JP2004230613A - Method for producing wood plastic material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a wood plastic material using a particle board waste material which can prevent the occurrence of a blister by ammonia gas after molding, can stabilize the shape after the molding, and can eliminate complicated material administration. <P>SOLUTION: The powder A of processed wood, A resin B for melting and mixing, an unsaturated carboxylic acid C, and an ammonia gas adsorbent material D1 are mixed while the resin B is melted with the acid C. The mixture is extrusion-molded to produce the wood plastic material G1. Ammonia gas is produced when the raw materials are heated, melted, and mixed or when the mixed raw materials are extruded. By adsorbing and fixing the ammonia gas by zeolite 60 mixed as the ammonia gas fixing material D1, the ammonia gas is removed from the mixed raw materials. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

すなわち、ポリプロピレンを１８重量％に固定し、マレイン酸を２重量％に固定し、加工木材の粉状体の量を８０，７０，６０，５０，４０重量％と段階的に減らすとともにゼオライトの量を０，１０，２０，３０，４０重量％と段階的に増やした５試験区で、製造されたウッドプラスティックに対して生成ガスによる膨れの有無と、ウッドプラスティックの木質感を相対的に比較している。木質感の欄に記した二重丸◎は木質感が非常に良好であったことを意味し、一重丸○は二重丸◎程ではないが木質感が良好であったことを意味し、三角△は木質感が不十分であったことを意味している。なお、生成ガスによる膨れの有無や木質感は、目視により評価した。
【００３８】
この場合、ゼオライトが１０％以上であると、押出成形時や押出成形後に生成ガスによる膨れが発生せず、ウッドプラスティックの形状を安定させることができた。また、ゼオライトが３０重量％以下であると、ウッドプラスティックの木質感が良好であった。従って、加工木材の粉状体、ポリプロピレン、マレイン酸の合計を９０〜７０重量％とし、ゼオライトを１０〜３０重量％とした試験区２，３，４で、製品として良好なウッドプラスティックを製造することができた。
【００３９】
（２）第二の実施形態：
図４は、本発明の第二の実施形態にかかるウッドプラスティックＧ２の製造方法を工程別に示す概略的な流れ図である。なお、第一の実施形態と構成が同じものについては、同じ符号を付して詳しい説明を省略する。
本実施形態では、第一の実施形態で使用したアンモニアガス吸着材料Ｄ１の代わりに、アンモニウム塩生成材料Ｄ２を使用している。
【００４０】
アンモニウム塩生成材料Ｄ２としては、生成するアンモニアガスと反応してアンモニウム塩を生成可能な種々の材料を採用可能である。本実施形態では、微粒状の明礬（弱塩基の硫酸塩）７０を原料として混合している。
明礬（硫酸アルミニウムカリウム、ＡｌＫ（ＳＯ_４）_２・１２Ｈ_２Ｏ）７０は、アンモニアガスと接すると反応してアンモニウム塩（硫酸アンモニウム、（ＮＨ_４）_２ＳＯ_４）を生成する。すなわち、明礬を原料として混合すると、生成するアンモニアガスと反応してアンモニアガスを減少させる。従って、アンモニアガスは、アンモニウム塩に変化させられ、溶融混合物Ｅ２の構成物質の一部となる。
【００４１】
なお、本発明を適用可能なアンモニウム塩生成材料は、明礬以外にも様々なものがある。
例えば、アンモニウム塩生成材料Ｄ２として、微粒状の硫酸バンド（硫酸カリウム、Ｋ_２（ＳＯ_４））を用いてもよい。硫酸バンドも弱塩基の硫酸塩であるため、この場合であっても、図４で示した流れによりウッドプラスティックＧ２を製造することができる。
アンモニウム塩生成材料Ｄ２として明礬、硫酸カリウムを用いることにより、原料中で生成したアンモニアガスが減少し、混合される原料に加えられる圧力が低下する押出成形時にウッドプラスティックは生成ガスによって膨れない。従って、ウッドプラスティックの押出成形時や押出成形後に生成ガスによる膨れは生じず、成形後の形状を安定させることが可能となる。むろん、アンモニウム塩生成材料に少なくとも明礬が含まれていれば同様の効果が得られ、アンモニウム塩生成材料に少なくとも硫酸バンドが含まれていれば同様の効果が得られる。また、アンモニウム塩生成材料Ｄ２を明礬と硫酸バンドの組み合わせで構成しても、同様の効果が得られる。
【００４２】
原料の配合比については、加工木材の粉状体Ａ、溶融混合用樹脂Ｂ、不飽和カルボン酸Ｃの合計を９０〜７０重量％とし、アンモニウム塩生成材料Ｄ２を１０〜３０重量％とするのが好ましい。不飽和カルボン酸等の添加剤を使用しないときには、加工木材の粉状体Ａと溶融混合用樹脂Ｂの合計を９０〜７０重量％とし、アンモニウム塩生成材料Ｄ２を１０〜３０重量％とするのが好ましい。アンモニウム塩生成材料Ｄ２が１０％以上であると、押出成形時や押出成形後に生成ガスによる膨れが発生せず、製造されるウッドプラスティックＧ２の形状を安定させることができる。また、アンモニウム塩生成材料Ｄ２が３０重量％以下であると、製造されるウッドプラスティックＧ２の木質感を良好にさせることができる。
【００４３】
加工木材の粉状体Ａ、溶融混合用樹脂Ｂ、不飽和カルボン酸Ｃの配合割合は、ウッドプラスティックの用途に応じて適宜決定可能である。木質系成形体に靱性を与え、ビス等の加工を可能にするための好ましい加工木材の粉状体Ａの配合割合は全原料Ａ，Ｂ，Ｃ，Ｄ２に対して５０重量％以上、より好ましくは７０重量％以上である。
全原料を加熱溶融混合させるための溶融混合用樹脂Ｂの好ましい配合割合は全原料Ａ，Ｂ，Ｃ，Ｄ２に対して５重量％以上、より好ましくは１０重量％以上である。溶融混合用樹脂Ｂを加工木材の粉状体Ａと十分に親和させるための好ましい不飽和カルボン酸Ｃの配合割合は全原料Ａ，Ｂ，Ｃ，Ｄ２に対して０．１重量％以上、より好ましくは０．５重量％以上である。なお、溶融混合用樹脂Ｂを１００質量部とするとき、不飽和カルボン酸Ｃの好ましい配合比は５〜５０質量部、より好ましくは１０〜２５質量部である。不飽和カルボン酸Ｃの代わりに酸変性樹脂を使用する場合、溶融混合用樹脂Ｂを加工木材の粉状体Ａと十分に親和させるための好ましい酸変性樹脂の配合割合は全原料に対して０．１重量％以上、より好ましくは０．５重量％以上である。溶融混合用樹脂Ｂを１００質量部とするとき、酸変性樹脂の好ましい配合比は５〜５０質量部、より好ましくは１０〜２５質量部である。
各原料Ａ〜Ｃの重量割合は、ウッドプラスティックに要求される性質に応じて適宜好ましい比率を選択可能である。
【００４４】
以上説明したように、ポリオレフィン樹脂２０（溶融混合用樹脂）はマレイン酸３０（不飽和カルボン酸）とともに加熱溶融され、加工木材の粉状体Ａ、明礬７０（アンモニウム塩生成材料）と混合される。生成するアンモニアガスは、混合された原料に含まれる明礬７０と反応してアンモニウム塩を生成する。すると、アンモニアガスが減少するので、混合された原料に加えられる圧力が低下する押出成形時にウッドプラスティックは生成ガスによって膨れない。従って、煩雑な原料選別作業や原料管理を行わなくても、成形されたウッドプラスティックの形状を安定させることが可能となる。
【００４５】
また、明礬は弱塩基の硫酸塩であるため、酸性であり、生成するアンモニアガスと反応してアンモニウム塩を生成する。すなわち、比較的多量のアンモニアガスと反応してアンモニウム塩を生成する。これにより、混合するアンモニア塩生成材料を少量とすることができ、混合された原料から確実に効率よくアンモニアガスを減少させてウッドプラスティックの押出成形時や押出成形後に生成ガスによる膨れが発生することを防止することができる。明礬の代わりに硫酸バンドも用いた場合も同様である。
【００４６】
表２は、アミノ樹脂を用いた加工木材の粉状体としてパーティクルボード廃材を粉砕した粉状体を用い、溶融混合用樹脂として粒状のポリプロピレンを用い、添加剤として粉末状のマレイン酸を用い、アンモニウム塩生成材料として微粒状の明礬を用いてウッドプラスティックを製造し、評価した実施例２を示している。なお、試験条件は第一の実施形態と同じにした。
【表２】

すなわち、ポリプロピレンを１８重量％に固定し、マレイン酸を２重量％に固定し、加工木材の粉状体の量を８０，７０，６０，５０，４０重量％と段階的に減らすとともに明礬の量を０，１０，２０，３０，４０重量％と段階的に増やした５試験区で、製造されたウッドプラスティックに対して生成ガスによる膨れの有無と、ウッドプラスティックの木質感を相対的に比較している。
【００４７】
この場合、明礬が１０％以上であると、押出成形時や押出成形後に生成ガスによる膨れが発生せず、ウッドプラスティックの形状を安定させることができた。また、明礬が３０重量％以下であると、ウッドプラスティックの木質感が良好であった。従って、加工木材の粉状体、ポリプロピレン、マレイン酸の合計を９０〜７０重量％とし、明礬を１０〜３０重量％とした試験区２，３，４で、製品として良好なウッドプラスティックを製造することができた。
【００４８】
表３は、アンモニウム塩生成材料として明礬の代わりに微粒状の硫酸バンドを用いてウッドプラスティックを製造し、評価した実施例３を示している。なお、試験条件は第一の実施形態と同じにした。
【表３】

すなわち、ポリプロピレンを１８重量％に固定し、マレイン酸を２重量％に固定し、加工木材の粉状体の量を８０，７０，６０，５０，４０重量％と段階的に減らすとともに硫酸バンドの量を０，１０，２０，３０，４０重量％と段階的に増やした５試験区で、製造されたウッドプラスティックに対して生成ガスによる膨れの有無と、ウッドプラスティックの木質感を相対的に比較している。
【００４９】
この場合、硫酸バンドが１０％以上であると、押出成形時や押出成形後に生成ガスによる膨れが発生せず、ウッドプラスティックの形状を安定させることができた。また、硫酸バンドが３０重量％以下であると、ウッドプラスティックの木質感が良好であった。従って、加工木材の粉状体、ポリプロピレン、マレイン酸の合計を９０〜７０重量％とし、硫酸バンドを１０〜３０重量％とした試験区２，３，４で、製品として良好なウッドプラスティックを製造することができた。
【００５０】
（３）第三の実施形態：
次に、ウッドプラスティック製造装置に関する第三の実施形態について説明する。本実施形態では、図２で示した手順で、アンモニアガス吸着材料やアンモニウム塩生成材料を使用せずにウッドプラスティックを製造する。
本実施形態のウッドプラスティック製造装置も、概略、図３で示した加熱混合機４１、押出機４２、切断機４３を備えている。
【００５１】
図５は、押出機４２を一部垂直断面にて断面視して示す側面図である。加熱混合機４１により２００℃前後で加熱溶融混合された原料が、押出機４２の内部空間４２ａに流れ込む。図の押出機４２では、加熱溶融混合された原料が左側から押出機の内部空間４２ａに流入し、同内部空間４２ａの中に配設されたスクリュー４５の回転により右方向へ押し出される。この押出機４２では、流入する溶融混合物Ｅを改めて加熱しながら、スクリュー４５を駆動させることにより板状に押し出す。
【００５２】
ここで、加工木材の粉状体Ａに尿素系樹脂が含まれていると、加工木材の粉状体Ａを加熱した際に、尿素系樹脂が分解されてアンモニアガス１４が発生することがある。このアンモニアガス１４は、ウッドプラスティックが形成された時などにウッドプラスティックの表面に膨らみを発生させる原因となる。そこで、ウッドプラスティック製造装置４０に真空脱気装置５０を設けることにより、アンモニアガス１４を効率よく除去して生成ガスによるウッドプラスティックの膨れを防止するようにしている。
【００５３】
押出機４２には、内部空間４２ａと繋がるように上側に開口された排気口４４ａと、下側に向けられた調圧口４４ｂとが設けられている。排気口４４ａの上端には、真空脱気装置５０の吸引口５０ａに連結された脱気用ホース５２が取り付けられている。
【００５４】
真空脱気装置５０が駆動されると、吸引口５０ａから空気が吸い込まれ、排気口４４ａと脱気用ホース５２を介して押出機の内部空間４２ａの空気が吸引されて排出される。従って、溶融混合物Ｅから発生されたアンモニアガス１４は、排気口４４ａから排出される。
【００５５】
押出機４２の内圧は、空気を内部空間４２ａに吸入可能な調圧口４４ｂにより、大気圧と略等圧となるように維持されている。排気口４４ａには逆流防止弁４４ｃが配設されており、同逆流防止弁４４ｃは内部空間４２ａへの空気の逆流を防止している。また、排気口４４ａにはフィルタ４４ｄが設けられており、排気口４４ａからは気体だけが排出可能な構造となっている。
【００５６】
このようにして、アミノ樹脂を用いた加工木材の粉状体Ａと、加熱溶融可能な溶融混合用樹脂Ｂと、不飽和カルボン酸Ｃとを、溶融混合用樹脂Ｂを不飽和カルボン酸Ｃとともに加熱溶融させながら混合し、脱気しつつ押し出し、成形してウッドプラスティックＧを製造する。押し出しの際に溶融混合物Ｅから脱気されるので、生成するアンモニアガスは吸引されて除去される。従って、混合された原料に加えられる圧力が低下する成形時にウッドプラスティックは生成ガスによって膨れない。これにより、煩雑な原料選別作業や原料管理を行わなくても、ウッドプラスティックの成形時や成形後に生成ガスによる膨れを防止して、成形されたウッドプラスティックの形状を安定させることが可能となる。
【００５７】
なお、図による説明を省略するが、加熱混合機４１を密閉可能な構造とし、真空脱気装置を同加熱混合機に設けてもよい。真空脱気装置を加熱混合機４１に配設すると、加工木材の粉状体Ａと、溶融混合用樹脂Ｂと、不飽和カルボン酸Ｃとを、溶融混合用樹脂Ｂを不飽和カルボン酸Ｃとともに加熱溶融させながら脱気しつつ混合し、押出成形してウッドプラスティックＧを製造することになる。すると、加熱溶融混合中の溶融混合物Ｅから発生されたアンモニアガスは同真空脱気装置に吸引されて外部へ排出され、溶融混合物Ｅから除去される。
【００５８】
このように、混合または押し出しを脱気しつつ行うことにより、原料中で生成したアンモニアガスが除去され、混合される原料に加えられる圧力が低下する成形時にウッドプラスティックは生成ガスによって膨れない。従って、ウッドプラスティックの成形時や成形後に生成ガスによる膨れは生じず、ウッドプラスティックの形状を安定させることが可能となる。むろん、混合と押し出しの両工程で脱気を行うと、より確実にアンモニアガスを除去して生成ガスによる膨れを防止することが可能となり、さらにウッドプラスティックの形状を安定させることが可能となる。
【００５９】
なお、混合や押し出しの処理回数を増やしたり処理速度を遅らせたりするほど、溶融混合物から発生するアンモニアガスの排出量が増える。そこで、押出機４２から溶融混合物を成形せずに押し出し、押し出した溶融混合物を再び加熱混合機４１に投入する作業を所定の回数繰り返してもよい。加熱混合機４１にて原料を加熱溶融混合した後に押出機４２にて溶融混合物を押し出す処理を繰り返す回数は、溶融混合物の物性等に応じて適宜設定すればよく、例えば４〜５回程度とすることができる。
混合や押し出しを所定の回数繰り返し行うことにより、アンモニアガスの発生量を増加させ、混合物中のアンモニアガスの発生原因物質を減少させる。これにより、より確実に混合された原料から効率よくアンモニアガスを減少させてウッドプラスティックの成形時や成形後に生成ガスによる膨れを防止して、さらにウッドプラスティックの形状を安定させることが可能となる。
【００６０】
むろん、押出機４２では、加熱しながらスクリュー４５によって押し出す押し出し工程を通常の処理時間よりも長めに行ってもよい。
【００６１】
なお、真空脱気装置は、加熱混合機４１と押出機４２のいずれか一方のみに配設されていてもよいし、両方に配設されていてもよい。さらに、加熱混合機４１での加熱溶融混合の処理時間を長くしたり、あるいは処理回数を増やしたり、押出機４２での押し出しの処理時間を長くしたり、これらを組み合わせることにより、真空脱気装置によるアンモニアガスの除去効果をさらに高めることができる。
【００６２】
上記の方法によって作成されたウッドプラスティック中には、アンモニアガスがほとんど含まれていない。従って、ウッドプラスティックが押出機４２から排出される際にウッドプラスティックの表面が膨れることはなく、実際にウッドプラスティックが使用される場合に加熱されるようなことが起きても、ウッドプラスティックの表面に膨れができるようなこともない。
【００６３】
また、さらに、第三の実施形態に記載したウッドプラスティック製造装置に第一の実施形態に記載のゼオライトを投入したり、第二の実施形態に記載の明礬７０を投入したりすれば、ガス状態のアンモニアの含有量がさらに低減され、形状変化の発生がさらに確実に防止された信頼性の高いウッドプラスティックを製造することが可能となる。
以上説明したように、本発明によると、種々の態様により、煩雑な原料選別作業や原料管理を行う必要がなく、ウッドプラスティックの押出成形時や押出成形後に生成ガスによる膨れが発生することを防止して、成形されたウッドプラスティックの形状を安定させることが可能となる。
【図面の簡単な説明】
【図１】本発明の第一の実施形態にかかるウッドプラスティックの製造方法を示す概略的な流れ図である。
【図２】従来の構成でウッドプラスティックを製造する様子を示す概略的な流れ図である。
【図３】ウッドプラスティック製造装置とウッドプラスティックの製造方法を模式的に示す図である。
【図４】本発明の第二の実施形態にかかるウッドプラスティックの製造方法を示す概略的な流れ図である。
【図５】第三の実施形態において、押出機を一部垂直断面にて断面視して示す側面図である。
【符号の説明】
Ａ…加工木材の粉状体
Ｂ…溶融混合用樹脂
Ｃ…不飽和カルボン酸
Ｄ１…アンモニアガス吸着材料
Ｄ２…アンモニウム塩生成材料
Ｅ，Ｅ１，Ｅ２…溶融混合物
Ｇ，Ｇ１，Ｇ２…ウッドプラスティック
ｇ…生成ガス
１４…アンモニアガス
２０…ポリオレフィン樹脂
３０…マレイン酸
４０…ウッドプラスティック製造装置
４１…加熱混合機
４２…押出機
４２ａ…内部空間
４３…切断機
４４ａ…排気口
４４ｂ…調圧口
４４ｃ…逆流防止弁
４４ｄ…フィルタ
４５…スクリュー
５０…真空脱気装置
５０ａ…吸引口
５２…脱気用ホース
６０…ゼオライト（多孔質無機材料）
７０…明礬（弱塩基の硫酸塩）[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a wood plastic using a resin for melting and mixing which can be heated and melted.
[0002]
[Prior art]
BACKGROUND ART Conventionally, wood plastic has been manufactured by mixing wood powder and a thermoplastic resin while heating and melting the thermoplastic resin to form a mixture. Further, as disclosed in Patent Document 1, a woody waste, a polyolefin, maleic acid, etc. are mixed, mechanically pulverized while heating, and granulated while cooling to form a woody composition for molding. Techniques for doing so are also known.
[0003]
[Patent Document 1]
JP 2002-225011 A
[0004]
[Problems to be solved by the invention]
When crushing waste materials of particle board processed using urea resin (urea), and trying to manufacture wood plastic from the crushed waste materials and thermoplastic resin, the thermoplastic resin is heated and melted and mixed. During extrusion molding, ammonia gas may be generated from the urea resin. Then, there is a problem that the wood plastic swells due to the generated gas at the time of extrusion molding in which the pressure applied to the mixed raw materials is reduced, the shape becomes unstable, and the value as a product is reduced.
In addition, it is conceivable to separate and remove the particleboard waste material using the urea resin from the waste material of the processed wood, but it is not practical because the sorting operation takes too much time. In addition, it is conceivable to manage so as not to mix particle board waste materials using urea resin, but the management becomes complicated and this is not practical.
[0005]
The present invention has been made in view of the above problems, and eliminates the need for complicated raw material selection work and raw material management, and prevents swelling due to generated gas during or after extrusion of wood plastic. It is an object of the present invention to provide a method for manufacturing a wood plastic which can prevent the shape after molding and stabilize the shape after molding.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, the invention according to claim 1 is a method for producing a wood plastic using a powdery material of processed wood using an amino resin and a resin for melting and mixing that can be heated and melted, The powdered material of the processed wood, the resin for melting and mixing, and the ammonia gas adsorbing material capable of adsorbing ammonia gas are mixed while heating and melting the resin for melting and mixing, and extruded to form the wood plastic. It is configured to be manufactured.
That is, the resin for melting and mixing is heated and melted and mixed with the powdered material of the processed wood and the ammonia gas adsorbing material. The mixed raw materials are extruded and made into wood plastic. At that time, since a powdered material of the processed wood using the amino resin is used, it is not necessary to perform a sorting operation of the processed wood, and it is not necessary to manage a raw material of the processed wood.
Since the processed wood uses an amino resin, ammonia gas may be generated when mixed with the melt-mixing resin heated and melted. Here, the ammonia gas adsorbing material contained in the raw materials to be mixed adsorbs the generated ammonia gas. Therefore, the wood plastic does not swell due to the generated gas during extrusion molding in which the pressure applied to the mixed raw materials decreases. Accordingly, it is possible to prevent the swelling due to the generated gas from occurring during or after extrusion of the wood plastic, and to stabilize the shape after the molding.
[0007]
As the amino resin to which the present invention can be applied, various resins such as a urea resin, a melamine resin, and a benzoguanamine resin can be considered as long as the resin generates an ammonia gas when the thermoplastic resin is heated and melted.
The processed wood may be any wood processed using an amino resin, and various types of wood such as particle board waste and plywood processed using a urea resin are conceivable. Further, the processed wood may be in the form of a powder, and even a granular or fibrous material is included in the powder according to the present invention. The strength of the wood plastic can be adjusted by adjusting the grain size of the processed wood.
The resin for melting and mixing may be any resin as long as it can be heated and melted, and various resins can be considered. For example, when a thermoplastic resin such as a polyolefin resin is used, the melt-mixing resin can be easily mixed while being heated and melted (hereinafter, also referred to as heat-melt mixing). Of course, it is possible to heat-melt and mix the raw materials even with a thermosetting resin. Further, the resin for melt mixing may be a single material or a plurality of materials.
A step of pulverizing the processed wood into a powder may be provided. Then, wood plastic can be manufactured using processed wood that is not a powdery material, and convenience is improved.
Various shapes such as a substantially plate shape and a pellet shape can be considered for the manufactured wood plastic.
[0008]
The ammonia gas adsorbing material may be configured to be a porous inorganic material. That is, the generated ammonia gas is adsorbed from many pores of the porous inorganic material. Since a porous inorganic material has a large surface area, a relatively large amount of ammonia gas can be adsorbed than a nonporous inorganic material. As a result, the amount of the ammonia gas adsorbing material to be mixed can be reduced to a small amount, and the ammonia gas can be efficiently adsorbed from the mixed raw material to prevent swelling due to the generated gas during or after extrusion of the wood plastic. can do.
[0009]
The above-mentioned porous inorganic material may be configured to be a zeolite. The zeolite has a function of selectively adsorbing and fixing a gas such as ammonia gas. Therefore, this zeolite takes in and fixes the ammonia gas generated in the mixture into the pores. As a result, the amount of the porous inorganic material to be mixed can be further reduced, and the ammonia gas can be more efficiently adsorbed to prevent swelling due to the generated gas during or after extrusion of the wood plastic. it can.
[0010]
By the way, as in the invention according to claim 4, a method for producing a wood plastic using a powdery material of processed wood using an amino resin and a resin for melting and mixing which can be heated and melted, And a melt-mixing resin, and an ammonium salt-forming material capable of reacting with ammonia gas to form an ammonium salt, while mixing and melting the resin for melt-mixing, and extruding the mixture. It is good also as a structure which manufactures a wood plastic.
That is, the melt-mixing resin is heated and melted, and mixed with the powdered material of the processed wood and the ammonia salt-forming material. The mixed raw materials are extruded and made into wood plastic. At that time, since a powdered material of the processed wood using the amino resin is used, it is not necessary to perform a sorting operation of the processed wood, and it is not necessary to manage a raw material of the processed wood.
Here, the ammonia salt generating material contained in the raw materials to be mixed reacts with the generated ammonia gas to generate an ammonium salt. Therefore, the wood plastic does not swell due to the generated gas during extrusion molding in which the pressure applied to the mixed raw materials decreases. Accordingly, it is possible to prevent the swelling due to the generated gas from occurring during or after extrusion of the wood plastic, and to stabilize the shape after the molding.
[0011]
The ammonium salt producing material may be a sulfate of a weak base. Since sulfuric acid is a strong acid, the sulfate of a weak base is acidic, and the generated ammonia gas reacts with the sulfate of the weak base to form an ammonium salt. Therefore, it can react with a relatively large amount of ammonia gas to produce an ammonium salt. This makes it possible to reduce the amount of ammonia salt-forming material to be mixed, and to efficiently reduce ammonia gas from the mixed raw material to prevent swelling due to generated gas during or after extrusion of wood plastic. can do.
[0012]
The above-mentioned sulfate may be configured to contain at least alum. Further, the sulfate may be configured to include at least a sulfate band. The alum and sulfate bands have the effect of reacting with ammonia gas to produce ammonia salts. Therefore, the ammonia gas is converted into an ammonia salt and decreases. As a result, the amount of sulfate to be mixed can be reliably reduced to a small amount, and ammonia gas can be reliably and efficiently converted to ammonium salt to prevent swelling due to generated gas during or after extrusion of wood plastic. can do.
[0013]
By the way, as in the invention according to claim 8, a powdered material of processed wood using an amino resin and a resin for melting and mixing that can be melted by heating are mixed while heating and melting the resin for melting and mixing, and extruded. A method of manufacturing a wood plastic by forming a wood plastic, wherein at least one of the mixing and the extrusion may be performed while degassing.
That is, the resin for melting and mixing is heated and melted and mixed with the powdered material of the processed wood. The mixed raw materials are extruded, molded and made into a plastic. At that time, since a powdered material of the processed wood using the amino resin is used, it is not necessary to perform a sorting operation of the processed wood, and it is not necessary to manage a raw material of the processed wood.
Here, since at least one of mixing and extrusion is degassed, the generated ammonia gas is removed by suction. Therefore, the wood plastic does not swell due to the generated gas during molding when the pressure applied to the mixed raw materials is reduced. Thereby, it is possible to prevent the swelling due to the generated gas from occurring during or after the molding of the wood plastic, and to stabilize the shape after the molding.
[0014]
At least one of the mixing and the extrusion performed while degassing may be repeatedly performed a predetermined number of times. By repeating mixing and extrusion a predetermined number of times, the amount of ammonia gas generated is increased, and the amount of ammonia gas-causing substances in the mixture is reduced. As a result, ammonia gas can be efficiently reduced from the mixed raw material more efficiently, and swelling due to the generated gas can be prevented during or after molding of the plastic.
[0015]
In any of the above configurations, as in the invention according to claim 10, a predetermined acid for imparting a hydrophilic group is added to the melt-mixing resin, mixed and extruded to produce the wood plastic. Is also good. That is, the added predetermined acid imparts a hydrophilic group to the melt-mixing resin. Then, the resin for melting and mixing and the powdery material of the processed wood can be easily blended, so that the strength of the wood plastic can be further improved.
Further, the resin for melting and mixing may include a resin modified with a predetermined acid. That is, the resin modified with the predetermined acid and the powder of the processed wood become easily compatible with each other, so that the strength of the wood plastic can be further improved.
Here, the predetermined acid may be any acid that imparts a hydrophilic group to the resin, and for example, various acids such as maleic acid can be used.
[0016]
【The invention's effect】
As described above, according to the first, fourth, and eighth aspects of the present invention, there is no need to perform complicated raw material selection work and raw material management. It is possible to provide a method for manufacturing a wood plastic capable of preventing the occurrence of swelling due to swelling and stabilizing the shape after molding.
According to the second, fifth, and ninth aspects of the present invention, the generated ammonia gas can be efficiently reduced to prevent swelling due to the generated gas, and the shape after molding can be stabilized.
According to the third aspect of the present invention, the ammonia gas can be more efficiently reduced to prevent swelling due to the generated gas, and the shape after molding can be stabilized.
According to the inventions according to claims 6 and 7, it is possible to reliably and efficiently reduce ammonia gas, prevent swelling due to generated gas, and stabilize the shape after molding.
According to the tenth aspect, it is possible to improve the strength of a wood plastic manufactured by extrusion.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in the following order.
(1) First embodiment:
(2) Second embodiment:
(3) Third embodiment:
[0018]
(1) First embodiment:
FIG. 1 is a schematic flowchart showing a method of manufacturing a wood plastic G1 according to the first embodiment of the present invention for each process.
[0019]
When manufacturing a wood plastic, first, a powder A of processed wood, a resin B for melting and mixing, an additive C, and an ammonia gas adsorbing material D1 are charged into the wood plastic manufacturing apparatus 40 (step S10). Next, the raw materials A, B, C, and D1 are mixed while the resin B for melting and mixing is heated and melted to change into a molten mixture E1 (step S11). Then, the molten mixture E1 is extruded while applying pressure (step S12), and is discharged out of the apparatus 40 (step S13), whereby the wood plastic G1 is manufactured.
[0020]
The powder A of the processed wood is obtained by pulverizing waste materials discharged from the particle board manufacturing process. Particleboard refers to processed wood formed by impregnating a synthetic resin adhesive made of urea resin, phenolic resin, urea melamine co-condensation resin, etc. into fine-grained wood flour made of plant fiber and solidifying it to form a plate. Say. In the present embodiment, urea resin, which is an amino resin produced by condensation polymerization of a compound containing an amino group and an aldehyde, urea melamine co-condensation resin, and the like, crushed particleboard waste material using a urea-based resin such as It is powder A.
[0021]
Particleboard is commonly used in homes, furniture factories, and any other scene.If wood chips are generated in these scenes, if such chips are collected, they can be used as a powder of processed wood in the present invention. it can. In addition, a large amount of waste material is generated after the particle board is used as a raw material for furniture, building materials, and the like. Such waste material may be pulverized. Further, when furniture and building materials are discarded, the waste may be crushed. According to such a configuration, the cost of the wood plastic is very low, and it can greatly contribute to reducing garbage, and can promote waste recycling.
[0022]
Various diameters can be adopted as the particle diameter of the powder A, and any particle diameter may be used as long as the powder A can be bound by the resin B for melt mixing. When the powder A is further pulverized, the strength of the wood plastic G1 can be improved.
In addition, what grind | pulverized the plywood etc. which used the amino resin may be used as the powdery substance A of processed wood.
[0023]
A urea-based resin is a kind of synthetic resin-based adhesive obtained by condensation polymerization of urea or the like with formaldehyde or a formaldehyde polymer and has a strong adhesive action. Then, it may be gradually hydrolyzed at room temperature to generate formaldehyde, or may be heated to generate ammonia gas.
[0024]
Various resins that can be heated and melted can be used as the melt-mixing resin B. For example, polypropylene, polyethylene, polystyrene, polymethyl methacrylate, vinyl chloride, nylon, polycarbonate, polyacetal, polybutylene terephthalate, polyethylene terephthalate, Etc. can be used. Of course, a thermosetting resin such as a phenol resin, a urea resin, a melamine resin, an unsaturated polyester resin, and an epoxy resin can also be used. Further, a plurality of these resins may be used in combination. Further, when it is charged into the wood plastic manufacturing apparatus 40, it may be charged as a solid raw material or may be charged in a molten state.
In the present embodiment, the polyolefin resin 20 which is a granular polymer is used. Of course, as the polyolefin resin, any shape may be used as long as it can be mixed with a powdered material of processed wood or the like. The polyolefin resin melts when heated, and binds the plant fibers contained in the powdered material of the processed wood. Therefore, when mixed with the powdered material A of the processed wood, the polyolefin resin 20 plays a role as a binder that binds the powdered materials A of the processed wood.
[0025]
The powdered material A of the processed wood having a strong hydrophilic property and the resin B for melting and mixing having a strong hydrophobic property tend to be hardly mixed due to low compatibility. Therefore, in order to impart hydrophilicity to the resin B for melt mixing, the additive C is a predetermined unsaturated carboxylic acid (predetermined acid). In the present embodiment, maleic acid 30 is added as unsaturated carboxylic acid C. When maleic acid is added to a resin for melt mixing and heated, it undergoes addition polymerization with the resin. Then, a carboxyl group, which is one of the hydrophilic groups, is added to the melt-mixing resin after the addition polymerization. Therefore, the resin for melt-mixing easily becomes compatible with the hydroxyl group and the like, and the powder A of the processed wood and the resin B for melt-mixing are easily mixed. Of course, the acid that modifies the melt-mixing resin is not limited to maleic acid.
Note that, instead of the unsaturated carboxylic acid C, an acid-modified resin obtained by modifying the melt-mixing resin with a predetermined acid such as maleic acid may be added. Needless to say, the acid that modifies the resin for melt mixing is not limited to maleic acid, and an acid-modified resin obtained by modifying a resin different from the resin B for melt mixing may be used. The acid-modified resin occupying the total weight of the melt-mixing resin B and the acid-modified resin may have various compounding ratios of, for example, 1 to 50% by weight. Further, the acid-modified resin may be used as the melt-mixing resin B without adding an additive separately.
[0026]
As shown in FIG. 2, while the resin B for melting and mixing is heated and melted together with the unsaturated carboxylic acid C, the powder A of the processed wood, the resin B for melting and mixing, and the unsaturated carboxylic acid C are mixed and extruded. When the wood plastic G is manufactured, ammonia gas may be generated from the urea resin contained in the particleboard waste material. Then, there is a problem that the wood plastic G swells due to the generated gas g at the time of extrusion molding in which the pressure applied to the mixed raw materials decreases, the shape becomes unstable, and the value as a product decreases. FIG. 2 schematically shows a state in which the surface of the wood plastic G swells due to the generated ammonia gas.
If the mixing and extrusion of the raw materials are performed slowly over a long period of time, no ammonia gas is generated, but it takes too much time and is not practical. It is also conceivable to select and remove particle board waste using urea resin from the waste wood of processed wood, or to manage so that particle board waste using urea resin does not mix. It is not practical because it takes too much and management becomes complicated.
Therefore, by mixing the ammonia gas-adsorbing material D1 capable of adsorbing ammonia gas as a raw material, swelling due to gas generated during or after extrusion of wood plastic can be performed without the need for complicated raw material selection work and raw material management. This prevents the occurrence and stabilizes the shape after molding.
[0027]
As the ammonia gas adsorbing material D1, various materials capable of adsorbing generated ammonia gas can be adopted. In this embodiment, fine zeolite (fine porous inorganic material) 60 is mixed as a raw material.
The zeolite 60 is made of silicon dioxide, aluminum oxide, or the like, and has a porous structure having a myriad of fine holes with stable shapes. The zeolite 60 has a function of selectively adsorbing and fixing a predetermined gas such as water vapor or ammonia gas inside the pores. That is, the ammonia gas generated from the molten mixture E1 obtained by heating and melting the zeolite 60 is adsorbed and fixed to the zeolite 60.
As a result, the ammonia gas is adsorbed and fixed to the zeolite 60, and becomes a part of the constituent material of the molten mixture E1 in the zeolite 60. When a calcium zeolite is used as the zeolite 60, the ammonia gas adsorption capacity is further increased.
[0028]
In addition, the fine zeolite can have various particle diameters depending on the application, but in order to find more suitable conditions, various tests were performed by changing the particle size of the zeolite, and when the particle size was reduced to 500 μm or less, It was possible to produce a very good quality wood plastic with a good wood texture.
Of course, activated carbon or the like may be used as the fine-grained porous inorganic material used as the ammonia gas adsorbing material as long as the material can adsorb and fix ammonia gas.
[0029]
FIG. 3 schematically illustrates a method of manufacturing the wood plastic manufacturing apparatus 40 and the wood plastic G1.
The raw materials A, B, C, and D1 are charged into the heating mixer 41 and mixed while being heated. The heating mixer 41 has a substantially cylindrical shape whose diameter gradually decreases downward, and includes a heater, a stirrer, a screw, and the like (not shown). Then, the charged raw material is heated by a heater, and mixed while stirring the raw material by a stirrer, and the mixed raw material is extruded downward by a screw. In the heating mixer 41, a mixture of the raw materials A, B, C, and D1 is heated to about 200 ° C. and kneaded with each other to generate a molten mixture E1.
Here, the heater only needs to be able to raise the temperature to melt the resin B for melting and mixing, and the heating capacity of the heater may be determined according to the type of the resin B for melting and mixing. When the heating of the heater is set so that the temperature of the raw material is higher than the melting point of the resin for melting and mixing, the powder of the processed wood does not carbonize, and is lower than the melting point of the ammonia gas adsorbing material, the powder of the processed wood Is not carbonized, and the raw material can be heated and melt-mixed without melting the ammonia gas adsorbing material.
Further, the capacity of the stirrer and the screw may be determined according to properties such as the viscosity of the raw material.
[0030]
Regarding the compounding ratio of the raw materials, the total of the powder A of the processed wood, the resin B for melting and mixing, and the unsaturated carboxylic acid C is 90 to 70% by weight, and the ammonia gas adsorbing material D1 is 10 to 30% by weight. Is preferred. When an additive such as an unsaturated carboxylic acid is not used, the total of the powder A of the processed wood and the resin B for melting and mixing is 90 to 70% by weight, and the ammonia gas adsorbing material D1 is 10 to 30% by weight. Is preferred. When the amount of the ammonia gas adsorbing material D1 is 10% or more, swelling due to a generated gas does not occur at the time of extrusion molding or after extrusion molding, and the shape of the produced wood plastic G1 can be stabilized. When the amount of the ammonia gas adsorbing material D1 is 30% by weight or less, the wood texture of the manufactured wood plastic G1 can be improved.
[0031]
The mixing ratio of the powder A of the processed wood, the resin B for melting and mixing, and the unsaturated carboxylic acid C can be appropriately determined depending on the use of the wood plastic. In general, when the amount of the powdered material A of the processed wood is large, the deformation due to the temperature change is small, the weight is reduced, and the feeling of wood is improved. On the other hand, when the amount of the resin B for melting and mixing is large, the fluidity of the heat-softened material is large, and the produced wood plastic has high mechanical performance, which means strength, and has improved water resistance. In order to impart toughness to the wood-based molded product and to enable processing of screws and the like, the mixing ratio of the powdered material A of the processed wood is preferably 50% by weight or more based on all the raw materials A, B, C, and D1. It is more preferably at least 70% by weight.
[0032]
The preferred mixing ratio of the resin B for melting and mixing all the raw materials is 5% by weight or more, more preferably 10% by weight or more, based on all the raw materials A, B, C and D1. A preferable mixing ratio of the unsaturated carboxylic acid C for making the resin B for melt mixing sufficiently compatible with the powder A of the processed wood is 0.1% by weight or more based on all the raw materials A, B, C and D1. It is preferably at least 0.5% by weight. When the amount of the resin B for melting and mixing is 100 parts by mass, a preferable mixing ratio of the unsaturated carboxylic acid C is 5 to 50 parts by mass, more preferably 10 to 25 parts by mass. When an acid-modified resin is used in place of the unsaturated carboxylic acid C, a preferable mixing ratio of the acid-modified resin for making the resin B for melting and mixing sufficiently compatible with the powdered material A of the processed wood is 0 with respect to all raw materials. 0.1% by weight or more, more preferably 0.5% by weight or more. When the amount of the resin B for melt mixing is 100 parts by mass, a preferable compounding ratio of the acid-modified resin is 5 to 50 parts by mass, more preferably 10 to 25 parts by mass.
The weight ratio of each of the raw materials A to C can be appropriately selected according to the properties required for the wood plastic.
[0033]
The resin B for melting and mixing supplied to the heating mixer 41 is heated and melted, and is mixed with the powdered material A of the processed wood, the unsaturated carboxylic acid C, and the ammonia gas adsorbing material D1. Although the processed wood is hydrophilic, the resin B for melt mixing is given a hydrophilic carboxyl group by the unsaturated carboxylic acid C, so that it easily permeates into the powder A of the hydrophilic processed wood. That is, the unsaturated carboxylic acid plays a role of bridging the resin for melting and mixing with the powdery material of the hydrophilic processed wood. Therefore, even if the melt-mixing resin is a hydrophobic resin such as a polyolefin resin, the melt-mixing resin is converted into a hydrophilic processed wood by using a resin having a hydrophilic group provided by a predetermined acid. It becomes possible to adhere firmly to the powder.
[0034]
Further, since the powdery material of the processed wood has a hydroxyl group or the like, the affinity with the resin is improved by a hydrophilic group such as a carboxyl group contained in the acid-modified resin.
Since the raw materials mixed by the heating mixer 41 are formed into a fluid, they are extruded downward and flow into the extruder 42. The present extruder 42 includes a screw (not shown), and extrudes the mixed raw material into a plate shape. In the figure, the mixed raw materials are continuously extruded rightward. Of course, it may be formed into a pellet and extruded. Then, the mixed raw material before solidification is cut by the cutting machine 43 attached to the material outlet of the extruder 42. In this manner, the raw materials mixed while heating and melting the resin for melting and mixing can be formed into a predetermined shape.
Then, when the cut mixed raw material is cooled, the mixed raw material is solidified to become a wood plastic G1. Here, in order to solidify the formed mixed raw material, the mixed raw material may be naturally cooled on a belt conveyor, or may be forcibly cooled, such as air cooling or water cooling, in order to improve production efficiency. You may make it.
[0035]
As described above, the polyolefin resin 20 (melt-mixing resin) is heated and melted together with the maleic acid 30 (unsaturated carboxylic acid), and mixed with the powder A of the processed wood and the zeolite 60 (ammonia gas-adsorbing material). . Since the processed wood uses a urea-based resin, ammonia gas may be generated when mixed with the heated and melted polyolefin resin 20. The produced ammonia gas is adsorbed and fixed on zeolite 60 contained in the mixed raw material. Then, the wood plastic does not swell due to the produced gas at the time of extrusion molding in which the pressure applied to the mixed raw materials is reduced. Therefore, it is possible to stabilize the shape of the formed wood plastic without performing complicated raw material selection work and raw material management.
[0036]
Further, since the added zeolite has a large surface area, it can adsorb a relatively large amount of ammonia gas as compared with a nonporous inorganic substance. As a result, the amount of the ammonia gas adsorbing material to be mixed can be reduced, and ammonia gas can be efficiently adsorbed from the mixed raw material to prevent swelling due to generated gas during or after extrusion of wood plastic. .
[0037]
Table 1 uses a powdered material obtained by pulverizing particleboard waste material as a powdered material of processed wood using an amino resin, uses a granular polypropylene as a resin for melting and mixing, uses a powdered maleic acid as an additive, Example 1 is shown in which a wood plastic was manufactured using fine zeolite as an ammonia gas adsorbing material and evaluated. In addition, a conical twin screw extruder manufactured by Cincinnati Extrusion was used as a wood plastic manufacturing apparatus, the screw diameter was 45 mm, the rotation speed was 5 rpm, and the temperature of the mixed raw materials was about 200 ° C.
[Table 1]

That is, polypropylene is fixed at 18% by weight, maleic acid is fixed at 2% by weight, the amount of powdered material of processed wood is reduced stepwise to 80, 70, 60, 50, 40% by weight, and the amount of zeolite is reduced. In five test plots in which the concentration was gradually increased to 0, 10, 20, 30, and 40% by weight, the presence or absence of swelling due to the generated gas and the wood texture of the wood plastic were compared relatively to the manufactured wood plastic. ing. The double circle し た described in the column of wood texture means that the wood texture was very good, and the single circle は means that the wood texture was good but not as good as the double circle 、, Triangle △ means that the wood texture was insufficient. The presence or absence of swelling due to the generated gas and the feeling of wood were evaluated by visual observation.
[0038]
In this case, when the zeolite content was 10% or more, swelling due to generated gas did not occur during or after extrusion molding, and the shape of the wood plastic could be stabilized. When the zeolite content was 30% by weight or less, the wood texture of the wood plastic was good. Therefore, a good wood plastic is produced as a product in the test sections 2, 3, and 4 in which the total of the powdery material of processed wood, polypropylene, and maleic acid is 90 to 70% by weight and zeolite is 10 to 30% by weight. I was able to.
[0039]
(2) Second embodiment:
FIG. 4 is a schematic flowchart showing a method of manufacturing a wood plastic G2 according to the second embodiment of the present invention for each process. Note that the same components as those of the first embodiment are denoted by the same reference numerals, and detailed description is omitted.
In the present embodiment, an ammonium salt generating material D2 is used instead of the ammonia gas adsorbing material D1 used in the first embodiment.
[0040]
As the ammonium salt producing material D2, various materials capable of producing an ammonium salt by reacting with the produced ammonia gas can be adopted. In this embodiment, fine alum (sulfate of a weak base) 70 is mixed as a raw material.
Alum (potassium aluminum sulfate, AlK (SO ₄ ) ₂ ・ 12H ₂ O) 70 reacts upon contact with ammonia gas to react with ammonium salts (ammonium sulfate, (NH ₄ ) ₂ SO ₄ ). That is, when alum is mixed as a raw material, it reacts with the generated ammonia gas to reduce the ammonia gas. Therefore, the ammonia gas is converted into an ammonium salt and becomes a part of the constituents of the molten mixture E2.
[0041]
There are various ammonium salt producing materials to which the present invention can be applied other than alum.
For example, as the ammonium salt producing material D2, a finely-divided sulfate band (potassium sulfate, K ₂ (SO ₄ )) May be used. Since the sulfate band is also a weak base sulfate, even in this case, the wood plastic G2 can be produced by the flow shown in FIG.
By using alum and potassium sulfate as the ammonium salt-forming material D2, the amount of ammonia gas generated in the raw material is reduced, and the pressure applied to the mixed raw material is reduced. Therefore, swelling due to the generated gas does not occur during or after extrusion of the wood plastic, and the shape after the molding can be stabilized. Of course, the same effect can be obtained if the ammonium salt-forming material contains at least alum, and the same effect can be obtained if the ammonium salt-forming material contains at least a sulfate band. The same effect can be obtained even if the ammonium salt-forming material D2 is composed of a combination of alum and a sulfate band.
[0042]
Regarding the mixing ratio of the raw materials, the total of the powder A of the processed wood, the resin B for melting and mixing, and the unsaturated carboxylic acid C is 90 to 70% by weight, and the amount of the ammonium salt forming material D2 is 10 to 30% by weight. Is preferred. When an additive such as an unsaturated carboxylic acid is not used, the total of the powder A of the processed wood and the resin B for melting and mixing is 90 to 70% by weight, and the amount of the ammonium salt forming material D2 is 10 to 30% by weight. Is preferred. When the amount of the ammonium salt-forming material D2 is 10% or more, swelling due to generated gas does not occur during or after extrusion molding, and the shape of the produced wood plastic G2 can be stabilized. When the amount of the ammonium salt-forming material D2 is 30% by weight or less, the wood texture of the manufactured wood plastic G2 can be improved.
[0043]
The mixing ratio of the powder A of the processed wood, the resin B for melting and mixing, and the unsaturated carboxylic acid C can be appropriately determined depending on the use of the wood plastic. A preferable mixing ratio of the powdered material A of the processed wood for imparting toughness to the wood-based molded product and enabling the processing of the screw or the like is 50% by weight or more, more preferably 50% by weight or more based on all the raw materials A, B, C and D2. Is 70% by weight or more.
The preferred mixing ratio of the resin B for melting and mixing all the raw materials is 5% by weight or more, more preferably 10% by weight or more, based on all the raw materials A, B, C and D2. A preferable mixing ratio of the unsaturated carboxylic acid C for making the resin B for melt mixing sufficiently compatible with the powder A of the processed wood is 0.1% by weight or more based on all the raw materials A, B, C and D2. It is preferably at least 0.5% by weight. When the amount of the resin B for melting and mixing is 100 parts by mass, a preferable mixing ratio of the unsaturated carboxylic acid C is 5 to 50 parts by mass, more preferably 10 to 25 parts by mass. When an acid-modified resin is used in place of the unsaturated carboxylic acid C, a preferable mixing ratio of the acid-modified resin for making the resin B for melting and mixing sufficiently compatible with the powdered material A of the processed wood is 0 with respect to all raw materials. 0.1% by weight or more, more preferably 0.5% by weight or more. When the amount of the resin B for melt mixing is 100 parts by mass, a preferable compounding ratio of the acid-modified resin is 5 to 50 parts by mass, more preferably 10 to 25 parts by mass.
The weight ratio of each of the raw materials A to C can be appropriately selected according to the properties required for the wood plastic.
[0044]
As described above, the polyolefin resin 20 (melt-mixing resin) is heated and melted together with the maleic acid 30 (unsaturated carboxylic acid), and mixed with the powder A of processed wood and alum 70 (an ammonium salt-forming material). . The generated ammonia gas reacts with alum 70 contained in the mixed raw materials to generate an ammonium salt. Then, since the amount of ammonia gas decreases, the wood plastic does not swell due to the generated gas during extrusion molding in which the pressure applied to the mixed raw materials decreases. Therefore, it is possible to stabilize the shape of the formed wood plastic without performing complicated raw material selection work and raw material management.
[0045]
Further, alum is a sulfate of a weak base, and is therefore acidic and reacts with the generated ammonia gas to form an ammonium salt. That is, it reacts with a relatively large amount of ammonia gas to produce an ammonium salt. This makes it possible to reduce the amount of the ammonia salt-forming material to be mixed, and to efficiently and efficiently reduce the ammonia gas from the mixed raw material, thereby causing swelling due to the generated gas during or after extrusion of the wood plastic. Can be prevented. The same applies when a sulfate band is used instead of alum.
[0046]
Table 2 uses a powdered material obtained by pulverizing particleboard waste material as a powdered material of processed wood using an amino resin, using a granular polypropylene as a resin for melting and mixing, using a powdered maleic acid as an additive, This shows Example 2 in which a wood plastic was manufactured using fine alum as an ammonium salt-forming material and evaluated. The test conditions were the same as in the first embodiment.
[Table 2]

That is, polypropylene is fixed at 18% by weight, maleic acid is fixed at 2% by weight, the amount of powdered material of processed wood is reduced stepwise to 80, 70, 60, 50, 40% by weight, and the amount of alum is reduced. In five test plots in which the concentration was gradually increased to 0, 10, 20, 30, and 40% by weight, the presence or absence of swelling due to the generated gas and the wood texture of the wood plastic were compared relatively to the manufactured wood plastic. ing.
[0047]
In this case, when the alum content was 10% or more, swelling due to generated gas did not occur during or after extrusion molding, and the shape of the wood plastic could be stabilized. When the alum content was 30% by weight or less, the wood texture of the wood plastic was good. Therefore, a good wood plastic is produced as a product in the test sections 2, 3, and 4 in which the total of the powdered material of processed wood, polypropylene, and maleic acid is 90 to 70% by weight and alum is 10 to 30% by weight. I was able to.
[0048]
Table 3 shows Example 3 in which wood plastic was produced and evaluated using fine-grained sulfuric acid bands instead of alum as an ammonium salt-forming material. The test conditions were the same as in the first embodiment.
[Table 3]

That is, polypropylene is fixed at 18% by weight, maleic acid is fixed at 2% by weight, the amount of powdered material of processed wood is reduced stepwise to 80, 70, 60, 50, 40% by weight, and the sulfate band is reduced. In five test plots where the amount was increased gradually to 0, 10, 20, 30, and 40% by weight, the presence or absence of swelling due to the generated gas and the wood texture of the wood plastic were compared relatively to the manufactured wood plastic. are doing.
[0049]
In this case, when the content of the sulfuric acid band was 10% or more, swelling due to generated gas did not occur during or after extrusion molding, and the shape of the wood plastic could be stabilized. When the content of the sulfate band was 30% by weight or less, the wood texture of the wood plastic was good. Therefore, a good wood plastic is produced as a product in the test sections 2, 3, and 4 in which the total of the powdered material of processed wood, polypropylene and maleic acid is 90 to 70% by weight, and the sulfate band is 10 to 30% by weight. We were able to.
[0050]
(3) Third embodiment:
Next, a third embodiment relating to a wood plastic manufacturing apparatus will be described. In the present embodiment, wood plastic is manufactured according to the procedure shown in FIG. 2 without using an ammonia gas adsorbing material or an ammonium salt generating material.
The wood plastic manufacturing apparatus of the present embodiment also includes the heating mixer 41, the extruder 42, and the cutting machine 43 shown in FIG.
[0051]
FIG. 5 is a side view showing the extruder 42 in a partially vertical sectional view. The raw material heated and melted and mixed at about 200 ° C. by the heating mixer 41 flows into the internal space 42 a of the extruder 42. In the extruder 42 shown in the figure, the heated and melted raw material flows into the internal space 42a of the extruder from the left side, and is extruded rightward by the rotation of a screw 45 arranged in the internal space 42a. The extruder 42 extrudes the molten mixture E into a plate shape by driving the screw 45 while heating the molten mixture E again.
[0052]
Here, if the urea resin is contained in the powder A of the processed wood, when the powder A of the processed wood is heated, the urea resin may be decomposed and the ammonia gas 14 may be generated. . The ammonia gas 14 causes swelling on the surface of the wood plastic when the wood plastic is formed. Therefore, by providing a vacuum deaerator 50 in the wood plastic manufacturing apparatus 40, the ammonia gas 14 is efficiently removed to prevent swelling of the wood plastic due to the generated gas.
[0053]
The extruder 42 is provided with an exhaust port 44a opened upward so as to be connected to the internal space 42a, and a pressure regulating port 44b directed downward. A deaeration hose 52 connected to the suction port 50a of the vacuum deaerator 50 is attached to the upper end of the exhaust port 44a.
[0054]
When the vacuum deaerator 50 is driven, air is sucked in from the suction port 50a, and air in the internal space 42a of the extruder is sucked and discharged through the exhaust port 44a and the deaeration hose 52. Therefore, the ammonia gas 14 generated from the molten mixture E is discharged from the exhaust port 44a.
[0055]
The internal pressure of the extruder 42 is maintained to be substantially equal to the atmospheric pressure by a pressure adjusting port 44b through which air can be sucked into the internal space 42a. A check valve 44c is provided at the exhaust port 44a, and the check valve 44c prevents backflow of air into the internal space 42a. Further, a filter 44d is provided at the exhaust port 44a, so that only gas can be exhausted from the exhaust port 44a.
[0056]
In this way, the powder A of the processed wood using the amino resin, the melt-mixable resin B that can be heated and melted, and the unsaturated carboxylic acid C are combined with the melt-mixed resin B together with the unsaturated carboxylic acid C. The mixture is heated and melted, extruded while being degassed, and molded to produce a wood plastic G. Since the molten mixture E is degassed during extrusion, the generated ammonia gas is sucked and removed. Therefore, the wood plastic does not swell due to the generated gas during molding when the pressure applied to the mixed raw materials is reduced. This makes it possible to prevent swelling due to generated gas at the time of molding or after molding of the plastic, and to stabilize the shape of the molded plastic, without performing a complicated raw material sorting operation and a raw material management.
[0057]
Although the description with reference to the drawings is omitted, the heating mixer 41 may have a sealable structure, and a vacuum deaerator may be provided in the heating mixer. When the vacuum deaerator is disposed in the heating mixer 41, the powder A of the processed wood, the resin B for melting and mixing, and the unsaturated carboxylic acid C are mixed together with the resin B for melting and mixing together with the unsaturated carboxylic acid C. The mixture is mixed while being degassed while being heated and melted, and is extruded to produce a wood plastic G. Then, the ammonia gas generated from the molten mixture E during the heating and melting and mixing is sucked by the vacuum deaerator, discharged to the outside, and removed from the molten mixture E.
[0058]
As described above, by performing the mixing or the extrusion while degassing, the ammonia gas generated in the raw material is removed, and the wood plastic is not swollen by the generated gas at the time of molding in which the pressure applied to the raw material to be mixed is reduced. Therefore, the swelling due to the generated gas does not occur during or after the molding of the wood plastic, and the shape of the wood plastic can be stabilized. Of course, if degassing is performed in both the mixing and extrusion steps, it becomes possible to more reliably remove the ammonia gas and prevent swelling due to the generated gas, and to further stabilize the shape of the wood plastic.
[0059]
It should be noted that as the number of mixing or extrusion processes is increased or the processing speed is reduced, the amount of ammonia gas generated from the molten mixture increases. Therefore, the operation of extruding the molten mixture from the extruder 42 without forming it, and charging the extruded molten mixture into the heating mixer 41 again may be repeated a predetermined number of times. The number of repetitions of the process of extruding the molten mixture by the extruder 42 after heating and melt-mixing the raw materials by the heating mixer 41 may be appropriately set according to the physical properties of the molten mixture, for example, about 4 to 5 times. be able to.
By repeating mixing and extrusion a predetermined number of times, the amount of ammonia gas generated is increased, and the amount of ammonia gas-causing substances in the mixture is reduced. This makes it possible to more efficiently reduce the ammonia gas from the mixed raw material, prevent swelling due to the generated gas during or after molding of the plastic, and further stabilize the shape of the plastic.
[0060]
Of course, in the extruder 42, the extruding step of extruding with the screw 45 while heating may be performed longer than a normal processing time.
[0061]
The vacuum deaerator may be provided in only one of the heating mixer 41 and the extruder 42, or may be provided in both. Further, the processing time of the heat melting and mixing in the heating mixer 41 is increased, or the number of times of the processing is increased, and the processing time of the extrusion in the extruder 42 is increased, or by combining these, the vacuum deaerator is provided. Can further enhance the effect of removing ammonia gas.
[0062]
The wood plastic produced by the above method hardly contains ammonia gas. Therefore, the surface of the wood plastic does not swell when the wood plastic is discharged from the extruder 42, and even if the wood plastic is heated when actually used, the surface of the wood plastic may be removed. There is no swelling.
[0063]
Further, if the zeolite described in the first embodiment is charged into the wood plastic manufacturing apparatus described in the third embodiment or the alum 70 described in the second embodiment is charged, the gas state is changed. Can further reduce the ammonia content, and can produce a highly reliable wood plastic in which the occurrence of shape change is more reliably prevented.
As described above, according to the present invention, according to various aspects, it is not necessary to perform complicated raw material selection work and raw material management, and it is possible to prevent swelling due to generated gas during or after extrusion of wood plastic. As a result, the shape of the formed wood plastic can be stabilized.
[Brief description of the drawings]
FIG. 1 is a schematic flowchart showing a method for manufacturing a wood plastic according to a first embodiment of the present invention.
FIG. 2 is a schematic flow chart showing how to produce a wood plastic with a conventional configuration.
FIG. 3 is a diagram schematically showing a wood plastic manufacturing apparatus and a wood plastic manufacturing method.
FIG. 4 is a schematic flowchart showing a method for manufacturing a wood plastic according to a second embodiment of the present invention.
FIG. 5 is a side view showing the extruder in a third embodiment in a partially vertical sectional view.
[Explanation of symbols]
A: Powder of processed wood
B: Melt-mixing resin
C: unsaturated carboxylic acid
D1 ... Ammonia gas adsorption material
D2: ammonium salt forming material
E, E1, E2 ... Molten mixture
G, G1, G2: Wood plastic
g ... Production gas
14 ... Ammonia gas
20 ... Polyolefin resin
30 ... maleic acid
40 ... Wood plastic manufacturing equipment
41 ... Heating mixer
42 ... Extruder
42a ... internal space
43 ... Cutting machine
44a ... Exhaust port
44b… pressure regulator
44c ... check valve
44d ... Filter
45 ... Screws
50 ... Vacuum deaerator
50a ... Suction port
52 ... Degassing hose
60 ... zeolite (porous inorganic material)
70 ... alum (sulfate of weak base)

Claims (10)

A process for producing a wood plastic using a powdered material of processed wood using an amino resin, and a resin for melting and mixing which can be heated and melted,
The powdered material of the processed wood, the resin for melting and mixing, and the ammonia gas adsorbing material capable of adsorbing ammonia gas are mixed while heating and melting the resin for melting and mixing, and extruded to form the wood plastic. A method for producing wood plastic, which comprises producing. The method according to claim 1, wherein the ammonia gas adsorbing material is a porous inorganic material. The method according to claim 2, wherein the porous inorganic material is zeolite. A process for producing a wood plastic using a powdered material of processed wood using an amino resin, and a resin for melting and mixing which can be heated and melted,
The powdered processed wood, the melt-mixing resin, and an ammonium salt-forming material capable of forming an ammonium salt by reacting with ammonia gas are mixed while heating and melting the melt-mixing resin, and extrusion molding is performed. And producing the above-mentioned wood plastic. The method according to claim 4, wherein the ammonium salt producing material is a sulfate of a weak base. The method for producing a wood plastic according to claim 5, wherein the sulfate contains at least alum. The method for producing a wood plastic according to claim 5, wherein the sulfate contains at least a sulfate band. A wood plastic powder that is manufactured by mixing a powdered processed wood material using an amino resin and a resin for melting and mixing that can be heated and melted while heating and melting the resin for melting and mixing, extruding and molding to produce a wood plastic. A manufacturing method,
A method for producing wood plastic, wherein at least one of the mixing and the extrusion is performed while degassing. The method for producing a wood plastic according to claim 8, wherein at least one of the mixing and the extruding performed while degassing is performed a predetermined number of times. The wood according to any one of claims 1 to 9, wherein a predetermined acid for imparting a hydrophilic group is added to the melt-mixing resin, mixed, and extruded to produce the wood plastic. Manufacturing method of plastic.

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