンを用いた発泡体が提案されている。これら中低
圧法によるポリエチレンやポリプロピレンは耐熱
性に優れているが、その反面、単独で用いると特
定の温度範囲でしか押出発泡させることができ
ず、さらに混練時に部分的に結晶化することがあ
る。そのため押出発泡性に著しく劣り独立気泡率
の高い発泡体が得られない。そのため上記公報で
は、中低圧法線状ポリエチレンやポリプロピレン
の分子に架橋構造を導入したりエラストマーを混
合することにより押出発泡性の改善が図られてい
る。例えば、特公昭58−47408号公報には中低圧
法ポリエチレンにポリブテン−１を添加して発泡
体を得る方法が開示されている。ポリブテン−１
が添加されると中低圧法ポリエチレンが溶融状態
において比較的広い温度範囲にわたつて安定とな
り、押出成形が容易になる。しかしながら得られ
た発泡体は耐熱性には優れているが熱安定性に劣
り、長時間高温の雰囲気下に放置されると大きく
収縮する。発泡体の独立発泡性も充分とは言えな
い。他の上記３件の公報に開示された方法におい
ても、同じく、得られた発泡体の熱安定性や耐熱
性をはじめ、製造工程における押出発泡性、生産
コストなどの面で充分ではない。
特開昭54−33569号公報には、高圧法ポリエチ
レンと高融点のポリオレフインとの混合物に特定
の低融点有機溶剤型発泡剤を混合し、低温低圧帯
域に押出して発泡体を得る方法が開示されてい
る。しかし、この方法によつても高圧法ポリエチ
レンの融点以上の耐熱性を有する発泡体は得られ
ない。
形成された発泡体に架橋構造をもたせて耐熱性
を向上させた例もある。例えば、特開昭55−
152724号公報、特開昭58−61129号公報および特
開昭58−1530号公報は高圧法ポリエチレンにシリ
ル化合物を反応させて加水分解性シリル基を有す
る架橋性高圧法ポリエチレンを得、これを用いて
発泡体を得る方法を開示している。これらの方法
は耐熱性に優れた発泡体を供給しうるが、熱安定
性に劣り加熱されると大きく収縮するという致命
的な欠点を有する。
（発明の目的）
本発明の目的は、耐熱性および熱安定性に優
れ、独立気泡率が高く、かつ安価に生産されうる
ポリエチレン系発泡体の製造方法を提供すること
にある。本発明の他の目的は、押出成形性に優
れ、したがつて発泡むらのないポリエチレン系発
泡体を製造する方法を提供することにある。
（発明の構成）
本発明は加水分解性シリル基を有する架橋性高
圧法分岐ポリエチレン、高融点の線状ポリエチレ
ンおよびポリブテン系樹脂を触媒の存在下に発泡
させて水分と接触させれば架橋構造を有する、耐
熱性に優れた独立気泡率の高い発泡体が得られう
るとの発明者の知見にもとづいて完成された。し
たがつて、本発明のポリエチレン系樹脂発泡体の
製造方法は高圧法分岐ポリエチレンに加水分解性
シリル基が結合した架橋性高圧法分岐ポリエチレ
ン95〜50重量％と、融点が120℃以上の線状ポリ
エチレン５〜50重量％との混合物、100重量部に
対し、ポリブテン系樹脂３〜30重量部を加えたポ
リエチレン組成物を加熱・溶融し、これにシラノ
ール縮合触媒の存在下で揮発性発泡剤を加えて低
圧帯域へ押出し、水分と接触させることを特徴と
し、そのことにより上記目的が達成される。
本発明の架橋性高圧法分岐ポリエチレンは高
圧法分岐ポリエチレンに加水分解可能な有機基を
もつ不飽和シランをラジカル発生剤の存在下にグ
ラフトさせる方法、もしくはエチレンと加水分
解可能な有機基をもつ不飽和シランを高圧下で共
重合させる方法により得られる。上記および
の加水分解可能な有機基としてはメトキシ基、エ
トキシ基およびブトキシ基のようなアルコキシ
基；ホルミルオキシ基、アセトキシ基、プロピオ
ノキシ基のようなアシルオキシ基；−ON＝Ｃ
（CH3）2，−ON＝CCH3C2H5，−ON＝Ｃ（C6H5）2
のようなオキシム基；−NHCH3，−NHC2H5，−
NH（C6H5）のような置換されたアミノ基などが
ある。これらのうちメトキシ基、エトキシ基が特
に好ましい。このような加水分解可能な有機基を
もつ不飽和シランのうちビニルトリメトキシシラ
ン、ビニルトリエトキシシラン、γ−メタクリロ
イルオキシプロピルトリメトキシシランなどが好
んで用いられる。高圧法分岐ポリエチレンの密度
は0.915〜0.935g／cm3である。メルトインデツク
ス（MI）は、0.1〜20.0の範囲にあることが好ま
しい。融点は高い方が好ましい。DSCで測定し
た融点が108℃以上であればよいが、112℃以上で
あることが好ましい。108℃以下であつても本発
明の目的は達成されうる。もしくはの方法に
よる架橋性高圧法分岐ポリエチレンの製造および
その組成は格別である必要はなく、例えば、特公
昭48−1711号公報や特開昭55−9611号公報に詳し
く開示されている。このようにして得られた架橋
性高圧法分岐ポリエチレンはシラノール縮合触媒
の存在下で水と接触すると容易に架橋する性質を
有する。
本発明の線状ポリエチレンとは、a.チーグラー
法などの中低圧重合法によつて得られる、長鎖分
岐が少なく密度0.940g／cm3以上の高密度ポリエチ
レン；もしくは、b.エチレンにα−オレフインを
添加し、これを共重合して得られる、密度0.915
〜0.945g／cm3の線状低密度ポリエチレンをいう。
線状ポリエチレンのMIには特に限定はないが、
融点は120℃以上であることが必要である。融点
が120℃を下まわると得られる発泡体の耐熱性は
不充分である。線状ポリエチレンが加水分解性シ
リル基を有する場合には架橋性高圧法分岐ポリエ
チレンとの反応性がさらに向上する。加水分解性
シリル基を有する線状ポリエチレンは架橋性高圧
法分岐ポリエチレンを得る場合と同様に線状ポリ
エチレンに不飽和シランをグラフトすることによ
り容易に得ることができる。
本発明においては、前記ポリエチレン組成物
は、上記高圧法分岐ポリエチレンと線状ポリエチ
レンとの混合物に、さらに、ブテン−１と少量の
オレフインの共重合体やポリブテン−１などのポ
リブテン系樹脂が混合されて得られる。ブテン−
１・オレフイン共重合体とポリブテン−１とは単
独もしくは混合して使用される。そのMIは0.1〜
10.0の範囲にあることが望ましい。特に0.3〜5.0
であることが好ましい。このようなポリブテン系
樹脂としては、市販のポリブテン系樹脂を利用す
ることもできる。
上記の架橋性高圧法分岐ポリエチレン95〜５重
量％と線状ポリエチレン５〜50重量％との混合物
100重量部にポリブテン系樹脂３〜30重量部を加
えて得られるポリエチレン組成物を加熱・溶融
し、これにシラノール縮合触媒と揮発性発泡剤と
を加えると発泡体組成物が得られる。これを低圧
帯域に押出し、発泡させて水分と接触させること
により発泡体が得られる。上記混合物中に線状ポ
リエチレンが５重量％を下まわると得られる発泡
体が耐熱性に劣る。過剰であると得られる発泡体
の独立発泡率が低い。この混合物にポリブテン系
樹脂を加えて得られるポリエチレン組成物は、加
熱・溶融されると、比較的広い温度範囲にわたつ
て安定であるため押出発泡成形が可能となる。こ
の溶融組成物の粘度は全体的に均一であるため、
得られる発泡体が部分的に変形することがない。
発泡体の気泡の大きさは均一であり、独立気泡率
も高い。ポリエチレン組成物100重量部に対しポ
リブテン系樹脂が３重量部を下まわると、上記効
果が得られない。ポリブテン系樹脂の含量が過剰
であつても問題はないがその効果は30重量部が含
有されたときとかわらない。ポリブテン系樹脂は
高価であるため多量に用いると発泡体が安価に提
供されえなくなる。ポリブテン系樹脂の含有量
は、したがつて、より好ましくは上記混合物100
重量部に対して５〜20重量部である。なお、加水
分解性シリル基をもたない高圧法分岐ポリエチレ
ンと加水分解性シリル基をもたない線状ポリエチ
レンとの混合物に不飽和シランをグラフトさせれ
ば、高圧法分岐ポリエチレンと線状ポリエチレン
との両者に加水分解性シリル基が導入される。上
記発泡体組成物中のシラノール縮合触媒には例え
ば特公昭48−1711号公報に開示された化合物が使
用可能である。それらのうちジブチル錫ジラウレ
ート、ジオクチル錫ジラウレートなどが好適に用
いられる。揮発性発泡剤としてはフルオロカーボ
ン類、クロロカーボン類、炭化水素類に属する低
沸点溶剤を利用することができる。それらのうち
ジクロルジフルオロメタン、トリクロルフルオロ
メタン、１・２−ジクロルテトラフルオロエタ
ン、トリクロロトリフルオロエタン、ペンタン、
ブタンなどが好適に用いられる。シラノール縮合
触媒や発泡剤とともに上記組成物には必要に応じ
て発泡核剤、抗酸化剤、光安定剤、難燃剤、帯電
防止剤、着色剤などが添加されうる。
発泡体組成物が低圧帯域に押出されて得られた
発泡体を室温で空気中に放置すると、空気中の水
分により架橋反応が進行する。発泡体を高温高湿
度下に放置すると架橋反応は促進される。このよ
うにして架橋構造を有し、耐熱性および成形性に
優れた発泡体を得ることができる。
（実施例）
如何に本発明を実施例について説明する。
実施例 １
(A) 架橋性高圧法分岐ポリエチレンの調製：高圧
法分岐ポリエチレンとしてユカロンNF−90
（三菱油化(株)製：密度0.930g／cm3，MI1.5、融点
116℃）を用いた。ユカロンNF−90のペレツ
ト100重量部にビニルトリメトキシシラン（チ
ツソ(株)製：VTS−Ｍ）1.2重量部およびジクミ
ルパーオキシド（パークミルＤ：日本油脂(株)
製）0.06重量部を加えた。これを口径50mm、
Ｌ／Ｄ＝26の二軸押出機を用い押出量15Kg／hr
で押出し架橋性高圧法分岐ポリエチレンとして
シラングラフトポリエチレンペレツトを得た。
このシラングラフトポリエチレンのMIは1.1、
到達ゲル分率（110℃キシレン不溶分率）は75
％であつた。押出の温度条件はバレルが160℃，
180℃，200℃，200℃、金型が200℃，180℃で
ある。
(B) 発泡体の調製：(A)項で得られたシラングラフ
トポリエチレン70重量部に線状ポリエチレンと
してリンレツクスAR4810（日本石油化学(株)
製：密度0.940g／cm3，MI4.0、融点127℃）のペ
レツト30重量部を加えた。これにポリブテン系
樹脂としてA.A.ポリブテン＃8640（アダカアー
ガス(株)製：密度0.908g／cm3，MI1.0）10重量部
を加えた。さらにユカロンNF−90 100重量
部、ジブチル錫ジラウレート２重量部、タルク
５重量部、ヒンダードフエノール系抗酸化剤
（アダカアーガス(株)製：MARK AO−60）３重
量部からなるマスターバツチペレツト５重量部
を添加しタンブラーミキサーで均一に混合し
た。これを口径３mmのノズル金型をとりつけた
口径40mm、Ｌ／Ｄ＝30の押出機を用いて押出量
８Kg／hrで押出しロツド状に成形し発泡させ
た。バレル温度は120℃，150℃，160℃，140℃
で、金型温度は117℃である。なお、バレル途
中から発泡剤として１・２ジクロルテトラフル
オロエタンを上記配合物100重量部に対して26
重量部、高圧ポンプにより圧入した。押出機を
24時間使用してロツド状発泡体を製造したが、
押出の際の圧力の変動は認められなかつた。
(C) 発泡体の性能評価：(B)項で得られた発泡体は
表面が平滑で弾力性があつた。ロツド状発泡体
の直径が変化することもなかつた。発泡体の密
度と独立気泡率を測定した。さらに発泡体を
120℃の乾燥機の中に24時間放置し、その体積
収縮率を測定した。その結果を表１に示す。
実施例 ２
(A) 架橋性高圧法分岐ポリエチレンの調製：実施
例１(A)項と同様である。
(B) 発泡体の調製：シラングラフトポリエチレン
を90重量部、線状ポリエチレンを10重量部用い
たこと以外は実施例１(B)項と同様である。な
お、実施例２〜６および比較例１〜５において
金型温度は、それぞれの発泡体組成物に最適の
温度に調製した。さらに、発泡体密度が約
0.3g／cm3となるように発泡剤の量を調整した。
(C) 発泡体の性能評価：実施例１(C)項と同様であ
る。
実施例 ３
(A) 架橋性高圧法分岐ポリエチレンの調製：実施
例１(A)項と同様である。
(B) 発泡体の調製：シラングラフトポリエチレン
を80重量部、線状ポリエチレンを20重量部用い
たこと以外は実施例１(B)項と同様である。
(C) 発泡体の性能評価：実施例１(C)項と同様であ
る。
実施例 ４
(A) 架橋性高圧法分岐ポリエチレンの調製：実施
例１(A)項と同様である。
(B) 発泡体の調製：シラングラフトポリエチレン
を60重量部、線状ポリエチレンを40重量部用い
たこと以外は実施例１(B)項と同様である。
(C) 発泡体の性能評価：実施例１(C)項と同様であ
る。
実施例 ５
(A) 架橋性高圧法分岐ポリエチレンの調製：実施
例１(A)項と同様である。
(B) 発泡体の調製：シラングラフトポリエチレン
を70重量部、線状ポリエチレンを30重量部、ポ
リブテン系樹脂を５重量部用いたこと以外は実
施例１(B)項と同様である。
(C) 発泡体の性能評価：実施例１(C)項と同様であ
る。
実施例 ６
(A) 架橋性高圧法分岐ポリエチレンの調製：実施
例１(A)項と同様である。
(B) 発泡体の調製：シラングラフトポリエチレン
を70重量部、線状ポリエチレンを30重量部、ポ
リブテン系樹脂を20重量部用いたこと以外は実
施例１(B)項と同様である。
(C) 発泡体の性能評価：実施例１(C)項と同様であ
る。
比較例 １
(A) 架橋性高圧法分岐ポリエチレンの調製：実施
例１(A)項と同様である。
(B) 発泡体の調製：シラングラフトポリエチレン
を100重量部を用い、線状ポリエチレンとポリ
ブテン系樹脂とを使用しなかつたこと以外は実
施例１(B)項と同様である。
(C) 発泡体の性能評価：実施例１(C)項と同様であ
る。
比較例 ２
(A) 架橋性高圧法分岐ポリエチレンの調製：実施
例１(A)項と同様である。
(B) 発泡体の調製：ポリブテン系樹脂を使用しな
かつたこと以外は実施例２と同様である。押出
を行うときに押出圧がやや変動した。
(C) 発泡体の性能評価：(B)項で得られたロツド状
発泡体の発泡状態は良好であるが、押出後、そ
の径がやや変動して不均一になつた。実施例１
(C)項と同様の試験を行い、その結果を表１に示
す。
比較例 ３
(A) 架橋性高圧法分岐ポリエチレンの調製：実施
例１(A)項と同様である。
(B) 発泡体の調製：ポリブテン系樹脂を使用しな
かつたこと以外は実施例３と同様である。
(C) 発泡体の性能評価：(B)項で得られたロツド状
発泡体の径は押出後、かなり変動して不均一に
なつた。実施例１(C)項と同様の試験を行い、そ
の結果を表１に示す。
比較例 ４
(A) 架橋性高圧法分岐ポリエチレンの調製：実施
例１(A)項と同様である。
(B) 発泡体の調製：ポリブテン系樹脂を使用しな
かつたこと以外は実施例５と同様である。
(C) 発泡体の性能評価：(B)項で得られた発泡体
は、発泡後の収縮率が非常に大きかつた。
比較例 ５
(A) 架橋性高圧法分岐ポリエチレンの調製：実施
例１(A)項と同様である。
(B) 発泡体の調製：シラングラフトポリエチレン
を40重量部、線状ポリエチレンを60重量部、そ
してポリブテン系樹脂を10重量部用いたこと以
外は実施例１(B)項と同様である。
(C) 発泡体の性能評価：(B)項で得られた発泡体
は、発泡後の収縮率が非常に大きかつた。
(Technical Field) The present invention relates to a method for producing a polyethylene resin foam having excellent heat resistance and closed cell properties by an extrusion foaming method. (Prior Art) A polyethylene foam obtained by foaming by an extrusion foaming method using a volatile foaming agent is widely used as a heat insulating material or a cushioning material. High-pressure polyethylene, which can be easily extruded and foam-molded, is used as the raw material for the polyethylene foam. This is because this high-pressure polyethylene is stable in the molten state over a relatively wide temperature range and has unique flow and crystallization properties. In the production of foam using this high-pressure polyethylene, the process is simple and no complicated equipment is required. However, the obtained foam does not have sufficient heat resistance because the raw material high-pressure polyethylene has a low melting point and does not have a crosslinked structure, and therefore, the uses of the foam are significantly limited. In order to improve the heat resistance of such polyethylene foams, for example, Japanese Patent Publication No. 53-34226, Japanese Patent Publication No. 58-47408, and Japanese Patent Application Laid-Open No. 54-161671 have been proposed.
JP-A-55-40739 proposes foams using medium-low pressure normal polyethylene or medium-low pressure normal polypropylene. Polyethylene and polypropylene produced by these medium-low pressure methods have excellent heat resistance, but on the other hand, when used alone, they can only be extruded and foamed within a specific temperature range, and may partially crystallize during kneading. . As a result, the extrusion foamability is extremely poor and a foam with a high closed cell ratio cannot be obtained. Therefore, in the above-mentioned publication, an attempt is made to improve the extrusion foamability by introducing a crosslinked structure into the molecules of normal polyethylene or polypropylene at medium and low pressures or by mixing an elastomer. For example, Japanese Patent Publication No. 58-47408 discloses a method of obtaining a foam by adding polybutene-1 to medium-low pressure polyethylene. polybutene-1
When added, medium-low pressure polyethylene becomes stable in a molten state over a relatively wide temperature range, making extrusion molding easier. However, although the obtained foam has excellent heat resistance, it has poor thermal stability, and if left in a high temperature atmosphere for a long time, it will shrink significantly. The independent foaming property of the foam is also not sufficient. The methods disclosed in the other three publications mentioned above are similarly insufficient in terms of thermal stability and heat resistance of the obtained foam, extrusion foamability in the manufacturing process, production cost, etc. JP-A No. 54-33569 discloses a method of obtaining a foam by mixing a specific low-melting point organic solvent type blowing agent with a mixture of high-pressure polyethylene and high-melting point polyolefin and extruding the mixture into a low-temperature, low-pressure zone. ing. However, even with this method, a foam having a heat resistance higher than the melting point of high-pressure polyethylene cannot be obtained. There are also examples in which the formed foam has a crosslinked structure to improve heat resistance. For example, JP-A-55-
No. 152724, JP-A No. 58-61129, and JP-A No. 58-1530 disclose methods of reacting high-pressure polyethylene with a silyl compound to obtain crosslinkable high-pressure polyethylene having hydrolyzable silyl groups, and using this. A method for obtaining a foam is disclosed. Although these methods can provide foams with excellent heat resistance, they have the fatal drawback of poor thermal stability and large shrinkage when heated. (Objective of the Invention) An object of the present invention is to provide a method for producing a polyethylene foam that has excellent heat resistance and thermal stability, has a high closed cell ratio, and can be produced at low cost. Another object of the present invention is to provide a method for producing a polyethylene foam that has excellent extrusion moldability and is therefore free from uneven foaming. (Structure of the Invention) The present invention provides a crosslinked structure by foaming a crosslinkable high-pressure branched polyethylene having a hydrolyzable silyl group, a high melting point linear polyethylene, and a polybutene resin in the presence of a catalyst and bringing them into contact with water. This was completed based on the inventor's knowledge that it is possible to obtain a foam with excellent heat resistance and a high closed cell ratio. Therefore, the method for producing polyethylene resin foam of the present invention consists of 95 to 50% by weight of crosslinkable high-pressure branched polyethylene in which hydrolyzable silyl groups are bonded to high-pressure branched polyethylene, and linear polyethylene with a melting point of 120°C or higher. A polyethylene composition prepared by adding 3 to 30 parts by weight of a polybutene resin to 100 parts by weight of a mixture with 5 to 50% by weight of polyethylene is heated and melted, and a volatile blowing agent is added to this in the presence of a silanol condensation catalyst. In addition, it is characterized by extrusion into a low pressure zone and contact with moisture, whereby the above object is achieved. The crosslinkable high-pressure branched polyethylene of the present invention can be obtained by grafting an unsaturated silane having a hydrolyzable organic group to the high-pressure branched polyethylene in the presence of a radical generator, or by grafting an unsaturated silane having a hydrolyzable organic group to ethylene. It is obtained by a method of copolymerizing saturated silane under high pressure. Hydrolyzable organic groups of the above and above include alkoxy groups such as methoxy, ethoxy and butoxy groups; acyloxy groups such as formyloxy, acetoxy and propionoxy groups; -ON=C
(CH 3 ) 2 , −ON=CCH 3 C 2 H 5 , −ON=C (C 6 H 5 ) 2
Oxime groups such as -NHCH 3 , -NHC 2 H 5 , -
Examples include substituted amino groups such as NH (C 6 H 5 ). Among these, methoxy group and ethoxy group are particularly preferred. Among such unsaturated silanes having a hydrolyzable organic group, vinyltrimethoxysilane, vinyltriethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, etc. are preferably used. The density of high-pressure branched polyethylene is 0.915 to 0.935 g/cm 3 . The melt index (MI) is preferably in the range of 0.1 to 20.0. A higher melting point is preferable. It is sufficient if the melting point measured by DSC is 108°C or higher, but preferably 112°C or higher. The object of the present invention can be achieved even at temperatures below 108°C. The production of crosslinkable high-pressure branched polyethylene by the above method and its composition do not need to be special, and are disclosed in detail in, for example, Japanese Patent Publication No. 48-1711 and Japanese Patent Application Laid-Open No. 55-9611. The crosslinkable high-pressure branched polyethylene thus obtained has the property of being easily crosslinked when it comes into contact with water in the presence of a silanol condensation catalyst. The linear polyethylene of the present invention refers to a. high-density polyethylene with few long chain branches and a density of 0.940 g/cm 3 or more obtained by medium-low pressure polymerization methods such as the Ziegler process; or b. Obtained by adding olefin and copolymerizing it, density 0.915
~0.945g/ cm3 linear low density polyethylene.
There are no particular limitations on the MI of linear polyethylene, but
The melting point must be 120°C or higher. If the melting point is below 120°C, the resulting foam will have insufficient heat resistance. When the linear polyethylene has a hydrolyzable silyl group, the reactivity with the crosslinkable high-pressure branched polyethylene is further improved. Linear polyethylene having hydrolyzable silyl groups can be easily obtained by grafting unsaturated silane to linear polyethylene in the same manner as in the case of obtaining crosslinkable high-pressure branched polyethylene. In the present invention, the polyethylene composition is a mixture of the high-pressure branched polyethylene and linear polyethylene, and a polybutene resin such as a copolymer of butene-1 and a small amount of olefin or polybutene-1. can be obtained. Butene
The olefin copolymer and polybutene-1 may be used alone or in combination. Its MI is 0.1 ~
Preferably in the 10.0 range. Especially 0.3~5.0
It is preferable that As such a polybutene resin, a commercially available polybutene resin can also be used. A mixture of 95 to 5% by weight of the above crosslinkable high-pressure branched polyethylene and 5 to 50% by weight of linear polyethylene
A polyethylene composition obtained by adding 3 to 30 parts by weight of a polybutene resin to 100 parts by weight is heated and melted, and a silanol condensation catalyst and a volatile blowing agent are added thereto to obtain a foam composition. A foam is obtained by extruding this into a low pressure zone, foaming it and bringing it into contact with moisture. If the amount of linear polyethylene in the mixture is less than 5% by weight, the resulting foam will have poor heat resistance. If it is in excess, the closed foam rate of the resulting foam will be low. The polyethylene composition obtained by adding a polybutene resin to this mixture is stable over a relatively wide temperature range when heated and melted, making it possible to perform extrusion foam molding. Since the viscosity of this molten composition is uniform throughout,
The resulting foam is not partially deformed.
The size of the cells in the foam is uniform and the closed cell ratio is high. If the amount of polybutene resin is less than 3 parts by weight per 100 parts by weight of the polyethylene composition, the above effects cannot be obtained. Although there is no problem even if the content of the polybutene resin is excessive, the effect is the same as when 30 parts by weight is contained. Since polybutene resin is expensive, if a large amount is used, a foam cannot be provided at a low price. Therefore, the content of the polybutene resin is more preferably 100%
The amount is 5 to 20 parts by weight. In addition, if unsaturated silane is grafted onto a mixture of high-pressure branched polyethylene that does not have a hydrolyzable silyl group and linear polyethylene that does not have a hydrolyzable silyl group, the high-pressure branched polyethylene and linear polyethylene can be grafted. Hydrolyzable silyl groups are introduced into both. As the silanol condensation catalyst in the above-mentioned foam composition, for example, the compounds disclosed in Japanese Patent Publication No. 1711/1982 can be used. Among them, dibutyltin dilaurate, dioctyltin dilaurate, etc. are preferably used. As the volatile blowing agent, low boiling point solvents belonging to fluorocarbons, chlorocarbons, and hydrocarbons can be used. Among them, dichlorodifluoromethane, trichlorofluoromethane, 1,2-dichlorotetrafluoroethane, trichlorotrifluoroethane, pentane,
Butane and the like are preferably used. In addition to the silanol condensation catalyst and the blowing agent, a foaming nucleating agent, an antioxidant, a light stabilizer, a flame retardant, an antistatic agent, a coloring agent, and the like may be added to the composition as necessary. When the foam composition is extruded into a low pressure zone and the resulting foam is left in the air at room temperature, the crosslinking reaction proceeds due to moisture in the air. The crosslinking reaction is accelerated when the foam is left under high temperature and high humidity. In this way, a foam having a crosslinked structure and excellent heat resistance and moldability can be obtained. (Example) The present invention will be described with reference to an example. Example 1 (A) Preparation of crosslinkable high-pressure branched polyethylene: Yucalon NF-90 as high-pressure branched polyethylene
(Mitsubishi Yuka Co., Ltd.: density 0.930g/cm 3 , MI1.5, melting point
116°C). To 100 parts by weight of Yucalon NF-90 pellets, 1.2 parts by weight of vinyltrimethoxysilane (VTS-M, manufactured by Chitsuso Corporation) and dicumyl peroxide (Percumyl D, manufactured by NOF Corporation) were added.
0.06 part by weight was added. This is caliber 50mm,
Extrusion amount 15Kg/hr using twin screw extruder with L/D=26
Silane-grafted polyethylene pellets were obtained as extrusion-crosslinkable high-pressure branched polyethylene.
The MI of this silane grafted polyethylene is 1.1,
The achieved gel fraction (xylene insoluble fraction at 110℃) is 75
It was %. The extrusion temperature condition is 160℃ for the barrel.
180℃, 200℃, 200℃, mold temperature is 200℃, 180℃. (B) Preparation of foam: 70 parts by weight of the silane grafted polyethylene obtained in section (A) was added with Rinrex AR4810 (Nippon Petrochemical Co., Ltd.) as linear polyethylene.
30 parts by weight of pellets (density 0.940 g/cm 3 , MI 4.0, melting point 127°C) were added. To this was added 10 parts by weight of AA polybutene #8640 (manufactured by Adaka Argus Co., Ltd., density 0.908 g/cm 3 , MI 1.0) as a polybutene resin. In addition, masterbatch pellets consisting of 100 parts by weight of Yucalon NF-90, 2 parts by weight of dibutyltin dilaurate, 5 parts by weight of talc, and 3 parts by weight of a hindered phenolic antioxidant (manufactured by Adaka Argus Co., Ltd.: MARK AO-60) were prepared. 5 parts by weight were added and mixed uniformly using a tumbler mixer. This was extruded into a rod shape and foamed using an extruder with a diameter of 40 mm and L/D=30 equipped with a nozzle mold of 3 mm diameter at an extrusion rate of 8 kg/hr. Barrel temperature is 120℃, 150℃, 160℃, 140℃
And the mold temperature is 117℃. In addition, from the middle of the barrel, 1.2 dichlorotetrafluoroethane was added as a blowing agent to 100 parts by weight of the above compound.
Part by weight was press-fitted using a high-pressure pump. extruder
A rod-shaped foam was produced by using it for 24 hours, but
No pressure fluctuation was observed during extrusion. (C) Performance evaluation of foam: The foam obtained in section (B) had a smooth surface and elasticity. There was also no change in the diameter of the rod-shaped foam. The density and closed cell ratio of the foam were measured. More foam
The sample was left in a dryer at 120°C for 24 hours, and its volumetric shrinkage rate was measured. The results are shown in Table 1. Example 2 (A) Preparation of crosslinkable high-pressure branched polyethylene: Same as Example 1 (A). (B) Preparation of foam: Same as Example 1 (B) except that 90 parts by weight of silane grafted polyethylene and 10 parts by weight of linear polyethylene were used. In addition, in Examples 2 to 6 and Comparative Examples 1 to 5, the mold temperature was adjusted to the optimum temperature for each foam composition. Additionally, the foam density is approximately
The amount of blowing agent was adjusted to 0.3 g/cm 3 . (C) Performance evaluation of foam: Same as Example 1 (C). Example 3 (A) Preparation of crosslinkable high-pressure branched polyethylene: Same as Example 1 (A). (B) Preparation of foam: Same as Example 1 (B) except that 80 parts by weight of silane grafted polyethylene and 20 parts by weight of linear polyethylene were used. (C) Performance evaluation of foam: Same as Example 1 (C). Example 4 (A) Preparation of crosslinkable high-pressure branched polyethylene: Same as Example 1 (A). (B) Preparation of foam: Same as Example 1 (B) except that 60 parts by weight of silane grafted polyethylene and 40 parts by weight of linear polyethylene were used. (C) Performance evaluation of foam: Same as Example 1 (C). Example 5 (A) Preparation of crosslinkable high-pressure branched polyethylene: Same as Example 1 (A). (B) Preparation of foam: Same as Example 1 (B) except that 70 parts by weight of silane grafted polyethylene, 30 parts by weight of linear polyethylene, and 5 parts by weight of polybutene resin were used. (C) Performance evaluation of foam: Same as Example 1 (C). Example 6 (A) Preparation of crosslinkable high-pressure branched polyethylene: Same as Example 1 (A). (B) Preparation of foam: Same as Example 1 (B) except that 70 parts by weight of silane grafted polyethylene, 30 parts by weight of linear polyethylene, and 20 parts by weight of polybutene resin were used. (C) Performance evaluation of foam: Same as Example 1 (C). Comparative Example 1 (A) Preparation of crosslinkable high-pressure branched polyethylene: Same as Example 1 (A). (B) Preparation of foam: Same as Example 1 (B) except that 100 parts by weight of silane grafted polyethylene was used and linear polyethylene and polybutene resin were not used. (C) Performance evaluation of foam: Same as Example 1 (C). Comparative Example 2 (A) Preparation of crosslinkable high-pressure branched polyethylene: Same as Example 1 (A). (B) Preparation of foam: Same as Example 2 except that polybutene resin was not used. The extrusion pressure fluctuated slightly when extruding. (C) Performance evaluation of foam: The foamed state of the rod-shaped foam obtained in section (B) was good, but after extrusion, the diameter varied slightly and became non-uniform. Example 1
The same test as in section (C) was conducted, and the results are shown in Table 1. Comparative Example 3 (A) Preparation of crosslinkable high-pressure branched polyethylene: Same as Example 1 (A). (B) Preparation of foam: Same as Example 3 except that polybutene resin was not used. (C) Performance evaluation of foam: The diameter of the rod-shaped foam obtained in section (B) varied considerably and became non-uniform after extrusion. A test similar to that in Example 1 (C) was conducted, and the results are shown in Table 1. Comparative Example 4 (A) Preparation of crosslinkable high-pressure branched polyethylene: Same as Example 1 (A). (B) Preparation of foam: Same as Example 5 except that polybutene resin was not used. (C) Performance evaluation of foam: The foam obtained in section (B) had a very high shrinkage rate after foaming. Comparative Example 5 (A) Preparation of crosslinkable high-pressure branched polyethylene: Same as Example 1 (A). (B) Preparation of foam: Same as Example 1 (B) except that 40 parts by weight of silane grafted polyethylene, 60 parts by weight of linear polyethylene, and 10 parts by weight of polybutene resin were used. (C) Performance evaluation of foam: The foam obtained in section (B) had a very high shrinkage rate after foaming.
【表】
実施例 ７
(A) 架橋性高圧法分岐ポリエチレンの調製：実施
例１(A)項と同様である。
(B) 線状ポリエチレンのシリル化：リンレツクス
AR4810 100重量部にビニルトリメトキシシラ
ン1.2重量部およびジクミルパーオキシド0.05
重量部を加えてシリル化しシラングラフト線状
ポリエチレン（MI1.2、到達ゲル分率63％）を
得た。
(C) 発泡体の調製：リンレツクスAR4810の代わ
りに(B)項で得られたシラングラフト線状ポリエ
チレンを使用したこと以外は実施例１(B)項と同
様である。
(D) 発泡体の性能評価：実施例１(C)項と同様であ
る。その結果は表２に示す。比較のため実施例
１の結果も表２に示す。
実施例 ８
(A) 発泡体の調製：ユカロンNF−90 70重量部
と、リンレツクスAR4810 30重量部とをタン
ブラーミキサーで均一に混合した混合物 100
重量部にビニルトリメトキシシラン1.2重量部
およびジクミルパーオキシド0.05重量部を添加
し、シラングラフトポリエチレン（MI1.8、到
達ゲル分率65％）を得た。以下、実施例１(B)項
と同様にポリブテン系樹脂とマスターバツチペ
レツトとを添加し発泡体を得た。 (B) 発泡体
の性能評価：実施例１(C)項と同様である。その
結果は表２に示す。[Table] Example 7 (A) Preparation of crosslinkable high-pressure branched polyethylene: Same as Example 1 (A). (B) Silylation of linear polyethylene: Rinrex
1.2 parts by weight of vinyltrimethoxysilane and 0.05 parts by weight of dicumyl peroxide in 100 parts by weight of AR4810
Parts by weight were added and silylated to obtain silane-grafted linear polyethylene (MI 1.2, achieved gel fraction 63%). (C) Preparation of foam: Same as Example 1 (B) except that the silane-grafted linear polyethylene obtained in Section (B) was used instead of Rinrex AR4810. (D) Performance evaluation of foam: Same as Example 1 (C). The results are shown in Table 2. For comparison, the results of Example 1 are also shown in Table 2. Example 8 (A) Preparation of foam: 70 parts by weight of Yucalon NF-90 and 30 parts by weight of Rinrex AR4810 were uniformly mixed using a tumbler mixer.100
1.2 parts by weight of vinyltrimethoxysilane and 0.05 parts by weight of dicumyl peroxide were added to the parts by weight to obtain silane grafted polyethylene (MI 1.8, achieved gel fraction 65%). Thereafter, a polybutene resin and masterbatch pellets were added in the same manner as in Example 1 (B) to obtain a foam. (B) Performance evaluation of foam: Same as Example 1 (C). The results are shown in Table 2.
【表】
（発明の効果）
本発明によれば、このように、加水分解性シリ
ル基を有する架橋性高圧法分岐ポリエチレンと高
い融点をもつ線状ポリエチレンとを含有する発泡
体組成物を用いて架橋構造を有する発泡体が製造
されるので、得られた発泡体は耐熱性に優れてい
る。さらに、発泡体組成物にはポリブテン系樹脂
が含有されるため、組成物が加熱・溶融されたと
き均一に混練されうる。しかも、その組成物が部
分的に結晶化することもない。そのため、発泡体
が発泡後に寸法変化を起こすことがない。気泡の
大きさも均一であり、独立発泡率も高い。熱安定
性も充分であり、得られた発泡体を高温に長時間
放置しても寸法変化は極小である。独立発泡率も
80〜90％と、従来のものに比較して著しく高い。
そのため、断熱材や緩衝材をはじめ広汎な用途に
利用されうる。[Table] (Effects of the Invention) According to the present invention, a foam composition containing a crosslinkable high-pressure branched polyethylene having a hydrolyzable silyl group and a linear polyethylene having a high melting point is used. Since a foam having a crosslinked structure is produced, the obtained foam has excellent heat resistance. Furthermore, since the foam composition contains a polybutene resin, it can be uniformly kneaded when the composition is heated and melted. Moreover, the composition does not partially crystallize. Therefore, the foam does not undergo dimensional changes after foaming. The size of the bubbles is uniform and the independent foaming rate is high. Thermal stability is also sufficient, and dimensional changes are minimal even when the resulting foam is left at high temperatures for a long period of time. Closed foam rate
80-90%, which is significantly higher than conventional ones.
Therefore, it can be used for a wide range of purposes including insulation and cushioning materials.
Claims (1)
基が結合した架橋性高圧法分岐ポリエチレン95〜
50重量％と、融点が120℃以上の線状ポリエチレ
ン５〜50重量％との混合物100重量部に対し、ポ
リブテン系樹脂３〜30重量部を加えたポリエチレ
ン組成物を加熱・溶融し、これにシラノール縮合
触媒の存在下で揮発性発泡剤を加えて低圧帯域へ
押出し、水分と接触させることを特徴とするポリ
エチレン系樹脂発泡体の製造方法。 ２ 前記ポリブテン系樹脂がブテン−１とオレフ
インとの共重合体およびポリブテン−１のうち少
なくとも１種である特許請求の範囲第１項に記載
の方法。 ３ 前記線状ポリエチレンが分子内に加水分解性
のシリル基を含有する特許請求の範囲第１項に記
載の方法。[Scope of Claims] 1. Crosslinkable high-pressure branched polyethylene 95~ in which a hydrolyzable silyl group is bonded to high-pressure branched polyethylene
A polyethylene composition prepared by adding 3 to 30 parts by weight of a polybutene resin to 100 parts by weight of a mixture of 50% by weight and 5 to 50% by weight of linear polyethylene with a melting point of 120°C or higher is heated and melted. A method for producing a polyethylene resin foam, which comprises adding a volatile blowing agent to the foam in the presence of a silanol condensation catalyst, extruding the foam into a low-pressure zone, and bringing the foam into contact with moisture. 2. The method according to claim 1, wherein the polybutene resin is at least one of a copolymer of butene-1 and olefin and polybutene-1. 3. The method according to claim 1, wherein the linear polyethylene contains a hydrolyzable silyl group in the molecule.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7551284A JPS60219236A (en) | 1984-04-13 | 1984-04-13 | Production of polyethylene resin foam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7551284A JPS60219236A (en) | 1984-04-13 | 1984-04-13 | Production of polyethylene resin foam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60219236A JPS60219236A (en) | 1985-11-01 |
| JPH0417221B2 true JPH0417221B2 (en) | 1992-03-25 |
Family
ID=13578362
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7551284A Granted JPS60219236A (en) | 1984-04-13 | 1984-04-13 | Production of polyethylene resin foam |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60219236A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102009028353A1 (en) * | 2009-08-07 | 2011-04-14 | Wacker Chemie Ag | Binders based on silane-containing hyperbranched polyolefins |
-
1984
- 1984-04-13 JP JP7551284A patent/JPS60219236A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60219236A (en) | 1985-11-01 |
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