JPH0228312B2 - - Google Patents
Info
- Publication number
- JPH0228312B2 JPH0228312B2 JP62187378A JP18737887A JPH0228312B2 JP H0228312 B2 JPH0228312 B2 JP H0228312B2 JP 62187378 A JP62187378 A JP 62187378A JP 18737887 A JP18737887 A JP 18737887A JP H0228312 B2 JPH0228312 B2 JP H0228312B2
- Authority
- JP
- Japan
- Prior art keywords
- vegetables
- fruits
- surface layer
- bag
- permeability
- 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 - Lifetime
Links
- 235000012055 fruits and vegetables Nutrition 0.000 claims description 56
- 230000035699 permeability Effects 0.000 claims description 51
- 239000002344 surface layer Substances 0.000 claims description 51
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 48
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 44
- 238000004806 packaging method and process Methods 0.000 claims description 43
- 239000010410 layer Substances 0.000 claims description 31
- 239000003795 chemical substances by application Substances 0.000 claims description 28
- 239000000463 material Substances 0.000 claims description 25
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 24
- 239000001569 carbon dioxide Substances 0.000 claims description 24
- 238000000034 method Methods 0.000 claims description 24
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 23
- 239000000470 constituent Substances 0.000 claims description 23
- 229910052760 oxygen Inorganic materials 0.000 claims description 23
- 239000001301 oxygen Substances 0.000 claims description 23
- 230000001766 physiological effect Effects 0.000 claims description 21
- 229920001577 copolymer Polymers 0.000 claims description 19
- 238000007789 sealing Methods 0.000 claims description 18
- 239000000203 mixture Substances 0.000 claims description 13
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 claims description 10
- 239000004711 α-olefin Substances 0.000 claims description 9
- 239000000178 monomer Substances 0.000 claims description 8
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 5
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 claims description 5
- SMZOUWXMTYCWNB-UHFFFAOYSA-N 2-(2-methoxy-5-methylphenyl)ethanamine Chemical compound COC1=CC=C(C)C=C1CCN SMZOUWXMTYCWNB-UHFFFAOYSA-N 0.000 claims description 4
- 125000004432 carbon atom Chemical group C* 0.000 claims description 4
- 229920000089 Cyclic olefin copolymer Polymers 0.000 claims description 3
- 229910052799 carbon Inorganic materials 0.000 claims description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims 1
- 230000000694 effects Effects 0.000 description 19
- 238000003860 storage Methods 0.000 description 17
- 239000007789 gas Substances 0.000 description 16
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 description 12
- 230000029058 respiratory gaseous exchange Effects 0.000 description 12
- 238000003306 harvesting Methods 0.000 description 9
- 230000007423 decrease Effects 0.000 description 8
- 238000009826 distribution Methods 0.000 description 8
- -1 polyethylene Polymers 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- LDVVTQMJQSCDMK-UHFFFAOYSA-N 1,3-dihydroxypropan-2-yl formate Chemical compound OCC(CO)OC=O LDVVTQMJQSCDMK-UHFFFAOYSA-N 0.000 description 5
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 5
- 239000005977 Ethylene Substances 0.000 description 5
- 230000014759 maintenance of location Effects 0.000 description 5
- 238000002156 mixing Methods 0.000 description 5
- 230000005068 transpiration Effects 0.000 description 5
- 230000008859 change Effects 0.000 description 4
- 239000002131 composite material Substances 0.000 description 4
- 235000014113 dietary fatty acids Nutrition 0.000 description 4
- 238000002845 discoloration Methods 0.000 description 4
- 235000013399 edible fruits Nutrition 0.000 description 4
- 150000002148 esters Chemical class 0.000 description 4
- 230000008020 evaporation Effects 0.000 description 4
- 238000001704 evaporation Methods 0.000 description 4
- 229930195729 fatty acid Natural products 0.000 description 4
- 239000000194 fatty acid Substances 0.000 description 4
- 150000004665 fatty acids Chemical class 0.000 description 4
- 238000003475 lamination Methods 0.000 description 4
- 230000000704 physical effect Effects 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000011160 research Methods 0.000 description 4
- 238000012360 testing method Methods 0.000 description 4
- 235000013311 vegetables Nutrition 0.000 description 4
- 239000004698 Polyethylene Substances 0.000 description 3
- 238000009833 condensation Methods 0.000 description 3
- 230000005494 condensation Effects 0.000 description 3
- 238000003851 corona treatment Methods 0.000 description 3
- 230000003247 decreasing effect Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 238000009792 diffusion process Methods 0.000 description 3
- 238000011049 filling Methods 0.000 description 3
- 239000012785 packaging film Substances 0.000 description 3
- 229920006280 packaging film Polymers 0.000 description 3
- 239000002356 single layer Substances 0.000 description 3
- 238000010998 test method Methods 0.000 description 3
- 238000009423 ventilation Methods 0.000 description 3
- LIKMAJRDDDTEIG-UHFFFAOYSA-N 1-hexene Chemical compound CCCCC=C LIKMAJRDDDTEIG-UHFFFAOYSA-N 0.000 description 2
- 235000001674 Agaricus brunnescens Nutrition 0.000 description 2
- 241000894006 Bacteria Species 0.000 description 2
- KAKZBPTYRLMSJV-UHFFFAOYSA-N Butadiene Chemical compound C=CC=C KAKZBPTYRLMSJV-UHFFFAOYSA-N 0.000 description 2
- 240000008067 Cucumis sativus Species 0.000 description 2
- 239000004743 Polypropylene Substances 0.000 description 2
- 244000061458 Solanum melongena Species 0.000 description 2
- 235000002597 Solanum melongena Nutrition 0.000 description 2
- 239000002216 antistatic agent Substances 0.000 description 2
- 229920001400 block copolymer Polymers 0.000 description 2
- IAQRGUVFOMOMEM-UHFFFAOYSA-N butene Natural products CC=CC IAQRGUVFOMOMEM-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 238000011156 evaluation Methods 0.000 description 2
- 238000009472 formulation Methods 0.000 description 2
- 239000000155 melt Substances 0.000 description 2
- ZGEGCLOFRBLKSE-UHFFFAOYSA-N methylene hexane Natural products CCCCCC=C ZGEGCLOFRBLKSE-UHFFFAOYSA-N 0.000 description 2
- 239000005022 packaging material Substances 0.000 description 2
- 230000035790 physiological processes and functions Effects 0.000 description 2
- 229920000573 polyethylene Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 2
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 2
- 229920005604 random copolymer Polymers 0.000 description 2
- KWKAKUADMBZCLK-UHFFFAOYSA-N 1-octene Chemical compound CCCCCCC=C KWKAKUADMBZCLK-UHFFFAOYSA-N 0.000 description 1
- 206010003497 Asphyxia Diseases 0.000 description 1
- 235000009849 Cucumis sativus Nutrition 0.000 description 1
- 235000010799 Cucumis sativus var sativus Nutrition 0.000 description 1
- 244000068988 Glycine max Species 0.000 description 1
- 235000010469 Glycine max Nutrition 0.000 description 1
- 206010021143 Hypoxia Diseases 0.000 description 1
- 241000218922 Magnoliophyta Species 0.000 description 1
- 244000046052 Phaseolus vulgaris Species 0.000 description 1
- 240000004713 Pisum sativum Species 0.000 description 1
- 235000010582 Pisum sativum Nutrition 0.000 description 1
- 239000006096 absorbing agent Substances 0.000 description 1
- 239000012190 activator Substances 0.000 description 1
- 125000001931 aliphatic group Chemical group 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 230000008952 bacterial invasion Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000002981 blocking agent Substances 0.000 description 1
- LMHUKLLZJMVJQZ-UHFFFAOYSA-N but-1-ene;prop-1-ene Chemical compound CC=C.CCC=C LMHUKLLZJMVJQZ-UHFFFAOYSA-N 0.000 description 1
- 239000003086 colorant Substances 0.000 description 1
- 238000007334 copolymerization reaction Methods 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 244000013123 dwarf bean Species 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 229920001038 ethylene copolymer Polymers 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 235000021331 green beans Nutrition 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- 229920001519 homopolymer Polymers 0.000 description 1
- 230000009545 invasion Effects 0.000 description 1
- 235000021332 kidney beans Nutrition 0.000 description 1
- 238000010030 laminating Methods 0.000 description 1
- 238000011068 loading method Methods 0.000 description 1
- 230000005923 long-lasting effect Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 125000005395 methacrylic acid group Chemical group 0.000 description 1
- AFFLGGQVNFXPEV-UHFFFAOYSA-N n-decene Natural products CCCCCCCCC=C AFFLGGQVNFXPEV-UHFFFAOYSA-N 0.000 description 1
- 230000036284 oxygen consumption Effects 0.000 description 1
- YWAKXRMUMFPDSH-UHFFFAOYSA-N pentene Chemical compound CCCC=C YWAKXRMUMFPDSH-UHFFFAOYSA-N 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000002985 plastic film Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000007639 printing Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000035755 proliferation Effects 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 230000002459 sustained effect Effects 0.000 description 1
- 230000008961 swelling Effects 0.000 description 1
- 229920003002 synthetic resin Polymers 0.000 description 1
- 239000000057 synthetic resin Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000002087 whitening effect Effects 0.000 description 1
- 238000004383 yellowing Methods 0.000 description 1
Landscapes
- Packging For Living Organisms, Food Or Medicinal Products That Are Sensitive To Environmental Conditiond (AREA)
- Wrappers (AREA)
- Storage Of Fruits Or Vegetables (AREA)
- Laminated Bodies (AREA)
Description
［産業上の利用分野］
本発明は、例えば野菜、根菜、果実、草花、花
木、きのこ類など（以下本明細書ではこれらを広
義の意味で青果物と称する）のうち、収穫後も激
しい生理作用を営む青果物を対象とし、保存時の
鮮度保持効果を高めることによつて、青果物の商
品価値を高めることのできる方法に関するもので
ある。
［従来の技術］
近年、生鮮野菜、果実、生花あるいはきのこ類
等の青果物は、露地栽培から園芸施設栽培による
計画的な多重・多角的栽培へと移行してきている
ものが多く、定められた期間内に大量の青果物を
収穫し包装しなければならないことが多い。また
露地栽培を主体とする青果物にしても収穫時期が
決まつているので、短期間内に大量の収穫物を包
装し出荷しなければならず、これら青果物の包装
物が一般消費者の手に渡るまでの流通過程で最も
問題となるのは、収穫時の鮮度を如何にうまく保
持するかということである。
こうした要望に答えるべく、鮮度保持に主眼を
置いた包装袋の改良研究が盛んに進められてお
り、本出願人も改良された幾つかの包装用フイル
ムおよび包装袋を提案している。
ところで前述の様な青果物は収穫によつて直ち
に生理作用を失なう訳ではなく、特に収穫後しば
らくの間は収穫前と殆んど変らない程の生理作用
を持続する。また適当な保存状態に保たれておれ
ば生理作用は更に長く持続され、且つ該生理作用
を持続している限り青果物は良好な鮮度を維持す
る。換言すれば保存状態が悪ければ生理作用の持
続が失われ、早期に腐敗してしまう。
包装状態における青果物の生理作用としては、
蒸散作用による水分の減少、
呼吸作用による雰囲気酸素の消費と炭酸ガス
の発生、
炭酸ガスの発生、発熱にともなう昇温、
が知られており、密閉状態では酸素濃度が減少す
ると共に炭酸ガス濃度が増加し、且つ熱が放散さ
れない為包装体の内部温度は上昇してくる。そし
て呼吸作用はある温度以上でより活発となり、高
温では蒸れ現象によつて腐敗し易くなる。また蒸
散作用は、高温あるいは低湿度の雰囲気でより大
きくなり、その結果形成される高温・高湿度中で
は一層腐敗し易くなる。
そこで上記の様な生理作用を考慮して保存時の
鮮度保持効果を高めるため、包装用袋に適当な大
きさの開孔を設けたり或は袋の底部をカツトする
等の手段で通気性を高め、酸素濃度の低下を防止
し、炭酸ガス濃度の増加を防止し、また昇温を抑
制することが試みられている。しかしながらこれ
らはあくまでも応急処置的なものであつて、包装
袋内部の温度分布やガス組成を必ずしも均一にな
し得る訳ではなく、局部的な腐敗、特に外部から
見えない部分での腐敗が進行し、消費者をあざむ
くという予期しない結果を招くことがある。しか
も現在実用化されている包装用フイルムを用いた
青果物の包装袋は、青果物の前記蒸散作用或は付
着水分の蒸発によつて生じる水分が包装用袋の内
面に付着して曇りを生じ、内容物が外部から見え
にくくなるといつた問題に加えて、該曇り部に凝
縮した水分に青果物が直接触れるといわゆる水腐
れを生ずるという難点もある。
この様なところから、袋に開孔やカツト処理等
を施さなくとも袋内の条件を青果物の生理作用に
とつて好適な温度およびガス組成に保ち、且つ優
れた防曇性を発揮し得るような包装用フイルムの
開発が望まれているが、生理作用の激しい青果物
を包装するのに充分なものは得られていない。
例えばポリエチレンフイルムは、適度の水蒸気
透過度は有しているものの、酸素及び炭酸ガスの
透過度が不足する為青果物が短期間の保存で窒息
状態となつて鮮度低下を来たし、またポリスチレ
ンフイルムは適度の酸素及び炭酸ガス透過性を有
し青果物の呼吸作用は長期間持続せしめ得るもの
の、水蒸気透過率が大きすぎる為水分の蒸散作用
が著しくなり、青果物が短期間のうちに変色また
は萎凋現象を生じ、良好な鮮度を長期的に維持す
ることはできておらない。
しかも上記の様なフイルムは何れも防曇性が乏
しく、外観において商品価値を低下させるばかり
でなく、曇り部に凝縮した水分に青果物が直接触
れると、いわゆる水腐れの原因となる。
［発明が解決しようとする問題点］
本発明者らは上記の様な事情に着目し、包装袋
に開口やカツト処理等を施さなくとも青果物の生
理作用に好適な水蒸気透過性、酸素および炭酸の
ガス透過性を発揮し、且つ内面に曇り現象を生じ
ることのない様な複層フイルムを開発すべく研究
を行なつた。その結果、複層フイルムの水蒸気透
過性、酸素透過性および炭酸ガス透過性を夫々適
正範囲に特定すると共に、複層フイルム構成材中
に適量の防曇剤を配合しておけば、上記の難点が
一応解消されることを確認し、こうした知見を基
にして先に特許出願を済ませた。
ところがその後更に研究を進めるうち、次の様
な事実が明らかとなつてきた。即ち上記先願発明
に係る複層フイルムで作製した袋を用いた場合、
収穫後の生理作用が比較的おだやかな青果物に対
しては鮮度保持の目的が有効に発揮されるが、収
穫後も激しい生理作用を営む青果物（例えばきゆ
うり、えだ豆、えのきだけ、いんげん豆など）の
包装に適用した場合、内部の湿度を適正に保つこ
とができないことがしばしば経験された。殊に昼
夜の温度変化あるいは冷蔵庫への出し入れ等によ
る急激な温度変化が生じた場合には、青果物の蒸
散作用によつて生ずる袋内の水蒸気が結露して包
装袋内に水がたまり、青果物が水腐れを起こすと
いう問題を生じることが明らかとなつてきた。し
かも呼吸作用の著しい青果物の場合は包装袋内に
おける酸素濃度および炭酸ガス濃度の変動も著し
くなるので、前記先願発明に係る複層フイルムを
使用した場合は、これらの急激な濃度変化に対し
て十分に追従させることが困難な場合もあり、当
該青果物の激しい生理作用に適したガス雰囲気を
保持し得なくなつて、鮮度保持効果も不十分とな
る。
本発明はこの様な問題点に着目して更に研究の
結果なされたものであつて、その目的は、生理作
用の激しい青果物の包装に適用した場合でも、ま
たその包装物が急激な温度変化を受けた場合で
も、結露水による水腐れの問題を生ずることがな
く、且つ内部を青果物の生理作用に好適な雰囲気
に保持し、その収穫時の鮮度を長時間維持するこ
とのできる方法を提供しようとするものである。
［問題点を解決する為の手段］
上記の目的を達成する為の要件として規定され
る本発明方法の構成は、
水蒸気透過度が15〜200g／m2・24hr・40℃、
酸素透過度が3000〜35000c.c.／m2・24hr・
atm・20℃・90％RH、
炭酸ガス透過度が12000〜130000c.c.／m2・
24hr・atm・20℃・90％RH、
であり、少なくとも片面側表面層には防曇剤が存
在し、該表面層は０40℃の間で温度変化を繰り
返す経過中防曇性を示すと共に、270℃で溶断シ
ールしたときに3.0Kg−cm／15mm以上の溶断シー
ル強度を示す複層フイルムを用い、該表面層が内
側になる様に少なくとも３方が閉じられた袋状に
形成され、且つ該袋の密封底辺には１個当たりの
切欠き長さ（平坦において切欠いたときの切欠か
れた部分の長さ：以下同じ）が４〜100mmである
切欠き孔が、当該底辺長さの50％以上を密封面と
して残す様に１個以上開口された包装袋を用いて
青果物を包装し、その鮮度を保持するところにと
ころに要旨を有するものである。
［作用］
本発明で使用される包装袋を構成する複層フイ
ルムは、まず第１の条件として水蒸気透過度、酸
素透過度、炭酸ガス透過度を特定すると共に、青
果物に接する側の表面層に防曇剤を存在せしめた
ところに特徴を有するものであるから、以下上記
各特性を定めた理由について説明する。
水蒸気透過度：15〜200g／m2・24hr・40℃
水蒸気透過度は、青果物に付着している水分の
蒸発及び蒸散作用により放出される水分による袋
内湿度を適正に保ち、湿度過剰によるむれ現象を
防止して腐敗を抑制すると共に、湿度不足による
青果物の萎凋、変色（黄変又は褐変）、軟化、弾
力性喪失等を防止するうえで重要な特性であり、
水蒸気透過度が15g／m2・24hr・40℃未満では湿
度過剰によるむれ現象によつて青果物が腐敗し易
く、一方200g／m2・24hr・40℃を超える場合は
包装袋内部が湿度不足となつて青果物が萎凋、変
色等を起こし易く、何れの場合も満足のいく鮮度
保持効果を得ることができない。良好な鮮度保持
効果を確保するうえでより好ましい水蒸気透過度
は20〜150g／m2・24hr・40℃の範囲である。
酸素透過度：3000〜35000c.c.／m2・24hr・
atm・20℃・90％RH
酸素透過度は、呼吸作用による酸素濃度の低下
を外部空気の透過侵入によつて補い、生理作用を
持続させるうえで極めて重要な特性であり、該透
過度が3000c.c.／m2・24hr・atm・20℃・90％RH
未満の場合は特に呼吸作用の著しい（酸素消費量
の多い）青果物を包装したときの内部酸素量が欠
乏し、窒息状態となつて十分な鮮度保持効果が発
揮されない。一方35000c.c.／m2・24hr・atm・20
℃・90％RHを超えた場合、酸素欠乏現象を生じ
る恐れはないが、外部からの細菌類の侵入により
かび等が生ずる青果物の場合は、鮮度保持効果が
かえつて低下する。
酸素透過度のより好ましい範囲は4000〜20000
c.c.／m2・24hr・atm・20℃・90％RHである。
炭酸ガス透過度：12000〜130000c.c.／m2・
24hr・atm・20℃・90％RH
炭酸ガス透過度は、包装袋内のガス組成を適正
に保ち、青果物の呼吸作用を保証すると共に炭酸
ガス障害を回避し、更には菌体の侵入・繁殖によ
る腐敗を防止するうえでも有効な特性であり、該
透過度が12000c.c.／m2・24hr・atm・20℃・90％
RH未満では包装袋内の炭酸ガス濃度が高くなり
過ぎて青果物の呼吸作用が阻害され、鮮度及び味
覚が急速に低下してくる。
一方130000c.c.／m2・24hr・atm・20℃・90％
RHを超えると、包装袋内部のCO2濃度が低くな
りすぎて腐敗防止効果及び劣化抑制効果が有効に
発揮されなくなる。
炭酸ガス透過度のより好ましい範囲は15000〜
100000c.c.／m2・24hr・atm・20℃・90％RHであ
る。
更に本発明で使用する複層フイルムにおける青
果物に接する側の表面層には保存乃至流通期間中
防曇性を示す様な防曇剤を含むものでなければな
らない。即ち本発明では、包装袋内面の曇り現象
を防止して商品価値を高めるばかりでなく、曇り
の進行によつて形成される水滴による内容物の水
腐れを防止するうえでも防曇作用は極めて重要な
特性であり、且つ流通過程で長期的に優れた防曇
性を持続させる為には、保存乃至流通時の気温変
化を考慮して、０40℃の間で温度変化を繰り返
す経過中継続して防曇性を示す様な防曇剤が表面
層に存在するものでなければならない。本発明は
前述の如く収穫後も激しい生理作用を持続する青
果物を包装対象とするものであり、冷凍保存より
もむしろ室温雰囲気での保存が望まれるが、冬季
の室内外の温度差等を考慮すると、本発明におけ
る防曇特性の設定に当たつては、たとえば後述す
る方法によつて求められる、「０40℃の間で温
度変化を繰り返したときの防曇持続性」により定
めるのがよく、本発明では下記の測定法で１日以
上防曇性を持続するものであることが望まれる。
（防曇性評価方法）
200c.c.ビーカーに150c.c.の40℃温水を入れ、試料
の防曇面を内側にしてビーカーにかぶせる。その
後、6Hr、０℃に保ち、次に40℃に6Hrに保つ。
この温度変化を２回繰り返し（合計24時間）、フ
イルム面を通して容器内容物が明瞭に観察できる
か否かによつて判定する。
表層部に存在させる防曇剤の種類は特に限定さ
れるものではなく、従来から知られた防曇剤の
他、帯電防止剤や活性剤の如く防曇特性を発揮し
得るすべてのものを使用することができ、必要に
よつては２種以上を併用することもできる。これ
らの防曇剤は表面層構成材中に直接混入し得る
他、基層構成材中にのみ混入させておき、積層後
表面層へ拡散移行させることによつて表面層に防
曇性を与えることも可能である。表面層における
防曇剤の存在量は、防曇剤の種類によつても変わ
つてくるので一律に規定することは適当でない
が、好ましいのは0.3〜３重量％の範囲である。
しかして0.3重量％未満では防曇性能が不十分で
ある為本発明の要求特性が満たされ難く、一方３
重量％を超える場合は表面層が白化現象を生じて
透明性が低下するばかりでなく、青果物の蒸散に
よつて袋の内面に付着した水分が白濁現象を起こ
し、商品価値が著しく低下するという問題も生じ
てくる。
尚製袋前のフイルムの状態では防曇性を評価す
る簡便法として表面層の表面張力で評価すること
も可能であり、本発明者らが確認したところによ
ると、該表面張力が38ダイン／cm以上となる様に
防曇剤の存在量を調整することによつて、目的に
かなう防曇持続性を確認し得ることが明らかとな
つた。
次に本発明で使用する包装袋は、上記の複層フ
イルムの防曇剤を含む層が内側となる様に重ね合
わせて３方を溶断シールするか、あるいは折り曲
げ辺と直交する２辺を溶断シールする、等の手段
で少なくとも３方の閉じられた袋状に作製される
ものであり、青果物の充填時或は流通時等にシー
ル部が剥離して開封される現象を阻止し得るに足
るシール強度を有するものでなければならず、
270℃で溶断シールしたときの溶断シール強度が
3.0Kg−cm／15mm以上が必要であり、該溶断シー
ル強度が不足する場合は、青果物の充填時或は取
扱い時にシール部が剥離する恐れがある。尚溶断
シール温度は現在実用化されている一般的な溶断
シール温度を基準にして定めたが、上記溶断シー
ル条件のもとで上記設定値以上の溶断シール強度
を示し得るものである限り、前述の範囲を外れる
溶断シール温度を採用することを排除するもので
はない。
以上の様な諸特性を有する複層フイルムは、
夫々の要求特性に合致し得る合成樹脂の共押出し
あるいはインラインラミネート法等によつて製造
することができるが、前述の要求特性との関係を
考慮して最も好ましい基層構成材及び表面層構成
材について説明すると次の通りである。
まず基層は、フイルムに要求される最低限の機
械的強度を確保すると共に、水蒸気、酸素及び炭
酸ガスの各透過性にも最も大きい影響を及ぼすも
のであり、次の様な素材を使用することによつて
前述の目的にかなう基層を得ることができる。即
ち基層構成材としては、炭素数が２〜10である
α−オレフイン系の共重合体の１種以上と、酢
酸ビニル、アクリル酸及びスチレンよりなる１種
以上のモノマー単位が全構成々分中の５〜80重量
％を占める共重合体の１種以上、との混合物で、
且つその混合比率が前者：30〜90重量％、後者
：10〜70重量％である混合物が好ましい。上記
を構成する炭素数２〜10のα−オレフインの具
体例としてはエチレン、プロピレン、ブテン、ヘ
キセン、ヘプテン等が挙げられるが、より一般的
なのはエチレン、プロピレン、ブテンである。上
記α−オレフインの２種以上のランダム共重合体
あるいはブロツク共重合体を使用すると、前記透
過度のすべてを満たす基層が一層容易に得られ
る。この場合の共重合比は、組合されるα−オレ
フインの種類に応じて任意に決定すればよい。ま
た上記を構成する共重合体としては、酢酸ビニ
ル、アクリル酸及びスチレンよりなるモノマー単
位を該共重合体全構成々分中に５〜80重量％含有
する共重合体が好ましく、これらのモノマーと組
合されるモノマーとしては共重合可能なモノマー
であればよいが、特に好ましいのはエチレン、
プロピレン等のα−オレフイン、アクリル酸エ
ステル、メタクリル酸エステルあるいはブタジ
エン等である。該共重合体中に占める酢酸ビニ
ル、アクリル酸及びスチレンよりなるモノマー単
位の重量が５％未満あるいは80％超である場合
は、前記各透過度のすべてを満足することが困難
になる他、80％超の場合は基層フイルムのヘイズ
が悪化する傾向が見られ、また溶断シール性の低
下あるいは溶断部にひげ状物ができる等の難点が
生じ易くなる。
上記及びの混合比率は前者30〜90重量％に
対して後者10〜70重量％の範囲とするのがよく、
この様な配合率範囲を特定することによつて、強
度等の機械的特性はもとより透明性や溶断シール
性及び前記各透過度のすべてにおいてバランスの
とれた性能を確保することができる。ちなみに
共重合体の配合率が30重量％未満である場合は、
基層フイルムの透明度が低くなる。一方共重合
体が90重量％を超える場合は、ガス透過性能を本
発明で規定する範囲に収め難くなる。たとえば、
酸素透過度及び炭酸ガス透過度が前記設定範囲に
入つたとしても水蒸気透過度が設定範囲から外れ
るといつた問題が生じ、その場合青果物の生理作
用に好適な包装雰囲気が得られ難くなる。
尚上記、を配合するに当たつては、230℃
における該配合物のメルトインデツクスが１〜
100／10min、より好ましくは２〜50g／10minと
なる様に上記、の配合物の選定するのが好ま
しい。
次に表面層構成材は、防曇剤の存在によつて長
期に亘り優れた防曇性を持続し得る特性が要求さ
れる他、優れた溶断シール性を有することが必要
であり、こうした要求を満たす為の表面層構成材
としては、炭素数が２〜10であるα−オレフイン
系モノマー（エチレン、プロピレン、ブテン、ペ
ンテン、ヘキセン、オクテン、デセン等）から選
ばれる２種以上によつて得られるランダム共重合
体もしくはブロツク共重合体が好ましく、この共
重合体は単独或は混合して使用される。溶断シー
ル性を高めるうえで特に好ましい表面層構成材
は、融点が80〜150℃のα−オレフイン単独重合
体、共重合体またはそれらの２種または３種以上
の混合物を主成分とする重合体である。該表面層
構成フイルム中に防曇剤を存在させる方法として
は、該表面層構成材自体の中に防曇剤を混入させ
ておく方法の他、基層フイルム中に適量の防曇剤
を含有させておき、積層後の拡散によつて表面層
構成フイルム中に防曇剤を移行させる方法を採用
することもできる。この場合、基層フイルム内へ
混入させる防曇剤の量は0.3〜３重量％、より好
ましくは0.4〜2.2重量％が好適であり、0.3重量％
未満では表面層フイルム方向への拡散移行量が不
十分となる為表面層に十分な防曇性能を与えるこ
とができず、一方３重量％を超えると、表面層部
側の防曇性は十分に高められるものの、表面層フ
イルムが白化現象を生じて商品価値が劣悪にな
る。ところが基層フイルム中に0.3〜３重量％の
防曇剤を含有させておいて表面層フイルムと積層
すると、基層フイルム中の防曇剤が表面層フイル
ム方向へ徐々に拡散移行していく結果、長期間に
亘つて良好な防曇特性を持続することとなる。
前述の基層構成材及び表面層構成材から複合フ
イルムを成形する為の手段は特に限定されず、共
押出し法やインラインラミネート法の如き周知の
方法によつて行なわれることは先に述べた通りで
あり、また基層及び表面層の肉厚も格別の制約は
ないが、経済性や物性等を加味して最も一般的な
のは、基層：４〜200μm程度、表面層：0.3〜
8μm程度である。また基層と表面層（両外面が表
面層であるときはその合計厚み）との厚み比は
99.5〜60：0.5〜40とするのが一般的である。尚
本発明フイルムの最も基本的な複合形態は、表面
層と基層を１層ずつ積層した形態のものである
が、この基層の両面に表面層を積層して両面に防
曇性とヒートシール性を持たせたり、或は基層の
片側（表面層積層面とは反対側、但し両表面層に
防曇性やヒートシール性をもたせている場合は該
表面層のうちいずれか一方）に印刷等の加工を施
すことも勿論可能であり、これらはすべて本発明
の技術的範囲に含まれる。
また基層及び表面層を構成するフイルム中には
更に必要に応じて滑剤、アンチブロツキング剤、
酸化防止剤、紫外線吸収剤、着色剤、帯電防止剤
等を配合することもでき、更に該複層フイルムは
所望により１軸延伸若しくは２軸延伸を施して物
性を改善することもできる。
この様にして得られる複層フイルムで包装袋を
作製し、生理作用の激しい青果物を装入して密封
した場合、先に述べた様に該フイルムのガス透過
性能だけでは、青果物の激しい生理作用に基づく
湿度の増大およびガス組成の変化に十分対応する
ことができず、温度の急変等により内部の水蒸気
が結露して袋底部に水がたまり、水腐れを起こす
ことがある。
そこで本発明では、結露水による障害を防止す
る為、包装袋の底辺に適当な大きさの切欠き孔を
形成することとしている。この切欠き孔は、前述
の如く特に袋内で生ずることのある結露水をすみ
やかに包装袋外へ漏出させることにより、青果物
の水腐れを防止しようとするものであるが、同時
に複層フイルムの有する前述の様なガス透過性能
だけでは追従することのできない袋内ガスの変動
に対し、内外の換気を促進することにより適正な
生理環境を保持する機能も果たすものであり、そ
の大きさは切欠き孔１個の切欠き長さを４〜100
mmの範囲のものとし、これを包装袋の底辺に１〜
数個（好ましくは６個程度まで）設ける必要があ
る。該切欠き孔の切欠き長さが４mm未満では、結
露水の外部への流出が不十分となるばかりでなく
内外気の相互拡散による換気効果も有効に発揮さ
れず、青果物の水腐れ防止及び鮮度保持の各効果
が十分に発揮されない。一方100mmを超える場合
も、例えば外気が乾燥状態のときに袋外部への水
分の蒸散が著しくなつて青果物が萎凋、黄変を起
こし易くなるばかりでなく、細菌の侵入によりカ
ビ等が発生し易くなり、更には青果物の装入時あ
るいは搬送中に袋が破れ易くなる。
尚該切欠き孔の大きさや数は、包装袋底辺部の
強度の点からも制限を設ける必要がある。即ちこ
の切欠き孔は包装袋の底辺部に設けられるもので
あり、該切欠き孔を設けた分だけ一辺当たりの強
度は低下してくる。従つて実用上差し支えのない
程度の底辺強度を確保するためには、底辺長さの
うち50％以上が密封面として残されるように切欠
き孔の大きさ及び数を制限する必要がある。尚底
辺が折り畳み縁で形成されるときには強度面の余
裕があるので切欠き長さをもう少し増加しても良
く、密封面として残す長さは40％位で良い。
上記の要件を満たす様に切欠き孔の大きさや数
を特定することによつて、包装用袋としての本来
の機能を損なうことなく、青果物の激しい生理作
用や外気温度の急変による結露水の発生を見た場
合でも該結露水をすみやかに外部へ流出させるこ
とができ、青果物の保存安定性を一段と高めるこ
とができる。
次に実施例を挙げて本発明を一層明確にする
が、本発明はもとより下記の実施例によつて制限
を受けるものではない。尚下記実施例において
「％」とあるのは特記しない限り「重量％」を意
味する。
また本発明で規定される水蒸気、酸素及び炭酸
ガスの各透過度の測定法は、夫々下記の通りとし
た。
水蒸気透過度：
JIS−Ｚ−0208のＢ法で定める防湿包装材料
の透湿度試験法に準拠して測定。
酸素透過度及び炭酸ガス透過度：
JIS−Ｚ−1707で定める「食品用プラスチツ
クフイルムの試験法」中、気体透過度の試験法
に準拠して測定。但し各気体については標準温
度に換算せず20℃における体積とし、且つ24時
間当たりの透過量として求めた。
［実施例］
実施例 １
エチレン・プロピレン共重合体（エチレン含有
量：５％）と、酢酸ビニル含有量が28％であるエ
チレン・酢酸ビニル共重合体とを、前者65％、後
者35％の比率で混合してなる基層構成材と、プロ
ピレン・ブテン−１共重合体（ブテン−１含有
量：18％）とブテン・エチレン共重合体（エチレ
ン含有量：3.5％）とを１：１の重量比率で配合
してなる混合組成物からなる表面層構成材（但し
該表面層構成材中には防曇剤として６％の高級脂
肪酸エステルモノグリセライドを混入させた）を
使用し、共押出し法によつて、基層の両面に表面
層の積層された複層フイルムを作製し（押出温
度：260℃、冷却：20℃）、引き続いて縦延伸倍率
３倍、横延伸倍率８倍の２軸延伸を施し、更に両
面にコロナ放電処理を行なつて、基層16μm、表
面層2μm×２（両面）の合計20μmの３層フイルム
を得た。このフイルムの片面(A)側の表面張力は42
ダイン／cm、他方面(B)側の表面張力は38ダイン／
cmであつた。該複層フイルムの諸特性を第１表に
示す。
[Industrial Application Field] The present invention is directed to the use of vegetables, root vegetables, fruits, flowers, flowering plants, mushrooms, etc. (hereinafter referred to as fruits and vegetables in a broad sense in this specification), which have strong physiological effects even after harvest. This invention relates to a method for increasing the commercial value of fruits and vegetables by increasing the freshness retention effect during storage. [Conventional technology] In recent years, many fruits and vegetables such as fresh vegetables, fruits, fresh flowers, and mushrooms have been transitioned from open-field cultivation to planned multiplex and diversified cultivation using horticultural facility cultivation. It is often necessary to harvest and package large quantities of fruits and vegetables within a country. In addition, since the harvest period for fruits and vegetables that are mainly grown in open fields is fixed, a large amount of the harvest must be packaged and shipped within a short period of time. The biggest problem in the distribution process up to the point of crossing the border is how best to maintain freshness at the time of harvest. In order to meet these demands, research is actively underway to improve packaging bags with a focus on preserving freshness, and the present applicant has also proposed several improved packaging films and packaging bags. By the way, fruits and vegetables such as those mentioned above do not immediately lose their physiological effects after being harvested, but especially for a while after being harvested, they continue to maintain their physiological effects to the extent that they are almost the same as before harvest. Furthermore, if they are kept under appropriate storage conditions, their physiological effects will continue for a longer period of time, and as long as they maintain their physiological effects, fruits and vegetables will maintain good freshness. In other words, if it is not stored in a good condition, it will lose its sustained physiological function and will deteriorate prematurely. It is known that the physiological effects of fruits and vegetables in a packaged state include a decrease in moisture due to transpiration, consumption of atmospheric oxygen and generation of carbon dioxide due to respiration, and temperature rise due to generation of carbon dioxide and heat generation. As the oxygen concentration decreases, the carbon dioxide concentration increases, and since heat is not dissipated, the internal temperature of the package rises. The respiration process becomes more active above a certain temperature, and at high temperatures it becomes more susceptible to decomposition due to the stuffiness phenomenon. In addition, the transpiration effect becomes greater in an atmosphere of high temperature or low humidity, and as a result, it becomes more likely to rot in the high temperature and high humidity environment. Therefore, in order to improve the freshness retention effect during storage by taking into account the physiological effects mentioned above, ventilation is improved by making holes of an appropriate size in the packaging bag or cutting the bottom of the bag. Attempts have been made to increase the temperature, prevent a decrease in oxygen concentration, prevent an increase in carbon dioxide concentration, and suppress temperature rise. However, these are only temporary measures, and do not necessarily equalize the temperature distribution and gas composition inside the packaging bag, leading to localized decay, especially in areas that cannot be seen from the outside. This can have the unintended consequence of deceiving consumers. Moreover, in the packaging bags for fruits and vegetables that use packaging films that are currently in practical use, the moisture produced by the transpiration of fruits and vegetables or the evaporation of adhering moisture adheres to the inner surface of the packaging bag, causing cloudiness and clouding of the contents. In addition to the problem that things become difficult to see from the outside, there is also the problem that when fruits and vegetables come into direct contact with moisture condensed in the cloudy area, so-called water rot occurs. From this point of view, it is possible to maintain the conditions inside the bag at a temperature and gas composition suitable for the physiological effects of fruits and vegetables, and to exhibit excellent antifogging properties, without having to make holes or cut the bag. Although it has been desired to develop a packaging film that is suitable for packaging fruits and vegetables that have strong physiological effects, it has not yet been developed. For example, although polyethylene film has a moderate water vapor permeability, it lacks oxygen and carbon dioxide gas permeability, which causes fruit and vegetables to suffocate during short-term storage, resulting in loss of freshness. Although the respiration effect of fruits and vegetables can be maintained for a long period of time due to their permeability to oxygen and carbon dioxide, the water vapor permeability is too high and the evaporation effect of water becomes significant, causing discoloration or wilting of fruits and vegetables in a short period of time. However, it is not possible to maintain good freshness over a long period of time. Moreover, all of the above-mentioned films have poor antifogging properties, which not only lowers the commercial value in terms of appearance, but also causes so-called water rot when fruits and vegetables come into direct contact with moisture condensed in the cloudy areas. [Problems to be Solved by the Invention] The present inventors have focused on the above-mentioned circumstances, and have developed a packaging bag that has water vapor permeability, oxygen and carbon dioxide properties that are suitable for the physiological effects of fruits and vegetables without opening or cutting the packaging bag. We conducted research to develop a multilayer film that exhibits gas permeability of 100% and does not cause clouding on the inner surface. As a result, if the water vapor permeability, oxygen permeability, and carbon dioxide permeability of the multilayer film are specified within appropriate ranges, and an appropriate amount of antifogging agent is blended into the multilayer film constituent materials, it is possible to solve the above problems. After confirming that the problem had been resolved, we filed a patent application based on this knowledge. However, as further research progressed, the following facts became clear. That is, when using a bag made of the multilayer film according to the prior invention,
The purpose of preserving freshness is effectively achieved for fruits and vegetables that have relatively mild physiological effects after harvest, but fruits and vegetables that have strong physiological effects even after harvest (e.g. yellow cucumber, edamame, enokidake, kidney beans, etc.) When applied to packaging, it was often experienced that the internal humidity could not be maintained properly. In particular, if there is a sudden change in temperature between day and night or when the fruit is put in and taken out of the refrigerator, the water vapor inside the bag that is generated by the transpiration of fruits and vegetables will condense and accumulate in the packaging bag, causing the fruit and vegetables to deteriorate. It has become clear that this causes problems such as water rot. Moreover, in the case of fruits and vegetables that have a significant respiration effect, the oxygen concentration and carbon dioxide concentration within the packaging bag will fluctuate significantly, so when the multilayer film according to the prior invention is used, it is possible to prevent these rapid concentration changes. In some cases, it is difficult to sufficiently follow the conditions, and it becomes impossible to maintain a gas atmosphere suitable for the intense physiological effects of the fruits and vegetables, resulting in insufficient freshness-keeping effects. The present invention was developed as a result of further research focusing on these problems, and its purpose is to prevent the packaging material from being exposed to rapid temperature changes even when applied to the packaging of fruits and vegetables that have strong physiological effects. To provide a method that does not cause the problem of water rot due to condensed water even if the fruit and vegetables are exposed to water, maintains an atmosphere suitable for the physiological functions of fruits and vegetables inside, and maintains the freshness of fruits and vegetables for a long time when they are harvested. That is. [Means for solving the problems] The configuration of the method of the present invention specified as requirements for achieving the above objectives is as follows: water vapor permeability is 15 to 200g/ m2・24hr・40℃, oxygen permeability is 3000～35000c.c./m 2・24hr・
ATM・20℃・90%RH、Carbon dioxide permeability 12000~130000c.c./ m2・
24 hours, ATM, 20℃, 90%RH, and an antifogging agent is present in the surface layer of at least one side, and the surface layer exhibits antifogging properties during repeated temperature changes between 040℃ and Using a multilayer film that exhibits a sealing strength of 3.0 Kg-cm/15 mm or more when melt-cut and sealed at 270°C, formed into a bag shape with at least three sides closed so that the surface layer is on the inside, and The sealed bottom of the bag has a notch hole with a notch length of 4 to 100 mm per piece (the length of the notched part when cut out on a flat surface: the same applies hereinafter) to 50 mm of the bottom length. The gist of this method is to preserve the freshness of fruits and vegetables by packaging them using a packaging bag with at least one opening so that more than % of the surface remains sealed. [Function] The multilayer film constituting the packaging bag used in the present invention first specifies water vapor permeability, oxygen permeability, and carbon dioxide gas permeability as the first condition, and also Since it is characterized by the presence of an antifogging agent, the reasons for determining each of the above characteristics will be explained below. Water vapor permeability: 15 to 200g/m 2 , 24hr, 40℃ Water vapor permeability is determined by keeping the humidity within the bag appropriate due to the moisture released by evaporation and transpiration of the moisture attached to fruits and vegetables, and preventing stuffiness due to excessive humidity. It is an important characteristic in preventing the phenomenon of rot and suppressing rot, as well as in preventing fruits and vegetables from wilting, discoloration (yellowing or browning), softening, loss of elasticity, etc. due to lack of humidity.
If the water vapor permeability is less than 15g/ m2 , 24hr, 40℃, fruits and vegetables are likely to rot due to swelling caused by excessive humidity, while if it exceeds 200g/ m2 , 24hr, 40℃, there may be insufficient humidity inside the packaging bag. Fruits and vegetables tend to wilt, change color, etc., and in either case, a satisfactory freshness-keeping effect cannot be obtained. In order to ensure a good freshness-keeping effect, the more preferable water vapor permeability is in the range of 20 to 150 g/m 2 24 hr 40°C. Oxygen permeability: 3000-35000c.c./m2・24hr・
ATM・20℃・90%RH Oxygen permeability is an extremely important characteristic for sustaining physiological effects by compensating for the decrease in oxygen concentration due to respiration by permeation of external air. .c.／ m2・24hr・atm・20℃・90%RH
If the amount is less than 100%, the amount of internal oxygen will be insufficient when packaging fruits and vegetables, which have a significant respiration effect (high oxygen consumption), resulting in suffocation, and a sufficient freshness-keeping effect will not be exhibited. On the other hand, 35000c.c./m 2・24hr・atm・20
If the temperature exceeds 90% ℃ and 90% RH, there is no risk of oxygen deficiency, but in the case of fruits and vegetables that develop mold due to the invasion of bacteria from the outside, the freshness-keeping effect will actually decrease. A more preferable range of oxygen permeability is 4000 to 20000
cc/ m2・24hr・atm・20℃・90%RH. Carbon dioxide permeability: 12000-130000c.c./m2・
24hr/ATM/20℃/90%RH Carbon dioxide gas permeability maintains the appropriate gas composition within the packaging bag, guarantees the respiration of fruits and vegetables, avoids carbon dioxide damage, and prevents bacterial invasion and proliferation. This property is also effective in preventing spoilage due to the permeability of 12000c.c./m2 , 24hr, ATM, 20℃, 90%.
If the RH is less than RH, the carbon dioxide concentration in the packaging bag becomes too high, which inhibits the respiration of fruits and vegetables, leading to a rapid decline in freshness and taste. On the other hand, 130000c.c./m 2 , 24hr, atm, 20℃, 90%
When the RH is exceeded, the CO 2 concentration inside the packaging bag becomes too low, and the anti-corrosion and deterioration suppressing effects are no longer effectively exhibited. A more preferable range of carbon dioxide permeability is 15,000~
100000c.c./m2・24hr・ATM・20℃・90%RH. Furthermore, the surface layer of the multilayer film used in the present invention on the side that comes into contact with fruits and vegetables must contain an antifogging agent that exhibits antifogging properties during storage and distribution. That is, in the present invention, the antifogging effect is extremely important not only to prevent the inner surface of the packaging bag from becoming cloudy and thereby increasing the product value, but also to prevent the contents from being spoiled by water droplets that are formed as clouding progresses. In addition, in order to maintain excellent anti-fogging properties over the long term during the distribution process, it is necessary to take into account temperature changes during storage and distribution, and to continue to maintain the temperature during storage and distribution. An antifogging agent that exhibits antifogging properties must be present in the surface layer. As mentioned above, the present invention is intended for packaging fruits and vegetables that continue to have strong physiological effects even after harvest, and it is preferable to store them at room temperature rather than freezing them, but it is important to take into account the temperature difference between indoors and outdoors in winter. Therefore, when setting the antifogging property in the present invention, it is preferable to determine it based on "antifogging durability when the temperature is repeatedly changed between 040°C", which is determined by the method described below, for example. In the present invention, it is desired that the antifogging property be maintained for one day or more as measured by the following measurement method. (Anti-fog property evaluation method) Fill a 200 c.c. beaker with 150 c.c. of 40°C warm water, and place the sample over the beaker with the anti-fog side facing inside. After that, it was kept at 0℃ for 6 hours, and then kept at 40℃ for 6 hours.
This temperature change is repeated twice (total of 24 hours), and judgment is made based on whether the contents of the container can be clearly observed through the film surface. The type of antifogging agent to be present in the surface layer is not particularly limited, and in addition to conventionally known antifogging agents, all substances that can exhibit antifogging properties such as antistatic agents and activators can be used. If necessary, two or more types can be used in combination. These antifogging agents can be directly mixed into the surface layer constituent materials, or they can be mixed only into the base layer constituent materials and diffused and transferred to the surface layer after lamination, thereby imparting antifogging properties to the surface layer. is also possible. The amount of antifogging agent present in the surface layer varies depending on the type of antifogging agent, so it is not appropriate to specify it uniformly, but it is preferably in the range of 0.3 to 3% by weight.
However, if it is less than 0.3% by weight, the antifogging performance will be insufficient, making it difficult to satisfy the required characteristics of the present invention;
If it exceeds % by weight, not only will the surface layer become white and the transparency will decrease, but also the water that adheres to the inner surface of the bag due to evaporation of fruits and vegetables will cause cloudiness, which will significantly reduce the product value. will also occur. In addition, it is also possible to evaluate the antifogging property of the film in its state before bag making by the surface tension of the surface layer as a simple method, and the present inventors have confirmed that the surface tension is 38 dynes/ It has become clear that by adjusting the amount of antifogging agent present so that it is at least cm, it is possible to confirm antifogging durability that meets the objective. Next, the packaging bag used in the present invention is made by stacking the above-mentioned multilayer film so that the layer containing the antifogging agent is on the inside and melt-sealing it on three sides, or by melt-sealing two sides perpendicular to the folded side. The bag is made into a bag shape with at least three sides closed by means such as sealing, and is sufficient to prevent the seal from peeling off and being opened during filling or distribution of fruits and vegetables. Must have sealing strength,
The strength of the fusing seal when fusing and sealing at 270℃ is
3.0Kg-cm/15mm or more is required, and if the strength of the fusing seal is insufficient, there is a risk that the seal portion will peel off during filling or handling of fruits and vegetables. The fusing seal temperature was determined based on the general fusing sealing temperature currently in practical use, but as long as it can exhibit fusing sealing strength equal to or higher than the above set value under the above fusing sealing conditions, This does not preclude the adoption of a fusing seal temperature outside the range of . Multilayer films with the above characteristics are
Although they can be manufactured by coextrusion of synthetic resins that meet the respective required characteristics, in-line lamination method, etc., the most preferable base layer constituent materials and surface layer constituent materials are given in consideration of the relationship with the above-mentioned required properties. The explanation is as follows. First, the base layer not only ensures the minimum mechanical strength required for the film, but also has the greatest effect on the permeability of water vapor, oxygen, and carbon dioxide, and should be made of the following materials: A base layer can be obtained which fulfills the above-mentioned purpose. That is, the base layer constituent materials include one or more α-olefin copolymers having 2 to 10 carbon atoms and one or more monomer units consisting of vinyl acetate, acrylic acid, and styrene. A mixture with one or more copolymers accounting for 5 to 80% by weight of
Preferably, the mixture ratio is 30 to 90% by weight for the former and 10 to 70% by weight for the latter. Specific examples of the above-mentioned α-olefin having 2 to 10 carbon atoms include ethylene, propylene, butene, hexene, heptene, etc., but ethylene, propylene, and butene are more common. When a random copolymer or block copolymer of two or more of the above α-olefins is used, a base layer satisfying all of the above permeability values can be obtained more easily. The copolymerization ratio in this case may be arbitrarily determined depending on the type of α-olefin to be combined. In addition, the copolymer constituting the above is preferably a copolymer containing 5 to 80% by weight of monomer units consisting of vinyl acetate, acrylic acid, and styrene in the total components of the copolymer, and these monomers and The monomers to be combined may be any copolymerizable monomers, but particularly preferred are ethylene,
These include α-olefins such as propylene, acrylic esters, methacrylic esters, and butadiene. If the weight of the monomer units consisting of vinyl acetate, acrylic acid, and styrene in the copolymer is less than 5% or more than 80%, it will be difficult to satisfy all of the above-mentioned permeability requirements. If it exceeds %, the haze of the base film tends to deteriorate, and problems such as a decrease in the sealing properties of the weld and the formation of whiskers at the weld are likely to occur. The mixing ratio of the above and above is preferably in the range of 30 to 90% by weight of the former and 10 to 70% by weight of the latter,
By specifying such a blending ratio range, it is possible to ensure well-balanced performance in all of the mechanical properties such as strength, transparency, fusing sealability, and each of the above-mentioned permeability. By the way, if the blending ratio of the copolymer is less than 30% by weight,
The transparency of the base film becomes low. On the other hand, if the copolymer content exceeds 90% by weight, it becomes difficult to keep the gas permeation performance within the range defined by the present invention. for example,
Even if the oxygen permeability and carbon dioxide gas permeability fall within the set ranges, problems may occur if the water vapor permeability falls outside of the set ranges, in which case it becomes difficult to obtain a packaging atmosphere suitable for the physiological effects of fruits and vegetables. In addition, when blending the above, 230℃
The melt index of the formulation in
It is preferable to select the above formulation so that the yield is 100 g/10 min, more preferably 2 to 50 g/10 min. Next, the surface layer constituent material is required to have properties that can maintain excellent antifogging properties over a long period of time due to the presence of an antifogging agent, and it is also necessary to have excellent melt sealing properties. The surface layer constituent material to meet the requirements can be obtained by using two or more types selected from α-olefin monomers having 2 to 10 carbon atoms (ethylene, propylene, butene, pentene, hexene, octene, decene, etc.). Random copolymers or block copolymers are preferred, and these copolymers may be used alone or in combination. A particularly preferable surface layer constituent material in order to improve the melt sealing property is a polymer whose main component is an α-olefin homopolymer, copolymer, or a mixture of two or more thereof with a melting point of 80 to 150°C. It is. Methods for making the antifogging agent present in the surface layer constituent film include a method in which the antifogging agent is mixed into the surface layer constituent material itself, and a method in which an appropriate amount of the antifogging agent is included in the base layer film. It is also possible to adopt a method in which the antifogging agent is transferred into the film constituting the surface layer by diffusion after lamination. In this case, the amount of antifogging agent mixed into the base film is preferably 0.3 to 3% by weight, more preferably 0.4 to 2.2% by weight, and 0.3% by weight.
If it is less than 3% by weight, the amount of diffusion and transfer in the direction of the surface layer film will be insufficient, making it impossible to provide sufficient antifogging performance to the surface layer.On the other hand, if it exceeds 3% by weight, the antifogging property of the surface layer side will be insufficient. However, the surface layer film undergoes a whitening phenomenon, resulting in poor commercial value. However, when the base layer film contains 0.3 to 3% by weight of an antifogging agent and is laminated with the surface layer film, the antifogging agent in the base layer film gradually diffuses and migrates toward the surface layer film, resulting in a long Good anti-fogging properties will be maintained over a period of time. The means for forming the composite film from the base layer constituent material and the surface layer constituent material is not particularly limited, and as mentioned above, it may be carried out by a well-known method such as coextrusion method or in-line lamination method. There are also no particular restrictions on the thickness of the base layer and surface layer, but the most common ones considering economic efficiency and physical properties are: base layer: about 4 to 200 μm, surface layer: about 0.3 to 200 μm.
It is about 8 μm. Also, the thickness ratio between the base layer and the surface layer (total thickness when both outer surfaces are surface layers) is
99.5-60: 0.5-40 is common. The most basic composite form of the film of the present invention is one in which a surface layer and a base layer are laminated, but surface layers are laminated on both sides of this base layer to provide antifogging and heat sealing properties on both sides. or printing on one side of the base layer (the side opposite to the surface layer laminated surface, however, if both surface layers have antifogging properties or heat sealing properties, one of the surface layers) Of course, it is also possible to perform processing, and all of these are included in the technical scope of the present invention. In addition, the films constituting the base layer and the surface layer may contain lubricants, anti-blocking agents, etc. as necessary.
Antioxidants, ultraviolet absorbers, colorants, antistatic agents, etc. can also be added, and if desired, the multilayer film can be uniaxially or biaxially stretched to improve its physical properties. When a packaging bag is made using the multilayer film obtained in this way, and fruits and vegetables with strong physiological effects are charged and sealed, the gas permeation performance of the film alone is not sufficient, as mentioned above. It is not possible to sufficiently respond to increases in humidity and changes in gas composition due to the temperature change, and water vapor inside the bag may condense due to sudden changes in temperature, causing water to accumulate at the bottom of the bag and causing water rot. Therefore, in the present invention, in order to prevent problems caused by condensed water, a notch hole of an appropriate size is formed at the bottom of the packaging bag. As mentioned above, this notch hole is intended to prevent water spoilage of fruits and vegetables by promptly leaking condensed water that may occur inside the bag to the outside of the packaging bag, but at the same time, the purpose of this notch is to prevent water rot of fruits and vegetables. It also functions to maintain an appropriate physiological environment by promoting ventilation inside and outside the bag against fluctuations in the gas inside the bag that cannot be followed by the aforementioned gas permeability alone. The notch length of one notch hole is 4 to 100.
mm range, and place this on the bottom of the packaging bag.
It is necessary to provide several (preferably up to about 6). If the notch length of the notch hole is less than 4 mm, not only will the condensed water not flow out to the outside sufficiently, but also the ventilation effect due to mutual diffusion of inside and outside air will not be effective, which will prevent fruit and vegetables from water rot. Each effect of maintaining freshness is not fully exhibited. On the other hand, if the diameter exceeds 100 mm, for example, when the outside air is dry, moisture evaporates to the outside of the bag, which not only makes fruits and vegetables more likely to wilt and yellow, but also makes it easier for bacteria to invade and cause mold, etc. Furthermore, the bag becomes more likely to tear during loading or transporting fruits and vegetables. The size and number of the notched holes must be limited also from the viewpoint of the strength of the bottom of the packaging bag. That is, this notch hole is provided at the bottom of the packaging bag, and the strength per side is reduced by the amount of the notch hole provided. Therefore, in order to ensure a base strength that is acceptable for practical use, it is necessary to limit the size and number of the notched holes so that 50% or more of the base length remains as a sealing surface. Note that when the bottom side is formed by a folded edge, there is a margin in terms of strength, so the length of the notch may be increased a little more, and the length left as a sealing surface may be about 40%. By specifying the size and number of notch holes to meet the above requirements, we can prevent condensation from occurring due to the intense physiological effects of fruits and vegetables or sudden changes in outside temperature, without impairing the original function of the packaging bag. Even if the fruit or vegetables are exposed, the condensed water can be quickly drained to the outside, and the storage stability of fruits and vegetables can be further improved. Next, examples will be given to further clarify the present invention, but the present invention is not limited by the following examples. In the following examples, "%" means "% by weight" unless otherwise specified. The methods for measuring the permeability of water vapor, oxygen, and carbon dioxide defined in the present invention were as follows. Water vapor permeability: Measured in accordance with the moisture permeability test method for moisture-proof packaging materials specified by JIS-Z-0208 Method B. Oxygen permeability and carbon dioxide permeability: Measured according to the gas permeability test method in the "Test method for food-use plastic films" specified in JIS-Z-1707. However, each gas was not converted to standard temperature, but was calculated as the volume at 20°C, and as the amount of permeation per 24 hours. [Example] Example 1 An ethylene/propylene copolymer (ethylene content: 5%) and an ethylene/vinyl acetate copolymer with a vinyl acetate content of 28% were mixed into 65% of the former and 35% of the latter. The base layer constituent material is mixed in a ratio of 1:1 with propylene/butene-1 copolymer (butene-1 content: 18%) and butene/ethylene copolymer (ethylene content: 3.5%). A surface layer constituent material consisting of a mixed composition in a weight ratio (however, 6% higher fatty acid ester monoglyceride was mixed as an antifogging agent in the surface layer constituent material) was used, and a coextrusion method was used. Therefore, a multilayer film with surface layers laminated on both sides of the base layer was prepared (extrusion temperature: 260°C, cooling: 20°C), and then biaxial stretching was performed at a longitudinal stretching ratio of 3 times and a transverse stretching ratio of 8 times. A three-layer film having a base layer of 16 μm and a surface layer of 2 μm×2 (both sides) having a total thickness of 20 μm was obtained by applying a corona discharge treatment to both surfaces. The surface tension of one side (A) of this film is 42
dynes/cm, surface tension on the other side (B) is 38 dynes/cm
It was cm. Table 1 shows the properties of the multilayer film.
【表】【table】
【表】
この複合フイルムの(A)面側を内面にして２方を
溶断シールし、縦280mm×横180mmの包装袋を作製
した。この包装袋の底辺２隅を第１図に示す如く
切欠き部が２等辺三角形となる様に５mmの長さに
カツトして２個の切欠き孔Ｈ（周辺長さ：５mm×
２＝10mm）を形成し、この中に収穫直後のなすを
装入して上方開口部をテープ（Ｔ）止めし保存時
の鮮度変化を調べた。尚なすの呼吸量は15℃にお
いて20CO2mg／Kg・hr、25℃において110CO2
mg／Kg・hrである。
結果は後記第３表に示す。
実施例 ２
プロピレン・ブテン−１共重合体（ブテン−１
含有量：20％）とエチレン・スチレン共重合体
（スチレン含有量：40％）とを、前者90％、後者
10％の比率で配合してなる基層構成材（防曇剤と
して高級脂肪酸エステルモノグリセライドを0.8
％配合）と、プロピレン・ブテン−１共重合体
（ブテン−１含有量：18％）とプロピレン・ブテ
ン−１共重合体（ブテン−１含有量：30％）とを
前者70％、後者30％の比率で配合してなる表面層
構成材とを用い、実施例１と同様にして３層構造
の複合フイルムを作製した（押出温度：250℃、
冷却：25℃）。その後引き続いて縦延伸倍率2.5
倍、横延伸倍率7.8倍の２軸延伸を行ない、基層
20μmの両面に表面層各1.5μmの積層された合計
肉厚23μmの３層フイルムを得た。このフイルム
の片面(A)側の表面張力は41ダイン／cm、反対面(B)
側の表面張力は38ダイン／cmであり、何れの面も
基層から拡散してきた防曇剤の良好な防曇性を示
した。
該フイルムの諸特性を第２表に示す。[Table] A packaging bag measuring 280 mm long x 180 mm wide was prepared by melt-sealing the two sides of this composite film with the (A) side facing inside. As shown in Figure 1, cut two corners of the bottom of this packaging bag to a length of 5 mm so that the notch part forms an isosceles triangle, and make two notch holes H (perimeter length: 5 mm x
2 = 10 mm), and the freshly harvested eggplants were put into this, the upper opening was taped (T), and changes in freshness during storage were examined. The respiration rate of eggplant is 20CO 2 mg/Kg・hr at 15℃, and 110CO 2 at 25℃.
mg/Kg・hr. The results are shown in Table 3 below. Example 2 Propylene-butene-1 copolymer (butene-1
content: 20%) and ethylene-styrene copolymer (styrene content: 40%), 90% of the former and 90% of the latter.
Base layer constituent material made by blending at a ratio of 10% (0.8% higher fatty acid ester monoglyceride as an antifogging agent)
% blend), propylene-butene-1 copolymer (butene-1 content: 18%) and propylene-butene-1 copolymer (butene-1 content: 30%), the former at 70% and the latter at 30%. A composite film with a three-layer structure was produced in the same manner as in Example 1 using the surface layer constituent materials blended at a ratio of
Cooling: 25℃). After that, the longitudinal stretching magnification was 2.5.
Biaxial stretching was performed at a transverse stretching ratio of 7.8 times and
A three-layer film with a total thickness of 23 μm was obtained, in which surface layers of 1.5 μm each were laminated on both sides of 20 μm. The surface tension of this film on one side (A) is 41 dynes/cm, and on the other side (B)
The surface tension of the side was 38 dynes/cm, and both sides showed good antifogging properties of the antifogging agent that had diffused from the base layer. The properties of the film are shown in Table 2.
【表】
このフイルムの(A)面側を内側にして２方を溶断
シールし、縦320mm×横150mmの袋を作製した。こ
の包装袋の底辺２隅および底辺略中央部を夫々第
２図に示す如く15mmの長さにカツトして３個の切
欠き孔Ｈ（周辺長さ：15mm×２＝30mmのもの３個）
を形成し、これに収穫直後のきゆうりを装入した
後上方開口部をテープ（Ｔ）止めして保存時の鮮
度変化を調べた。
尚きゆうりの呼吸量は、15℃において25CO2
mg／Kg・hr、25℃において130CO2mg／Kg・hrで
ある。
結果は後記第４表に示す。
実施例 ３
実施例１で得た包装用袋にえだ豆２本を封入
し、同様にして保存時の鮮度変化を調べた。尚え
だ豆の呼吸量は、15℃において170CO2mg／Kg・
hr、25℃において340CO2mg／Kg・hrである。
結果は第５表に示す。
尚第３、４、５表には比較の為無包装の場合及
びOPPフイルム（２軸延伸ポリプロピレンフイ
ルム）、PEフイルム（ポリエチレンフイルム）で
密封包装した場合、および上記実施例１〜３にお
いて切欠き孔を省略した他は夫々全く同様にして
得た袋（比較材）を用いた場合、並びに本発明の
規定範囲を外れる大きさの切欠きを設けた袋を用
いた場合の各実験結果も併記した。
尚第３、４、５表に示す鮮度保持試験の評価基
準は第６表に示す通りとした。[Table] This film was cut and sealed on two sides with the (A) side facing inside to produce a bag with a length of 320 mm and a width of 150 mm. Cut two corners and approximately the center of the bottom of this packaging bag into lengths of 15 mm as shown in Figure 2, and make three notch holes H (peripheral length: 15 mm x 2 = 3 pieces of 30 mm).
After filling the container with freshly harvested cucumbers, the upper opening was taped (T) to examine changes in freshness during storage. Furthermore, the respiration rate of Yuuri is 25CO 2 at 15℃.
mg/Kg・hr, 130CO 2 mg/Kg・hr at 25°C. The results are shown in Table 4 below. Example 3 Two green beans were sealed in the packaging bag obtained in Example 1, and changes in freshness during storage were examined in the same manner. The respiration rate of Edamame is 170 CO 2 mg/Kg at 15℃.
hr, 340 CO 2 mg/Kg·hr at 25°C. The results are shown in Table 5. For comparison, Tables 3, 4, and 5 show the case of no packaging, the case of sealed packaging with OPP film (biaxially stretched polypropylene film), PE film (polyethylene film), and the cases of notches in Examples 1 to 3 above. The results of experiments using bags obtained in exactly the same way (comparative materials) except for the holes omitted, and bags with notches of a size outside the specified range of the present invention are also listed. did. The evaluation criteria for the freshness retention test shown in Tables 3, 4, and 5 were as shown in Table 6.
【表】【table】
【表】【table】
【表】【table】
【表】【table】
【表】
実施例 ４
第７表に示す如く、種々の高分子素材よりなる
基層構成材の両面にプロピレン・ブテン１（18％）
共重合体よりなる表面層構成材（何れも防曇剤と
して高級脂肪族モノグリセライドを１％配合）を
共押出法により積層した後、縦2.5倍×横7.5倍に
２軸延伸し、次いで両面の表面張力が何れも39ダ
イン／cmとなる様にコロナ放電処理を施して複層
フイルムを得た。
得られた各複層フイルムの水蒸気透過度、酸素
透過度、炭酸ガス透過度、防曇性及び溶断シール
強度を第８表に一括して示す。[Table] Example 4 As shown in Table 7, propylene butene 1 (18%) was applied to both sides of the base layer constituent material made of various polymeric materials.
After laminating the surface layer constituent material made of a copolymer (each containing 1% higher aliphatic monoglyceride as an antifogging agent) by coextrusion, it was stretched biaxially to a size of 2.5 times in length and 7.5 times in width, and then stretched on both sides. A multilayer film was obtained by corona discharge treatment so that the surface tension of each film was 39 dynes/cm. Table 8 shows the water vapor permeability, oxygen permeability, carbon dioxide permeability, antifogging property, and fusing seal strength of each of the obtained multilayer films.
【表】【table】
【表】
上記で得た各複層フイルムＡ〜Ｈを用いて100
mm×180mmの袋を作製し、該袋の両下隅部に５mm
の切欠きを設け（底密封面：92.9％）、これにエ
ンドウ豆を70g充填して以下前記と同様にして保
存時の鮮度変化を調べた。尚保存条件は35℃×70
％RHとした。
結果は第９表に一括して示す通りであり、本発
明の規定要件を満たす複層フイルム（Ｂ，Ｄ，
Ｆ，Ｈ）を用いたものでは全体的に見て良好な鮮
度保持効果が得られているのに対し、フイルムＡ
は水蒸気透過度が低過ぎるため水分の放散が起こ
らず、ズルケ、臭気から見た劣化が著しい。これ
に対しフイルムＣは水蒸気透過度が高過ぎるた
め、内部が脱水状態となつて変色、軟化が見られ
る。またフイルムＥ及びＧは何れも酸素透過度と
炭酸ガス透過度が規定範囲を外れるものであり、
呼吸不足による変色が特に著しい。[Table] Using each of the multilayer films A to H obtained above,
Make a bag of mm x 180 mm, and add 5 mm to both lower corners of the bag.
A notch was provided (bottom sealed surface: 92.9%), and 70 g of peas were filled into the notch, and changes in freshness during storage were examined in the same manner as above. Storage conditions are 35℃ x 70
%RH. The results are summarized in Table 9, and the multilayer films (B, D,
Films using film A and film A had a good freshness retention effect overall.
Because water vapor permeability is too low, moisture dissipation does not occur, resulting in significant deterioration in terms of zulke and odor. On the other hand, since the water vapor permeability of Film C is too high, the interior becomes dehydrated, causing discoloration and softening. In addition, both films E and G have oxygen permeability and carbon dioxide permeability that are outside the specified range,
The discoloration caused by lack of breathing is particularly noticeable.
【表】【table】
【表】
比較例 ４
実施例１において表面層構成材中に防曇剤を配
合しなかつたほかは全く同様にして得た包装袋を
使用し、実施例３と同様にしてえだ豆の保存試験
を行なつた。
結果は第11表に示す通りであり、袋内面には短
期間の保存で水滴の付着が見られ、封入後４日目
からえだ豆の鮮度は急激に低下することが確認さ
れた。
比較例５，６
実施例１で用いた基層と同一組成（但し防曇剤
として１％の高級脂肪酸エステルモノグリセライ
ドを配合）のものを単独で使用し、実施例１と同
様にして20μmの単層フイルムを得た。該単層フ
イルムの物性を後記第10表に示す。この単層フイ
ルムを用いて袋を作製し、切欠きを設けたもの
（比較例５）と切欠きなしのもの（比較例６）に
ついて実施例３と同様のえだ豆保存試験を行なつ
た。
結果は後記第11表に示す通りであり、いずれの
場合も袋内面には短期間の保存で水滴の付着が見
られ、封入後４日目からえだ豆の鮮度は急激に低
下することが確認された。
比較例 ７
基層としてポリプロピレン（但し防曇剤として
１％の高級脂肪酸エステルモノグリセライドを配
合）を用い、表層としてエチレン・プロピレン共
重合体（エチレン含有量５重量％）を用いて共押
出しを行ない、２軸延伸の後表面層にコロナ処理
を施した（厚み、基層／表層＝23／2μm）。この
複層フイルムの物性を第10表に示す。
上記で得た複層フイルムを用いて袋を作製し、
実施例３と同様にしてえだ豆の鮮度保持試験を行
なつた。結果は後記第11表に示す通りであり、袋
内面には短期間の保存で水滴の付着が見られ、え
だ豆の鮮度は封入後４日目から急激に低下するこ
とが確認された。[Table] Comparative Example 4 Edamame was stored in the same manner as in Example 3 using a packaging bag obtained in exactly the same manner as in Example 1 except that no antifogging agent was added to the surface layer constituent material. I conducted a test. The results are shown in Table 11, and it was confirmed that water droplets were observed on the inner surface of the bag during short-term storage, and the freshness of the edamame rapidly decreased from the 4th day after the bag was sealed. Comparative Examples 5 and 6 A base layer having the same composition as that used in Example 1 (but containing 1% higher fatty acid ester monoglyceride as an antifogging agent) was used alone, and a 20 μm single layer was formed in the same manner as in Example 1. I got the film. The physical properties of the single layer film are shown in Table 10 below. Bags were made using this single-layer film, and the same edamame storage test as in Example 3 was conducted on bags with cutouts (Comparative Example 5) and bags without cutouts (Comparative Example 6). . The results are shown in Table 11 below, and in all cases, water droplets were observed on the inside of the bag during short-term storage, and the freshness of the edamame decreased rapidly from the 4th day after packaging. confirmed. Comparative Example 7 Coextrusion was carried out using polypropylene (containing 1% higher fatty acid ester monoglyceride as an antifogging agent) as the base layer and ethylene-propylene copolymer (ethylene content 5% by weight) as the surface layer. After axial stretching, the surface layer was subjected to corona treatment (thickness, base layer/surface layer = 23/2 μm). Table 10 shows the physical properties of this multilayer film. A bag is made using the multilayer film obtained above,
A freshness retention test of green soybeans was conducted in the same manner as in Example 3. The results are shown in Table 11 below, and it was confirmed that water droplets were observed on the inner surface of the bag after short-term storage, and the freshness of the edamame rapidly decreased from the fourth day after being sealed.
【表】【table】
【表】
［発明の効果］
本発明は以上の様に構成されており、用いる複
層フイルムは水蒸気、酸素及び炭酸ガスの各透過
度が適正に調整されているばかりでなく、製袋状
態で適正な大きさの切欠き孔が形成されているの
で、青果物は包装後も激しい生理作用を持続する
ことができ、鮮度保持期間を大幅に延長すること
ができる。しかもこの複層フイルムは優れた防曇
性及び防曇持続性を有しているので、流通過程で
内容物が見え難くなつて商品価値が低下したり、
或は曇り部に凝集した水分によつて青果物の腐敗
が促進される恐れもなく、又温度の急変等で仮に
結露水が生じたとしても、この結露水は直ちに切
欠き孔から袋外へ漏出するので、水腐れ等を起こ
す恐れもなく、青果物の外観点商品イメージの低
下を防止すると共に、消費者の手元に新鮮な状態
で供給することができる。[Table] [Effects of the Invention] The present invention is constructed as described above, and the multilayer film used not only has the permeability of water vapor, oxygen, and carbon dioxide appropriately adjusted, but also has a Since the notch holes are formed with an appropriate size, the fruits and vegetables can maintain their strong physiological effects even after packaging, and the freshness period can be significantly extended. Moreover, this multilayer film has excellent anti-fog properties and long-lasting anti-fog properties, so it may become difficult to see the contents during the distribution process, reducing the product value.
There is no risk that the moisture condensing in the cloudy area will accelerate the rotting of fruits and vegetables, and even if condensation occurs due to sudden changes in temperature, this condensation will immediately leak out of the bag through the notch holes. Therefore, there is no risk of water rot, etc., and deterioration of the appearance and product image of fruits and vegetables can be prevented, and they can be supplied to consumers in a fresh state.
第１，２図は実施例で用いた本発明の包装袋を
示す正面図である。
Ｈ：切欠き孔、Ｔ：テープ。
1 and 2 are front views showing the packaging bag of the present invention used in Examples. H: Notch hole, T: Tape.
Claims (1)
atm・20℃・90％RH、 炭酸ガス透過度が12000〜130000c.c.／m2・
24hr・atm・20℃・90％RH、 であり、少なくとも片面側表面層には防曇剤が存
在し、該表面層は０40℃の間で温度変化を繰り
返す経過中防曇性を示すと共に、270℃で溶断シ
ールしたときに3.0Kg−cm／15mm以上の溶断シー
ル強度を示す複層フイルムを用い、該表面層が内
側になる様に少なくとも３方が閉じられた袋状に
形成され、且つ該袋の密封底辺には１個当たりの
切欠き長さが４〜100mmである切欠き孔が、当該
底辺長さの50％以上を密封面として残す様に１個
以上開口されてなる包装袋に生理作用の激しい青
果物を収納することを特徴とする、青果物の鮮度
を保持する方法。 ２ 基層構成材が、炭素数２〜10のα−オレフイ
ン系共重合体の１種以上：30〜90重量％と、酢酸
ビニル、アクリル酸及びスチレンよりなる１種以
上のモノマー単位が全構成々分中の５〜80重量％
を占める共重合体の１種以上：10〜70重量％との
混合物である複層フイルムを使用する特許請求の
範囲第１項に記載の方法。 ３ 複層フイルムの表面層構成材が、炭素数２〜
10のα−オレフイン系共重合体である特許請求の
範囲第１又は２項に記載の方法。[Claims] 1. Water vapor permeability is 15 to 200 g/ m 2.24 hr. at 40°C. Oxygen permeability is 3000 to 35000 c.c./m 2.24 hr.
ATM・20℃・90%RH、Carbon dioxide permeability 12000~130000c.c./ m2・
24 hours, ATM, 20℃, 90%RH, and an antifogging agent is present in the surface layer of at least one side, and the surface layer exhibits antifogging properties during repeated temperature changes between 040℃ and Using a multilayer film that exhibits a sealing strength of 3.0 Kg-cm/15 mm or more when melt-cut and sealed at 270°C, formed into a bag shape with at least three sides closed so that the surface layer is on the inside, and A packaging bag in which one or more notch holes each having a notch length of 4 to 100 mm are opened in the sealed bottom of the bag so that 50% or more of the bottom length remains as a sealed surface. A method for preserving the freshness of fruits and vegetables, which is characterized by storing fruits and vegetables that have strong physiological effects. 2 The base layer constituent material is one or more α-olefin copolymers having 2 to 10 carbon atoms: 30 to 90% by weight, and one or more monomer units consisting of vinyl acetate, acrylic acid, and styrene. 5-80% by weight in minutes
2. The method according to claim 1, wherein the multilayer film is a mixture of 10 to 70% by weight of one or more copolymers. 3 The surface layer constituent material of the multilayer film has a carbon number of 2 to
10. The method according to claim 1 or 2, which is an α-olefin copolymer of No. 10.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62187378A JPS6344838A (en) | 1987-07-27 | 1987-07-27 | Method for keeping freshness of green vegetable |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62187378A JPS6344838A (en) | 1987-07-27 | 1987-07-27 | Method for keeping freshness of green vegetable |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16053086A Division JPH0811037B2 (en) | 1986-05-01 | 1986-07-08 | A packaging bag for fruits and vegetables with a strong physiological effect |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6344838A JPS6344838A (en) | 1988-02-25 |
| JPH0228312B2 true JPH0228312B2 (en) | 1990-06-22 |
Family
ID=16204966
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62187378A Granted JPS6344838A (en) | 1987-07-27 | 1987-07-27 | Method for keeping freshness of green vegetable |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6344838A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2014227192A (en) * | 2013-05-22 | 2014-12-08 | 株式会社トクヤマ | Storage bag for plaster printing sheet |
| JP7284493B2 (en) * | 2018-11-30 | 2023-05-31 | 株式会社ベルグリーンワイズ | food storage bag |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5075838A (en) * | 1973-10-26 | 1975-06-21 | ||
| JPS5099838A (en) * | 1973-12-18 | 1975-08-07 | ||
| JPS5538268A (en) * | 1978-09-08 | 1980-03-17 | Asahi Dow Ltd | Vegetablessanddfruits packing method |
| JPS5763251A (en) * | 1980-10-03 | 1982-04-16 | Toyo Boseki | Package of vegetable and fruit |
| JPS5991136A (en) * | 1982-11-17 | 1984-05-25 | Nippon Carbide Ind Co Ltd | Antifogging thermoplastic synthetic resin molding |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5996182U (en) * | 1982-12-21 | 1984-06-29 | 有限会社ゴー容器 | Fresh food. Bag containers for packaging plants, etc. |
-
1987
- 1987-07-27 JP JP62187378A patent/JPS6344838A/en active Granted
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5075838A (en) * | 1973-10-26 | 1975-06-21 | ||
| JPS5099838A (en) * | 1973-12-18 | 1975-08-07 | ||
| JPS5538268A (en) * | 1978-09-08 | 1980-03-17 | Asahi Dow Ltd | Vegetablessanddfruits packing method |
| JPS5763251A (en) * | 1980-10-03 | 1982-04-16 | Toyo Boseki | Package of vegetable and fruit |
| JPS5991136A (en) * | 1982-11-17 | 1984-05-25 | Nippon Carbide Ind Co Ltd | Antifogging thermoplastic synthetic resin molding |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6344838A (en) | 1988-02-25 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |