JP5150988B2

JP5150988B2 - Decorative sheet manufacturing method

Info

Publication number: JP5150988B2
Application number: JP2000386375A
Authority: JP
Inventors: 浩之阿竹
Original assignee: Dai Nippon Printing Co Ltd
Current assignee: Dai Nippon Printing Co Ltd
Priority date: 2000-12-20
Filing date: 2000-12-20
Publication date: 2013-02-27
Anticipated expiration: 2020-12-20
Also published as: JP2002187161A

Description

【０００１】
【発明の属する技術分野】
本発明は、各種物品の表面への加飾技術に関する。より詳細には、射出成形同時加飾等の加飾成形に好適なラミネ−トタイプの加飾シートとして、加飾成形品の表面に艶消し意匠を付与できる加飾シートと、該シートを用いた射出成形同時加飾方法及び加飾成形品に関する。
【０００２】
【従来の技術】
従来から、樹脂成形物等の物品の表面に加飾シートをラミネートして装飾した加飾品が各種用途で使用されている。そして、加飾シートを成形して用いる加飾法としては、例えば、特公昭５０−１９１３２号公報、特開平１１−９１０４１号公報等に開示される射出成形同時加飾方法があり、この方法では、樹脂成形物の成形と同時にその表面に加飾シートも成形した上で積層一体化する事で、表面が加飾された加飾成形品が得られる。
【０００３】
そして、表面に艶消し感が求められる場合、例えば、次の様な方法で対処していた。（１）射出成形同時加飾方法の場合に於いて、加飾シート自体には艶消し剤は無添加とし、その射出成形型の型面に絞等の凹凸を設けておく。そして、成形時に型面の凹凸が該型面に接触する加飾シート表面に賦形される事から、加飾成形品（加飾シート）表面を凹凸面として艶消しにする。（２）表面に予めエンボス加工等で凹凸を賦形して艶消しとした艶消し剤無添加の加飾シートを用いる。（３）基材シートに艶消し剤を添加して加飾シート自体を艶消しとしておく。
【０００４】
【発明が解決しようとする課題】
ところが、上記（１）の方法では、射出成形同時加飾方法において、絞等の凹凸で表面艶調整（艶消し、低光沢）ができるが、艶消しの製品と鏡面の製品との２種類を製造する場合、射出成形型（少なくともキャビティ面部分）が少なくと２個必要となる為に、コストアップとなる問題があった。
また、上記（２）の方法では、加飾シートが真空成形等で成形されるときに、シートを加熱軟化する熱で、加飾シート表面の凹凸が戻り、艶消しが消失して艶消し表面を付与出来なくなることがあった。更に、射出成形同時加飾の場合では、射出成形時の樹脂の熱圧でも凹凸が戻る為に、艶消し消失は更に起き易かった。
また、上記（３）の方法では、表面が艶消しとなる様にする為には、基材シートへの艶消し剤の添加量（配合比率）は多くなる。しかし、そうすると、射出成形等に用いる加飾シートは、膜厚が１００〜３００μｍ程度と厚い為、厚み方向の積算拡散光量が多くなり、外観が白っぽくなったり（白化）、艶消し剤によってシートが脆くなって加飾シートの成形性が低下する。かといって、基材シートの厚みを極端に薄くすると、成形時に皺、或いは破れ等の成形不良が不足する問題が起きた。
【０００５】
すなわち、本発明の課題は、加飾シートを成形して被着体を艶消しに加飾する場合に、加飾シート自体の白化（透明性低下）、成形不良（皺や破れ）、成形性低下、及び艶消し感消失を起こさないで、艶消し意匠を付与する事である。更に、加飾法が射出成形同時加飾の場合では、射出成形型のコスト上昇を起こさずに、艶消し意匠を付与する事である。
【０００６】
【課題を解決するための手段】
そこで、上記課題を解決すべく、本発明の加飾シートの製造方法は、成形用の加飾シートにおいて、表面から順に、艶消し剤を添加したフッ素樹脂からなる表面艶消しで透明な第１樹脂基材シートと、艶消し剤無添加のアクリル樹脂からなる透明な第２樹脂基材シートとを積層した積層体から成り、前記第１樹脂基材シートの厚さが１０μｍ以上５０μｍ以下であり、前記第２樹脂基材シートの厚さが５０〜２００μｍであり、前記第１樹脂基材シートと前記第２樹脂基材シートとが共押出し法ないし接着剤層を介するドライラミネーション法のいずれかで積層してなる構成とした。
【０００７】
この様に製造された加飾シートの基材シートを、艶消し剤を含有させて艶消し意匠を付与する為の層（第１樹脂基材シート）と、艶消し剤を含有させずに成形性を維持する層（第２樹脂基材シート）とに分け、なお且つ艶消し剤を含有させる層（第１樹脂基材シート）は、その樹脂をフッ素樹脂としてあるので、該樹脂が持つ滑り性、耐久性によって、（第１樹脂基材シートが）薄膜でも艶消し剤の脱落や層自体の磨耗を防げる様になる。この為、成形性を維持する方の層（第２樹脂基材シート）は厚くして加飾シートとしての総厚の主体をこちらで確保できる様になり、この層の樹脂はアクリル樹脂として、その熱可塑性により成形性が維持される。しかもアクリル樹脂の持つ透明性、易接着性も活かせるので、艶消し剤を用いても加飾シートの外観を白化させない様にできる。また、艶消し付与は艶消し剤添加による為に、成形時に艶消しが消失する事も無い。以上の結果、加飾シートは、該シートを成形して被着体を加飾する時に、加飾シートの成形不良（皺や破れ）、成形性低下、及び艶消し感消失を起さずに、艶消し意匠を付与できる。また、艶消しとした為に加飾シート自体が白化する事なく透明性が維持され、艶消しで透明感も備えた加飾が出来る。また、この加飾シートを射出成形同時加飾に適用すれば、加飾シート自体によって艶消し意匠を付与できるので、射出成形型で艶消し面を賦型する場合に比べて射出成形型のコスト上昇を回避して、艶消し意匠を付与できる。
【００１２】
【発明の実施の形態】
以下、図面を参照しながら本発明の実施の形態を説明する。
【００１３】
加飾シート：
先ず、加飾シートから説明する。
【００１４】
〔概要〕
図１の断面図で本発明の加飾シートの一形態を例示する。同図の加飾シートＳは、表面から順に、艶消し剤ａを添加したフッ素樹脂からなる表面艶消しで透明な第１樹脂基材シート１と、艶消し剤無添加のアクリル樹脂からなる透明な第２樹脂基材シート２とを積層した積層体から成り、更に裏面側の第２樹脂基材シート２の面に、装飾層４及び接着剤層５をこの順に積層して成る構成の加飾シートである。装飾層４、接着剤層５はそれぞれ必要に応じ適宜設けられる層である。本発明の加飾シートＳは第１樹脂基材シート１及び第２樹脂基材シート２とを必須の層とする。表面側の第１樹脂基材シート１で艶消し意匠を付与し、裏面側の第２樹脂基材シート２で成形性等を維持する。上記特定の第１樹脂基材シート１と特定の第２樹脂基材シート２とで基材シート３が構成される。
【００１５】
なお、本発明の加飾シートは、必須の層である第１樹脂基材シート１及び第２樹脂基材シート２以外に、更に適宜、装飾層４や接着剤層５等を設けても良いが、これら以外にも、図示は省くが、例えば、第１樹脂基材シート１と第２樹脂基材シート２間、第２樹脂基材シート２と装飾層４間等に、層間密着性向上の為のプライマー層等を設けた構成等としても良い。
【００１６】
〔第１及び第２樹脂基材シート〕
本発明では基材シート３は、第１樹脂基材シート１と第２樹脂基材シート２とから構成する。基材シート３の表面（被着体に積層した状態で最外面に露出する面）側に艶消し剤ａを添加した透明なフッ素樹脂からなる第１樹脂基材シート１を配置する。これによって、表面への艶消しと、フッ素樹脂が持つ耐摩耗性及び耐熱耐薬品性によって、表面の艶消し意匠をより良好に維持できる様にした。この結果、他の樹脂を用いる場合に比べて、第１樹脂基材シートは艶消し意匠を維持したまま、より薄くできる様になる。
そして、基材シート３の裏面側には、艶消し剤無添加の透明なアクリル樹脂から成る第２樹脂基材シート２を配置する。これによって、透明性、成形性（熱可塑性）、被着体との易接着性を付与する。また、上記第１樹脂基材シートがフッ素樹脂使用によって薄膜とできる分、こちらの第２樹脂基材シートで加飾シートとして必要な総厚を主体的に担わせることが可能なる。
【００１７】
第１樹脂基材シートの厚みとしては、要求される艶消し度合いによって設定すれば良く、一般的には５０μｍ以下にすれば性能を満足することが多い。なお、第１樹脂基材シートの最低厚みは、艶消し剤の平均粒径よりは大で、且つ成膜性、膜強度の点から１０μｍ程度以上が好ましい。
【００１８】
一方、艶消し剤を添加しない方の第２樹脂基材シートの厚みとしては、こちらで第１樹脂基材シート等の厚みと含めて加飾シートとしての成形性維持等に必要な総厚を確保すれば良く、一般的には５０〜２００μｍ程度の範囲である。
【００１９】
なお、第１樹脂基材シートにて、そのフッ素樹脂に添加する艶消し剤ａとしては、特に制限は無いが、例えば、シリカ、アルミナ、炭酸カルシウム、アルミノシリケート、硫酸バリウム等の無機物、ポリエチレン、ウレタン樹脂、ポリカーボネート、ポリアミド（ナイロン）等の有機高分子等、から成る粒子が用いられる。粒子の平均粒径は１〜１０μｍ程度、添加量は５〜３０質量％程度である。なお、粒子の形状は、多面体、球形、鱗片状等である。
【００２０】
なお、第１樹脂基材シートと第２樹脂基材シートとを積層するには、特にフッ素樹脂は化学的な易接着性に乏しい為、これら両シートとなる樹脂を各々加熱熔融した状態で、Ｔダイから共押出しして、成膜と同時に両シートを融着する方法が好ましい。
また、この他、既に一旦成膜済みシートを用い、接着面をコロナ放電処理、プラズマ処理等の表面易接着処理によって、ヒドロキシル基、カルボキシル基等の極性官能基を接着面に生成させて濡れ性を高めた上で、２液硬化型ウレタン樹脂、エポキシ樹脂等の接着剤層を介して、ドライラミネーション法により積層することも出来る。
【００２１】
なお、第１樹脂基材シートに用いるフッ素樹脂としては、ポリフッ化ビニル、ポリフッ化ビニリデン、エチレン−４フッ化エチレン共重合体、ポリ塩化３フッ化エチレン、４フッ化エチレン−６フッ化プロピレン共重合体等を用いることができる。
なお、耐摩耗性、耐熱耐薬品性を損なわない範囲で、最大２０質量％程度までアクリル樹脂を添加し、アクリル樹脂の第２樹脂基材シートとの易接着性を向上させても良い。
【００２２】
また、第２樹脂基材シートに用いるアクリル樹脂としては、例えば、ポリメチル（メタ）アクリレート、ポリエチル（メタ）アクリレート、ポリブチル（メタ）アクリレート、メチル（メタ）アクリレート−ブチル（メタ）アクリレート共重合体、エチル（メタ）アクリレート−ブチル（メタ）アクリレート共重合体、メチル（メタ）アクリレート−スチレン共重合体、メチル（メタ）アクリレート−２ヒドロキシエチル（メタ）アクリレート共重合体、メチル（メタ）アクリレート−エチレン共重合体等のアルキル（メタ）アクリレートモノマーの単独重合体、又は他のモノマーとの共重合体からなる樹脂を、単独で、又はこれら二種以上を混合して、用いることができる。
【００２３】
〔装飾層〕
装飾層４は、必要に応じ適宜設ける。装飾層４は、例えば代表的には模様や文字等の絵柄を表現する層である。絵柄は任意であるが、例えば、木目、石目、布目、砂目、幾何学模様、文字、記号、全面ベタ等が、用途に合わせて、１種又は２種以上組み合わせて使用される。
装飾層の形成は、グラビア印刷、シルクスクリーン印刷、オフセット印刷等の印刷法等の従来公知の形成方法、材料で形成すれば良い。また、アルミニウム、クロム等の金属を公知の蒸着法等で部分又は全面に形成した金属薄膜層等も装飾層として使用される。
【００２４】
なお、装飾層形成用のインキは、バインダー等からなるビヒクル、顔料や染料等の着色剤、これに適宜加える各種添加剤からなるが、バインダーの樹脂としては、例えば、アクリル樹脂、塩化ビニル−酢酸ビニル共重合体、ポリエステル樹脂、セルロース系樹脂、塩素化ポリプロピレン、ウレタン樹脂、ポリアミド樹脂等より選択される１種単独の樹脂、又は２種以上の混合樹脂が用いられる。また、着色剤としては、例えば、チタン白、亜鉛華、カーボンブラック、鉄黒、弁柄、カドミウムレッド、群青、コバルトブルー、黄鉛、チタンイエロー等の無機顔料、フタロシアニンブルー、インダスレンブルー、イソインドリノンイエロー、ベンジジンイエロー、キナクリドンレッド、ペリレンレッド等の有機顔料、アルミニウム、真鍮等の金属の粉末又は鱗片等の金属顔料、二酸化チタン被覆雲母の粉末又は鱗片等の真珠光沢（パール）顔料、或いは染料等が用いられる。
【００２５】
なお、第２樹脂基材シートに接して装飾層を印刷形成する場合、用いるインキのバインダーの樹脂としては、該第１樹脂基材シートがアクリル樹脂から成るので、アクリル樹脂は好ましい樹脂である。該アクリル樹脂としては、前記第１樹脂基材シートにて列記したものと同様のものの中から適宜選択する他、メチル（メタ）アクリレート、エチル（メタ）アクリレート、ブチル（メタ）アクリレート、２−エチルヘキシル（メタ）アクリレート、オクチル（メタ）アクリレート等の（メタ）アクリル酸アルキルエステルと、２−ヒドロキシエチル（メタ）アクリレート、２−ヒドロキシブチル（メタ）アクリレート、２−ヒドロキシ−３−フェノキシプロピル（メタ）アクリレート等の分子中に水酸基を有する（メタ）アクリル酸エステルとを共重合させて得られるアクリルポリオールを用いることも出来る。
【００２６】
なお、装飾層は、第１及び第２樹脂基材シートを保護シートとして利用できる点で、図１で例示の構成の如く、第１樹脂基材シート２の裏面側（樹脂成形物側）とする構成が一般的であるが、第１樹脂基材シート１の表面側、或いは第１樹脂基材シート１と第２樹脂基材シート２間等に設けても良い。例えば、図１の構成に対して更に、或いは第１樹脂基材シート１及び第２樹脂基材シート２のみからなる構成等に対して、第１樹脂基材シート１の表面に、その艶消しの為の凹凸を損なわない範囲で、薄く、或いはパターン状に、装飾層を設ける等である（図示略）。
【００２７】
また、装飾層としては、単に絵柄や文字、図形等の目視可能な模様を表現する層以外に、目視不可能な模様、あるいは導電性等の機能性を付与する層でも良い。例えば、導電体、帯電防止剤、蛍光体、磁性体、赤外線吸収剤、紫外線吸収剤等を含有する層である。上記着色剤の代わりにこれら物質を含有するインキを用いれば、これら層は形成できる。
【００２８】
〔接着剤層〕
加飾シートの裏面側は、必要に応じ適宜、樹脂成形物等の被着体との接着性を向上させるために、コロナ放電処理、プラズマ処理、プライマー塗工等の易接着処理の他、これら易接着処理を処理後或いは処理せずに、接着剤層５を設けても良い。
接着剤層５としては、例えば感熱型の接着剤として熱可塑性樹脂、熱硬化性樹脂等の公知の樹脂が用いられる。熱可塑性樹脂では、例えば、アクリル樹脂、塩素化ポリオレフィン樹脂、塩化ビニル−酢酸ビニル共重合体、熱可塑性ウレタン樹脂、熱可塑性ポリエステル樹脂、ポリアミド樹脂、ゴム系樹脂等の１種又は２種以上の混合物が用いられる。また、熱硬化性樹脂では、ウレタン樹脂、エポキシ樹脂等が用いられる。
接着剤層は、これら樹脂による接着剤を、グラビア印刷、ロールコート等の公知の印刷又は塗工法により形成する。また、接着剤層の厚さは特に制限は無いが、通常は１〜１００μｍ程度である。また、接着剤層中には、前記装飾層で列記した様な着色剤を添加しても良い。
【００２９】
〔加飾シートの被着体への積層法〕
本加飾シートを被着体へ積層する方法としては、積層時に熱及び圧が加飾シートに加わる方法が、本発明の加飾シートの特徴を活かせる方法として好適であるが、もちろん、これ以外の積層方法に本発明の加飾シートを用いても良い。なお、もちろん、いずれの場合も、第１樹脂基材シートに対して第２樹脂基材シート側が被着体側となる。加飾シートを被着体へ積層する事によって、被着体と加飾シートとの積層体として加飾物品が得られる。
【００３０】
被着体に加飾シートを積層時に熱圧が加わる積層方法としては、例えば、（１）射出成形同時加飾方法、（２）真空成形積層方法、（３）弾性体ローラを用いた積層方法等が挙げられる。（１）は後で詳述するので、ここでは、（２）と（３）の積層法を更に説明しておく。
【００３１】
（２）の真空成形積層方法は、特公昭５６−４５７６８号公報（オーバーレイ法）、特公昭６０−５８０１４号公報（真空プレス法）等に記載されるように、成形品等の立体形状の被着体の表面に加飾シートを間に接着剤を介して対向又は載置し、被着体側からの少なくとも真空吸引による圧力により加飾シートを被着体に積層する方法である。
（３）の弾性体ローラを用いた積層方法は、板状の被着体に対しては、加飾シートを間に接着剤を介して対向又は載置し、加飾シート側から弾性体ローラで加圧して、加飾シートを被着体に積層する方法である。また、円柱、多角柱等の柱状の被着体に対しては、特公昭６１−５８９５号公報、特公昭５６−２３７７１号公報等に記載されるように、柱状の被着体の長軸方向に、加飾シートを間に接着剤層を介して供給しつつ、複数の向きの異なるローラ（弾性体ローラを使用しない場合も含む）により、被着体を構成する複数の側面に順次加飾シートを加圧接着して加飾シートを積層してゆく、ラッピング加工方法もある。
【００３２】
射出成形同時加飾方法：
本発明の射出成形同時加飾方法は、前述した本発明の加飾シートを用いて、所謂射出成形同時加飾方法によって、樹脂成形物の表面に加飾シートを成形して積層する事で、該加飾シートで艶消し意匠に加飾された加飾成形品を得る方法である。
【００３３】
なお、射出成形同時加飾方法とは、特公昭５０−１９１３２号公報、特公昭４３−２７４８８号公報等に記載されるように、加飾シートを雌雄両型間に挿入した後、両型を型締めし、両型で形成されるキャビティ内に流動状態の樹脂を射出し固化させて、樹脂成形物の成形と同時にその表面に加飾シートを積層して加飾成形品を得る方法である。
【００３４】
本発明の射出成形同時加飾方法は、用いる加飾シートとして前述した本発明の加飾シートを用いる事以外は、従来公知の射出成形同時加飾方法に於ける各種形態をとり得るものである。例えば、基本的には、加飾シートの予備成形を行う形態でも行わない形態でも、いずれでも良い。また、加飾シートの予熱を行っても良く、行わなくても良い。なお、予備成形時には通常は加飾シートは予熱する。但し、前記本発明の加飾シートによる効果を最大限に活用するには、加飾シートはいずれにしろ成形される形態が好ましい。
【００３５】
なお、もちろんの事だが、加飾シートの絞りが大きい場合は、予備成形を行うのが好ましい。一方、加飾シートの絞りが少ない場合は、射出される流動状態の樹脂の樹脂圧のみで加飾シートを成形しても良い。この際、絞りが浅ければ、予備成形無しで樹脂射出と同時に型内に充填される流動状態の樹脂の樹脂圧のみで加飾シートを成形しても良い。また、樹脂圧で加飾シートを成形する場合でも、加飾シートは予熱せずに射出樹脂の熱を利用する事もある。また、加飾シートの予備成形は、通常は、射出成形型を真空成形型と兼用して行うが、型間に加飾シートを供給する前に、型外部で別の真空成形型で加飾シートを真空成形する様な予備成形（オフライン予備成形）でも良い。但し、予備成形は、射出成形型と真空成形型とを兼用して行う形態が効率的且つ精度良く加飾シートを積層できる点で好ましい。しかし、予備成形済みの加飾シートを予め別の場所で纏めて製造しておく場合等では、予備成形はオフライン予備成形の形態が好ましい。なお、本発明の説明に於いて真空成形とは真空圧空成形も包含する。
【００３６】
図２の概念図によって、本発明の射出成形同時加飾方法を、その或る一形態で説明する。なお、ここで説明する形態は、型締めする前に、加飾シートを型間で加熱し軟化させて射出成形型で真空成形により予備成形した後に、型締めして樹脂を射出する形態である。また、この形態は、上記した加飾シートの予備成形、予熱の各種組合わせ形態の中で、加飾シートの絞りが深い場合に、より好ましい形態である。また、前記本発明の加飾シートの効果を活かせる形態の一つでもある。
なお、本発明の射出成形同時加飾方法で用いる加飾シートは、枚葉、連続帯状のどちらでも良い事はもちろんである。
【００３７】
先ず、図２（Ａ）の如く、射出成形型としては、射出ノズルと連通する湯道（ランナー）及び湯口（ゲート）を有する型Ｍａと、キャビティ面に吸引孔４１を有しシートの予備成形型を兼用する型Ｍｂの一対の成形型を用いる。これらの型は鉄等の金属、或いはセラミックスからなる。型開き状態に於いて両型Ｍａ、Ｍｂ間に加飾シートＳを供給し、型Ｍｂに加飾シートＳを平面視枠状のシートクランプ４２で押圧する等して固定する。この際、加飾シートの（第１樹脂基材シートに対して）第２樹脂基材シート側は、図面右側の射出樹脂側を向く様にする事はもちろんである。次いで、適宜、両型間に挿入したヒータ（図示略）で加飾シートを加熱軟化させる。加熱は例えば非接触の輻射加熱とするが、接触による伝導加熱でも良い。そして、吸引孔から吸引して真空成形して、加飾シートを型Ｍｂのキャビティ面に沿わせ予備成形する。次いで、ヒータを両型間から退避させ、図２（Ｂ）の如く両型を型締めし、両型で形成されるキャビティに加熱熔融状態等の流動状態の樹脂を充填する。そして、樹脂が冷却等によって固化した後、型開きして成形物を取り出す。
そして、加飾シートの不要部分は適宜トリミングすれば、樹脂成形物に加飾シートが積層され構成の加飾成形品が得られる。
【００３８】
〔射出樹脂〕
なお、本発明の射出成形同時加飾方法に於いては、射出成形する樹脂としては、基本的には特に制限はなく公知の樹脂で良い。製品の要求物性やコスト等に応じて選定すれば良い。熱可塑性樹脂であれば、ＡＢＳ（アクリロニトリル−ブタジエン−スチレン共重合体）樹脂、スチレン樹脂、アクリル樹脂、塩化ビニル樹脂、ポリカーボネート樹脂、ポリオレフィン系樹脂等である。また、硬化性樹脂であれば、２液硬化型の樹脂、例えば、ウレタン樹脂、不飽和ポリエステル樹脂、エポキシ樹脂等の未硬化樹脂液等である。熱可塑性樹脂は加熱熔融して流動状態で射出し、また硬化性樹脂は（その未硬化物を）室温又は適宜加熱して流動状態で射出する。
なお、射出樹脂は、用途に応じて適宜、着色剤を添加して着色した樹脂を使用しても良い。着色剤には、前述装飾層で述べた如き公知の着色剤を使用すれば良い。また、射出樹脂には、必要に応じ適宜、シリカ、アルミナ、タルク、炭酸カルシウム、水酸化アルミニウム等の無機物粉末、ガラス繊維等の充填剤、安定剤、滑剤等の公知の各種添加剤を含有させる。
【００３９】
加飾成形品：
本発明の加飾成形品は、樹脂成形物上に、少なくとも、艶消し剤無添加のアクリル樹脂の透明な第２樹脂基材シートと、艶消し剤を添加したフッ素樹脂の表面艶消しで透明な第１樹脂基材シートとをこの順に積層することで、表面が艶消し意匠に加飾された成形品である。この様な構成の本発明の加飾成形品は、樹脂成形物上に、例えば好適には前述本発明の加飾シートを積層すれば得られる。また、その積層法としては、例えば上述本発明の射出成形同時加飾方法を利用できる。もちろん、本発明の加飾成形品は、前述本発明の加飾シート、或いは上述本発明の射出成形同時加飾方法を利用せずに、他の材料（例えば第１樹脂基材シートと第２樹脂基材シートとを別々に樹脂成形物に積層する）、他の方法（例えば真空成形積層方法）によって製造した物でも良い。但し、もちろん、本発明の射出成形同時加飾方法で製造するのが、成形と加飾とを同時に１工程で出来、生産効率も良い等の点で好ましい。
【００４０】
図３の断面図で例示する本発明の加飾成形品Ｐは、その一形態を例示するものであり、樹脂成形物６上に、接着剤層５、装飾層４、第２樹脂基材シート２、及び第１樹脂基材シート１が、この順に積層された構成の成形品である。樹脂成形物６上の各層は、例えば図１の加飾シートＳが積層された構成となっている。
【００４１】
樹脂成形物６の樹脂は、前述本発明の射出成形同時加飾方法で述べた射出樹脂等であり、第２樹脂基材シート２及び第１の樹脂基材シート１は前述本発明の加飾シートで述べた基材シートであるので、ここでは更なる説明は省略する。なお、前述本発明の加飾シートで述べた同様に、本発明の加飾成形品においても、図３に例示の如く、必要に応じ適宜、装飾層、接着剤層等のその他の層を更に設けた構成としても良い。
【００４２】
なお、加飾成形品は、通常、加飾シートの積層面が凹凸面等と非平面の立体物である。しかし、本発明の加飾成形品としては、加飾シートの積層面は平面だが他の面が非平面の立体物、積層面が平面となる板状物を排除するものではない。
【００４３】
【実施例】
以下、実施例及び比較例により本発明を更に詳述する。
【００４４】
〔実施例１〕
図１の如き構成の加飾シートＳを次の様にして作製した。ポリフッ化ビニリデンからなる透明フッ素樹脂１００質量部に対して艶消し剤ａとして平均粒径３μｍのシリカ粒子２０質量部を添加した樹脂組成物と、ポリメチルメタクリレート系の透明なアクリル樹脂とを熔融共押出しして、厚さ１０μｍの第１樹脂基材シート１と厚さ９０μｍ第２樹脂基材シート２とが熔融接着した基材シート３を得た。次いで、この基材シート３の第２樹脂基材シート２側の面に、木目模様の絵柄を表現した装飾層４を３色のグラビア印刷で形成し、更に、アクリル樹脂と塩化ビニル−酢酸ビニル共重合体と１対１質量比からなる厚さ４μの接着剤層５を２色のグラビア印刷で全面に形成して、加飾シートを得た。なお、装飾層形成に用いたインキは、バインダーの樹脂はアクリル樹脂を主成分とし、着色剤はイソインドリノンイエロー、キナクリドンレッド及びカーボンブラックを主成分とするインキを使用した。また、接着剤層は、１色目は、チタン白、イソインドリノンイエロー及びキナクリドンレッドを主成分とする着色剤を添加したインキを使用し、２色目は着色剤無添加のインキを使用した。接着剤層の各色はそれぞれ厚さ２μｍである。
【００４５】
そして、図２の概念図に示した様な本発明の射出成形同時加飾方法によって、上記加飾シートを樹脂成形物の成形と同時にその表面に積層して、図３に示す如き構成となる本発明の加飾成形品Ｐを得た。なお、射出成形同時加飾方法は、射出成形の雌型を真空成形型として、加飾シートを型間に挿入後、加熱軟化して真空成形で予備成形する形態で行った。加飾シートの予備成形は、赤外線輻射加熱によりシート温度１１０℃に加熱した後、雌型側から真空吸引して加飾シートを雌型キャビティ面に沿わせる様にした。その後、射出樹脂温度２４０℃で耐熱ＡＢＳ樹脂（耐熱温度９５℃）を、型温度７０℃の条件で射出し、加飾シートを樹脂成形物とを一体化して加飾成形品を成形した。なお、射出成形型には、キャビティ面が鏡面仕上げで、幅４０ｍｍ、長さ４００ｍｍの車両内装用パネルを成形する型を用いた。
【００４６】
射出成形同時加飾時に、加飾シートの皺や破れは無く、しかも、得られた加飾成形品の外観は木目模様の表面が艶消しとなっており、しかも木目模様の白く見える白化も認められなかった。
【００４７】
〔比較例１〕
実施例１に於いて、基材シート３として、ポリメチルメタクリレート系の透明なアクリル樹脂１００質量部に対して艶消し剤として平均粒径３μｍのシリカ粒子２０質量部を添加した樹脂組成物から成膜した厚さ１２５μｍの樹脂シートを用いて加飾シートを作製した。
しかし、この加飾シートは、艶消し効果が強すぎて基材シートの白化により木目模様が白く見えてしまい意匠外観上不良であり、これ以上の成形品試作までの評価は不必要と判断した。
【００４８】
〔比較例２〕
実施例１に於いて、基材シート３として、ポリメチルメタクリレート系の透明なアクリル樹脂１００質量部に対して艶消し剤として平均粒径３μｍのシリカ粒子２０質量部を添加した樹脂組成物から成膜した厚さ３０μｍの樹脂シートを用いて加飾シートを作製し、更に射出成形同時加飾にて加飾成形品を作製した。
その結果、基材シートによる木目模様の白化は認められ無かった。しかし、射出成形同時加飾の際に、射出樹脂の樹脂圧により、加飾シートが伸ばされて皺がよってしまった。
【００４９】
【発明の効果】
（１）本発明の方法で製造された加飾シートによれば、成形不良（皺や破れ）、成形性低下、及び艶消し感消失を起さずに、艶消し意匠を付与できる。また、艶消しとした為に加飾シート自体が白化する事なく透明性が維持され、艶消しで透明感も備えた加飾が出来る。また、この加飾シートを射出成形同時加飾に適用すれば、加飾シート自体によって艶消し意匠を付与できるので、射出成形型で艶消し面を賦型する場合に比べて射出成形型のコスト上昇を回避して、艶消し意匠を付与できる。
【図面の簡単な説明】
【図１】本発明の加飾シートの一形態を例示する断面図。
【図２】本発明の射出成形同時加飾方法をその一形態で説明する概念図。
【図３】本発明の加飾成形品の一形態を例示する断面図。
【符号の説明】
１第１樹脂基材シート
２第２樹脂基材シート
３基材シート
４装飾層
５接着剤層
６樹脂成形物
４１吸引孔
４２シートクランプ
ａ艶消し剤
Ｍａ射出成形型（雄型）
Ｍｂ射出成形型（雌型）
Ｐ加飾成形品
Ｓ加飾シート[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for decorating the surface of various articles. More specifically, as a laminated type decorative sheet suitable for decorative molding such as simultaneous injection molding, a decorative sheet capable of imparting a matte design to the surface of a decorative molded product, and the sheet were used. The present invention relates to an injection molding simultaneous decoration method and a decorative molded product.
[0002]
[Prior art]
Conventionally, decorative products in which a decorative sheet is laminated and decorated on the surface of an article such as a resin molded product have been used for various purposes. And as a decoration method which shape | molds and uses a decorating sheet, there exists the injection molding simultaneous decorating method disclosed by Japanese Patent Publication No.50-19132, Unexamined-Japanese-Patent No. 11-91041 etc., for example, A decorative molded product with a decorated surface can be obtained by molding a decorative sheet on the surface of the resin molded product at the same time as the molding of the resin molding and then integrating the layers.
[0003]
Then, when a matte feeling is required on the surface, for example, the following method is used. (1) In the case of the injection molding simultaneous decorating method, the decorating sheet itself is not added with a matting agent, and irregularities such as a drawing are provided on the mold surface of the injection mold. And since the unevenness | corrugation of a mold surface is shape | molded on the surface of a decorating sheet which contacts this mold surface at the time of shaping | molding, it makes the surface of a decorative molded product (decorative sheet) matt as an uneven surface. (2) Use a decorating sheet with no matting agent added to the surface in advance by embossing or the like to create irregularities. (3) A matting agent is added to the base sheet to make the decorating sheet itself matte.
[0004]
[Problems to be solved by the invention]
However, in the method of (1) above, the surface gloss adjustment (matte, low gloss) can be made by unevenness such as drawing in the injection molding simultaneous decorating method, but there are two types of products: matte product and mirror surface product. When manufacturing, since at least two injection molds (at least the cavity surface portion) are required, there is a problem of increasing the cost.
In the above method (2), when the decorative sheet is formed by vacuum forming or the like, the heat of softening the sheet returns the irregularities on the surface of the decorative sheet, and the matte surface disappears. Can no longer be granted. Further, in the case of simultaneous injection molding, the matte disappearance is more likely to occur because the unevenness is restored even by the heat pressure of the resin during injection molding.
In the method (3), the amount of the matting agent (mixing ratio) to the base sheet increases in order to make the surface matte. However, in that case, the decorative sheet used for injection molding or the like has a thickness of about 100 to 300 μm, so that the amount of accumulated diffused light in the thickness direction increases and the appearance becomes whitish (whitening). It becomes brittle and the formability of the decorative sheet decreases. However, when the thickness of the base sheet is extremely thin, there has been a problem that molding defects such as wrinkles or tearing are insufficient at the time of molding.
[0005]
That is, the object of the present invention is to form a decorative sheet and decorate the adherend in a matte manner, whitening (decrease in transparency) of the decorative sheet itself, poor molding (wrinkles and tearing), moldability It is to give a matte design without causing a drop and loss of matte feeling. Furthermore, when the decoration method is simultaneous injection molding, a matte design is imparted without causing an increase in cost of the injection mold.
[0006]
[Means for Solving the Problems]
  Then, in order to solve the said subject, the manufacturing method of the decorating sheet of this invention is the surface matte and transparent 1st which consists of a fluororesin which added the matting agent in order from the surface in the decorating sheet for shaping | molding. It consists of a laminate in which a resin base sheet and a transparent second resin base sheet made of an acrylic resin without a matting agent are laminated,The first resin base sheet has a thickness of 10 μm or more and 50 μm or less, and the second resin base sheet has a thickness of 50 to 200 μm,The first resin base sheet and the second resin base sheet are laminated by either a coextrusion method or a dry lamination method with an adhesive layer interposed therebetween.
[0007]
  Like thisOf the manufactured decorative sheetA layer (first resin substrate sheet) for adding a matting agent to the base sheet and providing a matting design, and a layer (second resin base) for maintaining moldability without containing the matting agent The layer (first resin base sheet) containing the matting agent is divided into the material sheet), and the resin is a fluororesin. Therefore, depending on the slipperiness and durability of the resin (first resin) Even if the base sheet is a thin film, the matting agent can be prevented from falling off or the layer itself can be worn away. For this reason, the layer (second resin base sheet) that maintains moldability is thickened, and the main component of the total thickness as a decorative sheet is here.Can be securedThus, the resin of this layer is an acrylic resin, and its moldability is maintained by its thermoplasticity. Moreover, since the transparency and easy adhesion property of the acrylic resin can be utilized, the appearance of the decorative sheet can be prevented from being whitened even if a matting agent is used. Further, since the matting is performed by adding a matting agent, the matting is not lost during molding. As a result of the above, the decorative sheet does not cause poor molding (decoration or tearing) of the decorative sheet, deterioration of formability, and loss of matte feeling when the adherend is decorated by molding the sheet. A matte design can be given. In addition, since the mat is matted, the decorative sheet itself is kept transparent without whitening, and the mat can be decorated with a matte transparency. In addition, if this decorative sheet is applied to the simultaneous injection molding, a matte design can be given by the decorative sheet itself, so the cost of the injection mold compared to the case where the matte surface is molded by the injection mold. A matte design can be given by avoiding the rise.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
Decorative sheet:
First, the decorative sheet will be described.
[0014]
〔Overview〕
The cross-sectional view of FIG. 1 illustrates one embodiment of the decorative sheet of the present invention. The decorative sheet S in the figure is, in order from the surface, a first resin base sheet 1 that is transparent with a matte surface made of a fluororesin to which a matting agent a is added, and a transparent resin that is made of an acrylic resin without a matting agent. The second resin base sheet 2 is laminated, and the decorative layer 4 and the adhesive layer 5 are laminated in this order on the surface of the second resin base sheet 2 on the back side. It is a decorative sheet. The decorative layer 4 and the adhesive layer 5 are layers that are appropriately provided as necessary. The decorative sheet S of the present invention includes the first resin base sheet 1 and the second resin base sheet 2 as essential layers. A matte design is imparted by the first resin base sheet 1 on the front side, and moldability and the like are maintained by the second resin base sheet 2 on the back side. The specific first resin base sheet 1 and the specific second resin base sheet 2 constitute a base sheet 3.
[0015]
In addition, the decorative sheet of the present invention may be appropriately provided with a decorative layer 4, an adhesive layer 5 and the like in addition to the first resin base sheet 1 and the second resin base sheet 2 which are essential layers. However, other than these, although illustration is omitted, for example, interlayer adhesion is improved between the first resin base sheet 1 and the second resin base sheet 2, between the second resin base sheet 2 and the decorative layer 4, and the like. It is good also as a structure etc. which provided the primer layer for this.
[0016]
[First and second resin base sheet]
In the present invention, the base sheet 3 is composed of a first resin base sheet 1 and a second resin base sheet 2. The first resin base sheet 1 made of a transparent fluororesin to which the matting agent a is added is disposed on the surface of the base sheet 3 (the surface exposed to the outermost surface in a state of being laminated on the adherend). As a result, the matte design on the surface can be better maintained by the matte surface and the abrasion resistance and heat and chemical resistance of the fluororesin. As a result, compared with the case where other resins are used, the first resin base sheet can be made thinner while maintaining the matte design.
And the 2nd resin base material sheet 2 which consists of a transparent acrylic resin without a matting agent addition is arrange | positioned at the back surface side of the base material sheet 3. FIG. This imparts transparency, moldability (thermoplasticity), and easy adhesion to the adherend. In addition, since the first resin base sheet can be formed into a thin film by using a fluororesin, the second resin base sheet can be used as a decorative sheet to mainly bear the total thickness required.
[0017]
The thickness of the first resin base sheet may be set according to the required matting degree, and generally the performance is often satisfied when the thickness is 50 μm or less. The minimum thickness of the first resin base sheet is preferably larger than the average particle diameter of the matting agent and about 10 μm or more from the viewpoint of film formability and film strength.
[0018]
On the other hand, as the thickness of the second resin base sheet to which no matting agent is added, the total thickness necessary for maintaining the moldability as a decorative sheet, including the thickness of the first resin base sheet, etc. What is necessary is just to ensure, and generally it is the range of about 50-200 micrometers.
[0019]
The matting agent a added to the fluororesin in the first resin base sheet is not particularly limited, but examples thereof include inorganic substances such as silica, alumina, calcium carbonate, aluminosilicate, barium sulfate, polyethylene, Particles made of an organic polymer such as urethane resin, polycarbonate, and polyamide (nylon) are used. The average particle diameter of the particles is about 1 to 10 μm, and the addition amount is about 5 to 30% by mass. In addition, the shape of particle | grains is a polyhedron, a spherical form, scale shape, etc.
[0020]
In addition, in order to laminate the first resin base sheet and the second resin base sheet, in particular, the fluororesin is poor in chemical easy-adhesiveness. A method of co-extrusion from a T die and fusing both sheets simultaneously with film formation is preferred.
In addition to this, a sheet that has already been formed once is used, and the adhesive surface is subjected to surface easy adhesion treatment such as corona discharge treatment and plasma treatment to generate polar functional groups such as hydroxyl groups and carboxyl groups on the adhesion surface, and wettability. In addition, it can be laminated by a dry lamination method through an adhesive layer such as a two-component curable urethane resin or an epoxy resin.
[0021]
The fluororesin used for the first resin base sheet is polyvinyl fluoride, polyvinylidene fluoride, ethylene-4 fluoroethylene copolymer, polychloroethylene trifluoride, tetrafluoroethylene-6 fluoropropylene copolymer. A polymer or the like can be used.
In addition, in the range which does not impair abrasion resistance and heat-resistant chemical resistance, an acrylic resin may be added to about 20 mass% at maximum, and easy adhesion with the 2nd resin base material sheet of an acrylic resin may be improved.
[0022]
Examples of the acrylic resin used for the second resin base sheet include polymethyl (meth) acrylate, polyethyl (meth) acrylate, polybutyl (meth) acrylate, methyl (meth) acrylate-butyl (meth) acrylate copolymer, Ethyl (meth) acrylate-butyl (meth) acrylate copolymer, methyl (meth) acrylate-styrene copolymer, methyl (meth) acrylate-2hydroxyethyl (meth) acrylate copolymer, methyl (meth) acrylate-ethylene A resin composed of a homopolymer of an alkyl (meth) acrylate monomer such as a copolymer, or a copolymer with another monomer can be used alone or in admixture of two or more.
[0023]
[Decoration layer]
The decoration layer 4 is provided as necessary. The decoration layer 4 is a layer that typically represents a pattern such as a pattern or a character. Although the pattern is arbitrary, for example, wood grain, stone grain, cloth grain, sand grain, geometric pattern, characters, symbols, full-color solids, and the like are used alone or in combination of two or more.
The decoration layer may be formed by a conventionally known formation method or material, such as a printing method such as gravure printing, silk screen printing, or offset printing. Further, a metal thin film layer or the like in which a metal such as aluminum or chromium is partially or entirely formed by a known vapor deposition method is also used as a decoration layer.
[0024]
The ink for forming the decorative layer is composed of a vehicle composed of a binder and the like, a colorant such as a pigment and a dye, and various additives appropriately added thereto. Examples of the binder resin include acrylic resin, vinyl chloride-acetic acid. One type of resin selected from vinyl copolymers, polyester resins, cellulosic resins, chlorinated polypropylene, urethane resins, polyamide resins and the like, or two or more types of mixed resins are used. Examples of the colorant include titanium white, zinc white, carbon black, iron black, dial, cadmium red, ultramarine, cobalt blue, yellow lead, titanium yellow, and other inorganic pigments, phthalocyanine blue, indanthrene blue, Organic pigments such as indolinone yellow, benzidine yellow, quinacridone red, perylene red, metal powders such as aluminum and brass, metal pigments such as scales, pearlescent pigments such as titanium dioxide-coated mica powders or scales, or A dye or the like is used.
[0025]
When the decorative layer is printed by being in contact with the second resin base sheet, the first resin base sheet is made of an acrylic resin as the resin for the ink binder to be used, and thus the acrylic resin is a preferred resin. The acrylic resin is appropriately selected from those listed in the first resin base sheet, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl. (Meth) acrylate, alkyl methacrylate (meth) acrylate such as octyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) An acrylic polyol obtained by copolymerizing a (meth) acrylic acid ester having a hydroxyl group in a molecule such as acrylate can also be used.
[0026]
In addition, the decoration layer can use the first and second resin base sheets as protective sheets, and as shown in the configuration illustrated in FIG. 1, the back side of the first resin base sheet 2 (resin molded product side) and Although the structure to perform is common, you may provide in the surface side of the 1st resin base material sheet 1, or between the 1st resin base material sheet 1 and the 2nd resin base material sheet 2, etc. FIG. For example, in addition to the configuration of FIG. 1 or for the configuration consisting of only the first resin base sheet 1 and the second resin base sheet 2, the matte surface of the first resin base sheet 1 is matted. For example, a decorative layer may be provided in a thin or pattern shape as long as the unevenness for the purpose is not impaired (not shown).
[0027]
Moreover, as a decoration layer, the layer which provides functionality, such as an invisible pattern or electroconductivity other than the layer which expresses visible patterns, such as a pattern, a character, and a figure, may be sufficient. For example, it is a layer containing a conductor, an antistatic agent, a phosphor, a magnetic material, an infrared absorber, an ultraviolet absorber and the like. If an ink containing these substances is used instead of the colorant, these layers can be formed.
[0028]
[Adhesive layer]
The back side of the decorative sheet is appropriately treated as necessary, in order to improve the adhesion to an adherend such as a resin molding, in addition to easy adhesion treatment such as corona discharge treatment, plasma treatment, primer coating, etc. The adhesive layer 5 may be provided after or without performing the easy adhesion treatment.
As the adhesive layer 5, for example, a known resin such as a thermoplastic resin or a thermosetting resin is used as a heat-sensitive adhesive. In the thermoplastic resin, for example, one or a mixture of two or more of acrylic resin, chlorinated polyolefin resin, vinyl chloride-vinyl acetate copolymer, thermoplastic urethane resin, thermoplastic polyester resin, polyamide resin, rubber resin, etc. Is used. In the thermosetting resin, a urethane resin, an epoxy resin, or the like is used.
The adhesive layer is formed by known printing or coating methods such as gravure printing, roll coating, and the like using an adhesive made of these resins. The thickness of the adhesive layer is not particularly limited, but is usually about 1 to 100 μm. In the adhesive layer, colorants as listed in the decoration layer may be added.
[0029]
[Lamination method of decorative sheet on adherend]
As a method for laminating the decorative sheet on the adherend, a method in which heat and pressure are applied to the decorative sheet at the time of lamination is suitable as a method for making use of the characteristics of the decorative sheet of the present invention. You may use the decorating sheet of this invention for the lamination | stacking methods other than. Of course, in either case, the second resin base sheet side is the adherend side with respect to the first resin base sheet. By stacking the decorative sheet on the adherend, a decorative article is obtained as a laminate of the adherend and the decorative sheet.
[0030]
Examples of the laminating method in which hot pressure is applied to the adherend when laminating a decorative sheet include, for example, (1) injection molding simultaneous decorating method, (2) vacuum forming laminating method, and (3) laminating method using an elastic roller. Etc. Since (1) will be described in detail later, the lamination method of (2) and (3) will be further described here.
[0031]
The vacuum forming and laminating method (2) is a three-dimensional object such as a molded product as described in JP-B-56-45768 (overlay method), JP-B-60-58014 (vacuum press method) and the like. This is a method in which a decorative sheet is opposed or placed on the surface of an adherend with an adhesive in between, and the decorative sheet is laminated on the adherend by at least pressure from the adherend side by vacuum suction.
In the lamination method using the elastic roller of (3), the decorative sheet is opposed to or placed on the plate-shaped adherend with an adhesive interposed therebetween, and the elastic roller is provided from the decorative sheet side. Pressure is applied and the decorative sheet is laminated on the adherend. For columnar adherends such as cylinders and polygonal columns, as described in Japanese Patent Publication No. 61-5895, Japanese Patent Publication No. 56-23377, etc., the long axis direction of the columnar adherend is described. In addition, while supplying the decorative sheet through the adhesive layer in between, the plurality of side surfaces constituting the adherend are sequentially decorated by a plurality of rollers having different directions (including the case where the elastic roller is not used). There is also a wrapping method in which sheets are pressure-bonded and decorative sheets are laminated.
[0032]
Injection molding simultaneous decoration method:
The injection molding simultaneous decorating method of the present invention uses the decorative sheet of the present invention described above, and by molding the decorative sheet on the surface of the resin molded product by the so-called injection molding simultaneous decorating method, This is a method for obtaining a decorative molded product decorated with a matte design with the decorative sheet.
[0033]
The injection molding simultaneous decorating method refers to a method in which a decorative sheet is inserted between both male and female molds as described in Japanese Patent Publication No. 50-19132 and Japanese Patent Publication No. 43-27488. The mold is clamped, a resin in a fluid state is injected into a cavity formed by both molds and solidified, and a decorative molded product is obtained by laminating a decorative sheet on the surface simultaneously with the molding of the resin molded product. .
[0034]
The injection molding simultaneous decorating method of the present invention can take various forms in the conventionally known injection molding simultaneous decorating method except that the above-described decorative sheet of the present invention is used as the decorative sheet to be used. . For example, basically, either a form in which a decorative sheet is preformed or a form in which it is not performed may be used. Further, the decorative sheet may or may not be preheated. In addition, at the time of preforming, the decorative sheet is usually preheated. However, in order to make the best use of the effect of the decorative sheet of the present invention, the decorative sheet is preferably formed in any way.
[0035]
Needless to say, when the decorative sheet has a large aperture, it is preferable to perform preforming. On the other hand, in the case where the decoration sheet has a small aperture, the decoration sheet may be formed only by the resin pressure of the injected resin in a fluid state. At this time, if the drawing is shallow, the decorative sheet may be molded only with the resin pressure of the resin in a fluid state filled in the mold at the same time as the resin injection without preforming. Even when the decorative sheet is molded with resin pressure, the decorative sheet may use the heat of the injection resin without preheating. In addition, the preforming of the decorative sheet is usually performed by using the injection mold as a vacuum mold, but before supplying the decorative sheet between the molds, decorate with another vacuum mold outside the mold. Pre-forming (off-line pre-forming) such as vacuum forming a sheet may be used. However, the pre-molding is preferably performed in the form of using both an injection mold and a vacuum mold because the decorative sheet can be laminated efficiently and accurately. However, when the preformed decorative sheet is manufactured in advance in another place, the preforming is preferably in the form of off-line preforming. In the description of the present invention, vacuum forming includes vacuum / pressure forming.
[0036]
With reference to the conceptual diagram of FIG. 2, the injection molding simultaneous decorating method of the present invention will be described in one form. The form described here is a form in which the decorative sheet is heated and softened between the molds and pre-molded by vacuum molding with an injection mold before the mold is clamped, and then the mold is clamped and the resin is injected. . Moreover, this form is a more preferable form when the decoration sheet | seat is deeply drawn in the above-mentioned various combinations of pre-molding and preheating of the decorative sheet. Moreover, it is also one of the forms which can make use of the effect of the decorating sheet of the present invention.
Of course, the decorative sheet used in the injection molding simultaneous decorating method of the present invention may be either a single sheet or a continuous strip.
[0037]
First, as shown in FIG. 2 (A), as an injection molding die, a mold Ma having a runner communicating with the injection nozzle and a gate (gate), a suction hole 41 on the cavity surface, and a sheet preforming. A pair of molds of a mold Mb that also serves as a mold is used. These molds are made of metal such as iron or ceramics. In the mold open state, the decorative sheet S is supplied between both molds Ma and Mb, and the decorative sheet S is fixed to the mold Mb by pressing it with a sheet clamp 42 having a frame shape in plan view. At this time, it goes without saying that the second resin substrate sheet side (with respect to the first resin substrate sheet) of the decorative sheet faces the injection resin side on the right side of the drawing. Subsequently, the decorative sheet is softened by heating with a heater (not shown) inserted between both molds as appropriate. The heating is, for example, non-contact radiation heating, but may be conduction heating by contact. Then, vacuuming is performed by suction from the suction hole, and the decorative sheet is preformed along the cavity surface of the mold Mb. Next, the heater is retracted from between both molds, and both molds are clamped as shown in FIG. 2B, and a resin formed in a fluid state such as a heat-melted state is filled in a cavity formed by both molds. And after resin solidifies by cooling etc., a mold is opened and a molding is taken out.
And if the unnecessary part of a decoration sheet is trimmed suitably, a decoration sheet will be laminated | stacked on a resin molding, and the decoration molded product of a structure will be obtained.
[0038]
[Injection resin]
In the injection molding simultaneous decorating method of the present invention, the resin for injection molding is basically not particularly limited and may be a known resin. It may be selected according to the required physical properties and cost of the product. Examples of the thermoplastic resin include ABS (acrylonitrile-butadiene-styrene copolymer) resin, styrene resin, acrylic resin, vinyl chloride resin, polycarbonate resin, and polyolefin resin. Further, in the case of a curable resin, it is a two-component curable resin, for example, an uncured resin solution such as a urethane resin, an unsaturated polyester resin, or an epoxy resin. The thermoplastic resin is melted by heating and injected in a fluid state, and the curable resin (its uncured product) is injected at room temperature or appropriately heated and injected in a fluid state.
Note that as the injection resin, a resin colored by adding a colorant may be used as appropriate according to the application. As the colorant, a known colorant as described in the decoration layer may be used. In addition, the injection resin contains various known additives such as silica, alumina, talc, calcium carbonate, aluminum hydroxide and other inorganic powders, fillers such as glass fibers, stabilizers, lubricants, and the like as necessary. .
[0039]
Decorative molded products:
The decorative molded product of the present invention is transparent on the resin molded product with at least a transparent second resin base sheet made of an acrylic resin without a matting agent and a surface of a fluororesin with a matting agent added. By stacking the first resin base sheet in this order, the surface is a molded product with a matte design. The decorative molded product of the present invention having such a configuration can be obtained by, for example, preferably laminating the decorative sheet of the present invention on a resin molded product. Moreover, as the lamination | stacking method, the injection molding simultaneous decorating method of the above-mentioned this invention can be utilized, for example. Of course, the decorative molded product of the present invention can be made of other materials (for example, the first resin base sheet and the second resin) without using the decorative sheet of the present invention or the injection molding simultaneous decorating method of the present invention. The resin substrate sheet may be separately laminated on the resin molded product), or may be a product produced by other methods (for example, vacuum molding lamination method). However, as a matter of course, it is preferable to manufacture by the injection molding simultaneous decorating method of the present invention in that molding and decorating can be simultaneously performed in one step and production efficiency is good.
[0040]
The decorative molded product P of the present invention illustrated in the cross-sectional view of FIG. 3 exemplifies one form thereof, on the resin molded product 6, an adhesive layer 5, a decorative layer 4, a second resin base sheet. 2 and the 1st resin base material sheet 1 are the molded articles of the structure laminated | stacked in this order. Each layer on the resin molded product 6 has a configuration in which, for example, the decorative sheet S of FIG. 1 is laminated.
[0041]
The resin of the resin molded product 6 is the injection resin described in the injection molding simultaneous decorating method of the present invention, and the second resin base sheet 2 and the first resin base sheet 1 are decorated of the present invention. Since it is the base material sheet described in the sheet, further explanation is omitted here. Similarly to the decorative sheet of the present invention described above, in the decorative molded product of the present invention, as illustrated in FIG. 3, other layers such as a decorative layer and an adhesive layer are further provided as necessary. It is good also as the provided structure.
[0042]
In addition, the decorative molded product is usually a three-dimensional object in which the decorative sheet has a non-planar surface such as an uneven surface. However, the decorative molded product of the present invention does not exclude a three-dimensional object in which the laminated surface of the decorative sheet is flat but the other surface is non-planar, and a plate-like object in which the laminated surface is flat.
[0043]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
[0044]
[Example 1]
A decorative sheet S configured as shown in FIG. 1 was produced as follows. A resin composition obtained by adding 20 parts by mass of silica particles having an average particle size of 3 μm as a matting agent a to 100 parts by mass of a transparent fluororesin made of polyvinylidene fluoride and a polymethylmethacrylate based transparent acrylic resin Extrusion was performed to obtain a base sheet 3 in which a first resin base sheet 1 having a thickness of 10 μm and a second resin base sheet 2 having a thickness of 90 μm were melt bonded. Next, a decorative layer 4 expressing a grain pattern is formed on the surface of the base sheet 3 on the second resin base sheet 2 side by three-color gravure printing, and further acrylic resin and vinyl chloride-vinyl acetate. A 4 μm-thick adhesive layer 5 having a 1: 1 mass ratio with the copolymer was formed on the entire surface by two-color gravure printing to obtain a decorative sheet. The ink used for forming the decorative layer was an ink mainly composed of an acrylic resin as a binder resin, and mainly composed of isoindolinone yellow, quinacridone red and carbon black as colorants. In the adhesive layer, an ink added with a colorant mainly composed of titanium white, isoindolinone yellow and quinacridone red was used for the first color, and an ink containing no colorant was used for the second color. Each color of the adhesive layer has a thickness of 2 μm.
[0045]
Then, by the injection molding simultaneous decorating method of the present invention as shown in the conceptual diagram of FIG. 2, the decorative sheet is laminated on the surface simultaneously with the molding of the resin molded product, and the configuration as shown in FIG. 3 is obtained. The decorative molded product P of the present invention was obtained. The injection molding simultaneous decorating method was carried out in a form in which a female mold for injection molding was used as a vacuum mold, and after the decorative sheet was inserted between the molds, it was softened by heating and preformed by vacuum molding. The preforming of the decorative sheet was performed by heating to a sheet temperature of 110 ° C. by infrared radiation heating, and then vacuum-sucking from the female mold side so that the decorative sheet was placed along the female cavity surface. Thereafter, a heat-resistant ABS resin (heat-resistant temperature 95 ° C.) was injected at an injection resin temperature of 240 ° C. under a mold temperature of 70 ° C., and the decorative sheet was integrated with a resin molded product to form a decorative molded product. As the injection mold, a mold for molding a vehicle interior panel having a cavity surface with a mirror finish and a width of 40 mm and a length of 400 mm was used.
[0046]
There is no wrinkling or tearing of the decorative sheet at the time of injection molding simultaneous decoration, and the appearance of the obtained decorative molded product is matte on the surface of the wood grain pattern, and whitening of the wood grain pattern that looks white is also recognized I couldn't.
[0047]
[Comparative Example 1]
In Example 1, the base sheet 3 was made of a resin composition in which 20 parts by mass of silica particles having an average particle size of 3 μm were added as a matting agent to 100 parts by mass of a transparent acrylic resin based on polymethyl methacrylate. A decorative sheet was prepared using a resin sheet having a thickness of 125 μm.
However, this decorative sheet has a too strong matting effect, and the whitening of the base material sheet makes the wood grain pattern look white, and the design appearance is poor. .
[0048]
[Comparative Example 2]
In Example 1, the base sheet 3 was made of a resin composition in which 20 parts by mass of silica particles having an average particle size of 3 μm were added as a matting agent to 100 parts by mass of a transparent acrylic resin based on polymethyl methacrylate. A decorative sheet was prepared using a resin sheet having a thickness of 30 μm, and a decorative molded product was prepared by simultaneous injection molding.
As a result, the whitening of the wood grain pattern by the base material sheet was not recognized. However, in the case of simultaneous injection molding, the decorative sheet was stretched by the resin pressure of the injection resin, which caused wrinkles.
[0049]
【Effect of the invention】
  (1)According to the decorative sheet produced by the method of the present invention, a matte design can be imparted without causing molding defects (such as wrinkles or tears), moldability degradation, and loss of matting feeling. In addition, since the mat is matted, the decorative sheet itself is kept transparent without whitening, and the mat can be decorated with a matte transparency. In addition, if this decorative sheet is applied to the simultaneous injection molding, a matte design can be given by the decorative sheet itself, so the cost of the injection mold compared to the case where the matte surface is molded by the injection mold. A matte design can be given avoiding the rise.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating one embodiment of a decorative sheet of the present invention.
FIG. 2 is a conceptual diagram illustrating an injection molding simultaneous decorating method of the present invention in one form thereof.
FIG. 3 is a cross-sectional view illustrating one embodiment of a decorative molded product of the present invention.
[Explanation of symbols]
1 First resin base sheet
2 Second resin base sheet
3 Base sheet
4 decoration layers
5 Adhesive layer
6 Resin molding
41 Suction hole
42 Sheet clamp
a Matting agent
Ma injection mold (male mold)
Mb injection mold (female)
P decorative molded product
S decoration sheet

Claims

In the decorative sheet for molding, in order from the surface, a first resin base sheet that is transparent with a matte surface made of a fluororesin to which a matting agent is added, and a transparent second material that is made of an acrylic resin without the addition of a matting agent. The first resin base sheet is 10 μm or more and 50 μm or less, the second resin base sheet is 50 to 200 μm, and the first resin base sheet has a thickness of 50 to 200 μm . A method for producing a decorative sheet, wherein one resin base sheet and the second resin base sheet are laminated by either a coextrusion method or a dry lamination method through an adhesive layer.