JPWO2003076360A1

JPWO2003076360A1 - Method for producing modified sulfur-containing binder and method for producing modified sulfur-containing material

Info

Publication number: JPWO2003076360A1
Application number: JP2003574584A
Authority: JP
Inventors: 橋本　博; 博橋本
Original assignee: Nippon Oil Corp
Current assignee: Eneos Corp
Priority date: 2002-03-08
Filing date: 2002-03-08
Publication date: 2005-07-07
Anticipated expiration: 2022-03-08
Also published as: WO2003076360A1; AU2002237558A1; JP4166702B2

Abstract

一般及び産業廃棄物を原料骨材として用いた場合でも、機械的強度、遮水性、耐着火性、耐硫黄酸化細菌性が良好で、土木・建設資材としての性能を充たす変性硫黄含有材料及び該材料の製造に用いる結合剤を、簡便な制御により得ることができる製造法であって、硫黄及びジシクロペンタジエンを１３５〜１５５℃で密閉状態で溶融混合する工程（Ａ）、該溶融物の１４０℃における粘度が０．０５〜１．２Ｐａ・ｓになった後に１３５℃以下に冷却し変性硫黄含有結合材を得る工程（Ｂ）、該結合材及び骨材を特定割合で１３５〜１５５℃の温度下、該結合材の１４０℃における粘度を０．０５〜１．２Ｐａ・ｓの範囲内に維持しながら溶融混合する工程（Ｃ）及び１３５℃以下に冷却する工程（Ｄ）とを含む。Even when general and industrial waste is used as a raw material aggregate, a modified sulfur-containing material that has good mechanical strength, water shielding, ignition resistance, and sulfur-oxidizing bacteria resistance, and satisfies the performance as a civil engineering / construction material, and It is a manufacturing method which can obtain the binder used for manufacture of material by simple control, Comprising: The process (A) which melt-mixes sulfur and dicyclopentadiene at 135-155 degreeC in a sealing state, 140 of this melt Step (B) of obtaining a modified sulfur-containing binder by cooling to 135 ° C. or less after the viscosity at 0.05 ° C. reaches 0.05 to 1.2 Pa · s, and the binder and aggregate at a specific ratio of 135 to 155 ° C. A step (C) of melt-mixing while maintaining the viscosity of the binder at 140 ° C. within a range of 0.05 to 1.2 Pa · s and a step (D) of cooling to 135 ° C. or lower under temperature.

Description

技術分野
本発明は、ジシクロペンタジエンで変性した変性硫黄含有結合材の製造法、更に一般及び産業廃棄物を土木用又は建設用の資材として再利用することを可能にする変性硫黄含有材料の製造法に関する。
背景技術
硫黄は、１１９℃を越えると溶解し、常温では固体である性質を利用して、土木用及び建設用資材としての利用が試みられている。例えば、舗装材料（米国特許第４２９０８１６号明細書）、建築材料用資材（特公昭５５−４９０２４号公報）又は廃棄物封鎖用結合材（特公昭６２−１５２７４号公報）としての使用が検討されている。
しかし、硫黄単独の結合材では、得られる成形物の外表面が硫黄であるために着火性を有し、更には、機械的強度及び耐硫黄酸化細菌性にも劣るなどの多くの問題があり、その利用は必ずしも拡大していない。
そこで、このような問題を改良するために多くの添加用化合物が検討されている。添加用化合物としてのジシクロペンタジエンは、安価で経済牲に優れると共に、ＮｅｗＵｓｅｓｏｆＳｕｌｆｕｒ−ＩＩ，１９７８，ｐ６８〜７７に示されるように機械的強度において良好な作用を示すことが知られている。また、ビニルトルエン、ジペンテン、その他オレフィンオリゴマーを添加し硫黄の性状を改良して、舗装材、接着剤、シール材に用いる例（特公平２−２５９２９号公報、特公平２−２８５２９号公報）も知られている。アスファルト及び硫黄を混合使用する舗装材は実用化されている。
これまで硫黄は、結合材としての用途が知られており、各種の骨材と混合して成型物を製造し、土木建設資材として使用されている。しかし、硫黄単独の結合材を用いた成型物は、物性上の多くの課題があり使用方法が限定されている。
硫黄は、引火点２０７℃、自然発火温度２４５℃であるため着火性があり、表面に露出した硫黄は燃え易く、燃焼性に問題がある。また、硫黄は安定な固体状態において欠陥が無ければ高強度を示すが、液体状態から冷却固化する場合、斜方晶系、単斜晶系、不定形硫黄の３種が混在し、冷却条件によりそれらの比率が変わると共に、経過時間により変化していくために実際には欠陥が生じ易く脆いという問題がある。
硫黄が固体状態で最も安定なのは斜方晶系硫黄であり、斜方晶系硫黄は３種の中で最も密度が高いために時間と共に隙間ができ機械的強度が低下し、極端な場合は割れが生じる。またその隙間に水が染み込み、内部の封鎖物を溶解するため有害物の封鎖性が低下し、更に、土壌中又は水中に存在する硫黄酸化細菌が入り込みその表面を腐食させる問題が生じる。
そこで、ジシクロペンタジエンを添加する方法が検討されている。ジシクロペンタジエンと硫黄との反応は、一種の重合反応といわれており、最初ジシクロペンタジエンと硫黄とが反応し、その後、硫黄がラジカル連鎖反応により高分子化する。従って、ジシクロペンタジエンと硫黄との反応は、大きな発熱を伴って急激に温度上昇し、粘度の急上昇が生じるため反応が制御できず、急激に固化して成形できない状態になる。これを防止するために、オレフィンオリゴマーを添加する方法も検討されている（特公平２−２８５２９号公報）。しかし、ジシクロペンタジエンを添加する場合の製造条件については十分検討されておらず、ジシクロペンタジエン濃度及び温度等の反応条件と、製造される結合材の望ましい性状との関係については十分判っていない。
また、冷却固化した前記結合材を、骨材と混合するために再加熱すると、再びジシクロペンタジエンとの重合反応が開始し硬化が進行する。この場合の結合材の適切な性状及び骨材と混合するための製造条件についても従来確立されていない。
更に、ジシクロペンタジエンにより改良した結合材を一般及び産業廃棄物封鎖用結合材として使用することは従来知られておらず、その製造条件も確立されてはいない。通常、一般及び産業廃棄物は埋め立てる方法又は焼却する方法で処分されるが、そのための処分場所は益々少なくなってきており、その再利用が極力求められている。例えば、鉄鋼スラグ、石炭灰、焼却灰等の廃棄物の場合、その成型物を土木埋立材、建設資材等に利用するには、圧縮強度、曲げ強度、引張り強度及び耐衝撃性等の機械的強度が必要である。また、産業廃棄物中に含まれる重金属化合物の溶出を防ぐための遮水性、裸火で着火しない難燃性、土中及び海中で表面硫黄を腐食する硫黄酸化細菌に対する耐久性も必要とされる。特に、焼却灰は、その中に重金属及びダイオキシン等の有害物質が含まれており、埋立に使用する場合には、その溶出を抑制する必要がある。鉄鋼業から排出される鉄鋼スラグは、舗装材用骨材及び土木材料に使用されるが、水に濡れるとポリ硫化物による黄濁水が発生し、環境に悪影響を与える。従って、これらの産業廃棄物を、土木建設資材として利用しうる上記各要求を満たし、循環使用を可能にした結合材が求められている。
発明の開示
本発明の目的は、一般及び産業廃棄物を原料骨材として利用して土木・建設資材を調製する際に、該資材に、機械的強度、遮水性、耐着火性及び耐硫黄酸化細菌性を付与でき、且つ一般及び産業廃棄物の封止用にも利用できる変性硫黄含有結合材を、容易な反応制御により効率良く得ることが可能な製造法を提供することにある。
本発明の別の目的は、一般及び産業廃棄物を原料骨材として用いた場合であっても、機械的強度、遮水性、耐着火性、耐硫黄酸化細菌性が良好で、土木・建設資材としての要求性能を十分充たす変性硫黄含有材料を、簡便な制御により得ることができる製造法を提供することにある。
本発明によれば、硫黄１００重量部とジシクロペンタジエン０．１重量部以上、２重量部未満とを１３５〜１５５℃で密閉状態で溶融混合する工程（Ａ）と、工程（Ａ）で得られる溶融物の１４０℃における粘度が０．０５〜１．２Ｐａ・ｓになった後に１３５℃以下に冷却し変性硫黄含有結合材を得る工程（Ｂ）とを含む変性硫黄含有結合材の製造法が提供される。
また本発明によれば、前記工程（Ａ）と、前記工程（Ｂ）と、工程（Ｂ）により得られた変性硫黄含有結合材及び骨材を重量比で１〜５：５〜９の割合で１３５〜１５５℃の温度下、該変性硫黄含有結合材の１４０℃における粘度を０．０５〜１．２Ｐａ・ｓの範囲内に維持しながら溶融混合する工程（Ｃ）と、工程（Ｃ）の溶融混合物を１３５℃以下に冷却する工程（Ｄ）とを含む変性硫黄含有材料の製造法が提供される。
更に本発明によれば、硫黄、ジシクロペンタジエン及び骨材を１３５〜１５５℃で０．０２〜５時間、密閉状態で溶融混合する工程（Ｘ）と、工程（Ｘ）の溶融混合物を１３５℃以下に冷却する工程（Ｙ）とを含む変性硫黄含有材料の製造法が提供される。
発明の好ましい実施の態様
本発明の変性硫黄含有結合材の製造法は、特定割合の硫黄とジシクロペンタジエンとを特定条件で溶融混合する工程（Ａ）と、工程（Ａ）で得られる溶融物を特定条件で冷却する工程（Ｂ）とを含む。
本発明の製造法に用いる硫黄は、通常の硫黄単体であり、例えば、天然硫黄、石油又は天然ガスの脱硫によって生成した硫黄が使用できる。
本発明の製造法に用いるジシクロペンタジエンは、ジシクロペンタジエンの単体、若しくはシクロペンタジエンの１〜４量体を主体に構成される混合物が挙げられる。該混合物は、ジシクロペンタジエンを通常７０ｍａｓｓ％以上、好ましくは８５ｍａｓｓ％以上含む。従って、いわゆるジシクロペンタジエンと称する市販品の多くが使用できる。
本発明においては、該ジシクロペンタジエンと硫黄との溶融反応を、密閉式撹拌混合機等を用いて密閉状態で行うので、ジシクロペンタジエンが蒸発するロスがなくなり効率良く反応させることができる。
工程（Ａ）において、ジシクロペンタジエンの使用割合は、硫黄１００重量部に対して、０．１重量部以上、２重量部未満、好ましくは１重量部以上、２重量部未満である。得られる結合材及び該結合材を使用し、骨材と混合する後述の変性硫黄含有材料の難燃性、遮水性、耐硫黄酸化細菌性等の性質は、ジシクロペンタジエンの使用量に関係し、通常は使用量が多いほど各性能が改善される。しかし、ジシクロペンタジエンの使用量は、硫黄１００重量部に対して約２重量部で前記改善効果が飽和し、それ以上使用しても改善が少ない。
前記ジシクロペンタジエンの使用量は、反応の制御性及び反応時間に加え、製品の性能からも決定できる。溶融した硫黄の粘度は、ジシクロペンタジエンによる硫黄の変性が進行するほど上昇する。該粘度上昇の速度は、ジシクロペンタジエンの量にも関係し、ジシクロペンタジエンの添加量が多いほど速い。例えば、１４０℃において、硫黄１００重量部に対してジシクロペンタジエン０．１重量部未満では１０時間以上かけても粘度が０．１Ｐａ・ｓに達しない。一方、ジシクロペンタジエン２重量部以上では０．０２〜３時間で粘度が０．１Ｐａ・ｓに達する。ジシクロペンタジエンの添加が少ない方が製造中の取り扱いが容易で好ましいが、効率良く短い時間で製造するには添加量が少なすぎても良くない。製品の性能面から弾性的な強度を出現させるにば、ジシクロペンタジエンの割合が、硫黄１００重量部に対して０．１重量部以上、２重量部未満が好ましい。ジシクロペンタジエンが０．１重量部未満では十分に強度が改善されない。得られる弾性体の強度が最も高くなるのは、硫黄１００重量部に対してジシクロペンタジエン１重量部以上、２重量部未満の時である。ジシクロペンタジエンが２重量部以上では、弾性に加え粘性的性質が加わり製品が粘弾性体になり歪み易く、粘りが増して容易に破壊しない。従って、これらの各性質を考慮してジシクロペンタジエンの使用量が決定される。
工程（Ａ）において、硫黄とジシクロペンタジエンとの密閉状態における溶融混合は、１３５〜１５５℃の範囲で、溶融物の１４０℃における粘度が０．０５〜１．２Ｐａ・ｓになるまで混合する。具体的には、先ず硫黄を加熱溶融する。固体硫黄を加熱すると１１９℃で固体から液体への相変化が始まるので、硫黄を液化してから全体を撹拌し、例えばＢ型粘度計で粘度を測定しながら１３０℃程度まで温度を上昇させる。次いで、所定量のジシクロペンタジエンを少しずつ添加する。１３５℃以下では硫黄は容易に変性しない。即ち１２０〜１３５℃の温度範囲では硫黄とジシクロペンタジエンとの重合反応は遅く、急な発熱及び粘度上昇は起こらず、僅かな温度上昇と粘度上昇とが生じ殆ど一定の粘度を維持する。発熱が生じないことを確認後、１３５〜１５５℃まで次第に温度上昇させる。１５５℃を超えると粘度上昇が急激で制御が困難となる。粘度上昇速度は、反応温度に関係し温度が高いほど速い。以上の点から硫黄とジシクロペンタジエンとの溶融混合温度は、硫黄を効率よく変性するように１３５〜１５５℃で行う必要がある。
溶融混合する時間は、ジシクロペンタジエンの使用量と溶融温度により異なる。例えば、硫黄１００重量部に対してジシクロペンタジエン０．２重量部では１３５℃で約１５時間、１４０℃で約５時間、１４５℃で約２時間、１５０℃で約０．５時間で各粘度が０．１Ｐａ・ｓに達する。温度制御及び製造時間の点から特に好適な温度範囲は１４０〜１４５℃である。
溶融混合による反応終了の時期は、溶融物の粘度により決定できる。該粘度は、１４０℃において０．０５〜１．２Ｐａ・ｓの範囲となる粘度であるが、得られる結合材から製造される成型物の強度、及び製造工程の作業性の観点から０．０８〜０．５Ｐａ・ｓが最適粘度である。該粘度が０．０５Ｐａ・ｓ未満では、得られる結合材を利用した土木建設資材の強度が低くなり、ジシクロペンタジエンによる変性効果が不十分となる。粘度が高くなるに従い変性が進行し、得られる結合材の強度も高くなるが、１．２Ｐａ・ｓを超えると撹拌・混合が困難となり、作業性が著しく悪化すると共に変性効果が飽和する。
前記溶融混合に使用する混合機は、密閉状態で十分な混合が可能であれば公知の混合機が使用でき、主に液体撹拌用の密閉型混合機の使用が好ましい。例えば、密閉型の、インターナルミキサー、ロールミル、ドラムミキサー、ボニーミキサー、リボンミキサー、ホモミキサー、スタティックミキサーが挙げられる。
工程（Ｂ）の冷却は、上記特定粘度になった時点で溶融混合を終了し、高粘度化しないように反応温度以下の１３５℃以下で行うことができる。冷却温度の下限は特に限定されず、室温程度でも良い。
本発明の製造法により得られる結合材は、硫黄がジシクロペンタジエンと反応して重合した変性硫黄を含み、また純硫黄を含んでいても良く、硫黄セメントとも称される。該結合材は、土木及び建設資材として有用であり、例えば、各種骨材と混合して舗装材用、建築材用又は廃棄物封鎖用資材として使用できる。
本発明の変性硫黄含有材料の製造法は、前記工程（Ａ）及び工程（Ｂ）により得られた結合材と、骨材とを特定割合で１３５〜１５５℃の温度下、該結合材の１４０℃における粘度を０．０５〜１．２Ｐａ・ｓの範囲内に維持しながら溶融混合する工程（Ｃ）と、工程（Ｃ）の溶融混合物を１３５℃以下に冷却する工程（Ｄ）を含む方法（以下、「第１の方法」という）、並びに硫黄、ジシクロペンタジエン及び骨材を特定条件で溶融混合する工程（Ｘ）と、工程（Ｘ）の溶融混合物を１３５℃以下に冷却する工程（Ｙ）を含む方法（以下、「第２の方法」という）である。
前記第１及び第２の方法に用いる骨材は、骨材として使用可能であれば特に限定されないが、再利用可能な産業廃棄物の使用が好ましい。産業廃棄物としては、例えば、焼却灰、焼却飛灰、都市ごみ高温溶融炉から発生する溶融飛灰、電力事業及び一般産業から排出される石炭灰、流動床焼却装置で使用した流動砂、重金属に汚染された土壌、研磨屑、各種金属製造時の副生物又はこれらの混合物が挙げられる。前記各種金属製造時の副生物としては、例えば、鉄鋼スラグ、鉄鋼ダスト、フェロニッケルスラグ、アルミドロス、鋼スラグ又はこれらの混合物が挙げられる。本発明の製造法では、鉄綱スラグ、焼却灰、石炭灰等の廃棄物を骨材として無害化しながら再利用できる。
鉄鋼スラグは、製鉄業から副生するスラグであって、高炉スラグ、平炉スラグ、転炉スラグ等が挙げられる。鉄鋼スラグの主成分は、シリカ、アルミナ、酸化カルシウム、酸化鉄等の酸化物及びその他無機硫化物も含まれる。
焼却灰は、都市ごみ焼却炉又は産業廃棄物焼却炉等の各種燃焼炉から排出され、主成分が、シリカ、アルミナ、酸化カルシウム、酸化鉄等の酸化物であり、鉛、カドミウム、砒素等の有害金属の含有量も多い。該焼却灰は、汚水を出さない最終処分場で埋め立て処理されているが、本発明では該焼却灰も骨材として使用できる。
石炭灰は、発電用、加熱用等の各種石炭焚燃焼炉から排出され、コンクリート又は土木資材混合材として利用されている石炭灰が使用できる。
本発明に用いる骨材としては、上記以外の他の骨材、例えば、粘土鉱物、活性炭、カーボンファイバー、グラスファイバー、ビニロン繊維、アラミド繊維、砂、砂利、同等の有害物質を含有しない無機系資材及び有機系資材が使用できる。
前記第１の方法の工程（Ｃ）において、結合材と骨材との混合割合は、重量比で１〜５：５〜９である。得られる材料の強度は、結合材の割合が、最密充填構造をとった骨材の空隙を埋める量の場合に最も高くなる。結合材の割合が１０重量％未満、即ち、骨材が９０重量％を超える場合は、骨材としての無機系資材表面を十分に濡らすことができず、骨材が露出した状態となり強度が十分発現しないと共に遮水性が維持できない。一方、結合材の割合が５０重量％を超える、即ち、骨材が５０重量％未満では強度が低下する。前記結合材と骨材の混合割合は、骨材の種類によっても変化し、骨材の種類に応じて上記範囲内から適宜選択できる。例えば、骨材として鉄鋼スラグを用いる場合には、骨材の混合割合は１５〜２５重量％程度が好ましい。
工程（Ｃ）において、結合材と骨材との溶融混合時の粘度は、時間と共に上昇するので取り扱いが容易な最適粘度範囲とする必要がある。該粘度は、１４０℃における粘度が０．０５〜１．２Ｐａ・ｓの範囲となる粘度である。粘度が０．０５Ｐａ・ｓ未満では、得られる変性硫黄含有材料の強度が低下し変性効果が不十分である。粘度が高くなるに従い得られる材料の強度も高くなるが、１．２Ｐａ・ｓを超えると製造時の撹拌が困難となり作業性が著しく悪化する。
工程（Ｃ）において、前記溶融混合は、結合材及び骨材のいずれの材料も、混合時の温度低下を避けるために予熱しておくことが好ましい。骨材は１２０〜１５５℃程度に予熱し、結合材は反応の進行を避けるため極力短時間で１２０〜１５５℃に予熱し、混合機も１２０〜１５５℃に予熱しておくことが好ましい。予熱した各成分は、ほぼ同時に混合機に投入し、１３５〜１５５℃で好ましくは５〜３０分間混合できる。１５５℃以下でより高温の方が結合材の流動性及び混合効率が高く、溶融混合が短時間で終了するが、高温では硬化反応が進行する。低温では流動性が低下する代りに硬化反応の進行が遅い。従って、好ましい温度範囲は１４０〜１４５℃である。この場合、骨材の予熱範囲は１４０〜１４５℃、結合材の予熱範囲は１３５〜１４０℃が好ましい。
混合時間は、硫黄とジシクロペンタジエンとの重合による高粘度化及び硬化を避けるために製造物の性状が許す範囲で極力短時間が望ましい。但し、混合時間が短かすぎると結合材と骨材とが十分混合されず、得られる材料が連続相とならず隙間が開いたり、表面が滑らかにならない。混合が十分であれば材料は完全な連続相となり表面も滑らかであるので、混合は得られる材料の性能を考慮して適宜決定する必要がある。
第１の方法においては、前記結合材及び骨材の他に所望により他の成分も混合できる。この場合は、前記結合材を再溶融して他の成分を混合する方法、若しくは工程（Ｂ）の冷却をする前に他の成分を混合する方法が挙げられる。
第１及び第２の方法において使用する混合機は、硫黄とジシクロペンタジエンとを含む系を混合する場合には、密閉状態で混合可能なものであれば良く、他は、十分な混合が可能であれば密閉状態で混合可能である必要はなく、好ましくは固液撹拌用が使用できる。例えば、インターナルミキサー、ロールミル、ボールミル、ドラムミキサー、スクリュー押出し機、パグミル、ポエーミキサー、リボンミキサー、ニーダー等が使用できる。
第２の方法における工程（Ｘ）の硫黄、ジシクロペンタジエン及び骨材の溶融混合は、密閉状態で骨材の混合と硫黄の変性とを同時に行うか、若しくは密閉状態で硫黄及びジシクロペンタジエンを溶融混合する工程（Ｘ１）と、該工程（Ｘ１）の溶融混合物に骨材を混合して特定条件で溶融混合する工程（Ｘ２）からなる方法等により実施できる。これらの方法で使用できる硫黄、ジシクロペンタジエン及び骨材は、上述と同様なものが好ましく挙げられる。また、各材料の使用量も前述の範囲から適宜選択することが好ましい。要するに、ジシクロペンタジエンの仕込み割合は、硫黄１００重量部に対して通常０．１重量部以上、２重量部未満、好ましくは１重量部以上、２重量部未満である。骨材の仕込み割合は、硫黄及びジシクロペンタジエンの合計量と骨材量との重量比が１〜５：５〜９となるように適宜選択することが望ましい。
第２の方法において、硫黄とジシクロペンタジエンと骨材とを同時に溶融混合する場合は、予め変性硫黄含有結合材を製造する第１の製造法とは異なり、１段階で変性硫黄含有材料が製造できる。従って、第２の方法では、製造工程が簡素化でき、溶融混合時間を長くしても全体的には短時間で変性硫黄含有材料が得られる。
工程（Ｘ）において、溶融混合は、密閉状態において溶融物全体が均一な温度になるように十分撹拌又は混練することが好ましく、該溶融温度は１３５〜１５５℃、混合時間は０．０２〜５時間である。混合時間が０．０２時間未満では、ジシクロペンタジエンと硫黄と骨材とは十分混合されず、得られる材料が連続相とならず隙間が開いたり表面が滑らかにならない。溶融混合が十分であれば、材料は完全な連続相となり表面も滑らかである。一方、混合時間が５時間を超えると、硫黄の変性が進行し、変性した硫黄の粘度が高くなり、更には硬化して作業性が低下する。
工程（Ｘ）において、硫黄をジシクロペンタジエンで変性させる際に骨材が存在すると、硫黄とジシクロペンタジエンとの反応の進行を粘度で直接測定することが非常に困難である。しかし、硫黄とジシクロペンタジエンとの反応は本質的には前述のとおりであり、反応を制御するには温度、混合方法及び混合時間を、硫黄変性の進行程度を予測しながら厳密に制御することで達成できる。例えば、溶融混合温度及び時間は、１４０℃で３〜５時間であり、１５０℃で４５〜９０分間である。
工程（Ｘ）における密閉状態での溶融混合の具体例としては、例えば、１２５〜１３５℃に加熱した硫黄、及び４０〜５０℃で溶融したジシクロペンタジエンを、１３５〜１５５℃の温度に予熱した密閉型の混合機にほぼ同時に投入し、その後１２５〜１５５℃程度に予熱した骨材を投入し１３５〜１５５℃の温度で０．０２〜５時間溶融混合する方法が挙げられる。より好ましい溶融混合方法としては、密閉型の混練機を１４０〜１５０℃で予熱しておき、１４５〜１５５℃の温度で溶融混合する方法が挙げられる。先に硫黄とジシクロペンタジエンとを混合するのは、骨材の存在により硫黄の重合反応が阻害されないためである。
第１又は第２の方法の工程（Ｄ）又は工程（Ｙ）では、工程（Ｃ）又は工程（Ｘ）の溶融混合物を１３５℃以下に冷却する。冷却温度の下限は特に限定されず、室温程度で良い。工程（Ｄ）又は工程（Ｙ）において、冷却を所望の金型、造粒装置、成形装置を用いることにより、得られる変性硫黄含有材料を、所望形状の成型物、ペレット、破砕物又は粒状物とすることができる。前記工程（Ｄ）及び工程（Ｙ）において、冷却は、変性した硫黄の粘度上昇のしすぎを回避するため、所定の流動状態になったところで温度を下げ、１２０〜１３５℃で混合をしばらく継続した後に行っても良い。
前記造粒装置は特に限定されず、例えば、ドラム又は傾斜サラを具備した転動型形式装置、水平板又は傾斜板を具備した振動型形式装置が使用できる。
第１及び第２の方法で得られる材料を粒状物とした場合、個々の粒状物の強度が高く、これらの粒度調整が可能であるため、建設用材料として適すると共に採石と同様に使用できる。また、第１及び第２の方法で得られる材料は、基本的に変性硫黄によって、骨材が周囲の水と接触することを遮断するため、該骨材が直接外部に露出することが少なく、含まれる有害物質の溶出がある程度抑制できる。従って、この材料は、例えば、セメント、コンクリート、石膏等のセメント系材料と混合する際に、その硬化及び最適含水比に影響を与えない。
従来、セメント系材料と焼却灰とを用いて硬化物を得る場合には、ポゾラン反応、サルホポゾラン反応により硬化させるが、含水比を最適値に整えることが重要である。特に、吸水性の高い都市ごみの焼却灰を混合する際は、水分の調整が非常に困難である。例えば、都市ごみの焼却灰を乾燥して混合する場合は、該焼却灰がセメント質混合物より水分を吸収するため水分が不足し、また湿潤状態の都市ごみの焼却灰を混合した場合は、セメント質混合物の水分が余剰となりいずれの場合も建設資材としての性能を損なう恐れがある。加えて、有害物質を含有した骨材が水分を吸収すると膨脹するため骨材としての使用が不可能となる。本発明の製造法で得られる材料は、有害物質を含む骨材であっても変性硫黄を用いて無害化することができるので、該骨材の再生利用に極めて有用である。
本発明で得られる材料は、成型体であれば任意の構造に作製可能な特性を生かし、例えば、パネル材、床材、壁材、瓦、水中構造物として利用でき、粒状物であれば、埋立材、路盤材、盛土材又はコンクリート用骨材として利用できる。
実施例
以下、本発明を実施例及び比較例により詳細に説明するが、本発明はこれらに限定されない。尚、例中で作製した各結合材及び成型物について、以下に示す方法に従い各測定及び評価を行なった。これらの結果を表１〜３に示す。
圧縮強度：φ５×１０ｃｍの円筒検体を作製し、作成後７日目に３０トン加圧テンシロン圧縮強度測定器を用いて測定した。破砕までに検体が縮んだ率を歪み率とした。
吸水率：φ５×１０ｃｍの円筒検体を作製し、常温の水中に一定時間浸積後、取り出して表面の水分を拭き取る。その後、重量変化を計測し重量増加分を水分量として計算した。
耐硫黄酸化細菌性：ＮＨ_４Ｃｌ２．０ｇ、ＫＨ_２ＰＯ_４４．０ｇ、ＭｇＣｌ_２・６Ｈ_２Ｏ０．３ｇ、ＣａＣｌ_２・２Ｈ_２Ｏ０．３ｇ、ＦｅＣｌ_２・４Ｈ_２Ｏ０．０１ｇ及びイオン交換水１．０Ｌからなる溶液を塩酸でｐＨ３．０に調整した培養液１００ｍｌと２ｃｍ×２ｃｍ×４ｃｍの角柱検体とを、５００ｍｌバッフル付きフラスコに入れ、種菌（硫黄酸化細菌：ＴｈｉｏｂａｃｉｌｌｕｓｔｈｉｏｏｘｉｄａｎｓＩＦＯ１２５４４）を植菌後、２８℃恒温室内で回転振とう培養（１７０ｒｐｍ）し、植菌後からのｐＨ変化及び試料状態を調べた。この際、ｐＨの低下は、硫黄酸化細菌により硫黄が資化され硫酸イオンが生成したことを意味する。
難燃性：消防法における可燃性固体（危険物第２類）評価のための着火性試験に準拠して評価した。３秒以内に着火し、かつ１０秒以上燃焼を継続する第１種可燃性固体並びに３秒を超えて１０秒以内に着火し、かつ燃焼を継続する第２種可燃性固体に相当するものを「着火性あり」、１０秒を超えて着火するもの及び燃焼を継続しないものを「危険性なし」とした。
実施例１
密閉式撹拌混合槽の中に固体硫黄９９５ｇを入れ、１２０℃で溶解後１３０℃に保持した。その時の粘度をＢ型粘度計で測定したところ０．００２Ｐａ・ｓであった。続いて、約５０℃に加熱溶解したジシクロペンタジエン５ｇをゆっくりと添加し、約５分間静かに撹拌して温度上昇のないことを確認してから１４０℃まで昇温した。反応が開始され、次第に粘度が上昇し、約５時間で粘度が０．１Ｐａ・ｓに達したところで直ちに加熱を停止し、適当な型又は容器に流し込んで室温で冷却し結合材Ａを得た。
次いで、１４０℃で予熱した、高炉スラグ６７０ｇ及び石炭灰１３０ｇからなる骨材と、前記結合材Ａ２００ｇを１３０℃に再加熱して溶解した溶解物とを１４０℃に保持した混練機内にほぼ同時に投入した。続いて２０分間混練し、直径５ｃｍ、高さ１０ｃｍの円柱型に流し込んで冷却し検体を作製した。この検体を成型物Ａとする。
実施例２
硫黄の量を９９０ｇ、ジシクロペンタジエンの量を１０ｇとした以外は全て実施例１と同様に操作して結合材Ａ及び成形物Ａに対応する結合材Ｂ及び成型物Ｂを調製した。
実施例３
硫黄の量を９８１ｇ、ジシクロペンタジエンの量を１９ｇとした以外は全て実施例１と同様に操作して結合材Ａ及び成形物Ａに対応する結合材Ｃ及び成型物Ｃを調製した。
比較例１
硫黄の量を１０００ｇとし、ジシクロペンタジエンを使用しなかった以外は全て実施例１と同様に操作してジシクロペンタジエンを含まない結合材Ｄ及び成型物Ｄを調製した。
実施例４
１２０℃に加熱して溶解した硫黄１９９ｇと、約５０℃に加熱溶解したジシクロペンタジエン１ｇと、１４０℃で予熱しておいた、高炉スラグ６７０ｇ及び石炭灰１３０ｇからなる骨材とを１４０℃に保持した密閉式撹拌混練機内にほぼ同時に投入した。そのまま約５分間混練後、１５０℃まで温度上昇し１５０℃に達してから引き続き６０分間混練した。得られた混練物を直径５．０ｃｍ、高さ１０ｃｍの円柱型に流し込んで冷却し、検体としての成型物Ｅを調製した。製造までに要した時間は６５分間であった。
実施例５
硫黄の量を１９８ｇ、ジシクロペンタジエンの量を２ｇとした以外は全て実施例４と同様に操作して成形物Ｅに対応する成型物Ｆを調製した。製造までに要した時間は６５分間であった。
実施例６
硫黄の量を１９７ｇ、ジシクロペンタジエンの量を３ｇとした以外は全て実施例４と同様に操作して成形物Ｅに対応する成型物Ｇを調製した。製造までに要した時間は６５分間であった。

表１より、実施例１〜６で得られた結合材及び成型物は、比較例１の結合材及び成型物より圧縮強度が高いか、或いは歪み率が大きく良好であった。また吸水率も非常に小さく良好であった。

表２より、実施例１及び実施例４で得られた結合材及び成型物は、比較例１の結合材及び成型物よりｐＨ低下が小さく耐硫黄酸化細菌性が高いことが判った。

表３より、実施例１〜６で得られた硫黄成型物は、着火性が認められた比較例１の硫黄成型物と異なり、全て着火性がなく良好であることが判った。
また、上記実施例及び比較例の成型物Ａ〜Ｇをビーカー中に浸積し、３０日後に色の変化を観察した。その結果、比較例１の成型物Ｄの溶液のみが黄色に着色し、黄濁水の発生が観察された。実施例の各成型物は、無色透明で変化が見られなかった。 Technical field
The present invention relates to a method for producing a modified sulfur-containing binder modified with dicyclopentadiene, and further to a method for producing a modified sulfur-containing material that makes it possible to reuse general and industrial waste as a material for civil engineering or construction. .
Background art
Sulfur dissolves when it exceeds 119 ° C., and has been attempted to be used as a civil engineering and construction material by utilizing the property of being solid at room temperature. For example, use as a pavement material (US Pat. No. 4,290,816), a building material (Japanese Patent Publication No. 55-49024) or a waste-sealing binder (Japanese Patent Publication No. 62-15274) has been studied. Yes.
However, the binding material of sulfur alone has many problems such as being ignitable because the outer surface of the obtained molded product is sulfur, and further, inferior in mechanical strength and resistance to sulfur-oxidizing bacteria. , Its use is not necessarily expanding.
Therefore, many additive compounds have been studied in order to improve such problems. It is known that dicyclopentadiene as an additive compound is inexpensive and excellent in economic efficiency, and has a good effect on mechanical strength as shown in New Uses of Sulfur-II, 1978, p68-77. . In addition, examples in which vinyl toluene, dipentene and other olefin oligomers are added to improve the properties of sulfur and used for pavement materials, adhesives, and sealing materials (Japanese Patent Publication Nos. 25-25929 and 2-28529) are also available. Are known. Pavement materials using a mixture of asphalt and sulfur have been put into practical use.
So far, sulfur is known for its use as a binder, and is used as a civil engineering construction material by mixing with various aggregates to produce molded products. However, a molded product using a single binder of sulfur has many problems in physical properties and its usage is limited.
Since sulfur has a flash point of 207 ° C. and a spontaneous ignition temperature of 245 ° C., it has an ignitability. Sulfur exposed on the surface easily burns and has a problem in combustibility. Sulfur exhibits high strength if there is no defect in a stable solid state, but when cooled and solidified from the liquid state, there are three types of orthorhombic, monoclinic and amorphous sulfur, depending on the cooling conditions. There is a problem that defects are likely to occur and are brittle because their ratios change and change with elapsed time.
The most stable form of sulfur in the solid state is orthorhombic sulfur. Since orthorhombic sulfur has the highest density among the three types, gaps are formed with time and mechanical strength decreases. In extreme cases, cracks occur. Occurs. Moreover, water permeates into the gap and dissolves the sequestered matter inside, so that the sequestering property of harmful substances is lowered, and further, sulfur oxidizing bacteria existing in the soil or in the water enter and corrode the surface.
Therefore, a method of adding dicyclopentadiene has been studied. The reaction between dicyclopentadiene and sulfur is said to be a kind of polymerization reaction. First, dicyclopentadiene and sulfur are reacted, and then sulfur is polymerized by radical chain reaction. Accordingly, the reaction between dicyclopentadiene and sulfur suddenly increases in temperature with a large exotherm, causing a sudden increase in viscosity, so that the reaction cannot be controlled, and rapidly solidifies and cannot be molded. In order to prevent this, a method of adding an olefin oligomer has also been studied (Japanese Patent Publication No. 2-28529). However, production conditions when dicyclopentadiene is added have not been sufficiently studied, and the relationship between reaction conditions such as dicyclopentadiene concentration and temperature and desirable properties of the binder to be produced is not fully understood. .
Further, when the cooled and solidified binder is reheated to be mixed with the aggregate, a polymerization reaction with dicyclopentadiene starts again and curing proceeds. The proper properties of the binder in this case and the production conditions for mixing with the aggregate have not been established.
Furthermore, the use of a binder improved with dicyclopentadiene as a binder for general and industrial waste blocking has not been known so far, and the production conditions have not been established. Generally, general and industrial wastes are disposed of by landfill or incineration. However, the number of disposal sites therefor has been reduced, and the reuse of these wastes is required as much as possible. For example, in the case of waste such as steel slag, coal ash, and incineration ash, mechanical properties such as compressive strength, bending strength, tensile strength, and impact resistance are required to use the molded product for civil engineering landfills and construction materials. Strength is required. Also required are water barrier to prevent elution of heavy metal compounds contained in industrial waste, flame retardancy not ignited by open flame, and durability against sulfur-oxidizing bacteria that corrode surface sulfur in soil and sea. . In particular, incineration ash contains harmful substances such as heavy metals and dioxins, and when used for landfill, it is necessary to suppress elution. Steel slag discharged from the iron and steel industry is used for aggregates and civil engineering materials for pavement materials, but when wetted with water, yellow water is generated by polysulfide, which adversely affects the environment. Accordingly, there is a demand for a binding material that satisfies the above-described requirements for using these industrial wastes as civil engineering construction materials and that can be recycled.
Disclosure of the invention
The purpose of the present invention is to prepare a civil engineering / construction material using general and industrial waste as a raw material aggregate, and to provide the material with mechanical strength, water barrier property, ignition resistance and sulfur oxidation bacteria resistance. An object of the present invention is to provide a production method capable of efficiently obtaining a modified sulfur-containing binder that can be imparted and can be used for sealing general and industrial wastes by easy reaction control.
Another object of the present invention is that civil engineering and construction materials have good mechanical strength, water barrier properties, ignition resistance, and sulfur oxidation bacteria resistance, even when general and industrial wastes are used as raw material aggregates. It is an object of the present invention to provide a production method capable of obtaining a modified sulfur-containing material sufficiently satisfying the required performance as a simple control.
According to the present invention, 100 parts by weight of sulfur and 0.1 part by weight or more of dicyclopentadiene and less than 2 parts by weight are obtained in the step (A) and the step (A) by melt-mixing in a sealed state at 135 to 155 ° C. And a step (B) of obtaining a modified sulfur-containing binder by cooling to 135 ° C. or less after the melt at 140 ° C. has a viscosity of 0.05 to 1.2 Pa · s. Is provided.
According to the invention, the modified sulfur-containing binder and aggregate obtained by the step (A), the step (B), and the step (B) are in a ratio of 1 to 5: 5 to 9 by weight. (C) and (C) in which melt-mixing is performed while maintaining the viscosity at 140 ° C. of the modified sulfur-containing binder within a range of 0.05 to 1.2 Pa · s at a temperature of 135 to 155 ° C. And a step (D) of cooling the molten mixture to 135 ° C. or lower.
Furthermore, according to the present invention, the step (X) of melting and mixing sulfur, dicyclopentadiene and aggregate in a sealed state at 135 to 155 ° C. for 0.02 to 5 hours, and the molten mixture of step (X) at 135 ° C. The manufacturing method of the modified | denatured sulfur containing material containing the process (Y) cooled below is provided.
Preferred embodiments of the invention
In the method for producing a modified sulfur-containing binder of the present invention, a step (A) in which a specific proportion of sulfur and dicyclopentadiene are melt-mixed under specific conditions, and the melt obtained in step (A) is cooled under specific conditions. Step (B).
Sulfur used in the production method of the present invention is ordinary sulfur alone. For example, natural sulfur, sulfur produced by petroleum or natural gas desulfurization can be used.
Examples of the dicyclopentadiene used in the production method of the present invention include a simple substance of dicyclopentadiene or a mixture mainly composed of a 1 to tetramer of cyclopentadiene. The mixture usually contains 70% by mass or more, preferably 85% by mass or more of dicyclopentadiene. Accordingly, many commercially available products called dicyclopentadiene can be used.
In the present invention, since the melting reaction between the dicyclopentadiene and sulfur is carried out in a sealed state using a closed stirring mixer or the like, the loss of evaporation of dicyclopentadiene can be eliminated and the reaction can be carried out efficiently.
In the step (A), the amount of dicyclopentadiene used is 0.1 parts by weight or more and less than 2 parts by weight, preferably 1 part by weight or more and less than 2 parts by weight, based on 100 parts by weight of sulfur. The properties of the obtained binder and the modified sulfur-containing material described later mixed with the aggregate using the resulting binder are related to the amount of dicyclopentadiene used, such as flame retardancy, water shielding, and sulfur oxidation bacteria resistance. Normally, the higher the amount used, the better each performance. However, when the amount of dicyclopentadiene used is about 2 parts by weight with respect to 100 parts by weight of sulfur, the above-mentioned improvement effect is saturated, and there is little improvement even if it is used more.
The amount of dicyclopentadiene used can be determined from the performance of the product in addition to the controllability of the reaction and the reaction time. The viscosity of the molten sulfur increases as sulfur modification with dicyclopentadiene proceeds. The rate of increase in the viscosity is also related to the amount of dicyclopentadiene, and increases as the amount of dicyclopentadiene added increases. For example, at 140 ° C., if the amount of dicyclopentadiene is less than 0.1 parts by weight with respect to 100 parts by weight of sulfur, the viscosity does not reach 0.1 Pa · s even over 10 hours. On the other hand, at 2 parts by weight or more of dicyclopentadiene, the viscosity reaches 0.1 Pa · s in 0.02 to 3 hours. Less addition of dicyclopentadiene is preferable because it is easy to handle during production, but the amount added may be too small for efficient production in a short time. In order to make the elastic strength appear from the viewpoint of product performance, the proportion of dicyclopentadiene is preferably 0.1 parts by weight or more and less than 2 parts by weight with respect to 100 parts by weight of sulfur. If dicyclopentadiene is less than 0.1 part by weight, the strength is not sufficiently improved. The strength of the obtained elastic body is highest when the amount of dicyclopentadiene is 1 part by weight or more and less than 2 parts by weight with respect to 100 parts by weight of sulfur. When the amount of dicyclopentadiene is 2 parts by weight or more, a viscous property is added in addition to elasticity, and the product becomes a viscoelastic body and is easily distorted. Therefore, the amount of dicyclopentadiene used is determined in consideration of these properties.
In step (A), melt mixing in a sealed state of sulfur and dicyclopentadiene is performed in a range of 135 to 155 ° C. until the viscosity of the melt at 140 ° C. is 0.05 to 1.2 Pa · s. . Specifically, first, sulfur is heated and melted. When solid sulfur is heated, a phase change from solid to liquid starts at 119 ° C., so the whole is stirred after liquefying sulfur, and the temperature is raised to about 130 ° C. while measuring the viscosity with a B-type viscometer, for example. Then, a predetermined amount of dicyclopentadiene is added little by little. Below 135 ° C, sulfur is not easily denatured. That is, in the temperature range of 120 to 135 ° C., the polymerization reaction between sulfur and dicyclopentadiene is slow, no sudden heat generation and viscosity increase occur, a slight temperature increase and viscosity increase occur, and an almost constant viscosity is maintained. After confirming that no heat is generated, the temperature is gradually raised to 135 to 155 ° C. If it exceeds 155 ° C., the viscosity rises rapidly and it becomes difficult to control. The rate of increase in viscosity is related to the reaction temperature, and the higher the temperature, the faster. From the above points, the melt mixing temperature of sulfur and dicyclopentadiene must be 135 to 155 ° C. so as to efficiently modify sulfur.
The time for melt mixing varies depending on the amount of dicyclopentadiene used and the melting temperature. For example, with 100 parts by weight of sulfur, 0.2 parts by weight of dicyclopentadiene is about 15 hours at 135 ° C, about 5 hours at 140 ° C, about 2 hours at 145 ° C, and about 0.5 hours at 150 ° C. Reaches 0.1 Pa · s. A particularly preferred temperature range is 140 to 145 ° C. in terms of temperature control and production time.
The timing of completion of the reaction by melt mixing can be determined by the viscosity of the melt. The viscosity is in the range of 0.05 to 1.2 Pa · s at 140 ° C., but is 0.08 from the viewpoint of the strength of the molded product produced from the resulting binder and the workability of the production process. ˜0.5 Pa · s is the optimum viscosity. When the viscosity is less than 0.05 Pa · s, the strength of the civil engineering material using the obtained binder is low, and the modification effect by dicyclopentadiene is insufficient. As the viscosity increases, the modification progresses and the strength of the resulting binder increases. However, if it exceeds 1.2 Pa · s, stirring and mixing becomes difficult, workability is significantly deteriorated, and the modification effect is saturated.
As the mixer used for the melt mixing, a known mixer can be used as long as sufficient mixing is possible in a sealed state, and the use of a sealed mixer mainly for liquid stirring is preferable. For example, a closed type internal mixer, roll mill, drum mixer, bonnie mixer, ribbon mixer, homomixer, and static mixer can be used.
The cooling in the step (B) can be performed at 135 ° C. or lower, which is equal to or lower than the reaction temperature, so that the melt mixing is finished when the specific viscosity is reached and the viscosity is not increased. The lower limit of the cooling temperature is not particularly limited, and may be about room temperature.
The binder obtained by the production method of the present invention contains modified sulfur obtained by polymerization of sulfur by reacting with dicyclopentadiene, may contain pure sulfur, and is also referred to as sulfur cement. The binder is useful as a civil engineering and construction material. For example, it can be mixed with various aggregates and used as a material for paving materials, building materials, or waste sealing materials.
In the method for producing a modified sulfur-containing material of the present invention, the binding material obtained in the steps (A) and (B) and the aggregate are combined at a specific ratio at a temperature of 135 to 155 ° C., and 140 of the binding material. A method comprising a step (C) of melt-mixing while maintaining a viscosity at 0.05 ° C. within a range of 0.05 to 1.2 Pa · s, and a step (D) of cooling the molten mixture of step (C) to 135 ° C. or lower. (Hereinafter referred to as “first method”), and a step (X) of melting and mixing sulfur, dicyclopentadiene and aggregate under specific conditions, and a step of cooling the molten mixture of step (X) to 135 ° C. or lower ( Y) (hereinafter referred to as “second method”).
The aggregate used in the first and second methods is not particularly limited as long as it can be used as an aggregate, but it is preferable to use reusable industrial waste. Industrial waste includes, for example, incineration ash, incineration fly ash, molten fly ash generated from municipal high-temperature melting furnaces, coal ash discharged from the electric power business and general industries, fluidized sand used in fluidized bed incinerators, heavy metals Contaminated soil, polishing scraps, various by-products in the production of various metals, or mixtures thereof. Examples of the by-products during the production of the various metals include steel slag, steel dust, ferronickel slag, aluminum dross, steel slag, or a mixture thereof. In the production method of the present invention, waste such as iron slag, incineration ash, and coal ash can be reused while detoxifying as an aggregate.
Steel slag is slag by-produced from the steel industry, and examples include blast furnace slag, open hearth slag, converter slag, and the like. The main component of steel slag includes oxides such as silica, alumina, calcium oxide, iron oxide, and other inorganic sulfides.
Incineration ash is discharged from various combustion furnaces such as municipal waste incinerators or industrial waste incinerators. The main components are oxides of silica, alumina, calcium oxide, iron oxide, etc., and lead, cadmium, arsenic, etc. There is also a lot of harmful metal content. The incinerated ash is landfilled at a final disposal site that does not produce sewage, but the incinerated ash can also be used as an aggregate in the present invention.
Coal ash is discharged from various types of coal-fired combustion furnaces for power generation, heating, etc., and can be used as concrete or a civil engineering material mixture.
As aggregates used in the present invention, other aggregates than the above, for example, clay minerals, activated carbon, carbon fibers, glass fibers, vinylon fibers, aramid fibers, sand, gravel, inorganic materials that do not contain equivalent harmful substances Organic materials can be used.
In the step (C) of the first method, the mixing ratio of the binder and the aggregate is 1 to 5: 5 to 9 by weight ratio. The strength of the resulting material is highest when the proportion of binder is the amount that fills the voids in the aggregate with the closest packing structure. When the ratio of the binder is less than 10% by weight, that is, the aggregate exceeds 90% by weight, the surface of the inorganic material as the aggregate cannot be sufficiently wetted, and the aggregate is exposed and the strength is sufficient. It does not develop and water impermeability cannot be maintained. On the other hand, when the proportion of the binder exceeds 50% by weight, that is, when the aggregate is less than 50% by weight, the strength decreases. The mixing ratio of the binder and the aggregate also varies depending on the type of aggregate, and can be appropriately selected from the above range depending on the type of aggregate. For example, when steel slag is used as the aggregate, the mixing ratio of the aggregate is preferably about 15 to 25% by weight.
In the step (C), the viscosity at the time of melt mixing of the binder and the aggregate increases with time, so it is necessary to set the viscosity within the optimum viscosity range that is easy to handle. The viscosity is a viscosity at which the viscosity at 140 ° C. is in the range of 0.05 to 1.2 Pa · s. When the viscosity is less than 0.05 Pa · s, the strength of the resulting modified sulfur-containing material is lowered and the modification effect is insufficient. The strength of the material obtained increases as the viscosity increases, but if it exceeds 1.2 Pa · s, stirring during production becomes difficult and workability is significantly deteriorated.
In the step (C), the melt mixing is preferably performed by preheating both the binder and the aggregate in order to avoid a temperature drop during mixing. It is preferable that the aggregate is preheated to about 120 to 155 ° C, the binder is preheated to 120 to 155 ° C in a short time to avoid the progress of the reaction, and the mixer is also preheated to 120 to 155 ° C. The preheated components can be charged into the mixer almost simultaneously and mixed at 135 to 155 ° C., preferably for 5 to 30 minutes. The fluidity and mixing efficiency of the binder are higher at a temperature higher than 155 ° C. and the melt mixing is completed in a short time, but the curing reaction proceeds at a higher temperature. At low temperatures, the fluidity decreases, but the curing reaction proceeds slowly. Therefore, a preferable temperature range is 140 to 145 ° C. In this case, the preheating range of the aggregate is preferably 140 to 145 ° C, and the preheating range of the binder is preferably 135 to 140 ° C.
The mixing time is preferably as short as possible within the range allowed by the properties of the product to avoid high viscosity and curing due to polymerization of sulfur and dicyclopentadiene. However, if the mixing time is too short, the binder and the aggregate are not sufficiently mixed, and the resulting material does not become a continuous phase, and a gap is not formed or the surface is not smooth. If the mixing is sufficient, the material becomes a completely continuous phase and the surface is smooth. Therefore, the mixing needs to be determined appropriately in consideration of the performance of the obtained material.
In the first method, in addition to the binder and aggregate, other components can be mixed as desired. In this case, a method of remelting the binder and mixing other components, or a method of mixing other components before cooling in the step (B) can be mentioned.
The mixer used in the first and second methods may be a mixture containing sulfur and dicyclopentadiene as long as it can be mixed in a sealed state, and the other can be mixed sufficiently. If it is, it is not necessary to be able to mix in a sealed state, and preferably for solid-liquid stirring. For example, an internal mixer, a roll mill, a ball mill, a drum mixer, a screw extruder, a pug mill, a poise mixer, a ribbon mixer, a kneader and the like can be used.
The melt mixing of sulfur, dicyclopentadiene and aggregate in step (X) in the second method is performed by simultaneously mixing the aggregate and modifying the sulfur in a sealed state, or by adding sulfur and dicyclopentadiene in the sealed state. It can be carried out by a method comprising the step (X1) of melting and mixing and the step (X2) of mixing the aggregate in the molten mixture of the step (X1) and melting and mixing under specific conditions. Preferable examples of sulfur, dicyclopentadiene and aggregate that can be used in these methods are the same as those described above. Moreover, it is preferable to select the usage-amount of each material suitably from the above-mentioned range. In short, the charging ratio of dicyclopentadiene is usually 0.1 parts by weight or more and less than 2 parts by weight, preferably 1 part by weight or more and less than 2 parts by weight with respect to 100 parts by weight of sulfur. It is desirable to appropriately select the charging ratio of the aggregate so that the weight ratio of the total amount of sulfur and dicyclopentadiene to the amount of aggregate is 1 to 5: 5 to 9.
In the second method, when sulfur, dicyclopentadiene and aggregate are melt-mixed at the same time, the modified sulfur-containing material is produced in one step, unlike the first production method in which the modified sulfur-containing binder is produced in advance. it can. Therefore, in the second method, the production process can be simplified, and even if the melt mixing time is increased, the modified sulfur-containing material can be obtained in a short time as a whole.
In the step (X), the melt mixing is preferably sufficiently stirred or kneaded so that the entire melt has a uniform temperature in a sealed state, the melt temperature is 135 to 155 ° C., and the mixing time is 0.02 to 5 It's time. If the mixing time is less than 0.02 hours, the dicyclopentadiene, sulfur, and aggregate are not sufficiently mixed, and the resulting material does not become a continuous phase, and a gap is not formed or the surface is not smooth. If melt mixing is sufficient, the material is a completely continuous phase and the surface is smooth. On the other hand, when the mixing time exceeds 5 hours, the modification of sulfur proceeds, the viscosity of the modified sulfur increases, and further, it hardens and the workability decreases.
In the step (X), if aggregate is present when sulfur is modified with dicyclopentadiene, it is very difficult to directly measure the progress of the reaction between sulfur and dicyclopentadiene by viscosity. However, the reaction between sulfur and dicyclopentadiene is essentially as described above, and in order to control the reaction, the temperature, mixing method and mixing time must be strictly controlled while predicting the degree of progress of sulfur modification. Can be achieved. For example, the melt mixing temperature and time are 3 to 5 hours at 140 ° C. and 45 to 90 minutes at 150 ° C.
As specific examples of the melt mixing in the sealed state in the step (X), for example, sulfur heated to 125 to 135 ° C and dicyclopentadiene melted at 40 to 50 ° C were preheated to a temperature of 135 to 155 ° C. There is a method in which the mixture is charged almost simultaneously into a closed mixer, and then the aggregate preheated to about 125 to 155 ° C is added and melt mixed at a temperature of 135 to 155 ° C for 0.02 to 5 hours. As a more preferable melt mixing method, a method in which a closed kneader is preheated at 140 to 150 ° C. and melted and mixed at a temperature of 145 to 155 ° C. can be mentioned. The reason why sulfur and dicyclopentadiene are mixed first is that the polymerization reaction of sulfur is not inhibited by the presence of aggregate.
In step (D) or step (Y) of the first or second method, the molten mixture in step (C) or step (X) is cooled to 135 ° C. or lower. The lower limit of the cooling temperature is not particularly limited, and may be about room temperature. In step (D) or step (Y), the modified sulfur-containing material obtained by using a desired mold, granulator, or molding device for cooling is converted into a molded product, pellet, crushed material or granular material in a desired shape. It can be. In the step (D) and the step (Y), in order to avoid excessive increase in the viscosity of the modified sulfur, the temperature is lowered when it reaches a predetermined flow state, and mixing is continued at 120 to 135 ° C. for a while. You may go after.
The granulating apparatus is not particularly limited, and for example, a rolling type apparatus equipped with a drum or an inclined flatbed, or a vibration type apparatus equipped with a horizontal plate or an inclined plate can be used.
When the material obtained by the 1st and 2nd method is made into a granular material, since the intensity | strength of each granular material is high and these particle size adjustment is possible, it is suitable as a construction material and can be used similarly to quarrying. In addition, the material obtained by the first and second methods basically prevents the aggregate from coming into contact with the surrounding water due to the modified sulfur, so that the aggregate is less likely to be directly exposed to the outside. Elution of contained harmful substances can be suppressed to some extent. Therefore, this material does not affect its hardening and optimum water content when mixed with cementitious materials such as cement, concrete, gypsum and the like.
Conventionally, when a cured product is obtained using a cement-based material and incinerated ash, it is hardened by a pozzolanic reaction or a sulfopozzolanic reaction, but it is important to adjust the water content ratio to an optimum value. In particular, when mixing incineration ash from municipal waste with high water absorption, it is very difficult to adjust moisture. For example, when incineration ash from municipal waste is dried and mixed, the incineration ash absorbs moisture from the cementitious mixture, so that moisture is insufficient, and when incineration ash from wet municipal waste is mixed, The water content of the quality mixture becomes excessive, and in any case, the performance as a construction material may be impaired. In addition, since the aggregate containing harmful substances expands when it absorbs moisture, it cannot be used as an aggregate. Since the material obtained by the production method of the present invention can be detoxified even with an aggregate containing harmful substances using modified sulfur, it is extremely useful for recycling the aggregate.
The material obtained in the present invention can be used as a panel material, a flooring material, a wall material, a roof tile, an underwater structure, taking advantage of the characteristics that can be produced in any structure as long as it is a molded body. It can be used as landfill material, roadbed material, embankment material or concrete aggregate.
Example
EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention in detail, this invention is not limited to these. In addition, each measurement and evaluation were performed according to the method shown below about each binding material and molding which were produced in the example. These results are shown in Tables 1-3.
Compressive strength: A cylindrical specimen having a diameter of 5 × 10 cm was prepared and measured using a 30-ton pressurized Tensilon compressive strength measuring instrument on the seventh day after the preparation. The rate at which the specimen contracted before crushing was taken as the strain rate.
Water absorption: A cylindrical specimen having a diameter of 5 × 10 cm is prepared, immersed in water at room temperature for a certain period of time, and then taken out to wipe off moisture on the surface. Thereafter, the weight change was measured, and the weight increase was calculated as the amount of water.
Sulfur oxidation bacterial resistance: NH₄Cl2.0g, KH₂PO₄4.0g, MgCl₂・ 6H₂O0.3g, CaCl₂・ 2H₂O0.3g, FeCl₂・ 4H₂100 ml of a culture solution prepared by adjusting a solution comprising 0.01 g of O and 1.0 L of ion-exchanged water to pH 3.0 with hydrochloric acid and a 2 cm × 2 cm × 4 cm prism sample are placed in a 500 ml baffled flask, and an inoculum (sulfur-oxidizing bacteria: Thiobacillus thiooxidans IFO 12544) was inoculated and then cultured with shaking in a constant temperature room at 28 ° C. (170 rpm), and the pH change and sample state after inoculation were examined. At this time, the decrease in pH means that sulfur was assimilated by sulfur-oxidizing bacteria and sulfate ions were generated.
Flame retardance: Evaluated in accordance with an ignitability test for the evaluation of flammable solids (dangerous goods type 2) in the Fire Service Act. A type 1 combustible solid that ignites within 3 seconds and continues to burn for 10 seconds or more and a type 2 combustible solid that ignites within 10 seconds over 3 seconds and continues to burn “Ignition”, those that ignite for more than 10 seconds, and those that do not continue combustion were designated as “no danger”.
Example 1
995 g of solid sulfur was put in a closed stirring and mixing tank, dissolved at 120 ° C. and kept at 130 ° C. The viscosity at that time was measured with a B-type viscometer and found to be 0.002 Pa · s. Subsequently, 5 g of dicyclopentadiene dissolved by heating at about 50 ° C. was slowly added, and the mixture was gently stirred for about 5 minutes to confirm that there was no temperature rise, and then the temperature was raised to 140 ° C. The reaction started, the viscosity gradually increased, and when the viscosity reached 0.1 Pa · s in about 5 hours, the heating was stopped immediately, poured into an appropriate mold or container, and cooled at room temperature to obtain a binder A. .
Next, the aggregate composed of 670 g of blast furnace slag and 130 g of coal ash preheated at 140 ° C. and the melted material obtained by reheating the binder A200 g to 130 ° C. are almost simultaneously charged into a kneader maintained at 140 ° C. did. Subsequently, the mixture was kneaded for 20 minutes, poured into a cylindrical shape having a diameter of 5 cm and a height of 10 cm, and cooled to prepare a specimen. This specimen is referred to as molded product A.
Example 2
Except that the amount of sulfur was 990 g and the amount of dicyclopentadiene was 10 g, all operations were performed in the same manner as in Example 1 to prepare a binding material B and a molding B corresponding to the binding material A and the molding A.
Example 3
Except that the amount of sulfur was 981 g and the amount of dicyclopentadiene was 19 g, all operations were performed in the same manner as in Example 1 to prepare a binding material C and a molding C corresponding to the binding material A and the molding A.
Comparative Example 1
A binder D and a molding D containing no dicyclopentadiene were prepared in the same manner as in Example 1 except that the amount of sulfur was 1000 g and dicyclopentadiene was not used.
Example 4
199 g of sulfur dissolved by heating to 120 ° C., 1 g of dicyclopentadiene dissolved by heating to about 50 ° C., and an aggregate composed of 670 g of blast furnace slag and 130 g of coal ash preheated at 140 ° C. to 140 ° C. They were charged almost simultaneously into the held closed stirring kneader. After kneading for about 5 minutes, the temperature was raised to 150 ° C. and reached 150 ° C., and then kneaded for 60 minutes. The obtained kneaded product was poured into a cylindrical shape having a diameter of 5.0 cm and a height of 10 cm and cooled to prepare a molded product E as a specimen. The time required for production was 65 minutes.
Example 5
A molding F corresponding to the molding E was prepared in the same manner as in Example 4 except that the amount of sulfur was 198 g and the amount of dicyclopentadiene was 2 g. The time required for production was 65 minutes.
Example 6
A molding G corresponding to the molding E was prepared in the same manner as in Example 4 except that the amount of sulfur was 197 g and the amount of dicyclopentadiene was 3 g. The time required for production was 65 minutes.

From Table 1, the binding materials and molded products obtained in Examples 1 to 6 were higher in compressive strength or better in distortion rate than the binding materials and molded products in Comparative Example 1. Also, the water absorption was very small and good.

From Table 2, it was found that the binders and molded articles obtained in Example 1 and Example 4 had a lower pH drop and higher resistance to sulfur-oxidizing bacteria than the binders and molded articles of Comparative Example 1.

From Table 3, it was found that the sulfur molded products obtained in Examples 1 to 6 were all good without ignitability unlike the sulfur molded product of Comparative Example 1 in which ignitability was observed.
Further, the molded products A to G of the above examples and comparative examples were immersed in a beaker, and the color change was observed after 30 days. As a result, only the solution of the molded product D of Comparative Example 1 was colored yellow, and generation of cloudy water was observed. Each molded product of the example was colorless and transparent, and no change was observed.

Claims

Step (A) in which 100 parts by weight of sulfur and 0.1 part by weight or more and less than 2 parts by weight of dicyclopentadiene are melt-mixed in a sealed state at 135 to 155 ° C., and 140 ° C. of the melt obtained in Step (A) And a step (B) of obtaining a modified sulfur-containing binder by cooling to 135 ° C. or lower after the viscosity in the glass becomes 0.05 to 1.2 Pa · s.

Step (A) in which 100 parts by weight of sulfur and 0.1 part by weight or more and less than 2 parts by weight of dicyclopentadiene are melt-mixed in a sealed state at 135 to 155 ° C., and 140 ° C. of the melt obtained in Step (A) Step (B) for obtaining a modified sulfur-containing binder by cooling to 135 ° C. or less after the viscosity at 0.05 to 1.2 Pa · s, and the modified sulfur-containing binder and bone obtained by step (B) The viscosity of the modified sulfur-containing binder at 140 ° C. is maintained in the range of 0.05 to 1.2 Pa · s at a temperature of 135 to 155 ° C. at a ratio of 1 to 5: 5 to 9 by weight. A process for producing a modified sulfur-containing material, comprising: a step (C) of melting and mixing while a step (D) of cooling the molten mixture of step (C) to 135 ° C. or lower.

Step (X) of melting and mixing sulfur, dicyclopentadiene and aggregate in a sealed state at 135 to 155 ° C. for 0.02 to 5 hours, and step of cooling the molten mixture of step (X) to 135 ° C. or less (Y ) Containing a modified sulfur-containing material.

In step (X), the charge ratio of dicyclopentadiene is 0.1 parts by weight or more and less than 2 parts by weight with respect to 100 parts by weight of sulfur, and the charge ratio of aggregate is the total amount of sulfur and dicyclopentadiene. The method according to claim 3, wherein the weight ratio of the amount of aggregate to the amount of aggregate is 1 to 5: 5 to 9.

Step (X) is a step (X1) in which sulfur and dicyclopentadiene are melt-mixed in a sealed state, and the aggregate is mixed with the molten mixture in step (X1), and the temperature is 135 to 155 ° C. for 0.02 to 5 hours The production method according to claim 4, comprising the step of melt mixing (X2).