JP4704631B2

JP4704631B2 - Method for producing mold and multilayer molded body

Info

Publication number: JP4704631B2
Application number: JP2001283890A
Authority: JP
Inventors: 由卓小林; 信裕臼井
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2001-03-30
Filing date: 2001-09-18
Publication date: 2011-06-15
Anticipated expiration: 2021-09-18
Also published as: JP2002355836A

Description

【０００１】
【発明の属する技術分野】
本発明は、熱可塑性樹脂製基材に表皮材が貼りあわされた多層成形体を製造するのに有用な金型、及び多層成形体の製造方法に関するものである。
【０００２】
【従来の技術】
熱可塑性樹脂で形成された基材の表面に表皮材が貼り合わされた多層成形体は、製造コスト、軽量性、及び賦形性に優れており、自動車の内装部品（例えば、ドアトリム、インストルメントパネルなど）、家電製品の内外装部品をはじめ広い分野で多く使用されている。
【０００３】
前記多層成形体としては、成形体の表面に複数の意匠面が形成された成形体（以下、多面成形体と称する場合がある）が知られている。例えば、柄、材質などが異なる複数の意匠面を形成すると、基材の表面を効果的に装飾できる。前記多面成形体としては、複数の意匠面を有する１枚の表皮材が基材に貼り合わされた成形体や、複数枚の表皮材が基材に貼り合わされた成形体が知られている。複数枚の表皮材が貼りあわされた成形体は、例えば、単一の表皮材の裏側に溶融樹脂を供給し、表皮材と樹脂とを貼り合わせながら成形する方法（射出成形法、圧縮成形法など）によって多層成形体を複数個製造し、これら多層成形体を熱融着等によって平面方向に接合することによって製造されている。また前記多面成形体は、射出成形法、圧縮成形法などによって樹脂基材を製造し、この基材の表面に複数枚の表皮材を接着することによっても製造されている。しかし前者の方法では、基材同士の接合部の強度が不足する場合がある。また後者の方法では表皮材が剥離する場合がある。
【０００４】
これらの問題を解決する方法として、例えば、雄雌一対の金型を用い、２枚の表皮材を平面方向に隣接して貼り合わせた後、表皮材の裏面を雄型に向けて表皮材を前記金型に挿入し、雄型から溶融樹脂を供給して、表皮材と樹脂とを貼り合わせながら成形する方法が知られている。図１４はこの製造方法によって製造しようとする多面成形体（目標）の平面図であり、図１５は前記多面成形体（目標）を正面からみた断面図であり、図１６は前記製造方法を説明するための概略断面図であり、図１７は前記製造方法によって現実に製造される多面成形体の平面図である。図１４及び１５に示すように目標とする多面成形体は、熱可塑性樹脂製基材４の表面に、２枚の表皮材（第１の表皮材１、第２の表皮材２）が隣接して貼り合わされている。前記表皮材１及び表皮材２の境界部（境界線）３は、ゆがむことなくきれいなラインを形成している。図１６に示すように、前記多面成形体を製造する場合、雄型１４と雌型１５とで構成された金型に、第１の表皮材１及び第２の表皮材２が境界部３で接合された表皮材を挿入する。この接合表皮材は裏面を雄型１４に向けて挿入し、表面を雌型１５に接触させる。前記雄型１４の成形面には、前記第１の表皮材１の裏面に溶融樹脂を供給するための第１のゲート１１と、前記第２の表皮材２の裏面に溶融樹脂を供給するための第２のゲート１２とが形成されており、これらゲート１１，１２から溶融樹脂を供給する［図１６（ａ）参照］。そして雌型１５を雄型１４に向けて移動させることによって、プレスしながら成形する［図１６（ｂ）参照］。ところがこのような方法では、一方のゲートから射出された樹脂（この例では、第１のゲート１１から射出された樹脂２１）が、他方のゲートから射出された樹脂（この例では、第２のゲート１２から射出された樹脂２２）よりも先に境界部（貼り合わせ部）３に到達する場合があり、境界部の位置がずれる場合がある。そのため図１７に示すように、第１の表皮材１と第２の表皮材２との境界部３は蛇行してしまい、きれいなラインを形成するのが困難である。
【０００５】
前記例では２枚の表皮材を用いる例について示したが、１枚の表皮材を用いても、前記２枚の表皮材を用いる例と同様に、境界部の位置がずれる場合がある。すなわち２枚の表皮材（第１の表皮材１、第２の表皮材２）を境界部３で接合した接合表皮材に代えて、第１の表皮材（表皮部）及び第２の表皮材（表皮部）を有する１枚の表皮材を用いても、一方の樹脂が他方の樹脂よりも先に境界部に到達すると、この先に到達する樹脂の流れに引っ張られて境界部の位置がずれる場合がある。
【０００６】
２枚の表皮材を用いる場合及び１枚の表皮材を用いる場合のいずれであっても、第１の表皮材（表皮部）と第２の表皮材（表皮部）との面積が大きく異なる場合、成形体が複雑な凹凸形状を有する場合、又は成形体が大きくなってゲートの数が多くなる場合、境界部への樹脂の到達のタイミングのずれが大きくなり、境界部の位置がずれたり境界部付近に皺が発生し、外観を損ね易くなる。
【０００７】
【発明が解決しようとする課題】
本発明は上記の様な事情に着目してなされたものであって、その目的は、平面方向に隣接する複数の表皮材［複数枚の表皮材、複数の表皮材（表皮部）で構成された１枚の表皮材など］が熱可塑性樹脂製の基材に貼りあわされた成形体（多面成形体）を製造する場合でも、表皮材（表皮部）の境界部（境界線）の位置ずれや皺の発生を確実に防止できる金型、及び成形体の製造方法を提供することにある。
【０００８】
【課題を解決するための手段】
本発明者らは、前記課題を解決するために鋭意研究を重ねた結果、複数の表皮材［複数枚の表皮材、複数の表皮材（表皮部）で構成された１枚の表皮材など］の裏側に樹脂を供給する場合に、表皮材の裏側に位置する金型において、表皮材（表皮部）の境界部に対応する位置の両側又は片側に樹脂止め板を突出可能に埋設し、ゲートから流入して表皮材（表皮部）の境界部に向かう樹脂の流れを前記樹脂止め板で制御すると、樹脂が境界部に到着するタイミングを略そろえることができることを見出し、本発明を完成した。
【０００９】
すなわち上記目的を達成し得た本発明の金型とは、平面方向に互いに隣接する第１及び第２の表皮材（第１及び第２の表皮部を有する表皮材）の裏側に溶融状熱可塑性樹脂を供給して表皮材と熱可塑性樹脂とを貼り合わせて多層成形体を製造するための金型でありかつ、第１の表皮材（表皮部）の裏側に溶融状熱可塑性樹脂を供給するための第１のゲートと、第２の表皮材（表皮部）の裏側に溶融状熱可塑性樹脂を供給するための第２のゲートとが表皮材の裏側に位置する金型に形成された雄雌一対の金型において、前記表皮材の裏側に位置する雄型又は雌型いずれか一方の金型の成形面のうち第１及び第２の表皮材（表皮部）の境界部に対応する位置の両側又は片側（好ましくは両側）であって、この境界部に対応する位置とゲートとの間に、前記境界部に対応する位置に略沿って樹脂止め板が突出可能に埋設されている点に要旨を有するものである。表皮材の裏側に位置する金型の成形面のうち表皮材（表皮部）の境界部に対応する位置には、前記境界部を挟持するための挟着体を埋設してもよい。また表皮材の表側に位置する金型は、表皮材（表皮部）の境界部に対応する位置に、境界部に沿って連続する突起部が形成されたものであってもよい。
【００１０】
また上記目的を達成し得た本発明の成形体の製造方法とは、雄雌一対の金型の雄型及び雌型の間に、平面方向に互いに隣接する第１及び第２の表皮材（第１及び第２の表皮部を有する表皮材）を配設し、表皮材の裏側に位置する雄型又は雌型いずれか一方の金型の成形面に、第１の表皮材（表皮部）の裏側に溶融状熱可塑性樹脂を供給するための第１のゲートと、第２の表皮材（表皮部）の裏側に溶融状熱可塑性樹脂を供給するための第２のゲートとを形成し、これら第１及び第２のゲートから溶融状熱可塑性樹脂を供給し、前記表皮材と熱可塑性樹脂とを貼り合わせて多層成形体を製造する方法であって、前記表皮材の裏側の金型面のうち表皮材（表皮部）の境界部に対応する位置の両側又は片側（好ましくは両側）に樹脂止め板を突出可能に埋設し、樹脂止め板を金型キャビティ内に突出した状態で前記各ゲートから溶融状熱可塑性樹脂を供給し、ゲートから流入して前記境界部に向かう樹脂を前記樹脂止め板で遮ると共に金型キャビティ内への樹脂の充填が終了するまでに前記樹脂止め板を金型内に収容することにより、樹脂が境界部に到着するタイミングを制御する点に要旨を有するものである。片側に樹脂止め板を埋設する場合、第１及び第２のゲートは、一方のゲートから境界部に対応する位置までの距離が他方のゲートから境界部に対応する位置までの距離よりも短くなるように形成され、境界部までの距離が短いゲートが形成されている側に前記樹脂止め板を突出可能に埋設し、この樹脂止め板によって前記境界部までの距離が短いゲートから供給された樹脂を一旦遮り、境界部までの距離が長いゲートから供給された樹脂の境界部への到達タイミングに合わせて前記樹脂止め板を金型内に収容することにより、樹脂が境界部に到達するタイミングを制御するのが望ましい。両側に樹脂止め板を埋設する場合、境界部までの距離が短いゲートから供給された樹脂を一方の側の樹脂止め板で一旦遮ると共に、境界部までの距離が長いゲートから供給された樹脂を他方の側の樹脂止め板で一旦遮った後、両側の樹脂止め板を金型内に収容して樹脂が境界部に到達するタイミングを制御するのが望ましい。樹脂止め板は、ゲートから流入した樹脂が樹脂止め板の埋設位置に到達するまでに、表皮材を介して表皮材の表側に位置する金型の成形面に突き当てておくのが望ましい。前記表皮材は、金型内に配設するに先立って、成形体の形状に合わせて賦形しておいてもよい。好ましい成形方法はプレス成形である。金型キャビティ内に突出した樹脂止め板は、樹脂の賦形圧力で金型内に収容するのが望ましい。上記製造方法においては、前記第１及び第２のゲートから供給する樹脂として発泡剤を含む溶融状熱可塑性樹脂（発泡性樹脂）を用いてもよい。発泡性樹脂を用いる場合、金型キャビティ内への該樹脂の充填が終了した後、金型キャビティを拡大させ、該樹脂を発泡させてもよい。
【００１１】
なお本明細書において用語「熱可塑性樹脂」は、熱可塑性エラストマーを含む意味で使用する。
【００１２】
【発明の実施の形態】
以下、添付図面を参照しながら本発明を詳細に説明するが、本発明はもとより図示例に限定される訳ではなく、前・後記の趣旨に適合し得る範囲で適当に変更を加えて実施することも可能であり、それらはいずれも本発明の技術的範囲に包含される。例えば、以下、表皮材の表側に位置する金型として雌型を使用し、表皮材の裏側に位置する金型として雄型を使用する場合を例にとって説明するが、反対、すなわち表皮材の表側に位置する金型として雄型を使用し、表皮材の裏側に位置する金型として雌型を使用してもよい。
【００１３】
図１は本発明の金型及びその金型を用いた成形体の製造方法の一例を示す概略断面図であり、図２は前記金型のうち雄型１４の成形面の平面図であり、図３は前記金型で使用する樹脂止め板を側方から見た概略斜視図である。前記金型を用いれば、図１４及び図１５に示す多層多面成形体を製造できる。
【００１４】
すなわち図１及び図２に示す金型１０ａは、平面方向に互いに隣接する第１の表皮材１及び第２の表皮材２の裏側に溶融状（流動状）熱可塑性樹脂を供給して表皮材と熱可塑性樹脂とを貼り合わせて多層成形体（多層多面成形体）を製造するための金型である。なお前記第２の表皮材の面積は、前記第１の表皮材の面積よりも大きい。また表皮材１及び２は、境界部（合縁部）３において予め接合されており、この例では、接着剤によって接着されている。
【００１５】
前記金型１０ａは、対になって熱可塑性樹脂を成形するための雄型１４と雌型１５とで構成されている。前記雄型１４の成形面には、前記第１の表皮材１の裏側に溶融状樹脂を供給するための第１のゲート（樹脂供給口）１１ａ，１１ｂと、前記第２の表皮材２の裏側に溶融状樹脂を供給するための第２のゲート（樹脂供給口）１２ａ，１２ｂとが形成されている。前記第１のゲート１１から前記境界部に対応（対向）する位置（以下、境界予定位置又は境界予定線と称する場合がある）までの距離は、第２のゲート１２から境界予定位置までの距離よりも短い。そしてこれら第１のゲート１１及び第２のゲート１２から流入した溶融状樹脂が、表皮材１及び表皮材２の境界部３（又は雄型１４の成形面のうち、前記境界部３に対応する境界予定位置１３）に向かうのを抑制するため、前記雄型の成形面に樹脂止め板４１，４２が突出可能に埋設されている。
【００１６】
より詳細には、前記樹脂止め板４１，４２は、前記境界予定位置（境界予定線）１３の両側に境界予定位置に略沿って配設されている。そしてシャフト４３，４４を介してシリンダー（図示せず）に接続しており、前進して成形面から突出可能であると共に、後進（この例では、降下）して雄型内に収容可能である。これら樹脂止め板４１，４２のうち、一方の樹脂止め板（第１の樹脂止め板）４１は第１ゲート１１から流入する樹脂が境界部３（又は境界予定位置１３）に向かうのを抑制可能であり、他方の樹脂止め板（第２の樹脂止め板）４２は第２ゲート１２から流入する樹脂が境界部３（又は境界予定位置１３）に向かうのを抑制可能である。さらに図３に示すように、前記樹脂止め板４１，４２の上面は成形体の形状（すなわち、表皮材１，２の形状）に沿った形状を有しており、この例では成形体の形状が平坦であるため、樹脂止め板４１，４２の上面４５も平坦になっている。そのため、樹脂を略完全に止めることができる。
【００１７】
上記のような金型１０ａを用いれば、以下に説明するようにして多層多面成形体を製造できる。図１（ａ）〜（ｃ）に製造方法の一例を示す。すなわち図１（ａ）に示すように、この例では成形体に該当する空間よりも大きな空間を形成するように金型１０ａを大きく開き、この金型１０ａ内に表皮材１及び２を裏面が雄型１４に向くように配設する。そして両樹脂止め板４１，４２を金型キャビティ内に突出させた状態で、第１ゲート１１ａ，１１ｂから表皮材１の裏側に溶融状熱可塑性樹脂を供給し、第２ゲート１２ａ，１２ｂから表皮材２の裏側に溶融状熱可塑性樹脂を供給する。
【００１８】
そしてこの例では、溶融状熱可塑性樹脂の供給後、雌型１５を雄型１４に向けて移動させ（すなわち、型締めを開始し）、樹脂をプレスしながら表皮材の裏側に溶融状熱可塑性樹脂を充満させていく［図１（ｂ）参照］。溶融状熱可塑性樹脂を充満させていく段階では、樹脂止め板４１，４２は成形面から突出し、表皮材１，２を介して雌型１５に突き当てられた状態である。仮に樹脂止め板４１，４２を突出させないで溶融状熱可塑性樹脂を充満させていくとすると、境界部までの距離が短い第１ゲート１１ａ，１１ｂから供給された樹脂２１は、境界部までの距離が長い第２ゲート１２ａ、１２ｂから供給された樹脂２２よりも先に境界部３に到達し、境界部３を大きく位置ずれさせる虞があるのに対して、本発明では樹脂止め板４１，４２を金型キャビティ内に突出させ、該樹脂止め板４１，４２を表皮材１，２を介して雌型１５に突き当てた状態で溶融状熱可塑性樹脂を充満させていくため、樹脂２１，２２が境界部に到達するタイミングを制御できる。より具体的には、境界部までの距離が短い第１ゲート１１ａ，１１ｂから供給された樹脂２１は第１樹脂止め板４１で遮られる。そのため前記樹脂２１が境界部３に到達するタイミングを遅延でき、境界部までの距離が長い第２ゲート１２ａ，１２ｂから供給された樹脂２２が境界部３へ到達するタイミングと略そろえることができ、境界部３の位置ずれを防止できる。
【００１９】
さらにこの例では、境界部までの距離が長い第２ゲート１２ａ，１２ｂから供給された樹脂２２も第２樹脂止め板４２で遮られており、第１樹脂止め板４１及び第２樹脂止め板４２の降下のタイミングを調節することにより、境界部３への樹脂２１，２２の到達タイミングを簡便に制御できる。
【００２０】
またこの例では、雌型１５が前記図１（ｂ）の段階よりも型締め方向に移動し、雄型１４と雌型１５とのクリアランスが成形体の厚みｑ（図１５参照）に略等しくなり、熱可塑性樹脂で形成される基材部４の高さが基材厚みｐ（図１５参照）に略等しくなるまでに（すなわち、型締めが完了するまでに）、樹脂止め板４１，４２の収容を終了させておく［図１（ｃ）参照］。なお樹脂止め板４１，４２の収容（この例では、降下）の開始は、前記型締めが完了する段階よりも早いのが望ましく、例えば、樹脂止め板４１，４２の外側（すなわち境界部３が存在する側を内側としたときの外側）に溶融樹脂が略充満した段階で収容（降下）を開始するのが望ましい。
【００２１】
図１（ｃ）に示す型締めの完了後、樹脂を冷却・固化し、金型１０ａを開放（型開き）することにより、境界部３に位置ずれや皺がない図１４，１５に示すような成形体を得ることができる。
【００２２】
なお上記図示例（図２）では、雄型１４の成形面に境界予定位置（境界予定線）１３を破線でしめしたが、当該破線は境界予定位置を明示して説明するための便宜上のものであり、雄型１４の成形面に現実に破線状のものが形成されているわけではない。このことは後述の図示例でも同様である。
【００２３】
なお型締めを行うに際しては、雄型１４及び雌型１５のいずれを移動させてもよく、両方を移動させてもよい。また前記図示例では、樹脂の供給完了後に型締めを行って樹脂をプレスするプレス成形によって成形体を製造する例を示したが、型締めは必ずしも樹脂の供給完了後に行う必要はなく、樹脂を供給しながら行ってもよい。なお樹脂の供給完了後に型締めを行う際には、供給完了後速やかに型締めを開始するのが望ましい。また前記図示例では、垂直方向に型締めを行う例を示したが、垂直方向以外の方向（例えば、水平方向）に型締めを行ってもよい。さらに成形法はプレス成形に限定されず、射出成形であってもよくプレス成形と射出成形とを組合わせてもよい。例えば、射出成形によって成形体を製造する場合、プレス成形と同様にして表皮材１，２を挿入した後、型締めを完了させ、樹脂止め板４１，４２を金型キャビティ内に突出させ、該樹脂止め板４１，４２を表皮材１，２を介して雌型１５に突き当てた状態で、ゲート１１，１２から溶融状熱可塑性樹脂の供給を開始する。そして各ゲート１１，１２から供給された樹脂２１，２２に高圧がかかり過ぎない程度の段階で、樹脂止め板４１，４２を収容すると共に、溶融状熱可塑性樹脂の供給を継続して樹脂止め板４１，４２と境界部３との間まで樹脂を供給して成形体を製造する。またプレス成形と射出成形とを組合わせる場合、初期の樹脂供給量が少ない点を除いては前記プレス成形の例と同様に操作し、不足する樹脂を適当な段階で射出供給する方法が挙げられる。
【００２４】
なおプレス成形及び射出成形のいずれの場合であっても、樹脂止め板は、ゲートから流入した樹脂が樹脂止め板の埋設位置に到達するまでに、表皮材を介して表皮材の表側に位置する金型の成形面に突き当てておくのが望ましい。
【００２５】
またプレス成形及び射出成形のいずれの場合であっても、樹脂止め板４１，４２の収容は、金型キャビティ内（成形体に該当する空間部分）への樹脂の充填が終了するまでに完了すればよい［図１（ｃ）参照］。すなわちプレス成形の場合は、型締めが完了して金型キャビティ内に樹脂が充満するまでに樹脂止め板４１，４２の降下（収容）を完了すればよく、射出成形の場合は、必要な樹脂が全て射出供給されて金型キャビティ内に樹脂が充満するまでに、樹脂止め板４１，４２の収容を完了すればよい。
【００２６】
好ましい成形方法はプレス成形である。射出成形の場合、射出された溶融樹脂が直ちに表皮材と接触するため、表皮材が高温及び高圧にさらされ表皮材が損傷する場合があるのに対して、プレス成形では金型を大きく開いて樹脂を供給するため、樹脂の供給圧によって表皮材を損傷させる虞が少ない。
【００２７】
なお本発明においては、後述するように、第１及び第２のゲートから供給する樹脂として、発泡剤を含む溶融状熱可塑性樹脂（発泡性樹脂）を使用することができる。発泡性樹脂を用いる場合、得られた成形体を金型から取り出した後で発泡させてもよいが、成形体を金型内で発泡させるのが望ましい。
【００２８】
図４は、樹脂を発泡させる場合について説明するための概略断面図である。この例では、前記金型１０ａを用いており、前記成形（プレス成形、射出成形など）によって金型キャビティ内への発泡性樹脂２１、２２の充填が完了した後［図１（ｃ）参照］、雄型１４又は雌型１５を型締方向とは逆の方向に移動させることにより金型キャビティを拡大し、充填樹脂（基材樹脂）４を発泡させている（図４）。
【００２９】
なお前記金型キャビティ内に溶融状の発泡性樹脂２１、２２を充填する場合、充填時に雄型１４及び雌型１５で形成されるキャビティクリアランスを制御することにより発泡ガスの抜けを防止して、充填完了後の発泡操作時の発泡不足を防止するのが望ましい。すなわち前記キャビティクリアランスは、通常、表皮材１，２の種類や樹脂温度などの成形条件に応じて適宜設定されるが、発泡性樹脂を充填する場合にはキャビティクリアランスが小さくなるように留意して発泡ガスの抜けを防止するのが望ましい。
【００３０】
金型キャビティ内への発泡性樹脂２１、２２の充填が完了した後は、金型キャビティの拡大に先立って、樹脂表面層を冷却してスキン層を形成するのが望ましい。スキン層は、厚すぎると十分な発泡倍率が得られないため、十分な発泡倍率が得られる程度の厚みに制御するのが望ましい。スキン層の厚みの制御は、例えば、成形品厚み、金型温度などを考慮してスキン層の形成時間を調節することにより行うことができる。
【００３１】
金型キャビティを拡大するにあたって、拡大の程度（拡大代）は、製造する製品厚み（発泡倍率）に応じて適宜決定できる。なお金型キャビテイの拡大及び発泡を行うにあたっては、樹脂止め板４１、４２は金型内に収容したままにしておくのが望ましい。
【００３２】
前記発泡方法は、図１に示す金型１０ａを用いる場合に限定されず、後述の金型を含めた他の種々の金型を用いる場合にも採用できる。
【００３３】
表皮材１及び２は、前記図１に示すように、金型内に配設するに先立って、成形体の形状（すなわち、雌型１５の形状）に合わせて賦形（予備賦形）してもよいが、予備賦形しておかなくてもよい。特に下記に述べる挟着体を用いる場合、表皮材１，２を予備賦形しないことが多い。
【００３４】
表皮材１及び２は、種々の方法で接合でき、例えば、化学的接着方法（接着剤やヒートシールによる接着）の他、治具を用いる方法（糸による縫い付け；針、ピン、ホッチキスなどによる固定；挟着体による固定など）が挙げられる。
【００３５】
図５は前記挟着体（挟持体）の一例を示す概略斜視図であり、図６は前記図５の挟着体のＡ−Ａ’線断面図であり、図７は前記図５の挟着体のＢ−Ｂ’線断面図である。前記挟着体５０は、挟持する表皮材１，２に対して対称な一対の挟持片５１，５２で構成されており、これら挟持片５１，５２は表皮材１，２を挟持するための挟持部５４と、溶融樹脂を収容して表皮材１，２を樹脂と接着するための凹部５３とを有している。
【００３６】
図８は前記挟着体５０を用いた金型１０ｂの概略断面図である。この金型１０ｂは、雄型１４の成形面に前記挟着体５０が埋設されている以外は、前記図１の金型１０ａと同様である。なお前記挟着体５０は、表皮材１，２の境界部３に対応する場所（境界予定位置）に埋設されている。このような金型１０ｂを用いても、前記図１の場合と同様に成形（プレス成形、射出成形など）することにより、多面多層成形体を製造できる。なお金型１０ｂを型開きして、成形体を取り出す場合に、挟着体５０も成形体から取り外してもよい。挟着体５０の凹部５３に入り込んだ樹脂が第１表皮材１及び第２表皮材２の両方に接触しながら固化しているため、挟着体５０を取り外しても表皮材１，２が分離する虞はない。
【００３７】
本発明では、雌型１５のうち表皮材１，２の境界部３に対応する位置（境界予定位置）に、境界部に沿って連続する突起部（木目込み矢）を設けるのが望ましい。図９は前記突起部（木目込み矢）を備えた金型の一例を示す概略断面図である。この金型１０ｃでは、雌型１５の境界予定位置に突起部６１が形成されていると共に、雄型１４の境界予定位置には前記突起部６１の突起形状に対応する窪み６２が形成されている。このような金型１０ｃを用いて、前記図１の金型１０ａの場合と同様に成形体を製造すると、突起部６１によって境界部３の変形をより高度に防止できる。なお前記窪み６２は、必ずしも必要ではない。
【００３８】
前記突起部６１は、挟着体５０を埋設した前記図８に示す成形体１０ｂの雌型１５に形成してもよい。
【００３９】
本発明において、樹脂止め板は、境界予定位置（境界予定線）の両側に設けるのが望ましいが、片側だけに設けてもよい。片側だけに設ける場合、境界部までの距離が短いゲートが形成されている側（上記各図示例では、面積の小さい表皮材１に樹脂を供給するゲート１１）の側に樹脂止め板を設けることが多い。このようにしても、境界部までの距離が長いゲートから供給された樹脂（上記各図示例では、ゲート１２から供給された樹脂２２）の境界部への到達タイミングに合わせて前記樹脂止め板を降ろすことにより、樹脂が境界部に到達するタイミングを制御できる。
【００４０】
樹脂止め板は境界予定線の近くに設けるのが望ましく、樹脂止め板と境界予定線との距離ｙ（図２参照）は、ゲートと境界予定線との距離ｘ（図２参照）を１００としたとき、例えば、５０以下、好ましくは４０以下、さらに好ましくは３０以下である。また樹脂止め板を境界予定位置の両側に設ける場合には、境界予定位置と両側の樹脂止め板との距離を略同一にすることが好ましい。
【００４１】
さらには樹脂止め板は、境界予定線に略（概ね）沿ってさえいれば、境界予定線の形状とわずかにかけ離れていてもよく、例えば、境界予定線から近い部分と遠い部分とがあってもよい。図１０は、このような樹脂止め板を用いた雄型１４の成形面の平面図である。図１０では、一方の側（この例では、第２ゲート１２ａ，１２ｂの側）の樹脂止め板４２ｂは、境界予定線の形状とわずかにかけ離れている。
【００４２】
境界予定線から最も遠い部分の距離ｙ2は、最も近い部分の距離ｙ1に対して、例えば、３倍以下、好ましくは２倍以下、さらに好ましくは１．５倍以下である。
【００４３】
樹脂の到達のタイミングを制御できる限り、樹脂止め板の長さは、境界予定線の全長より短くてもよい。また樹脂止め板は、境界予定位置（境界予定線）の片側につき、１枚であってもよく複数枚であってもよい。図１１は、短い樹脂止め板を用いた雄型１４の一例を示す平面図であり、図１２（ａ），（ｂ）は、片側につき複数枚の樹脂止め板を用いた雄型１４の一例を示す平面図である。図１１の例では、境界予定線１３の両側に、前記予定線の全長より短い樹脂止め板４１ａ、４２ａが配設されている。また図１２（ａ）の例では、一方の側（この例では、第２ゲート１２ａ、１２ｂ側）に境界予定線１３よりも若干短い樹脂止め板４２ａを１枚配設し、他方の側（この例では、第１ゲート１１ａ、１１ｂ側）に境界予定線１３の半分以下の長さの２枚の樹脂止め板４１ｂ，４１ｃを配設している。さらに図１２（ｂ）の例では、境界予定線１３のいずれの側にも、２枚の樹脂止め板（両側の合計で４枚の樹脂止め板）４１ｂ，４１ｃ，４２ｃ，４２ｄを配設し、そのうち一方の側（この例では、第２ゲート１２ａ，１２ｂ側）の樹脂止め板４２ｃ，４２ｄは、境界予定線の形状とわずかにかけ離れている。
【００４４】
樹脂止め板の長さ（片側につき複数枚用いる場合は、その合計の長さ）は、境界線の全長に対して、例えば、２０％以上、好ましくは５０％以上、さらに好ましくは８０％以上である。また樹脂止め板の長さの上限は、通常、１００％以下であるが、樹脂止め板の形状が境界予定線の形状とわずかにかけ離れている場合には、樹脂止め板の長さは境界線の全長より若干長くなってもよい。その場合、樹脂止め板の長さの上限は、例えば、１２０％以下（好ましくは１１０％以下）である。
【００４５】
樹脂止め板は、前記図３に示すような樹脂の流れを完全に止めることができるタイプ（完全シール型）であってもよいが、樹脂を遮ることによって境界部３の変形を防止できる限り、樹脂が漏れ出すタイプ（不完全シール型）であってもよい。図１３（ａ）〜（ｃ）は、不完全シール型の樹脂止め板の種々の例を示す概略側面図である。例えば、図１３（ａ）に示すように樹脂止め板４１，４２の上面を波打たせて樹脂が漏れるすきま４６ａを形成してもよく、図１３（ｂ）に示すように樹脂止め板４１，４２の上面にスリット状のすきま４６ｂを形成してもよく、図１３（ｃ）に示すように樹脂止め板４１，４２の上面を湾曲させて樹脂が漏れるすきま４６ｃを形成してもよい。なお複数枚の樹脂止め板を使用する場合、同一形状の樹脂止め板を使用する必要はなく、前記完全シール型及び不完全シール型の内から適宜組合わせて使用すればよい。
【００４６】
成形面からの樹脂止め板の突出高さは、樹脂の流れを抑制できる限り特に制限されないが、例えば、基材厚みｐ（図１５参照）に対して、２０％以上、好ましくは５０％以上、さらに好ましくは８０％以上である。なお突出高さの上限は成形方法（射出成形、プレス成形など）に応じて適宜選択でき、射出成形の場合、基材厚みｐの１００％以下である。一方、プレス成形の場合、雄雌金型を開いた状態で樹脂を供給するため、供給した樹脂を境界部に到達させないだけの高さがあればよく、製品形状やゲート配置によって適宜決定される。
【００４７】
樹脂止め板の前進（突出）及び後進（収容）は、シリンダー（エアーシリンダー、油圧シリンダー）によって制御してもよく、他の手段によって制御してもよい。例えば、樹脂止め板の前進はバネの力を利用してもよいが、樹脂止め板の後進には樹脂の賦形圧力を利用するのが好ましい。
【００４８】
樹脂止め板の保持圧力は一定であってもよく、圧力制御のために変化させてもよい。圧力制御する場合、例えば、樹脂止め板よりもゲート側の成形体部分に樹脂を充満させる時には保持圧力を高くして樹脂止め効果を高め、前記ゲート側の成形体部分への樹脂の充満が略完了した時点で保持圧力を低くし、樹脂の賦形圧力によって樹脂止め板を金型内に収容させてもよい。
【００４９】
表皮材１と表皮材２との面積差（成形体製造後、成形体の上面を見たときの表皮材１と表皮材２との面積差）が大きい程、境界部３の位置ずれや皺の発生が生じやすいにも拘わらず、本発明によれば樹脂止め板４１，４２によって樹脂の流れを制御しているため、位置ずれや皺の発生を抑制できる。そのため表皮材１と表皮材２との面積差が大きい程、本発明を有利に使用できる。表皮材１と表皮材２との面積比が、例えば、表皮材１：表皮材２＝１：１〜１：１０程度、特に１：１．５〜１：１０程度の場合、本発明を利用するのが有利である。
【００５０】
一方、表皮材１と表皮材２との面積差が小さくても（特に、面積が等しい場合であっても）、成形体の形状が大きくなってゲートの数が増大する場合や、成形体の形状が複雑になる場合、樹脂の流れに偏りが生じて境界部３の位置ずれや皺の発生が生じやすくなるため、本発明はそのような成形体（大型の成形体、複雑形状の成形体）を製造する場合にも有利に使用できる。大型又は複雑形状の成形体としては、例えば、自動車のドアトリムやインストルメントパネルなどが挙げられる。
【００５１】
本発明で使用する表皮材は、意匠面に境界部がある限り表皮材の枚数は特に限定されず、例えば、２枚の表皮材（第１の表皮材、第２の表皮材）２を境界部３で接合した前記接合表皮材に代えて、第１の表皮材（表皮部）及び第２の表皮材（表皮部）を有する１枚の表皮材を用いてもよい。なお２枚の表皮材（第１の表皮材、第２の表皮材）を用いる場合、必ず境界部が形成されるため、第１の表皮材と第２の表皮材とは同一であってもよく、異なっていてもよい。
【００５２】
表皮材（表皮部）の数は２つに限定されず、３つ以上であってもよい。例えば、前記第１の表皮材（表皮部）１及び第２の表皮材（表皮部）２に加えて、第３の表皮材（表皮部）を形成する場合、この第３の表皮材（表皮部）との境界予定位置の両側又は片側に、樹脂止め板を配設し、上記と同様にして成形すればよい。
【００５３】
各表皮材（表皮部）の裏側に樹脂を供給するゲートの数は、それぞれ、少なくとも１つあればよく、表皮材（表皮部）の面積に応じて複数個形成してもよい。これらのゲートから供給する樹脂量やタイミングは成形品の大きさや形状に応じて適宜決定される。
【００５４】
また前記図示例では、共通の樹脂導入通路９を通じて熱可塑性樹脂を金型内に導入し、金型内で前記通路を分岐させることによって第１のゲート１１及び第２のゲート１２から熱可塑性樹脂を供給しているものの、別々の樹脂導入通路（第１のゲート１１用の樹脂導入通路、第２のゲート１２用の樹脂導入通路）を設けてもよい。
【００５５】
本発明で使用できる表皮材としては、布帛類（例えば、モケット、トリコットなどの織り物又は編物；不織布など）、合成樹脂シート又はフィルム、金属箔（金属フォイル）などが挙げられる。
【００５６】
前記不織布を構成する繊維としては、天然繊維（綿、毛、絹、麻など）、合成繊維（ナイロンなどのポリアミド系繊維、ポリエステル系繊維）などが使用できる。これら繊維は、単独で又は複数組合わせて使用でき、必要に応じて紡績（混紡など）してもよい。不織布としては、前記繊維を用いて慣用の方法（ニードルパンチ法、サーマルボンド法、スパンボンド法、メルトブロー法、スパンレース法など）に従って製造した不織布が使用できる。
【００５７】
前記合成樹脂シート又はフィルムとしては、例えば、熱可塑性樹脂（例えば、ポリプロピレン、ポリエチレンなどのポリオレフィン系熱可塑性樹脂）のシート又はフィルム、ポリオレフィン系熱可塑性エラストマーのシート又はフィルムが使用できる。ポリオレフィン系熱可塑性樹脂（又はエラストマー）は、基材に対する熱融着性に優れている。
【００５８】
前記表皮材は、必要に応じて、裏打ち層（発泡層、補強層、耐熱層など）と積層してもよい。発泡層としては、ポリオレフィン発泡体（ポリプロピレン、ポリエチレンなどの発泡体）、ポリハロゲン化ビニル発泡体（ポリ塩化ビニル発泡体など）、ポリウレタン発泡体（軟質又は半硬質ポリウレタン発泡体など）などが使用できる。
【００５９】
補強層としては、不織布、合成樹脂製シート又はフィルムが挙げられる。これら不織布及び合成樹脂製シート又はフィルムとしては、前記表皮材で例示したものと同様のものが使用できる。
【００６０】
前記裏打ち層は、単独で又は複数組合わせて使用できる。また裏打ち層は、表皮材の熱融着又は裏打ち層の熱融着のいずれかによって、表皮材と熱ラミネート可能なものが好ましい。
【００６１】
成形体の基材４を構成する熱可塑性樹脂としては、圧縮成形又は射出成形が可能である限り特に限定されないが、例えば、ポリオレフィン系樹脂（ポリプロピレン、ポリエチレンなど）、スチレン系樹脂（ポリスチレン、スチレン−ブタジエンブロック共重合体、アクリロニトリル−スチレン−ブタジエンブロック共重合体など）、ポリアミド系樹脂（ナイロンなど）、ハロゲン含有樹脂（ポリ塩化ビニルなど）、ポリカーボネート系樹脂、（メタ）アクリル酸エステルの単独又は共重合体（アクリル樹脂など）などが使用できる。前記熱可塑性樹脂は、熱可塑性エラストマーであってもよく、例えば、オレフィン系熱可塑性エラストマー［例えば、エチレン−プロピレン共重合体（ＥＰＭ）、エチレン−プロピレン−ジエン共重合体（ＥＰＤＭ）］が使用できる。
【００６２】
前記熱可塑性樹脂（及び熱可塑性エラストマー）は、単独で又は２種以上組合わせて使用でき、例えばポリマーアロイとして使用してもよい。
【００６３】
さらに前記熱可塑性樹脂（及び熱可塑性エラストマー）は、各種添加成分、例えば、充填材（ガラス繊維などの無機フィラー；有機フィラーなど）、顔料、滑剤、帯電防止剤、安定剤などを含有していてもよい。
【００６４】
また前記熱可塑性樹脂（及び熱可塑性エラストマー）は、発泡剤を含有していてもよい。この発泡剤で樹脂を発泡させることにより、発泡基材４で形成された成形体を得ることができる。前記発泡剤としては、熱可塑性樹脂を発泡する際に使用されている公知の化学発泡剤（分解性発泡剤など）を使用でき、例えば、重炭酸ナトリウム、重炭酸アンモニウム、炭酸アンモニウムなどの無機系発泡剤；Ｎ，Ｎ’−ジニトロソペンタメチレンテトラミンなどのニトロソ化合物；アゾジカルボンアミド、アゾビスイソブチロニトリルなどのアゾ化合物；ベンゼンスルホニルヒドラジド、トルエンスルホニルヒドラジド、ジフェニルスルホン−３，３’−ジスルホニルヒドラジドなどのスルホニルヒドラジド類；ｐ−トルエンスルホニルセミカルバジドなどが挙げられる。さらに、必要に応じて、サリチル酸、尿素、及びこれらを含む発泡助剤を添加するのが好ましい。前記発泡剤は、使用する熱可塑性樹脂の溶融温度、及び要求される発泡倍率などを考慮して適宜選択できる。また添加量は、成形品の要求強度、要求密度などを考慮して適宜設定できるが、一般的には、樹脂１００質量部に対して０．１〜５質量部程度である。なお上述の発泡操作を行う場合、化学発泡剤を熱可塑性樹脂に含有させておく方法の他、揮発性液体発泡剤、気体発泡剤などを金型内の溶融樹脂中に直接圧入してもよい。前記揮発性液体発泡剤や気体発泡剤としては、二酸化炭素、窒素などが使用できる。
【００６５】
【発明の効果】
本発明によれば、表皮材（表皮部）の境界予定位置に略沿って樹脂止め板を突出可能に埋設しているため、前記境界部に向かう樹脂を前記樹脂止め板で遮ることにより樹脂が境界部に到着するタイミングを制御でき、境界部の位置ずれや皺の発生を確実に防止できる。
【図面の簡単な説明】
【図１】図１は本発明の金型の一例を示す概略断面図である。
【図２】図２は本発明で使用する雄型成形面の一例を示す平面図である。
【図３】図３は本発明で使用する樹脂止め板の一例を示す概略斜視図である。
【図４】図４は本発明の製造方法の一例を説明するための概略断面図である。
【図５】図５は本発明で使用する挟着体の一例を示す概略斜視図である。
【図６】図６は前記図５の挟着体のＡ−Ａ’線断面図である。
【図７】図７は前記図５の挟着体のＢ−Ｂ’線断面図である。
【図８】図８は本発明の金型の他の例を示す概略断面図である。
【図９】図９は本発明の金型のさらに他の例を示す概略断面図である。
【図１０】図１０は本発明で使用する雄型の成形面の他の例を示す平面図である。
【図１１】図１１は本発明で使用する雄型の成形面のさらに他の例を示す平面図である。
【図１２】図１２は本発明で使用する雄型の成形面の別の例を示す平面図である。
【図１３】図１３は本発明で使用する樹脂止め板の他の例を示す側面図である。
【図１４】図１４は本発明によって製造できる成形体の一例を示す平面図である。
【図１５】図１５は前記図１４の成形体を正面からみた断面図である。
【図１６】図１６は従来の金型の断面図である。
【図１７】図１７は従来の金型によって製造された成形体を示す平面図である。
【符号の説明】
１，２…表皮材
３…境界部
１０ａ，１０ｂ，１０ｃ…金型
１１，１１ａ，１１ｂ，１２，１２ａ，１２ｂ…ゲート
１３…境界予定位置
１４…表皮材の裏側に位置する金型
１５…表皮材の表側に位置する金型
２１，２２…溶融状熱可塑性樹脂
４１，４１ａ，４１ｂ，４１ｃ，４２，４２ａ，４２ｂ，４２ｃ，４２ｄ，…樹脂止め板
５０…挟着体
６１…突起部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a mold useful for manufacturing a multilayer molded body in which a skin material is bonded to a thermoplastic resin substrate, and a method for manufacturing the multilayer molded body.
[0002]
[Prior art]
A multilayer molded body in which a skin material is bonded to the surface of a base material made of a thermoplastic resin is excellent in manufacturing cost, light weight, and formability, and is used for automobile interior parts (for example, door trims, instrument panels). Are widely used in a wide range of fields, including interior and exterior parts of home appliances.
[0003]
As the multilayer molded body, a molded body in which a plurality of design surfaces are formed on the surface of the molded body (hereinafter may be referred to as a multi-surface molded body) is known. For example, when a plurality of design surfaces having different patterns and materials are formed, the surface of the base material can be effectively decorated. As the multi-faced molded body, a molded body in which a single skin material having a plurality of design surfaces is bonded to a base material, and a molded body in which a plurality of skin materials are bonded to a base material are known. A molded body in which a plurality of skin materials are pasted together is, for example, a method in which molten resin is supplied to the back side of a single skin material, and the skin material and the resin are bonded to each other (injection molding method, compression molding method). Etc.) and a plurality of multilayer molded bodies are manufactured, and these multilayer molded bodies are manufactured by joining them in the plane direction by heat fusion or the like. The multi-sided molded body is also manufactured by manufacturing a resin base material by an injection molding method, a compression molding method, or the like, and bonding a plurality of skin materials to the surface of the base material. However, in the former method, the strength of the joint between the substrates may be insufficient. In the latter method, the skin material may peel off.
[0004]
As a method for solving these problems, for example, using a pair of male and female molds, two skin materials are bonded together adjacent to each other in the plane direction, and then the skin material is placed with the back surface of the skin material facing the male mold. A method is known in which a mold is inserted into the mold, a molten resin is supplied from a male mold, and the skin material and the resin are bonded together. FIG. 14 is a plan view of a multi-sided molded body (target) to be manufactured by this manufacturing method, FIG. 15 is a cross-sectional view of the multi-sided molded body (target) viewed from the front, and FIG. 16 illustrates the manufacturing method. FIG. 17 is a plan view of a multi-sided molded body that is actually manufactured by the manufacturing method. As shown in FIGS. 14 and 15, the target multi-face molded body has two skin materials (first skin material 1 and second skin material 2) adjacent to the surface of the thermoplastic resin substrate 4. Are pasted together. The boundary part (boundary line) 3 between the skin material 1 and the skin material 2 forms a clean line without distortion. As shown in FIG. 16, when the multi-faced molded body is manufactured, the first skin material 1 and the second skin material 2 are formed at the boundary portion 3 on the mold constituted by the male mold 14 and the female mold 15. Insert the joined skin material. The joining skin material is inserted with the back surface facing the male mold 14, and the front surface is brought into contact with the female mold 15. In order to supply the molten resin to the back surface of the second skin material 2 and the first gate 11 for supplying the molten resin to the back surface of the first skin material 1 on the molding surface of the male mold 14 The second gate 12 is formed, and molten resin is supplied from these gates 11 and 12 [see FIG. 16 (a)]. Then, the female mold 15 is moved toward the male mold 14 to be molded while pressing [see FIG. 16B]. However, in such a method, the resin injected from one gate (in this example, the resin 21 injected from the first gate 11) is changed to the resin injected from the other gate (in this example, the second gate). In some cases, the boundary portion (bonding portion) 3 may be reached before the resin 22) injected from the gate 12, and the position of the boundary portion may shift. For this reason, as shown in FIG. 17, the boundary portion 3 between the first skin material 1 and the second skin material 2 meanders, and it is difficult to form a clean line.
[0005]
In the above example, an example in which two skin materials are used is shown. However, even if one skin material is used, the position of the boundary portion may be shifted as in the example in which the two skin materials are used. That is, instead of the joining skin material in which the two skin materials (first skin material 1 and second skin material 2) are joined at the boundary 3, the first skin material (skin part) and the second skin material Even if one skin material having (skin part) is used, if one resin reaches the boundary part earlier than the other resin, it is pulled by the flow of the resin that reaches the other part and the position of the boundary part is shifted. There is a case.
[0006]
Whether the first skin material (skin part) and the second skin material (skin part) are significantly different in the case of using two skin materials and the case of using one skin material When the molded body has a complicated uneven shape, or when the molded body becomes large and the number of gates increases, the shift of the arrival timing of the resin to the boundary portion increases, and the boundary position shifts or the boundary Wrinkles are generated in the vicinity of the part, and the appearance is liable to be damaged.
[0007]
[Problems to be solved by the invention]
The present invention has been made paying attention to the circumstances as described above, and the object thereof is composed of a plurality of skin materials adjacent to each other in a plane direction [a plurality of skin materials, a plurality of skin materials (skin portions). Even when manufacturing a molded product (multi-surface molded product) in which a single skin material, etc.] is bonded to a thermoplastic resin base material, the position of the boundary part (boundary line) of the skin material (skin part) is shifted. An object of the present invention is to provide a mold capable of reliably preventing generation of wrinkles and wrinkles and a method for producing a molded body.
[0008]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have obtained a plurality of skin materials [a plurality of skin materials, a single skin material composed of a plurality of skin materials (skin portions), etc.] When the resin is supplied to the back side of the mold, a resin stopper plate is embedded in the mold located on the back side of the skin material so that it can protrude on both sides or one side of the position corresponding to the boundary of the skin material (skin part). The present invention has been completed by finding that the timing at which the resin arrives at the boundary portion can be substantially aligned by controlling the flow of the resin flowing into the boundary portion of the skin material (skin portion) with the resin stopper plate.
[0009]
In other words, the mold of the present invention that has achieved the above-mentioned object is the heat on the back side of the first and second skin materials (skin materials having the first and second skin portions) adjacent to each other in the plane direction. A mold for supplying a plastic resin and bonding the skin material and the thermoplastic resin to produce a multilayer molded body, and supplying a molten thermoplastic resin to the back side of the first skin material (skin part) And a second gate for supplying the molten thermoplastic resin to the back side of the second skin material (skin portion) is formed on the mold located on the back side of the skin material. In the pair of male and female molds, the mold corresponds to the boundary between the first and second skin materials (skin parts) among the molding surfaces of either the male mold or the female mold located on the back side of the skin material. A position on either side or one side (preferably both sides) between the position corresponding to this boundary and the gate The resin stop plate substantially along the position corresponding to the boundary portion and has a gist in that is embedded so as to be projected. A sandwich for sandwiching the boundary portion may be embedded at a position corresponding to the boundary portion of the skin material (skin portion) on the molding surface of the mold located on the back side of the skin material. Moreover, the metal mold | die located in the surface side of a skin material may be a thing by which the projection part which continues along a boundary part was formed in the position corresponding to the boundary part of a skin material (skin part).
[0010]
In addition, the method for producing a molded article of the present invention that can achieve the above-described object is the first and second skin materials (a first and second skin materials adjacent to each other in a plane direction) between a male mold and a female mold of a pair of male and female molds A first skin material (skin part) on the molding surface of either the male or female mold located on the back side of the skin material. Forming a first gate for supplying the molten thermoplastic resin to the back side of the first and a second gate for supplying the molten thermoplastic resin to the back side of the second skin material (skin portion); A method of supplying a molten thermoplastic resin from the first and second gates and bonding the skin material and the thermoplastic resin to produce a multilayer molded body, the mold surface on the back side of the skin material Resin stopper plate can be projected on both sides or one side (preferably both sides) of the position corresponding to the boundary of the skin material (skin part) In the state where the resin stopper plate protrudes into the mold cavity, the molten thermoplastic resin is supplied from each gate, and the resin flowing into the gate and going to the boundary portion is blocked by the resin stopper plate and the mold. The present invention has a gist in that the timing at which the resin reaches the boundary portion is controlled by accommodating the resin stopper plate in the mold before the filling of the resin into the mold cavity is completed. When embedding a resin stopper plate on one side, the distance from the first gate to the position corresponding to the boundary portion of the first and second gates is shorter than the distance from the other gate to the position corresponding to the boundary portion. The resin stopper plate is embedded so as to protrude on the side where the gate having a short distance to the boundary is formed, and the resin supplied from the gate having a short distance to the boundary by the resin stopper plate The timing when the resin reaches the boundary is accommodated by accommodating the resin stopper plate in the mold in accordance with the arrival timing of the resin supplied from the gate having a long distance to the boundary. It is desirable to control. When embedding resin stopper plates on both sides, the resin supplied from the gate with a short distance to the boundary is temporarily blocked by the resin stopper plate on one side, and the resin supplied from the gate with a long distance to the boundary is used. It is desirable to temporarily block the resin stopper plate on the other side and then accommodate the resin stopper plates on both sides in the mold to control the timing at which the resin reaches the boundary. The resin stopper plate is preferably abutted against the molding surface of the mold located on the front side of the skin material through the skin material until the resin flowing in from the gate reaches the embedded position of the resin stopper plate. Prior to disposing the skin material in the mold, the skin material may be shaped according to the shape of the molded body. A preferred molding method is press molding. The resin stopper plate protruding into the mold cavity is preferably accommodated in the mold with resin molding pressure. In the said manufacturing method, you may use the molten thermoplastic resin (foamable resin) containing a foaming agent as resin supplied from the said 1st and 2nd gate. In the case of using a foamable resin, after the filling of the resin into the mold cavity is completed, the mold cavity may be enlarged to foam the resin.
[0011]
In this specification, the term “thermoplastic resin” is used to include a thermoplastic elastomer.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the examples shown in the drawings, and may be implemented with appropriate modifications within a range that can meet the purpose described above and below. All of which are within the scope of the present invention. For example, a case where a female mold is used as a mold located on the front side of the skin material and a male mold is used as a mold located on the back side of the skin material will be described as an example. A male mold may be used as the mold located on the back surface, and a female mold may be used as the mold located on the back side of the skin material.
[0013]
FIG. 1 is a schematic cross-sectional view showing an example of a mold of the present invention and a method for producing a molded body using the mold, and FIG. 2 is a plan view of a molding surface of a male mold 14 among the molds. FIG. 3 is a schematic perspective view of a resin stopper plate used in the mold as viewed from the side. If the said metal mold | die is used, the multilayer multi-sided molded object shown in FIG.14 and FIG.15 can be manufactured.
[0014]
That is, the mold 10a shown in FIG. 1 and FIG. 2 supplies a molten (fluid) thermoplastic resin to the back sides of the first skin material 1 and the second skin material 2 that are adjacent to each other in the plane direction. It is a metal mold for manufacturing a multilayer molded body (multilayer multi-sided molded body) by bonding together a thermoplastic resin. The area of the second skin material is larger than the area of the first skin material. Further, the skin materials 1 and 2 are bonded in advance at a boundary portion (joint portion) 3, and in this example, are bonded by an adhesive.
[0015]
The mold 10a is composed of a male mold 14 and a female mold 15 for forming a thermoplastic resin in pairs. On the molding surface of the male mold 14, first gates (resin supply ports) 11 a and 11 b for supplying a molten resin to the back side of the first skin material 1, and the second skin material 2 are provided. Second gates (resin supply ports) 12a and 12b for supplying the molten resin to the back side are formed. The distance from the first gate 11 to a position corresponding to (facing) the boundary portion (hereinafter sometimes referred to as a planned boundary position or a planned boundary line) is a distance from the second gate 12 to the planned boundary position. Shorter than. The molten resin flowing in from the first gate 11 and the second gate 12 corresponds to the boundary portion 3 of the skin material 1 and the skin material 2 (or the boundary portion 3 of the molding surfaces of the male mold 14). In order to suppress the movement toward the planned boundary position 13), resin stopper plates 41 and 42 are embedded in the male mold surface so as to protrude.
[0016]
More specifically, the resin stopper plates 41 and 42 are disposed substantially along the planned boundary position on both sides of the planned boundary position (boundary planned line) 13. It is connected to a cylinder (not shown) via shafts 43 and 44, can move forward and protrude from the molding surface, and can move backward (in this example, descend) and be accommodated in the male mold. . Of these resin stopper plates 41, 42, one resin stopper plate (first resin stopper plate) 41 can suppress the resin flowing from the first gate 11 from moving toward the boundary portion 3 (or the boundary boundary position 13). The other resin stopper plate (second resin stopper plate) 42 can suppress the resin flowing from the second gate 12 from moving toward the boundary portion 3 (or the boundary boundary position 13). Further, as shown in FIG. 3, the upper surfaces of the resin stopper plates 41 and 42 have a shape along the shape of the molded body (that is, the shape of the skin materials 1 and 2). In this example, the shape of the molded body Is flat, the upper surfaces 45 of the resin stopper plates 41 and 42 are also flat. Therefore, the resin can be stopped almost completely.
[0017]
By using the mold 10a as described above, a multi-layered multi-face molded body can be manufactured as described below. An example of a manufacturing method is shown to Fig.1 (a)-(c). That is, as shown in FIG. 1 (a), in this example, the mold 10a is opened widely so as to form a space larger than the space corresponding to the molded body, and the skin materials 1 and 2 are placed on the back surface in the mold 10a. Arranged to face the male mold 14. Then, in a state where both the resin stopper plates 41 and 42 protrude into the mold cavity, the molten thermoplastic resin is supplied from the first gates 11a and 11b to the back side of the skin material 1, and the skin is supplied from the second gates 12a and 12b. A molten thermoplastic resin is supplied to the back side of the material 2.
[0018]
In this example, after supplying the molten thermoplastic resin, the female mold 15 is moved toward the male mold 14 (that is, mold clamping is started), and the molten thermoplastic resin is pressed on the back side of the skin material while pressing the resin. The resin is filled [see FIG. 1 (b)]. At the stage of filling the molten thermoplastic resin, the resin stopper plates 41 and 42 protrude from the molding surface and are in contact with the female die 15 through the skin materials 1 and 2. If the molten thermoplastic resin is filled without projecting the resin stopper plates 41 and 42, the resin 21 supplied from the first gates 11a and 11b having a short distance to the boundary portion is the distance to the boundary portion. May reach the boundary portion 3 before the resin 22 supplied from the long second gates 12a and 12b, and the boundary portion 3 may be greatly displaced. The resin 21 and 22 are filled with the molten thermoplastic resin in a state where the resin stopper plates 41 and 42 are abutted against the female mold 15 via the skin materials 1 and 2. It is possible to control the timing at which reaches the boundary. More specifically, the resin 21 supplied from the first gates 11 a and 11 b having a short distance to the boundary is blocked by the first resin stopper plate 41. Therefore, the timing at which the resin 21 reaches the boundary portion 3 can be delayed, and the resin 22 supplied from the second gates 12a and 12b having a long distance to the boundary portion can be substantially aligned with the timing at which the resin 22 reaches the boundary portion 3. The position shift of the boundary part 3 can be prevented.
[0019]
Further, in this example, the resin 22 supplied from the second gates 12a and 12b having a long distance to the boundary is also blocked by the second resin stopper plate 42, and the first resin stopper plate 41 and the second resin stopper plate 42 are blocked. By adjusting the timing of descent, the arrival timing of the resins 21 and 22 to the boundary portion 3 can be easily controlled.
[0020]
Further, in this example, the female mold 15 moves in the mold clamping direction from the stage of FIG. 1B, and the clearance between the male mold 14 and the female mold 15 is substantially equal to the thickness q (see FIG. 15) of the molded body. Thus, until the height of the base material portion 4 formed of the thermoplastic resin becomes substantially equal to the base material thickness p (see FIG. 15) (that is, until the mold clamping is completed), the resin stopper plates 41 and 42 are formed. (See FIG. 1C). It should be noted that the start of housing of the resin stopper plates 41 and 42 (in this example, lowering) is preferably earlier than the stage where the mold clamping is completed. For example, the outside of the resin stopper plates 41 and 42 (that is, the boundary portion 3 is It is desirable to start housing (lowering) when the molten resin is substantially filled on the outer side when the existing side is the inner side.
[0021]
After completion of the mold clamping shown in FIG. 1 (c), the resin is cooled and solidified, and the mold 10a is opened (die opening), so that there is no positional deviation or wrinkles in the boundary portion 3 as shown in FIGS. Can be obtained.
[0022]
In the illustrated example (FIG. 2), the boundary boundary position (boundary boundary line) 13 is indicated by a broken line on the molding surface of the male mold 14, but the broken line is for convenience to clearly describe the boundary boundary position. In other words, a broken line shape is not actually formed on the molding surface of the male mold 14. This also applies to the illustrated examples described later.
[0023]
When performing mold clamping, either the male mold 14 or the female mold 15 may be moved, or both may be moved. In the illustrated example, an example in which a molded body is manufactured by press molding in which mold clamping is performed after resin supply is completed and the resin is pressed is shown. However, mold clamping is not necessarily performed after resin supply is completed. You may carry out, supplying. In addition, when performing mold clamping after completion of resin supply, it is desirable to start mold clamping immediately after completion of supply. In the illustrated example, the example in which the mold clamping is performed in the vertical direction is shown. However, the mold clamping may be performed in a direction other than the vertical direction (for example, the horizontal direction). Further, the molding method is not limited to press molding, and may be injection molding or a combination of press molding and injection molding. For example, when a molded body is manufactured by injection molding, after the skin materials 1 and 2 are inserted in the same manner as in press molding, the mold clamping is completed, and the resin stopper plates 41 and 42 are protruded into the mold cavity. Supply of molten thermoplastic resin from the gates 11 and 12 is started in a state where the resin stopper plates 41 and 42 are abutted against the female mold 15 through the skin materials 1 and 2. The resin stopper plates 41 and 42 are accommodated at a stage where the high pressure is not applied to the resins 21 and 22 supplied from the gates 11 and 12, and the supply of the molten thermoplastic resin is continued. Resin is supplied to between 41 and 42 and the boundary part 3, and a molded object is manufactured. Also, when combining press molding and injection molding, there is a method of operating in the same manner as in the above press molding example except that the initial resin supply amount is small, and injecting and supplying insufficient resin at an appropriate stage. .
[0024]
In either case of press molding or injection molding, the resin stopper plate is positioned on the front side of the skin material through the skin material until the resin flowing in from the gate reaches the embedded position of the resin stopper plate. It is desirable to abut against the molding surface of the mold.
[0025]
In either case of press molding or injection molding, the resin stopper plates 41 and 42 are accommodated by the end of filling of the resin into the mold cavity (the space corresponding to the molded body). [See FIG. 1 (c)]. That is, in the case of press molding, the lowering (accommodation) of the resin stopper plates 41 and 42 may be completed before the mold clamping is completed and the resin is filled in the mold cavity. In the case of injection molding, the necessary resin is used. It is only necessary to complete the housing of the resin stopper plates 41 and 42 until all the resin is injected and supplied and the mold cavity is filled with the resin.
[0026]
A preferred molding method is press molding. In the case of injection molding, the injected molten resin immediately comes into contact with the skin material, so the skin material may be exposed to high temperatures and high pressures, and the skin material may be damaged. Since the resin is supplied, there is little risk of damaging the skin material due to the supply pressure of the resin.
[0027]
In the present invention, as will be described later, a molten thermoplastic resin (foamable resin) containing a foaming agent can be used as the resin supplied from the first and second gates. In the case of using a foamable resin, the obtained molded body may be foamed after being taken out of the mold, but it is desirable to foam the molded body in the mold.
[0028]
FIG. 4 is a schematic cross-sectional view for explaining the case where the resin is foamed. In this example, the mold 10a is used, and after the filling of the foamable resins 21 and 22 into the mold cavity is completed by the molding (press molding, injection molding, etc.) [see FIG. 1 (c)]. The mold cavity is enlarged by moving the male mold 14 or the female mold 15 in the direction opposite to the mold clamping direction, and the filling resin (base resin) 4 is foamed (FIG. 4).
[0029]
When filling the mold cavity with the molten foamable resin 21 or 22, by controlling the cavity clearance formed by the male mold 14 and the female mold 15 during filling, It is desirable to prevent insufficient foaming during the foaming operation after completion of filling. That is, the cavity clearance is usually set as appropriate according to the molding conditions such as the type of the skin materials 1 and 2 and the resin temperature, but care should be taken to reduce the cavity clearance when filling with foamable resin. It is desirable to prevent escape of the foaming gas.
[0030]
After the filling of the foamable resins 21 and 22 into the mold cavity is completed, it is desirable to cool the resin surface layer to form a skin layer prior to the expansion of the mold cavity. If the skin layer is too thick, a sufficient foaming ratio cannot be obtained. Therefore, it is desirable to control the skin layer so that a sufficient foaming ratio can be obtained. The thickness of the skin layer can be controlled, for example, by adjusting the formation time of the skin layer in consideration of the thickness of the molded product, the mold temperature, and the like.
[0031]
In enlarging the mold cavity, the degree of expansion (expansion allowance) can be appropriately determined according to the product thickness (foaming ratio) to be manufactured. It should be noted that when the mold cavities are expanded and foamed, it is desirable that the resin stopper plates 41 and 42 remain accommodated in the mold.
[0032]
The foaming method is not limited to the case where the mold 10a shown in FIG. 1 is used, and can also be used when other various molds including a mold described later are used.
[0033]
As shown in FIG. 1, the skin materials 1 and 2 are shaped (preliminarily shaped) according to the shape of the molded body (that is, the shape of the female die 15) prior to being placed in the mold. However, it may not be preshaped. In particular, when the sandwiched body described below is used, the skin materials 1 and 2 are often not preshaped.
[0034]
The skin materials 1 and 2 can be joined by various methods. For example, in addition to a chemical bonding method (adhesive or adhesive by heat sealing), a method using a jig (sewing with a thread; needle, pin, staple, etc.) Fixing; fixing with a sandwiched body).
[0035]
FIG. 5 is a schematic perspective view showing an example of the sandwiched body (clamping body), FIG. 6 is a cross-sectional view taken along line AA ′ of the sandwiched body of FIG. 5, and FIG. It is a BB 'line sectional view of a kimono. The sandwich body 50 is composed of a pair of sandwiching pieces 51 and 52 that are symmetrical with respect to the skin materials 1 and 2 to be sandwiched, and these sandwiching pieces 51 and 52 sandwich the skin materials 1 and 2. It has the part 54 and the recessed part 53 for accommodating molten resin and adhere | attaching the skin materials 1 and 2 with resin.
[0036]
FIG. 8 is a schematic sectional view of a mold 10b using the sandwiching body 50. As shown in FIG. The mold 10b is the same as the mold 10a of FIG. 1 except that the sandwiched body 50 is embedded in the molding surface of the male mold 14. Note that the sandwich body 50 is embedded in a location corresponding to the boundary portion 3 of the skin materials 1 and 2 (planned boundary position). Even when such a mold 10b is used, a multi-sided multilayer molded body can be manufactured by molding (press molding, injection molding, etc.) as in the case of FIG. When the mold 10b is opened and the molded body is taken out, the sandwiched body 50 may be removed from the molded body. Since the resin that has entered the concave portion 53 of the sandwich body 50 is solidified while being in contact with both the first skin material 1 and the second skin material 2, the skin materials 1 and 2 are separated even if the sandwich body 50 is removed. There is no fear.
[0037]
In the present invention, it is desirable to provide a protruding portion (wood grain arrow) continuous along the boundary portion at a position corresponding to the boundary portion 3 of the skin materials 1 and 2 (planned boundary position) in the female die 15. FIG. 9 is a schematic cross-sectional view showing an example of a mold provided with the protrusion (wood grain arrow). In this mold 10 c, a protrusion 61 is formed at a predetermined boundary position of the female mold 15, and a recess 62 corresponding to the protrusion shape of the protrusion 61 is formed at a predetermined boundary position of the male mold 14. . When a molded body is manufactured using such a mold 10 c as in the case of the mold 10 a of FIG. 1, the deformation of the boundary portion 3 can be prevented to a higher degree by the protrusion 61. The depression 62 is not always necessary.
[0038]
The protrusion 61 may be formed on the female die 15 of the molded body 10b shown in FIG.
[0039]
In the present invention, the resin stopper plate is preferably provided on both sides of the planned boundary position (planned boundary line), but may be provided only on one side. When provided only on one side, a resin stopper plate is provided on the side where the gate having a short distance to the boundary portion is formed (the gate 11 for supplying the resin to the skin material 1 having a small area in each of the illustrated examples). There are many. Even if it does in this way, the said resin stop board is match | combined with the arrival timing to the boundary part of the resin (the resin 22 supplied from the gate 12 in each said example) with which the distance to a boundary part is long. By lowering, the timing at which the resin reaches the boundary can be controlled.
[0040]
The resin stopper plate is preferably provided near the planned boundary line, and the distance y (see FIG. 2) between the resin stopper plate and the boundary boundary line is 100 as the distance x (see FIG. 2) between the gate and the boundary boundary line. For example, it is 50 or less, preferably 40 or less, and more preferably 30 or less. When the resin stopper plates are provided on both sides of the planned boundary position, it is preferable that the distance between the planned boundary position and the resin stopper plates on both sides is substantially the same.
[0041]
Furthermore, the resin stopper plate may be slightly separated from the shape of the boundary boundary line as long as it is substantially (approximately) along the boundary boundary line. For example, there are a portion near and a portion far from the boundary boundary line. Also good. FIG. 10 is a plan view of the molding surface of the male mold 14 using such a resin stopper plate. In FIG. 10, the resin stopper plate 42b on one side (in this example, the second gates 12a and 12b side) is slightly separated from the shape of the boundary line.
[0042]
The distance y2 of the part farthest from the planned boundary line is, for example, 3 times or less, preferably 2 times or less, more preferably 1.5 times or less, with respect to the distance y1 of the nearest part.
[0043]
As long as the arrival timing of the resin can be controlled, the length of the resin stopper plate may be shorter than the total length of the boundary line. Further, one or more resin stopper plates may be provided on one side of the planned boundary position (boundary planned line). FIG. 11 is a plan view showing an example of a male mold 14 using a short resin stopper plate. FIGS. 12A and 12B are examples of the male mold 14 using a plurality of resin stopper plates per side. FIG. In the example of FIG. 11, resin stopper plates 41 a and 42 a shorter than the total length of the planned line are disposed on both sides of the planned boundary line 13. In the example of FIG. 12A, one resin stopper plate 42a slightly shorter than the planned boundary line 13 is provided on one side (in this example, the second gate 12a, 12b side), and the other side ( In this example, two resin retaining plates 41b and 41c having a length equal to or less than half of the planned boundary line 13 are disposed on the first gates 11a and 11b side). Further, in the example of FIG. 12B, two resin stopper plates (a total of four resin stopper plates on both sides) 41b, 41c, 42c, and 42d are disposed on either side of the boundary line 13. The resin stopper plates 42c and 42d on one side (in this example, the second gates 12a and 12b side) are slightly separated from the shape of the boundary line.
[0044]
The length of the resin stopper plate (when using a plurality of resin stoppers per side) is, for example, 20% or more, preferably 50% or more, more preferably 80% or more with respect to the total length of the boundary line. is there. In addition, the upper limit of the length of the resin stopper plate is usually 100% or less, but when the shape of the resin stopper plate is slightly different from the shape of the boundary line, the length of the resin stopper plate is the boundary line. It may be slightly longer than the total length. In that case, the upper limit of the length of the resin stopper plate is, for example, 120% or less (preferably 110% or less).
[0045]
The resin stopper plate may be of a type that can completely stop the resin flow as shown in FIG. 3 (complete seal type), but as long as the deformation of the boundary portion 3 can be prevented by blocking the resin, A type in which resin leaks (incomplete seal type) may be used. FIGS. 13A to 13C are schematic side views showing various examples of incompletely sealed resin stopper plates. For example, as shown in FIG. 13 (a), the upper surfaces of the resin stopper plates 41 and 42 may be corrugated to form a clearance 46a through which the resin leaks. As shown in FIG. A slit-like clearance 46b may be formed on the upper surface of 42, or a clearance 46c through which the resin leaks by curving the upper surfaces of the resin stopper plates 41 and 42 as shown in FIG. When a plurality of resin stopper plates are used, it is not necessary to use resin stopper plates having the same shape, and the resin stopper plates may be appropriately combined from the complete seal type and the incomplete seal type.
[0046]
The protrusion height of the resin stopper plate from the molding surface is not particularly limited as long as the flow of the resin can be suppressed, but is, for example, 20% or more, preferably 50% or more, relative to the base material thickness p (see FIG. 15). More preferably, it is 80% or more. The upper limit of the protrusion height can be appropriately selected according to the molding method (injection molding, press molding, etc.), and in the case of injection molding, it is 100% or less of the substrate thickness p. On the other hand, in the case of press molding, since the resin is supplied with the male and female molds opened, it is sufficient that the supplied resin has a height that does not reach the boundary, and is determined as appropriate according to the product shape and gate arrangement. .
[0047]
Advance (protrusion) and reverse (accommodation) of the resin stopper plate may be controlled by a cylinder (air cylinder, hydraulic cylinder) or may be controlled by other means. For example, the force of the spring may be used for the advancement of the resin stopper plate, but it is preferable to use the shaping pressure of the resin for the backward movement of the resin stopper plate.
[0048]
The holding pressure of the resin stopper plate may be constant or may be changed for pressure control. When controlling the pressure, for example, when filling the molded body part on the gate side with respect to the resin stopper plate, the holding pressure is increased to increase the resin stopper effect, and the filling of the resin to the molded part on the gate side is substantially reduced. At the time of completion, the holding pressure may be lowered, and the resin stopper plate may be accommodated in the mold by the resin shaping pressure.
[0049]
As the area difference between the skin material 1 and the skin material 2 (the area difference between the skin material 1 and the skin material 2 when the upper surface of the molded body is viewed after the molded body is manufactured) is larger, the positional deviation and wrinkles of the boundary portion 3 are increased. However, according to the present invention, since the resin flow is controlled by the resin stopper plates 41 and 42, the occurrence of misalignment and wrinkles can be suppressed. Therefore, the present invention can be advantageously used as the area difference between the skin material 1 and the skin material 2 increases. The present invention is used when the area ratio between the skin material 1 and the skin material 2 is, for example, the skin material 1: the skin material 2 is about 1: 1 to 1:10, particularly about 1: 1.5 to 1:10. It is advantageous to do so.
[0050]
On the other hand, even if the area difference between the skin material 1 and the skin material 2 is small (particularly even when the areas are equal), the shape of the molded body is increased and the number of gates is increased. When the shape is complicated, the flow of the resin is biased and the boundary portion 3 is likely to be displaced and wrinkles are easily generated. Therefore, the present invention provides such a molded body (a large molded body, a molded body having a complicated shape). ) Can also be used advantageously. Examples of large or complex shaped articles include automobile door trims and instrument panels.
[0051]
The skin material used in the present invention is not particularly limited as long as there is a boundary portion on the design surface. For example, two skin materials (first skin material, second skin material) 2 are bounded. Instead of the joining skin material joined at the part 3, a single skin material having a first skin material (skin part) and a second skin material (skin part) may be used. When two skin materials (first skin material and second skin material) are used, a boundary portion is always formed, so even if the first skin material and the second skin material are the same. Well, it can be different.
[0052]
The number of skin materials (skin portions) is not limited to two and may be three or more. For example, in the case where a third skin material (skin part) is formed in addition to the first skin material (skin part) 1 and the second skin material (skin part) 2, the third skin material (skin) A resin stopper plate may be provided on both sides or one side of the planned boundary position with respect to the (part) and molded in the same manner as described above.
[0053]
The number of gates supplying the resin to the back side of each skin material (skin part) may be at least one, and a plurality of gates may be formed according to the area of the skin material (skin part). The amount and timing of the resin supplied from these gates are appropriately determined according to the size and shape of the molded product.
[0054]
In the illustrated example, the thermoplastic resin is introduced into the mold through the common resin introduction passage 9, and the passage is branched in the mold, so that the thermoplastic resin from the first gate 11 and the second gate 12. However, separate resin introduction passages (the resin introduction passage for the first gate 11 and the resin introduction passage for the second gate 12) may be provided.
[0055]
Examples of the skin material that can be used in the present invention include fabrics (for example, woven or knitted fabrics such as moquettes and tricots; nonwoven fabrics, etc.), synthetic resin sheets or films, metal foils (metal foils), and the like.
[0056]
As the fibers constituting the nonwoven fabric, natural fibers (cotton, wool, silk, hemp, etc.), synthetic fibers (polyamide fibers such as nylon, polyester fibers) and the like can be used. These fibers can be used singly or in combination, and may be spun (such as mixed spinning) as necessary. As the non-woven fabric, a non-woven fabric produced using the above-described fibers according to a conventional method (needle punch method, thermal bond method, spun bond method, melt blow method, spun lace method, etc.) can be used.
[0057]
As the synthetic resin sheet or film, for example, a sheet or film of a thermoplastic resin (for example, a polyolefin-based thermoplastic resin such as polypropylene or polyethylene) or a sheet or film of a polyolefin-based thermoplastic elastomer can be used. A polyolefin-based thermoplastic resin (or elastomer) is excellent in heat-fusibility to a substrate.
[0058]
The skin material may be laminated with a backing layer (a foam layer, a reinforcing layer, a heat-resistant layer, etc.) as necessary. As the foam layer, polyolefin foam (polypropylene, polyethylene, etc.), polyhalogenated vinyl foam (polyvinyl chloride foam, etc.), polyurethane foam (soft or semi-rigid polyurethane foam, etc.) can be used. .
[0059]
Examples of the reinforcing layer include a nonwoven fabric, a synthetic resin sheet, or a film. As these non-woven fabric and synthetic resin sheet or film, those similar to those exemplified for the skin material can be used.
[0060]
The backing layer can be used alone or in combination. The backing layer is preferably one that can be heat-laminated with the skin material by either thermal fusion of the skin material or thermal fusion of the backing layer.
[0061]
The thermoplastic resin constituting the substrate 4 of the molded body is not particularly limited as long as compression molding or injection molding is possible. For example, polyolefin resins (polypropylene, polyethylene, etc.), styrene resins (polystyrene, styrene- Butadiene block copolymer, acrylonitrile-styrene-butadiene block copolymer, etc.), polyamide resin (nylon, etc.), halogen-containing resin (polyvinyl chloride, etc.), polycarbonate resin, (meth) acrylic acid ester alone or in combination A polymer (such as an acrylic resin) can be used. The thermoplastic resin may be a thermoplastic elastomer, and for example, an olefin-based thermoplastic elastomer [for example, ethylene-propylene copolymer (EPM), ethylene-propylene-diene copolymer (EPDM)] can be used. .
[0062]
The said thermoplastic resin (and thermoplastic elastomer) can be used individually or in combination of 2 or more types, for example, may be used as a polymer alloy.
[0063]
Further, the thermoplastic resin (and thermoplastic elastomer) contains various additive components such as fillers (inorganic fillers such as glass fibers; organic fillers), pigments, lubricants, antistatic agents, stabilizers, and the like. Also good.
[0064]
Further, the thermoplastic resin (and the thermoplastic elastomer) may contain a foaming agent. By molding the resin with this foaming agent, a molded body formed of the foamed substrate 4 can be obtained. As the foaming agent, a known chemical foaming agent (decomposable foaming agent, etc.) used when foaming a thermoplastic resin can be used. For example, inorganic systems such as sodium bicarbonate, ammonium bicarbonate, ammonium carbonate, etc. Blowing agents; nitroso compounds such as N, N′-dinitrosopentamethylenetetramine; azo compounds such as azodicarbonamide and azobisisobutyronitrile; benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, diphenylsulfone-3,3′-di Sulfonyl hydrazides such as sulfonyl hydrazide; p-toluenesulfonyl semicarbazide and the like. Furthermore, it is preferable to add salicylic acid, urea, and a foaming aid containing these as required. The foaming agent can be appropriately selected in consideration of the melting temperature of the thermoplastic resin used and the required expansion ratio. The addition amount can be appropriately set in consideration of the required strength, required density and the like of the molded product, but is generally about 0.1 to 5 parts by mass with respect to 100 parts by mass of the resin. In addition, when performing the above-mentioned foaming operation, in addition to the method of containing a chemical foaming agent in the thermoplastic resin, a volatile liquid foaming agent, a gas foaming agent, or the like may be directly press-fitted into the molten resin in the mold. . Carbon dioxide, nitrogen, etc. can be used as the volatile liquid blowing agent or gas blowing agent.
[0065]
【The invention's effect】
According to the present invention, since the resin stopper plate is embedded so as to protrude substantially along the boundary position of the skin material (skin portion), the resin is blocked by blocking the resin toward the boundary portion with the resin stopper plate. It is possible to control the timing of arrival at the boundary portion, and to reliably prevent the displacement of the boundary portion and the occurrence of wrinkles.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing an example of a mold according to the present invention.
FIG. 2 is a plan view showing an example of a male molding surface used in the present invention.
FIG. 3 is a schematic perspective view showing an example of a resin stopper plate used in the present invention.
FIG. 4 is a schematic cross-sectional view for explaining an example of the production method of the present invention.
FIG. 5 is a schematic perspective view showing an example of a sandwiched body used in the present invention.
6 is a cross-sectional view of the sandwiched body of FIG. 5 along the line AA ′.
FIG. 7 is a cross-sectional view of the sandwiched body of FIG. 5 taken along the line BB ′.
FIG. 8 is a schematic sectional view showing another example of the mold of the present invention.
FIG. 9 is a schematic sectional view showing still another example of the mold of the present invention.
FIG. 10 is a plan view showing another example of the molding surface of the male mold used in the present invention.
FIG. 11 is a plan view showing still another example of the male molding surface used in the present invention.
FIG. 12 is a plan view showing another example of the molding surface of the male mold used in the present invention.
FIG. 13 is a side view showing another example of the resin stopper plate used in the present invention.
FIG. 14 is a plan view showing an example of a molded body that can be produced according to the present invention.
FIG. 15 is a cross-sectional view of the molded body of FIG. 14 as viewed from the front.
FIG. 16 is a cross-sectional view of a conventional mold.
FIG. 17 is a plan view showing a molded body manufactured by a conventional mold.
[Explanation of symbols]
1, 2, ... skin material
3 ... Boundary part
10a, 10b, 10c ... mold
11, 11a, 11b, 12, 12a, 12b ... gate
13 ... Boundary planned position
14 ... Mold located on the back side of the skin
15 ... Mold located on the front side of the skin material
21, 22 ... Molten thermoplastic resin
41, 41a, 41b, 41c, 42, 42a, 42b, 42c, 42d, ... resin stopper plate
50 ... sandwiched body
61 ... Protrusions

Claims

A mold for producing a multilayer molded body by supplying a molten thermoplastic resin to the back sides of the first and second skin materials adjacent to each other in the planar direction and bonding the skin material and the thermoplastic resin together, A first gate for supplying the molten thermoplastic resin to the back side of the first skin material and a second gate for supplying the molten thermoplastic resin to the back side of the second skin material are the skins. In a pair of male and female molds formed on a mold located on the back side of the material, the first and second of the molding surfaces of either the male mold or the female mold located on the back side of the skin material Embedded on both sides or one side of the position corresponding to the boundary portion of the skin material, between the position corresponding to the boundary portion and the gate, so that the resin stopper plate can protrude substantially along the position corresponding to the boundary portion The mold that has been.

2. The mold according to claim 1, wherein a resin stopper plate is embedded on both sides of the position corresponding to the boundary portion so as to protrude.

The metal mold | die of Claim 1 by which the clamping body for clamping the said boundary part is embed | buried in the position corresponding to the boundary part of a skin material among the molding surfaces of the metal mold | die located in the back side of a skin material.

The mold according to claim 1, wherein the mold located on the front side of the skin material is formed with a protruding portion continuous along the boundary portion at a position corresponding to the boundary portion of the skin material.

Between the male and female dies of a pair of male and female molds, the first and second skin materials adjacent to each other in the plane direction are disposed, and either the male or female die located on the back side of the skin material A first gate for supplying a molten thermoplastic resin to the back surface of the first skin material, and a molten thermoplastic resin for supplying the molten thermoplastic resin to the back surface of the second skin material. Forming a second gate, supplying a molten thermoplastic resin from these first and second gates, and bonding the skin material and the thermoplastic resin to produce a multilayer molded article, A resin stopper plate is embedded in the mold surface on the back side of the skin material so as to protrude on both sides or one side of the position corresponding to the boundary portion of the skin material, and the resin stopper plate protrudes into the mold cavity. Resin that supplies molten thermoplastic resin from the gate and flows from the gate toward the boundary Manufacture of a molded body that blocks the resin stopper plate and controls the timing at which the resin arrives at the boundary by accommodating the resin stopper plate in the mold until the resin filling into the mold cavity is completed. Method.

The first and second gates are formed such that the distance from one gate to the position corresponding to the boundary is shorter than the distance from the other gate to the position corresponding to the boundary. The resin stopper plate is embedded on both sides of the position corresponding to the boundary portion on the side where the gate having a short distance to the boundary portion is formed, and the distance to the boundary portion is short by the resin stopper plate. The resin supplied from the gate is once blocked, and the resin stopper plate is accommodated in the mold in accordance with the arrival timing of the resin supplied from the gate having a long distance to the boundary, so that the resin is bounded. The manufacturing method of Claim 5 which controls the timing which reaches | attains a part.

The first and second gates are formed such that the distance from one gate to the position corresponding to the boundary is shorter than the distance from the other gate to the position corresponding to the boundary, and the skin material A resin stopper plate is embedded on both sides of the position corresponding to the boundary of the resin so that it can protrude, and the resin supplied from the gate with a short distance to the boundary is temporarily blocked by the resin stopper plate on one side, 6. The resin supplied from a gate with a long distance is once blocked by the resin stopper plate on the other side, and then the resin stopper plates on both sides are accommodated in a mold to control the timing at which the resin reaches the boundary. The manufacturing method as described.

The resin stopper plate is abutted against the molding surface of the mold located on the front side of the skin material through the skin material until the resin flowing in from the gate reaches the embedding position of the resin stopper plate. Item 8. The production method according to any one of Items 5 to 7.

The manufacturing method according to any one of claims 5 to 8, wherein the skin material is shaped according to the shape of the molded body prior to disposing the skin material in a mold.

The manufacturing method according to any one of claims 5 to 9, wherein the resin is filled in the mold cavity by pressing the molten resin supplied from the gate with a male mold and a female mold.

The manufacturing method according to any one of claims 5 to 10, wherein the resin stopper plate protruding into the mold cavity is accommodated in the mold with a resin forming pressure.

A molten thermoplastic resin containing a foaming agent is used as the resin supplied from the first and second gates. After filling the mold cavity with the resin, the mold cavity is enlarged, and the resin is The production method according to claim 5, wherein foaming is performed.