JP4508520B2 - Decorative plate and method for producing the same - Google Patents

Description

（但し、全体の分子量は、Σ（各成分の配合モル数×各成分の分子量）であり、架橋点の数は、Σ［｛（各成分の官能基数−１）×２｝×各成分のモル数］である。）
架橋性樹脂の種類が同じ場合、平均架橋間分子量が小さい程（即ち、架橋密度が大きい）、バインダーの架橋性樹脂が球状粒子をしっかりと保持し、耐摩耗性が更に向上することを示すものである。従って、可撓性を損なわない範囲で架橋性樹脂の平均架橋間分子量を小さく調節することで、更に耐摩耗性を向上させることができる。
【００４１】
架橋性樹脂として用いる電離放射線硬化性樹脂は、具体的には、分子中に重合性不飽和結合または、エポキシ基を有するプレポリマー、オリゴマー、及び／又はモノマーを適宜混合した、電離放射線により硬化可能な組成物が用いられる。尚、ここで電離放射線とは、電磁波または荷電粒子線のうち分子を重合或いは架橋し得るエネルギー量子を有するものを意味し、通常紫外線または電子線が用いられる。
【００４２】
上記プレポリマー、オリゴマーの例としては不飽和ジカルボン酸と多価アルコールの縮合物等の不飽和ポリエステル類、ポリエステルメタクリレート、ポリエーテルメタクリレート、ポリオールメタクリレート、メラミンメタクリレート等のメタクリレート類、ポリエステルアクリレート、エポキシアクリレート、ウレタンアクリレート、ポリエーテルアクリレート、ポリオールアクリレート、メラミンアクリレート等のアクリレート、カチオン重合型エポキシ化合物等が挙げられる。
【００４３】
ウレタンアクリレートとしては、例えばポリエーテルジオールとジイソシアネートとを反応させて得られる、下記一般式で表されるポリエーテル系ウレタン（メタ）アクリレートが挙げられる。
【００４４】
【化１】

（式中、Ｒ¹、Ｒ²はそれぞれ水素またはメチル基であり、Ｘはジイソシアネート残基、ｎは１〜３の整数、ｍは６〜６０の整数である。）
上記のポリエーテル系ウレタン（メタ）アクリレートに使用されるジイソシアネートとしては、例えば、イソホロンジイソシアネート、ジシクロヘキシルメタンジイソシアネート、ヘキサメチレンジイソシアネート、ジフェニルメタンジイソシアネート、トリレンジイソシアネート等が挙げられる。上記のポリエーテルジオールとしては、分子量が５００〜３０００のポリオキシプロピレングリコール、ポリオキシエチレングリコール、ポリオキシテトラメチレングリコール等が挙げられる。
【００４５】
以下、ウレタンアクリレートの製造例を示す。滴下ロート、温度計、還流冷却管及び攪拌棒を備えたガラス製反応容器中に、分子量１０００のポリテトラメラレングリコール１０００部と、イソホロンジイソシアネート４４４部とを仕込み、１２０℃で３時間反応させた後、８０℃以下に冷却し、２−ヒドロキシエチルアクリレートを２３２質量部加え、８０℃でイソシアネート基が消失するまで反応させて、ウレタンアクリレートが得られた。
【００４６】
電離放射線硬化性樹脂に用いるモノマーの例としては、スチレン、αメチルスチレン等のスチレン系モノマー、アクリル酸メチル、アクリル酸−２−エチルヘキシル、アクリル酸メトキシエチル、アクリル酸ブトキシエチル、アクリル酸ブチル、アクリル酸メトキシブチル、アクリル酸フェニル等のアクリル酸エステル類、メタクリル酸メチル、メタクリル酸エチル、メタクリル酸プロピル、メタクリル酸メトキシエチル、メタクリル酸エトキシメチル、メタクリル酸フェニル、メタクリル酸ラウリル等のメタクリル酸エステル類、アクリル酸−２−（Ｎ、Ｎ−ジエチルアミノ）エチル、メタクリル酸−２−（Ｎ、Ｎ−ジメチルアミノ）エチル、アクリル酸−２−（Ｎ、Ｎ−ジベンジルアミノ）メチル、アクリル酸−２−（Ｎ、Ｎ−ジエチルアミノ）プロピル等の不飽和置酸の置換アミノアルコールエステル類、アクリルアミド、メタクリルアミド等の不飽和カルボン酸アミド、エチレングリコールジアクリレート、プロピレングリコールジアクリレート、プロピレングリコールジアクリレート、ネオペンチルグリコールジアクリレート、１，６ヘキサンジオールジアクリレート、トリエチレングリコールジアクリレート等の化合物、ジプロピレングリコールジアクリレート、エチレングリコールジアクリレート、プロピレングリコールジメタクリレート、ジエチレングリコールジメタクリレート等の多官能性化合物、及び／又は、分子中に２個以上のチオール基を有するポリチオール化合物、例えばトリメチロールプロパントリチオグリコレート、トリメチロールプロパントリチオプロピレート、ペンタエリスリトールテトラチオグリコール等が挙げられる。
【００４７】
通常、以上の化合物を必要に応じて１種もしくは２種以上を混合して用いるが、電離放射線硬化性樹脂に通常の塗工適性を付与するために、前記プレポリマーまたはポリチオールを５重量％以上、前記モノマー及びまたはポリチオールを９５重量％以下とするのが好ましい。
【００４８】
モノマーの選定に際しては、硬化物の可撓性が要求される場合は塗工適性上支障のない範囲でモノマーの量を少なめにしたり、１官能または２官能アクリレートモノマーを用い、比較的低架橋密度の構造とする。また、硬化物の耐摩耗性、耐熱性、耐溶剤性等が要求される場合には、塗工適性上支障のない範囲でモノマーの量を多めにしたり、３官能以上のアクリレートモノマーを用いることで高架橋密度の構造とすることができる。尚、１、２官能モノマーと３官能以上のモノマーを混合し塗工適性と硬化物の物性とを調整することもできる。
【００４９】
以上のような１官能性アクリレートモノマーとしては、２−ヒドロキシアクリレート、２−ヘキシルアクリレート、フェノキシエチルアクリレート等が挙げられる。又、２官能アクリレートとしてはエチレングリコールジアクリレート、１，６−ヘキサンジオールジアクリレート等が、また３官能以上のアクリレートとしては、トリメチロールプロパントリアクリレート、ペンタエリスリトールトリ（テトラ）アクリレート、ジペンタエリスリトールヘキサアクリレート等が挙げられる。
【００５０】
更に、電離放射線硬化性樹脂には、硬化物の可撓性、表面硬度等の物性を調整するための電離放射線非硬化性樹脂を添加することができる。尚、該電離放射線非硬化性樹脂としてはウレタン系、繊維素系、ポリエステル系、アクリル系、ブチラール系、ポリ塩化ビニル、ポリ酢酸ビニル等の熱可塑性樹脂が用いられ、特に繊維素系、ウレタン系、ブチラール系が可撓性の点から好ましい。
【００５１】
又、以上の如き組成の電離放射線硬化性樹脂を硬化させるために紫外線を照射する場合には、光重合開始剤として、アセトフェノン類、ベンゾフェノン類、ミヒラーベンゾイルベンゾエート、α−アミノキシムエステル、テトラメチルチウラムモノサルファイド、チオキサントン類、芳香族ジアゾニウム塩、芳香族スルホニウム塩、メタロセン、又、光重合促進剤（増感剤）としてｎ−ブチルアミン、トリエチルアミン、トリ−ｎ−ブチルホスフィン等を、更に混合して用いることができる。
【００５２】
架橋性樹脂として用いられる熱硬化性樹脂は、具体的には、フェノール樹脂、尿素樹脂、ジアリルフタレート樹脂、メラミン樹脂、グアナミン樹脂、不飽和ポリエステル系樹脂、ポリウレタン系樹脂（２液型ポリウレタンも含む）、エポキシ樹脂、アミノアルキッド樹脂、メラミン−尿素共縮合樹脂、珪素樹脂、ポリシロキサン樹脂等がある。これらに必要に応じて架橋剤、重合開始剤等の硬化剤、重合促進剤等を添加して用いる。上記の硬化剤として通常、イソシアネート又は有機スルホン酸塩が不飽和ポリエステル系樹脂やポリウレタン系樹脂に、アミンがエポキシ樹脂に、メチルエチルケトンパーオキサイド等の過酸化物やアゾイソブチルニトリル等のラジカル開始剤が不飽和ポリエステル等によく使用される。
【００５３】
上記のイソシアネートとしては、２価以上の脂肪族又は芳香族イソシアネートを使用できるが、熱変色防止、耐候性の点から脂肪族イソシアネートが望ましい。具体的なイソシアネートとしてトリレンジイソシアネート、キシリレンジイソシアネート、４，４′−ジフェニルメタンジイソシアネート、ヘキサメチレンジイソシアネート、リジンジイソシアネート等が挙げられる。
【００５４】
上記２液型ポリウレタンとしては、その分子構造中に水酸基を平均して２個以上有するポリオール化合物からなる第１液と、ポリイソシアネート化合物からなる第２液とを、水酸基とイソシアネート基の当量比が０．７〜１．５になるように配合したものが挙げられる。
【００５５】
上記エポキシ樹脂としては、その分子構造中にエポキシ基を平均２個以上有するエポキシ樹脂とエポキシ基と反応する活性水素を１分子中に３個以上有するモノ−、またはポリ−アミンとをエポキシ樹脂のエポキシ当量とモノ、またはポリアミンの活性水素当量の比が、０．７〜１．５になるように配合したものが挙げられる。
【００５６】
また、被覆樹脂は、熱硬化性樹脂と電離放射線硬化性樹脂との混合樹脂を用いることができる。
【００５７】
さらに、被覆樹脂として、未硬化又は半硬化等の完全に硬化しない状態に於いて、常温では固体であり、かつ熱可塑性、溶剤溶解性を有していながら、塗工後の乾燥又は冷却によって、見かけ上、又は手で触った時にも非流動性（指触乾燥性）であり、かつ非粘着性である塗膜を与える樹脂（以下、完全に硬化しない状態で常温で固体である樹脂という）を用いることもできる。例えば、無溶剤の組成物で、加熱により流動性を有し、冷却により常温で固体状となるような硬化性を有する樹脂組成物や、溶剤を含む組成物で、溶剤を含有した状態では流動性を有し溶剤を揮発させると固体状となる硬化性を有する樹脂等がある。
【００５８】
さらに別の実施形態においては、化粧紙原紙１１への被覆樹脂１３として、紙質化粧材１０を化粧板用基材２０上に接着するための上記したような水性接着剤３０と同じものを用いることも可能である。この実施形態においては、化粧紙原紙１１の両面に前記水性接着剤をディッピング等により付着させた後、化粧板用基材２０上に載置し、その上部に適当な離型紙等を載せて硬化処理することも可能である。
【００５９】
化粧紙原紙１１への被覆樹脂１３の含浸量（化粧紙原紙に対する重量％）としては、特に限定されるものではないが、一般的には、４０％〜８０％が好ましい。含浸量が４０％未満では化粧紙原紙全体が樹脂により充分含浸されない虞れがあり、一方含浸量が８０％を超えると過剰な含浸となる虞れがある。
【００６０】
上記の被覆樹脂層を形成するための塗工組成物には、上記の樹脂成分以外に、各種球状粒子、染料や顔料等の着色剤、その他のＣａＣＯ₃ 、ＢａＳＯ₄ 、ナイロン樹脂ビーズ等の公知の艶消調整剤や増量剤といった充填剤、消泡剤、レベリング剤、チクソトロピー性付与剤などの塗料、インキに通常添加される添加剤を加えることができる。
【００６１】
又、上記の耐摩耗性樹脂層の塗工組成物には、粘度を調整するために、架橋性樹脂の成分を溶解可能であり、常圧における沸点が７０℃〜１５０℃の溶剤を、組成物中に３０重量％以下の範囲で用いることができる。溶剤の添加量が３０重量％以下の範囲であれば、乾燥がスムーズであり、生産スピードの大きな低下がない。
【００６２】
上記の溶剤としては、塗料、インキ等に通常使用されるものが使用でき、具体例としては、トルエン、キシレン等の芳香族炭化水素、アセトン、メチルエチルケトンメチルイソブチルケトン、シクロヘキサノン等のケトン類、酢酸エチル、酢酸イソプロピル、酢酸アミルなどの酢酸エステル類、メチルアルコール、エチルアルコール、イソプロピルアルコールなどのアルコール類、ジオキサン、テトラヒドロフラン、ジイソプロピルエーテルなどのエーテル類およびこれらの２種以上の混合物が挙げられる。
【００６３】
本発明における被覆樹脂層としては、特に、上記のごとき架橋性樹脂からなるバインダーと該架橋性樹脂よりも高硬度の球状粒子とを含有する塗工組成物から形成された被覆樹脂層が、基材の表面に設けられ、被覆樹脂層の平均膜厚をｔ（ｍｍ）とし、球状粒子の平均粒径をｄ（ｍｍ）とした場合、下記の（１）式
【００６４】
【数２】

を満足する実施形態が、特に好ましいものとして挙げることができる。
【００６５】
球状粒子は、真球状、あるいは球を偏平にした楕円球状ならびに該真球や楕円球状に近い形状等のように、表面が滑らかな曲面で囲まれていればよい。球状粒子は、特に粒子表面に突起や角のない、いわゆるカッティングエッジのない球状が好ましい。球状粒子は同じ材質の不定形の粒子と比較して、表面樹脂層それ自身の耐摩耗性を大きく向上させると共に、塗工装置を摩耗させず、塗膜の硬化後もこれと接する他の物を摩耗させず、更に塗膜の透明度も高くなるという特徴があり、カッティングエッジがない場合特にその効果が大きい。
【００６６】
球状粒子が被覆樹脂層に含有される量は、硬化後の架橋性樹脂からなるバインダー成分１００質量部に対し５〜２０質量部となるように塗工組成物を調整するのが好ましい。球状粒子の添加量が少ない場合、耐摩耗性向上等の球状粒子の添加による効果が充分発揮できない虞れがあり、一方、球状粒子の添加量が多くなりすぎると、架橋性樹脂のバインダーとしての効果が損なわれ、塗膜の可撓性が低下する虞れや、塗工組成物の作業性が低下する等の弊害が出て来る。
【００６７】
球状粒子の粒子径は、通常５〜１００μｍ（平均粒径）のものが好ましく使用可能である。球状粒子の平均粒径が５μｍ未満になると皮膜が不透明になる虞れがあり、一方、平均粒径が１００μｍを超えると、皮膜の表面平滑性が低下する虞れがある。球状粒子の粒子径が小さくなると、耐摩耗性は低下する。一方、球状粒子の粒子径が大きくなると耐摩耗性が向上するが、あまり大きくなりすぎると、塗工の際の均一な塗工が困難になってしまう。例えば、耐摩耗性樹脂層の厚みを１０〜３０μｍに形成する場合には、球状粒子５の粒子径は１０〜５０μｍの範囲が好ましい。
【００６８】
球状粒子の平均粒径を、被覆樹脂層の厚みに応じて選定することが、更に好ましい。特に、耐摩耗性樹脂層の平均膜厚をｔ（ｍｍ）とし、球状粒子の平均粒径をｄ（ｍｍ）とした場合、上記式（１）を満足するように球状粒子を選択するのが望ましい。球状粒子の平均粒径ｄ（ｍｍ）が２．０ｔを超えると、被覆樹脂層の表面に球状粒子がはみ出し、該層の外観が低下する虞れがある。一方球状粒子の平均粒径ｄ（ｍｍ）が０．３ｔ未満の場合には充分な耐摩耗性が得られない虞れがある。
【００６９】
球状粒子の材質は架橋性樹脂よりも高硬度であればよく、無機粒子及び有機樹脂粒子のいずれも用いることができる。球状粒子の架橋性樹脂との硬度の差は、硬度はモース硬度、ビッカース硬度等の方法で計測され、例えばモース硬度で表した場合１以上あるのが好ましい。又、球状粒子の硬度は、ヌープ硬度が１３００ｋｇ／ｍｍ²以上が好ましく、更に好ましくは、ヌープ硬度が１８００ｋｇ／ｍｍ²以上である。
【００７０】
尚、ここで言うヌープ硬度とは、ヌープ圧子を用いて測定される微小押し込み硬さで、試験前に菱形の圧痕をつけたときの荷重を、永久凹みの長い方の対角線の長さより求めた凹みの投影面積で除した商で表される値である。この試験方法は、ＡＳＴＭ Ｃ−８４９に記載されている。
【００７１】
球状粒子の材質は、具体的には、α−アルミナ、シリカ、酸化クロム、酸化鉄、ダイヤモンド、黒鉛等の無機粒子、及び、架橋アクリル等の合成樹脂ビーズ等の有機樹脂粒子が挙げられる。又、上記のα−アルミナとしては溶融アルミナ、バイヤー法アルミナ等があり、又上記以外の無機粒子として、ジルコニア、チタニア、あるいはこれらや溶融アルミナ、バイヤー法アルミナ等との共融混合物が挙げられる。これらの無機粒子の形状を球形にする方法としては、粉砕した不定形の上記無機化合物を融点以上の高温炉中に投入し溶融させ、表面張力を利用して球状にする方法や、上記無機物を融点以上の高温で溶融したものを霧状に吹き出して球状にする方法等が挙げられる。
【００７２】
特に好ましい球状粒子は、非常に硬度が高く耐摩耗性に対する効果が大きいことと球形状のものが比較的容易に得やすい等の理由から、球形のα−アルミナを挙げることができる。球形のα−アルミナは、特開平２−５５２６９号公報に記載されているように、アルミナ水和物、ハロゲン化合物、硼素化合物等の鉱化剤あるいは結晶剤を、電融アルミナあるいは焼結アルミナの粉砕品に少量添加し、１４００℃以上の温度で２時間以上熱処理することで、アルミナ中のカッティングエッジが減少し同時に形状が球形化したものが得られる。このような球形状のアルミナは、昭和電工（株）より「球状アルミナ（Ｓｐｈｅｒｉｃａｌ Ａｌｕｍｉｎａ）ＡＳ−１０、ＡＳ−２０、ＡＳ−３０、ＡＳ−４０、ＡＳ−５０」として各種の平均粒子径のものが市販されている。
【００７３】
球状粒子はその粒子表面を処理することができる。例えばステアリン酸等の脂肪酸で処理することで分散性が向上する。又、表面をシランカップリング剤で処理することで、バインダーとして使用する架橋性樹脂との間の密着性や塗工組成物中での粒子の分散性が向上する。シランカップリング剤としては、分子中にビニルやメタクリル等のラジカル重合性不飽和結合を有するアルコキシシランや、分子中にエポキシ、アミノ、メルカプト等の官能基を有するアルコキシシランが挙げられる。シランカップリング剤は、球状粒子と共に使用する架橋性樹脂の種類に応じて、例えば（メタ）アクリレートで等の電離放射線硬化性樹脂の場合にはラジカル重合性不飽和結合を有するアルコキシシランを用い、二液硬化型のウレタン樹脂の場合にはエポキシ基やアミノ基を有するアルコキシシランを用いるように、ラジカル重合性不飽和結合や官能基の種類等を選択することが好ましい。ラジカル重合性不飽和結合を有するアルコキシシランは具体的には、γ−メタクリロキシプロピルトリメトキシシラン、γ−メタクリロキシプロピルメチルジメトキシシラン、γ−メタクリロキシプロピルジメチルメトキシシラン、γ−メタクリロキシプロピルジメチルエトキシシラン、γ−アクリロキシプロピルトリメトキシシラン、γ−アクリロキシプロピルメチルジメトキシシラン、γ−アクリロキシプロピルジメチルメトキシシラン、γ−アクリロキシプロピルトリエトキシシラン、γ−アクリロキシプロピルメチルジエトキシシラン、γ−アクリロキシプロピルジメチルエトキシシラン、ビニルトリエトキシシランなどの分子中にラジカル重合性不飽和結合を有するアルコキシシランや、分子中にエポキシ、アミノ、メルカプト等の官能基を有するアルコキシシラン等がある。
【００７４】
球状粒子の表面をシランカップリング剤で処理する方法は特に制限はなく、公知の方法が使用できる。例えば、乾式法として球状粒子を激しく攪拌しながら所定量のシランカップリング剤を吹きつける方法や、湿式法としてトルエン等の溶剤中に球状粒子を分散させた後に、所定量のシランカップリング剤を加え反応させる方法が挙げられる。球状粒子に対するシランカップリング剤の処理量（所要量）としては、球状粒子の比表面積１００に対してシランカップリング剤の最小被覆面積が１０以上となる処理量が好ましい。球状粒子の最小被覆面積が球状粒子の比表面積１００に対して１０未満の場合はあまり効果がない。
【００７５】
次に、上記の塗工組成物を用いて化粧紙原紙１１の表面に樹脂被覆層１３を形成する方法について説明する。樹脂被覆層１３は、化粧紙原紙１１の表面に塗工組成物を直接塗工する直接コーティング法、又は、剥離性の基材表面に樹脂被覆層１３を予め形成した後、該層を化粧紙原紙１１の表面に転写する、転写コーティング法が用いられる。一般に基材２の材質として、塗工組成物が浸透しないものを使用した場合には上記のいずれの方法を用いてもよいが、塗工組成物を浸透させる化粧紙原紙１１を使用した場合や、表面に凹凸のある化粧紙原紙、ならびに、塗膜厚みの均一性を出す場合、電離放射線の強度を均一にして均一な耐摩耗性を形成したい場合には、転写コーティング法が用いるのが好ましい。
【００７６】
直接コーティング法は、グラビアコート、グラビアリバースコート、グラビアオフセットコート、スピンナーコート、ロールコート、リバースロールコート、キスコート、ホイラーコート、ディップコート、シルクスクリーンによるベタコート、ワイヤーバーコート、フローコート、コンマコート、かけ流しコート、刷毛塗り、スプレーコート等を用いることができるが、好ましいのはグラビアコートである。
【００７７】
転写コーティング法は、下記の（ａ）〜（ｄ）に示す、一旦、薄いシート（フィルム）基材に塗膜を形成し架橋硬化せしめ、しかる後基材の表面に被覆する方法であり、塗工組成物の塗膜を基材と共に立体物に接着するラミネート法（ａ、ｂ）、一旦離型性支持体シート上に塗膜と必要に応じて接着材層を形成し塗膜を架橋硬化させてなる転写シートを、その塗膜側を立体物に接着後、支持体シートのみ剥離する転写法（ｃ）等の手段を利用することができる。尚、薄いシート基材に、耐摩耗性樹脂層を形成する方法は上記の直接コーティング法と同じ各種のコーティング手段を用いることができる。
（ａ）特公平２−４２０８０号公報、特公平４−１９９２４号公報等に開示されるような射出成形同時転写法。或いは特公昭５０−１９１３２号公報に開示されるような射出成形同時ラミネート法。
（ｂ）特開平４−２８８２１４号公報、特開平５−５７７８６号公報に開示されるような真空成形同時転写法。或いは特公昭５６−４５７６８号公報に開示されるような真空成形同時ラミネート法。
（ｃ）特公昭５９−５１９００号公報、特公昭６１−５８９５号公報、特公平３−２６６６号公報等に開示されるように、ラッピング同時転写法、又はラッピング同時ラミネート法。
（ｄ）実公大１５−３１１２２号公報等に開示されているＶカット加工同時ラミネート法、或いは特公昭５６−７８６６号公報等に開示されているＶカット加工同時転写法。
【００７８】
又、転写コーティング法の一つとして、例えば架橋性樹脂として電離放射線硬化性樹脂を用いる場合には、下記の（Ａ）〜（Ｄ）の工程を順次行う方法を用いることもできる（特開平２−２６６７３号公報等記載）。
（Ａ）非吸収性且つ離型性の合成樹脂シートに、未硬化液状の電離放射線硬化性樹脂組成物を塗工する工程。
（Ｂ）前記電離放射線硬化性樹脂組成物の塗布面が基材と接するようにラミネートする工程。
（Ｃ）前記電離放射線硬化性樹脂組成物の塗膜に電離放射線を照射して架橋、硬化させる工程。
（Ｄ）合成樹脂シートを剥離除去する工程。
【００７９】
上記の工程において、電離放射線硬化性樹脂として溶剤で希釈されたものを使用する場合には、工程（Ａ）と（Ｂ）との間に溶剤を乾燥する工程を行う。上記の方法によれば、浸透性の高い化粧紙原紙１１の場合であっても、樹脂が基材の裏側に抜ける、いわゆる「うらぬけ」を確実に防止して、基材表面に良好な耐摩耗性樹脂層を容易に形成可能である。
【００８０】
架橋性樹脂として電離放射線硬化性樹脂を用いた場合の、該樹脂を硬化させるために用いられる電離放射線照射装置は、紫外線を照射する場合、超高圧水銀灯、高圧水銀灯、低圧水銀灯、カーボンアーク、ブラックライトランプ、メタルハライドランプ等の光源が用いられ、又、電子線を照射する場合には、コックロフトワルトン型、バンデグラフ型、共振変圧器型、絶縁コア変圧器型、あるいは直線型、ダイナミトロン型、高周波型等の各種電子線加速器等を用いる。
【００８１】
電子線の照射量は、通常１００〜１０００ｋｅＶ、好ましくは１００〜３００ｋｅＶのエネルギーを持つ電子を０．１〜３０Ｍｒａｄ程度の照射量で照射する。照射量が０．１Ｍｒａｄ未満の場合、硬化が不十分となる虞れがあり、又、照射量が３０Ｍｒａｄを超えると、硬化した塗膜或いは基材が損傷を受ける虞れが出てくる。又、紫外線により硬化させる場合の照射量は、好ましくは５０〜１０００ｍＪ／ｃｍ²である。紫外線の照射量が５０ｍＪ／ｃｍを未満では硬化が不十分となる虞れがあり、又、照射量が１０００ｍＪ／ｃｍ²を超えると、硬化した塗膜が黄変化する虞れがある。
【００８２】
又、架橋性樹脂として熱硬化性樹脂を使用した場合には、熱硬化性樹脂の硬化反応を促進するために、塗工組成物を塗工後加熱しても良い。この加熱時間は例えば、イソシアネート硬化型不飽和ポリエステル系樹脂、又はポリウレタン樹脂の場合は、通常４０〜６０℃で１〜５日程度、又ポリシロキサン樹脂の場合は、通常８０〜１５０℃で１〜３００分程度である。
【００８３】
また、紙質化粧材１０上に形成される絵柄１２は、化粧紙原紙１１の表面側に上記樹脂被覆層１３を形成前又は後のいずれに形成してもよいが、樹脂被覆層を形成前に形成するのが好ましい。絵柄１２は、ベヒクルに必要に応じて、公知の顔料、染料等の着色剤、体質顔料、溶剤、安定剤、可塑剤、触媒、硬化剤等を適宜混合した公知の絵柄形成用印刷インキ等でグラビア印刷、オフセット印刷、又はシルクスクリーン印刷等の既知の印刷手段を用いて設ける。絵柄層１２は、一部にパターン状（例えば木目、布目、図形、文字等の絵柄模様）に設けても、また全面に設けても良い。例えば絵柄を部分的に設けるのは、絵柄の一部（例えば木目柄の照り部分）を特に強調させたい場合等であり、全面的に設けるのはベタ状の絵柄模様において全体的にパール感や干渉的外観を現出させる場合等である。尚、特に図示しないが本発明では絵柄１２を形成せずに化粧紙原紙１１自体に着色や絵柄が形成されたものを用いてもよい。
【００８４】
上記ベヒクルとしては熱可塑性樹脂、熱硬化性樹脂、電離放射線硬化性樹脂等の中から必要な物性、印刷適性等に応じて適宜選択したものを使用する。また、顔料としては、通常使用される有機系または無機系の顔料が使用できる。希釈溶剤としてはベヒクルの樹脂、顔料等の着色剤、その他添加物の溶解、分散能力があり、また適度な乾燥性を有する液体溶剤が使用される。一般には溶解度パラメータがベヒクルと近似する液体溶剤を選定するのが溶解性の点から好ましい。
【００８５】
本発明の別の実施形態においては、紙質化粧材は、原紙の表面に樹脂被覆層を設け、その表面に模様状凹部を形成し、該樹脂被覆層の表面の凹部に通常の着色インキをワイピング充填しワイピングインキ層を設け、その最表面にさらに耐摩耗性樹脂層を形成することもできる。また原紙の表面に直接、部分的に凹部及びワイピングインキ層を設けてもよい。
【００８６】
ワイピング充填した着色インキのワイピングインキ層を形成するには以下に示す方法が用いられる。原紙上に形成された表面樹脂層に公知のエンボス方法にて模様状の凹凸が設けられた原紙の全面に、着色インキを含む塗工組成物を塗工した後、その塗工物の塗工された表面樹脂層の上を、ドクターブレード、エアーナイフ或いはスポンジ等を表面材とするローラー等で拭き取り凸部の塗工組成物を除去して、凹部のみに着色インキ樹脂層が形成される。このワイピング加工は、着色した塗工組成物を用いることで、特に絵柄を木目として絵柄と凹部を同調させ、木目の導管部の外観を良好に再現することができる。尚、この場合にはその上部に形成される耐摩耗性樹脂層は透明樹脂を用いる。
化粧板の製造方法
本発明の化粧板は、上記したような、ガラス基板上に当該接着剤を塗布し硬化後に得られた被膜がＪＩＳ Ｋ５４００に準拠する鉛筆硬度試験において３Ｈ以上の硬度となる水性接着剤を、化粧板用基材表面と上記のごとき紙質化粧材との接合界面に配し、加熱加圧して接着剤を硬化させることより製造される。
【００８７】
水性接着剤の塗布量は、水性接着剤の固形分濃度、被着体の種類などによっても左右されるが、例えば、乾燥後に１０〜１００ｇ／ｍ²、好ましくは２５〜５０ｇ／ｍ²、さらに好ましくは３０〜４０ｇ／ｍ²程度の範囲となる塗布量とすることが好ましい。塗布量が上記した範囲よりも極端に少ないものであると、十分な接合強度が得られないのみでなく製品の表面硬度が十分なものとならない虞れがあり、一方、塗布量が上記した範囲よりも極端に多いものであると、表面に接着剤がしみ出したり、プレス時にはみ出した接着剤が下に垂れてプレス面を汚してしまう虞れがあるためである。水性接着剤の塗布は、はけ塗り、ロールコーター，グラビアコーターなど公知の任意の方法を用いて行うことができる。
【００８８】
接着剤を硬化させるため加熱加圧条件としては、使用する接着剤の種類等によっても左右されるが、例えば、温度４０〜２００℃で、圧力３〜２０ｋｇｆ／ｍ²程度、より好ましくは１００〜１５０℃で、圧力７〜１５ｋｇｆ／ｍ²程度であることが好ましい。上記したような加熱加圧条件において接着剤を硬化させれば、化粧板の所望の表面硬度が比較的容易に得られる。使用する装置としては特に限定されるものではなく、公知のホットプレス、例えば、油圧式単板プレス機、多段プレス機、サーボモータ式精密プレス機、ダブルベルトプレス機等を用いて実施できる。
【００８９】
このようにして得られる本発明の化粧材は、非常に高い表面硬度、具体的には、例えば、ＪＩＳ Ｋ５４００に準拠する鉛筆硬度試験において３Ｈ以上の硬度、より好ましくは４Ｈ以上の硬度を有し、表面の耐熱性も高く、また廃棄の際の問題もなく対環境性という面でも良好なものであるので、種々の用途に適し、例えばテーブルの天板等の家具、キャビネット類、建築物、車両船舶、楽器等の表面の装飾、包装材料の装飾用として有用である。特に本発明の化粧材は耐摩耗性の要求される分野に最適である。
【００９０】
【実施例】
以下、本発明の具体的実施例を示し、本発明を更に詳細に説明する。
実施例１
（接着剤の調製）
還流冷却機、攪拌機、配量装置、窒素導入管並びに加熱および冷却装置を備えた１リットル容の反応容器内に、窒素置換後、水４２５ｇ、ポリビニルアルコール（重合度１５００、鹸化度８８％）４０ｇを添加して９０℃で１時間加熱攪拌してポリビニルアルコールを溶解し、６５℃まで冷却し、その温度に維持した。以後、このように調製した溶液をポリビニルアルコール溶液と呼ぶ。
【００９１】
酢酸ビニルモノマー４６０ｇ、アクリル酸メチル２０ｇ、ｔ−ブチルハイドロパーオキシド０．５ｇを混合し、モノマー混合液とした。水５０ｇにＮ−メチロールアクリルアミド２０ｇを溶解しＮ−メチロールアクリルアミド溶液とした。水２５ｇにロンガリット０．８ｇおよび重炭酸ナトリウム０．８ｇを溶解し開始剤溶液とした。
【００９２】
ポリビニルアルコール溶液にモノマー混合液、開始剤溶液を定量で滴下し、重合を行った。重合温度は６５〜７０℃とした。その際、モノマー混合液は還流が起こらないように調節した。モノマー混合液滴下開始後、Ｎ−メチロールアクリルアミドの滴下を開始した。モノマー混合液とＮ−メチロールアクリルアミド溶液の滴下は同時に終了するようにした。
モノマー混合液滴下終了後、１時間７０℃に保持した。開始剤溶液の滴下はモノマー混合液の滴下終了後、１時間長く行った。その後室温まで冷却し取り出した。固形分は約５０％であった。
【００９３】
得られたエマルジョン１００質量部に対し、チタン白（チタン工業株式会社製：ＫＤ）３質量部を配合して主剤エマルジョン（Ａ）とした。
【００９４】
そして、この主剤エマルジョン（Ａ）１００質量部に硬化剤として硬化剤Ｙ（コニシ株式会社製：塩化アルミニウム５０％水溶液）５質量部を配合して、接着剤を調製した。
【００９５】
なお、平滑なガラス基板上に当該接着剤を塗布し、硬化させて、１００μｍ程度の厚さの硬化被膜を形成し、この硬化被膜に対し、常温（２３℃±３℃）にて、ＪＩＳ Ｋ５４００に準拠する鉛筆硬度試験を行った。その後、押し当てた鉛筆の芯の形の窪みが被膜に形成されているか否かを、斜め前方から光を当て、目視および指での触感により確認し、５本引いた線のうち、２本以上に窪みができていた場合には、その鉛筆硬度は不合格と判定し、窪みが全く見られないか１本においてのみ窪みが確認された場合にはその鉛筆硬度は合格と判定する硬度試験において、得られた接着剤は、３Ｈであると評価された。
（紙質化粧材の調製）
基材としてアクリル樹脂ラテックス含浸紙（６０ｇ／ｍ²）の表面に、グラビア印刷機を用いて着色ベタ層（アクリル硝化綿混合系インキ）、絵柄層（硝化綿アルキッド混合系インキ）を順次印刷して形成し、該絵柄層の上からプライマー塗工液（二液硬化型ウレタン樹脂とブチラール樹脂の１：１の混合樹脂を酢酸エチルとメチルイソブイチルケトン（ＭＩＢＫ）の１：１（重量比）の混合溶剤で塗料化したもの）をグラビア印刷方式で塗布、乾燥して、膜厚２ｇ／ｍ²のプライマー層１５を形成した。さらにグラビアコーターを用いて下記塗料を塗工し（塗工量：２５ｇ／ｍ²ｄｒｙ）、電子線照射装置を用いて電子線を照射（１７５ｋｖ、５Ｍｒａｄ）して塗膜を架橋・硬化させて耐摩耗性表面樹脂層を設けて化粧材を得た。

（化粧板の製造）
厚さ１５ｍｍのパーティクルボード（小名浜合板製）に、上記で得られた水性接着剤を７０ｇ／ｍ² の塗布量（乾燥後の塗布量 ３５ｇ／ｍ²）で５℃雰囲気下に塗布した後、上記で得られた紙質化粧材を載置した。なお、載置は開放１分以内、閉鎖２分以内とした。その後、ホットプレス装置を用い１５０℃、３０ｋｇｆ／ｍ²にて３０秒という条件で熱圧し、接着剤を硬化させ化粧板を得た。得られた化粧板につき以下に示す評価方法によって表面硬度、耐熱性を評価した。また別途、以下に述べる方法で作業性の評価を行った。得られた結果を表１に示す。
実施例２
実施例１におけるものと同様に、基材としてアクリル樹脂ラテックス含浸紙（６０ｇ／ｍ²）の表面に、グラビア印刷機を用いて着色ベタ層（アクリル硝化綿混合系インキ）、絵柄層（硝化綿アルキッド混合系インキ）を順次印刷して形成し、該絵柄層の上からプライマー塗工液（二液硬化型ウレタン樹脂とブチラール樹脂の１：１の混合樹脂を酢酸エチルとメチルイソブイチルケトン（ＭＩＢＫ）の１：１（重量比）の混合溶剤で塗料化したもの）をグラビア印刷方式で塗布、乾燥して、膜厚２ｇ／ｍ²のプライマー層１５を形成した。さらにグラビアコーターを用いて下記樹脂組成物（２）を塗工し（塗工量：１５ｇ／ｍ²ｄｒｙ）、電子線照射装置を用いて電子線を照射（１７５ｋｖ、５Ｍｒａｄ）して塗膜を架橋・硬化させて耐摩耗性表面樹脂層を設けて化粧材を得た。
＜樹脂組成物（２）＞
ジペンタエリスリトールヘキサアクリレート １４重量部
トリメチロールプロパントリアクリレート ５０重量部
エチレングリコールジアクリレート １０重量部
シリカ微粉体 ０．５重量部
アクリロイル変性シリコーン ６重量部
シリコーンオイル ７重量部
このようにして得られた化粧材を実施例１における化粧材の代りに用いた以外は、実施例１と同様にして化粧板を製造し、同様の評価を行った。得られた結果を表１に示す。
実施例３
秤量３０ｇ／ｍ²の建材用薄葉紙の表面に２液硬化型ウレタン系樹脂からなる印刷インキにて着色ベタ印刷層をグラビア印刷法によって形成した。次いで、前記着色ベタ印刷層上に、絵柄層（硝化綿アルキッド混合系インキ）を順次印刷して形成し、該絵柄層の上から下記組成よりなるトップコートインキを１０ｇ／ｍ²（ｄｒｙ）の塗工量になるように塗布した後、９０℃の熱風で乾燥して耐摩耗性表面樹脂層を有する化粧材を得た。
＜トップコートインキ＞
アクリルポリオール ４２ 重量部
ヘキサメチレンジイソシアネート ２０ 重量部
メチル化メラミン ３．５重量部
アクリル樹脂ビーズ １８ 重量部
消泡剤 ０．７重量部
溶剤 ６７ 重量部
このようにして得られた化粧材を実施例１における化粧材の代りに用いた以外は、実施例１と同様にして化粧板を製造し、同様の評価を行った。得られた結果を表１に示す。
実施例４
ＬＳ−１２ＡＷ（株式会社オーシカ製、ユリア系接着剤）５０質量部に塩化アンモニウム（純正化学試薬１級）の２０％水溶液１．２５質量部を加え、良く攪拌した後、ＣＨ７冬型（コニシ株式会社製、酢酸ビニルエマルジョン）５０質量部を加え、攪拌し、接着剤として使用した以外は、実施例１と同様にして化粧板を製造し、同様の評価を行った。得られた結果を表１に示す。
【００９６】
なお、用いた接着剤の被膜につき実施例１と同様の硬度試験を行ったところ、鉛筆硬度は５Ｈであると評価された。
比較例１
接着剤としてＣＨ７４ＢＬ３（コニシ株式会社製、酢酸ビニル樹脂エマルジョン）を用いた以外は実施例１と同様にして化粧板を製造し、同様の評価を行った。得られた結果を表１に示す。
【００９７】
なお、用いた接着剤の被膜につき実施例１と同様の硬度試験を行ったところ、鉛筆硬度は６Ｂであると評価された。
比較例２
秤量３０ｇ／ｍ²の建材用薄葉紙の表面に２液硬化型ウレタン系樹脂からなる印刷インキにて着色ベタ印刷層をグラビア印刷法によって形成した。次いで、前記着色ベタ印刷層上に、絵柄層（硝化綿アルキッド混合系インキ）を順次印刷して形成して、化粧材とした。
【００９８】
このようにして得られた化粧材を実施例１における化粧材の代りに用いた以外は、実施例１と同様にして化粧板を製造し、同様の評価を行った。得られた結果を表１に示す。
評価方法
表面硬度の評価
得られた化粧板表面の硬度を、常温（２３℃±３℃）にて、ＪＩＳ Ｋ５４００に準拠する鉛筆硬度試験方法により調べた。試験の後、押し当てた鉛筆の芯の形の窪みが被膜に形成されているか否かを、斜め前方から光を当て、目視および指での触感により確認し、５本引いた線のうち、２本以上に窪みができていた場合には、その鉛筆硬度は不合格と判定し、窪みが全く見られないか１本においてのみ窪みが確認された場合にはその鉛筆硬度は合格と判定し、以下の３段階によって評価した。
○：３Ｈ以上
△：Ｈ〜２Ｈ
×：Ｆ以下
耐熱性の評価：アイロン試験
接着後の化粧板を３日間養生の後、化粧板表面に２００℃にしたアイロン（松下電工株式会社：ＮＩ−Ａ３６）を載せて１分間加熱し、直ちにカッターで表面をクロスカットして化粧紙を引き剥がし、そのときの状態を以下の２段階で評価した。
○：化粧紙が紙破する。または、パーティクルボードが材破する。
×：化粧紙が容易に剥離し、材破が見られない。
作業性の評価
雰囲気温度および材温１０℃にて、前記パーティクルボード（小名浜合板製）に各実施例および各比較例の所定の接着剤を、７０ｇ／ｍ² の塗布量（乾燥後の塗布量３５ｇ／ｍ²）でそれぞれ塗布し、その上部に所定の紙質化粧材を重ね、ハンドロールで５回押えて、脱気、仮圧締し、静置した。その後、３分間経過後の紙質化粧材の状態を観察し、以下の２段階で評価した。
○：化粧材がパーティクルボードに被着した状態でおさまっている。
×：化粧材が巻き上がってしまい、端部側においてパーティクルボードより剥がれてしまう。
【００９９】
【表１】

【０１００】
【発明の効果】
以上述べたように、本発明によれば、非常に高い表面硬度、および高い耐熱性を有し、かつ廃棄の際の問題もなく、対環境性という面でも良好な化粧材を得ることできる。
【図面の簡単な説明】
【図１】 本発明に係る化粧材の一実施形態の構造を模式的に示す断面図である。
【符号の簡単な説明】
１０ 紙質化粧材
１１ 化粧紙原紙
１２ 絵柄
１３ 被覆樹脂
２０ 化粧板用基材
３０ 水性接着剤[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a decorative board and a manufacturing method thereof. More specifically, the present invention relates to a decorative board having good surface hardness, good workability during production, and few problems during disposal, and a method for producing the same.
[0002]
[Prior art]
Conventionally, as a decorative board for creating furniture, building interiors, cabinets, etc., melamine in which decorative materials as surface materials are laminated on wooden boards such as MDF, particle board, plywood, and inorganic boards such as dielight So-called synthetic resin decorative boards such as decorative boards, dup decorative boards, and polyester decorative boards are often used.
[0003]
Generally, a melamine decorative board uses melamine resin-impregnated paper as a surface layer and phenol resin-impregnated paper as a backing material (and it is possible to laminate one or more paper materials and the like as necessary). And it laminates | stacks on base materials, such as a plywood, For example, it manufactures by a high pressure hot press using DAP resin (diallyl phthalate) resin.
[0004]
Also, in general, a dap decorative board is made by impregnating a DAP resin after printing on a paper material with good thermosetting resin impregnation property, and drying it from above. The laminates are produced by stacking the substrates in order and pressing them at high temperature and high pressure.
[0005]
Furthermore, the polyester decorative board by the film method is a method in which a decorative material printed on a wooden base material such as plywood is bonded, and after the polyester resin is applied thereon, the surface is covered with a film and the resin is cured and molded. Produced.
[0006]
However, these decorative plates have a relatively thick resin layer formed on the surface thereof, and it is necessary to separate and dispose of the base material portion and the resin layer on the surface in consideration of the environment during disposal. This is a problem because the disposal process becomes complicated.
[0007]
In addition, these decorative plates use a backing material or a core material impregnated with at least one resin selected from a phenol resin and a diallyl phthalate resin, so that the material is expensive. That is, since these are impregnated with a prepreg of a phenol resin or a diallyl phthalate resin and then dried, the number of steps is increased and the cost is increased.
[0008]
On the other hand, there is also known a decorative board formed by adhering decorative paper or a decorative sheet to a substrate surface using an aqueous adhesive such as vinyl acetate emulsion or ethylene vinyl alcohol.
[0009]
Such a decorative board does not cause the problem as in the melamine decorative board as described above. However, the decorative board manufactured using such a water-based adhesive does not sufficiently improve the surface hardness. The surface is likely to be scratched, dented, etc. due to contact with it, and for example, it is not sufficient in terms of heat resistance of the surface when assuming use for a table top, etc., and its use is limited It was a thing.
[0010]
In addition, as a method for improving the wear resistance of the decorative paper itself used, for example, as disclosed in Japanese Patent No. 2740943, a binder made of a crosslinkable resin and spherical particles having a hardness higher than that of the crosslinkable resin There is known a method of forming a resin coating layer by applying a coating composition containing. If the decorative paper obtained in this way is used, the surface hardness of the decorative board formed by applying the decorative paper using an aqueous adhesive such as vinyl acetate emulsion or ethylene vinyl alcohol as described above has a surface hardness. It can be expected to improve, but there is still room for improvement.
[0011]
[Problems to be solved by the invention]
Accordingly, it is an object of the present invention to provide a decorative board having good surface hardness and surface heat resistance, good workability at the time of production, and few problems at the time of disposal, and a method for producing the same.
[0012]
[Means for Solving the Problems]
The above-described problem is a decorative board formed by applying a paper-type decorative material on a base material for a decorative board via an adhesive, and the adhesive is applied after the adhesive is applied onto a glass substrate and cured. The obtained coating film is achieved by a decorative board characterized by being a water-based adhesive having a hardness of 3H or more in a pencil hardness test according to JIS K5400.
[0013]
In one embodiment of the present invention, the adhesive is 10 to 100 g / m after drying.²A decorative board that is applied at a coating amount of
[0014]
In a preferred embodiment of the present invention, there is further shown a decorative board in which the adhesive is an aqueous adhesive having at least one reactive group selected from the group consisting of a methylol group and an acetoacetyl group.
[0015]
In a further preferred embodiment of the present invention, the water-based adhesive is selected from an organic acid, an acidic metal salt, and an inorganic acid in an emulsion containing polyvinyl alcohol and a vinyl acetate polymer having a methylol group in the molecule. A decorative board which is a water-based adhesive containing at least one kind of curing agent is shown.
[0016]
In a preferred embodiment of the present invention, the paper-type decorative material is precoated paper obtained by previously forming a resin coating layer on the surface, and more preferably, the resin coating layer is formed of a crosslinkable resin and a binder. A decorative board is shown which is formed from a coating composition containing spherical particles having a hardness higher than that of the functional resin.
[0017]
The above-described problem is also achieved by using a water-based adhesive in which a coating obtained by applying the adhesive on a glass substrate and curing it has a hardness of 3H or more in a pencil hardness test in accordance with JIS K5400. It is also achieved by a method for manufacturing a decorative board, which is provided at a bonding interface with a decorative material and is heated and pressed to cure the adhesive.
[0018]
In one embodiment of the method of the present invention, the water-based adhesive is 10 to 100 g / m after drying.²A method for producing a decorative board is shown to be applied in an application amount.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail based on embodiments.
[0020]
FIG. 1 is a cross-sectional view schematically showing the configuration of one embodiment of the decorative board of the present invention.
[0021]
As shown in FIG. 1, in the decorative board of the present invention, a paper-type decorative material 10 is applied onto a decorative board substrate 20 via an adhesive 30. In this embodiment, the paper decorative material 10 is provided with a predetermined pattern 12 on the surface of the base paper 11, and a resin coating layer 13 is further formed thereon.
adhesive
The adhesive 30 used in the decorative board of the present invention is such that the coating obtained after applying the adhesive on a glass substrate and curing is 3H or more, more preferably 4H or more in a pencil hardness test according to JIS K5400. It is a water-based adhesive that provides hardness. The “water-based adhesive” in this specification includes a water-soluble adhesive and a water-dispersible adhesive.
[0022]
The evaluation method of this pencil hardness test in this specification is as follows in detail. That is, the adhesive is applied onto a smooth glass substrate and cured at 130 ° C. for 5 minutes to form a cured film having a thickness of about 100 μm. The cured film is cooled at room temperature (23 ° C. ± 3 ° C.) for 1 hour, and then subjected to a pencil hardness test (8.4.1 testing method) according to JIS K5400 at room temperature (23 ° C. ± 3 ° C.). . After the test, whether or not a depression in the shape of a pressed pencil core is formed on the film is illuminated from diagonally forward and confirmed by visual and tactile sensation with fingers, and among the five drawn lines, When two or more dents are formed, the pencil hardness is determined to be unacceptable, and when no dent is observed or only one dent is confirmed, the pencil hardness is determined to be acceptable. Is.
[0023]
In the test conducted by the present inventors, the depth is about 5 μm or more by surface measurement with a contact surface roughness meter having a sample pitch (resolution in the length direction) of 5 μm and a resolution in the depth direction of 0.0333 μm. If there was, it could be identified as a depression surely by visual observation and tactile sensation with a finger in the pencil hardness test as described above. However, although the rubbing trace can be confirmed visually, it may not be confirmed by the tactile sensation with the finger and the above surface measurement. In this case, it was determined that there was a dent according to the visual result. Also, there was a case where the rubbing trace could be confirmed only at a specific angle, but this was basically judged according to JIS by the presence or absence of the rubbing trace from the angle of 45 degrees with respect to the plate surface perpendicular to the pencil moving direction. .
[0024]
As described above, in the present invention, when a decorative board is produced using a water-based adhesive, a makeup finally obtained by using a water-based adhesive having a surface hardness of a formed film of a predetermined value or more is used. It was possible to obtain a product having a very high surface hardness of the plate, sufficient heat resistance, and high workability during production.
[0025]
Although it does not necessarily limit as an aqueous adhesive which becomes 3H or more in such a pencil hardness test based on JIS K5400, For example, at least any one chosen from the group which consists of a methylol group and an acetoacetyl group A water-based adhesive having a reactive group can be exemplified.
[0026]
Examples of the adhesive having a methylol group include urea resins, melamine resins, phenol resins, resorcinol resins alone or the like, such as polyvinyl acetate emulsion, polyvinyl alcohol, aqueous acrylic resin, aqueous polyester resin, aqueous polyolefin resin, etc. Examples thereof include those containing a polymer emulsion obtained by copolymerizing a monomer containing a methylol group such as N-methylol (meth) acrylamide with vinyl acetate.
[0027]
Examples of the compound having an acetoacetyl group include (a) acetoacetylated polyvinyl alcohol and acetoacetyl in the form of an aqueous solution obtained by acetoacetylating a water-soluble polymer compound such as polyvinyl alcohol, hydroxyalkyl cellulose, and starch. Hydroxyalkylcellulose, acetoacetylated starch, etc., and (b) monomers containing acetoacetyl groups, such as allyl acetoacetate, vinyl acetoacetate, 2-acetoacetoxyethyl acrylate, 2-acetoacetoxyethyl methacrylate, Vinyl esters such as 2-acetoacetoxypropyl acrylate, 2-acetoacetoxypropyl methacrylate, and α and β ethylenic monomers such as vinyl acetate and vinyl esters of saturated fatty acids branched at the α-position , Methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) acrylate such as nonyl (meth) acrylate, vinyl such as styrene, acrylonitrile, ethylene, vinyl chloride Examples include acetoacetyl group-containing polymer compounds in the form of aqueous emulsions obtained by emulsion copolymerization with monomers and the like, and (c) aqueous polymer emulsions obtained by emulsion polymerization using acetoacetylated polyvinyl alcohol as an emulsifier. it can.
[0028]
In the present invention, various types of water-based adhesives as described above can be combined, and various known additives can be blended as necessary, and various water-soluble polymers, water-dispersible polymers, etc. It is also possible to blend.
[0029]
In addition, the aqueous adhesive used in the present invention desirably has a viscosity (23 ° C. ± 3 ° C.) in use of 1 to 100 Pa · s, more preferably about 7 to 15 Pa · s. When the viscosity is extremely smaller than the above-mentioned range, the penetration into the paper-type decorative material and the base material for the decorative board is too large. In addition, the workability is not bad because the adhesive adheres to the press device, etc., and a sufficient amount of adhesive does not remain at the bonding interface by penetrating into the base material for the decorative plate, Sufficient bonding strength cannot be obtained, delamination is likely to occur at the bonding interface, and when the paper-type decorative material is placed on the decorative board substrate, the adhesive strength is temporarily weak. This is because there is a great risk of inconveniences such as roll-up at the edge of the paper-type decorative material and the need for temporary pressing with an iron or the like, resulting in poor workability. On the other hand, the viscosity is extremely higher than the above range. The bigger one is the coat Fear of resulting in problems such as uneven surface of the product occurs because the ring work can not be difficult and uniform coating because large.
[0030]
In the present invention, among such water-based adhesives, at least one selected from organic acids, acidic metal salts, and inorganic acids is used in an emulsion containing polyvinyl alcohol and a vinyl acetate polymer having a methylol group in the molecule. A water-based adhesive containing the above curing agent is particularly preferred. This type of water-based adhesive is suitable in terms of viscosity as described above, and is not only good from the viewpoint of workability, but also can be obtained with a particularly high surface hardness of the decorative board finally obtained. is there.
[0031]
As an example of such a preferred methylol group-containing vinyl acetate-based adhesive, 0 to 100 parts by mass of a (meth) acrylic acid ester having 1 to 8 carbon atoms with respect to 100 parts by mass of the vinyl acetate monomer in the presence of polyvinyl alcohol, N -The thing which makes the main ingredient the emulsion obtained by carrying out the emulsion copolymerization of 0.1-20 mass parts of methylol (meth) acrylamide by a well-known method can be illustrated preferably.
[0032]
Polyvinyl alcohol also acts as a protective colloid during emulsion copolymerization. As the polyvinyl alcohol, polyvinyl alcohol having a saponification degree of 80 mol% or more and a polymerization degree of about 500 to 3000 can be used. The amount of the protective colloid used can be selected within a range that does not impair the stability and initial adhesiveness of the emulsion. For example, 0.5 to 30 parts by mass with respect to 100 parts by mass of the total amount of vinyl acetate and copolymerizable monomers. Degree. If necessary, a surfactant may be further combined with a protective colloid made of polyvinyl alcohol.
[0033]
If desired, various additives such as tackifier (for example, rosin, rosin ester, dicyclopentadiene resin, petroleum resin, styrene resin, terpene resin, coumarone-indene resin and hydrogenated products thereof) , Plasticizer [phthalic acid ester (dibutyl phthalate, dihexyl phthalate, dioctyl phthalate, di-2-ethylhexyl phthalate, etc.), long chain aliphatic polyvalent carboxylic acid ester (dibutyl apeate, di-2-ethylhexyl apeate, dibutyl sebate, etc.), Phosphoric acid derivatives (triphenyl phosphate, tri (2-ethylhexyl) phosphate, etc.), polyester, etc.], film-forming aids (cellosolves such as ethyl cellosolve, butyl cellosolve), methyl carbitol, ethyl carbitol, butyl carbonate Carbitols such as bitol), organic solvents (water-soluble or water-insoluble solvents selected from alcohols, esters, ketones, ethers, hydrocarbons), water-soluble polymers [for example, the polyvinyl alcohol, water-soluble cellulose, etc. Derivatives (such as cellulose ethers such as methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, hydroxypropyl methyl cellulose, carboxymethyl cellulose, water-soluble acrylic resins, etc.), fillers, colorants, preservatives, antifoaming agents, and the like may be included. In addition, the usage-amount of these components can be selected in the range which does not impair the film forming property, the initial adhesiveness of a water-based adhesive, stability, etc.
Cosmetic base material
The base material 20 for a decorative board used in producing the decorative board of the present invention is not particularly limited as long as it is a porous base material, and those used as a substrate for a conventionally known decorative board can be used. . For example, wood veneer, wood plywood, particle board, MDF (medium density fiber board) and other wood boards, gypsum boards, plaster boards such as gypsum slag boards, calcium silicate boards, asbestos slate boards, lightweight foam concrete boards, hollow extrusion Cement board such as cement board, pulp cement board, asbestos cement board, fiber cement board such as wood chip cement board, ceramic board such as earthenware, magnetism, earthenware, earthenware, glass, firewood, iron plate, galvanized steel sheet, polyvinyl chloride sol Metal plates such as coated steel plates, aluminum plates, copper plates, polyolefin resin plates, acrylic resin plates, ABS plates, polycarbonate plates, etc., phenol resin plates, urea resin plates, unsaturated polyester resin plates, polyurethane resin plates , Epoxy resin plate, thermosetting resin plate such as melamine resin plate, phenol resin, urea resin, unsaturated polyester A resin plate such as a so-called FRP plate in which a resin, a polyurethane resin, an epoxy resin, a melamine resin, a diallyl phthalate resin or the like is impregnated and cured into a glass fiber nonwoven fabric, fabric, paper, or other various fibrous base materials. Can be mentioned.
[0034]
In the present invention, among these, it is particularly preferable to use a wooden substrate from the viewpoint that good adhesive strength can be obtained by the aqueous adhesive as described above.
Paper-type cosmetics
On the other hand, the base paper 11 of the paper-type decorative material 10 may be any material as long as it can penetrate a water-based adhesive 30 (and an impregnating resin that forms a resin coating layer 13 provided as necessary) as will be described later. For thin paper, fine paper, Japanese paper, kraft paper, titanium paper, linter paper, paperboard, gypsum board paper, coated paper, art paper, sulfated paper, glassine paper, parchment paper, paraffin paper, paper, polyvinyl chloride resin sol A so-called vinyl wallpaper original fabric that has been coated or dry-laminated, a paper-reinforced paper reinforced with a resin, a resin-impregnated paper, or the like can be used. Furthermore, a paper-like sheet can also be used as the decorative paper base paper 11 as long as the water-based adhesive 30 (and the impregnating resin that forms the resin coating layer 13 provided as necessary) can penetrate. Examples of the paper-like sheet include glass fibers, asbestos, potassium titanate fibers, alumina fibers, silica fibers, inorganic fibers such as carbon fibers, and woven or non-woven fabrics using organic resins such as polyester and vinylon. . Of these, thin papers that have been improved in suitability for building materials, inter-paper reinforced papers, resin-impregnated papers, so-called construction base papers such as titanium papers, and the like can be preferably used as the base paper 11.
[0035]
The base paper 11 has a basis weight of 10 g / m.²~ 150g / m²Degree, especially the basis weight is 20 g / m²~ 100g / m²Degree, more preferably the basis weight is 25 g / m²~ 90g / m²A degree is preferred.
[0036]
Further, as the base paper 11, the basis weight is 30 g / m from the viewpoint of obtaining good characteristics more economically.²~ 45g / m²From the standpoint of obtaining a better surface hardness, a thin paper of the order of 50 g / m²~ 85g / m²From the viewpoint of the concealability of the substrate, paper called titanium paper mixed with a concealing pigment such as titanium oxide can be cited as appropriate.
[0037]
As in the embodiment shown in FIG. 1, the paper-type decorative material 10 has a resin coating layer 13 formed on the surface in order to improve its surface hardness, wear resistance, antifouling property, and the like. Is desirable.
[0038]
As resin which forms the resin coating layer 13, it is used as crosslinkable resin of conventionally well-known cosmetics, such as ionizing radiation curable resin or a thermosetting resin (a room temperature curable resin and a two-component reaction curable resin are included). Resin can be used. As a crosslinkable resin, an ionizing radiation curable resin has a fast curing speed and good workability, and it is easy to adjust the physical properties of the resin such as flexibility and hardness. A sheet-like decorative material is preferable because it can be continuously produced efficiently. Moreover, selection of said crosslinkable resin can be suitably selected according to the use of a decorative material. The crosslinkable resin is coated by dispersing spherical particles in an uncrosslinked state, followed by crosslinking and curing to complete the coating film.
[0039]
As the crosslinking density of the crosslinkable resin increases, the wear resistance improves, but the flexibility decreases. Therefore, it is preferable that the crosslink density of the crosslinkable resin is appropriately selected in accordance with the wear resistance and flexibility depending on the use of the decorative material and the like in accordance with the type of the base material. The crosslink density can be expressed by, for example, the average molecular weight between crosslinks shown in the following formula (2).
[0040]
[Expression 1]

(However, the total molecular weight is Σ (number of moles of each component × molecular weight of each component), and the number of crosslinking points is Σ [{(number of functional groups of each component−1) × 2} × each component). Mole number].)
When the type of crosslinkable resin is the same, the smaller the average molecular weight between crosslinks (that is, the higher the crosslink density), the more the crosslinkable resin of the binder will hold the spherical particles firmly and the wear resistance will be further improved. It is. Therefore, the wear resistance can be further improved by adjusting the average molecular weight between crosslinks of the crosslinkable resin as small as possible without impairing flexibility.
[0041]
The ionizing radiation curable resin used as the crosslinkable resin is specifically curable by ionizing radiation in which prepolymers, oligomers, and / or monomers having polymerizable unsaturated bonds or epoxy groups are appropriately mixed in the molecule. Composition is used. Here, the ionizing radiation means an electromagnetic wave or a charged particle beam having an energy quantum capable of polymerizing or cross-linking molecules, and usually an ultraviolet ray or an electron beam is used.
[0042]
Examples of the above prepolymers and oligomers include unsaturated polyesters such as unsaturated dicarboxylic acid and polyhydric alcohol condensates, polyester methacrylates, polyether methacrylates, polyol methacrylates, methacrylates such as melamine methacrylates, polyester acrylates, epoxy acrylates, Examples thereof include acrylates such as urethane acrylate, polyether acrylate, polyol acrylate, and melamine acrylate, and a cationic polymerization type epoxy compound.
[0043]
Examples of the urethane acrylate include polyether-based urethane (meth) acrylates represented by the following general formula obtained by reacting polyether diol and diisocyanate, for example.
[0044]
[Chemical 1]

(Wherein R¹, R²Each represents hydrogen or a methyl group, X is a diisocyanate residue, n is an integer of 1 to 3, and m is an integer of 6 to 60. )
Examples of the diisocyanate used in the polyether-based urethane (meth) acrylate include isophorone diisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, and tolylene diisocyanate. Examples of the polyether diol include polyoxypropylene glycol, polyoxyethylene glycol, and polyoxytetramethylene glycol having a molecular weight of 500 to 3000.
[0045]
Hereinafter, production examples of urethane acrylate will be shown. In a glass reaction vessel equipped with a dropping funnel, a thermometer, a reflux condenser, and a stirring rod, 1000 parts of polytetramelalene glycol having a molecular weight of 1000 and 444 parts of isophorone diisocyanate were charged and reacted at 120 ° C. for 3 hours. Then, it cooled to 80 degrees C or less, 232 mass parts of 2-hydroxyethyl acrylate was added, and it was made to react until an isocyanate group lose | disappeared at 80 degreeC, and urethane acrylate was obtained.
[0046]
Examples of monomers used for ionizing radiation curable resins include styrene monomers such as styrene and α-methylstyrene, methyl acrylate, 2-ethylhexyl acrylate, methoxyethyl acrylate, butoxyethyl acrylate, butyl acrylate, acrylic Acrylic acid esters such as methoxybutyl acid and phenyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, methoxyethyl methacrylate, ethoxymethyl methacrylate, phenyl methacrylate, methacrylic acid esters such as lauryl methacrylate, Acrylic acid-2- (N, N-diethylamino) ethyl, methacrylic acid-2- (N, N-dimethylamino) ethyl, acrylic acid-2- (N, N-dibenzylamino) methyl, acrylic acid-2- (N, N-diethyl Mino) Substituted amino alcohol esters of unsaturated acid such as propyl, unsaturated carboxylic acid amides such as acrylamide and methacrylamide, ethylene glycol diacrylate, propylene glycol diacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate, 1 , 6 Hexanediol diacrylate, compounds such as triethylene glycol diacrylate, polyfunctional compounds such as dipropylene glycol diacrylate, ethylene glycol diacrylate, propylene glycol dimethacrylate, diethylene glycol dimethacrylate, and / or 2 in the molecule Polythiol compounds having more than one thiol group, such as trimethylolpropane trithioglycolate, trimethylolpropane trithio Examples include propylate and pentaerythritol tetrathioglycol.
[0047]
Usually, the above compounds are used alone or in combination of two or more as required, but in order to impart ordinary coating suitability to the ionizing radiation curable resin, the prepolymer or polythiol is added in an amount of 5% by weight or more. The monomer and / or polythiol is preferably 95% by weight or less.
[0048]
When selecting the monomer, if the cured product is required to be flexible, the amount of the monomer is reduced within a range that does not hinder the suitability of coating, or a monofunctional or bifunctional acrylate monomer is used. The structure is as follows. If the cured product requires wear resistance, heat resistance, solvent resistance, etc., use a larger amount of monomer or use a tri- or higher functional acrylate monomer as long as there is no problem in coating suitability. Thus, a high crosslink density structure can be obtained. It is also possible to adjust the coating suitability and the physical properties of the cured product by mixing a 1,2-functional monomer and a tri- or higher functional monomer.
[0049]
Examples of the monofunctional acrylate monomer as described above include 2-hydroxy acrylate, 2-hexyl acrylate, phenoxyethyl acrylate, and the like. Further, ethylene glycol diacrylate, 1,6-hexanediol diacrylate, etc. are used as the bifunctional acrylate, and trimethylolpropane triacrylate, pentaerythritol tri (tetra) acrylate, dipentaerythritol hexaacrylate are used as the trifunctional or higher acrylate. An acrylate etc. are mentioned.
[0050]
Furthermore, an ionizing radiation non-curable resin for adjusting physical properties such as flexibility and surface hardness of the cured product can be added to the ionizing radiation curable resin. As the ionizing radiation non-curable resin, thermoplastic resins such as urethane-based, fiber-based, polyester-based, acrylic-based, butyral-based, polyvinyl chloride, and polyvinyl acetate are used. The butyral system is preferable from the viewpoint of flexibility.
[0051]
In the case of irradiating with ultraviolet rays to cure the ionizing radiation curable resin having the above composition, acetophenones, benzophenones, Michler benzoylbenzoate, α-aminoxime ester, tetramethyl are used as photopolymerization initiators. Thiuram monosulfide, thioxanthones, aromatic diazonium salts, aromatic sulfonium salts, metallocenes, and n-butylamine, triethylamine, tri-n-butylphosphine as photopolymerization accelerators (sensitizers) Can be used.
[0052]
Specifically, the thermosetting resin used as the crosslinkable resin is phenol resin, urea resin, diallyl phthalate resin, melamine resin, guanamine resin, unsaturated polyester resin, polyurethane resin (including two-component polyurethane). Epoxy resin, amino alkyd resin, melamine-urea cocondensation resin, silicon resin, polysiloxane resin, and the like. A crosslinking agent, a curing agent such as a polymerization initiator, a polymerization accelerator or the like is added to these as necessary. As the curing agent, usually, isocyanate or organic sulfonate is unsaturated polyester resin or polyurethane resin, amine is epoxy resin, peroxide such as methyl ethyl ketone peroxide and radical initiator such as azoisobutyl nitrile is not suitable. Often used for saturated polyester.
[0053]
As the isocyanate, a divalent or higher aliphatic or aromatic isocyanate can be used, but an aliphatic isocyanate is desirable from the viewpoint of preventing thermal discoloration and weather resistance. Specific examples of the isocyanate include tolylene diisocyanate, xylylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, and lysine diisocyanate.
[0054]
As the above-mentioned two-component polyurethane, a first liquid composed of a polyol compound having an average of two or more hydroxyl groups in its molecular structure and a second liquid composed of a polyisocyanate compound have an equivalent ratio of hydroxyl groups to isocyanate groups. What was mix | blended so that it might become 0.7-1.5 is mentioned.
[0055]
Examples of the epoxy resin include an epoxy resin having an average of two or more epoxy groups in its molecular structure and a mono- or poly-amine having three or more active hydrogens that react with the epoxy group in one molecule. What mix | blended so that ratio of an epoxy equivalent and the active hydrogen equivalent of a mono or polyamine may be 0.7-1.5 is mentioned.
[0056]
Further, as the coating resin, a mixed resin of a thermosetting resin and an ionizing radiation curable resin can be used.
[0057]
Furthermore, as a coating resin, in a state where it is not completely cured such as uncured or semi-cured, it is solid at room temperature, and has thermoplasticity and solvent solubility, but by drying or cooling after coating, Resin that gives a coating that is non-flowable (touch-drying) and non-tacky even when touched by hand (hereinafter referred to as a resin that is solid at room temperature without being completely cured) Can also be used. For example, it is a solvent-free composition that has fluidity when heated and has a curable resin composition that becomes solid at room temperature when cooled, or a composition that contains a solvent and flows in a solvent-containing state. And a curable resin that becomes solid when the solvent is volatilized.
[0058]
In yet another embodiment, the same resin as the above-described aqueous adhesive 30 for bonding the paper-like decorative material 10 onto the decorative board substrate 20 is used as the coating resin 13 on the decorative paper base paper 11. Is also possible. In this embodiment, after the water-based adhesive is attached to both sides of the decorative paper base paper 11 by dipping or the like, it is placed on the base material 20 for decorative board, and an appropriate release paper or the like is placed on the upper part and cured. It is also possible to process.
[0059]
The amount of the covering resin 13 impregnated into the decorative paper base paper 11 (% by weight with respect to the decorative paper base paper) is not particularly limited, but is generally preferably 40% to 80%. If the impregnation amount is less than 40%, the entire decorative paper base paper may not be sufficiently impregnated with the resin. On the other hand, if the impregnation amount exceeds 80%, excessive impregnation may occur.
[0060]
In addition to the above resin components, the coating composition for forming the coating resin layer includes various spherical particles, colorants such as dyes and pigments, and other CaCO._Three, BaSO_FourAdditives usually added to paints and inks such as fillers such as known matting modifiers and extenders such as nylon resin beads, defoaming agents, leveling agents and thixotropic agents can be added.
[0061]
In addition, in the coating composition for the abrasion-resistant resin layer, a solvent having a boiling point of 70 ° C. to 150 ° C. at normal pressure can be dissolved in order to adjust the viscosity. It can be used in the range of 30% by weight or less in the product. When the amount of the solvent added is in the range of 30% by weight or less, the drying is smooth and the production speed is not greatly reduced.
[0062]
As the above-mentioned solvent, those usually used for paints, inks and the like can be used. Specific examples include aromatic hydrocarbons such as toluene and xylene, ketones such as acetone, methyl ethyl ketone methyl isobutyl ketone, cyclohexanone, and ethyl acetate. , Acetates such as isopropyl acetate and amyl acetate, alcohols such as methyl alcohol, ethyl alcohol and isopropyl alcohol, ethers such as dioxane, tetrahydrofuran and diisopropyl ether, and mixtures of two or more thereof.
[0063]
As the coating resin layer in the present invention, in particular, a coating resin layer formed from a coating composition containing a binder made of a crosslinkable resin as described above and spherical particles having a hardness higher than that of the crosslinkable resin is used. When the average film thickness of the coating resin layer provided on the surface of the material is t (mm) and the average particle diameter of the spherical particles is d (mm), the following formula (1)
[0064]
[Expression 2]

Embodiments satisfying the above can be cited as particularly preferred.
[0065]
The spherical particles only need to be surrounded by a smooth curved surface such as a true sphere, or an elliptic sphere obtained by flattening the sphere and a shape close to the true sphere or the elliptic sphere. The spherical particles are particularly preferably spherical with no protrusions or corners on the particle surface and so-called cutting edges. Spherical particles greatly improve the wear resistance of the surface resin layer itself compared to irregularly shaped particles of the same material, and do not wear the coating device, and other objects that are in contact with the coating after it is cured The film is not worn, and the transparency of the coating film is increased. This is particularly effective when there is no cutting edge.
[0066]
It is preferable to adjust the coating composition so that the amount of the spherical particles contained in the coating resin layer is 5 to 20 parts by mass with respect to 100 parts by mass of the binder component composed of the cured crosslinkable resin. If the added amount of spherical particles is small, the effect of adding spherical particles, such as improved wear resistance, may not be sufficiently exerted. On the other hand, if the added amount of spherical particles is too large, it may serve as a binder for a crosslinkable resin. The effects are impaired, and there are problems such as the possibility that the flexibility of the coating film is lowered and the workability of the coating composition is lowered.
[0067]
The particle diameter of the spherical particles is usually preferably 5 to 100 μm (average particle diameter). If the average particle size of the spherical particles is less than 5 μm, the film may become opaque. On the other hand, if the average particle size exceeds 100 μm, the surface smoothness of the film may be reduced. As the particle size of the spherical particles decreases, the wear resistance decreases. On the other hand, when the particle size of the spherical particles is increased, the wear resistance is improved. However, if the particle size is too large, uniform coating at the time of coating becomes difficult. For example, when the thickness of the abrasion-resistant resin layer is formed to 10 to 30 μm, the particle diameter of the spherical particles 5 is preferably in the range of 10 to 50 μm.
[0068]
More preferably, the average particle size of the spherical particles is selected according to the thickness of the coating resin layer. In particular, when the average film thickness of the wear-resistant resin layer is t (mm) and the average particle diameter of the spherical particles is d (mm), the spherical particles are selected so as to satisfy the above formula (1). desirable. If the average particle diameter d (mm) of the spherical particles exceeds 2.0 t, the spherical particles may protrude from the surface of the coating resin layer, and the appearance of the layer may be deteriorated. On the other hand, when the average particle diameter d (mm) of the spherical particles is less than 0.3 t, sufficient wear resistance may not be obtained.
[0069]
The material of the spherical particles only needs to be higher in hardness than the crosslinkable resin, and both inorganic particles and organic resin particles can be used. The difference in hardness between the spherical particles and the crosslinkable resin is measured by a method such as Mohs hardness or Vickers hardness, and is preferably 1 or more when expressed in terms of, for example, Mohs hardness. The spherical particles have a Knoop hardness of 1300 kg / mm.²More preferably, Knoop hardness is 1800 kg / mm²That's it.
[0070]
The Knoop hardness referred to here is the micro indentation hardness measured using a Knoop indenter, and the load when the diamond-shaped indentation was made before the test was obtained from the length of the diagonal line of the longer permanent recess. It is a value represented by the quotient divided by the projected area of the dent. This test method is described in ASTM C-849.
[0071]
Specific examples of the material of the spherical particles include inorganic particles such as α-alumina, silica, chromium oxide, iron oxide, diamond and graphite, and organic resin particles such as synthetic resin beads such as crosslinked acrylic. The α-alumina includes fused alumina, Bayer method alumina and the like, and inorganic particles other than the above include zirconia, titania, and eutectic mixtures with these, fused alumina, Bayer method alumina and the like. As a method of making the shape of these inorganic particles spherical, the above-mentioned pulverized amorphous inorganic compound is charged into a high-temperature furnace having a melting point or higher and melted, and is made spherical by using surface tension. Examples include a method in which a material melted at a high temperature equal to or higher than the melting point is blown out in a mist shape to form a sphere.
[0072]
Spherical α-alumina can be mentioned as a particularly preferable spherical particle because it is very hard and has a great effect on wear resistance, and a spherical shape can be obtained relatively easily. As described in JP-A-2-55269, the spherical α-alumina is made of a mineralizing agent or a crystallizing agent such as an alumina hydrate, a halogen compound, or a boron compound, fused with alumina or sintered alumina. By adding a small amount to the pulverized product and heat-treating it at a temperature of 1400 ° C. or more for 2 hours or more, a cutting edge in alumina is reduced and a spherical shape is obtained at the same time. Such spherical alumina has various average particle diameters as “Spherical Alumina AS-10, AS-20, AS-30, AS-40, AS-50” from Showa Denko Co., Ltd. Is commercially available.
[0073]
Spherical particles can treat the particle surface. For example, dispersibility is improved by treatment with a fatty acid such as stearic acid. Further, by treating the surface with a silane coupling agent, the adhesion with the crosslinkable resin used as the binder and the dispersibility of the particles in the coating composition are improved. Examples of the silane coupling agent include alkoxysilanes having radically polymerizable unsaturated bonds such as vinyl and methacryl in the molecule, and alkoxysilanes having functional groups such as epoxy, amino, and mercapto in the molecule. The silane coupling agent uses an alkoxysilane having a radical polymerizable unsaturated bond in the case of an ionizing radiation curable resin such as (meth) acrylate, depending on the type of the crosslinkable resin used together with the spherical particles, In the case of a two-component curable urethane resin, it is preferable to select the radical polymerizable unsaturated bond, the type of functional group, and the like so that an alkoxysilane having an epoxy group or an amino group is used. Specific examples of the alkoxysilane having a radical polymerizable unsaturated bond include γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyldimethylmethoxysilane, and γ-methacryloxypropyldimethylethoxy. Silane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropylmethyldimethoxysilane, γ-acryloxypropyldimethylmethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropylmethyldiethoxysilane, γ- Alkoxysilanes with radically polymerizable unsaturated bonds in the molecule such as acryloxypropyldimethylethoxysilane and vinyltriethoxysilane, and functionalities such as epoxy, amino and mercapto in the molecule There are alkoxysilanes having.
[0074]
The method for treating the surface of the spherical particles with the silane coupling agent is not particularly limited, and a known method can be used. For example, a method of spraying a predetermined amount of a silane coupling agent while stirring the spherical particles vigorously as a dry method, or a method of spraying a predetermined amount of a silane coupling agent after dispersing the spherical particles in a solvent such as toluene as a wet method. In addition, there is a method of reacting. The processing amount (required amount) of the silane coupling agent with respect to the spherical particles is preferably a processing amount in which the minimum covering area of the silane coupling agent is 10 or more with respect to the specific surface area 100 of the spherical particles. When the minimum covering area of the spherical particles is less than 10 with respect to the specific surface area 100 of the spherical particles, there is not much effect.
[0075]
Next, a method for forming the resin coating layer 13 on the surface of the decorative paper base paper 11 using the above coating composition will be described. The resin coating layer 13 may be formed by applying the coating composition directly on the surface of the decorative paper base paper 11 or by directly forming the resin coating layer 13 on the surface of the peelable substrate, and then applying the layer to the decorative paper. A transfer coating method for transferring to the surface of the base paper 11 is used. In general, as the material of the base material 2, any of the above methods may be used when the coating composition does not penetrate, but when the decorative paper base paper 11 that penetrates the coating composition is used, In order to provide uniform decorative paper base paper with a rough surface, as well as uniform coating thickness, it is preferable to use the transfer coating method when uniform ionizing radiation intensity and uniform wear resistance are desired. .
[0076]
Direct coating methods include gravure coat, gravure reverse coat, gravure offset coat, spinner coat, roll coat, reverse roll coat, kiss coat, wheeler coat, dip coat, solid coat with silk screen, wire bar coat, flow coat, comma coat, coat A cast coat, a brush coat, a spray coat or the like can be used, but a gravure coat is preferred.
[0077]
The transfer coating method is a method shown in the following (a) to (d), in which a coating film is once formed on a thin sheet (film) substrate, crosslinked and cured, and then coated on the surface of the substrate. Laminating method (a, b) that adheres the coating film of the construction composition to the three-dimensional object together with the base material, once the coating film and, if necessary, an adhesive layer is formed on the releasable support sheet, the coating film is crosslinked and cured. A transfer sheet (c) or the like that peels only the support sheet after the coating sheet side is bonded to a three-dimensional object can be used. In addition, the same various coating means as said direct coating method can be used for the method of forming an abrasion-resistant resin layer in a thin sheet | seat base material.
(A) Injection molding simultaneous transfer method as disclosed in JP-B-2-42080, JP-B-4-19924 and the like. Alternatively, an injection molding simultaneous laminating method as disclosed in Japanese Patent Publication No. 50-19132.
(B) A vacuum forming simultaneous transfer method as disclosed in JP-A-4-288214 and JP-A-5-57786. Alternatively, a vacuum forming simultaneous laminating method as disclosed in Japanese Patent Publication No. 56-45768.
(C) A lapping simultaneous transfer method or a lapping simultaneous laminating method as disclosed in JP-B-59-51900, JP-B-61-5895, JP-B-3-2666, and the like.
(D) V-cutting simultaneous laminating method disclosed in Japanese Utility Model Publication No. 15-31122, or V-cutting simultaneous transfer method disclosed in Japanese Patent Publication No. 56-7866.
[0078]
As one of transfer coating methods, for example, when an ionizing radiation curable resin is used as a crosslinkable resin, a method of sequentially performing the following steps (A) to (D) can be used (Japanese Patent Laid-Open No. 2). -26673 publication etc.).
(A) A step of applying an uncured liquid ionizing radiation curable resin composition to a non-absorbable and releasable synthetic resin sheet.
(B) The process of laminating so that the application surface of the said ionizing radiation curable resin composition may contact a base material.
(C) A step of irradiating the coating film of the ionizing radiation curable resin composition with ionizing radiation to crosslink and cure.
(D) A step of peeling and removing the synthetic resin sheet.
[0079]
In the above step, when using an ionizing radiation curable resin diluted with a solvent, a step of drying the solvent is performed between steps (A) and (B). According to the above-described method, even in the case of the base paper 11 having high permeability, the so-called “backlash” in which the resin escapes to the back side of the base material is surely prevented, and the surface of the base material has good resistance. An abradable resin layer can be easily formed.
[0080]
When an ionizing radiation curable resin is used as the crosslinkable resin, the ionizing radiation irradiating device used for curing the resin is an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc, black when irradiating ultraviolet rays. A light source such as a light lamp or a metal halide lamp is used, and when irradiating an electron beam, a cockroft Walton type, a bandegraph type, a resonant transformer type, an insulated core transformer type, or a linear type, a dynamitron type, Various electron beam accelerators such as a high-frequency type are used.
[0081]
The irradiation amount of an electron beam is usually 100 to 1000 keV, preferably 100 to 300 keV. The electron beam is irradiated at an irradiation amount of about 0.1 to 30 Mrad. If the irradiation amount is less than 0.1 Mrad, curing may be insufficient, and if the irradiation amount exceeds 30 Mrad, the cured coating film or substrate may be damaged. Moreover, the irradiation amount in the case of curing with ultraviolet rays is preferably 50 to 1000 mJ / cm.²It is. If the irradiation amount of ultraviolet rays is less than 50 mJ / cm, curing may be insufficient, and the irradiation amount is 1000 mJ / cm.²If it exceeds, the cured coating film may turn yellow.
[0082]
When a thermosetting resin is used as the crosslinkable resin, the coating composition may be heated after coating in order to accelerate the curing reaction of the thermosetting resin. For example, in the case of an isocyanate curable unsaturated polyester resin or a polyurethane resin, the heating time is usually about 1 to 5 days at 40 to 60 ° C., and in the case of a polysiloxane resin, usually 1 to 80 to 150 ° C. It is about 300 minutes.
[0083]
Further, the pattern 12 formed on the paper-type decorative material 10 may be formed either before or after the resin coating layer 13 is formed on the surface side of the decorative paper base paper 11, but before the resin coating layer is formed. Preferably formed. The pattern 12 is a known pattern-forming printing ink or the like in which a vehicle is appropriately mixed with known pigments, colorants such as dyes, extender pigments, solvents, stabilizers, plasticizers, catalysts, curing agents, and the like as required. It is provided using known printing means such as gravure printing, offset printing, or silk screen printing. The pattern layer 12 may be partially provided in a pattern (for example, a pattern such as a wood grain, a texture, a figure, or a character), or may be provided on the entire surface. For example, the pattern is partially provided when particularly a part of the pattern (for example, the shining part of the wood grain pattern) is particularly emphasized, and the entire pattern is provided with a solid pearl pattern or a solid pattern. This is the case when an interference appearance is revealed. Although not particularly illustrated, in the present invention, the decorative paper base paper 11 itself may be formed with coloring or a pattern without forming the pattern 12.
[0084]
As the vehicle, those appropriately selected from thermoplastic resins, thermosetting resins, ionizing radiation curable resins and the like according to necessary physical properties, printability and the like are used. As the pigment, a commonly used organic or inorganic pigment can be used. As the diluting solvent, a liquid solvent having the ability to dissolve and disperse vehicle resins, colorants such as pigments, and other additives, and has an appropriate drying property is used. In general, it is preferable from the viewpoint of solubility to select a liquid solvent whose solubility parameter approximates that of the vehicle.
[0085]
In another embodiment of the present invention, the paper-type decorative material is provided with a resin coating layer on the surface of the base paper, a patterned recess is formed on the surface, and normal colored ink is wiped on the recess of the surface of the resin coating layer. It is also possible to provide a wiping ink layer that is filled, and to further form an abrasion-resistant resin layer on the outermost surface. Moreover, you may provide a recessed part and a wiping ink layer partially directly on the surface of a base paper.
[0086]
In order to form a wiping ink layer of colored ink filled with wiping, the following method is used. After coating the surface resin layer formed on the base paper with a coating composition containing a colored ink on the entire surface of the base paper provided with pattern-like irregularities by a known embossing method, the coating of the coated product is applied. The surface of the surface resin layer is wiped off with a roller or the like using a doctor blade, air knife or sponge as a surface material to remove the coating composition of the convex portions, and a colored ink resin layer is formed only in the concave portions. In this wiping process, by using a colored coating composition, it is possible to synchronize the pattern and the recess particularly with the pattern as a wood grain, and to reproduce the appearance of the conduit portion of the wood well. In this case, a transparent resin is used for the wear-resistant resin layer formed on the upper part.
Decorative plate manufacturing method
The decorative board of the present invention is a decorative sheet made of the above-mentioned water-based adhesive that has a hardness of 3H or more in a pencil hardness test in accordance with JIS K5400. It is manufactured by placing it at the bonding interface between the board substrate surface and the paper-like decorative material as described above, and curing the adhesive by heating and pressing.
[0087]
The application amount of the aqueous adhesive depends on the solid content concentration of the aqueous adhesive, the type of adherend, etc., for example, 10 to 100 g / m after drying.², Preferably 25-50 g / m²More preferably, it is 30-40 g / m²It is preferable to set the coating amount within a range. If the coating amount is extremely smaller than the above-mentioned range, there is a possibility that not only sufficient bonding strength cannot be obtained but also the surface hardness of the product may not be sufficient, while the coating amount is in the above-mentioned range. If the amount is too much, the adhesive may ooze out on the surface, or the adhesive that oozes out during pressing may hang down and soil the press surface. The aqueous adhesive can be applied by any known method such as brush coating, roll coater, or gravure coater.
[0088]
The heating and pressurizing conditions for curing the adhesive depend on the type of adhesive used and the like. For example, the temperature is 40 to 200 ° C. and the pressure is 3 to 20 kgf / m.²Degree, more preferably 100-150 ° C., pressure 7-15 kgf / m²It is preferable that it is about. If the adhesive is cured under the heating and pressing conditions as described above, the desired surface hardness of the decorative board can be obtained relatively easily. The apparatus to be used is not particularly limited, and can be carried out using a known hot press, for example, a hydraulic single plate press, a multistage press, a servo motor precision press, a double belt press or the like.
[0089]
The decorative material of the present invention thus obtained has a very high surface hardness, specifically, for example, a hardness of 3H or more, more preferably a hardness of 4H or more in a pencil hardness test in accordance with JIS K5400. Since the surface has high heat resistance, and there is no problem in disposal, it is good in terms of environmental friendliness, so it is suitable for various applications, such as furniture such as table tops, cabinets, buildings, It is useful for decoration of the surface of vehicle ships, musical instruments, etc., and for decoration of packaging materials. In particular, the decorative material of the present invention is most suitable for a field requiring wear resistance.
[0090]
【Example】
Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention.
Example 1
(Preparation of adhesive)
In a 1 liter reaction vessel equipped with a reflux condenser, a stirrer, a metering device, a nitrogen inlet tube and a heating and cooling device, after substitution with nitrogen, water 425 g, polyvinyl alcohol (polymerization degree 1500, saponification degree 88%) 40 g Was added and heated and stirred at 90 ° C. for 1 hour to dissolve the polyvinyl alcohol, cooled to 65 ° C., and maintained at that temperature. Hereinafter, the solution thus prepared is referred to as a polyvinyl alcohol solution.
[0091]
A monomer mixed solution was prepared by mixing 460 g of vinyl acetate monomer, 20 g of methyl acrylate, and 0.5 g of t-butyl hydroperoxide. 20 g of N-methylolacrylamide was dissolved in 50 g of water to prepare an N-methylolacrylamide solution. Rongalite 0.8 g and sodium bicarbonate 0.8 g were dissolved in 25 g of water to form an initiator solution.
[0092]
A monomer mixed solution and an initiator solution were added dropwise to the polyvinyl alcohol solution in a fixed amount to carry out polymerization. The polymerization temperature was 65 to 70 ° C. At that time, the monomer mixture was adjusted so that reflux did not occur. After the start of dropping under the monomer mixture droplet, the dropwise addition of N-methylolacrylamide was started. The dropping of the monomer mixture and the N-methylolacrylamide solution was completed at the same time.
After completion of dropping under the monomer mixture droplet, the temperature was maintained at 70 ° C. for 1 hour. The initiator solution was dropped for 1 hour after the monomer mixture was dropped. Thereafter, it was cooled to room temperature and taken out. The solid content was about 50%.
[0093]
With respect to 100 parts by mass of the obtained emulsion, 3 parts by mass of titanium white (manufactured by Titanium Industry Co., Ltd .: KD) was blended to obtain a main emulsion (A).
[0094]
Then, 5 parts by mass of curing agent Y (manufactured by Konishi Co., Ltd .: 50% aqueous solution of aluminum chloride) as a curing agent was blended with 100 parts by mass of the main emulsion (A) to prepare an adhesive.
[0095]
In addition, the said adhesive agent is apply | coated on a smooth glass substrate, it is made to harden | cure, and the cured film about 100 micrometers thick is formed, JIS K5400 with respect to this cured film at normal temperature (23 degreeC +/- 3 degreeC). The pencil hardness test according to After that, whether or not a depression in the shape of the pressed pencil core is formed on the film is confirmed by shining light from the front in front and visually and touching with a finger. If there is a dent above, the pencil hardness is judged as unacceptable, and if no dent is seen at all or only one dent is confirmed, the pencil hardness is judged as acceptable. The resulting adhesive was evaluated to be 3H.
(Preparation of paper cosmetics)
Acrylic resin latex impregnated paper (60 g / m²), A colored solid layer (acrylic nitrified cotton mixed ink) and a pattern layer (nitrified cotton alkyd mixed ink) are sequentially printed on the surface of the pattern layer using a gravure printing machine. Gravure printing of liquid (coating of 1: 1 mixed resin of two-component curable urethane resin and butyral resin with 1: 1 (weight ratio) mixed solvent of ethyl acetate and methyl isobutyl ketone (MIBK)) Coating and drying by the method, film thickness 2g / m²The primer layer 15 was formed. Further, apply the following paint using a gravure coater (coating amount: 25 g / m²dry), an electron beam irradiation apparatus was used to irradiate an electron beam (175 kv, 5 Mrad) to crosslink and cure the coating film to provide a wear-resistant surface resin layer to obtain a cosmetic material.

(Manufacture of decorative panels)
The particle board (made of Onahama plywood) with a thickness of 15 mm is coated with the aqueous adhesive obtained above at 70 g / m.²Coating amount (coating amount after drying 35 g / m²) Was applied in an atmosphere at 5 ° C., and the paper decorative material obtained above was placed. The placement was within 1 minute for opening and within 2 minutes for closing. Then, using a hot press device, 150 ° C., 30 kgf / m²And pressure was applied for 30 seconds to cure the adhesive and obtain a decorative board. The obtained decorative board was evaluated for surface hardness and heat resistance by the following evaluation methods. Separately, workability was evaluated by the method described below. The obtained results are shown in Table 1.
Example 2
As in Example 1, acrylic resin latex impregnated paper (60 g / m²), A colored solid layer (acrylic nitrified cotton mixed ink) and a pattern layer (nitrified cotton alkyd mixed ink) are sequentially printed on the surface of the pattern layer using a gravure printer. Gravure printing liquid (1: 1 mixed resin of two-component curable urethane resin and butyral resin made into paint with 1: 1 (weight ratio) mixed solvent of ethyl acetate and methyl isobutyl ketone (MIBK)) Coating and drying by the method, film thickness 2g / m²The primer layer 15 was formed. Furthermore, the following resin composition (2) was applied using a gravure coater (coating amount: 15 g / m).²dry), an electron beam irradiation apparatus was used to irradiate an electron beam (175 kv, 5 Mrad) to crosslink and cure the coating film to provide a wear-resistant surface resin layer to obtain a cosmetic material.
<Resin composition (2)>
14 parts by weight of dipentaerythritol hexaacrylate
50 parts by weight of trimethylolpropane triacrylate
10 parts by weight of ethylene glycol diacrylate
Silica fine powder 0.5 parts by weight
6 parts by weight of acryloyl-modified silicone
7 parts by weight of silicone oil
A decorative board was produced in the same manner as in Example 1 except that the decorative material thus obtained was used instead of the decorative material in Example 1, and the same evaluation was performed. The obtained results are shown in Table 1.
Example 3
Weighing 30g / m²A colored solid printing layer was formed on the surface of the thin paper for building materials with a printing ink made of a two-component curable urethane resin by a gravure printing method. Subsequently, a pattern layer (nitrified cotton alkyd mixed ink) is sequentially printed on the colored solid print layer, and a top coat ink having the following composition is formed on the pattern layer by 10 g / m.²After applying so that the coating amount was (dry), it was dried with hot air at 90 ° C. to obtain a cosmetic material having a wear-resistant surface resin layer.
<Topcoat ink>
Acrylic polyol 42 parts by weight
Hexamethylene diisocyanate 20 parts by weight
3.5 parts by weight of methylated melamine
Acrylic resin beads 18 parts by weight
Antifoaming agent 0.7 parts by weight
Solvent 67 parts by weight
A decorative board was produced in the same manner as in Example 1 except that the decorative material thus obtained was used instead of the decorative material in Example 1, and the same evaluation was performed. The obtained results are shown in Table 1.
Example 4
After adding 1.25 parts by mass of a 20% aqueous solution of ammonium chloride (pure chemical reagent grade 1) to 50 parts by mass of LS-12AW (made by Ushika Co., Ltd., urea-based adhesive), and stirring well, CH7 winter type (Konishi Co., Ltd.) A decorative board was produced in the same manner as in Example 1 except that 50 parts by mass of (made by vinyl acetate emulsion) was added, stirred, and used as an adhesive, and the same evaluation was performed. The obtained results are shown in Table 1.
[0096]
In addition, when the hardness test similar to Example 1 was done about the coating film of the used adhesive agent, pencil hardness was evaluated to be 5H.
Comparative Example 1
A decorative board was produced in the same manner as in Example 1 except that CH74BL3 (manufactured by Konishi Co., Ltd., vinyl acetate resin emulsion) was used as an adhesive, and the same evaluation was performed. The obtained results are shown in Table 1.
[0097]
In addition, when the hardness test similar to Example 1 was done about the coating film of the used adhesive agent, pencil hardness was evaluated to be 6B.
Comparative Example 2
Weighing 30g / m²A colored solid printing layer was formed on the surface of the thin paper for building materials by a gravure printing method using a printing ink made of a two-component curable urethane resin. Next, a pattern layer (nitrified cotton alkyd mixed ink) was sequentially printed on the colored solid print layer to form a decorative material.
[0098]
A decorative board was produced in the same manner as in Example 1 except that the decorative material thus obtained was used instead of the decorative material in Example 1, and the same evaluation was performed. The obtained results are shown in Table 1.
Evaluation methods
Evaluation of surface hardness
The hardness of the obtained decorative board surface was examined by a pencil hardness test method according to JIS K5400 at normal temperature (23 ° C. ± 3 ° C.). After the test, whether or not a depression in the shape of a pressed pencil core is formed on the film is confirmed by applying light from diagonally forward and visually and tactilely with a finger. If there are two or more dents, the pencil hardness is judged to be unacceptable, and if no dent is seen or only one dent is confirmed, the pencil hardness is judged to be acceptable. The evaluation was made according to the following three stages.
○: 3H or more
Δ: H to 2H
×: F or less
Evaluation of heat resistance: Iron test
After the bonded decorative plate is cured for 3 days, an iron (Matsushita Electric Industrial Co., Ltd .: NI-A36) at 200 ° C. is placed on the decorative plate surface and heated for 1 minute, and the surface is immediately cross-cut with a cutter to make decorative paper Was peeled off, and the state at that time was evaluated in the following two stages.
○: The decorative paper breaks. Or, the particle board breaks down.
X: The decorative paper peels easily and no material breakage is observed.
Evaluation of workability
At an atmospheric temperature and a material temperature of 10 ° C., the predetermined adhesive of each example and each comparative example was 70 g / m on the particle board (made by Onahama plywood).²Coating amount (coating amount 35 g / m after drying)²), A predetermined paper-like decorative material was stacked on the upper part, pressed with a hand roll five times, deaerated, temporarily pressed, and allowed to stand. Thereafter, the state of the paper-type decorative material after the elapse of 3 minutes was observed and evaluated in the following two stages.
○: The cosmetic material is covered with the particle board.
X: The decorative material rolls up and peels off from the particle board on the end side.
[0099]
[Table 1]

[0100]
【The invention's effect】
As described above, according to the present invention, it is possible to obtain a cosmetic material having a very high surface hardness and high heat resistance, no problem in disposal, and good environmental resistance.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view schematically showing the structure of an embodiment of a decorative material according to the present invention.
[Brief description of symbols]
10 Paper-type cosmetics
11 Base paper for decorative paper
12 designs
13 Coating resin
20 Base material for decorative board
30 Water-based adhesive

Claims (8)

A decorative board formed by applying a paper-type decorative material on a base material for a decorative board via an adhesive, wherein the adhesive is a film obtained by applying the adhesive on a glass substrate and curing it. but, JIS K5400 ing and hardness of at least 5H in pencil hardness test conforming to, the emulsion comprising a urea resin and vinyl acetate polymers having a methylol group, at least one selected from organic acids, acidic metal salts and inorganic acids, A decorative board, characterized in that it is a water-based adhesive containing at least one type of curing agent , and the base paper of the paper-type decorative material is a paper-reinforced paper having a basis weight of 50 to 85 g / m ² . The decorative board according to claim 1 , wherein the adhesive is applied at an application amount of 10 to 100 g / m ² after drying. The decorative board according to claim 1 or 2 , wherein the paper-type decorative material is precoated paper in which a coating layer made of a crosslinkable resin is previously formed on the surface. The decorative board according to claim 3 , wherein the resin coating layer is formed from a coating composition containing a binder made of a crosslinkable resin and spherical particles having a hardness higher than that of the crosslinkable resin. The adhesive was coated on a glass substrate was obtained after curing the coating has ing and hardness of at least 5H measured by a pencil hardness test conforming to JIS K5400, the hard coating layer to the emulsion containing urea resin and vinyl acetate polymers having a methylol group, an organic A base paper made of a base material for a decorative board and an inter-paper reinforced paper having a basis weight of 50 to 85 g / m ² is blended with an aqueous adhesive containing at least one curing agent selected from acids, acidic metal salts, and inorganic acids. A method for producing a decorative board, comprising: arranging at a bonding interface with a paper-type decorative material and curing the adhesive by heating and pressing. The method for producing a cosmetic material according to claim 5 , wherein the heating and pressurization are performed at a temperature of 40 to 200 ° C. and a pressure of 3 to 20 kgf / m ² . The method for producing a cosmetic material according to claim 5 or 6 , wherein the heat and pressure are a temperature of 100 to 150 ° C and a pressure of 7 to 15 kgf / m ² . The said coating amount is 30-40 g / m < ² >, The manufacturing method of the decorative board as described in any one of Claims 5-7 .

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