JPH0641344A - Biodegradable thermoplastic resin foam and its production - Google Patents
Biodegradable thermoplastic resin foam and its productionInfo
- Publication number
- JPH0641344A JPH0641344A JP21916891A JP21916891A JPH0641344A JP H0641344 A JPH0641344 A JP H0641344A JP 21916891 A JP21916891 A JP 21916891A JP 21916891 A JP21916891 A JP 21916891A JP H0641344 A JPH0641344 A JP H0641344A
- Authority
- JP
- Japan
- Prior art keywords
- resin
- weight
- thermoplastic resin
- microbial
- foam
- 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.)
- Granted
Links
Landscapes
- Compositions Of Macromolecular Compounds (AREA)
- Biological Depolymerization Polymers (AREA)
- Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は微生物崩壊性熱可塑性樹
脂発泡体及びその製造方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biodegradable thermoplastic resin foam and a method for producing the same.
【０００２】[0002]
【従来技術及びその問題点】最近、欧米において廃棄物
処理に関連して、プラスチックの包装材料としての使用
禁止や規制の動きが活発化している中で、米国などでは
プラスチックに澱粉を混ぜた崩壊性プラスチックが実用
化されている。この場合の崩壊は、プラスチック中の澱
粉が微生物により分解されることによって起こる。しか
し、この澱粉混入プラスチックは澱粉の混入量が少ない
場合には崩壊せず、一方、多量に混入した場合では崩壊
は起こるものの、プラスチック中の澱粉が粒子状で可塑
性を有しないことから、得られたシートの機械物性や、
容器等への二次加工性は澱粉未混入のプラスチックに比
べて著しく劣るという問題があり、また用途的にも二次
加工をあまり必要としない、フィルムや、袋に限られて
いた。そこで、本発明者らは、先に、微生物崩壊性に優
れると共に、機械的物性及び二次加工性に優れた発泡体
及びその製造方法を既に提案した（特願平１−３３９１
９６号）。ところで、上記発泡体の微生物崩壊能を高め
る為には微生物分解性熱可塑性樹脂をできるだけ多量に
配合する必要がある。しかしながら、この場合、微生物
分解性熱可塑性樹脂の配合量が４０重量％を越えると得
られる発泡体は独立気泡率が低下すると共に表面に凹凸
が目立つようになり、この点において改良の余地を残す
ものであった。2. Description of the Related Art Recently, in Europe and the United States, the use of plastics as a packaging material has been banned or regulated in connection with waste disposal. Plastic has been put to practical use. The disintegration in this case occurs because the starch in the plastic is decomposed by microorganisms. However, this starch-containing plastic does not disintegrate when the amount of starch mixed is small, and on the other hand, it disintegrates when a large amount of starch is mixed, but because the starch in the plastic is particulate and not plastic, Mechanical properties of the seat,
The secondary processability for containers and the like has a problem that it is significantly inferior to that of a plastic without starch, and it is limited to a film or a bag that does not require secondary processing in terms of its application. Therefore, the present inventors have already proposed a foam which is excellent in microbial disintegration property, mechanical properties and secondary processability, and a method for producing the foam (Japanese Patent Application No. 1-3391).
96). By the way, in order to enhance the microbial disintegration ability of the foam, it is necessary to blend the microbial degradable thermoplastic resin as much as possible. However, in this case, when the compounding amount of the microbial decomposable thermoplastic resin exceeds 40% by weight, the obtained foam has a reduced closed cell rate and becomes conspicuous on the surface, which leaves room for improvement. It was a thing.
【０００３】[0003]
【発明が解決しようとする課題】本発明は上記問題点を
解決した発泡体及びその製造方法を提供することをその
課題とする。SUMMARY OF THE INVENTION It is an object of the present invention to provide a foam and a method for producing the same which solve the above problems.
【０００４】[0004]
【課題を解決するための手段】本発明者らは、前記課題
を解決すべく鋭意研究を重ねた結果、本発明を完成する
に至った。即ち、本発明によれば、微生物分解性熱可塑
性樹脂４０重量％超〜７０重量％と微生物非分解性熱可
塑性樹脂６０重量％未満〜３０重量％との混合樹脂を基
材樹脂とする発泡体であって、該発泡体を構成する気泡
の平均膜厚が１〜１００μｍ、かつ見掛け密度が０．５
ｇ／ｃｍ3以下であることを特徴とする微生物崩壊性熱
可塑性樹脂発泡体が提供される。また、本発明によれ
ば、微生物分解性熱可塑性樹脂４０重量％超〜７０重量
%と微生物非分解性熱可塑性樹脂６０重量％未満〜３０
重量％からなる混合樹脂を押出機内において、前記混合
樹脂の溶融温度以上の高温高圧下で溶融混練し、次いで
溶融混練物中に発泡剤を注入して両者を混合し、この混
合物を低圧帯域に押出して見掛密度０．５ｇ／ｃｍ3以
下の発泡体を得る方法であって、前記混合樹脂の発泡剤
注入直前における溶融混練を、式 ０．６≦η(B)／η(A)≦１．５ （式中、η(A)は発泡剤注入直前の溶融混練温度での微
生物分解性熱可塑性樹脂の溶融粘度（ポイズ）を示し、
η(B)は発泡剤注入直前の溶融混練温度での微生物非分
解性熱可塑性樹脂の溶融粘度（ポイズ）を示す）を満足
する条件にて行なうことを特徴とする微生物崩壊性熱可
塑性樹脂発泡体の製造方法が提供される。The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, according to the present invention, a foam using as a base resin a mixed resin of a microbial degradable thermoplastic resin of more than 40% by weight to 70% by weight and a microbial non-degradable thermoplastic resin of less than 60% by weight to 30% by weight. And the average film thickness of the bubbles constituting the foam is 1 to 100 μm, and the apparent density is 0.5.
Provided is a biodegradable thermoplastic resin foam characterized by having a content of g / cm 3 or less. Further, according to the present invention, the microbial degradable thermoplastic resin is more than 40% by weight to 70% by weight.
% And microbial non-degradable thermoplastic resin less than 60% by weight to 30
In an extruder, a mixed resin consisting of wt% is melt-kneaded under high temperature and high pressure above the melting temperature of the mixed resin, and then a foaming agent is injected into the melt-kneaded product to mix both, and this mixture is put into a low-pressure zone. A method of extruding to obtain a foam having an apparent density of 0.5 g / cm 3 or less, wherein the melt kneading of the mixed resin immediately before injecting the foaming agent is performed according to the formula 0.6 ≦ η (B) / η (A) ≦ 1.5 (where η (A) represents the melt viscosity (poise) of the microbial-degradable thermoplastic resin at the melt-kneading temperature immediately before the injection of the foaming agent,
η (B) is the microbial degradable thermoplastic resin foaming, characterized in that it is performed under the condition that the melt viscosity (poise) of the microbial non-degradable thermoplastic resin at the melt-kneading temperature immediately before the injection of the blowing agent is satisfied) A method of manufacturing a body is provided.
【０００５】本発明における微生物分解性熱可塑樹脂
(以下、樹脂Aともいう)としては、従来公知のものが示
され、例えば、脂肪族ポリエステル樹脂や、脂肪族ポリ
エステルに低分子量のポリアミドをブロック的に共重合
させたものや、ポリビニルアルコール等が挙げられる。
脂肪族ポリエステル樹脂には、脂肪族系の2価カルボン
酸を含む多価カルボン酸と、脂肪族系ジオールを含む多
価アルコールとの重縮合物、ヒドロキシ脂肪族カルボン
酸の重縮合物、ラクトンの開環重合物が包含され、その
具体例としては、例えば、エチレンジアジペート、プロ
ピオラクトン、カプロラクトン、β-ヒドロキシ酪酸等
から誘導される単独重合体や共重合体が例示される。こ
れらの重合体は、2種以上を混合して用いることができ
る。また、これらの重合体はいずれもリパーゼの作用に
よって加水分解されるものである。微生物非分解性熱可
塑性樹脂(以下、樹脂Bとも言う)としては、従来公知の
各種のものが挙げられる。このようなものとしては、好
ましくは、ポリスチレン系樹脂が挙げられる。このポリ
スチレン系樹脂は、スチレンを主体とする重合体であ
り、スチレン単独重合体及びその他のスチレンと共重合
し得るビニル系単量体との共重体、また一般に耐衝撃性
ポリスチレン樹脂と呼ばれているポリスチレンを主体と
するゴム系ポリマーとの共重合物又は混合物、さらに、
ジエン系単量体との共重合体等が包含される。耐衝撃性
ポリスチレン樹脂は、これを使用した場合には得られる
発泡体の柔軟性、弾性を向上させることができるので、
好適なものである。他の微生物非分解性熱可塑性樹脂と
しては、ポリエチレン、ポリプロピレン、プロピレン-
エチレン共重合体、ポリブテン、プロピレン-ブテン共
重合体、ポリ塩化ビニル、ポリ塩化ビニリデン、ポリエ
チレンテレフタレート、ポリブチレンテレフタレート、
各種ナイロン等が例示される。Microbial degradable thermoplastic resin in the present invention
As (hereinafter, also referred to as resin A), those conventionally known are shown, for example, an aliphatic polyester resin, an aliphatic polyester in which a low molecular weight polyamide is block-copolymerized, polyvinyl alcohol, and the like. Can be mentioned.
The aliphatic polyester resin includes a polycondensation product of a polyvalent carboxylic acid containing an aliphatic divalent carboxylic acid and a polyhydric alcohol containing an aliphatic diol, a polycondensation product of a hydroxy aliphatic carboxylic acid, and a lactone The ring-opening polymer is included, and specific examples thereof include homopolymers and copolymers derived from ethylene diadipate, propiolactone, caprolactone, β-hydroxybutyric acid and the like. These polymers can be used as a mixture of two or more kinds. All of these polymers are hydrolyzed by the action of lipase. Examples of the microbial non-degradable thermoplastic resin (hereinafter, also referred to as resin B) include various conventionally known resins. Preferred examples of such a material include polystyrene resins. This polystyrene resin is a polymer mainly composed of styrene, and is a styrene homopolymer and a copolymer of a vinyl monomer copolymerizable with other styrene, and is generally called an impact-resistant polystyrene resin. Copolymer or mixture with a rubber-based polymer mainly composed of polystyrene,
A copolymer with a diene monomer is included. Impact-resistant polystyrene resin can improve the flexibility and elasticity of the foam obtained when it is used,
It is suitable. Other microbial non-degradable thermoplastics include polyethylene, polypropylene, propylene-
Ethylene copolymer, polybutene, propylene-butene copolymer, polyvinyl chloride, polyvinylidene chloride, polyethylene terephthalate, polybutylene terephthalate,
Examples include various nylons.
【０００６】発泡剤としては、脂肪族炭化水素やハロゲ
ン化炭化水素あるいは分子中に水素原子を1個以上有す
るフロンガスが単独又は混合して用いられる。脂肪族炭
化水素の具体例として、例えば、プロパン、ノルマルブ
タン、イソブタン、ペンタン、イソペンタン等が挙げら
れ、ハロゲン化炭化水素としては、それら脂肪族炭化水
素の塩素又は臭素置換体が挙げられる。また、分子中に
水素原子を1個以上有するフロンガスとしては、クロロ
ジフロロメタン、トリフロロメタン、1,2,2,2-テトラフ
ロロエタン、1-クロロ-1,1-ジフロロエタン、1,1,-ジフ
ロロエタン、1-クロロ-1,2,2,2-テトラフロロエタン等
が挙げられる。上記の如き発泡剤を使用するに際して
は、沸点(1気圧下)が80℃以下のものを選択する必要が
ある。上記沸点が80℃を越えるものでは、発泡効率が劣
り不経済である。特に発泡剤としては、上記沸点範囲が
-20〜20℃のものを主成分として選択することが望まし
い。As the foaming agent, an aliphatic hydrocarbon, a halogenated hydrocarbon, or a CFC gas having at least one hydrogen atom in the molecule is used alone or as a mixture. Specific examples of the aliphatic hydrocarbon include propane, normal butane, isobutane, pentane, isopentane and the like, and examples of the halogenated hydrocarbon include chlorine or bromine substitution products of these aliphatic hydrocarbons. Further, as a CFC gas having one or more hydrogen atoms in the molecule, chlorodifluoromethane, trifluoromethane, 1,2,2,2-tetrafluoroethane, 1-chloro-1,1-difluoroethane, 1,1 , -Difluoroethane, 1-chloro-1,2,2,2-tetrafluoroethane and the like can be mentioned. When using the foaming agent as described above, it is necessary to select one having a boiling point (under 1 atmosphere) of 80 ° C. or less. If the boiling point exceeds 80 ° C, the foaming efficiency is poor and it is uneconomical. Particularly, as the foaming agent, the above boiling point range is
It is desirable to select the one whose main component is -20 to 20 ° C.
【０００７】本発明においては、樹脂A及び樹脂Bの使用
割合は、両者の合計量に対して、樹脂A:４０重量％超〜
７０重量%、好ましくは４５〜６５重量%、樹脂B:６０重
量％未満〜３０重量%、好ましくは５５〜３５重量%の割
合である。樹脂Aの割合が前記範囲より少なくなると、
得られる発泡体の崩壊性が低下し、一方、前記範囲より
多くなると得られる発泡体にフィッシュアイが発生する
ようになる。発泡剤の使用割合は、樹脂Aと樹脂Bの合計
量100重量部に対し、1〜60重量部、好ましくは2〜50重
量部であり、所望する発泡体の密度に応じて適当に定め
る。In the present invention, the proportion of the resin A and the resin B used is such that the resin A: more than 40% by weight based on the total amount of both.
70% by weight, preferably 45-65% by weight, resin B: less than 60% by weight-30% by weight, preferably 55-35% by weight. When the ratio of the resin A is less than the above range,
The disintegration property of the obtained foam decreases, while when it exceeds the above range, fish eyes are generated in the obtained foam. The use ratio of the foaming agent is 1 to 60 parts by weight, preferably 2 to 50 parts by weight, based on 100 parts by weight of the total amount of the resin A and the resin B, and is appropriately determined according to the desired density of the foam.
【０００８】本発明における発泡成形法としては、以下
に示す如き従来公知の各種の方法が挙げられる。 押出発泡成形法 発泡剤と樹脂と必要に応じて添加剤とを押出機内で溶融
混練し、次いで押出機先端に位置するダイスを通して低
圧下に押出す方法であり、目的に応じてフィルム状、シ
ート状、あるいは板状に押出し成形される。フィルム状
及びシート状のものはその後袋や容器などに加熱成形さ
れる。 アキューム発泡成形法 発泡剤と樹脂と必要に応じて添加剤とを押出機内で溶融
混練し、次いでこれ等を発泡の生じない条件でアキュー
ムレターに蓄積して一旦保持した後、低圧下に排出する
方法であり、通常は板状に押出し成形される。 射出発泡成形法 発泡剤と樹脂と必要に応じて添加剤とを押出機内で溶融
混練し、次いで押出機先端に取り付けられた所望の形状
を有する金型内に射出する方法であって、金型に内形状
に合致した成形品が得られる。Examples of the foam molding method in the present invention include various conventionally known methods as shown below. Extrusion foaming molding method A method of melt-kneading a foaming agent, a resin and, if necessary, an additive in an extruder, and then extruding under low pressure through a die located at the tip of the extruder. It is extruded into a sheet shape or a plate shape. The film-shaped and sheet-shaped ones are then heat-molded into bags, containers and the like. Accumulation foaming method A foaming agent, a resin and, if necessary, additives are melted and kneaded in an extruder, and then these are accumulated in an accumulation letter under the condition that foaming does not occur and once held, then discharged under low pressure. It is a method and is usually extruded into a plate shape. Injection foam molding method A method of melting and kneading a foaming agent, a resin and, if necessary, an additive in an extruder, and then injecting the mixture into a mold having a desired shape attached to the tip of the extruder. A molded product conforming to the inner shape can be obtained.
【０００９】本発明においては、押出機内における溶融
混練の溶融混練を前記式（１）を満足する条件を採用す
る。η(B)／η(A)が１．５を超える場合や、０．６未満
の場合には、得られる発泡体の独立気泡率が低下すると
ともに、発泡体表面に凹凸が目立つようになる。好まし
いη(B)／η(A)の範囲は０．７〜１．４である。なお、
η(A)及びη(B)は、樹脂Ａ及び樹脂Ｂのそれぞれの温度
と溶融粘度との関係をあらかじめフローテスタ等により
測定したデータに基づいて決めることができる。本発明
において、微生物崩壊性の良好な発泡体を得るには、発
泡体には、十分な発泡構造を保持させることが必要であ
る。本発明者らの研究によれば、発泡体の見掛け密度
を、一般的には、0.5g/cm3以下、好ましくは0.3〜0.01g
/cm3及び発泡体を構成する平均気泡膜厚を1〜100μｍに
規定することによって、微生物崩壊性の良好な発泡体が
得られることを見出した。上記発泡体において見掛け密
度が0.5g/cm3より大きな場合には良好な微生物崩壊を示
さない。一方、上記気泡の平均膜厚が１００μｍを超え
る場合には、発泡体の崩壊速度が低下し、1μｍより薄
い場合には、その発泡体は連続気泡構造部分が多くな
り、二次加工時に種々の問題が発生する(例えば二次発
泡力が弱く、シートの加熱成形不良を起こしたりす
る）。また、発泡体中の独立気泡率は８０％以上、好ま
しくは９０〜１００％の範囲である。In the present invention, the melt kneading of the melt kneading in the extruder is carried out under the condition that the above formula (1) is satisfied. When η (B) / η (A) is more than 1.5 or less than 0.6, the closed cell ratio of the obtained foam decreases and the surface of the foam becomes conspicuous. . The preferred range of η (B) / η (A) is 0.7 to 1.4. In addition,
η (A) and η (B) can be determined on the basis of the data obtained by previously measuring the relationship between the temperature of each of the resin A and the resin B and the melt viscosity by a flow tester or the like. In the present invention, in order to obtain a foam having good microbial disintegration, it is necessary that the foam has a sufficient foam structure. According to the studies by the present inventors, the apparent density of the foam is generally 0.5 g / cm 3 or less, preferably 0.3 to 0.01 g.
It has been found that a foam having good microbial disintegration can be obtained by defining the average cell membrane thickness of / cm 3 and the average cell membrane thickness constituting the foam to be 1 to 100 μm. When the apparent density of the foam is larger than 0.5 g / cm 3, good microbial disintegration is not exhibited. On the other hand, when the average film thickness of the bubbles exceeds 100 μm, the collapse rate of the foam decreases, and when the average thickness is less than 1 μm, the foam has a large number of open-cell structure portions, which causes various foaming during secondary processing. A problem occurs (for example, the secondary foaming force is weak, and the sheet may not be hot-molded). Further, the closed cell ratio in the foam is 80% or more, preferably 90 to 100%.
【００１０】発泡体の密度及び気泡膜厚は、上記した如
く発泡剤の使用量及びいわゆる気泡核剤の使用量により
容易に調整することができる。この気泡核生成剤として
は、たとえば、タルク、炭酸カルシウム、炭酸マグネシ
ウム、クレー、天然ケイ酸、カーボンブラック、ホワイ
トカーボン、シラス、石膏の如き無機物質、あるいは押
出機内の温度で分解してガスを発生する重炭酸ナトリウ
ム、炭酸アンモニウム、アジド化合物、アゾビスイソブ
チルニトリル、ジアゾアミノベンゼン、ベンゼンスルホ
ニルヒドラジド、P-トルエンスルホニルヒドラジドまた
は該温度で反応して炭酸ガスを発生する酸-アルカリの
組合わせ、たとえば、クエン酸のモノアルカリ金属塩と
炭酸のアルカリ金属塩、クエン酸のモノアルカリ金属塩
と重炭酸のアルカリ金属塩の如き化学発泡剤である。The density and cell film thickness of the foam can be easily adjusted by the amount of the foaming agent and the amount of the so-called cell nucleating agent as described above. Examples of the cell nucleating agent include inorganic materials such as talc, calcium carbonate, magnesium carbonate, clay, natural silicic acid, carbon black, white carbon, shirasu, and gypsum, or decomposed at the temperature in the extruder to generate gas. Sodium bicarbonate, ammonium carbonate, azide compound, azobisisobutyl nitrile, diazoaminobenzene, benzenesulfonyl hydrazide, P-toluenesulfonyl hydrazide or an acid-alkali combination which reacts at the temperature to generate carbon dioxide gas, for example, Chemical blowing agents such as monoalkali metal salts of citric acid and alkali metal carbonates, and monoalkali metal salts of citric acid and alkali metal bicarbonates.
【００１１】上記無機物質を気泡核剤として使用する場
合には、混合樹脂100重量部に対して0.01重量部以上5重
量部未満である。また、上記化学発泡剤を気泡核剤とし
て使用する場合には、同様に0.05〜5重量部である。本
発明においては、混合樹脂発泡体中に該樹脂100重量部
に対して上記で例示した無機物質からなる充填材を5〜8
0重量部配合することが望ましい。この様に多量に充填
材を混合樹脂発泡体中に配合させたものは微生物による
崩壊がいっそう促進される。特に多量に充填材を使用す
る場合には、発泡成形方法としては、前記の押出発泡成
形法、アキューム発泡成形法あるいは射出発泡成形法を
採用することが望ましい。When the above inorganic substance is used as a cell nucleating agent, the amount is 0.01 part by weight or more and less than 5 parts by weight with respect to 100 parts by weight of the mixed resin. When the chemical foaming agent is used as a cell nucleating agent, the amount is likewise 0.05 to 5 parts by weight. In the present invention, the filler made of the above-exemplified inorganic substances is added to the mixed resin foam in an amount of 5 to 8 with respect to 100 parts by weight of the resin.
It is desirable to add 0 part by weight. In this way, the mixture of a large amount of the filler in the mixed resin foam further promotes the disintegration by microorganisms. Especially when a large amount of the filler is used, it is desirable to adopt the extrusion foam molding method, the accumulation foam molding method or the injection foam molding method as the foam molding method.
【００１２】さらに、本発明においては、混合樹脂に対
して、必要に応じ、発泡に際しての発泡剤の樹脂から急
速な透過を防いで発泡体の収縮を抑制するために、収縮
防止剤を添加することもできる。このようなものとして
は、例えば、ポリオキシエチレンモノミリステート、ポ
リオキシプロピレンモノミリステート、ポリオキシエチ
レンモノパルミテート、ポリオキシプロピレンモノパル
ミテート、ポリオキシエチレンモノステアレート、ポリ
オキシプロピレンモノステアレート、ポリオキシエチレ
ンジステアレート、モノラウリン酸グリセライド、モノ
ミノスチン酸グリセライド、モノパルミチン酸グリセラ
イド、モノステアリン酸グリセライド、モノアラキン酸
グリセライド、ジラウリン酸グリセライド、ジパルミチ
ン酸グリセライド、ジステアリン酸グリセライド、1-パ
ルミト-2-ステアリン酸グリセライド、1-ステアロ-2-ミ
リスチン酸グリセライド、トリステアリン酸グリセライ
ド等の各種脂肪族エステルが挙げられる。この様な収縮
防止剤は、樹脂Bとしてポリオレフィン系樹脂を使用す
る場合に好適に用いられる。Further, in the present invention, a shrinkage-preventing agent is added to the mixed resin, if necessary, in order to prevent rapid permeation of the foaming agent from the resin during foaming and suppress shrinkage of the foam. You can also Examples of such substances include polyoxyethylene monomyristate, polyoxypropylene monomyristate, polyoxyethylene monopalmitate, polyoxypropylene monopalmitate, polyoxyethylene monostearate, polyoxypropylene monostearate. , Polyoxyethylene distearate, glyceride monolaurate, glyceride monominosuccinate, glyceride monopalmitate, glyceride monostearate, glyceride monoarachiate, glyceride dilaurate, glyceride dipalmitate, glyceride distearate, 1-palmito-2-stearin Examples thereof include various aliphatic esters such as acid glyceride, 1-stearo-2-myristate glyceride, and tristearic acid glyceride. Such a shrinkage inhibitor is preferably used when a polyolefin resin is used as the resin B.
【００１３】[0013]
【発明の効果】本発明による発泡体は、良好な微生物崩
壊性を有するものである。このような微生物崩壊性は、
微生物分解性樹脂の混入と、特定の発泡構造によって発
現されるものである。同じ樹脂組成の成形物であって
も、特定の発泡構造を有していないものや非発泡体のも
のはすぐれた微生物の崩壊性を示さない。本発明の微生
物崩壊性熱可塑樹脂発泡体は、廃棄後は微生物の存在す
る環境において容易に崩壊し、その嵩を減少させること
ができるため、廃棄物処理問題の解決に有効な手段を与
えるものである。また、この発泡体は、廃棄後回収もれ
により自然環境中に放置されても、微生物により崩壊さ
れるため、自然界の動植物の生命を危険にさらすことは
ない。更に、この発泡体中に充填材を含有させたもので
は、微生物による崩壊をいっそう促進させることができ
る。The foam according to the present invention has good microbial disintegration property. Such microbial disintegration is
It is expressed by mixing a microbial degradable resin and a specific foam structure. Molded products having the same resin composition but not having a specific foaming structure or non-foamed products do not exhibit excellent microbial disintegration. The microbial-disintegrating thermoplastic resin foam of the present invention can easily disintegrate in an environment where microorganisms are present after disposal and can reduce the volume thereof, and thus provide an effective means for solving the waste treatment problem. Is. Further, this foam does not endanger the life of animals and plants in the natural world because it is destroyed by microorganisms even if it is left in the natural environment due to leakage after recovery. Furthermore, in the case where the foam contains a filler, disintegration by microorganisms can be further promoted.
【００１４】[0014]
【実施例】次に本発明を実施例によりさらに詳細に説明
する。EXAMPLES Next, the present invention will be described in more detail by way of examples.
【００１５】実施例１〜６、比較例１〜５ 表1に示した組成の混合樹脂100重量部と表1に示す量の
気泡核剤（充填剤）とを、吐出量50kg/hrの押出機内に
おいて圧力190kg/cm2Gで溶融混練し、次いで、この溶融
混練物に発泡剤としてのブタン(ノルマルブタン:イソブ
タン7:3)を表1に示した量（混練樹脂１００重量部に対
する量）を押出機の途中より圧入して混合した後、この
溶融混練物を表1に示した温度(発泡温度)で押出機先端
に設けた環状ダイスを通して大気圧下に筒状に押出すと
ともに、その筒状押出物を押出方向に切開して厚さ2.5m
mのシート状発泡体を得た。得られた発泡体の発泡状
態、見掛け密度、平均気泡膜厚及び微生物崩壊性を表1
に併せて示した。尚、発泡剤を圧入する直前の溶融混練
物の温度はいずれも２００℃であった。Examples 1 to 6 and Comparative Examples 1 to 5 100 parts by weight of the mixed resin having the composition shown in Table 1 and the amount of the bubble nucleating agent (filler) shown in Table 1 were extruded at a discharge rate of 50 kg / hr. Melt kneading in the machine at a pressure of 190 kg / cm 2 G, and then the butane (normal butane: isobutane 7: 3) as a foaming agent was added to the melt kneaded material in the amounts shown in Table 1 (amount based on 100 parts by weight of the kneading resin). After being pressed in and mixed from the middle of the extruder, the melt-kneaded product was extruded into a cylinder under atmospheric pressure through an annular die provided at the tip of the extruder at the temperature shown in Table 1 (foaming temperature), and its The cylindrical extrudate is cut in the extrusion direction to a thickness of 2.5 m.
A sheet foam of m was obtained. Table 1 shows the foaming state, apparent density, average cell membrane thickness and microbial disintegration of the obtained foam.
Are also shown. The temperature of the melt-kneaded product immediately before press-fitting the foaming agent was 200 ° C.
【００１６】[0016]
【表１】 [Table 1]
【００１７】なお、表中に示した測定項目は、以下のよ
うにして測定されたものである。 (平均気泡膜厚の測定)平均気泡膜厚は、発泡シートを任
意の所で厚さ方向に切断し、その切断面の任意の5箇所
を選び、その厚さ方向にある気泡の膜厚を各々測定して
平均した値である。尚、上記測定は、(株)オリンパス製
の光学顕微鏡BH-2に同社のMOSカラーカメラOV100を取り
付け、これによって映し出された映像を(株)朋栄製のビ
テオマイクロスケーラIV-550を通し、モニター上で行な
った。The measurement items shown in the table are measured as follows. (Measurement of average cell film thickness) The average cell film thickness is obtained by cutting the foamed sheet in the thickness direction at any position, selecting any 5 positions on the cut surface, and measuring the film thickness of the cells in the thickness direction. The values are measured and averaged. In addition, the above measurement was carried out by mounting the MOS color camera OV100 of Olympus Co., Ltd. on the optical microscope BH-2 manufactured by Olympus Co., Ltd., and the image projected by this was passed through the Video Micro Scaler IV-550 manufactured by Toei Co., Ltd. Done above.
【００１８】(微生物崩壊性試験)オリーブ油から1分間
に220μmoleの脂肪酸を生成することができる力価をも
つリパーゼ溶液0.6ｍｌ、pH緩衝液(pH7)2ｍｌ、界面活
性剤1ｍｌ、水１６．４ｍｌ及び試料(試料巾の樹脂Aを
常に100mgとする。)を100ｍｌ三角フラスコに入れ30℃
で16時間反応させ、反応後生成した有機物量を全有機物
量を全有機炭素計で測定した。また、参考までに微生物
による分解速度を知るために8時間反応させた段階にお
いても全有機物量を測定した。測定に際し、対照実験と
して同じ方法でリパーゼ液を使用しないものも実施し、
測定値を補正した。(Microbial disintegration test) 0.6 ml of lipase solution having a titer capable of producing 220 μmole of fatty acid per minute from olive oil, 2 ml of pH buffer solution (pH 7), 1 ml of surfactant, 16.4 ml of water and Put the sample (resin A of the sample width is always 100 mg) in a 100 ml Erlenmeyer flask and 30 ℃.
After reacting for 16 hours, the amount of organic matter produced after the reaction was measured with a total organic carbon meter. For reference, the total amount of organic matter was also measured at the stage of reaction for 8 hours in order to know the rate of decomposition by microorganisms. At the time of measurement, the same method as the control experiment without lipase solution was also carried out,
The measured value was corrected.
【００１９】(溶融粘度の測定)η(A)、η(B)の測定は、
各々島津フローテスタＣＦＴ−５００型Ａ（（株）島津
製作所製）を使用して行なった。測定温度は上記溶融混
練物の温度で２００℃とした。(Measurement of Melt Viscosity) η (A) and η (B) are measured by
Shimadzu Flow Tester CFT-500 type A (manufactured by Shimadzu Corporation) was used for each test. The measurement temperature was 200 ° C. as the temperature of the melt-kneaded product.
【００２０】なお、表1において符号で示した樹脂の具
体的内容は次の通りである。 PCL :ポリカプロラクトン PS :ポリスチレン また、発泡状態についての符号A,B及びCの具体的内容は
次の通りである。 Ａ：独立気泡率が高く、表面状態も良好 Ｂ：独立気泡率が低く、表面には凹凸が多数発生 Ｃ：フィッシュアイ発生The concrete contents of the resins indicated by the symbols in Table 1 are as follows. PCL: Polycaprolactone PS: Polystyrene The specific contents of the symbols A, B and C for the foamed state are as follows. A: High closed cell rate and good surface condition B: Low closed cell rate, many irregularities on the surface C: Fish eye generation
───────────────────────────────────────────────────── フロントページの続き (72)発明者 岩本 晃 茨城県つくば市東２丁目１番16号 大野ハ イツ101号 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akira Iwamoto 2-16, Higashi 2-chome, Tsukuba, Ibaraki Prefecture No. 101, Ohno Heights
Claims (4)
〜７０重量％と微生物非分解性熱可塑性樹脂６０重量％
未満〜３０重量％との混合樹脂を基材樹脂とする発泡体
であって、該発泡体を構成する気泡の平均膜厚が１〜１
００μｍ、かつ見掛け密度が０．５ｇ／ｃｍ3以下であ
ることを特徴とする微生物崩壊性熱可塑性樹脂発泡体。1. A microbial-decomposable thermoplastic resin of more than 40% by weight to 70% by weight and a microbial-nondegradable thermoplastic resin of 60% by weight.
It is a foam using a mixed resin of less than 30% by weight as a base resin, and the average film thickness of the bubbles constituting the foam is 1 to 1.
A microbial-disintegrating thermoplastic resin foam, which has an apparent density of 00 μm and is 0.5 g / cm 3 or less.
重量部に対して５〜８０重量部の充填剤を含有すること
を特徴とする微生物崩壊性熱可塑性樹脂発泡体。2. The mixed resin 100 according to claim (1).
A biodegradable thermoplastic resin foam, comprising 5 to 80 parts by weight of a filler with respect to parts by weight.
〜７０重量%と微生物非分解性熱可塑性樹脂６０重量％
未満〜３０重量％からなる混合樹脂を押出機内におい
て、前記混合樹脂の溶融温度以上の高温高圧下で溶融混
練し、次いで溶融混練物中に発泡剤を注入して両者を混
合し、この混合物を低圧帯域に押出して見掛密度０．５
ｇ／ｃｍ3以下の発泡体を得る方法であって、前記混合
樹脂の発泡剤注入直前における溶融混練を、式 ０．６≦η(B)／η(A)≦１．５ （式中、η(A)は発泡剤注入直前の溶融混練温度での微
生物分解性熱可塑性樹脂の溶融粘度（ポイズ）を示し、
η(B)は発泡剤注入直前の溶融混練温度での微生物非分
解性熱可塑性樹脂の溶融粘度（ポイズ）を示す）を満足
する条件にて行なうことを特徴とする微生物崩壊性熱可
塑性樹脂発泡体の製造方法。3. A microbial degradable thermoplastic resin of more than 40% by weight to 70% by weight and a microbial non-degradable thermoplastic resin of 60% by weight.
In the extruder, a mixed resin consisting of less than 30 wt% is melt-kneaded under high temperature and high pressure above the melting temperature of the mixed resin, and then a foaming agent is injected into the melt-kneaded product to mix them, and this mixture is mixed. Apparent density 0.5 extruded into low pressure zone
A method for obtaining a foamed body of g / cm 3 or less, wherein melt kneading of the mixed resin immediately before injecting a foaming agent is carried out by formula 0.6 ≦ η (B) / η (A) ≦ 1.5 (wherein η (A) represents the melt viscosity (poise) of the microbial-degradable thermoplastic resin at the melt-kneading temperature immediately before the injection of the foaming agent,
η (B) is the microbial degradable thermoplastic resin foaming, characterized in that it is performed under the condition that the melt viscosity (poise) of the microbial non-degradable thermoplastic resin at the melt-kneading temperature immediately before the injection of the blowing agent is satisfied) Body manufacturing method.
５〜８０重量部混合することを特徴とする請求項３に記
載の微生物崩壊性熱可塑性樹脂発泡体の製造方法。4. The method for producing a microbial-degradable thermoplastic resin foam according to claim 3, wherein 5 to 80 parts by weight of the filler is mixed with 100 parts by weight of the mixed resin.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3219168A JPH0717780B2 (en) | 1991-08-05 | 1991-08-05 | Microbial degradable thermoplastic resin foam and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3219168A JPH0717780B2 (en) | 1991-08-05 | 1991-08-05 | Microbial degradable thermoplastic resin foam and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0641344A true JPH0641344A (en) | 1994-02-15 |
| JPH0717780B2 JPH0717780B2 (en) | 1995-03-01 |
Family
ID=16731270
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3219168A Expired - Fee Related JPH0717780B2 (en) | 1991-08-05 | 1991-08-05 | Microbial degradable thermoplastic resin foam and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0717780B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2852599A1 (en) * | 2003-03-17 | 2004-09-24 | Odil | Biodegradable material useful for making horticultural containers or outer packaging comprises an alloy of polycaprolactone and polystyrene and a vegetable filler |
| US8307120B2 (en) | 2006-03-07 | 2012-11-06 | Nec Corporation | Resource information managing device, system, method, and program |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02298525A (en) * | 1988-12-30 | 1990-12-10 | Natl Starch & Chem Corp | Biodegradable molding and its manufacture |
-
1991
- 1991-08-05 JP JP3219168A patent/JPH0717780B2/en not_active Expired - Fee Related
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02298525A (en) * | 1988-12-30 | 1990-12-10 | Natl Starch & Chem Corp | Biodegradable molding and its manufacture |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2852599A1 (en) * | 2003-03-17 | 2004-09-24 | Odil | Biodegradable material useful for making horticultural containers or outer packaging comprises an alloy of polycaprolactone and polystyrene and a vegetable filler |
| WO2004084619A3 (en) * | 2003-03-17 | 2005-02-10 | Alliance 47 | Adjustably biodegradable material for a horticultural container and overpackaging for containers |
| US8307120B2 (en) | 2006-03-07 | 2012-11-06 | Nec Corporation | Resource information managing device, system, method, and program |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0717780B2 (en) | 1995-03-01 |
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