JP3733080B2 - Printing resin film for laminating high-design decorative metal plates and metal plates coated therewith - Google Patents

Description

[但し、φは無極性ビニルモノマーの配合比(体積比)を示す。]
で与えられるゴム状弾性体樹脂(B)とビニル重合体(C)との相溶性を示すΧ_B/C及びポリエステル樹脂(A)とビニル重合体(C)との相溶性を示すΧ_A/Cを0に近付けるようにすれば、λ_{(Resin C)/(Resin B)}を正にすることが可能となる。
【００５６】
したがって、好ましいビニル重合体(C)は、ポリエステル樹脂(A)及びゴム状弾性体樹脂(B)の種類に応じて、これらの樹脂との相溶性を考慮して決定される。具体的に好ましい組み合わせを例示すると、ポリエステル樹脂(A)が芳香族ジカルボン酸残基とジオール残基より構成される芳香族ポリエステル樹脂で、ゴム状弾性体樹脂(B)がポリオレフィン樹脂である場合、ビニル重合体(C)としてエチレンと極性基を有するユニットとの共重合体や、無水マレイン酸若しくはグリシジルメタクリレートを1質量%以上導入したSEBSが好ましく、中でもエチレンと極性基を有するユニットとの共重合体は、エチレンと極性基を有するユニット間の配合比を適切に制御することにより、λ_{(Resin C)/(Resin B)}を正に制御し易い。より好ましくは、エチレンと極性基を有するユニットとの共重合体にポリエステル樹脂(A)と共有結合、配位結合、水素結合、イオン結合等の化学作用を有する官能基が導入されていると、カプセル化した際にポリエステル樹脂(A)とビニル重合体(C)との界面を熱力学的により安定化できることから望ましい。
【００５７】
エチレンと極性基を有するユニットとの共重合体をより具体的に示せば、エチレン-ビニル酸共重合体、エチレン-ビニル酸エステル共重合体やこれらのアイオノマー樹脂、エチレンとα,β-不飽和酸のグリシジルエステルとの共重合体、エチレンとビニル酸若しくはビニル酸エステルとα,β-不飽和酸のグリシジルエステルとの3元共重合体、等である。中でも、アイオノマー樹脂、エチレンとα,β-不飽和酸のグリシジルエステルとの共重合体、エチレンとビニル酸若しくはビニル酸エステルとα,β-不飽和酸のグリシジルエステルとの3元共重合体が好ましい。これらの樹脂は、ポリエステル樹脂(A)と比較的強い化学的相互作用を示し、ゴム状弾性体樹脂(B)と安定したカプセル構造を形成する。その中でも、アイオノマー樹脂は、温度によってポリエステル樹脂(A)との化学作用の強度が変化するので、成形性の観点から最も好ましいものである。
【００５８】
アイオノマー樹脂としては、公知のアイオノマー樹脂を広く使用することができる。具体的には、ビニルモノマーとα,β-不飽和カルボン酸との共重合体で共重合体中のカルボン酸の一部若しくは全部を金属陽イオンにより中和したものである。
【００５９】
ビニルモノマーを例示すると、上記のα-オレフィンやスチレン系モノマー等であり、α,β-不飽和カルボン酸を例示すると炭素数3〜8のα,β-不飽和カルボン酸でより具体的にはアクリル酸、メタクリル酸、マレイン酸、イタコン酸、マレイン酸モノメチルエステル、無水マレイン酸、マレイン酸モノエチルエステル等が挙げられる。
【００６０】
中和する金属陽イオンを例示すると、Na⁺、K⁺、Li⁺、Zn²⁺、Mg²⁺、Ca²⁺、Co²⁺、Ni²⁺、Pb²⁺、Cu²⁺、Mn²⁺等の1価又は2価の金属陽イオンが挙げられる。また、金属陽イオンで中和されていない残余のカルボキシル基の一部は低級アルコールでエステル化されていても良い。
【００６１】
アイオノマー樹脂を具体的に例示すると、エチレンとアクリル酸、メタクリル酸等の不飽和モノカルボン酸との共重合体、あるいはエチレンとマレイン酸、イタコン酸等の不飽和ジカルボン酸との共重合体であって、共重合体中のカルボキシル基の一部若しくは全部がナトリウム、カリウム、リチウム、亜鉛、マグネシウム、カルシウム等の金属イオンで中和された樹脂が挙げられる。これらの中で、ポリエステル樹脂(A)とゴム状弾性体樹脂(B)との相溶性を改善する目的で最も好ましいのが、エチレンとアクリル酸又はメタクリル酸の共重合体(カルボキシル基を有する構成単位が2〜15モル%)で、重合体中のカルボキシル基の30〜70%がNa、Zn等の金属陽イオンで中和されている樹脂である。
【００６２】
また、本発明に使用するゴム状弾性体樹脂(B)とビニル重合体(C)でコア-シェルタイプゴム状弾性体を構成し、ゴム状弾性体樹脂(B)がコア部、ビニル重合体(C)がシェル部とすることにより、本発明のポリエステル樹脂層の分散構造を比較的容易に形成することが可能である。このコア-シェルタイプゴム状弾性体は、コア部とシェル部から構成される2層構造を有しており、コア部は軟質なゴム状態であって、その表面のシェル部は硬質な樹脂状態である。
【００６３】
コア-シェルタイプゴム状弾性体を例示すると、コア部をアクリル系ゴム状弾性体、ジエン系ゴム状弾性体、若しくはシリコン系ゴム状弾性体で構成し、これにグラフトしたアクリレート若しくはメタクリレートを主成分とするアクリル系重合体がシェル部を構成するゴム状弾性体が挙げられる。なお、グラフトとは、コア部の樹脂とシェル部の樹脂とのグラフト共重合化を意味する。
【００６４】
コア部を構成するゴム状弾性体を具体的に示すと、一般式(c)の構造を有するユニットで構成されるアクリレート系重合体、又は、ジエン系重合体、あるいは、ジメチルシロキサンを主体とするゴム状弾性体である。
【００６５】
CH₂=CR₁-CO-O-R₂ (c)
上記のアクリレート系重合体の構成ユニットを具体的に例示すると、アルキルアクリレートやアルキルメタクリレート、アルキルエタクリレート等であり、R₁は水素又は炭素数1〜12のアルキル基を、また、R₂は炭素数1〜12のアクリル基を有するものが好ましい。さらに具体的には、メチルアクリレート、エチルアクリレート、ブチルアクリレート、2-エチルヘキシルアクリレート、メチルメタクリレート、エチルメタクリレート、ブチルメタクリレート、n-オクチルメタクリレート等が挙げられる。中でも耐衝撃性付与と言う観点から、エチルアクリレート、ブチルアクリレート、2-ヘキシルアクリレート、メチルメタクリレート、n-オクチルメタクリレートが好ましい。コア部を形成するアクリレート系重合体は、これらの単独重合体であっても、2種類以上の共重合体であっても良い。
【００６６】
また、コア部を構成するアクリレート系重合体は、上記のアクリレートが主成分であれば、他のビニルモノマーが共重合されていても良い。主成分とは50質量%以上である。具体的にビニルモノマーを例示すると、α-オレフィンモノマーやスチレン系モノマー、極性ビニルモノマーが挙げられる。より具体的に示すと、α-オレフィンモノマーとしては、エチレン、プロピレン、1-ブテン、1-ペンテン、4-メチル-1-ペンテン、1-ヘキセン、1-オクテン、1-デセン、1-ドデセン等が挙げられ、スチレン系モノマーとしては、スチレンモノマーの他にo,m,p-エチルスチレン、t-ブチルスチレン等のアルキル化スチレン、モノフルオロスチレン等のCl、Brを除くハロゲン化スチレン、α-メチルスチレン等が挙げられ、また、極性ビニルモノマーとしてはアクリル酸、アクリロニトリル、無水マレイン酸及びそのイミド誘導体、酢酸ビニル、塩化ビニル、プロピオン酸ビニル等が挙げられる。
【００６７】
更に、コア部を構成するアクリレート系重合体は、ゴム弾性を発揮するために架橋剤により一部架橋されていることが好ましい。架橋剤を例示すると、ポリエチレン性不飽和を有するビニルモノマーで、ジビニルベンゼン、ブチレンジアクリレート、エチレンジメタクリレート、ブチレンジメタクリレート、トリメチロールプロパントリメタクリレート、トリアリシルアヌレート、トリアリルイソシアネート等が挙げられる。架橋剤の添加量は30質量%以下、好ましくは20質量%以下、より好ましくは5質量%以下である。30質量%超では硬化してゴム弾性が発揮できない場合が多い。
【００６８】
また、コア部を構成するジエン系重合体は、ジエンモノマーの重合体若しくはその水添重合体であり、具体的にはポリブタジエン及びその水添重合体、ブタジエンとスチレンとの共重合体及びその水添重合体等が挙げられる。
【００６９】
コア部を構成する重合体の分子量は、特に制限するものではないが、数平均分子量で2000以上が好ましい。2000未満では十分なゴム弾性を発揮できない。また、コア部が架橋したアクリレート系重合体である場合は、架橋点間分子量が2000以上であることが十分なゴム弾性を付与する観点から好ましい。
【００７０】
コア部を構成する重合体のガラス転移温度(昇温速度10℃/分、示差型熱分析装置(DSC)で測定)は、30℃以下であることが好ましく、より好ましくは10℃以下、さらに好ましくは-10℃以下である。ガラス転移温度が30℃超では、室温以下でのゴム弾性が発揮し難い。
【００７１】
次に、コア-シェルタイプゴム状弾性体のシェル部について説明する。シェル部は、アクリレート系重合体で構成されていることが重要であり、アクリレート系重合体の極性を利用することにより、コア-シェルタイプゴム状弾性体が金属板に接触した際に密着性が確保できる。
【００７２】
シェル部を構成するアクリレート系重合体は、一般式(c)のユニットからなる重合体である。具体的には先に挙げたモノマーの重合体であり、アクリレートユニットが主成分である限り、上記のビニルモノマーと共重合していても良い。ここで主成分とは50質量%以上である。他のビニルモノマーと共重合した場合、アクリレート成分の組成比は70質量%以上であることが好ましい。70質量%未満では、アクリレートユニットの極性が十分に利用できず、金属板との密着性が不充分な場合がある。
【００７３】
コア-シェルタイプゴム状弾性体は、コア部が軟質なゴム状物質であるので、シェル部を構成する樹脂は硬質であることがハンドリング性から必要である。このためには、シェル部を構成するアクリレート系重合体のガラス転移温度(昇温速度10℃/分、示差型熱分析装置(DSC)で測定)が30℃以上であることが好ましく、より好ましくは50℃以上である。
【００７４】
シェル部を構成するアクリレート系重合体ユニットとして最も好ましいのは、ガラス転移温度が上記の範囲にあり、また、重合速度の制御が容易であることからメチルメタクリレートである。
【００７５】
更に、シェル部を構成するアクリレート系重合体には、ポリエステル樹脂(A)との相溶性を確保するために、ポリエステル樹脂(A)の残留末端官能基やエステル結合と反応可能な官能基若しくは結合基が導入されていることが好ましい。官能基を具体的に例示すれば、エポキシ基、カルボキシル基、水酸基、酸無水物基、アミノ基が挙げられ、シェル部をグラフト化する際に、これらの官能基を有する公知のビニルモノマーを添加することにより官能基が導入できる。また、結合基を例示すれば、エステル結合、カーボネート結合、アミド結合等が挙げられ、シェル部をグラフト化する際に、T. O. Ahn, et al.; J. Polym. Sci. PartA Vol.31, 435(1993)に開示されているようなこれらの結合を有する開始剤を使用することにより結合基が導入できる。これらの官能基や結合基の中で、反応性の観点から最も好ましいのが、エポキシ基及び芳香族-芳香族のエステル結合であり、シェル部を重合する際に、それぞれ、グリシジルメタクリレート、 T. O. Ahn, et al.; J. Polym. Sci. Part A Vol.31, 435(1993)に開示されているポリアリレートアゾ開始剤を添加することにより、上記のエポキシ基及びエステル結合が導入できる。
【００７６】
これらの官能基、結合基を含有するユニットの導入量は、各々反応性によって導入量が決定され、アクリレートユニットが主成分である範囲においては特に限定するものではない。しかし、官能基の場合は、官能基含有ユニットの導入量が15質量%以下であることが好ましく、より好ましくは5質量%以下である。15質量%超では混練工程で櫛形ポリマーが生成され、ポリエステル樹脂(A)に対する相溶性が十分に向上しない場合がある。また、結合基である場合は、結合基含有ユニットの導入量が15質量%以下であることが好ましい。15質量%超では結合基を有するユニットがドメインを形成し、ポリエステル樹脂(A)に対する相溶性が向上できない場合がある。
【００７７】
コア-シェルタイプゴム状弾性体は、ゴム状重合体であるコア部を20質量%以上、好ましくは50質量%以上、より好ましくは80質量%以上含有していることが望ましい。20質量%未満では十分な耐衝撃性が発揮できない場合がある。
【００７８】
本発明のポリエステル樹脂組成物は、公知の混合法により製造することができる。
【００７９】
具体的には、適切な界面張力の差を有するポリエステル樹脂(A)、ゴム状弾性体樹脂(B)及びビニル重合体(C)を所定の温度、例えば200〜350℃で公知の各種混合機を用いて溶融混練することにより、界面張力差を利用してカプセル構造を形成して製造することができる。
【００８０】
また、ゴム状弾性体樹脂(B)とビニル重合体(C)とをグラフト化してコア-シェルタイプゴム状弾性体を形成させた後、ポリエステル樹脂(A)と混合することによっても製造できる。コア-シェルタイプゴム状弾性体は、公知のラジカル重合法で重合できるが，中でも米国特許第4096202号に記載されているような乳化重合法が生成した重合体の粒径をミクロに制御する観点から好適である。重合法を具体的に示すと、以下の方法が挙げられるが、コア-シェルタイプグラフトゴム状弾性体でシェル部がアクリレート系重合体であれば良く、製法を当該製法に制限するものではない。
【００８１】
第一段階の重合として、上述のコア部を構成するユニットモノマーをラジカル重合する。この際に、グラフト剤として、ポリエチレン性不飽和を有し複数の2重結合を有するモノマーを約0.1〜5質量%添加する。本グラフト剤の複数の2重結合は各々反応速度が異なることが好ましく、具体的にはアリルメタクリレート、ジアリルマレード等である。コア部の重合体を重合後、第二段階の重合として、シェル部を構成するモノマー及び開始剤を添加してシェル部をグラフト重合することによりコア-シェルタイプゴム状弾性体を得る。
【００８２】
次に、コア-シェルタイプゴム状弾性体を具体的に例示すると、コア部がポリブチルアクリレート、シェル部がポリメチルメタクリレートからなるMBA樹脂、コア部がブタジエン-スチレン共重合体、シェル部がポリメチルメタクリレートからなるMBS樹脂、コア部がポリジメチルシロキサン、シェル部がポリメチルメタクリレートからなる重合体等が挙げられ、更には、米国特許第4096202号に開示されているアクリレートベースコア-重合アクリレートシェル重合体を本発明に使用することができる。
【００８３】
本発明に使用するポリエステル樹脂(A)とコア-シェルタイプゴム状弾性体からなるポリエステル樹脂層(A)には、ポリエステル樹脂(A)とコア-シェルタイプゴム状弾性体との相溶性を向上する目的で、公知の相溶化剤を添加しても良い。相溶化剤の添加量は15質量%以下が好ましく、より好ましくは5質量%以下である。15質量%超では、相溶化剤が独自に相構造を形成する場合があり、十分な相溶性向上効果が発揮し難い。具体的に相溶化剤を例示すると、反応型相溶化剤と非反応型相溶化剤が挙げられ、反応型相溶化剤としては、コア-シェルタイプゴム状弾性体と相溶なポリエステル樹脂(A)の末端残留官能基や結合手と反応可能な官能基や結合手を導入したポリマーが挙げられる。より具体的には、コア-シェルタイプゴム状弾性体のシェル部を構成するポリマーにグリシジルメタクリレート、無水マレイン酸をランダム共重合した重合物や、シェル部を構成するポリマーに芳香族ポリエステルをブロック、グラフト共重合した重合物が挙げられる。また、非反応型相溶化剤としては、コア-シェルタイプゴム状弾性体のシェル部を構成するポリマーとポリエステル樹脂(A)のブロック、グラフト共重合体が挙げられる。
【００８４】
本発明のポリエステル樹脂層には、必要に応じて着色剤を添加することができる。特に隠蔽性や特殊色調を賦与して柄意匠性を向上させるために、顔料を添加することができる。添加する顔料としては、二酸化チタン、亜鉛華、弁柄、朱、群青、コバルトブルー、チタン黄、カーボンブラック等の無機顔料、イソインドリノン、ハンザイエローＡ、キナクリドン、パーマネントレッド４Ｒ、フタロシアニンブルー、インダスレンブルーＲＳ、インダスレンブルーＲＳ、アニリンブラック等の有機顔料（或いは染料を含む。）、アルミニウム、真鍮等の金属箔顔料、二酸化チタン被覆雲母、塩基性炭酸鉛等の箔紛からなる真珠光沢（パール）顔料等がある。着色剤添加による着色は。透明着色でも、不透明（隠蔽性）着色でもよい。これらは、粉末或いは鱗片状箔片として、添加、分散せしめられる。特に、基板の地色の隠蔽を目的とする場合には、二酸化チタン、弁柄、墨などの隠蔽性顔料を好ましく用いることができる。中でも、印刷による多意匠付与の観点から、白色であることが好ましく、二酸化チタンが好適である。
【００８５】
また、ポリエステル樹脂層に顔料を添加する場合には印刷層を省略しても高意匠性を得ることが可能である。
【００８６】
本発明のポリエステル樹脂組成物の混合には、樹脂混練法、溶媒混合法等の公知の樹脂混合方法を広く使用できる。樹脂混練法を例示すると、タンブラーブレンダー、ヘンシェルミキサー、V型ブレンダー等によりドライブレンドで混合した後、1軸若しくは2軸押出機、ニーダー、バンバリーミキサー等で溶融混練する方法が挙げられる。また、溶媒混合法を例示すると、ポリエステル樹脂(A)、ゴム状弾性体樹脂(B)及びビニル重合体(C)の共通溶媒に各樹脂を溶解した後、溶媒を蒸発させたり、共通の貧溶媒に添加して混合物を回収する方法等がある。溶融により混練する場合には、必要に応じていずれか一つもしくは複数の樹脂内に着色顔料を予め混合したマスターバッチを用意し、これらのマスターバッチを一部もしくは全部に使用して溶融混合してもよい。また逆に予め樹脂成分のみを溶融混合したのち、着色顔料を添加して溶融混合してもよい。
【００８７】
また、本発明のポリエステル樹脂層には、剛性や線膨張特性の改善等を目的に、ガラス繊維、金属繊維、チタン酸カリウィスカー、炭素繊維のような繊維強化剤、タルク、炭酸カルシウム、マイカ、ガラスフレーク、ミルドファイバー、金属フレーク、金属粉末のようなフィラー系強化剤を混入させても良い。これらの充填剤の内、ガラス繊維、炭素繊維の形状としては、6〜60μmの繊維径と30μm以上の繊維長を有することが望ましい。また、これらの添加量としては、全樹脂組成物質量に対して5〜15質量部であることが望ましい。
【００８８】
更に、本ポリエステル樹脂層には、目的に応じて、熱安定剤、酸化防止剤、光安定剤、離型剤、滑剤、顔料、難燃剤、可塑剤、帯電防止剤、抗菌抗カビ剤等を適正量添加することも可能である。
【００８９】
本発明に使用するポリエステル樹脂層(A)の厚さは、特に制約はないが、１０〜１００μｍの範囲内が好ましく、４０〜７５μｍの範囲内がより好ましい。１０μｍより薄いと、本来の目的である伸縮応力緩和効果が十分に発揮できない場合があり、かつ隠蔽効果も十分に発揮することができない。１００μｍ超では経済性が悪くなる。
【００９０】
ポリエステル樹脂層とその上の印刷層及びポリエチレンテレフタレート、変性ポリエチレンテレフタレート、ポリブチレンテレフタレート、変性ポリブチレンテレフタレート、又は、これらの 2 種以上を混合した樹脂、もしくはポリカーボネート、ポリアリレート、ポリスチレン、スチレン - スチレン誘導体共重合体樹脂からなる透明保護層は、化粧金属板を製造する目的からは金属板の表面に塗工してもよいが、本発明ではポリエステル樹脂フィルムを形成し印刷層及び透明保護層との積層体フィルムとした後、その積層体フィルムを金属板に積層することが生産性の上から好ましい。従って、先ずポリエステル樹脂フィルムを製造する。
【００９１】
ポリエステル樹脂フィルムを製造する方法は公知であり、例えば、上記ポリエステル樹脂組成物を溶融押出すればよい。具体的には溶融キャスト法、熱圧着法、タレンダー法、Ｔダイスキャスト法、Ｔダイス１軸または２軸延伸法、インフレーション法などが挙げられるが、特にこれらに限定されるものではない。
【００９２】
本発明の高意匠化粧金属板積層用印刷樹脂フィルムは、上記ポリエステル樹脂層の上に印刷層を有し、その上に透明樹脂層を有する。
【００９３】
印刷層としては、最低、高意匠を得るために必要な反射層を形成するものであればよいが、柄模様を有する印刷層であってもよい。印刷材料、印刷方法などは知られており、格別に限定されない。印刷インキとしては、例えば、塩素化ポリオレフィン、ポリエステル樹脂、ビニル系、アクリル系、ウレタン系、セルロース系などのバインダに金属紛、無機顔料、有機顔料を練りこんだもの、又はそれを溶剤で溶いたものを使用できる。印刷方法としてはグラビア印刷、オフセット印刷、シルクスクリーン印刷、転写印刷など公知の方法でよい。
【００９４】
印刷層の厚さは、多色印刷において１色の印刷により乾燥後厚み２〜５μｍであることが好ましい。５μｍ超の場合、印刷模様によっては印刷凹凸が透明樹脂層に影響し、高鮮映性発現の妨げになる。この観点から、印刷方法は、シルクスクリーン印刷法が好ましい。一方、印刷エンボス（印刷の凹凸によりエンボス様意匠賦与：ワイピング印刷）を目的とする場合にはこの限りではない。
【００９５】
本発明の印刷層は上記の如くポリエステル樹脂層上に形成してからその上に透明樹脂層を形成するのではなく、透明樹脂層の裏面側に印刷層を形成してそれをポリエステル樹脂層と積層してもよい。特に高鮮映性発現の場合は透明樹脂層の裏面側に印刷層を形成するのが平滑性賦与の観点から好ましい。
【００９６】
本発明で用いる透明保護層は、ポリエチレンテレフタレート、変性ポリエチレンテレフタレート、ポリブチレンテレフタレート、変性ポリブチレンテレフタレート、又は、これらの 2 種以上を混合した樹脂、もしくはポリカーボネート、ポリアリレート、ポリスチレン、スチレン - スチレン誘導体共重合体樹脂からなる透明層であれば使用することができる。高意匠を得る目的から、透明保護層は光線透過率が60%以上、より好ましくは70%以上であることが好ましい。
【００９７】
本発明の透明保護層は印刷層の上に形成して、高鮮映性あるいはエンボスを賦与して高意匠性を発現させるものである。ただし、エンボス加工は、金属板積層用印刷樹脂フィルムに予めエンボス加工したものを金属板に積層する方法と、エンボス加工をしていない金属板積層用印刷樹脂フィルムを金属板に積層しその積層の際に又は積層の後にエンボス加工を行う方法があり、本発明の高意匠化粧金属板積層用印刷樹脂フィルムは透明保護層にエンボス加工をすればエンボス化粧金属板積層用印刷樹脂フィルムとしても使用できるが、予めエンボス加工した化粧金属板積層用印刷樹脂フィルム（本発明の透明保護層を形成時に又は形成後にエンボス加工すればよい）は本願と同日に出願した別の出願の対象であるので、本発明は未だエンボス加工していない透明保護層を有する高意匠化粧金属板積層用印刷樹脂フィルム（高鮮映性化粧金属板積層用印刷樹脂フィルムとエンボス化粧金属板積層用印刷樹脂フィルムの両方を含む）と、高鮮映性化粧金属板積層用印刷樹脂フィルムを金属板に積層して得られる高鮮映性化粧金属板を対象としている。即ち、本発明の高意匠化粧金属板積層用印刷樹脂フィルムは、金属板への積層前のフィルム段階でエンボス加工されていない限り、高鮮映性化粧金属板積層用印刷樹脂フィルムとエンボス化粧金属板積層用印刷樹脂フィルムの両方を対象としている。
【００９８】
本発明で用いる透明保護層は、生産性から透明フィルムが好適である。
【００９９】
本発明の透明保護層は印刷層の上に形成して、高鮮映性あるいはエンボスを賦与して高意匠性を発現させるものである。いずれの場合も透明保護層の光学的性質が影響する点で共通するが、エンボス加工には熱変形特性が影響する。従って、印刷層に高意匠を賦与するために必要な光学的性質の点では共通性があるが、高鮮映性あるいはエンボスのいずれを目的にするかに依存して、最適な透明保護層の材質等は異なり得る。
【０１００】
本発明の高意匠化粧金属板積層用印刷樹脂フィルムは接着剤を使用するか否かに関わり一般的に金属板に焼き付けて積層するので、透明保護層は熱処理の際に熱収縮の少ないものが好ましい。高鮮映性賦与の場合、下地となるポリエステル樹脂層の結晶融解温度（融点：Tm、昇温速度10℃/分の示差型熱分析装置（DSC）で測定）より５〜４０℃まで高い温度に金属板を加熱し（２００〜２６０℃）てポリエステル樹脂フィルムを積層する際にポリエステル樹脂フィルムを軟化させ、１９０〜２２０℃に加熱した金属ロールで透明保護層側を押圧し（数秒）、急冷し、透明樹脂層の表裏面の平滑性を確保する。このことにより高鮮映性を賦与することが可能になる。この場合、透明保護層としては数秒（１〜５秒）の加熱のみであるので、たとえば、本来加熱すると収縮する二軸延伸ポリエチレンテレフタレートを透明保護層として用いても問題がなく好適である。一方、エンボス加工を施す際には透明保護層の融点より１００〜１０℃低い温度まで加熱される（方法によっては融点以上に加熱される）。従って、この用途に用いる場合には、透明保護層は、その融点より１００〜１０℃低い温度での収縮率が２０％以下である材料又はフィルムからなることが好ましい。より好ましくは収縮率が１０％以下、さらには５％以下であることが好ましい。この目的から好ましい材料は、ポリエチレンテレフタレート(PET)、変性ポリエチレンテレフタレート、ポリブチレンテレフタレート(PBT)、変性ポリブチレンテレフタレート、およびこれらの２種以上を混合した樹脂フィルムであるが、特に結晶化率が飽和結晶化率の５０％以上であるポリブチレンテレフタレートが最適である。
【０１０１】
またユニットバスの内装材などに使用する場合には高温、多湿、特に沸騰水に長期間触れることになるので、透明保護層はガラス転移温度が１００℃より高い、更には１１０℃以上の非晶質フィルムであることが好ましい。樹脂フィルムは多湿条件下ではガラス転移温度が通常条件下での測定値より低下するので、通常測定値が１０５℃以上であることがより好ましい。このような条件を満たす樹脂フィルムとしてはポリカーボネート、ポリアリレート、ポリスチレン、スチレンースチレン誘導体共重合体のフィルムなどがある。
【０１０２】
ユニットバスの内装材などに使用する場合に関して、結晶質フィルムの場合であっても非晶部のガラス転移温度が１００℃を超えていれば、高温、多湿、沸騰水に接触する環境下でも熱変形はない。従って、このような材料は好適である。また、結晶質フィルムにおいて、フィルムの結晶化度が飽和結晶化率の１０％以上であれば、たとえ沸騰水下で結晶化が進んでも、その度合いは小さいので、密度変化が小さいので変形、白化を防止することが可能である。フィルムの結晶化度が飽和結晶化率の２０％以上、さらには５０％以上であることがより好ましい。このような条件を満たす樹脂フィルムとしては、ニ軸延伸ポリエチレンテレフタレート、ポリブチレンテレフタレートを挙げることができる。なかでも、ニ軸延伸ポリエチレンテレフタレートは光線透過率、表裏面の平滑性が高いので、高鮮映性賦与層として透明保護層に最も適した樹脂フィルムである。
【０１０３】
透明保護層の厚さは特に制約するものではないが、長期使用しても印刷層を保護できればよい。形成性、コストなどの観点からは５〜２００μｍ、さらには１３〜１５０μｍ程度の厚みが好ましい。またエンボス加工などで意匠を賦与する場合、構成フィルムトータル厚みがエンボス溝の深さの２倍以上であることが好ましい。２倍未満では金属板にラミネートするような場合にエンボス溝が変化する場合がある。
【０１０４】
本発明の高意匠化粧金属板積層用印刷樹脂フィルムに使用する透明保護層は、高鮮映性を得る目的からは表裏面が平滑かつ膜厚が均一であることが好ましい。透明保護層の表裏面粗度はフィルム表面粗度を任意に１ｍｍ長測定した結果のＲｍａｘが５００ｎｍ以下であることが好ましい。本発明ではポリエステル樹脂層が熱応力を吸収する能力があるので、より高温で化粧フィルムを金属板に焼き付けることが可能になり、また下地ポリエステル樹脂層が軟化し、種々の要因にて発生するフィルムの凹凸を吸収することが可能になる。その結果、焼き付けられた化粧フィルムの透明保護層表裏面の平坦性が改良される効果、即ち、より優れた高意匠を得ることができる効果がある。本発明では高鮮映性化粧金属板を得るために行う鏡面処理の方法については先に説明した。
【０１０５】
ポリエステル樹脂層と透明保護層のいずれかに印刷層を形成したものどうしを積層して本発明の高意匠化粧金属板積層用印刷樹脂フィルムとする方法は、接着剤を用いて、あるいは印刷層を形成したポリエステル樹脂層上に透明保護層を溶融押出しして形成する、あるいは印刷層の意匠性を損なわない範囲の温度で熱圧着するなど、いずれの方法でもよい。
【０１０６】
単独成形したフィルムに熱圧着もしくは接着剤を介して積層する場合は、単独成形したフィルムの表面張力を増大して密着性を増強するため、コロナ放電処理やプラズマ処理などの公知のフィルム処理し、表面張力を５００μＮ／cm以上に制御することが好ましい。特にコロナ放電処理をする場合は、装置に応じて放電量（ワット密度）を調整し、低放電量下、具体的には１０〜４０Ｗ／ｍ^２／min で処理することが好ましい。処理放電量が高いと、表面で局部的に加熱され、表面が変形してシワなどの欠陥が発生し、意匠性が低下する場合がある。
【０１０７】
さらに接着剤を介する場合は、公知のグラビア法もしくはロールコーター法などでより接着剤を塗布できる。塗布法は用途により選択できるが、非常に高鮮映な意匠が必要な場合は、接着剤むらが少ないので、ロールコーター法がより好ましい。
【０１０８】
接着剤には、特公昭６０−１２２３３号公報に開示されるポリエステル樹脂系の水系分散剤、特公昭６３−１３８２９号公報に開示されるエポキシ系接着剤、特開昭６１−１４９３４１号公報に開示される各種官能基を有する重合体等公知の接着剤を広く使用できる。接着する層、本発明の樹脂組成物層の主成分に応じて主成分樹脂に有効な接着剤を選択することが好ましい。
【０１０９】
本発明の高意匠化粧金属板積層用印刷樹脂フィルムは、ポリエステル樹脂層、印刷層、透明保護層をこの順に有し、高意匠化粧金属板を製造する目的を阻害しないかぎり、他の層を各層の間あるいはポリエステル樹脂層と金属板の間あるいは透明保護層の上に１又は2以上の別の層を含んでいてもよい。
【０１１０】
特に、本発明の高意匠化粧金属板積層用印刷樹脂フィルムは、ポリエステル樹脂層、印刷層及び透明保護層の間のそれぞれに任意に接着層（接着改良層、プライマーを含む。以下同じ。）を用いてもよい。またポリエステル樹脂層と金属板の間に接着層を用いても良い。接着剤としては、例えば、１液型または２液型のポリエステル樹脂系接着剤、ポリウレタン樹脂系接着剤などを用いることができる。必要に応じて着色顔料、防錆顔料、体質顔料等を添加してもよい。接着剤の厚みは乾燥後厚みで２〜２０μｍ程度が好ましい。
【０１１１】
本発明の高意匠化粧金属板積層用印刷樹脂フィルムを製造するには、ポリエステル樹脂層を製造した後、その表面に印刷を施し、さらに透明塗料を塗工するか又は別に製造した透明樹脂フィルムを積層すればよい。
【０１１２】
本発明の高意匠化粧金属板積層用印刷樹脂フィルムは、高鮮映性フィルムとして使用するために透明保護層の表面を鏡面処理するが鏡面化方法は先に述べた。
【０１１３】
本発明の高意匠化粧金属板積層用印刷樹脂フィルムは、特に金属板に被覆することを目的として開発されたものである。金属板は特に限定しないが、例えば、ユニットバス内壁その他の建築物の内装材や、電気冷蔵庫のドア、エアコンカバーなどの家庭電化製品外装や、鋼製家具、エレベーターのように、特に高意匠の印刷模様を要求される用途に適したものである。
【０１１４】
こうして、本発明によれば、同様に、高意匠化粧板積層用印刷樹脂フィルムを被覆して高意匠模様の意匠を施した金属板又はそれと同様の構造を有する金属板が提供される。
【０１１５】
金属板としては、特に限定するものではないが、ステンレス鋼板のほか、溶融亜鉛めっき鋼板、溶融亜鉛-鉄合金めっき鋼板、溶融亜鉛-アルミニウム-マグネシウム合金めっき鋼板、ブリキ、薄錫めっき鋼板、電解クロム酸処理鋼板(ティンフリースチール)、ニッケルめっき鋼板等の缶用めっき鋼板や、溶融アルミニウム-シリコン合金めっき鋼板、溶融鉛-錫合金めっき鋼板等の溶融めっき鋼板や、電気亜鉛めっき鋼板、電気亜鉛-ニッケルめっき鋼板、電気亜鉛-鉄合金めっき鋼板、電気亜鉛-クロム合金めっき鋼板等の電気めっき鋼板等の表面処理鋼板、冷延鋼板やアルミニウム、銅、ニッケル、亜鉛、マグネシウム等の金属板等が挙げられる。必要に応じてリン酸塩処理、クロメート処理などの前処理を施したものでもよい。金属板の厚みは特に限定するものではなく、用途に応じて選択すればよいが、一般的には０．０１〜５μｍであることが好ましい。０．０１ｍｍ未満では強度が発現しがたく、５ｍｍ超では加工が困難である。
【０１１６】
本発明に従い、高意匠化粧板積層用印刷樹脂フィルムを金属板に被覆するには、樹脂フィルムを金属板に接着剤を用い又は用いずに熱圧着すればよい。熱圧着する方法は金属板を所定温度に加熱した上で、樹脂フィルムを積層し、必要に応じてローラなどで押圧すればよい。接着剤を用いる場合は金属板表面または樹脂フィルムの表面に塗布するか、予めフィルム表面に接着剤層を形成しておけばよい。熱圧着温度はフィルム厚みにもよるが金属板温度２１０〜２６０℃程度が用いられるが、印刷色調保護（色落ち）、エンボス形状をそこなわない（エンボス戻り）温度が好ましい。
【０１１７】
本発明の高意匠模様の意匠を施した金属板は、高意匠化粧板積層用印刷樹脂フィルムを金属板に被覆する方法のほか、金属板に上記ポリエステル樹脂層を形成してから、印刷層及び透明保護層を形成する方法で製造することも可能である。
【０１１８】
また、本発明の高意匠化粧金属板積層用印刷樹脂フィルムは、先に説明したように高鮮映性化粧金属板及びエンボス化粧金属板の両方を製造する目的で使用できる。高鮮映性化粧金属板を製造する場合には、本発明の高意匠化粧金属板積層用印刷樹脂フィルムを金属板に積層し、任意に鏡面処理を施せばよい。エンボス化粧金属板を製造する場合には、本発明の高意匠化粧金属板積層用印刷樹脂フィルムを金属板に積層し、金属板に積層する前、又は積層する際に、又は積層後に、表面にエンボス加工を施してエンボス加工化粧金属板とすることが可能である。
【０１１９】
一般に、樹脂フィルムにエンボス加工を施す方法としては、製膜時に付与する方法、一度巻き取った後に加熱しエンボス加工する方法、冷間エンボス加工（ショットブラスト）方法がある。製膜時にエンボスを付与する方法は押出されたフィルムが冷却する前にエンボスを付与するものであり、本来本発明のポリエステル樹脂層はこの目的に最適の性質を有するものであるが、この態様は本出願の対象ではない。本発明の高意匠化粧金属板積層用印刷樹脂フィルムを一旦製造した後にエンボス加工を施して使用する場合、透明樹脂層の表面を融点近くまで加熱するので、従来のポリエステル樹脂フィルムでは熱収縮が大きいので困難であったが、本発明の伸縮応力緩和剤微分散ポリエステル樹脂フィルムでは熱収縮を防止できる性質があるので、エンボス加工に最適である。
【０１２０】
特に、本発明の高意匠化粧金属板積層用印刷樹脂フィルムは、金属板に積層する工程でエンボス付与したり、あるいは金属板に積層後にエンボス加工してもよい。これらの場合にも、本発明の高意匠化粧金属板積層用印刷樹脂フィルムは積層時及びエンボス加工時の熱収縮を防止できる効果があるので、良好なエンボス化粧金属板を提供する。
【０１２１】
エンボス加工は、公知の方法、条件を採用できる。典型的には樹脂を熱軟化させ、エンボス板で加圧、賦形し、冷却固化して形成される。枚様あるいは輪転式のエンボス機などが公知である。エンボスの凹凸形状としては、木目導管溝、石版表面凹凸、梨地、砂目、ヘラライン等がある。エンボス加工後に、つや消しや、エンボス意匠を害さない範囲で他のフィルムの積層、コーティングをしてもよい。通常、エンボス加工は、フィルム状でのエンボス加工する場合、フィルム温度は透明保護層樹脂の（昇温速度１０℃／分の示唆型熱分析装置（ＤＳＣ）で測定）融解開始温度から結晶融解温度すなわち融点（Ｔｍ）まで加熱し、エンボスロール温度は２５〜３０℃（常温）、金属板ラミネート時にエンボス加工する場合では板温は融解終了温度以上、エンボスロール温度は融解終了温度以上、金属板ラミネート後にエンボス加工する場合では板温は融解終了温度以上、エンボスロール温度は２５〜３０℃(常温)と温度設定することが一般的であるが、これに限定されるものではない。
【０１２２】
【実施例】
次に、実施例及び比較例に基づいて、本発明をより具体的に説明するが、本発明は、その要旨を逸脱しない限り、以下の実施例に限定されるものではない。
【０１２３】
以下の実施例及び比較例において、ポリエステル樹脂（Ａ）としてポリエチレンテレフタレート（ＰＥＴ）［ユニチカ（株）製ＳＡ−１３４６Ｐ，ＭＡ−１３４４］、ポリブチレンテレフタレート（ＰＢＴ）［ポリプラスチックス（株）製ジュラネックス２００１および東レ（株）製トレコン１２００Ｓ］、極性基を有するユニットを１質量％以上有するビニル重合体（Ｂ）としてエチレン−メタクリル酸グリシジル共重合物［住友化学工業（株）製ボンドファースト２Ｃ］、エチレン−アクリル酸アルキル−メタクリル酸グリシジル共重合物［住友化学工業（株）製ボンドファースト７Ｌ］、エチレン系アイオノマー［三井デュポン（株）製ハイミラン１７０６］、ゴム状弾性体樹脂（Ｃ）としてエチレン−ブテンゴム（ＥＢＭ）［ＪＳＲ（株）製ＥＢＭ２０４１Ｐ］を使用した。また、溶融混練に際しては、ブレンド系抗酸化剤［旭電化（株）製アデカスタブＡ−６１２］を用いた。なお、ポリエステル樹脂（Ａ）としてポリエチレンテレフタレート（ＰＥＴ）［ユニチカ（株）製ＳＡ−１３４６Ｐ，ＭＡ−１３４４］のそれぞれに二酸化チタン（平均粒径０．２〜０．３μｍ）を５０mass％含有するマスターバッチポリエチレンテレフタレートをあらかじめ調製した。また、ポリエステル樹脂（Ａ）としてポリブチレンテレフタレート（ＰＢＴ）［ポリプラスチックス（株）製ジュラネックス２００１および東レ（株）製トレコン１２００Ｓ］のそれぞれに二酸化チタン（平均粒径０．２〜０．３μｍ）を５０mass％含有するマスターバッチポリブチレンテレフタレートをあらかじめ調製した。
【０１２４】
（実施例１−１０）
各樹脂と対応する二酸化チタンマスターバッチ樹脂を用い、表１に示す各組成比となるように、Ｖ型ブレンダーを使用してドライブレンドした。各樹脂の最終組成比は表１に示すとおりで、ブレンド系抗酸化剤Ａ−６１２は、いずれの場合も樹脂組成物１００質量部に対して０．５質量部を添加した。この混合物を２軸押出機で２６０℃で溶融混練して、白色樹脂組成物ペレットを得た。
【０１２５】
本樹脂組成物からミクロトームで超薄切片を切り出した後、ルテニウム酸で染色し、ポリエステル樹脂（Ａ）中のビニル重合体（Ｂ）及びゴム状弾性体樹脂（Ｃ）の分散状態を透過型電子顕微鏡で解析した。この結果、何れもゴム状弾性体樹脂（Ｃ）は、ビニル重合体（Ｂ）でほぼ１００％カプセル化されており、ゴム状弾性体樹脂（Ｃ）の等価球換算径は１μｍ以下でポリエステル樹脂（Ａ）中に微細分散していた。
【０１２６】
【表１】

【０１２７】
本ペレットを使用して、押出しＴダイスで５０μｍ厚みの白色フィルムを得た（押出温度：２５０−２８０℃）。これら得られた白色樹脂組成物フィルムの任意部位を１０cm×１０cmの正方形に切り出し（ｎ＝１０）、同フィルムサンプルを２００℃、１０分での加熱処理した場合、それぞれ収縮率が５％以下であった。
【０１２８】
前記これらの白色樹脂組成物フィルムの表面張力は３００−３８０μＮ／cmであり、片面に放電量（ワット密度）約２０−２５Ｗ／ｍ^２／min 条件にてコロナ放電処理を行い、表面張力を５００μＮ／cm以上とした。
【０１２９】
一方、膜厚２５μｍの透明二軸延伸ポリエチレンテレフタレートフィルム（東レ製ルミラー）の片面にアクリルポリオール（イソシアネート架橋タイプ）系インクを用い、絵柄印刷層および着色ベタ印刷層をグラビア輸転機にて印刷した（乾燥後の印刷厚み６−８μｍ）。
【０１３０】
前記白色樹脂組成物フィルム（コロナ処理済み）と、印刷した市販透明二軸延伸ＰＥＴフィルムとを、二液タイプのウレタン系接着剤を用い（乾燥後の接着剤塗布厚み６μｍ）、定法にてドライラミネートし、樹脂組成物フィルム層、印刷層、トップ層の３層からなる高鮮映化粧金属板積層用印刷樹脂フィルムを得た。
【０１３１】
この３層フィルムの樹脂組成物フィルム層側と、二液タイプのポリエステル系接着剤（塩化ビニル樹脂用、乾燥後接着剤塗布厚み４μｍ）を塗布後、２４０℃に加熱した４５０μｍ厚みの溶融亜鉛メッキ鋼板の片面に、１９０℃に加熱した金属鏡面ロール（フィルム側）とゴムロール（鋼板側）を用いて加熱圧着し、鋼板裏面水冷により５秒以内に１００℃以下まで急冷し、化粧鋼板を得た。
【０１３２】
このようにして得られた常温の化粧鋼板について、下記に示す評価方法により、密着性、耐沸騰水性、加工性、耐汚染性、耐溶剤性、鮮映性の各項目の評価を行った。
【０１３３】
＜密着性＞
上記の化粧鋼板にクロスカットを入れ、蒸留水に５０℃で１０日間浸漬した後、クロスカット部のフィルムの剥離幅（mm）（１０サンプルの平均）を評価した。評価は、◎：０．０mm、○：０．０〜０．５mm、△：０．５〜２．０mm、及び×：２．０mm超とした。密着試験の結果を表２に示す。
【０１３４】
＜耐沸騰水性＞
上記の化粧鋼板を、沸騰水に連続４８時間浸漬しフィルムの剥離状況、外観変化（凹凸、収縮、剥離等）を目視で確認した。評価は、◎：異常なし、○：若干の変化、△：表面がかなり変化する、及び×：下地が露出とした。耐沸騰水試験の結果を表２に示す。
【０１３５】
＜加工性＞
上記の化粧鋼板を、２５℃でＯＴ曲げを行い、割れ、白化等、加工性の良否を目視で確認した。評価は、◎：異常なし、○：若干の変化、△：表面がかなり変化する、及び×：下地が露出とした。加工性試験の結果を表２に示す。
【０１３６】
＜耐汚染性＞
上記の化粧鋼板のフィルム面に、黒色の油性マジックインキで描画し２４時間放置した後、エタノールを含浸させた布で清拭し、フィルム面に残存するマジックインキの程度を目視で確認した。評価は、◎：マジックインキは全く認められない、○：実用上問題のない程度の極わずかなマジックインキの残存が認められる、△：実用上問題となる程度のわずかなマジックインキの残存が認められる、及び×：かなりの程度にマジックインキの残存が認められる、とした。耐汚染性試験の結果を表２に示す。
【０１３７】
＜耐溶剤性＞
上記の化粧鋼板のフィルム面に、メチルエチルケトンを含浸させたスポンジを載せ、２４時間放置した後、フィルム表面の変色および膨れの発生の程度を目視で観察した。評価は、◎：変色および膨れの発生は全く認められない、○：実用上問題のない程度の極わずかな変色および膨れの発生が認められる、△：実用上問題となる程度のわずかな変色および膨れの発生が認められる、及び×：かなりの程度に変色および膨れの発生が認められる、とした。耐溶剤性試験の結果を表２に示す。
【０１３８】
＜鮮映度＞
上記の化粧鋼板のフィルム面の鮮映度を、（財）日本色彩研究所製の携帯用鮮明度光沢度計ＰＧＤ−４型により測定した。なお、本発明でいう鮮映性とは、写像鮮映性すなわち化粧面に写した正反射の像の鮮明さを意味し、高鮮映とは前記鮮映度が０．７以上をさす。鮮映度測定結果を表２に示す。
【０１３９】
【表２】

【０１４０】
表２に示すように、本発明の高鮮映化粧鋼板は、密着性、耐沸騰水性、加工性、耐汚染性、耐溶剤性、鮮映性のいずれにおいても優れた特性を示す。なかでも、下地ポリエステル樹脂層のマトリックスポリエステル樹脂としてＰＢＴを用いることにより、高い鮮映性を示すことが明らかとなった。
【０１４１】
（比較例１−５）
比較例１および２は市販の５０μｍの白色フィルムを用いた。
【０１４２】
また、比較例３−５は対応する二酸化チタンマスターバッチを用い上記実施例と同様な方法にて、ビニル重合体、ゴム弾性体を含まない樹脂組成物を表３に示す各終組成比で、Ｖ型ブレンダーを使用してドライブレンドした。各樹脂の最終組成比は表３に示すとおりで、混合物を２軸押出機で２６０℃で溶融混練して、ペレットを得、実施例１−１０と同様に、本ペレットを使用して押出しＴダイスで５０μｍ厚みのフィルムを得た（押出温度：２６０℃）。
【０１４３】
【表３】

【０１４４】
実施例１−１０と同様に、市販フィルムおよび得られた白色フィルムをコロナ放電処理し、印刷した２５μｍ厚みの市販二軸延伸ＰＥＴフィルムとドライラミネートし、ビニル重合体、ゴム弾性体を含まない樹脂組成物層、印刷層、トップ層の３層からなる化粧フィルムを得た。
【０１４５】
さらに、実施例１−１０と同様に、この３層フィルムと、二液タイプのポリエステル系接着剤（塩化ビニル樹脂用、乾燥後接着剤塗布厚み４μｍ）を塗布後、２４０℃に加熱した４５０μｍ厚みの溶融亜鉛メッキ鋼板の片面に、１９０℃に加熱した金属鏡面ロール（フィルム側）とゴムロール（鋼板側）を用いて加熱圧着し、鋼板裏面水冷により５秒以内に１００℃以下まで急冷し、化粧鋼板を得た。
【０１４６】
このようにして得られた常温の化粧鋼板について、実施例１−１０と同様な評価方法により、密着性、耐沸騰水性、加工性、耐汚染性、耐溶剤性、鮮映性の各項目の評価を行った。結果を表４に示す。
【０１４７】
【表４】

【０１４８】
表４に示すように、比較例１は、ラミネート時に収縮が発生し表面形状が著しく悪化し、ゆず肌外観を示し、求める鮮映性を得ることはできなかった。また、密着性が得られなかった。比較例２も、ラミネート時に収縮が発生し表面形状が著しく悪化し、ゆず肌外観を示し、求める鮮映性を得ることはできなかった。耐沸騰水性がなく、膨れ、割れが発生した。比較例３は、ラミネート時に若干の収縮が発生し表面形状が悪化し、高い鮮映性を得ることはできなかった。また、耐沸騰水にて若干の膨れが発生した。比較例４は鮮映性は得られるものの、密着性が不十分で、加工性時に剥離が観察された。比較例５は十分な鮮映性、密着性が得られなかった。
【０１４９】
（実施例１１，１２）
ＰＢＴ［東レ（株）製トレコン１２００Ｓ］単独、およびＰＢＴ［東レ（株）製ＢＰＴトレコン１２００Ｓ］とＰＥＴ［ユニチカ（株）製ＭＡ−１３４４］を質量比で２：１の割合で混合したもの、それぞれを押出しＴダイスで５０μｍ厚みの透明フィルムを得た（押出温度２６０℃）。これら得られた透明フィルムの任意部位を１０cm×１０cmの正方形に切り出し（ｎ＝１０）、同フィルムサンプルを２００℃、１０分での加熱処理をした場合、それぞれ収縮率は１０％以下であった。
【０１５０】
前記これらの透明フィルムの表面張力は３２０−３８０μＮ／cmであり、片面に放電量（ワット密度）約２０−２５Ｗ／ｍ^２／min 条件にてコロナ放電処理を行い、表面張力を５００μＮ／cm以上とした。さらに、これらのフィルムの片面にアクリルポリオール（イソシアネート架橋タイプ）系インクを用い、絵柄印刷層および着色ベタ印刷層をグラビア輪転機にて印刷した（乾燥後の印刷厚み６−８μｍ）。
【０１５１】
前記表１に示す、実施例８の組成を有する白色樹脂組成物フィルム（コロナ処理済み）と、前記印刷したＰＢＴフィルム（実施例１１）およびＰＢＴ：ＰＥＴ＝２：１フィルム（実施例１２）のそれぞれ二液タイプのウレタン系接着剤を用い（乾燥後の接着剤塗布厚み６μｍ）、定法にてドライラミネートし、樹脂組成物フィルム層、印刷層、透明樹脂層の３層からなる化粧金属板積層用印刷樹脂フィルム２種を得た。
【０１５２】
これら２種の３層からなる化粧金属板積層用印刷樹脂フィルムを用い、樹脂組成物フィルム層側と、２６０℃に加熱した４５０μｍ厚みの溶融亜鉛メッキ鋼板に、２４０℃に加熱した梨地エンボス金属ロール（フィルム側）とゴムロール（鋼板側）を用いて加熱圧着し、鋼板裏面水冷により５秒以内に１００℃以下まで急冷し、梨地エンボス外観を有する化粧鋼板を得た。
【０１５３】
このようにして得られた常温のエンボス外観を有する化粧鋼板について、実施例１〜１０に示す評価方法により、密着性、耐沸騰水性、加工性、耐汚染性、耐溶剤性の各項目、およびエンボス加工性の評価を行った。なお、エンボス加工性については、化粧鋼板のフィルム面のエンボス加工性の良否を、肉眼観察し下記の３段階の基準で判断した。○：良好、△：やや不良、×：不良とした。結果を表５に示す。
【０１５４】
（実施例１３，１４）
実施例１１，１２に示す２種の３層からなる化粧金属板積層用印刷樹脂フィルム（透明樹脂ＰＢＴフィルム（実施例１３）およびＰＢＴ：ＰＥＴ＝２：１フィルム（実施例１４））を、二液タイプのポリエステル系接着剤（塩化ビニル樹脂用、乾燥後接着剤塗布厚み４μｍ）を塗布し２１０℃に加熱した４５０μｍ厚みの溶融亜鉛メッキ鋼板の片面に、ゴムロール−ゴムロールを用いて圧着し、同鋼板を加熱オーブンで２３０℃以上に加熱した後、表面温度３０℃の梨地エンボスロールによりエンボス加工を施し、裏面水冷により５秒以内に１００℃以下まで急冷し、梨地エンボス外観を有する化粧鋼板を得た。
【０１５５】
このようにして得られた常温のエンボス外観を有する化粧鋼板について、実施例１１，１２と同様に、密着性、耐沸騰水性、加工性、耐汚染性、耐溶剤性、エンボス加工性の各項目の評価を行った。結果を表５に示す。
【０１５６】
【表５】

【０１５７】
表５に示すように、本発明のエンボス化粧鋼板は、密着性、耐沸騰水性、加工性、耐汚染性、耐溶剤性、エンボス性のいずれにおいても優れた特性を示す。
【０１５８】
【発明の効果】
本発明によれば、環境負荷のない樹脂材料を用い、基板金属板との密着性、成形加工性、耐疵付性、耐沸騰水性などの特性に優れた高意匠性化粧金属板積層用印刷樹脂フィルム及びそれを被覆した高意匠性化粧金属板が提供される。環境負荷の大きい塩素系樹脂、耐疵付き性・耐白化性に問題のあるポリオレフィン系樹脂ではなく、機械的性質、耐熱性、耐薬品性、光学的性質、加工性などに優れたポリエステル樹脂をベースとしているが、本発明の高意匠性化粧金属板積層用印刷樹脂フィルムはポリエステル樹脂フィルムに伸縮応力緩和剤を微分散させたことにより、樹脂フィルムを金属板に積層する際の高鮮映性付与のための加熱処理や、エンボス加工の際の加熱処理や、高温多湿環境下での使用においても、変形応力を吸収し、形状安定性を有する特徴を有する。また伸縮応力緩和剤としてゴム弾性体を用いる場合にビニル重合体でカプセル化しているので金属板や印刷層との接着性が向上する。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a printed resin film for laminating a high-design decorative metal plate and a high-design decorative metal plate coated therewith, and more specifically, a home appliance exterior such as a unit bath inner wall, an electric refrigerator door, an air conditioner cover, etc. And a high-resisting decorative laminated resin film suitable for applications that require a high-design printing pattern, such as steel furniture, elevators, and interior decorations of buildings, and the like. The present invention relates to a metal plate coated with a resin film and subjected to a design with a high design pattern.
[0002]
[Prior art]
Stainless steel plate with high-definition or embossed pattern design is used on the inner wall of the unit bath, etc. The basic structure is that the stainless steel plate has vinyl chloride resin on the surface, printed on the surface, and biaxially stretched A laminate in which a polyethylene terephthalate film is laminated, and an adhesive layer provided between each resin layer and a printing layer as required (Japanese Patent Laid-Open No. 11-115096) are known.
[0003]
Such a high-design decorative stainless steel sheet has been put into practical use, but recently, since vinyl chloride resin contains chlorine, its use is withheld from the viewpoint of environmental burden. Therefore, it has been proposed to use a polyolefin resin layer, a polyester resin layer, or the like as an alternative material. For example, a decorative sheet in which a thermoplastic olefin-based resin layer and a thermoplastic polyester resin layer are laminated is proposed in JP-A-11-179858, and a polyester resin layer and a pattern printing layer are provided on an electric field chromate treatment layer. No. 2000-167978, and a decorative film formed by sequentially laminating a copolyester adhesive resin layer, a polybutylene terephthalate colored resin layer, a base resin layer, a pattern printing layer, and a transparent resin layer is disclosed in Japanese Patent Application Laid-Open No. 2000-246832. Proposed in the Gazette.
[0004]
[Problems to be solved by the invention]
However, the decorative sheet disclosed in JP-A-11-179858 is poor in stretchability of polyolefin-based resins, and thus whitening or cracks occur at places where stress is locally concentrated especially during processing at low temperatures such as in winter, and the decorative sheet is resistant to resistance. There is a drawback that the tackiness is low. In addition, with a polyester resin, there is no problem in the rust resistance and whitening resistance, but in the configuration of Japanese Patent Application Laid-Open No. 2000-167978, the shrinkage at the time of lamination is large, a high design cannot be expressed, and it is deformed when used under high temperature and high humidity. However, the decorative film disclosed in Japanese Patent Application Laid-Open No. 2000-246832 has a drawback in that the adhesiveness with the substrate metal plate is insufficient, such as requiring an adhesive resin layer.
[0005]
The present invention has been made in view of the current state of the prior art, and uses a resin material having no environmental load, such as adhesion to a substrate metal plate, molding processability, scratch resistance, boiling water resistance, and the like. An object of the present invention is to provide a printing resin film for laminating a high-design decorative metal plate that has excellent characteristics, a sharp appearance, an embossed appearance, and the like, and a metal plate coated therewith.
[0006]
[Means for Solving the Problems]
The present invention is achieved by using a polyester resin layer in which a stretching stress relaxation agent is finely dispersed in a polyester resin as a basic resin layer of a printing layer, and providing a printing layer and a transparent protective layer thereon. It was made by finding out. Thus, the present invention provides the following.
[0007]
  (1) Polyester resin layer and printing layer and polyethylene terephthalate, modified polyethylene terephthalate, polybutylene terephthalate, modified polybutylene terephthalate, or a resin in which two or more of these are mixed, or polycarbonate, polyarylate, polystyrene, styrene-styrene derivatives A transparent protective layer made of copolymer resin is laminated in this order, and in the polyester resin layerEquivalent sphere equivalent diameter is 1 μm or lessA printed resin film for laminating a high-design decorative metal plate, characterized in that a stretching stress relaxation agent is finely dispersed.
[0008]
(2) The polyester resin layer is obtained by finely dispersing rubber-like elastic resin (B) as a stretching stress relaxation agent in polyester resin (A) as a matrix, and at least rubber-like elastic resin (B). A printed resin film for laminating a high-design decorative metal plate as described above, wherein a part of the resin is encapsulated with a vinyl polymer (C) having a polar group.
[0010]
  (ThreeThe above-mentioned high-design decorative metal sheet laminate printing resin film, wherein the matrix resin of the polyester resin layer is polyethylene terephthalate, modified polyethylene terephthalate, polybutylene terephthalate, modified polybutylene terephthalate, or a combination thereof.
[0011]
  (Four) The printed resin film for laminating a high-design decorative metal sheet, wherein the transparent protective layer is composed of a transparent resin film having a shrinkage rate of 20% or less at a temperature lower than the melting point by 100 to 10 ° C.
[0012]
  (Five) The printed resin film for laminating a high-design decorative metal plate, wherein the transparent protective layer is an amorphous resin film having a glass transition temperature of 100 ° C. or higher.
[0013]
  (6) The high design makeup described above, wherein the transparent protective layer is made of a crystalline resin film, and the glass transition temperature of the crystalline resin is 100 ° C. or higher, or the crystallization rate of the film is 10% or more of the saturated crystallization rate. Printing resin film for metal plate lamination.
[0014]
  (7) From (1) to (ThreeThe printed resin film for laminating a high-design decorative metal sheet, wherein the transparent protective layer is a biaxially stretched polyethylene terephthalate.
[0015]
  (8) A high-design decorative metal plate characterized by having a structure formed by coating the above-mentioned printed resin film for laminating a high-design decorative metal plate on the surface of the metal plate.
[0016]
  (9) High-definition decorative metal plate (8) High-design decorative metal plate.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
The present invention is characterized in that, in a high-design decorative metal plate, a polyester resin layer in which a stretching stress relaxation agent is finely dispersed in a polyester resin is used as a printing base resin layer.
[0018]
Polyester resin has no problem of whitening and scratching at low temperature processing like polyolefin resin, impact resistance and other mechanical properties, chemical resistance, stain resistance, insulation, heat resistance, gas barrier property, and Excellent adhesion to metal. However, since properties such as impact resistance, boiling water resistance, water aging resistance, and chemical resistance cannot be obtained without increasing the crystallization of the polyester resin, the polyester resin can be stretched biaxially, etc. When using as a base resin layer for printing resin film for high-design decorative metal plate lamination, when embossing is performed when laminating (baking) at high temperature to ensure adhesion with the metal plate, or after lamination on the metal plate When it was applied to obtain a high design of the surface transparent resin layer, there were problems such as thermal deformation and poor adhesion to the metal plate and design. In addition, there is a problem that it is easily deformed when used in a hot and humid environment such as the interior material of a unit bath that also comes in contact with boiling water. The present invention can prevent thermal deformation of the polyester resin layer by finely dispersing the stretching stress relaxation agent in the polyester resin, and thus has a high-design decorative metal sheet laminate printing resin film having desired characteristics and the laminate. The present inventors have found that a high-design decorative metal plate can be obtained.
[0019]
In order to finely disperse the stretching stress relaxation agent in the polyester resin, the rubber-like elastic resin (B) and / or vinyl polymer is used as the stretching stress relaxation agent, and in particular, the rubber-like elastic body in the polyester resin (A). A structure in which the resin (B) is finely dispersed and at least a part of the rubber-like elastic resin (B) is encapsulated with a vinyl polymer (C) having a polar group is particularly preferable. By using a vinyl polymer (C) having a partly polar group, it is easy to finely disperse the rubber-like elastic resin (B) in the polyester resin (A), and the metal of the polyester resin layer. There is also an effect that the adhesion to the plate is improved.
[0020]
In the following, in order to finely disperse the stretching stress relaxation agent in the polyester resin, a rubbery elastic resin (B) is used as the stretching stress relaxation agent in the polyester resin (A), and at least the rubbery elastic resin (B). An embodiment in which a part is encapsulated with a vinyl polymer (C) having a polar group, that is, a preferred embodiment of the present invention will be mainly described.
[0021]
  Here, the fine dispersion means that the rubber-like elastic resin (B) is1 μ mThe following equivalent sphere equivalent diameter is dispersed in the polyester resin (A).. GoodPleaseIs 0An equivalent sphere equivalent diameter of .5 μm or less is desirable. If it exceeds 1 μm, sufficient impact resistance may not be exhibited.
[0022]
The rubber-like elastic resin (B) encapsulated with the vinyl polymer (C) is 80% or more of the rubber-like elastic resin (B) interface, preferably 95% or more of the vinyl polymer (C). And the direct contact area between the polyester resin (A) and the rubber-like elastic resin (B) is less than 20%. By adopting such a structure, even if the rubber-like elastic resin (B) is in contact with the metal plate, the vinyl polymer (C) has adhesiveness with the metal plate, so that the polyester resin layer and the metal plate are in close contact with each other. Can be secured.
[0023]
It is not necessary that all of the rubber-like elastic resin (B) is encapsulated with the vinyl polymer (C), and at least 70% by volume of the rubber-like elastic resin (B) is the vinyl polymer (C). As long as it is encapsulated. When the rubber-like elastic resin (B) that is not encapsulated exceeds 30% by volume, the rubber-like elastic resin that directly contacts the metal plate when the polyester resin composition is coated on the metal plate ( The ratio of B) increases, and it becomes impossible to ensure the adhesion between the polyester resin composition and the metal plate. The equivalent spherical equivalent diameter of the non-encapsulated rubber-like elastic resin (B) is not particularly specified, but is preferably 0.5 μm or less from the viewpoint of impact resistance and workability.
[0024]
Further, an excessive amount of the vinyl polymer (C) may be dispersed alone in the polyester resin (A) without encapsulating the rubber-like elastic resin (B). The amount and diameter of the vinyl polymer (C) that is not encapsulated is not particularly limited, but may be 20% or less by volume ratio of the total vinyl polymer (C) and 0.5 μm or less by equivalent spherical equivalent diameter. desirable. If the volume ratio exceeds 20%, the basic properties such as heat resistance of the polyester resin layer may change. Further, when the equivalent sphere equivalent diameter is more than 0.5 μm, the workability may be deteriorated.
[0025]
The polyester resin layer of the present invention is not particularly limited as long as it has the above-described structure, but the rubber-like elastic resin (B) is added to 100 parts by mass of the polyester resin (A). It is preferable that it is a resin composition for metal plate coating which consists of 1-50 mass parts and 1-50 mass parts of vinyl polymers (C). If the rubber-like elastic resin (B) is less than 1 part by mass, sufficient impact resistance may not be imparted, and if it exceeds 50 parts by mass, the heat resistance may be reduced. If the vinyl polymer (C) is less than 1 part by mass, the rubber-like elastic resin (B) may not be fully encapsulated, and if it exceeds 50 parts by mass, the heat resistance may be reduced.
[0026]
The intrinsic viscosity of the polyester resin (A) used in the present invention is preferably 0.5 to 2.0 dl / g, more preferably 0.65 to 1.7 dl / g, still more preferably 0.8 to 1.5 dl / g. When the intrinsic viscosity is less than 0.5 dl / g, the rubber-like elastic resin (B) and the polar monomer-containing vinyl polymer (C) are not uniformly mixed, so the mechanical strength and impact resistance are low. If it exceeds 2.0 dl / g, the moldability becomes poor and neither is preferable.
[0027]
The intrinsic viscosity is measured at a concentration of 0.5% in o-chlorophenol at 25 ° C. and is obtained by the following equation (i). Where C is the concentration expressed in grams of resin per 100 ml of solution, t₀Represents the solvent flow time, and t represents the solution flow time.
[0028]
Intrinsic viscosity = {ln (t / t₀)} / C (i)
The polyester resin (A) used in the present invention includes only hydroxycarboxylic acid compound residues, dicarboxylic acid residues and diol compound residues, or hydroxycarboxylic acid compound residues and dicarboxylic acid residues and diols. It is a thermoplastic polyester having compound residues as constituent units. Moreover, these mixtures may be sufficient.
[0029]
Examples of hydroxycarboxylic acid compounds used as raw materials for hydroxycarboxylic acid compound residues include p-hydroxybenzoic acid, p-hydroxyethylbenzoic acid, 2- (4-hydroxyphenyl) -2- (4′-carboxyphenyl) propane These may be used alone or in combination of two or more.
[0030]
Examples of dicarboxylic acid compounds that form dicarboxylic acid residues include terephthalic acid, isophthalic acid, orthophthalic acid, 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2 , 7-Naphthalenedicarboxylic acid, diphenic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid and other aromatic dicarboxylic acids and adipic acid, vimelic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, malonic acid, succinic acid, malic acid And aliphatic dicarboxylic acids such as citric acid, and alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid. These may be used alone or in combination of two or more.
[0031]
Next, diol compounds that form diol residues are exemplified by 2,2′-bis (4-hydroxyphenyl) propane (hereinafter abbreviated as “bisphenol A”), bis (4-hydroxyphenyl) methane, bis (2-hydroxyphenyl) methane, o-hydroxyphenyl-p-hydroxyphenylmethane, bis (4-hydroxyphenyl) ether, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfide, bis (4- Hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) ketone, bis (4-hydroxyphenyl) diphenylmethane, bis (4-hydroxyphenyl) -p-diisopropylbenzene, bis (3,5-dimethyl-4-hydroxyphenyl) methane Bis (3-methyl-4-hydroxyphenyl) methane, bis (3,5-dimethyl-4-hydroxyphenyl) ether, bis (3,5-dimethyl-4-hydro Xylphenyl) sulfone, bis (3,5-dimethyl-4-hydroxyphenyl) sulfide, 1,1-bis (4-hydroxyphenyl) ethane, 1,1-bis (3,5-dimethyl-4-hydroxyphenyl) ethane 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl) -1-phenyl Ethane, 1,1-bis (4-hydroxyphenyl) -1-phenylmethane, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 2,2-bis (3,5-difluoro-4-hydroxyphenyl) propane, 2,2-bis (3,5-difluoro-4-hydroxyphenyl) Propane, 2,2-bis (3-methyl-4-hydroxyphenyl) propane, 2,2-bis (3-fluoro-4-hydroxyphenyl) propane, 2,2-bis (3-Fluoro-4-hydroxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (4-hydroxyphenyl) propane, 4,4'-biphenol, 3,3 Aromatic diols such as', 5,5'-tetramethyl-4,4'-dihydroxybiphenyl, 4,4'-dihydroxybenzophenone and ethylene glycol, trimethylene glycol, propylene glycol, tetramethylene glycol, 1,4-butane Diol, pentamethylene glycol, neopentyl glycol, hexamethylene glycol, dodecamethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, aliphatic diols such as hydrogenated bisphenol A, and alicyclic diols such as cyclohexanedimethanol These can be used alone or in combination with two It is also possible to use a mixture of more than one. In addition, the polyester resins obtained from these may be used alone or in combination of two or more.
[0032]
The polyester resin (A) used in the present invention may be composed of these residues or a combination thereof, and among them, it is an aromatic polyester resin composed of an aromatic dicarboxylic acid residue and a diol residue. Is preferable from the viewpoints of workability and thermal stability.
[0033]
The polyester resin (A) used in the present invention is a small amount of structural units derived from polyfunctional compounds such as trimesic acid, pyromellitic acid, trimethylolethane, trimethylolpropane, trimethylolmethane, pentaerythritol, for example, An amount of 2 mol% or less may be included.
[0034]
From the viewpoint of heat resistance and processability, the most preferred combination of these dicarboxylic acid compounds and diol compounds is dicarboxylic acid of terephthalic acid 50 to 95 mol%, isophthalic acid and / or orthophthalic acid 50 to 5 mol%. It is a combination of a compound and a diol compound of a glycol having 2 to 5 carbon atoms.
[0035]
Examples of the preferred polyester resin (A) used in the present invention include polyethylene terephthalate, polybutylene terephthalate, polyhexamethylene terephthalate, polycyclohexylene dimethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene-2,6-naphthalate, etc. Among them, polyethylene terephthalate (PET) having moderate mechanical properties, gas barrier properties, and metal adhesion, modified PET obtained by substituting a part of the acid component of PET with isophthalic acid, polybutylene terephthalate (PBT), PBT Most preferred are modified PBT, polyethylene-2,6-naphthalate, and polybutylene-2,6-naphthalate in which a part of the acid component is substituted with isophthalic acid.
[0036]
The polyester resin (A) used in the present invention has a glass transition temperature (Tg, sample amount of about 10 mg, measured by a differential thermal analyzer (DSC) with a heating rate of 10 ° C./min), usually 30 to 120 ° C., Preferably it is 60-100 degreeC. This polyester resin (A) may be amorphous or crystalline, and when it is crystalline, the crystal melting temperature (Tm) is usually 210 to 265 ° C., preferably 210 to 245. The low-temperature crystallization temperature (Tc) is usually 110 to 220 ° C., preferably 120 to 215 ° C. If Tm is less than 210 ° C or Tc is less than 110 ° C, the heat resistance may be insufficient and the film shape may not be maintained during drawing. Further, when Tm exceeds 265 ° C. or Tc exceeds 220 ° C., the resin may not sufficiently enter the surface irregularities of the metal plate, resulting in poor adhesion.
[0037]
Next, the stretching stress relaxation agent used in the present invention is generally a rubber elastic body, but it is sufficient if it has the same function, and the stretching fluctuation caused by the tension and heat in the polyester resin. Any substance that absorbs or reduces can be used.
[0038]
As the rubber-like elastic resin (B), which is a stretching stress relaxation agent that can be preferably used in the present invention, known rubber-like elastic resins can be widely used. Above all, the glass transition temperature (Tg, sample amount about 10 mg, measured with a differential thermal analyzer (DSC) of 10 ° C / min) is 50 ° C or less, and Young's modulus at room temperature is 1000 MPa or less. And a rubber-like elastic resin having an elongation at break of 50% or more is preferred. Sufficient impact resistance cannot be achieved when the Tg of the rubber-elastic portion is more than 50 ° C., the Young's modulus at room temperature is more than 1000 MPa, and the elongation at break is less than 50%. In order to ensure impact resistance at low temperatures, Tg is preferably 10 ° C. or lower, more preferably −30 ° C. or lower. In order to ensure more reliable impact resistance, the Young's modulus at room temperature should be 100 MPa or less, more desirably 10 MPa or less, and the elongation at break should be 100% or more, more desirably 300% or more. Is preferred.
[0039]
Specific examples of rubber-like elastic resin (B) used in the present invention include polyolefin resin, butadiene-styrene copolymer (SBR), acrylonitrile-butadiene copolymer (NBR), polyisoprene (IPR), Diene elastomers such as polybutadiene (BR), styrene-butadiene-styrene copolymer (SBS) and its hydrogenated product (SEBS), rubber-modified styrene (HIPS), acrylonitrile-styrene-butadiene copolymer (ABS), etc. Examples thereof include styrene-based elastomers, silicone elastomers mainly composed of dimethylsiloxane, polyester elastomers such as aromatic polyester-aliphatic polyester copolymers or aromatic polyester-polyether copolymers, and nylon elastomers.
[0040]
Among these, polyolefin resin is preferable because it has low water vapor permeability. The polyolefin resin has the following general formula (a)
-R₁CH-CR₂R_Three-(a)
(Where R₁And R_ThreeEach independently represents an alkyl group having 1 to 12 carbon atoms or hydrogen, and R₂Is a resin having a repeating unit represented by an alkyl group having 1 to 12 carbon atoms, a phenyl group or hydrogen.
[0041]
The polyolefin resin used in the present invention may be a homopolymer of these structural units or a copolymer of two or more types, and further a copolymer of resin units formed by these units. It may be a coalescence.
[0042]
Examples of repeating units include propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene and other α-olefins O-, m-, p-methylstyrene, o-, m-, p-ethylstyrene, t-butylstyrene in addition to aliphatic olefins such as repeating units that appear, and repeating units when isobutene is added, styrene monomers And aromatic olefins such as addition polymer units of styrenic monomers such as halogenated styrene excluding Cl and Br, such as alkylated styrene and monofluorostyrene, and α-methylstyrene.
[0043]
Examples of the polyolefin resin include polyethylene, polypropylene, polybutene, polypentene, polyhexene, polyoctenylene and the like which are homopolymers of α-olefin. Further, the copolymer of the above unit includes ethylene / propylene copolymer, ethylene / butene copolymer, ethylene / propylene / 1,6-hexadiene copolymer, ethylene / propylene / 5-ethylidene-2-norbornene copolymer. Examples thereof include aliphatic polyolefins such as coalescence, aromatic polyolefins such as styrene-based polymers, and the like, but are not limited thereto, as long as the above repeating units are satisfied. These resins may be used alone or in combination of two or more.
[0044]
Moreover, the polyolefin resin should just have said olefin unit as a main component, and the vinyl monomer, polar vinyl monomer, and diene monomer which are the substituted bodies of said unit may be copolymerized by the monomer unit or the resin unit. The copolymer composition is 50 mol% or less, preferably 30 mol% or less with respect to the unit. If it exceeds 50 mol%, the properties as a polyolefin resin such as dimensional stability will deteriorate.
[0045]
Examples of polar vinyl monomers include acrylic acid derivatives such as acrylic acid, methyl acrylate and ethyl acrylate, methacrylic acid derivatives such as methacrylic acid, methyl methacrylate and ethyl methacrylate, acrylonitrile, maleic anhydride and maleic anhydride. Examples thereof include imide derivatives.
[0046]
Examples of the diene monomer include butadiene, isoprene, 5-methylidene-2-norbornene, 5-ethylidene-2-norbornene, ginglopentadiene, 1,4-hexadiene, and the like.
[0047]
The most preferred resins for imparting impact strength as a polyolefin resin are ethylene-propylene copolymer, ethylene-butene-1 copolymer, ethylene-pentene-1 copolymer, ethylene-3-ethylpentene copolymer. , A copolymer of ethylene and an α-olefin having 3 or more carbon atoms, such as an ethylene-octacene-1 copolymer, or the binary copolymer, butadiene, isoprene, 5-methylidene-2-norbornene, 5-ethylidene It is a terpolymer composed of ethylene copolymerized with 2-norbornene, ginglopentadiene, 1,4-hexadiene, etc., an α-olefin having 3 or more carbon atoms, and a non-conjugated diene. Among these, from the ease of handling, to the binary copolymer of ethylene-propylene copolymer and ethylene-butene-1 copolymer, or ethylene-propylene copolymer and ethylene-butene-1 copolymer, 5-Methyleiden-2-norbornene, 5-ethylidene-2-norbornene, zinglopentadiene, 1,4-hexadiene are used as non-conjugated dienes, the amount of α-olefin is 20-60 mol%, and non-conjugated dienes are 0.5- Most preferred is a 10% copolymerized resin.
[0048]
Next, the vinyl polymer (C) containing 1% by mass or more of the unit having a polar group used in the present invention has a Pauling electronegativity difference of 0.9 (eV).^0.5A vinyl polymer containing 1% by mass or more of a unit having a group in which a certain element is bonded. When the unit having a polar group is less than 1% by mass, sufficient adhesion to the metal plate cannot be exhibited even when the rubber-like elastic resin (B) is encapsulated with the vinyl polymer (C).
[0049]
The difference in polling electronegativity is 0.9 (eV)^0.5Specific examples of the group to which the above elements are bonded include -C-O-, -C = O, -COO-, an epoxy group, C₂O_Three, C₂O₂N-, -CN, -NH₂, -NH-, -X (X; F), -SO_Three-, Etc.
[0050]
Examples of units having a polar group are: vinyl alcohol as an example having a —CO— group, vinyl fluoromethyl ketone as an example having a —C═O group, acrylic acid, methacrylic acid, vinyl acetate as an example having a —COO— group , Vinyl acids such as propionic acid and their metal salts or ester derivatives, examples having an epoxy group include glycidyl esters of α, β-unsaturated acids such as glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, and glycidyl acrylate. , C₂O_ThreeExamples having groups include maleic anhydride, C₂O₂Examples having an N-group include maleic anhydride imide derivatives, examples having a -CN group, acrylonitrile, -NH₂Acrylic amine as an example having a group, acrylamide as an example having a -NH- group, vinyl fluoride as an example having a -X group, -SO_ThreeExamples of having a group include styrene sulfonic acid and the like, and these may be contained alone or in plural in the vinyl polymer (C). Units with polar groups contained in the vinyl polymer (C) have a Pauling electronegativity difference of 0.9 (eV)^0.5Any unit may be used as long as it has a group in which a certain element is bonded, and is not limited to the above specific example.
[0051]
Examples of the vinyl polymer (C) used in the present invention include the above polar group-containing unit alone or two or more polymers, and the polar group-containing unit and the nonpolar vinyl represented by the following general formula (b) Examples thereof include a copolymer with a monomer.
[0052]
-R₁CH = CR₂R_Three-(b)
(Where R₁, R_ThreeEach independently represents an alkyl group having 1 to 12 carbon atoms or hydrogen, R₂Represents an alkyl group having 1 to 12 carbon atoms, a phenyl group or hydrogen. )
Specific examples of the nonpolar vinyl monomer represented by the general formula (b) include ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1 -Α-olefins such as dodecene, aliphatic vinyl monomers such as isobutene and isobutylene, styrene monomers, o-, m-, p-methylstyrene, o-, m-, p-ethylstyrene, t-butylstyrene, etc. And aromatic vinyl monomers such as addition polymer units of styrene monomers such as alkylated styrene and α-methylstyrene.
[0053]
Examples of the homopolymer of the polar group-containing unit include polyvinyl alcohol, polymethyl methacrylate, polyvinyl acetate and the like. Examples of copolymers of polar group-containing units and nonpolar vinyl monomers include ethylene-methacrylic acid copolymers, ethylene-acrylic acid copolymers, ethylene-vinyl acetate copolymers, and copolymers thereof. Ionomer resin, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate, partially or wholly neutralized with metal ions Copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-maleic anhydride copolymer, butene-ethylene-glycidyl methacrylate copolymer, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-anhydrous A maleic acid copolymer etc. are mentioned. From the viewpoint of ensuring barrier properties, a copolymer of an α-olefin and a unit having a polar group is a preferred combination. The vinyl polymer (C) used in the present invention is not limited to the above specific examples as long as it is a vinyl polymer containing 1% by mass or more of units having a polar group. The molecular weight of the vinyl polymer (C) is not particularly limited, but is preferably 2000 or more and 500000 or less in terms of number average molecular weight. If it is less than 2000 or more than 500000, the rubber-like elastic resin (B) may not be sufficiently encapsulated.
[0054]
In order to finely disperse the rubber-like elastic resin (B) encapsulated with the vinyl polymer (C) in the polyester resin (A), the vinyl polymer (C), the polyester resin (A), and the rubber-like elastic resin It is important to properly balance the interfacial tension with (B). Preferably, the Spread parameter (λ) for the rubber-like elastic resin (B) of the vinyl polymer (C)_{(Resin C) / (Resin B)}It is desirable to control the content of the unit having a polar group so that) becomes positive. λ_{(Resin C) / (Resin B)}By making this positive, thermodynamic stability can be secured even when the rubber-like elastic resin (B) is encapsulated with the vinyl polymer (C). The Spread Parameter between different types of polymers is a parameter defined in S. Y. Hobbs; Polym., Vol. 29, p1598 (1989), and the following formula (ii)
λ_{(Resin C) / (Resin B)}= Υ_{(Resin B) / (Resin A)}-Υ_{(Resin C) / (Resin B)}-Υ_{(Resin C) / (Resin A)}    (ii)
[In the formula, Resin A represents a polyester resin (A), Resin B represents a rubbery elastic resin (B), Resin C represents a vinyl polymer (C), and_{i / j}Is the interfacial tension between resin i and resin j, and is approximately a parameter Χ indicating the compatibility between resin i and resin j._{i / j}It is proportional to the 0.5th power (the smaller the value, the better the compatibility). ]
Given in.
[0055]
The compatibility between the polyester resin (A) and the rubber-like elastic resin (B) is low._{(Resin B) / (Resin A)}Since> 0, the mixing ratio of the nonpolar vinyl monomer (Monomer V) and the polar group-containing unit (Monomer U) of the vinyl polymer (C) is adjusted, and the following formulas (iii) and (iv)

[However, φ indicates the blending ratio (volume ratio) of the nonpolar vinyl monomer. ]
The compatibility between the rubber-like elastic resin (B) and the vinyl polymer (C) given in_{B / C}In addition, it should be compatible with the polyester resin (A) and vinyl polymer (C)._{A / C}If we approach 0, λ_{(Resin C) / (Resin B)}Can be made positive.
[0056]
Accordingly, the preferred vinyl polymer (C) is determined in consideration of the compatibility with these resins depending on the types of the polyester resin (A) and the rubber-like elastic resin (B). As a specific example of a preferred combination, when the polyester resin (A) is an aromatic polyester resin composed of an aromatic dicarboxylic acid residue and a diol residue, and the rubber-like elastic resin (B) is a polyolefin resin, As the vinyl polymer (C), a copolymer of ethylene and a unit having a polar group, and SEBS into which maleic anhydride or glycidyl methacrylate is introduced in an amount of 1% by mass or more are preferable. The coalescence can be achieved by appropriately controlling the blending ratio between units having ethylene and polar groups._{(Resin C) / (Resin B)}Is easy to control. More preferably, when a functional group having a chemical action such as a covalent bond, a coordination bond, a hydrogen bond, and an ionic bond is introduced to the polyester resin (A) and a copolymer of ethylene and a unit having a polar group, It is desirable because the interface between the polyester resin (A) and the vinyl polymer (C) can be thermodynamically stabilized when encapsulated.
[0057]
More specifically, a copolymer of ethylene and a unit having a polar group can be represented by ethylene-vinyl acid copolymer, ethylene-vinyl acid ester copolymer or their ionomer resin, ethylene and α, β-unsaturation. A copolymer of an acid with a glycidyl ester, a terpolymer of ethylene and vinyl acid or a vinyl acid ester and a glycidyl ester of an α, β-unsaturated acid, and the like. Among them, ionomer resins, copolymers of ethylene and glycidyl esters of α, β-unsaturated acids, terpolymers of ethylene and vinyl acid or vinyl acid esters and glycidyl esters of α, β-unsaturated acids. preferable. These resins show a relatively strong chemical interaction with the polyester resin (A) and form a stable capsule structure with the rubber-like elastic resin (B). Among them, the ionomer resin is most preferable from the viewpoint of moldability since the strength of the chemical action with the polyester resin (A) varies depending on the temperature.
[0058]
As ionomer resins, known ionomer resins can be widely used. Specifically, a copolymer of a vinyl monomer and an α, β-unsaturated carboxylic acid is obtained by neutralizing a part or all of the carboxylic acid in the copolymer with a metal cation.
[0059]
Examples of vinyl monomers include the above α-olefins and styrene monomers, and examples of α, β-unsaturated carboxylic acids include α, β-unsaturated carboxylic acids having 3 to 8 carbon atoms. Examples include acrylic acid, methacrylic acid, maleic acid, itaconic acid, maleic acid monomethyl ester, maleic anhydride, and maleic acid monoethyl ester.
[0060]
An example of a metal cation to be neutralized is Na⁺, K⁺, Li⁺, Zn²⁺, Mg²⁺, Ca²⁺, Co²⁺, Ni²⁺, Pb²⁺, Cu²⁺, Mn²⁺And monovalent or divalent metal cations. Further, a part of the remaining carboxyl group that is not neutralized with the metal cation may be esterified with a lower alcohol.
[0061]
Specific examples of the ionomer resin include a copolymer of ethylene and an unsaturated monocarboxylic acid such as acrylic acid or methacrylic acid, or a copolymer of ethylene and an unsaturated dicarboxylic acid such as maleic acid or itaconic acid. Examples thereof include a resin in which a part or all of the carboxyl groups in the copolymer are neutralized with a metal ion such as sodium, potassium, lithium, zinc, magnesium, calcium. Among these, the most preferable for the purpose of improving the compatibility between the polyester resin (A) and the rubber-like elastic resin (B) is a copolymer of ethylene and acrylic acid or methacrylic acid (configuration having a carboxyl group). The unit is 2 to 15 mol%), and 30 to 70% of the carboxyl groups in the polymer are neutralized with a metal cation such as Na or Zn.
[0062]
The rubber-like elastic resin (B) and vinyl polymer (C) used in the present invention constitute a core-shell type rubber-like elastic body, and the rubber-like elastic resin (B) is the core portion, the vinyl polymer. By using (C) as the shell portion, the dispersion structure of the polyester resin layer of the present invention can be formed relatively easily. This core-shell type rubber-like elastic body has a two-layer structure composed of a core part and a shell part. The core part is in a soft rubber state, and the shell part on the surface is in a hard resin state. It is.
[0063]
For example, a core-shell type rubber-like elastic body is composed of an acrylic rubber-like elastic body, a diene rubber-like elastic body, or a silicon-based rubber-like elastic body, and acrylate or methacrylate grafted thereon is the main component. And a rubber-like elastic body in which the acrylic polymer constitutes the shell portion. The graft means graft copolymerization of the core resin and the shell resin.
[0064]
Specifically, the rubber-like elastic body constituting the core portion is mainly composed of an acrylate polymer, a diene polymer, or dimethylsiloxane composed of units having the structure of the general formula (c). It is a rubber-like elastic body.
[0065]
CH₂= CR₁-CO-O-R₂      (c)
Specific examples of the structural unit of the acrylate polymer include alkyl acrylate, alkyl methacrylate, alkyl ethacrylate, and the like.₁Is hydrogen or an alkyl group having 1 to 12 carbon atoms, and R₂Preferably have an acrylic group having 1 to 12 carbon atoms. More specifically, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, n-octyl methacrylate and the like can be mentioned. Of these, ethyl acrylate, butyl acrylate, 2-hexyl acrylate, methyl methacrylate, and n-octyl methacrylate are preferable from the viewpoint of imparting impact resistance. The acrylate polymer forming the core part may be a homopolymer of these or two or more kinds of copolymers.
[0066]
In addition, the acrylate polymer constituting the core part may be copolymerized with another vinyl monomer as long as the above acrylate is the main component. The main component is 50% by mass or more. Specific examples of vinyl monomers include α-olefin monomers, styrene monomers, and polar vinyl monomers. More specifically, α-olefin monomers include ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, and the like. In addition to styrene monomers, styrene monomers include alkylated styrene such as o, m, p-ethyl styrene and t-butyl styrene, halogenated styrene excluding Cl and Br such as monofluorostyrene, α- Examples of the polar vinyl monomer include acrylic acid, acrylonitrile, maleic anhydride and imide derivatives thereof, vinyl acetate, vinyl chloride, vinyl propionate, and the like.
[0067]
Further, the acrylate polymer constituting the core part is preferably partially crosslinked with a crosslinking agent in order to exhibit rubber elasticity. Examples of the cross-linking agent include vinyl monomers having polyethylenic unsaturation such as divinylbenzene, butylene diacrylate, ethylene dimethacrylate, butylene dimethacrylate, trimethylolpropane trimethacrylate, trialisyl annulate, triallyl isocyanate and the like. The addition amount of the crosslinking agent is 30% by mass or less, preferably 20% by mass or less, more preferably 5% by mass or less. If it exceeds 30% by mass, it often hardens and cannot exhibit rubber elasticity.
[0068]
The diene polymer constituting the core part is a polymer of a diene monomer or a hydrogenated polymer thereof, specifically, polybutadiene and a hydrogenated polymer thereof, a copolymer of butadiene and styrene and a water thereof. An addition polymer etc. are mentioned.
[0069]
The molecular weight of the polymer constituting the core part is not particularly limited, but is preferably 2000 or more in terms of number average molecular weight. If it is less than 2000, sufficient rubber elasticity cannot be exhibited. In the case where the core part is a crosslinked acrylate polymer, the molecular weight between crosslinking points is preferably 2000 or more from the viewpoint of imparting sufficient rubber elasticity.
[0070]
The glass transition temperature of the polymer constituting the core part (temperature increase rate 10 ° C./min, measured with a differential thermal analyzer (DSC)) is preferably 30 ° C. or less, more preferably 10 ° C. or less, and further Preferably it is -10 degrees C or less. When the glass transition temperature is higher than 30 ° C., rubber elasticity at room temperature or lower is hardly exhibited.
[0071]
Next, the shell part of the core-shell type rubber-like elastic body will be described. It is important that the shell portion is composed of an acrylate polymer. By using the polarity of the acrylate polymer, the shell-type rubber-like elastic body has good adhesion when it contacts the metal plate. It can be secured.
[0072]
The acrylate polymer constituting the shell portion is a polymer composed of units of the general formula (c). Specifically, it is a polymer of the above-mentioned monomers, and may be copolymerized with the vinyl monomer as long as the acrylate unit is the main component. Here, the main component is 50% by mass or more. When copolymerized with other vinyl monomers, the composition ratio of the acrylate component is preferably 70% by mass or more. If it is less than 70% by mass, the polarity of the acrylate unit cannot be fully utilized, and the adhesion to the metal plate may be insufficient.
[0073]
Since the core-shell type rubber-like elastic body is a rubber-like material having a soft core, it is necessary for handling that the resin constituting the shell is hard. For this purpose, the glass transition temperature of the acrylate polymer constituting the shell part (temperature increase rate 10 ° C./min, measured with a differential thermal analyzer (DSC)) is preferably 30 ° C. or more, more preferably Is above 50 ° C.
[0074]
Most preferred as the acrylate polymer unit constituting the shell part is methyl methacrylate because the glass transition temperature is in the above range and the polymerization rate is easily controlled.
[0075]
Furthermore, in order to ensure compatibility with the polyester resin (A), the acrylate polymer constituting the shell part has functional groups or bonds that can react with the residual terminal functional groups and ester bonds of the polyester resin (A). It is preferred that a group is introduced. Specific examples of functional groups include epoxy groups, carboxyl groups, hydroxyl groups, acid anhydride groups, and amino groups. When grafting the shell part, known vinyl monomers having these functional groups are added. By doing so, a functional group can be introduced. Examples of the linking group include an ester bond, a carbonate bond, an amide bond, and the like. When grafting the shell part, TO Ahn, et al .; J. Polym. Sci. Part A Vol. 31, 435 By using initiators having these bonds as disclosed in (1993), linking groups can be introduced. Among these functional groups and bonding groups, the epoxy group and the aromatic-aromatic ester bond are most preferable from the viewpoint of reactivity. When polymerizing the shell part, glycidyl methacrylate and TO Ahn are respectively used. By adding the polyarylate azo initiator disclosed in J. Polym. Sci. Part A Vol. 31, 435 (1993), the above epoxy group and ester bond can be introduced.
[0076]
The introduction amount of the unit containing these functional groups and bonding groups is not particularly limited as long as the introduction amount is determined by the reactivity and the acrylate unit is the main component. However, in the case of a functional group, the introduction amount of the functional group-containing unit is preferably 15% by mass or less, more preferably 5% by mass or less. If it exceeds 15% by mass, comb polymers are produced in the kneading step, and the compatibility with the polyester resin (A) may not be sufficiently improved. In the case of a linking group, the amount of the linking group-containing unit introduced is preferably 15% by mass or less. If it exceeds 15% by mass, the unit having a bonding group forms a domain, and the compatibility with the polyester resin (A) may not be improved.
[0077]
The core-shell type rubber-like elastic body desirably contains 20% by mass or more, preferably 50% by mass or more, more preferably 80% by mass or more of the core part which is a rubber-like polymer. If it is less than 20% by mass, sufficient impact resistance may not be exhibited.
[0078]
The polyester resin composition of the present invention can be produced by a known mixing method.
[0079]
Specifically, the polyester resin (A), rubber-like elastic resin (B) and vinyl polymer (C) having an appropriate interfacial tension difference are mixed at a predetermined temperature such as 200 to 350 ° C. Can be produced by forming a capsule structure utilizing the difference in interfacial tension.
[0080]
The rubber-like elastic resin (B) and the vinyl polymer (C) can be grafted to form a core-shell type rubber-like elastic body, and then mixed with the polyester resin (A). The core-shell type rubber-like elastic body can be polymerized by a known radical polymerization method. Among them, the viewpoint of controlling the particle size of the polymer produced by the emulsion polymerization method as described in US Pat. To preferred. Specific examples of the polymerization method include the following methods, but the core-shell type graft rubber-like elastic body and the shell portion may be an acrylate polymer, and the production method is not limited to the production method.
[0081]
As the first stage polymerization, the unit monomer constituting the core part is radically polymerized. At this time, about 0.1 to 5% by mass of a monomer having a polyethylenic unsaturation and having a plurality of double bonds is added as a grafting agent. The plurality of double bonds of the graft agent preferably have different reaction rates, and specifically include allyl methacrylate, diallyl maleide and the like. After polymerizing the polymer of the core part, a core-shell type rubber-like elastic body is obtained by graft polymerization of the shell part by adding a monomer and an initiator constituting the shell part as a second stage polymerization.
[0082]
Next, a specific example of a core-shell type rubber-like elastic body is as follows: the core part is polybutyl acrylate, the shell part is an MBA resin made of polymethyl methacrylate, the core part is a butadiene-styrene copolymer, and the shell part is poly. MBS resin made of methyl methacrylate, polymer having a core part made of polydimethylsiloxane, shell part made of polymethyl methacrylate, and the like, and further an acrylate base core-polymerized acrylate shell weight disclosed in US Pat. No. 4096202. Coalescence can be used in the present invention.
[0083]
The polyester resin layer (A) comprising the polyester resin (A) and the core-shell type rubber-like elastic body used in the present invention has improved compatibility between the polyester resin (A) and the core-shell type rubber-like elastic body. For this purpose, a known compatibilizer may be added. The addition amount of the compatibilizing agent is preferably 15% by mass or less, more preferably 5% by mass or less. If it exceeds 15% by mass, the compatibilizer may form a phase structure by itself, and it is difficult to achieve a sufficient compatibility improvement effect. Specific examples of the compatibilizing agent include a reactive compatibilizing agent and a non-reactive compatibilizing agent, and the reactive compatibilizing agent includes a polyester resin (A ) And a polymer introduced with a functional group or bond capable of reacting with the terminal residual functional group or bond. More specifically, the polymer constituting the shell part of the core-shell type rubber-like elastic body is a polymer obtained by random copolymerization of glycidyl methacrylate and maleic anhydride, and the aromatic polyester is blocked on the polymer constituting the shell part. Examples include graft-polymerized polymers. Examples of the non-reactive compatibilizing agent include a block and graft copolymer of a polymer and a polyester resin (A) constituting the shell portion of the core-shell type rubber-like elastic body.
[0084]
A colorant can be added to the polyester resin layer of the present invention as necessary. In particular, a pigment can be added in order to impart a concealing property or a special color tone to improve the pattern design. As pigments to be added, inorganic pigments such as titanium dioxide, zinc white, petal, vermilion, ultramarine, cobalt blue, titanium yellow, carbon black, isoindolinone, Hansa Yellow A, quinacridone, permanent red 4R, phthalocyanine blue, indus Pearl luster consisting of organic pigments (or dyes included) such as Lenblue RS, Induslen Blue RS, aniline black, metal foil pigments such as aluminum and brass, titanium dioxide-coated mica, and foil powders such as basic lead carbonate ( Pearl) pigments. Coloring by adding colorant. It may be transparent or opaque (hiding). These are added and dispersed as powder or scaly foil pieces. In particular, for the purpose of concealing the background color of the substrate, concealing pigments such as titanium dioxide, petals, and ink can be preferably used. Among these, from the viewpoint of providing a multi-design by printing, white is preferable, and titanium dioxide is preferable.
[0085]
Further, when a pigment is added to the polyester resin layer, it is possible to obtain a high design property even if the printing layer is omitted.
[0086]
For mixing the polyester resin composition of the present invention, known resin mixing methods such as a resin kneading method and a solvent mixing method can be widely used. Examples of the resin kneading method include a method of mixing by dry blending with a tumbler blender, Henschel mixer, V-type blender, etc., and then melt-kneading with a single screw or twin screw extruder, kneader, Banbury mixer or the like. Further, as an example of the solvent mixing method, after each resin is dissolved in a common solvent of the polyester resin (A), the rubber-like elastic resin (B) and the vinyl polymer (C), the solvent is evaporated, There is a method of collecting the mixture by adding it to a solvent. When kneading by melting, if necessary, prepare a master batch in which one or more resins are pre-mixed with color pigments, and melt or mix these master batches in part or in whole. May be. Conversely, after melting and mixing only the resin component in advance, a color pigment may be added and melt mixed.
[0087]
Further, the polyester resin layer of the present invention has a fiber reinforcing agent such as glass fiber, metal fiber, potassium titanate whisker, carbon fiber, talc, calcium carbonate, mica, for the purpose of improving rigidity and linear expansion characteristics, etc. A filler reinforcing agent such as glass flake, milled fiber, metal flake, and metal powder may be mixed. Among these fillers, the glass fiber and the carbon fiber preferably have a fiber diameter of 6 to 60 μm and a fiber length of 30 μm or more. Moreover, as these addition amount, it is desirable that it is 5-15 mass parts with respect to the total resin composition substance amount.
[0088]
In addition, the polyester resin layer contains a heat stabilizer, an antioxidant, a light stabilizer, a release agent, a lubricant, a pigment, a flame retardant, a plasticizer, an antistatic agent, an antibacterial and antifungal agent, etc., depending on the purpose. It is also possible to add an appropriate amount.
[0089]
The thickness of the polyester resin layer (A) used in the present invention is not particularly limited, but is preferably in the range of 10 to 100 μm, and more preferably in the range of 40 to 75 μm. If the thickness is less than 10 μm, the original purpose of stretching stress relaxation effect may not be sufficiently exhibited, and the hiding effect may not be sufficiently exhibited. If it exceeds 100 μm, the economical efficiency is deteriorated.
[0090]
  Polyester resin layer and printed layer thereon andPolyethylene terephthalate, modified polyethylene terephthalate, polybutylene terephthalate, modified polybutylene terephthalate, or these 2 Resin mixed with more than seeds, or polycarbonate, polyarylate, polystyrene, styrene - Made of styrene derivative copolymer resinThe transparent protective layer may be applied to the surface of the metal plate for the purpose of producing a decorative metal plate, but in the present invention, after forming a polyester resin film and forming a laminate film with a printed layer and a transparent protective layer From the viewpoint of productivity, it is preferable to laminate the laminate film on a metal plate. Therefore, a polyester resin film is first manufactured.
[0091]
A method for producing a polyester resin film is known. For example, the polyester resin composition may be melt-extruded. Specific examples include a melt casting method, a thermocompression bonding method, a tarender method, a T-die casting method, a T-die uniaxial or biaxial stretching method, and an inflation method, but are not particularly limited thereto.
[0092]
The printing resin film for laminating a high-design decorative metal plate of the present invention has a printing layer on the polyester resin layer and a transparent resin layer on the printing layer.
[0093]
The printed layer may be any layer as long as it forms a reflective layer necessary for obtaining a high design, but may be a printed layer having a pattern. Printing materials, printing methods, etc. are known and not particularly limited. As printing ink, for example, a metal powder, an inorganic pigment, an organic pigment kneaded in a binder such as chlorinated polyolefin, polyester resin, vinyl, acrylic, urethane, or cellulose, or dissolved in a solvent. Things can be used. The printing method may be a known method such as gravure printing, offset printing, silk screen printing, or transfer printing.
[0094]
The thickness of the printing layer is preferably 2 to 5 μm after drying by printing one color in multicolor printing. In the case of more than 5 μm, depending on the printed pattern, the printed unevenness affects the transparent resin layer, which hinders the expression of high definition. From this viewpoint, the printing method is preferably a silk screen printing method. On the other hand, this is not the case when the purpose is printing embossing (embossed design imparted by printing unevenness: wiping printing).
[0095]
The printing layer of the present invention is not formed on the polyester resin layer as described above, and then the transparent resin layer is not formed thereon. Instead, the printing layer is formed on the back surface side of the transparent resin layer and is formed as the polyester resin layer. You may laminate. In particular, in the case of high definition, it is preferable from the viewpoint of imparting smoothness to form a printing layer on the back side of the transparent resin layer.
[0096]
  The transparent protective layer used in the present invention isPolyethylene terephthalate, modified polyethylene terephthalate, polybutylene terephthalate, modified polybutylene terephthalate, or these 2 Resin mixed with more than seeds, or polycarbonate, polyarylate, polystyrene, styrene - Made of styrene derivative copolymer resinAny transparent layer can be used. For the purpose of obtaining a high design, the transparent protective layer preferably has a light transmittance of 60% or more, more preferably 70% or more.
[0097]
The transparent protective layer of the present invention is formed on the printed layer and imparts high definition or embossing to express high design. However, embossing is a method of laminating a metal plate laminated printing resin film previously embossed on a metal plate, and laminating an unembossed metal plate laminating printing resin film on a metal plate. There is a method of embossing at the time of or after lamination, and the high-design decorative metal plate lamination printing resin film of the present invention can be used as an embossing decorative metal plate lamination printing resin film if the transparent protective layer is embossed. However, the pre-embossed decorative metal sheet laminated printing resin film (which may be embossed at the time of or after forming the transparent protective layer of the present invention) is the subject of another application filed on the same day as the present application. The invention is a printing resin film for laminating a high-design decorative metal plate having a transparent protective layer that has not yet been embossed (a printing resin film for laminating a high-definition decorative metal plate). And high-definition decorative metal plates obtained by laminating high-definition decorative metal plate-laminated printing resin films on metal plates) . That is, the printed resin film for laminating a high-design decorative metal plate of the present invention is a high-definition decorative metal plate laminating printed resin film and an embossed decorative metal, unless embossed in the film stage before lamination to the metal plate. It is intended for both printed resin films for board lamination.
[0098]
  The transparent protective layer used in the present invention is,LivingA transparent film is suitable from the standpoint of productivity.
[0099]
The transparent protective layer of the present invention is formed on the printed layer and imparts high definition or embossing to express high design. Both cases are common in that the optical properties of the transparent protective layer influence, but thermal deformation characteristics affect embossing. Therefore, although there is a commonality in terms of optical properties necessary to impart a high design to the printed layer, depending on whether the purpose is high definition or embossing, an optimal transparent protective layer The material etc. can be different.
[0100]
Since the printing resin film for laminating a high-design decorative metal plate of the present invention is generally baked and laminated on a metal plate regardless of whether or not an adhesive is used, the transparent protective layer has a low thermal shrinkage during heat treatment. preferable. In the case of imparting high image clarity, the temperature is 5 to 40 ° C. higher than the crystal melting temperature of the polyester resin layer (melting point: Tm, measured with a differential thermal analyzer (DSC) at a heating rate of 10 ° C./min). When the polyester resin film is laminated by heating the metal plate (200 to 260 ° C.), the polyester resin film is softened, the transparent protective layer side is pressed with a metal roll heated to 190 to 220 ° C. (several seconds), and rapidly cooled And ensuring the smoothness of the front and back surfaces of the transparent resin layer. This makes it possible to impart high definition. In this case, since the transparent protective layer is only heated for several seconds (1 to 5 seconds), for example, biaxially stretched polyethylene terephthalate that shrinks when heated originally is suitable for use as the transparent protective layer. On the other hand, when embossing is performed, it is heated to a temperature lower by 100 to 10 ° C. than the melting point of the transparent protective layer (in some methods, it is heated to the melting point or higher). Therefore, when used in this application, the transparent protective layer is preferably made of a material or film having a shrinkage rate of 20% or less at a temperature lower by 100 to 10 ° C. than its melting point. More preferably, the shrinkage rate is 10% or less, and further preferably 5% or less. Preferred materials for this purpose are polyethylene terephthalate (PET), modified polyethylene terephthalate, polybutylene terephthalate (PBT), modified polybutylene terephthalate, and a resin film in which two or more of these are mixed, but the crystallization rate is particularly saturated. Polybutylene terephthalate having an crystallization rate of 50% or more is optimal.
[0101]
In addition, when used as an interior material for a unit bath or the like, the transparent protective layer has a glass transition temperature higher than 100 ° C., more preferably 110 ° C. or higher because it is exposed to high temperature and humidity, especially boiling water for a long time. A quality film is preferred. Since the glass transition temperature of the resin film is lower than that measured under normal conditions under humid conditions, the normal measured value is more preferably 105 ° C. or higher. Examples of the resin film that satisfies such conditions include polycarbonate, polyarylate, polystyrene, and a styrene-styrene derivative copolymer film.
[0102]
When used as an interior material for a unit bath, even in the case of a crystalline film, if the glass transition temperature of the amorphous part exceeds 100 ° C., it can be heated even in an environment that is in contact with high temperature, high humidity, and boiling water. There is no deformation. Such materials are therefore preferred. In addition, in a crystalline film, if the degree of crystallinity of the film is 10% or more of the saturation crystallization rate, even if crystallization proceeds under boiling water, the degree is small, so the density change is small, so deformation and whitening Can be prevented. More preferably, the crystallinity of the film is 20% or more, more preferably 50% or more of the saturation crystallization rate. Examples of the resin film satisfying such conditions include biaxially stretched polyethylene terephthalate and polybutylene terephthalate. Among these, biaxially stretched polyethylene terephthalate is a resin film that is most suitable for a transparent protective layer as a high-definition providing layer because of its high light transmittance and smoothness on the front and back surfaces.
[0103]
The thickness of the transparent protective layer is not particularly limited as long as it can protect the printed layer even after long-term use. From the viewpoints of formability and cost, a thickness of about 5 to 200 μm, more preferably about 13 to 150 μm is preferable. Moreover, when a design is imparted by embossing or the like, the total thickness of the constituent films is preferably at least twice the depth of the embossed grooves. If it is less than 2 times, the embossed groove may change when it is laminated on a metal plate.
[0104]
The transparent protective layer used in the printed resin film for laminating high-design decorative metal plates of the present invention preferably has a smooth front and back surface and a uniform film thickness for the purpose of obtaining high definition. The front and back surface roughness of the transparent protective layer is preferably such that Rmax is 500 nm or less as a result of arbitrarily measuring the film surface roughness by 1 mm length. In the present invention, since the polyester resin layer has the ability to absorb thermal stress, the decorative film can be baked on the metal plate at a higher temperature, and the base polyester resin layer is softened, and the film is generated due to various factors. It becomes possible to absorb the unevenness of the surface. As a result, there is an effect that flatness of the front and back surfaces of the transparent protective layer of the baked decorative film is improved, that is, there is an effect that a more excellent high design can be obtained. In the present invention, the method of the mirror surface treatment for obtaining a high-definition decorative metal plate has been described above.
[0105]
A method of laminating a polyester resin layer and a transparent protective layer on which a printing layer is formed to form a printing resin film for laminating a high-design decorative metal plate according to the present invention uses an adhesive or a printing layer. Any method may be used such as forming the transparent protective layer by melt extrusion on the formed polyester resin layer, or thermocompression bonding at a temperature within a range that does not impair the design properties of the printed layer.
[0106]
When laminating a single molded film via thermocompression bonding or an adhesive, in order to increase the surface tension of the single molded film and enhance adhesion, a known film treatment such as corona discharge treatment or plasma treatment, It is preferable to control the surface tension to 500 μN / cm or more. In particular, when corona discharge treatment is performed, the discharge amount (watt density) is adjusted according to the device, and under a low discharge amount, specifically, 10 to 40 W / m.²It is preferable to process at / min. When the amount of treatment discharge is high, the surface is locally heated, the surface is deformed and defects such as wrinkles are generated, and the designability may be lowered.
[0107]
Further, when an adhesive is used, the adhesive can be applied by a known gravure method or roll coater method. The coating method can be selected depending on the application, but when a very high-definition design is required, since the adhesive unevenness is small, the roll coater method is more preferable.
[0108]
Examples of adhesives include polyester resin-based aqueous dispersants disclosed in JP-B-60-12233, epoxy-based adhesives disclosed in JP-B-63-13829, and JP-A-61-149341. Known adhesives such as polymers having various functional groups can be widely used. It is preferable to select an adhesive effective for the main component resin in accordance with the main component of the layer to be bonded and the resin composition layer of the present invention.
[0109]
The printed resin film for laminating a high-design decorative metal plate according to the present invention has a polyester resin layer, a printed layer, and a transparent protective layer in this order. One or two or more other layers may be included between the polyester resin layer and the metal plate or on the transparent protective layer.
[0110]
In particular, the printed resin film for laminating a high-design decorative metal plate of the present invention optionally has an adhesive layer (including an adhesion improving layer and a primer; the same applies hereinafter) between the polyester resin layer, the printed layer, and the transparent protective layer. It may be used. An adhesive layer may be used between the polyester resin layer and the metal plate. As the adhesive, for example, a one-component or two-component polyester resin adhesive, polyurethane resin adhesive, or the like can be used. You may add a coloring pigment, a rust preventive pigment, an extender pigment, etc. as needed. The thickness of the adhesive is preferably about 2 to 20 μm after drying.
[0111]
In order to produce the printed resin film for laminating a high-design decorative metal plate of the present invention, after producing a polyester resin layer, printing is performed on the surface and a transparent paint is applied or a transparent resin film produced separately is prepared. What is necessary is just to laminate.
[0112]
The printed resin film for laminating a high-design decorative metal plate of the present invention is prepared by mirror-treating the surface of the transparent protective layer for use as a high-definition film.
[0113]
The printed resin film for laminating high-design decorative metal plates of the present invention has been developed particularly for the purpose of coating a metal plate. The metal plate is not particularly limited. For example, the interior wall of a unit bath or other building interior materials, the exterior of home appliances such as an electric refrigerator door, an air conditioner cover, steel furniture, an elevator, etc. It is suitable for applications that require printed patterns.
[0114]
Thus, according to the present invention, there is similarly provided a metal plate coated with a printed resin film for laminating a high design decorative plate and subjected to a design with a high design pattern or a metal plate having a similar structure thereto.
[0115]
Although it does not specifically limit as a metal plate, In addition to a stainless steel plate, a hot-dip galvanized steel plate, a hot-dip zinc-iron alloy plating steel plate, a hot-dip zinc-aluminum-magnesium alloy plating steel plate, tinplate, a thin tin plating steel plate, electrolytic chromium Canned steel sheets such as acid-treated steel sheets (tin-free steel), nickel-plated steel sheets, hot-dip galvanized steel sheets such as molten aluminum-silicon alloy-plated steel sheets, molten lead-tin alloy-plated steel sheets, electrogalvanized steel sheets, electrogalvanized steel Surface-treated steel sheets such as nickel-plated steel sheets, electro-galvanized steel sheets, electro-plated steel sheets such as electro-zinc-chromium alloy plated steel sheets, cold-rolled steel sheets, and metal sheets such as aluminum, copper, nickel, zinc, and magnesium It is done. If necessary, it may be subjected to pretreatment such as phosphate treatment and chromate treatment. The thickness of the metal plate is not particularly limited, and may be selected according to the use, but is generally preferably 0.01 to 5 μm. If the thickness is less than 0.01 mm, the strength is hardly exhibited, and if it exceeds 5 mm, the processing is difficult.
[0116]
According to the present invention, in order to coat the printed resin film for laminating a high-design decorative board on a metal plate, the resin film may be thermocompression bonded to the metal plate with or without an adhesive. The method of thermocompression bonding may be performed by heating the metal plate to a predetermined temperature, laminating a resin film, and pressing with a roller or the like as necessary. When an adhesive is used, it may be applied to the surface of the metal plate or the surface of the resin film, or an adhesive layer may be formed on the film surface in advance. Although the thermocompression bonding temperature depends on the film thickness, a metal plate temperature of about 210 to 260 ° C. is used, but a printing color tone protection (color loss) and a temperature that does not impair the emboss shape (emboss return) are preferable.
[0117]
The metal plate subjected to the design of the high design pattern of the present invention is not only a method for coating a metal plate with a printing resin film for laminating a high design decorative plate, but also after forming the polyester resin layer on the metal plate, It is also possible to manufacture by a method of forming a transparent protective layer.
[0118]
Moreover, the printing resin film for lamination | stacking of the high design decorative metal plate of this invention can be used in order to manufacture both a high-definition decorative metal plate and an embossed decorative metal plate as demonstrated previously. When producing a high-definition decorative metal plate, the high-design decorative metal plate laminating printing resin film of the present invention may be laminated on the metal plate and optionally subjected to a mirror finish. When producing an embossed decorative metal plate, the printed resin film for high-design decorative metal plate lamination of the present invention is laminated on the metal plate, and before or after lamination, or after lamination, on the surface. It can be embossed to form an embossed decorative metal plate.
[0119]
In general, as a method for embossing a resin film, there are a method of imparting at the time of film formation, a method of heating and embossing after winding once, and a method of cold embossing (shot blasting). The embossing method at the time of film formation is to give embossing before the extruded film cools, and the polyester resin layer of the present invention originally has optimal properties for this purpose. It is not the subject of this application. When the printed resin film for laminating a high-design decorative metal plate of the present invention is once manufactured and then embossed, the surface of the transparent resin layer is heated to near the melting point, so that the conventional polyester resin film has a large thermal shrinkage. However, although it was difficult, the stretchable stress relaxation agent finely dispersed polyester resin film of the present invention has the property of preventing thermal shrinkage, and is therefore optimal for embossing.
[0120]
In particular, the printed resin film for laminating a high-design decorative metal plate of the present invention may be embossed in a step of laminating on a metal plate, or embossed after being laminated on a metal plate. Also in these cases, since the printing resin film for laminating a high-design decorative metal plate of the present invention has an effect of preventing thermal shrinkage during lamination and embossing, a good embossed decorative metal plate is provided.
[0121]
The embossing can employ known methods and conditions. Typically, the resin is formed by heat softening, pressing and shaping with an embossed plate, and cooling and solidifying. Sheet-like or rotary embossing machines are known. Embossed irregularities include wood grain conduit grooves, lithographic surface irregularities, satin, grain, spatula lines, and the like. After embossing, other films may be laminated or coated within a range that does not damage the matte or embossed design. Usually, when embossing is carried out in the form of a film, the film temperature is the crystal melting temperature from the melting start temperature of the transparent protective layer resin (measured with a suggested thermal analyzer (DSC) at a heating rate of 10 ° C./min). That is, heating to the melting point (Tm), the embossing roll temperature is 25-30 ° C. (room temperature), and when embossing at the time of metal plate lamination, the plate temperature is higher than the melting end temperature, the embossing roll temperature is higher than the melting end temperature, metal plate lamination When embossing is performed later, it is common to set the plate temperature to the melting end temperature or higher and the embossing roll temperature to 25 to 30 ° C. (normal temperature), but it is not limited to this.
[0122]
【Example】
Next, based on an Example and a comparative example, this invention is demonstrated more concretely, However, This invention is not limited to a following example, unless it deviates from the summary.
[0123]
In the following examples and comparative examples, as the polyester resin (A), polyethylene terephthalate (PET) [SA-1346P, MA-1344 manufactured by Unitika Co., Ltd.], polybutylene terephthalate (PBT) [Jura manufactured by Polyplastics Co., Ltd. Nex 2001 and Toray Industries, Inc. Toraycon 1200S], ethylene-glycidyl methacrylate copolymer [Sumitomo Chemical Co., Ltd. Bond First 2C] as vinyl polymer (B) having 1% by mass or more of units having polar groups , Ethylene-alkyl acrylate-glycidyl methacrylate copolymer [Bond First 7L manufactured by Sumitomo Chemical Co., Ltd.], ethylene ionomer [High Milan 1706 manufactured by Mitsui DuPont Co., Ltd.], and rubbery elastic resin (C) as ethylene -Butene rubber (EBM) [JSR Co., Ltd.) EBM2041P] was used. For melt kneading, a blended antioxidant [Adeka Stub A-612 manufactured by Asahi Denka Co., Ltd.] was used. In addition, the master which contains 50 mass% of titanium dioxide (average particle diameter 0.2-0.3 micrometer) in each of polyethylene terephthalate (PET) [unit-1 Co., Ltd. SA-1346P, MA-1344] as a polyester resin (A). Batch polyethylene terephthalate was prepared in advance. In addition, as polyester resin (A), polybutylene terephthalate (PBT) [Polyplastics DURANEX 2001 and Toray KK Toraycon 1200S] are each made of titanium dioxide (average particle size 0.2 to 0.3 μm). ) Was previously prepared as a master batch polybutylene terephthalate containing 50 mass%.
[0124]
(Example 1-10)
Using a titanium dioxide masterbatch resin corresponding to each resin, dry blending was performed using a V-type blender so as to achieve each composition ratio shown in Table 1. The final composition ratio of each resin is as shown in Table 1, and in each case, 0.5 parts by mass of blend-based antioxidant A-612 was added to 100 parts by mass of the resin composition. This mixture was melt-kneaded at 260 ° C. with a twin-screw extruder to obtain white resin composition pellets.
[0125]
After cutting out an ultrathin section from this resin composition with a microtome, it was stained with ruthenic acid, and the dispersion state of the vinyl polymer (B) and the rubber-like elastic resin (C) in the polyester resin (A) was determined as a transmission electron. Analyzed with a microscope. As a result, the rubber-like elastic resin (C) is almost 100% encapsulated with the vinyl polymer (B), and the equivalent spherical diameter of the rubber-like elastic resin (C) is 1 μm or less and is a polyester resin. It was finely dispersed in (A).
[0126]
[Table 1]

[0127]
Using this pellet, a white film having a thickness of 50 μm was obtained by extrusion T die (extrusion temperature: 250-280 ° C.). When any part of the obtained white resin composition film was cut into a 10 cm × 10 cm square (n = 10) and the film sample was heat-treated at 200 ° C. for 10 minutes, the shrinkage was 5% or less, respectively. there were.
[0128]
The surface tension of these white resin composition films is 300-380 μN / cm, and the discharge amount (watt density) is about 20-25 W / m on one side.²Corona discharge treatment was performed under the conditions of / min, and the surface tension was set to 500 μN / cm or more.
[0129]
On the other hand, an acrylic polyol (isocyanate crosslinking type) ink was used on one side of a transparent biaxially stretched polyethylene terephthalate film (Toray Lumirror) with a film thickness of 25 μm, and a pattern printing layer and a colored solid printing layer were printed on a gravure rotator ( Print thickness after drying 6-8 μm).
[0130]
The white resin composition film (corona-treated) and a printed commercially available transparent biaxially stretched PET film are dried by a conventional method using a two-component urethane adhesive (adhesive coating thickness after drying 6 μm). Lamination was performed to obtain a printing resin film for laminating a high-definition decorative metal plate composed of a resin composition film layer, a printing layer, and a top layer.
[0131]
Resin composition film layer side of this three-layer film and a two-component type polyester adhesive (for vinyl chloride resin, adhesive coating thickness after drying 4 μm), then heated to 240 ° C. and hot dip galvanized with a thickness of 450 μm One side of the steel plate was thermocompression bonded using a metal mirror roll (film side) and rubber roll (steel side) heated to 190 ° C., and rapidly cooled to 100 ° C. or less within 5 seconds by water cooling on the back side of the steel plate to obtain a decorative steel plate. .
[0132]
The room temperature decorative steel sheet thus obtained was evaluated for each of the items of adhesion, boiling water resistance, workability, stain resistance, solvent resistance, and sharpness by the following evaluation methods.
[0133]
<Adhesion>
A cross cut was put into the above decorative steel sheet and immersed in distilled water at 50 ° C. for 10 days, and then the peel width (mm) (average of 10 samples) of the film at the cross cut portion was evaluated. The evaluation was made as follows: A: 0.0 mm, O: 0.0 to 0.5 mm, Δ: 0.5 to 2.0 mm, and x: over 2.0 mm. The results of the adhesion test are shown in Table 2.
[0134]
<Boiling water resistance>
The above-mentioned decorative steel sheet was immersed in boiling water for 48 hours, and the peeling state of the film and changes in appearance (unevenness, shrinkage, peeling, etc.) were visually confirmed. The evaluation was as follows: ：: no abnormality, ◯: slight change, Δ: surface changed considerably, and x: the ground was exposed. Table 2 shows the results of the boiling water resistance test.
[0135]
<Processability>
The decorative steel sheet was subjected to OT bending at 25 ° C. and visually confirmed for good workability such as cracking and whitening. The evaluation was as follows: ：: no abnormality, ◯: slight change, Δ: surface changed considerably, and x: the ground was exposed. Table 2 shows the results of the workability test.
[0136]
<Contamination resistance>
The film surface of the decorative steel sheet was drawn with black oil-based magic ink and allowed to stand for 24 hours, then wiped with a cloth impregnated with ethanol, and the degree of magic ink remaining on the film surface was visually confirmed. Evaluation: ◎: Magic ink is not recognized at all, ○: A slight amount of magic ink remaining to the extent that there is no practical problem is recognized, △: A slight amount of magic ink remaining that causes a practical problem is recognized And x: Remaining magic ink was recognized to a considerable extent. Table 2 shows the results of the stain resistance test.
[0137]
<Solvent resistance>
A sponge impregnated with methyl ethyl ketone was placed on the film surface of the decorative steel sheet and allowed to stand for 24 hours, and then the degree of discoloration and swelling of the film surface was visually observed. Evaluation: A: No occurrence of discoloration and blistering was observed, ○: Very slight discoloration and blistering were observed with no practical problems, Δ: slight discoloration with practical problems, and The occurrence of blistering was observed, and x: the occurrence of discoloration and blistering was observed to a considerable extent. The results of the solvent resistance test are shown in Table 2.
[0138]
<Vividness>
The sharpness of the film surface of the decorative steel sheet was measured with a portable sharpness gloss meter PGD-4 manufactured by Nippon Color Research Laboratory. The sharpness as used in the present invention means the sharpness of the image, that is, the sharpness of the specularly reflected image on the decorative surface, and the high sharpness means that the sharpness is 0.7 or more. Table 2 shows the sharpness measurement results.
[0139]
[Table 2]

[0140]
As shown in Table 2, the high-definition decorative steel sheet of the present invention exhibits excellent properties in any of adhesion, boiling water resistance, workability, stain resistance, solvent resistance, and sharpness. Especially, it became clear by using PBT as a matrix polyester resin of a base polyester resin layer, showing high definition.
[0141]
(Comparative Example 1-5)
In Comparative Examples 1 and 2, a commercially available 50 μm white film was used.
[0142]
Further, Comparative Example 3-5 is a method similar to the above example using the corresponding titanium dioxide masterbatch, and each resin composition containing no vinyl polymer and rubber elastic body at each final composition ratio shown in Table 3, Dry blended using a V-type blender. The final composition ratio of each resin is as shown in Table 3, and the mixture was melt-kneaded at 260 ° C. with a twin-screw extruder to obtain pellets, which were extruded using the pellets as in Example 1-10. A film having a thickness of 50 μm was obtained with a die (extrusion temperature: 260 ° C.).
[0143]
[Table 3]

[0144]
Similarly to Example 1-10, a commercially available film and the obtained white film were subjected to corona discharge treatment, printed and laminated with a printed 25 μm-thick commercially available biaxially stretched PET film, and did not contain a vinyl polymer or rubber elastic body. A decorative film comprising three layers of a composition layer, a printing layer, and a top layer was obtained.
[0145]
Further, in the same manner as in Example 1-10, after applying this three-layer film and a two-component type polyester-based adhesive (for vinyl chloride resin, adhesive coating thickness after drying 4 μm), the thickness was 450 μm heated to 240 ° C. Is hot-pressed on one side of the hot-dip galvanized steel sheet using a metal mirror roll (film side) and rubber roll (steel side) heated to 190 ° C, and rapidly cooled to 100 ° C or less within 5 seconds by water cooling on the back side of the steel A steel plate was obtained.
[0146]
About the room-temperature decorative steel sheet thus obtained, each of the items of adhesion, boiling water resistance, workability, stain resistance, solvent resistance, and sharpness was evaluated by the same evaluation method as in Example 1-10. Evaluation was performed. The results are shown in Table 4.
[0147]
[Table 4]

[0148]
As shown in Table 4, in Comparative Example 1, shrinkage occurred during laminating, the surface shape was remarkably deteriorated, the yuzu skin appearance was shown, and the required sharpness could not be obtained. Moreover, adhesiveness was not obtained. Also in Comparative Example 2, shrinkage occurred during lamination, the surface shape was remarkably deteriorated, the skin appearance was shown, and the required sharpness could not be obtained. There was no boiling water resistance, and swelling and cracking occurred. In Comparative Example 3, some shrinkage occurred during lamination, the surface shape deteriorated, and high definition could not be obtained. In addition, some blistering occurred in boiling water. In Comparative Example 4, although sharpness was obtained, adhesion was insufficient and peeling was observed during workability. In Comparative Example 5, sufficient sharpness and adhesion were not obtained.
[0149]
(Examples 11 and 12)
PBT [Toray Industries, Inc. Toraycon 1200S] alone, and PBT [Toray Industries, Inc. BPT Toraycon 1200S] and PET [Unitika Ltd. MA-1344] mixed in a mass ratio of 2: 1, Each was extruded to obtain a transparent film having a thickness of 50 μm using a T-die (extrusion temperature 260 ° C.). When arbitrary portions of these obtained transparent films were cut into 10 cm × 10 cm squares (n = 10) and the film samples were heat-treated at 200 ° C. for 10 minutes, the respective shrinkage rates were 10% or less. .
[0150]
The surface tension of these transparent films is 320-380 μN / cm, and the discharge amount (watt density) is about 20-25 W / m on one side.²Corona discharge treatment was performed under the conditions of / min, and the surface tension was set to 500 μN / cm or more. Furthermore, an acrylic polyol (isocyanate cross-linking type) ink was used on one side of these films, and a pattern printing layer and a colored solid printing layer were printed on a gravure rotary press (printing thickness after drying 6-8 μm).
[0151]
The white resin composition film (corona-treated) having the composition of Example 8 shown in Table 1 above, the printed PBT film (Example 11), and the PBT: PET = 2: 1 film (Example 12). A two-component type urethane adhesive is used (the adhesive coating thickness after drying is 6 μm), and dry lamination is performed by a conventional method, and a decorative metal plate laminate consisting of a resin composition film layer, a printing layer, and a transparent resin layer is laminated. Two kinds of printing resin films were obtained.
[0152]
Using these two types of three-layer decorative metal sheet laminated printing resin film, the satin embossed metal roll heated to 240 ° C on the resin composition film layer side and 450 µm thick hot-dip galvanized steel sheet heated to 260 ° C (Film side) and rubber roll (steel plate side) were used for thermocompression bonding, and rapidly cooled to 100 ° C. or less within 5 seconds by water cooling on the back surface of the steel plate to obtain a decorative steel plate having a satin embossed appearance.
[0153]
About the decorative steel sheet having an embossed appearance at room temperature obtained in this way, according to the evaluation methods shown in Examples 1 to 10, each item of adhesion, boiling water resistance, workability, contamination resistance, solvent resistance, and The embossability was evaluated. In addition, about the embossing property, the quality of the embossing property of the film surface of a decorative steel plate was judged by visual observation and judged according to the following three-stage criteria. ○: Good, Δ: Somewhat bad, ×: Bad. The results are shown in Table 5.
[0154]
(Examples 13 and 14)
A decorative resin sheet laminating printing resin film (transparent resin PBT film (Example 13) and PBT: PET = 2: 1 film (Example 14)) composed of two types of three layers shown in Examples 11 and 12 was used. A liquid type polyester adhesive (for vinyl chloride resin, adhesive thickness after drying 4 μm) was applied and heated to 210 ° C. and bonded to one side of a 450 μm thick hot-dip galvanized steel sheet using a rubber roll-rubber roll. After heating the steel plate to 230 ° C or higher in a heating oven, it is embossed with a satin embossing roll with a surface temperature of 30 ° C and rapidly cooled to 100 ° C or less within 5 seconds by backside water cooling to obtain a decorative steel plate having a satin embossed appearance. It was.
[0155]
About the decorative steel sheet having an embossed appearance at room temperature thus obtained, each of the items of adhesion, boiling water resistance, workability, stain resistance, solvent resistance, and embossability as in Examples 11 and 12 Was evaluated. The results are shown in Table 5.
[0156]
[Table 5]

[0157]
As shown in Table 5, the embossed decorative steel sheet of the present invention exhibits excellent properties in all of adhesion, boiling water resistance, workability, stain resistance, solvent resistance, and embossability.
[0158]
【The invention's effect】
According to the present invention, a printing material for laminating high-design decorative metal plates that uses a resin material having no environmental impact and has excellent properties such as adhesion to a substrate metal plate, molding processability, scratch resistance, and boiling water resistance. A resin film and a highly-designed decorative metal plate coated therewith are provided. Not a chlorinated resin with a large environmental load, but a polyolefin resin that has problems with scratch resistance and whitening resistance, and a polyester resin with excellent mechanical properties, heat resistance, chemical resistance, optical properties, workability, etc. The printed resin film for laminating high-design decorative metal plates of the present invention is based on the high-definition property when laminating a resin film on a metal plate by finely dispersing a stretching stress relaxation agent in a polyester resin film. Even in heat treatment for application, heat treatment during embossing, and use in a high-temperature and high-humidity environment, it has a feature of absorbing shape stress and having shape stability. Further, when a rubber elastic body is used as the stretching stress relaxation agent, it is encapsulated with a vinyl polymer, so that the adhesion with a metal plate or a printing layer is improved.

Claims (9)

Polyester resin layer and printing layer and polyethylene terephthalate, modified polyethylene terephthalate, polybutylene terephthalate, modified polybutylene terephthalate, or a mixture of two or more of these, or polycarbonate, polyarylate, polystyrene, styrene-styrene derivative copolymer A laminate of high-design decorative metal plates, wherein transparent protective layers made of resin are laminated in this order, and a stretch stress relaxation agent having an equivalent sphere equivalent diameter of 1 μm or less is finely dispersed in the polyester resin layer Printing resin film.   The polyester resin layer is obtained by finely dispersing a rubber-like elastic resin (B) as a stretching stress relaxation agent in a polyester resin (A) as a matrix, and at least a part of the rubber-like elastic resin (B). The printed resin film for laminating a high-design decorative metal sheet according to claim 1, which has a structure encapsulated with a vinyl polymer (C) having a polar group. The polyester resin layer of the matrix resin is polyethylene terephthalate, modified polyethylene terephthalate, polybutylene terephthalate, modified polybutylene terephthalate, or a high design decorative metal plate laminating printing resin film according to claim 1 or 2, wherein a combination thereof. The printing resin for high-design decorative metal sheet lamination according to any one of claims 1 to 3 , wherein the transparent protective layer is composed of a transparent resin film having a shrinkage rate of 20% or less at a temperature lower than the melting point by 100 to 10 ° C. the film. High design decorative metal plate printing resin film for lamination according to any one of claims 1-4 glass transition temperature of the amorphous resin film that is at 100 ° C. or more of the transparent protective layer. Wherein a transparent protective layer is a crystalline resin film, any claim 1-4 Crystallinity a glass transition temperature of 100 ° C. or higher or is a film of the crystalline resin is more than 10% of saturation crystallization ratio 2. A printed resin film for laminating a high-design decorative metal sheet according to item 1. 4. The printed resin film for high-design decorative metal plate lamination according to any one of claims 1 to 3 , wherein the transparent protective layer is biaxially stretched polyethylene terephthalate. A high-design decorative metal plate, characterized in that the surface of the metal plate is coated with the printed resin film for laminating a high-design decorative metal plate according to any one of claims 1 to 7 . A high-definition decorative metal plate having a structure in which the surface of the metal plate is coated with the printed resin film for laminating a high-design decorative metal plate according to any one of claims 1 to 7 .