JP2525611B2 - Heat resistant container manufacturing method - Google Patents
Heat resistant container manufacturing methodInfo
- Publication number
- JP2525611B2 JP2525611B2 JP62161843A JP16184387A JP2525611B2 JP 2525611 B2 JP2525611 B2 JP 2525611B2 JP 62161843 A JP62161843 A JP 62161843A JP 16184387 A JP16184387 A JP 16184387A JP 2525611 B2 JP2525611 B2 JP 2525611B2
- Authority
- JP
- Japan
- Prior art keywords
- container
- sheet
- heat
- resin foam
- heating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000004519 manufacturing process Methods 0.000 title claims description 4
- 239000006260 foam Substances 0.000 claims description 22
- 229920005990 polystyrene resin Polymers 0.000 claims description 21
- 238000010438 heat treatment Methods 0.000 claims description 20
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 claims description 16
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 claims description 6
- 229920006015 heat resistant resin Polymers 0.000 claims description 5
- FPYJFEHAWHCUMM-UHFFFAOYSA-N maleic anhydride Chemical compound O=C1OC(=O)C=C1 FPYJFEHAWHCUMM-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
- NIXOWILDQLNWCW-UHFFFAOYSA-N 2-Propenoic acid Natural products OC(=O)C=C NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 claims description 4
- 238000006116 polymerization reaction Methods 0.000 claims 1
- 238000000465 moulding Methods 0.000 description 18
- 238000000034 method Methods 0.000 description 11
- 239000003921 oil Substances 0.000 description 11
- 238000011156 evaluation Methods 0.000 description 8
- 239000004793 Polystyrene Substances 0.000 description 7
- 229920002223 polystyrene Polymers 0.000 description 7
- 229920005989 resin Polymers 0.000 description 7
- 239000011347 resin Substances 0.000 description 7
- 235000013305 food Nutrition 0.000 description 4
- 238000010030 laminating Methods 0.000 description 4
- PYSRRFNXTXNWCD-UHFFFAOYSA-N 3-(2-phenylethenyl)furan-2,5-dione Chemical compound O=C1OC(=O)C(C=CC=2C=CC=CC=2)=C1 PYSRRFNXTXNWCD-UHFFFAOYSA-N 0.000 description 3
- 240000008415 Lactuca sativa Species 0.000 description 3
- 229920000147 Styrene maleic anhydride Polymers 0.000 description 3
- 239000000853 adhesive Substances 0.000 description 3
- 230000001070 adhesive effect Effects 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000010411 cooking Methods 0.000 description 3
- 230000002950 deficient Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- 238000005187 foaming Methods 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 235000012045 salad Nutrition 0.000 description 3
- 238000007666 vacuum forming Methods 0.000 description 3
- 230000037303 wrinkles Effects 0.000 description 3
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 2
- 241000287828 Gallus gallus Species 0.000 description 2
- 240000005856 Lyophyllum decastes Species 0.000 description 2
- 235000013194 Lyophyllum decastes Nutrition 0.000 description 2
- 239000012790 adhesive layer Substances 0.000 description 2
- 229920001577 copolymer Polymers 0.000 description 2
- 229920005669 high impact polystyrene Polymers 0.000 description 2
- 239000004797 high-impact polystyrene Substances 0.000 description 2
- -1 if necessary Substances 0.000 description 2
- 229920003145 methacrylic acid copolymer Polymers 0.000 description 2
- 229940117841 methacrylic acid copolymer Drugs 0.000 description 2
- 238000004806 packaging method and process Methods 0.000 description 2
- 229920006267 polyester film Polymers 0.000 description 2
- 238000004080 punching Methods 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- JQXYBDVZAUEPDL-UHFFFAOYSA-N 2-methylidene-5-phenylpent-4-enoic acid Chemical compound OC(=O)C(=C)CC=CC1=CC=CC=C1 JQXYBDVZAUEPDL-UHFFFAOYSA-N 0.000 description 1
- 239000004743 Polypropylene Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000008157 edible vegetable oil Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 239000012760 heat stabilizer Substances 0.000 description 1
- 239000003779 heat-resistant material Substances 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 229920005672 polyolefin resin Polymers 0.000 description 1
- 229920001155 polypropylene Polymers 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 229920003048 styrene butadiene rubber Polymers 0.000 description 1
Landscapes
- Package Specialized In Special Use (AREA)
- Laminated Bodies (AREA)
- Blow-Moulding Or Thermoforming Of Plastics Or The Like (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、ポリスチレン樹脂発泡シート成形容器に耐
熱性を付与する方法に関し、具体的には、電子レンジ加
熱調理の際にも変形を起こさない耐熱性と優れた実用強
度を兼ね備えた耐熱容器を製造する方法に関する。Description: TECHNICAL FIELD The present invention relates to a method for imparting heat resistance to a polystyrene resin foam sheet molding container, and specifically, does not cause deformation even in microwave oven cooking. The present invention relates to a method for producing a heat-resistant container having both heat resistance and excellent practical strength.
ポリスチレン樹脂発泡シートの成形体は、適度の剛性
を有し、断熱性も良好なので、食品包装用の軽量容器に
大量に使用されている。Molded products of polystyrene resin foamed sheets have appropriate rigidity and good heat insulation properties, and are therefore used in large quantities in lightweight containers for food packaging.
しかしながら、ポリスチレン樹脂発泡シートの成形容
器は、耐熱性に劣るため、近年急速に普及した電子レン
ジによる加熱調理用途には全く使用されていない。However, since the molded container of the polystyrene resin foamed sheet is inferior in heat resistance, it has not been used at all for heating and cooking applications using a microwave oven which has rapidly spread in recent years.
そこで、これを改善すべく、樹脂そのものの耐熱性を
向上させたものとして、スチレン系耐熱樹脂を用いて、
例えば、スチレン−無水マレイン酸共重合体の発泡シー
トを成形した容器が、実開昭55-117975号公報に提案さ
れている。又、一方、特開昭61-137740号公報、実開昭6
1-103302号公報には、スチレン系−アクリル酸系共重合
体の発泡シート、接着材層、及びポリオレフィン系樹脂
又はポリエステル系樹脂からなる無発泡フイルムの３層
積層シートを用いた容器が、電子レンジ加熱用として好
適であると提案されている。Therefore, in order to improve this, by using a styrene-based heat-resistant resin as an improved heat resistance of the resin itself,
For example, a container formed by molding a foamed sheet of a styrene-maleic anhydride copolymer has been proposed in Japanese Utility Model Publication No. 55-117975. On the other hand, on the other hand, Japanese Patent Laid-Open No. 61-137740 and Shokai Sho 6
Japanese Patent No. 1-103302 discloses a container using a foamed sheet of a styrene-acrylic acid copolymer, an adhesive layer, and a three-layer laminated sheet of a non-foamed film made of a polyolefin resin or a polyester resin. It is proposed to be suitable for heating a microwave oven.
しかしながら、上記容器でも現在の市場要求品質を満
たしておらず、電子レンジ加熱容器として未だ完成され
たものとは言えない。However, even the above-mentioned container does not satisfy the current market demand quality, and it cannot be said that it has been completed as a microwave oven heating container.
例えば、スチレン−無水マレイン酸共重合体の発泡シ
ート及び成形容器に関しては、次のような問題点があっ
た。For example, the foamed sheet of styrene-maleic anhydride copolymer and the molded container have the following problems.
発泡シートの成形性が著しく悪く、成形ロスが50％を
超える。The moldability of the foam sheet is extremely poor and the molding loss exceeds 50%.
実用強度が弱い。具体的には、例えば（ａ）容器のフ
ランジ部は成形後の打抜き時に割れてしまう。（ｂ）内
容物の入った容器は、僅か0.5mの高さから落下させても
割れてしまう。Practical strength is weak. Specifically, for example, (a) the flange portion of the container is cracked during punching after molding. (B) The container containing the contents will break even if dropped from a height of only 0.5 m.
耐油性に劣る。具体的には、例えば、（ａ）容器にサ
ラダ油を満たして室温に放置すると、２〜３日でクラッ
クが発生する。（ｂ）容器にフライドチキンを入れて電
子レンジ加熱すると、チキンに接している部分にクラッ
クが発生したり、変形する。Poor oil resistance. Specifically, for example, when (a) a container is filled with salad oil and left at room temperature, cracks occur in 2 to 3 days. (B) When the fried chicken is put in a container and heated in a microwave oven, cracks occur in a portion in contact with the chicken or the portion is deformed.
又、スチレン系−アクリル酸系共重合体の発泡シート
を用いた積層シート及び成形容器に関しても、次の如き
問題点があった。Further, there are the following problems with a laminated sheet and a molding container using a foamed sheet of a styrene-acrylic acid copolymer.
ポリスチレン樹脂発泡シートに比較して大幅に成形性
が劣る。具体的には、例えば、（ａ）型再現性が悪く、
絞り比も0.6以上の容器を得るのが難しい。（ｂ）成形
サイクルが約３倍以上に長くなり、生産性が低い。Moldability is significantly inferior to polystyrene resin foam sheets. Specifically, for example, (a) type reproducibility is poor,
It is difficult to obtain a container with a drawing ratio of 0.6 or more. (B) The molding cycle is about three times longer or longer and the productivity is low.
耐熱性が不充分で105℃を超えると容器が変形してし
まう。Insufficient heat resistance causes the container to deform if it exceeds 105 ℃.
本発明は、これらの問題点を全部解決しようとするも
のであり、換言すれば、本発明の目的は、ポリスチレン
樹脂発泡シートと同等な成形性（型再現性、深絞り性）
と成形サイクルを有しながら、110℃×10分間以上の優
れた実用耐熱性と耐油性及び実用強度のすべてを満足し
得る耐熱容器を得る製造方法を提供することである。The present invention is intended to solve all of these problems, in other words, the object of the present invention is the same moldability (mold reproducibility, deep drawability) as the polystyrene resin foam sheet.
It is to provide a manufacturing method for obtaining a heat-resistant container capable of satisfying all of excellent practical heat resistance of 110 ° C. × 10 minutes or more, oil resistance and practical strength while having a molding cycle.
本発明は、ポリスチレン樹脂発泡シートにスチレン系
耐熱樹脂からなるシートを積層することによって、ポリ
スチレン樹脂発泡シートの成形容器に大幅な耐熱性向上
を付与することに成功したものであり、本発明によって
前述のすべての問題点を解決できることを見出した。The present invention has succeeded in imparting a significant heat resistance improvement to a molded container of a polystyrene resin foam sheet by laminating a sheet made of a styrene-based heat-resistant resin on a polystyrene resin foam sheet. It was found that all the problems of can be solved.
本発明の主要点を分説すると、 ポリスチレン系樹脂発泡シートに積層したスチレン系
耐熱樹脂シートは、アクリル酸、メタクリル酸、又は無
水マレイン酸の何れか１成分或いは２成分以上を、その
合計量で５〜20重量％含むものであること、 又、該樹脂シートは、二軸延伸されたシートであり、
厚みが50μ〜250μの範囲であること、 該積層体を成形するに当たっては、延伸シート面側の
温度が発泡シート面側の温度より５〜30℃高温になるよ
うに積層体の両面から加熱した後、延伸シート面が成形
体の内側になるように成形すること、 を特徴とする耐熱容器の製造方法に係るものである。To explain the main points of the present invention, a styrene-based heat-resistant resin sheet laminated on a polystyrene-based resin foam sheet is one component or two or more components of acrylic acid, methacrylic acid, or maleic anhydride in the total amount. 5 to 20% by weight, and the resin sheet is a biaxially stretched sheet,
The thickness is in the range of 50 μ to 250 μ, and in molding the laminate, heating was performed from both sides of the laminate so that the temperature on the stretched sheet surface side was 5 to 30 ° C. higher than the temperature on the foamed sheet surface side. Then, the stretched sheet surface is molded so that the surface of the stretched sheet is on the inside of the molded body.
以下、本発明について詳細に説明する。 Hereinafter, the present invention will be described in detail.
まず上記したの要件、即ち、アクリル酸、メタクリ
ル酸、又は無水マレイン酸の含有量を５〜20重量％の範
囲にする理由については、まずポリスチレン樹脂発泡シ
ートの剛性を保持したまま耐熱性向上効果を大きくした
い観点から、又、発泡シートの熱融着性の良さや発泡シ
ートとの混合系においても再利用できると言った観点か
ら、本発明では、アクリル酸、メタクリル酸、又は無水
マレイン酸を含むスチレン系耐熱樹脂が選ばれている。
その含有量は、ポリスチレン樹脂発泡シートに110℃以
上の実用耐熱性を付与するものとして、少なくとも５重
量％は必要である。含有量の増加に伴い耐熱性は向上
し、その向上効果は、含有量が20重量％まで認められ
る。容器の深絞り性や偏肉分布を良くしたい観点から、
上記含有量は８〜15重量％の範囲で選ぶことが望まし
い。又、これら樹脂の重量平均分子量は20〜40万の範囲
が良い。更には、上記樹脂には、必要に応じて熱安定剤
等の慣用の添加剤が含まれていても良いし、ポリスチレ
ン、耐衝撃性ポリスチレン、スチレン−ブタジエン共重
合体等を本発明の耐熱性を阻害しない範囲において含有
させることができる。First, regarding the above-mentioned requirements, that is, the reason why the content of acrylic acid, methacrylic acid, or maleic anhydride is set in the range of 5 to 20% by weight, first, the heat resistance improving effect while maintaining the rigidity of the polystyrene resin foam sheet From the viewpoint of increasing the heat-sealing property of the foamed sheet and the fact that it can be reused in a mixed system with the foamed sheet, in the present invention, acrylic acid, methacrylic acid, or maleic anhydride is used. A styrene-based heat-resistant resin containing is selected.
The content is required to be at least 5% by weight in order to impart practical heat resistance of 110 ° C. or higher to the polystyrene resin foam sheet. With the increase of the content, the heat resistance is improved, and the improvement effect is recognized up to the content of 20% by weight. From the viewpoint of improving the deep drawability and uneven thickness distribution of the container,
It is desirable to select the above content in the range of 8 to 15% by weight. The weight average molecular weight of these resins is preferably in the range of 200,000 to 400,000. Further, the above-mentioned resin may contain a conventional additive such as a heat stabilizer, if necessary, and polystyrene, impact-resistant polystyrene, styrene-butadiene copolymer or the like may be added to the heat-resistant material of the present invention. Can be contained within a range that does not inhibit
次にの要件のうち、まず二軸延伸シートである理由
は、ポリスチレン樹脂発泡シートの成形容器に、その優
れた実用強度を保持しながら、耐油性を付与させるため
である。シートを無延伸のものに代えると、成形後の打
抜き工程でシートに割れが発生してしまう。又、この脆
さは、成形容器全体の強度を低下させるように作用する
ため、輸送時や取扱時に容器破損を引き起こす。更に食
用油を付着させると、シートに多数クラックが生じてし
まい、容器全体としても耐油性の悪いものになると言っ
た新たな問題を生じるからである。Among the following requirements, the reason why it is a biaxially stretched sheet is that it imparts oil resistance to a polystyrene resin foam sheet molded container while maintaining its excellent practical strength. If the sheet is replaced with a non-stretched sheet, cracks will occur in the sheet in the punching step after molding. Further, this brittleness acts so as to reduce the strength of the entire molded container, so that the container is damaged during transportation or handling. This is because if edible oil is further adhered, many cracks will occur in the sheet, which will cause a new problem that the oil resistance of the entire container will be poor.
二軸延伸シートを用いることにより、これらの問題が
解消する。熱融着による積層のし易さ、積層体にした後
での成形し易さも考慮すると、シートの配向状態は、最
大熱収縮応力（ASTM D-1504に準拠して測定）で４〜15K
g/cm2の範囲で選ぶことが望ましい。These problems are solved by using a biaxially stretched sheet. Considering the ease of lamination by heat fusion and the ease of forming after forming a laminate, the orientation state of the sheet is 4 to 15K at the maximum heat shrinkage stress (measured according to ASTM D-1504).
It is desirable to select in the range of g / cm 2 .
更にこの二軸延伸されたシートであっても厚みが50μ
〜250μの範囲であることが重要である。実施例４の第
２表を用いて説明すると、まずスチレン樹脂発泡シート
の成形容器そのものは90℃を超えると、変形を生じるも
のであるが、本発明の延伸シートを積層してなる積層シ
ートの成形容器は、いずれも耐熱性が大幅に向上してい
るのが分かる。しかも、僅か50μ厚みの薄肉シートを積
層することによっても、110℃の耐熱性を発揮すること
は、驚くべきことであり、本発明者によって初めて見出
されたものである。厚みが50μを下回ると延伸シート部
にしわが発生するようになり、40μ以下では、スチレン
樹脂発泡シート単体と全く同じレベルの耐熱性を有する
ものになってしまう。高度に耐熱性を付与するために
は、80μ以上がより好ましい。一方、250μを超えて厚
くしても、耐熱性の向上は少ない。Furthermore, even this biaxially stretched sheet has a thickness of 50μ.
It is important to be in the range of ~ 250μ. Explaining with reference to Table 2 of Example 4, first, the molded container of the styrene resin foam sheet itself deforms when the temperature exceeds 90 ° C., but a laminated sheet formed by laminating the stretched sheet of the present invention is used. It can be seen that the heat resistance of each of the molded containers is significantly improved. Moreover, it is surprising that the heat resistance of 110 ° C. is exhibited even by stacking thin sheets having a thickness of only 50 μ, which was first discovered by the present inventor. If the thickness is less than 50 μ, wrinkles will be generated in the stretched sheet portion, and if it is 40 μ or less, the styrene resin foam sheet will have exactly the same level of heat resistance. In order to impart high heat resistance, 80 μm or more is more preferable. On the other hand, even if the thickness exceeds 250 μ, there is little improvement in heat resistance.
積層体を形成する方法としては、延伸シートを直接発
泡シートに熱融着する方法が、生産性、経済性の観点か
ら採用できるが、例えば、深絞り成形のように延伸シー
トと発泡シートとの接着強度を高度に必要とする場合に
は、接着層として、耐衝撃性ポリスチレンフイルムやポ
リスチレンフイルムを介在させることが更に好ましい。As a method of forming a laminate, a method of directly heat-sealing a stretched sheet to a foamed sheet can be adopted from the viewpoint of productivity and economical efficiency. For example, as in deep drawing, a stretched sheet and a foamed sheet can be used. When high adhesive strength is required, it is more preferable to interpose an impact resistant polystyrene film or polystyrene film as the adhesive layer.
更にの要件の必要性については、まず延伸シート面
が成形体の内側になるように成形する理由は、成形容器
の食品と接する面に耐熱・耐油性能を付与するために重
要である。Regarding the necessity of further requirements, the reason why the stretched sheet surface is first formed inside the molded body is important for imparting heat resistance and oil resistance to the surface of the molded container that comes into contact with food.
次に、この成形体を得るに当たっては、ポリスチレン
樹脂発泡シートを二次発泡させる加熱条件と、積層体全
体を成形する加熱条件とを調和させる必要がある。即
ち、発泡シートを二次発泡させる最適な温度では、延伸
シートの成形温度としては不充分で、積層体が成形でき
なし、又、積層体としての成形が可能な温度では、発泡
シートの二次発泡が進みすぎ、気泡が破壊すると言った
脱泡現象が発生してしまうからである。Next, in obtaining this molded product, it is necessary to harmonize the heating conditions for secondary foaming of the polystyrene resin foam sheet and the heating conditions for molding the entire laminate. That is, at the optimum temperature for secondary foaming of the foamed sheet, the forming temperature of the stretched sheet is insufficient, and the laminate cannot be formed. This is because the defoaming phenomenon that the foaming proceeds too much and the bubbles are broken occurs.
従って、このどちらも満足し得る加熱方法としては、
積層体の両面側から加熱する方法を採用し、しかも、延
伸シート面側を発泡シート面側の温度より高くしなけれ
ばならない。具体的な温度差としては、５〜30℃の範囲
から選定するのが好ましい。Therefore, as a heating method that can satisfy both of these,
The method of heating from both sides of the laminate must be adopted, and the temperature of the stretched sheet surface side must be higher than the temperature of the foamed sheet surface side. The specific temperature difference is preferably selected from the range of 5 to 30 ° C.
上記加熱方法を用いることにより、ポリスチレン樹脂
発泡シート単体と同等な成形サイクルで成形することが
できる。By using the above heating method, it is possible to perform molding in a molding cycle equivalent to that of a polystyrene resin foam sheet alone.
なお、成形方法は、一般にシート成形に用いられてい
る圧空成形法、真空成形法何れの方法でも良いが、その
中でも輻射加熱式真空プラグアシスト成形法（シートを
輻射加熱し、後、真空圧で型内に吸引しながら、逆方向
からプラグを挿入して型内に添わせ成形する方法）が深
絞り成形に有利なため最も好ましい。The forming method may be either a pressure forming method or a vacuum forming method which is generally used for sheet forming. Among them, a radiant heating type vacuum plug assist forming method (a sheet is radiantly heated and then a vacuum pressure is applied). The method of inserting a plug from the opposite direction while suctioning into the mold and molding along the mold) is most preferable because it is advantageous for deep drawing.
本発明で用いている各評価項目は、次の評価方法、評
価尺度に基づくものである。Each evaluation item used in the present invention is based on the following evaluation method and evaluation scale.
（１）耐熱性テスト 容器を110℃の乾熱オーブン中に10分間加熱した時の
容器深さの寸法変化率を測定する（ｎ＝５の平均値を求
める）。(1) Heat resistance test The dimensional change rate of the container depth is measured when the container is heated in a dry heat oven at 110 ° C for 10 minutes (an average value of n = 5 is obtained).
◎ −２％未満 ○ −２％以上−４％未満 × −４％以上 （２）耐油クラックテスト 容器の内表面全体にサラダ油を塗布した状態で40℃の
室内に30日間放置し、クラックの発生を観察する（ｎ＝
10の平均値を求める）。◎ Less than -2% ○ -2% or more and less than -4% × -4% or more (2) Oil resistance crack test Leave the entire interior surface of the container with salad oil left in a room at 40 ° C for 30 days to generate cracks. (N =
Calculate the average of 10).
◎ 全容器にクラックの発生が見られない ○ 容器内面の一部にクラック発生が認められる × 容器内面全体にクラック発生 （３）実用テスト（１） 容器に水200ml、サラダ油20mlを入れて、電子レンジ
（500W）にて10分間加熱した後、容器を観察する（ｎ＝
10）。◎ No cracks were found in all containers ○ Cracks were found in a part of the inner surface of the container × Cracks were found in the entire inner surface of the container (3) Practical test (1) 200 ml of water and 20 ml of salad oil were put into the container After heating in a microwave oven (500W) for 10 minutes, observe the container (n =
Ten).
◎ 容器に何ら変化が見られない ○ 容器内面に若干のシワが見られる × 容器内面のシワが著しく、変形も見られる （４）実用テスト（２） 冷蔵保存されたフライドチキン（150g）を容器に入れ
て電子レンジ（500W）にて1.5分間加熱した後、容器を
観察する（ｎ＝10）。◎ No change in the container ○ Some wrinkles on the inner surface of the container × Significant wrinkles on the inner surface of the container and deformation (4) Practical test (2) Refrigerated fried chicken (150 g) in the container After heating in a microwave oven (500 W) for 1.5 minutes, observe the container (n = 10).
◎ 容器に何ら変化が見られない ○ 容器のチキン接触部に僅かにクラック発生 × クラック発生著しく、変化も見られる （５）容器落下テスト 水を充填した容器を所定の高さから落下させ、50％の
容器に割れ、破れの発生する高さを求める（ｎ＝20）。◎ No change is seen in the container ○ Slight cracks occur in the chicken contact part of the container × Significant cracks and changes are also seen (5) Drop test of container Drop the container filled with water from the specified height, and % Find the height at which the container breaks and breaks (n = 20).
◎ 70cm以上 ○ 50cm以上70cm未満 × 50cm未満 （６）成形性評価 500個の成形を行い、型再現性不良等の不良品発生率
を調べる。◎ 70 cm or more ○ 50 cm or more and less than 70 cm x less than 50 cm (6) Moldability evaluation Perform molding of 500 pieces and examine the defective product occurrence rate such as defective mold reproducibility.
◎ ２％未満 ○ ２％以上10％未満 × 10％以上 〔実施例〕 以下に実施例を示す。◎ Less than 2% ○ 2% or more and less than 10% × 10% or more [Examples] Examples are shown below.
実施例１ メタクリル酸含有量が12重量％のスチレン−メタクリ
ル酸共重合体（重量平均分子量27万）からなり、最大熱
収縮応力がタテ方向7Kg/cm2、ヨコ方向7Kg/cm2で厚み15
0μの二軸延伸シートを、ポリスチレン樹脂発泡シート
（目付量200g/m2、厚み2.1mm）の上に重ね、加熱ローラ
ミネーター（ロール温度180℃）に通して積層体を得
た。Example 1 methacrylic acid content of 12 wt% styrene - consists methacrylic acid copolymer (weight average molecular weight 270,000), the maximum thermal shrinkage stress longitudinal direction 7 Kg / cm 2, thickness 15 in the transverse direction 7 Kg / cm 2
A 0 μ biaxially stretched sheet was placed on a polystyrene resin foam sheet (basis weight: 200 g / m 2 , thickness: 2.1 mm) and passed through a heating roller laminator (roll temperature 180 ° C.) to obtain a laminate.
次に、この積層体をイーリッヒ社製輻射加熱式プラグ
アシスト型真空成形機を用いて、二軸延伸シート表面が
145℃、発泡シート表面が130℃になるように積層体両面
側から、遠赤外線ヒーターにより、５秒間加熱した後、
二軸延伸シート面が内側になるように、プラグ真空成形
（プラグ温度95℃、金型80℃）を行い、開口部170mm×1
50mm、底部120mm×120mm、深さ50mmの角トレー容器を得
た。Next, the surface of the biaxially stretched sheet of this laminate was measured using a radiation heating type plug assist type vacuum forming machine manufactured by Erich.
After heating for 5 seconds with a far-infrared heater from both sides of the laminate so that the surface of the foamed sheet becomes 145 ° C and 130 ° C,
Plug vacuum forming (plug temperature 95 ℃, mold 80 ℃) is performed so that the biaxially stretched sheet surface is on the inside, and the opening is 170mm × 1
A square tray container of 50 mm, bottom 120 mm × 120 mm, and depth 50 mm was obtained.
上記成形機、加熱条件における成形サイクルは8sec/1
shotであり、ポリスチレン樹脂発泡シート単体と同等な
生産性を有していた。Molding cycle under the above molding machine and heating conditions is 8sec / 1
It was a shot, and had the same productivity as the polystyrene resin foam sheet alone.
得られた容器に対し、前述の評価を行った結果を第１
表に示す。The result of the above-mentioned evaluation of the obtained container is the first
Shown in the table.
実施例２ 実施例１で二軸延伸シートを、無水マレイン酸含有量
が10重量％のスチレン−無水マレイン酸共重合体（重量
平均分子量24万）からなり、最大熱収縮応力がタテ方向
10Kg/cm2、ヨコ方向10Kg/cm2で厚み80μに変更する以外
は、すべて実施例１と同様な実験を行い、実施例１と同
じ形状の容器を得た。Example 2 The biaxially stretched sheet of Example 1 was composed of a styrene-maleic anhydride copolymer having a maleic anhydride content of 10% by weight (weight average molecular weight 240,000) and having a maximum heat shrinkage stress in the vertical direction.
10 kg / cm 2, except for changing the thickness 80μ in transverse direction 10 kg / cm 2, all performing the same experiment as in Example 1 to obtain a container having the same shape as in Example 1.
又、比較のために、実施例１の二軸延伸シートの代わ
りに、25μの無延伸ポリエステルフイルムを用いてウレ
タン系接着剤を介して積層した積層体と、350μの無延
伸ポリプロピレンシート／ウレタン系接着剤/25μ耐衝
撃性ポリスチレンフイルムの３層シートを用いて、耐衝
撃性ポリスチレンフイルム側をポリスチレン樹脂発泡シ
ートと熱融着した積層体を作成し、各々実施例１の成形
機で条件を選びながら、同一形状の容器を得た。For comparison, instead of the biaxially stretched sheet of Example 1, a laminate obtained by laminating a 25 μm unstretched polyester film via a urethane adhesive and a 350 μm unstretched polypropylene sheet / urethane system A three-layer sheet of adhesive / 25μ impact-resistant polystyrene film was used to prepare a laminate in which the impact-resistant polystyrene film side was heat-sealed with the polystyrene resin foam sheet, and the conditions were selected by the molding machine of Example 1, respectively. However, a container having the same shape was obtained.
ポリエステルフイルムを積層した容器を比較品Ａ、該
３層シートを積層した容器を比較品Ｂとする。The container in which the polyester film is laminated is referred to as comparative product A, and the container in which the three-layer sheet is laminated is referred to as comparative product B.
得られた容器に対し、前述の評価を行った結果を第１
表に示す。The result of the above-mentioned evaluation of the obtained container is the first
Shown in the table.
実施例３ 実施例１で二軸延伸シートを、メタクリル酸含有量が
８重量％のスチレン−メタクリル酸共重合体（重量平均
分子量30万）からなり、最大熱収縮応力がタテ方向5Kg/
cm2、ヨコ方向5Kg/cm2で厚み200μに変更し、この二軸
延伸シートとポリスチレン樹脂発泡シートとの間に、20
μの耐衝撃性ポリスチレン（HIPS）の無延伸フイルムを
介在させる以外は、総て実施例１と同様な実験を行い、
開口部110mmφ、底部80mmφ、深さ70mmの深絞り容器
（絞り比0.64）を得た。Example 3 The biaxially stretched sheet of Example 1 was made of a styrene-methacrylic acid copolymer having a methacrylic acid content of 8% by weight (weight average molecular weight 300,000) and having a maximum heat shrinkage stress of 5 kg / vertical direction.
cm 2, and change in thickness 200μ in transverse direction 5Kg / cm 2, between the biaxially oriented sheet and the polystyrene resin foam sheet, 20
The same experiment as in Example 1 was carried out except that an unstretched film of high impact polystyrene (HIPS) was used.
A deep drawing container (opening ratio 0.64) having an opening of 110 mmφ, a bottom of 80 mmφ and a depth of 70 mm was obtained.
得られた容器に対し、前述の評価を行った結果を第１
表に示す。The result of the above-mentioned evaluation of the obtained container is the first
Shown in the table.
実施例１で得られた容器は、耐熱性テスト、耐油クラ
ックテスト、実用テスト（１）、（２）、容器落下テス
ト、成形性評価の総ての結果が◎で、優れた性能を兼ね
備えていることが分かった。The container obtained in Example 1 was excellent in all of the heat resistance test, oil crack resistance test, practical tests (1) and (2), container drop test, and moldability evaluation, and had excellent performance. I found out that
又、実施例２で得られた本発明の容器も、実施例１と
同様に優れた性能を発揮したが、比較品Ａ、Ｂは何れも
30％を超える型再現不良品を出し、更 に得られた容器も耐熱性テスト、実用テスト（１）に劣
ったものであり、電子レンジ加熱容器としては不適当で
あると判断した。Further, the container of the present invention obtained in Example 2 also showed excellent performance as in Example 1, but both Comparative Products A and B
We issued defective products with a mold reproducibility exceeding 30% and The container obtained in 1) was also inferior to the heat resistance test and the practical test (1), and was judged to be unsuitable as a microwave heating container.
一方、実施例３では、深絞り容器についても、成形性
に優れ、かつ、優れた性能を兼ね備えた容器になること
が理解できる。On the other hand, in Example 3, it can be understood that the deep-drawing container is also a container having excellent formability and excellent performance.
実施例４ 実施例１で二軸延伸シートの厚みを50μ、80μ、180
μ、250μ、300μに変更し、二軸延伸シート表面が135
℃〜160℃の範囲から、厚みに合わせ最適成形加熱条件
に変更する以外は、すべて実施例１と同様な実験を行
い、実施例１と同じ形状の容器を得た。Example 4 The thickness of the biaxially stretched sheet in Example 1 was 50μ, 80μ, 180
Change to μ, 250μ, 300μ, and the surface of biaxially stretched sheet is 135
All experiments were performed in the same manner as in Example 1 except that the optimum molding and heating conditions were changed from the range of ℃ to 160 ℃ according to the thickness, and a container having the same shape as that of Example 1 was obtained.
又、比較のためにポリスチレン樹脂発泡シートのみの
場合及び二軸延伸シートの厚みが40μの場合について
も、同一形状の容器を得た。Also, for comparison, a container having the same shape was obtained in the case where only the polystyrene resin foam sheet was used and the case where the thickness of the biaxially stretched sheet was 40 μ.
これら容器を５℃間隔の温度にコントロールされた乾
熱オーブン中に10分間放置した際に容器深さが2mm以上
縮む時のオーブン温度を求めた。結果を第２表に示す。When these containers were left in a dry heat oven controlled at a temperature of 5 ° C. for 10 minutes, the oven temperature when the container depth contracted by 2 mm or more was determined. The results are shown in Table 2.
僅か50μのシートとの積層によって、ポリスチレン樹
脂発泡シート容器に110℃の耐熱性を付与できること
は、驚くべきことである。 It is surprising that a polystyrene resin foam sheet container can be provided with a heat resistance of 110 ° C. by laminating it with a sheet of only 50 μm.
本発明は、上述の構成を持つことにより、ポリスチレ
ン樹脂発泡シート成形容器に、110℃×10分間以上の実
用耐熱性と耐油性及び実用強度を兼備させ、優れた耐熱
容器を得ることができる。According to the present invention, the polystyrene resin foamed sheet molded container having the above-described configuration has practical heat resistance of 110 ° C. × 10 minutes or more, oil resistance and practical strength, and an excellent heat resistant container can be obtained.
従って、従来のポリスチレン樹脂発泡シート成形容器
では不可能とされていた電子レンジによる加熱調理用途
に、本発明容器は、最適なものとして使用できる。Therefore, the container of the present invention can be optimally used for heating and cooking applications by a microwave oven, which has been impossible with the conventional polystyrene resin foam sheet molded container.
上記電子レンジ用容器を強く要望していた食品業界及
び食品包装業界に対し、本発明は、貢献度の非常に高
い、優れた発明である。The present invention is an excellent invention having a very high degree of contribution to the food industry and the food packaging industry, which strongly demand the container for a microwave oven.
Claims (1)
クリル酸、メタクリル酸、又は無水マレイン酸の少なく
とも１種を、重合成分として、その合計量で５〜20重量
％含むスチレン系耐熱樹脂からなる厚み50μ〜250μの
二軸延伸シートを配した積層体を、該延伸シート面側の
温度が該発泡シート面側の温度より５〜30℃高温になる
よにう該積層体の両面から加熱した後、該延伸シート面
が成形体の内側になるように成形することを特徴とする
耐熱容器の製造方法。1. A thickness of a styrene-based heat-resistant resin containing at least one of acrylic acid, methacrylic acid, and maleic anhydride as a polymerization component in a total amount of 5 to 20% by weight on one surface of a polystyrene resin foam sheet. After heating the laminated body on which the biaxially stretched sheet of 50 μ to 250 μ is placed from both sides of the laminated body such that the temperature of the stretched sheet surface side is 5 to 30 ° C. higher than the temperature of the foamed sheet surface side. A method for producing a heat-resistant container, characterized in that the stretched sheet surface is formed inside the molded body.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62161843A JP2525611B2 (en) | 1987-06-29 | 1987-06-29 | Heat resistant container manufacturing method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62161843A JP2525611B2 (en) | 1987-06-29 | 1987-06-29 | Heat resistant container manufacturing method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS645817A JPS645817A (en) | 1989-01-10 |
| JP2525611B2 true JP2525611B2 (en) | 1996-08-21 |
Family
ID=15742997
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62161843A Expired - Fee Related JP2525611B2 (en) | 1987-06-29 | 1987-06-29 | Heat resistant container manufacturing method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2525611B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6487339A (en) * | 1987-09-30 | 1989-03-31 | Kanegafuchi Chemical Ind | Laminated foamed sheet for molding |
| US5177399A (en) * | 1988-06-27 | 1993-01-05 | Kabushiki Kaisha Toshiba | Color cathode ray tube apparatus |
| JP6572191B2 (en) * | 2016-10-06 | 2019-09-04 | 中央化学株式会社 | Packaging container, and method for producing and using packaging container |
-
1987
- 1987-06-29 JP JP62161843A patent/JP2525611B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS645817A (en) | 1989-01-10 |
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