JP3582920B2 - Aqueous paint composition for road marking - Google Patents

Description

（ここで、Ｘはラジカル重合性官能基、Ｒ^１、Ｒ^２は炭素数１〜４のアルキル基、ｎは１〜３の整数を示す。）
【００１０】
具体的には、アクリル酸又はメタクリル酸と有機シランとのエステルであるγ−（メタ）アクリロキシプロピルトリメトキシシラン、γ−（メタ）アクリロキシプロピルメチルジメトキシシラン、γ−（メタ）アクリロキシプロピルジメチルメトキシシラン、γ−（メタ）アクリロキシプロピルトリエトキシシラン、γ−（メタ）アクリロキシプロピルメチルジエトキシシラン、γ−（メタ）アクリロキシプロピルジメチルエトキシシラン；ビニルトリメトキシシラン、ビニルメチルジメトキシシラン、ビニルトリエトキシシラン、ビニルメチルジエトキシシラン；トリメトキシシリルスチレン、ジメトキシメチルシリルスチレン、トリエトキシシリルスチレン、ジエトキシメチルシリルスチレン等が例示される。
これらの中では、（ａ）γ−（メタ）アクリロキシプロピルトリメトキシシランから選択されるシランならびに（ｂ）γ−（メタ）アクリロキシプロピルメチルジメトキシシラン、γ−（メタ）アクリロキシプロピルメチルジエトキシシラン及びγ−（メタ）アクリロキシプロピルトリエトキシシランから選択されるシランを、（ａ）成分のシラン／（ｂ）成分のシランの重量比が６０／４０〜０／１００ となるように使用するのが特にエマルジョンの保存安定性の点で好ましい。
【００１１】
これら（ロ）成分の単量体は、１種のみ又は２種以上を組み合わせて用いることができるが、エマルジョンの保存安定性と塗膜の特性からみて、その使用量はラジカル重合性単量体全量の１〜２０重量％とするのが好ましい。
（ロ）成分の量がラジカル重合性単量体全量の１重量％未満では形成された塗膜の架橋密度が低く、耐摩耗性、耐汚染性や路面との接着性が不十分であるし、また２０重量％を超えると架橋密度が高すぎ、形成された塗膜がもろくなり、さらにはエマルジョンの保存安定性も損なわれる。
【００１２】
（ハ）成分のその他のラジカル重合性単量体は、必要に応じてエマルジョンの安定性、塗料組成物の安定性、塗装時の作業性、塗膜の諸物性の向上のために用いられるが、本発明の目的を損なわないため、（ハ）成分はラジカル重合性単量体全量の２０重量％以下の使用量とする。このような単量体としては具体的に、アクリル酸、メタクリル酸、無水マレイン酸等のカルボキシル基又はその無水物基含有単量体、アクリル酸又はメタクリル酸のエステル、アミド及びその他の２−ヒドロキシエチル（メタ）アクリレート、２−ヒドロキシプロピル（メタ）アクリレート等のヒドロキシル基含有単量体、（メタ）アクリルアミド、Ｎ−メチロール（メタ）アクリルアミド、Ｎ−メトキシメチル（メタ）アクリルアミド、Ｎ−ブトキシメチル（メタ）アクリルアミド、ダイアセトン（メタ）アクリルアミド等のアミド基含有単量体、ジメチルアミノエチル（メタ）アクリレート等のアミノ基含有単量体、メトキシエチル（メタ）アクリレート、ブトキシエチル（メタ）アクリレート等のアルコキシル基含有単量体、グリシジル（メタ）アクリレート、グリシジルアリルエーテル等のグリシジル基含有単量体、ジビニルベンゼン、アリル（メタ）アクリレート、エチレングリコールジ（メタ）アクリレート、ジエチレングリコールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、ブタンジオールのジ（メタ）アクリレート、ヘキサンジオールのジ（メタ）アクリレート等の１分子中にラジカル重合性不飽和基を２個以上有する単量体、酢酸ビニル、プロピオン酸ビニル等のビニルエステル単量体、スチレン、ビニルトルエン、α−メチルスチレン等の芳香族ビニル単量体、アクリロニトリル、メタクリロニトリル等のシアン化ビニル単量体、塩化ビニル、臭化ビニル等のハロゲン化ビニル単量体などが例示され、これらの中から１種又は２種以上が用いられる。
【００１３】
（１）成分のアルコキシシリル基含有アクリル系エマルジョンに導入されているアルコキシシリル基は水中で徐々に加水分解してシラノール基を生成し、水の蒸発とともにシラノール基同士の脱水縮合、あるいはシラノール基とアルコキシシリル基の脱アルコール縮合によりアクリル系共重合体の分子内又は分子間の架橋反応が起り、塗膜の強度、耐水性、耐摩耗性向上に寄与する。また、アルコキシシリル基あるいはシラノール基は配合される無機微粉末との親和性が強く、着色顔料、充填剤の分散を容易にし、高充填化による乾燥性の向上がはかれるし、更にまた、路面のコンクリート等との接着性を大巾に向上させる。
【００１４】
アクリル系共重合体に結合したアルコキシシリル基は、このように極めて有用である反面、エマルジョンあるいはこれを配合した塗料の貯蔵中にアルコキシシリル基の加水分解が進みすぎると、エマルジョンの粒子中で既に共重合体分子内あるいは分子間架橋が起り、最低造膜温度を上昇させて塗装後の水蒸発時に連続塗膜を形成し得なくなったり、あるいは、さらにエマルジョンや配合塗料の粘度を著しく上昇せしめ、甚だしい時はゲル化したりして配合や塗装が不能になる。いずれにせよ、実用的価値が失われるので貯蔵中の最低造膜温度の上昇を防止することが望ましい。
そのためには、前述のような種類と量比、あるいはラジカル重合性単量体全量中の割合で、（ロ）成分のアルコキシシリル基含有ラジカル重合性単量体を使用することが好ましい。さらに、後述するコア／シェル重合法や、エマルジョンのｐＨの調整もこの目的に有効である。
【００１５】
（１）成分のアルコキシシリル基含有アクリル系エマルジョン中のアクリル系共重合体のガラス転移温度（以下Ｔｇと略す）は造膜性、塗膜特性の点から０〜７０℃とされるが、好ましくは１０〜５０℃である。Ｔｇが０℃未満では塗膜が柔らかすぎて耐摩耗性、耐汚染性、塗膜強度が劣り、７０℃を超えると、通常の造膜助剤量の添加では常温造膜が難しく、特に寒冷地では５〜１０℃でも造膜しなければならないため、過剰の造膜助剤の添加が必要となり、塗料の粘度上昇を引きおこし、塗装機による塗装が困難となり、更には塗膜の耐水性が低下する。
また、アクリル系共重合体の平均分子量（ポリスチレン換算重量平均分子量）は１５万以上とされるが、検討の結果、意外にも１５万以上という高い方がすべてに優れることが見出されたのである。平均分子量が１５万未満では塗膜強度、耐摩耗性、耐汚染性が劣り、良好な塗膜が得られない。平均分子量１５万以上は、ラジカル重合開始剤量及び重合温度を調整すれば、通常、達成することができる。
さらに、エマルジョンの固形分濃度は４３重量％以上とされる。４３重量％未満では塗料中の不揮発分が相対的に低くなり乾燥性が劣るので、４３重量％以上が必要である。
【００１６】
（１）成分のアルコキシシリル基含有アクリル系エマルジョンは、通常の乳化重合法により製造できる。即ち、単量体を一括して重合させる一括重合法、単量体単独又はイオン交換水、界面活性剤と共に乳化した単量体乳化液の追加重合法、コアとシェルの単量体組成を変えたコア／シェル重合法、連続的に単量体組成を変えて重合するパワー重合法等が例示される。エマルジョンあるいは塗料の保管中のアルコキシシリル基の架橋反応の進行を抑えるには、コア／シェル重合法も有用である。即ちコア部にアルコキシシリル基含有ラジカル重合性単量体を共重合させ、アルコキシシリル基を含まないシェル部でコア部を保護するか、又は反応性の高いトリメトキシシリル基含有ラジカル重合性単量体をコア部に共重合させ、反応性の低いジメトキシシリル基、トリエトキシシリル基、ジエトキシシリル基含有ラジカル重合性単量体をシェル部に共重合させる方法もある。
【００１７】
乳化重合時に使用する界面活性剤としては、アルキル又はアルキルアリル硫酸塩、アルキル又はアルキルアリルスルホン酸塩、ジアルキルスルホコハク酸塩等のアニオン性界面活性剤、アルキルトリメチルアンモニウムクロライド、アルキルベンジルアンモニウムクロライド等のカチオン性界面活性剤、ポリオキシエチレンアルキルフェニルエーテル、ポリオキシエチレンアルキルエーテル、ポリオキシエチレンカルボン酸エステル等のノニオン性界面活性剤などが例示される。これらの界面活性剤は１種のみ用いても２種以上を併用してもよいが、その量が少なすぎると製造したエマルジョンに凝塊物が多く発生するようになるし、得られる塗膜も良好な物性を示さないようになる。また、多すぎる場合にもエマルジョンの粒径が細かくなってエマルジョンの粘度が上りすぎるし、塗膜の耐水性も悪くなってくる。従って、界面活性剤の使用量は全単量体 １００重量部に対し ０．５〜１５重量部が好ましく、特には１〜７重量部が好ましい。
【００１８】
また、本発明で使用されるエマルジョンから形成される塗膜の耐水性等の耐久性を著しく向上させ、溶液タイプに近い性能を得るためには、重合時に界面活性剤として反応性界面活性剤を使用するのが好ましい。この反応性界面活性剤の例としては、特開昭５４−１４４３１７ 、特開昭５５−１１５４１９ 、特開昭６２−３４９４７、特開昭５８−２０３９６０ 、特開平４−５３８０２ 、特開昭６２−１０４８０２ 、特開昭４９−４０３８８、特開昭５２−１３４６５８ 、特公昭４９−４６２９１各号公報等に記載されているアニオン性反応性界面活性剤、および特開昭５３−１２６０９３ 、特開昭５６−２８２０８、特開平４−５０２０４ 、特開昭６２−１０４８０２ 、特開昭５０−９８４８４各号公報等に記載されている非イオン性反応性界面活性剤、あるいは第４級アンモニウム塩や第３級アミン塩の基とラジカル重合性基とを含むカチオン性反応性界面活性剤などが挙げられる。
【００１９】
本発明で使用されるラジカル重合開始剤としては過硫酸カリウム、過硫酸アンモニウム等の過硫酸塩、過酸化水素水、ｔ−ブチルハイドロパーオキシド、アゾビスアミジノプロパンの塩酸塩等の水溶性タイプ、ベンゾイルパーオキシド、キュメンハイドロパーオキシド、ジブチルパーオキシド、ジイソプロピルパーオキシジカーボネート、クミルパーオキシネオデカノエート、クミルパーオキシオクトエート、アゾビスイソブチロニトリル等の油溶性タイプなどが例示される。さらに必要に応じ、酸性亜硫酸ナトリウム、ロンガリット、Ｌ−アスコルビン酸等の還元剤を併用したレドックス系も使用することができる。この重合開始剤の使用量は全単量体 １００重量部に対して通常は ０．１〜１０重量部とすればよいが、好ましくは ０．５〜５重量部である。
【００２０】
本発明で使用されるアルコキシシリル基含有アクリル系エマルジョンを製造するにあたって、アルコキシシリル基の加水分解や縮合を抑えるため重合中のｐＨを ６．５〜７．５ にコントロールすることが好ましい。重合は通常１０〜９０℃の温度で行われる。乳化重合の最後には、得られた共重合体の望ましくない架橋反応を防ぎ保存安定性をさらに良好とするために、塩基性物質を添加してエマルジョンのｐＨを７〜８に調整することが好ましく、そのための添加物としてアンモニア、アミン類、アルカノールアミン類、苛性アルカリ等が例示される。
【００２１】
（２）成分の着色顔料としては、白色顔料である酸化チタン、黄色顔料である黄鉛その他、弁柄、カーボンブラック、シアニンブルー、シアニングリーン等が例示され、その使用量はエマルジョンの固形分 １００重量部に対して６０〜 ２００重量部とされる。６０重量部未満では隠蔽力が不足し、 ２００重量部を超えると分散が困難になり、塗料粘度が高くなってくるし、経済的にも不利になる。
【００２２】
（３）成分の充填剤には、炭酸カルシウム、炭酸バリウム、珪酸マグネシウム、珪酸カルシウム、硫酸カルシウム、硅石粉、セライト、クレー、タルク、マイカ、アルミナ等が例示され、その使用量はエマルジョンの固形分 １００重量部に対して １００〜 ４００重量部とされる。 １００重量部未満では、塗料の不揮発分が低くなり、乾燥性が劣り、 ４００重量部を超えると充填剤の分散が困難になり、塗料の粘度が高くなりすぎ、流動性が乏しくなって塗装機による塗装が困難となる。
【００２３】
本発明の塗料組成物には、更に必要に応じて分散剤、湿潤剤、可塑剤、消泡剤、造膜助剤、凍結防止剤、増粘剤等適宜添加することができる。好ましい造膜助剤としては、ブチルカルビトールアセテート、ブチルカルビトール、ブチルセロソルブ、ブチルセロソルブアセテート、ベンジルアセテート、２，２，４−トリメチル−１，３−ペンタンジオールモノイソブチレート等が例示される。
また、消泡効果のある湿潤剤としては、アセチレンアルコール、アセチレングリコール及びそれらのエチレンオキサイド付加物等が例示される。
【００２４】
【発明の実施の形態】
次に、本発明の実施の形態を例をあげて説明するが、本発明は実施例に限定されるものではない。なお、例中の部及び配合と濃度に関する％はそれぞれ重量部と重量％を示す。また、得られた各エマルジョン及び塗料組成物についてその特性を下記の方法で測定又は計算した。
【００２５】
（１）エマルジョンの特性
▲１▼共重合体のガラス転移温度（Ｔｇ）
共重合体のＴｇを下記の Ｆｏｘの式より算出した。
１／Ｔｇ＝Σ（Ｗｉ／Ｔｇｉ ）
Ｔｇ：共重合体のガラス転移温度（°Ｋ）
Ｔｇｉ ：単量体成分（ｉ）の単独重合体のガラス転移温度（°Ｋ）
Ｗｉ：共重合体中の成分（ｉ）の重量分率
▲２▼平均分子量
ＧＰＣによりポリスチレン換算の重量平均分子量として求めた。
▲３▼固形分濃度
エマルジョンを １０５℃×１時間乾燥した時の不揮発分を固形分として計算した。
▲４▼保存安定性
エマルジョンを５０℃×３０日間保存した後の造膜しうる最低温度を理学工業社製の最低造膜温度測定機で測定し、保存前のエマルジョンの最低造膜温度と比較した。上昇温度の幅により下記の基準で表示した。
◎：５℃以下、〇：５℃超〜１０℃、△：１０℃超〜２０℃、×：２０℃超
【００２６】
（２）塗料組成物の特性
▲１▼粘度
クレブストーマー粘度計で配合塗料の粘度（ＫＵ値）を測定し、下記の基準で表示した。
◎：７０〜１００ 、〇： １００超〜１３０ 、△：７０未満、×： １３０超
▲２▼塗料の保存安定性
塗料を５０℃×３０日間保存した前後の粘度変化を測定し、下記の基準で表示した。
〇：初期の粘度の１０％以内、×：初期の粘度の１０％を超える
【００２７】
（３）塗膜の特性
▲１▼不粘着乾燥性、耐摩耗性、隠蔽率及びガラスビーズ固着性標記特性をＪＩＳ Ｋ ５６６５に基づいて測定し、下記の基準で表示した。
１）不粘着乾燥性
試験ロールのタイヤに塗料が付着したか否かを肉眼で観察
◎：１０分後に付着なし、〇：１０分後付着、１５分後に付着なし、×：１５分後付着
２）耐摩耗性（１００ 回転換算の摩耗減量）
◎：２００ｍｇ 以下、〇：２００ｍｇ 超〜５００ｍｇ 以下、×：５００ｍｇ 超
３）隠蔽率
〇：０．９７以上、×：０．９７未満
４）ガラスビーズ固着性
◎：９５％以上、〇：９０％以上〜９５％未満、×：９０％未満
【００２８】
▲２▼耐汚染性
配合塗料をガラス板上にアプリケーターを用いて塗膜厚が １００±２０μｍになるように塗工し、２０℃×６５％ＲＨで８時間放置後、その塗膜上に園芸用赤玉土を付着させた試験用ロールをころがし、塗膜の汚染状況を観察して下記の基準で表示した。
◎：汚染が殆どなし、〇：少し汚染した、×：かなり汚染した
▲３▼路面との接着性
ＪＩＳ Ｋ ５４１０に規定するセメントモルタル板及びアスファルトブロックに塗膜厚が １００±２０μｍになるように塗工し、２０℃×６５％ＲＨで２４時間放置後、ＪＩＳ Ｋ ５４００に準拠し、すきま間隔５ｍｍ、ます目の数９ヶでゴバン目法により塗
膜の接着性試験を行ない下記の基準で表示した。
◎：評価点数８以上、〇：評価点数６以上〜８未満、
△：評価点数４以上〜６未満、×：評価点数４未満
▲４▼耐水性
配合塗料をガラス板上にアプリケーターを用いて塗膜厚が １００±２０μｍになるように塗工し、２０℃×６５％ＲＨで７日間放置後、５０℃の温水中に２４時間浸漬
し、表面状態を観察した。
◎：異常なし、〇：一部ブリスター発生、×：多数のブリスター発生
【００２９】
【実施例】
実施例１
攪拌機、コンデンサー、温度計及び窒素ガス導入口を備えた重合容器に、脱イオン水 １００部及びｐＨ緩衝剤として炭酸ソーダ０．０３部、ホウ酸 ０．３部を仕込み、攪拌しながら６０℃に昇温させたのち窒素置換した。これにロンガリット０．１５部、エチレンジアミン四酢酸二ナトリウムの１％水溶液０．０９部、硫酸第１鉄の１％水溶液０．０３部を添加すると同時に、メタクリル酸メチル６５部、アクリル酸ブチル１５部、スチレン１０部、γ−アクリロキシプロピルメチルジメトキシシラン１０部、ノニオン性界面活性剤ノイゲンＥＡ−１７０（第一工業製薬社製商品名） ３．２部、アニオン性界面活性剤エマールＯ（花王社製商品名） １．４部及びｔ−ブチルハイドロパーオキシド（純分６９％） ０．３部の混合液 １０４．９部を内温を６０℃に保持しながら３時間かけて攪拌下に均一に添加し、さらに６０℃で１時間反応させて重合を終了した。得られたエマルジョンの固形分濃度は５０．９％、ｐＨ ７．２であった。
このエマルジョン及び下記の標準配合例により塗料化した塗料及び塗膜の特性は表１、表２に示すとおりであった。
（標準配合例）
エマルジョンの固形分換算 １００部と、酸化チタン １００部、炭酸カルシウム ２００部、３０％ポリカルボン酸ナトリウム水溶液（分散剤）１４部、シリコーン系消泡剤４部をドライピグメンテーション法により塗料化し、レットダウンでブチルカルビトールアセテート（造膜助剤）２０部、５０％メタノール水（凍結防止剤）２０部を添加した。
【００３０】
実施例２
攪拌機、コンデンサー、温度計及び窒素ガス導入口を備えた重合容器に、脱イオン水３５部及びｐＨ緩衝剤として炭酸ソーダ０．０３部、ホウ酸 ０．３部を仕込み、攪拌しながら３０℃に昇温させたのち窒素置換した。これにＬ−アスコルビン酸０．１５部、硫酸第１鉄の１％水溶液０．０３部を添加すると同時に、メタクリル酸メチル５３部、アクリル酸ブチル３６部、アクリロニトリル５部、γ−メタクリロキシプロピルトリメトキシシラン２部、γ−メタクリロキシプロピルトリエトキシシラン２部、２−ヒドロキシエチルメタクリレート２部及びｔ−ブチルハイドロパーオキシド（純分６９％） ０．３部の混合物を下記構造式で示される反応性界面活性剤アクアロンＲＮ−２０（第一工業製薬社製商品名） ３．２部、アクアロンＨＳ−１０（第一工業製薬社製商品名） １．４部及び脱イオン水５０部の溶液中に投入し、そしてホモミキサーで乳化した １５４．９部の乳化液の中から ７．７部を重合容器に加えて重合反応させ、発熱がおさまった後、残りの乳化液を器内温を３０℃に保持しながら ２．５時間かけて攪拌下に均一に添加し、さらに３０℃で１時間反応させてエマルジョンを得た。このエマルジョンを１０％アンモニア水でｐＨ ７．０に中和した。
【化２】

上記で得られたエマルジョン及び標準配合例により塗料化した塗料及び塗膜の特性は表１、表２に示すとおりであった。
【００３１】
実施例３
実施例１の脱イオン水 １００部を １２５部におきかえる以外は実施例１と同様にして表１に示される単量体で重合を行なった。
得られたエマルジョン及びこれを標準配合例により塗料化した塗料及び塗膜の特性は表１、表２に示すとおりであった。
実施例４〜６
実施例１と同様にして表１に示される単量体で重合を行なった。得られたエマルジョン及びこれを標準配合例により塗料化した塗料及び塗膜の特性は表１、表２に示すとおりであった。
【００３２】
比較例１
攪拌機、コンデンサー、温度計及び窒素ガス導入口を備えた重合容器に、脱イオン水 １００部及びｐＨ緩衝剤として炭酸ソーダ０．０３部、ホウ酸 ０．３部を仕込み、攪拌しながら６０℃に昇温させたのち窒素置換した。器内温を８０℃にさらに昇温させたのち、これにロンガリット０．１５部、エチレンジアミン四酢酸二ナトリウムの１％水溶液０．０９部、硫酸第１鉄の１％水溶液０．０３部を添加すると同時に、メタクリル酸メチル６０部、アクリル酸ブチル３６部、γ−メタクリロキシプロピルトリメトキシシラン２部、γ−メタクリロキシプロピルトリエトキシシラン２部、ノイゲンＥＡ−１７０（前出） ３．２部、エマールＯ（前出） １．４部、ｔ−ブチルハイドロパーオキシド（純分６９％） ０．３部及びドデシルメルカプタン ０．５部の混合液 １０５．４部を内温を８０℃に保持しながら３時間かけて攪拌下に均一に添加し、さらに８０℃で１時間反応させて重合を終了した。得られたエマルジョンの固形分濃度は５０．２％、ｐＨ ６．９であった。また、得られたエマルジョン及びこれを標準配合例により塗料化した塗料及び塗膜の特性は表１、表２に示すとおりであった。
【００３３】
比較例２〜４
実施例１と同様にして表１に示される単量体で重合を行なった。得られたエマルジョン及びこれを標準配合例により塗料化した塗料及び塗膜の特性は表１、表２に示すとおりであった。
特に比較例３は共重合体のガラス転移温度が高すぎて、造膜助剤であるブチルカルビトールアセテート１０部では２０℃において良好な塗膜を形成しえず、標準配合例（ブチルカルビトールアセテート２０部配合）においては塗料の粘度がＫＵ値 １３０以上となり、作業性の悪いものであった。
【００３４】
【表１】

【００３５】
【表２】

【００３６】
比較例５
実施例１で得られたエマルジョンに脱イオン水を添加して固形分濃度４０％に希釈した後、標準配合例に従って配合した塗料から得た塗膜の不粘着乾燥性を評価したが、判定は×であった。
比較例６〜９
実施例１のエマルジョンを使用して表３に示される配合で得た塗料及びその塗膜の特性は表３に示すとおりであった。
【００３７】
【表３】

【００３８】
【発明の効果】
本発明の路面標示用水性塗料組成物は、乾燥性、耐摩耗性、耐汚染性及び路面との接着性に優れ、かつ水性であるため安全性が高く、大気汚染の心配がないため路面標示用として極めて有用である。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a road marking aqueous coating composition having excellent drying properties, abrasion resistance, stain resistance, and adhesion to a road surface.
[0002]
[Prior art]
Conventional road marking paints are mainly of two types: solvent type and hot melt type. Of these, organic solvents such as ketone type, ester type, aliphatic type and aromatic type are used. Non-dangerous goods that are difficult to control in storage and handling because they are classified as dangerous goods under the Fire Service Law, and have environmentally friendly VOC regulations. There is a need for a road marking water-based paint. Further, the hot-melt type requires a heat source because the paint must be melted at a high temperature at the coating site, requires safety measures against high temperatures, and has a problem of generating a strong odor.
[0003]
As a water-based paint for road marking, there is one proposed in Japanese Patent Application Laid-Open No. Hei 6-271789. However, since the molecular weight of the polymer in the emulsion constituting the paint is as low as 10,000 to 100,000, the drying property and the drying resistance are reduced. There is a problem that abrasion, stain resistance, coating film strength, and adhesion to a road surface are insufficient. In order to improve the stain resistance, expensive reactive oligomers must be used, which is economically disadvantageous. At the same time, among the reactive groups of the oligomers, acryloyl groups have a radical reaction activity in air. Since the crosslinking reaction of the dicyclopentenyl group also proceeds only gradually in the presence of the metal oxide, it takes a long time to exhibit stain resistance.
[0004]
[Problems to be solved by the invention]
From the above situation, the present invention focuses on an alkoxysilyl group-containing acrylic emulsion, and by using this, is excellent in dryness, abrasion resistance, stain resistance, and adhesion to a road surface, and is easy to construct. It is intended to provide a suitable road marking paint.
[0005]
[Means for Solving the Problems]
The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and as a result of using an acrylic silyl group-containing acrylic emulsion as a vehicle for this paint, the average molecular weight of the acrylic copolymer in the emulsion was 150,000 or more. It has been found that these problems can be solved by setting the glass transition temperature to 0 to 70 ° C. and setting the solid content of the emulsion to 43% by weight or more. Tests were conducted on the types and amounts of pigments and fillers to arrive at the present invention.
[0006]
The road marking aqueous coating composition of the present invention has solved the above problems,
(1) Alkoxysilyl having an average molecular weight of 150,000 or more, having a glass transition temperature of 0 to 70 ° C., containing an acrylic copolymer having an alkoxysilyl group, and having a solid concentration of 43% by weight or more. The group-containing acrylic emulsion has a solid content of 100 parts by weight,
(2) 60 to 200 parts by weight of a coloring pigment, and
(3) 100-400 parts by weight of filler
It is a blended aqueous coating composition.
[0007]
Hereinafter, the present invention will be described in more detail.
The alkoxysilyl group-containing acrylic emulsion of the component (1) in the present invention constitutes a vehicle of the road marking aqueous coating composition of the present invention, and has (a) an alkyl group having 1 to 18 carbon atoms ( Emulsion obtained by copolymerizing (meth) acrylic acid alkyl ester and (b) alkoxysilyl group-containing radical polymerizable monomer and (c) other radical polymerizable monomer used as required Is usually used.
[0008]
The (meth) alkyl (meth) acrylate is a radical polymerizable monomer that is a main component for forming the skeleton of the acrylic copolymer, and specific examples thereof include methyl acrylic acid or methacrylic acid, Examples thereof include ethyl, propyl, isopropyl, butyl, isobutyl, octyl, 2-ethylhexyl, lauryl and stearyl esters, and one or more monomers selected from these groups can be used.
[0009]
As the alkoxysilyl group-containing radical polymerizable monomer of the component (b), those represented by the following general formula are usually used.
Embedded image

(Where X is a radical polymerizable functional group, R ¹ , R ² Represents an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 1 to 3. )
[0010]
Specifically, γ- (meth) acryloxypropyltrimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropyl which is an ester of acrylic acid or methacrylic acid and an organic silane Dimethylmethoxysilane, γ- (meth) acryloxypropyltriethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane, γ- (meth) acryloxypropyldimethylethoxysilane; vinyltrimethoxysilane, vinylmethyldimethoxysilane , Vinyltriethoxysilane, vinylmethyldiethoxysilane; and trimethoxysilylstyrene, dimethoxymethylsilylstyrene, triethoxysilylstyrene, diethoxymethylsilylstyrene and the like.
Among them, (a) silane selected from γ- (meth) acryloxypropyltrimethoxysilane and (b) γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldimethoxysilane A silane selected from ethoxysilane and γ- (meth) acryloxypropyltriethoxysilane is used such that the weight ratio of the silane of the component (a) / the silane of the component (b) is 60/40 to 0/100. This is particularly preferred in view of the storage stability of the emulsion.
[0011]
These (b) monomers can be used alone or in combination of two or more. However, in view of the storage stability of the emulsion and the properties of the coating film, the amount of the monomer used is a radical polymerizable monomer. It is preferable that the content be 1 to 20% by weight of the total amount.
If the amount of the component (b) is less than 1% by weight of the total amount of the radical polymerizable monomer, the formed coating film has a low crosslinking density, and the abrasion resistance, stain resistance and adhesion to the road surface are insufficient. If it exceeds 20% by weight, the crosslinking density is too high, and the formed coating film becomes brittle, and the storage stability of the emulsion is impaired.
[0012]
(C) Other radically polymerizable monomers of the component are used, if necessary, for improving the stability of the emulsion, the stability of the coating composition, the workability during coating, and the properties of the coating film. In order not to impair the object of the present invention, component (c) is used in an amount of 20% by weight or less based on the total amount of the radical polymerizable monomer. Specific examples of such a monomer include acrylic acid, methacrylic acid, a monomer containing a carboxyl group such as maleic anhydride or an anhydride group thereof, an ester of acrylic acid or methacrylic acid, an amide, and other 2-hydroxy groups. Hydroxyl group-containing monomers such as ethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate, (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl ( Amide group-containing monomers such as meth) acrylamide and diacetone (meth) acrylamide; amino group-containing monomers such as dimethylaminoethyl (meth) acrylate; methoxyethyl (meth) acrylate and butoxyethyl (meth) acrylate Monomers containing alkoxyl group, glycidyl (Meth) acrylates, glycidyl group-containing monomers such as glycidyl allyl ether, divinylbenzene, allyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Monomers having two or more radically polymerizable unsaturated groups in one molecule, such as butanediol di (meth) acrylate and hexanediol di (meth) acrylate, and vinyl esters such as vinyl acetate and vinyl propionate Styrene, vinyltoluene, aromatic vinyl monomers such as α-methylstyrene, vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, and vinyl chloride monomers such as vinyl chloride and vinyl bromide. Illustrated, one of these or Two or more are used.
[0013]
The alkoxysilyl groups introduced into the (1) alkoxysilyl group-containing acrylic emulsion are gradually hydrolyzed in water to produce silanol groups, which are dehydrated and condensed with each other as water evaporates, or the silanol groups are dehydrated. The dealcoholization condensation of the alkoxysilyl group causes a cross-linking reaction within or between the molecules of the acrylic copolymer, which contributes to the improvement of the strength, water resistance and abrasion resistance of the coating film. In addition, the alkoxysilyl group or silanol group has a strong affinity with the inorganic fine powder to be compounded, facilitates the dispersion of the coloring pigment and the filler, improves the drying property by increasing the filling, and further improves the road surface. Adhesion to concrete etc. is greatly improved.
[0014]
The alkoxysilyl group bonded to the acrylic copolymer is extremely useful in this way, but if the hydrolysis of the alkoxysilyl group proceeds too much during storage of the emulsion or the paint containing the same, the alkoxysilyl group is already present in the emulsion particles. Intramolecular or intermolecular cross-linking of the copolymer occurs, raising the minimum film-forming temperature and making it impossible to form a continuous coating film at the time of water evaporation after coating, or significantly increasing the viscosity of emulsions and blended coatings, In severe cases, it becomes gelled and cannot be blended or painted. In any case, it is desirable to prevent a rise in the minimum film forming temperature during storage since the practical value is lost.
For this purpose, it is preferable to use the alkoxysilyl group-containing radical polymerizable monomer (b) in the above-described type and amount ratio, or in the total amount of the radical polymerizable monomer. Further, a core / shell polymerization method described later and adjustment of the pH of the emulsion are also effective for this purpose.
[0015]
The glass transition temperature (hereinafter abbreviated as Tg) of the acrylic copolymer in the alkoxysilyl group-containing acrylic emulsion of the component (1) is from 0 to 70 ° C. from the viewpoint of film forming properties and coating film properties, but is preferably used. Is 10 to 50 ° C. If the Tg is less than 0 ° C, the coating film is too soft, resulting in poor abrasion resistance, stain resistance, and coating film strength. In the ground, it is necessary to form a film even at 5 to 10 ° C, so it is necessary to add an excessive film-forming aid, causing an increase in the viscosity of the paint, making it difficult to apply the paint using a coating machine, and furthermore, the water resistance of the paint film. Decreases.
The average molecular weight (weight average molecular weight in terms of polystyrene) of the acrylic copolymer is 150,000 or more. As a result of the investigation, it was unexpectedly found that a higher value of 150,000 or more was superior to all. is there. If the average molecular weight is less than 150,000, the coating film strength, abrasion resistance, and stain resistance are poor, and a good coating film cannot be obtained. The average molecular weight of 150,000 or more can usually be achieved by adjusting the amount of the radical polymerization initiator and the polymerization temperature.
Further, the solid content concentration of the emulsion is 43% by weight or more. If the content is less than 43% by weight, the non-volatile content in the coating material is relatively low, and the drying property is poor.
[0016]
The acrylic emulsion containing an alkoxysilyl group as the component (1) can be produced by a usual emulsion polymerization method. That is, a batch polymerization method in which monomers are polymerized collectively, a monomer alone or ion-exchanged water, an additional polymerization method of a monomer emulsion emulsified with a surfactant, and changing the monomer composition of the core and shell. Core / shell polymerization method, power polymerization method of continuously changing the monomer composition and performing polymerization, and the like. To suppress the progress of the crosslinking reaction of the alkoxysilyl group during storage of the emulsion or paint, a core / shell polymerization method is also useful. That is, an alkoxysilyl group-containing radical polymerizable monomer is copolymerized in the core portion, and the core portion is protected by a shell portion containing no alkoxysilyl group, or a highly reactive trimethoxysilyl group-containing radical polymerizable monomer. There is also a method in which the polymer is copolymerized in the core portion and a dimethoxysilyl group, triethoxysilyl group, or diethoxysilyl group-containing radically polymerizable monomer having low reactivity is copolymerized in the shell portion.
[0017]
Surfactants used at the time of emulsion polymerization include anionic surfactants such as alkyl or alkyl allyl sulfate, alkyl or alkyl allyl sulfonate, dialkyl sulfosuccinate, and cations such as alkyltrimethylammonium chloride and alkylbenzylammonium chloride. And nonionic surfactants such as polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, and polyoxyethylene carboxylate. These surfactants may be used alone or in combination of two or more. However, if the amount is too small, a large amount of coagulum will be generated in the produced emulsion, and the resulting coating film It does not show good physical properties. If the amount is too large, the particle size of the emulsion becomes too small, the viscosity of the emulsion becomes too high, and the water resistance of the coating film also becomes poor. Therefore, the amount of the surfactant to be used is preferably 0.5 to 15 parts by weight, particularly preferably 1 to 7 parts by weight based on 100 parts by weight of the total monomers.
[0018]
Further, in order to significantly improve the durability such as water resistance of a coating film formed from the emulsion used in the present invention and obtain a performance close to a solution type, a reactive surfactant is used as a surfactant during polymerization. It is preferred to use. Examples of the reactive surfactant include JP-A-54-144317, JP-A-55-115419, JP-A-62-34947, JP-A-58-203960, JP-A-4-53802, and JP-A-62-264. 104802, JP-A-49-40388, JP-A-52-134658, JP-B-49-46291, anionic reactive surfactants described in JP-B-49-46291, JP-A-53-126093 and JP-A-53-12693. Non-ionic reactive surfactants described in JP-A-28208, JP-A-4-50204, JP-A-62-104802, JP-A-50-98484 and the like, or quaternary ammonium salts and tertiary compounds. Cationic reactive surfactants containing an amine salt group and a radical polymerizable group are exemplified.
[0019]
Examples of the radical polymerization initiator used in the present invention include water-soluble types such as persulfates such as potassium persulfate and ammonium persulfate, aqueous hydrogen peroxide, t-butyl hydroperoxide, hydrochloride of azobisamidinopropane, and benzoyl. Examples thereof include oil-soluble types such as peroxide, cumene hydroperoxide, dibutyl peroxide, diisopropyl peroxydicarbonate, cumyl peroxy neodecanoate, cumyl peroxy octoate, and azobisisobutyronitrile. Further, if necessary, a redox system using a reducing agent such as sodium acid sulfite, Rongalit, or L-ascorbic acid can be used. The amount of the polymerization initiator to be used is usually 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the total monomers.
[0020]
In producing the alkoxysilyl group-containing acrylic emulsion used in the present invention, it is preferable to control the pH during polymerization to 6.5 to 7.5 in order to suppress hydrolysis and condensation of the alkoxysilyl group. The polymerization is usually carried out at a temperature of from 10 to 90C. At the end of the emulsion polymerization, a basic substance is added to adjust the pH of the emulsion to 7 to 8 in order to prevent undesired crosslinking reaction of the obtained copolymer and to further improve the storage stability. Preferably, ammonia, amines, alkanolamines, caustic and the like are exemplified as additives for that purpose.
[0021]
Examples of the color pigment of the component (2) include titanium oxide which is a white pigment, graphite which is a yellow pigment, etc., red iron oxide, carbon black, cyanine blue, cyanine green, and the like. It is 60 to 200 parts by weight based on parts by weight. If it is less than 60 parts by weight, the hiding power is insufficient, and if it is more than 200 parts by weight, dispersion becomes difficult, the viscosity of the coating material becomes high, and it is economically disadvantageous.
[0022]
Examples of the filler of the component (3) include calcium carbonate, barium carbonate, magnesium silicate, calcium silicate, calcium sulfate, silica stone powder, celite, clay, talc, mica, and alumina. 100 to 400 parts by weight for 100 parts by weight. If the amount is less than 100 parts by weight, the non-volatile content of the paint will be low and the drying property will be inferior. Makes painting difficult.
[0023]
If necessary, a dispersant, a wetting agent, a plasticizer, a defoaming agent, a film-forming aid, an antifreezing agent, a thickener, and the like can be appropriately added to the coating composition of the present invention. Preferred examples of the film-forming aid include butyl carbitol acetate, butyl carbitol, butyl cellosolve, butyl cellosolve acetate, benzyl acetate, and 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.
Examples of the wetting agent having an antifoaming effect include acetylene alcohol, acetylene glycol, and their ethylene oxide adducts.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described with examples, but the present invention is not limited to the embodiments. In the examples, the parts and the percentages relating to the composition and concentration indicate parts by weight and% by weight, respectively. The properties of each of the obtained emulsions and coating compositions were measured or calculated by the following methods.
[0025]
(1) Emulsion characteristics
(1) Glass transition temperature (Tg) of copolymer
The Tg of the copolymer was calculated from the Fox equation below.
1 / Tg = Σ (Wi / Tgi)
Tg: glass transition temperature of copolymer (° K)
Tgi: glass transition temperature (° K) of the homopolymer of the monomer component (i)
Wi: weight fraction of component (i) in the copolymer
(2) Average molecular weight
It was determined as a weight average molecular weight in terms of polystyrene by GPC.
(3) Solid concentration
The nonvolatile content when the emulsion was dried at 105 ° C. for 1 hour was calculated as a solid content.
(4) Storage stability
The minimum temperature at which film formation was possible after the emulsion was stored at 50 ° C. for 30 days was measured with a minimum film formation temperature measuring device manufactured by Rigaku Corporation, and compared with the minimum film formation temperature of the emulsion before storage. The following criteria were used to indicate the range of the temperature increase.
◎: 5 ° C. or less, Δ: over 5 ° C. to 10 ° C., Δ: over 10 ° C. to 20 ° C., ×: over 20 ° C.
[0026]
(2) Characteristics of coating composition
▲ 1 ▼ Viscosity
The viscosity (KU value) of the compounded paint was measured with a Klebstormer viscometer, and indicated by the following criteria.
◎: 70 to 100, Δ: more than 100 to 130, Δ: less than 70, ×: more than 130
(2) Storage stability of paint
The change in viscosity before and after the coating was stored at 50 ° C. for 30 days was measured and indicated by the following criteria.
〇: Within 10% of initial viscosity, ×: Over 10% of initial viscosity
[0027]
(3) Characteristics of coating film
{Circle around (1)} Non-adhesive drying property, abrasion resistance, concealing rate and glass bead sticking property were measured in accordance with JIS K 5665, and indicated by the following criteria.
1) Non-stick drying
Visually observe whether paint has adhered to the test roll tires
：: no adhesion after 10 minutes, Δ: no adhesion after 10 minutes, ×: adhesion after 15 minutes
2) Abrasion resistance (100 rotation equivalent abrasion loss)
◎: 200 mg or less, Δ: more than 200 mg to 500 mg or less, ×: more than 500 mg
3) Concealment rate
〇: 0.97 or more, ×: less than 0.97
4) Sticking property of glass beads
◎: 95% or more, Δ: 90% or more to less than 95%, ×: less than 90%
[0028]
(2) Stain resistance
Apply the blended paint on a glass plate using an applicator so that the coating thickness is 100 ± 20 μm, leave it at 20 ° C. × 65% RH for 8 hours, and attach horticultural red clay to the coating film. The test roll was rolled, and the state of contamination of the coating film was observed and indicated by the following criteria.
◎: almost no contamination, Δ: slightly contaminated, ×: considerably contaminated
(3) Adhesion to road surface
A cement mortar board and an asphalt block specified in JIS K 5410 are coated so that the coating thickness becomes 100 ± 20 μm, left at 20 ° C. × 65% RH for 24 hours, and conform to JIS K 5400 with a clearance of 5 mm. , And paint with the Goban method
The adhesion test of the film was performed and indicated by the following criteria.
：: Evaluation score of 8 or more, Δ: Evaluation score of 6 or more to less than 8,
Δ: Evaluation score of 4 or more to less than 6; X: Evaluation score of less than 4
(4) Water resistance
Apply the compound paint on a glass plate using an applicator so that the coating thickness becomes 100 ± 20 μm, leave it at 20 ° C. × 65% RH for 7 days, and then immerse it in 50 ° C. warm water for 24 hours
Then, the surface condition was observed.
◎: No abnormality, △: Some blisters occurred, ×: Many blisters occurred
[0029]
【Example】
Example 1
A polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet was charged with 100 parts of deionized water, 0.03 part of sodium carbonate as a pH buffer, and 0.3 part of boric acid. After the temperature was raised, the atmosphere was replaced with nitrogen. To this were added 0.15 parts of Rongalite, 0.09 part of a 1% aqueous solution of disodium ethylenediaminetetraacetate, and 0.03 part of a 1% aqueous solution of ferrous sulfate, and at the same time, 65 parts of methyl methacrylate and 15 parts of butyl acrylate. Styrene, 10 parts, γ-acryloxypropylmethyldimethoxysilane, 10 parts, nonionic surfactant Neugen EA-170 (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 3.2 parts, anionic surfactant Emal O (Kaosha) 104.9 parts of a mixed liquid of 1.4 parts and 0.3 part of t-butyl hydroperoxide (69% pure) were uniformly stirred over 3 hours while maintaining the internal temperature at 60 ° C. And further reacted at 60 ° C. for 1 hour to complete the polymerization. The resulting emulsion had a solid content of 50.9% and a pH of 7.2.
The properties of this emulsion and the paints and coating films formed by the following standard formulation examples are as shown in Tables 1 and 2.
(Example of standard formulation)
100 parts of the solid content of the emulsion, 100 parts of titanium oxide, 200 parts of calcium carbonate, 14 parts of a 30% aqueous solution of sodium polycarboxylate (dispersant), and 4 parts of a silicone-based antifoaming agent were formed into a paint by a dry pigmentation method. 20 parts of butyl carbitol acetate (film-forming aid) and 20 parts of 50% methanol water (antifreeze) were added by letdown.
[0030]
Example 2
In a polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet, 35 parts of deionized water, 0.03 part of sodium carbonate as a pH buffer and 0.3 part of boric acid are charged, and the mixture is heated to 30 ° C. while stirring. After the temperature was raised, the atmosphere was replaced with nitrogen. To this were added 0.15 part of L-ascorbic acid and 0.03 part of a 1% aqueous solution of ferrous sulfate, and at the same time, 53 parts of methyl methacrylate, 36 parts of butyl acrylate, 5 parts of acrylonitrile, 5 parts of γ-methacryloxypropyl tri A mixture of 2 parts of methoxysilane, 2 parts of γ-methacryloxypropyltriethoxysilane, 2 parts of 2-hydroxyethyl methacrylate and 0.3 part of t-butyl hydroperoxide (pure content 69%) is reacted by the following structural formula. Aqueous surfactant Aqualon RN-20 (trade name, manufactured by Daiichi Kogyo Seiyaku) 3.2 parts, Aqualon HS-10 (trade name, manufactured by Daiichi Kogyo Seiyaku) 1.4 parts and 50 parts of deionized water in a solution And 7.7 parts of 154.9 parts of the emulsified liquid emulsified by a homomixer were added to a polymerization vessel to carry out a polymerization reaction. Ri uniformly added with stirring over a period while 2.5 hour hold an emulsion the vessel internal temperature at 30 ° C., to obtain an emulsion reacted at further 30 ° C.. This emulsion was neutralized to pH 7.0 with 10% aqueous ammonia.
Embedded image

Tables 1 and 2 show the properties of the emulsion obtained above and the paint and the coating film formed by the standard formulation.
[0031]
Example 3
Polymerization was carried out using the monomers shown in Table 1 in the same manner as in Example 1 except that 100 parts of deionized water of Example 1 was replaced with 125 parts.
The properties of the obtained emulsion and the paint and the coating film obtained by coating the emulsion according to the standard formulation were as shown in Tables 1 and 2.
Examples 4 to 6
Polymerization was carried out using the monomers shown in Table 1 in the same manner as in Example 1. The properties of the obtained emulsion and the paints and coating films obtained by coating them according to the standard formulation examples are as shown in Tables 1 and 2.
[0032]
Comparative Example 1
A polymerization vessel equipped with a stirrer, condenser, thermometer and nitrogen gas inlet was charged with 100 parts of deionized water, 0.03 part of sodium carbonate as a pH buffer, and 0.3 part of boric acid. After the temperature was raised, the atmosphere was replaced with nitrogen. After the internal temperature was further raised to 80 ° C., 0.15 part of Rongalite, 0.09 part of a 1% aqueous solution of disodium ethylenediaminetetraacetate, and 0.03 part of a 1% aqueous solution of ferrous sulfate were added thereto. At the same time, 60 parts of methyl methacrylate, 36 parts of butyl acrylate, 2 parts of γ-methacryloxypropyltrimethoxysilane, 2 parts of γ-methacryloxypropyltriethoxysilane, 3.2 parts of Neugen EA-170 (described above), A mixture of 105.4 parts of a mixture of 1.4 parts of Emar O (described above), 0.3 part of t-butyl hydroperoxide (69% pure) and 0.5 part of dodecyl mercaptan was maintained at 80 ° C. While stirring, the mixture was uniformly added over 3 hours, and further reacted at 80 ° C. for 1 hour to complete the polymerization. The solid content concentration of the obtained emulsion was 50.2% and the pH was 6.9. Table 1 and Table 2 show the properties of the obtained emulsion and the paints and coatings obtained by coating them according to the standard formulation examples.
[0033]
Comparative Examples 2 to 4
Polymerization was carried out using the monomers shown in Table 1 in the same manner as in Example 1. The properties of the obtained emulsion and the paint and the coating film obtained by coating the emulsion according to the standard formulation were as shown in Tables 1 and 2.
Particularly, in Comparative Example 3, the glass transition temperature of the copolymer was too high, and a good coating film could not be formed at 20 ° C. with 10 parts of butyl carbitol acetate as a film forming aid. (20 parts acetate)), the viscosity of the paint became KU value of 130 or more, and the workability was poor.
[0034]
[Table 1]

[0035]
[Table 2]

[0036]
Comparative Example 5
After deionized water was added to the emulsion obtained in Example 1 to dilute it to a solid concentration of 40%, the non-adhesive drying property of a coating film obtained from a coating compound formulated according to the standard formulation example was evaluated. X.
Comparative Examples 6 to 9
The properties of the paint and the coating film obtained by using the emulsion of Example 1 and having the composition shown in Table 3 were as shown in Table 3.
[0037]
[Table 3]

[0038]
【The invention's effect】
The water-based coating composition for road marking of the present invention is excellent in dryness, abrasion resistance, stain resistance and adhesion to road surfaces, and is highly safe because of being water-based. It is extremely useful for applications.

Claims (3)

(1) Alkoxysilyl having an average molecular weight of 150,000 or more, having a glass transition temperature of 0 to 70 ° C., containing an acrylic copolymer having an alkoxysilyl group, and having a solid concentration of 43% by weight or more. The group-containing acrylic emulsion has a solid content of 100 parts by weight,
(2) A road marking aqueous coating composition comprising 60 to 200 parts by weight of a coloring pigment and (3) 100 to 400 parts by weight of a filler. Alkoxysilyl group-containing acrylic emulsion, for the introduction of alkoxysilyl groups,
(A) silane selected from γ- (meth) acryloxypropyltrimethoxysilane and (b) γ- (meth) acryloxypropylmethyldimethoxysilane, γ- (meth) acryloxypropylmethyldiethoxysilane and γ- A silane selected from (meth) acryloxypropyltriethoxysilane [provided that the weight ratio of the silane of the component (a) / the silane of the component (b) is 60/40 to 0/100. ]
The aqueous coating composition for road marking according to claim 1, which is obtained by emulsion copolymerization using An alkoxysilyl group-containing acrylic emulsion is obtained by emulsifying and copolymerizing an alkoxysilyl group-containing radical polymerizable monomer in an amount of 1 to 20% by weight of the total amount of the radical polymerizable monomer to introduce an alkoxysilyl group. The aqueous coating composition for road marking according to claim 1, wherein