JP3720562B2

JP3720562B2 - Laminate manufacturing method

Info

Publication number: JP3720562B2
Application number: JP04022198A
Authority: JP
Inventors: 恒男高野; 睦正佐々木
Original assignee: Mitsubishi Chemical Corp; Mitsubishi Rayon Co Ltd
Current assignee: Mitsubishi Chemical Corp; Mitsubishi Rayon Co Ltd
Priority date: 1998-02-23
Filing date: 1998-02-23
Publication date: 2005-11-30
Anticipated expiration: 2018-02-23
Also published as: JPH11235726A

Description

【０００１】
【発明の属する技術分野】
本発明は、熱可塑性樹脂成形品を重合硬化樹脂補強層で補強した浴槽等の所定形状の積層物の製造方法に関し、更に詳しくは、熱可塑性樹脂成形品から成る型を成形型の一部として用い、型のセル内に重合硬化性樹脂原料を注入し、重合硬化させ、この熱可塑性樹脂成形品と一体化させて所定形状の積層物を製造する方法に関する。
【０００２】
【従来の技術】
従来より、型内に重合硬化性樹脂原料を注入充満させ、硬化後離型して得られる重合硬化樹脂成形品や、さらにガラス繊維を含んだ繊維強化重合硬化樹脂（以下、ＦＲＰと称す）の成形品が、各種製品として上市されている。
【０００３】
また、熱可塑性樹脂成形品を型の一方に用い、もう一方の型と組み合わせてセルを形成し、重合硬化性樹脂原料を注入し、重合硬化させ、その熱可塑性樹脂成形品と一体化する方法が、特開昭５１−９１９６５号公報、特開平５−２３７８５４号公報、特開平９−５７７６８号公報等に開示されている。ここでは、例えば、外観に優れるアクリル樹脂（熱可塑性樹脂成形品）を表層に用い、裏面をＦＲＰにより補強した構成のバスタブを製造する例などが記載されている。
【０００４】
【発明が解決しようとする課題】
上述した熱可塑性樹脂成形品から成る型を用いて一体化する積層物の製造方法においては、セル内の重合硬化性樹脂原料の硬化反応を十分完了させてから、その積層物を離型している。これは、重合硬化性樹脂原料の硬化が不十分の状態で離型すると、硬化の進行に伴う収縮による変形が生じたり、離型時の型面との擦れ等の接触により積層物の表面が傷つくからである。
【０００５】
しかしながら、硬化反応を十分完了させてから離型する工程では、型の占有時間が長く、生産性が低い。
【０００６】
本発明は、かかる問題点を解決すべくなされたものである。すなわち、本発明の目的は、型の占有時間が短く、生産性を向上できる積層物の製造方法を提供することにある。
【０００７】
【課題を解決するための手段】
本発明は、熱可塑性樹脂成形品から成る型を所定形状の積層物を成形するための型の一部として用い、該型のセル内に重合硬化性樹脂原料を注入し、重合硬化させ、前記熱可塑性樹脂成形品と一体化させて積層物とした後、該積層物を前記熱可塑性樹脂成形品から成る型以外の型から離型する工程を含む積層物の製造方法において、
前記熱可塑性樹脂成形品から成る型以外の型１個に対して、熱可塑性樹脂成形品からなる型および押え具を複数個用意し、
ガラス繊維マットまたは熱可塑性樹脂成形品から成る型に対応する形状に成形したガラス繊維を、重合硬化性樹脂原料を注入するに先立ってセル中に載置しておき、
成形の際に、前記熱可塑性樹脂成形品から成る型を、押え具によって支え、
前記重合硬化性樹脂原料の重合発熱開始から重合発熱ピークまでの時間内に、積層物を前記熱可塑性樹脂成形品から成る型以外の型から離型した後、
該積層物を押え具で支えた状態で重合硬化性樹脂原料の発熱硬化反応を進行させる間に、他の押え具で支えた他の熱可塑性樹脂成形品から成る型と、前記離型後の熱可塑性樹脂成形品から成る型以外の型を用いてセルを形成し、積層物を製造するための前記工程を繰返すことを特徴とする積層物の製造方法である。
【０００８】
【発明の実施の形態】
本発明の方法により製造される積層物の代表的な例としては、浴槽、洗面ボール、シャワーパン等が挙げられる。以下、代表例としての浴槽について、すなわち、熱可塑性樹脂成形品の所定形状が浴槽形状であるものについて、本発明を説明する。
【０００９】
図１は、本発明の製造方法の一実施形態を示す模式的断面図である。
【００１０】
図１に示す例においては、ほぼ相似形をなすバスタブ形状（浴槽形状）の２つの型（雌型１と雄型３）を組み合わせることにより、バスタブ形状のセル９を形成し、また、このセル９の外周部をシールパッキン４により密閉している。これら２つの型のうち、雄型３は熱可塑性樹脂成形品から成るものであり、重合硬化性樹脂原料７により形成する補強層と一体化され、バスタブの表層を構成する部材でもある。すなわち、ここで得られる積層物から成るバスタブにおいては、外観に優れる熱可塑性樹脂成形品が表層側になり、その裏面は重合硬化性樹脂原料７により形成した補強層になる。この補強層の厚みは、セル間隔で調整すればよい。さらに、この例では、注入した重合硬化性樹脂原料７によって熱可塑性樹脂成形品から成る型３が変形しないように、型３のセル９とは反対側の面（以下、セル外面と称す）側を押え具１０によって支えている。
【００１１】
また、雌型１の上側中央部には重合硬化性樹脂原料７を注入するための注入口５が設けられ、その下側両端部には、重合硬化性樹脂原料７を充満させる過程でセル９内の空気を排除するための排気口６が設けられている。
【００１２】
このような雌型１としては、例えば、エポキシ樹脂、ビニルエステル樹脂、不飽和ポリエステル樹脂等を用いたＦＲＰから成る型、ＦＲＰとレジンコンクリート等との積層体から成る型、Ｎｉ電鋳の型（ＦＲＰの表面にニッケルをコートしたもの）、アルミニウム等の金属から成る型、さらにこれらをリブ構造により補強した型などが挙げられる。
【００１３】
熱可塑性樹脂成形品から成る型３は、例えば、熱可塑性樹脂板を、真空成形、圧空成形、プレス成形などの方法により熱成形して得られる。ここで用いる熱可塑性樹脂板としては、アクリル樹脂板、ポリスチレン板、ＡＢＳ樹脂板、またはこれらの積層板など、熱成形可能な樹脂板が使用できる。真空成形や圧空成形には、プラグなどによる補助成形を行うこともできる。また、これらの樹脂板に予め印刷を施したり、フィルムをラミネートすることもできる。
【００１４】
特に、この熱可塑性樹脂板として、熱成形加工性および耐溶剤性に優れたアクリル樹脂板を用いることが好ましい。この好適なアクリル樹脂板としては、例えば、特公平６−７００９８号公報に記載のように、メタクリル酸メチル単独、または、メタクリル酸メチル６０重量％以上とアクリル酸エステル４０重量％以下との単量体混合物を、重合開始剤の存在下で重合させてアクリル樹脂板を製造するに当たり、予め単量体全体に対して０.０１〜２０重量％の連鎖移動剤を添加してシラップを製造し、次いでそのシラップに対して０.０２〜１.０重量％の架橋剤を添加して、鋳型中で注型重合させることによって得られるアクリル樹脂板が挙げられる。
【００１５】
次に、図１に示す型を用いてバスタブ形状の積層物を製造する方法について説明する。
【００１６】
まず、セル９内にガラス繊維プリフォーム８を載置する。このガラス繊維プリフォーム８は、例えば、吹き付けやプレスするなどして型３に対応する形状（ほぼ同形状）に成形したガラス繊維で構成することができる。また、この代わりに、ガラス繊維を織布や不織布などにマット化したガラス繊維マットを用いることもできる。このガラス繊維プリフォーム８やガラス繊維マット（および後に詳述するフィラー）は、主に、積層物の強度を向上させ、かつ耐熱性を向上させるため所望に応じて用いる。その含有量は、セル９内に充填する材料の合計量に対して、１０重量％〜９０重量％の範囲内とすることが好ましい。
【００１７】
また、補強材として一枚または複数に分割したベニヤ板や樹脂板などをセル９内に入れ込み、重合硬化性樹脂７と一体化することも有効である。
【００１８】
次に、注入口５から重合硬化性樹脂原料７を注入し、セル９内に充満させる。この重合硬化性樹脂原料７としては、熱可塑性樹脂成形品から成る型３と親和性を有し、重合硬化してかかる熱可塑性樹脂成形品と密着一体化可能なものであればよく、熱可塑性樹脂成形品の種類等に応じて適宜選択すればよい。例えば、不飽和ポリエステル樹脂、アクリル樹脂、ビニルエステル樹脂、ウレタン樹脂、エポキシ樹脂、およびこれらを変性した樹脂などが挙げられる。このうち、不飽和ポリエステル樹脂としては、オルソフタル酸系、イソフタル酸系、テレフタル酸系またはビスフェノール系不飽和ポリエステル樹脂、およびこれらのアクリル変性不飽和ポリエステル樹脂、ならびに、オルソフタル酸系、イソフタル酸系、テレフタル酸系またはビスフェノール系不飽和ポリエステル樹脂に、アクリル樹脂を添加した樹脂組成物などが用いられる。
【００１９】
また、重合硬化性樹脂原料７に補強用フィラーを混合して用いてもよい。この補強用フィラーとして、例えば、水酸化アルミニウム、炭酸カルシウム、ガラス繊維、炭素繊維、アラミド繊維、ポリエステル繊維など、従来より知られる各種フィラーを用いることができる。これらは、一種または二種以上を適宜組み合わせて使用できる。また、これらフィラーは、カップリング処理を施して用いることが好ましい。
【００２０】
図１に示す例においては、重合硬化性樹脂原料７を充満させる過程で、セル９内の空気が排気口６から排除される。ただし、本発明はこのような方式に限定されない。例えば、型１と型３を組み合わせたセル９の外周部から空気を排気する方式等も採用できる。
【００２１】
ここで、重合硬化性樹脂原料７に気泡が残留することがあっても、図１に示すように、熱可塑性樹脂成形品から成る型３を下に配置し、雌型１を上に配置することにより、型３側から型１側に気泡を集め、外観や強度などの性能の低下を防ぐこともできる。
【００２２】
次に、セル９内に充填した重合硬化性樹脂原料７を重合硬化し、この重合硬化性樹脂原料７の重合発熱開始から重合発熱ピークまでの時間内に、型１から離型する。離型前の重合硬化反応においては、硬化発熱により熱可塑性樹脂成形品から成る型３が変形することがないように、硬化条件を制御することが望ましい。具体的には、硬化剤量を減らすなどして発熱温度が高くならないようにすればよい。さらに、硬化時に重合硬化性樹脂原料７が発泡しないように、充填する重合硬化性樹脂原料７の脱泡を行うことも有効である。
【００２３】
また、離型性を良好にする目的で、あらかじめ型１のセル９を構成する面（重合硬化性樹脂原料７が接する面）に離型剤を塗布したり、その面をテフロン等密着し難い材料でラミネートすることが好ましい。
【００２４】
ここで、重合硬化性樹脂原料７の硬化反応がまだ完了していない時点で型１から離型すれば、型１の占有時間は短縮できる。しかし、離型時における重合硬化性樹脂原料７が未硬化で流動性が高いと、その形状が保持されず、良好な積層物は得られない。すなわち、その離型する時点は、重合硬化性樹脂原料７の重合硬化の度合いに大きく影響される。しかしながら、成形中の型内における硬化状態を逐次観察することは困難である。そこで、本発明においては、この離型の時点の基準を、その重合硬化性樹脂原料７の重合発熱開始から重合発熱ピークまでの時間内とすることにより、型に設けられる通常の測温手段などを用い、簡易に適切な離型時を判断できるようにしている。
【００２５】
この離型時の具体的な温度については、重合硬化性樹脂原料７の種類、熱可塑性樹脂成形品から成る型３の形状、両型１、３の熱容量など、各種条件に応じて最適な値が異なる。したがって、本発明において、具体的な温度については特に限定は無い。例えば、予めその重合発熱ピークの温度の具体値を調べておき、その具体値以前の温度段階であって、その形状が保持される程度に重合硬化性樹脂原料７の流動性が無い状態の温度時に離型すればよい。ただし、この離型時の温度は、発熱ピーク時よりもある程度前である方が好ましく、具体的には発熱ピーク時の温度よりも約５℃以上低い温度の時点で離型することが好ましい。
【００２６】
この離型後、硬化反応が完了していない重合硬化性樹脂原料７は、熱可塑性樹脂成形品から成る型３によって形状が保持され、その変形が防止される。また、さらに熱可塑性樹脂成形品から成る型３自体も変形しないように、型３のセル外面を押え具１０によって支え、変形防止をより確実にしている。
【００２７】
また、離型時の型１の面との擦れ等の接触による積層物の傷については、本例で得られるバスタブでは、外観に優れる熱可塑性樹脂成形品が表面になり、重合硬化性樹脂原料７により形成した傷のつき易い補強層は裏面になるので、その傷は問題にならない。
【００２８】
離型後、この積層物、すなわち熱可塑性樹脂成形品からなる型３と硬化反応途中の重合硬化性樹脂原料７から成る補強層から成る積層物は、押え具１０で支えられた状態で、そのまま発熱硬化反応が進行する。
【００２９】
押え具１０としては、例えば、一体化されたまたは分割された押え具を使用できる。具体的には、エポキシ樹脂、ビニルエステル樹脂、不飽和ポリエステル樹脂などのＦＲＰ、アルミニウムなどの金属、木材などで構成される押え具を好適に使用できる。また、固体から成る押え具１０の代わりに、気体、液体などの流体を用いて型３を支えることもできる。具体的には、型３側のセル外面に密閉空間を形成し、空気や窒素などの気体、水やシリコンオイルなどの液体により支持する方法がある。また、この押え具１０や支持用流体を温調可能な構成にすれば、成形サイクルアップなど、成形性向上の点でも有効である。
【００３０】
型３のセル外面を支持する際、型３の形状および寸法が変動した場合、流体による支持は特に問題ないが、固体による加圧は嵌合に問題が生じることがある。この場合は、変形し難いコーナー部などを除き、平面部などの変形し易い部分のみを押え具１０により支持することで、型３と押え具１０との形状余裕、および得られる積層物の形状安定性を向上させることもできる。
【００３１】
さらに、セル外面を一体化された押え具または分割された押え具により支持する場合、押え具１０の押え面と、熱可塑性樹脂成形品から成る型３側のセル外面の間を、例えば減圧状態にすることにより密着させ、熱可塑性樹脂成形品から成る型３の面のたわみを矯正することができる。この場合は、押え具１０に減圧孔を設けておき、そこから脱気減圧すればよい。
【００３２】
以上のような工程に従い、重合硬化性樹脂原料７の重合発熱ピーク前に型１を離型すれば、型１の占有時間が短くなり、その有効利用が可能である。
【００３３】
図２は、その離型した型１等を有効に利用すべく、積層物の硬化を完了させる間に、型１等を次の成形に使用する実施形態を示す模式的断面図である。この実施形態においては、予め１個の型１に対して複数個の熱可塑性樹脂成形品から成る型３、３'、および、押え具１０、１０'を用意しておく。そして、型１、熱可塑性樹脂成形品からなる型３、押え具１０を用い、先に述べた工程を一回目の成形として実施し、重合硬化性樹脂原料７の重合発熱ピーク前に型１を離型する。
【００３４】
この離型後も、一回目の成形による積層物は、押え具１０で支られた状態で、発熱硬化反応が進行する。この反応が進行している間に、離型した型１を、押え具１０'で支えた熱可塑性樹脂成形品から成る型３'に対して用い、同様のセルを形成し、二回目の成形を繰返す。これにより、型１やその型締めの装置などの台数を抑えることができ、その占有時間を短縮でき、その結果、生産性を向上できる。
【００３５】
以上説明した各実施形態においては、バスタブ（浴槽）形状の例を挙げたが、本発明はこれに限定されず、例えば洗面ボールやシャワーパンなど、各種の立体形状の樹脂成形品の製造に有用である。
【００３６】
【実施例】
以下、本発明を実施例により更に詳細に説明する。
【００３７】
［参考例］
図１を用いて説明した工程に従い、以下のようにして、バスタブ形状の積層物を作製した。
【００３８】
まず、不飽和ポリエステル樹脂（商品名ユピカ４５２１Ｐ、日本ユピカ（株）製）１００重量部に対し、触媒（商品名パーメックＮ、日本油脂（株）製）１.５重量部を、注入直前にスタティックミキサーにより混合し、重合硬化性樹脂原料７とした。
【００３９】
次に、バスタブ形状のＦＲＰから成る雌型１と、アクリル樹脂成形品から成る雄型３の間に、予め成形したガラス繊維プリフォーム８を入れ、型１、３を組み合せ、セル９内の型間隔を補強目標厚さの４ｍｍとし、弾性体のシールパッキン４により密閉した。また、押え具１０をアクリル樹脂成形品から成る型３のセル外面に配置して支えた。
【００４０】
次に、先に調合した重合硬化性樹脂原料７を注入口５より１ｋｇ／ｃｍ²の圧力で注入し、セル９内に充満させた。この重合硬化性樹脂原料７は硬化反応により発熱した。２５℃から４０℃程度まで発熱したところで、発熱ピーク温度（５０℃程度）になる前に型１から離型し、押え具１０のみで支えた状態にした。
【００４１】
このような状態で４０分間放置したところ、重合硬化性樹脂原料７は発熱ピーク温度約５０℃に達した。この重合硬化反応が十分完了してから、押え具１０を取り外し、アクリル樹脂成形品に補強層を一体化した積層物から成るバスタブを得た。
【００４２】
本参考例では、重合硬化性樹脂原料７の発熱ピーク温度になる前の硬化が不十分な状態で離型したが、アクリル樹脂成形品自体と押え具１０により形状を保持することができ、形状変化の無い良好なバスタブが得られた。また、このバスタブは、外観上も問題無く、ＪＩＳＡ１７１８にしたがって性能評価をしたところ、変形やクラックは無く、全ての項目に合格した。
【００４３】
［実施例１］
図２に示すように、さらに、もう一組の熱可塑性樹脂成形品からなる型３'および押え具１０'を用意した。
【００４４】
そして、一回目の成形を参考例と同様の工程で実施し、重合硬化性樹脂原料７の発熱ピーク温度になる前に積層物を型１から離型し、押え具１０のみで支えた状態で重合硬化反応を完了させ、一回目の成形によるバスタブを得た。
【００４５】
また、一回目の成形における重合硬化反応が進行している間に、一回目の成形で離型した型１や型締め等の装置を、もう一組の熱可塑性樹脂成形品からなる型３'および押え具１０'に対して使用し、同様の成形を繰返し、二回目の成形によるバスタブを得た。
【００４６】
本実施例では、一回目の成形が完了する前に、型１等を用いて二回目の成形を行なうことができ、その型１等の占有時間を短縮でき、生産効率を向上できた。また、一回目および二回目の成形で得たバスタブは、参考例と同様に形状変化が無く、外観上も問題無く、ＪＩＳＡ１７１８にしたがって性能評価をしたところ、変形やクラックは無く、全ての項目に合格した。
【００４７】
［比較例１］
図３に示すように、アクリル樹脂成形品から成る型３および押え具１０の代わりに、雌型１と同様のＦＲＰ製の雄型２を使用したこと以外は、参考例と同様の工程に従い、重合硬化性樹脂原料７の硬化成形物を得ようとした。
【００４８】
しかし、重合硬化性樹脂原料７が２５℃から４０℃まで発熱した時点で、発熱ピーク温度になる前の硬化が不十分な状態で両型１、２から離型したところ、その後の硬化の進行に伴い成形物に反り変形が生じた。さらに、表面である雄型２側に擦り傷が生じ、外観の劣るバスタブとなった。
【００４９】
【発明の効果】
以上説明した本発明によれば、熱可塑性樹脂成形品を重合硬化樹脂で補強した所定形状の積層物を製造するに当たり、使用する型の占有時間を短縮でき、生産性を向上できる。
【図面の簡単な説明】
【図１】本発明の製造方法の一実施形態を示す模式的断面図である。
【図２】本発明において、離型した型等を有効に利用するための実施形態を示す模式的断面図である。
【図３】比較例１の製造方法を示す模式的断面図である。
【符号の説明】
１雌型
２雄型
３、３' 熱可塑性樹脂成形品から成る型
４シールパッキン
５注入口
６排気口
７重合硬化性樹脂原料
８ガラス繊維プリフォーム
９セル
１０、１０' 押え具[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a laminate having a predetermined shape, such as a bathtub, in which a thermoplastic resin molded article is reinforced with a polymerized cured resin reinforcing layer, and more specifically, a mold made of a thermoplastic resin molded article is used as a part of the mold. The present invention relates to a method for producing a laminate having a predetermined shape by injecting a polymerization curable resin raw material into a cell of a mold, polymerizing and curing it, and integrating it with this thermoplastic resin molded product.
[0002]
[Prior art]
Conventionally, a polymer curable resin molded product obtained by injecting and filling a polymer curable resin raw material into a mold and releasing after curing, and a fiber reinforced polymer curable resin (hereinafter referred to as FRP) further containing glass fibers. Molded products are marketed as various products.
[0003]
Also, a method in which a thermoplastic resin molded article is used in one of the molds, combined with the other mold to form a cell, a polymerization curable resin raw material is injected, polymerized and cured, and integrated with the thermoplastic resin molded article Are disclosed in JP-A-51-91965, JP-A-5-237854, JP-A-9-57768, and the like. Here, for example, an example of manufacturing a bathtub having a configuration in which an acrylic resin (thermoplastic resin molded product) having an excellent appearance is used as a surface layer and the back surface is reinforced by FRP is described.
[0004]
[Problems to be solved by the invention]
In the manufacturing method of the laminate integrated using the mold composed of the thermoplastic resin molded product described above, the polymerization reaction is sufficiently completed for the polymerization curable resin raw material in the cell, and then the laminate is released from the mold. Yes. This is because if the polymerization curable resin raw material is released in a state where the curing is insufficient, deformation due to shrinkage occurs as the curing progresses, or the surface of the laminate is caused by contact with the mold surface at the time of release. Because it hurts.
[0005]
However, in the step of releasing the mold after sufficiently completing the curing reaction, the occupation time of the mold is long and the productivity is low.
[0006]
The present invention has been made to solve such problems. That is, an object of the present invention is to provide a method for manufacturing a laminate that can improve the productivity with a short mold occupation time.
[0007]
[Means for Solving the Problems]
The present invention uses a mold made of a thermoplastic resin molded article as a part of a mold for molding a laminate having a predetermined shape, and injects a polymerization curable resin raw material into the cell of the mold, polymerizes and cures, In a method for producing a laminate comprising a step of integrating with a thermoplastic resin molded article to form a laminate, and then releasing the laminate from a mold other than the mold comprising the thermoplastic resin molded article,
For one mold other than the mold made of the thermoplastic resin molded product, prepare a plurality of molds and pressers made of a thermoplastic resin molded product,
Prior to injecting the polymerization curable resin raw material, the glass fiber molded into a shape corresponding to a mold comprising a glass fiber mat or a thermoplastic resin molded article is placed in a cell,
During molding, the mold made of the thermoplastic resin molded product is supported by a presser,
After releasing the laminate from a mold other than the mold made of the thermoplastic resin molded product within the time from the polymerization heat generation start of the polymerization curable resin raw material to the polymerization heat generation peak ,
While the exothermic curing reaction of the polymerization curable resin raw material proceeds while the laminate is supported by a presser, a mold composed of another thermoplastic resin molded product supported by another presser, A method for producing a laminate, comprising forming a cell using a mold other than a mold made of a thermoplastic resin molded article and repeating the above-described steps for producing the laminate.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Typical examples of the laminate produced by the method of the present invention include a bathtub, a wash bowl, and a shower pan. Hereinafter, the present invention will be described for a bathtub as a representative example, that is, a case where the predetermined shape of the thermoplastic resin molded product is a bathtub shape.
[0009]
FIG. 1 is a schematic cross-sectional view showing an embodiment of the production method of the present invention.
[0010]
In the example shown in FIG. 1, a bathtub-shaped cell 9 is formed by combining two bathtub-shaped (tub-shaped) molds (female mold 1 and male mold 3) that are substantially similar to each other. 9 is sealed with a seal packing 4. Of these two molds, the male mold 3 is made of a thermoplastic resin molded product, and is also a member that is integrated with a reinforcing layer formed by the polymerization curable resin raw material 7 and constitutes the surface layer of the bathtub. That is, in the bathtub made of the laminate obtained here, a thermoplastic resin molded article having an excellent appearance is on the surface layer side, and the back surface is a reinforcing layer formed by the polymerization curable resin raw material 7. What is necessary is just to adjust the thickness of this reinforcement layer with a cell space | interval. Further, in this example, the surface of the mold 3 opposite to the cell 9 (hereinafter referred to as the cell outer surface) side so that the injected mold-curing resin raw material 7 does not deform the mold 3 made of the thermoplastic resin molded product. Is supported by the presser 10.
[0011]
Further, an inlet 5 for injecting the polymerization curable resin raw material 7 is provided in the upper central portion of the female mold 1, and the cell 9 is filled in the lower both ends thereof with the polymerization curable resin raw material 7 being filled. An exhaust port 6 for removing the air inside is provided.
[0012]
Examples of such a female mold 1 include a mold made of FRP using an epoxy resin, a vinyl ester resin, an unsaturated polyester resin, a mold made of a laminate of FRP and resin concrete, a Ni electroforming mold ( FRP surface coated with nickel), a mold made of metal such as aluminum, and a mold reinforced with a rib structure.
[0013]
The mold 3 made of a thermoplastic resin molded product is obtained, for example, by thermoforming a thermoplastic resin plate by a method such as vacuum molding, pressure molding, or press molding. As the thermoplastic resin plate used here, a thermoformable resin plate such as an acrylic resin plate, a polystyrene plate, an ABS resin plate, or a laminated plate thereof can be used. For vacuum forming or pressure forming, auxiliary forming using a plug or the like can also be performed. Moreover, printing can be performed on these resin plates in advance, or a film can be laminated.
[0014]
In particular, it is preferable to use an acrylic resin plate excellent in thermoforming processability and solvent resistance as the thermoplastic resin plate. As this suitable acrylic resin plate, for example, as described in JP-B-6-70098, methyl methacrylate alone, or a single amount of methyl methacrylate of 60% by weight or more and acrylate ester of 40% by weight or less In the production of an acrylic resin plate by polymerizing the body mixture in the presence of a polymerization initiator, a chain transfer agent of 0.01 to 20% by weight based on the whole monomer is added in advance to produce syrup, Next, an acrylic resin plate obtained by adding 0.02 to 1.0% by weight of a crosslinking agent to the syrup and performing cast polymerization in a mold may be mentioned.
[0015]
Next, a method for manufacturing a bathtub-shaped laminate using the mold shown in FIG. 1 will be described.
[0016]
First, the glass fiber preform 8 is placed in the cell 9. The glass fiber preform 8 can be made of glass fiber formed into a shape corresponding to the mold 3 (substantially the same shape) by, for example, spraying or pressing. Alternatively, a glass fiber mat obtained by matting glass fibers into a woven fabric or a non-woven fabric can be used. The glass fiber preform 8 and the glass fiber mat (and the filler described in detail later) are used as desired mainly to improve the strength of the laminate and to improve the heat resistance. The content thereof is preferably in the range of 10 wt% to 90 wt% with respect to the total amount of materials filled in the cell 9.
[0017]
It is also effective to insert a veneer board or a resin board divided into one sheet or a plurality of reinforcing materials into the cell 9 and integrate it with the polymerization curable resin 7.
[0018]
Next, the polymerization curable resin raw material 7 is injected from the injection port 5 to fill the cell 9. The polymerization curable resin raw material 7 may be any material that has an affinity for the mold 3 made of a thermoplastic resin molded product and can be tightly integrated with the thermoplastic resin molded product after polymerization and curing. What is necessary is just to select suitably according to the kind etc. of a resin molded product. Examples thereof include unsaturated polyester resins, acrylic resins, vinyl ester resins, urethane resins, epoxy resins, and resins obtained by modifying these. Among these, the unsaturated polyester resins include orthophthalic acid-based, isophthalic acid-based, terephthalic acid-based or bisphenol-based unsaturated polyester resins, acrylic modified unsaturated polyester resins thereof, and orthophthalic acid-based, isophthalic acid-based, terephthalic acid resins. A resin composition obtained by adding an acrylic resin to an acid-based or bisphenol-based unsaturated polyester resin is used.
[0019]
Further, the polymerization curable resin raw material 7 may be mixed with a reinforcing filler. As the reinforcing filler, various conventionally known fillers such as aluminum hydroxide, calcium carbonate, glass fiber, carbon fiber, aramid fiber, and polyester fiber can be used. These can be used alone or in combination of two or more. These fillers are preferably used after being subjected to a coupling treatment.
[0020]
In the example shown in FIG. 1, air in the cell 9 is excluded from the exhaust port 6 in the process of filling the polymerization curable resin raw material 7. However, the present invention is not limited to such a method. For example, a method of exhausting air from the outer peripheral portion of the cell 9 in which the mold 1 and the mold 3 are combined can be adopted.
[0021]
Here, even if bubbles remain in the polymerization curable resin raw material 7, as shown in FIG. 1, the mold 3 made of a thermoplastic resin molded product is arranged on the lower side and the female mold 1 is arranged on the upper side. Accordingly, it is possible to collect bubbles from the mold 3 side to the mold 1 side, and to prevent deterioration in performance such as appearance and strength.
[0022]
Next, the polymerization curable resin material 7 filled in the cell 9 is polymerized and cured, and is released from the mold 1 within the time from the start of the polymerization heat generation to the polymerization heat generation peak of the polymerization curable resin material 7. In the polymerization curing reaction before release, it is desirable to control the curing conditions so that the mold 3 made of the thermoplastic resin molded product is not deformed by the heat generated by the curing. Specifically, the exothermic temperature may be prevented from increasing by reducing the amount of the curing agent. Further, it is also effective to defoam the polymerization curable resin material 7 to be filled so that the polymerization curable resin material 7 does not foam during curing.
[0023]
In addition, for the purpose of improving the releasability, it is difficult to apply a release agent to the surface of the cell 9 of the mold 1 (the surface in contact with the polymerization curable resin raw material 7) in advance or to adhere the surface to Teflon or the like. It is preferable to laminate with a material.
[0024]
Here, if the mold 1 is released from the mold 1 when the curing reaction of the polymerization curable resin raw material 7 is not yet completed, the occupation time of the mold 1 can be shortened. However, when the polymerization curable resin raw material 7 at the time of mold release is uncured and has high fluidity, its shape is not maintained and a good laminate cannot be obtained. That is, the release time is greatly influenced by the degree of polymerization and curing of the polymerization curable resin raw material 7. However, it is difficult to sequentially observe the cured state in the mold during molding. Therefore, in the present invention, a normal temperature measuring means provided in the mold, etc., by setting the reference for the time of release within the time from the start of the heat generation of the polymerization curable resin raw material 7 to the peak of the heat generation of polymerization. Is used to easily determine the appropriate release time.
[0025]
The specific temperature at the time of mold release is an optimum value according to various conditions such as the type of the polymerization curable resin raw material 7, the shape of the mold 3 made of a thermoplastic resin molded product, and the heat capacities of both molds 1 and 3. Is different. Therefore, in the present invention, the specific temperature is not particularly limited. For example, a specific value of the temperature of the polymerization exothermic peak is examined in advance, and the temperature is in a temperature stage before the specific value and in a state in which the polymerization curable resin raw material 7 is not fluid enough to maintain the shape. It may be released from time to time. However, the temperature at the time of mold release is preferably somewhat before the peak of the exotherm, and specifically, it is preferable to release the mold at a temperature that is about 5 ° C. lower than the temperature at the peak of exotherm.
[0026]
After the mold release, the polymerization curable resin raw material 7 in which the curing reaction has not been completed is held in shape by the mold 3 made of a thermoplastic resin molded product, and its deformation is prevented. Further, the outer surface of the cell of the mold 3 is supported by the presser 10 so as to prevent deformation, so that the mold 3 itself made of a thermoplastic resin molded product is not deformed.
[0027]
Regarding the scratches on the laminate due to contact with the surface of the mold 1 at the time of mold release, in the bathtub obtained in this example, a thermoplastic resin molded article having an excellent appearance becomes the surface, and the polymerization curable resin raw material Since the easily damaged scratched reinforcing layer formed by 7 is the back surface, the scratch is not a problem.
[0028]
After the mold release, this laminate, that is, the laminate composed of the mold 3 composed of the thermoplastic resin molded product and the reinforcing layer composed of the polymerization curable resin raw material 7 in the middle of the curing reaction, is supported as it is by the presser 10. An exothermic curing reaction proceeds.
[0029]
For example, an integrated or divided presser can be used as the presser 10. Specifically, a presser composed of FRP such as epoxy resin, vinyl ester resin, unsaturated polyester resin, metal such as aluminum, wood, or the like can be suitably used. Further, the mold 3 can be supported by using a fluid such as gas or liquid instead of the presser 10 made of solid. Specifically, there is a method in which a sealed space is formed on the outer surface of the cell on the mold 3 side and supported by a gas such as air or nitrogen, or a liquid such as water or silicon oil. Further, if the presser 10 and the supporting fluid are configured to be temperature-controllable, it is also effective in improving moldability such as a molding cycle up.
[0030]
When supporting the cell outer surface of the mold 3, if the shape and dimensions of the mold 3 fluctuate, the support by the fluid is not particularly problematic, but the pressurization by the solid may cause a problem in fitting. In this case, except for a corner portion that is difficult to deform, only the deformable portion such as a flat portion is supported by the presser 10, so that the shape margin between the mold 3 and the presser 10 and the shape of the obtained laminate are obtained. Stability can also be improved.
[0031]
Further, when the outer surface of the cell is supported by an integrated presser or divided presser, between the presser surface of the presser 10 and the cell outer surface on the mold 3 side made of a thermoplastic resin molded product, for example, in a reduced pressure state. It is possible to correct the deflection of the surface of the mold 3 made of a thermoplastic resin molded product. In this case, a pressurizing hole may be provided in the presser 10, and degassing and depressurization may be performed therefrom.
[0032]
If the mold 1 is released before the polymerization exothermic peak of the polymerization curable resin raw material 7 in accordance with the steps as described above, the occupation time of the mold 1 is shortened and its effective use is possible.
[0033]
FIG. 2 is a schematic cross-sectional view showing an embodiment in which the mold 1 or the like is used for the next molding while the curing of the laminate is completed in order to effectively use the released mold 1 or the like. In this embodiment, molds 3 and 3 ′ and pressers 10 and 10 ′ made of a plurality of thermoplastic resin molded products are prepared in advance for one mold 1. Then, using the mold 1, the mold 3 made of a thermoplastic resin molded product, and the presser 10, the above-described process is performed as the first molding, and the mold 1 is placed before the polymerization heat generation peak of the polymerization curable resin raw material 7. Release.
[0034]
Even after the mold release, the exothermic curing reaction proceeds in a state where the laminate formed by the first molding is supported by the presser 10. While this reaction is in progress, the released mold 1 is used for the mold 3 ′ made of a thermoplastic resin molded product supported by the presser 10 ′ to form a similar cell, and the second molding is performed. Repeat. As a result, the number of molds 1 and their clamping devices can be reduced, and the occupation time can be shortened. As a result, productivity can be improved.
[0035]
In each of the embodiments described above, an example of a bathtub (bathtub) shape has been given. However, the present invention is not limited to this, and is useful for manufacturing various three-dimensional resin molded products such as a wash bowl and a shower pan, for example. It is.
[0036]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
[0037]
[ Reference example ]
In accordance with the steps described with reference to FIG. 1, a bathtub-shaped laminate was produced as follows.
[0038]
First, 1.5 parts by weight of a catalyst (trade name Permec N, manufactured by Nippon Oil & Fats Co., Ltd.) is added to 100 parts by weight of unsaturated polyester resin (trade name: Iupica 4521P, manufactured by Nippon Iupika Co., Ltd.) immediately before injection. It mixed with the mixer and it was set as the polymerization curable resin raw material 7.
[0039]
Next, a preformed glass fiber preform 8 is put between a female mold 1 made of bathtub-shaped FRP and a male mold 3 made of an acrylic resin molded product, and the molds 1 and 3 are combined together. The interval was set to 4 mm, which is the reinforcement target thickness, and the sealing was performed with an elastic seal packing 4. Further, the presser 10 was placed and supported on the cell outer surface of the mold 3 made of an acrylic resin molded product.
[0040]
Next, the previously prepared polymerization curable resin material 7 was injected from the injection port 5 at a pressure of 1 kg / cm ² to fill the cell 9. The polymerization curable resin material 7 generated heat due to the curing reaction. When heat was generated from about 25 ° C. to about 40 ° C., the mold was released from the mold 1 before reaching the exothermic peak temperature (about 50 ° C.), and was supported only by the presser 10.
[0041]
When left in such a state for 40 minutes, the polymerization curable resin raw material 7 reached an exothermic peak temperature of about 50 ° C. After the polymerization and curing reaction was sufficiently completed, the presser 10 was removed to obtain a bathtub made of a laminate in which a reinforcing layer was integrated with an acrylic resin molded product.
[0042]
In this reference example , the polymer curable resin raw material 7 was released in a state where the curing before reaching the exothermic peak temperature was insufficient, but the shape could be retained by the acrylic resin molded product itself and the presser 10. A good bathtub with no change was obtained. Further, this bathtub had no problem in appearance and was evaluated for performance according to JIS A 1718. As a result, there was no deformation or crack, and all the items passed.
[0043]
[Example 1 ]
As shown in FIG. 2, a mold 3 ′ and a presser 10 ′ made of another set of thermoplastic resin molded products were further prepared.
[0044]
Then, the first molding is performed in the same process as in the reference example, and the laminate is released from the mold 1 before reaching the exothermic peak temperature of the polymerization curable resin raw material 7 and supported by only the presser 10. The polymerization curing reaction was completed, and a bathtub was obtained by the first molding.
[0045]
Further, while the polymerization curing reaction in the first molding is in progress, the mold 1 or mold clamping apparatus released from the first molding is replaced with another mold 3 ′ made of a thermoplastic resin molded product. The same molding was repeated and a bathtub was obtained by the second molding.
[0046]
In this example, before the first molding was completed, the second molding could be performed using the mold 1 or the like, the occupation time of the mold 1 or the like could be shortened, and the production efficiency could be improved. In addition, the bathtub obtained by the first and second moldings has no change in shape as in the reference example, and there is no problem in appearance, and when performance evaluation was performed according to JIS A 1718, there was no deformation or cracking. Passed the item.
[0047]
[Comparative Example 1]
As shown in FIG. 3, according to the same steps as in the reference example , except that the FRP male mold 2 similar to the female mold 1 was used instead of the mold 3 and the presser 10 made of the acrylic resin molded product, An attempt was made to obtain a cured molded product of the polymerization curable resin raw material 7.
[0048]
However, when the polymerization curable resin raw material 7 generates heat from 25 ° C. to 40 ° C., the mold is released from both molds 1 and 2 in a state where the curing before reaching the exothermic peak temperature is insufficient. As a result, warpage deformation occurred in the molded product. Furthermore, scratches were generated on the surface of the male mold 2 side, resulting in a bathtub with poor appearance.
[0049]
【The invention's effect】
According to the present invention described above, when manufacturing a laminate having a predetermined shape in which a thermoplastic resin molded article is reinforced with a polymerized and cured resin, the occupation time of a mold to be used can be shortened, and productivity can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing an embodiment of a production method of the present invention.
FIG. 2 is a schematic cross-sectional view showing an embodiment for effectively using a released mold in the present invention.
3 is a schematic cross-sectional view showing the production method of Comparative Example 1. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Female type | mold 2 Male type | mold 3, 3 'Type | mold 4 which consists of thermoplastic resin molded products 4 Seal packing 5 Inlet 6 Exhaust port 7 Polymerization hardening resin raw material 8 Glass fiber preform 9 Cell 10, 10' Presser

Claims

A mold made of a thermoplastic resin molded product is used as a part of a mold for forming a laminate having a predetermined shape, a polymerization curable resin raw material is injected into a cell of the mold, polymerized and cured, and the thermoplastic resin molding is performed. In a manufacturing method of a laminate including a step of releasing the laminate from a mold other than the mold made of the thermoplastic resin molded article after being integrated with a product to form a laminate,
For one mold other than the mold made of the thermoplastic resin molded product, prepare a plurality of molds and pressers made of a thermoplastic resin molded product,
Prior to injecting the polymerization curable resin raw material, the glass fiber molded into a shape corresponding to a mold comprising a glass fiber mat or a thermoplastic resin molded article is placed in a cell,
During molding, the mold made of the thermoplastic resin molded product is supported by a presser,
After releasing the laminate from a mold other than the mold made of the thermoplastic resin molded product within the time from the polymerization heat generation start of the polymerization curable resin raw material to the polymerization heat generation peak ,
While the exothermic curing reaction of the polymerization curable resin raw material proceeds while the laminate is supported by a presser, a mold composed of another thermoplastic resin molded product supported by another presser, A method for producing a laminate, comprising forming a cell using a mold other than a mold made of a thermoplastic resin molded article, and repeating the step for producing the laminate.