JP4614634B2 - Recycling method of thermoplastic resin composition waste, manufacturing method of thermoplastic resin composition molded body, and thermoplastic resin composition molded body - Google Patents

Description

【００５５】
【表２】

【００５６】
これらの表から明らかなように、家電４品目のプラスチック部材において、ポリオレフィン系熱可塑性樹脂組成物およびポリスチレン系熱可塑性樹脂組成物の占める割合は、一般的に６０質量％を超えることがわかる。
【００５７】
よって、家電４品目のプラスチック部材うち、少なくともポリオレフィン系熱可塑性樹脂組成物およびポリスチレン系熱可塑性樹脂組成物からなるプラスチック部材をマテリアルリサイクルすることができれば、家電４品目のプラスチック部材の再資源化率は６０％を超えるといえる。
【００５８】
また、これらの表から明らかなように、家電４品目に多量に使用されているポリオレフィン系熱可塑性樹脂組成物の比重の範囲は、一般的に０．８５〜１．００の範囲に含まれることがわかる。また、ポリスチレン系熱可塑性樹脂組成物の比重の範囲は、一般的に１．００〜１．０８の範囲に含まれることがわかる。そして、その他の系統の熱可塑性樹脂組成物からなる部材の大部分は、その比重が、一般的に１．０８〜２．００の範囲に含まれることがわかる。
【００５９】
ここで、本明細書において、熱可塑性樹脂組成物と呼称する際には、狭義の熱可塑性樹脂組成物のみを示すのではなく、熱可塑性エラストマ−組成物や高分子組成物なども含む広い意味での熱可塑性樹脂組成物を示すものとする。
【００６０】
そして、上記より、一般的には、比重が１．０１〜１．０８の範囲にある分離液を用いることにより、ポリオレフィン系熱可塑性樹脂組成物およびポリスチレン系熱可塑性樹脂組成物からなる部材と、その他の系統の熱可塑性樹脂組成物からなる部材の大部分とを分離することが可能であることがわかる。
【００６１】
また、上記より、一般的には、比重が０．９２〜１．００の範囲にある分離液を用いることにより、ポリオレフィン系熱可塑性樹脂組成物からなる部材と、ポリスチレン系熱可塑性樹脂組成物からなる部材とを分離することが可能であることがわかる。
【００６２】
＜廃棄物の再資源化方法の手順＞
ここで、本発明の熱可塑性樹脂組成物廃材の再資源化方法について、図１および図２に示すような、ポリスチレン系熱可塑性樹脂組成物のマテリアルリサイクルする場合の具体例を用いて、さらに詳細に説明する。
【００６３】
この具体例においては、まず、図１に示すように、家庭などから廃棄された使用済みの家電４品目を回収する（ステップ１０１）。そして、該家電４品目の廃棄物を解体して、コンプレッサ−、熱交換器などの大型の金属部品などを部品ごとに回収する（ステップ１０２）。
【００６４】
次に、大型金属部品などが回収された家電４品目の廃棄物の残りの部材は、大型破砕機で６０ｍｍ程度に粗破砕する（ステップ１０３）。
【００６５】
続いて、該家電４品目の廃棄物の破砕物を、金属選別機で金属系破砕物とプラスチック系破砕物に選別し（ステップ１０４）、鉄、銅、アルミニウムなどの金属を回収した後、プラスチック系破砕物から、風力選別機を用いてポリウレタン断熱材や発泡ポリスチレンを除去する（ステップ１０５）。
【００６６】
そして、比重１．０８の比重液、たとえば塩化ナトリウム水溶液を用いてプラスチック系破砕物を比重分離し（ステップ１０６）、ポリオレフィン系熱可塑性樹脂組成物とポリスチレン系熱可塑性樹脂組成物をその他の系統の熱可塑性樹脂組成物から分離し、さらに、ステップ１０６で分離したポリオレフィン系熱可塑性樹脂組成物とポリスチレン系熱可塑性樹脂組成物の混合破砕物は、比重１．００の比重液、たとえば水を用いてポリオレフィン系熱可塑性樹脂組成物とポリスチレン系熱可塑性樹脂組成物に分離する（ステップ１０７）。
【００６７】
さらに、ステップ１０７で分離したポリスチレン系熱可塑性樹脂組成物は、ポリスチレン（ＰＳ）、スチレン−ブタジエン（ＳＢ）、アクリロニトリル−スチレン（ＡＳ）、アクリロニトリル−スチレン−ブタジエン（ＡＢＳ）に分離する（ステップ１０８）。
【００６８】
次に、図２に示すように、図１において分離したポリスチレン系熱可塑性樹脂組成物の破砕物を、それぞれ１０ｍｍ程度に微破砕したのち（ステップ２０１）、洗浄し付着している異物を除去する（ステップ２０２）。さらに、洗浄した各熱可塑性樹脂組成物の破砕物を均一に混合する（ステップ２０３）し、加熱溶融した後に成形して（ステップ２０４）、ペレット状の成形用樹脂原料とする（ステップ２０５）。そして、このペレット状の樹脂原料を射出成形機に投入し成形体を作製する（ステップ２０６）。
【００６９】
本発明の熱可塑性樹脂組成物廃材の再資源化方法は、図１および図２に示した各ステップのすべてを備える必要はないが、プラスチック廃棄物を回収するステップと、該プラスチック廃棄物を破砕するステップと、該プラスチック系破砕物から金属系破砕物と低嵩比重破砕物とを分離するステップと、該分離されたプラスチック廃棄物から熱可塑性樹脂組成物を主体とするプラスチック系破砕物を分離するステップと、該プラスチック系破砕物を均一に混合するステップと、該プラスチック系破砕物の混合物を加熱溶融した後に成形するステップとを少なくとも備えていることが好ましい。
【００７０】
また、本発明の熱可塑性樹脂組成物廃材の再資源化方法には、図１および図２に示されていないステップが必要により付加、あるいは削除されていてもかまわない。
【００７１】
そして、本発明の熱可塑性樹脂組成物廃材の再資源化方法は、図１の手解体ステップ（ステップ１０２）において選択的に分離回収された熱可塑性樹脂組成物廃材と、ステップ１０８で分離した熱可塑性樹脂組成物廃材とを混合し、加熱溶融して熱可塑性樹脂組成物成形体を得る方法であってもかまわない。
【００７２】
また、本発明の熱可塑性樹脂組成物廃材の再資源化方法は、図１の手解体ステップ（ステップ１０２）において選択的に分離回収された複数種類の熱可塑性樹脂組成物廃材を混合し、加熱溶融して熱可塑性樹脂組成物成形体を得る方法であってもかまわない。
【００７３】
＜廃棄物の手解体ステップ＞
本発明の熱可塑性樹脂組成物廃材の再資源化方法は、同一系統の熱可塑性樹脂組成物からなる部材の比重は一定の範囲内にあることを利用して、熱可塑性樹脂組成物からなる部材を備えた製品の廃棄物を選択的に回収するステップを含むことが好ましい。
【００７４】
ここで、本発明の熱可塑性樹脂組成物廃材の再資源化方法においては、選択的に回収される製品において、熱可塑性樹脂組成物からなる部材は、ポリスチレン系熱可塑性樹脂組成物からなる部材およびその他の系統の熱可塑性樹脂組成物からなる部材であることが好ましい。
【００７５】
ここで、本発明の熱可塑性樹脂組成物廃材の再資源化方法においては、廃棄された製品を構成する熱可塑性樹脂組成物の部材に記載および／または添付された標章を認識することにより、同一系統の熱可塑性樹脂組成物からなる部材を選択的に回収することが望ましい。
【００７６】
たとえば、ポリスチレン系熱可塑性樹脂組成物廃材として冷蔵庫の棚板材を回収し、ポリスチレン（ＰＳ）とアクリロニトリル−スチレン（ＡＳ）に分離すると、部材として回収した熱可塑性樹脂組成物廃材は、図１のステップ１０８で分離回収した熱可塑性樹脂組成物廃材よりも、異なった組成の熱可塑性樹脂組成物廃材の混入が少なくなる。よって、加熱溶融によって得られた熱可塑性樹脂組成物成形体の特性が安定し、マテリアルリサイクルしたポリスチレン系熱可塑性樹脂組成物からなる部材またはその原料の特性は大幅に向上でき、より一層の用途の拡大が可能となる。
【００７７】
ここで、廃棄された製品を構成する熱可塑性樹脂組成物の部材に記載および／または添付された標章の認識方法は、肉眼によるものであっても、自動認識装置によるものであってもよい。
【００７８】
また、廃棄された製品を構成する熱可塑性樹脂組成物の部材に記載および／または添付された標章としては、特に限定するものではないが、肉眼または自動認識装置により容易に認識して自他の識別機能を発揮するものであればよく、たとえば、特定の図形、特定の数値、特定の記号、特定の文字、特定の模様、特定の色彩、特定のバーコード、またはそれらの組合せなどが挙げられる。
【００７９】
さらに、この標章は、平面状のものであっても立体状のものであってもよく、廃棄された製品に直接記載されてもよく、シール状の用紙に記載して廃棄された製品に添付してもよい。あるいは、たとえば紫外線などの照射により発色するような特殊なインキで記載されたものであってもよい。
【００８０】
そして、この標章の製品への記載および／または添付の時期は、該商品の製造段階、出荷段階、販売段階、廃棄段階、回収段階などのいずれの段階であってもよいが、特に製造段階または出荷段階において記載および／または添付されることが好ましい。
【００８１】
さらに、この標章を肉眼または自動認識装置により認識することにより、容易に製品を構成する熱可塑性樹脂組成物の組成が読取れることが好ましい。
【００８２】
＜廃棄物の破砕ステップ＞
本発明の熱可塑性樹脂組成物廃材の再資源化方法は、廃棄物を破砕するステップを含むことが好ましい。
【００８３】
ここで、プラスチック部材を含む廃棄物は、特に限定するものではないが、たとえば破砕機または細断機などにより破砕されることが好ましい。
【００８４】
そして、破砕された熱可塑性樹脂組成物廃材の粒径は１０ｍｍ以上であることが好ましく、特に４０ｍｍ以上であることがより好ましい。また、この粒径は８０ｍｍ以下であることが好ましく、特に６０ｍｍ以下であることが好ましい。
【００８５】
この粒径が１０ｍｍ未満あるいは８０ｍｍを超える場合には次ステップでの金属の選別精度が低下するという傾向があり、さらに、この粒径が１０ｍｍ未満の場合には、破砕に長時間を要するためプラスチックが溶融あるいは熱酸化劣化をおこすという傾向があり、この粒径が８０ｍｍを超えると、嵩比重が小さくなり以後のステップでの作業性に悪影響を及ぼすという傾向がある。
【００８６】
なお、コンプレッサ−、熱交換器をはじめとする大型の金属部材などの破砕が困難な部材は、あらかじめ分解してプラスチック部材を含む廃棄物から取り外しておいてもよい。
【００８７】
＜金属系破砕物の選別ステップ＞
本発明の熱可塑性樹脂組成物廃材の再資源化方法は、破砕された廃棄物を金属系破砕物とプラスチック系破砕物と低嵩比重破砕物とに選別するステップを含むことが好ましい。
【００８８】
ここで、低嵩比重破砕物は、特に限定するものではないが、たとえば風力を用いて選別することが好ましい。なお、低嵩比重破砕物とは、嵩比重が０．３以下の破砕物を意味するものとする。低嵩比重破砕物の具体例としては、特に限定するものではないが、ポリウレタン系断熱材の破砕物や、発泡スチロ−ル系の破砕物などが挙げられる。
【００８９】
そして、金属系破砕物のうち鉄系金属は、特に限定するものではないが、たとえば磁力を用いて選別することが好ましい。さらに、金属系破砕物のうちアルミニウム系金属や銅系金属は、特に限定するものではないが、たとえば渦電流を用いて選別することが好ましい。
【００９０】
さらに、破砕された廃棄物を金属系破砕物とプラスチック系破砕物と低嵩比重破砕物に選別する際に、風力による選別、磁力による選別、渦電流による選別を行う場合には、その順序は特に限定するものではないが、選別の効率の観点からは、まず磁力により鉄系金属を分離し、次いで渦電流によりアルミニウム系金属や銅系金属を選別し、続いて風力により低嵩比重破砕物を選別し、残った混合プラスチック系の破砕物を、下記の熱可塑性樹脂組成物の比重差による分離ステップに移すことが好ましい。
【００９１】
＜熱可塑性樹脂組成物の比重差による分離ステップ＞
本発明の熱可塑性樹脂組成物廃材の再資源化方法は、プラスチック系破砕物を比重の異なる複数の分離液を用いて熱可塑性樹脂組成物の系統別に分離するステップを含むことが好ましい。
【００９２】
ここで、互いに比重の異なる２種類のＸ分離液と、Ｙ分離液とを用いて、プラスチック系破砕物を熱可塑性樹脂組成物の系統別に分離することが好ましい。
【００９３】
また、Ｘ分離液の比重は１．００以上であることが好ましく、特に１．０１以上であることがより好ましい。また、この比重は１．１０以下であることが好ましく、特に１．０８以下であることがより好ましい。この比重が１．００未満の場合には、ポリオレフィン系プラスチックが混入するという傾向があり、この比重が１．１０を超えると、ポリアミド系、ポリカーボネート系、ゴムなどが混入するという傾向がある。
【００９４】
さらに、Ｙ分離液の比重は０．９２以上であることが好ましく、特に０．９５以上であることがより好ましい。また、この比重は１．０１以下であることが好ましく、特に１．００以下であることがより好ましい。この比重が０．９２未満の場合には、ポリオレフィン系プラスチックの一部が沈降し回収率が低下するという傾向があり、この比重が１．０１を超えると、ポリスチレン系プラスチックの一部が混入するという傾向がある。
【００９５】
熱可塑性樹脂組成物の比重差による分離ステップは、特に必要するものではないが、下記のポリスチレン系樹脂組成物の分離ステップの作業（ステップ１０８）を簡易にするために、Ｘ分離液を用いてポリオレフィン系熱可塑性樹脂組成物からなる部材およびポリスチレン系熱可塑性樹脂組成物からなる部材と、その他の系統の熱可塑性樹脂組成物からなる部材とを分離した後、Ｙ分離液を用いてポリオレフィン系熱可塑性樹脂組成物からなる部材と、ポリスチレン系熱可塑性樹脂組成物からなる部材とを分離することが好ましい。
【００９６】
このステップを行うことによって、ポリオレフィン系熱可塑性樹脂組成物のマテリアルリサイクルが可能となるほか、次ステップの熱可塑性樹脂組成物廃材の量を大幅に低減できるため、分離作業が容易となる。
【００９７】
＜ポリスチレン系樹脂組成物の分離ステップ＞
本発明の熱可塑性樹脂組成物廃材の再資源化方法は、ポリスチレン系熱可塑性樹脂組成物を分離するステップを含むことが好ましい。
【００９８】
比重差による分離ステップで分離回収されたポリスチレン系熱可塑性樹脂組成物は、ポリスチレン（ＰＳ）、スチレン−ブタジエン（ＳＢ）、アクリロニトリル−スチレン（ＡＳ）、アクリロニトリル−スチレン−ブタジエン（ＡＢＳ）、およびそれ以外に分離される。
【００９９】
ここで、ポリスチレン系熱可塑性樹脂組成物の分離は、主に目視によってなされるが、燃焼性、溶剤による溶解性、さらには樹脂組成の分析装置（赤外分光光度計、ガスクロマトグラフ質量分析装置など）などの方法を併用することが好ましい。
【０１００】
また、目視によるポリスチレン系熱可塑性樹脂組成物の分離について説明すると、ポリスチレン（ＰＳ）およびアクリロニトリル−スチレン（ＡＳ）は、透明性が高いことから、その他のポリスチレン系熱可塑性樹脂組成物とは容易に識別できる。そして、ポリスチレン（ＰＳ）とアクリロニトリル−スチレン（ＡＳ）の分離は、目視、打音のほか、燃焼性、溶剤による溶解性、さらには樹脂組成の分析装置などによりなされる。
【０１０１】
そして、廃棄物の手解体ステップの項で述べたように、ポリスチレン（ＰＳ）、アクリロニトリル−スチレン（ＡＳ）で構成される冷蔵庫の棚板などは、手解体で分離回収し、該部材の材質表示に基いてポリスチレン（ＰＳ）とアクリロニトリル−スチレン（ＡＳ）を分離するのが好ましく、より効果的である。
【０１０２】
次に、スチレン−ブタジエン（ＳＢ）とアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）の目視による分離について説明する。ポリスチレン（ＰＳ）およびアクリロニトリル−スチレン（ＡＳ）を分離したポリスチレン系熱可塑性樹脂組成物は、主にスチレン−ブタジエン（ＳＢ）とアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）で構成される。
【０１０３】
そして、スチレン−ブタジエン（ＳＢ）とアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）の分離は、目視、打音のほか、燃焼性、溶剤による溶解性、さらには樹脂組成の分析装置などによりなされる。
【０１０４】
ここで、冷蔵庫の内箱材等に使用されている真空成形により付形されたスチレン−ブタジエン（ＳＢ）あるいはアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）の肉厚は１．０ｍｍ程度であり、射出成形で付形されたその他の部材からなるプラスチック破砕物の肉厚（２．０ｍｍ）程度よりも薄いため容易に識別可能である。
【０１０５】
さらに、真空成形により付形されたスチレン−ブタジエン（ＳＢ）あるいはアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）は、一般のスチレン−ブタジエン（ＳＢ）あるいはアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）よりも剛性、粘性とも優れているため、脆性材料であるポリスチレン（ＰＳ）あるいはアクリロニトリル−スチレン（ＡＳ）と混合することが好ましい。
【０１０６】
＜熱可塑性樹脂組成物の成形ステップ＞
本発明の熱可塑性樹脂組成物廃材の再資源化方法は、系統別に分離された熱可塑性樹脂組成物を特定の形状に成形するステップを含むことが好ましい。
【０１０７】
熱可塑性樹脂組成物の成形ステップにおいては、系統別に分離された熱可塑性樹脂組成物の中でも、熱可塑性樹脂組成物を溶融した後、特定の形状に成形することにより、マテリアルリサイクルを行うことが好ましい。この場合、マテリアルリサイクルされない系統の熱可塑性樹脂組成物は、油化あるいは固化された上で、燃料としてサーマルリサイクルに用いられることが望ましい。
【０１０８】
さらに、系統別に分離された熱可塑性樹脂組成物のうち熱可塑性樹脂組成物と、同系統の未使用の熱可塑性樹脂組成物とを混合して溶融した後、特定の形状に成形することが好ましい。この際、加えられる未使用の熱可塑性樹脂組成物の量は、マテリアルリサイクルの用途などにより適宜調製することが望ましい。
【０１０９】
本発明の熱可塑性樹脂組成物廃材の再資源化方法においては、マテリアルリサイクルされる熱可塑性樹脂組成物は、特に限定されるものではなく、熱可塑性樹脂組成物の比重差による分離ステップで用いられる分離液の比重を適宜選択することで、従来公知のいずれの熱可塑性樹脂組成物もマテリアルリサイクルすることが可能である。
【０１１０】
マテリアルリサイクルされる熱可塑性樹脂組成物の具体例としては、ポリオレフィン系、ポリスチレン系、ポリカーボネート系、ポリメチルメタクリレート系などの熱可塑性樹脂組成物が挙げられる。これらの中でも、ポリエチレン系やポリプロピレン系などのポリオレフィン系熱可塑性樹脂組成物、およびポリスチレン系、ＡＢＳ系などのポリスチレン系熱可塑性樹脂組成物は、下記の表３に示されるように、他の熱可塑性樹脂組成物に比べて加工性、経済性などの点で優れているので、本発明の熱可塑性樹脂組成物廃材の再資源化方法において好適にマテリアルリサイクルすることが可能である。
【０１１１】
【表３】

【０１１２】
ここで、表３における主要な熱可塑性樹脂組成物の特性は、下記の基準に従って評価されたものである。
○：優れている
△：どちらともいえない
×：劣る
なお、熱可塑性樹脂組成物の成形ステップにおいては、熱可塑性樹脂組成物を加熱して溶融することにより、マテリアルリサイクルすることが望ましい。
【０１１３】
それゆえ、該熱可塑性樹脂組成物の融点をＴ℃とすると、この時の加熱温度はＴ℃以上であることが好ましく、特に（Ｔ＋１０）℃以上であることがより好ましい。また、この時の加熱温度は（Ｔ＋１２０）℃以下であることが好ましく、特に（Ｔ＋８０）℃以下であることがより好ましい。この時の加熱温度がＴ℃未満の場合には、該熱可塑性樹脂組成物が充分に溶融しないために成形し難いという傾向があり、この時の加熱温度が（Ｔ＋１２０）℃を超えると、該熱可塑性樹脂組成物が熱劣化するという傾向がある。
【０１１４】
＜廃棄物の再資源化方法の手順（その２）＞
ここで、本発明の熱可塑性樹脂組成物廃材の再資源化方法について、図１および図２に示すような、ポリオレフィン系およびポリスチレン系熱可塑性樹脂組成物のマテリアルリサイクルする場合の具体例を用いて、さらに詳細に説明する。
【０１１５】
この具体例では、まず、図１に示すように、家庭などから廃棄された使用済みの家電４品目を回収する（ステップ１０１）。そして、該家電４品目の廃棄物を解体して、コンプレッサ−、熱交換器などの大型の金属部品などを部品ごとに回収する（ステップ１０２）。
【０１１６】
次に、大型金属部品などが回収された家電４品目の廃棄物の残りの部材は、大型破砕機で６０ｍｍ程度に粗破砕する（ステップ１０３）。
【０１１７】
続いて、該家電４品目の廃棄物の破砕物を、金属選別機で金属系破砕物とプラスチック系破砕物に選別し（ステップ１０４）、鉄、銅、アルミニウムなどの金属を回収した後、プラスチック系破砕物から、風力選別機を用いてポリウレタン断熱材や発泡ポリスチレンを除去する（ステップ１０５）。
【０１１８】
そして、比重１．０８の比重液、たとえば塩化ナトリウム水溶液を用いてプラスチック系破砕物を比重分離し（ステップ１０６）、ポリオレフィン系熱可塑性樹脂組成物とポリスチレン系熱可塑性樹脂組成物をその他の系統の熱可塑性樹脂組成物から分離し、さらに、ステップ１０６で分離したポリオレフィン系熱可塑性樹脂組成物とポリスチレン系熱可塑性樹脂組成物の混合破砕物は、比重１．００の比重液、たとえば水を用いてポリオレフィン系熱可塑性樹脂組成物とポリスチレン系熱可塑性樹脂組成物に分離する（ステップ１０７）。
【０１１９】
そして、ポリスチレン系熱可塑性樹脂組成物を目視、燃焼性、溶剤による溶解性、さらには樹脂組成の分析装置（赤外分光光度計、ガスクロマトグラフ質量分析装置など）などの方法を併用して、ポリスチレン（ＰＳ）、スチレン−ブタジエン（ＳＢ）、アクリロニトリル−スチレン（ＡＳ）、アクリロニトリル−スチレン−ブタジエン（ＡＢＳ）、およびそれ以外に分離する（ステップ１０８）。
【０１２０】
次に、図２に示すように、図１において分離したポリスチレン（ＰＳ）とスチレン−ブタジエン（ＳＢ）、およびアクリロニトリル−スチレン（ＡＳ）とアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）の破砕物を混合し、それぞれ１０ｍｍ程度に微破砕したのち（ステップ２０１）、洗浄し付着している異物を除去する（ステップ２０２）。
【０１２１】
さらに、洗浄した各熱可塑性樹脂組成物の破砕物を均質に混合する（ステップ２０３）し、加熱成形して（ステップ２０４）、ペレット状の成形用樹脂原料とする（ステップ２０５）。そして、このペレット状の樹脂原料を射出成形機に投入し成形体を作製する（ステップ２０６）。
【０１２２】
ここで、ポリスチレン（ＰＳ）とスチレン−ブタジエン（ＳＢ）、およびアクリロニトリル−スチレン（ＡＳ）とアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）の破砕物の混合は、微破砕（ステップ２０１）後、あるいは洗浄（ステップ２０２）後であってもかまわない。
【０１２３】
さらに、図１において分離したポリオレフィン系プラスチックについても、同様に、図２のステップ２０１〜２０６を行い成形体を作製する。
【０１２４】
本発明の熱可塑性樹脂組成物廃材の再資源化方法は、図１および図２に示した各ステップのすべてを備える必要はなく、プラスチック廃棄物を回収するステップと、該プラスチック廃棄物を破砕するステップと、該プラスチック系破砕物から金属系破砕物と低嵩比重破砕物とを分離するステップと、該分離されたプラスチック廃棄物から熱可塑性樹脂組成物を主体とするプラスチック系破砕物を分離するステップと、該熱可塑性樹脂組成物をマテリアルリサイクルするステップとを少なくとも備えていることが好ましい。
【０１２５】
また、本発明の熱可塑性樹脂組成物廃材の再資源化方法には、図１および図２に示されていないステップが必要により付加されていてもかまわない。
【０１２６】
＜廃棄物の再資源化システム＞
本発明の熱可塑性樹脂組成物廃材の再資源化方法を実施するには、下記の熱可塑性樹脂組成物廃材の再資源化システムを用いることが好ましい。
【０１２７】
本発明に用いる熱可塑性樹脂組成物廃材の再資源化システムは、上記の本発明の熱可塑性樹脂組成物廃材の再資源化方法に用いる廃棄物の再資源化システムであって、廃棄物を破砕する機構と、破砕された廃棄物を金属系破砕物とプラスチック系破砕物と低嵩比重破砕物とに選別する機構と、プラスチック系破砕物を比重の異なる複数の分離液を用いて熱可塑性樹脂組成物の系統別に分離する機構と、系統別に分離された熱可塑性樹脂組成物を混合する機構と、混合された熱可塑性樹脂組成物を特定の形状に成形する機構とを含むことを特徴とする。
【０１２８】
ここで、廃棄物を破砕する機構は、特に限定されず、一般に金属や熱可塑性樹脂組成物からなる部材を破砕する際に用いられる装置を好適に使用可能である。Ｂ機構に使用する破砕装置の具体例としては、衝撃式破砕装置やせん断式破砕装置などが挙げられる。
【０１２９】
また、破砕された廃棄物を金属系破砕物とプラスチック系破砕物と低嵩比重破砕物とに選別する機構は、特に限定されず、一般に金属系破砕物や低嵩密度破砕物を選別する際に用いられる装置を好適に使用可能である。
【０１３０】
さらに、破砕された廃棄物を金属系破砕物とプラスチック系破砕物と低嵩比重破砕物とに選別する機構に使用する金属系破砕物の選別装置の具体例としては、鉄の選別に適した磁力を用いた選別装置、アルミニウムや銅の選別に適した渦電流を用いた選別装置、粒度を均一にしてふるいにかけるトロンメル装置などが挙げられる。
【０１３１】
また、破砕された廃棄物を金属系破砕物とプラスチック系破砕物と低嵩比重破砕物とに選別する機構に使用する低嵩密度破砕物の選別装置の具体例としては、風力を用いた選別装置、振動ふるいを用いた装置などが挙げられる。
【０１３２】
ここで、プラスチック系破砕物を比重の異なる複数の分離液を用いて熱可塑性樹脂組成物の系統別に分離する機構は、２つの異なる比重の分離液を満たした混合撹拌槽を有する比重分離装置を備えた機構であることが好ましい。ここで、２つの異なる比重の分離液を、Ｘ分離液およびＹ分離液と呼称することとする。
【０１３３】
この場合、Ｘ分離液の比重は１．００以上であることが好ましく、特に１．０１以上であることがより好ましい。また、Ｘ分離液の比重は１．１０以下であることが好ましく、特に１．０８以下であることがより好ましい。Ｘ分離液の比重が１．００未満の場合には、ポリオレフィン系プラスチックが混入するという傾向があり、Ｘ分離液の比重が１．１０を超えると、ポリアミド系、ポリカーボネート系、ゴムなどが混入するという傾向がある。
【０１３４】
また、この場合、Ｙ分離液の比重は０．９２以上であることが好ましく、特に０．９５以上であることがより好ましい。また、Ｙ分離液の比重は１．０１以下であることが好ましく、特に１．００以下であることがより好ましい。Ｙ分離液の比重が０．９２未満の場合には、ポリオレフィン系プラスチックの一部が沈降し回収率が低下するという傾向があり、Ｙ分離液の比重が１．０１を超えると、ポリスチレン系プラスチックの一部が混入するという傾向がある。
【０１３５】
なお、分離液の組成は、特に限定するものではないが、たとえばＮａＣｌなどの塩類を水に溶解させて比重を調製した溶液を好適に用いることができる。
【０１３６】
また、プラスチック系破砕物を比重の異なる複数の分離液を用いて熱可塑性樹脂組成物の系統別に分離する機構において、比重分離装置は、プラスチック系破砕物を供給する手段と、分離液を供給する手段と、分離液を満たした混合撹拌槽と、分離液の液面に浮遊するプラスチック系破砕物を回収する手段と、混合撹拌槽の槽底に沈殿するプラスチック系破砕物を回収する手段とを有することが好ましい。
【０１３７】
しかし、これらの手段を全て備える必要はなく、少なくともプラスチック系破砕物と分離液が投入されて混合攪拌される槽を備えていればよい。
【０１３８】
さらに、プラスチック系破砕物を分離した後の回収手段は、手作業で浮遊物をすくい出したり、オーバーフロー方式で溢出させる方法であってもよい。また、沈殿物を吸引装置で分離液とともに吸上げたり、あるいはスクリュー型搬送装置で移送したり、分離液を別の槽に回収したのちに浮遊物を回収する方法を用いてもよい。なお、浮遊物や沈殿物を回収した際に流出した分離液は、ポンプで汲上げて再び混合撹拌槽内に供給し、繰返して使用してもよい。
【０１３９】
ここで、ポリスチレン系熱可塑性樹脂組成物を系統別に分離する機構は、特に限定するものではないが、主に目視によってなされるが、燃焼性、溶剤による溶解性、さらには樹脂組成の分析装置（赤外分光光度計、ガスクロマトグラフ質量分析装置など）などの方法を併用することが好ましい。
【０１４０】
また、系統別に分離された熱可塑性樹脂組成物を特定の形状に成形する機構は、押出成形装置を備えた機構であることが好ましい。
【０１４１】
ここで用いる押出成形機としては、特に限定するものではないが、たとえば単軸押出成形機、二軸押出成形機あるいは多軸式押出成形機などが挙げられる。
【０１４２】
ここで、熱可塑性樹脂組成物をペレット状に成形してマテリアルリサイクルする場合には、押出成形した後に、シートカット、ストランドカット、ホットエアカット、アンダーウォーターカットなどのいずれの方法により造粒してもよい。これらの造粒方法の中でも、後に射出成形により特定の形状に成形する場合には、樹脂原料の供給が円滑におこなえ、大量処理にも対応できるアンダーウォーターカットが特に好ましい。
【０１４３】
＜熱可塑性樹脂組成物原料＞
上記の本発明の熱可塑性樹脂組成物廃材の再資源化方法は、本発明の熱可塑性樹脂組成物成形体の製造方法としても使用可能である。
【０１４４】
そして、上記の本発明の熱可塑性樹脂組成物成形体の製造方法により製造された本発明の熱可塑性樹脂組成物成形体は、熱可塑性樹脂組成物原料であってもよい。この場合、この熱可塑性樹脂組成物原料は、ペレット状であることが好ましい。このとき、このペレットの粒径は１ｍｍ以上であることが好ましく、特に２ｍｍ以上であることがより好ましい。また、このペレットの粒径は８ｍｍ以下であることが好ましく、特に５ｍｍ以下であることがより好ましい。
【０１４５】
このペレットの粒径が１ｍｍ未満の場合には、浮遊するため作業性が低下するという傾向があり、このペレットの粒径が８ｍｍを超えると、成形機のシリンダ−内で充分に溶融しないため均一混練されないという傾向がある。
【０１４６】
なお、本発明の熱可塑性樹脂組成物原料の形状としては、ペレット状に特に限定されるものではなく、たとえばシ−ト状、フィルム状、パイプ状などいずれの形態であってもよく、押出成形機の種類、使用の態様あるいは求められる特性などから適宜決定すればよい。
【０１４７】
さらに、本発明の熱可塑性樹脂組成物原料には、熱安定剤や光安定剤、帯電防止剤、滑剤、フィラ−、銅害防止剤、抗菌剤、着色剤などの添加剤を、必要により、本発明の効果を害しない範囲の量で添加してもよい。
【０１４８】
＜熱可塑性樹脂組成物からなる部材＞
上記の本発明の熱可塑性樹脂組成物廃材の再資源化方法は、本発明の熱可塑性樹脂組成物成形体の製造方法としても使用可能である。そして、上記の本発明の熱可塑性樹脂組成物成形体の製造方法により製造された本発明の熱可塑性樹脂組成物成形体は、熱可塑性樹脂組成物からなる部材であってもよい。この場合、この熱可塑性樹脂組成物からなる部材は、エアコン、テレビ、冷蔵庫および洗濯機よりなる群から選ばれる製品に用いられることが好ましい。
【０１４９】
また、この熱可塑性樹脂組成物からなる部材は、上記の熱可塑性樹脂組成物原料から、射出成形などの方法を用いて成形することができる。このとき用いる射出成形機としては、特に限定するものではないが、たとえばスクリューインライン式射出成形機、プランジャ式射出成形機などが挙げられる。
【０１５０】
また、この熱可塑性樹脂組成物からなる部材の成形のステップをより簡略化するために、ペレット状などの形状を有する熱可塑性樹脂組成物原料を作製することなく、破砕した熱可塑性樹脂組成物を射出成形機にそのまま投入し、熱可塑性樹脂組成物からなる部材を直接作製してもかまわない。
【０１５１】
さらに、この熱可塑性樹脂組成物からなる部材は、熱安定剤や光安定剤、帯電防止剤、滑剤、フィラ−、銅害防止剤、抗菌剤、着色剤などの添加剤を、必要により、本発明の効果を害しない範囲の量で添加したうえで成形して作製してもよい。これらの添加剤を添加するステップとしては、押出成形機または射出成形機への上記の熱可塑性樹脂組成物原料または破砕した熱可塑性樹脂組成物の投入時が好ましい。
【０１５２】
【実施例】
以下、実施例を挙げて本発明をより詳細に説明するが、本発明はこれらに限定されるものではない。
【０１５３】
＜実験材料の調製＞
まず、下記の実施例において用いる実験材料を調製した。具体的には、使用済みの冷蔵庫、洗濯機、エアコン、テレビを用いて、手解体によりコンプレッサ−、熱交換器などの大型の金属部品などを部品ごとに回収したのち、通常の破砕機を用いて破砕して得られた破砕物から、通常の磁力を用いた選別機により金属系破砕物を選別し、さらに通常の風力を用いた選別機により低嵩比重破砕物を選別した、残りのプラスチック系破砕物をポリスチレン系熱可塑性樹脂組成物、ポリオレフィン系熱可塑性樹脂組成物、およびその他のプラスチックに分離し、さらに、ポリスチレン系熱可塑性樹脂組成物は、ポリスチレン（ＰＳ）、スチレン−ブタジエン（ＳＢ）、アクリロニトリル−スチレン（ＡＳ）、アクリロニトリル−スチレン−ブタジエン（ＡＢＳ）に分離し、先に分離したポリオレフィン系熱可塑性樹脂組成物とともに、実験材料として調製した。
【０１５４】
＜測定方法＞
なお、以下の実施例で用いられた物性の測定は以下に示す方法で行った。
【０１５５】
（ｉ）引張降伏強さおよび引張破断伸び
ＪＩＳ Ｋ７１１３に準じて測定した。
【０１５６】
（ｉｉ）曲げ強さおよび曲げ弾性率
ＪＩＳ Ｋ７２０３に準じて測定した。
【０１５７】
（ｉｉｉ）アイゾット衝撃値
ＪＩＳ Ｋ７１１０に準じて測定した。
【０１５８】
（ｉｖ）メルトフローレート（ＭＦＲ）
ＪＩＳ Ｋ７２１０に準じて測定した。
【０１５９】
＜実施例１＞
図１の手順に従って、比重１．０８および比重１．００の分離液を用いて、実験材料（Ｉ）に含まれるポリオレフィン系熱可塑性樹脂組成物とポリスチレン系熱可塑性樹脂組成物を比重の差を利用して分離した。
【０１６０】
比重分離方法としては、実験材料（Ｉ）を比重１．０８の塩化ナトリウム水溶液で満たされた混合撹拌槽内に投入し、攪拌したのち、浮遊したもの（ポリオレフィン系およびポリスチレン系熱可塑性樹脂組成物）をオーバーフロー方式で回収し、沈殿したもの（その他の系統の熱可塑性樹脂組成物、ゴム、金属など）は塩化ナトリウム水溶液とともに吸引回収するという方法を用いた。
【０１６１】
ここで、オーバーフロー方式で流出した塩化ナトリウム水溶液、および吸引回収時に同時回収された塩化ナトリウム水溶液は、ポンプを用いて混合撹拌槽内に注入して再利用した。
【０１６２】
次に、浮遊したものとして回収されたポリオレフィン系およびポリスチレン系熱可塑性樹脂組成物を、比重１．００の水で満たされた混合撹拌槽内に投入し、攪拌したのち、浮遊したもの（ポリオレフィン系熱可塑性樹脂組成物）と沈殿したもの（ポリスチレン系熱可塑性樹脂組成物）を回収した。
【０１６３】
そして、ポリスチレン系熱可塑性樹脂組成物は、目視、燃焼性、溶剤による溶解性、さらには樹脂組成の分析装置（赤外分光光度計、ガスクロマトグラフ質量分析装置など）などの方法を併用し、ポリスチレン（ＰＳ）、スチレン−ブタジエン（ＳＢ）、アクリロニトリル−スチレン（ＡＳ）、アクリロニトリル−スチレン−ブタジエン（ＡＢＳ）に分離した。
【０１６４】
次に、図２の手順にしたがって、上記で得られたポリスチレン（ＰＳ）、スチレン−ブタジエン（ＳＢ）、アクリロニトリル−スチレン（ＡＳ）、アクリロニトリル−スチレン−ブタジエン（ＡＢＳ）をそれぞれ微破砕した後、洗浄し、さらに均一混合し、組成ごとのポリスチレン系熱可塑性樹脂組成物微破砕品を調製した。
【０１６５】
そして、これらの熱可塑性樹脂組成物微破砕品を単独、あるいは必要に応じて混合し、スクリュー系４５ｍｍの二軸溶融混練押出機を用いて２３０℃で溶融混練し、ペレット状の熱可塑性樹脂組成物原料を作製した。
【０１６６】
続いて、これらの熱可塑性樹脂組成物原料をそれぞれ１０トン射出成形機のホッパーに投入し、成形温度２３０℃、金型温度４０℃の射出成形条件でＡＳＴＭ準拠の物性測定用の試験片を作製し、それぞれの物性を測定した。
【０１６７】
併せて、同一系統の熱可塑性樹脂組成物のバージン材料についても物性測定用試験片を作製し、それぞれの物性を測定した。これらの測定結果を表４に示す。
【０１６８】
【表４】

【０１６９】
なお、表４に記載された略号のうち、「Ｒ−ＰＳ」は分離回収し調製したポリスチレン組成物、「Ｒ−ＳＢ」は分離回収し調製したスチレン−ブタジエン組成物、「Ｒ−ＡＳ」は分離回収し調製したアクリロニトリル−スチレン組成物、「Ｒ−ＡＢＳ」は分離回収し調製したアクリロニトリル−スチレン−ブタジエン、「Ｖ−ＳＢ」は未使用のスチレン−ブタジエン組成物、「Ｖ−ＡＢＳ」は未使用のアクリロニトリル−スチレン−ブタジエンを示すものとする。
【０１７０】
ここで、表４から理解されるように、本実施例で分離回収し調製したスチレン−ブタジエン（ＳＢ）、アクリロニトリル−スチレン−ブタジエン（ＡＢＳ）の物性は、未使用のスチレン−ブタジエン（ＳＢ）、アクリロニトリル−スチレン−ブタジエン（ＡＢＳ）とはかなり相違するものであった。
【０１７１】
また、本実施例で分離回収し調製したポリスチレン（ＰＳ）、アクリロニトリル−スチレン（ＡＳ）は、長期の使用によりよごれが付着しているため、該プラスチック組成物の本来の特徴である透明性がかなり劣るものであった。
【０１７２】
したがって、本実施例で分離回収し調製したポリスチレン（ＰＳ）、スチレン−ブタジエン（ＳＢ）、アクリロニトリル−スチレン（ＡＳ）、アクリロニトリル−スチレン−ブタジエン（ＡＢＳ）は、中品位、ないしは低品位への再利用となり、用途は限定されていた。
【０１７３】
そこで、本実施例で分離回収し調製したポリスチレン（ＰＳ）、およびアクリロニトリル−スチレン（ＡＳ）の用途展開を図るため、スチレン−ブタジエン（ＳＢ）、およびアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）を混合し、物性を測定した。
【０１７４】
実験材料の調製は、本実施例で分離回収し調製した、ポリスチレン（ＰＳ）とスチレン−ブタジエン（ＳＢ）を混合し、スクリュー系４５ｍｍの二軸溶融混練押出機を用いて２３０℃で溶融混練し、ペレット状の熱可塑性樹脂組成物原料を作製し、続いて、これらの熱可塑性樹脂組成物原料をそれぞれ１０トン射出成形機のホッパーに投入し、成形温度２３０℃、金型温度４０℃の射出成形条件でＡＳＴＭ準拠の物性測定用の試験片を作製し、物性を測定した。
【０１７５】
併せて、本実施例で分離回収したポリスチレン（ＰＳ）とスチレン−ブタジエン（ＳＢ）に未使用のスチレン−ブタジエン（ＳＢ）、本実施例で分離回収し調製したアクリロニトリル−スチレン（ＡＳ）とアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）、本実施例で分離回収し調製したアクリロニトリル−スチレン（ＡＳ）とアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）に未使用のアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）についても同様に物性測定用試験片を作製し、それぞれの物性を測定した。
【０１７６】
これらの測定結果を表５に示す。
【０１７７】
【表５】

【０１７８】
なお、表５に記載された略号のうち、「Ｒ−ＰＳ／Ｒ−ＳＢ」は分離回収し調製したポリスチレン組成物２０％とスチレン−ブタジエン組成物８０％を混合したもの、「Ｒ−ＰＳ／Ｒ−ＳＢ／Ｖ−ＳＢ」は分離回収し調製したポリスチレン組成物２０％、スチレン−ブタジエン組成物２０％に、未使用のスチレン−ブタジエン組成物６０％を混合したもの、「Ｒ−ＡＳ／Ｒ−ＡＢＳ」は分離回収し調製したアクリロニトリル−スチレン組成物２０％とアクリロニトリル−スチレン−ブタジエン組成物８０％を混合したもの、「Ｒ−ＡＳ／Ｒ−ＡＢＳ／Ｖ−ＡＢＳ」は分離回収し調製したアクリロニトリル−スチレン組成物２０％、アクリロニトリル−スチレン−ブタジエン２０％に、未使用のアクリロニトリル−スチレン−ブタジエン組成物６０％を混合したものを示すものとする。
【０１７９】
ここで、表５から理解されるように、本実施例で分離回収し調製したポリスチレン系熱可塑性樹脂組成物の混合物、およびその混合物に同系統の未使用の熱可塑性樹脂組成物を配合し、成形した物性測定用試験片の引張強度、伸び、曲げ強度、曲げ弾性率、アイゾット衝撃強度、メルトフローレートの各物性測定値は、バージン材料とはやや異なるが、中品位の再生品が得られ、再利用の用途拡大が可能となったといえる。
【０１８０】
＜実施例２＞
実施例１において得られたポリスチレン系熱可塑性樹脂組成物を、さらに高品位にするべく、また、バージン材料の配合量を低減すべく、実施例２において下記の実験を行った。
【０１８１】
本実施例では、分離回収し調製したポリスチレン（ＰＳ）、およびアクリロニトリル−スチレン（ＡＳ）の用途展開を図るため、冷蔵庫の内箱材などに使用されている真空成形で付形されたスチレン−ブタジエン（ＳＢ）あるいはアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）を分離回収し、ポリスチレン（ＰＳ）あるいはアクリロニトリル−スチレン（ＡＳ）に混合して物性を測定した。
【０１８２】
実験材料の調製は、本実施例で分離回収し調製した、ポリスチレン（ＰＳ）とスチレン−ブタジエン（ＳＢ）真空成形回収品を混合し、スクリュー系４５ｍｍの二軸溶融混練押出機を用いて２３０℃で溶融混練し、ペレット状の熱可塑性樹脂組成物原料を作製し、続いて、これらの熱可塑性樹脂組成物原料をそれぞれ１０トン射出成形機のホッパーに投入し、成形温度２３０℃、金型温度４０℃の射出成形条件でＡＳＴＭ準拠の物性測定用の試験片を作製し、物性を測定した。
【０１８３】
併せて、本実施例で分離回収したポリスチレン（ＰＳ）とスチレン−ブタジエン（ＳＢ）真空成形回収品に未使用のスチレン−ブタジエン（ＳＢ）、本実施例で分離回収し調製したアクリロニトリル−スチレン（ＡＳ）とアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）真空成形回収品、本実施例で分離回収し調製したアクリロニトリル−スチレン（ＡＳ）とアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）真空成形回収品に未使用のアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）についても同様に物性測定用試験片を作製し、それぞれの物性を測定した。
【０１８４】
これらの測定結果を表６に示す。
【０１８５】
【表６】

【０１８６】
なお、表６に記載された略号のうち、「Ｒ−ＰＳ／Ｒ−ｖ−ＳＢ」は分離回収し調製したポリスチレン組成物３０％とスチレン−ブタジエン組成物真空成形回収品７０％を混合したもの、「Ｒ−ＰＳ／Ｒ−ｖ−ＳＢ／Ｖ−ＳＢ」は分離回収し調製したポリスチレン組成物３０％、スチレン−ブタジエン組成物真空成形回収品４０％に、未使用のスチレン−ブタジエン組成物３０％を混合したもの、「Ｒ−ＡＳ／Ｒ−ｖ−ＡＢＳ」は分離回収し調製したアクリロニトリル−スチレン組成物３０％とアクリロニトリル−スチレン−ブタジエン組成物真空成形回収品７０％を混合したもの、「Ｒ−ＡＳ／Ｒ−ｖ−ＡＢＳ／Ｖ−ＡＢＳ」は分離回収し調製したアクリロニトリル−スチレン組成物３０％、アクリロニトリル−スチレン−ブタジエン４０％真空成形回収品に、未使用のアクリロニトリル−スチレン−ブタジエン組成物３０％を混合したものを示すものとする。
【０１８７】
ここで、表６から理解されるように、本実施例で分離回収し調製したポリスチレン系熱可塑性樹脂組成物の混合物、およびその混合物に同系統の未使用の熱可塑性樹脂組成物を配合し、成形した物性測定用試験片の引張強度、伸び、曲げ強度、曲げ弾性率、アイゾット衝撃強度、メルトフローレートの各物性測定値は、バージン材料に近似、あるいはそれ以上の物性を有する高品位な再生品が得られ、再利用の用途が大幅に拡大可能となったといえる。
【０１８８】
上記の実施例１および実施例２の結果より、家電４品目に使用する熱可塑性樹脂組成物廃材を選択的に分離回収し、複数種類を混合して熱可塑性樹脂組成物成形体を得ることで再資源化が可能となり、再生品の用途を拡大できる。
【０１８９】
たとえば、従来はポリスチレン（ＰＳ）やアクリロニトリル−スチレン（ＡＮ）の熱可塑性樹脂組成物廃材は、長期間の使用による汚染により、本来の特徴である優れた透明性が阻害されるため、マテリアルリサイクルが困難であったが、選択的に分離回収されたスチレン−ブタジエン（ＳＢ）やアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）と混合することで、中品位から低品位の再生品が得られ、ハンガーや植木鉢などの日用品雑貨への利用が可能となる。
【０１９０】
さらに、本発明の熱可塑性樹脂組成物廃材の再資源化方法によれば、上記の系統を含む熱可塑性樹脂組成物廃材の混合物に、冷蔵庫部材から回収した真空成形のスチレン−ブタジエン（ＳＢ）やアクリロニトリル−スチレン−ブタジエン（ＡＢＳ）をさらに混合することで、高品位の再生品が得られるため、たとえば洗濯機の後蓋や冷蔵庫のしきり板など、耐久消費材への使用が可能となる。
【０１９１】
また、ポリスチレン廃材は、ポリスチレン本来の特性である透明性が汚れなどの付着によって大きく低下するため、焼却処理、埋立処理されているのが現状であるが、上記の実施例の結果より、ポリスチレン廃材に廃冷蔵庫から回収したスチレンーブタジエン真空成形品を混合することで、バージン材料にはやや劣るものの、カスケード的な用途には十分対応可能なリサイクル材料が得られることが判明した。このようなリサイクル方法を採ることによって、リサイクル率の向上はもとより、リサイクルコストの低減に大きく貢献することができる。
【０１９２】
さらに、アクリロニトリル-スチレン廃材についても、本来の特性である透明性が汚れなどの付着によって大きく低下するため、焼却処理、埋立処理されているのが現状であるが、上記の実施例の結果より、廃冷蔵庫から回収したアクリロニトリル−スチレン−ブタジエン真空成形品を混合することで、バージン材料にはやや劣るものの、カスケード的な用途には十分対応可能なリサイクル材料が得られることが判明した。このようなリサイクル方法を採ることによっても、リサイクル率の向上はもとより、リサイクルコストの低減に大きく貢献することができる。
【０１９３】
また、本発明の熱可塑性樹脂組成物廃材の再資源化方法は、該家電４品目の熱可塑性樹脂組成物廃材の再資源化方法に限定されるものではなく、熱可塑性樹脂組成物からなる部材を備えた製品であれば、どのような製品にも好適に使用可能である。
【０１９４】
今回開示された実施の形態および実施例はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて特許請求の範囲によって示され、特許請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。
【０１９５】
【発明の効果】
上記の結果より、本発明の熱可塑性樹脂組成物廃材の再資源化方法は、熱可塑性樹脂組成物廃材から、熱可塑性樹脂組成物廃材を主原料とするマテリアルリサイクルにより、多様な用途に応じた特性を有する熱可塑性樹脂組成物成形体を得ることができ、サーマルリサイクルされる熱可塑性樹脂組成物廃材を低減することができる、効率的な熱可塑性樹脂組成物廃材の再資源化方法である。
【０１９６】
また、本発明の熱可塑性樹脂組成物廃材の再資源化方法は、ポリスチレン（ＰＳ）あるいはアクリロニトリル−スチレン（ＡＳ）からなる熱可塑性樹脂組成物廃材を用いた場合には、熱可塑性樹脂組成物廃材を主原料とするマテリアルリサイクルにより、さらに多様な用途に応じた特性を有する熱可塑性樹脂組成物成形体を得ることができ、より一層サーマルリサイクルされる熱可塑性樹脂組成物廃材を低減することができる、効率的な熱可塑性樹脂組成物廃材の再資源化方法である。
【０１９７】
さらに、本発明の熱可塑性樹脂組成物成形体の製造方法は、熱可塑性樹脂組成物廃材から、熱可塑性樹脂組成物廃材を主原料とするマテリアルリサイクルにより、多様な用途に応じた特性を有する熱可塑性樹脂組成物成形体の製造方法である。
【０１９８】
そして、本発明の熱可塑性樹脂組成物成形体は、熱可塑性樹脂組成物廃材を主原料とするマテリアルリサイクルにより得られる、多様な用途に応じた特性を有する熱可塑性樹脂組成物成形体を提供することである。
【図面の簡単な説明】
【図１】 本発明の熱可塑性樹脂組成物廃材の再資源化方法の前半部のステップの一例を示すフロー図である。
【図２】 本発明の熱可塑性樹脂組成物廃材の再資源化方法の後半部のステップの一例を示すフロー図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for recycling a thermoplastic resin composition waste material. More specifically, the present invention relates to a method for recycling a thermoplastic resin composition waste material by mixing a plurality of types of thermoplastic resin composition waste material to obtain a thermoplastic resin composition molded article.
[0002]
Moreover, this invention relates also to the manufacturing method of the thermoplastic resin molding by said recycling method. Furthermore, this invention relates also to the thermoplastic resin composition molded object obtained by said recycling method.
[0003]
[Prior art]
In recent years, with the improvement in income levels in Japan, home appliances such as air conditioners (also referred to as air conditioners in this specification), television receivers (also referred to as TVs in this specification), refrigerators, and washing machines. Information devices such as personal computers and word processors, office equipment such as printers and fax machines, and various other furniture, stationery, and toys are now available at a high penetration rate in general households. Therefore, convenience in family life has been dramatically improved.
[0004]
On the other hand, as a result, the amount of discarded products such as home appliances tends to increase year by year. Here, conventionally, the recycling of waste materials of products including these home appliances is often performed through a scrap scrap collection route.
[0005]
However, in recent years, the constituent materials of various products such as home appliances have changed, and the number of members made of metals such as iron has decreased and the proportion of members made of thermoplastic resin compositions has increased. is there. Thermoplastic resin compositions have a greater degree of design freedom than metals such as iron, and can provide various properties that are difficult to achieve with metals by preparing components and using additives. This is because it has many advantages such as high durability.
[0006]
And the waste material of various products including recent home appliances, the material composition of various components is complicated, the ratio of members made of valuable metals such as iron and copper is small, the value is low, In addition, the proportion of members made of a thermoplastic resin composition, which requires a lot of labor and cost in the conventional treatment method, is large, and profits are obtained even if such waste materials are recycled in the conventional iron scrap recovery route. It is becoming difficult to deal with the situation.
[0007]
And most of the members made of these thermoplastic resin compositions are synthesized using embedded fossil fuels such as crude oil as a basic raw material. From the viewpoint of effective utilization of resources, members made of these thermoplastic resin compositions are often used. In recent years, there has been a strong demand for the promotion of recycling of products provided.
[0008]
Also, environmental destruction such as global warming and acid rain due to the release of carbon dioxide and sulfur oxides from combustion of buried fossil fuels such as crude oil, and generation and scattering of dioxins by incineration of thermoplastic resin compositions containing chlorine compounds From the viewpoint of suppressing problems such as environmental pollution and the shortage of waste landfill treatment sites due to an increase in waste materials containing bulky thermoplastic resin compositions, products having members made of these thermoplastic resin compositions are also included. Recycling waste materials is becoming an important and urgent issue.
[0009]
In the present specification, a member made of a thermoplastic resin composition is also referred to as a plastic member. Moreover, in this specification, the product provided with the plastic member is also described as a plastic product. Furthermore, in this specification, the waste material of a plastic product is also described as a plastic waste material.
[0010]
In response to the above situation, the Home Appliance Recycling Law was enforced in April 2001. Here, in the Home Appliance Recycling Law, as of April 2003, it is obliged to recycle four items of home appliances such as air conditioners, televisions, refrigerators, and washing machines. Legal reference values are set for% or more, television 55% or more, refrigerator 50% or more, and washing machine 50% or more.
[0011]
And, following the enforcement of the Home Appliance Recycling Law, the recovery of plastic waste materials is progressing. As a method of recycling plastic waste materials recovered in this way, the so-called plastic waste materials are used as fuel. Many methods related to thermal recycling have been used in the past. However, according to such a method, it is possible to recycle plastic waste by thermal recycling, but there is a problem such as the generation of carbon dioxide gas by combustion, so it is a method that fully meets social demands. I can't say that.
[0012]
Therefore, the plastic member is separated from the plastic waste collected in this way by a method such as manual dismantling for each thermoplastic resin composition system, and the plastic member is processed again into a product member or its raw material. Recycling methods of plastic waste materials used in the past have been proposed. Such a recycling method is described as material recycling in contrast to the thermal recycling described above.
[0013]
And among the plastic members separated for each system of the thermoplastic resin composition as described above, a member made of a thermoplastic resin composition (also referred to as a thermoplastic resin composition waste material in the present specification), It is possible to relatively easily recycle materials by heating and melting and molding again.
[0014]
Therefore, at present, in order to increase the material recycling ratio of plastic waste materials, research and development of a recycling method by material recycling of thermoplastic resin composition waste materials has been carried out with great efforts in various fields.
[0015]
However, when thermoplastic resin composition waste, especially thermoplastic resin composition waste used in home appliances and office equipment, is often used for a long time in harsh environments, In many cases, the material is poor in durability, not only in appearance characteristics such as discoloration or fading, but also in physical properties such as strength and flexibility.
[0016]
For this reason, the thermoplastic resin composition waste material is often used as a raw material for a plastic member having low required properties, not as a substitute for the virgin material of the thermoplastic resin composition used for a plastic member having high required properties.
[0017]
In addition, when a thermoplastic resin composition characterized by excellent transparency such as polystyrene (PS) or acrylonitrile-styrene (AS) is separated and collected from used products, it is contaminated by long-term use. A thermoplastic resin composition molded article having excellent properties could not be obtained, and material recycling was not performed.
[0018]
And at present, such cascade recycling has become the mainstream as material recycling of thermoplastic resin composition waste. Therefore, the use of the thermoplastic resin composition molded body regenerated from the thermoplastic resin composition waste is limited, and there is a problem that a large amount of thermoplastic composition waste is thermally recycled.
[0019]
Here, in the present specification, the virgin material means an unused resin composition. Further, in this specification, the plastic waste material having a reduced characteristic is not used as a substitute for the virgin material of the thermoplastic resin composition used for a plastic member having a high required characteristic, but as a raw material for a plastic member having a low required characteristic. This shall be described as cascade recycling.
[0020]
In order to overcome such problems, the properties of the thermoplastic resin composition molded body obtained by material recycling from the above-mentioned thermoplastic resin composition waste material are improved, so that it can be used as a plastic member having high required properties. Many research and development efforts have been made to achieve this.
[0021]
For example, many methods have been proposed for maintaining characteristics by mixing a virgin material with a thermoplastic resin composition waste material (material recycled material) (see, for example, Patent Document 1).
[0022]
However, in such a material recycling method, the physical properties are improved with the mixing of the virgin material, but as long as the thermoplastic resin composition waste material having a deteriorated physical property is mixed, the physical properties equivalent to the virgin material are recovered. Impossible. In addition, in order to approximate the physical properties of virgin materials, it is often necessary to mix a larger amount of virgin material than waste thermoplastic resin composition, and it is difficult to say that it corresponds to a resource recycling society. is there. Moreover, even if it is a thermoplastic resin composition waste material in which the physical property has not fallen, the lifetime has fallen greatly by long-term use, and there exists a problem in long-term reliability, when it recycles.
[0023]
On the other hand, a technology regarding a recycling system that determines a recycling policy based on the component parts and the degree of deterioration of a used product and repeatedly recycles the same is also disclosed (for example, see Patent Document 2).
[0024]
However, in this recycling system, the degree of deterioration, which is a criterion for determining measures, is based on physical properties that can be determined by comparison with virgin materials, and only when the initial characteristics of recovered waste materials are known. It becomes effective. However, the amount of waste materials actually collected is enormous, and it takes a lot of time and processing capacity to grasp the initial characteristics of each of these and to compare the characteristics of the waste materials with each other. In reality, there is a problem that such a recycling system is difficult to realize and disadvantageous in cost.
[0025]
In addition, the parts used inside the products that become waste materials are less susceptible to light and the like than the parts used for appearance, so the degree of apparent deterioration is low, and it deteriorates as a significant difference in physical property values. In some cases, the progress of Therefore, in such a recycling system, there is also a problem that although it is possible to identify the material composition of the waste material, it is difficult to distribute the materials according to the degree of deterioration.
[0026]
[Patent Document 1]
JP 2000-159900 A
[0027]
[Patent Document 2]
Japanese Patent Laid-Open No. 7-24437
[0028]
[Problems to be solved by the invention]
As described above, it can be reused from the thermoplastic resin composition waste recovered from the market by material recycling using the thermoplastic resin composition waste as the main raw material, and it is widely used as a plastic member or its raw material. Despite the strong demand for the development of an efficient and low-cost method for recycling thermoplastic resin composition waste that can provide a molded thermoplastic resin composition with usable properties Such a recycling method is not yet publicly known.
[0029]
In general, polystyrene (PS) or acrylonitrile-styrene (AS) is used for applications utilizing excellent transparency. However, since these thermoplastic resin composition waste materials separated and recovered from used products are contaminated by long-term use, depending on the conventionally known methods for recycling thermoplastic resin composition waste materials, it may become transparent. An excellent thermoplastic resin composition molded article could not be obtained, and material recycling was not performed.
[0030]
Based on the above-mentioned present situation, the object of the present invention is to form a thermoplastic resin composition having properties corresponding to various uses by recycling the thermoplastic resin composition waste material as a main raw material from the thermoplastic resin composition waste material. It is an object to provide an efficient method for recycling a thermoplastic resin composition waste material that can obtain a body and can reduce the thermoplastic resin composition waste material that is thermally recycled.
[0031]
In addition, more specifically, the problems of the present invention can be variously achieved by material recycling using a thermoplastic resin composition waste as a main raw material from a thermoplastic resin composition waste made of polystyrene (PS) or acrylonitrile-styrene (AS). Efficient recycling of thermoplastic resin composition waste that can be used to obtain molded thermoplastic resin compositions having properties according to the application and reduce the number of waste thermoplastic resin compositions that are thermally recycled. Is to provide a method.
[0032]
Another object of the present invention is to provide a thermoplastic resin composition molded article having properties corresponding to various uses by recycling the thermoplastic resin composition waste material as a main raw material from the thermoplastic resin composition waste material. It is to provide a manufacturing method.
[0033]
Furthermore, another object of the present invention is to provide a thermoplastic resin composition molded article having properties corresponding to various uses, obtained by material recycling using thermoplastic resin composition waste as a main raw material. It is.
[0034]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the present inventor has obtained an idea that a thermoplastic resin composition molded article may be obtained by mixing plural types of thermoplastic resin composition waste materials selected and recovered. In order to develop a method for recycling such thermoplastic resin composition waste materials, we prepared raw material pellet-shaped thermoplastic resin composition molded bodies obtained from many types of thermoplastic resin composition waste materials, and their physical properties The experiment was conducted and earnestly examined.
[0035]
And after examination, this inventor pays attention to a polystyrene-type thermoplastic resin composition from among the thermoplastic resin composition waste materials selected and collected, and polystyrene (PS) and styrene-butadiene (BS) are It has been found that a thermoplastic resin composition molded body may be obtained by mixing and heating and melting so as to be the main component.
[0036]
In addition, the inventor selects and separates and recovers the thermoplastic resin composition waste material, mixes and heat-melts acrylonitrile-styrene (AS) and acrylonitrile-styrene-butadiene (ABS) as main components, The present inventors have found that a molded article of a thermoplastic resin composition may be obtained and completed the present invention.
[0037]
That is, according to the method for recycling the thermoplastic resin composition waste material of the present invention, the thermoplastic resin composition waste material is selectively selected according to the system of the thermoplastic resin composition which is a main component in the thermoplastic resin composition waste material. Specify by mixing multiple types of the step of separating and recovering, the thermoplastic resin composition waste material or the heated melt thereof selectively separated and / or the unused thermoplastic resin composition or the heated melt thereof A thermoplastic resin composition waste material, or a step of heat-melting the thermoplastic resin composition waste material or the mixture; and molding and heat-melting the thermoplastic resin composition waste material to form a thermoplastic resin composition molded body. And recycling the waste thermoplastic resin composition.
[0038]
Here, it is preferable that the step of obtaining the mixture having the specific composition includes the step of obtaining a mixture mainly composed of the polystyrene-based thermoplastic resin composition.
[0039]
In addition, it is desirable that the step of obtaining a mixture of this specific composition includes the step of obtaining a mixture based on polystyrene and / or styrene-butadiene.
[0040]
Here, the step of selectively separating and recovering preferably includes a step of selectively separating and recovering the thermoplastic resin composition mainly composed of styrene-butadiene from the refrigerator.
[0041]
The step of obtaining the mixture having the specific composition mainly comprises the thermoplastic resin composition waste material or the heated melt thereof selectively separated and recovered, and the unused styrene-butadiene or the heated melt thereof. It is desirable to include the step of obtaining a mixture of the compositions to be obtained.
[0042]
Moreover, the step of obtaining the mixture of this specific composition may include the step of obtaining a mixture based on acrylonitrile-styrene and / or acrylonitrile-styrene-butadiene.
[0043]
Here, the step of selectively separating and collecting may include a step of selectively separating and collecting the thermoplastic resin composition mainly composed of acrylonitrile-styrene-butadiene from the refrigerator.
[0044]
Furthermore, the step of obtaining a mixture of this specific composition mainly comprises the selectively separated and recovered thermoplastic resin composition waste material or heated melt thereof, and unused acrylonitrile-styrene-butadiene or heated melt thereof. A step of obtaining a mixture as a component may be included.
[0045]
And the manufacturing method of the thermoplastic resin composition molded article of the present invention is the production of a thermoplastic resin composition molded article, wherein the thermoplastic resin composition molded article is obtained by the above-mentioned method for recycling the thermoplastic resin composition waste material. Is the method.
[0046]
Here, the thermoplastic resin composition molded body is preferably a thermoplastic resin composition molded body having a pellet shape.
[0047]
And the thermoplastic resin composition molded object of this invention is a thermoplastic resin composition molded object obtained by the recycling method of said thermoplastic resin composition waste material.
[0048]
Here, the thermoplastic resin composition molded body is preferably a thermoplastic resin composition molded body having a pellet shape.
[0049]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail with reference to embodiments.
[0050]
<Outline of recycling method of thermoplastic resin composition waste>
The thermoplastic resin composition waste material recycling method of the present invention selectively separates and recovers the thermoplastic resin composition waste material according to the system of the thermoplastic resin composition which is a main component in the thermoplastic resin composition waste material. A specific composition obtained by mixing a plurality of types of the thermoplastic resin composition waste material or the heated melt thereof and / or the unused thermoplastic resin composition or the heated melt thereof selectively separated and recovered A thermoplastic resin composition waste material or a step of heat-melting the mixture, and molding the thermoplastic resin composition waste material mixed and heat-melted to obtain a molded thermoplastic resin composition. And recycling a thermoplastic resin composition waste material.
[0051]
<Plastic materials contained in the waste of 4 household appliances>
In the method for recycling a thermoplastic resin composition waste material according to the present invention, the product including a member made of the thermoplastic resin composition may be a product selected from the group consisting of an air conditioner, a television set, a refrigerator, and a washing machine. Recommended.
[0052]
Here, by type of thermoplastic resin composition of thermoplastic resin crushed material collected from used air-conditioners, televisions, refrigerators, washing machines (also referred to herein as four home appliances) A typical example of the composition ratio and specific gravity range will be described with reference to Tables 1 and 2.
[0053]
Table 1 shows a typical example of the composition ratio of each thermoplastic resin composition used for the plastic member used in the four items of home appliances. Table 2 shows a typical example of the range of specific gravity of the thermoplastic resin composition for each main system.
[0054]
[Table 1]

[0055]
[Table 2]

[0056]
As is clear from these tables, it can be seen that the proportion of the polyolefin-based thermoplastic resin composition and the polystyrene-based thermoplastic resin composition generally exceeds 60% by mass in the plastic members of the four household appliances.
[0057]
Therefore, if the plastic material consisting of at least a polyolefin-based thermoplastic resin composition and a polystyrene-based thermoplastic resin composition can be material-recycled among the plastic materials of the four items of home appliances, the recycling rate of the plastic members of the four items of home appliances is It can be said that it exceeds 60%.
[0058]
In addition, as is clear from these tables, the range of specific gravity of the polyolefin-based thermoplastic resin composition that is used in a large amount in four home appliances is generally included in the range of 0.85 to 1.00. I understand. Moreover, it turns out that the range of specific gravity of a polystyrene-type thermoplastic resin composition is generally contained in the range of 1.00-1.08. And it turns out that the specific gravity is mostly contained in the range of 1.08-2.00 generally for the member consisting of the thermoplastic resin composition of another system | strain.
[0059]
Here, in the present specification, the term “thermoplastic resin composition” means not only a narrowly defined thermoplastic resin composition but also a broad meaning including a thermoplastic elastomer composition, a polymer composition, and the like. The thermoplastic resin composition in is shown.
[0060]
And from the above, in general, by using a separation liquid having a specific gravity in the range of 1.01 to 1.08, a member composed of a polyolefin-based thermoplastic resin composition and a polystyrene-based thermoplastic resin composition, It can be seen that it is possible to separate most of the members made of thermoplastic resin compositions of other systems.
[0061]
From the above, generally, by using a separation liquid having a specific gravity in the range of 0.92 to 1.00, a member made of a polyolefin-based thermoplastic resin composition and a polystyrene-based thermoplastic resin composition are used. It can be seen that the member can be separated.
[0062]
<Procedure for waste recycling method>
Here, the recycling method of the thermoplastic resin composition waste material of the present invention is further detailed using a specific example in the case of material recycling of a polystyrene-based thermoplastic resin composition as shown in FIGS. 1 and 2. Explained.
[0063]
In this specific example, first, as shown in FIG. 1, four used home appliances discarded from homes and the like are collected (step 101). Then, the wastes of the four items of home appliances are disassembled, and large metal parts such as compressors and heat exchangers are collected for each part (step 102).
[0064]
Next, the remaining members of the four items of household electrical appliances from which large metal parts and the like have been collected are roughly crushed to about 60 mm with a large crusher (step 103).
[0065]
Subsequently, the crushed waste of the four items of home appliances is sorted into a metal-based crushed material and a plastic-based crushed material with a metal sorter (step 104), and metals such as iron, copper, and aluminum are collected, and then plastic The polyurethane heat insulating material and the expanded polystyrene are removed from the system crushed material using a wind power sorter (step 105).
[0066]
Then, the plastic crushed material is separated by specific gravity using a specific gravity liquid having a specific gravity of 1.08, for example, an aqueous sodium chloride solution (step 106), and the polyolefin-based thermoplastic resin composition and the polystyrene-based thermoplastic resin composition are separated from other systems. The mixed crushed product of the polyolefin-based thermoplastic resin composition and the polystyrene-based thermoplastic resin composition separated from the thermoplastic resin composition and further separated in step 106 is obtained by using a specific gravity liquid having a specific gravity of 1.00, for example, water. Separated into a polyolefin-based thermoplastic resin composition and a polystyrene-based thermoplastic resin composition (step 107).
[0067]
Further, the polystyrene-based thermoplastic resin composition separated in Step 107 is separated into polystyrene (PS), styrene-butadiene (SB), acrylonitrile-styrene (AS), and acrylonitrile-styrene-butadiene (ABS) (Step 108). .
[0068]
Next, as shown in FIG. 2, the crushed polystyrene-based thermoplastic resin composition separated in FIG. 1 is finely crushed to about 10 mm, respectively (step 201), and then washed to remove adhering foreign matter. (Step 202). Further, the washed crushed pieces of each thermoplastic resin composition are uniformly mixed (step 203), heated and melted, and then molded (step 204) to obtain a pellet-shaped molding resin material (step 205). Then, the pellet-shaped resin material is put into an injection molding machine to produce a molded body (step 206).
[0069]
The method for recycling thermoplastic resin composition waste material according to the present invention does not have to include all the steps shown in FIGS. 1 and 2, but a step of recovering plastic waste, and crushing the plastic waste. Separating the metal crushed material and the low bulk specific gravity crushed material from the plastic crushed material, and separating the plastic crushed material mainly composed of a thermoplastic resin composition from the separated plastic waste. Preferably, the method includes at least a step of uniformly mixing the plastic crushed material, and a step of molding the mixture of the plastic crushed material after heating and melting.
[0070]
Further, in the method for recycling the thermoplastic resin composition waste material of the present invention, steps not shown in FIGS. 1 and 2 may be added or deleted as necessary.
[0071]
The method for recycling the thermoplastic resin composition waste material according to the present invention includes the thermoplastic resin composition waste material selectively separated and recovered in the manual disassembly step (step 102) in FIG. 1 and the heat separated in step 108. A method of mixing a plastic resin composition waste and heating and melting it to obtain a thermoplastic resin composition molded article may be used.
[0072]
Further, the method for recycling the thermoplastic resin composition waste material of the present invention comprises mixing a plurality of types of thermoplastic resin composition waste materials selectively separated and recovered in the manual disassembly step (step 102) of FIG. A method of melting and obtaining a thermoplastic resin composition molded body may also be used.
[0073]
<Waste dismantling step>
The method of recycling a thermoplastic resin composition waste material of the present invention is a member made of a thermoplastic resin composition by utilizing the fact that the specific gravity of members made of the thermoplastic resin composition of the same system is within a certain range. Preferably, the method includes a step of selectively recovering product waste.
[0074]
Here, in the method for recycling the thermoplastic resin composition waste material of the present invention, in the selectively recovered product, the member made of the thermoplastic resin composition is a member made of a polystyrene-based thermoplastic resin composition and A member made of a thermoplastic resin composition of another system is preferable.
[0075]
Here, in the recycling method of the thermoplastic resin composition waste material of the present invention, by recognizing the mark described and / or attached to the member of the thermoplastic resin composition constituting the discarded product, It is desirable to selectively recover members made of the same series of thermoplastic resin compositions.
[0076]
For example, when the refrigerator shelf material is recovered as polystyrene-based thermoplastic resin composition waste and separated into polystyrene (PS) and acrylonitrile-styrene (AS), the thermoplastic resin composition waste recovered as a member is the step of FIG. The thermoplastic resin composition waste material having a different composition is less mixed than the thermoplastic resin composition waste material separated and recovered in 108. Therefore, the properties of the molded thermoplastic resin composition obtained by heating and melting are stabilized, the material of the material-recycled polystyrene-based thermoplastic resin composition or its raw material properties can be greatly improved, Enlargement is possible.
[0077]
Here, the method for recognizing the mark described and / or attached to the member of the thermoplastic resin composition constituting the discarded product may be by the naked eye or by an automatic recognition device. .
[0078]
Further, the mark described and / or attached to the thermoplastic resin composition member constituting the discarded product is not particularly limited, but it can be easily recognized by the naked eye or an automatic recognition device. For example, a specific figure, a specific numerical value, a specific symbol, a specific character, a specific pattern, a specific color, a specific bar code, or a combination thereof may be used. It is done.
[0079]
Furthermore, the mark may be flat or three-dimensional and may be directly described on the discarded product, or on the product discarded on the sticker paper. You may attach it. Alternatively, it may be described with a special ink that develops color by irradiation with ultraviolet rays, for example.
[0080]
The mark may be described and / or attached to the product at any stage, such as the manufacturing stage, shipping stage, sales stage, disposal stage, collection stage, etc. Alternatively, it is preferably described and / or attached at the shipping stage.
[0081]
Furthermore, it is preferable that the composition of the thermoplastic resin composition constituting the product can be easily read by recognizing the mark with the naked eye or an automatic recognition device.
[0082]
<Waste crushing step>
The method for recycling a thermoplastic resin composition waste material according to the present invention preferably includes a step of crushing the waste.
[0083]
Here, although the waste containing a plastic member is not specifically limited, For example, it is preferable that it is crushed with a crusher or a shredder.
[0084]
The particle size of the crushed thermoplastic resin composition waste material is preferably 10 mm or more, and more preferably 40 mm or more. The particle size is preferably 80 mm or less, and particularly preferably 60 mm or less.
[0085]
If this particle size is less than 10 mm or more than 80 mm, the metal selection accuracy in the next step tends to be reduced. Furthermore, if this particle size is less than 10 mm, it takes a long time to crush plastic. Tends to cause melting or thermal oxidative degradation. When the particle diameter exceeds 80 mm, the bulk specific gravity tends to be small, and the workability in the subsequent steps tends to be adversely affected.
[0086]
In addition, members that are difficult to be crushed, such as a large metal member such as a compressor and a heat exchanger, may be disassembled in advance and removed from the waste including the plastic member.
[0087]
<Selection step for crushed metal>
The method for recycling a thermoplastic resin composition waste material according to the present invention preferably includes a step of sorting the crushed waste material into a metal-based crushed material, a plastic-based crushed material, and a low bulk specific gravity crushed material.
[0088]
Here, the low-bulk specific gravity crushed material is not particularly limited, but is preferably selected using, for example, wind power. In addition, a low bulk specific gravity crushed material shall mean a crushed material having a bulk specific gravity of 0.3 or less. Although it does not specifically limit as a specific example of a low bulk specific gravity crushed material, The crushed material of a polyurethane-type heat insulating material, a styrene-based crushed material, etc. are mentioned.
[0089]
And iron-type metal is not specifically limited among metal-based crushed materials, but it is preferable to sort using magnetic force, for example. Further, among the metal-based crushed materials, aluminum-based metal and copper-based metal are not particularly limited, but are preferably selected using, for example, eddy current.
[0090]
Furthermore, when sorting crushed waste into metal-based crushed material, plastic-based crushed material, and low-bulk specific gravity crushed material, when sorting by wind, sorting by magnetic force, sorting by eddy current, the order is Although not particularly limited, from the viewpoint of sorting efficiency, first, iron-based metal is separated by magnetic force, then aluminum-based metal or copper-based metal is sorted by eddy current, and then low bulk specific gravity crushed material by wind force. It is preferable that the remaining mixed plastic crushed material is transferred to a separation step based on the specific gravity difference of the thermoplastic resin composition described below.
[0091]
<Separation step due to specific gravity difference of thermoplastic resin composition>
The method for recycling a thermoplastic resin composition waste material according to the present invention preferably includes a step of separating the plastic crushed material according to the system of the thermoplastic resin composition using a plurality of separation liquids having different specific gravities.
[0092]
Here, it is preferable to separate the plastic crushed material according to the system of the thermoplastic resin composition using two kinds of X separation liquids and Y separation liquids having different specific gravities.
[0093]
Further, the specific gravity of the X separation liquid is preferably 1.00 or more, and more preferably 1.01 or more. The specific gravity is preferably 1.10 or less, more preferably 1.08 or less. When this specific gravity is less than 1.00, there is a tendency that polyolefin-based plastics are mixed, and when this specific gravity exceeds 1.10, there is a tendency that polyamide-based, polycarbonate-based, rubber and the like are mixed.
[0094]
Furthermore, the specific gravity of the Y separation liquid is preferably 0.92 or more, and more preferably 0.95 or more. The specific gravity is preferably 1.01 or less, and more preferably 1.00 or less. When this specific gravity is less than 0.92, a part of the polyolefin plastic tends to settle and the recovery rate decreases, and when this specific gravity exceeds 1.01, a part of the polystyrene plastic is mixed. There is a tendency.
[0095]
The separation step based on the difference in specific gravity of the thermoplastic resin composition is not particularly necessary. However, in order to simplify the operation (step 108) of the separation step of the polystyrene resin composition described below, an X separation liquid is used. After separating a member made of a polyolefin-based thermoplastic resin composition and a member made of a polystyrene-based thermoplastic resin composition from a member made of a thermoplastic resin composition of another system, a polyolefin-based heat using a Y separation liquid It is preferable to separate the member made of the plastic resin composition from the member made of the polystyrene-based thermoplastic resin composition.
[0096]
By performing this step, material recycling of the polyolefin-based thermoplastic resin composition becomes possible, and since the amount of the thermoplastic resin composition waste material in the next step can be greatly reduced, the separation work is facilitated.
[0097]
<Separation step of polystyrene resin composition>
The method for recycling a thermoplastic resin composition waste material according to the present invention preferably includes a step of separating the polystyrene-based thermoplastic resin composition.
[0098]
The polystyrene-based thermoplastic resin composition separated and recovered in the separation step due to the specific gravity difference is polystyrene (PS), styrene-butadiene (SB), acrylonitrile-styrene (AS), acrylonitrile-styrene-butadiene (ABS), and others Separated.
[0099]
Here, the separation of the polystyrene-based thermoplastic resin composition is mainly made by visual observation, but it is combustible, soluble in a solvent, and further an analysis apparatus for resin composition (infrared spectrophotometer, gas chromatograph mass spectrometer, etc.) It is preferable to use a method such as
[0100]
The separation of the polystyrene-based thermoplastic resin composition by visual inspection will be described. Since polystyrene (PS) and acrylonitrile-styrene (AS) have high transparency, they are easily different from other polystyrene-based thermoplastic resin compositions. Can be identified. The separation of polystyrene (PS) and acrylonitrile-styrene (AS) is performed by visual inspection and hammering, as well as by combustibility, solubility by a solvent, and a resin composition analyzer.
[0101]
And as mentioned in the section of manual waste dismantling step, refrigerator shelves composed of polystyrene (PS) and acrylonitrile-styrene (AS) are separated and recovered by manual dismantling, and the material display of the members It is preferred and more effective to separate polystyrene (PS) and acrylonitrile-styrene (AS) based on
[0102]
Next, the visual separation of styrene-butadiene (SB) and acrylonitrile-styrene-butadiene (ABS) will be described. The polystyrene-based thermoplastic resin composition from which polystyrene (PS) and acrylonitrile-styrene (AS) are separated is mainly composed of styrene-butadiene (SB) and acrylonitrile-styrene-butadiene (ABS).
[0103]
Separation of styrene-butadiene (SB) and acrylonitrile-styrene-butadiene (ABS) is performed by visual inspection and sound, as well as by combustibility, solvent solubility, and a resin composition analyzer.
[0104]
Here, the thickness of styrene-butadiene (SB) or acrylonitrile-styrene-butadiene (ABS) shaped by vacuum forming used for the inner box material of the refrigerator is about 1.0 mm, Since it is thinner than the thickness (2.0 mm) of the crushed plastic made of other shaped members, it can be easily identified.
[0105]
Furthermore, styrene-butadiene (SB) or acrylonitrile-styrene-butadiene (ABS) shaped by vacuum forming is superior in rigidity and viscosity to general styrene-butadiene (SB) or acrylonitrile-styrene-butadiene (ABS). Therefore, it is preferable to mix with polystyrene (PS) or acrylonitrile-styrene (AS) which is a brittle material.
[0106]
<Molding step of thermoplastic resin composition>
The method for recycling a thermoplastic resin composition waste material according to the present invention preferably includes a step of molding the thermoplastic resin composition separated for each system into a specific shape.
[0107]
In the molding step of the thermoplastic resin composition, among the thermoplastic resin compositions separated according to the system, it is preferable to perform material recycling by melting the thermoplastic resin composition and then molding it into a specific shape. . In this case, it is desirable that the thermoplastic resin composition of the system that is not material-recycled is used for thermal recycling as a fuel after being oiled or solidified.
[0108]
Further, among the thermoplastic resin compositions separated for each system, the thermoplastic resin composition and the unused thermoplastic resin composition of the same system are preferably mixed and melted, and then molded into a specific shape. . At this time, it is desirable that the amount of the unused thermoplastic resin composition to be added is appropriately adjusted depending on the purpose of material recycling.
[0109]
In the method for recycling the thermoplastic resin composition waste material according to the present invention, the thermoplastic resin composition to be material recycled is not particularly limited, and is used in the separation step due to the specific gravity difference of the thermoplastic resin composition. By appropriately selecting the specific gravity of the separation liquid, any conventionally known thermoplastic resin composition can be material-recycled.
[0110]
Specific examples of the thermoplastic resin composition that is material-recycled include polyolefin-based, polystyrene-based, polycarbonate-based, polymethylmethacrylate-based thermoplastic resin compositions, and the like. Among these, polyolefin-based thermoplastic resin compositions such as polyethylene and polypropylene, and polystyrene-based thermoplastic resin compositions such as polystyrene and ABS are other thermoplastics as shown in Table 3 below. Since it is superior in terms of processability and economy as compared with the resin composition, it is possible to suitably recycle the material in the method for recycling the thermoplastic resin composition waste material of the present invention.
[0111]
[Table 3]

[0112]
Here, the characteristics of the main thermoplastic resin compositions in Table 3 were evaluated according to the following criteria.
○: Excellent
Δ: Neither
×: Inferior
In the molding step of the thermoplastic resin composition, it is desirable to recycle the material by heating and melting the thermoplastic resin composition.
[0113]
Therefore, when the melting point of the thermoplastic resin composition is T ° C., the heating temperature at this time is preferably T ° C. or higher, and more preferably (T + 10) ° C. or higher. Further, the heating temperature at this time is preferably (T + 120) ° C. or less, and more preferably (T + 80) ° C. or less. When the heating temperature at this time is less than T ° C., the thermoplastic resin composition does not sufficiently melt and tends to be difficult to mold, and when the heating temperature at this time exceeds (T + 120) ° C., There is a tendency that the thermoplastic resin composition is thermally deteriorated.
[0114]
<Procedure for waste recycling method (2)>
Here, about the recycling method of the thermoplastic resin composition waste material of this invention, using the specific example in the case of material recycling of the polyolefin-type and polystyrene-type thermoplastic resin composition as shown in FIG. 1 and FIG. This will be described in more detail.
[0115]
In this specific example, first, as shown in FIG. 1, four used home appliances discarded from homes and the like are collected (step 101). Then, the wastes of the four items of home appliances are disassembled, and large metal parts such as compressors and heat exchangers are collected for each part (step 102).
[0116]
Next, the remaining members of the four items of household electrical appliances from which large metal parts and the like have been collected are roughly crushed to about 60 mm with a large crusher (step 103).
[0117]
Subsequently, the crushed waste of the four items of home appliances is sorted into a metal-based crushed material and a plastic-based crushed material with a metal sorter (step 104), and metals such as iron, copper, and aluminum are collected, and then plastic The polyurethane heat insulating material and the expanded polystyrene are removed from the system crushed material using a wind power sorter (step 105).
[0118]
Then, the plastic crushed material is separated by specific gravity using a specific gravity liquid having a specific gravity of 1.08, for example, an aqueous sodium chloride solution (step 106), and the polyolefin-based thermoplastic resin composition and the polystyrene-based thermoplastic resin composition are separated from other systems. The mixed crushed product of the polyolefin-based thermoplastic resin composition and the polystyrene-based thermoplastic resin composition separated from the thermoplastic resin composition and further separated in step 106 is obtained by using a specific gravity liquid having a specific gravity of 1.00, for example, water. Separated into a polyolefin-based thermoplastic resin composition and a polystyrene-based thermoplastic resin composition (step 107).
[0119]
The polystyrene-based thermoplastic resin composition is then used in combination with methods such as visual inspection, flammability, solvent solubility, and resin composition analyzers (infrared spectrophotometer, gas chromatograph mass spectrometer, etc.). (PS), styrene-butadiene (SB), acrylonitrile-styrene (AS), acrylonitrile-styrene-butadiene (ABS), and others are separated (step 108).
[0120]
Next, as shown in FIG. 2, the polystyrene (PS) and styrene-butadiene (SB) separated in FIG. 1, and the crushed material of acrylonitrile-styrene (AS) and acrylonitrile-styrene-butadiene (ABS) are mixed, After each finely pulverized to about 10 mm (step 201), the adhered foreign matter is removed by washing (step 202).
[0121]
Further, the washed crushed pieces of each thermoplastic resin composition are homogeneously mixed (step 203) and heat-molded (step 204) to obtain pellet-shaped molding resin materials (step 205). Then, the pellet-shaped resin material is put into an injection molding machine to produce a molded body (step 206).
[0122]
Here, mixing of the crushed material of polystyrene (PS) and styrene-butadiene (SB), and acrylonitrile-styrene (AS) and acrylonitrile-styrene-butadiene (ABS) is performed after fine crushing (step 201) or washing (step (step)). 202) It may be after.
[0123]
Further, with respect to the polyolefin-based plastic separated in FIG. 1, similarly, steps 201 to 206 in FIG. 2 are performed to produce a molded body.
[0124]
The method for recycling a thermoplastic resin composition waste material according to the present invention does not have to include all the steps shown in FIGS. 1 and 2, but a step of recovering plastic waste and crushing the plastic waste. Separating the metal-based crushed material and the low bulk density crushed material from the plastic-based crushed material, and separating the plastic-based crushed material mainly composed of the thermoplastic resin composition from the separated plastic waste. It is preferable to include at least a step and a step of material recycling of the thermoplastic resin composition.
[0125]
Moreover, the process which is not shown by FIG. 1 and FIG. 2 may be added to the recycling method of the thermoplastic resin composition waste material of this invention as needed.
[0126]
<Waste recycling system>
In order to carry out the method for recycling the thermoplastic resin composition waste material of the present invention, it is preferable to use the following thermoplastic resin composition waste material recycling system.
[0127]
The thermoplastic resin composition waste recycling system used in the present invention is a waste recycling system used in the above-described thermoplastic resin composition waste recycling method of the present invention. A mechanism that sorts crushed waste into metal-based crushed material, plastic-based crushed material, and low-bulk specific gravity crushed material, and thermoplastic resin using a plurality of separated liquids with different specific gravity A mechanism for separating the composition by system, a mechanism for mixing the thermoplastic resin composition separated by system, and a mechanism for molding the mixed thermoplastic resin composition into a specific shape. .
[0128]
Here, the mechanism for crushing the waste is not particularly limited, and an apparatus generally used for crushing a member made of a metal or a thermoplastic resin composition can be suitably used. Specific examples of the crushing device used for the B mechanism include an impact crushing device and a shearing crushing device.
[0129]
In addition, the mechanism for sorting crushed waste into metal-based crushed material, plastic-based crushed material, and low-bulk specific gravity crushed material is not particularly limited, and generally when selecting metal-based crushed material and low-bulk density crushed material. It is possible to suitably use an apparatus used for the above.
[0130]
Furthermore, as a specific example of a metal-based crushed material sorting device used in a mechanism for sorting crushed waste into metal-based crushed material, plastic-based crushed material, and low bulk specific gravity crushed material, it is suitable for iron sorting. Examples include a sorting device that uses magnetic force, a sorting device that uses eddy currents suitable for sorting aluminum and copper, and a trommel device that sifts with a uniform particle size.
[0131]
In addition, as a specific example of a low-bulk density crushed material used in a mechanism for sorting crushed waste into metal-based crushed material, plastic-based crushed material and low-bulk specific gravity crushed material, sorting using wind power is possible. Examples thereof include a device and a device using a vibrating screen.
[0132]
Here, the mechanism for separating the plastic-based crushed material using a plurality of separation liquids having different specific gravities according to the system of the thermoplastic resin composition is a specific gravity separation apparatus having a mixing and stirring tank filled with two different specific gravity separation liquids. It is preferable that the mechanism is provided. Here, two separation liquids having different specific gravities are referred to as an X separation liquid and a Y separation liquid.
[0133]
In this case, the specific gravity of the X separation liquid is preferably 1.00 or more, and more preferably 1.01 or more. The specific gravity of the X separation liquid is preferably 1.10 or less, and more preferably 1.08 or less. When the specific gravity of the X separation liquid is less than 1.00, there is a tendency that polyolefin-based plastics are mixed. When the specific gravity of the X separation liquid exceeds 1.10, polyamide, polycarbonate, rubber, etc. are mixed. There is a tendency.
[0134]
In this case, the specific gravity of the Y separation liquid is preferably 0.92 or more, more preferably 0.95 or more. Further, the specific gravity of the Y separation liquid is preferably 1.01 or less, and more preferably 1.00 or less. When the specific gravity of the Y separation liquid is less than 0.92, a part of the polyolefin-based plastic tends to settle and the recovery rate tends to decrease. When the specific gravity of the Y separation liquid exceeds 1.01, the polystyrene plastic There is a tendency that a part of.
[0135]
The composition of the separation liquid is not particularly limited. For example, a solution prepared by dissolving a salt such as NaCl in water to adjust the specific gravity can be suitably used.
[0136]
Moreover, in the mechanism which isolate | separates the plastic crushed material according to the system of the thermoplastic resin composition using a plurality of separation liquids having different specific gravities, the specific gravity separation device supplies the plastic crushed material and the separation liquid. Means, a mixing agitation tank filled with the separation liquid, a means for recovering the plastic crushed material floating on the liquid surface of the separation liquid, and a means for recovering the plastic crushed material precipitated at the bottom of the mixing agitation tank. It is preferable to have.
[0137]
However, it is not necessary to provide all these means, and it is sufficient to provide at least a tank in which the plastic crushed material and the separated liquid are charged and mixed and stirred.
[0138]
Further, the recovery means after separating the plastic crushed material may be a method of scooping out the floating material manually or overflowing by an overflow method. Alternatively, a method may be used in which the sediment is sucked up together with the separation liquid by a suction device, transferred by a screw-type conveying device, or the suspended liquid is collected after the separation liquid is collected in another tank. The separation liquid that flows out when the suspended matter or sediment is recovered may be pumped up and supplied again into the mixing and stirring tank, and may be used repeatedly.
[0139]
Here, the mechanism for separating the polystyrene-based thermoplastic resin composition by system is not particularly limited, but it is mainly made by visual inspection. However, it is combustible, soluble in a solvent, and further a resin composition analyzer ( It is preferable to use a method such as an infrared spectrophotometer or a gas chromatograph mass spectrometer in combination.
[0140]
Moreover, it is preferable that the mechanism which shape | molds the thermoplastic resin composition isolate | separated according to type | system | group into a specific shape is a mechanism provided with the extrusion molding apparatus.
[0141]
Although it does not specifically limit as an extruder used here, For example, a single screw extruder, a biaxial extruder, a multi-screw type extruder, etc. are mentioned.
[0142]
Here, when the thermoplastic resin composition is formed into pellets and recycled, it may be granulated by any method such as sheet cut, strand cut, hot air cut, underwater cut after extrusion. Good. Among these granulation methods, when forming into a specific shape by injection molding later, an underwater cut that can smoothly supply the resin raw material and can cope with a large amount of processing is particularly preferable.
[0143]
<Raw material of thermoplastic resin composition>
The method for recycling a thermoplastic resin composition waste material according to the present invention can also be used as a method for producing the molded thermoplastic resin composition according to the present invention.
[0144]
And the thermoplastic resin composition molded body of the present invention produced by the method for producing the molded thermoplastic resin composition of the present invention may be a thermoplastic resin composition raw material. In this case, the thermoplastic resin composition raw material is preferably in the form of pellets. At this time, the particle diameter of the pellet is preferably 1 mm or more, and more preferably 2 mm or more. Further, the particle diameter of the pellet is preferably 8 mm or less, and more preferably 5 mm or less.
[0145]
If the particle size of the pellet is less than 1 mm, the workability tends to be lowered due to floating, and if the particle size of the pellet exceeds 8 mm, the pellet does not melt sufficiently in the cylinder of the molding machine and is uniform. There is a tendency not to be kneaded.
[0146]
In addition, the shape of the thermoplastic resin composition raw material of the present invention is not particularly limited to a pellet form, and may be any form such as a sheet form, a film form, a pipe form, and extrusion molding. What is necessary is just to determine suitably from the kind of machine, the aspect of use, or the characteristic calculated | required.
[0147]
Furthermore, additives such as heat stabilizers, light stabilizers, antistatic agents, lubricants, fillers, copper damage inhibitors, antibacterial agents, and coloring agents are added to the thermoplastic resin composition raw material of the present invention as necessary. You may add in the quantity of the range which does not impair the effect of this invention.
[0148]
<Member made of thermoplastic resin composition>
The method for recycling a thermoplastic resin composition waste material according to the present invention can also be used as a method for producing the molded thermoplastic resin composition according to the present invention. The thermoplastic resin composition molded article of the present invention produced by the method for producing a thermoplastic resin composition molded article of the present invention may be a member made of a thermoplastic resin composition. In this case, the member made of the thermoplastic resin composition is preferably used for a product selected from the group consisting of an air conditioner, a television, a refrigerator, and a washing machine.
[0149]
Moreover, the member which consists of this thermoplastic resin composition can be shape | molded using methods, such as injection molding, from said thermoplastic resin composition raw material. Although it does not specifically limit as an injection molding machine used at this time, For example, a screw in-line type injection molding machine, a plunger type injection molding machine, etc. are mentioned.
[0150]
Further, in order to further simplify the molding step of the member made of this thermoplastic resin composition, a crushed thermoplastic resin composition is prepared without producing a thermoplastic resin composition raw material having a shape such as a pellet. A member made of a thermoplastic resin composition may be directly produced by directly putting it into an injection molding machine.
[0151]
Furthermore, the members made of this thermoplastic resin composition may contain additives such as heat stabilizers, light stabilizers, antistatic agents, lubricants, fillers, copper damage inhibitors, antibacterial agents, and coloring agents, if necessary. It may be formed by molding after adding in an amount that does not impair the effects of the invention. The step of adding these additives is preferably at the time of charging the thermoplastic resin composition raw material or the crushed thermoplastic resin composition into an extrusion molding machine or an injection molding machine.
[0152]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these.
[0153]
<Preparation of experimental materials>
First, experimental materials used in the following examples were prepared. Specifically, using a used refrigerator, washing machine, air conditioner, and TV, collect large metal parts such as compressors and heat exchangers by manual disassembly, and then use a normal crusher. From the crushed material obtained by crushing, the metal-based crushed material is sorted by a sorter using normal magnetic force, and the low bulk specific gravity crushed material is sorted by a sorter using normal wind power. The crushed material is separated into a polystyrene-based thermoplastic resin composition, a polyolefin-based thermoplastic resin composition, and other plastics. Furthermore, the polystyrene-based thermoplastic resin composition includes polystyrene (PS) and styrene-butadiene (SB). , Acrylonitrile-styrene (AS), acrylonitrile-styrene-butadiene (ABS) With plastic resin composition was prepared as an experimental material.
[0154]
<Measurement method>
The physical properties used in the following examples were measured by the following methods.
[0155]
(I) Tensile yield strength and tensile elongation at break
Measurement was performed according to JIS K7113.
[0156]
(Ii) Flexural strength and flexural modulus
Measurement was performed according to JIS K7203.
[0157]
(Iii) Izod impact value
It measured according to JIS K7110.
[0158]
(Iv) Melt flow rate (MFR)
It measured according to JIS K7210.
[0159]
<Example 1>
In accordance with the procedure of FIG. 1, using a separated liquid having a specific gravity of 1.08 and a specific gravity of 1.00, the difference in specific gravity between the polyolefin-based thermoplastic resin composition and the polystyrene-based thermoplastic resin composition contained in the experimental material (I) is determined. Separated using.
[0160]
As a specific gravity separation method, the experimental material (I) was put into a mixing and stirring tank filled with a sodium chloride aqueous solution having a specific gravity of 1.08, stirred, and then floated (polyolefin-based and polystyrene-based thermoplastic resin composition). ) Was recovered by the overflow method, and the precipitated (thermoplastic resin composition of other systems, rubber, metal, etc.) was collected by suction with an aqueous sodium chloride solution.
[0161]
Here, the sodium chloride aqueous solution which flowed out by the overflow method and the sodium chloride aqueous solution simultaneously recovered at the time of suction recovery were injected into the mixing and stirring tank using a pump and reused.
[0162]
Next, the polyolefin-based and polystyrene-based thermoplastic resin compositions recovered as floating were put into a mixing and stirring tank filled with water having a specific gravity of 1.00, stirred, and then floated (polyolefin-based). The thermoplastic resin composition) and the precipitated one (polystyrene thermoplastic resin composition) were collected.
[0163]
The polystyrene-based thermoplastic resin composition is used in combination with methods such as visual analysis, flammability, solvent solubility, and resin composition analyzers (infrared spectrophotometer, gas chromatograph mass spectrometer, etc.). (PS), styrene-butadiene (SB), acrylonitrile-styrene (AS), and acrylonitrile-styrene-butadiene (ABS).
[0164]
Next, according to the procedure of FIG. 2, the polystyrene (PS), styrene-butadiene (SB), acrylonitrile-styrene (AS), and acrylonitrile-styrene-butadiene (ABS) obtained above are finely crushed and washed. Then, the mixture was further uniformly mixed to prepare a pulverized polystyrene-based thermoplastic resin composition for each composition.
[0165]
These finely crushed thermoplastic resin compositions are mixed alone or as necessary, and melt-kneaded at 230 ° C. using a screw-type 45 mm biaxial melt-kneading extruder to produce a pellet-shaped thermoplastic resin composition. A raw material was prepared.
[0166]
Subsequently, each of these thermoplastic resin composition raw materials is put into a hopper of a 10-ton injection molding machine, and a test piece for measuring physical properties in accordance with ASTM is produced under injection molding conditions of a molding temperature of 230 ° C. and a mold temperature of 40 ° C. Each physical property was measured.
[0167]
In addition, test specimens for measuring physical properties of virgin materials of the same series of thermoplastic resin compositions were prepared, and the respective physical properties were measured. These measurement results are shown in Table 4.
[0168]
[Table 4]

[0169]
Of the abbreviations described in Table 4, “R-PS” is a polystyrene composition prepared by separation and recovery, “R-SB” is a styrene-butadiene composition prepared by separation and recovery, and “R-AS” is Separately recovered and prepared acrylonitrile-styrene composition, “R-ABS” is separated and recovered acrylonitrile-styrene-butadiene, “V-SB” is unused styrene-butadiene composition, and “V-ABS” is not The acrylonitrile-styrene-butadiene used is indicated.
[0170]
Here, as understood from Table 4, the physical properties of styrene-butadiene (SB) and acrylonitrile-styrene-butadiene (ABS) separated and recovered in this example are as follows: unused styrene-butadiene (SB), It was quite different from acrylonitrile-styrene-butadiene (ABS).
[0171]
In addition, since the polystyrene (PS) and acrylonitrile-styrene (AS) separated and recovered in this example are contaminated due to long-term use, the transparency that is the original characteristic of the plastic composition is considerably high. It was inferior.
[0172]
Therefore, the polystyrene (PS), styrene-butadiene (SB), acrylonitrile-styrene (AS), and acrylonitrile-styrene-butadiene (ABS) prepared by separation and recovery in this example are reused for medium or low grade. The application was limited.
[0173]
Therefore, in order to develop applications of polystyrene (PS) and acrylonitrile-styrene (AS) separated and recovered in this example, styrene-butadiene (SB) and acrylonitrile-styrene-butadiene (ABS) were mixed, Physical properties were measured.
[0174]
The experimental materials were prepared by mixing polystyrene (PS) and styrene-butadiene (SB), which were separated and recovered in this example, and melt-kneading them at 230 ° C. using a screw system 45 mm biaxial melt-kneading extruder. Then, pellet-shaped thermoplastic resin composition raw materials are prepared, and then these thermoplastic resin composition raw materials are respectively put into a hopper of a 10-ton injection molding machine, and injection at a molding temperature of 230 ° C. and a mold temperature of 40 ° C. Test specimens for measuring physical properties in accordance with ASTM were produced under molding conditions, and the physical properties were measured.
[0175]
In addition, polystyrene (PS) and styrene-butadiene (SB) separated and recovered in this example, unused styrene-butadiene (SB), and acrylonitrile-styrene (AS) and acrylonitrile—separated and prepared in this example. Styrene-butadiene (ABS), acrylonitrile-styrene-butadiene (ABS), which has not been used for acrylonitrile-styrene (AS) and acrylonitrile-styrene-butadiene (ABS) separated and recovered in this example, are also used for measuring physical properties. Test specimens were prepared and their physical properties were measured.
[0176]
These measurement results are shown in Table 5.
[0177]
[Table 5]

[0178]
Of the abbreviations listed in Table 5, “R-PS / R-SB” is a mixture of 20% polystyrene composition prepared by separation and recovery and 80% styrene-butadiene composition, “R-PS / “R-SB / V-SB” is a mixture of 20% polystyrene composition prepared by separation and recovery, 20% styrene-butadiene composition and 60% unused styrene-butadiene composition, “R-AS / R”. -ABS "is a mixture of 20% acrylonitrile-styrene composition prepared by separation and recovery and 80% acrylonitrile-styrene-butadiene composition, and" R-AS / R-ABS / V-ABS "is prepared by separation recovery. Unused acrylonitrile-styrene-butadiene composition to 20% acrylonitrile-styrene composition, 20% acrylonitrile-styrene-butadiene composition Intended to indicate a mixture of 0%.
[0179]
Here, as understood from Table 5, a mixture of the polystyrene-based thermoplastic resin composition separated and recovered in this example, and an unused thermoplastic resin composition of the same system were blended in the mixture, The measured physical properties of the molded specimens for measuring physical properties, such as tensile strength, elongation, bending strength, flexural modulus, Izod impact strength, and melt flow rate, are slightly different from virgin materials, but a medium quality recycled product is obtained. Therefore, it can be said that the reuse of reuse has become possible.
[0180]
<Example 2>
The following experiment was conducted in Example 2 in order to further improve the quality of the polystyrene-based thermoplastic resin composition obtained in Example 1 and to reduce the amount of virgin material.
[0181]
In this example, styrene-butadiene shaped by vacuum forming used for inner box materials of refrigerators, etc., for the purpose of developing applications of polystyrene (PS) separated and recovered and acrylonitrile-styrene (AS). (SB) or acrylonitrile-styrene-butadiene (ABS) was separated and recovered and mixed with polystyrene (PS) or acrylonitrile-styrene (AS) to measure physical properties.
[0182]
The experimental materials were prepared by mixing and recovering the polystyrene (PS) and styrene-butadiene (SB) vacuum formed and recovered products separated and recovered in this example, and using a screw system 45 mm biaxial melt kneading extruder at 230 ° C. The mixture is melt-kneaded to produce pellet-shaped thermoplastic resin composition raw materials, and then these thermoplastic resin composition raw materials are respectively put into a hopper of a 10-ton injection molding machine, and a molding temperature of 230 ° C. and a mold temperature Test specimens for measuring physical properties in accordance with ASTM were produced under injection molding conditions of 40 ° C., and the physical properties were measured.
[0183]
In addition, polystyrene (PS) separated and recovered in this example and styrene-butadiene (SB) unused in the vacuum-formed recovered product of styrene-butadiene (SB), and acrylonitrile-styrene (AS) separated and recovered in this example were prepared. ) And acrylonitrile-styrene-butadiene (ABS) vacuum molded and recovered product, and acrylonitrile-styrene unused in the acrylonitrile-styrene (AS) and acrylonitrile-styrene-butadiene (ABS) vacuum molded and recovered product separated and recovered in this example. -Test specimens for measuring physical properties were similarly prepared for butadiene (ABS), and the respective physical properties were measured.
[0184]
These measurement results are shown in Table 6.
[0185]
[Table 6]

[0186]
Among the abbreviations listed in Table 6, “R-PS / Rv-SB” is a mixture of 30% polystyrene composition prepared by separation and recovery and 70% styrene-butadiene composition vacuum-formed recovery product. "R-PS / Rv-SB / V-SB" is 30% of the polystyrene composition prepared by separation and recovery, 40% of the styrene-butadiene composition vacuum molding recovery product, and unused styrene-butadiene composition 30 "R-AS / R-v-ABS" is a mixture of 30% acrylonitrile-styrene composition prepared by separation and recovery and 70% acrylonitrile-styrene-butadiene composition vacuum molding recovery product, "R-AS / Rv-ABS / V-ABS" is 30% acrylonitrile-styrene composition, 40% acrylonitrile-styrene-butadiene prepared by separation and recovery. Vacuum formed collection items, unused acrylonitrile - styrene - denote the a mixture of butadiene composition 30%.
[0187]
Here, as understood from Table 6, a mixture of the polystyrene-based thermoplastic resin composition separated and recovered in this example, and an unused thermoplastic resin composition of the same system were blended in the mixture, The measured physical properties of tensile strength, elongation, bending strength, flexural modulus, Izod impact strength, and melt flow rate of the molded specimen for measuring physical properties are high-quality reproductions that have physical properties that are similar to or better than virgin materials. It can be said that the use of reusable products can be greatly expanded.
[0188]
From the results of Example 1 and Example 2 above, it is possible to selectively separate and recover the thermoplastic resin composition waste material used for four items of home appliances, and to mix a plurality of types to obtain a thermoplastic resin composition molded article. Recycling becomes possible and the use of recycled products can be expanded.
[0189]
For example, conventional thermoplastic resin waste materials such as polystyrene (PS) and acrylonitrile-styrene (AN) are contaminated by long-term use, and the excellent transparency that is the original feature is hindered. Although it was difficult to mix with styrene-butadiene (SB) and acrylonitrile-styrene-butadiene (ABS) that were selectively separated and recovered, regenerated products of medium to low quality were obtained, such as hangers and flower pots. Can be used for daily necessities.
[0190]
Furthermore, according to the method for recycling the thermoplastic resin composition waste material of the present invention, the mixture of the thermoplastic resin composition waste material including the above-mentioned system is subjected to vacuum-molded styrene-butadiene (SB) recovered from the refrigerator member. By further mixing acrylonitrile-styrene-butadiene (ABS), a high-quality recycled product can be obtained, so that it can be used as a durable consumer material such as a rear cover of a washing machine or a refrigerator plate.
[0191]
In addition, since the transparency of polystyrene, which is an inherent property of polystyrene, is greatly reduced by adhesion of dirt and the like, it is currently incinerated and landfilled, but from the results of the above examples, polystyrene waste In addition, it was found that by mixing the styrene-butadiene vacuum molded product recovered from the waste refrigerator, a recycled material that is sufficiently inferior to cascade applications can be obtained although it is somewhat inferior to the virgin material. By adopting such a recycling method, it is possible to greatly contribute to the reduction of the recycling cost as well as the improvement of the recycling rate.
[0192]
Furthermore, the acrylonitrile-styrene waste material is also incinerated and landfilled because the transparency, which is the original property, is greatly reduced by adhesion of dirt, etc., but from the results of the above examples, It was found that by mixing the acrylonitrile-styrene-butadiene vacuum molded product recovered from the waste refrigerator, a recycled material that is sufficiently inferior to cascade use can be obtained although it is somewhat inferior to the virgin material. By adopting such a recycling method, it is possible to greatly contribute to the reduction of the recycling cost as well as the improvement of the recycling rate.
[0193]
Further, the method of recycling the thermoplastic resin composition waste material of the present invention is not limited to the method of recycling the thermoplastic resin composition waste material of the four items of home appliances, but a member made of a thermoplastic resin composition. If it is a product provided with, it can be used conveniently for any product.
[0194]
It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
[0195]
【The invention's effect】
From the above results, the method for recycling the thermoplastic resin composition waste material according to the present invention was adapted to various uses by recycling the thermoplastic resin composition waste material from the thermoplastic resin composition waste material as a main raw material. This is an efficient method for recycling a thermoplastic resin composition waste material, which can obtain a thermoplastic resin composition molded article having characteristics and can reduce the thermoplastic resin composition waste material that is thermally recycled.
[0196]
In addition, when the thermoplastic resin composition waste material of the present invention is used, the thermoplastic resin composition waste material is made of polystyrene (PS) or acrylonitrile-styrene (AS). Recycled materials that use as the main raw material can produce molded thermoplastic resin compositions that have properties according to a variety of uses, and can further reduce the waste of thermoplastic resin compositions that are further thermally recycled. This is an efficient method for recycling waste thermoplastic resin composition.
[0197]
Furthermore, the method for producing a molded article of a thermoplastic resin composition according to the present invention is a method for producing a thermoplastic resin composition waste material from a thermoplastic resin composition waste material by material recycling using the thermoplastic resin composition waste material as a main raw material. It is a manufacturing method of a plastic resin composition molded object.
[0198]
And the thermoplastic resin composition molded article of the present invention provides a thermoplastic resin composition molded article having properties according to various uses, obtained by material recycling using thermoplastic resin composition waste as a main raw material. That is.
[Brief description of the drawings]
FIG. 1 is a flowchart showing an example of steps in the first half of a method for recycling a thermoplastic resin composition waste material according to the present invention.
FIG. 2 is a flowchart showing an example of steps in the latter half of the method for recycling a thermoplastic resin composition waste material according to the present invention.

Claims (5)

A method for recycling thermoplastic resin composition waste,
The thermoplastic resin composition waste material is selectively made into polystyrene, acrylonitrile-styrene, and styrene-butadiene molded by vacuum molding according to the type of thermoplastic resin composition that is a main component in the thermoplastic resin composition waste material. Separating and recovering acrylonitrile-styrene-butadiene shaped by vacuum forming ;
Selectively separated and recovered polystyrene or its heated melt and selectively separated and recovered styrene-butadiene or its heated melt, or selectively separated and recovered polystyrene or its heated melt and selectively separated and recovered Styrene-butadiene or its heated melt and unused styrene-butadiene or its heated melt are mixed to obtain a mixture based on polystyrene and styrene-butadiene, or selectively separated and recovered acrylonitrile -Styrene or its heated melt and selectively separated and recovered acrylonitrile-Styrene-butadiene or its heated melt, or selectively separated and recovered acrylonitrile-Styrene or its heated melt and selectively recovered Acrylonitrile Styrene - obtaining a mixture composed mainly of butadiene, - styrene and acrylonitrile - - Styrene acrylonitrile were mixed with butadiene or molten product thereof - butadiene or its molten product and unused acrylonitrile - styrene
Heating and melting the mixture ;
Molding the thermoplastic resin composition waste material that has been mixed and heated and melted to obtain a thermoplastic resin composition molded body, and a method for recycling the thermoplastic resin composition waste material. The step of selectively separating and recovering includes a step of selectively separating and recovering a thermoplastic resin composition mainly composed of styrene-butadiene from a refrigerator, and recycling the waste thermoplastic resin composition according to claim 1. Recycling method . The thermoplastic resin composition according to claim 1 or 2, wherein the step of selectively separating and collecting includes a step of selectively separating and collecting a thermoplastic resin composition mainly composed of acrylonitrile-styrene-butadiene from a refrigerator. Recycling method for waste materials . The manufacturing method of the thermoplastic resin composition molded object which obtains a thermoplastic resin composition molded object by the recycling method of the thermoplastic resin composition waste material in any one of Claims 1-3 . The method for producing a thermoplastic resin composition molded article according to claim 4, wherein the thermoplastic resin composition molded article is a thermoplastic resin composition molded article having a pellet shape .

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