JPS631976B2 - - Google Patents
Info
- Publication number
- JPS631976B2 JPS631976B2 JP55151904A JP15190480A JPS631976B2 JP S631976 B2 JPS631976 B2 JP S631976B2 JP 55151904 A JP55151904 A JP 55151904A JP 15190480 A JP15190480 A JP 15190480A JP S631976 B2 JPS631976 B2 JP S631976B2
- Authority
- JP
- Japan
- Prior art keywords
- vinyl acetate
- ethylene
- weight
- foam
- acetate copolymer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 239000006260 foam Substances 0.000 claims description 25
- 229920001200 poly(ethylene-vinyl acetate) Polymers 0.000 claims description 21
- 239000005038 ethylene vinyl acetate Substances 0.000 claims description 19
- 239000000203 mixture Substances 0.000 claims description 18
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 claims description 15
- 238000010438 heat treatment Methods 0.000 claims description 10
- 229920005989 resin Polymers 0.000 claims description 9
- 239000011347 resin Substances 0.000 claims description 9
- 238000004132 cross linking Methods 0.000 claims description 8
- 239000003431 cross linking reagent Substances 0.000 claims description 8
- 238000005187 foaming Methods 0.000 claims description 8
- 229920001577 copolymer Polymers 0.000 claims description 6
- 239000004604 Blowing Agent Substances 0.000 claims description 5
- 238000004519 manufacturing process Methods 0.000 claims description 5
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims 1
- 239000005977 Ethylene Substances 0.000 claims 1
- 238000000034 method Methods 0.000 description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- -1 polyethylene Polymers 0.000 description 6
- 229920000642 polymer Polymers 0.000 description 6
- 238000007791 dehumidification Methods 0.000 description 5
- 238000001035 drying Methods 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 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 3
- 239000004156 Azodicarbonamide Substances 0.000 description 3
- 239000004698 Polyethylene Substances 0.000 description 3
- XOZUGNYVDXMRKW-AATRIKPKSA-N azodicarbonamide Chemical compound NC(=O)\N=N\C(N)=O XOZUGNYVDXMRKW-AATRIKPKSA-N 0.000 description 3
- 235000019399 azodicarbonamide Nutrition 0.000 description 3
- 239000002274 desiccant Substances 0.000 description 3
- 229920001971 elastomer Polymers 0.000 description 3
- 239000000806 elastomer Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 229920000573 polyethylene Polymers 0.000 description 3
- 239000000741 silica gel Substances 0.000 description 3
- 229910002027 silica gel Inorganic materials 0.000 description 3
- XFCMNSHQOZQILR-UHFFFAOYSA-N 2-[2-(2-methylprop-2-enoyloxy)ethoxy]ethyl 2-methylprop-2-enoate Chemical compound CC(=C)C(=O)OCCOCCOC(=O)C(C)=C XFCMNSHQOZQILR-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
- MXRIRQGCELJRSN-UHFFFAOYSA-N O.O.O.[Al] Chemical compound O.O.O.[Al] MXRIRQGCELJRSN-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 2
- 238000010382 chemical cross-linking Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 239000003063 flame retardant Substances 0.000 description 2
- 239000000499 gel Substances 0.000 description 2
- 229910052736 halogen Inorganic materials 0.000 description 2
- 150000002367 halogens Chemical class 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000001451 organic peroxides Chemical class 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 229920002379 silicone rubber Polymers 0.000 description 2
- NALFRYPTRXKZPN-UHFFFAOYSA-N 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane Chemical compound CC1CC(C)(C)CC(OOC(C)(C)C)(OOC(C)(C)C)C1 NALFRYPTRXKZPN-UHFFFAOYSA-N 0.000 description 1
- RDKJRSZNUXGKTG-UHFFFAOYSA-N 1,4-bis(tert-butylperoxy)-2,3-di(propan-2-yl)benzene Chemical compound CC(C)C1=C(OOC(C)(C)C)C=CC(OOC(C)(C)C)=C1C(C)C RDKJRSZNUXGKTG-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
- HQOVXPHOJANJBR-UHFFFAOYSA-N 2,2-bis(tert-butylperoxy)butane Chemical compound CC(C)(C)OOC(C)(CC)OOC(C)(C)C HQOVXPHOJANJBR-UHFFFAOYSA-N 0.000 description 1
- DMWVYCCGCQPJEA-UHFFFAOYSA-N 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane Chemical compound CC(C)(C)OOC(C)(C)CCC(C)(C)OOC(C)(C)C DMWVYCCGCQPJEA-UHFFFAOYSA-N 0.000 description 1
- 239000004709 Chlorinated polyethylene Substances 0.000 description 1
- 229920002943 EPDM rubber Polymers 0.000 description 1
- 229920000181 Ethylene propylene rubber Polymers 0.000 description 1
- BVVRPVFKRUVCJX-UHFFFAOYSA-N OC(=O)C=C.OC(=O)C=C.OC(=O)C=C.OCC(CO)CO Chemical compound OC(=O)C=C.OC(=O)C=C.OC(=O)C=C.OCC(CO)CO BVVRPVFKRUVCJX-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- DAKWPKUUDNSNPN-UHFFFAOYSA-N Trimethylolpropane triacrylate Chemical compound C=CC(=O)OCC(CC)(COC(=O)C=C)COC(=O)C=C DAKWPKUUDNSNPN-UHFFFAOYSA-N 0.000 description 1
- OKKRPWIIYQTPQF-UHFFFAOYSA-N Trimethylolpropane trimethacrylate Chemical compound CC(=C)C(=O)OCC(CC)(COC(=O)C(C)=C)COC(=O)C(C)=C OKKRPWIIYQTPQF-UHFFFAOYSA-N 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 229920002433 Vinyl chloride-vinyl acetate copolymer Polymers 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- ADCOVFLJGNWWNZ-UHFFFAOYSA-N antimony trioxide Chemical group O=[Sb]O[Sb]=O ADCOVFLJGNWWNZ-UHFFFAOYSA-N 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 229920005549 butyl rubber Polymers 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
- 239000004927 clay Substances 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- WHHGLZMJPXIBIX-UHFFFAOYSA-N decabromodiphenyl ether Chemical compound BrC1=C(Br)C(Br)=C(Br)C(Br)=C1OC1=C(Br)C(Br)=C(Br)C(Br)=C1Br WHHGLZMJPXIBIX-UHFFFAOYSA-N 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229920006242 ethylene acrylic acid copolymer Polymers 0.000 description 1
- 229920001038 ethylene copolymer Polymers 0.000 description 1
- 229920006244 ethylene-ethyl acrylate Polymers 0.000 description 1
- 239000004088 foaming agent Substances 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011256 inorganic filler Substances 0.000 description 1
- 229910003475 inorganic filler Inorganic materials 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- 239000011147 inorganic material Substances 0.000 description 1
- ZFSLODLOARCGLH-UHFFFAOYSA-N isocyanuric acid Chemical compound OC1=NC(O)=NC(O)=N1 ZFSLODLOARCGLH-UHFFFAOYSA-N 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000003607 modifier Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920002589 poly(vinylethylene) polymer Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000004945 silicone rubber Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000012756 surface treatment agent Substances 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- GJBRNHKUVLOCEB-UHFFFAOYSA-N tert-butyl benzenecarboperoxoate Chemical compound CC(C)(C)OOC(=O)C1=CC=CC=C1 GJBRNHKUVLOCEB-UHFFFAOYSA-N 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
- C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
- C08J9/04—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent
- C08J9/06—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof using blowing gases generated by a previously added blowing agent by a chemical blowing agent
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L31/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an acyloxy radical of a saturated carboxylic acid, of carbonic acid or of a haloformic acid; Compositions of derivatives of such polymers
- C08L31/02—Homopolymers or copolymers of esters of monocarboxylic acids
- C08L31/04—Homopolymers or copolymers of vinyl acetate
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
- Molding Of Porous Articles (AREA)
- Compositions Of Macromolecular Compounds (AREA)
Description
本発明は多量に酢酸ビニルを含有するエチレン
−酢酸ビニル共重合体を含む樹脂より架橋発泡体
を製造する方法に関するものである。
従来酢酸ビニルの含有量が少い例えば15重量％
以下のエチレン−酢酸ビニル共重合体は優れた柔
軟性と弾力性を有するため、該共重合体よりなる
架橋発泡体はサンダル、靴底等の用途として大量
に使用されているものである。又一方多量の酢酸
ビニルが含有された非結晶性のエチレン−酢酸ビ
ニル共重合体は塩化ビニル樹脂等のプラスチツク
スと混和して該プラスチツクの性能を改良する改
質材として多量に使用されている。然しながらこ
のようなエチレン−酢酸ビニル共重合体による架
橋発泡体は未だ出現していないものである。
本発明者等は多量に酢酸ビニルを含有するエチ
レン−酢酸ビニル共重合体に無機物質粉末及びハ
ロゲン系難燃剤等を配合した組成物より難燃性に
優れた高倍率の架橋発泡体を製造する方法を提案
した。然しながらこの方法においては、その製造
過程において外的条件の変動の影響をうけやす
く、得られる発泡体の発泡倍率と気泡性状に著し
く変動を生ずることがしばしばであり、一定の気
泡径並に発泡倍率を有する気泡体を工業的に製造
することが困難であつた。即ち酢酸ビニル含有量
40〜95wt％のエチレン−酢酸ビニル共重合体を
含む樹脂に発泡剤、有機過酸化物系架橋剤、無機
質充てん剤及びその他の添加剤を添加したものを
練和し、この混和物を押出機等によりシート化し
た後、加熱恒温槽を用いて常圧下に加熱して架橋
発泡体を製造するに際し、一定品質の発泡体を歩
留りよく得ることが難しいものであつた。
本発明はかかる欠点を改善せんとして鋭意研究
を行つた結果、常時一定の発泡倍率並に気泡性状
を有し品質良好な発泡体を歩留りよく得るための
製造方法を見出したものである。即ち本発明方法
は酢酸ビニル含有量40〜95重量％のエチレン−酢
酸ビニル共重合体を含む樹脂に発泡剤、架橋剤、
必要により充填剤等を配合した組成物を常圧下に
加熱してエチレン−酢酸ビニル共重合体フオーム
を製造するにおいて、架橋発泡のための加熱に先
立つて該組成物を脱湿処理することを特徴とする
ものである。
本発明は特に上記組成物において、その含有水
分を0.15重量％未満望ましくは0.1重量％未満、
更に好ましくは0.05重量％未満にすることにより
微細な独立気泡構造を有する高倍率の発泡体をう
るという著しい効果を発揮することが出来たもの
である。
この理由については詳にすることは出来えない
がエチレン−酢酸ビニル共重合体の架橋に及ぼす
微量水分の影響について検討を行つたところ、水
分の存在によつてゲル分率はそれ程影響を受ける
ものではないが、ゲル膨潤度については著しく影
響することを知見した。従つて水分の存在は架橋
網目の均一性を阻害するものと考えられる。又酢
酸ビニル含有量が多量のポリマーはポリエチレン
に比して水との親和性が良好であるため、必然的
に吸収しうる水分量が多いということも見逃がす
ことの出来ない要因である。
本発明においてエチレン−酢酸ビニル共重合体
の酢酸ビニル含有量は40〜95重量％望ましくは55
〜70重量％である。その理由は高発泡倍率の発泡
体を得るためであり、40重量％未満の場合にはそ
の効果があらわれないためである。
なおその密度は１〜1.2ｇ／cm2、分子量はメル
トインデツクスで表示して0.01〜300、望ましく
は20〜100の範囲することが好ましい。
又本発明におけるエチレン−酢酸ビニル共重合
体を含む樹脂とは、該共重合体単独でもよいが、
該共重合体と他の樹脂又はエラストマーとの混合
物でもよい。これらの樹脂又はエラストマーとし
ては、例えば、ポリエチレン、酢酸ビニル含有量
40重量％未満の結晶性エチレン−酢酸ビニル共重
合体、エチレン−エチルアクリレート共重合体、
エチレン−アクリル酸共重合体、ポリプロピレ
ン、ポリ塩化ビニル、塩化ビニル−酢酸ビニル共
重合体、エチレン−酢酸ビニル−塩化ビニル共重
合体、塩素化ポリエチレン、エチレン−プロピレ
ン共重合体、１，２−ポリブタジエン、エチレン
−プロピレンゴム、エチレン−プロピレン−ジエ
ン３元共重合体、ブチルゴム、シリコーンゴム等
である。
本発明において、酢酸ビニル含有量40〜95重量
％のエチレン−酢酸ビニル共重合体を含む樹脂に
おける該共重合体の含有率は、通常30％以上であ
るが、好ましくは50％以上である。この比率はブ
レンドされる他の樹脂又はエラストマーの種類に
より異なり、エチレン系共重合体の場合には上記
含有率はより低い数値となる。即ち、例えば、酢
酸ビニル含有率が40％未満のエチレン−酢酸ビニ
ル共重合体やポリエチレンの場合には上記含有率
が30％までブレンド可能である。また、シリコー
ンエラストマー等エチレン−酢酸ビニル共重合体
と相溶性に乏しいポリマーの場合には、上記含有
率は80％以上となる等である。
又本発明方法において使用する化学架橋剤は有
機過酸化物例えばジクミルパーオキサイド、ｔ−
ブチルパ−ベンゾエート、１，１−ジ−（ｔ−ブ
チルパ−オキシ）−３、３，５−トリメチルシク
ロヘキサン、２，２−ビス−（ｔ−ブチルパ−オ
キシ）ブタン、２，５−ビス−（ｔ−ブチルパ−
オキシ）−２，５−ジメチルヘキサン、１，４−
ビス（ｔ−ブチルパ−オキシ）ジイソプロピルベ
ンゼン、２，５−ジメチル−２，５−ジ−（ｔ−
ブチルパ−オキシ）ヘキサン−３などである。
又架橋促進剤として各種の多官能性化合物を上
記の化学架橋剤と併用することが好ましく、例え
ばテトラメチロールメタンテトラアクリレート、
トリメチロールメタントリアクリレート、トリメ
チロールプロパントリアクリレート、ジエチレン
グリコールジメタクリート、トリアリールイソシ
アヌレート等である。
本発明はエチレンー酢酸ビニル共重合体に上記
の架橋剤、架橋助剤の他に、アゾジカーボンアミ
ドの如き発泡剤を添加し、更に必要に応じて炭酸
カルシウム、水酸化アルミニウム、クレー等の無
機充てん剤、ハロゲン系難燃剤、滑剤、表面処理
剤、酸化防止剤、発泡助剤、着色剤等を添加し混
和した組成物を脱湿処理−例えばシリカゲル等の
乾燥剤による方法、熱風、赤外線にて加熱乾燥す
る方法、或は真空乾燥する方法、成形加工中に脱
湿処理する方法を行つた後、熱風加熱、赤外線
加熱、溶融塩加熱等を用いて常圧下に、加熱
して架橋発泡せしめて本発明発泡体をうるもので
ある。
なおこの場合、架橋が先行した後発泡膨脹する
ものであるが、加熱が急速であるため架橋剤と発
泡剤とはほぼ同時に熱分解と開始して架橋と発泡
とが常圧下でほぼ同時に進行するために水分等の
不純物の影響が一層現れやすいものと推定され
る。
なお、本発明において、組成物を脱湿処理する
手段として、原料の混和工程以前にポリマーを含
む原料の状態で脱湿処理する場合も含まれるもの
とする。このときにはポリマー中に含まれる水分
を除去することが必須であるから、ポリマーを除
外した諸原料及び混和物の脱湿処理は有効でな
い。
又本発明において脱湿処理した組成物を、その
まま空気中に放置すると再度水分を吸収するた
め、該組成物を直ちに加熱架橋発泡せしめること
が必要であり、脱湿した組成物を放置する場合に
は脱湿状態の空間に収納することが必要である。
なお、吸湿量の測定方法は下記とする。ポリマ
ー原料もしくは発泡組成物を乾燥剤としてシリカ
ゲルを使用したデシケーター中にて脱湿処理する
とき、その脱湿量は第１図のような挙動を示す。
即ち10日間デシケーター中に放置すればほぼ恒量
となる。
従て、本発明ではデシケーター中で10日間脱湿
処理したサンプルの吸湿量はzeroとして、これを
基準とするものである。
次に本発明の実施例について説明する。（以下
部とあるは何れも重量部を示す）
実施例 １
酢酸ビニル含有量61％のエチル−酢酸ビニル共
重合体（大日本インキ株式会社製品；エバスレン
450−Ｐ）80重量部、酢酸ビニル含有量25％のエ
チレン−酢酸ビニル共重合体（三井ポリケミカル
株式会社製品；エバフレツクス360）20重量部、
水酸化アルミニウム微粉末（昭和電工株式会社製
品；ハイジライトＨ−42M）140重量部発泡剤と
してアゾジカルボンアミド（永和化成株式会社製
品；ヴイニホールAC＃IU）25重量部、ステアリ
ン酸カルシウム２重量部及び、第１表に示した割
合で架橋剤ジクミルパ−オキサイド（DCP：三
井石油化学株式会社製品）と架橋促進剤トリメチ
ロールプロパントリメタクリレート（新中村化学
株式会社製品）とからなる組成物を実験用小型ミ
キサーにて練和した後、熱プレスにて厚さ３mmの
シートに成形した。
この成形シートを乾燥剤としてシリカゲルを用
いた大型デシケーター中に投入して所定時間脱湿
処理した後とり出して、210℃に加熱した熱風恒
温槽中に７分間置き発泡させた。得られた発泡体
の発泡倍率（発泡前のシートの密度ρ0／発泡体の
密度ρで表示）を第１表にまとめた。表中脱湿処
理時間ゼロとは成形シートをそのまま発泡させた
比較例である。
この表のデータが示しているように、脱湿処理
すると未処理のものに比して大巾に発泡倍率が向
上するものである。
The present invention relates to a method for producing a crosslinked foam from a resin containing an ethylene-vinyl acetate copolymer containing a large amount of vinyl acetate. Conventionally, the content of vinyl acetate is low, e.g. 15% by weight.
Since the following ethylene-vinyl acetate copolymer has excellent flexibility and elasticity, crosslinked foams made of this copolymer are used in large quantities for applications such as sandals and shoe soles. On the other hand, amorphous ethylene-vinyl acetate copolymers containing a large amount of vinyl acetate are widely used as modifiers to improve the performance of plastics such as vinyl chloride resin when mixed with them. . However, such a crosslinked foam made of ethylene-vinyl acetate copolymer has not yet appeared. The present inventors have produced a high-density crosslinked foam with superior flame retardancy than a composition prepared by blending an ethylene-vinyl acetate copolymer containing a large amount of vinyl acetate with an inorganic substance powder, a halogen flame retardant, etc. proposed a method. However, this method is susceptible to changes in external conditions during the manufacturing process, and the expansion ratio and cell properties of the resulting foam often vary significantly. It has been difficult to industrially produce foams having this. i.e. vinyl acetate content
A resin containing 40 to 95 wt% ethylene-vinyl acetate copolymer is mixed with a blowing agent, an organic peroxide crosslinking agent, an inorganic filler, and other additives, and this mixture is passed through an extruder. When producing a crosslinked foam by forming a sheet into a sheet using a heating constant temperature bath under normal pressure, it is difficult to obtain a foam of constant quality with a good yield. The present invention has been made as a result of intensive research aimed at improving these drawbacks, and as a result has discovered a manufacturing method for obtaining a foam of good quality with a constant expansion ratio and cell properties at a high yield. That is, in the method of the present invention, a blowing agent, a crosslinking agent,
In producing an ethylene-vinyl acetate copolymer foam by heating a composition containing fillers and the like as necessary under normal pressure, the composition is characterized by dehumidifying the composition prior to heating for crosslinking and foaming. That is. The present invention particularly provides the above composition with a water content of less than 0.15% by weight, preferably less than 0.1% by weight,
More preferably, by setting the content to less than 0.05% by weight, a remarkable effect of obtaining a high-magnification foam having a fine closed cell structure can be exhibited. The reason for this cannot be explained in detail, but when we investigated the effect of trace amounts of water on the crosslinking of ethylene-vinyl acetate copolymers, we found that the gel fraction was significantly affected by the presence of water. However, it was found that the degree of gel swelling was significantly affected. Therefore, the presence of water is considered to impede the uniformity of the crosslinked network. Another factor that cannot be overlooked is that polymers containing a large amount of vinyl acetate have a better affinity with water than polyethylene, so they naturally absorb a larger amount of water. In the present invention, the vinyl acetate content of the ethylene-vinyl acetate copolymer is 40 to 95% by weight, preferably 55% by weight.
~70% by weight. The reason for this is to obtain a foam with a high expansion ratio, and if the amount is less than 40% by weight, the effect will not be achieved. The density is preferably 1 to 1.2 g/cm 2 and the molecular weight is preferably 0.01 to 300, preferably 20 to 100, expressed as a melt index. In addition, the resin containing an ethylene-vinyl acetate copolymer in the present invention may be the copolymer alone, but
A mixture of the copolymer and other resins or elastomers may also be used. These resins or elastomers include, for example, polyethylene, vinyl acetate content
Less than 40% by weight of crystalline ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer,
Ethylene-acrylic acid copolymer, polypropylene, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, chlorinated polyethylene, ethylene-propylene copolymer, 1,2-polybutadiene , ethylene-propylene rubber, ethylene-propylene-diene terpolymer, butyl rubber, silicone rubber, etc. In the present invention, the content of the ethylene-vinyl acetate copolymer in the resin containing the vinyl acetate content of 40 to 95% by weight is usually 30% or more, but preferably 50% or more. This ratio varies depending on the type of other resin or elastomer to be blended, and in the case of an ethylene copolymer, the above content will be a lower value. That is, for example, in the case of an ethylene-vinyl acetate copolymer or polyethylene having a vinyl acetate content of less than 40%, it is possible to blend the content up to 30%. Further, in the case of a polymer having poor compatibility with the ethylene-vinyl acetate copolymer, such as a silicone elastomer, the above content may be 80% or more. The chemical crosslinking agent used in the method of the present invention may also be an organic peroxide such as dicumyl peroxide, t-
Butyl perbenzoate, 1,1-di-(t-butylperoxy)-3,3,5-trimethylcyclohexane, 2,2-bis-(t-butylperoxy)butane, 2,5-bis-(t- -Butylper-
oxy)-2,5-dimethylhexane, 1,4-
Bis(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-
butylperoxy)hexane-3, etc. It is also preferable to use various polyfunctional compounds as a crosslinking accelerator in combination with the above chemical crosslinking agent, such as tetramethylolmethanetetraacrylate,
These include trimethylolmethane triacrylate, trimethylolpropane triacrylate, diethylene glycol dimethacrylate, and triaryl isocyanurate. In the present invention, in addition to the above-mentioned crosslinking agent and crosslinking aid, a blowing agent such as azodicarbonamide is added to the ethylene-vinyl acetate copolymer, and if necessary, an inorganic material such as calcium carbonate, aluminum hydroxide, clay, etc. A composition in which fillers, halogen flame retardants, lubricants, surface treatment agents, antioxidants, foaming aids, colorants, etc. are added and mixed is subjected to dehumidification treatment - for example, using a drying agent such as silica gel, hot air, or infrared rays. After drying by heating or vacuum drying, or dehumidifying during molding, the material is heated under normal pressure using hot air heating, infrared heating, molten salt heating, etc. to crosslink and foam. The foam of the present invention can be obtained using the following methods. In this case, foaming and expansion occurs after crosslinking occurs, but since the heating is rapid, the crosslinking agent and foaming agent begin to thermally decompose almost simultaneously, and crosslinking and foaming proceed almost simultaneously under normal pressure. Therefore, it is presumed that the influence of impurities such as moisture is more likely to appear. In the present invention, the means for dehumidifying the composition also includes a case where the raw material containing the polymer is subjected to the dehumidifying treatment before the step of mixing the raw materials. At this time, since it is essential to remove water contained in the polymer, dehumidification treatment of raw materials and mixtures excluding the polymer is not effective. In addition, if the dehumidified composition of the present invention is left in the air, it will absorb moisture again, so it is necessary to heat and crosslink and foam the composition immediately. must be stored in a dehumidified space. The method for measuring the amount of moisture absorption is as follows. When a polymer raw material or a foamed composition is dehumidified in a desiccator using silica gel as a desiccant, the amount of moisture removed exhibits the behavior shown in FIG.
That is, if it is left in a desiccator for 10 days, the weight becomes almost constant. Therefore, in the present invention, the moisture absorption amount of a sample that has been dehumidified for 10 days in a desiccator is defined as zero, and this is used as a reference. Next, examples of the present invention will be described. (The following parts indicate parts by weight.) Example 1 Ethyl-vinyl acetate copolymer with a vinyl acetate content of 61% (product of Dainippon Ink Co., Ltd.; Everthrene)
450-P) 80 parts by weight, 20 parts by weight of ethylene-vinyl acetate copolymer with a vinyl acetate content of 25% (Mitsui Polychemical Co., Ltd. product; Evaflex 360),
140 parts by weight of aluminum hydroxide fine powder (product of Showa Denko Co., Ltd.; Higilite H-42M), 25 parts by weight of azodicarbonamide (product of Eiwa Kasei Co., Ltd.; Vinihole AC#IU) as a blowing agent, 2 parts by weight of calcium stearate, and A composition consisting of a crosslinking agent dicumyl peroxide (DCP: a product of Mitsui Petrochemicals Co., Ltd.) and a crosslinking accelerator trimethylolpropane trimethacrylate (a product of Shin Nakamura Chemical Co., Ltd.) in the proportions shown in Table 1 was mixed in a small experimental mixer. After kneading the mixture, it was formed into a sheet with a thickness of 3 mm using a hot press. This formed sheet was put into a large desiccator using silica gel as a desiccant, dehumidified for a predetermined period of time, then taken out, and placed in a hot air constant temperature bath heated to 210° C. for 7 minutes to cause foaming. The expansion ratios (expressed as sheet density ρ 0 before foaming/foam density ρ) of the obtained foams are summarized in Table 1. In the table, the dehumidification treatment time of zero is a comparative example in which the molded sheet was foamed as it was. As shown in the data in this table, the dehumidifying treatment significantly improves the foaming ratio compared to the untreated material.
【表】
実施例 ２
市販の酢酸ビニル含有量61％のエチレン−酢酸
ビニル共重合体（大日本インキ株式会社製、エバ
スレン450−Ｐ）60部と酢酸ビニル含有量25％の
エチレン酢酸ビニル共重合体（三井ポリケミカル
株式会社製エバフレツクス360）40部、市販水酸
化アルミニウム粉末（昭和電工株式会社製、ハイ
ジライトＨ−42M）100部、デカブロモデイフエ
ニールオキサイド20重量部、三酸化アンチモン10
重量部、アゾジカーボンアミド23部、ジクミルパ
−オキサイド２部及びテトラメチロールメタンテ
トラアクリーレート（新中村化学株式会社製）
1.0部をニーダにて混和した後、ペレタイズした。
この組成物ペレツトを40φ押出機のホツパーより
供給して装着したＴ−ダイより押出シートを得
た。
このシートを次の如き方法により脱湿処理を行
つた。
(A) 熱風循環式恒温槽を用いて120℃、20分間乾
燥処理を行つた。然る後、上記シートを熱風恒
温槽中にて220℃７分間加熱して発泡体を得た。
(B) 真空乾燥装置を使用し、60℃×60分乾燥処理
を行つた。然る後上記シートを熱風恒温槽中に
て220℃、７分間加熱して発泡体をえた。
(C) シリカゲル乾燥剤を入れたデシケータ中にて
室温４日間放置して乾燥処理を行つた。然る後
上記シートを熱風恒温槽中にて220℃７分間加
熱して発泡体をえた。
斯くして得た本発明発泡体Ａ，Ｂ，Ｃの性能を
測定した結果を示すと第２表の如くである。なお
本発明発泡体と比較するために乾燥処理前のシー
ト（比較例品）についても同様性能を測定して比
較した。[Table] Example 2 60 parts of a commercially available ethylene-vinyl acetate copolymer with a vinyl acetate content of 61% (manufactured by Dainippon Ink Co., Ltd., Everthrene 450-P) and ethylene-vinyl acetate copolymer with a vinyl acetate content of 25% 40 parts of combination (Evaflex 360, manufactured by Mitsui Polychemical Co., Ltd.), 100 parts of commercially available aluminum hydroxide powder (Hygilite H-42M, manufactured by Showa Denko Co., Ltd.), 20 parts by weight of decabromodiphenyl oxide, 10 parts by weight of antimony trioxide
Parts by weight, 23 parts of azodicarbonamide, 2 parts of dicumyl peroxide, and tetramethylolmethanetetraacrylate (manufactured by Shin Nakamura Chemical Co., Ltd.)
After mixing 1.0 part with a kneader, it was pelletized.
The pellets of this composition were fed from the hopper of a 40φ extruder and extruded from a T-die equipped with the extruder to obtain a sheet. This sheet was dehumidified by the following method. (A) Drying treatment was performed at 120°C for 20 minutes using a hot air circulation type constant temperature bath. Thereafter, the sheet was heated at 220° C. for 7 minutes in a hot air constant temperature bath to obtain a foam. (B) Using a vacuum dryer, drying was performed at 60°C for 60 minutes. Thereafter, the sheet was heated at 220° C. for 7 minutes in a hot air constant temperature bath to obtain a foam. (C) Drying treatment was carried out by leaving it at room temperature for 4 days in a desiccator containing a silica gel desiccant. Thereafter, the sheet was heated at 220°C for 7 minutes in a hot air constant temperature bath to obtain a foam. Table 2 shows the results of measuring the performance of the foams A, B, and C of the present invention thus obtained. In addition, in order to compare with the foam of the present invention, the performance of a sheet before drying treatment (comparative example product) was also measured and compared.
【表】
以上詳述した如く本発明方法によれば均一で独
立気泡からある高発泡倍率のエチレン−酢酸ビニ
ル共重合体の発泡体をえる等顕著な効果を有す
る。[Table] As detailed above, the method of the present invention has remarkable effects such as obtaining a foam of ethylene-vinyl acetate copolymer having uniform closed cells and a high expansion ratio.
図面は本発明において脱湿処理日数と脱湿量と
の関係を示す曲線図である。
The drawing is a curve diagram showing the relationship between the number of days of dehumidification treatment and the amount of dehumidification in the present invention.
Claims (1)
酢酸ビニル共重合体を含む樹脂に、発泡剤架橋剤
等を配合した組成物を加熱してエチレン−酢酸ビ
ニル共重合体フオームを製造する方法において、
架橋発泡のための加熱に先立つて該組成物を脱湿
処理することを特徴とするエチレン−酢酸ビニル
共重合体フオームの製造方法。1 Ethylene with vinyl acetate content of 40-95% by weight
In a method for producing an ethylene-vinyl acetate copolymer foam by heating a composition containing a resin containing a vinyl acetate copolymer and a blowing agent crosslinking agent, etc.,
1. A method for producing an ethylene-vinyl acetate copolymer foam, which comprises dehumidifying the composition prior to heating for crosslinking and foaming.
Priority Applications (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55151904A JPS5774128A (en) | 1980-10-29 | 1980-10-29 | Manufacture of eehylene vinyl acetate copolymer foam |
| GB8100158A GB2070021B (en) | 1980-02-21 | 1981-01-05 | Crosslinked ethylene-vinyl acetate copolymer foam containing an inorganic material and its production |
| DE3100370A DE3100370C2 (en) | 1980-02-21 | 1981-01-09 | Crosslinked foam containing inorganic fillers and based on an ethylene-vinyl acetate copolymer and process for its production |
| KR1019810000054A KR850000703B1 (en) | 1980-10-29 | 1981-01-10 | Crosslinked polyolefin foam containing a high concentration of an inorganic material |
| US06/367,045 US4446254A (en) | 1980-02-21 | 1982-04-09 | Crosslinked polyolefin foam containing a high concentration of an inorganic material and process for producing the same |
| KR1019840005021A KR850000720B1 (en) | 1980-10-29 | 1984-08-20 | A process for producing polyolefin foam containing a high concentration of an inorganic material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP55151904A JPS5774128A (en) | 1980-10-29 | 1980-10-29 | Manufacture of eehylene vinyl acetate copolymer foam |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5774128A JPS5774128A (en) | 1982-05-10 |
| JPS631976B2 true JPS631976B2 (en) | 1988-01-14 |
Family
ID=15528727
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP55151904A Granted JPS5774128A (en) | 1980-02-21 | 1980-10-29 | Manufacture of eehylene vinyl acetate copolymer foam |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS5774128A (en) |
| KR (2) | KR850000703B1 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100899112B1 (en) * | 2008-07-14 | 2009-05-25 | 주식회사 네오엑스테크 | Incombustible composition for aluminun composite panel |
| KR101013827B1 (en) * | 2008-11-25 | 2011-02-14 | 주식회사 유니언스 | Heat-Expandable Flame-Retardant Polyolefin Resin Composition and Panel Using the Same |
| KR100988249B1 (en) * | 2009-09-10 | 2010-10-18 | 주식회사 투에이취켐 | Manufacturing method of thermoplastic powder coating material containing non-halogen hybrid flame retardant |
| KR101320354B1 (en) * | 2011-06-08 | 2013-10-29 | 이창호 | Thermoplastic composites for a building interior containing natural materials and manufacturing method thereof |
-
1980
- 1980-10-29 JP JP55151904A patent/JPS5774128A/en active Granted
-
1981
- 1981-01-10 KR KR1019810000054A patent/KR850000703B1/en active
-
1984
- 1984-08-20 KR KR1019840005021A patent/KR850000720B1/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| KR850002019A (en) | 1985-04-10 |
| KR850000720B1 (en) | 1985-05-23 |
| JPS5774128A (en) | 1982-05-10 |
| KR830005299A (en) | 1983-08-13 |
| KR850000703B1 (en) | 1985-05-15 |
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