JP3913876B2 - Discolorable laminate - Google Patents

Description

湿式法微粒子状珪酸は、以下に示されるように、珪酸が縮合して長い分子配列を形成した、所謂、二次元構造部分を有している。従って、前記乾式法微粒子状珪酸と比較して分子構造が粗になるため、湿式法微粒子状珪酸を多孔質層に適用した場合、乾式法微粒子状珪酸を用いる系と比較して乾燥状態における光の乱反射性に優れ、よって、常態での隠蔽性が大きくなるものと推察される。
【化２】

又、前記多孔質層に含まれる低屈折率顔料は、吸液する媒体が主に水であることから、湿式法微粒子状珪酸は乾式法微粒子状珪酸に比べて粒子表面にシラノール基として存在する水酸基が多く、従って、適度の親水性を有するため好適に用いられる。
【０００９】
前記湿式法微粒子状珪酸を低屈折率顔料として用いる場合、湿式法微粒子状珪酸の種類、粒子径、比表面積、吸油量等の性状に左右されるが、常態での隠蔽性と吸液状態での透明性を共に満足するためには、塗布量が１ｇ／ｍ^２〜３０ｇ／ｍ^２であることが好ましく、より好ましくは、５ｇ／ｍ^２〜２０ｇ／ｍ^２である。１ｇ／ｍ^２未満では、常態で十分な隠蔽性を得ることが困難であり、又、３０ｇ／ｍ^２を越えると吸液時に十分な透明性を得ることが困難である。
前記低屈折率顔料はバインダー樹脂を結合剤として含むビヒクル中に分散され、対象物に塗布した後、揮発分を乾燥させて多孔質層を形成する。
【００１０】
前記の如くして形成される多孔質層中には、従来より公知の二酸化チタン被覆雲母、酸化鉄−二酸化チタン被覆雲母、酸化鉄被覆雲母、グアニン、絹雲母、塩基性炭酸鉛、酸性砒酸鉛、オキシ塩化ビスマス等の金属光沢顔料を添加したり、一般染料や顔料、蛍光染料や顔料を添加して色変化を多様にすることもできる。
更に、温度変化により可逆的に色変化する可逆熱変色性材料を多孔質層中に含有させたり、可逆熱変色性材料を含む可逆熱変色層を配設することもできる。
【００１１】
前記可逆熱変色層の形成に用いられる可逆熱変色性材料には、例えば、電子供与性呈色性有機化合物、電子受容性化合物及び前記両者の呈色反応を可逆的に生起させる有機化合物媒体の三成分を含む可逆熱変色性組成物、液晶、Ａｇ_２ＨｇＩ_４、Ｃｕ_２ＨｇＩ_４等が用いられる。
前記電子供与性呈色性有機化合物と電子受容性化合物と呈色反応を可逆的に生起させる有機化合物媒体の三成分を含む可逆熱変色性組成物として、具体的には、特公昭５１−３５４１４号公報、特公昭５１−４４７０６号公報、特公昭５１−４４７０８号公報、特公昭５２−７７６４号公報、特公平１−２９３９８号公報、特開平７−１８６５４６号公報等に記載のものが挙げられる。前記は所定の温度（変色点）を境としてその前後で変色し、変化前後の両状態のうち常温域では特定の一方の状態しか存在しえない。即ち、もう一方の状態は、その状態が発現するのに要する熱又は冷熱が適用されている間は維持されるが、前記熱又は冷熱の適用がなくなれば常温域で呈する状態に戻る、所謂、温度変化による温度−色濃度について小さいヒステリシス幅（ΔＨ）を示して変色するタイプである。
【００１２】
又、本出願人が提案した特公平４−１７１５４号公報、特開平７−１７９７７７号公報、特開平７−３３９９７号公報等に記載されている大きなヒステリシス特性を示して変色する感温変色性色彩記憶性組成物、即ち、温度変化による着色濃度の変化をプロットした曲線の形状が、温度を変色温度域より低温側から温度を上昇させていく場合と逆に変色温度域より高温側から下降させていく場合とで大きく異なる経路を辿って変色するタイプの変色材であり、低温側変色点と高温側変色点の間の常温域において、前記低温側変色点以下又は高温側変色点以上の温度で変化させた状態を記憶保持できる特徴を有する可逆熱変色性組成物も有効である。
【００１３】
前記した電子供与性呈色性有機化合物と電子受容性化合物と呈色反応を可逆的に生起させる有機化合物媒体の三成分を含む可逆熱変色性組成物は、そのままの適用でも有効であるが、マイクロカプセルに内包したマイクロカプセル顔料として使用することが好ましい。即ち、種々の使用条件において可逆熱変色性組成物は同一の組成に保たれ、同一の作用効果を奏することができるからである。
前記マイクロカプセルに内包させることにより、化学的、物理的に安定な顔料を構成でき、粒子径０．１〜１００μｍ、好ましくは１〜５０μｍ、より好ましくは２〜３０μｍの範囲が実用性を満たす。
尚、マイクロカプセル化は、従来より公知の界面重合法、ｉｎ Ｓｉｔｕ重合法、液中硬化被覆法、水溶液からの相分離法、有機溶媒からの相分離法、融解分散冷却法、気中懸濁被覆法、スプレードライング法等があり、用途に応じて適宜選択される。更にマイクロカプセルの表面には、目的に応じて更に二次的な樹脂皮膜を設けて耐久性を付与させたり、表面特性を改質させて実用に供することもできる。
【００１４】
前記可逆熱変色性組成物（好適にはマイクロカプセル顔料）は、膜形成材料である樹脂を含むビヒクル中に分散されて、インキ、塗料等の色材として塗布され可逆熱変色層を形成させることができる。又、熱可塑性樹脂や熱硬化性樹脂中に分散してシート状或いはその他各種形態に成形され、それ自体が可逆熱変色層を備えた層として適用することもできる。
尚、非熱変色性の一般染料や顔料、蛍光染料や顔料等を前記熱変色層中に混在させて多彩に変色させることもできる。
【００１５】
前記ビヒクル中に含まれる樹脂は透明状の膜形成樹脂が好適であり、以下に例示する。
アイオノマー樹脂、イソブチレン−無水マレイン酸共重合樹脂、アクリロニトリル−アクリリックスチレン共重合樹脂、アクリロニトリル−スチレン共重合樹脂、アクリロニトリル−ブタジエン−スチレン共重合樹脂、アクリロニトリル塩素化ポリエチレン−スチレン共重合樹脂、エチレン−塩化ビニル共重合樹脂、エチレン−酢酸ビニル共重合樹脂、エチレン−酢酸ビニル−塩化ビニルグラフト共重合樹脂、塩化ビニリデン樹脂、塩化ビニル樹脂、塩素化塩化ビニル樹脂、塩化ビニル−塩化ビニリデン共重合樹脂、塩素化ポリエチレン樹脂、塩素化ポリプロピレン樹脂、ポリアミド樹脂、高密度ポリエチレン樹脂、中密度ポリエチレン樹脂、リニヤ低密度ポリエチレン樹脂、ポリエチレンテレフタレート樹脂、ポリブチレンテレフタレート樹脂、ポリカーボネート樹脂、ポリスチレン樹脂、ハイインパクトポリスチレン樹脂、ポリプロピレン樹脂、ポリメチルスチレン樹脂、ポリアクリル酸エステル樹脂、ポリメチルメタクリレート樹脂、エポキシアクリレート樹脂、アルキルフェノール樹脂、ロジン変性フェノール樹脂、ロジン変性アルキド樹脂、フェノール変性アルキド樹脂、エポキシ変性アルキド樹脂、スチレン変性アルキド樹脂、アクリル変性アルキド樹脂、アミノアルキド樹脂、塩化ビニル−酢酸ビニル樹脂、スチレン−ブタジエン樹脂、エポキシ樹脂、不飽和ポリエステル樹脂、ポリウレタン樹脂、酢酸ビニル系エマルジョン樹脂、スチレン−ブタジエン系エマルジョン樹脂、アクリル酸エステル系エマルジョン樹脂、水溶性アルキド樹脂、水溶性メラミン樹脂、水溶性尿素樹脂、水溶性フェノール樹脂、水溶性エポキシ樹脂、水溶性ポリブタジエン樹脂、酢酸セルローズ、硝酸セルローズ、エチルセルローズ等を挙げることができる。
【００１６】
前記支持体としては、織物、編物、組物、不織布等の布帛以外に、紙、合成紙、合成皮革、レザー、プラスチック、ガラス、陶磁器、木材、石材等が挙げられ、すべて有効である。
布帛を支持体とする場合、前記多孔質層の皮膜形成性の点で、布帛表面の平滑性に優れる織物が好適に用いられる。布帛表面の平滑性が悪い場合や、インキ等の布帛内部への浸透性が大きく、前記多孔質層の皮膜形成性が悪い場合には、布帛にはっ水加工等の処理を施すことにより、前記多孔質層の皮膜形成性を向上させることができる。
【００１７】
前記多孔質層及び可逆熱変色層を形成する方法としては、従来より公知の塗布方法、例えば、スクリーン印刷、オフセット印刷、グラビヤ印刷、コーター、タンポ印刷、転写等の印刷手段、刷毛塗り、スプレー塗装、静電塗装、電着塗装、流し塗り、ローラー塗り、浸漬塗装、等の手段が挙げられる。
【００１８】
更に本発明の変色性積層体には、必要によって、一般染料や顔料、蛍光染料や顔料を含む非変色性インキを塗布して非変色層を設けたり、二酸化チタン被覆雲母、酸化鉄−二酸化チタン被覆雲母、酸化鉄被覆雲母、グアニン、絹雲母、塩基性炭酸鉛、酸性砒酸鉛、オキシ塩化ビスマス等の金属光沢顔料を含むインキを塗布して金属光沢層を設けることもできる。
又、保護層や光安定剤層を適宜設けることもできる。具体的には、前記光安定剤層は紫外線吸収剤、酸化防止剤、老化防止剤、一重項酸素消光剤、スーパーオキシドアニオン消光剤、オゾン消色剤、可視光線吸収剤、赤外線吸収剤から選ばれる光安定剤を分散状態に固着した層である。
尚、帯電防止剤、極性付与剤、揺変性付与剤、消泡剤等を必要に応じ、各層に添加して機能を向上させることもできる。
【００１９】
次に、本発明の変色性積層体の構成と乾燥状態（非吸液状態）及び水等を吸液した状態の変化について説明する。
前述のように、本発明の変色性積層体は、支持体上に積層されてなる低屈折率顔料とバインダー樹脂を含有する多孔質層が、乾燥時には隠蔽性を有して下層を隠蔽し、水等を吸液した状態で透明又は半透明化して下層を顕出させる。従って、支持体が単一色であっても、筆、刷毛、ペン、スタンプ等を用いて多孔質層を部分的に濡らすことにより、濡れた部分が透明又は半透明化して下層の色調が視認され、所望の像を現出させることができる。
前記多孔質層中の水が蒸発、乾燥すると再び多孔質層が下層を隠蔽して元の状態に戻る。よって、支持体上に図柄や多色柄を設けて多孔質層で隠蔽することは勿論、多孔質層が吸液により透明化した状態で視認される図柄と関連或いは一体化する図柄を多孔質層上に設けて、吸液状態で前記図柄どうしが組み合わさった像を視認させることも可能である。
又、一般顔料等を添加して着色した多孔質層により図柄を形成することも可能であり、多孔質層が吸液して透視される支持体の色調によって視覚的に判別不可能となるように、前記多孔質層の色調を設定することもできる。
更に、透明性を有する支持体として、例えば、透明性立体物に多孔質層を設け、前記多孔質層が吸液により透明化して立体物自体を透視することもできる。
【００２０】
更に、本発明の変色性積層体に可逆熱変色層を配設する場合には、可逆熱変色層の色変化、変色温度及び変色タイプのそれぞれの組み合わせにより、さらに多彩な変化が可能となる。
又、可逆熱変色層と前記多孔質層を含む変色性積層体の構成としては、（Ａ）支持体上に可逆熱変色層を設け、該可逆熱変色層上に多孔質層を積層（可逆熱変色層自体が支持体であってもよい。）、（Ｂ）支持体上に多孔質層を設け、該多孔質層上に可逆熱変色層を積層、（Ｃ）多孔質層と可逆熱変色層が非積層状態で支持体上に併設、等が挙げられる。尚、前記の構成における可逆熱変色層は、有色から無色の可逆的熱変色、有色（１）から有色（２）の可逆的熱変色のいずれであってもよく、非変色層上に有色から無色に変色する可逆熱変色層を設けて有色（１）から有色（２）へとの可逆的に変色したように視覚させる構成であってもよい。
【００２１】
前記（Ａ）の構成の場合、可逆熱変色層の変色点を含まない温度域の水等の媒体を付着させると、多孔質層に媒体が浸透して透明化し、下層の可逆熱変色層による色調が視認される。
一方、可逆熱変色層の変色点を含む温度域の水等の媒体を付着させると、多孔質層に媒体が浸透して透明化すると共に、下層の可逆熱変色層を変色させる。
又、具体例として、体温により変色する変色点を有する可逆熱変色層を設け、前記可逆熱変色層の変色点を含まない水等の媒体を付着させて多孔質層を透明化状態となした後、手触により可逆熱変色層を変色させることができ、非熱変色層との併用等により更に多彩な変色を示す。
【００２２】
次に、（Ｂ）の構成の場合について説明すると、多孔質層に水等の媒体が浸透するためには、上層に設けた可逆熱変色層も水媒体が浸透する性質を有する層であることが好ましい。
可逆熱変色層が有色から無色に可逆的に変色し、環境温度において発色状態の場合は、前記組成物が変色する温度域の水等の媒体を変色体に付着させると、可逆熱変色層が消色すると共に多孔質層も透明化して支持体の色調が視認される。 又、手触したり、温風、冷風等を吹きつける等、水等の媒体を付着させずに加温、又は冷却すると、可逆熱変色層が消色して多孔質層の色調が視認される。
更に、可逆熱変色層が有色から無色に可逆的に変色し、環境温度において消色状態の場合は、可逆熱変色層の変色点を含まない温度域の水等の媒体を付着させると多孔質層が透明化して支持体の色調が視認され、前記可逆熱変色層が変色する温度域の媒体を変色体に付着させると、熱変色層が発色状態で視認される。
尚、前記した構成における可逆熱変色層は、有色から無色に可逆的に変色するものが好適である。
【００２３】
（Ｃ）の構成の場合には、可逆熱変色層と多孔質層の両者が常態で視認され、乾燥状態では、可逆熱変色層の部分のみが温度変化によって変色し、可逆熱変色層の変色点を含まない温度域の水等の媒体を付着させると、多孔質層の部分は媒体が浸透して透明化し、支持体上の色調が視認される。
一方、可逆熱変色層の変色点を含む温度域の水等の媒体を付着させると、可逆熱変色層の部分が変色するとともに、多孔質層も媒体が浸透して透明化し、支持体上の色調が視認される。
特に、両層を近接配置することにより、前記のように、熱及び水のいずれかによって変色させることができ、変色手段の多様化、其に伴う多彩化とが相まって玩具性、意匠的効果を高める。
【００２４】
又、支持体上に可逆熱変色性組成物及び低屈折率顔料を含む可逆熱変色性多孔質層を設けることもできる。前記構成によって、可逆熱変色性組成物が有色から無色に可逆的に変色し、環境温度において発色状態の場合は、前記組成物が変色する温度域の媒体を積層体に付着させると、支持体の色調が視認される。又、手触したり、温風、冷風等を吹きつける等、媒体を付着させずに加温、又は冷却すると、可逆熱変色性組成物が消色して低屈折率顔料の色調が視認される。
更に、可逆熱変色性組成物が有色から無色に可逆的に変色し、環境温度において消色状態の場合は、可逆熱変色性組成物を変色させることのない温度域の媒体を積層体に付着させると支持体の色調が視認され、前記組成物が変色する温度域の媒体を積層体に付着させると、発色した組成物の色調が視認される。尚、前記した構成における可逆熱変色性組成物は、有色から無色に可逆的に変色する組成物が好適に用いられる。
【００２５】
可逆熱変色層として、前記の温度変化による温度−色濃度について大きなヒステリシス幅（ΔＨ）を示して変色するタイプの可逆熱変色性材料を用いた場合には、可逆熱変色性材料の変色状態を特定温度領域で保持できるため、本発明の変色性積層体の可逆熱変色性材料による変色状態を特定温度領域で保持することが可能であり、本発明の変色性積層体に、更に多様性を付与することができる。
【００２６】
【発明の実施の形態】
前記した積層構造において、多孔質層は必要により文字、記号、図形等の図柄層であってもよい。又、可逆熱変色層や非変色層を介在させたり、上層に設けてもよく、同様に文字、記号、図形等の図柄層であってもよい。
本発明の変色性積層体は平面状に限らず、線状、凹凸状、立体状等、様々な形態が有効である。
前記変色性積層体の具体的な実施形態としては、例えば、ぬいぐるみ、人形、レインコート等の人形用衣装、傘や鞄等の人形用付属品、水鉄砲の標的、車や船を模した模型、人間と人形の手形や足形等の形跡を現すボード等の玩具類、水筆紙、水筆シート等の教習具類、文房具類、ドレス、水着、レインコート等の衣類、雨靴等の靴類、防水加工を施した本、カレンダー等の印刷物類、スタンプカード、パズル、各種ゲーム等の娯楽用具類、ウェットスーツ、浮袋、水泳用浮板等の遊泳又は潜水用具類、コースター、コップ等の台所用具類、その他、傘、造花、当りくじ等が挙げられる。
又、各種インジケーターとして適用することもでき、例えば、配管、パイプ、水槽、タンク等の液洩れ検知、禁水性薬品の輸送や保管場所での水濡れ検知、結露、降雨等の検知、使い捨ておむつの尿の検知、各種容器やプールの液量、水深検知、土壌中の水分検知等が挙げられる。
【００２７】
【実施例】
以下に実施例を示す。尚、実施例中の部は重量部を示す。
実施例１（図１参照）
支持体２として白色のナイロンタフタ生地を用い、前記生地上にピンク色蛍光顔料〔商品名：エポカラーＦＰ−１０、（株）日本触媒製〕１０部、水性アクリル酸エステルエマルジョン樹脂（固形分５０％）５０部、シリコーン系消泡剤０．２部、増粘剤５部、レベリング剤１部、水１０部、エポキシ系架橋剤２．５部を均一に混合攪拌してなる蛍光ピンク色のスクリーン印刷用インキにて、１５０メッシュのスクリーン版を用いて全面にベタ印刷を行い、１３０℃で５分間乾燥、硬化させて非変色層４を形成した。
次いで、低屈折率顔料として湿式法微粒子状珪酸〔商品名：ニップシールＥ−２００Ａ、日本シリカ工業（株）製〕１５部、バインダー樹脂として水性ウレタン樹脂〔商品名：ハイドランＡＰ−１０、ポリエステル系ウレタン樹脂、固形分３０％、大日本インキ化学工業（株）製〕５０部、水３０部、シリコーン系消泡剤０．５部、水系インキ用増粘剤３部、エチレングリコール１部、ブロックイソシアネート系架橋剤２部を均一に混合攪拌してなる白色スクリーン印刷用インキにて、１８０メッシュのスクリーン版を用いて、前記非変色層４上の全面にベタ印刷し、１３０℃で５分間乾燥、硬化させて、乾燥状態で白色の多孔質層３を形成して変色性積層体１を得た。
前記変色性積層体１は乾燥状態で白色を呈して下層を十分に隠蔽しており、又、水に濡らした時の透明性にも優れ、蛍光ピンク色が鮮明に視認された。
又、前記水で濡らした変色性積層体を室温下に放置したところ、水が蒸発するに従い、徐々に蛍光ピンク色から白色に戻り、乾燥状態に戻ると元の白色となった。
【００２８】
実施例２
実施例１の多孔質層形成用の白色スクリーン印刷用インキのバインダー樹脂を水性ウレタン樹脂〔商品名：ハイドランＡＰ−１０、大日本インキ化学工業（株）製〕２５部及び水性アクリル酸エステルエマルジョン樹脂（固形分５０％）１５部に替えて、水を４０部にした以外は同様にして変色性積層体を得た。
前記変色性積層体は実施例１と同様に乾燥状態で白色を呈して下層を十分に隠蔽しており、又、水に濡らした時の透明性にも優れ、蛍光ピンク色が鮮明に視認された。
【００２９】
実施例３
実施例１の多孔質層形成用の白色スクリーン印刷用インキのバインダー樹脂を水性ウレタン樹脂〔商品名：ハイドランＡＰ−１０、大日本インキ化学工業（株）製〕１５部及び水性アクリル酸エステルエマルジョン樹脂（固形分５０％）２１部に替えて、水を４４部にした以外は同様にして変色性積層体を得た。
前記変色性積層体は実施例１と同様に乾燥状態で白色を呈して下層を十分に隠蔽しており、又、水に濡らした時の透明性にも優れ、蛍光ピンク色が鮮明に視認された。
【００３０】
実施例４
実施例１の多孔質層形成用の白色スクリーン印刷用インキの低屈折率顔料を湿式法微粒子状珪酸〔商品名：ニップシールＥ−７４Ｐ、日本シリカ工業（株）製〕に替えた以外は同様にして変色性積層体を得た。
前記変色性積層体は実施例１と同様に乾燥状態で白色を呈して下層を十分に隠蔽しており、又、水に濡らした時の透明性にも優れ、蛍光ピンク色が鮮明に視認された。
【００３１】
実施例５
支持体として、白色のポリエステルサテン生地上に、黄色、ピンク色、緑色、紫色、赤色の蛍光色スクリーン印刷用インキにて、スクリーン印刷し、花柄の非変色層を形成した。
次いで、低屈折率顔料として、湿式法微粒子状珪酸〔商品名：ニップシールＥ−７４Ｐ、日本シリカ工業（株）製〕１５部、バインダー樹脂として水性ウレタン樹脂〔商品名：ネオタンＵＥ−１３００、ポリカーボネート系ウレタン樹脂、固形分４０％、東亜合成（株）製〕３７．５部、水４２．５部、シリコーン系消泡剤０．５部、水系インキ用増粘剤３部、エチレングリコール１部、ブロックイソシアネート系架橋剤２部を均一に混合攪拌してなる白色スクリーン印刷用インキを１８０メッシュのスクリーン版を用いて、前記非変色層上に全面にベタ印刷し、１３０℃にて５分間乾燥硬化させて、乾燥状態で白色の多孔質層を形成し、変色性積層体を得た。
前記変色性積層体は、乾燥状態では白色の多孔質層が視認されるが、水を付着させると、多孔質層が透明化して、支持体上の花柄が鮮明に視認され、乾燥するに従って多孔質層が不透明化し、完全に乾燥すると再び多孔質層が白色となり、支持体上の花柄が隠蔽された。
前記の操作は、変色性積層体の皮膜を劣化させることなく、繰り返し再現することができた。
【００３２】
実施例６（図２参照）
支持体２として青色に着色されたポリエステルシート（シート厚み：５０μｍ）上に、低屈折率顔料として湿式法微粒子状珪酸〔商品名：ニップシールＥ−１０１１、日本シリカ工業（株）製〕１５部、バインダー樹脂として水性ウレタン樹脂〔商品名：パーマリンＵＡ−１５０、ポリエーテル系ウレタン樹脂、固形分３０％、三洋化成工業（株）製〕５０部、ピンク色水性顔料分散体〔商品名：ＴＣ Ｒｕｂｉｎ ＦＲ−Ｈ、顔料分２６〜３１％、大日本精化工業（株）製〕１部、水３０部、シリコーン系消泡剤０．５部、水系インキ用増粘剤３部、エチレングリコール１部、ブロックイソシアネート系架橋剤２部を均一に混合攪拌してなるピンク色スクリーン印刷用インキを１８０メッシュのスクリーン版を用いて、全面にベタ印刷し、１３０℃にて５分間乾燥硬化させて、乾燥状態でピンク色の多孔質層３を形成し、変色性積層体１を得た。
前記変色性積層体１は、乾燥状態では多孔質層３のピンク色を呈しているが、水を付着させると、多孔質層３が水で濡れることにより透明化し、支持体２の青色と多孔質層３のピンク色が混色となった紫色が鮮明に視認された。前記水に濡れた変色性積層体１を室温下に放置したところ、水が蒸発するに従い、徐々に紫色からピンク色に戻り、乾燥状態に戻ると元のピンク色となった。
【００３３】
実施例７（図３参照）
支持体２としてＡＢＳ樹脂で射出成形した白色のミニチュアカーのボンネット部分にＡＢＳ樹脂用の油性緑色塗料を用いてローマ字の「Ａ」をスプレー塗装して非変色層４を形成した。
低屈折率顔料として湿式法微粒子状珪酸〔商品名：ニップシールＥ−１０１１、日本シリカ工業（株）製〕１５部、バインダー樹脂として水性ウレタン樹脂〔商品名：パーマリンＵＡ−１５０、ポリエーテル系ウレタン樹脂、固形分３０％、三洋化成工業（株）製〕５０部、水３０部、シリコーン系消泡剤０．５部、ブロックイソシアネート系架橋剤２部を均一に混合攪拌してなる白色水性スプレー塗料を、前記非変色層４上にスプレー塗装して多孔質層３を形成し、更に７０℃にて３０分間乾燥硬化させ、ミニチュアカー形態の変色性積層体１を得た。
前記ミニチュアカーは、乾燥状態では全体が白色であるが、ボンネット部分に水を付着させると、多孔質層３が水で濡れることにより透明化し、緑色の「Ａ」の文字が視認された。前記ミニチュアカーを室温下に放置したところ、水が蒸発するに従い、ボンネット部分の「Ａ」の文字が緑色から白色になり、乾燥状態に戻ると元の白色となった。
前記の操作は、変色性積層体１の多孔質層の皮膜を劣化させることなく、繰り返し再現することができた。
【００３４】
実施例８（図４参照）
支持体２として白色のポリエステルタフタ生地上に、感温変色性色彩記憶性組成物を内包したマイクロカプセル顔料（橙色←→無色、１５℃以下で橙色、３０℃以上で無色）１０部、ピンク色蛍光顔料〔商品名：エポカラーＦＰ−１０、（株）日本触媒製〕１部、水性アクリル酸エステルエマルジョン樹脂（固形分５０％）１０部、シリコーン系消泡剤０．２部、水１部、エチレングリコール０．５部、増粘剤０．５部、イソシアネート系架橋剤０．５部を均一に混合攪拌してなる可逆熱変色性スクリーンインキ（赤色←→ピンク色、１５℃以下で赤色、３０℃以上でピンク色）を１０９メッシュのスクリーン版を用いて全面にベタ印刷を行ない、１３０℃にて５分間乾燥硬化させて可逆熱変色層５を形成した。
尚、前記可逆熱変色層５は、１５℃以下に冷却すると赤色が視覚され、この色調は３０℃未満の温度域で保持され、又、３０℃以上に加温するとピンク色になり、この色調は１５℃を越える温度域で保持される。
次いで、実施例１で作製した多孔質層形成用の白色スクリーン印刷用インキを１８０メッシュのスクリーン版を用いて、前記可逆熱変色層５上に全面にベタ印刷し、１３０℃にて５分間乾燥硬化させて、乾燥状態で白色の多孔質層３を形成し変色性積層体１を得た。
前記多孔質層３は、水もしくは水溶性液体の付着により、白色状態から無色透明状態に変化する。
【００３５】
前記変色性積層体１は、乾燥状態では白色を呈し、冷却或いは加温しても同様に白色のままであるが、１５℃以下の冷水を付着させると多孔質層３が水の付着により透明化して、下層の可逆熱変色層５による赤色に瞬時に変化した。前記赤色の変色性積層体１を２４℃の室温下で放置したところ、水が付着した状態では、赤色を呈していたが、水が蒸発するに従い、徐々に赤色から白色に戻り、乾燥状態に戻ると元の白色となった。
次に、前記変色性積層体１に３０℃以上の温水を付着させると、多孔質層３が水の付着により透明化すると共に、可逆熱変色層５が赤色から蛍光ピンク色に変色して蛍光ピンク色が視認された。
前記変色性積層体１を水が付着した状態で、２４℃の室温下に放置したところ、蛍光ピンク色を呈していたが、水が蒸発するに従い、徐々に蛍光ピンク色から白色に戻り、乾燥状態に戻ると元の白色となった。
次に、乾燥状態の変色性積層体１に１５℃以下の冷水を付着させて赤色に変色させた状態で、前記変色性積層体１の一部分に３０℃以上の温水を付着させると赤色からピンク色に変化し、この状態は水が蒸発して乾燥状態になるまでの間、赤色とピンク色の両状態を保持していた。
この様に、前記変色性積層体１は、全面が白色の状態から冷水又は温水の適用により、赤色、或いは蛍光ピンク色に変化させることができ、乾燥させることにより、再び元の白色状態に戻すことができる多彩な色変化を示し、前記様相変化は多孔質層３の皮膜を劣化させること無く、繰り返し再現させることができた。
【００３６】
実施例９（図５参照）
支持体２として白色のポリエステルサテン生地上に、黄色蛍光顔料〔商品名：エポカラーＦＰ−１１７、（株）日本触媒製〕１０部、水性アクリル酸エステルエマルジョン樹脂（固形分５０％）５０部、シリコーン系消泡剤０．２部、増粘剤５部、レベリング剤１部、水１０部、エポキシ系架橋剤２．５部を均一に混合攪拌してなる蛍光黄色のスクリーン印刷用インキで、１５０メッシュのスクリーン版を用いて全面にベタ印刷を行い、１３０℃にて５分間乾燥硬化させて非変色層４を形成した。
次いで前記非変色層４上に、可逆熱変色性組成物を内包したマイクロカプセル顔料（ピンク色←→無色、１５℃未満でピンク色、１５℃以上で無色）１０部、水性アクリル酸エステルエマルジョン樹脂（固形分５０％）１０部、シリコーン系消泡剤０．２部、水１部、エチレングリコール０．５部、増粘剤０．５部、イソシアネート系架橋剤０．５部を均一に混合攪拌してなる可逆熱変色性スクリーンインキで１０９メッシュのスクリーン版を用いて、花の図柄を印刷し、１３０℃にて５分間乾燥硬化させ、可逆熱変色層５を形成した。
非変色層４と可逆熱変色層５を積層した前記状態では、１５℃以上の室温下では非変色層４により全面が蛍光黄色であり、１５℃未満の温度に冷却すると、可逆熱変色層５がピンク色に発色して、黄色地の中に赤色の花柄が視認され、再び１５℃以上の温度に加温すると可逆熱変色層５が消色して全面が蛍光黄色になる。
前記可逆熱変色層５の上面に、実施例１で作製した多孔質層形成用の白色スクリーン印刷用インキを用いて全面にベタ印刷し、乾燥硬化させて多孔質層３を形成して変色性積層体１を得た。
前記多孔質層３は、水もしくは水溶性液体の付着により、白色状態から無色透明状態に変化する。
【００３７】
前記変色性積層体１は、乾燥状態では白色を呈し、冷却或いは加温しても同様に白色のままであるが、１５℃以上の水を付着させると、多孔質層３が透明化すると共に可逆熱変色層５が無色になるため、全面が黄色となり、２４℃の室温下で放置すると水が蒸発、乾燥して白色に戻った。
次いで、１５℃未満の冷水を付着させると、多孔質層３が透明化すると共に、可逆熱変色層５が無色からピンク色になるため、黄色地の中に赤色の花柄が描かれた様相に変化した。２４℃の室温下で放置すると、１５℃以上の温度になった時点で可逆熱変色層５が消色して全面が黄色になり、暫くその状態を示していたが、乾燥すると白色に戻った。
この様に、前記変色性積層体１は、全面が白色の状態から冷水又は温水の適用により、全面が黄色、或いは黄色地に赤色の花柄に変化させることができ、乾燥させることにより、再び元の白色状態に戻すことができる多彩な色変化を示し、前記様相変化を多孔質層の皮膜を劣化させること無く、繰り返し再現させることができた。
【００３８】
実施例１０（図６参照）
支持体２として白色の合成紙上に、黄色、ピンク色、紫色、緑色、赤色の合成紙用蛍光一般色インキにて、花柄をスクリーン印刷して非変色層４を設けた。
前記非変色層４上に、可逆熱変色性組成物を内包したマイクロカプセル顔料（黒色←→無色、３２℃未満で黒色、３２℃以上で無色）１０部、水性ウレタン樹脂〔ハイドランＡＰ−１０、ポリエステル系ウレタン樹脂、固形分３０％、大日本インキ化学工業（株）製〕２０部、シリコーン系消泡剤０．４部、水１部、エチレングリコール０．５部、増粘剤１．０部、イソシアネート系架橋剤０．５部を均一に混合攪拌してなる可逆熱変色性スクリーンインキを１０９メッシュのスクリーン版を用いて、全面にベタ印刷を行ない、１３０℃にて５分間乾燥硬化させて可逆熱変色層５を形成した。
前記、非変色層４上に可逆熱変色層５を積層した状態では、３２℃未満の室温下では黒色を呈しており、３２℃以上に加温すると可逆熱変色層５が消色して非変色層４による花柄が視認され、再び３２℃未満の温度になると可逆熱変色層５が黒色に発色して花柄が隠蔽される。
次いで、前記可逆熱変色層５上に実施例１で作製した多孔質層形成用の白色スクリーン印刷用インキを用いて、１５０メッシュのスクリーン版により、蝶の図柄を印刷し、蝶の図柄の多孔質層３を形成して変色性積層体１を得た。
前記多孔質層３は、水もしくは水溶性液体の付着により、白色状態から無色透明状態に変化する。
【００３９】
前記変色性積層体１は、３２℃未満の室温下では、黒色の可逆熱変色層５上に多孔質層３による白色の蝶の図柄が視認される。前記変色性積層体１を３２℃以上に加温すると、可逆熱変色層５が黒色から無色に変色して、非変色層４による花柄が現出して、花柄に白色の蝶の図柄が描かれた様相となる。再び３２℃未満の温度に冷却すると黒地に白色の蝶の図柄が描かれた様相に戻った。
又、前記変色性積層体１に３２℃未満の水を付着させると、多孔質層３が透明化するため蝶の図柄が消えて全面が黒色となり、２４℃の室温下で放置すると水が蒸発、乾燥するに従って白色の蝶の図柄が現出し、完全に乾燥した状態では、再び黒地に白色の蝶の図柄が視認された。
次いで、３２℃以上の温水を付着させると、多孔質層３が透明化して蝶の図柄が消えると共に、可逆熱変色層５が黒色から無色になるため、非変色層４による花柄のみが視認され、２４℃の室温下で放置すると、３２℃未満の温度になった時点で可逆熱変色層５が発色して花柄が黒色に隠蔽され、暫くその状態を示していたが、乾燥するに従って黒色の可逆熱変色層５上に徐々に白色の蝶の図柄が現出し、完全乾燥すると、黒地上に白色の蝶の図柄が描かれた様相に戻った。
この様に、布帛の温度変化、温水、冷水への浸漬により、黒地に白色の蝶の図柄が描かれた様相、黒色ベタの様相、カラフルな花柄上に白色の蝶の図柄が描かれた様相、カラフルな花柄のみの様相の、４つの様相を現出させることができ、前記様相変化を多孔質層３の皮膜を劣化させること無く、繰り返し再現させることができた。
【００４０】
比較例１
実施例１の多孔質層形成用の白色スクリーン印刷用インキのバインダー樹脂を水性アクリル酸エステルエマルジョン樹脂（固形分５０％）３０部に替えて、水を５０部にした以外は同様にして、変色性積層体を得た。
【００４１】
比較例２
実施例１の多孔質層形成用の白色スクリーン印刷用インキのバインダー樹脂を水性エチレン−酢酸ビニル共重合エマルジョン樹脂（固形分５０％）３０部に替えて、水を５０部にした以外は同様にして、変色性積層体を得た。
【００４２】
比較例３
実施例１の多孔質層形成用の白色スクリーン印刷用インキのバインダー樹脂を水性メタクリル酸メチル−ブタジエン共重合エマルジョン樹脂（固形分５０％）３０部に替えて、水を５０部にした以外は同様にして、変色性積層体を得た。
【００４３】
比較例４
実施例１の多孔質層形成用の白色スクリーン印刷用インキの低屈折率顔料を乾式法微粒子状珪酸〔商品名：アエロジル１３０〔日本アエロジル（株）製〕に替えた以外は同様にして、変色性積層体を得た。
【００４４】
比較例５
実施例１の多孔質層形成用の白色スクリーン印刷用インキの低屈折率顔料を乾式法微粒子状珪酸〔商品名：アエロジルＯＸ−５０〔日本アエロジル（株）製〕に替えた以外は同様にして変色性積層体を得た。
【００４５】
比較例６
実施例６の多孔質層形成用の白色スクリーン印刷用インキのバインダー樹脂を水性アクリル酸エステルエマルジョン樹脂（固形分５０％）３０部に替えて、水を５０部にした以外は同様にして、変色性積層体を得た。
【００４６】
以下に実施例１〜４、６及び比較例１〜３、６の多孔質層の摩擦試験機による耐擦過性試験の結果を表に示す。
【００４７】
【表１】

【００４８】
耐擦過性の評価
◎：擦過による皮膜の劣化がない。
○：擦過によるわずかな皮膜の劣化があるが、実用的な皮膜強度を有する。
△：擦過による皮膜の劣化が大きく、実用的な皮膜強度を有さない。
×：擦過により、多孔質層が消失する。
【００４９】
耐擦過性試験は、摩擦試験機２型（学振型）〔スガ試験機（株）製〕を用い、上部の摩擦子に綿布（かなきん３号、ＪＩＳ Ｌ ０８０３準拠、ＪＩＳ染色堅ろう度試験用）を取り付け、前記摩擦子を７００ｇの荷重下で変色性積層体の試験片上に毎分３０往復の速度で１０ｃｍの間を水平往復運動させることにより、行った（表１において、擦過回数は摩擦子の往復回数を示す。）。
前記耐擦過性試験は、乾燥状態および吸液状態について行い、吸液状態は試験片を水で濡らした状態で行った。
試験結果にみられるように、本発明の変色性積層体は比較例の積層体と比べて良好な耐擦過性を示した。
【００５０】
又、実施例１、４、比較例４、５の乾燥状態での隠蔽性と水に濡らした時の透明性の目視による評価及びＣＩＥ表色系における３刺激値Ｘ、Ｙ、Ｚの測定値を表に示す。
【００５１】
【表２】

【００５２】
目視での乾燥状態での隠蔽性の評価
○：十分な隠蔽性を有する。
△：下層の色調が視認され実用的な隠蔽性が無い。
×：下層の色調が著しく視認される。
目視での水に濡らした時の透明性の評価
○：十分な透明性を有する。
△：下層の色調が不鮮明に視認され実用的な透明性が無い。
×：多孔質層の色調が著しく視認される。
【００５３】
３刺激値Ｘ、Ｙ、Ｚは、色差計ＴＣ−３６００〔東京電色（株）製〕を用いて測定した。
【００５４】
試験結果にみられるように、本発明の変色性積層体は乾燥状態での隠蔽性及び水に濡らした時の透明性共に優れており、水を付着させると多孔質層が水で濡れることにより透明化し、支持体の色調が鮮明に視認された。
【００５５】
【発明の効果】
本発明は、多孔質層中にウレタン系樹脂を含有するため、皮膜耐久性に優れ、且つ、繰り返しの使用によっても乾燥状態での隠蔽性と吸液状態での透明性を損なうことなく有効に機能し、玩具分野、装飾分野、デザイン分野等、多様な分野への実用性に優れた変色性積層体を提供することができる。
【図面の簡単な説明】
【図１】 本発明の変色性積層体の一実施例の縦断面説明図である。
【図２】 本発明の変色性積層体の他の実施例の縦断面説明図である。
【図３】 本発明の変色性積層体の他の実施例の縦断面説明図である。
【図４】 本発明の変色性積層体の他の実施例の縦断面説明図である。
【図５】 本発明の変色性積層体の他の実施例の縦断面説明図である。
【図６】 本発明の変色性積層体の他の実施例の縦断面説明図である。
【符号の説明】
１ 変色性積層体
２ 支持体
３ 多孔質層
４ 非変色層
５ 可逆熱変色層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a discolorable laminate. More specifically, the present invention relates to a discolorable laminate that absorbs a liquid such as water and changes to a state different from the normal state and returns to the normal state again by drying.
[0002]
[Prior art]
Conventionally, a processed paper or sheet has been disclosed in which a porous layer containing a low-refractive index pigment is provided on a support, and the porous layer is made transparent by absorbing liquid to reveal the color tone of the lower layer. (Japanese Patent Publication No. 50-5097, Japanese Patent Publication No. 5-15389).
Although the above-mentioned processed paper and sheet are expected to be applied to various fields such as teaching tools and toys, it is a binder for the pigment component in order to exhibit a unique effect as compared with a conventionally known general coating film. Since it is necessary to reduce the mixing ratio of the resin, it is difficult to obtain film durability such as washing resistance and scratch resistance. Therefore, it has been difficult to apply to applications requiring durability, such as doll costumes in the toy field and swimwear in the clothing field.
[0003]
[Problems to be solved by the invention]
The present invention provides a discolorable laminate having excellent film durability of a porous layer containing the low refractive index pigment described above, and intends to develop applications in various fields such as toy field, decoration field, and design field. To do.
[0004]
[Means for Solving the Problems]
The present invention provides a support on Refractive index is 1.4-1.7 A laminated body in which a low-refractive-index pigment is fixed in a binder resin in a dispersed state to form a porous layer, and the porous layer is transparent or translucent in a liquid-absorbing state so as to make a visual change. A requirement is a discolorable laminate in which the resin contains at least a urethane-based resin. Furthermore, the solid content ratio of the urethane-based resin in the binder resin is 30% by weight or more, the low refractive index pigment is a particulate silicic acid produced by a wet method, and the fine particles in the porous layer 1-30 g / m of silicic acid ² The support is a fabric, On the support A reversible thermochromic layer is provided. A porous layer is disposed on the reversible thermochromic layer. It is a requirement that
[0005]
The porous layer in which the low refractive index pigment is fixed to the binder resin in a dispersed state has a white state with a concealing property in a normal state, that is, in a dry state, and is transparent or translucent in a state in which a liquid such as water is absorbed. To reveal the color tone of the lower layer.
In the present invention, a urethane resin is used as the binder resin, or at least a urethane resin is contained.
By including a urethane-based resin in the binder resin, the film strength of the porous layer can be improved, and it can be applied to various uses that require durability, and also has concealability and absorption in a dry state. Transparency in the liquid state is not impaired.
Examples of the urethane resin include a polyester urethane resin, a polycarbonate urethane resin, a polyether urethane resin, and the like, and two or more kinds can be used in combination. In addition, a urethane emulsion resin in which the resin is emulsified and dispersed in water, or a colloid that is self-emulsified without the need for an emulsifier due to the ionic groups of the ionic urethane resin (urethane ionomer) itself, and is dissolved and dispersed in water. A dispersion type (ionomer type) urethane resin can also be used.
The urethane-based resin may be either an aqueous urethane-based resin or an oil-based urethane-based resin, but in the present invention, an aqueous urethane-based resin, in particular, a urethane-based emulsion resin or a colloidally dispersed urethane-based resin is suitable. Used for. The urethane resin is preferably used alone, but other binder resins may be used in combination depending on the type of support and the performance required for the coating. When a binder resin other than the urethane resin is used in combination, in order to obtain a practical film strength, it is preferable to contain 30% or more of the urethane resin in a solid content weight ratio in the binder resin of the porous layer.
[0006]
As a binder resin other than the urethane resin, nylon resin, vinyl acetate resin, acrylic ester resin, acrylic ester copolymer resin, acrylic polyol resin, vinyl chloride-vinyl acetate copolymer resin, maleic resin, polyester resin, Styrene resin, styrene copolymer resin, polyethylene resin, polycarbonate resin, epoxy resin, styrene-butadiene copolymer resin, acrylonitrile-butadiene copolymer resin, methyl methacrylate-butadiene copolymer resin, butadiene resin, chloroprene resin, melamine resin, and Examples of the resin emulsion, casein, starch, cellulose derivative, polyvinyl alcohol, urea resin, phenol resin, and epoxy resin.
The binder resin is appropriately selected depending on the properties of the support. For example, when the support is a fabric, a nylon resin or the like is preferably used in addition to the urethane resin.
[0007]
The mixing ratio of the binder resin and the low-refractive index pigment depends on the type and properties of the low-refractive index pigment, but preferably the binder resin solid content is 0.5 to 2 wt. Part, more preferably 0.8 to 1.5 parts by weight. When the binder resin solid content is less than 0.5 parts by weight with respect to 1 part by weight of the low refractive index pigment, it is difficult to obtain a practical film strength of the porous layer, and the content exceeds 2 parts by weight. In this case, the permeability of the liquid into the porous layer is deteriorated.
In the binder resin, the crosslinkable resin can be further improved in film strength by adding an arbitrary crosslinking agent and crosslinking.
The binder resin has a large and small affinity for water. By combining these, the penetration time into the porous material, the degree of penetration, and the slow speed of drying after the penetration can be adjusted. Furthermore, the said adjustment can be controlled by adding a dispersing agent suitably.
[0008]
Examples of the low refractive index pigment include fine particle silicic acid, barite powder, precipitated barium sulfate, barium carbonate, precipitated calcium carbonate, gypsum, clay, talc, alumina white, basic magnesium carbonate, and the like. Is in the range of 1.4 to 1.7 and exhibits good transparency when water or the like is absorbed.
The particle size of the low refractive index pigment is not particularly limited, but 0.03 to 10.0 μm is preferably used.
Two or more of the low refractive index pigments can be used in combination.
In addition, a particulate silica is mentioned as a low refractive index pigment used suitably. Particulate silicic acid is produced as amorphous amorphous silicic acid, and is produced by a dry process using a gas phase reaction such as thermal decomposition of silicon halide such as silicon tetrachloride (hereinafter referred to as dry process particulate silicic acid). And by a wet method using a liquid phase reaction such as decomposition with an acid such as sodium silicate (hereinafter referred to as wet method fine particle silicic acid), and any of them can be used. When wet method fine particle silicic acid is used, since the concealment property in the normal state is larger than that of dry method fine particle silicic acid, it is possible to increase the mixing ratio of the binder resin to the fine particle silicic acid. Since the film strength of the film can be improved, it is more preferably used.
As described above, as the fine particulate silicic acid used for satisfying the normal concealing property of the porous layer, wet method fine particulate silicic acid is preferable. This is because the dry method fine particle silicic acid and the wet method fine particle silicic acid have different structures, whereas the dry method fine particle silicic acid forms a three-dimensional structure in which silicic acid is closely bound as shown below. ,
[Chemical 1]

As shown below, the wet method fine particle silicic acid has a so-called two-dimensional structure part in which a long molecular arrangement is formed by condensation of silicic acid. Accordingly, since the molecular structure is coarser than that of the above-mentioned dry method fine particle silicic acid, when wet method fine particle silicic acid is applied to the porous layer, the light in the dry state compared to the system using the dry method fine particle silicic acid. Therefore, it is presumed that the concealability in the normal state is increased.
[Chemical 2]

Further, since the low refractive index pigment contained in the porous layer is mainly composed of water as the liquid absorbing medium, the wet method fine particle silicic acid is present as a silanol group on the particle surface as compared with the dry method fine particle silicic acid. Since it has many hydroxyl groups and therefore has moderate hydrophilicity, it is preferably used.
[0009]
When the wet method fine particle silicic acid is used as a low refractive index pigment, it depends on the properties of the wet method fine particle silicic acid, the particle diameter, the specific surface area, the oil absorption amount, etc. In order to satisfy the transparency of the coating, the coating amount is 1 g / m ² ~ 30g / m ² And more preferably 5 g / m. ² ~ 20g / m ² It is. 1g / m ² Is less than 30 g / m, it is difficult to obtain sufficient concealability in a normal state. ² If it exceeds the range, it is difficult to obtain sufficient transparency during liquid absorption.
The low refractive index pigment is dispersed in a vehicle containing a binder resin as a binder, and is applied to an object, and then the volatile matter is dried to form a porous layer.
[0010]
In the porous layer formed as described above, conventionally known titanium dioxide-coated mica, iron oxide-titanium dioxide-coated mica, iron oxide-coated mica, guanine, sericite, basic lead carbonate, acidic lead arsenate It is also possible to add a metallic luster pigment such as bismuth oxychloride or to add a general dye or pigment, a fluorescent dye or a pigment to make the color change various.
Furthermore, a reversible thermochromic material that changes color reversibly with temperature changes can be contained in the porous layer, or a reversible thermochromic layer containing a reversible thermochromic material can be provided.
[0011]
Examples of the reversible thermochromic material used for forming the reversible thermochromic layer include an electron donating color-forming organic compound, an electron-accepting compound, and an organic compound medium that reversibly causes a color reaction of the both. Reversible thermochromic composition containing three components, liquid crystal, Ag ₂ HgI ₄ , Cu ₂ HgI ₄ Etc. are used.
As the reversible thermochromic composition comprising the three components of the organic compound medium that reversibly causes a color reaction with the electron-donating color-forming organic compound and the electron-accepting compound, specifically, Japanese Patent Publication No. 51-35414. And Japanese Patent Publication No. 51-44706, Japanese Patent Publication No. 51-44708, Japanese Patent Publication No. 52-7764, Japanese Patent Publication No. 1-29398, and Japanese Patent Application Laid-Open No. 7-186546. . The color changes before and after a predetermined temperature (discoloration point), and only one specific state can exist in the normal temperature range among both states before and after the change. That is, the other state is maintained while the heat or cold necessary to develop the state is applied, but when the heat or cold is no longer applied, the state returns to the state exhibited in the normal temperature range, so-called, This is a type in which the temperature-color density due to temperature change shows a small hysteresis width (ΔH) and changes color.
[0012]
In addition, the temperature-sensitive color-changing color that changes color with a large hysteresis characteristic described in Japanese Patent Publication No. 4-17154, Japanese Patent Application Laid-Open No. 7-179777, Japanese Patent Application Laid-Open No. 7-33997, etc. proposed by the present applicant. The shape of the memory composition, that is, the curve plotting the change in color density due to the temperature change, lowers the temperature from the higher temperature side than the color change temperature range, as opposed to increasing the temperature from the lower temperature side than the color change temperature range. It is a type of color change material that changes color by following a path that differs greatly from the low temperature side discoloration point. It is also effective to use a reversible thermochromic composition having the characteristics that the state changed in step 1 can be stored in memory.
[0013]
The reversible thermochromic composition containing the three components of the organic compound medium that reversibly causes a color reaction with the electron-donating color-forming organic compound and the electron-accepting compound described above is effective even when applied as it is, It is preferably used as a microcapsule pigment encapsulated in microcapsules. That is, the reversible thermochromic composition is maintained in the same composition under various use conditions, and can exhibit the same effects.
By encapsulating in the microcapsule, a chemically and physically stable pigment can be formed, and a particle diameter of 0.1 to 100 μm, preferably 1 to 50 μm, more preferably 2 to 30 μm satisfies the practicality.
Microencapsulation includes conventionally known interfacial polymerization methods, in situ polymerization methods, in-liquid curing coating methods, phase separation methods from aqueous solutions, phase separation methods from organic solvents, melt dispersion cooling methods, air suspensions. There are a coating method, a spray drying method, and the like, which are appropriately selected according to the application. Further, a secondary resin film may be provided on the surface of the microcapsule according to the purpose to impart durability, or the surface characteristics may be modified for practical use.
[0014]
The reversible thermochromic composition (preferably microcapsule pigment) is dispersed in a vehicle containing a resin that is a film forming material, and is applied as a coloring material such as ink or paint to form a reversible thermochromic layer. Can do. Further, it can be dispersed in a thermoplastic resin or a thermosetting resin and formed into a sheet shape or other various forms, and can itself be applied as a layer having a reversible thermochromic layer.
It should be noted that non-thermochromic general dyes and pigments, fluorescent dyes and pigments can be mixed in the thermochromic layer, and various colors can be changed.
[0015]
The resin contained in the vehicle is preferably a transparent film-forming resin, and is exemplified below.
Ionomer resin, isobutylene-maleic anhydride copolymer resin, acrylonitrile-acrylic styrene copolymer resin, acrylonitrile-styrene copolymer resin, acrylonitrile-butadiene-styrene copolymer resin, acrylonitrile chlorinated polyethylene-styrene copolymer resin, ethylene-vinyl chloride Copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene-vinyl acetate-vinyl chloride graft copolymer resin, vinylidene chloride resin, vinyl chloride resin, chlorinated vinyl chloride resin, vinyl chloride-vinylidene chloride copolymer resin, chlorinated polyethylene Resin, chlorinated polypropylene resin, polyamide resin, high density polyethylene resin, medium density polyethylene resin, linear low density polyethylene resin, polyethylene terephthalate resin, polybutylene terephthalate Fat, polycarbonate resin, polystyrene resin, high impact polystyrene resin, polypropylene resin, polymethylstyrene resin, polyacrylate resin, polymethyl methacrylate resin, epoxy acrylate resin, alkylphenol resin, rosin modified phenolic resin, rosin modified alkyd resin, phenol Modified alkyd resin, epoxy modified alkyd resin, styrene modified alkyd resin, acrylic modified alkyd resin, amino alkyd resin, vinyl chloride-vinyl acetate resin, styrene-butadiene resin, epoxy resin, unsaturated polyester resin, polyurethane resin, vinyl acetate emulsion Resin, styrene-butadiene emulsion resin, acrylic ester emulsion resin, water-soluble alkyd resin, water-soluble melamine resin, water Sex urea resins, water-soluble phenolic resin, water-soluble epoxy resin, water-soluble polybutadiene resins, cellulose acetate, nitrate cellulose, mention may be made of ethylcellulose, and the like.
[0016]
Examples of the support include paper, synthetic paper, synthetic leather, leather, plastic, glass, ceramics, wood, stone, and the like in addition to fabrics such as woven fabrics, knitted fabrics, braided fabrics, and nonwoven fabrics.
When the fabric is used as a support, a woven fabric having excellent smoothness on the surface of the fabric is preferably used from the viewpoint of film formation of the porous layer. When the smoothness of the fabric surface is poor, or when the permeability of the ink inside the fabric is large and the film formation of the porous layer is poor, the fabric is subjected to a treatment such as water repellency, The film forming property of the porous layer can be improved.
[0017]
As a method for forming the porous layer and the reversible thermochromic layer, conventionally known coating methods such as screen printing, offset printing, gravure printing, coater, tampo printing, transfer printing means, brush coating, spray coating, etc. , Electrostatic coating, electrodeposition coating, flow coating, roller coating, dip coating, and the like.
[0018]
Further, the discolorable laminate of the present invention may be provided with a non-discoloring layer by applying a non-discoloring ink containing general dyes and pigments, fluorescent dyes and pigments, if necessary, or a titanium dioxide-coated mica, iron oxide-titanium dioxide. A metallic luster layer can also be provided by applying an ink containing a metallic luster pigment such as coated mica, iron oxide-coated mica, guanine, sericite, basic lead carbonate, lead acid arsenate, or bismuth oxychloride.
Further, a protective layer and a light stabilizer layer can be appropriately provided. Specifically, the light stabilizer layer is selected from ultraviolet absorbers, antioxidants, anti-aging agents, singlet oxygen quenchers, superoxide anion quenchers, ozone decolorizers, visible light absorbers, and infrared absorbers. This is a layer in which the light stabilizer is fixed in a dispersed state.
In addition, an antistatic agent, a polarity imparting agent, a thixotropic agent, an antifoaming agent, and the like can be added to each layer as necessary to improve the function.
[0019]
Next, the structure of the discolorable laminate of the present invention and the change in the dry state (non-liquid absorption state) and the state in which water or the like is absorbed will be described.
As described above, in the discolorable laminate of the present invention, the porous layer containing the low refractive index pigment and the binder resin laminated on the support has a concealing property when dried, and conceals the lower layer, Transparent or semi-transparent with water or the like absorbed, revealing the lower layer. Therefore, even if the support is a single color, the wet layer becomes transparent or semi-transparent by partially wetting the porous layer using a brush, brush, pen, stamp, etc., and the color tone of the lower layer is visually recognized. A desired image can be displayed.
When the water in the porous layer evaporates and dries, the porous layer again conceals the lower layer and returns to its original state. Therefore, it is possible to provide a pattern or multicolor pattern on the support and conceal it with a porous layer, as well as a pattern that is associated with or integrated with a pattern that is visually recognized when the porous layer is made transparent by liquid absorption. It is also possible to visually recognize an image in which the symbols are combined in the liquid absorption state by being provided on the layer.
It is also possible to form a pattern with a porous layer colored by adding a general pigment, etc., so that the porous layer absorbs liquid and cannot be visually discriminated by the color tone of the support seen through. In addition, the color tone of the porous layer can be set.
Furthermore, as a support having transparency, for example, a porous three-dimensional object can be provided with a porous layer, and the three-dimensional object itself can be seen through when the porous layer becomes transparent by liquid absorption.
[0020]
Further, when a reversible thermochromic layer is provided in the color-change laminate of the present invention, various changes can be made by combining each of the color change, the color change temperature, and the color change type of the reversible thermochromic layer.
The structure of the color changeable laminate including the reversible thermochromic layer and the porous layer is as follows. (A) A reversible thermochromic layer is provided on a support, and a porous layer is laminated on the reversible thermochromic layer (reversible). The thermochromic layer itself may be a support.), (B) a porous layer is provided on the support, a reversible thermochromic layer is laminated on the porous layer, and (C) the porous layer and reversible heat. For example, the discoloration layer may be provided on the support in a non-laminated state. The reversible thermochromic layer in the above-described configuration may be any of reversible thermochromic from colored to colorless and reversible thermochromic from colored (1) to colored (2). It may be configured to provide a reversible thermochromic layer that changes colorlessly so that it is visually reversibly changed from colored (1) to colored (2).
[0021]
In the case of the configuration (A), when a medium such as water in a temperature range that does not include the discoloration point of the reversible thermochromic layer is adhered, the medium penetrates into the porous layer and becomes transparent, and the reversible thermochromic layer is formed by the lower reversible thermochromic layer. The color tone is visible.
On the other hand, when a medium such as water in a temperature range including the color change point of the reversible thermochromic layer is attached, the medium penetrates into the porous layer and becomes transparent, and the lower reversible thermochromic layer changes color.
As a specific example, a reversible thermochromic layer having a color change point that changes color with body temperature is provided, and a porous layer is made transparent by attaching a medium such as water that does not include the color change point of the reversible thermochromic layer. Thereafter, the reversible thermochromic layer can be discolored by touch, and various color changes are exhibited by the combined use with a non-thermochromic layer.
[0022]
Next, the case of the configuration of (B) will be described. In order for a medium such as water to penetrate into the porous layer, the reversible thermochromic layer provided in the upper layer is also a layer having the property of penetrating the aqueous medium. Is preferred.
When the reversible thermochromic layer reversibly discolors from colored to colorless and is in a colored state at ambient temperature, a reversible thermochromic layer is formed by attaching a medium such as water in a temperature range where the composition changes color to the discolored body. In addition to decoloring, the porous layer also becomes transparent and the color tone of the support is visually recognized. In addition, when heating or cooling without touching a medium such as water, such as touching or blowing warm air or cold air, the reversible thermochromic layer disappears and the color tone of the porous layer is visually recognized. The
Furthermore, when the reversible thermochromic layer is reversibly discolored from colored to colorless and is in a decolored state at ambient temperature, a porous medium such as water in a temperature range that does not include the discoloration point of the reversible thermochromic layer is porous. When the layer becomes transparent and the color tone of the support is visually recognized, and the medium in the temperature range where the reversible thermochromic layer changes color is adhered to the color changer, the thermochromic layer is visually recognized in a colored state.
The reversible thermochromic layer having the above-described configuration is preferably one that reversibly discolors from colored to colorless.
[0023]
In the case of the structure of (C), both the reversible thermochromic layer and the porous layer are visually recognized in a normal state, and in the dry state, only the reversible thermochromic layer changes color due to temperature change, and the reversible thermochromic layer discolors. When a medium such as water in a temperature range that does not include dots is adhered, the medium penetrates and becomes transparent in the portion of the porous layer, and the color tone on the support is visually recognized.
On the other hand, when a medium such as water in a temperature range including the discoloration point of the reversible thermochromic layer is attached, the reversible thermochromic layer part is discolored and the porous layer also penetrates and becomes transparent, so that the The color tone is visible.
In particular, by arranging both layers close to each other, as described above, the color can be changed by either heat or water. Increase.
[0024]
A reversible thermochromic porous layer containing a reversible thermochromic composition and a low refractive index pigment can also be provided on the support. With the above structure, when the reversible thermochromic composition reversibly discolors from colored to colorless and is in a colored state at ambient temperature, a medium in a temperature range where the composition changes color is attached to the laminate, The color tone is visually recognized. In addition, when heated or cooled without attaching a medium, such as by touching or blowing warm air or cold air, the reversible thermochromic composition is decolored and the color tone of the low refractive index pigment is visually recognized. The
Furthermore, when the reversible thermochromic composition is reversibly discolored from colored to colorless and is in a decolored state at ambient temperature, a medium in a temperature range that does not discolor the reversible thermochromic composition is attached to the laminate. Then, the color tone of the support is visually recognized, and the color tone of the colored composition is visually recognized when a medium in a temperature range in which the composition changes color is attached to the laminate. As the reversible thermochromic composition having the above-described configuration, a composition that reversibly discolors from colored to colorless is preferably used.
[0025]
When a reversible thermochromic material that changes color with a large hysteresis width (ΔH) for the temperature-color density due to the temperature change is used as the reversible thermochromic layer, the color change state of the reversible thermochromic material is changed. Since it can be maintained in a specific temperature range, the discoloration state of the discolorable laminate of the present invention due to the reversible thermochromic material can be maintained in a specific temperature range, and the discolorable laminate of the present invention has further diversity. Can be granted.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
In the above-described laminated structure, the porous layer may be a pattern layer such as a letter, a symbol, or a figure as necessary. Further, a reversible thermochromic layer or a non-color-changing layer may be interposed, or may be provided in an upper layer, and may be a pattern layer of characters, symbols, figures or the like.
The discolorable laminate of the present invention is not limited to a planar shape, and various forms such as a linear shape, an uneven shape, and a solid shape are effective.
Specific embodiments of the discolorable laminate include, for example, dolls such as stuffed animals, dolls, and raincoats, accessories for dolls such as umbrellas and helmets, water gun targets, models imitating cars and ships, Boards and toys that show traces of human and doll's handprints, footprints, etc., school supplies such as water brush paper, water brush sheets, stationery, dresses, swimwear, raincoats, shoes such as rain boots, waterproofing Books, calendars and other printed materials, stamp cards, puzzles, entertainment equipment such as various games, wet suits, floats, swimming or diving equipment such as swimming floats, kitchen equipment such as coasters and cups, Other examples include umbrellas, artificial flowers, and winning lotteries.
It can also be applied as various indicators, for example, detection of liquid leaks in pipes, pipes, water tanks, tanks, etc., detection of water wetting in transport and storage of non-water-soluble chemicals, detection of condensation, rainfall, etc., disposable diapers Examples include detection of urine, amount of liquid in various containers and pools, detection of water depth, and detection of moisture in soil.
[0027]
【Example】
Examples are shown below. In addition, the part in an Example shows a weight part.
Example 1 (see FIG. 1)
A white nylon taffeta fabric is used as the support 2, and 10 parts of a pink fluorescent pigment [trade name: Epocolor FP-10, manufactured by Nippon Shokubai Co., Ltd.] on the fabric, an aqueous acrylic ester emulsion resin (solid content 50%) ) A fluorescent pink screen obtained by uniformly mixing and stirring 50 parts, 0.2 part of a silicone-based antifoaming agent, 5 parts of a thickening agent, 1 part of a leveling agent, 10 parts of water, and 2.5 parts of an epoxy-based crosslinking agent. Solid printing was performed on the entire surface using a 150-mesh screen plate with a printing ink, followed by drying and curing at 130 ° C. for 5 minutes to form the non-discoloring layer 4.
Subsequently, 15 parts of wet method fine particle silicic acid [trade name: Nipseal E-200A, manufactured by Nippon Silica Kogyo Co., Ltd.] as a low refractive index pigment, and aqueous urethane resin [trade name: Hydran AP-10, polyester urethane] as a binder resin Resin, solid content 30%, manufactured by Dainippon Ink & Chemicals, Inc.] 50 parts, water 30 parts, silicone antifoam 0.5 parts, aqueous ink thickener 3 parts, ethylene glycol 1 part, blocked isocyanate Using a white screen printing ink obtained by uniformly mixing and stirring 2 parts of the system cross-linking agent, using a 180 mesh screen plate, solid-printed on the entire surface of the non-color-changing layer 4 and dried at 130 ° C. for 5 minutes. After curing, a white porous layer 3 was formed in a dry state to obtain a discolorable laminate 1.
The discolorable laminate 1 exhibited a white color in a dry state and sufficiently concealed the lower layer, was excellent in transparency when wet with water, and the fluorescent pink color was clearly visible.
Further, when the color-changing laminate wetted with water was allowed to stand at room temperature, it gradually returned from a fluorescent pink color to white as the water evaporated, and returned to its original white color when it returned to a dry state.
[0028]
Example 2
The binder resin of the white screen printing ink for forming the porous layer in Example 1 is 25 parts of an aqueous urethane resin [trade name: Hydran AP-10, manufactured by Dainippon Ink & Chemicals, Inc.] and an aqueous acrylic ester emulsion resin. (50% solid content) A discolorable laminate was obtained in the same manner except that the water content was changed to 40 parts instead of 15 parts.
As in Example 1, the discolorable laminate exhibits a white color in a dry state and sufficiently hides the lower layer, and also has excellent transparency when wet with water, and the fluorescent pink color is clearly visible. It was.
[0029]
Example 3
The binder resin of the white screen printing ink for forming the porous layer of Example 1 is 15 parts of an aqueous urethane resin [trade name: Hydran AP-10, manufactured by Dainippon Ink & Chemicals, Inc.] and an aqueous acrylic ester emulsion resin. (50% solid content) A discolorable laminate was obtained in the same manner except that the water content was changed to 44 parts instead of 21 parts.
As in Example 1, the discolorable laminate exhibits a white color in a dry state and sufficiently hides the lower layer, and also has excellent transparency when wet with water, and the fluorescent pink color is clearly visible. It was.
[0030]
Example 4
The same procedure as in Example 1 except that the low-refractive-index pigment of the white screen printing ink for forming the porous layer was changed to a wet process fine particle silicic acid [trade name: NIPSEAL E-74P, manufactured by Nippon Silica Kogyo Co., Ltd.] To obtain a discolorable laminate.
As in Example 1, the discolorable laminate exhibits a white color in a dry state and sufficiently hides the lower layer, and also has excellent transparency when wet with water, and the fluorescent pink color is clearly visible. It was.
[0031]
Example 5
On a white polyester satin fabric as a support, screen printing was performed with yellow, pink, green, purple, and red fluorescent screen printing inks to form a non-discolored layer of floral pattern.
Subsequently, 15 parts of wet process fine particle silicic acid [trade name: NIPSEAL E-74P, manufactured by Nippon Silica Kogyo Co., Ltd.] as a low refractive index pigment, aqueous urethane resin [trade name: Neotan UE-1300, polycarbonate type as binder resin] Urethane resin, solid content 40%, manufactured by Toagosei Co., Ltd.] 37.5 parts, water 42.5 parts, silicone-based antifoaming agent 0.5 parts, water-based ink thickener 3 parts, ethylene glycol 1 part, A white screen printing ink obtained by uniformly mixing and stirring 2 parts of a blocked isocyanate crosslinking agent is solidly printed on the entire surface of the non-color-changing layer using a 180-mesh screen plate, and dried and cured at 130 ° C. for 5 minutes. Thus, a white porous layer was formed in a dry state to obtain a discolorable laminate.
In the discolorable laminate, a white porous layer is visually recognized in a dry state, but when water is attached, the porous layer becomes transparent, the floral pattern on the support is clearly visible, and as it dries When the porous layer became opaque and completely dried, the porous layer became white again and the floral pattern on the support was concealed.
The above operation could be repeated repeatedly without deteriorating the coating of the discolorable laminate.
[0032]
Example 6 (see FIG. 2)
On a polyester sheet (sheet thickness: 50 μm) colored in blue as the support 2, 15 parts of a wet process fine particle silicic acid [trade name: NIPSEAL E-1011, manufactured by Nippon Silica Kogyo Co., Ltd.] as a low refractive index pigment, Aqueous urethane resin [Brand name: Permarin UA-150, polyether urethane resin, solid content 30%, manufactured by Sanyo Chemical Industries, Ltd.] 50 parts, pink aqueous pigment dispersion [trade name: TC Rubin FR -H, pigment content 26-31%, manufactured by Dainippon Seika Kogyo Co., Ltd.] 1 part, water 30 parts, silicone-based antifoaming agent 0.5 part, water-based ink thickener 3 parts, ethylene glycol 1 part Using a 180 mesh screen plate, a pink screen printing ink obtained by uniformly mixing and stirring 2 parts of a blocked isocyanate-based crosslinking agent was solid printed on the entire surface. It was dried and cured at 0 ° C. for 5 minutes to form a pink porous layer 3 in a dry state, whereby a discolorable laminate 1 was obtained.
The discolorable laminate 1 exhibits the pink color of the porous layer 3 in a dry state. However, when water is attached, the porous layer 3 becomes transparent by being wetted with water, and the blue color of the support 2 and the porous layer 3 become porous. A purple color in which the pink color of the quality layer 3 was a mixed color was clearly visible. When the color-change laminate 1 wet with water was left at room temperature, it gradually returned from purple to pink as the water evaporated, and when it returned to the dry state, it became the original pink.
[0033]
Example 7 (see FIG. 3)
A non-discolored layer 4 was formed by spray painting Roman letter “A” on the bonnet portion of a white miniature car injection-molded with ABS resin as the support 2 using an oil-based green paint for ABS resin.
15 parts wet type fine particle silicic acid [trade name: Nipseal E-1011, manufactured by Nippon Silica Kogyo Co., Ltd.] as low refractive index pigment, aqueous urethane resin [trade name: Permarin UA-150, polyether urethane resin] , Solid content 30%, manufactured by Sanyo Chemical Industries Co., Ltd.] 50 parts of water, 30 parts of water, 0.5 parts of a silicone-based antifoaming agent, and 2 parts of a blocked isocyanate-based crosslinking agent are uniformly mixed and stirred. Was spray-coated on the non-discoloring layer 4 to form a porous layer 3 and further dried and cured at 70 ° C. for 30 minutes to obtain a discolorable laminate 1 in the form of a miniature car.
The miniature car was white as a whole in a dry state, but when water was attached to the bonnet portion, the porous layer 3 became transparent when wet with water, and a green letter “A” was visually recognized. When the miniature car was left at room temperature, the letter “A” in the bonnet part changed from green to white as the water evaporated, and when it returned to the dry state, it returned to its original white color.
The above operation could be reproduced repeatedly without deteriorating the coating of the porous layer of the color changing laminate 1.
[0034]
Example 8 (see FIG. 4)
10 parts of microcapsule pigment (orange ← → colorless, orange at 15 ° C or lower, colorless at 30 ° C or higher), pink, on white polyester taffeta fabric as support 2 Fluorescent pigment [trade name: Epocolor FP-10, manufactured by Nippon Shokubai Co., Ltd.] 1 part, aqueous acrylic ester emulsion resin (solid content 50%) 10 parts, silicone-based antifoaming agent 0.2 part, water 1 part, Reversible thermochromic screen ink obtained by uniformly mixing and stirring 0.5 parts of ethylene glycol, 0.5 parts of a thickener and 0.5 parts of an isocyanate crosslinking agent (red ← → pink, red at 15 ° C. or lower, A reversible thermochromic layer 5 was formed by performing solid printing on the entire surface using a 109 mesh screen plate and drying and curing at 130 ° C. for 5 minutes.
The reversible thermochromic layer 5 is visually red when cooled to 15 ° C. or lower, and this color tone is maintained in a temperature range below 30 ° C., and becomes pink when heated to 30 ° C. or higher. Is maintained in a temperature range exceeding 15 ° C.
Next, the white screen printing ink for forming the porous layer produced in Example 1 was solid-printed on the entire surface of the reversible thermochromic layer 5 using a 180 mesh screen plate and dried at 130 ° C. for 5 minutes. After curing, a white porous layer 3 was formed in a dry state to obtain a discolorable laminate 1.
The porous layer 3 changes from a white state to a colorless and transparent state due to adhesion of water or a water-soluble liquid.
[0035]
The discolorable laminate 1 is white in a dry state and remains white even when cooled or heated. However, when cold water of 15 ° C. or less is adhered, the porous layer 3 becomes transparent due to adhesion of water. And instantly changed to red by the lower reversible thermochromic layer 5. When the red color-change laminate 1 was left at room temperature of 24 ° C., it was red when water was attached, but gradually returned from red to white as the water evaporated, and became dry. When it returned, it turned white.
Next, when hot water of 30 ° C. or higher is attached to the discolorable laminate 1, the porous layer 3 becomes transparent due to the attachment of water, and the reversible thermochromic layer 5 changes color from red to fluorescent pink. Pink color was visible.
When the color-change laminate 1 was left at room temperature of 24 ° C. with water attached, it exhibited a fluorescent pink color, but gradually returned from the fluorescent pink color to white as the water evaporated and dried. It returned to the original white color.
Next, when hot water of 30 ° C. or higher is attached to a part of the color-changing laminate 1 in a state where cold water of 15 ° C. or lower is attached to the dried color-changing laminate 1 and changed to red, red to pink It changed to a color, and this state kept both red and pink until the water evaporated to dryness.
As described above, the discolorable laminate 1 can be changed from a white state to a red color or a fluorescent pink color by applying cold water or hot water and returning to the original white state again by drying. The color change can be reproduced repeatedly without deteriorating the film of the porous layer 3.
[0036]
Example 9 (see FIG. 5)
10 parts of a yellow fluorescent pigment [trade name: Epocolor FP-117, manufactured by Nippon Shokubai Co., Ltd.], 50 parts of an aqueous acrylate emulsion resin (solid content 50%), silicone, on white polyester satin fabric as support 2 A fluorescent yellow screen-printing ink comprising 0.2 parts of a defoaming agent, 5 parts of a thickening agent, 1 part of a leveling agent, 10 parts of water, and 2.5 parts of an epoxy crosslinking agent. Solid printing was performed on the entire surface using a mesh screen plate, followed by drying and curing at 130 ° C. for 5 minutes to form a non-discoloring layer 4.
Next, on the non-discoloring layer 4, 10 parts of a microcapsule pigment containing a reversible thermochromic composition (pink ← → colorless, pink below 15 ° C., colorless at 15 ° C. or higher), aqueous acrylic ester emulsion resin (50% solid content) 10 parts, 0.2 part of silicone-based antifoaming agent, 1 part of water, 0.5 part of ethylene glycol, 0.5 part of thickener, 0.5 part of isocyanate-based crosslinking agent are uniformly mixed The reversible thermochromic layer 5 was formed by printing a floral design using a 109 mesh screen plate with a reversible thermochromic screen ink obtained by stirring and drying and curing at 130 ° C. for 5 minutes.
In the state where the non-color-changing layer 4 and the reversible thermochromic layer 5 are laminated, the entire surface is fluorescent yellow by the non-color-changing layer 4 at room temperature of 15 ° C. or higher, and when cooled to a temperature of less than 15 ° C., the reversible thermo-chromic layer 5 Is colored pink, a red floral pattern is visually recognized in the yellow ground, and when heated again to a temperature of 15 ° C. or higher, the reversible thermochromic layer 5 is decolored and the entire surface becomes fluorescent yellow.
The upper surface of the reversible thermochromic layer 5 is solid-printed on the entire surface using the white screen printing ink for forming the porous layer prepared in Example 1, and then dried and cured to form the porous layer 3 and change the color. A laminate 1 was obtained.
The porous layer 3 changes from a white state to a colorless and transparent state due to adhesion of water or a water-soluble liquid.
[0037]
The discolorable laminate 1 is white in a dry state and remains white even when cooled or heated. However, when water at 15 ° C. or higher is attached, the porous layer 3 becomes transparent. Since the reversible thermochromic layer 5 became colorless, the entire surface turned yellow, and when left at room temperature of 24 ° C., the water evaporated and dried to return to white.
Next, when cold water of less than 15 ° C. is attached, the porous layer 3 becomes transparent and the reversible thermochromic layer 5 changes from colorless to pink, so that a red floral pattern is drawn in a yellow background. Changed. When left at a room temperature of 24 ° C., the reversible thermochromic layer 5 was decolored when it reached a temperature of 15 ° C. or more, and the entire surface turned yellow, showing this state for a while, but returned to white when dried. .
As described above, the discolorable laminate 1 can be changed from a white state to a red floral pattern on the entire surface by applying cold water or hot water from a white state, and again by drying it. Various color changes that can be restored to the original white state were exhibited, and the above-described change in the appearance could be repeatedly reproduced without deteriorating the film of the porous layer.
[0038]
Example 10 (see FIG. 6)
A non-discoloring layer 4 was provided on a white synthetic paper as a support 2 by screen-printing a floral pattern with fluorescent general color inks for yellow, pink, purple, green and red synthetic paper.
On the non-discoloring layer 4, 10 parts of a microcapsule pigment (black ← → colorless, black at less than 32 ° C., colorless at 32 ° C. or more) encapsulating a reversible thermochromic composition, an aqueous urethane resin (hydran AP-10, Polyester urethane resin, solid content 30%, manufactured by Dainippon Ink & Chemicals, Inc.] 20 parts, silicone antifoam 0.4 parts, water 1 part, ethylene glycol 0.5 parts, thickener 1.0 Using a 109 mesh screen plate, a reversible thermochromic screen ink obtained by uniformly mixing and stirring 0.5 part of an isocyanate cross-linking agent was solid-printed on the entire surface and dried and cured at 130 ° C. for 5 minutes. Thus, the reversible thermochromic layer 5 was formed.
In the state where the reversible thermochromic layer 5 is laminated on the non-color-changing layer 4, it exhibits a black color at a room temperature of less than 32 ° C., and when heated to 32 ° C. or higher, the reversible thermochromic layer 5 is discolored and becomes non-colored. When the floral pattern by the discoloration layer 4 is visually recognized and the temperature is again lower than 32 ° C., the reversible thermochromic layer 5 is colored black and the floral pattern is concealed.
Next, using the white screen printing ink for forming the porous layer produced in Example 1 on the reversible thermochromic layer 5, a butterfly pattern was printed with a 150 mesh screen plate, and the butterfly pattern was made porous. The discoloration layered product 1 was obtained by forming the quality layer 3.
The porous layer 3 changes from a white state to a colorless and transparent state due to adhesion of water or a water-soluble liquid.
[0039]
In the discolorable laminate 1, a white butterfly pattern by the porous layer 3 is visually recognized on the black reversible thermochromic layer 5 at a room temperature of less than 32 ° C. When the discolorable laminate 1 is heated to 32 ° C. or more, the reversible thermochromic layer 5 changes from black to colorless, and a floral pattern by the non-discoloring layer 4 appears, and a white butterfly pattern appears on the floral pattern. It looks like it was drawn. When it was cooled again to a temperature below 32 ° C., it returned to the appearance of a white butterfly pattern drawn on a black background.
Moreover, when water of less than 32 ° C. is attached to the discolorable laminate 1, the porous layer 3 becomes transparent, so the butterfly pattern disappears and the entire surface becomes black, and when left at room temperature of 24 ° C., the water evaporates. As it dries, a white butterfly pattern appears, and when it is completely dry, the white butterfly pattern is visible again on a black background.
Next, when warm water of 32 ° C. or higher is attached, the porous layer 3 becomes transparent and the butterfly pattern disappears, and the reversible thermochromic layer 5 changes from black to colorless, so only the floral pattern of the non-discolored layer 4 is visible. When left at a room temperature of 24 ° C., the reversible thermochromic layer 5 is colored when the temperature is lower than 32 ° C., and the floral pattern is concealed in black, showing the state for a while, but as it dries A white butterfly pattern gradually appeared on the black reversible thermochromic layer 5, and when completely dried, the pattern returned to a state in which a white butterfly pattern was drawn on the black ground.
In this way, a white butterfly pattern was drawn on a black background, a black solid pattern, and a white butterfly pattern on a colorful floral pattern due to changes in the temperature of the fabric, immersion in hot water, and cold water. It was possible to reveal the four aspects of the appearance, the appearance of only the colorful floral pattern, and to reproduce the change in the appearance repeatedly without deteriorating the film of the porous layer 3.
[0040]
Comparative Example 1
The color change was carried out in the same manner except that the binder resin of the white screen printing ink for forming the porous layer in Example 1 was changed to 30 parts of an aqueous acrylic ester emulsion resin (solid content 50%) and water was changed to 50 parts. A conductive laminate was obtained.
[0041]
Comparative Example 2
The same procedure as in Example 1 except that the binder resin of the white screen printing ink for forming the porous layer was changed to 30 parts of an aqueous ethylene-vinyl acetate copolymer emulsion resin (solid content 50%), and water was changed to 50 parts. As a result, a discolorable laminate was obtained.
[0042]
Comparative Example 3
The same except that the binder resin of the white screen printing ink for forming the porous layer in Example 1 was replaced with 30 parts of aqueous methyl methacrylate-butadiene copolymer emulsion resin (solid content 50%), and the water was changed to 50 parts. Thus, a discolorable laminate was obtained.
[0043]
Comparative Example 4
The color change is the same as in Example 1 except that the low refractive index pigment of the white screen printing ink for forming the porous layer is changed to dry-type fine-particle silicic acid [trade name: Aerosil 130 [manufactured by Nippon Aerosil Co., Ltd.]. A conductive laminate was obtained.
[0044]
Comparative Example 5
The same procedure as in Example 1 except that the low refractive index pigment of the white screen printing ink for forming the porous layer was changed to dry method fine particle silicic acid [trade name: Aerosil OX-50 [manufactured by Nippon Aerosil Co., Ltd.]. A discolorable laminate was obtained.
[0045]
Comparative Example 6
The color change was carried out in the same manner except that the binder resin of the white screen printing ink for forming the porous layer of Example 6 was replaced with 30 parts of an aqueous acrylate emulsion resin (solid content 50%) and water was changed to 50 parts. A conductive laminate was obtained.
[0046]
The result of the abrasion resistance test by the friction tester of the porous layers of Examples 1 to 4 and 6 and Comparative Examples 1 to 3 and 6 is shown in the table below.
[0047]
[Table 1]

[0048]
Evaluation of scratch resistance
A: There is no deterioration of the film due to abrasion.
○: Although there is slight deterioration of the film due to rubbing, it has practical film strength.
(Triangle | delta): The deterioration of the film | membrane by abrasion is large and does not have practical film | membrane intensity | strength.
X: A porous layer lose | disappears by abrasion.
[0049]
For the abrasion resistance test, a friction tester type 2 (Gakushin Type) [manufactured by Suga Test Instruments Co., Ltd.] was used, and the upper friction piece was cotton cloth (Kanakin No. 3, JIS L 0803 compliant, JIS dye fastness test) And the friction element was moved back and forth horizontally for 10 cm at a speed of 30 reciprocations per minute on the test piece of the discolorable laminate under a load of 700 g (in Table 1, the number of abrasions was Indicates the number of reciprocations of the friction element.)
The rubbing resistance test was performed for a dry state and a liquid absorption state, and the liquid absorption state was performed in a state where the test piece was wet with water.
As seen in the test results, the discolorable laminate of the present invention showed better scratch resistance than the laminate of the comparative example.
[0050]
Moreover, the visual evaluation of the concealability in the dry state of Examples 1 and 4 and Comparative Examples 4 and 5 and the transparency when wet with water, and the measured values of tristimulus values X, Y, and Z in the CIE color system Is shown in the table.
[0051]
[Table 2]

[0052]
Evaluation of concealment in the dry state by visual inspection
○: Sufficient concealment.
(Triangle | delta): The color tone of a lower layer is visually recognized and there is no practical concealing property.
X: The color tone of the lower layer is remarkably visually recognized.
Evaluation of transparency when wet with water
○: Sufficient transparency.
(Triangle | delta): The color tone of a lower layer is visually recognized unclearly, and there is no practical transparency.
X: The color tone of the porous layer is remarkably visually recognized.
[0053]
The tristimulus values X, Y, and Z were measured using a color difference meter TC-3600 [manufactured by Tokyo Denshoku Co., Ltd.].
[0054]
As seen in the test results, the discolorable laminate of the present invention is excellent in both the concealability in the dry state and the transparency when wetted with water, and when the porous layer is wetted with water, It became transparent and the color tone of the support was clearly visible.
[0055]
【The invention's effect】
Since the porous layer contains a urethane resin, the present invention has excellent film durability, and is effective without impairing the concealability in the dry state and the transparency in the liquid absorption state even after repeated use. It is possible to provide a discolorable laminate that functions and is excellent in practicality in various fields such as toy field, decoration field, and design field.
[Brief description of the drawings]
FIG. 1 is a longitudinal cross-sectional explanatory view of an example of a color-changing laminate of the present invention.
FIG. 2 is an explanatory view of a longitudinal section of another embodiment of the color-change laminate of the present invention.
FIG. 3 is an explanatory view of a longitudinal section of another embodiment of the color-change laminate of the present invention.
FIG. 4 is a longitudinal cross-sectional explanatory view of another example of the color-change laminate of the present invention.
FIG. 5 is an explanatory view of a longitudinal section of another embodiment of the color-change laminate of the present invention.
FIG. 6 is an explanatory view of a longitudinal section of another embodiment of the color-change laminate of the present invention.
[Explanation of symbols]
1 Discolorable laminate
2 Support
3 Porous layer
4 Non-discoloring layer
5 Reversible thermochromic layer

Claims (6)

A porous layer in which a low refractive index pigment having a refractive index of 1.4 to 1.7 is fixed to a binder resin in a dispersed state is formed on a support, and the porous layer is transparent or translucent in a liquid absorption state. A discolorable laminate, wherein the binder resin contains at least a urethane-based resin, wherein the binder resin visualizes a changed appearance.   The discolorable laminate according to claim 1, wherein a solid content ratio of the urethane resin in the binder resin is 30% by weight or more.   The discolorable laminate according to claim 1 or 2, wherein the low refractive index pigment is a particulate silicic acid produced by a wet method. The discolorable laminate according to claim 3, wherein the particulate silicic acid in the porous layer is 1 to 30 g / m ² .   The discolorable laminate according to any one of claims 1 to 4, wherein the support is a fabric. The discolorable laminate according to any one of claims 1 to 5 , wherein a reversible thermochromic layer is disposed on a support , and a porous layer is disposed on the reversible thermochromic layer .

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