JP2004292661A - Method of decomposition treatment of rigid urethane resin and method for producing regenerated resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a regenerated resin suitable for practical use by setting suitable conditions in the decomposition treatment of urethane resins. <P>SOLUTION: A urethane resin and a decomposer are charged into an extruder 1 to allow decomposition of the urethane resin to proceed. It is determined whether the decomposition of the urethane resin is sufficient or not based on the proportion of the urethane resin to the decomposer, heating temperature and the time for the decomposition treatment. When it is determined that the decomposition of the urethane resin is insufficient, supplementary heating to heat a treated object obtained from the decomposition treatment is conducted. An isocyanate compound or a compound with an epoxy group is mixed with the treated object which has been subjected to the decomposition treatment and the supplementary heating to be conducted depending on circumstances to obtain a regenerated resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【化２】

これらの反応の最終生成物には、原料イソシアネート由来のアミン成分が生成する。イソシアネート成分の大半はＭＤＩやＴＤＩなどであり、これらから最終的にＭＤＡやＴＤＡが残存する。これらの芳香族アミンは、実際にエポキシ樹脂の硬化剤として使用されていることもあり、エポキシ基と極めて反応しやすい。これらが分解物中に多ければ多いほど、エポキシ樹脂との反応性が増し、再生樹脂の強度も上がる。本発明は、ウレタン樹脂の分解が最後まで進み、且つ、炭化のような過剰反応を起こさない処理条件を求めて分解処理を調節するウレタン樹脂の分解処理方法である。最終生成物として芳香族ジアミンが生じる、モノエタノールアミン又はジエタノールアミンによる分解において特に有効である。
【００１６】
ウレタン樹脂のウレタン結合の切断は、分解方法や分解剤の違いにより程度の差はあるが、分解剤によって徐々に低分子化するのであって、すべてのウレタン結合が一斉に切れて分解物が生成するという事はまず無い。つまり、分解処理中のウレタン樹脂中には、未分解ウレタン樹脂、ウレタン樹脂構成成分のオリゴマー及びモノマーと、残存分解剤とが混在する。品質のよいウレタン樹脂分解物を得るために重要なことは、添加した分解剤がすべて消費されて、ウレタン樹脂構成成分のオリゴマー及びモノマーのみ、望ましくはモノマーだけになることである。筆者らの研究では、ウレタン樹脂に熱を加え過ぎると、樹脂分解物が次第に炭化して物性が低下することを確認している。また、ウレタン樹脂に加える熱が不足すると、十分に分解されないだけでなく、その樹脂分解物に再度熱をかけた際に再度分解が進む場合もあり得るので、樹脂分解物を用いて再生する製品の品質安定化が難しい。従って、品質のよい樹脂分解物を得るために、ウレタン樹脂の分解処理における加熱温度と加熱時間とを適正な値に設定する必要がある。
【００１７】
一方、ウレタン樹脂の分解反応を均一に進行させるには、ウレタン樹脂と分解剤との混合均一化をできる限り素早く効率的に行う必要があり、この点で、使用する分解処理装置としては押出機が適している。押出機は、加熱、混合及び圧縮（加圧）を同時に行うことができ、混合効率がよいので、投入したウレタン樹脂の分解を均一に進行させ易く、分解の進行を制御し易い。また、バッチ式などの処理装置と比べると、分解の進行を速くすることができるので、経済効率も高い。しかし、押出機は、押出し長さの設計限界や押出し抵抗によって加熱時間を余り長く設定することができない。このため、必要な加熱時間を確保するには、押出機での加熱処理の後に補助的な加熱処理が必要となる。この場合、一旦押出機を経た被処理物は、ウレタン樹脂と分解剤とが混合され被処理物の均一性が高いので、バッチ式の装置を用いても補助加熱処理は良好に行える。
【００１８】
本発明においては、上記を勘案して、品質のよい樹脂分解物が得られるウレタン樹脂の分解処理の処理温度及び処理時間の適正な値を決定する。そして、これらを用いて、押出機における分解処理（一次処理）の設定条件を評価して、補助加熱処理（二次処理）が必要か否かを判断し、必要な補助加熱処理の条件を決定することができる。
【００１９】
先ず、品質のよい樹脂分解物が得られるウレタン樹脂の処理温度及び処理時間の適正値及び分解進行の評価について説明する。
【００２０】
（処理温度及び処理時間の適正値及び分解進行の評価）
本願発明者らの実験結果によれば、ウレタン樹脂に一定量の分解剤を混合して一定温度で加熱処理した時、処理時間の増加に従ってウレタン樹脂の分解が進行し、被処理物の粘度が低下する。しかし、その後、被処理物の粘度は上昇し始め、樹脂分解物が次第に炭化する。そして、被処理物が最も均一で被処理物を用いてウレタン樹脂又はエポキシ樹脂を再生した時の再生樹脂の品質が安定するのは、被処理物の粘度が最低値の時である。つまり、被処理物の粘度が最低値となる処理時間が、その加熱温度における最適処理時間となる。これに従って、加熱温度ｔと最適処理時間ｈ_ｓとの関係を調べると、下記式（１）が成り立つことを見出した。
【００２１】
【数１】
ｈ_ｓ＝ａ・ｔ^{−２１．５} （但し、ａ＝１０^５６） （１）
加熱温度＝ｔ_ｃ（一定）の時、単位時間当りの分解進行度ΔＤ（最適処理時間における分解進行度を１とする割合）は、下記式（２）で表すことができ、処理時間ｈの時の分解進行度Ｄ_ｈは、Ｄ_ｈ＝ΔＤ×ｈ＝ｈ／ｈ_ｓとなる。
【００２２】
【数２】
ΔＤ＝１／ｈ_ｓ＝ａ’・ｔ_ｃ ^２１．５ （２）
（但し、ａ’＝１／ａ）
他方、加熱温度が時間によって変化する場合、単位時間毎に加熱温度ｔ_ｎ（ｎ＝１，２，・・・）をとると、単位時間当りの分解進行度ΔＤ_ｎ＝ａ’・ｔ_ｎ ^２１．５（ｎ＝１，２，・・・）を処理開始から時間ｈ_ｎまで合計すれば、その合計値は時間ｈ_ｎにおける分解進行度Ｄ_ｎであり、下記式（３）のように合計値が１となる時間が最適処理時間ｈ_ｓとなる。
【００２３】
【数３】

但し、ウレタン樹脂に加える分解剤の量が上記の場合と異なる場合、ａ及びａ’が異なるので、上記から得られる分解進行度ΔＤ_ｎの合計値及び最適処理時間ｈ_ｓも異なる。
【００２４】
（補助加熱処理の設定）
押出機を用いてウレタン樹脂を加熱し分解処理（一次処理）した時、押出機の入口から出口まで上記の単位時間当りの分解進行度ΔＤ_ｎを合計し、合計値が１に至らなければ、不足分に相当する分解処理を補助加熱処理（二次処理）として行えばよい。例えば、押出機から排出した被処理物をそのまま保温容器中でほぼ一定温度に保つ場合、分解進行度の不足分から補助加熱処理の時間を求める計算は理論的には比較的容易である。
【００２５】
しかし、実際の分解処理においては、被処理物の分解進行度は、処理装置の構造や作業条件等によって部分的なばらつきや誤差が生じるので、最適値を含むある程度の幅をもった範囲を適正処理時間とすることが実際的である。
【００２６】
上記を勘案して、単位時間当りの分解進行度の合計の計算による補助加熱処理（二次処理）の条件決定は、以下のような近似的な処理に従って行うことができ、センサーにより検出される押出機の温度データやそれを用いて得られる温度勾配データ等を用いて、以下の手順によってコンピュータ等により簡単に実施できる。
【００２７】
１）分解処理の温度Ｔ［゜Ｋ］における定数ｋを下記のように設定する。
【００２８】
ｋ＝２ （３００＜Ｔ）
ｋ＝１ （２７０＜Ｔ≦３００）
ｋ＝１／３ （２４０＜Ｔ≦２７０）
ｋ＝１／１０ （２１０＜Ｔ≦２４０）
ｋ＝１／４０ （１８０＜Ｔ≦２１０）
ｋ＝１／２００（１４０≦Ｔ≦１８０）
ｋ＝０ （Ｔ＜１４０）
２）押出機による一次処理において温度Ｔ［゜Ｋ］で処理される処理時間ΔＨ_Ｔ［時間］及び上記定数ｋから、温度Ｔ［゜Ｋ］の処理におけるパラメータΔＺ_Ｔ＝ｋ×ΔＨ_Ｔ×１００を算出し、分解処理工程の全処理温度についてパラメータΔＺ_Ｔを加算し合計値Ｚを算出する。
【００２９】
３）分解剤１重量部に対するウレタン樹脂の重量部数Ｎに応じて、上記パラメータΔＺ_Ｔの合計値Ｚを下記式で示すＺの適正範囲と比較し、適正範囲にあるか否かを判断する。
【００３０】
Ｎ＜２．５の時 ３≦Ｚ≦１５
２．５≦Ｎ≦５の時 ５≦Ｚ≦２５
５＜Ｎの時 １０≦Ｚ≦３０
４）合計値Ｚが上記３）のＺの適正範囲にある場合は、二次処理（補助加熱処理）は行わない。合計値Ｚが上記適正範囲未満である場合は、この合計値Ｚと補助加熱処理のパラメータの合計値Ｚ_ｓとの和が上記３）の適正範囲に入るように、補助加熱処理における温度Ｔ_ｓ［゜Ｋ］及び温度Ｔ_ｓで処理される処理時間ΔＨ_Ｔｓ［時間］を設定する。この設定は、温度Ｔ_ｓ［゜Ｋ］におけるパラメータΔＺ_Ｔｓ＝ｋ×ΔＨ_Ｔｓ×１００及びパラメータΔＺ_Ｔｓの合計値Ｚ_ｓの計算によって行う。合計値Ｚが過剰である場合は、上記適正範囲に入るように、一次処理における温度Ｔ［゜Ｋ］及び温度Ｔ［゜Ｋ］で処理される処理時間Ｈ_Ｔ［時間］を設定し直す。
【００３１】
必要に応じて、更に、三次処理以降を補足設定してもよい。
【００３２】
パラメータの合計値の値が低いとウレタン樹脂が充分に分解されず分子量の大きい分解物ができる。合計値が高いと分解物が熱劣化し、炭化が始まる。但し、処理温度Ｔ及びＴ_ｓ［゜Ｋ］は、４１３〜５７３゜Ｋ（１４０〜３００℃）が好ましく、より好ましくは４７３〜５５３゜Ｋ（２００〜２８０℃）がよい。これより温度が低いと、処理時間が長すぎるため経済的に好ましくなく、温度が高すぎると処理時間が短すぎてその制御が難しい。
【００３３】
被処理物の温度、つまり、処理装置内の温度が測定できない場合は、処理装置の設定温度を被処理物の温度とみなしても差し支えない。この点に関しても、バッチ式装置の場合は、樹脂に圧力を加えて熱伝導を促進できないので装置の温度と被処理物の温度が大きく異なっている場合があり、押出機による処理が有利である。
【００３４】
分解剤とウレタン樹脂の比は特に制限されないが、分解剤１重量部に対してウレタン樹脂の量が２．５重量部以上５重量部以下にすることが好ましい。この範囲よりウレタン樹脂の量が少ないと、分解物中に反応しなかった分解剤が残って分解物及び再生品の物性の低下を引き起こし、これよりウレタン樹脂の量が多いと、処理時間がかかってしまうため経済的に好ましくない。
【００３５】
上記Ｚの値が得られる被処理物すべてにおいて上記の範囲内にあるのが好ましいが、実際には、被処理物の分解進行度は、分解装置の構造などによって部分的なばらつきが生じる。例えば、装置の形状によって部分的に分解開始時間の差が生じたり、被処理物の取り扱い作業によってばらつきが生じたりする。こういった場合、被処理物中に異なる分解進行度の分解物が存在することになるが、重量比で全量の８５％以上が適正な分解進行度にあれば、得られる被処理物の物性は良好となる。
【００３６】
上記評価方法による処理時間の決定の一例を以下に示す。
【００３７】
例えば、２５０℃の押出機で５分分解し、その後２００℃の反応容器で３０分保温、その後１０分に１０℃ずつ１４０℃まで除冷したとすると、ΔＺの値は表１のようになる。
【００３８】
【表１】

この場合のウレタン樹脂の分解処理におけるパラメータΔＺは上記の通りとなり、この合計値Ｚによってウレタン樹脂の分解進行状況が把握できる。故に、分解剤の添加量に応じて、パラメータΔＺの合計値Ｚが適正範囲となるように上記加熱プロセスを適宜調整・変更すればよい。決定した条件に従って分解処理を経ることにより、品質が安定した樹脂分解物を得ることができるので、樹脂の再生が容易になる。
【００３９】
なお、上記の近似的方法より正確な方法として、処理温度［゜Ｋ］を処理時間ｈ［時間］の関数Ｔ（ｈ）として、我々の実験によって求められた下記式（４）に従ってＺ値を計算し、Ｚの値が３０以上２００以下（ただし、分解剤１重量部に対してウレタン樹脂は２．５〜５重量部）となるように好ましい処理時間を決定する方法がある。本来はこの式の積分計算により分解進行度を求めるのがよいが、式が複雑で計算が煩雑になるため、先に述べた方法の方が簡易である。
【００４０】
【数４】

（ウレタン樹脂、分解剤及び分解装置）
被処理物であるウレタン樹脂としては、ウレタン結合、尿素結合などを持つ硬質ウレタン樹脂であれば如何なるものでも良い。ここでは、原料ポリオールの水酸基価が２５０ｍｇＫＯＨ／ｇ以上のものを硬質ウレタンと定義する。またイソシアヌレート結合を持つイソシアヌレート材も含み、ウレタン樹脂と同様に本発明の分解処理方法を適用できる。この場合、原料のイソシアネートの分子量はいくらであってもよい。このようなウレタン樹脂の用途として、例えば、冷蔵庫や建材などの断熱材などが挙げられる。
【００４１】
本発明は、アミン化合物単独で分解する場合に特に適していて、その中でもモノアルカノールアミンまたはジアルカノールアミンを用いた分解において最も適している。アミン化合物としては、例えば、モノエタノールアミン、ジエタノールアミン、トリエタノールアミン、エチレンジアミン、テトラメチレンジアミン、ヘキサメチレンジアミン、プロパンジアミン、２−エチルヘキシルアミン、イソプロパノールアミン、２−（２−アミノエチルアミノ）エタノール、２−アミノ−２−ヒドロキシメチル−１，３−プロパンジオール、エチルアミノエタノール、アミノブタノール、ｎ−プロピルアミン、ジ−ｎ−プロピルアミン、ｎ−アミルアミン、イソブチルアミン、メチルジエチルアミン、シクロヘキシルアミン、ピペラジン、ピペリジン、アニリン、トルイジン、ベンジルアミン、フェニレンジアミン、キシリレンジアミン、クロロアニリン、ピリジン、ピコリン、Ｎ−メチルモルフォリン、エチルモルフォリン、ピラゾール等があげられる。これらの分解剤の中で、モノエタノールアミン又はジエタノールアミンを用いた時、よりよい効果が得られる。必要に応じて、上記の分解剤に添加剤を加えてもよい。添加剤は、分解剤の反応を極端に阻害しないものであれば添加することができ、例えば、水、アルコール、ポリオールなどの希釈剤や、無機粒子、有機粒子などの充填材などが挙げられる。ポリオール化合物の例としては、エチレングリコール、ジエチレングリコール、プロピレングリコール、トリメチレングリコール、１，４−ブタンジオール、１，５−ペンタジオール、１，６−ヘキサンジオール、ポリオキシエチレングリコール、ポリオキシプロピレングリコール、グリセリン、ポリエチレングリコールなどが挙げられる。その添加量は、添加剤の物性に応じて適宜調節すればよい。水や低分子アルコールなどの沸点が１５０℃以下の添加剤については、分解装置中で揮発して最終的にウレタン樹脂分解物から離脱することから、その添加量に特に制限をつける必要は無いが、多量の添加は揮発熱によって装置の温度を低下させるので注意が必要である。好ましくは、ウレタン樹脂の重量の半分以下に抑える。また、無機粒子、有機粒子などの充填材については、反応を阻害しない程度であれば添加量に特に制限は無いが、ウレタン樹脂と同重量以下に抑えることが好ましい。
【００４２】
分解装置としては、一次処理については押出機型のような加熱、混合及び圧縮が同時に可能な分解装置が望ましいが、二次処理についてはいかなるものであってもよく、公知の各種分解装置が用いられる。また、複数の分解装置を適宜組み合わせて用いることができ、例えば、ある分解装置で分解処理した被処理物をドラム缶などに詰めて保温、加温などすることによって二次処理としてもよい。図１に示すような押出機１を用いて分解処理を実施すると、処理を連続的に効率よく行うことができる。
【００４３】
図１は、前述の一次処理を行うための押出機の一例を示し、押出機１は、温度制御可能なヒータを備えたシリンダ部３、シリンダ部３の内壁に内接する回転制御可能なスクリュ５、シリンダ部３の一端に設けられる投入口７、シリンダ部３の他端に設けられる排出管９、及び、投入口７と排出管９との間に設けられる供給口１１を有する。シリンダ部３のヒータは、シリンダ部３の温度が局部的に異なるように設定可能で、例えば、供給口１１の前後で加熱温度を変化させることができる。シリンダ部３の温度をウレタン樹脂の分解温度に設定し、押出機への投入物がスクリュ５の回転によって投入口７から供給口１１迄進行する時間がウレタン樹脂の分解に要する時間に合うようにスクリュ５の回転速度を設定して、ウレタン樹脂及び分解剤を投入口７から投入すると、ウレタン樹脂の分解が始まり、排出管９の方向へ移動する。必要に応じて、添加剤を供給口１１から被処理物に混合することもできる。最終的に、ウレタン樹脂は液状の分解物となって排出管９から排出される。このような分解装置では、ウレタン樹脂の分解開始時間のばらつきを抑えることができるため、分解処理条件の調整が容易且つ正確である。
【００４４】
押出機１による一次処理が不十分である場合、押出機１から排出される被処理物は、排出管９から二次処理（補助加熱処理）を行うための二次処理装置へ供給される。
【００４５】
図２は、二次処理装置の一例を示し、この二次処理装置２１は、押出機１の排出管９から供給される被処理物を収容するための容器２３と、容器２３を覆う断熱材２５とを有し、被処理物を保温することにより余熱で分解を進行させる。容器２３の蓋２３’に取り付けた温度センサー２７によって内部温度を継続的に検出することにより、二次処理条件の予測とのずれを修正することができる。
【００４６】
図３は、バッチ式の二次処理装置の例を示し、この二次処理装置３１は、押出機１の排出管９から供給される被処理物を収容するための処理槽３３と、処理槽３３に付設され温度調節機能を備えたヒータ３５と、攪拌装置３７とを有し、ヒータ３５で被処理物を加熱することにより分解を進行させる。二次処理を終えた被処理物は、処理槽３３の底部に設けられた排出管３９のバルブを開けて排出する。
【００４７】
図４は、押出機を二次処理装置として用いた例を示し、この二次処理装置４１は、温度制御可能なヒータを備えたシリンダ部４３、シリンダ部４３の内壁に内接する回転制御可能なスクリュ４５、押出機１の排出管９に接続される投入口４７、及び、シリンダ部３３の他端に設けられる排出管４９を有する。シリンダ部４３及びスクリュ４５は、押出機１のシリンダ部３及びスクリュ５と同様の働きをする。シリンダ４３は、ヒータに代えて断熱材で覆って保温するように構成してもよい。
【００４８】
図５は、保温型の二次処理装置の他の例を示し、この二次処理８装置５１は、断熱材で形成された保温槽５３と、保温槽５３内に設けられ押出機１の排出管９に接続される螺旋管５５とを有する。排出管９から供給される被処理物は、螺旋管５５を通過する間保温されて余熱により分解が進行し、排出管５７から排出される。
【００４９】
（再生樹脂の製造方法及び再生剤）
ウレタン樹脂の分解物から樹脂を再生するには、分解物を再硬化させる再生剤が用いられる。再生剤としては、エポキシ樹脂及びイソシアネート化合物が知られており、公知のものから必要に応じて適宜選択して用いることができる。エポキシ樹脂は、１分子中に２個以上のエポキシ基を有するものであればよく、その具体的例としては、ビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、フェノールノボラック型エポキシ樹脂、クレゾールノボラック型エポキシ樹脂、ナフトール系のノボラック型エポキシ樹脂、ビスフェノールＡのノボラック型エポキシ樹脂、ナフタレンジオール型エポキシ樹脂、脂環式エポキシ樹脂、トリまたはテトラ（ヒドロキシフェニル）アルカンから誘導されるエポキシ樹脂、ビスヒドロキシビフェニル系エポキシ樹脂、フェノールアラルキル樹脂のエポキシ化物などが挙げられるが、特に限定されるものではない。エポキシ化合物は、単独でまたは２種以上混合して使用することもできる。イソシアネート化合物は、１分子中に２個以上のイソシアネート基を有するものであれば良く、その具体的例としては、１，５−ナフタレンジイソシアネート、４，４’−ジフェニルメタンジイソシアネート、４，４’−ジフェニルジメチルメタンジイソシアネート、４，４’−ジベンジルイソシアネート、ジアルキルジフェニルメタンジイソシアネート、テトラアルキルジフェニルメタンジイソシアネート、１，３−フェニレンジイソシアネート，１，４−フェニレンジイソシアネート、トリレンジイソシアネート、ブタン−１，４−ジイソシアネート、ヘキサメチレンジイソシアネート、２，２，４−トリメチルヘキサメチレンジイソシアネート、シクロヘキサン−１，４−ジイソシアネート、キシリレンジイソシアネート、イソホロンジイソシアネート，ピリジンジイソシアネート、ジシクロヘキシルメタン−４，４−ジイソシアネート，メチルシクロヘキサンジイソシアネート等のジイソシアネート化合物；ジメチレントリフェニルメタンテトライソシアネート、トリフェニルメタントリイソシアネート、ポリメチレンポリフェニルポリイソシアネート等の多官能イソシアネート化合物；グリセリンやトリメチロールプロパン等のポリオール類と上記ジイソシアネート化合物との付加反応物、等が挙げられるが、特に限定されるものではない。イソシアネート化合物は、単
独で用いても２種以上を混合して用いてもよい。
【００５０】
再生樹脂の成形方法は、必要に応じて適宜決定される。例えば、再生剤として液状のエポキシ樹脂を用いる場合は、分解物とエポキシ樹脂とを万能攪拌機等を用いて混合して、混合物を室温〜２００℃の温度で成形型に流し込み、１時間〜１晩程度加熱硬化させることによって再生樹脂の成形体が得られる。混合の際に、有機物粒子又は無機物粒子などを充填材として加えたり、可塑剤、カップリング剤等を配合たりしてもよい。
【００５１】
また、ウレタン発泡体を生成する場合は、被処理物にイソシアネート化合物を添加混合するが、イソシアネート化合物の添加によって結合生成及び発泡が温度に応じた速度で進行するので、室温〜１５０℃の温度で混合物を成形型に投入して成形する。必要に応じて、ウレタン樹脂原料であるポリオール化合物や、発泡剤、整泡剤、充填剤、触媒等を被処理物に添加してもよい。
【００５２】
被処理物つまりウレタン樹脂分解物を冷却により固化させた固形物を用いる場合は、この固形物と、固形のエポキシ樹脂又はイソシアネート化合物とを細かく粉砕して木粉や無機物粒子等と混合し、プレス成形機等を用いて加熱・加圧成形して硬化させることにより、成形体を得ることができる。硬化温度は、使用するウレタン樹脂分解物、エポキシ樹脂及びイソシアネート化合物の融点又は軟化点等によって異なるが、概して８０〜２００℃程度がよい。
【００５３】
【実施例】
以下、実施例に基づいて本発明を詳細に説明する。
【００５４】
なお、以下の操作において用いるウレタン樹脂は下記のものであり、Ｚ値の算出は、前述のパラメータΔＺの合計による近似的方法に従った。
【００５５】
［ウレタン樹脂Ａ］
水酸基価約４５５ｍｇＫＯＨ／ｇのポリオールＳＵ−４６４（三井化学（株）製）と、ＴＤＩ主体のコスモネートＴ−８０（三井化学（株）製）を等量混合して得られたウレタン樹脂。
【００５６】
［ウレタン樹脂Ｂ］
冷蔵庫の断熱材に用いられているウレタン樹脂。ポリオールの水酸基価＝４５０ｍｇＫＯＨ／ｇ、イソシアネートの％ＮＣＯ＝３１．４。
【００５７】
［ウレタン樹脂Ｃ］
水酸基価２８０ｍｇＫＯＨ／ｇのポリエチレングリコール１００重量部にピュアＭＤＩを６５．２重量部混合して発泡させたポリウレタン樹脂。
【００５８】
［ヌレート樹脂］
建材の断熱材として使用されて、建築現場より廃棄されたイソシアヌレート樹脂。
【００５９】
（実施例１）
押出機の加熱温度を２５０℃に設定し、投入から２分後に投入物が排出されるように押出し速度を設定した。ウレタン樹脂Ａ／ジエタノールアミン（以下、ＤＥＡ）＝３／１の混合比でウレタン樹脂Ａ及びＤＥＡを押出機に投入して混練による分解処理（一次処理）を行い、排出された被処理物を２００℃の反応容器中で３０分保温した後１０分に２０℃ずつ自然冷却した（二次処理）ウレタン樹脂分解物を用意した。被処理物を押出機から反応容器に移す時間は数分であり、ここではその間のΔＺ値を無視した。二次処理を経た樹脂分解物のＺ値は２．９４であり、その粘度は７８００ｍＰａ・ｓ（６０℃）であった。この分解物を少量ずつとり、更に、１７５℃のオーブンにそれぞれ投入して表２に示す時間の加熱による分解処理を行った（三次処理）。
【００６０】
得られたウレタン樹脂分解物は、原料のポリオール（ＳＵ−４６４）に１０重量％の割合で混合し、イソシアネート（コスモネートＴ−８０）を加えて発泡させることによりウレタン再生を行った。
【００６１】
また、エポキシ再生については、上述で得られたウレタン樹脂分解物をビスフェノールＡ型エポキシ樹脂（ＥＰ４１００Ｅ、旭電化（株）製）と重量比１：１で混合した後１５０℃で反応させることにより、再生エポキシ樹脂を得た。
【００６２】
その結果を表２に示す。なお、表中の粘度は、ウレタン樹脂分解物の６０℃における値である。また、ウレタン再生については、問題なく再生できたものは○、再生に支障があったものは△、再生できなかったものは×を示した。エポキシ再生については、問題なく再生できたものは○、問題なく再生できて特にガラス転移温度が高かったものは◎、再生に支障があったものは△、再生できなかったものは×を示した。
【００６３】
Ｚ値が５〜２５の範囲となるウレタン樹脂分解物はおおむね粘度が低くなっていることが確認できた。又、その範囲では良好にウレタン樹脂に再生できることが確認できた。Ｚ値＝２０の付近において樹脂分解物に黒い固形分が析出し始め、Ｚ値が２５以上ではその存在が顕著になり、ウレタンの再生に支障をきたした。エポキシの再生では、Ｚ値が５以下の範囲では、樹脂分解物の粘度が高くエポキシ樹脂との混合が困難であったが、再生することができた。Ｚ値が５以上２５以下の範囲では、樹脂分解物の粘度が低くなり作業性も向上し、Ｚ値が１０近辺で最も高いガラス転移温度を示した。Ｚ値が２０以上の範囲でも、樹脂分解物はエポキシ樹脂と反応し硬化したが、黒い固形成分が混ざったため見栄えが悪かった。
【００６４】
【表２】

（実施例２〜４）
三次処理の処理温度を２００℃（実施例２）、２２５℃（実施例３）又は２５０℃（実施例４）に変更したこと以外は実施例１と同じ条件で、ウレタン樹脂Ａの分解処理、再生ウレタン樹脂及び再生エポキシ樹脂の調製を行った。その結果を表３〜５（表３：実施例２、表４：実施例３、表５：実施例４）に示す。いずれの温度においても、Ｚ値が５〜２５の範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００６５】
【表３】

【表４】

【表５】

（実施例５）
実施例１と同様の設定の押出機で、ウレタン樹脂Ａ／ＤＥＡの混合比を４／１に変更してウレタン樹脂Ａ及びＤＥＡを投入して分解処理し（一次処理）、液状の被処理物を得た。この被処理物のＺは２．９４で、粘度は約５００００ｍＰａ・ｓであった。この被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して再度表６の時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を得た。これらは各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加えて再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後に１５０℃に加熱して再生エポキシ樹脂を得た。その結果を表６に示す。Ｚ値が５〜２５の範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００６６】
【表６】

（実施例６）
実施例１と同様の設定の押出機で、ウレタン樹脂Ａ／モノエタノールアミン（以下、ＭＥＡ）＝３／１の割合でウレタン樹脂Ａ及びＭＥＡを混合して分解処理（一次処理）し、液状の被処理物を得た。この被処理物のＺ値は２．９４で、６０℃における粘度は約３１００ｍＰａ・ｓであった。この被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表７に示す時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を得た。これらは、各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加えて再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果を表７に示す。樹脂分解物のＺ値が５〜２５の範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００６７】
【表７】

（実施例７）
実施例１と同様の押出機で、ウレタン樹脂Ａ／ＭＥＡ＝４／１の割合でウレタン樹脂Ａ及びＭＥＡを混合して分解処理し、液状の被処理物を得た（一次処理）。この被処理物のＺ値は２．９４で、６０℃における粘度は約４９００ｍＰａ・ｓであった。この被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表８の時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を各々得た。これらは、各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加え再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果を表８に示す。Ｚ値が５〜２５の範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００６８】
【表８】

（実施例８）
実施例１と同様の設定の押出機で、ウレタン樹脂Ａ／ＭＥＡ＝５．５／１の割合でウレタン樹脂Ａ及びＭＥＡを混合して分解処理し、液状の被処理物を得た（一次処理）。この被処理物のＺ値は２．９４で、６０℃における粘度は約２１５００ｍＰａ・ｓであった。この被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表９の時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を得た。これらは、各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加え再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果を表９に示す。Ｚ値が１０〜２５の範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００６９】
【表９】

（実施例９）
実施例１と同様の設定の押出機で、ウレタン樹脂Ａ／ＭＥＡ＝７／１の割合でウレタン樹脂Ａ及びＭＥＡを混合して分解処理し、液状の被処理物を得た。この被処理物のＺ値は２．９４で、６０℃における粘度は約３８７００ｍＰａ・ｓであった。この被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表１０の時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を得た。これらは、各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加えて再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果を表１０に示す。Ｚ値が１０〜３０の範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００７０】
【表１０】

（実施例１０）
実施例１と同様の設定の押出機で、ウレタン樹脂Ａ／ＭＥＡ＝２／１の割合でウレタン樹脂Ａ及びＭＥＡを混合して分解処理し、液状の被処理物を得た（一次処理）。この被処理物のＺ値は２．９４で、６０℃における粘度は約２５６０ｍＰａ・ｓであった。この被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表１１の時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を得た。これらを、各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加え再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果を表１１に示す。Ｚ値が３〜１５の範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００７１】
【表１１】

（実施例１１）
実施例１と同様の設定の押出機で、ウレタン樹脂Ａ／ヘキサメチレンジアミン（以下、ＨＭＤＡ）＝２／１の割合でウレタン樹脂Ａ及びＨＭＤＡを混合して分解し、液状の被処理物を得た。この被処理物のＺ値は２．９４で、６０℃における粘度は約３８６０ｍＰａ・ｓであった。この分解物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表１２の時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を得た。これらを、各々、実施例１１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加え再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果を表１２に示す。Ｚ値が３〜１５の範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００７２】
【表１２】

（実施例１２）
実施例１と同様の設定の押出機で、ウレタン樹脂Ａ／ＨＭＤＡ＝３／１の割合でウレタン樹脂Ａ及びＨＭＤＡを混合して分解処理し、液状の被処理物を得た（一次処理）。この被処理物のＺ値は２．９４で、６０℃における粘度は約７１００ｍＰａ・ｓであった。この被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表１３の時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を得た。これらを、各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加え再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果を表１３に示す。Ｚ値が５〜２５の範囲ではおおむね粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００７３】
【表１３】

（実施例１３）
実施例１と同様の設定の押出機で、ウレタン樹脂Ａ／ＤＥＡ／ポリエチレングリコール＃２００（以下、ＰＥＧ２００）＝３／１／０．５の割合でウレタン樹脂Ａ、ＤＥＡ及びＰＥＧを混合して分解処理し、液状の被処理物を得た（一次処理）。この被処理物のＺ値は２．９４で、６０℃における粘度は約４５００ｍＰａ・ｓであった。この被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表１４の時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を得た。これらを、各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加え再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果を表１４に示す。Ｚ値が５〜２５の範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。但し、エポキシ樹脂のガラス転移温度は、ＰＥＧ２００を加えなかった実施例１〜４と比べると低い値を示した。
【００７４】
【表１４】

（実施例１４）
実施例１と同様の設定の押出機で、ウレタン樹脂Ａ／ＭＥＡ／ＰＥＧ２００＝５．５／１／０．５の割合でウレタン樹脂Ａ、ＭＥＡ及びＰＥＧを混合して分解処理し、液状の被処理物を得た（一次処理）。この被処理物のＺ値は２．９４で、６０℃における粘度は約１２５００ｍＰａ・ｓであった。この被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表１５の時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を得た。これらを、各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加え再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果を表１５に示す。Ｚ値が１０〜３０の範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。但し、エポキシ樹脂のガラス転移温度は、ＰＥＧ２００を加えなかった実施例８と比べると低い値を示した。
【００７５】
【表１５】

（実施例１５〜１７）
実施例１と同様の設定の押出機で、ウレタン樹脂Ｂ／ＤＥＡ＝２／１（実施例１５）、３／１（実施例１６）又は５／１（実施例１７）の割合でウレタン樹脂Ｂ及びＤＥＡを混合して分解処理し、液状の被処理物を得た（一次処理）。この被処理物のＺ値は２．９４であった。この被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表１６〜１８（表１６：実施例１５、表１７：実施例１６、表１８：実施例１７）の時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を得た。これらを、各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加え再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果をそれぞれ表１６〜１８に示す。Ｚ値が前記の適正範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００７６】
【表１６】

【表１７】

【表１８】

（実施例１８〜２０）
実施例１と同様の設定の押出機で、ウレタン樹脂Ｃ／ＤＥＡ＝２／１（実施例１８）、３／１（実施例１９）又は５／１（実施例２０）の割合でウレタン樹脂Ｃ及びＤＥＡを混合して分解処理し、液状の被処理物を得た（一次処理）。被処理物のＺは実施例１８〜２０のいずれも２．９４であった。被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表１９〜２１（表１９：実施例１８、表２０：実施例１９、表２１：実施例２０）の時間の加熱による分解処理を行って（二次処理）ウレタン樹脂分解物を得た。これらは、各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加え再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果をそれぞれ表１９〜２１に示す。Ｚ値が前記適正範囲ではおおむねウレタン樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００７７】
【表１９】

【表２０】

【表２１】

（実施例２１〜２３）
実施例１と同様の設定の押出機で、ヌレート樹脂／ＤＥＡ＝２／１（実施例２１）、３／１（実施例２２）又は５／１（実施例２３）の割合でヌレート樹脂及びＤＥＡを混合して分解処理し（一次処理）、液状の被処理物を得た。被処理物のＺ値は、実施例２１〜２３のいずれも２．９４であった。被処理物を少量ずつとり、２００℃のオーブンにそれぞれ投入して表２２〜２４（表２２：実施例２１、表２３：実施例２２、表２４：実施例２３）の時間の加熱による分解処理を行って（二次処理）ヌレート樹脂分解物を得た。これらは、各々、実施例１と同様に、原料のポリオールに１０重量％の割合で混合してイソシアネートを加え再生ウレタン樹脂を、あるいは、エポキシ樹脂と重量比１：１で混合した後１５０℃に加熱して再生エポキシ樹脂を得た。その結果をそれぞれ表２２〜２４に示す。
【００７８】
Ｚ値が前述の適正範囲ではおおむねヌレート樹脂分解物の粘度が低くなっていて、良好にウレタン樹脂やエポキシ樹脂に再生できることが確認できた。
【００７９】
【表２２】

【表２３】

【表２４】

上記実施例１〜２３の要旨をまとめたものを表２５に示す。尚、表中の「再生に適したＺの値」は結果の評価から定めた値であって、誤差等を含み得るものであり、絶対的なものではないことは言うまでも無い。いずれのウレタン樹脂の分解処理においても、分解剤１重量部に対しウレタン２．５重量部未満の場合は３≦Ｚ≦１５、ウレタン２．５重量部以上５重量部以下では５≦Ｚ≦２５、ウレタン５重量部を超える場合は１０≦Ｚ≦３０となる時に再生に適した状態となっていることが確認された。
【００８０】
【表２５】

（実施例２４）
ウレタン樹脂Ａをガラス棒を用いて押しつぶして熱を伝え易くし、ウレタン樹脂Ａ／ＤＥＡ＝３／１の混合比で試験管にウレタン樹脂Ａ及びＤＥＡを入れ、２００℃のオイルバス中で加熱して分解処理を行った。目視観察でウレタン樹脂Ａが液状と確認できた時間は約５分であり、この時ウレタン樹脂分解液は均一であったので、ウレタン樹脂分解物は均一に分解しているとみなした。
【００８１】
オイルバス投入から取出しまでの時間を表２６のように変更したこと以外は上記分解処理と同様の操作を繰り返し行い、得られたウレタン樹脂分解物の粘度を測定した。また、一番粘度の低かった分解物について、ゲル浸透クロマトグラフィー（ＧＰＣ）を用いて分子量分布を測定した。その結果を表２６に示す。尚、表中の分子量は、ポリスチレン換算の分子量であり、実際の分子量とは異なる。表２６の結果によると、粘度はＺ値が５〜２０の範囲付近で最も低い値を示し、Ｚ値が２５以上の範囲では多数の炭化物の生成が確認された。
【００８２】
【表２６】

（比較例１）
容量１０００ｍｌのフラスコ中に２００ｇのジエタノールアミンを入れ、２００℃のオイルバスを用いて加熱し、これに６００ｇのウレタン樹脂を少しずつ投入して分解処理を行った。全ウレタン樹脂の投入終了までに要した時間は１０時間半であり、投入終了後さらに３０分オイルバス中で加熱を継続した。ウレタン樹脂分解物のＺ値は１．２５〜２７．５の範囲で、このうちＺ値が５〜２５の範囲にあるものは７６％であった。ウレタン樹脂分解物には炭化した固形成分が多数見られた。また、粘度は３８００ｍＰａ・ｓ（６０℃）であり、実施例１〜４や実施例２４に比べて高い粘度を示した。分子量分布は１００００以下の広範囲にあり、数平均分子量は１９００であった。
【００８３】
得られたウレタン樹脂分解物の一部を、原料のポリオールに１０重量％の割合で混合し、イソシアネート（コスモネートＴ−８０）を加えて発泡させたところ、分解物中にある炭化物の影響でセル荒れを起こし、うまく再生できなかった。また、ウレタン樹脂分解物の残部をビスフェノールＡ型エポキシ樹脂と重量比１：１で混合した後１５０℃で反応させたところ、再生エポキシ樹脂を得たが、炭化物を多数含んでいたため見た目も悪く、実施例１〜４や実施例２４にて作成した樹脂よりもガラス転移温度が低かった。
【００８４】
（実施例２５）
ウレタン樹脂Ａ／ＭＥＡ＝４／１の混合比でウレタン樹脂Ａ及びＭＥＡを２５０℃の押出機に投入して分解処理し（一次処理）、投入から２分後に排出された被処理物を２５０℃に保たれた管の中を１５分間かけて通過させてさらに分解処理を進めた。この時の被処理物のＺ値は約８．５であった。その後、冷却液と熱交換して被処理物の温度を２分間で１００℃まで冷却し、得られたウレタン樹脂分解物をドラム缶に採取した。得られたウレタン樹脂分解物を、原料のポリオールに１０重量％の割合で混合し、イソシアネート（コスモネートＴ−８０）を加えて発泡したところ、良好な発泡体が得られた。また、ウレタン樹脂分解物をビスフェノールＡ型エポキシ樹脂と重量比１：１で混合した後１５０℃で反応させることにより再生エポキシ樹脂を得ることができ、そのガラス転移温度は１００℃以上であった。
【００８５】
（実施例２６）
ウレタン樹脂Ａ／ＭＥＡ＝４／１の混合比で２５０℃の押出機にウレタン樹脂Ａ及びＭＥＡを投入して滞留時間２分の分解処理を行い（一次処理）、その後、周囲を断熱材で覆ったドラム缶に被処理物を採取し、１０分でドラム缶いっぱいに被処理物を詰めた。ドラム缶中の被処理物の温度は１９０〜２００℃であった。ドラム缶内の被処理物は１８０℃に冷却するまでに２時間、１４０℃にまで冷却するまでに６時間かかった。この時点のＺの値を計算すると、表２７のように、Ｚ＝１０．８〜１１．２であった。得られたウレタン樹脂分解物を、原料のポリオールに１０重量％の割合で混合し、イソシアネート（コスモネートＴ−８０）を加えて発泡したところ、良好な発泡体が得られた。また、得られたウレタン樹脂分解物をビスフェノールＡ型エポキシ樹脂と重量比１：１で混合した後１５０℃で反応させることにより、再生エポキシ樹脂を得ることができ、そのガラス転移温度は１００℃以上であった。
【００８６】
【表２７】

【００８７】
【発明の効果】
本発明によれば、ウレタン樹脂やエポキシ樹脂に再生し易いウレタン樹脂分解物を得るためのウレタン樹脂の分解条件が容易に決定でき、良好な再生樹脂が提供されるので、ウレタン樹脂のリサイクルを促進することができる。
【図面の簡単な説明】
【図１】本発明に係るウレタン樹脂の分解処理方法の一次処理を実施する押出機型の装置の一実施形態を示す概略構成図。
【図２】本発明に係るウレタン樹脂の処理方法の二次処理を実施する二次処理装置の一実施形態を示す概略構成図。
【図３】本発明に係るウレタン樹脂の処理方法の二次処理を実施する二次処理装置の他の実施形態を示す概略構成図。
【図４】本発明に係るウレタン樹脂の処理方法の二次処理を実施する二次処理装置の更に他の実施形態を示す概略構成図。
【図５】本発明に係るウレタン樹脂の処理方法の二次処理を実施する二次処理装置の更に他の実施形態を示す概略構成図。
【符号の説明】
１ 押出機、 ３ シリンダ部、 ５ スクリュ、
７ 投入口７、 ９ 排出管、 １１ 供給口
１１，２１，３１，４１ 二次処理装置[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a urethane resin recycling technique, and more particularly, to a method for decomposing a hard urethane resin to obtain a high-quality urethane resin decomposed product, and a method for manufacturing a recycled resin using the urethane resin decomposed product.
[0002]
[Prior art]
Urethane resins are widely used, for example, as heat insulating materials for refrigerators, building materials, cushioning materials, etc.In recent years, there has been an increasing demand for recycling these wastes, and the reuse of these wastes has been studied in various fields. ing. However, since urethane resin is a thermosetting resin having a three-dimensional network structure, it is difficult to recycle it, and at present, it is disposed of by landfill or incineration.
[0003]
Various methods for chemically decomposing urethane resin have been reported for a long time. Patent Document 1 listed below describes a method in which a polyurethane foam is decomposed with an amine compound such as an alkanolamine, and then the decomposed product is separated and recovered. However, this method is not industrially suitable because it is very difficult to separate the amine compound and the polyol having good compatibility. Further, Patent Document 2 below describes a method of decomposing a polyurethane foam using a polyol and aminoethanol as decomposing agents and regenerating the polyurethane foam as an adhesion aid. However, since this method is performed in a batch system, it takes 11 hours at 190 ° C. and 2 hours even at 230 ° C. for processing. In addition, when the urethane resin is decomposed in a batch system, the bulkiness and low thermal conductivity of the urethane resin greatly affect the quality. For example, when urethane is decomposed by heating in an oil bath using a flask, urethane on the wall in contact with the oil bath is immediately decomposed, but heat is not easily transmitted to the center of the flask, so urethane in the center is difficult. Decomposition start time is delayed. Further, it is difficult to supply bulky urethane into the flask at one time, and even if the urethane is decomposed while being added little by little, there is a difference in the decomposition start time depending on the urethane charging time. In this example, the decomposition start time is shifted up to 11 hours, and the quality of the urethane resin decomposed product is inferior because those that are not sufficiently decomposed or those that have been thermally degraded due to excessive application of heat reduce the uniformity of the urethane resin decomposed product. is there.
[0004]
On the other hand, there is also a method of decomposing using an extruder, for example, as in Patent Document 3 below. In this case, since the time for performing the decomposition treatment of the urethane resin is limited by the design of the extrusion length, it is not possible to perform the treatment for a long time.
[0005]
[Patent Document 1]
Japanese Patent Publication No. 42-10634
[0006]
[Patent Document 2]
JP-A-6-184513
[0007]
[Patent Document 3]
JP 2000-281831 A
[0008]
[Problems to be solved by the invention]
Various decomposition methods other than those described above have been proposed.Even though studies have been made to decompose and liquefy urethane resin, any method for obtaining a urethane resin decomposition product capable of producing a regenerated resin of satisfactory quality has been proposed. At present, it is not considered whether to set the conditions of the decomposition process as described above. Therefore, even if a urethane decomposition product can be obtained, only a product having unstable quality can be obtained, and it is difficult to obtain a recycled resin having physical properties suitable for practical use. Therefore, there is a major obstacle in recycling urethane resin.
[0009]
The present invention has been made in view of such a problem, and a method for decomposing a urethane resin to obtain a urethane resin decomposed product capable of producing a recycled resin suitable for practical use, and production of a recycled resin using the same. The aim is to provide a method.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, according to one embodiment of the present invention, a method for decomposing a hard urethane resin comprises the steps of charging a hard urethane resin and a decomposing agent into an extruder and heating the same to progress the decomposition of the hard urethane resin. A decomposition treatment step, a determination step of determining whether or not the decomposition of the hard urethane resin is sufficient based on the ratio of the hard urethane resin and the decomposer, a heating temperature and a decomposition processing time; and The gist of the present invention is to include an auxiliary heating step of heating an object to be processed obtained in the decomposition treatment step when it is determined that the decomposition of the hard urethane resin is not sufficient.
[0011]
The determining step includes setting a constant k at the temperature T [゜ K] as follows:
k = 2 (300 <T)
k = 1 (270 <T ≦ 300)
k = 1/3 (240 <T ≦ 270)
k = 1/10 (210 <T ≦ 240)
k = 1/40 (180 <T ≦ 210)
k = 1/200 (140 ≦ T ≦ 180)
k = 0 (T <140)
Processing time ΔH for processing at temperature T [゜ K] in the decomposition processing step_TFrom [time] and the constant k, a parameter ΔZ at a temperature T [゜ K] is obtained._T= K × ΔH_T× 100 is calculated, and the parameter ΔZ is calculated for all processing temperatures in the decomposition processing step._TAnd calculating the total value Z according to the number of parts by weight N of the hard urethane resin with respect to 1 part by weight of the decomposing agent in the decomposition treatment step. The process of
When N <2.5 3 ≦ Z ≦ 15
2.5 ≦ N ≦ 5 5 ≦ Z ≦ 25
When 5 <N 10 ≦ Z ≦ 30
Determining that the decomposition of the hard urethane resin is not sufficient when the total value Z is less than the appropriate range of Z.
[0012]
Further, according to one aspect of the present invention, a method for producing a recycled resin includes: a decomposition treatment step in which a urethane resin and a decomposing agent are charged into an extruder and heated to promote decomposition of the urethane resin; A determination step of determining whether the urethane resin is sufficiently decomposed based on the ratio of the urethane resin and the decomposer, the heating temperature and the decomposition time, and that the urethane resin is not sufficiently decomposed in the determination step. When determined, an auxiliary heating step of heating the object to be processed obtained in the decomposition treatment step, and a compound having an isocyanate compound or an epoxy group in the object to be processed through the decomposition treatment step and the auxiliary heating step performed depending on the situation. And a step of obtaining a recycled resin by blending
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
The decomposition of the urethane resin includes a chemical decomposition method and a hydrolysis method using a decomposing agent, and the present invention relates to a decomposition treatment of the urethane resin performed by the chemical decomposition method. An amine compound is used as the decomposing agent, and may be used in combination with a polyol compound or a metal alcoholate of a polyol. Accordingly, examples of the use form of the decomposing agent include forms such as an amine compound alone, and a mixture of an amine compound with a polyol compound or a metal alcoholate of a polyol.
[0014]
The decomposition reaction of the urethane resin is as follows when, for example, monoethanolamine or diethanolamine is used.
[0015]
Embedded image

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In the final products of these reactions, an amine component derived from the raw isocyanate is formed. Most of the isocyanate component is MDI, TDI, or the like, from which MDA or TDA ultimately remains. These aromatic amines are actually used as a curing agent for an epoxy resin, and are very easily reacted with an epoxy group. The more these are contained in the decomposition product, the more the reactivity with the epoxy resin is increased, and the strength of the regenerated resin is also increased. The present invention is a method for decomposing a urethane resin, in which the decomposition of the urethane resin proceeds to the end, and the decomposing process is adjusted by finding processing conditions that do not cause an excessive reaction such as carbonization. It is particularly effective in decomposition with monoethanolamine or diethanolamine, which produces aromatic diamines as end products.
[0016]
The degree of urethane bond cleavage of the urethane resin varies depending on the decomposition method and decomposition agent, but the molecular weight is gradually reduced by the decomposition agent, and all urethane bonds are cut at once to produce a decomposition product. It is unlikely that you will. That is, the undecomposed urethane resin, the oligomers and monomers of the urethane resin constituent components, and the remaining decomposer are mixed in the urethane resin being decomposed. What is important for obtaining a good-quality urethane resin decomposed product is that all the added decomposing agents are consumed, and only the oligomers and monomers of the urethane resin constituent components, and preferably only the monomers, are consumed. The authors' research has confirmed that when too much heat is applied to the urethane resin, the resin decomposition product is gradually carbonized to deteriorate the physical properties. In addition, if the heat applied to the urethane resin is insufficient, not only is it not sufficiently decomposed, but also if the resin decomposed product is heated again, the decomposition may proceed again. Quality stabilization is difficult. Therefore, in order to obtain a high-quality resin decomposition product, it is necessary to set the heating temperature and the heating time in the urethane resin decomposition process to appropriate values.
[0017]
On the other hand, in order for the decomposition reaction of the urethane resin to proceed uniformly, it is necessary to mix and homogenize the urethane resin and the decomposing agent as quickly and efficiently as possible. Is suitable. The extruder can simultaneously perform heating, mixing, and compression (pressurization), and has a high mixing efficiency. Therefore, it is easy to uniformly progress the decomposition of the charged urethane resin and to control the progress of the decomposition. Further, as compared with a processing apparatus of a batch type or the like, the progress of the decomposition can be accelerated, so that the economic efficiency is high. However, the extruder cannot set the heating time too long due to the design limit of the extrusion length or the extrusion resistance. For this reason, in order to secure a necessary heating time, an auxiliary heating process is required after the heating process in the extruder. In this case, since the urethane resin and the decomposing agent are mixed and the uniformity of the processed object is high in the processed object once passed through the extruder, the auxiliary heat treatment can be favorably performed even by using a batch type apparatus.
[0018]
In the present invention, in consideration of the above, appropriate values of the processing temperature and the processing time of the urethane resin decomposition processing that can obtain a high-quality resin decomposition product are determined. Using these, the set conditions of the decomposition process (primary process) in the extruder are evaluated, it is determined whether or not the auxiliary heating process (secondary process) is necessary, and the necessary conditions of the auxiliary heating process are determined. can do.
[0019]
First, a description will be given of an appropriate value of a processing temperature and a processing time of a urethane resin from which a high-quality resin decomposition product is obtained and an evaluation of the progress of decomposition.
[0020]
(Appropriate values of processing temperature and processing time and evaluation of decomposition progress)
According to the experimental results of the present inventors, when a certain amount of a decomposing agent is mixed with a urethane resin and heated at a constant temperature, the decomposition of the urethane resin progresses as the treatment time increases, and the viscosity of the object to be treated is increased. descend. However, thereafter, the viscosity of the object to be processed starts to increase, and the resin decomposition product is gradually carbonized. The quality of the regenerated resin when the object to be processed is the most uniform and the urethane resin or the epoxy resin is regenerated by using the object to be processed is stable when the viscosity of the object to be processed is the lowest value. That is, the processing time at which the viscosity of the object to be processed becomes the minimum value is the optimum processing time at the heating temperature. Accordingly, the heating temperature t and the optimal processing time h_sBy examining the relationship with, it was found that the following equation (1) holds.
[0021]
(Equation 1)
h_s= At^-21.5    (However, a = 10⁵⁶(1)
Heating temperature = t_cIn the case of (constant), the decomposition progress rate ΔD per unit time (the ratio of the decomposition progress rate in the optimal processing time as 1) can be expressed by the following equation (2), and the decomposition progress rate in the processing time h D_hIs D_h= ΔD × h = h / h_sBecomes
[0022]
(Equation 2)
ΔD = 1 / h_s= A '· t_c ^21.5                  (2)
(However, a '= 1 / a)
On the other hand, if the heating temperature changes with time, the heating temperature t_n(N = 1, 2,...), The degree of decomposition ΔD per unit time_n= A '· t_n ^21.5(N = 1, 2,...) Is the time h from the start of processing._nSum up to the time h_nDegree of decomposition D_nThe time when the total value becomes 1 as in the following equation (3) is the optimal processing time h._sBecomes
[0023]
(Equation 3)

However, when the amount of the decomposing agent added to the urethane resin is different from the above case, a and a 'are different, so that the decomposition progression ΔD obtained from the above is obtained._nTotal value and optimal processing time h_sIs also different.
[0024]
(Setting of auxiliary heat treatment)
When the urethane resin is heated and decomposed (primary treatment) using an extruder, the decomposition progress rate ΔD per unit time is from the inlet to the outlet of the extruder._nIf the total value does not reach 1, a decomposition process corresponding to the shortage may be performed as an auxiliary heating process (secondary process). For example, when the object discharged from the extruder is kept at a substantially constant temperature in a heat-insulating container, it is theoretically relatively easy to calculate the auxiliary heating time from the shortage of the degree of decomposition.
[0025]
However, in actual disassembly processing, the degree of decomposition of the object to be treated may vary within a certain range including the optimum value because partial variations and errors may occur depending on the structure of the processing apparatus, operating conditions, and the like. It is practical to set the processing time.
[0026]
In consideration of the above, the condition determination of the auxiliary heating process (secondary process) by calculating the sum of the degree of decomposition progress per unit time can be performed according to the following approximate process and detected by the sensor. Using the temperature data of the extruder, the temperature gradient data obtained by using the data, and the like, it can be easily performed by a computer or the like according to the following procedure.
[0027]
1) The constant k at the temperature T [゜ K] of the decomposition process is set as follows.
[0028]
k = 2 (300 <T)
k = 1 (270 <T ≦ 300)
k = 1/3 (240 <T ≦ 270)
k = 1/10 (210 <T ≦ 240)
k = 1/40 (180 <T ≦ 210)
k = 1/200 (140 ≦ T ≦ 180)
k = 0 (T <140)
2) Processing time ΔH at temperature T [゜ K] in primary processing by the extruder_TFrom the [time] and the constant k, the parameter ΔZ in the process of the temperature T [゜ K] is obtained._T= K × ΔH_T× 100 is calculated, and the parameter ΔZ is calculated for all the processing temperatures in the decomposition processing step._TAre added to calculate a total value Z.
[0029]
3) According to the number N of parts by weight of the urethane resin with respect to 1 part by weight of the decomposing agent, the above parameter ΔZ_TIs compared with an appropriate range of Z represented by the following equation to determine whether or not the value is within the appropriate range.
[0030]
When N <2.5 3 ≦ Z ≦ 15
When 2.5 ≦ N ≦ 5 5 ≦ Z ≦ 25
When 5 <N 10 ≦ Z ≦ 30
4) When the total value Z is within the appropriate range of Z in the above 3), the secondary processing (auxiliary heating processing) is not performed. If the total value Z is less than the appropriate range, the total value Z and the total value Z of the parameters of the auxiliary heat treatment are set._sAnd the temperature T in the auxiliary heat treatment so that the sum of_s[゜ K] and temperature T_sProcessing time ΔH_TsSet [Time]. This setting is based on the temperature T_sParameter ΔZ in [゜ K]_Ts= K × ΔH_Ts× 100 and parameter ΔZ_TsTotal value Z of_sIs calculated. When the total value Z is excessive, the processing time H at the temperature T [゜ K] and the temperature T [゜ K] in the primary processing is set so as to fall within the appropriate range._TReset [Time].
[0031]
If necessary, the tertiary process and the subsequent processes may be additionally set.
[0032]
When the value of the total value of the parameters is low, the urethane resin is not sufficiently decomposed, and a decomposition product having a large molecular weight is formed. If the total value is high, the decomposition product is thermally degraded and carbonization starts. However, the processing temperatures T and T_s[ΔK] is preferably 413 to 573 ° K (140 to 300 ° C), and more preferably 473 to 553 ° K (200 to 280 ° C). If the temperature is lower than this, the processing time is too long, which is not economically preferable. If the temperature is too high, the processing time is too short and the control thereof is difficult.
[0033]
When the temperature of the processing object, that is, the temperature in the processing apparatus cannot be measured, the set temperature of the processing apparatus may be regarded as the temperature of the processing object. Also in this regard, in the case of a batch type apparatus, heat cannot be promoted by applying pressure to the resin, so that the temperature of the apparatus may be greatly different from the temperature of the object to be processed, and the treatment by an extruder is advantageous. .
[0034]
The ratio of the decomposing agent to the urethane resin is not particularly limited, but it is preferable that the amount of the urethane resin is not less than 2.5 parts by weight and not more than 5 parts by weight based on 1 part by weight of the decomposing agent. If the amount of the urethane resin is smaller than this range, the unreacted decomposing agent remains in the decomposed product, causing degradation of the properties of the decomposed product and the regenerated product.If the amount of the urethane resin is larger than this, processing time is increased. This is not economically desirable.
[0035]
It is preferable that the value of Z is within the above range for all the objects to be processed. However, in practice, the degree of decomposition of the object to be processed partially varies depending on the structure of the decomposition apparatus. For example, a difference in the decomposition start time partially occurs depending on the shape of the apparatus, and variation occurs due to the work of handling the workpiece. In such a case, the decomposition products having different degrees of decomposition progress exist in the object to be processed. If 85% or more of the total amount in the weight ratio is at the appropriate degree of decomposition, the physical properties of the obtained object to be processed are obtained. Is good.
[0036]
An example of the determination of the processing time by the above evaluation method is shown below.
[0037]
For example, assuming that the composition is decomposed in an extruder at 250 ° C. for 5 minutes, then kept in a reaction vessel at 200 ° C. for 30 minutes, and then cooled in 10 minutes at 10 ° C. to 140 ° C., the value of ΔZ is as shown in Table 1. .
[0038]
[Table 1]

In this case, the parameter ΔZ in the urethane resin decomposition process is as described above, and the progress of the urethane resin decomposition can be grasped from the total value Z. Therefore, the heating process may be appropriately adjusted or changed in accordance with the amount of the decomposing agent so that the total value Z of the parameter ΔZ is in an appropriate range. By subjecting the resin to a decomposition treatment in accordance with the determined conditions, it is possible to obtain a resin decomposition product having a stable quality, thereby facilitating the regeneration of the resin.
[0039]
As a more accurate method than the above approximate method, the Z value is calculated according to the following equation (4) obtained by our experiment, using the processing temperature [゜ K] as a function T (h) of the processing time h [time]. There is a method of calculating and determining a preferable treatment time such that the value of Z is 30 or more and 200 or less (however, the urethane resin is 2.5 to 5 parts by weight with respect to 1 part by weight of the decomposing agent). Originally, it is better to calculate the degree of decomposition by the integral calculation of this equation. However, since the equation is complicated and the calculation is complicated, the above-described method is simpler.
[0040]
(Equation 4)

(Urethane resin, decomposition agent and decomposition equipment)
As the urethane resin to be processed, any hard urethane resin having a urethane bond, a urea bond, or the like may be used. Here, a raw material polyol having a hydroxyl value of 250 mgKOH / g or more is defined as hard urethane. It also includes an isocyanurate material having an isocyanurate bond, and the decomposition treatment method of the present invention can be applied similarly to the urethane resin. In this case, the molecular weight of the raw material isocyanate may be any. Applications of such urethane resins include, for example, heat insulating materials such as refrigerators and building materials.
[0041]
The present invention is particularly suitable for decomposing with an amine compound alone, and is most suitable for decomposing with a monoalkanolamine or dialkanolamine. Examples of the amine compound include monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, tetramethylenediamine, hexamethylenediamine, propanediamine, 2-ethylhexylamine, isopropanolamine, 2- (2-aminoethylamino) ethanol, -Amino-2-hydroxymethyl-1,3-propanediol, ethylaminoethanol, aminobutanol, n-propylamine, di-n-propylamine, n-amylamine, isobutylamine, methyldiethylamine, cyclohexylamine, piperazine, piperidine , Aniline, toluidine, benzylamine, phenylenediamine, xylylenediamine, chloroaniline, pyridine, picoline, N-methylmorpholine, ethyl Folin, pyrazole, and the like. A better effect is obtained when monoethanolamine or diethanolamine is used among these decomposing agents. If necessary, an additive may be added to the above-mentioned decomposing agent. The additive can be added as long as it does not extremely hinder the reaction of the decomposing agent, and examples thereof include diluents such as water, alcohol, and polyol, and fillers such as inorganic particles and organic particles. Examples of the polyol compound include ethylene glycol, diethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentadiol, 1,6-hexanediol, polyoxyethylene glycol, polyoxypropylene glycol, Glycerin, polyethylene glycol and the like can be mentioned. What is necessary is just to adjust the addition amount suitably according to the physical property of an additive. Additives with a boiling point of 150 ° C. or less, such as water and low molecular alcohols, are volatilized in the decomposer and eventually separated from the urethane resin decomposed product, so there is no need to particularly limit the amount added. Attention must be paid to the fact that a large amount of addition lowers the temperature of the apparatus due to the heat of evaporation. Preferably, the weight is suppressed to half or less of the weight of the urethane resin. The amount of the filler such as inorganic particles and organic particles is not particularly limited as long as the reaction is not hindered, but is preferably suppressed to the same weight or less as the urethane resin.
[0042]
As the decomposer, a decomposer capable of simultaneously heating, mixing and compressing, such as an extruder type, is desirable for the primary treatment, but any secondary treatment may be used, and various known decomposers are used. Can be In addition, a plurality of decomposition apparatuses can be used in appropriate combination. For example, a secondary treatment may be performed by packing an object to be processed decomposed by a certain decomposition apparatus in a drum or the like and keeping the temperature or heating. When the decomposition treatment is performed using the extruder 1 as shown in FIG. 1, the treatment can be continuously and efficiently performed.
[0043]
FIG. 1 shows an example of an extruder for performing the above-mentioned primary treatment. The extruder 1 includes a cylinder section 3 having a temperature-controllable heater, and a screw 5 capable of rotating and inscribed on the inner wall of the cylinder section 3. , A charging port 7 provided at one end of the cylinder section 3, a discharge pipe 9 provided at the other end of the cylinder section 3, and a supply port 11 provided between the charging port 7 and the discharge pipe 9. The heater of the cylinder unit 3 can be set so that the temperature of the cylinder unit 3 is locally different. For example, the heating temperature can be changed before and after the supply port 11. The temperature of the cylinder section 3 is set to the decomposition temperature of the urethane resin, and the screw to be fed into the extruder is advanced so that the time required for the rotation of the screw 5 to proceed from the input port 7 to the supply port 11 matches the time required for the decomposition of the urethane resin. When the rotation speed of 5 is set and the urethane resin and the decomposing agent are introduced from the introduction port 7, the urethane resin starts to be decomposed and moves toward the discharge pipe 9. If necessary, the additive can be mixed into the object through the supply port 11. Finally, the urethane resin is discharged from the discharge pipe 9 as a liquid decomposition product. In such a decomposer, it is possible to suppress the variation of the urethane resin decomposition start time, and therefore, it is easy and accurate to adjust the decomposition processing conditions.
[0044]
When the primary treatment by the extruder 1 is insufficient, the workpiece to be discharged from the extruder 1 is supplied from a discharge pipe 9 to a secondary treatment device for performing a secondary treatment (auxiliary heating treatment).
[0045]
FIG. 2 shows an example of the secondary processing device. The secondary processing device 21 includes a container 23 for accommodating the workpiece to be supplied from the discharge pipe 9 of the extruder 1 and a heat insulating material covering the container 23. 25, and the decomposition proceeds with residual heat by keeping the material to be treated warm. By continuously detecting the internal temperature by the temperature sensor 27 attached to the lid 23 'of the container 23, it is possible to correct a deviation from the prediction of the secondary processing condition.
[0046]
FIG. 3 shows an example of a batch-type secondary processing apparatus. The secondary processing apparatus 31 includes a processing tank 33 for storing an object to be processed supplied from the discharge pipe 9 of the extruder 1, and a processing tank 33. The apparatus has a heater 35 provided with a temperature control function attached to 33, and a stirring device 37. The heater 35 heats an object to be processed to cause decomposition. The object to be processed after the secondary processing is discharged by opening a valve of a discharge pipe 39 provided at the bottom of the processing tank 33.
[0047]
FIG. 4 shows an example in which an extruder is used as a secondary processing device. This secondary processing device 41 has a cylinder portion 43 having a temperature-controllable heater, and a rotation controllable inscribed inside wall of the cylinder portion 43. It has a screw 45, an input port 47 connected to the discharge pipe 9 of the extruder 1, and a discharge pipe 49 provided at the other end of the cylinder section 33. The cylinder part 43 and the screw 45 have the same function as the cylinder part 3 and the screw 5 of the extruder 1. The cylinder 43 may be configured so as to keep the temperature covered by a heat insulating material instead of the heater.
[0048]
FIG. 5 shows another example of the heat retaining type secondary treatment device. The secondary treatment 8 device 51 includes a heat retaining tank 53 formed of a heat insulating material and a discharge tank of the extruder 1 provided in the heat retaining tank 53. A spiral tube 55 connected to the tube 9. The object to be processed supplied from the discharge pipe 9 is kept warm while passing through the spiral pipe 55, undergoes decomposition by residual heat, and is discharged from the discharge pipe 57.
[0049]
(Method for producing recycled resin and regenerating agent)
In order to regenerate the resin from the decomposed product of the urethane resin, a regenerant for re-hardening the decomposed product is used. As the regenerating agent, an epoxy resin and an isocyanate compound are known, and can be appropriately selected from known ones as needed. The epoxy resin has only to have two or more epoxy groups in one molecule, and specific examples thereof include a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a phenol novolak type epoxy resin, and a cresol novolak type. Epoxy resin, naphthol novolak epoxy resin, bisphenol A novolak epoxy resin, naphthalene diol epoxy resin, alicyclic epoxy resin, epoxy resin derived from tri or tetra (hydroxyphenyl) alkane, bishydroxybiphenyl Examples include epoxy resins and epoxidized phenol aralkyl resins, but are not particularly limited. Epoxy compounds can be used alone or in combination of two or more. The isocyanate compound only needs to have two or more isocyanate groups in one molecule, and specific examples thereof include 1,5-naphthalenediisocyanate, 4,4′-diphenylmethane diisocyanate, and 4,4′-diphenyl. Dimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene Diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone Diisocyanate compounds such as isocyanate, pyridine diisocyanate, dicyclohexylmethane-4,4-diisocyanate, and methylcyclohexane diisocyanate; polyfunctional isocyanate compounds such as dimethylenetriphenylmethanetetraisocyanate, triphenylmethanetriisocyanate, and polymethylenepolyphenylpolyisocyanate; glycerin And addition products of polyols such as trimethylolpropane and the above-mentioned diisocyanate compounds, but are not particularly limited. Isocyanate compounds are simply
They may be used alone or as a mixture of two or more.
[0050]
The method of molding the recycled resin is appropriately determined as needed. For example, when a liquid epoxy resin is used as a regenerant, the decomposed product and the epoxy resin are mixed using a universal stirrer or the like, and the mixture is poured into a mold at a temperature of room temperature to 200 ° C., for 1 hour to 1 night. By performing heat curing to a certain degree, a molded article of a recycled resin is obtained. At the time of mixing, organic or inorganic particles may be added as a filler, or a plasticizer, a coupling agent, or the like may be blended.
[0051]
When a urethane foam is produced, an isocyanate compound is added to and mixed with the object to be treated.Since the addition of the isocyanate compound causes the bond generation and foaming to proceed at a rate according to the temperature, the temperature is from room temperature to 150 ° C. The mixture is put into a mold and molded. If necessary, a polyol compound as a urethane resin raw material, a foaming agent, a foam stabilizer, a filler, a catalyst, and the like may be added to the object.
[0052]
When using a solid material obtained by solidifying the material to be treated, that is, the urethane resin decomposed product by cooling, the solid material and the solid epoxy resin or isocyanate compound are finely pulverized, mixed with wood powder or inorganic particles, and pressed. A molded article can be obtained by heating and pressure molding using a molding machine or the like and curing. The curing temperature varies depending on the melting point or softening point of the urethane resin decomposed product, the epoxy resin, and the isocyanate compound, but is generally preferably about 80 to 200 ° C.
[0053]
【Example】
Hereinafter, the present invention will be described in detail based on examples.
[0054]
The urethane resin used in the following operation is as follows, and the Z value was calculated according to the above-described approximate method using the sum of the parameters ΔZ.
[0055]
[Urethane resin A]
A urethane resin obtained by mixing equal amounts of a polyol SU-464 (manufactured by Mitsui Chemicals, Inc.) having a hydroxyl value of about 455 mgKOH / g and Cosmonate T-80 (manufactured by Mitsui Chemicals, Inc.) mainly composed of TDI.
[0056]
[Urethane resin B]
Urethane resin used for refrigerator insulation. Hydroxyl value of polyol = 450 mgKOH / g,% NCO of isocyanate = 31.4.
[0057]
[Urethane resin C]
Polyurethane resin foamed by mixing 65.2 parts by weight of pure MDI with 100 parts by weight of polyethylene glycol having a hydroxyl value of 280 mgKOH / g.
[0058]
[Nurate resin]
Isocyanurate resin used as a heat insulating material for building materials and discarded from building sites.
[0059]
(Example 1)
The heating temperature of the extruder was set at 250 ° C., and the extrusion speed was set so that the charge was discharged 2 minutes after the charge. The urethane resin A and DEA are mixed at a mixing ratio of urethane resin A / diethanolamine (hereinafter, DEA) = 3/1 into an extruder to perform a decomposition treatment (primary treatment) by kneading, and the discharged material to be treated is heated to 200 ° C. After keeping the temperature in the reaction vessel for 30 minutes, the urethane resin decomposed product was naturally cooled (secondary treatment) at 20 ° C. every 10 minutes (secondary treatment). The time required to transfer the object from the extruder to the reaction vessel was several minutes, and the ΔZ value during that time was ignored here. The Z value of the resin decomposition product after the secondary treatment was 2.94, and the viscosity was 7,800 mPa · s (60 ° C.). This decomposed product was taken little by little, and further placed in an oven at 175 ° C., respectively, and subjected to a decomposition treatment by heating for the time shown in Table 2 (tertiary treatment).
[0060]
The resulting urethane resin decomposed product was mixed with a raw material polyol (SU-264) at a ratio of 10% by weight, and was added with isocyanate (Cosmonate T-80) to foam, thereby performing urethane regeneration.
[0061]
For epoxy regeneration, the urethane resin decomposition product obtained above was mixed with a bisphenol A type epoxy resin (EP4100E, manufactured by Asahi Denka Co., Ltd.) at a weight ratio of 1: 1 and reacted at 150 ° C. A recycled epoxy resin was obtained.
[0062]
Table 2 shows the results. In addition, the viscosity in a table | surface is a value in 60 degreeC of a urethane resin decomposition product. Regarding urethane regeneration, ○ indicates that it could be reproduced without any problem, Δ indicates that it had trouble in reproduction, and X indicates that it could not be reproduced. Regarding epoxy regeneration, those that could be regenerated without any problems were marked with ○, those that could be regenerated without any problems with particularly high glass transition temperature, ◎, those that had trouble with the regeneration, and those that could not be regenerated were indicated with x. .
[0063]
It was confirmed that the urethane resin decomposed product having a Z value in the range of 5 to 25 generally had a low viscosity. In addition, it was confirmed that the urethane resin could be well regenerated in that range. When the Z value was around 20, black solids began to precipitate in the resin decomposition product, and when the Z value was 25 or more, the presence thereof became remarkable, which hindered urethane regeneration. In the regeneration of epoxy, when the Z value was in the range of 5 or less, the viscosity of the resin decomposition product was so high that mixing with the epoxy resin was difficult, but the epoxy resin could be regenerated. When the Z value was in the range of 5 or more and 25 or less, the viscosity of the resin decomposition product was lowered and workability was improved, and the highest glass transition temperature was exhibited when the Z value was around 10. Even when the Z value was in the range of 20 or more, the resin decomposition product reacted with the epoxy resin and was cured, but the appearance was poor because a black solid component was mixed.
[0064]
[Table 2]

(Examples 2 to 4)
Decomposition treatment of urethane resin A under the same conditions as in Example 1 except that the treatment temperature of the tertiary treatment was changed to 200 ° C. (Example 2), 225 ° C. (Example 3) or 250 ° C. (Example 4), A recycled urethane resin and a recycled epoxy resin were prepared. The results are shown in Tables 3 to 5 (Table 3: Example 2, Table 4: Example 3, Table 5: Example 4). At any temperature, when the Z value was in the range of 5 to 25, the viscosity of the urethane resin decomposed product was generally low, and it was confirmed that the urethane resin or epoxy resin could be satisfactorily regenerated.
[0065]
[Table 3]

[Table 4]

[Table 5]

(Example 5)
In an extruder having the same settings as in Example 1, the mixing ratio of urethane resin A / DEA was changed to 4/1, and urethane resins A and DEA were charged and subjected to decomposition treatment (primary treatment) to obtain a liquid object. Got. The Z to be processed was 2.94 and the viscosity was about 50,000 mPa · s. A small amount of the object to be treated was taken, placed in an oven at 200 ° C., and decomposed by heating again for the time shown in Table 6 (secondary treatment) to obtain a urethane resin decomposed product. Each of them was mixed with the raw material polyol at a ratio of 10% by weight, and isocyanate was added thereto in the same manner as in Example 1 to mix a regenerated urethane resin or an epoxy resin at a weight ratio of 1: 1, and then heated to 150 ° C. Upon heating, a regenerated epoxy resin was obtained. Table 6 shows the results. When the Z value was in the range of 5 to 25, the viscosity of the urethane resin decomposed product was generally low, and it was confirmed that the urethane resin or epoxy resin could be favorably regenerated.
[0066]
[Table 6]

(Example 6)
Using an extruder having the same settings as in Example 1, urethane resin A and MEA were mixed at a ratio of urethane resin A / monoethanolamine (hereinafter referred to as MEA) of 3/1 and subjected to a decomposition treatment (primary treatment) to obtain a liquid An object to be treated was obtained. The Z value of this object was 2.94, and the viscosity at 60 ° C. was about 3100 mPa · s. A small amount of the object to be treated was placed in an oven at 200 ° C. and subjected to a decomposition treatment by heating for the time shown in Table 7 (secondary treatment) to obtain a urethane resin decomposition product. These were mixed with the starting polyol at a ratio of 10% by weight and mixed with the isocyanate in the same manner as in Example 1 to obtain a regenerated urethane resin or an epoxy resin at a weight ratio of 1: 1. To obtain a regenerated epoxy resin. Table 7 shows the results. When the Z value of the resin decomposition product is in the range of 5 to 25, the viscosity of the urethane resin decomposition product is generally low, and it has been confirmed that the urethane resin or epoxy resin can be favorably regenerated.
[0067]
[Table 7]

(Example 7)
In the same extruder as in Example 1, urethane resin A and MEA were mixed at a ratio of urethane resin A / MEA = 4/1 and subjected to a decomposition treatment to obtain a liquid object to be treated (primary treatment). The Z value of this object was 2.94, and the viscosity at 60 ° C. was about 4900 mPa · s. A small amount of the object to be treated was taken, placed in an oven at 200 ° C., and decomposed by heating for the time shown in Table 8 (secondary treatment) to obtain urethane resin decomposed products. Each of them was mixed with the raw material polyol at a ratio of 10% by weight and added with isocyanate in the same manner as in Example 1, and then mixed with a regenerated urethane resin or an epoxy resin at a weight ratio of 1: 1. Upon heating, a regenerated epoxy resin was obtained. Table 8 shows the results. When the Z value was in the range of 5 to 25, the viscosity of the urethane resin decomposed product was generally low, and it was confirmed that the urethane resin or epoxy resin could be favorably regenerated.
[0068]
[Table 8]

(Example 8)
In an extruder having the same settings as in Example 1, urethane resin A and MEA were mixed at a ratio of urethane resin A / MEA = 5.5 / 1 and subjected to decomposition treatment to obtain a liquid object to be treated (primary treatment). ). The Z value of this object was 2.94, and the viscosity at 60 ° C. was about 21500 mPa · s. A small amount of the object to be treated was placed in an oven at 200 ° C. and subjected to a decomposition treatment by heating for the time shown in Table 9 (secondary treatment) to obtain a urethane resin decomposition product. Each of them was mixed with the raw material polyol at a ratio of 10% by weight and added with isocyanate in the same manner as in Example 1, and then mixed with a regenerated urethane resin or an epoxy resin at a weight ratio of 1: 1. Upon heating, a regenerated epoxy resin was obtained. Table 9 shows the results. When the Z value is in the range of 10 to 25, the viscosity of the urethane resin decomposed product is generally low, and it has been confirmed that the urethane resin and the epoxy resin can be favorably regenerated.
[0069]
[Table 9]

(Example 9)
Using an extruder having the same settings as in Example 1, urethane resin A and MEA were mixed at a ratio of urethane resin A / MEA = 7/1 and subjected to decomposition treatment to obtain a liquid object to be processed. The Z value of the object was 2.94, and the viscosity at 60 ° C. was about 38,700 mPa · s. A small amount of the object to be treated was taken, placed in an oven at 200 ° C., and decomposed by heating for the time shown in Table 10 (secondary treatment) to obtain a urethane resin decomposed product. These were mixed with the starting polyol at a ratio of 10% by weight and mixed with the isocyanate in the same manner as in Example 1 to obtain a regenerated urethane resin or an epoxy resin at a weight ratio of 1: 1. To obtain a regenerated epoxy resin. Table 10 shows the results. When the Z value is in the range of 10 to 30, the viscosity of the urethane resin decomposed product is generally low, and it has been confirmed that the urethane resin or epoxy resin can be satisfactorily regenerated.
[0070]
[Table 10]

(Example 10)
Using an extruder having the same settings as in Example 1, urethane resin A and MEA were mixed at a ratio of urethane resin A / MEA = 2/1 and subjected to decomposition treatment to obtain a liquid object to be treated (primary treatment). The Z value of this object was 2.94, and the viscosity at 60 ° C. was about 2560 mPa · s. A small amount of the object to be treated was taken, placed in an oven at 200 ° C., and subjected to decomposition treatment by heating for the time shown in Table 11 (secondary treatment) to obtain a urethane resin decomposition product. Each of these was mixed with the raw material polyol at a ratio of 10% by weight and the isocyanate was added thereto in the same manner as in Example 1, and the regenerated urethane resin or the epoxy resin was mixed at a weight ratio of 1: 1. Upon heating, a regenerated epoxy resin was obtained. Table 11 shows the results. When the Z value was in the range of 3 to 15, the viscosity of the urethane resin decomposed product was generally low, and it was confirmed that the urethane resin or epoxy resin could be favorably regenerated.
[0071]
[Table 11]

(Example 11)
In an extruder having the same settings as in Example 1, urethane resin A and HMDA were mixed and decomposed at a ratio of urethane resin A / hexamethylenediamine (hereinafter, HMDA) of 2/1 to obtain a liquid processed object. Was. The Z value of the object was 2.94, and the viscosity at 60 ° C. was about 3860 mPa · s. A small amount of this decomposed product was taken, placed in an oven at 200 ° C., and decomposed by heating for the time shown in Table 12 (secondary treatment) to obtain a urethane resin decomposed product. Each of these was mixed with the raw material polyol at a ratio of 10% by weight and the isocyanate was added thereto in the same manner as in Example 11, and the regenerated urethane resin or the epoxy resin was mixed at a weight ratio of 1: 1. Upon heating, a regenerated epoxy resin was obtained. Table 12 shows the results. When the Z value was in the range of 3 to 15, the viscosity of the urethane resin decomposed product was generally low, and it was confirmed that the urethane resin or epoxy resin could be favorably regenerated.
[0072]
[Table 12]

(Example 12)
Using an extruder having the same settings as in Example 1, urethane resin A and HMDA were mixed at a ratio of urethane resin A / HMDA = 3/1 and subjected to a decomposition treatment to obtain a liquid object to be treated (primary treatment). The Z value of this object was 2.94, and the viscosity at 60 ° C. was about 7100 mPa · s. A small amount of the object to be treated was placed in an oven at 200 ° C. and subjected to decomposition treatment by heating for the time shown in Table 13 (secondary treatment) to obtain a urethane resin decomposition product. Each of these was mixed with the raw material polyol at a ratio of 10% by weight and the isocyanate was added thereto in the same manner as in Example 1, and the regenerated urethane resin or the epoxy resin was mixed at a weight ratio of 1: 1. Upon heating, a regenerated epoxy resin was obtained. Table 13 shows the results. When the Z value was in the range of 5 to 25, the viscosity was generally low, and it was confirmed that the urethane resin and the epoxy resin could be well reproduced.
[0073]
[Table 13]

(Example 13)
Using an extruder having the same settings as in Example 1, urethane resin A, DEA and PEG were mixed and decomposed at a ratio of urethane resin A / DEA / polyethylene glycol # 200 (hereinafter, PEG200) = 3/1 / 0.5. It processed and obtained the liquid to-be-processed object (primary processing). The Z value of this object was 2.94, and the viscosity at 60 ° C. was about 4500 mPa · s. A small amount of the object to be treated was taken, placed in an oven at 200 ° C., and decomposed by heating for the time shown in Table 14 (secondary treatment) to obtain a urethane resin decomposed product. Each of these was mixed with the raw material polyol at a ratio of 10% by weight and the isocyanate was added thereto in the same manner as in Example 1, and the regenerated urethane resin or the epoxy resin was mixed at a weight ratio of 1: 1. Upon heating, a regenerated epoxy resin was obtained. Table 14 shows the results. When the Z value was in the range of 5 to 25, the viscosity of the urethane resin decomposed product was generally low, and it was confirmed that the urethane resin or epoxy resin could be favorably regenerated. However, the glass transition temperature of the epoxy resin was lower than those of Examples 1 to 4 in which PEG200 was not added.
[0074]
[Table 14]

(Example 14)
In an extruder having the same settings as in Example 1, urethane resin A, MEA and PEG were mixed at a ratio of urethane resin A / MEA / PEG200 = 5.5 / 1 / 0.5 to be subjected to a decomposition treatment to obtain a liquid coating. A processed product was obtained (primary treatment). The Z value of this object was 2.94, and the viscosity at 60 ° C. was about 12,500 mPa · s. A small amount of the object to be treated was placed in an oven at 200 ° C. and subjected to a decomposition treatment by heating for the time shown in Table 15 (secondary treatment) to obtain a urethane resin decomposed product. Each of these was mixed with the raw material polyol at a ratio of 10% by weight and the isocyanate was added thereto in the same manner as in Example 1, and the regenerated urethane resin or the epoxy resin was mixed at a weight ratio of 1: 1. Upon heating, a regenerated epoxy resin was obtained. Table 15 shows the results. When the Z value is in the range of 10 to 30, the viscosity of the urethane resin decomposed product is generally low, and it has been confirmed that the urethane resin or epoxy resin can be satisfactorily regenerated. However, the glass transition temperature of the epoxy resin was lower than that of Example 8 in which PEG200 was not added.
[0075]
[Table 15]

(Examples 15 to 17)
In an extruder having the same setting as in Example 1, urethane resin B / DEA was set at a ratio of 2/1 (Example 15), 3/1 (Example 16) or 5/1 (Example 17). And DEA were mixed and decomposed to obtain a liquid object to be treated (primary treatment). The Z value of this object was 2.94. A small amount of the object to be treated is taken, placed in a 200 ° C. oven, and decomposed by heating for the time shown in Tables 16 to 18 (Table 16: Example 15, Table 17: Example 16, Table 18: Example 17). The treatment was performed (secondary treatment) to obtain a urethane resin decomposition product. Each of these was mixed with the raw material polyol at a ratio of 10% by weight and the isocyanate was added thereto in the same manner as in Example 1, and the regenerated urethane resin or the epoxy resin was mixed at a weight ratio of 1: 1. Upon heating, a regenerated epoxy resin was obtained. The results are shown in Tables 16 to 18, respectively. When the Z value is in the above-mentioned appropriate range, the viscosity of the urethane resin decomposed product is generally low, and it has been confirmed that the urethane resin or epoxy resin can be satisfactorily regenerated.
[0076]
[Table 16]

[Table 17]

[Table 18]

(Examples 18 to 20)
Using an extruder having the same settings as in Example 1, the urethane resin C / DEA was set at a ratio of 2/1 (Example 18), 3/1 (Example 19) or 5/1 (Example 20). And DEA were mixed and decomposed to obtain a liquid object to be treated (primary treatment). The Z of the object to be treated was 2.94 in all of Examples 18 to 20. A small amount of the object to be treated is taken, put into a 200 ° C. oven, and decomposed by heating for the time shown in Tables 19 to 21 (Table 19: Example 18, Table 20: Example 19, Table 21: Example 20). (Secondary treatment) to obtain a urethane resin decomposition product. Each of them was mixed with the raw material polyol at a ratio of 10% by weight and added with isocyanate in the same manner as in Example 1, and then mixed with a regenerated urethane resin or an epoxy resin at a weight ratio of 1: 1. Upon heating, a regenerated epoxy resin was obtained. The results are shown in Tables 19 to 21, respectively. When the Z value is in the appropriate range, the viscosity of the urethane resin decomposed product is generally low, and it has been confirmed that the urethane resin or epoxy resin can be satisfactorily regenerated.
[0077]
[Table 19]

[Table 20]

[Table 21]

(Examples 21 to 23)
In an extruder having the same setting as in Example 1, a nullate resin / DEA = 2/1 (Example 21), a 3/1 (Example 22) or a 5/1 (Example 23) ratio of a nullate resin and DEA. Were mixed and decomposed (primary treatment) to obtain a liquid object to be treated. The Z value of the object to be processed was 2.94 in all of Examples 21 to 23. A small amount of the object to be treated is taken, placed in a 200 ° C. oven, and decomposed by heating for the time shown in Tables 22 to 24 (Table 22, Example 21, Table 23, Example 22, Table 24, Example 23). (Secondary treatment) to obtain a degraded nurate resin. Each of them was mixed with the raw material polyol at a ratio of 10% by weight and added with isocyanate in the same manner as in Example 1, and then mixed with a regenerated urethane resin or an epoxy resin at a weight ratio of 1: 1. Upon heating, a regenerated epoxy resin was obtained. The results are shown in Tables 22 to 24, respectively.
[0078]
When the Z value is in the above-mentioned appropriate range, the viscosity of the decomposed product of the nurate resin is generally low, and it has been confirmed that the urethane resin and the epoxy resin can be satisfactorily regenerated.
[0079]
[Table 22]

[Table 23]

[Table 24]

Table 25 shows the summary of Examples 1 to 23. It should be noted that the “value of Z suitable for reproduction” in the table is a value determined from the evaluation of the result and may include an error or the like, and it is needless to say that it is not absolute. In any of the urethane resin decomposition treatments, 3 ≦ Z ≦ 15 when the urethane resin is less than 2.5 parts by weight per 1 part by weight of the decomposing agent, and 5 ≦ Z ≦ 25 when the urethane is 2.5 to 5 parts by weight. When the urethane content exceeds 5 parts by weight, it is confirmed that the condition suitable for reproduction is satisfied when 10 ≦ Z ≦ 30.
[0080]
[Table 25]

(Example 24)
The urethane resin A is crushed with a glass rod to facilitate heat transmission, and the urethane resin A and DEA are put in a test tube at a mixing ratio of urethane resin A / DEA = 3/1, and heated in a 200 ° C. oil bath. To perform a decomposition process. The time during which the urethane resin A was confirmed to be liquid by visual observation was about 5 minutes. At this time, since the urethane resin decomposed liquid was uniform, it was considered that the urethane resin decomposed product was decomposed uniformly.
[0081]
The same operation as the above-described decomposition treatment was repeated except that the time from oil bath introduction to removal was changed as shown in Table 26, and the viscosity of the obtained urethane resin decomposition product was measured. The molecular weight distribution of the decomposed product having the lowest viscosity was measured using gel permeation chromatography (GPC). The results are shown in Table 26. In addition, the molecular weight in the table is a molecular weight in terms of polystyrene, and is different from an actual molecular weight. According to the results in Table 26, the viscosity exhibited the lowest value near the range where the Z value was 5 to 20, and the formation of many carbides was confirmed when the Z value was 25 or more.
[0082]
[Table 26]

(Comparative Example 1)
200 g of diethanolamine was placed in a 1000 ml flask, heated using a 200 ° C. oil bath, and 600 g of a urethane resin was gradually added thereto to perform a decomposition treatment. The time required until the completion of the introduction of all the urethane resins was 10 and a half hours, and heating was continued in the oil bath for another 30 minutes after the completion of the introduction. The Z value of the decomposed product of the urethane resin was in the range of 1.25 to 27.5, and among them, the Z value in the range of 5 to 25 was 76%. Many carbonized solid components were found in the urethane resin decomposition product. The viscosity was 3800 mPa · s (60 ° C.), which was higher than those of Examples 1 to 4 and Example 24. The molecular weight distribution was in a wide range of 10,000 or less, and the number average molecular weight was 1,900.
[0083]
A part of the obtained urethane resin decomposed product was mixed with the raw material polyol at a ratio of 10% by weight, and isocyanate (Cosmonate T-80) was added to foam the product. The cell was rough and could not be reproduced properly. Further, when the remaining portion of the urethane resin decomposed product was mixed with the bisphenol A type epoxy resin at a weight ratio of 1: 1 and reacted at 150 ° C., a regenerated epoxy resin was obtained, but the appearance was poor because it contained many carbides. The glass transition temperature was lower than the resins prepared in Examples 1 to 4 and Example 24.
[0084]
(Example 25)
The urethane resin A and the MEA were introduced into a 250 ° C. extruder at a mixing ratio of urethane resin A / MEA = 4/1 to perform a decomposition treatment (primary treatment). For 15 minutes to further disassemble. At this time, the Z value of the object to be processed was about 8.5. Thereafter, heat exchange was performed with the cooling liquid to cool the temperature of the object to be treated to 100 ° C. in two minutes, and the obtained urethane resin decomposition product was collected in a drum. The obtained urethane resin decomposed product was mixed with a polyol as a raw material at a ratio of 10% by weight, and foamed by adding isocyanate (Cosmonate T-80), whereby a good foam was obtained. Further, the urethane resin decomposed product was mixed with the bisphenol A type epoxy resin at a weight ratio of 1: 1 and reacted at 150 ° C. to obtain a regenerated epoxy resin, and the glass transition temperature was 100 ° C. or higher.
[0085]
(Example 26)
The urethane resin A and MEA were charged into a 250 ° C. extruder at a mixing ratio of urethane resin A / MEA = 4/1, and a decomposition treatment was performed for a residence time of 2 minutes (primary treatment). The to-be-processed material was collected in the drum which was made, and the to-be-processed material was filled up to the drum in 10 minutes. The temperature of the object in the drum was 190 to 200 ° C. It took 2 hours for the object in the drum to cool to 180 ° C. and 6 hours for cooling to 140 ° C. When the value of Z at this time was calculated, Z = 10.8 to 11.2 as shown in Table 27. The obtained urethane resin decomposed product was mixed with a polyol as a raw material at a ratio of 10% by weight, and foamed by adding isocyanate (Cosmonate T-80), whereby a good foam was obtained. Also, by mixing the obtained urethane resin decomposed product with a bisphenol A type epoxy resin at a weight ratio of 1: 1 and reacting at 150 ° C., a regenerated epoxy resin can be obtained, and its glass transition temperature is 100 ° C. or higher. Met.
[0086]
[Table 27]

[0087]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, since the decomposition conditions of the urethane resin for obtaining the urethane resin decomposition product which can be easily regenerated into a urethane resin or an epoxy resin can be easily determined and a good regenerated resin is provided, the recycling of the urethane resin is promoted. can do.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an embodiment of an extruder-type apparatus for performing a primary treatment of a urethane resin decomposition treatment method according to the present invention.
FIG. 2 is a schematic configuration diagram showing an embodiment of a secondary processing device that performs secondary processing of the urethane resin processing method according to the present invention.
FIG. 3 is a schematic configuration diagram showing another embodiment of a secondary processing device that performs secondary processing of the urethane resin processing method according to the present invention.
FIG. 4 is a schematic configuration diagram showing still another embodiment of a secondary processing device that performs secondary processing of the urethane resin processing method according to the present invention.
FIG. 5 is a schematic configuration diagram showing still another embodiment of a secondary processing device for performing secondary processing of the urethane resin processing method according to the present invention.
[Explanation of symbols]
1 extruder, 3 cylinder part, 5 screw,
7 input port 7, 9 discharge pipe, 11 supply port
11, 21, 31, 41 Secondary treatment device

Claims (4)

A decomposition treatment step in which the hard urethane resin and the decomposing agent are charged into an extruder and heated to progress the decomposition of the hard urethane resin,
A determination step of determining whether or not the decomposition of the hard urethane resin is sufficient based on the ratio of the hard urethane resin and the decomposing agent, a heating temperature and a decomposition time,
An auxiliary heating step of heating an object to be processed obtained in the decomposition step when it is determined in the determination step that the decomposition of the hard urethane resin is not sufficient. The determining step includes:
Setting a constant k at the temperature T [゜ K] as follows:
k = 2 (300 <T)
k = 1 (270 <T ≦ 300)
k = 1/3 (240 <T ≦ 270)
k = 1/10 (210 <T ≦ 240)
k = 1/40 (180 <T ≦ 210)
k = 1/200 (140 ≦ T ≦ 180)
k = 0 (T <140)
A parameter ΔZ _T = k × ΔH _T × 100 at the temperature T [゜ K] is calculated from the processing time ΔH _T [time] and the constant k in the decomposition processing step at the temperature T [゜ K]. Calculating a total value Z by adding a parameter ΔZ _T for all processing temperatures in the decomposition processing step;
A step of comparing the total value Z with an appropriate range of Z represented by the following formula according to the number N of parts by weight of the hard urethane resin with respect to 1 part by weight of the decomposing agent in the decomposition treatment step;
When N <2.5 3 ≦ Z ≦ 15
2.5 ≦ N ≦ 5 5 ≦ Z ≦ 25
When 5 <N 10 ≦ Z ≦ 30
2. The method according to claim 1, further comprising: judging that the hard urethane resin is not sufficiently decomposed when the total value Z is less than an appropriate range of Z. The method according to claim 1, wherein the decomposing agent is a monoalkanolamine or a dialkanolamine. A decomposition treatment step in which a urethane resin and a decomposing agent are charged into an extruder and heated to promote decomposition of the urethane resin,
A determining step of determining whether the urethane resin has been sufficiently decomposed based on the ratio of the urethane resin and the decomposing agent in the decomposition step, a heating temperature and a decomposition time,
When it is determined that the urethane resin is not sufficiently decomposed in the determining step, an auxiliary heating step of heating the object to be processed obtained in the decomposing step,
Blending an isocyanate compound or a compound having an epoxy group with the object to be processed after the decomposition treatment step and the auxiliary heating step performed depending on the situation to obtain a recycled resin. .

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