JP4225402B2 - Zinc oxide fine particles and their uses - Google Patents

Description

【０１７１】
【数２】

【０１７２】
【数３】

【０１７３】
（分散体中の微粒子濃度）
分散体の一部を１００℃に於て溶媒等の揮発成分を完全に除去し得るまで真空乾燥することにより乾燥粉末を得、これを空気中、５００℃で１時間加熱したときの残分を金属酸化物として、金属酸化物分の分散体に対する重量分率を求め、この値を分散体中の微粒子濃度（金属酸化物換算濃度）とした。
（微粒子組成）
粉末試料を、蛍光Ｘ線分析、原子吸光分析及び重量分析等より求めた。
（微粒子の熱線カット性能）
反応により得られた微粒子分散体を微粒子濃度１０重量％に濃縮することにより、濃縮分散体を得、該濃縮分散体を、バーコーターを用いて、厚さ２ｍｍのガラス板上に塗布し、乾燥（窒素雰囲気下８０℃）することによって乾燥膜を得る。塗布量を微粒子換算で１〜１０ｇ／ｍ² の範囲で種々変え、各乾燥膜の分光特性（波長２２００〜２００ｎｍ）を、自記分光光度計（UV-3100 、（株）島津製作所）により測定する。得られた分光曲線より、塗布量が微粒子換算で３ｇ／ｍ² の場合の膜について、以下の基準に比較して、各性能を評価する。
【０１７４】

＜２０％ ×＊熱線カット量：［基材に於ける波長２μｍに対する光透過率（％）］
−［塗装品に於ける波長２μｍに対する光透過率（％）］

参考）使用したガラス基板の透過率
波長 ３５０ｎｍ ６００ｎｍ ２μｍ
透過率（％） ８６ ９１ ９１
（塗装品等の光学的特性）
分光特性については、自記分光光度計（UV-3100 、（株）島津製作所）により、照射波長２２００〜２００ｎｍに於ける、各波長光に対する透過率を測定評価した。
【０１７５】
測定された分光特性より、熱線カット性能、紫外線カット性能等は以下の基準に基づき評価した。
熱線カット量：基材自体の波長２μｍに対する光透過率（％）−塗装品の波長２μｍに対する光透過率（％）
〔微粒子を含有する／しない成形品の場合は、１００（％）−成形品の波長２μｍに対する光透過率（％）〕
紫外線カット能：波長３５０ｎｍに於ける光透過率で上記の基準に従って評価した。
【０１７６】
全光線透過率とヘイズ：濁度計（ＮＤＨ−１００１ ＤＰ 日本電色工業（株））により、測定評価した。
（微粒子の導電性）
前記した粉末試料０．１ｍｌを、予め、金の櫛型電極を蒸着したパイレックスガラス（１．５ｃｍ角）と何も蒸着していないパイレックスガラス（１．５ｃｍ角）の間に挟み、一定圧力を印加した状態で、温度２０℃、相対湿度６０％の雰囲気下、遮光状態で１時間放置した後、ケスレー社製エレクトロメータ６１７型を用いて、同条件下に於ける、電流値（暗電流）を測定し、抵抗値（Ω）に換算し評価した。
【０１７７】
標準試料として、市販の酸化亜鉛（堺化学製、亜鉛華１号特製）を用い、これの抵抗値と粉末試料の抵抗値の相対値で導電性を評価した。すなわち、
標準試料の抵抗値／実施例または比較例の試料の抵抗値＝ｒとすると

［微粒子分散体の製造］
実施例Ｉ−１
攪拌機、滴下口、温度計、還流冷却器を備えた１０Ｌのガラス製反応器中で、酢酸１．６ｋｇ及びイオン交換水１．６ｋｇの混合溶媒に酸化亜鉛粉末０．３ｋｇ、酢酸インジウム２水和物３６．３ｇを添加混合した後、攪拌しながら１００℃まで昇温することにより、均一溶液の亜鉛含有溶液（Ａ１）を得た。
【０１７８】
次に、外部より熱媒加熱し得る、攪拌機、滴下口、温度計、留出ガス出口を備えた２０Ｌのガラス製反応器に、２−ブトキシエタノール１４ｋｇを仕込み、内温を１５３℃まで加熱昇温し保持した。これに、１００℃に保持された亜鉛含有溶液（Ａ１）全量を、定量ポンプにより３０分かけて滴下した。ボトムの温度は１５３℃から１３１℃まで変化した。滴下終了後、内温を１６８℃まで昇温した時点で、ラウリン酸３６．９ｇを溶解した２−ブトキシエタノール溶液４００ｇを１分かけて添加し、さらに該温度で５時間加熱保持することにより、青灰色の分散体（ＤＩ−１）７．８９ｋｇを得た。分散体（ＤＩ−１）は、平均粒子径が５ｎｍの薄片状の微粒子が３．５重量％の濃度で分散したものであった。分散体中の微粒子は、Ｘ線回折学的には結晶性酸化亜鉛であり、金属酸化物含有量９４．５重量％、Ｉｎが金属原子総量に対し原子数比で３．０％の組成からなる微粒子であった。
【０１７９】
得られた分散体、および微粒子の物性を表３に示す。
実施例Ｉ−２
実施例Ｉ−１に於ける亜鉛含有溶液（Ａ１）に於ける原料の種類、量を表１に示す如く変えた以外は、実施例Ｉ−１と同様にして亜鉛含有溶液（Ａ２）を得、さらに、実施例Ｉ−１に於ける２−ブトキシエタノール仕込量を１２ｋｇとし、ラウリン酸を添加しなかった以外は、実施例Ｉ−１と同様にして、分散体（ＤＩ−２）を得た。
得られた分散体、および微粒子の物性を表３に示す。
【０１８０】
実施例Ｉ−２で得られた分散体（ＤＩ−２）２２７重量部にオクタデシルトリエトキシシラン１重量部を添加し攪拌した後、エバポレータに於いて、減圧下、バス温度１３０℃で、加熱溶媒除去し、さらに１００℃で真空乾燥処理することにより微粒子粉末（ＰＩ−２−１）１２重量部を得た。
実施例Ｉ−３
実施例Ｉ−１と同様の、攪拌機、滴下口、温度計、還流冷却器を備えた１０Ｌのガラス製反応器中で、酢酸２．２ｋｇ及びイオン交換水２．２ｋｇの混合溶媒に酢酸亜鉛２水和物０．８０９ｋｇを添加混合した後、攪拌しながら１００℃まで昇温することにより、均一溶液の亜鉛含有溶液（Ａ３）を得た。
【０１８１】
次に、外部より熱媒加熱し得る、攪拌機、滴下口、温度計、留出ガス出口を備えた２０Ｌのガラス製反応器に、２−ブトキシエタノール８ｋｇと酢酸エチレングリコール−ｎ−ブチルエーテル５ｋｇを仕込み、内温を１６２℃まで加熱昇温し保持した。これに、１００℃に保持された亜鉛含有溶液（Ａ３）全量を、定量ポンプにより３０分かけて滴下した。滴下終了後、内温を１６８℃まで昇温した時点で、アルミニウムトリス（sec −ブトキシド）９０．８ｇを２−ブトキシエタノール４００ｇに均一溶解した溶液を一気に添加し、さらに１７０℃で５時間加熱保持することにより、分散体（ＤＩ−３）を得た。
【０１８２】
得られた分散体、および微粒子の物性を表３に示す。
実施例Ｉ−４
実施例Ｉ−１と同様の、攪拌機、滴下口、温度計、還流冷却器を備えた１０Ｌのガラス製反応器中で、酢酸２．２ｋｇ及びイオン交換水２．２ｋｇの混合溶媒に酢酸亜鉛２水和物０．８０９ｋｇ、アルミナゾル−２００（日産化学社製、ＡＳ−２００、Ａｌ2 Ｏ3 ）を順次添加混合した後、攪拌しながら１００℃まで昇温することにより、均一溶液の亜鉛含有溶液（Ａ４）を得た。
次に、外部より熱媒加熱し得る、攪拌機、滴下口、温度計、留出ガス出口を備えた２０Ｌのガラス製反応器に、２−ブトキシエタノール１４ｋｇを仕込み、内温を１５０℃まで加熱昇温し保持した。これに、１００℃に保持された亜鉛含有溶液（Ａ４）全量を、定量ポンプにより３０分かけて滴下した。滴下終了後、内温を１６８℃まで昇温した時点で、ポリエチレングリコール（平均分子量６０００）３０．０ｇを２−ブトキシエタノール１００ｇに均一溶解した溶液を数秒間で添加し、さらに１７０℃で５時間加熱保持することにより、分散体（ＤＩ−４）を得た。
【０１８３】
得られた分散体、および微粒子の物性を表３に示す。
実施例Ｉ−５
実施例Ｉ−１と同様の、攪拌機、滴下口、温度計、還流冷却器を備えた１０Ｌのガラス製反応器中で、酢酸１．５ｋｇ及びイオン交換水１．５ｋｇの混合溶媒に酸化亜鉛０．３０ｋｇを添加混合した後、攪拌しながら８０℃まで昇温することにより、均一溶液の亜鉛含有溶液（Ａ５）を得た。
次に、外部より熱媒加熱し得る、攪拌機、滴下口、温度計、留出ガス出口を備えた２０Ｌのガラス製反応器に、２−ブトキシエタノール１４ｋｇとエチルアセトアセテートアルミニウムジイソプロピレート６０．６ｇを仕込み、内温を１５０℃まで加熱昇温し保持した。これに、８０℃に保持された亜鉛含有溶液（Ａ５）全量を、定量ポンプにより３０分かけて滴下した。滴下終了後、内温を１７０℃まで昇温し、１７０℃で５時間加熱保持することにより、分散体（ＤＩ−５）を得た。
【０１８４】
得られた分散体、および微粒子の物性を表３に示す。
さらに分散体（ＤＩ−５）中に含有されている微粒子を遠心分離操作によって分散媒から分離し、分離された微粒子をメタノールで洗浄した後、５０℃で２４時間真空乾燥（１０Ｔｏｒｒ）することによって微粒子粉体（ＰＩ−５）を得た。
得られた微粒子粉体（ＰＩ−５）は、厚みの平均径が０．０２５μｍ、長径の平均粒子径０．０８μｍ、長短度２、偏平度３．２であり、金属酸化物含有量８７．３重量％、Ａｌが金属原子総量に対し原子数比で５．５％の組成からなり、結晶性酸化亜鉛のＸ線回折パターンを示す薄片状（りん片状）の結晶が２〜５層積層した微粒子であった。
【０１８５】
比較例Ｉ−１
実施例Ｉ−１に於いて、酢酸インジウムを使用せず、２−ブトキシエタノールの仕込量を１２．０ｋｇとした以外は、実施例Ｉ−１と同様にして微粒子分散体（ＤＩ−Ｒ１）を得た。得られた分散体、および微粒子の物性を表３に示す。
実施例Ｉ−６
攪拌機、滴下口、温度計、還流冷却器を備えた１０Ｌのガラス製反応器中で、酢酸１．６ｋｇ及びイオン交換水１．６ｋｇの混合溶媒に酸化亜鉛粉末０．３ｋｇ、酢酸インジウム２水和物３６．３ｇを添加混合した後、攪拌しながら１００℃まで昇温することにより、均一溶液の亜鉛含有溶液（Ａ６）を得た。
【０１８６】
次に、外部より熱媒加熱し得る、攪拌機、滴下口、温度計、留出ガス出口を備えた２０Ｌのガラス製反応器に、２−ブトキシエタノール１２ｋｇを仕込み、内温を１５８℃まで加熱昇温し保持した。これに、１００℃に保持された亜鉛含有溶液（Ａ６）全量を、定量ポンプにより６０分かけて滴下した。滴下終了後、内温を１６８℃まで昇温した時点で、アクリル系ポリマー：メタクリル酸メチル−ヒドロキシエチルメタクリレート−マレイン酸共重合体（重量比で８：１：１、重量平均分子量４，５００）３００．０ｇを含有する２−ブトキシエタノール溶液５００ｇを１分間で添加し、さらに１６８℃で５時間加熱保持することにより、青灰色の分散体（ＤＩ−６）９．８０ｋｇを得た。
【０１８７】
分散体（ＤＩ−６）は、平均粒子径が２０ｎｍの微粒子が３．１重量％の濃度で分散したものであった。分散体中の微粒子は、Ｘ線回折学的には結晶性酸化亜鉛であり、金属酸化物含有量５５重量％、Ｉｎが金属原子総量に対し原子数比で３．０％の組成からなる微粒子であった。さらに、該微粒子は透過型電子顕微鏡観察により、金属酸化物表面が添加したアクリル系ポリマーで被覆されたものであることが確認された。
次に、分散体（ＤＩ−６）中に含有されている微粒子を遠心分離操作によって分散媒から分離し、分離された微粒子をイソプロピルアルコールで洗浄した後、５０℃で２４時間真空乾燥（１０Ｔｏｒｒ）することによって微粒子粉体（ＰＩ−６）を得た。
【０１８８】
得られた微粒子粉体（ＰＩ−６）中の微粒子は、分散体中に於けるものと実質的に変わらないものであることが確認された。
さらに、微粒子粉体（ＰＩ−６）は、メタノール、イソプロパノール，ｎ−ブタノール、ベンジルアルコール、２ーエトキシエタノール等のアルコール類、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、酢酸ブチル、酢酸エチル等のエステル類、ベンセン、トルエン等の芳香族化合物など有機溶媒に対する分散性に優れるものであり、容易に単粒子状に再分散するものであった。
【０１８９】
実施例Ｉ−７
攪拌機、滴下口、温度計、還流冷却器を備えた１０Ｌのガラス製反応器中で、酢酸１．６ｋｇ及びイオン交換水１．６ｋｇの混合溶媒に酸化亜鉛粉末０．３ｋｇ、酢酸インジウム２水和物３６．３ｇを添加混合した後、攪拌しながら１００℃まで昇温することにより、均一溶液の亜鉛含有溶液（Ａ７）を得た。
次に、外部より熱媒加熱し得る、攪拌機、滴下口、温度計、留出ガス出口を備えた２０Ｌのガラス製反応器に、２−ブトキシエタノール１２ｋｇを仕込み、内温を１５８℃まで加熱昇温し保持した。これに、１００℃に保持された亜鉛含有溶液（Ａ７）全量を、定量ポンプにより３０分かけて滴下した。滴下終了後、内温を１６８℃まで昇温した時点で、メタクリル酸メチル−アクリル酸共重合体（重量比で９：１、重量平均分子量７，２００）５０．０ｇを含有する２−ブトキシエタノール溶液４００ｇを数秒間で添加し、さらに１６８℃で５時間加熱保持することにより、青灰色の分散体（ＤＩ−７）１１．７９ｋｇを得た。分散体（ＤＩ−６）は、約２０〜３０ｎｍの微結晶が厚み０．２μｍの外殻層を形成する、中空体構造の、平均粒子径０．５μｍ、微粒子中の金属酸化物含有量８６．０重量％の球状微粒子が、３．１重量％の濃度で分散して成る分散体であった。
【０１９０】
さらに、分散体（ＤＩ−７）中に含有されている微粒子を遠心分離操作によって分散媒から分離し、分離された微粒子をイソプロピルアルコールで洗浄した後、５０℃で２４時間真空乾燥（１０Ｔｏｒｒ）することによって微粒子粉体（ＰＩ−７）を得た。
得られた微粒子粉体（ＰＩ−７）は、平均粒子径０．５μｍ、金属酸化物含有量８６．０重量％、Ｉｎが金属原子総量に対し原子数比で３．０％の組成からなり、結晶性酸化亜鉛のＸ線回折パターンを示す球状微粒子であった。さらに、微粒子の内部構造は、約２５ｎｍの粒状の金属酸化物微粒子とメタクリル酸メチル−アクリル酸共重合体が外殻に局在化する中空体微粒子であることが確認された。中空部分の直径は平均で０．１μｍであった。また、微粒子表面は、凹凸に富むものであることが走査型電子顕微鏡観察により確認された。
【０１９１】
さらに、微粒子粉体（ＰＩ−７）は、メタノール、イソプロパノール，ｎ−ブタノール、ベンジルアルコール、２ーエトキシエタノール等のアルコール類、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、酢酸ブチル、酢酸エチル等のエステル類、ベンセン、トルエン等の芳香族化合物など有機溶媒に対する分散性に優れるものであった。
実施例Ｉ−８
実施例Ｉ−７に於いて、酢酸インジウム２水和物３６．３ｇの代わりに酢酸インジウム２水和物７２．５ｇ、メタクリル酸メチル−アクリル酸共重合体の２−ブトキシエタノール溶液の代わりにポリメチルメタクリレート（ＰＭＭＡ、重量平均分子量：６万）３０ｇを溶解したプロピレングリコールメチルエーテルアセテート溶液８００ｇを使用する以外は、実施例Ｉ−６と同様にして、反応を行うことにより、青灰色の分散体（ＤＩ−８）１０．０ｋｇを得た。
【０１９２】
さらに分散体（ＤＩ−８）中に含有されている微粒子を遠心分離操作によって分散媒から分離し、分離された微粒子をイソプロピルアルコールで洗浄した後、５０℃で２４時間真空乾燥（１０Ｔｏｒｒ）することによって微粒子粉体（ＰＩ−８）を得た。
得られた微粒子粉体（ＰＩ−８）は、平均粒子径３．０μｍ、金属酸化物含有量９０．１重量％、Ｉｎが金属原子総量に対し原子数比で５．８％の組成からなり、結晶性酸化亜鉛のＸ線回折パターンを示す球状微粒子であった。さらに、微粒子の内部構造は、約２０ｎｍの粒状の金属酸化物微粒子がＰＭＭＡ中に均一に分散したものであることが確認された。
【０１９３】
実施例Ｉ−９
実施例Ｉ−７に於いて、酢酸インジウム２水和物３６．３ｇの代わりに酢酸インジウム２水和物６．０５ｇ、メタクリル酸メチル−アクリル酸共重合体の２−ブトキシエタノール溶液の代わりに乳酸７ｇを溶解した２−ブトキシエタノール溶液２００ｇを使用する以外は、実施例Ｉ−７と同様にして、反応を行うことにより、青灰色の分散体（ＤＩ−９）を得た。
さらに分散体（ＤＩ−９）中に含有されている微粒子を遠心分離操作によって分散媒から分離し、分離された微粒子をメタノールで洗浄した後、５０℃で２４時間真空乾燥（１０Ｔｏｒｒ）することによって微粒子粉体（ＰＩ−９）を得た。
【０１９４】
得られた微粒子粉体（ＰＩ−９）は、平均粒子径１．２μｍ、金属酸化物含有量９６．０重量％、Ｉｎが金属原子総量に対し原子数比で０．５％の組成からなり、結晶性酸化亜鉛のＸ線回折パターンを示す球状微粒子であった。さらに、微粒子の内部構造は、長径０．３μｍ、偏平度１８の薄片状の金属酸化物微粒子が密に積層したものであり、中空径０．６μｍの中空体微粒子であった。
さらに、微粒子粉体（ＰＩ−９）は、水、メタノール、イソプロパノール，ｎ−ブタノール、ベンジルアルコール、２ーエトキシエタノール等のアルコール類、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、酢酸ブチル、酢酸エチル等のエステル類などの極性溶媒に対する分散性に優れる微粒子粉末であった。
【０１９５】
実施例Ｉ−１０
実施例Ｉ−１における亜鉛含有溶液（Ａ１）における原料の種類・量を表２に示すごとく変えた以外は、実施例Ｉ−１と同様にして亜鉛含有溶液（Ａ１０）を得、さらに、実施例Ｉ−１における２−ブトキシエタノール仕込み量を１２ｋｇとし、ラウリン酸の代わりにモノエタノールアミン３０．０ｇを添加した以外は、実施例Ｉ−１と同様にして分散体（ＤＩ−１０）を得た。
得られた分散体、および微粒子の物性を表３に示す。
実施例Ｉ−１、比較例Ｉ−１に於いて得られた分散体（ＤＩ−１）、（ＤＩ−Ｒ１）をそれぞれエバポレータに於いて、減圧下、バス温度１３０℃で、微粒子濃度が１０重量％となるように濃縮し、濃縮分散体（ＤＩ−１Ｃ）、（ＤＩ−ＲＣ）を得た。各濃縮分散体１００重量部にアクリル系樹脂溶液：アロセット５２１０（固形分４５重量％、（株）日本触媒製）１．１１重量部を添加混合した後２時間攪拌することにより、塗布液を調製した。
【０１９６】
予め、金の櫛型電極を蒸着したパイレックスガラス上に、各塗布液を用いて、スピンコーターにより成膜し、常温で乾燥し、５０℃で加熱乾燥することにより、乾燥膜（ＤＩ−１Ｍ）、（ＤＩ−ＲＭ）を得た。得られた膜はいずれも厚み１．０μｍの均質な膜であった。
各乾燥膜を温度２０℃、相対湿度６０％の雰囲気下、遮光状態で１時間放置した後、ケスレー社製エレクトロメータ６１７型を用いて、同条件下に於ける、表面抵抗値を測定した結果、以下のとおりであった。
ＤＩ−１Ｍ ２．７×１０¹¹Ω／□
ＤＩ−ＲＭ ３．９×１０¹⁴Ω／□
さらに、ＤＩ−１Ｍについて、温度２０℃、以下の相対湿度雰囲気下で１時間放置したときの遮光状態に於ける表面抵抗値を測定した結果を以下に示す。
【０１９７】

実施例Ｉ−２〜Ｉ−５に於いてそれぞれ得られた分散体（ＤＩ−２）〜（ＤＩ−５））についても同様に塗布液を調製し、厚み１μｍの膜に成膜し、温度２０℃、相対湿度６０％の雰囲気下での表面抵抗値を測定した結果、いずれの膜の表面抵抗値（単位：Ω／□）も１０¹¹オーダーもしくは１０¹²オーダーであり、しかも、実施例Ｉ−１の場合と同様に湿度によらず表面抵抗値は一定であることが確認された。
【０１９８】
以上の結果から、実施例Ｉ−１〜Ｉ−５に於いて得られた各分散体中の微粒子は、従来の酸化亜鉛に比べて導電化された導電性微粒子であり、しかも、実質的に湿度依存性のないものであることが確認された。従って、本発明で得られる微粒子（分散体）は例えば帯電防止膜の好適な原料であるといえる。
実施例Ｉ−２および比較例Ｉ−１で得られた分散体（ＤＩ−２）、分散体（ＤＩ−Ｒ１）より、前記した方法に従って、粉末試料を得、Ｘ線回折測定を行った結果（各粉末のＸ線回折パターン）を、図２に示す。図２において、横軸は回折角度（２θ）〔単位：°〕、縦軸は強度〔ｃｐｓ〕である。図２にみるように、ＤＩ−２およびＤＩ−Ｒ１は、いずれもＺｎＯに帰属されるシャープな回折ピークを示すことがわかる。
【０１９９】
比較例Ｉ−２
重炭酸アンモニウム３５．０ｇをイオン交換水５００ｇに溶解することによりＡ液を得た。
硫酸アルミニウム水和物（ Al₂(SO₄)₃・nH₂O, n=１４〜１８）６．１７７８ｇをイオン交換水に溶解して５０ｇとしＢ液を得た。
酸化亜鉛（フランス法１号特注，堺化学製）１００ｇをイオン交換水１８０ｇに添加混合し、スラリーＣを得た。
シリカ微粉末（エアロジル２００，日本アエロジル社）１．００ｇをイオン交換水５０ｇに添加混合し、攪拌することにより、分散液Ｄを得た。
【０２００】
室温にて、液Ａを攪拌しながら、液Ａに液Ｂを添加することにより、混合物を得た。該混合物は、混合後すみやかに乳濁した。得られた乳濁物をそのまま、１０分間攪拌した。
次に、外部より熱媒加熱し得る、攪拌機、滴下口、温度計、還流冷却器を備えた１Ｌのガラス製反応器中に、スラリーＣを仕込み、室温で攪拌しながら、滴下口より、先に得られた乳濁物を添加混合し、熱媒温度を８０℃に設定して昇温を開始した。約３０分後、内温が６１℃に達した時点で、分散液Ｄを添加混合し、加熱下で１時間攪拌を続けた。１時間後、内温が７６．６℃の時点で、攪拌は続けながら、加熱を停止し、放冷した。内温が室温になった時点で、得られたスラリー全量を減圧濾過によって、微粒子を分離し、さらに、イオン交換水で十分に洗浄した後、５０℃で１２時間真空乾燥し、さらに１００℃で４時間、真空乾燥することにより、白色粉末を得た。
【０２０１】
得られた白色粉末は、Ｘ線回折測定の結果、ＺｎＯに帰属する回折ピーク以外に塩基性炭酸亜鉛 Zn₄CO₃(OH)₆・H₂O と考えられる不純物ピークの混在する回折パターンを示すものであり、ＺｎＯの結晶性は低いものであることが確認された。該粉末のＸ線回析パターンを図３に示す。
比較例Ｉ−３
塩化亜鉛（ZnCl2 ）８．３７５３ｇ，塩化アルミニウム（ AlCl₃・6H₂O）０．３１６７ｇをイオン交換水５０ｇに溶解させることにより均一溶液を得た。次に、該溶液を室温で攪拌しながら、１４ｗｔ％アンモニア水を滴下し、ｐＨ８．２１になった時点で滴下を終了した。１４ｗｔ％アンモニア水の滴下量は２０．０ｇであった。
【０２０２】
滴下終了後、１０分間攪拌した後、全量を濾過し、さらに水洗を十分に行った後、遠心分離操作によって微粒子分を取り出し、５０℃で１２時間、さらに１００℃で４時間真空乾燥を行うことより、白色粉末を得た。
得られた白色粉末は、Ｘ線回析測定の結果、ＺｎＯに帰属される回折ピークを示さないものであることが確認された。該粉末のＸ線回折パターンを図３に示す。
比較例Ｉ−４
比較例Ｉ−２と全く同様にして、白色粉末を得た後、該白色粉末を、加熱焼成炉中で、窒素雰囲気下、室温より６４０℃に昇温し、６４０℃で１時間保持した後、室温まで冷却することにより、灰白色の粉末を得た。
【０２０３】
得られた粉末は、Ｘ線回折測定の結果、ＺｎＯ結晶であることが確認された。該粉末のＸ線回折パターンを図３に示す。
また、得られた粉末を利用して、下記組成の塗料を作成し、ガラス基板上に成膜し、厚み３．１μｍの膜の形成された塗装品（II−Ｒ４Ｃ）を得た。得られた塗装品（II−Ｒ４Ｃ）は、ヘイズ値が７８％と高い白濁したものであり、可視光に対する透明性が低く、紫外線（ＵＶ）に対しては遮蔽性を示すものの、熱線遮蔽性を示さないものであった。塗装品（II−Ｒ４Ｃ）の分光透過率曲線を図４に示す。
【０２０４】
（塗料組成）
粉末 １０重量部
２−ブトキシエタノール ９０重量部
アクリル系樹脂溶液* ５０重量部
＊アロセット５２４７（日本触媒製，固形分４５重量％）をトルエンで固形分濃度２０重量％に希釈したもの
（塗料化方法）
粉末を２−ブトキシエタノールに添加混合後、超音波ホモジナイザーで２０分間分散処理を行った後、アクリル樹脂溶液を添加し、攪拌を２時間行った。さらに、超音波ホモジナイザーで２０分間分散処理を施すことにより塗料を得た。
【０２０５】
比較例Ｉ−５
比較例Ｉ−３と全く同様にして、白色粉末を得た。該白色粉末を、加熱焼成炉中で、窒素雰囲気下、室温より６４０℃に昇温し、６４０℃で１時間保持した後、室温まで冷却することにより僅かに緑灰がかった粉末を得た。
得られた粉末は、Ｘ線回折測定の結果、ＺｎＯ結晶であることが確認された。該粉末のＸ線回折パターンを図３に示す。
図３において、横軸は回折角度（２θ）〔単位：°〕、縦軸は強度〔ｃｐｓ〕である。
【０２０６】
また、得られた粉末を利用して、比較例Ｉ−４の場合と同様にして、塗料を作成し、ガラス基板上に成膜し、厚み３．２μｍの膜の形成された塗装品（II−Ｒ５Ｃ）を得た。得られた塗装品（II−Ｒ５Ｃ）は、ヘイズ値が８３％と高い白濁したものであり、可視光に対する透明性が低く、ＵＶ遮蔽性は示すものの、熱線遮蔽性を示さないものであった。塗装品（II−Ｒ５Ｃ）の分光透過率曲線を図４に示す。
［塗料、塗装品の製造例］
実施例II−１
実施例Ｉ−１に於いて得られた分散体（ＤＩ−１）をエバポレータに於いて、減圧下、バス温度１３０℃で、微粒子濃度が１０重量％となるように濃縮し、濃縮分散体（ＤＩ−１Ｃ）を得た。
【０２０７】
次に、アクリル系樹脂溶液（アロセット５２１０；日本触媒製、固形分４５重量％）をバインダー成分として、塗料を調製した。
すなわち、上記アクリル樹脂溶液をトルエンで希釈し、樹脂濃度２０重量％とした樹脂溶液５０重量部に、濃縮分散体（ＤＩ−１Ｃ）１００重量部を添加混合した後、攪拌することにより、塗料（II−１）１５０重量部を得た。
実施例II−２
実施例Ｉ−２に於いて得られた分散体（ＤＩ−２）をエバポレータに於いて、減圧下、バス温度１３０℃で、微粒子濃度が１０重量％となるように濃縮し、濃縮分散体（ＤＩ−２Ｃ）を得た。
【０２０８】
次に、得られた濃縮分散体（ＤＩ−２Ｃ）を遠心分離操作によって微粒子沈降物と溶媒分（上澄み）に分離し、微粒子沈降物を、イオン交換水に添加し、サンドミルによって分散処理することによって、微粒子が、１０重量％で微分散した水分散体（ＤＩ−２Ｗ）を得た。
ビニル系樹脂（ポバールＲ２１０５，（株）クラレ製）１０重量％含む水溶液１００重量部に、水分散体（ＤＩ−２Ｗ）１００重量部を添加した後、攪拌することにより、微粒子、バインダーをそれぞれ５重量％含有する塗料（II−２）を得た。
【０２０９】
実施例II−３
実施例Ｉ−１に於いて得られた分散体（ＤＩ−１）をエバポレータに於いて、減圧下、バス温度１３０℃で、微粒子濃度が１０重量％となるように濃縮し、濃縮分散体（ＤＩ−１Ｃ）を得た。
一方、還流冷却器、攪拌機、温度計を備えた４つ口フラスコにイソプロピルアルコール２４重量部、水１６重量部、３５％塩酸０．００５重量部を順次仕込み、攪拌しながら、メチルトリメトキシシラン１０重量部、テトラエトキシシラン３０重量部を添加した後、８０℃に昇温して８０℃で２時間反応させた後、冷却した。得られた混合物（ｘ）は、不揮発分１７．０重量％の均一溶液であった。
【０２１０】
次に、濃縮分散体（ＤＩ−１Ｃ）８０重量部を攪拌しながら、混合物（ｘ）１２重量部を添加混合することにより、塗料（II−３）を得た。
実施例II−４
実施例II−２と同様にして、実施例Ｉ−２に於いて得られた分散体（ＤＩ−２）より、微粒子が、１０重量％で微分散した水分散体（ＤＩ−２Ｗ）を得た。
ビニル系樹脂（ポバール２０５，（株）クラレ製）１０重量％含む水溶液２０重量部に、水分散体（ＤＩ−２Ｗ）１００重量部を添加し、さらに、酢酸銅１水和物の１．２３重量部を含む水溶液２０重量部を添加した後、攪拌し、超音波照射処理することにより、塗料（II−４）を得た。
【０２１１】
実施例II−１〜４に於いて得られた塗料（II−１）〜（II−４）を用いて、各種基材に、バーコーターにより塗布し、乾燥することによって、塗装品（II−１Ｃ１）、（II−１Ｃ２）、（II−２Ｃ），（II−３Ｃ），（II−４Ｃ）を製造した。
成膜条件、得られた塗装品の膜厚、光学的物性を表４に示す。
得られた塗装品は、いずれも均質であり、可視光に対する透明性に優れながら、紫外線および熱線を遮蔽する膜であった。
塗装品（II−１Ｃ１），（II−１Ｃ２）について日射透過率および可視光透過率を測定した結果、透明でありながら熱遮断性を有する膜であることが確認された。
【０２１２】
また、塗装品（II−３Ｃ）は、表面硬度が鉛筆硬度で６Ｈと硬く、しかも、表面抵抗が１×１０⁹ Ω／□と帯電防止レベルのものであることが確認された。
比較例II−１
実施例II−１に於いて、分散体（ＤＩ−１）を使用する代わりに、比較例Ｉ−１で得られた分散体（ＤＩ−Ｒ１）を使用する以外は、実施例II−１と同様にして塗料（II−Ｒ１）を調整した。該塗料（II−Ｒ１）を用いて、塗装品II−１および２で用いたと同じガラス基板上に塗装品II−１，２の場合と同様に塗布し乾燥することにより、膜厚６．３μｍのＺｎＯ微粒子含有膜の形成された塗装品（II−Ｒ１Ｃ）を得た。得られた塗装品（II−Ｒ１Ｃ）は、紫外線を有効に遮蔽するものの、熱線に対しては遮蔽効果を示さないものであった。
【０２１３】
実施例でそれぞれ得られた塗装品（II−１Ｃ１）、（II−１Ｃ２）および比較例（II−１）で得られた塗装品（II−Ｒ１Ｃ）の分光透過率曲線を図１に示す。図１には、用いたガラス基板の分光透過率曲線も示す。図１において、横軸は入射光の波長（ｎｍ）、縦軸は透過率（％）を表す。
実施例II−５
実施例II−２と同様にして、実施例Ｉ−２に於いて得られた分散体（ＤＩ−２）より、微粒子が、１０重量％で微分散した水分散体（ＤＩ−２Ｗ）を得た。
該水分散体１００重量部、バインダー樹脂としてアクリルエマルション（株式会社日本触媒製アクリセットＲ ＥＳ−２８５Ｅ、固形分５０重量％）２０重量部を混合することにより塗料（II−５）を調製した。該塗料にポリエステル繊維を浸漬して乾燥することにより、微粒子目付量４．０ｇ／ｍ2 のポリエステル繊維を得た。得られた繊維は、紫外線および熱線をカットする、透明感に優れるものであった。
【０２１４】
比較例II−５
実施例II−２と同様にして、比較例Ｉ−１に於いて得られた分散体（ＤＩ−Ｒ１）より、微粒子が、１０重量％で微分散した水分散体を得た。
該水分散体１００重量部、バインダー樹脂としてアクリルエマルション（株式会社日本触媒製アクリセットＲ ＥＳ−２８５Ｅ、固形分５０重量％）２０重量部を混合することにより塗料（II−Ｒ５）を調製した。該塗料にポリエステル繊維を浸漬して乾燥することにより、微粒子目付量４．２ｇ／ｍ2 のポリエステル繊維を得た。得られた繊維は、紫外線をカットする、透明感に優れるものであったが、熱線に対して遮蔽効果を有しないものであった。
【０２１５】
実施例II−６
実施例II−２と同様にして、実施例Ｉ−２に於いて得られた分散体（ＤＩ−２）より、微粒子が、１０重量％で微分散した水分散体（ＤＩ−２Ｗ）を得た。
該水分散体１００重量部、バインダー樹脂としてアクリルエマルション（株式会社日本触媒製アクリセットＲ ＥＳ−２８５Ｅ、固形分５０重量％）３０重量部を混合することにより塗料（II−５）を調製した。該塗料に綿繊維を浸漬して乾燥することにより、微粒子目付量３．０ｇ／ｍ2 のポリエステル繊維を得た。得られた繊維は、紫外線および熱線をカットする、透明感に優れるものであった。
【０２１６】
実施例II−７
実施例Ｉ−２で得られた微粒子粉末（ＰＩ−２−１）１０重量部を、ＰＰ（ポリプロピレン）ペレット９０重量部と溶融混練することにより、微粒子粉末（ＰＩ−２−１）を１０重量％含有するＰＰペレット（Ａ）を得た。
次に、多層用フィードブロックダイを備えた押し出し機を用いて２層ＰＰフィルムを得た。すなわち、微粒子成分を含有しないＰＰペレット（Ｂ）を主押出機に供給、２２０℃で溶融し、ＰＰペレット（Ａ）を副押出機に供給、１８０℃で溶融し、各押出機の吐出量を調節することにより、ＰＰ（Ａ）層（微粒子粉末含有）とＰＰ層（Ｂ）からなる積層シートを得、さらに、得られたシートを延伸処理することにより、厚み８μｍのＰＰ（Ａ）層と厚み２０μｍのＰＰ層（Ｂ）の積層されたＯＰＰフィルム（二軸延伸ポリプロピレンフィルム）を得た。
【０２１７】
該フィルムは、微粒子が均一に高分散した薄膜層（Ａ）を有する多層フィルムであり、可視光透過性に優れながら、紫外線遮蔽性および熱線遮蔽性に優れるものであった。
実施例II−８
実施例Ｉ−６で得られた微粒子粉体（ＰＩ−６）５０重量部とＰＥＴペレット５０重量部を溶融混練することにより、微粒子粉末（ＰＩ−６）を５０重量％含有するＰＥＴペレット（Ａ）を得た。
次に、実施例II−７で使用したと同じ押し出し機、延伸機を用いて、２層ＰＥＴフィルムを製造した。すなわち、微粒子成分を含有しないＰＥＴペレット（Ｂ）を主押出機に供給、３１０℃で溶融し、ＰＥＴペレット（Ａ）を副押出機に供給、２８０℃で溶融し、各押出機の吐出量を調節することにより、ＰＥＴ（Ａ）層（微粒子粉末含有）とＰＥＴ層（Ｂ）からなる積層シートを得、さらに、得られたシートを延伸処理することにより、厚み２μｍのＰＥＴ（Ａ）層と厚み２０μｍのＰＥＴ（Ｂ）層の積層されたＰＥＴフィルムを得た。
【０２１８】
該フィルムは、微粒子が均一に高分散した薄膜層（Ａ）を含有する多層フィルムであり、可視光透過性に優れながら、紫外線遮蔽性および熱線遮蔽性に優れるものであった。
［微粒子含有成型品の製造例］
実施例III −１
実施例Ｉ−６で得られた微粒子粉体（ＰＩ−６）５重量部とポリカーボネート樹脂ペレット９９５重量部を混合し溶融混練りすることにより、微粒子０．５重量％が均一に分散した溶融物を得、引き続き押し出し成形することによって、厚み２．０ｍｍのポリカーボネート板を得た。得られたポリカーボネート板は、微粒子が高分散した、全光線透過率が８５％以上と可視光透過性に優れ、紫外線遮蔽性及び熱線遮蔽性を示すものであった。
【０２１９】
実施例III −２
実施例Ｉ−７で得られた微粒子粉体（ＰＩ−７）２５重量部とメタクリル樹脂ペレット４７５重量部を混合し溶融混練りすることにより、微粒子５重量％が均一に分散した溶融物を得、引き続き押し出し成形することによって、厚み２ｍｍのメタクリル樹脂シートを得た。得られたシートは、微粒子が高分散した、全光線透過率が８３％、ヘイズが８６％と、高い可視光透過性と優れた光拡散透過性を有し、しかも紫外線防止効果、熱線遮蔽効果に優れるものであった。
比較例III −１
実施例III −１に於いて、粉体（ＰＩ−６）の代わりに、フランス法で得られた酸化亜鉛微粒子（亜鉛華１号：堺化学製）５重量部を用いる以外は、実施例III −１と同様にして、微粒子を０．５重量％含有する、厚み２ｍｍのポリカーボネート板を得た。得られたポリカーボネート板は、微粒子が２次凝集した不均一な状態で含有された、実施例III −１で得られたものと比べて透明感がなく白濁したものであり、しかも紫外線遮蔽性が低いばかりか、熱線に対する遮蔽性能を有しないものであった。
【０２２０】
実施例III −３
実施例Ｉ−６で得られた微粒子粉体（ＰＩ−６）２重量部とポリエステル樹脂ペレット９８重量部を混合し溶融混練りすることにより酸化亜鉛微粒子が２重量％均一に分散したポリエステル組成物を得、押し出し成形によってシート状に成形した後、さらに延伸することによって厚み４０μｍのポリエステルフィルムを得た。該フィルムは、微粒子が均一に高分散したフィルムであり、可視光透過性に優れ、紫外線遮蔽性および熱線遮蔽性に優れるものであった。
比較例III −２
実施例III −３に於いて、粉体（ＰＩ−６）の代わりに、フランス法で得られた酸化亜鉛微粒子（亜鉛華１号：堺化学製）２重量部を用いる以外は、実施例III −３と同様にして、微粒子を２重量％含有する、厚み４０μｍのポリエステルフィルムを得た。得られたフィルムは、微粒子が２次凝集した状態で含有されたものであり、そのために紫外線防止効果が低く、しかも透明感がなく白濁したものであった。また、熱線に対する遮蔽性能を有しないものであった。
【０２２１】
実施例III −３および比較例III −２でそれぞれ得られたフィルムの断面を透過型電子顕微鏡により観察した結果、実施例III −３で得られたフィルムでは、微粒子が高分散した実質的に均質なフィルムであり、比較例III −２で得られたフィルムでは、微粒子が凝集しているためにフィルム表面に粗大な突起が存在するなど表面特性が良くないばかりか、微粒子とマトリックスであるＰＥＴとの間に間隙が存在するために耐摩耗性、耐スクラッチ性などにおいて不十分なものであった。
実施例III −４
実施例III −３と同様にして、微粒子（ＰＩ−６）が２重量％含有されたポリエステル組成物を得た後、溶融紡糸することによって、ポリエステル繊維を得た。該繊維は、微粒子が均一に高分散した繊維であり、透明感があり、紫外線遮蔽性、熱線遮蔽性に優れるものであった。
【０２２２】
比較例III −３
実施例III −４に於ける微粒子粉体（ＰＩ−６）の代わりに、フランス法で得られた酸化亜鉛微粒子（亜鉛華１号：堺化学製）を用いる以外は、実施例III −４と同様にして、該酸化亜鉛微粒子が含有されたポリエステル繊維を得た。得られた繊維は、微粒子が２次凝集した状態で含有されたものであり、そのために紫外線防止効果が低く、しかも透明感がなく白濁したものであった。また、熱線に対する遮蔽性能を有しないものであった。
［化粧品の製造例］
実施例IV−１
実施例II−２と同様にして、実施例Ｉ−１に於いて得られた分散体（ＤＩ−１）より、微粒子が、１０重量％で微分散した水分散体（ＤＩ−１Ｗ）を得た。該水分散体を配合した、下記組成を有する化粧料（Ｏ／Ｗ型クリーム）を製造した。
【０２２３】
＜組成＞
（水相部）
（ａ）微粒子の水分散体 ５０重量部
（ｂ）プロピレングリコール ５重量部
（ｃ）グリセリン １０重量部
（ｄ）水酸化カリウム ０．２重量部
（油相部）
（ｅ）セタノール ５重量部
（ｆ）流動パラフィン ５重量部
（ｇ）ステアリン酸 ３重量部
（ｈ）ミリスチン酸イソステアリル ２重量部
（ｉ）モノステアリン酸グリセリン ２重量部
成分（ａ）〜（ｄ）を攪拌混合して８０℃に保って水相部を調製した。一方、成分（ｅ）〜（ｉ）を均一混合して８０℃に保つことにより油相部を調製した。水相部に油相部を加えて攪拌し、ホモミキサーで乳化させた後、室温に冷却することによってクリームを製造した。得られたクリームは透明感に優れながら、紫外線防止効果および熱線遮蔽効果に優れるものであった。
【０２２４】
比較例IV−１
実施例IV−１に於いて、水分酸体（ＤＩ−１Ｗ）の代わりにフランス法で得られた酸化亜鉛微粒子粉末（亜鉛華１号；堺化学製）５重量部を１０重量％の割合で含有する水分酸体５０重量部を用いる以外は、実施例IV−１と同様にして、クリームを製造した。
得られたクリームは、微粒子の分散性が不良であるために、紫外線防止効果が不十分であり、しかも白色度が高いために透明感に欠けるものであった。また、熱線に対する遮蔽性は有しないものであった。
［紙の製造例］
実施例Ｖ−１
実施例II−２と同様にして、実施例Ｉー２に於いて得られた分散体（ＤＩ−２）より、微粒子が、１０重量％で微分散した水分散体（ＤＩ−２Ｗ）を得た。
【０２２５】
次に、定量用濾紙（東洋製紙（株）製：品番５Ｃ）をナイアガラ式ビーターにて叩解し、カナディアン・スタンダード・フリーネス４００ｍｌに調製したパルプに、水分散体を、パルプに対する微粒子重量比が１重量％となるよう添加混合した。次に得られたパルプスラリーを、固形分濃度０．１重量％となるよう希釈し、タッピ・シートマシンにより脱水し、プレスすることによって坪量７５ｇ／ｍ2 に抄紙した。引き続いて回転型乾燥機で１００℃で乾燥することによって、微粒子を１重量％含有する紙を得た。得られた紙は、微粒子の分散状態が良好であり、そのために紫外線遮蔽性に優れ、熱線遮蔽効果を有し、表面平坦性に優れるものであった。さらに、埃などの付着しがたいものであった。
【０２２６】
比較例Ｖ−１
実施例Ｖ−１に於ける水分酸体（ＤＩ−２Ｗ）の代わりに、フランス法で得られた酸化亜鉛微粒子粉末（亜鉛華１号：堺化学製）を１０重量％分散含有して成る水分酸体を用いる以外は、実施例Ｖ−１と同様にして、紙を製造した。得られた紙は、微粒子が２次凝集した状態で含有されたものであり、そのために紫外線防止効果が低く、さらに表面に凝集粒子に基づく粗大な突起が存在する等表面性状が粗悪なものであった。しかも、熱線遮蔽性を有さず、また埃などの付着しやすいものであった。
【０２２７】
【表１】

【０２２８】
【表２】

【０２２９】
【表３】

【０２３０】
【表４】

【０２３１】
実施例Ｉ−１１
実施例Ｉ−１に於ける亜鉛含有溶液（Ａ１）に於ける原料の種類、量を表５に示す如く変えた以外は、実施例Ｉ−１と同様にして亜鉛含有溶液（Ａ１１）を得、さらに、実施例Ｉ−１に於ける２−ブトキシエタノール仕込量を２０ｋｇとし、ラウリン酸を添加する代わりに、表５、７に示す化合物を表５に示す量添加した以外は、実施例Ｉ−１と同様にして、分散体（ＤＩ−１１）を得た。
得られた分散体および微粒子の物性を表９に示す。
実施例Ｉ−１２
反応原料を表５に示す如く変えた以外は実施例Ｉー１と同様にして反応を行い、微粒子が分散した分散体（ＤＩ−１２pre ）を得た後、表５、７に示す化合物を表５に示す量添加した後、該分散体を、熱媒加熱し得るステンレス製の耐圧容器（オートクレーブ）に仕込み、系内を窒素パージし、室温での窒素圧を２０ｋｇｆ／ｃｍ2 となるように窒素で充たした後、攪拌しながら、液温を２２０℃まで昇温し、同温度で５時間保持した後、放冷することにより、分散体（ＤＩ−１２）を得た。
【０２３２】
得られた分散体および微粒子の物性を表９に示す。
実施例Ｉ−１３
反応原料を表５に示す如く変えた以外は実施例Ｉ−１と同様にして反応を行い、微粒子が分散した分散体（ＤＩ−１３pre ）を得た後、室温で攪拌しながら、表５、７に示す化合物を表５に示す量添加した後、攪拌を３時間行うことにより分散体（ＤＩ−１３）を得た。
得られた分散体および微粒子の物性を表９に示す。
実施例Ｉ−１４〜Ｉ−１９
反応原料を表５、６に示す如く変えた以外は実施例Ｉ−１と同様にして反応を行い、微粒子が分散した分散体（ＤＩ−１４pre 〜ＤＩ−１９pre ）を得、加熱処理を行った後に添加する化合物を表５〜８に示すものに変え、添加後の処理条件を表５、６に示す内容とした以外は、実施例Ｉ−１３と同様にして、分散体（ＤＩ−１４〜ＤＩ−１９）を得た。
【０２３３】
得られた分散体および微粒子の物性を表９に示す。
実施例Ｉ−２０
反応原料を表６に示す如く変えた以外は実施例Ｉ−１と同様にして反応を行い、微粒子が分散した分散体（ＤＩ−２０）を得た。
得られた分散体および微粒子の物性を表９に示す。
【０２３４】
【表５】

【０２３５】
【表６】

【０２３６】
【表７】

【０２３７】
【表８】

【０２３８】
【表９】

【０２３９】
＜各種溶媒分散体の合成＞
実施例Ｉ−１１（２）
実施例Ｉ−１１で得られた分散体（ＤＩ−１１）を遠心分離した後、沈殿物をトルエンに添加混合し攪拌することにより、金属酸化物換算濃度２０ｗｔ％のトルエン分散体（ＤＩ−１１−Ｔ）を得た。
トルエン分散体（ＤＩ−１１−Ｔ）は、分散平均粒径が０．０３μｍであり、沈降安定性に優れる（評価○）ものであった。また、合成して１か月後に於いて測定した分散平均粒径は０．０３μｍと変化がないことも確認された。
【０２４０】
分散体の分散粒子径は、分散体を分散体中の主溶媒（ＤＩ−１１−Ｔの場合はトルエン）を測定溶媒として遠心沈降式粒度分布測定装置により測定したものであり、また沈降安定性は、分散体を１か月間３０℃の恒温下で静置したときの沈降状態を以下の基準で評価したものである。
沈降安定性 ○：沈降堆積物がなく、沈降がまったくみられない。
△：沈降堆積物が僅かに生成。
×：沈降堆積物が多量に生成。
得られた分散体の物性を表１０に示す。
【０２４１】
実施例Ｉ−２（２）
一方、実施例Ｉ−２で得られた分散体（ＤＩ−２）を遠心分離した後、沈殿物をトルエンに添加混合し攪拌し、金属酸化物換算濃度２０ｗｔ％のトルエン分散体（ＤＩ−２−Ｔ）を得た。
トルエン分散体（ＤＩ−２−Ｔ）は、分散平均粒径が１．５１μｍであり、沈降安定性の悪い（評価×）ものであった。
従って、実施例Ｉ−１１で得られた分散体（ＤＩ−１１）およびトルエン分散体（ＤＩ−１１−Ｔ）中の微粒子は、化合物Ｓ１で表面改質されたものであることが明らかである。
【０２４２】
得られた分散体の物性を表１０に示す。
実施例Ｉ−１１（３）
実施例Ｉ−１１で得られた分散体（ＤＩ−１１）を、エバポレータにより減圧加熱しペースト状になるまで溶媒を留去した後、酢酸エチルを混合し、攪拌することにより、微粒子（金属酸化物換算）濃度２０ｗｔ％の酢酸エチル分散体（ＤＩ−１１−ＥＡ）を得た。
得られた分散体の物性を表１０に示す。
実施例Ｉ−１２（２）〜Ｉ−１９（２）
実施例Ｉ−１２〜Ｉ−１９で得られた分散体（ＤＩ−１２〜ＤＩ−１９）に関しても、上記（ＤＩ−１１−ＥＡ）と同様にして、ペースト状物を得た後、表１０に示す溶媒を混合することにより、各種溶媒分散体を得た。
【０２４３】
得られた分散体の物性を表１０に示す。
実施例Ｉ−２０（２）
分散体（ＤＩ−２０）より、上記（ＤＩ−１１−ＥＡ）と同様にして、ペースト状物を得た後、ｎ−ブタノールを混合することにより、ｎ−ブタノール分散体（ＤＩ−２０−BuOH）を得た。
得られた分散体の物性を表１０に示す。
【０２４４】
【表１０】

【０２４５】
＜可塑剤分散体＞
実施例Ｉ−２１
原料Ａとして実施例Ｉ−２０で得られた分散体（ＤＩ−２０）５００重量部に、原料Ｂとしてフタル酸ジ−２−エチルヘキシル４００重量部を添加混合した後、得られた分散液を減圧下で１５０℃まで昇温し、同温度で分散液中の溶媒を留去せしめた後、ステンレス製金網でろ過することにより、微粒子濃度（金属酸化物換算）２０．１重量％のフタル酸ジ−２−エチルヘキシル分散体（ＤＩ−２０−ＰＬ）を得た。
【０２４６】
該分散体中の溶媒成分は＜１重量％以下であることが、ガスクロマトグラフィーにより確認された。
また、得られた分散体は、青みを帯びた透明感のある、沈降安定性に優れるものであった。該分散体の物性を表１２に示す。
実施例Ｉ−２２〜Ｉ−２５
実施例Ｉ−２１に於いて、原料Ａ、Ｂの種類、混合比を表１１の如く変えた以外は、実施例１−２１と同様にして、各種分散体を得た。
各実施例で得られた分散体に於いては、原料Ａおよび原料Ｂに含まれていた溶媒成分含有量が総量で１重量％以下であることが確認された。
【０２４７】
各分散体の物性を表１２に示す。
【０２４８】
【表１１】

【０２４９】
【表１２】

【０２５０】
＜塗料、塗工品＞
実施例II−９
実施例Ｉ−２０に於いて得られたｎ−ブタノール分散体（ＤＩ−２０−BuOH）より、アクリル系樹脂溶液（アロセット５８５８：日本触媒製、固形分６０重量％）をバインダー成分として、塗料を調整した。
すなわち、上記アクリル樹脂溶液１７重量部、分散体（ＤＩ−２０−BuOH）５０重量部およびｎ−ブタノール１３重量部を混合し、攪拌した後、超音波ホモジナイザーで分散処理を行うことにより、塗料（II−９）８０重量部を得た。
【０２５１】
実施例II−１０
実施例II−２と同様にして、実施例Ｉ−２０に於いて得られたｎ−ブタノール分散体（ＤＩ−２０−BuOH）より、微粒子が、１０重量％で微分散した水分散体（ＤＩ−２０Ｗ）を得た。
ビニル系樹脂（ポバール２０５，（株）クラレ製）１０重量％含む水溶液１００重量部に、水分散体（ＤＩ−２０Ｗ）１００重量部を添加した後、攪拌し、超音波ホモジナイザーで分散処理することにより、塗料（II−１０）を得た。
実施例II−１１
実施例Ｉ−２０において得られたｎ−ブタノール分散体（ＤＩ−２０−BuOH）１００重量部を攪拌しながら、混合物（ｘ）（実施例II−３で合成したもの）１５０重量部を添加混合した後、攪拌し、超音波ホモジナイザーで分散処理することにより、塗料（II−１１）を得た。
【０２５２】
得られた塗料（II−９）〜（II−１１）を用いて、表１３に示す各種基材に、バーコーターにより塗布し、乾燥することによって、塗装品（９Ｃ）、（１０Ｃ），（１１Ｃ）を製造した。得られた塗工品の物性を表１３に示す。
【０２５３】
【表１３】

【０２５４】
実施例II−１２〜II−２４
表１４、１５に示す実施例Ｉ−１１〜Ｉ−２０に於いて得られた各種分散体、各種バインダーを用いて、各溶媒系の塗料を合成し、表１６〜１８に示す、基材に塗布することにより、各塗工品を得た。
各塗工品の物性を表１６、１７に示す。
実施例II−１１、１６、１８、２０でそれぞれ得られた塗工品１１Ｃ，１６Ｃ，１８Ｃ，２０Ｃの鉛筆硬度が、１１Ｃ：ＨＢ，１６Ｃ：＞９Ｈ、１８Ｃ：７Ｈ、２０Ｃ：３Ｈであり、しかも耐摩耗性、耐擦傷性に優れるものであった。
【０２５５】
また、実施例II−１３、１４でそれぞれ得られた、塗工品１３Ｃ，１４Ｃはいずれも酸素、水蒸気のバリアー性に優れるものであった。
また、実施例II−２４で得られた塗工品２４Ｃは、塗工面がガラス、ポリカーボネート等に対し優れた粘着性を示すフィルムであった。
【０２５６】
【表１４】

【０２５７】
【表１５】

【０２５８】
【表１６】

【０２５９】
【表１７】

【０２６０】
【表１８】

【０２６１】
＜樹脂組成物、成形体＞
実施例III −５
実施例Ｉ−２１で得られた、フタル酸ジ−２−エチルヘキシル分散体（DI-20-PL）５０重量部、ポリ塩化ビニル樹脂（ＰＶＣ）１００重量部を、１６０℃にて溶融混合し、ＰＶＣコンパウンドを製造した。該コンパウンドを用いて、押し出し成形することにより、微粒子の分散含有された、厚さ５０μｍの塩化ビニルフィルムを得た。
得られたフィルムは、可視光に対する透明性に優れ、しかも紫外線および熱線を有効に遮蔽するものであった。
【０２６２】
得られたフィルムの物性を表１９に示す。
実施例 III−６〜 III−９
実施例Ｉ−２２〜Ｉ−２５で得られた、各種分散体を微粒子原料として、微粒子が分散含有された各種樹脂フィルムを製造した。即ち、表１９に示す、分散体原料、樹脂原料、必要に応じてフタル酸ジ−ｎ−オクチルを、表１９に示す割合で、加熱混合することにより、各種樹脂コンパウンドを得た後、さらに各コンパウンドを成形することにより、各種フィルムを得た。
得られたフィルムはいずれも、可視光に対する透明性に優れ、しかも紫外線および熱線を有効に遮蔽するものであった。得られた各フィルムの物性を表１９に示す。
【０２６３】
実施例III −７で得られたフィルムは難燃性にも優れるものであった。
比較例III −４
実施例III −５に於いて、微粒子の分散体を使用せず、フタル酸ジ−ｎ−オクチルとポリ塩化ビニル樹脂を、表１９に示す割合で使用した以外は、実施例III−５と同様にして、ＰＶＣコンパウンドを製造し、さらにフィルムを製造した。
得られたフィルムは、可視光に対する透明性に優れるものの、紫外線および熱線を遮蔽しないものであった。得られたフィルムの物性を表１９に示す。
【０２６４】
【表１９】

【０２６５】
【発明の効果】
本発明の酸化亜鉛系微粒子は、 IIIＢ族金属元素とIVＢ族金属元素からなる群のうちから選ばれた少なくとも１種の添加元素と亜鉛とを金属成分とし、亜鉛の含有量が該金属成分の総原子数に対する亜鉛の原子数の比で表して８０〜９９．９％であり、Ｘ線回折学的に見て酸化亜鉛（Ｚｎ０）結晶性を示す金属酸化物共沈体を少なくとも主たる構成成分とするので、酸化亜鉛が本来持つ紫外線遮蔽性に加えて熱線を始めとする赤外線遮蔽性と導電性を備える。しかも、これらの性能を有する微粒子を低温下（例えば２００℃以下）でも製造できるため、２次凝集性の抑制された、分散性に優れる微粒子として使用できる。
【０２６６】
本発明の酸化亜鉛系微粒子は、金属酸化物共沈体を構成する添加元素としてインジウム及び／又はアルミニウムを含むときには、熱線遮蔽性と導電性により優れ、特にインジウムを含むときには熱線遮蔽性と導電性に一層優れたものとなる。
本発明にかかる酸化亜鉛系微粒子は、前記金属酸化物共沈体からなる単一粒子のみからなるときには、透明性に優れる。この場合、単一粒子の大きさは、最短部で見て平均粒子径０．００１〜０．１μｍの範囲であることが好ましく、０．００１〜０．０５μｍの範囲であることがより好ましい。前記範囲の平均粒子径を有する単一粒子は超微粒子であり特に透明性に優れるため、透明な紫外線・熱線遮蔽膜や導電膜、帯電防止膜の原料粒子として使用できる。この用途では単一粒子を上述の分散媒に分散してなる分散体として用いるのが好ましい。
【０２６７】
本発明にかかる酸化亜鉛系微粒子は、前記単一粒子を１次粒子とし、この１次粒子が集合してなる２次粒子であるときには、光拡散性の要求される用途に好適である。特に、２次粒子が外殻部のみを構成してなる中空状のものであるときには、光拡散透過性により優れる。この場合において、単一粒子とその集合体である酸化亜鉛系微粒子の大きさの関係は、単一粒子の最短部粒子径の微粒子最短部粒子径に対する比率が１／１０以下であることが好ましい。酸化亜鉛系微粒子の平均粒子径としては、０．００１〜１０μｍの範囲が好ましい。
本発明にかかる酸化亜鉛系微粒子は、前記単一粒子がポリマーと複合してなるときには、樹脂に対する親和性および分散性に特に優れるという利点をさらに有する。単一粒子とポリマーとの複合化した粒子が中空状であると、光拡散透過性に優れることは第２の場合と同様である。この場合、ポリマーの含有量は特に限定する訳ではないが、単一粒子とポリマーの合計量に対し１〜９０重量％の範囲である。酸化亜鉛系微粒子の平均粒子径としては、０．００１〜１０μｍの範囲が好ましい。
【０２６８】
光拡散性の要求される用途には集合体が好適であり、透明性が要求される用途には単一粒子がポリマーと複合してなり、かつ単一粒子が微粒子中で局在化せずに均質に分散した状態で存在する微粒子が好ましい。この微粒子は有機溶剤や樹脂に対する親和性、分散性に優れる。例えば樹脂成形体中に分散したり塗料中に分散したり化粧料に配合したりし易い。
本発明にかかる酸化亜鉛系微粒子の製造方法は、亜鉛源とモノカルボン酸を、少なくともアルコールからなる媒体中で、かつ、 IIIＢ族金属元素とIVＢ族金属元素からなる群のうちから選ばれた少なくとも１種の添加元素を含む化合物の共存下で１００℃以上の温度に保持することにより微粒子を生成させるので、上述した本発明の酸化亜鉛系微粒子を高い生産性で得ることができる。
【０２６９】
本発明にかかる酸化亜鉛系微粒子を製造する方法としては、亜鉛源とモノカルボン酸を水に混合してなる混合物を、１００℃以上に加熱した、少なくともアルコールからなる媒体に添加混合することにより、前記水及び／又はモノカルボン酸の少なくとも一部を蒸発除去する工程を含ませるようにするのが好ましい。亜鉛源とモノカルボン酸は水に溶解させて使用するのが良いのであるが、微粒子の結晶性が損なわれることを防ぎ、かつ、２次凝集を防止して微粒子の寸法、形状の均一性を得るためには、水やモノカルボン酸をなるべく系外に除去するのが良いからである。なお、混合物の加熱媒体への添加中にも微粒子の生成が起きることもあるが、通常はそののち反応系を１００℃以上の温度に保持し続けることにより生成が起きる。この間にも水やモノカルボン酸の蒸発除去が起きるのが普通である。
【０２７０】
上記の酸化亜鉛系微粒子の製法では、金属酸化物共沈体を構成する添加元素としてインジウム及び／又はアルミニウムを含むときには、熱線遮蔽性と導電性により優れ、特にインジウムを含むときには熱線遮蔽性と導電性に一層優れた酸化亜鉛系微粒子が得られる。
上記の酸化亜鉛系微粒子の製法では、前記亜鉛源が酸化亜鉛、水酸化亜鉛及び酢酸亜鉛からなる群より選ばれた少なくとも１種であるときには、加熱過程における酸化亜鉛の結晶の生成反応を阻害するような不純物を実質的に含まず、しかも、結晶と微粒子との大きさと形状を制御しやすい。上記の酸化亜鉛系微粒子の製法では、前記モノカルボン酸が、常圧下の沸点が２００℃以下の飽和脂肪酸であるときには、反応系内におけるモノカルボン酸の量を制御しやすく、酸化亜鉛結晶性を示す金属酸化物共沈体の析出反応を厳密に制御しやすい。
【０２７１】
上記の酸化亜鉛系微粒子の製法では、亜鉛源とモノカルボン酸を、少なくともアルコールからなる媒体中で、かつ、 IIIＢ族金属元素とIVＢ族金属元素からなる群のうちから選ばれた少なくとも１種の添加元素を含む化合物の共存下で１００℃以上の温度に保持する際に、この系に、▲１▼ポリマーを共存させたり、▲２▼分子中にカルボキシル基、アミノ基、４級アンモニオ基、アミド基、イミド結合、アルコール性及び／又はフェノール性の水酸基、カルボン酸エステル結合、ウレタン基、ウレタン結合、ウレイド基、ウレイレン結合、イソシアネート基、エポキシ基、リン酸基、金属水酸基、金属アルコキシ基及びスルホン酸基からなる群のうちから選ばれた少なくとも１種の原子団を１個又は２個以上有し、分子量が１０００未満の添加化合物を共存させたり、▲３▼二酸化炭素及び／又は炭酸源を共存させたり、▲４▼乳酸源を共存させたりすることがある。
【０２７２】
系を１００℃以上の温度に保持する際に、ポリマーを共存させると、前記単一粒子がポリマーと複合してなる酸化亜鉛系微粒子が得られる。
系を１００℃以上の温度に保持する際に、上述した特定の官能基を持つ化合物を共存させると、微粒子の表面処理が可能となり、粒子径制御もできる。
系を１００℃以上の温度に保持する際に、二酸化炭素及び／又は炭酸源を共存させると、水分散性に優れ、しかも微細（０．０５μｍ以下）な微粒子が得られやすい。
系を１００℃以上の温度に保持する際に、乳酸源を共存させると、金属酸化物の共沈体からなる単一粒子を１次粒子とし、この１次粒子が集合してなる２次粒子の形で酸化亜鉛系微粒子が得られやすい。
【０２７３】
本発明の塗料組成物は、前記本発明の酸化亜鉛系微粒子と、この酸化亜鉛系微粒子を結合する被膜を形成しうるバインダー成分とを、これら両者の固形分合計重量に対して、上記酸化亜鉛系微粒子０．１〜９９重量％、前記バインダー成分１〜９９．９重量％の割合で含むので、紫外線遮蔽能と、熱線を始めとする赤外線遮蔽能とを有し、導電性の制御された塗装品を形成することができる。この場合、酸化亜鉛系微粒子とバインダー成分の固形分合計重量が１〜８０重量％であり、残部が溶媒であることが好ましい。
本発明の塗装品は、樹脂成形品、ガラスおよび紙からなる群のうちから選ばれた１つの基材とその表面に形成された塗膜とを備え、この塗膜は、前記本発明の酸化亜鉛系微粒子と、この酸化亜鉛系微粒子を結合するバインダー成分とを、これら両者の合計重量に対して、上記酸化亜鉛系微粒子０．１〜９９重量％、前記バインダー成分１〜９９．９重量％の割合で含むので、紫外線遮蔽能と、熱線を始めとする赤外線遮蔽能とを有し、導電性の制御されたものとなる。この場合、前記樹脂成形品は、例えば、板、シート、フィルムおよび繊維からなる群から選ばれる少なくとも１つである。
【０２７４】
本発明の樹脂組成物は、前記本発明の酸化亜鉛系微粒子と、この酸化亜鉛系微粒子が分散された連続相を形成しうる樹脂とを、これら両者の固形分合計重量に対して、上記酸化亜鉛系微粒子０．１〜９９重量％、上記樹脂１〜９９．９重量％の割合で含むので、紫外線遮蔽能と、熱線を始めとする赤外線遮蔽能とを有し、導電性の制御された樹脂成形品を形成することができる。
本発明の樹脂成形品は、上記本発明の樹脂組成物を、板、シート、フィルムおよび繊維からなる群のうちから選ばれたいずれかの形状に成形したものであるので、紫外線遮蔽能と、熱線を始めとする赤外線遮蔽能とを有し、導電性の制御されたものとなる。
【図面の簡単な説明】
【図１】塗装品の分光透過率曲線を示す図である。
【図２】粉末のＸ線回折パターンを示す図である。
【図３】粉末のＸ線回折パターンを示す図である。
【図４】塗装品の分光透過率曲線を示す図である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to zinc oxide-based fine particles containing zinc as a main component and a group IIIB metal element and / or a group IVB metal element as an accessory component, and uses thereof.
[0002]
[Prior art]
In recent years, there is a growing need for antistatic treatment to prevent dust and dirt from adhering to resin products such as glass products, films, and fibers used in clean room windows, cathode ray tubes, floors, wall materials, clothing, etc. Yes.
Conventionally, as a method of imparting conductivity to an insulator such as a resin, a method of dispersing a conductive agent in an insulator such as a resin, or forming a conductive layer on a substrate using a paint containing a conductive agent in a dispersed manner A method is mentioned. Conductive agents include metal-based fine particles such as nickel (Ni), copper (Cu), and aluminum (Al); metal oxides obtained by reducing metal oxides typified by titanium black, and different elements Metal oxide fine particles such as white conductive metal oxides (tin oxide, indium oxide, zinc oxide) activated by carbon; carbon fine particles such as carbon black and graphite; nonions, anions, cations, amphoteric Organic conductive agents represented by any of the surfactants are known.
[0003]
Of these, organic conductive agents are based on ionic conductivity, so the conductivity is highly dependent on humidity and does not work effectively at low humidity. There is a problem of performance degradation.
In contrast, metal-based, metal oxide-based, and carbon-based conductive agents are superior to organic-based conductive agents in that they have substantially no humidity dependency because their conduction mechanism is based on electronic conduction. However, the metal oxide-based conductive agent and carbon-based conductive agent obtained by reduction treatment of titanium black or the like have a black color or a hue close thereto, and strongly reflect visible light even in the metal-based fine particles. Or it is very difficult to maintain the transparency of the matrix, and the application is limited.
[0004]
On the other hand, white conductive fine particles such as antimony-doped tin oxide and tin-doped indium oxide are formed by coating a film obtained by coating an ink or paint in which these fine particles are already dispersed or a powder of these fine particles. It is known that antistatic conductivity can be imparted without substantially damaging the hue of the base material and matrix in a film or the like obtained by dispersing in a resin. In addition, since these oxide films formed on glass or plastic films by vapor phase methods such as sputtering have high conductivity, transparent electrodes and word processors for flat displays such as liquid crystal displays and electroluminescence displays, It is used as an electrode material for touch panels for electronic games, antistatic films and the like. However, tin oxide-based and indium oxide-based materials are extremely expensive, and the vapor phase method is not a versatile conductive method because it requires expensive equipment.
[0005]
By the way, in recent years, in glass products such as window glass, and resin products such as polyester and (meth) acrylic films and sheets, ultraviolet rays can be used without impairing the transparency and hue of the substrate due to coating or internal addition: There is a demand for a material that effectively shields UV-B (280 to 320 nm, UV-A (320 to 400 nm) and heat rays.
Conventionally, as materials having an ultraviolet blocking effect, organic ultraviolet absorbers such as benzotriazole and benzophenone, and inorganic ultraviolet absorbers such as titanium oxide, zinc oxide, and cerium oxide are known. Does not have a heat ray blocking effect.
[0006]
Known heat ray blocking agents include anthraquinone-based, polymethine-based, cyanine-based, aminium-based / diimonium-based organic dyes that absorb in the infrared region, and the above-described conductive tin oxide-based and indium oxide-based materials. However, none of them can effectively block ultraviolet rays.
It is known that mica coated with a titanium oxide thin film absorbs ultraviolet rays by the titanium oxide thin film and scatters electromagnetic waves in the heat ray region to some extent based on the multilayer structure. Therefore, it cannot be said that it is a fine particle material that sufficiently meets the aforementioned needs.
[0007]
Therefore, it is conceivable to use an ultraviolet blocker and a heat ray blocker in combination. However, organic dyes (heat ray blockers) are absorbed in the visible region, so coloring cannot be avoided or the heat ray absorption region is narrow. In addition, tin oxide and indium oxide are disadvantageous in that they are inferior in economic efficiency because they are expensive as described above.
In this respect, zinc oxide optically absorbs both ultraviolet A wave and B wave optically and does not have selective absorptivity with respect to visible light. The homogeneous zinc oxide thin film obtained by the method becomes a transparent ultraviolet absorbing film. Furthermore, by doping a trivalent or tetravalent metal element into zinc oxide, conductivity is imparted, and in some cases, heat ray blocking is imparted.
[0008]
Conventionally, zinc oxide fine particles, so-called zinc white, are (1) a method of vapor phase oxidation of zinc vapor (French method, American method), or (2) a zinc salt and an alkali metal carbonate are reacted in an aqueous solution, washed with water and dried. After the zinc carbonate powder is obtained through the process, it is manufactured by a method of thermally decomposing in the air. Zinc oxide obtained by the method (1) is said to have a particle size of submicron, but it is strongly agglomerated in the manufacturing process, so it requires a great deal of mechanical labor to disperse in paints and resins. In addition, a homogeneous dispersion state cannot be obtained. The method (2) is finer than the method (1) in that the particle diameter (primary particle diameter) is 0.1 μm or less, but the cohesive force between the primary particles is strong and fine. The effect based on the particle diameter cannot be sufficiently obtained. Furthermore, by these methods, it is not possible to obtain zinc oxide fine particles in which the morphology of the primary particle size, particle shape, surface state, dispersion / aggregation state, and the like are strictly controlled in accordance with the purpose of use. Currently.
[0009]
In recent years, zinc oxide fine particles having a particle diameter of substantially 0.1 μm or less have been developed as a material capable of absorbing ultraviolet rays having excellent weather resistance and heat resistance and excellent transparency in the visible range, so-called transparent / ultraviolet absorbers. It is desired. As a method for producing such fine particles, in addition to (3) gas phase oxidation of zinc vapor, (4) hydrolysis of zinc salt with an alkaline aqueous solution (JP-A-4-164813, JP-A-4-357114). Etc.), a wet method such as a method of further oxidizing zinc sulfide obtained by autoclave treatment using a mixed solution of zinc acid salt and ammonium acetate and hydrogen sulfide as a starting material (Japanese Patent Laid-Open No. 2-311314) A law has been proposed. The fine particles obtained by the method (3) are strongly secondary agglomerated powders, and are blended into plastic moldings such as fibers, plates and films, or paints for the purpose of imparting UV absorption or improving weather resistance. Even if it makes it, the thing with favorable transparency cannot be obtained. In addition, for the purpose of imparting ultraviolet absorbing ability to glass, plastic film, etc., it is possible to apply this powder to a transparent substrate as a coating agent by dispersing the powder in an appropriate solvent and mixing a binder resin as necessary. However, there is a problem that only an insufficient film can be obtained in terms of transparency and homogeneity. In the method (4), since the production process is complicated, the ultrafine particles obtained must be expensive. Thus, the manufacturing method of the zinc oxide microparticles | fine-particles which can fully exhibit the function and characteristic as microparticles | fine-particles, and are versatile is not known until now. In addition, all of the zinc oxide fine particles obtained by these conventional production methods have ultraviolet absorbing ability but cannot block (near) infrared rays.
[0010]
On the other hand, it is described that, for example, a zinc oxide film doped with aluminum (Al) in zinc oxide by a vapor phase method has high conductivity and heat ray blocking ability (Nanuchi, Applied Physics, Vol. 61, No. 12, '92). However, this is an impractical manufacturing method and the ultraviolet absorption edge is shifted to the short wavelength side, so that the shielding property against the A wave is not sufficient.
Further, silicon (Si), germanium (Ge), zirconium (Zr), etc. are dissolved in zinc oxide (Japanese Patent Publication No. 5-6766), boron (B), scandium (Sc), yttrium (Y), zinc oxide, By dissolving a group IIIB element such as indium (In), thallium (Tl), etc. (Japanese Patent Publication No. 3-72011), and by dissolving aluminum (Al) in zinc oxide (Japanese Patent Publication No. 4-929), conductivity, Although it has been proposed to obtain a transparent zinc oxide film having excellent infrared reflectivity, both are vapor phase methods such as sputtering, and cannot be a highly versatile production method.
[0011]
In addition to the zinc oxide film conductivity method, in addition to the zinc oxide thin film manufacturing method utilizing the zinc salt thermal decomposition method, the zinc oxide film is finally heat-treated in a reducing atmosphere at a high temperature, or the dopant is contained in a zinc salt solution. There is also known a method of finally performing a high temperature treatment (for example, JP-A-1-301515). However, it is not known that heat ray shielding properties can be obtained even with this method.
As a conductive method of conductive zinc oxide powder, there are a method of firing zinc oxide powder at a high temperature in a reducing atmosphere, a method of mixing zinc oxide powder with a dopant such as aluminum oxide and baking at a high temperature in a reducing atmosphere, etc. However, the former method has a limitation in electrical conductivity, and in either method, since it is exposed at a high temperature, it is not possible to obtain fine particles, particularly fine ultrafine particles of 0.1 μm or less. .
[0012]
The specific surface area diameter obtained by a specific manufacturing method is 0.1 μm or less, and the volume resistivity in a specific pressurized state is 10^Four A transparent conductive film-forming composition containing conductive zinc oxide fine powder activated with aluminum (Al) having a resistance of Ωcm or less is known (Japanese Patent Laid-Open No. 1-153769). However, since the zinc oxide powder is baked at a high temperature, even if the specific surface area diameter is 0.1 μm or less, the dispersed particle diameter in the paint is still larger, and therefore the composition (paint) obtained by this method It can be presumed that the film obtained by coating the film has a limit in transparency. Even with this method, heat ray shielding is not known.
[0013]
[Problems to be solved by the invention]
Accordingly, the present invention provides zinc oxide-based fine particles based on zinc oxide excellent in ultraviolet shielding properties, imparted with heat ray shielding properties and conductivity, and easy to obtain transparency. 1 issue.
[0014]
Further, by containing the zinc oxide-based fine particles of the present invention, a coating composition having excellent transparency, capable of shielding ultraviolet rays and infrared rays including heat rays, and having controlled conductivity such as antistatic properties, Painted product, resin composition, resin moldingGoodsSecond to provide2It is an issue.
[0015]
[Means for Solving the Problems]
The zinc oxide-based fine particles of the present invention comprise at least one additive element selected from the group consisting of a group IIIB metal element and a group IVB metal element and zinc as a metal component, and the content of zinc is that of the metal component. Expressed by the ratio of the number of zinc atoms to the total number of atoms, it is 80 to 99.9%, and at least the main component of the metal oxide coprecipitate exhibiting zinc oxide (Zn0) crystallinity as seen from X-ray diffraction WhenAnd the infrared shielding property defined below is 20% or more.Zinc oxide-based fine particles.
[Definition of infrared shielding properties of fine particles]
A dry film made of the fine particles on a substrate (coating amount: 3 g / m in terms of fine particles) ² ) To obtain a painted product. The light transmittance (%) for the wavelength of 2 μm of the dry film, that is, the value obtained by subtracting the light transmittance (%) for the wavelength of 2 μm of the coated product from the light transmittance (%) of the base material for the wavelength of 2 μm, It is defined as the infrared shielding property of fine particles.
Infrared shielding property of fine particles (%) = [light transmittance (%) of substrate with wavelength 2 μm] − [light transmittance (%) of coated product with wavelength 2 μm]
ThisHere, the crystal form of zinc oxide is not particularly limited. For example, hexagonal crystal (wurtzite structure), cubic crystal (salt type structure), cubic face centered structure, etc. are known. Any material that exhibits such an X-ray diffraction pattern may be used. In the zinc oxide fine particles of the present invention, the zinc content of the metal oxide coprecipitate is 80 to 99.9%, preferably 90 to 99.5, expressed as the ratio of the number of zinc atoms to the total number of atoms of the metal component. %. Below the above range, it is difficult to obtain fine particles with controlled uniformity such as particle shape, particle diameter, and higher order structure, and when it exceeds the above range, the function as a coprecipitate, that is, the infrared shielding property including heat rays becomes insufficient.
[0016]
As long as the zinc oxide fine particles referred to in the present invention are as described above, for example, a coupling agent such as a silane coupling agent or an aluminum coupling agent, or an organometallic compound such as an organosiloxane or a chelate compound may be used. Fine particles formed by bonding or forming a coating layer on the surface of zinc oxide crystals, inorganic acids such as halogen elements, sulfate radicals, nitrate radicals, or organic compounds such as fatty acids, alcohols, amines, etc. inside the fine grains and / or The particles contained on the surface are also included in the zinc oxide-based fine particles of the present invention. At least one additive element selected from the group consisting of Group IIIB metal elements and Group IVB metal elements and metal elements other than zinc include alkali metals and alkaline earth metals dissolved in ZnO crystals, etc. It is not preferable that the coprecipitate is present, and it is 1/10 of the total number of atoms of at least one additional element selected from the group consisting of Group IIIB metal elements and Group IVB metal elements constituting the coprecipitate. The following is preferable, and 1/100 or less is more preferable.
[0017]
In the zinc oxide-based fine particles of the present invention, group IIIB metal elements as additive elements constituting the metal oxide coprecipitate are, for example, boron, aluminum (Al), gallium (Ga), indium (In), and thallium (Tl). The group IVB metal element is, for example, at least one selected from silicon (Si), germanium (Ge), tin (Sn), and lead (Pb). Of these, indium and / or aluminum are most preferred.
The zinc oxide fine particles according to the present invention include a state in which the single particles are formed of the metal oxide coprecipitate, a state in which the single particles are aggregated, and a case in which the single particles are a polymer. And those that have been combined. The above three cases will be described below.
[0018]
In the first case, the zinc oxide-based fine particles consist only of single particles of the metal oxide coprecipitate. In this case, the size of the single particle is preferably in the range of an average particle diameter of 0.001 to 0.1, more preferably in the range of 0.001 to 0.05 μm, as viewed at the shortest part.
Furthermore, as described above, the zinc oxide fine particles of the present invention are not particularly limited in the surface composition of zinc oxide crystals and fine particles, and those in which the main component metal oxide crystals are exposed may be organic compounds on the surface. Those formed by forming a surface layer made of inorganic compounds are also included in the zinc oxide-based fine particles of the present invention. Hereinafter, such fine particles are referred to as surface-modified fine particles, the surface layer is referred to as a surface-modified layer, and a substance used for forming the surface-modified layer is referred to as a surface modifier. However, when simply referred to as zinc oxide-based fine particles, surface-modified fine particles are also included.
[0019]
The above-mentioned single particles composed of a metal oxide coprecipitate and fine particles formed by aggregating a plurality of single particles include surface-modified fine particles, and the fine particles formed by combining single particles with a polymer are: It can be said that it is one form of the surface-modified fine particles.
In the present invention, the particle diameter (including the average particle diameter, number average particle diameter, etc.) means the particle diameter of the shortest part of the particle unless otherwise specified, and the particle diameter of the shortest part is the center of the particle It means the shortest diameter through. For example, the shape of the fine particles is:
If it is spherical, it means the diameter of the sphere,
If it is elliptical, it means the minor axis of the minor axis and major axis,
For cubes, cuboids, and pyramids, it means the shortest length through the center of the cube, cuboid, or triangular pyramid,
If it is needle-like, columnar, rod-like, cylindrical, it means the length through the center measured in the direction perpendicular to the length direction,
In the case of a flake shape such as a flake shape or a (hexagonal) plate shape, it means the shortest length (= thickness) through the center in the direction perpendicular to the plate surface direction, that is, in the thickness direction.
[0020]
However, for particles such as particles and spheres, the longest diameter is preferably in the same range as the shortest diameter. For anisotropically shaped particles (flakes, needles, etc.), the longest diameter is preferably in the range of 0.002 μm to less than 0.5 μm. In the present invention, the shape of the metal oxide coprecipitate / zinc oxide fine particles is arbitrary. For example, flakes such as scales or (hexagonal) plates; needles, columns, rods, cylinders; cubes, pyramids, etc .;
In the second case, the zinc oxide fine particles are secondary particles in which the single particles are primary particles and the primary particles are aggregated. In this case, the secondary particles may have a hollow shape formed only from the outer shell. If it is hollow, the light diffusibility is excellent. In this case, the relationship between the size of the single particles and the zinc oxide-based fine particles that are aggregates thereof is preferably such that the ratio of the shortest particle diameter of the single particles to the shortest particle diameter of the fine particles is 1/10 or less. .
[0021]
In the third case, the zinc oxide fine particles are formed by combining the single particles with a polymer. In this case, the form of the composite includes a form that behaves as a single particle, a form that behaves as a secondary particle, etc., and may be any one. For example, first, (A) the polymer is the single particle. There is a form in which one surface and / or a surface of a collection of a plurality of single particles are coated, and then there is a form in which (B) the polymer binds the single particles to each other. (C) There is a form in which the polymer constitutes a matrix, and the single particles are not aggregated and / or a plurality of the single particles are dispersed in the matrix. Also in this case, the single particle and the polymer may be a hollow one that constitutes only the outer shell, and if it is hollow, the light diffusibility is excellent as in the second case. is there. In this case, the content of the polymer is not particularly limited, but is in the range of 1 to 90% by weight based on the total amount of the single particles and the polymer.
[0022]
In the third case, the polymer used for the composite is acrylic resin polymer, alkyd resin polymer, amino resin polymer, vinyl resin polymer, epoxy resin polymer, polyamide resin polymer, polyimide resin polymer, Thermoplastics such as polyurethane resin polymers, polyester resin polymers, phenol resin polymers, organopolysiloxane polymers, acrylic silicone resin polymers, polyalkylene glycols, polyolefin polymers such as polyethylene and polypropylene, and polystyrene polymers Alternatively, there are thermosetting resins; synthetic rubbers such as ethylene-propylene copolymer rubber, polybutadiene rubber, acrylonitrile-butadiene rubber, and natural rubbers; polysiloxane group-containing polymers.
[0023]
In the second and third cases, except for the case where the particles complexed with the polymer behave substantially as single particles (in this case, the particles are surface-modified single particles), the zinc oxide system The shape of the fine particles is preferably spherical or elliptical. Regardless of the outer shape of the particles, the surface is preferably rich in irregularities. This is because if the surface is uneven, light scattering on the particle surface acts synergistically and light scattering performance is improved. In both the second and third cases, the average particle diameter of the zinc oxide-based fine particles is not particularly limited, but is usually in the range of 0.001 to 10 μm. For example, in the case of the third (A), 0.001 to 0.1 μm is preferable in terms of high transparency, and in the case of a hollow body shape, 0.1 to 5 μm in terms of high light diffusion transmittance. Is preferred. In the second and third cases, when the zinc oxide-based fine particles are hollow, the shape of the fine particles is preferably spherical or elliptical. The reason is that the light diffusibility and transparency are increased.
[0024]
In the surface-modified fine particles of the present invention, the surface-modified layer may have any of inorganic, organic, and inorganic-organic composite compositions, and the surface of a single particle composed of a metal oxide coprecipitate is completely covered. The coated continuous layer may be formed, or the surface modifier may be discontinuously present. Further, the ratio and thickness of the surface modification layer in the fine particles are not particularly limited. However, from the viewpoint of the modification effect by the surface modification layer and the economical efficiency, the ratio of the surface modification layer to the metal oxide (oxide containing zinc, group IIIB, group IVB metal as metal component) is 0.01 by weight. ~ 1 is preferred. Moreover, the average particle diameter, shape, etc. of the surface-modified fine particles are not particularly limited. However, in applications where transparency is important, such as a transparent ultraviolet / infrared cut film, which will be described later, in order to sufficiently exhibit transparency, the particle size is fine, and the coating composition, Since the resin composition is required to have extremely high dispersibility, the average particle size must be 0.005 to 0.1 μm, preferably 0.005 to 0.05 μm. Therefore, the surface-modified fine particles of the present invention can exhibit their performances.
[0025]
The zinc oxide-based fine particles of the present invention may be used as a dispersion formed by dispersing in a solvent. This solvent dispersion is also included in the present invention.
The solvent dispersion includes at least zinc oxide-based fine particles and a solvent, and the zinc oxide-based fine particles are dispersed and contained in the solvent at a ratio of 2 to 70% by weight in terms of metal oxide with respect to the total amount of the dispersion. It is. Solvents include water, alcohols, ketones, aliphatic and aromatic carboxylic acid esters, ethers, ether esters, aliphatic and aromatic hydrocarbons, halogenated hydrocarbons, and mineral oils. , Vegetable oil, wax oil, silicone oil and the like. Furthermore, these solvents may contain other components such as organic binders and inorganic binders that are used as binders for paint applications. Examples of the organic binder include (meth) acrylic, vinyl chloride, vinylidene chloride, silicone, melamine, urethane, styrene, alkyd, phenol, epoxy, polyester, and other thermoplastic or heat Curable resin; UV curable resin such as UV curable acrylic resin, UV curable acrylic silicone resin; synthetic rubber such as ethylene-propylene copolymer rubber, polybutadiene rubber, acrylonitrile-butadiene rubber, or natural rubber. Examples of the binder include silica sol, alkali silicate, silicon alkoxide, and phosphate.
[0026]
Preferred solvents from the viewpoint of versatility are alcohols, aliphatic and aromatic hydrocarbons, halogenated hydrocarbons, aromatic and aliphatic carboxylic acid esters having a boiling point of 40 ° C. to 250 ° C. at normal pressure. , Ketones, (cyclic) ethers, ether esters, and one or more mixed solvents selected from water.
further, MeTanol, ethanol, n-propanol, isopropyl alcohol, n-butanol, ethylene glycol, propylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl etherTheEthylene glycol monoethyl ether, diethylene glycol monobutyl ether, DTylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, ethylene glycol butyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, tripropylene glycol monomethyl ether, propylene glycol methyl ether acetate, propylene glycol ethyl ether Acetate, 3-methyl-3-methoxybutanol, 3-methyl-3-methoxybutyl acetate, toluene, xylene, benzene, cyclohexane, n-hexane, ethyl acetate, propyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, Tetrahydrofuran,waterA solvent dispersion containing at least one or two or more mixed solvents selected from the group consisting of these can be used in various coating systems and is particularly preferable.
[0027]
The zinc oxide-based fine particles of the present invention can be used as a plasticizer dispersion that is dispersed in a resin plasticizer or a plasticizer-containing solution. This plasticizer dispersion is also included in the present invention.
The plasticizer dispersion includes at least zinc oxide-based fine particles and a plasticizer. The total weight of the zinc oxide-based fine particles and the plasticizer is 50 to 100 wt% with respect to the total amount of the dispersion. It means that the ratio is 0.01 to 5 by weight. The balance is, for example, a resin and / or a solvent component.
The plasticizer includes all conventionally known plasticizers of resin, for example,
Phthalate esters (dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, di-n-octyl phthalate, di-2-ethylhexyl phthalate, isononyl phthalate, octyldecyl phthalate, diisodecyl phthalate, phthalate Acid butyl benzyl etc.),
Fatty acid monobasic acid esters (butyl oleate, glycerin monooleate, etc.),
Fatty acid dibasic acid esters (adipic acid esters such as dibutyl adipate, di-n-hexyl adipate, di-2-ethylhexyl adipate and alkyl 610; sebacic acid esters such as dibutyl sebacate and di-2-ethylhexyl sebacate) Azelaic acid esters such as di-2-ethylhexyl azelate)
Phosphate ester (tributyl phosphate, tri-2-ethylhexyl phosphate, triphenyl phosphate, tricresyl phosphate, etc.)
Dihydric alcohol esters (diethylene glycol dibenzoate, triethylene glycol di-2-ethylbutyrate, etc.),
Oxy acid esters (such as methyl acetyl ricinoleate, butyl acetyl ricinoleate, butyl phthalyl butyl glycolate, tributyl acetyl citrate),
Chlorinated paraffin (C_{twenty five}H₄₅C_l17Such),
Polyester plasticizers (polypropylene glycol adipate, 1,3-butylene glycol adipate, etc., with an average molecular weight of 1000 to 15000, dibasic acids such as adipic acid, phthalic acid, azelaic acid, sebacic acid, glycols, glycerins and Co-condensation polymers with monobasic acids, etc.),
Epoxy plasticizer (epoxy alkyl stearate, epoxy triglyceride, etc.),
Others (stearic acid plasticizer; chlorinated biphenyl, 2-nitrobiphenyl, dinonylnaphthalene; o-toluenesulfone ethylamide, show brain, methyl abietic acid, etc.),
Etc., and any one or more of them are used.
[0028]
Among them, at least selected from the group consisting of phthalate ester plasticizers, fatty acid monobasic acid ester plasticizers, fatty acid dibasic acid ester plasticizers, phosphate ester plasticizers, polyester plasticizers, and epoxy plasticizers One is preferable because of high compatibility with resins, particularly vinyl chloride resins.
The plasticizer dispersion described above is the original purpose of the plasticizer, which is to improve the processability of the polymer material and to provide flexibility. It can be used as a raw material for fine particles when producing a product, a molded article, or a coating composition or a coated product. That is, resin compositions such as vinyl chloride resins, polyvinylidene chloride resins, methacrylic acid resins, acetate cellulose resins, nitrocellulose resins, polystyrene resins, vinyl acetate resin resins, polyvinyl butyral resins containing zinc oxide fine particles, When manufacturing a molded product such as a sheet, a film, or the like processed from the above, or a coating composition containing these resin components as a binder component and a coated product formed by forming a film of the coating composition, fine particles and a plasticizer It can be used as part or all of the raw material. Moreover, the plasticizer dispersion containing a phosphoric ester plasticizer can simultaneously impart flame retardancy to the above-described resin molded body and coated product.
[0029]
Also, conventionally developed or used for the purpose of improving the surface hardness, wear resistance, etc. of polyester films, polycarbonate resins, methacrylic resin films or sheets, plates, diethylene glycol bisallyl carbonate lenses, etc. A material called a so-called hard coat agent that gives a film having equivalent or near surface hardness, scratch resistance, etc., or a material synthesized by the present inventors for the same purpose (for example, Example II-11 described later) The mixture (x)) can also be used as a binder component, a dispersion medium component such as a solvent or a vehicle.
Furthermore, since the main component of the fine particles of the present invention is a metal oxide crystal, by combining with these hard coating agents, it is possible to easily obtain a film that is transparent, blocks ultraviolet rays and infrared rays, and has excellent wear resistance. Can do.
[0030]
Below, the zinc oxide-based fine particles according to the present inventionTheManufacturingDoA method will be described.
Zinc oxide fine particles according to the present inventionTheManufacturingDoMethodAsIn the presence of a compound containing at least one additive element selected from the group consisting of a group IIIB metal element and a group IVB metal element in a medium comprising at least an alcohol and a zinc source and a monocarboxylic acid The method of generating fine particles by maintaining the temperature at 100 ° C. or higherIs mentionedThe In this case, for example, those described above as the group IIIB metal element are exemplified, and among these additive elements, indium and / or aluminum are preferable.
[0031]
the aboveSpecifically, the method for producing the zinc oxide-based fine particles includes, for example, a first step of producing a first mixture containing a zinc source and a monocarboxylic acid, and the first mixture as a medium comprising at least an alcohol. A second step of mixing to form a second mixture and a third step of maintaining the second mixture at a temperature of 100 ° C. or higher, of the first, second and third steps In any of the steps, a compound containing at least one additional element selected from the group consisting of a group IIIB metal element and a group IVB metal element is added and mixed to the first and / or second mixture. . At this time, the compound containing the additive element may be added alone, or may be added after being dissolved in a medium containing at least alcohol. In the first step, the zinc source is preferably dissolved in a mixed solvent in which a monocarboxylic acid is dissolved in water.
[0032]
aboveIn the method for producing zinc oxide-based fine particles, a mixture obtained by mixing a zinc source and a monocarboxylic acid with water is added to and mixed with a medium comprising at least an alcohol heated to 100 ° C. or higher, whereby the water and / or It is preferable to include a step of evaporating and removing at least a part of the monocarboxylic acid. The zinc source and monocarboxylic acid should be dissolved in water and used. However, the crystallinity of the fine particles is prevented from being impaired, and secondary agglomeration is prevented to make the size and shape of the fine particles uniform. This is because water and monocarboxylic acid are preferably removed out of the system as much as possible. Although fine particles may be generated during addition of the mixture to the heating medium, the generation is usually performed by keeping the reaction system at a temperature of 100 ° C. or higher after that. In the meantime, water and monocarboxylic acid are usually removed by evaporation.
[0033]
the aboveIn the method for producing zinc oxide-based fine particles, the zinc source is at least one selected from the group consisting of zinc oxide, zinc hydroxide and zinc acetate, for example.the aboveIn the method for producing zinc oxide-based fine particles, the monocarboxylic acid is preferably a saturated fatty acid having a boiling point of 200 ° C. or lower under normal pressure.
the aboveIn the method for producing zinc oxide-based fine particles, a zinc source and a monocarboxylic acid are added in a medium comprising at least an alcohol and at least one selected from the group consisting of a group IIIB metal element and a group IVB metal element When maintaining at a temperature of 100 ° C. or higher in the presence of a compound containing an element, (1) a polymer is allowed to coexist in this system, or (2) a carboxyl group, an amino group, a quaternary ammonio group, an amide in the molecule. Groups, imide bonds, alcoholic and / or phenolic hydroxyl groups, carboxylic acid ester bonds, urethane groups, urethane bonds, ureido groups, ureylene bonds, isocyanate groups, epoxy groups, phosphate groups, metal hydroxyl groups, metal alkoxy groups and sulfones Addition having at least one atomic group selected from the group consisting of acid groups, one or more, and a molecular weight of less than 1000 Or coexist things, ▲ 3 ▼ or coexistence of carbon dioxide and / or carbonate source, ▲ 4 ▼ sometimes or the coexistence of lactic acid source.
[0034]
The surface-modified fine particles are produced by mixing zinc oxide-based fine particles obtained by an arbitrary production method with a surface modifier under appropriate conditions. The surface modifier and the method for surface modification (hereinafter referred to as surface modification method) are: The type and amount of the surface modifier and the surface modification method may be appropriately selected depending on the purpose of the surface modification.
The compounds having a polymer or a specific atomic group, as shown in (1) to (4) above, can effectively act as a so-called surface modifier for controlling the surface of the fine particles. According to the method of the present invention, there are merits that the form, size, higher order structure and the like of the fine particles can be controlled and the composition and properties of the fine particle surface can be controlled.
[0035]
However, for the purpose of modifying the surface and improving the dispersibility in a hydrocarbon solvent with low polarity and the affinity with the resin, or for the purpose of dispersing the secondary agglomerated fine particles into a single particle When surface modification is performed, the method is not particularly limited as described above.
When the system is kept at a temperature of 100 ° C. or higher, if a polymer is allowed to coexist, zinc oxide-based fine particles in which single particles are combined with the polymer are obtained. Depending on the type of polymer, for example, after producing a dispersion of zinc oxide-based fine particles that are not complexed with the polymer, a complex is formed even if the polymer is added at a temperature of 100 ° C. or higher or 100 ° C. or lower. In order to obtain fine particles with a higher order structure such as hollow fine particles, the above-mentioned “method of coexisting a polymer when maintaining the system at a temperature of 100 ° C. or higher” is effective. In addition, this method is economical in that it can be combined with the production of single particles made of a metal oxide coprecipitate. Suitable polymers used in this case include the above-mentioned acrylic resin polymers, alkyd resin polymers, amino resin polymers, vinyl resin polymers, epoxy resin polymers, polyamide resin polymers, polyimide resin polymers, polyurethanes. Resin-based polymer, polyester-resin-based polymer, phenolic-resin-based polymer, organopolysiloxane-based polymer, acrylic silicone resin-based polymer, polyalkylene glycol, etc., polyolefin-based polymers such as polyethylene and polypropylene, and thermoplastics such as polystyrene-based polymers Thermosetting resins; synthetic rubbers such as ethylene-propylene copolymer rubber, polybutadiene rubber, acrylonitrile-butadiene rubber, and natural rubbers; polysiloxane group-containing polymers.
[0036]
When the system is kept at a temperature of 100 ° C. or higher, if the compound having the specific functional group described above and / or the polymer described above coexist, the particle diameter and shape of the single particle, and the particle diameter and shape of the fine particle In addition, it is possible to produce surface-modified fine particles in which the higher order structure is controlled.
When the system is kept at a temperature of 100 ° C. or higher, if carbon dioxide and / or a carbonic acid source is present, fine particles having excellent water dispersibility and fine (0.05 μm or less) are easily obtained. In this case, the carbonic acid source can be replaced by using (basic) zinc carbonate as a part of the zinc raw material. However, the amount of the carbonic acid source is suitably 0.1 to 20 mol% in terms of molar ratio with respect to zinc. If the amount is too large, crystallization of zinc oxide may be hindered, and the heat treatment temperature needs to be increased. Examples of the carbonate source include a compound that generates carbonate ion or carbon dioxide gas by heating such as ammonium carbonate, ammonium hydrogen carbonate, urea; yttrium carbonate, cadmium carbonate, silver carbonate, samarium carbonate, zirconium carbonate, cerium carbonate, carbonate Metal carbonates such as thallium, lead carbonate, bismuth carbonate, basic zinc carbonate, basic cobalt carbonate (1I), basic copper carbonate (II), basic lead carbonate (II), basic nickel carbonate (II), etc. Metal basic carbonates and the like are exemplified, and each is used alone or in combination of two or more.
[0037]
One effective method for obtaining zinc oxide-based fine particles in the form of secondary particles in which single particles composed of a coprecipitate of metal oxide are formed as primary particles is as follows. A method of allowing a lactic acid source to coexist when the temperature is maintained is exemplified.
The lactic acid source used in the present invention is lactic acid; ammonium lactate, sodium lactate, lithium lactate, calcium lactate, magnesium lactate, zinc lactate, aluminum lactate, manganese lactate, iron lactate, nickel lactate, silver lactate and other metal lactates; lactic acid Lactic acid ester compounds that can produce lactic acid by hydrolysis, such as methyl, ethyl lactate, and n-butyl lactate, etc., any one of which may be used alone, or two or more of them may be used in combination Also good.
[0038]
Below, the use of the zinc oxide fine particles of the present invention will be described.
The zinc oxide fine particles of the present invention protect the contents from ultraviolet rays, prevent discoloration / degeneration / deterioration of various materials such as printed matter by ultraviolet rays, block ultraviolet rays for the purpose of protecting the human body from ultraviolet rays, Various fields that require suppression of indoor temperature rise, thermal insulation of the room during heating, etc., prevention of static electricity damage, prevention of electrification such as imparting electrical conductivity to plastic, paper, cloth, etc. It is useful in various fields that require electrical conductivity, and various dispersions, coating compositions, coated products, resin fat compositions, resin moldings, paper, cosmetics, and the like containing the fine particles are used. One or more functions are exhibited.
[0039]
For example, various packaging films and containers used for food packaging, pharmaceutical packaging, cosmetic packaging, electronic material packaging, etc., agricultural films, greenhouse films, building materials, protective films for automobiles, buildings, automobiles, Adhesive film, adhesive film or paint that can be used for window materials such as high-temperature furnaces, textile products with excellent coolness or heat retention for clothing such as clothes and hats, protective film materials for spectacle lenses such as sunglasses, umbrellas, sunroofs, cosmetics For example, ultraviolet rays and infrared rays can be effectively blocked by using the zinc oxide fine particles of the present invention. At the same time, antistatic properties can be imparted.
In addition, the zinc oxide-based fine particles of the present invention can be contained in paints, films and the like that are also useful for bar coater materials such as stealth bar coaters. In addition, it is also used to make windows for vehicles such as clean rooms and automobiles, clothing, various display screens such as CRTs and LCDs, anti-statics such as touch panels, and conducting electrical recording such as electrostatic recording paper such as facsimile recording paper. It can be used in various forms such as film-forming materials, films, and papers containing the zinc oxide fine particles of the invention.
[0040]
Further, the zinc oxide-based fine particles of the present invention are used as components of paints for forming transparent conductive films used in solar cells, various displays, touch panels, optical elements, optical sensors, etc., or sintered raw material fine particles for sputtering. It is also useful.
The coating composition of the present invention comprises the zinc oxide-based fine particles of the present invention and a binder component capable of forming a film that binds the zinc oxide-based fine particles, with respect to the total solid weight of both of them. The fine particles are contained in a proportion of 0.1 to 99% by weight, and the binder component is 1 to 99.9% by weight. In this case, the total solid weight of the zinc oxide-based fine particles and the binder component may be 1 to 80% by weight, and the balance may be a solvent.
[0041]
The coated product of the present invention includes an arbitrary base material and a coating film formed on the surface thereof, and the coating film includes the zinc oxide-based fine particles of the present invention and a binder component that binds the zinc oxide-based fine particles. In a proportion of 0.1 to 99% by weight of the zinc oxide-based fine particles and 1 to 99.9% by weight of the binder component based on the total weight of both of them. And a base material selected from the group consisting of paper and a coating film formed on the surface of the base material. The coating film combines the zinc oxide fine particles of the present invention and the zinc oxide fine particles. The binder component to be added is contained in a proportion of 0.1 to 99% by weight of the zinc oxide-based fine particles and 1 to 99.9% by weight of the binder component with respect to the total weight of both. In this case, the resin molded product is, for example, at least one selected from the group consisting of a plate, a sheet, a film, and a fiber.
[0042]
The resin composition of the present invention comprises the above-described zinc oxide-based fine particles of the present invention and a resin capable of forming a continuous phase in which the zinc oxide-based fine particles are dispersed, with respect to the total solid weight of the two. The zinc-based fine particles are contained at a ratio of 0.1 to 99% by weight and the resin at a ratio of 1 to 99.9% by weight.
The resin molded product of the present invention is obtained by molding the above-described resin composition of the present invention into any shape selected from the group consisting of a plate, a sheet, a film and a fiber.
The paper of the present invention comprises a paper-made pulp and the zinc oxide fine particles of the present invention dispersed in the pulp, and the amount of the zinc oxide fine particles is 0.01 to 50 weight based on the pulp. %. The cosmetic of the present invention contains 0.1% by weight or more of the zinc oxide fine particles of the present invention.
[0043]
In the present invention, the size of a single particle of fine particles (0.05 μm or less, preferably 0.02 μm or less), surface composition, dispersed state (average particle diameter in a dispersed state is 0.1 μm or less, preferably 0.05 μm). The following are controlled zinc oxide fine particles, and by selecting the composition in the coating composition or the composition in the resin composition, a coated product provided with a transparent film, a transparent resin molded product Obtainable.
In the present invention, “transparent” is defined as follows.
For the coated product, the visible light transmittance of the coated product obtained by forming the coating composition containing the zinc oxide-based fine particles of the present invention on the substrate (visible light transmittance is the total light for visible light) The difference between the transmittance and the visible light transmittance of the substrate is 10% or less:
−10% ≦ (Visible light transmittance of substrate) − (Visible light transmittance of coated product) ≦ 10%
Preferably 5% or less:
−5% ≦ (Visible light transmittance of substrate) − (Visible light transmittance of coated product) ≦ 5%
Particularly preferably 3% or less:
−3% ≦ (visible light transmittance of substrate) − (visible light transmittance of coated product) ≦ 3%
The difference between the haze of the coated product (haze is the haze for visible light; the same applies hereinafter) and the haze of the substrate is 10% or less:
−10% ≦ (Haze of coated product) − (Haze of substrate) ≦ 10%
Preferably 3% or less:
-3% ≦ (Haze of coated product) − (Haze of substrate) ≦ 3%
Particularly preferably 1% or less:
−1% ≦ (Haze of coated product) − (Haze of substrate) ≦ 1%
It is.
[0044]
Furthermore, in addition to the above, when the substrate is a plate, sheet, film-like resin molded product or glass, the visible light transmittance of the coated product is preferably 80% or more and the haze is preferably 10% or less. More preferably, the visible light transmittance is 85% or more and the haze is 5% or less.
The resin composition and the molded product are manufactured in the same manner except that the resin composition and the molded product obtained by molding the resin composition containing the zinc oxide-based fine particles of the present invention do not contain the fine particles. The difference from the visible light transmittance of the molded product is 10% or less:
−10% ≦ (Visible light transmittance of molded product without fine particles) − (Visible light transmittance of molded product containing fine particles) ≦ 10%
Preferably 5% or less:
−5% ≦ (Visible light transmittance of molded product without fine particles) − (Visible light transmittance of molded product containing fine particles) ≦ 5%
Particularly preferably 3% or less:
−3% ≦ (visible light transmittance of molded product without fine particles) − (visible light transmittance of molded product containing fine particles) ≦ 3%
The difference between the haze of the molded product containing fine particles and the haze of the molded product containing no fine particles is 10% or less:
−10% ≦ (Haze of molded product containing fine particles) − (Haze of molded product containing no fine particles) ≦ 10%
Preferably 3% or less:
−3% ≦ (Haze of molded product containing fine particles) − (Haze of molded product without fine particles) ≦ 3%
Particularly preferably 1% or less:
−1% ≦ (Haze of molded product containing fine particles) − (Haze of molded product containing no fine particles) ≦ 1%
It is. In addition, a resin that is excellent in transparency is one that has a visible light transmittance of 80% or more, a haze of 10% or less, more preferably a visible light transmittance of 85% or more and a haze of 5% or less of the molded article containing fine particles It is useful as a molded article and can be easily obtained by the present invention.
[0045]
DETAILED DESCRIPTION OF THE INVENTION
In the zinc oxide-based fine particles of the present invention, when the metal oxide coprecipitate is a single particle, the single particle may be uniformly dispersed throughout, but is partially agglomerated. Also good. In particular, when the single particles are aggregated as primary particles to form the outer shell of the secondary particles, the secondary particles have a multilayer structure. In addition to the conventional scattering of light on the surface of inorganic transparent fine particles), the scattering of light on the surface of the primary particles in the secondary particles and the interface between the outer shell and the inner shell in the secondary particles Scattering of light occurs in, and exhibits high diffusivity while having high light transmittance. The thickness of the outer shell formed by aggregation of single particles is not particularly limited, but is preferably 0.1 to 0.4 with respect to the value of the number average particle diameter of the secondary particles. If it is below the range, the mechanical strength of the zinc oxide-based fine particles may be reduced, and if it exceeds the range, the above-described effect due to having a multilayer structure may not be sufficiently exhibited.
[0046]
The shape and size of the primary particles are not particularly limited, but must be smaller than the secondary particles. For example, when the secondary particles have a number average particle diameter of 0.1 to 10 μm (preferably 0.1 to 2 μm), the number average particle diameter of the primary particles is 0.001 to 0.1 μm. It is 1/10 to 1/10000 with respect to the number average particle diameter of the secondary particles. If the number average particle size of the primary particles is below the above range, the ultraviolet shielding ability of the zinc oxide-based fine particles may be reduced, and if it exceeds the above range, the light transmittance may be reduced. If the ratio of the number average particle diameter of the primary particles to the number average particle diameter of the secondary particles is below the above range, the ultraviolet shielding ability of the secondary particles may be reduced. In addition, the mechanical strength may not be sufficient, or the aggregation effect may not be sufficiently exhibited.
[0047]
In addition, when the secondary particles have many pores between the primary particles, and when the secondary particles are hollow, they function as porous fine particles or microcapsules, such as oil absorption ability, moisture absorption ability, adsorption ability of harmful metal ions. Adsorption separation, removal, and collection functions such as absorption of toxic gases and odors; heat and sound shielding functions such as heat insulation and sound insulation (heat insulation filler, sound insulation filler); metal ions, enzyme / bacteria immobilization, etc. Immobilization function (catalyst carrier, chromatographic filler, etc.); light weight; it comes to have a sustained release function of liquid, fragrance, etc. held inside.
The zinc oxide-based fine particles of the present invention in which single particles and a polymer are combined (composite particles) will be described. First, there is one in which single particles made of a metal oxide coprecipitate are combined with a polymer and behave substantially as single particles. This includes surface-modified fine particles in which a polymer forms a surface-modified layer. In this case, the average particle size of the individual surface-modified fine particles is 0.1 μm or less, preferably 0.05 μm or less, which is particularly useful for obtaining a coated product or a transparent resin molded product having a transparent coating film. is there. Next, when single particles are aggregated and localized to form the outer shell, the polymer is contained only in the outer shell, only in the inner shell, or both in the outer shell and the inner shell. May be. However, it is preferable that the polymer is contained only in the outer shell and the zinc oxide-based fine particles are hollow. When the zinc oxide-based fine particles are hollow, the light diffusion function becomes higher. In this case, the shape and size of the primary particles are not particularly limited, but must be smaller than the composite particles. For example, when the composite particles have a number average particle diameter of 0.1 to 10 μm (preferably 0.1 to 2 μm), the number average particle diameter of the primary particles is 0.001 to 0.1 μm, and the composite particles The number average particle diameter is 1/10 to 1/10000. If the number average particle size of the primary particles is below the above range, the ultraviolet shielding ability of the zinc oxide-based fine particles may be reduced, and if it exceeds the above range, the light transmittance may be reduced. If the ratio of the number average particle diameter of the primary particles to the number average particle diameter of the composite particles is less than the above range, the ultraviolet shielding ability of the composite particles may be reduced. If the ratio exceeds the above range, the composite particles are practically sufficient. There is a possibility that it does not have mechanical strength or the combined effect is not sufficiently exhibited. When the polymer is present in the outer shell and covers the primary particle (single particle) or the secondary particle surface layer, the zinc oxide fine particles are excellent in dispersibility and binding property with the matrix polymer in the composition. Is further increased.
[0048]
The polymer contained in the zinc oxide-based fine particles of the present invention is not particularly limited, but includes, for example, those having a weight average molecular weight of 1,000 to 1,000,000 and those generally referred to as oligomers, prepolymers and the like. Such a polymer is easily dissolved or easily emulsified or suspended in the finest possible state in the heating process for depositing the mixture (n), the mixture (m), or the zinc oxide-based fine particles. Zinc oxide-based fine particles having a uniform particle shape with a uniform particle size (the variation coefficient of the particle size is 30% or less) are easily obtained. The polymer contained in the zinc oxide-based fine particles of the present invention is, for example, at least one resin selected from the following resin groups (1) to (14). When these resins are used, for example, zinc oxide-based fine particles having an average particle diameter of 0.001 to 10 μm are easily obtained.
[0049]
(1) Acrylic resin polymer
(1) Homopolymers / copolymers of (meth) acrylic monomers such as acrylic acid esters and methacrylic acid esters; maleic acid esters, itaconic acid ester monomers, styrene / p-chlorostyrene / vinyltoluene / vinyl acetate / Polymerizable monomers having no functional groups other than (meth) acrylic monomers, such as vinyl monomers such as vinyl chloride, vinyl methyl ether, and vinyl butyral, olefins such as ethylene and propylene, dienes such as butadiene, and trienes (2) Acrylic acid / methacrylic acid / acrylamide / methacrylic, such as copolymers with (meth) acrylic monomers, thermoplastic acrylic resins, modified products thereof, derivatives thereof, etc. Amides, acrylonitrile, methacrylonitrile, (meth) A copolymer of a polymerizable monomer having a functional group, such as hydroxyalkyl ester of crylic acid, glycidyl ester of (meth) acrylic acid, aminoalkyl ester of (meth) acrylic acid, and the (meth) acrylic monomer; A thermosetting acrylic resin such as a copolymer of a polymerizable monomer having a group, the (meth) acrylic monomer, and a polymerizable monomer having no functional group, a modified product thereof, a derivative thereof (substituent Introduced ones, neutralized functional groups, etc.), UV curable acrylic resins, etc.
[0050]
(2) Alkyd resin-based polymer
Polybasic acids such as phthalic anhydride, isophthalic acid, terephthalic acid, benzoic acid, rosin, adipic acid, maleic anhydride, succinic acid, sebacic acid, fumaric anhydride, trimellitic acid, pyromellitic acid, ethylene glycol, propylene Polyethylene glycol, neopentyl glycol, 1,6-hexanediol, glycerin, trimethylolethane, pentaerythritol, diethylene glycol, dipropylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, hydrogenated bisphenol A and other polyhydric alcohols Condensate (oil-free alkyd resin); modified product obtained by modifying the polycondensate with oils and fats (for example, fatty acid) (alkyd resin); polycondensate or modified product, natural resin such as rosin, phenol resin / epoxy resin・ Synthetic resins such as urethane resin, silicone resin and amino resin, and modified products modified with the monomers described in (1) above (rosin-modified alkyd resin, phenol-modified alkyd resin, epoxy-modified alkyd resin, styrenated alkyd resin, acrylic) Modified alkyd resins such as modified alkyd resins, urethane modified alkyd resins, silicone modified alkyd resins, amino resin modified alkyd resins); the polycondensates, the alkyd resins, derivatives of the modified alkyd resins (one functional group such as a carboxyl group). Part or all of which has been neutralized, or a substituent introduced).
[0051]
(3) Amino resin polymer
Melamine resin such as melamine formaldehyde resin, butylated melamine resin, methylated melamine resin, benzoguanamine resin; urea resin such as urea formaldehyde resin, butylated urea resin, butylated urea melamine resin; 2) amino resin-modified alkyd resin modified by co-condensation reaction; modified product of melamine resin, urea resin, amino resin-modified alkyd resin (for example, methylated methylol melamine, methylol melamine initial condensate and Adducts with monohydric alcohols, condensates of melamine or urea with polyvalent amines, butylated melamines with hydrophilic groups introduced, amino resins using benzoguanamines with hydrophilic groups introduced, etc.).
[0052]
(4) Vinyl resin polymer
Homopolymers and copolymers of vinyl monomers such as vinyl chloride, vinyl acetate, vinyl propionate, vinylidene chloride, vinyl butyral, styrene, p-chlorostyrene, vinyltoluene (polyvinyl chloride, vinyl chloride-vinyl acetate copolymer) Polymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, modified ethylene-vinyl acetate copolymer, polyvinyl butyral, polyvinyl alcohol, polystyrene, etc.); vinyl monomers, olefins such as ethylene / propylene, dienes such as butadiene Copolymers with other unsaturated monomers such as styrene and trienes; Copolymers of vinyl monomers with the (meth) acrylic monomers and / or other unsaturated monomers; derivatives of these polymers.
[0053]
(5) Epoxy resin polymer
Bisphenol A type epoxy resin, phenoxy resin (high molecular weight (molecular weight ≧ 30,000) type resin of bisphenol A type epoxy resin), phenol novolac type epoxy resin, orthocresol novolak type epoxy resin, bisphenol A novolak type epoxy resin, brominated Glycidyl ether type epoxy resins such as phenol novolac type epoxy resins and tetraphenylolethane type epoxy resins; Glycidyl ester type epoxy resins; Glycidyl amine type epoxy resins; Epoxidized polybutadienes; These epoxy resins can be crosslinked with epoxy groups. , Compounds having active hydrogen such as amino group, carboxyl group, amide group, thiol group and / or (pre) polymer (aliphatic (poly) amine, aromatic (poly) amine, Bruno propylamine, cycloaliphatic amines, poly mercaptans, etc.) and the like reacted polymers.
[0054]
(6) Polyamide resin polymer
Nylon resin obtained by polycondensation of diamine and dicarboxylic acid (for example, nylon 66), nylon resin obtained by ring-opening polymerization of lactam (for example, nylon 6), polypeptide obtained by polycondensation of amino acids (for example, polyglycine, Poly (α-L-alanine), etc.), an amino group obtained by dehydration condensation of a polycarboxylic acid represented by a polymerized fatty acid (dimer acid) which is a polymer of a vegetable oil fatty acid and a polyamine such as ethylenediamine / diethylenepolyamine Amide derivatives of polyamines and the like that may be present.
[0055]
(7) Polyimide resin polymer
Polycondensation reaction of dianhydride of tetracarboxylic acid such as pyromellitic acid anhydride and aromatic diamine, bismaleimide such as bishexamethylenemaleimide and biscyclopentadienyl compound, 2,5-dimethyl-3,4- Polyimide polymers obtained by Diles-Alder polymerization reaction with diphenylcyclopentadienone and the like.
(8) Polyurethane resin polymer
Any resin having a urethane bond in the molecule may be used, for example, a polymer obtained by substituting a dibasic acid with a diisocyanate in an alkyd resin; and a monomer containing a (meth) acrylic monomer having a hydroxyl group such as methacrylic acid hydroxy ester. A polymer obtained by reacting an acrylic polymer with an isocyanate compound; a polymer obtained by reacting a polyester polymer comprising a dibasic acid and an excess of a polyhydric alcohol and an isocyanate compound; propylene oxide or ethylene oxide on the polyhydric alcohol. Polymer obtained by reacting an isocyanate compound with an addition-polymerized polyalkylene glycol; Polymer obtained by reacting an isocyanate compound with an epoxy resin having a hydroxyl group; Moisture curable polyurethane resin, heat curable polyurethane resin Polyurethane resins conventionally used for paints such as catalyst-curable polyurethane resins; phenyl glycidyl ether acrylate hexamethylene diisocyanate urethane prepolymer, phenyl glycidyl ether acrylate isophorone diisocyanate urethane prepolymer, phenyl glycidyl ether acrylate tolylene diisocyanate urethane pre Polymer ・ Glycerin dimethacrylate hexamethylene diisocyanate urethane prepolymer ・ Glycerin dimethacrylate isophorone diisocyanate urethane prepolymer ・ Pentaerythritol triacrylate hexamethylene diisocyanate urethane prepolymer ・ Pentaerythritol triacrylate isophorone diisocyanate urethane prepolymer -Prepolymers containing urethane bonds such as pentaerythritol triacrylate tolylene diisocyanate urethane prepolymer and having a polymerizable double bond, homopolymers / copolymers of these prepolymers, these prepolymers and others Polymerizable monomers (for example, (meth) acrylic monomers such as (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylonitrile, (meth) acrylamide); maleic acid, maleic acid ester, styrene, p-chloro Styrene monomers such as styrene and vinyl toluene; olefins such as ethylene and propylene; dienes or trienes such as butadiene; vinyl monomers such as vinyl acetate, vinyl chloride, vinyl methyl ether, vinyl alcohol, and vinyl butyral) A urethane acrylate polymer obtained by reacting a polyisocyanate such as hexamethylene diisocyanate or toluylene diisocyanate with (meth) acrylic acid or a (meth) acrylic acid oligomer.
[0056]
(9) Polyester resin polymer
Aliphatic glycols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,6-hexanediol, and neopentyl glycol, aromatic diols such as hydroquinone and resorcin, polyethylene glycol, polypropylene glycol, etc. At least one glycol selected from the group consisting of polyalkylene glycols and the like, (anhydrous) aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid and naphthalenedicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid and sebacic acid At least one dicarboxylic acid selected from the group consisting of alicyclic dicarboxylic acids such as cyclohexane-1,4-dicarboxylic acid, unsaturated dicarboxylic acids such as maleic anhydride and fumaric acid, etc. Resulting condensed, saturated or polyester polymer unsaturation; and unsaturated polyesters of styrene, (meth) by polymerization reaction with the polymerizable monomers such as acrylic acid ester polymer.
[0057]
(10) Phenol resin polymer
Phenol resins such as phenols, alkyl-substituted phenols, allyl-substituted phenols, bisphenol A, and the like, which are obtained by polycondensation of phenol and formaldehyde, are generally referred to as novolak-type and resol-type, and these phenol resins are modified or substituted. Derivatives etc.
(11) Organopolysiloxane polymer
Polymer having a siloxane bond as a skeleton and an organic group containing a carbon atom directly bonded to a silicon atom in the siloxane bond (eg, alkyl group) (eg, polyalkylsiloxane such as polydimethylsiloxane, polymethylphenylsiloxane, etc.) ); Some organic groups in these polymers bonded to silicon atoms through oxygen atoms, Modified silicones in which some organic groups in these polymers are modified (for example, alkyd-modified silicones, epoxy-modified silicones) Polyester modified silicone, acrylic modified silicone, urethane modified silicone, etc.).
[0058]
(12) Acrylic silicone resin polymer
A polymer obtained by copolymerizing an organosilicon compound having a polymerizable double bond such as methacryloxypropyltrimethoxysilane or vinyltrimethoxysilane with an unsaturated monomer such as an acrylic monomer (for example, containing an alkoxysilyl group) Acrylic copolymer).
(13) Fluororesin polymer
Homopolymers / copolymers of fluorine-containing polymerizable monomers, such as ethylene fluoride, vinylidene fluoride, vinyl fluoride, fluorine-containing polymerizable monomers, and other vinyl-based, olefin-based, acrylic-based, etc. Copolymer with polymerizable monomer.
[0059]
(14) Other resin polymers
Conventionally known resins such as xylene resin, petroleum resin, ketone resin, liquid polybutadiene, rosin-modified maleic acid resin, coumarone resin, and derivatives of these resins.
Preferred polymers are those having one or more polar atomic groups. When this polymer and a single particle composed of a metal oxide coprecipitate are combined, it has excellent chemical stability such as solvent resistance and chemical resistance (when the fine particles are hollow particles or aggregate particles). Is excellent in mechanical properties such as compressive strength), and fine (average particle size 0.001 to 0.1 μm) single particles are easily obtained with a uniform particle size (coefficient of variation in particle size). Zinc oxide-based fine particles having a uniform particle shape are easily obtained. Preferred polar atomic groups are carboxyl group, amino group (primary amino group, secondary amino group, tertiary amino group, imino group, imino bond), quaternary ammonio group, amide group, imide bond, hydroxyl group (alcoholic) Phenolic), carboxylic acid ester bond, urethane group, urethane bond, ureido group, ureylene bond, isocyanate group, epoxy group, phosphoric acid group, metal hydroxyl group, metal alkoxy group, and sulfonic acid group. One.
[0060]
Examples of the polymer having one or more carboxyl groups include (meth) acrylic acid, 2- (meth) acryloyloxyethyl succinic acid, 2- (meth) acryloyloxyethyl phthalic acid, and 2-acryloyloxyethyl hexahydrophthal. Homopolymers / copolymers of carboxyl group-containing polymerizable monomers such as acid and maleic acid; the carboxyl group-containing polymerizable monomers and (meth) acrylic acid ester / (meth) acrylamide / (meth) acrylonitrile etc. ) Acrylic monomers, (meth) acrylic monomer substitution products such as α-chloromethyl methacrylate, maleic acid esters, styrene monomers such as styrene / p-chlorostyrene / vinyltoluene, olefins such as ethylene / propylene, butadiene Diene or trier Copolymers with vinyl monomers such as vinyl acetate, vinyl chloride, vinyl methyl ether, vinyl butyral and vinyl alcohol, and polymerizable monomers such as polymerizable organosilicon compounds such as vinyltrimethoxysilane and methacryloxytrimethoxysilane A polymer having a carboxyl group at its terminal or side chain among the alkyd resin-based polymer and polyester resin-based polymer; a terminal and / or side chain such as polydimethylsiloxane having carboxypropyl or the like at its terminal or side chain. Examples thereof include carboxyl-modified organopolysiloxane polymers containing carboxyl groups.
[0061]
The polymer having one or more amino groups and / or quaternary ammonio groups is selected from the group consisting of primary amino groups, secondary amino groups, tertiary amino groups, imino groups, imino bonds and quaternary ammonio groups. Any polymer may be used as long as it has at least one, such as dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, 4-vinylpyridine, p-aminostyrene, 3-vinylaniline, 4-vinylimidazole, vinylpyrrole, dimethyldiallyl. Homopolymers / copolymers of polymerizable monomers containing amino groups, imino groups, and ammonio groups such as ammonium chloride; these monomers and (meth) acrylic acid / (meth) acrylic acid ester / (meth) acrylamide / (meta ) (Meth) acrylic such as acrylonitrile Monomers, substituted (meth) acrylic monomers such as α-chloromethyl methacrylate, maleic acid, maleic acid esters, styrene monomers such as styrene / p-chlorostyrene / vinyltoluene, olefins such as ethylene / propylene, butadiene Polymeric monomers such as vinylene monomers such as vinyl acetate, vinyl chloride, vinyl methyl ether, vinyl butyral, vinyl alcohol, and polymerizable organosilicon compounds such as vinyltrimethoxysilane and methacryloxytrimethoxysilane A polymer having an amino group of the polyamide resin-based polymer; the amino resin-based polymer; a polydimethylsiloxane having a dimethylamino group or an aminopropyl group at a terminal or a side chain; An amino-modified organopolysiloxane polymer having an amino group at the terminal and / or side chain; a polymer of alkyleneimine such as polyethyleneimine or polypropyleneimine; a polymer such as pyrrolidine or piperidine; a polydiallylammonium halide; an ionene compound; Chitosan; porphins such as tetramethylporphine and tetraphenylporphine are exemplified.
[0062]
Examples of the polymer having one or more amide groups include homopolymers / copolymers of amide group-containing polymerizable monomers such as (meth) acrylamide and 2-acrylamido-2-methylpropanesulfonic acid; , (Meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylic monomer such as (meth) acrylonitrile, (meth) acrylic monomer substitution such as methyl α-chloromethacrylate, maleic acid, maleic acid ester Styrene monomers such as styrene / p-chlorostyrene / vinyltoluene, olefins such as ethylene / propylene, dienes or trienes such as butadiene, vinyl such as vinyl acetate / vinyl chloride / vinyl methyl ether / vinyl butyral / vinyl alcohol Monomer, vinyl trimethoxy A copolymer with a polymerizable monomer such as a polymerizable organosilicon compound such as silane / methacryloxytrimethoxysilane; the polyamide resin polymer; an amide-modified organopolysiloxane polymer containing an amide group at the terminal and / or side chain Etc. are exemplified.
[0063]
Examples of the polymer having one or more imide bonds include the polyimide resin-based polymer.
Examples of the polymer having one or more alcoholic hydroxyl groups include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, glycerin dimethacrylate, glycerol monomethacrylate, 3-chloro-2-hydroxypropyl methacrylate, 2-acryloyloxyethyl-2-hydroxyethylphthalic acid, pentaerythritol triacrylate, 2-hydroxy-3-phenoxypropyl acrylate, bisphenol A-diepoxy- (meth) acrylic acid adduct Homopolymers / copolymers of hydroxyl group-containing polymerizable monomers such as vinyl alcohol; these monomers and (meth) acrylic acid / (meth) acrylic acid ester / (meth) acrylonitrile・ (Meth) acrylic monomers such as (meth) acrylamide, (meth) acrylic monomer substitutes such as α-chloromethyl methacrylate, maleic acid, maleic acid esters, styrene such as styrene / p-chlorostyrene / vinyltoluene Polymerization of ethylene monomers, olefins such as ethylene and propylene, dienes or trienes such as butadiene, vinyl monomers such as vinyl acetate, vinyl chloride, vinyl methyl ether, vinyl butyral, vinyltrimethoxysilane, methacryloxytrimethoxysilane, etc. Copolymers with polymerizable monomers such as water-soluble organosilicon compounds; Cellulose polymers such as hydroxypropylcellulose, methylcellulose, and hydroxyethylmethylcellulose; by condensation reaction of polybasic acids such as aliphatic dicarboxylic acids and polyamines Polyamide resin polymer obtained; organopolysiloxane polymer containing an alcoholic hydroxyl group at the terminal and / or side chain, such as polydimethylsiloxane terminated with carbinol or hydroxypropyl, polydimethyl-hydroxyalkylene oxide methylsiloxane Etc. are exemplified.
[0064]
Examples of the polymer having one or more phenolic hydroxyl groups include the phenol resin polymer.
Examples of the polymer having one or more carboxylic acid ester bonds include methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, isoamyl acrylate, 2-ethylhexyl methacrylate, isodecyl methacrylate, n-lauryl (meth) acrylate, and benzyl acrylate.・ Tridecyl methacrylate ・ n-stearyl (meth) acrylate ・ isooctyl acrylate ・ isostearyl methacrylate ・ behenyl methacrylate ・ butoxyethyl acrylate ・ methoxydiethylene glycol methacrylate ・ n-butoxyethyl methacrylate ・ 2-phenoxyethyl (meth) acrylate ・ methoxydiethylene glycol acrylate・ Methoxypolyethylene glycol meta Relate, cyclohexyl methacrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, benzyl methacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, tri Methylolpropane tri (meth) acrylate, glycerin dimethacrylate, trifluoroethyl methacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, neopentyl glycol acrylic benzoate, 3-acryloyloxyglycerin monomethacrylate, propylene Oxide-modified bisphenol A (Meth) acrylates such as acrylate, hydrogenated dicyclopentadienyl diacrylate, perfluorooctylethyl acrylate, maleates such as methyl maleate and butyl maleate, vinyl acetate, methacryloxypropyltrimethoxysilane Homopolymers / copolymers of carboxylic acid ester-containing polymerizable monomers such as: these monomers and other monomers ((meth) acrylic monomers such as (meth) acrylic acid, (meth) acrylonitrile, (meth) acrylamide) Styrene monomers such as maleic acid, styrene / p-chlorostyrene / vinyltoluene, olefins such as ethylene / propylene, dienes or trienes such as butadiene, vinyl chloride / vinyl methyl ether / vinyl alcohol / vinyl butyral, etc. A vinyl monomer, a copolymer with a polymerizable monomer such as a polymerizable organosilicon compound such as vinyltrimethoxysilane; the polyester resin polymer; a terminal and / or side chain such as a polydimethylsiloxane having an acetoxy or stearyloxy terminal Examples thereof include organopolysiloxane polymers containing an ester bond.
[0065]
Examples of the polymer having one or more urethane groups and / or urethane bonds include the polyurethane resin-based polymer.
Examples of the polymer having one or more ureido groups and / or ureylene bonds include polyurea obtained by polycondensation reaction of nonamethylenediamine and urea.
Examples of the polymer having one or more isocyanate groups include polymethylene polyphenyl polyisocyanate; polyol-modified isocyanate; polyfunctional aromatic or polyfunctional aliphatic isocyanate compounds such as hexamethylene diisocyanate and toluylene diisocyanate, amino groups, Obtained by reacting with a (pre) polymer containing a functional group having an active hydrogen such as a carboxyl group or a hydroxyl group (reacting a part of the isocyanate group contained in the isocyanate compound with a functional group having an active hydrogen). Examples thereof include polymers.
[0066]
Examples of the polymer having one or more epoxy groups include epoxy group-containing (meth) acrylic monomers such as glycidyl methacrylate and N- [4- (2,3-epoxypropoxy) -3,5-dimethylbenzyl] acrylamide. Homopolymers / copolymers of epoxy group-containing polymerizable monomers, such as: (meth) acrylic monomers such as (meth) acrylic acid esters that do not react with epoxy groups in the polymerization process, for example, α-chloro Substituted (meth) acrylic monomers such as methyl methacrylate, maleic acid esters, styrene monomers such as styrene / p-chlorostyrene / vinyltoluene, olefins such as ethylene / propylene, dienes or trienes such as butadiene, acetic acid Vinyl, vinyl chloride, vinyl methyl ester Copolymers with vinyl monomers such as ter-vinyl butyral and vinyl alcohol, and polymerizable monomers such as polymerizable organosilicon compounds such as vinyltrimethoxysilane and methacryloxytrimethoxysilane; the epoxy resin polymer; Organopolysiloxane-based polymers containing glycidoxy groups at the terminal and / or side chain, such as polydimethylsiloxane, polyglycidoxypropylmethylsiloxane, polyglycidoxypropylmethyl-dimethylsiloxane copolymer, etc. Illustrated.
[0067]
Examples of the polymer having one or more phosphate groups include phosphate groups such as mono (2-methacryloyloxyethyl) acid phosphate, mono (2-acryloyloxyethyl) acid phosphate, and 2-acryloyloxyethyl acid phosphate. Homopolymers / copolymers of polymerizable monomers; these monomers and (meth) acrylic monomers such as (meth) acrylic acid, (meth) acrylic acid ester, (meth) acrylonitrile, (meth) acrylamide, α- Substituted (meth) acrylic monomers such as chloromethyl methacrylate, maleic acid, maleic esters, styrene monomers such as styrene / p-chlorostyrene / vinyltoluene, olefins such as ethylene / propylene, dienes such as butadiene, or Trienes Vinyl monomers such as vinyl acetate, vinyl chloride, vinyl methyl ether, vinyl alcohol, and vinyl butyral, and copolymers with polymerizable monomers such as polymerizable organosilicon compounds such as vinyltrimethoxysilane and methacryloxytrimethoxysilane Illustrated.
[0068]
Examples of the polymer having one or more metal hydroxyl groups and / or metal alkoxy groups include a silicon compound having a polymerizable double bond, such as methacryloxypropyltrimethoxysilane, and (meth) acrylic acid / (meth) acrylic. (Meth) acrylic monomers such as acid esters, (meth) acrylonitrile, (meth) acrylamides, (meth) acrylic monomer substitutes such as methyl α-chloromethacrylate, maleic acid, maleic esters, styrene p-chloro Styrene monomers such as styrene and vinyltoluene, olefins such as ethylene and propylene, dienes or trienes such as butadiene, vinyl monomers such as vinyl acetate, vinyl chloride, and vinyl methyl ether, vinyltrimethoxysilane, methacryloxytrimethoxy A copolymer with a polymerizable monomer such as a polymerizable organosilicon compound such as lan; and a polymer obtained by (partially) hydrolyzing an alkoxysilyl group in these copolymers; a polydimethylsiloxane having a terminal silanol; Silanol group-containing organopolysiloxanes such as polydiphenylsiloxane having terminal silanol, polydimethyl-diphenylsiloxane having terminal silanol, polytetramethyl-p-silphenylenesiloxane; (N-trimethoxysilylpropyl) polyethyleneimine, (N-trimethoxysilylpropyl) -o-polyethylene oxide urethane, triethoxysilyl-modified poly (1,2-butadiene) and polymers obtained by (partially) hydrolyzing alkoxysilyl groups in these polymers; Examples include resin-based polymers.
[0069]
Furthermore, examples of the polymer having one or more metal hydroxyl groups and / or metal alkoxy groups include polysiloxane group-containing polymers.
The polysiloxane group referred to in the present invention means that at least one alkoxy group in which two or more Si atoms are connected in a linear or branched manner by a siloxane bond (Si—O—Si) and bonded to the Si atom. , A hydroxyl group, or a polysiloxane chain having at least one group selected from the group consisting of an acyloxy group capable of generating a hydroxyl group by hydrolysis and an acetoxy group (hereinafter referred to as X group). The polymer is defined as a polymer having at least one polysiloxane group in one molecule, and a composite of an arbitrary polymer (hereinafter referred to as polymer P) and a polysiloxane group. The molecular weight of the polysiloxane group-containing polymer is not particularly limited as long as the number average molecular weight is 1000 or more. Moreover, there is no restriction | limiting in particular regarding the molecular weight of a polysiloxane group and polymer (P) in this polymer. The number of polysiloxane groups is at least one per molecule of the polysiloxane group-containing polymer, and is not further limited. For example, in order to obtain fine particles dispersed at a single particle level (ultrafine particles), 1 to 3 are preferable. . When the number exceeds 3, the polymer acts as an aggregating agent, so that it is difficult to form fine particles dispersed at a single particle level. In order to obtain aggregate fine particles and hollow fine particles, a polymer having a large number of polysiloxane groups per molecule of the polysiloxane group-containing polymer may be used.
[0070]
The polysiloxane group is at least one group selected from an alkyl group, an aryl group, an aralkyl group, a cycloalkyl group, an acyl group, or a hydrogen atom, which may be substituted, in addition to the X group directly bonded to the Si atom. You may have.
The composition of the polymer P is not particularly limited, but usually, the polymers (1) to (14) described above are exemplified.
The composite form of the polymer P and the polysiloxane group is arbitrary. For example, (1) a polymer P having a main chain and a polysiloxane group bonded thereto, and (2) a polysiloxane group having a main chain. Examples include those in which the polymer P is bonded, and (3) those in which the polysiloxane chain and the polymer P are alternately bonded to form a linear structure or a cyclic structure. Any form is effective for the purpose of synthesizing the zinc oxide fine particles combined with the polymer.
[0071]
As a method for synthesizing such a polysiloxane group-containing polysiloxane, for example, (1) a polysiloxane having a polymerizable group such as C = C (polymerizable polysiloxane) on an organopolysiloxane having a hydrosilyl group (polymer P) ) Using a hydrosilylation reaction to complex organopolysiloxane and polysiloxane, and (2) copolymerizing polymerizable polysiloxane with (meth) acrylic or vinyl polymerizable monomers. A method of synthesis by
(3) A polymer (P) having an alcoholic hydroxyl group, a carboxyl group, a metal alkoxy group, etc., and a polysiloxane group are obtained by utilizing the reaction with a functional group capable of forming a bond by the reaction with the X group. A method in which the polymer (P) and the polysiloxane group are complexed through Si—O—C bond and Si—OCO bond by coexistence and heating,
Etc. are exemplified. Among these, the method (2) is a method in which the composition of the polymer (P) can be selected relatively arbitrarily, so that the polarity parameter of the polymer can be arbitrarily controlled. A polymer having a structure bonded directly or indirectly to (P), having excellent thermal stability and solvent resistance, and being economical, is preferable.
[0072]
The method and the polysiloxane group-containing polymer obtained by the method are described in detail as a silicon-containing polymer in JP-A-6-228457.
The polymerizable polysiloxane is obtained, for example, by a cohydrolysis condensation reaction between a polymerizable silane compound and a non-polymerizable silane compound.
What is a polymerizable silane compound?
γ-methacryloxypropyltrimethoxysilane,
γ-methacryloxypropyltriethoxysilane,
γ-methacryloxypropylmethyldimethoxysilane,
γ-methacryloxypropylmethyldiethoxysilane,
γ-acryloxypropyltrimethoxysilane,
γ-acryloxypropylmethyldimethoxysilane,
γ-methacryloxyethoxypropyltrimethoxysilane,
γ-methacryloxypropylphenyldimethoxysilane,
Vinyltrimethoxysilane,
Vinyltriethoxysilane,
Vinylmethyldimethoxysilane,
1-hexenyltrimethoxysilane,
1-octenyltrimethoxysilane,
Vinyloxypropyltrimethoxysilane,
3-vinylphenyltrimethoxysilane,
3- (vinylbenzylaminopropyl) trimethoxysilane,
As such, it is a silane compound having a polymerizable group.
[0073]
Non-polymerizable silane compounds are, for example,
Tetrafunctional silane monomers such as tetraalkoxysilane, such as tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, dimethoxydiethoxysilane;
Alkyltrialkoxysilanes such as methyltrimethoxysilane, isopropyltrimethoxysilane and octyltrimethoxysilane, aryltrialkoxysilanes such as phenyltrimethoxysilane, phenyltrihydroxysilane, aminoethylaminopropyltriethoxysilane, mercaptopropyltrimethoxysilane , Trifunctional silane monomers such as γ-chloropropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane,
Bifunctional silane monomers such as dimethyldimethoxysilane, diphenyldimethoxysilane, and diphenyldihydroxysilane;
Etc. are exemplified.
[0074]
Examples of polymers having one or more sulfonic acid groups include homopolymers of sulfonic acid group-containing polymerizable monomers such as acrylamide methanesulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, and sodium salts thereof. Copolymers; these monomers and (meth) acrylic acid, (meth) acrylic ester, (meth) acrylonitrile, (meth) acrylic monomers such as (meth) acrylamide, ) Acrylic monomer substitution product, maleic acid, maleic acid ester, styrene monomer such as styrene / p-chlorostyrene / vinyltoluene, olefins such as ethylene / propylene, diene or triene such as butadiene, vinyl acetate / vinyl chloride・ Vinyl methyl ether ・ Vini Copolymers with vinyl monomers such as alcohol and vinyl butyral, and polymerizable monomers such as polymerizable organosilicon compounds such as vinyltrimethoxysilane and methacryloxytrimethoxysilane; styrene polymers with concentrated sulfuric acid, chlorosulfonic acid, anhydrous Examples thereof include a sulfonic acid group-containing polymer obtained by the action of a sulfonating agent such as sulfuric acid.
[0075]
Examples of polymers having other polar atomic groups include poly-N-formylethyleneimine and poly-N-acetylethyleneimine obtained by ring-opening polymerization of oxazoline, 2-methyloxazoline and the like (2- ) Ring-opening compounds of cyclic iminoethers such as substituted oxazolines and / or (2-substituted) oxazines; ring-opening co-polymerization of cyclic iminoethers and lactones, such as an alternating copolymer of oxazoline and β-propiolactone Among polymers having at least one functional group such as a coalescence polymer having a structure used for a chelate resin having a coordination group (functional group) to which a metal ion can coordinate (for example, polyvinyl alcohol, polyvinyltriacrylmethane, Polyvinylmethacryloylacetone, poly (4-hydroxystyrene), pyroga Phenol phenol formaldehyde resin, salicylic acid formaldehyde resin, polyvinyl salicylic acid, polyacrylic acid, polymethacrylic acid, polyitaconic acid, aminophenol formaldehyde resin, poly (8-hydroxy-5-vinylquinoline), polyvinylamine, polyethyleneimine, poly (4 -Aminostyrene), poly (3-vinylaniline), poly (4-vinylpyridine), poly (4-vinylbipyridine), poly (4-vinylimidazole), polyvinylpyrrole, polyglycine, poly (α-L-alanine) ) Etc.), or a metal ion adsorbed and coordinated partially or to all the coordinating groups (functional groups); carboxyl groups, sulfonic acid groups, etc. are alkali metals such as sodium and potassium, magnesium and calcium, etc. Of alkaline earth Such polymers in the form of a metal salt such as a metal are exemplified.
[0076]
Among the polymers exemplified in the above (1) to (14), at least one selected from the group consisting of (meth) acrylic, styrene, vinyl, copolymers thereof, alkyd, polyester, and polyamide. A composite of one main chain and a polymer having at least one polar atomic group selected from the group consisting of a carboxyl group, an amino group, an amide group, a silanol group, and an alkoxysilyl group, or a polysiloxane group-containing polymer described above Particles or surface-modified fine particles are preferred because they are particularly excellent in affinity and dispersibility for the resin.
The composition of the surface modification layer in the surface modified fine particles of the present invention may be any of inorganic, organic, and inorganic-organic composite compositions. It is appropriately selected depending on the purpose of use of the fine particles.
[0077]
When the fine particles of the present invention are used in coating compositions and resin compositions, it is preferable that the dispersibility in these compositions is high, while the surface modification layer and the bulk metal oxide coprecipitate. From the standpoints of adhesion to a single particle made of, and chemical and thermal stability of the surface modification layer and fine particles, the balanced surface modification layer is preferably an inorganic-organic composite composition.
The surface modification layer of the surface-modified fine particles may be one that forms a continuous layer that completely covers the surface of a single particle made of a metal oxide coprecipitate, or may be one in which surface modifiers are discontinuously present. Further, the ratio and thickness of the surface modification layer in the fine particles are not particularly limited.
[0078]
As the surface modification layer, a metal oxide film such as silica or titania, a layer in which metalloxane chains such as polysiloxane are cross-linked or independently bonded to the surface by a Zn-OM bond, an organic compound is adsorbed An organic compound layer formed by chemical bonding such as hydrogen bonding or Zn—O—C is exemplified. Dispersibility improvement effect for solvents and resins by surface modifiers, chemical resistance such as alteration by acid and alkali, reduction by alteration by carbon dioxide, gas resistance improvement effect, heat oxidation resistance (resistance to oxidation when exposed to high temperature, Any modification effect such as an effect of improving crystal growth prevention or the like, or a reduction or improvement effect of catalytic activity may be substantially exhibited.
[0079]
However, it is preferable that the surface modification layer be present as uniformly as possible on the surface in order to sufficiently exert the modification effect, and metal oxide (zinc and group IIIB, group IVB metal are used as metal components). The ratio of the surface modification layer to the oxide) is preferably 0.01 to 1 by weight. Even if the weight ratio exceeds 1, the surface modification effect is saturated, which is economically disadvantageous. A particularly preferred weight ratio is 0.02 to 0.5 from the viewpoint of the modification effect and economy.
Moreover, the average particle diameter, shape, etc. of the surface-modified fine particles are not particularly limited. However, in applications where transparency is important, such as a transparent ultraviolet / infrared cut film, which will be described later, in order to sufficiently exhibit transparency, the particle diameter is fine and the coating composition, Since extremely high dispersibility in a resin composition or the like is required, surface-modified fine particles that are preferably fine particles having an average particle size of 0.1 μm or less, more preferably 0.05 μm or less are particularly important.
[0080]
The surface modifier is not limited in terms of its composition, molecular weight and the like. The above-mentioned polymer (a polymer that coexists in this system when the system is maintained at a temperature of 100 ° C. or higher in the method for producing zinc oxide-based fine particles of the present invention), the specific polymer described above or below used for the purpose of particle size control, etc. An additive compound having a functional group (an additive compound that coexists in this system when the system is maintained at a temperature of 100 ° C. or higher in the method for producing zinc oxide-based fine particles of the present invention) can be used.
However, as described above, for the purpose of use in coating compositions, resin compositions, etc., the surface modification layer is preferably an inorganic-organic composite composition. A siloxane group-containing polymer is preferred.
[0081]
A preferred embodiment of the polysiloxane group-containing polymer that is particularly preferred as the surface modifier is described below. The molecular weight of the polysiloxane group-containing polymer is not particularly limited as long as the number average molecular weight is 1000 or more, but is preferably 1,000 or more and 1,000,000 or less from the viewpoint that fine particles are excellent in high dispersibility without agglomerating in a solvent or resin. Furthermore, 2000 or more and 100,000 or less are preferable. There are no particular limitations on the molecular weight of the polysiloxane group and polymer (P) in the polymer. However, the number of Si atoms possessed by the polysiloxane group is preferably 4 or more on average per polysiloxane group from the viewpoint of high reactivity, bonding force or affinity between the polymer and the fine particle surface, and 11 or more is preferable. Further preferred. The number of polysiloxane groups is at least one per molecule of the polysiloxane group-containing polymer, and in order to obtain fine particles dispersed at a single particle level (ultrafine particles), 1 to 3 are preferable. When the number exceeds 3, the polymer acts as an aggregating agent, so that it is difficult to form fine particles dispersed at a single particle level.
[0082]
Hereinafter, the present inventionThose who produce zinc oxide fine particlesExplain the law in detail.
Of the present inventionThose who produce zinc oxide fine particlesLawAsFor example, a mixture (m) obtained by dissolving or dispersing the zinc source and the monocarboxylic acid in a medium composed of at least an alcohol is selected from the group consisting of Group IIIB metal elements and Group IVB metal elements. A compound containing at least one selected additive element (hereinafter sometimes referred to as “metal (M)”) (this compound is a concept including a metal such as a simple metal or an alloy. By holding at a temperature of 100 ° C. or higher in the presence of a metal (M) compound ”, the ratio of the number of atoms to the total number of atoms of the metal element is 80 to 99.9% zinc and metal (M ) A process for depositing zinc oxide fine particles comprising a crystalline coprecipitate of metal oxide containing 0.1 to 20%Is mentionedThe
[0083]
The zinc source is converted to X-ray diffractionally crystalline zinc oxide by heating a mixture (m) containing a monocarboxylic acid and an alcohol. At this time, the metal (M) compound is contained in the medium. By coexisting, a dispersion containing the zinc oxide fine particles of the present invention can be obtained. At this time, if any one of the three components of the zinc source, the monocarboxylic acid and the alcohol is lacking as a starting material, the zinc oxide crystal precipitation reaction does not occur, and the metal (M) does not exist. Zinc oxide fine particles cannot be obtained.
The zinc used in the present invention is supplied from at least one zinc source selected from the group consisting of metallic zinc and zinc compounds. The source of zinc is not particularly limited, but metal zinc (zinc powder), zinc oxide (such as zinc white), zinc hydroxide, basic zinc carbonate, mono- or di-carboxylates which may have a substituent (for example, At least one selected from the group consisting of zinc acetate, zinc octylate, zinc stearate, zinc oxalate, zinc lactate, zinc tartrate and zinc naphthenate) is preferred. When these zinc sources are used, a desalting step is not necessary, and the number of steps is reduced compared to when zinc chloride, zinc nitrate or zinc sulfate that requires a desalting step is used.
[0084]
Among them, at least one zinc source selected from the group consisting of metallic zinc (zinc powder), zinc oxide (zinc white), zinc hydroxide, basic zinc carbonate, and zinc acetate is inexpensive and easy to handle. Is preferable.
At least one zinc source selected from the group consisting of zinc oxide, zinc hydroxide and zinc acetate is substantially free of impurities that inhibit the formation reaction of zinc oxide crystals during the heating process, Moreover, it is more preferable because the size and shape of the crystal and fine particles can be easily controlled.
Zinc oxide and / or zinc hydroxide are not only available at a low price, but also the type of monocarboxylic acid can be arbitrarily selected. In addition, fine particles having a controlled shape or particle size can be obtained by using these raw materials. Since it is easy, it is especially preferable.
[0085]
The amount of the zinc source is, for example, 0.1 to 95% by weight, preferably 0.5 to 50% by weight, and more preferably 1 to 50% by weight in terms of ZnO with respect to the total amount of the zinc source, monocarboxylic acid and the medium. 30% by weight. If it is below the above range, the productivity may be lowered, and if it exceeds the range, secondary aggregation between the fine particles tends to occur, and fine particles having good dispersibility and uniform particle size distribution may be difficult to obtain.
The monocarboxylic acid used in the present invention is a compound having only one carboxyl group in the molecule. Specific examples of the compound include saturated fatty acids (saturated monocarboxylic acids) such as formic acid, acetic acid, propionic acid, isobutyric acid, caproic acid, caprylic acid, lauric acid, myristic acid, palmitic acid, stearic acid; acrylic acid, methacrylic acid Unsaturated fatty acids (unsaturated monocarboxylic acids) such as crotonic acid, oleic acid, and linolenic acid; cyclic saturated monocarboxylic acids such as cyclohexanecarboxylic acid; aromatic monocarboxylic acids such as benzoic acid, phenylacetic acid, and toluic acid; And monocarboxylic acid anhydrides such as acetic anhydride; halogen-containing monocarboxylic acids such as trifluoroacetic acid, monochloroacetic acid, and o-chlorobenzoic acid; and lactic acid. Any one of these compounds is used alone, or two or more compounds are used in combination.
[0086]
Preferred monocarboxylic acids are saturated fatty acids having a boiling point of 200 ° C. or less at 1 atmosphere. Specifically, formic acid, acetic acid, propionic acid, butyric acid, and isobutyric acid are preferable. This is because the monocarboxylic acid content in the reaction system can be easily controlled in the process of heating from the process of preparing the mixture, and therefore the precipitation reaction of zinc oxide crystals can be easily controlled. The saturated fatty acid is preferably used in the range of 60 to 100 mol%, more preferably 80 to 100 mol%, based on the total amount of monocarboxylic acid. Below the above range, the crystallinity of zinc oxide in the resulting fine particles may be lowered.
[0087]
Examples of the monocarboxylic acid include zinc monocarboxylates such as zinc acetate. When the zinc salt is used, it is not always necessary to add the monocarboxylic acid as a raw material.
the aboveThe amount of monocarboxylic acid used (or charged) in the production method is, for example, 0.5 to 50, preferably 2.2 to 10, in a molar ratio with respect to the amount of Zn atom of the zinc source. Within the above range, it is preferable from the viewpoints of economic efficiency, ease of producing fine particles, ease of obtaining fine particles that are less likely to aggregate and have excellent dispersibility. If it is below the above range, zinc oxide fine particles having good ZnO crystallinity and fine particles having excellent uniformity such as shape and particle size may be difficult to obtain. May be difficult to obtain.
[0088]
Alcohols used in the present invention include aliphatic monohydric alcohols (methanol, ethanol, isopropyl alcohol, n-butanol, t-butyl alcohol, stearyl alcohol, etc.), aliphatic unsaturated monohydric alcohols (allyl alcohol, crotyl alcohol, Propargyl alcohol, etc.), alicyclic monohydric alcohols (cyclopentanol, cyclohexanol, etc.), aromatic monohydric alcohols (benzyl alcohol, cinnamyl alcohol, methylphenyl carbinol, etc.), heterocyclic monohydric alcohols (full Monohydric alcohols such as furyl alcohol; alkylene glycol (ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,8-octane Diol, 1,10-decanediol, pinacol, diethylene glycol, triethylene glycol, etc.), aliphatic glycols having an aromatic ring (hydrobenzoin, benzpinacol, phthalyl alcohol, etc.), alicyclic glycols (cyclopentane-1) , 2-diol, cyclohexane-1,2-diol, cyclohexane-1,4-diol, etc.), glycols such as polyoxyalkylene glycol (polyethylene glycol, polypropylene glycol, etc.); ethylene glycol monoethyl ether, ethylene glycol monobutyl ether , Monoethers and monoesters of the above glycols such as triethylene glycol monomethyl ether and ethylene glycol monoacetate; hydroquinone, resorcin, 2,2-bis ( - aromatic diols such as hydroxyphenyl) propane and their monoethers and monoesters, trihydric alcohols and their monoethers such as glycerin, and the like monoesters, diethers and diesters. Any one of these alcohols may be used alone, or two or more may be used in combination.
[0089]
The amount of alcohol in the medium comprising at least alcohol is not particularly limited, but in order to perform the zinc oxide-based fine particle production reaction in a short time, the molar ratio of alcohol to Zn atoms derived from the zinc source is, for example, 1 to 100. , Preferably 5-80, more preferably 10-50. If it is below the above range, zinc oxide fine particles having good ZnO crystallinity are difficult to obtain, or fine particles having excellent dispersibility, uniformity in shape and particle size may be difficult to obtain. There is a possibility.
The medium is a medium composed only of the alcohol, a mixed solvent of the alcohol and water, a mixed solvent of the alcohol and an organic solvent other than alcohol, such as ketones, esters, aromatic hydrocarbons, and ethers. The ratio of the alcohol to the other solvent is 5 to 100% by weight of alcohol, preferably 40 to 100% by weight, in terms of the charge (use) used to prepare the mixture (m). Preferably it is 60 to 100 weight%. If the amount of alcohol is below the above range, fine particles having good crystallinity, uniformity of shape / particle diameter and dispersibility may be difficult to obtain.
[0090]
the aboveExamples of the metal (M) compound used in the production method of the metal include, for example, metals (M) such as simple metals and alloys; oxides; hydroxides; (basic) carbonates, nitrates, sulfates, and chlorides. , Inorganic salts such as halides such as fluoride, fluoride; carboxylates such as acetate, propionate, butyrate and laurate; metal alkoxides; β-diketone, hydroxycarboxylic acid, ketoester, ketoalcohol, amino All compounds containing a trivalent or tetravalent metal (A) such as a metal chelate compound with alcohol, glycol, quinoline, etc .; In the case of a metal element that can take a plurality of valences such as In, Tl, At least one compound selected from the group consisting of compounds containing a low-valent metal that can finally change to trivalent or tetravalent during the fine particle production process (this compound is a simple metal) Alloy is a concept including a metal such) is used.
[0091]
III When aluminum is used as the group B metal element, examples of the aluminum-containing compound include aluminum, aluminum hydroxide, aluminum oxide, aluminum chloride, aluminum fluoride, aluminum nitrate, aluminum sulfate, basic aluminum acetate, and aluminum. Trisacetylacetonate, aluminum trimethoxide, aluminum triethoxide, aluminum triisopropoxide, aluminum tri-n-butoxide, acetoalkoxy aluminum diisopropylate, aluminum laurate, aluminum stearate, diisopropoxy aluminum stearate, Ethyl acetoacetate aluminum diisopropylate or the like is used.
[0092]
III When boron is used as the group B metal element, examples of the boron-containing compound include boron trioxide, boric acid, boron oxalate, boron trifluoride diethyl ether complex, boron trifluoride monoethylamine complex, trimethyl borate, triethyl. Borate, triethoxyborane, tri-n-butyl borate and the like are used.
III When gallium is used as the group B metal element, examples of the compound containing gallium include gallium, gallium hydroxide, gallium oxide, gallium chloride (III), gallium bromide (III), gallium nitrate (III), Gallium (III) sulfate, gallium ammonium sulfate, triethoxygallium, tri-n-butoxygallium and the like are used.
[0093]
When indium is used as the III-B group metal element, examples of compounds containing indium include indium, indium (III) oxide, indium (III) hydroxide, indium (III) sulfate, indium (III) chloride, fluorine. Indium (III) iodide, indium (III) iodide, indium isopropoxide, indium (III) acetate, triethoxyindium, tri-n-butoxyindium and the like are used.
III When thallium is used as the group B metal element, the thallium-containing compounds include, for example, thallium, thallium oxide (I), thallium oxide (III), basic thallium hydroxide (I), thallium chloride (I) , Thallium (I) iodide, thallium nitrate (I), thallium sulfate (I), thallium hydrogen sulfate (I), basic thallium sulfate (I), thallium acetate (I), thallium formate (I), malonic acid Thallium (I), thallium chloride (III), thallium nitrate (III), thallium carbonate (III), thallium sulfate (III), thallium hydrogen sulfate (III) and the like are used.
[0094]
When silicon is used as the IVB group metal element, examples of the silicon-containing compound include silicon, silicon oxide, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, and other tetraalkoxysilanes, methyltrimethoxysilane, and trimethoxy. Silane, 3-chloropropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, III-glycidoxypropyltrimethoxysilane, III- (II-aminoethylaminopropyl) trimethoxysilane, phenyltrimethoxysilane, diethoxydimethyl Alkyl alkoxysilanes such as silane, trimethylethoxysilane, hydroxyethyltriethoxysilane, phenyltrimethoxysilane, benzyltriethoxysilane, γ-aminopropyltriethoxysilane, N β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, stearyltri Silicon alkoxide compounds such as silane coupling agents such as methoxysilane; chlorosilanes such as silicon tetrachloride, trichlorosilane, and methyltrichlorosilane; acetoxysilanes such as triacetoxysilane are used.
[0095]
When germanium is used as the group IVB metal element, examples of the compound containing germanium include germanium, germanium (IV) oxide, germanium chloride (IV), germanium iodide (IV), germanium acetate (IV), and germanium chloride. (IV) Bibilidyl complex, β-carboxyethyl germanium sesquioxide, germanium (IV) ethoxide and the like are used.
When tin is used as the group IVB metal element, examples of the tin-containing compound include tin, tin (IV) oxide, tin (IV) chloride, tin (IV) acetate, and di-n-butyltin (IV) dichloride. , Di-n-butyltin (IV) dilaurate, di-n-butyltin (IV) malate (polymer), di-n-butyltin (IV) oxide, di-n-methyltin (IV) dichloride, di-n-octyltin (IV) Malate (polymer), di-n-octyltin (IV) oxide, diphenyltin (IV) dichloride, mono-n-butyltin (IV) oxide, tetra-n-butyltin (IV), tin oxalate (II) , Tri-n-butyltin (IV) acetate, tributyltin ethoxide, trimethyltin chloride, triphenyltin acetate, triphenyltin (IV) hydroxide, tetraethoxytin, tetra-n-butyl Such as Kishisuzu is used.
[0096]
When lead is used as a group IVB metal element, for example, lead, lead acetate (IV), lead chloride (IV), lead fluoride (IV), lead oxide (IV), lead oxide as lead-containing compounds (II + IV), lead (II) oxalate, etc. are used.
The metal (M) oxide; hydroxide may be in the form of powder, but colloidal level metal oxides such as alumina sol and silica sol and / or metal hydroxide aqueous sols and alcohol sols may also be used.
The production method of the present invention has, for example, the following steps I to III as essential steps, and a metal (M) compound in any one or two or more of steps I, II and III: Can be added.
[0097]
(I) The 1st process which makes the mixture (n) which consists of a zinc source and monocarboxylic acid.
(II) A second step of making the mixture (m) in which the zinc source and the monocarboxylic acid are dissolved or dispersed in the medium consisting of at least alcohol by mixing the mixture (n) with the medium consisting of at least alcohol.
(III) By maintaining the mixture (m) at a temperature of 100 ° C. or higher, the ratio of the number of atoms to the total number of atoms of the metal element is 80 to 99.9% zinc and 0.1 to 20% metal (M). A third step of depositing zinc oxide-based fine particles comprising a crystalline coprecipitate of a metal oxide containing
[0098]
the aboveIn the production method, it is preferable that the step I is a step of making a mixture (n) further containing water. By this step, a solution-like mixture (n) can be easily obtained. The order of addition of the zinc source, monocarboxylic acid and water is arbitrary. For example, the mixture (n) is made by dissolving the zinc source in a mixed solvent of monocarboxylic acid and water.
the aboveIn this production method, the steps II and III are preferably constituted by adding and mixing the mixture (n) to a medium composed of at least an alcohol maintained at a temperature of 100 ° C. or higher. By this step, the mixture (m) is easily made.
When the mixture (n) consisting of the zinc source and monocarboxylic acid or consisting of these and a metal (M) compound is added to a medium consisting of at least alcohol, the mixture (n) is preferably a solution. . When the mixture (n) is a solution, the zinc source and the monocarboxylic acid, or these and the metal (M) compound are compatible with each other, or dissolved in a solvent having high compatibility with them. It is desirable. As a solvent used for that purpose, a zinc source and a monocarboxylic acid, or these and a metal (M) compound can be easily dissolved at a temperature from room temperature to about 100 ° C., and in addition to the above medium. From the viewpoint of high solubility, water, alcohols, ketones and esters are preferred. The alcohols mentioned here include all the alcohols described above.
[0099]
In the process in which the zinc source is converted to X-ray diffractively crystalline zinc oxide, one or more zinc oxide precursors (which may or may not include a metal (M)) May not be). For example, the case where zinc oxide etc. are used for a zinc source is mentioned. The zinc oxide precursor means an ion or compound state containing at least a zinc atom other than zinc oxide, such as zinc (hydrate) ion (Zn2 +), zinc polynuclear hydroxide ion, zinc acetylacetone, etc. Β-dicarbonyl compound or a compound having a chelating ability such as lactic acid, ethylene glycol, ethanolamine or the like, a state in which a part or all of the above ions are chelated, (basic) zinc acetate, (basic ) When present as (basic) carboxylates such as zinc salicylate and (basic) zinc lactate. The case where a part or all of the precursor is present as a complex composition such as a complex salt with a monocarboxylic acid and / or alcohol is also included.
[0100]
In the process of converting the zinc source and the metal (M) compound used as raw materials into the zinc oxide-based fine particles in the mixture (m), the monocarboxylic acid present in the mixture (m) does not change, Alternatively, part or all of the monocarboxylic acid undergoes an esterification reaction with part or all of the alcohol in the mixture (m) to produce an ester compound.
The mixture (m) only needs to be obtained by mixing four components of the zinc source, the monocarboxylic acid, the alcohol, and the metal (M) compound as essential components. In addition to these four components, for example, water, ketones, esters, (cyclo) paraffins, ethers, organic solvents such as aromatic compounds, components such as additives described later, or zinc and metal (M) Other metal components such as inorganic salts such as metal acetates, nitrates and chlorides, and organometallic alkoxides such as metal alkoxides may be included. However, the alkali metal and alkaline earth metal may reduce the heat ray cutting function and conductivity of the fine particles, and is preferably 1/10 or less of the number of atoms of the metal (M) in the mixture (m), It is more preferable that it is 1/100 or less. Moreover, water and an organic solvent are normally contained as a solvent component.
[0101]
The presence state of the four components and the presence form in the mixture (m) of each component are not particularly limited. For example, when the presence state of the zinc source is exemplified, the zinc source and / or the metal (M) compound is dissolved as it is, with the alcohol and / or the water and the organic solvent as solvent components. It is in a state of being changed and dissolved, or in a state of being dispersed in a colloidal, emulsified or suspended state.
Accordingly, the state of the mixture (m) is not particularly limited. For example, there is no problem even if it is liquid, sol, emulsion, or suspension.
The mixture (m) is prepared by mixing the respective components in the above-described range. The preparation method is not particularly limited.
[0102]
In particular, in order to obtain a dispersion of zinc oxide-based fine particles in which the average particle diameter of single particles is controlled in the range of 0.001 to 10 μm, the first mixture (n) comprising the zinc source and monocarboxylic acid is used. Is preferably added to an alcohol-containing solution with heating to prepare the mixture (m) from the viewpoint of practical productivity.
The preparation method at this time will be described below.
As a method for adding the mixture (n), for example, a method in which the mixture (n) is added and mixed all at once, a method in which the mixture (n) is dropped on or in an alcohol-containing solution, or a mixture (n ) May be employed.
[0103]
Moreover, although addition mixing of the mixture (n) may be performed at normal pressure, pressurization, or reduced pressure, it is preferably performed at normal pressure in terms of production cost. When adding and mixing under normal pressure, if you want to obtain a zinc oxide-based fine particle dispersion with excellent uniformity in particle size, shape, etc. and controlled dispersion and agglomeration, alcohol is added during the addition and mixing. It is preferable to maintain the solution at a temperature of 60 ° C. or higher, particularly 60 ° C. or higher and 300 ° C. or lower. If the temperature of the alcohol-containing solution at the time of addition mixing is less than 60 ° C., the viscosity of the mixture (m) may rapidly increase during the addition mixing or after the addition mixing to become a gel. In such a case, stirring cannot be performed and uniform mixing is not achieved, or the next step, that is, when heating is performed, problems such as insufficient heat transfer and temperature distribution are induced, crystallinity, It is difficult not only to obtain uniform zinc oxide-based fine particles in terms of particle diameter, particle shape, etc., but also to obtain only aggregates. Such a problem is related to the zinc concentration in the mixture (m) and is more likely to occur when the zinc concentration is higher. Accordingly, the lower limit temperature of these optimum temperatures varies depending on the pressure of the system, and when performing under reduced pressure or under pressure, it is necessary to appropriately select the temperature of the alcoholic solvent according to the pressure. As described above, when the mixture (n) is added while heating the alcohol-containing solution, a part of the monocarboxylic acid and / or a part of the alcohol in the mixture (m) remains outside the system due to evaporation. The mixture (m) is also included in the mixture obtained in this way.
[0104]
Although the raw material composition in preparing the mixture (n) is not particularly limited, the amount of the zinc source used as the raw material of the mixture (n) is 1 to 90 in terms of ZnO with respect to the total amount of the mixture (n). It is preferable that the amount of the monocarboxylic acid used as a raw material of the mixture (n) is in the range of 0.5 to 50 times mol in terms of molar ratio to Zn atoms in the zinc source. .
The mixture (m) is obtained by adding and mixing the mixture (n) prepared as described above to the alcohol-containing solution.
When the mixture (n) is added and mixed, the mixture (n) may be at room temperature or in a heated state. Moreover, when adding and mixing, it is especially preferable that the alcohol-containing solution is stirred for the purpose of obtaining uniform mixing.
[0105]
At this time, the content of the alcohol to be contained in the alcohol-containing solution is not particularly limited, but in order to perform the zinc oxide-based fine particle formation reaction during heating in a short time, it is contained in a mixture (m) of alcohol. The range of 1 to 100 times mol is preferable in terms of the molar ratio to Zn atoms derived from the zinc source. The concentration of the alcohol in the alcohol-containing solution is usually in the range of 5 to 100% by weight with respect to the total amount of the solution.
In addition, as a method for producing the zinc oxide-based fine particles of the present invention, a zinc source, a monocarboxylic acid and an alcohol are necessary without going through the above steps (I) and (II) (without making a mixture (n)). And a mixture (m) containing water and dissolved or dispersed in the zinc source and the monocarboxylic acid is prepared, and the mixture (m) is maintained at a temperature of 100 ° C. or higher as in the step (III). Thus, zinc oxide comprising a crystalline coprecipitate of a metal oxide containing 80 to 99.9% zinc and 0.1 to 20% metal (M) in the ratio of the number of atoms to the total number of atoms of the metal element. Another method of precipitating the system fine particles can also be adopted. In this alternative method, the state of the solution in which the zinc source and the monocarboxylic acid are uniformly dissolved during the preparation of the mixture (m) or the subsequent heat treatment to 100 ° C. or higher until any fine particles are precipitated. In order to obtain a uniform solution-like mixture (m), for example, a method such as heating is employed. The metal (M) compound may be added and mixed, for example, when making the mixture (m), or may be added separately during the heat treatment at 100 ° C. or higher. When added during the heat treatment, for example, a method of adding the obtained solution after dissolving the metal (M) compound in a solvent system in which it can be (heated) dissolved may be employed. In the case of the above-mentioned alternative method, the raw material composition for preparing the mixture (m) is not particularly limited, but the amount of zinc source used as the raw material for the mixture (m) is based on the total amount of the mixture (m). The amount of the monocarboxylic acid used as a raw material of the mixture (m) is 0.5 to 10 times mol in terms of a molar ratio with respect to Zn atoms in the zinc source. It is preferable that it is the range of these. Further, the alcohol content is preferably 10 to 50 times in terms of a weight ratio of the total weight of alcohol to the ZnO equivalent weight of Zn atoms contained in the mixture (m).
[0106]
By heating the mixture (m) obtained as described above, a dispersion containing zinc oxide-based fine particles can be obtained with high yield.
The heating temperature is not particularly limited, and the heating temperature is of course not less than the temperature at which crystalline zinc oxide precipitates. However, the particle diameter, shape, dispersion / aggregation state, etc. of the zinc oxide fine particles to be finally obtained It is necessary to select the heating temperature and the heating time from a comprehensive viewpoint including the initial composition of the mixture (m) and the various parameters described above. In particular, in order to obtain a dispersion of zinc oxide-based fine particles in which the average particle size of single particles is controlled in the range of 0.001 to 10 μm with practical productivity, 100 ° C. or higher, particularly 100 ° C. or higher and 300 ° C. It is preferable to carry out at the following heating temperature.
[0107]
In this case, for example, when the mixture (m) is obtained by adding and mixing the mixture (n) to an alcohol-containing solution maintained at a temperature of 100 ° C. or higher, the temperature may be maintained as it is. Heating treatment may be performed after raising or lowering the temperature to a predetermined temperature. Moreover, what is necessary is just to heat-process, after heating up to the temperature of 100 degreeC or more, when the mixture (m) is obtained by adding and mixing the mixture (n) to alcohol at the temperature of less than 100 degreeC. Setting the heating temperature of the mixture (m) to 100 ° C. or higher strictly controls the composition of the reaction system including the speed and amount of evaporation or removal of excess or unnecessary components in order to obtain zinc oxide fine particles. Therefore, there is an advantage that it is easy to control the particle size and the like of the fine particles obtained.
[0108]
Further, in the heating process for obtaining the dispersion, components other than the above components, that is, alcohol, the ester compound produced by heating, or, if necessary, part or all of the solvent component present in the mixture are evaporated. It may be removed.
Moreover, although it does not specifically limit about heating time, In order to complete reaction, about 0.1 hour-30 hours are preferable normally.
Further, when water is present in the mixture (m), the free water concentration in the dispersion is preferably 5% by weight in order to be converted into zinc oxide fine particles in the heating process. It is preferable to carry out the distillation until it becomes less than 1%, more preferably less than 1% by weight. The reason for this is that when the water concentration exceeds this range, depending on the type of other components such as alcohol contained in the dispersion, the crystallinity of the zinc oxide-based fine particles is low, and the above-mentioned function is not sufficiently exhibited. Because there is.
[0109]
In addition, as the (final) composition in the produced zinc oxide-based fine particle dispersion, the amount of the monocarboxylic acid was set to 0. 0 relative to the total amount in terms of zinc atoms contained in the produced dispersion. It is preferable to make it 5 times or less. The reason is that when it exceeds 0.5 mole, the crystallinity of the zinc oxide-based fine particles is lowered and the function as zinc oxide may not be sufficiently exhibited. Therefore, if the amount of monocarboxylic acid present in the mixture (m) exceeds 0.5 times the total amount in terms of zinc atoms contained in the produced dispersion, heating is performed. In the process, at least the excess must be distilled off. Of course, even when the ratio is 0.5 times or less, distillation may be performed during the heating process.
[0110]
In the case where the single particles are used as primary particles and secondary particles obtained by aggregating the primary particles are obtained, it is an effective method to allow a lactic acid source to coexist when the temperature is maintained at 100 ° C. or higher. Lactic acid source is lactic acid; ammonium lactate, sodium lactate, lithium lactate, calcium lactate, magnesium lactate, zinc lactate, aluminum lactate, manganese lactate, iron lactate, nickel lactate, silver lactate and other metal lactates; methyl lactate, ethyl lactate, Lactic acid ester compounds such as n-butyl lactate that can generate lactic acid by hydrolysis and the like, and any one of them may be used alone, or two or more may be used in combination.
[0111]
Although the quantity of the lactic acid source used is not specifically limited, For example, it is performed in the range of 0.001-0.4 by molar ratio with respect to zinc in a mixture (m). Below the above range, the coexistence effect of lactic acid is insufficient, so that zinc oxide crystals cannot be obtained. On the other hand, when the above range is exceeded, precipitation reaction of zinc oxide crystals is difficult to occur, making it difficult to obtain the desired fine particles. In order to obtain fine particles having a uniform particle shape, the molar ratio of lactic acid to zinc is preferably in the range of 0.001 to 0.2, and in order to obtain fine particles having a uniform particle diameter and good dispersibility, The molar ratio of lactic acid is preferably 0.001 to 0.1.
[0112]
The addition of the lactic acid source is, for example, as follows. Lactic acid (CH_ThreeWhen CH (OH) COOH) and / or lactic acid ester is used, the above steps I, II and III (hereinafter, step III includes a step corresponding to III in the above alternative method), or I and II Any method selected from the above may be used, and a method of adding directly or a method of adding a solution dissolved in a solvent (for example, alcohol) may be employed. The latter addition method is preferred particularly when the lactic acid source is added in Step III because lactic acid is likely to diffuse quickly. When a metal lactate is used, it may be at any time selected from the above-mentioned Steps I, II, III, or between I and II, and preferably a mixture (n ) Dissolves in. For example, a uniform solution is prepared by adding and mixing a zinc source powder and a metal lactate powder to a solution containing a monocarboxylic acid and stirring. At this time, stirring while heating to increase the dissolution rate and solubility of each powder is preferably employed because a high-concentration solution can be obtained in a short time.
[0113]
When lactic acid is dissolved or dispersed in the medium, the zinc oxide crystals grow anisotropically to form flaky zinc oxide crystals, and the flaky zinc oxide crystals are gathered with the tips facing outward. In some cases, a dispersion containing zinc oxide-based fine particles having the above can be obtained. At this time, when the molar ratio of lactic acid to zinc is in the range of 0.001 to 0.4, the single particles to be produced are flaky (anisotropic), for example, a length of 1.0 to 5.0 ( (Major axis / minor axis), flatness (major axis / thickness) of 2 to 200, and major axis of 5 to 1000 nm, which are excellent in light diffusion permeability and preferable. The major axis is the longest length of the triaxial diameters measured for the particles, and the thickness is the lesser of the width and height of the triaxial diameters (particle diameter of the shortest part). .
[0114]
the aboveThe polymer used in this production method is the same as that described for the polymer contained in the zinc oxide fine particles of the present invention.
The amount of the polymer to be used is not particularly limited, but the weight ratio of the zinc atom in the zinc source (that is, in the second mixture) to the amount converted to zinc oxide, for example, in the range of 0.01 to 2.0. Done. If it is below the range, composite particles are difficult to obtain, and if it exceeds the range, precipitation reaction of zinc oxide crystals may be difficult to occur, so that the intended zinc oxide-based fine particles are difficult to obtain. Of the composite particles, in order to obtain zinc oxide-based fine particles having the above-mentioned multi-layer structure, and having a uniform particle shape and particle diameter and good dispersibility, although depending on the type of polymer and other reaction conditions, The amount is preferably a weight ratio of 0.05 to 0.5 with respect to the zinc oxide equivalent.
[0115]
the aboveIn the production method, the polymer is added in any one of the above steps or in two or more steps. The polymer is added at an arbitrary time until the zinc oxide-based fine particles are precipitated. For example, a method of adding and mixing to the mixture (n) or adding and mixing to the mixture (m) is exemplified.
the aboveIn this production method, the polymer may be added at any time as long as it is a stage before the zinc oxide-based fine particles are formed.
The polymer is preferably preliminarily dissolved in the alcohol used for the medium, or dissolved in an arbitrary solvent and added to the reaction system because it can spread quickly in the reaction system. The solvent used for dissolving the polymer is not particularly limited as long as it is a liquid capable of dissolving the polymer. For example, alcohols (the above-mentioned), aliphatic and aromatic carboxylic acids, aliphatic and aromatic carboxylic esters , Ketones, ethers, ether esters, aliphatic and aromatic hydrocarbons, halogenated hydrocarbons and other organic solvents; water; mineral oil; vegetable oil; wax oil; at least one selected from the group consisting of silicone oils One.
[0116]
The mixture (m) only needs to be obtained by mixing four components of zinc, monocarboxylic acid, alcohol, and metal (M) as essential components. Added.
Maintaining the polymer-containing mixture (m) at a temperature in the range of 100 ° C. or higher, preferably 100 to 300 ° C., more preferably 150 to 200 ° C. for 0.1 to 30 hours, preferably 0.5 to 10 hours. As a result, the zinc oxide-based fine particles of the present invention according to the type and composition ratio of the raw material can be obtained with practical productivity as zinc oxide-based crystal-polymer composite particles. That is, zinc dissolved or dispersed in the medium is converted into X-ray diffractionally crystalline zinc oxide by maintaining the second mixture at a temperature within the above range for a time within the above range. . Since the polymer is also dissolved or dispersed in the medium, zinc oxide crystal nuclei are precipitated, and the polymer is compounded in the process of crystallization, whereby a dispersion containing zinc oxide-polymer composite particles is obtained. can get. Reaction liquid composition and temperature when composite particles are generated based on the type of polymer used, the type of raw material such as the type of alcohol contained in the medium, the raw material charging composition and the temperature history until composite particles are generated, etc. By controlling the above, it is possible to control the internal structure and particle shape / particle diameter of the composite particles, the particle diameter of the contained single particles (metal oxide coprecipitate), and the like.
[0117]
the aboveIn the production method of the above, by heat treatment at a temperature of 100 ° C. or higher in the presence of the above-described polymer, the metal oxide coprecipitate and the polymer are contained, and the number average particle diameter of 0.001 to 10 μm Zinc oxide-based fine particles having a coefficient of variation of particle size of 30% or less are dispersed and contained in the range of 1 to 80% by weight, and a dispersion using alcohol and / or the ester compound and / or organic solvent as a solvent is obtained. .
Furthermore, for the purpose of controlling the particle size, particle shape, dispersion state or higher order structure of the zinc oxide fine particles finally obtained and / or the polarity or composition of the fine particle surface, a specific additive is added. It is also possible to coexist in the heating process. The addition timing of the additive is not particularly limited, and may be any of the process of preparing the mixture (m) or the mixture (n) or the process of heat treatment, and is appropriately selected according to the purpose and the type of additive. For example, when it is added immediately before or after the precipitation of zinc oxide crystals, the effect of the additive is likely to be sufficiently exerted, which is often preferable.
[0118]
In particular, in order to obtain zinc oxide-based fine particles having a uniform particle size and particle shape, a carboxyl group, amino group, imino group, amide group, amide bond, imide group, imide At least one atom selected from the group consisting of a bond, ureido group, ureylene bond, isocyanato group, sulfonic acid group, sulfuric acid group, phosphoric acid group, metal hydroxyl group, metal alkoxy group, epoxy group, urethane group, urethane bond, and ester bond Heating using as an additive a compound having one or more groups and having a molecular weight of less than 1000 and / or a so-called chelating agent (multidentate ligand) that forms a chelate compound by multidentate coordination to zinc ions It is preferable to coexist when processing.
[0119]
Examples of the additive include the above-mentioned carboxyl group-containing compounds including long-chain saturated fatty acids such as caprylic acid, lauric acid, myristic acid, palmitic acid and stearic acid, and ester compounds thereof; monoethanolamine, diethanolamine, N , N-dimethylethanolamine and other primary, secondary and tertiary amino group-containing alcohols, tetramethylammonium hydroxide, quaternary ammonium salts such as n-hexadecyltrimethylammonium hydroxide, 6-aminocaproic acid, N, Amino acids such as N-bis (octylaminoethyl) glycine, p-aminobenzoic acid, aspartic acid, glutamic acid, amino (di) carboxylic acids and esters or anhydrides thereof, 2-hydroxypyridine, pyridine-2,6-dicarboxylic acid Pyridine derivatives such as acids Amino group-containing compounds such as aliphatic amines such as octadecylamine and stearylamine; amides such as dimethylformamide, dimethylacetamide, benzamide, oxamide and oxamic acid; acid imides such as succinimide and phthalimide, and imino (di) acetic acid Imino group-containing compounds such as imino (di) carboxylic acid and imino ether; dicarboxylic acid ureides such as parabanic acid, alloxan, barbituric acid and dialuric acid, ureido acids such as oxalic acid and malonuric acid, diureides such as uric acid, uracil and the like β-aldehyde acid ureido, ureido group-containing compounds and derivatives such as α-oxyacid ureido such as 5-methylhydantoin; urethane compounds such as ethyl carbamate and derivatives thereof such as N-nitrosated compounds and N-chloroacetylated compounds; Tollrange Isocyanate group-containing compounds such as isocyanate, diisocyanyl diphenylmethane, hexamethylene diisocyanate, isobutyl isocyanate, phenyl isocyanate; 1,2-epoxycyclohexene, 1,8-cineol, ethylene glycol diglycidyl ether, 1,6- Aliphatic diglycidyl ethers such as hexanediol diglycidyl ether, polyglycidyl ethers such as glycerol triglycidyl ether, pentaerythritol tetraglycidyl ether, aliphatic and aromatic diglycidyl esters such as adipic acid diglycidyl ester, etc. Other compounds containing an epoxy group such as resorcin diglycidyl ether, bisphenol A diglycidyl ether, oligomers having an epoxy group as a functional group; Titanate coupling agents such as propyl triisostearoyl titanate, bis (dioctylpyrophosphate) oxyacetate titanate, tetraoctyl bis (ditridecyl phosphite) titanate, isopropyltri (N-aminoethylaminoethyl) titanate, methyltrimethoxy Silane, 3-chloropropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, III-glycidoxypropyltrimethoxysilane, III- (II-aminoethylaminopropyl) trimethoxysilane, phenyltrimethoxysilane, diethoxydimethyl Silane, trimethylethoxysilane, alkylalkoxysilane such as hydroxyethyltriethoxysilane, phenyltrimethoxysilane, benzyltriethoxysilane, γ-amino Nopropyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ- Silane coupling agents such as chloropropyltrimethoxysilane and stearyltrimethoxysilane, acetoalkoxyaluminum diisopropylate, aluminum laurate, aluminum stearate, diisopropoxyaluminum stearate, ethylacetoacetate aluminum diisopropylate, etc. Various coupling agents such as aluminum coupling agents and partial hydrolysates thereof; for example, tetraethoxy titanium, tetrabutoxy titanium other than the above coupling agents Diethyldiethoxytitanium, tetrabutoxytitanium, tetramethoxyzirconium, tetrabutoxyzirconium, hexaethoxytungsten, di-n-butoxymanganese, diisopropoxycobalt, diethoxynickel, di-n-butoxynickel, triethoxylanthanum, triethoxy Representative metal alkoxides such as yttrium, diethoxy copper, di-n-butoxy copper, pentaethoxy niobium, penta-n-butoxy niobium, pentaethoxy tantalum, penta-n-butoxy tantalum, triethoxy iron, tri-n-butoxy iron Specific examples of the derivatives include organometallic compounds containing metal hydroxyl groups and / or metal alkoxy groups and derivatives thereof, and (partially) hydrolysis and / or mixtures of these organometallic compounds. Or a condensate such as a (partial) hydrolyzate obtained by a condensation reaction; trimethyl phosphate, triethyl phosphate, tributyl phosphate, tris (2-chloroethyl) phosphate, (polyoxyethylene) bis [bis (2-chloroethyl) Phosphate esters such as phosphate], acid phosphate esters such as methyl acid phosphate, propyl acid phosphate, lauryl acid phosphate, stearyl acid phosphate, bis-2-ethylhexyl phosphate, diisodecyl phosphate, phosphite esters such as trimethyl phosphite, Organic phosphorus compounds such as thiophosphates such as dimethyldithiophosphoric acid and diisopropyldithiophosphoric acid; at least a primary amino group, a secondary amino group, a tertiary amino group in the molecule, 4 Organopolysiloxanes having a molecular weight of less than 1000 containing the above-mentioned atomic groups such as amino groups such as secondary ammonio groups, carboxyl groups, sulfonic acid groups, phosphoric acid groups, hydroxyl groups, epoxy groups; sodium lauryl sulfate, dodecylbenzenesulfonic acid ( Sodium), anionic surfactants such as sodium polyoxyethylene lauryl ether sulfate, sodium dialkylsulfosuccinate, calcium stearate, polyoxyethylene lauryl ether, polyoxyethylene alkylamine, polyethylene glycol monolaurate, glycerol monostearate, etc. Nonionic surfactants; cationic surfactants such as lauryldimethylamine and stearyltrimethylammonium chloride; amphoteric boundaries such as laurylbetaine and stearylamine acetate Active agent, various surfactants or the like having the above-mentioned atomic group are exemplified.
[0120]
Also, as so-called chelating agents (polydentate ligands) that form chelate compounds by multidentate coordination to zinc ions, β-diketones such as acetylacetone, ethyl acetoacetate, benzoylacetone, ethylenediamine, dimethylglyoxime , Benzyldioxime, cyclohexane 1,2-dione dioxime, dithizone, oxine, glycine, glycolic acid, oxalic acid, catechol, dipyridyl, 1,10-phenanthroline, α-hydroxypropionic acid, monoethanolamine, diethanolamine, ethylene glycol Etc. are exemplified.
As described above, the size and shape of single particles of the obtained zinc oxide-based fine particles, the state of dispersion of single particles, higher order structure, surface polarity, surface composition, and the like vary greatly depending on the type and amount of additive. For example, when a compound having a hydrophilic main chain such as methoxypoly (oxyethylene) monoglycolic acid is used as an additive, the size and shape of the primary particles are uniform, and the primary particles with respect to a polar solvent such as water In the meantime, when a compound having a main chain having high hydrophobicity or lipophilicity such as alkyltrialkoxysilane and octadecylamine is used as an additive, the size of primary particles can be obtained. In addition, zinc oxide-based fine particles having a uniform shape and excellent primary particle dispersibility in a low polarity solvent such as toluene or a nonpolar solvent can be obtained.
[0121]
Needless to say, the size, shape, dispersed state and higher order structure of single particles, surface polarity, surface composition, and the like of single particles are also controlled by the aforementioned polymer and surface modifier.
The addition amount of the above-mentioned additive is not particularly limited, but usually it is preferably 0.1% or more and 80% or less, expressed as a weight ratio of the additive to zinc oxide contained in the zinc oxide-based fine particle dispersion. If the content is less than 0.1%, the additive effect is not substantially observed. On the other hand, if the content exceeds 80%, zinc oxide fine particles may not be obtained.
The above-described additives can be used alone or in combination, and the method of adding is not particularly limited, and may be appropriately selected according to the kind of additive, the addition timing, and the like. For example, when adding during heating, a method of adding an additive directly or dissolved and / or diluted in an arbitrary solvent such as alcohol is exemplified, but the latter method is added to the reaction system. Is preferable in that it readily diffuses quickly and the effect of addition can be sufficiently exhibited.
[0122]
A method for producing surface-modified fine particles will be described. The surface-modified fine particles are produced by mixing zinc oxide-based fine particles obtained by an arbitrary production method with a surface modifier under appropriate conditions. The surface modifier and the surface modification method are not particularly limited, The type, amount, and surface modification method of the surface modifier may be appropriately selected depending on the purpose. However, in order that each fine particle is uniformly surface-modified and the surface-modified layer in each fine particle is homogeneous, the surface of the zinc oxide-based fine particle is dispersed in a solvent and sufficiently stirred. It is preferable that a modifier is added and mixed. Therefore, preferably, in the method for producing zinc oxide-based fine particles of the present invention, a method of coexisting a surface modifier in the process of producing fine particles, or a dispersion of zinc oxide-based fine particles once in accordance with the production method of the present invention. A method of adding and mixing a surface modifier after the production is preferable. As the latter method, for example, an appropriate amount of a surface modifier selected according to the purpose of use is added to and mixed in a dispersion in which single particles having an average particle diameter of 0.1 μm or less are dispersed or in a secondary aggregation. In addition, there is a method of obtaining surface-modified fine particles having a modified surface by stirring at a temperature of 100 ° C. or higher or a temperature of 100 ° C. or lower, usually for about 0.5 to 24 hours.
[0123]
The surface modifier may be the same as or different from the above-described polymer, additive and the like, and may be used in combination with these polymer and additive. Two or more surface modifiers may be added sequentially or simultaneously. Examples of the surface modifier include, in addition to the aforementioned polymers and additives, for example, methyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, III-glycidoxypropyltrimethoxysilane, III- (II-aminoethylaminopropyl) trimethoxysilane, phenyltrimethoxysilane, diethoxydimethylsilane, trimethylethoxysilane, alkylethylsilane such as hydroxyethyltriethoxysilane, phenyltrimethoxysilane, benzyltriethoxysilane, γ-amino Propyltriethoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-mercapto Silane coupling agents such as propyltrimethoxysilane, γ-chloropropyltrimethoxysilane, stearyltrimethoxysilane, acetoalkoxyaluminum diisopropylate, aluminum laurate, aluminum stearate, diisopropoxyaluminum stearate, ethylacetoacetate Examples thereof include aluminum coupling agents such as trialuminum diisopropylate.
[0124]
The addition amount of the surface modifier with respect to the fine particles is not particularly limited, but for the purpose of surface modification, a metal oxide (zinc and IIIB group, IVB in the fine particles) is required in order to sufficiently exert the modification effect. It is preferable that the ratio of the surface modifier to the oxide having a group metal as a metal component is 0.01 to 1 by weight ratio. Even if the weight ratio exceeds 1, the surface modification effect is saturated, which is economically disadvantageous. Moreover, a particularly preferable weight ratio is 0.02 to 0.5 from the viewpoint of the modification effect and economy.
Next, in the above-described present invention, a preferable embodiment for obtaining zinc oxide-based fine particles in which the average particle diameter of single particles is controlled in the range of 0.001 to 0.1 μm is as follows. Among them, the following conditions (I) to (IV) are particularly mentioned, preferably two or three conditions (I) to (IV), more preferably (I) to (IV). It is to be done under conditions that satisfy all.
[0125]
(I) The zinc source includes, as a main component, at least one selected from the group consisting of zinc oxide, zinc hydroxide and zinc acetate, particularly preferably zinc oxide and / or its compound. Alternatively, zinc hydroxide is the main component.
The reason for this is that zinc oxide, zinc hydroxide, and zinc acetate are substantially 0.001-0.1 μm because they contain substantially no impurities that inhibit the zinc oxide-based fine particle formation reaction during the heating process. This is because it is easy to strictly control the particle size in a fine region. Among them, zinc oxide and zinc hydroxide are not only available at a low price, but also the type of carboxyl group-containing compound can be arbitrarily selected. This is because it is particularly easy to obtain fine particles having the above-mentioned particle diameter range by using the above raw materials.
[0126]
(II) The monocarboxylic acid is a saturated fatty acid having a boiling point of 200 ° C. or less at normal pressure.
Specifically, formic acid, acetic acid, propionic acid, butyric acid, and isobutyric acid are preferable, and acetic acid is particularly preferable. This is because the content of carboxyl groups in the reaction system can be easily controlled in the process of heating from the preparation process of the mixture, and thus the particle diameter can be easily controlled in a fine region. Furthermore, it is preferable to use this saturated fatty acid in the range which is 80 mol% or more in the ratio which occupies for the said monocarboxylic acid total amount.
Further, the monocarboxylic acid content is not particularly limited as long as it is within the above-mentioned range, but the monocarboxylic acid content in the mixture (n) is based on the Zn atom in the zinc oxide. A range of 2.2 to 10 moles in terms of molar ratio is particularly preferable in that fine particles having excellent dispersibility in which secondary aggregation is suppressed can be obtained.
[0127]
(III) As a method for preparing the mixture (m), the zinc source and the monocarboxylic acid, and in some cases, the mixture (n) obtained by mixing the zinc source, the monocarboxylic acid and the metal (M) compound ) In an alcohol-containing solution maintained at a temperature of 100 ° C. or higher, preferably 100 ° C. or higher and 300 ° C. or lower, continuously or intermittently.
In this case, the mixture (n) is preferably in a liquid state, and when the zinc source and monocarboxylic acid also contain a metal (M) compound, the zinc source, monocarboxylic acid and metal (M) compound are It is desirable that it is dissolved in a compatible or highly compatible solvent. As a solvent used for that purpose, a zinc source and monocarboxylic acid described later can be easily dissolved by heating from room temperature to about 100 ° C., and water and alcohols are highly compatible with alcoholic solvents. , Ketones and esters are preferred. The alcohols mentioned here include all the alcohols described above.
[0128]
(IV) The heating temperature of the mixture (m) is 100 to 300 ° C., particularly preferably 150 to 300 ° C.
By heating the mixture (m), ZnO crystals are precipitated, and when the fine particles of the present invention are produced, the ZnO equivalent concentration with respect to the mixture (m) is 0.5 wt% or more and 20 wt% or less, and further 2.0 wt% or more. By carrying out at less than 10 wt%, it is preferable that fine particles in which secondary aggregation is suppressed are easily obtained when the average particle diameter of primary particles is in the range of 0.001 to 0.1 μm.
Furthermore, in zinc oxide fine particles having an average particle diameter in the range of 0.001 to 0.1 μm, the particle diameter and shape are controlled more uniformly, and the surface condition such as hydrophilicity / hydrophobicity is controlled. An effective method for controlling the aggregation state is described below. Even in a preferable method for producing zinc oxide-based fine particles having an average particle size in the range of 0.001 to 0.1 μm, by using the above-described additives in the same manner as described above, the shape of the particles, the dispersion state of the particles, and the high Zinc oxide-based fine particles with controlled secondary structure, surface polarity and the like can be obtained. In addition, when obtaining zinc oxide-based fine particles in which the particle size distribution of primary particles is uniform, the average particle size is substantially in the above range, and secondary aggregation is suppressed, zinc used as a raw material or a compound thereof A basic zinc carbonate and / or a zinc salt of a monocarboxylic acid whose boiling point at normal pressure is higher than the heating temperature, the main component being at least one selected from the group consisting of zinc oxide, zinc hydroxide and zinc acetate A method using a material containing as a subcomponent is also preferably used. The ratio of the subcomponent to the main component is usually 0.01% or more and 20% or less in terms of the atomic ratio of zinc in the component. If the proportion is less than 0.01%, the combined effect of subcomponents is insufficient, while if it exceeds 20%, zinc oxide with high crystallinity may not be obtained.
[0129]
As another method for obtaining zinc oxide fine particles having a uniform shape and particle size distribution and excellent dispersibility, a method of coexisting carbonate ions and / or CO2 in the heat treatment process is also effective. For example, prior to and / or during the reaction of zinc oxide formation in the heat treatment process, carbon dioxide gas is intermittently or continuously supplied into the mixture (m), urea, ammonium hydrogen carbonate, basic Examples thereof include a method of adding a compound that generates carbon dioxide or carbonate ions under heating conditions such as zinc carbonate.
In addition to the preferred production method described above, by modifying the surface with the above-described surface modifier, the average particle size is 0.001 to 0.1 μm, the shape is controlled, and the particle size distribution is uniform. Fine particles having extremely excellent affinity and dispersibility for solvent systems, paint systems and resin systems can be obtained. In particular, by using a preferable surface modifier, a fine particle (ultrafine particle) dispersion having an average particle size of 0.05 μm or less, which is excellent in dispersibility of single particles, is obtained, and by processing this according to the method described later, Various solvent dispersions, coating compositions and resin compositions can be produced economically and easily without impairing the finely dispersed state of the fine particles.
[0130]
the aboveIn particular, according to the above-mentioned production conditions, the zinc oxide concentration is controlled in terms of particle shape, surface state, dispersion / aggregation state, etc., with an average particle diameter in the range of 0.001 to 0.1 μm. In the range of ˜80 wt%, a dispersion of zinc oxide fine particles using alcohol and / or the ester compound and / or organic solvent as a solvent is obtained.
the aboveThe zinc oxide-based fine particle dispersion obtained in (1) can be used as it is, but if necessary, zinc oxide-based fine particle powder, paint containing zinc oxide-based fine particles, zinc oxide in another solvent by solvent replacement It can be easily converted into a dispersion in which system fine particles are dispersed.
[0131]
the aboveAs a method for obtaining the powder of the zinc oxide-based fine particles obtained in step 1, the fine particles are separated by subjecting the dispersion to usual methods such as filtration, centrifugation, and solvent evaporation, and then dried or as necessary. A method of firing can be employed. Among them, the powdering method by the solvent evaporation method using a vacuum flash evaporator after performing the concentration operation of the dispersion as required is a method in which secondary aggregation of fine particles that tend to occur in the drying process is suppressed. Therefore, it is preferable as a method for pulverizing zinc oxide-based fine particles having excellent dispersibility.
As a method of obtaining a dispersion in which zinc oxide-based fine particles are dispersed in a solvent different from the dispersion containing zinc oxide-based fine particles obtained in the present invention, the powder obtained after pulverizing according to the above-described method is used. After mixing with a solvent to be replaced, such as water, a known method of dispersing by mechanical energy such as ball mill, sand mill, ultrasonic homogenizer or the dispersion is heated to evaporate or distill part or all of the solvent in the dispersion. However, a so-called heated solvent replacement method in which a solvent to be replaced is mixed can be employed. The solvent component constituting the dispersion is not particularly limited, and alcohols, aliphatic and aromatic carboxylic acid esters, ketones, ethers, ether esters, aliphatic and aromatic hydrocarbons, halogenated carbonization Organic solvents such as hydrogen, water, mineral oil, vegetable oil, wax oil, silicone oil, etc. are exemplified, and may be appropriately selected according to the purpose of use. Preferred solvent components are as described above.
[0132]
the aboveAs a method for obtaining a plasticizer dispersion containing the zinc oxide-based fine particles obtained in step 1, as in the case of the solvent dispersion described above, the finely powdered fine particles are converted into a plasticizer or a solution containing a plasticizer. A method of dispersing by mechanical energy after mixing and mixing, or a method of mixing a dispersion of fine particles with a plasticizer or a solution containing a plasticizer and evaporating the solvent component by heating can be employed. In addition, when a plasticizer dispersion is produced, a compound of fine particles, a plasticizer and a resin is produced by preliminarily mixing the resin component with a fine particle dispersion or a plasticizer. You can also
[0133]
Zinc oxide fine particles of the present inventionThe child isFor example, the composition containing at least one of these can be used in various industrial applications or industrial applications. Resin composition constituting film, sheet, fiber, resin plate, etc. to increase added value of film, sheet, fiber, resin plate, glass, paper, cosmetics, etc .; film, fiber, resin plate, glass, paper Coating composition to be coated on paper; paper; zinc oxide-based fine particles of the present invention for cosmetics, etc.ChildAdded.
[1] Coating composition and coated article of the present invention
The coating composition of the present invention comprises the zinc oxide fine particles of the present invention.With childAnd a binder component capable of forming a film that binds the zinc oxide-based fine particles. The amount of the zinc oxide-based fine particles and the binder component is a ratio of 0.1 to 99% by weight of the fine particles and 1 to 99.9% by weight of the binder component with respect to the total solid weight of both.
[0134]
The coated product of the present invention includes a base material selected from the group consisting of a resin molded product, glass and paper, and a coating film formed on the surface (for example, one side or both sides) of the base material. The coating film is a zinc oxide fine particle of the present invention.With childAnd a binder component that binds the zinc oxide-based fine particles. The amount of the zinc oxide-based fine particles and the binder component is a ratio of 0.1 to 99% by weight of the fine particles and 1 to 99.9% by weight of the binder component with respect to the total solid weight of both. The form of the resin molded product is, for example, at least one selected from the group consisting of plates, sheets, films, and fibers. The substrate may be a transparent substrate or a translucent substrate.
[0135]
If the amount of fine particles exceeds the above range, there is a problem that the adhesion of the coating film to the substrate, the scratch resistance, abrasion resistance, etc. of the coating film itself are insufficient. There is a problem of becoming.
In the coating composition of the present invention, the total amount of the zinc oxide-based fine particles and the binder component is, for example, in the range of 1 to 80% by weight relative to the total amount of the coating composition, depending on the purpose of use, workability, etc. It is selected appropriately. The balance of the coating composition is an additive such as a solvent that disperses the fine particles and dissolves or disperses the binder component, and a pigment that is used according to the intended use of the coating composition.
[0136]
The binder component that can be used in the coating composition is not particularly limited. For example, (1) (meth) acrylic, vinyl chloride, vinylidene chloride, silicone, melamine, urethane, styrene, alkyd, phenol -Based, epoxy-based, polyester-based thermoplastic or thermosetting synthetic resins; UV-curable resins such as UV-curable acrylic resins and UV-curable acrylic silicone resins; ethylene-propylene copolymer rubber, polybutadiene rubber, styrene-butadiene Organic binders such as rubber, synthetic rubber such as acrylonitrile-butadiene rubber or natural rubber, (2) silica sol, alkali silicate, silicon alkoxide and their hydrolysis condensates, inorganic binders such as phosphate, etc. can be used . These binder components are appropriately selected according to the purpose of use, such as required performance such as heat resistance and scratch resistance for the film obtained by applying and drying the coating composition onto the substrate, and the type of the substrate. One is used alone, or two or more are used in combination.
[0137]
Also, conventionally developed or used for the purpose of improving the surface hardness, wear resistance, etc. of polyester films, polycarbonate resins, methacrylic resin films or sheets, plates, diethylene glycol bisallyl carbonate lenses, etc. A material called a so-called hard coat agent that gives a film having equivalent or near surface hardness, scratch resistance, etc., or a material synthesized by the present inventors for the same purpose (for example, Example II-11 described later) The mixture (x) can also be used as a binder component, a dispersion medium component such as a solvent or a vehicle for dispersing the fine particles of the present invention.
[0138]
Examples of the hard coating agent include UV curable acrylic resin, thermosetting, and moisture curable silicone (polysiloxane), all of which are used as an effective binder component in the present invention. Can do.
Furthermore, since the main component of the fine particles of the present invention is a metal oxide crystal, by combining with these hard coating agents, it is possible to easily obtain a film that is transparent, blocks ultraviolet rays and infrared rays, and has excellent wear resistance. Can do.
The main raw materials for silicone-based hardcoat agents are usually tetraalkoxysilanes (tetrafunctional silane compounds) such as tetramethoxysilane and tetraethoxysilane, and trifunctional silane compounds such as methyltrimethoxysilane and phenyltrimethoxysilane. These monomers or (co) hydrolyzed / condensed products are dissolved in a solvent such as alcohol or exist in a sol state. Also in the present invention, a hard coat paint can be synthesized by mixing such a solution or sol with zinc oxide fine particles. However, in consideration of the type of base material, desired surface hardness, flexibility, etc., colloidal silica is used as a tetrafunctional silane compound, or a normal silane cup such as γ-glycidoxypropyltrimethoxysilane is used. A compound generically called a ring agent can be blended.
[0139]
In the coating composition of the present invention, the binder component may be dissolved, emulsified or suspended in a solvent.
The solvent for the binder component is appropriately selected according to the intended use of the coating composition, the type of binder, etc., for example, alcohols, aliphatic and aromatic carboxylic acid esters, ketones, ethers, ether esters, Organic solvents such as aliphatic and aromatic hydrocarbons, halogenated hydrocarbons, etc .; water; mineral oil, vegetable oil, wax oil, silicone oil, etc. are exemplified, and may be appropriately selected according to the purpose of use Depending on, two or more may be mixed and used in an arbitrary ratio. As the solvent of the binder component, the solvent of the above dispersion of fine particles of the present invention can be used.
[0140]
When a polyvinylidene chloride or vinylidene chloride-vinyl chloride copolymer is used as a binder component, an excellent water vapor barrier property such as polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinylidene chloride, or the like is used as a binder component. In this case, an excellent barrier coating film (coated product) against gases such as oxygen and carbon dioxide can be obtained. These coated products, particularly coated films, are extremely useful in food packaging and the like as films having high gas barrier ability while having the ultraviolet and infrared shielding ability inherent in the zinc oxide-based fine particles of the present invention. It is.
The method for producing the coating composition of the present invention is not particularly limited. For example, the fine particles of the present inventionOf childA method in which powder is added to and mixed with a solvent containing a binder component, a method in which a dispersion in which fine particles are dispersed in a solvent and a solvent in which a binder component is mixed, and a binder component in a dispersion in which fine particles are dispersed in a solvent. The method of adding and mixing can be adopted. The dispersion method is not particularly limited, and for example, a conventionally known method using a stirrer, a ball mill, a sand mill, an ultrasonic homogenizer, or the like can be adopted.
[0141]
In the coating composition of the present invention, a binder component or a solvent containing a binder component is directly added to and mixed with a solvent dispersion of zinc oxide-based fine particles obtained by the above-described production method and / or a dispersion such as a plasticizer dispersion. Can also be obtained.
According to the method for producing a coating composition described above, a coating composition containing at least fine particles, a binder component and a solvent can be obtained.
The obtained coating composition may be any substrate, for example, a plastic film or sheet such as a polyester film; a fiber such as a natural fiber or a synthetic fiber; a transparent material such as a vinyl chloride resin, a polycarbonate resin, an acrylic resin, or a polyethylene terephthalate resin; A film containing zinc oxide-based fine particles can be formed by coating and drying on a translucent synthetic resin plate; glass; paper or the like.
[0142]
In order to form a film, the film may be heated at a temperature equal to or lower than the deformation temperature of the substrate, if necessary. For example, heating can be performed by forming a tough film by using an inorganic binder such as silicon alkoxide as the binder component and sufficiently promoting the condensation reaction between the molecules of the binder component, or by using a thermosetting resin as the binder component. A resin and isocyanates having a cured film formed by sufficiently advancing the curing reaction of the thermosetting resin by using a resin, or having two or more active hydrogen atoms such as polyether and / or polyester in at least one part of the binder component This is because the cross-linking reaction is efficiently performed when the cross-linking reaction is performed, for example, when a polyurethane film is finally formed by using a cross-linking agent such as the above.
[0143]
The binder component in the coated product of the present invention is a film formed by drying or dry-curing (dry-crosslinking) the organic and / or inorganic binder.
The method for applying the coating composition of the present invention is not particularly limited, and conventionally known methods such as a dipping method, a spray method, a screen printing method, a roll coater method, and a flow coating method are employed.
The coating film formed from the coating composition of the present invention as described above and the coated product of the present invention obtained as described above have the zinc oxide fine particles according to the present invention dispersed in the binder component. Contained. For this reason, the coating film and the coated product have functions reflecting the characteristics of the fine particles, that is,
(1) UV-cutting ability,
(2) Infrared cutting ability (near infrared = heat ray and far infrared),
Having at least
(3) Give a coated product with controlled conductivity,
further,
-Ultra fine particles have excellent transparency to visible light (= transparency)
・ Excellent light diffusibility for fine particles with a multilayer structure such as hollow bodies.
A film may be formed.
[0144]
In addition, since the zinc oxide-based fine particles of the present invention contain ZnO as a main component, they are excellent in antibacterial properties, and the obtained coated products also have antibacterial properties.
When all the particles of the fine particles of the present invention have the same shape and have a number average particle size of 0.1 to 10 μm and a particle size variation coefficient of 30% or less, a coating film formed from the coating composition of the present invention, and The coated product of the present invention has at least the above properties (1) to (3), and has slipperiness and antiblocking properties without impairing surface flatness.
[2] Resin composition and resin molded product of the present invention
The resin composition of the present invention comprises the zinc oxide fine particles of the present invention.With childAnd a resin capable of forming a continuous phase in which the zinc oxide-based fine particles are dispersed. The amount of the zinc oxide-based fine particles and the resin is 0.1 to 99% by weight of the fine particles, 1 to 99.9% by weight of the resin, preferably 0.1 to 50% by weight of the fine particles, based on the total solid weight of both of them. The ratio is 50 to 99.9% by weight of the resin.
[0145]
If the amount of the fine particles exceeds the above range, a molded product having no problem in mechanical strength may not be obtained, and if it is less than the above range, there is a problem that the mixing effect of the fine particles is not sufficiently exhibited.
The resin molded product of the present invention is obtained by molding the resin composition of the present invention into a shape selected from the group consisting of plates, sheets, films and fibers.
Although the kind of resin which can be used for the resin composition and resin molded product of this invention is not specifically limited, It selects suitably according to the intended purpose. Examples of the resin include: (1) Polyolefin resin such as polyethylene and polypropylene; polystyrene resin; vinyl chloride resin; vinylidene chloride resin; polyvinyl alcohol; polyester resin such as polyethylene terephthalate and polyethylene naphthalate; polyamide resin; (Meth) acrylic resins such as (meth) acrylates, phenolic resins; urea resins; melamine resins; unsaturated polyester resins; polycarbonate resins; thermoplastic or thermosetting resins such as epoxy resins; (2) ethylene-propylene copolymer rubber; Examples include synthetic rubber or natural rubber such as polybutadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, and any one of them is used alone, or two or more are used in combination. Or.
[0146]
The method for producing the resin composition of the present invention is not particularly limited. The target resin composition can be obtained by mixing and dispersing the fine particles of the present invention in a resin. For example, when a pellet-like or powdery resin is melt-kneaded, a master batch for adding and mixing fine particle powder is used. A conventionally known method such as a method of removing a solvent after mixing and dispersing fine particles in a solution in which a resin is dissolved can be employed. Another method is to mix and disperse the fine particles in the process of producing the resin. For example, when the resin is a polyester resin, the fine particles are produced during the polyester production process, that is, at any time in a series of steps in the ester exchange reaction to the polymerization reaction. It is also possible to employ a method of adding and mixing a dispersion prepared by dispersing fine particles, preferably fine particles, in glycol, which is a polyester raw material. Further, when it is necessary to improve the workability during molding or to provide flexibility, one or more plasticizers and / or the above-described fine plasticizer dispersion of the present invention are used. 1 type (s) or 2 or more types can be added. Each addition amount is appropriately selected according to the type of resin, processing conditions, purpose of use, and the like. When the plasticizer is contained, the content (total) of the plasticizer is usually 2 to 70% by weight with respect to the total amount of the resin composition or the resin molded body. If it is less than 2% by weight, the effect of adding a plasticizer is difficult to obtain, and if it exceeds 70% by weight, stable physical properties as a molded article may not be obtained.
[0147]
Furthermore, the resin composition and molded product of the present invention may be prepared by using conventionally known heat stabilizers, antioxidants, light stabilizers, fungicides, dyes, pigments, antistatic agents, ultraviolet absorbers, and the like as necessary. Various resin additives can be included in conventional amounts.
According to the above-described method, a resin composition in which the fine particles of the present invention are dispersed and contained in the resin is obtained. The resin composition may be in the form of a normal molding material such as pellets. By molding the obtained resin composition into a plate shape, a sheet shape, a film shape, a fiber shape or the like, a resin molded product containing the fine particles of the present invention and having the following functions can be obtained.
(1) With UV-cutting ability
(2) With infrared cut ability (near infrared = heat ray and far infrared)
Having at least
(3) Give a resin molded article with controlled conductivity;
further,
-Ultra fine particles have excellent transparency to visible light (= transparency)
・ Excellent light diffusibility for fine particles with a multilayer structure such as hollow bodies.
A resin molded product can be formed.
[0148]
In addition, when the resin is a polyvinylidene chloride-based, vinylidene chloride-vinyl chloride copolymer, it has excellent water vapor barrier properties, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, polyvinylidene chloride-based, stretched nylon. And so on, it exhibits excellent barrier properties against gases such as oxygen and carbon dioxide. In particular, a film comprising the resin as a resin component is extremely useful in food packaging and the like as a film having high gas barrier ability while having the ultraviolet and infrared shielding ability inherent in the zinc oxide fine particles of the present invention. is there.
Moreover, since the zinc oxide type | system | group fine particle of this invention uses ZnO as a main component, it is excellent also in antibacterial property, and the obtained resin molded product also has antibacterial property.
[0149]
When all the fine particles of the present invention have the same shape, the number average particle diameter is 0.1 to 10 μm and the particle diameter variation coefficient is 30% or less, the resin molded product of the present invention does not impair the surface flatness. Has slipperiness and antiblocking properties. The molded article is formed into a film, particularly a film stretched by a stretching operation or the like, whereby irregularities based on the presence of fine particles are formed. When the fine particles obtained according to a preferred embodiment of the present invention are contained, the unevenness of the film surface becomes uniform and fine because the particle size distribution of the fine particles is uniform and highly dispersed. A film excellent in slipping property and anti-blocking property while being excellent. For example, the polyester film thus obtained is useful as a base film for magnetic tape, a packaging film, a capacitor film and the like.
[0150]
A method for obtaining a molded article having a desired shape from the resin composition of the present invention is not particularly limited, and a conventionally known method can be employed as it is. An example will be described below.
When it is desired to obtain a polycarbonate resin plate containing dispersed fine particles of the present invention, for example, a composition in which fine particles are uniformly mixed in a resin by melting and kneading polycarbonate resin pellets or powder and a predetermined amount of fine particle powder. Then, the pellets are continuously or once pelletized, and then processed into a flat or curved plate by injection molding, extrusion molding, compression molding or the like. Of course, it is also possible to shape | mold into arbitrary shapes, such as a corrugated sheet shape, by further post-processing a flat molded object. Resin plates such as acrylic resin plates, vinyl chloride resin plates, and polyester resin plates can be obtained in the same manner.
[0151]
When it is desired to obtain a fiber such as nylon fiber or polyester fiber containing dispersed fine particles of the present invention, a film such as a polyolefin film, a polyamide film, or a polyester film, for example, a fine particle powder and a resin pellet or powder are melt-kneaded. Thus, after obtaining a composition in which fine particles are uniformly mixed in the resin, it is continuously or once pelletized as it is, and then formed into a sheet by a conventionally known fiberizing method such as melt spinning, or extrusion molding. Thereafter, a conventionally known (stretched) film production method may be employed in which stretching is performed uniaxially or biaxially as necessary.
[0152]
The resin molded product of the present invention also includes laminated films and sheets containing one or more layers containing the fine particles of the present invention, including packaging films including food packaging, heat insulating films, gas barriers. It can be used as a film or the like. As a manufacturing method of the laminated film sheet, for example,
A method of laminating a film or sheet containing the fine particles of the present invention described above with another film or sheet by a method such as heat fusion or a method using an adhesive (layer),
A method for applying the above-described coating composition of the present invention to a film or sheet;
Etc. Alternatively,
・ When forming a film or sheet as a base material or other functional film or sheet by extrusion molding, (1) the fine particle powder and resin pellet or resin powder of the present invention, or (2) the present invention A method of obtaining a laminated film or sheet by co-extrusion using resin pellets or resin powder containing fine particles in advance as a raw material is also mentioned. At that time, as a device to be used, a conventionally known extrusion molding machine used for production of a multilayer film or sheet can be used.
[0153]
In order to obtain the polyester fiber or polyester film containing fine particles dispersed therein according to the present invention, the following other known methods can be employed.
That is, as a method for obtaining a polyester fiber, fine particles are dispersed in glycol at, for example, a ratio of 0.1 to 50% by weight at any time in a series of steps in a polyester production process, that is, a transesterification reaction to a polymerization reaction. If a polyester polymer in which fine particles are dispersed and contained in a polyester is obtained by adding and mixing the resulting dispersion to complete the polymerization reaction of the polyester, then a melt spinning method according to a conventionally known method may be employed. Good.
[0154]
On the other hand, in order to obtain a polyester film, a polyester polymer in which fine particles are dispersed and contained in the polyester is obtained in the same manner, and then extruded into a sheet by extrusion, and then uniaxially or biaxially as required. A method of performing a stretching process can be employed.
[3〕paper
Of the present inventionUsing zinc oxide fine particlesPaper is a paper pulp and the zinc oxide fine particles of the present invention dispersed in the pulpWith childHave The amount of the zinc oxide fine particles is 0.01 to 50% by weight, preferably 0.1 to 20% by weight, based on the pulp. Below the above range, there is a problem that the effect of adding fine particles is insufficient, and when above the above range, there is a problem that the mechanical properties of the paper are deteriorated.
[0155]
The paper may be any paper as long as it contains the fine particles of the present invention, and examples thereof include processed paper such as internal paper, coated paper, impregnated paper, and film laminated paper.
The internally added paper is obtained by adding and mixing the fine particles at any time in the process from beating the pulp to paper making, and dispersing and containing the fine particles in the inside and / or the outer surface of the paper. Means paper. The method of adding and mixing the fine particles is not particularly limited, and it can be usually performed in the form of a fine particle of the present invention as it is or in the form of a dispersion in which it is dispersed in water or the like. Moreover, what is necessary is just to perform the process until papermaking and drying according to a conventionally well-known papermaking method. Conventionally known materials can be used as they are. For example, a pulp slurry is prepared by beating pulp with a pulper or the like. After the aqueous dispersion of fine particles of the present invention is added to and mixed with the slurry, a paper containing fine particles dispersed therein can be obtained through a papermaking step and a drying step. At this time, if necessary, a sizing agent, a sulfuric acid band, a paper strength enhancer, and the like may be added at an arbitrary stage.
[0156]
The coated paper is one in which a film containing fine particles is formed by applying a coating containing the fine particles on a paper substrate and drying. The impregnated paper is one in which the fine particles are fixed to the inner and outer surfaces of the paper by impregnating the paper base with an aqueous or organic solvent dispersion containing or not containing a binder in which the fine particles are dispersed and dried. Means.
The production method of these coated paper and impregnated paper is not particularly limited, except that the fine particles of the present invention are used, a paper obtained by a conventionally known general production method as a base material, a conventionally known coating method, The impregnation method can be applied as it is.
[0157]
The coating composition containing the fine particles to be used, the composition of the dispersion, the solvent to be used, the kind of the binder, the preparation method thereof, and the like can be prepared using conventionally known raw materials as they are, and may be prepared according to the conventionally known preparation methods.
The content of the fine particles in the coating composition and the dispersion is not further limited as long as it is in the range of 0.1 to 100% by weight in the solid content, and is appropriately selected depending on the purpose of use and the like.
The solid content here means the total amount of the fine particles of the present invention and the binder contained in the paint and dispersion. As a coating composition used in order to make a coated paper, what contains the solvent among the coating compositions of the above-mentioned this invention is mentioned. Examples of the dispersion medium for the dispersion liquid used for producing the coated paper include solvents that can be used in the above-described coating composition of the present invention. In the coating composition, additives other than these, such as pigments, water resistance agents, lubricants, antifoaming agents, flow modifiers, water retention agents, etc. may be mixed.
[0158]
The film-laminated paper means one obtained by attaching a polymer film containing the fine particles dispersed according to the above-described method to a paper substrate. As the polymer film, the above-described resin molded product of the present invention can be used.
Paper obtained by blending the fine particles of the present invention obtained according to the above production method is useful as paper having excellent appearance. The use of the obtained paper is arbitrary, and can be used for various purposes including, for example, art paper and wallpaper.
When all the particles of the fine particles of the present invention have the same shape, the number average particle size is 0.1 to 10 μm, and the variation coefficient of the particle size is 30% or less, the surface flatness is unprecedented and printability is good. Improved paper can be obtained.
[0159]
[4]Makeup
Of the present inventionUsing zinc oxide fine particlesCosmetics are zinc oxide fine particles of the present inventionChildContains 0.1% by weight or more. The amount of the zinc oxide-based fine particles is usually 0.1 to 50% by weight based on the total weight of the solid content of the cosmetic. In addition to the above essential components, at least selected from the group consisting of (1) oils such as liquid fats and oils, solid fats and oils, waxes, hydrocarbons, and polyhydric alcohols such as polyethylene glycol and propylene glycol. One, (2) surfactants, thickeners, fragrances, chemicals, antioxidants, chelating agents, pigments, water, at least one selected from the group consisting of antiseptic / antifungal agents, etc. The components used are blended within a range not impairing the effects of the present invention. Furthermore, (3) at least one selected from the group consisting of extender pigments such as kaolin, talc and mica, inorganic color pigments such as iron oxide and TiO2, and organic color pigments such as red 202 and yellow 4; And / or (4) At least one selected from the group consisting of organic ultraviolet absorbers such as benzoic acid, cinnamic acid, salicylic acid, and benzophenone can also be used in combination with the fine particles of the present invention.
[0160]
the aboveCosmetics are cosmetics that can block ultraviolet rays and heat rays. That is,the aboveThe purpose of blending fine particles in cosmetics is mainly to provide sunscreen and beauty.the aboveThe use of the cosmetic is not particularly limited, and can be used as a facial cosmetic such as powder, cream or oily foundation, lotion, milky lotion, cosmetic oil, cream, makeup cosmetic such as lipstick, eye shadow, etc. .
The composition of the cosmetic is not limited as long as it contains the fine particles, and the fine particles are contained in a conventionally known cosmetic composition corresponding to the use (type) of the cosmetic. . Therefore, raw materials generally used in cosmetics can be used as they are.
[0161]
Therefore,the aboveThe method for producing the cosmetic is not particularly limited, and the fine particles can be added and mixed in a desired amount and dispersed at any time for producing a conventionally known cosmetic composition according to the use (type) of the cosmetic. That's fine. The fine particles of the present invention hardly aggregate and can be easily dispersed in a normal cosmetic composition. Therefore, as a method for dispersing the fine particles, a mixing and dispersing method generally used for cosmetic powders can be applied as it is, and according to the method, a cosmetic in which the fine particles are highly dispersed can be obtained. Further, when the fine particles are added and mixed, the fine particles may be added and mixed as they are. However, if necessary, for example, anionic, cationic, nonionic and amphoteric surfactants, metal soap, silicone, etc. Further, a surface treatment method for the purpose of oleophilicity or hydrophilicity generally used for cosmetic powders may be performed. The surface treatment may be performed prior to the addition mixing, or may be performed during the addition mixing process.
[0162]
the aboveCosmetics
(1) With UV-cutting ability
(2) With infrared cut ability (near infrared = heat ray and far infrared)
Having at least
further,
-Ultra fine particles have excellent transparency to visible light (= transparency)
・ Excellent light diffusibility for fine particles with a multilayer structure such as hollow bodies.
Is.
[0163]
In addition, since the zinc oxide-based fine particles of the present invention contain ZnO as a main component, they are excellent in antibacterial properties, and the resulting cosmetics also have antibacterial properties.
When the fine particles of the present invention have pores in the gaps between crystals and / or are hollow, the cosmetics of the present invention can have moisturizing properties and moist feeling. It is also possible to give a sustained release function such as a fragrance by holding it.
The zinc oxide fine particle solvent dispersion and zinc oxide fine particle plasticizer dispersion of the present invention are as described above.
[0164]
However, the fine particles of the present inventionOf childApplications are not limited to those described above.
[0165]
[Action]
Zinc oxide has a high ultraviolet shielding ability but does not have a heat ray shielding ability. On the other hand, oxides of Group IIIB metal elements and Group IVB metal elements do not have heat ray shielding ability. However, when a Group IIIB metal element or a Group IVB metal element is added to make zinc oxide a crystalline coprecipitate with these metals, a heat ray shielding ability is produced by the synergistic action of both metal elements. Here, the ultraviolet ray shielding ability refers to an absorptivity having an absorption edge at a wavelength of 360 nm or more among ultraviolet rays, and the heat ray shielding ability is a shielding property having a cutoff wavelength of 2.0 μm or less in a heat ray region. Point to.
[0166]
In this case, it is important that the zinc oxide fine particles are crystalline coprecipitates. If it is non-crystalline, it does not produce heat ray shielding ability even if it is a coprecipitate, and the zinc oxide fine particles obtained by baking the amorphous coprecipitate to crystallize are crystalline but have heat ray shielding ability. do not do.
When a group IIIB metal element or a group IVB metal element is added to zinc oxide, conductivity can be imparted to the zinc oxide.
[0167]
【Example】
Examples The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.
About the obtained dispersion of zinc oxide-based fine particles, the crystallinity, particle shape, primary particle diameter, dispersion / aggregation state, fine particle concentration, composition and other physical properties or physical property values of the contained fine particles are analyzed by the following methods. evaluated. When it was necessary to pulverize prior to analysis and evaluation, the powder obtained was used as a measurement sample after pulverization according to the following method unless otherwise specified. In addition, the powdered product was used for all analysis as it was.
[0168]
(Preparation method of powder sample)
Fine particles in the obtained dispersion were separated by a centrifugal separation operation and then vacuum-dried at 80 ° C. to completely remove volatile components to obtain fine particle powder, which was used as a powder sample.
(crystalline)
Evaluation was made by powder X-ray diffraction measurement.
(Particle shape)
Judgment was made with a 10,000 times scanning electron microscope or transmission electron microscope.
[0169]
(Average particle size)
The particle diameter of 100 arbitrary particles of a 10,000-fold scanning electron microscope image or transmission electron microscope image was measured and obtained from the following equation. In the case of a scanning electron microscope image, the precious metal alloy is vapor-deposited prior to the measurement, but the value of the particle size obtained is larger than that of the transmission electron microscopic image by the thickness of the vapor deposition layer. It was shown by the value after.
[0170]
[Expression 1]

[0171]
[Expression 2]

[0172]
[Equation 3]

[0173]
(Concentration of fine particles in the dispersion)
A part of the dispersion was vacuum-dried at 100 ° C. until volatile components such as a solvent could be completely removed to obtain a dry powder, and the residue when heated at 500 ° C. in air for 1 hour was obtained. As a metal oxide, a weight fraction with respect to the dispersion of the metal oxide was determined, and this value was defined as a fine particle concentration (concentration in terms of metal oxide) in the dispersion.
(Fine particle composition)
The powder sample was obtained by fluorescent X-ray analysis, atomic absorption analysis, gravimetric analysis and the like.
(Heat cutting performance of fine particles)
The fine particle dispersion obtained by the reaction is concentrated to a fine particle concentration of 10% by weight to obtain a concentrated dispersion. The concentrated dispersion is applied onto a glass plate having a thickness of 2 mm using a bar coater and dried. (A nitrogen atmosphere at 80 ° C.) to obtain a dry film. The coating amount is 1 to 10 g / m in terms of fine particles² The spectral characteristics (wavelength 2200 to 200 nm) of each dry film are measured with a self-recording spectrophotometer (UV-3100, Shimadzu Corporation). From the obtained spectral curve, the coating amount is 3 g / m in terms of fine particles.² Each performance of the film in this case is evaluated by comparison with the following criteria.
[0174]

<20% × * Heat ray cut amount: [light transmittance (%) with respect to wavelength of 2 μm in substrate]
-[Light transmittance (%) for coated products with a wavelength of 2 μm]

Reference) Transmittance of the glass substrate used
Wavelength 350nm 600nm 2μm
Transmittance (%) 86 91 91
(Optical characteristics of painted products)
Regarding the spectral characteristics, the transmittance for each wavelength light at an irradiation wavelength of 2200 to 200 nm was measured and evaluated by a self-recording spectrophotometer (UV-3100, Shimadzu Corporation).
[0175]
From the measured spectral characteristics, the heat ray cut performance, the ultraviolet ray cut performance and the like were evaluated based on the following criteria.
Amount of heat ray cut: Light transmittance (%) with respect to wavelength 2 μm of base material itself—Light transmittance (%) with respect to wavelength 2 μm of coated product
[In the case of a molded product containing / without fine particles, 100 (%)-light transmittance (%) with respect to a wavelength of 2 μm of the molded product]
Ultraviolet ray cutting ability: The light transmittance at a wavelength of 350 nm was evaluated according to the above criteria.
[0176]
Total light transmittance and haze: Measured and evaluated with a turbidimeter (NDH-1001 DP Nippon Denshoku Industries Co., Ltd.).
(Conductivity of fine particles)
Place 0.1 ml of the above powder sample in advance between Pyrex glass (1.5 cm square) on which gold comb electrodes are deposited and Pyrex glass (1.5 cm square) on which nothing is deposited, and apply a constant pressure. After being applied for 1 hour in a light-shielded state in an atmosphere of a temperature of 20 ° C. and a relative humidity of 60%, an electric current value (dark current) under the same conditions using an electrometer 617 manufactured by Kessley Was measured and converted into a resistance value (Ω) for evaluation.
[0177]
As a standard sample, a commercially available zinc oxide (manufactured by Sakai Chemicals, specially manufactured by Zinc Hua 1) was used, and the electrical conductivity was evaluated by the relative value of the resistance value of this and the resistance value of the powder sample. That is,
When the resistance value of the standard sample / the resistance value of the sample of the example or comparative example = r

[Production of fine particle dispersion]
Example I-1
In a 10 L glass reactor equipped with a stirrer, dripping port, thermometer, reflux condenser, zinc oxide powder 0.3 kg, indium acetate dihydrate in a mixed solvent of 1.6 kg acetic acid and 1.6 kg ion-exchanged water After adding 36.3 g of the product, the mixture was heated to 100 ° C. with stirring to obtain a zinc-containing solution (A1) as a uniform solution.
[0178]
Next, 14 kg of 2-butoxyethanol was charged into a 20 L glass reactor equipped with a stirrer, a dripping port, a thermometer, and a distillate gas outlet, which could be heated by an external heat medium, and the internal temperature was raised to 153 ° C. Keep warm. To this, the entire amount of the zinc-containing solution (A1) kept at 100 ° C. was dropped by a metering pump over 30 minutes. The bottom temperature varied from 153 ° C to 131 ° C. When the internal temperature was raised to 168 ° C. after the completion of the dropwise addition, 400 g of 2-butoxyethanol solution in which 36.9 g of lauric acid was dissolved was added over 1 minute, and further heated and held at the temperature for 5 hours, 7.89 kg of a blue-gray dispersion (DI-1) was obtained. Dispersion (DI-1) was a dispersion of flaky fine particles having an average particle diameter of 5 nm at a concentration of 3.5% by weight. The fine particles in the dispersion are X-ray diffractometrically crystalline zinc oxide having a metal oxide content of 94.5% by weight and In having a composition with an atomic ratio of 3.0% to the total amount of metal atoms. The resulting fine particles.
[0179]
Table 3 shows the physical properties of the obtained dispersion and fine particles.
Example I-2
A zinc-containing solution (A2) was obtained in the same manner as in Example I-1, except that the types and amounts of the raw materials in the zinc-containing solution (A1) in Example I-1 were changed as shown in Table 1. Furthermore, a dispersion (DI-2) was obtained in the same manner as in Example I-1, except that the amount of 2-butoxyethanol charged in Example I-1 was 12 kg and lauric acid was not added. It was.
Table 3 shows the physical properties of the obtained dispersion and fine particles.
[0180]
After 1 part by weight of octadecyltriethoxysilane was added to 227 parts by weight of the dispersion (DI-2) obtained in Example I-2 and stirred, the solvent was heated in an evaporator under reduced pressure at a bath temperature of 130 ° C. After removing and further vacuum drying at 100 ° C., 12 parts by weight of fine particle powder (PI-2-1) was obtained.
Example I-3
In a 10 L glass reactor equipped with a stirrer, a dripping port, a thermometer, and a reflux condenser as in Example I-1, zinc acetate 2 was added to a mixed solvent of 2.2 kg of acetic acid and 2.2 kg of ion-exchanged water. After 0.809 kg of hydrate was added and mixed, the temperature was raised to 100 ° C. with stirring to obtain a zinc-containing solution (A3) as a uniform solution.
[0181]
Next, 8 kg of 2-butoxyethanol and 5 kg of ethylene glycol-n-butyl ether are charged into a 20 L glass reactor equipped with a stirrer, a dripping port, a thermometer, and a distillate gas outlet, which can be heated by an external heat medium. The internal temperature was raised to 162 ° C. and held. To this, the entire amount of the zinc-containing solution (A3) maintained at 100 ° C. was dropped over 30 minutes with a metering pump. When the internal temperature was raised to 168 ° C. after completion of the dropwise addition, a solution in which 90.8 g of aluminum tris (sec-butoxide) was uniformly dissolved in 400 g of 2-butoxyethanol was added all at once, and further heated and maintained at 170 ° C. for 5 hours. As a result, a dispersion (DI-3) was obtained.
[0182]
Table 3 shows the physical properties of the obtained dispersion and fine particles.
Example I-4
In a 10 L glass reactor equipped with a stirrer, a dripping port, a thermometer, and a reflux condenser as in Example I-1, zinc acetate 2 was added to a mixed solvent of 2.2 kg of acetic acid and 2.2 kg of ion-exchanged water. Hydrate 0.809 kg and alumina sol-200 (Nissan Chemical Co., Ltd., AS-200, Al2 O3) were sequentially added and mixed, and then heated to 100 ° C. with stirring to obtain a homogeneous zinc-containing solution (A4 )
Next, 14 kg of 2-butoxyethanol was charged into a 20 L glass reactor equipped with a stirrer, a dripping port, a thermometer, and a distillate gas outlet, which could be heated by an external heat medium, and the internal temperature was raised to 150 ° C. Keep warm. To this, the entire amount of the zinc-containing solution (A4) maintained at 100 ° C. was dropped over 30 minutes using a metering pump. After completion of the dropwise addition, when the internal temperature was raised to 168 ° C., a solution in which 30.0 g of polyethylene glycol (average molecular weight 6000) was uniformly dissolved in 100 g of 2-butoxyethanol was added in several seconds, and further at 170 ° C. for 5 hours. A dispersion (DI-4) was obtained by heating and holding.
[0183]
Table 3 shows the physical properties of the obtained dispersion and fine particles.
Example I-5
In a 10 L glass reactor equipped with a stirrer, a dripping port, a thermometer, and a reflux condenser as in Example I-1, zinc oxide was added to a mixed solvent of 1.5 kg of acetic acid and 1.5 kg of ion-exchanged water. After adding and mixing 30 kg, the mixture was heated to 80 ° C. with stirring to obtain a homogeneous zinc-containing solution (A5).
Next, 14 kg of 2-butoxyethanol and 60.6 g of ethyl acetoacetate aluminum diisopropylate were added to a 20 L glass reactor equipped with a stirrer, a dripping port, a thermometer, and a distillate gas outlet, which can be heated with an external heat medium. The internal temperature was raised to 150 ° C. and maintained. To this, the entire amount of the zinc-containing solution (A5) maintained at 80 ° C. was dropped over 30 minutes using a metering pump. After completion of the dropwise addition, the internal temperature was raised to 170 ° C., and the mixture was heated and held at 170 ° C. for 5 hours to obtain a dispersion (DI-5).
[0184]
Table 3 shows the physical properties of the obtained dispersion and fine particles.
Further, the fine particles contained in the dispersion (DI-5) are separated from the dispersion medium by centrifugal separation, and the separated fine particles are washed with methanol and then vacuum-dried (10 Torr) at 50 ° C. for 24 hours. Fine particle powder (PI-5) was obtained.
The obtained fine particle powder (PI-5) had an average thickness of 0.025 μm, a long average particle size of 0.08 μm, a length of 2 and a flatness of 3.2, and a metal oxide content of 87. 3% by weight, Al is composed of 5.5% by atomic ratio to the total amount of metal atoms, and 2-5 layers of flaky (flaky) crystals showing X-ray diffraction pattern of crystalline zinc oxide are laminated Fine particles.
[0185]
Comparative Example I-1
A fine particle dispersion (DI-R1) was prepared in the same manner as in Example I-1, except that indium acetate was not used and the amount of 2-butoxyethanol charged was 12.0 kg. Obtained. Table 3 shows the physical properties of the obtained dispersion and fine particles.
Example I-6
In a 10 L glass reactor equipped with a stirrer, dripping port, thermometer, reflux condenser, zinc oxide powder 0.3 kg, indium acetate dihydrate in a mixed solvent of 1.6 kg acetic acid and 1.6 kg ion-exchanged water After adding 36.3 g of the product, the mixture was heated to 100 ° C. with stirring to obtain a zinc-containing solution (A6) as a uniform solution.
[0186]
Next, 12 kg of 2-butoxyethanol was charged into a 20 L glass reactor equipped with a stirrer, a dripping port, a thermometer, and a distillate gas outlet, which could be heated with a heat medium from the outside, and the internal temperature was raised to 158 ° C. Keep warm. To this, the entire amount of the zinc-containing solution (A6) maintained at 100 ° C. was added dropwise over 60 minutes with a metering pump. After completion of the dropping, when the internal temperature was raised to 168 ° C., acrylic polymer: methyl methacrylate-hydroxyethyl methacrylate-maleic acid copolymer (weight ratio 8: 1: 1, weight average molecular weight 4,500) 500 g of 2-butoxyethanol solution containing 300.0 g was added in 1 minute, and further heated and held at 168 ° C. for 5 hours to obtain 9.80 kg of a blue-gray dispersion (DI-6).
[0187]
The dispersion (DI-6) was a dispersion in which fine particles having an average particle diameter of 20 nm were dispersed at a concentration of 3.1% by weight. The fine particles in the dispersion are crystalline zinc oxide in X-ray diffractometry, and have a composition of a metal oxide content of 55% by weight and an In composition of 3.0% in terms of the number of atoms with respect to the total amount of metal atoms. Met. Further, it was confirmed by observation with a transmission electron microscope that the fine particles were coated with an acrylic polymer to which the metal oxide surface was added.
Next, the fine particles contained in the dispersion (DI-6) are separated from the dispersion medium by a centrifugal separation operation, and the separated fine particles are washed with isopropyl alcohol and then vacuum-dried at 50 ° C. for 24 hours (10 Torr). As a result, a fine particle powder (PI-6) was obtained.
[0188]
It was confirmed that the fine particles in the fine particle powder (PI-6) obtained were not substantially different from those in the dispersion.
Further, the fine particle powder (PI-6) is composed of alcohols such as methanol, isopropanol, n-butanol, benzyl alcohol and 2-ethoxyethanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, butyl acetate and ethyl acetate. These are excellent in dispersibility in organic solvents such as esters, aromatic compounds such as benzene and toluene, and easily redispersed into single particles.
[0189]
Example I-7
In a 10 L glass reactor equipped with a stirrer, dripping port, thermometer, reflux condenser, zinc oxide powder 0.3 kg, indium acetate dihydrate in a mixed solvent of 1.6 kg acetic acid and 1.6 kg ion-exchanged water After adding 36.3 g of the product, the mixture was heated to 100 ° C. with stirring to obtain a zinc-containing solution (A7) as a uniform solution.
Next, 12 kg of 2-butoxyethanol was charged into a 20 L glass reactor equipped with a stirrer, a dripping port, a thermometer, and a distillate gas outlet, which could be heated with a heat medium from the outside, and the internal temperature was raised to 158 ° C. Keep warm. To this, the entire amount of the zinc-containing solution (A7) maintained at 100 ° C. was dropped over 30 minutes with a metering pump. 2-butoxyethanol containing 50.0 g of methyl methacrylate-acrylic acid copolymer (9: 1 by weight, weight average molecular weight 7,200) at the time when the internal temperature was raised to 168 ° C. after the completion of the dropping 400 g of the solution was added in a few seconds, and further heated and held at 168 ° C. for 5 hours to obtain 11.79 kg of a blue-gray dispersion (DI-7). The dispersion (DI-6) has a hollow body structure in which fine crystals of about 20 to 30 nm form an outer shell layer having a thickness of 0.2 μm, an average particle diameter of 0.5 μm, and a metal oxide content of 86 in the fine particles. A dispersion formed by dispersing 0.0% by weight of spherical fine particles at a concentration of 3.1% by weight.
[0190]
Further, the fine particles contained in the dispersion (DI-7) are separated from the dispersion medium by a centrifugal separation operation, and the separated fine particles are washed with isopropyl alcohol and then vacuum-dried (10 Torr) at 50 ° C. for 24 hours. As a result, fine particle powder (PI-7) was obtained.
The obtained fine particle powder (PI-7) has a composition with an average particle diameter of 0.5 μm, a metal oxide content of 86.0% by weight, and an In ratio of 3.0% in terms of the number of atoms with respect to the total amount of metal atoms. The spherical fine particles exhibiting an X-ray diffraction pattern of crystalline zinc oxide. Furthermore, the internal structure of the fine particles was confirmed to be hollow fine particles in which granular metal oxide fine particles of about 25 nm and methyl methacrylate-acrylic acid copolymer were localized in the outer shell. The average diameter of the hollow portion was 0.1 μm. Moreover, it was confirmed by scanning electron microscope observation that the surface of the fine particles was rich in unevenness.
[0191]
Further, the fine particle powder (PI-7) is composed of alcohols such as methanol, isopropanol, n-butanol, benzyl alcohol and 2-ethoxyethanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, butyl acetate and ethyl acetate. These were excellent in dispersibility in organic solvents such as esters, aromatic compounds such as benzene and toluene.
Example I-8
In Example I-7, 72.5 g of indium acetate dihydrate was used instead of 36.3 g of indium acetate dihydrate, and polybutoxyethanol was used instead of the 2-butoxyethanol solution of methyl methacrylate-acrylic acid copolymer. A blue-gray dispersion was obtained by carrying out the reaction in the same manner as in Example I-6 except that 800 g of a propylene glycol methyl ether acetate solution in which 30 g of methyl methacrylate (PMMA, weight average molecular weight: 60,000) was dissolved was used. 10.0 kg of (DI-8) was obtained.
[0192]
Further, the fine particles contained in the dispersion (DI-8) are separated from the dispersion medium by centrifugation, and the separated fine particles are washed with isopropyl alcohol and then vacuum-dried (10 Torr) at 50 ° C. for 24 hours. To obtain fine particle powder (PI-8).
The obtained fine particle powder (PI-8) has an average particle size of 3.0 μm, a metal oxide content of 90.1% by weight, and an In composition of 5.8% in terms of the number of atoms with respect to the total amount of metal atoms. The spherical fine particles exhibiting an X-ray diffraction pattern of crystalline zinc oxide. Furthermore, it was confirmed that the internal structure of the fine particles was that about 20 nm of granular metal oxide fine particles were uniformly dispersed in PMMA.
[0193]
Example I-9
In Example I-7, 6.05 g of indium acetate dihydrate was used instead of 36.3 g of indium acetate dihydrate, and lactic acid was used instead of the 2-butoxyethanol solution of methyl methacrylate-acrylic acid copolymer. A blue-gray dispersion (DI-9) was obtained by carrying out the reaction in the same manner as in Example I-7, except that 200 g of 2-butoxyethanol solution in which 7 g was dissolved was used.
Further, the fine particles contained in the dispersion (DI-9) are separated from the dispersion medium by centrifugal separation, and the separated fine particles are washed with methanol and then vacuum-dried (10 Torr) at 50 ° C. for 24 hours. A fine particle powder (PI-9) was obtained.
[0194]
The obtained fine particle powder (PI-9) has a composition with an average particle diameter of 1.2 μm, a metal oxide content of 96.0% by weight, and an In ratio of 0.5% in terms of the number of atoms with respect to the total amount of metal atoms. The spherical fine particles exhibiting an X-ray diffraction pattern of crystalline zinc oxide. Furthermore, the internal structure of the fine particles was a hollow fine particle having a long diameter of 0.3 μm and a flake-shaped metal oxide fine particle having a flatness of 18 that was densely laminated, and having a hollow diameter of 0.6 μm.
Further, the fine particle powder (PI-9) is composed of water, alcohols such as methanol, isopropanol, n-butanol, benzyl alcohol and 2-ethoxyethanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, butyl acetate and acetic acid. It was a fine particle powder excellent in dispersibility in polar solvents such as esters such as ethyl.
[0195]
Example I-10
A zinc-containing solution (A10) was obtained in the same manner as in Example I-1, except that the type and amount of the raw material in the zinc-containing solution (A1) in Example I-1 were changed as shown in Table 2. A dispersion (DI-10) was obtained in the same manner as in Example I-1, except that the amount of 2-butoxyethanol charged in Example I-1 was 12 kg, and 30.0 g of monoethanolamine was added instead of lauric acid. It was.
Table 3 shows the physical properties of the obtained dispersion and fine particles.
The dispersions (DI-1) and (DI-R1) obtained in Example I-1 and Comparative Example I-1 were each evaporated in an evaporator under reduced pressure at a bath temperature of 130 ° C. and a fine particle concentration of 10 It concentrated so that it might become weight%, and concentrated dispersion (DI-1C) and (DI-RC) were obtained. A coating solution is prepared by adding 1.11 parts by weight of acrylic resin solution: Alloset 5210 (solid content 45% by weight, manufactured by Nippon Shokubai Co., Ltd.) to 100 parts by weight of each concentrated dispersion, followed by stirring for 2 hours. did.
[0196]
A dry film (DI-1M) is prepared by depositing a film on a Pyrex glass on which a gold comb-shaped electrode has been deposited in advance, using a coating solution, using a spin coater, drying at room temperature, and drying at 50 ° C. , (DI-RM) was obtained. All of the obtained films were homogeneous films having a thickness of 1.0 μm.
Each dry film was allowed to stand for 1 hour in a light-shielded state at 20 ° C. and 60% relative humidity, and then measured for surface resistance under the same conditions using an electrometer 617 manufactured by Kessley. It was as follows.
DI-1M 2.7 × 10¹¹Ω / □
DI-RM 3.9 × 10¹⁴Ω / □
Furthermore, the results of measuring the surface resistance value in a light-shielded state when DI-1M is left for 1 hour in an atmosphere having a temperature of 20 ° C. and a relative humidity below are shown below.
[0197]

For dispersions (DI-2) to (DI-5)) obtained in Examples I-2 to I-5, respectively, a coating solution was similarly prepared and formed into a film having a thickness of 1 μm. As a result of measuring the surface resistance value in an atmosphere of 20 ° C. and a relative humidity of 60%, the surface resistance value (unit: Ω / □) of any film was 10¹¹Order or 10¹²It was confirmed that the surface resistance value was constant regardless of the humidity as in the case of Example I-1.
[0198]
From the above results, the fine particles in each dispersion obtained in Examples I-1 to I-5 are conductive fine particles made conductive compared to conventional zinc oxide, and substantially. It was confirmed that there was no humidity dependency. Therefore, the fine particles (dispersion) obtained in the present invention can be said to be a suitable raw material for an antistatic film, for example.
From the dispersion (DI-2) and dispersion (DI-R1) obtained in Example I-2 and Comparative Example I-1, a powder sample was obtained according to the method described above, and X-ray diffraction measurement results were obtained. (X-ray diffraction pattern of each powder) is shown in FIG. In FIG. 2, the horizontal axis represents the diffraction angle (2θ) [unit: °], and the vertical axis represents the intensity [cps]. As can be seen from FIG. 2, DI-2 and DI-R1 both show sharp diffraction peaks attributed to ZnO.
[0199]
Comparative Example I-2
Liquid A was obtained by dissolving 35.0 g of ammonium bicarbonate in 500 g of ion-exchanged water.
Aluminum sulfate hydrate (Al₂(SO_Four)_Three・ NH₂O, n = 14-18) 6.1778 g was dissolved in ion-exchanged water to make 50 g, and a liquid B was obtained.
100 g of zinc oxide (French method No. 1 special order, manufactured by Sakai Chemical) was added to and mixed with 180 g of ion-exchanged water to obtain slurry C.
Dispersion D was obtained by adding and mixing 1.00 g of silica fine powder (Aerosil 200, Nippon Aerosil Co., Ltd.) with 50 g of ion-exchanged water and stirring.
[0200]
The liquid B was added to the liquid A while stirring the liquid A at room temperature to obtain a mixture. The mixture became emulsified immediately after mixing. The obtained emulsion was directly stirred for 10 minutes.
Next, the slurry C was charged into a 1 L glass reactor equipped with a stirrer, a dripping port, a thermometer, and a reflux condenser, which can be heated with a heat medium from the outside, and stirred at room temperature, before the dripping port. The obtained emulsion was added and mixed, and the temperature of the heating medium was set to 80 ° C. to start the temperature increase. After about 30 minutes, when the internal temperature reached 61 ° C., the dispersion D was added and mixed, and stirring was continued for 1 hour under heating. One hour later, when the internal temperature was 76.6 ° C., the heating was stopped and the mixture was allowed to cool while stirring was continued. When the internal temperature reaches room temperature, the resulting slurry is filtered under reduced pressure to separate the fine particles, further washed thoroughly with ion-exchanged water, vacuum-dried at 50 ° C. for 12 hours, and further at 100 ° C. White powder was obtained by vacuum-drying for 4 hours.
[0201]
As a result of X-ray diffraction measurement, the obtained white powder was found to contain basic zinc carbonate in addition to the diffraction peak attributed to ZnO._FourCO_Three(OH)₆・ H₂It shows a diffraction pattern in which impurity peaks considered to be O are mixed, and it was confirmed that the crystallinity of ZnO is low. The X-ray diffraction pattern of the powder is shown in FIG.
Comparative Example I-3
8.3753 g of zinc chloride (ZnCl2), aluminum chloride (AlCl_Three・ 6H₂O) A uniform solution was obtained by dissolving 0.3167 g in 50 g of ion-exchanged water. Next, while stirring the solution at room temperature, 14 wt% aqueous ammonia was added dropwise, and the addition was terminated when the pH reached 8.21. The dripping amount of 14 wt% ammonia water was 20.0 g.
[0202]
After the completion of dripping, after stirring for 10 minutes, the whole amount is filtered, and after sufficient washing with water, the fine particles are taken out by centrifugation and vacuum dried at 50 ° C. for 12 hours and further at 100 ° C. for 4 hours. From this, a white powder was obtained.
As a result of X-ray diffraction measurement, it was confirmed that the obtained white powder did not show a diffraction peak attributed to ZnO. The X-ray diffraction pattern of the powder is shown in FIG.
Comparative Example I-4
After obtaining a white powder in exactly the same manner as in Comparative Example I-2, the white powder was heated from room temperature to 640 ° C. in a heating and firing furnace under a nitrogen atmosphere and held at 640 ° C. for 1 hour. By cooling to room temperature, an off-white powder was obtained.
[0203]
As a result of X-ray diffraction measurement, the obtained powder was confirmed to be a ZnO crystal. The X-ray diffraction pattern of the powder is shown in FIG.
Moreover, the coating material of the following composition was created using the obtained powder, and it formed into a film on the glass substrate, and obtained the coated article (II-R4C) with which the film | membrane with a thickness of 3.1 micrometers was formed. The obtained coated product (II-R4C) is cloudy with a high haze value of 78%, has low transparency to visible light, and exhibits shielding properties against ultraviolet rays (UV), but has a heat ray shielding property. Was not shown. The spectral transmittance curve of the coated product (II-R4C) is shown in FIG.
[0204]
(Paint composition)
10 parts by weight of powder
90 parts by weight of 2-butoxyethanol
Acrylic resin solution * 50 parts by weight
* Alloset 5247 (Nippon Shokubai, 45 wt% solid content) diluted with toluene to a solid content concentration of 20 wt%
(Painting method)
The powder was added to 2-butoxyethanol and mixed, and then subjected to a dispersion treatment with an ultrasonic homogenizer for 20 minutes. Then, an acrylic resin solution was added, and stirring was performed for 2 hours. Furthermore, the coating material was obtained by performing a dispersion | distribution process for 20 minutes with an ultrasonic homogenizer.
[0205]
Comparative Example I-5
A white powder was obtained in exactly the same manner as Comparative Example I-3. The white powder was heated from room temperature to 640 ° C. in a heating and firing furnace in a nitrogen atmosphere, held at 640 ° C. for 1 hour, and then cooled to room temperature to obtain a slightly greenish powder.
As a result of X-ray diffraction measurement, the obtained powder was confirmed to be a ZnO crystal. The X-ray diffraction pattern of the powder is shown in FIG.
In FIG. 3, the horizontal axis represents the diffraction angle (2θ) [unit: °], and the vertical axis represents the intensity [cps].
[0206]
In addition, using the obtained powder, a paint was prepared in the same manner as in Comparative Example I-4, and a coating was formed on a glass substrate to form a film having a thickness of 3.2 μm (II -R5C) was obtained. The obtained coated product (II-R5C) was clouded with a high haze value of 83%, had low transparency to visible light, and exhibited UV shielding properties but did not exhibit heat ray shielding properties. . The spectral transmittance curve of the coated product (II-R5C) is shown in FIG.
[Manufacturing examples of paint and painted products]
Example II-1
The dispersion (DI-1) obtained in Example I-1 was concentrated in an evaporator under reduced pressure at a bath temperature of 130 ° C. so that the fine particle concentration was 10% by weight. DI-1C) was obtained.
[0207]
Next, a coating material was prepared using an acrylic resin solution (Alloset 5210; manufactured by Nippon Shokubai Co., Ltd., solid content: 45% by weight) as a binder component.
That is, the acrylic resin solution was diluted with toluene, and 100 parts by weight of the concentrated dispersion (DI-1C) was added to and mixed with 50 parts by weight of the resin solution having a resin concentration of 20% by weight. II-1) 150 weight part was obtained.
Example II-2
The dispersion (DI-2) obtained in Example I-2 was concentrated in an evaporator under reduced pressure at a bath temperature of 130 ° C. to a fine particle concentration of 10% by weight. DI-2C) was obtained.
[0208]
Next, the obtained concentrated dispersion (DI-2C) is separated into a fine particle sediment and a solvent (supernatant) by a centrifugal separation operation, and the fine particle sediment is added to ion-exchanged water and dispersed by a sand mill. Thus, an aqueous dispersion (DI-2W) in which fine particles were finely dispersed at 10% by weight was obtained.
After adding 100 parts by weight of an aqueous dispersion (DI-2W) to 100 parts by weight of an aqueous solution containing 10% by weight of a vinyl resin (Poval R2105, manufactured by Kuraray Co., Ltd.), the mixture is stirred to obtain 5 parts each of fine particles and binder. A paint (II-2) containing wt% was obtained.
[0209]
Example II-3
The dispersion (DI-1) obtained in Example I-1 was concentrated in an evaporator under reduced pressure at a bath temperature of 130 ° C. so that the fine particle concentration was 10% by weight. DI-1C) was obtained.
On the other hand, in a four-necked flask equipped with a reflux condenser, a stirrer, and a thermometer, 24 parts by weight of isopropyl alcohol, 16 parts by weight of water, and 0.005 part by weight of 35% hydrochloric acid were sequentially added. After adding parts by weight and 30 parts by weight of tetraethoxysilane, the temperature was raised to 80 ° C. and reacted at 80 ° C. for 2 hours, followed by cooling. The obtained mixture (x) was a homogeneous solution having a nonvolatile content of 17.0% by weight.
[0210]
Next, 12 parts by weight of the mixture (x) was added and mixed while stirring 80 parts by weight of the concentrated dispersion (DI-1C) to obtain a paint (II-3).
Example II-4
In the same manner as in Example II-2, an aqueous dispersion (DI-2W) in which fine particles were finely dispersed at 10% by weight was obtained from the dispersion (DI-2) obtained in Example I-2. It was.
100 parts by weight of an aqueous dispersion (DI-2W) was added to 20 parts by weight of an aqueous solution containing 10% by weight of a vinyl resin (Poval 205, manufactured by Kuraray Co., Ltd.), and 1.23 of copper acetate monohydrate was further added. After adding 20 parts by weight of an aqueous solution containing parts by weight, the mixture was stirred and subjected to ultrasonic irradiation to obtain paint (II-4).
[0211]
By applying the coating materials (II-1) to (II-4) obtained in Examples II-1 to 4 to various substrates with a bar coater and drying, a coated product (II- 1C1), (II-1C2), (II-2C), (II-3C), and (II-4C) were produced.
Table 4 shows the film forming conditions, the film thickness of the obtained coated product, and the optical properties.
The obtained coated products were all uniform and were films that shielded ultraviolet rays and heat rays while being excellent in transparency to visible light.
As a result of measuring the solar radiation transmittance and the visible light transmittance of the coated products (II-1C1) and (II-1C2), it was confirmed that the film was transparent and had a heat shielding property.
[0212]
The coated product (II-3C) has a surface hardness of 6H in pencil hardness and a surface resistance of 1 × 10.⁹ Ω / □ and antistatic level were confirmed.
Comparative Example II-1
In Example II-1, Example II-1 was different from Example II-1 except that the dispersion (DI-R1) obtained in Comparative Example I-1 was used instead of using the dispersion (DI-1). Similarly, paint (II-R1) was prepared. By applying the coating material (II-R1) on the same glass substrate as used in the coated products II-1 and 2 in the same manner as in the coated products II-1 and 2, and drying, a film thickness of 6.3 μm is obtained. A coated product (II-R1C) having a ZnO fine particle-containing film was obtained. The obtained coated product (II-R1C) effectively shielded ultraviolet rays but did not show a shielding effect against heat rays.
[0213]
The spectral transmittance curves of the coated articles (II-1C1) and (II-1C2) obtained in Examples and the coated article (II-R1C) obtained in Comparative Example (II-1) are shown in FIG. FIG. 1 also shows the spectral transmittance curve of the glass substrate used. In FIG. 1, the horizontal axis represents the wavelength (nm) of incident light, and the vertical axis represents the transmittance (%).
Example II-5
In the same manner as in Example II-2, an aqueous dispersion (DI-2W) in which fine particles were finely dispersed at 10% by weight was obtained from the dispersion (DI-2) obtained in Example I-2. It was.
A coating material (II-5) was prepared by mixing 100 parts by weight of the aqueous dispersion and 20 parts by weight of an acrylic emulsion (Nippon Shokubai Acreset RE-285E, solid content 50% by weight) as a binder resin. Polyester fibers having a basis weight of 4.0 g / m @ 2 were obtained by immersing polyester fibers in the paint and drying. The obtained fiber cuts ultraviolet rays and heat rays and was excellent in transparency.
[0214]
Comparative Example II-5
In the same manner as in Example II-2, an aqueous dispersion in which fine particles were finely dispersed at 10% by weight was obtained from the dispersion (DI-R1) obtained in Comparative Example I-1.
A coating material (II-R5) was prepared by mixing 100 parts by weight of the aqueous dispersion and 20 parts by weight of an acrylic emulsion (Nippon Shokubai Acreset RE-285E, solid content 50% by weight) as a binder resin. A polyester fiber having a basis weight of 4.2 g / m @ 2 was obtained by immersing the polyester fiber in the paint and drying it. The obtained fiber cuts ultraviolet rays and was excellent in transparency, but did not have a shielding effect against heat rays.
[0215]
Example II-6
In the same manner as in Example II-2, an aqueous dispersion (DI-2W) in which fine particles were finely dispersed at 10% by weight was obtained from the dispersion (DI-2) obtained in Example I-2. It was.
A coating material (II-5) was prepared by mixing 100 parts by weight of the aqueous dispersion and 30 parts by weight of an acrylic emulsion (Nippon Shokubai Co., Ltd. Acreset R ES-285E, solid content 50% by weight) as a binder resin. Cotton fibers were immersed in the paint and dried to obtain polyester fibers having a fine particle weight of 3.0 g / m2. The obtained fiber cuts ultraviolet rays and heat rays and was excellent in transparency.
[0216]
Example II-7
10 parts by weight of the fine particle powder (PI-2-1) obtained in Example I-2 was melt-kneaded with 90 parts by weight of PP (polypropylene) pellets to obtain 10 parts by weight of the fine particle powder (PI-2-1). % PP pellets (A) were obtained.
Next, a two-layer PP film was obtained using an extruder equipped with a multilayer feedblock die. That is, PP pellets (B) not containing fine particle components are supplied to the main extruder, melted at 220 ° C., PP pellets (A) are supplied to the sub-extruder, melted at 180 ° C., and the discharge amount of each extruder is set. By adjusting, a laminated sheet composed of a PP (A) layer (containing fine particle powder) and a PP layer (B) is obtained, and further, by stretching the obtained sheet, a PP (A) layer having a thickness of 8 μm is obtained. An OPP film (biaxially stretched polypropylene film) in which a PP layer (B) having a thickness of 20 μm was laminated was obtained.
[0217]
The film is a multilayer film having a thin film layer (A) in which fine particles are uniformly and highly dispersed, and has excellent ultraviolet light shielding properties and heat ray shielding properties while being excellent in visible light transmittance.
Example II-8
PET pellets (A) containing 50% by weight of fine particle powder (PI-6) by melt-kneading 50 parts by weight of fine particle powder (PI-6) obtained in Example I-6 and 50 parts by weight of PET pellets (A) )
Next, a two-layer PET film was produced using the same extruder and stretching machine as used in Example II-7. That is, PET pellets (B) containing no fine particle component are supplied to the main extruder, melted at 310 ° C., PET pellets (A) are supplied to the sub-extruder, melted at 280 ° C., and the discharge amount of each extruder is set. By adjusting, a laminated sheet composed of a PET (A) layer (containing fine particle powder) and a PET layer (B) is obtained, and by further stretching the obtained sheet, a PET (A) layer having a thickness of 2 μm is obtained. A PET film on which a PET (B) layer having a thickness of 20 μm was laminated was obtained.
[0218]
The film is a multilayer film containing a thin film layer (A) in which fine particles are uniformly and highly dispersed, and has excellent ultraviolet light shielding properties and heat ray shielding properties while being excellent in visible light transmittance.
[Production example of molded product containing fine particles]
Example III-1
A melt in which 0.5% by weight of fine particles are uniformly dispersed by mixing and kneading 5 parts by weight of the fine particle powder (PI-6) obtained in Example I-6 and 995 parts by weight of polycarbonate resin pellets. Was obtained by subsequent extrusion molding to obtain a polycarbonate plate having a thickness of 2.0 mm. The obtained polycarbonate plate was highly dispersed in fine particles, had a total light transmittance of 85% or more, had excellent visible light transmittance, and exhibited ultraviolet shielding properties and heat ray shielding properties.
[0219]
Example III-2
25 parts by weight of the fine particle powder (PI-7) obtained in Example I-7 and 475 parts by weight of methacrylic resin pellets are mixed and melt-kneaded to obtain a melt in which 5% by weight of fine particles are uniformly dispersed. Subsequently, a methacrylic resin sheet having a thickness of 2 mm was obtained by extrusion molding. The obtained sheet has a high dispersion of fine particles, a total light transmittance of 83%, a haze of 86%, a high visible light transmittance and an excellent light diffusing transmittance, and also an ultraviolet ray prevention effect and a heat ray shielding effect. It was excellent.
Comparative Example III-1
In Example III-1, Example III was used except that 5 parts by weight of zinc oxide fine particles (Zinc Hana 1 manufactured by Sakai Chemical) obtained by the French method were used instead of the powder (PI-6). In the same manner as in Example 1, a 2 mm thick polycarbonate plate containing 0.5% by weight of fine particles was obtained. The obtained polycarbonate plate contained a non-uniform state in which fine particles were secondarily aggregated, and had no transparency and became cloudy compared to that obtained in Example III-1, and had an ultraviolet shielding property. Not only was it low, it did not have a shielding performance against heat rays.
[0220]
Example III-3
Polyester composition in which 2 parts by weight of fine particle powder (PI-6) obtained in Example I-6 and 98 parts by weight of polyester resin pellets are mixed and melt-kneaded to uniformly disperse 2% by weight of zinc oxide fine particles. After being formed into a sheet by extrusion molding, it was further stretched to obtain a polyester film having a thickness of 40 μm. The film is a film in which fine particles are uniformly highly dispersed, has excellent visible light transmittance, and has excellent ultraviolet shielding properties and heat ray shielding properties.
Comparative Example III-2
In Example III-3, Example III was used except that 2 parts by weight of zinc oxide fine particles (Zinc Hua 1 manufactured by Sakai Chemical) obtained by the French method were used instead of the powder (PI-6). As in -3, a 40 μm thick polyester film containing 2% by weight of fine particles was obtained. The obtained film was contained in a state in which fine particles were secondarily aggregated. Therefore, the effect of preventing ultraviolet rays was low, and there was no transparency and white turbidity. Moreover, it did not have the shielding performance with respect to a heat ray.
[0221]
As a result of observing the cross sections of the films obtained in Example III-3 and Comparative Example III-2 with a transmission electron microscope, the film obtained in Example III-3 was substantially homogeneous in which fine particles were highly dispersed. The film obtained in Comparative Example III-2 is not only good in surface properties such as coarse projections on the film surface because the fine particles are aggregated, but also the fine particles and the matrix PET Since there is a gap between them, the wear resistance and scratch resistance are insufficient.
Example III-4
In the same manner as in Example III-3, a polyester composition containing 2% by weight of fine particles (PI-6) was obtained, and then polyester fiber was obtained by melt spinning. The fiber is a fiber in which fine particles are uniformly and highly dispersed, has transparency, and has excellent ultraviolet shielding properties and heat ray shielding properties.
[0222]
Comparative Example III-3
Example III-4 and Example III-4 except that zinc oxide fine particles (Zinc Hua 1 manufactured by Sakai Chemical) obtained by the French method were used instead of the fine particle powder (PI-6) in Example III-4 Similarly, a polyester fiber containing the zinc oxide fine particles was obtained. The obtained fiber was contained in a state in which fine particles were secondarily aggregated. Therefore, the effect of preventing ultraviolet rays was low, and there was no transparency and white turbidity. Moreover, it did not have the shielding performance with respect to a heat ray.
[Cosmetics production example]
Example IV-1
In the same manner as in Example II-2, an aqueous dispersion (DI-1W) in which fine particles were finely dispersed at 10% by weight was obtained from the dispersion (DI-1) obtained in Example I-1. It was. A cosmetic (O / W type cream) having the following composition was prepared by blending the aqueous dispersion.
[0223]
<Composition>
(Water phase)
(A) Fine particle aqueous dispersion 50 parts by weight
(B) 5 parts by weight of propylene glycol
(C) Glycerin 10 parts by weight
(D) 0.2 part by weight of potassium hydroxide
(Oil phase)
(E) Cetanol 5 parts by weight
(F) Liquid paraffin 5 parts by weight
(G) 3 parts by weight of stearic acid
(H) 2 parts by weight of isostearyl myristate
(I) 2 parts by weight of glyceryl monostearate
Components (a) to (d) were stirred and mixed and maintained at 80 ° C. to prepare an aqueous phase part. On the other hand, an oil phase part was prepared by uniformly mixing components (e) to (i) and maintaining the mixture at 80 ° C. The oil phase part was added to the water phase part, stirred, emulsified with a homomixer, and then cooled to room temperature to produce a cream. The obtained cream was excellent in transparency, but also excellent in ultraviolet ray preventing effect and heat ray shielding effect.
[0224]
Comparative Example IV-1
In Example IV-1, 5 parts by weight of zinc oxide fine particle powder (Zinc Hua 1; manufactured by Sakai Chemical Co., Ltd.) obtained by the French method in place of the water acid body (DI-1W) at a ratio of 10% by weight. A cream was produced in the same manner as in Example IV-1, except that 50 parts by weight of the hydrous acid contained was used.
The obtained cream had insufficient dispersibility of the fine particles, so that the effect of preventing ultraviolet rays was insufficient, and the whiteness was high, so that the transparency was not satisfactory. Moreover, it did not have a shielding property against heat rays.
[Paper production example]
Example V-1
In the same manner as in Example II-2, an aqueous dispersion (DI-2W) in which fine particles were finely dispersed at 10% by weight was obtained from the dispersion (DI-2) obtained in Example I-2. It was.
[0225]
Next, a filter paper for quantitative determination (manufactured by Toyo Paper Co., Ltd .: product number 5C) was beaten with a Niagara type beater, and the aqueous dispersion was added to pulp prepared to 400 ml of Canadian Standard Freeness. The mixture was added and mixed so as to be in weight percent. Next, the obtained pulp slurry was diluted to a solid content concentration of 0.1% by weight, dehydrated by a tapi sheet machine, and pressed to make a basis weight of 75 g / m2. Subsequently, paper containing 1% by weight of fine particles was obtained by drying at 100 ° C. with a rotary dryer. The obtained paper has a good dispersion state of fine particles, and therefore has excellent ultraviolet shielding properties, has a heat ray shielding effect, and has excellent surface flatness. Furthermore, dust and the like are difficult to adhere.
[0226]
Comparative Example V-1
Water containing 10% by weight of zinc oxide fine particle powder (Zinc Hua 1 manufactured by Sakai Chemical) obtained by the French method in place of the water acid body (DI-2W) in Example V-1 A paper was produced in the same manner as in Example V-1, except that the acid body was used. The obtained paper contains fine particles in a secondary aggregated state, and therefore has a poor surface property, such as a low UV protection effect, and the presence of coarse protrusions based on the aggregated particles on the surface. there were. In addition, it has no heat ray shielding property and easily adheres dust and the like.
[0227]
[Table 1]

[0228]
[Table 2]

[0229]
[Table 3]

[0230]
[Table 4]

[0231]
Example I-11
A zinc-containing solution (A11) was obtained in the same manner as in Example I-1, except that the types and amounts of the raw materials in the zinc-containing solution (A1) in Example I-1 were changed as shown in Table 5. In addition, the amount of 2-butoxyethanol charged in Example I-1 was 20 kg, and instead of adding lauric acid, the compound shown in Tables 5 and 7 was added in the amount shown in Table 5 except that Example I was added. In the same manner as in Example 1, a dispersion (DI-11) was obtained.
Table 9 shows the physical properties of the resulting dispersion and fine particles.
Example I-12
The reaction was carried out in the same manner as in Example I-1 except that the reaction raw materials were changed as shown in Table 5 to obtain a dispersion (DI-12pre) in which fine particles were dispersed, and then the compounds shown in Tables 5 and 7 were listed. After the amount shown in 5 is added, the dispersion is charged into a stainless steel pressure vessel (autoclave) that can be heated with a heat medium, the inside of the system is purged with nitrogen, and the nitrogen pressure at room temperature is 20 kgf / cm 2. After charging, the temperature of the solution was raised to 220 ° C. while stirring, and kept at the same temperature for 5 hours, and then allowed to cool to obtain a dispersion (DI-12).
[0232]
Table 9 shows the physical properties of the resulting dispersion and fine particles.
Example I-13
The reaction was carried out in the same manner as in Example I-1 except that the reaction raw materials were changed as shown in Table 5. After obtaining a dispersion (DI-13pre) in which fine particles were dispersed, Table 5 was obtained while stirring at room temperature. After the amount of the compound shown in Table 7 was added in the amount shown in Table 5, the dispersion (DI-13) was obtained by stirring for 3 hours.
Table 9 shows the physical properties of the resulting dispersion and fine particles.
Examples I-14 to I-19
A reaction was performed in the same manner as in Example I-1 except that the reaction raw materials were changed as shown in Tables 5 and 6, to obtain dispersions (DI-14pre to DI-19pre) in which fine particles were dispersed, and heat treatment was performed. The compound (DI-14 to the dispersion) was added in the same manner as in Example I-13 except that the compounds added later were changed to those shown in Tables 5 to 8 and the treatment conditions after the addition were changed to the contents shown in Tables 5 and 6. DI-19) was obtained.
[0233]
Table 9 shows the physical properties of the resulting dispersion and fine particles.
Example I-20
A reaction was carried out in the same manner as in Example I-1 except that the reaction raw materials were changed as shown in Table 6 to obtain a dispersion (DI-20) in which fine particles were dispersed.
Table 9 shows the physical properties of the resulting dispersion and fine particles.
[0234]
[Table 5]

[0235]
[Table 6]

[0236]
[Table 7]

[0237]
[Table 8]

[0238]
[Table 9]

[0239]
<Synthesis of various solvent dispersions>
Example I-11 (2)
After the dispersion (DI-11) obtained in Example I-11 was centrifuged, the precipitate was added to and mixed with toluene, and the resulting mixture was stirred to give a toluene dispersion (DI-11 with a metal oxide equivalent concentration of 20 wt%). -T) was obtained.
The toluene dispersion (DI-11-T) had a dispersion average particle size of 0.03 μm and was excellent in sedimentation stability (evaluation ○). It was also confirmed that the dispersion average particle diameter measured one month after the synthesis was 0.03 μm and no change.
[0240]
The dispersion particle size of the dispersion was measured with a centrifugal sedimentation type particle size distribution measuring apparatus using the dispersion as a main solvent (toluene in the case of DI-11-T) in the dispersion, and the sedimentation stability. Is an evaluation of the sedimentation state when the dispersion is allowed to stand at a constant temperature of 30 ° C. for one month according to the following criteria.
Sedimentation stability ○: There is no sedimentation deposit and no sedimentation is observed.
Δ: Sedimentation deposits are slightly generated.
X: A large amount of sediment is generated.
Table 10 shows the physical properties of the resulting dispersion.
[0241]
Example I-2 (2)
On the other hand, after centrifuging the dispersion (DI-2) obtained in Example I-2, the precipitate was added to and mixed with toluene and stirred, and the toluene dispersion (DI-2 with a metal oxide equivalent concentration of 20 wt%) was stirred. -T) was obtained.
The toluene dispersion (DI-2-T) had a dispersion average particle size of 1.51 μm and poor sedimentation stability (evaluation ×).
Therefore, it is clear that the fine particles in the dispersion (DI-11) and the toluene dispersion (DI-11-T) obtained in Example I-11 were surface-modified with the compound S1. .
[0242]
Table 10 shows the physical properties of the resulting dispersion.
Example I-11 (3)
The dispersion (DI-11) obtained in Example I-11 was heated under reduced pressure with an evaporator to remove the solvent until it became a paste, and then mixed with ethyl acetate and stirred to obtain fine particles (metal oxide). Product conversion) An ethyl acetate dispersion (DI-11-EA) having a concentration of 20 wt% was obtained.
Table 10 shows the physical properties of the resulting dispersion.
Examples I-12 (2) to I-19 (2)
Regarding the dispersions (DI-12 to DI-19) obtained in Examples I-12 to I-19, a paste-like material was obtained in the same manner as in the above (DI-11-EA). Various solvent dispersions were obtained by mixing the solvents shown in (1).
[0243]
Table 10 shows the physical properties of the resulting dispersion.
Example I-20 (2)
From the dispersion (DI-20), a paste-like product was obtained in the same manner as (DI-11-EA) above, and then n-butanol was mixed to obtain a n-butanol dispersion (DI-20-BuOH). )
Table 10 shows the physical properties of the resulting dispersion.
[0244]
[Table 10]

[0245]
<Plasticizer dispersion>
Example I-21
After adding and mixing 400 parts by weight of di-2-ethylhexyl phthalate as raw material B to 500 parts by weight of the dispersion (DI-20) obtained in Example I-20 as raw material A, the resulting dispersion was decompressed. The temperature in the dispersion was raised to 150 ° C., and the solvent in the dispersion was distilled off at the same temperature, followed by filtration through a stainless steel wire mesh to obtain a fine particle concentration (converted to metal oxide) of 20.1% by weight of diphthalic acid. A 2-ethylhexyl dispersion (DI-20-PL) was obtained.
[0246]
It was confirmed by gas chromatography that the solvent component in the dispersion was <1% by weight.
Further, the obtained dispersion had a bluish transparency and excellent sedimentation stability. Table 12 shows the physical properties of the dispersion.
Examples I-22 to I-25
Various dispersions were obtained in the same manner as in Example 1-21, except that the types and mixing ratios of raw materials A and B in Example I-21 were changed as shown in Table 11.
In the dispersion obtained in each example, it was confirmed that the content of the solvent component contained in the raw material A and the raw material B was 1% by weight or less.
[0247]
Table 12 shows the physical properties of each dispersion.
[0248]
[Table 11]

[0249]
[Table 12]

[0250]
<Paints and coated products>
Example II-9
From the n-butanol dispersion (DI-20-BuOH) obtained in Example I-20, an acrylic resin solution (Alloset 5858, manufactured by Nippon Shokubai Co., Ltd., solid content 60% by weight) was used as a binder component to prepare a coating material. It was adjusted.
That is, 17 parts by weight of the acrylic resin solution, 50 parts by weight of the dispersion (DI-20-BuOH) and 13 parts by weight of n-butanol were mixed, stirred, and then subjected to a dispersion treatment with an ultrasonic homogenizer to obtain a paint ( II-9) 80 parts by weight were obtained.
[0251]
Example II-10
In the same manner as in Example II-2, an aqueous dispersion (DI) in which fine particles were finely dispersed at 10% by weight from the n-butanol dispersion (DI-20-BuOH) obtained in Example I-20. −20 W).
100 parts by weight of an aqueous dispersion (DI-20W) is added to 100 parts by weight of an aqueous solution containing 10% by weight of a vinyl-based resin (Poval 205, manufactured by Kuraray Co., Ltd.), and then stirred and dispersed with an ultrasonic homogenizer. As a result, paint (II-10) was obtained.
Example II-11
While stirring 100 parts by weight of the n-butanol dispersion (DI-20-BuOH) obtained in Example I-20, 150 parts by weight of the mixture (x) (synthesized in Example II-3) was added and mixed. Then, the mixture was stirred and dispersed with an ultrasonic homogenizer to obtain paint (II-11).
[0252]
Using the obtained paints (II-9) to (II-11), the various substrates shown in Table 13 were applied by a bar coater and dried to give coated products (9C), (10C), ( 11C) was produced. Table 13 shows the physical properties of the obtained coated product.
[0253]
[Table 13]

[0254]
Examples II-12 to II-24
Using various dispersions and various binders obtained in Examples I-11 to I-20 shown in Tables 14 and 15, various solvent-based paints were synthesized, and the base materials shown in Tables 16 to 18 were used. Each coated product was obtained by coating.
The physical properties of each coated product are shown in Tables 16 and 17.
The pencil hardness of each of the coated articles 11C, 16C, 18C, and 20C obtained in Examples II-11, 16, 18, and 20 is 11C: HB, 16C:> 9H, 18C: 7H, 20C: 3H, Moreover, it was excellent in wear resistance and scratch resistance.
[0255]
Also, the coated products 13C and 14C obtained in Examples II-13 and 14, respectively, were excellent in oxygen and water vapor barrier properties.
In addition, the coated product 24C obtained in Example II-24 was a film having a coated surface with excellent adhesion to glass, polycarbonate and the like.
[0256]
[Table 14]

[0257]
[Table 15]

[0258]
[Table 16]

[0259]
[Table 17]

[0260]
[Table 18]

[0261]
<Resin composition, molded body>
Example III-5
50 parts by weight of di-2-ethylhexyl phthalate dispersion (DI-20-PL) obtained in Example I-21 and 100 parts by weight of polyvinyl chloride resin (PVC) were melt-mixed at 160 ° C. A PVC compound was produced. The compound was subjected to extrusion molding to obtain a vinyl chloride film having a thickness of 50 μm and containing fine particles dispersed therein.
The obtained film was excellent in transparency to visible light, and effectively shielded ultraviolet rays and heat rays.
[0262]
Table 19 shows the physical properties of the obtained film.
Examples III-6 to III-9
Using various dispersions obtained in Examples I-22 to I-25 as raw material for fine particles, various resin films containing fine particles dispersed therein were produced. That is, after obtaining various resin compounds by heating and mixing the dispersion raw material, the resin raw material, and if necessary, di-n-octyl phthalate shown in Table 19 in the ratio shown in Table 19, Various films were obtained by molding the compound.
Each of the obtained films was excellent in transparency to visible light, and effectively shielded ultraviolet rays and heat rays. Table 19 shows the physical properties of the obtained films.
[0263]
The film obtained in Example III-7 was excellent in flame retardancy.
Comparative Example III-4
Example III-5 was the same as Example III-5 except that the fine particle dispersion was not used and di-n-octyl phthalate and polyvinyl chloride resin were used in the proportions shown in Table 19. Thus, a PVC compound was produced, and a film was further produced.
The obtained film was excellent in transparency to visible light, but did not shield ultraviolet rays and heat rays. Table 19 shows the physical properties of the obtained film.
[0264]
[Table 19]

[0265]
【The invention's effect】
The zinc oxide-based fine particles of the present invention comprise at least one additive element selected from the group consisting of a group IIIB metal element and a group IVB metal element and zinc as a metal component, and the content of zinc is that of the metal component. Expressed by the ratio of the number of zinc atoms to the total number of atoms, it is 80 to 99.9%, and at least the main component of the metal oxide coprecipitate exhibiting zinc oxide (Zn0) crystallinity as seen from X-ray diffraction Therefore, in addition to the ultraviolet shielding property inherent in zinc oxide, it has infrared shielding properties including heat rays and conductivity. In addition, since fine particles having these properties can be produced even at low temperatures (for example, 200 ° C. or lower), they can be used as fine particles having excellent dispersibility in which secondary aggregation is suppressed.
[0266]
When the zinc oxide fine particles of the present invention contain indium and / or aluminum as an additive element constituting the metal oxide coprecipitate, the zinc oxide fine particles are excellent in heat ray shielding and conductivity, and particularly in the case of containing indium, the heat ray shielding and conductivity. It will be even better.
The zinc oxide fine particles according to the present invention are excellent in transparency when they are composed of only single particles comprising the metal oxide coprecipitate. In this case, the size of the single particle is preferably in the range of an average particle diameter of 0.001 to 0.1 μm, and more preferably in the range of 0.001 to 0.05 μm when viewed at the shortest part. Single particles having an average particle diameter in the above range are ultrafine particles and are particularly excellent in transparency, and therefore can be used as raw material particles for transparent ultraviolet / heat ray shielding films, conductive films, and antistatic films. In this application, it is preferable to use a single particle dispersed in the above dispersion medium.
[0267]
When the zinc oxide fine particles according to the present invention are secondary particles in which the single particles are primary particles and the primary particles are aggregated, they are suitable for applications requiring light diffusibility. In particular, when the secondary particles are hollow particles comprising only the outer shell, the light diffusibility is superior. In this case, the relationship between the size of the single particles and the zinc oxide-based fine particles that are aggregates thereof is preferably such that the ratio of the shortest particle diameter of the single particles to the shortest particle diameter of the fine particles is 1/10 or less. . The average particle size of the zinc oxide-based fine particles is preferably in the range of 0.001 to 10 μm.
The zinc oxide-based fine particles according to the present invention further have the advantage of being particularly excellent in affinity and dispersibility for the resin when the single particles are combined with a polymer. As in the second case, when the composite particles of single particles and polymer are hollow, the light diffusibility is excellent. In this case, the content of the polymer is not particularly limited, but is in the range of 1 to 90% by weight based on the total amount of the single particles and the polymer. The average particle size of the zinc oxide-based fine particles is preferably in the range of 0.001 to 10 μm.
[0268]
Aggregates are suitable for applications requiring light diffusivity, and for applications requiring transparency, single particles are combined with a polymer, and single particles are not localized in fine particles. Fine particles present in a homogeneously dispersed state are preferred. These fine particles are excellent in affinity and dispersibility for organic solvents and resins. For example, it is easy to disperse in a resin molded body, disperse in a paint, or blend in cosmetics.
The method for producing zinc oxide-based fine particles according to the present invention includes a zinc source and a monocarboxylic acid in at least an alcohol medium and at least selected from the group consisting of a group IIIB metal element and a group IVB metal element Since the fine particles are generated by maintaining at a temperature of 100 ° C. or higher in the presence of a compound containing one kind of additive element, the above-described zinc oxide-based fine particles of the present invention can be obtained with high productivity.
[0269]
Zinc oxide fine particles according to the present inventionTheManufacturingDoMethodAsIs a mixture of a zinc source and a monocarboxylic acid mixed with water, and is added to and mixed with a medium comprising at least an alcohol heated to 100 ° C. or higher, whereby at least a part of the water and / or the monocarboxylic acid is added. It is preferable to include a step of evaporating and removing. The zinc source and monocarboxylic acid should be dissolved in water and used. However, the crystallinity of the fine particles is prevented from being impaired, and secondary agglomeration is prevented to make the size and shape of the fine particles uniform. This is because water and monocarboxylic acid are preferably removed out of the system as much as possible. Although fine particles may be generated during addition of the mixture to the heating medium, the generation is usually performed by keeping the reaction system at a temperature of 100 ° C. or higher after that. In the meantime, water and monocarboxylic acid are usually removed by evaporation.
[0270]
the aboveIn the manufacturing method of zinc oxide-based fine particles, when containing indium and / or aluminum as an additive element constituting a metal oxide coprecipitate, heat ray shielding and conductivity are excellent, and particularly when containing indium, heat ray shielding and conductivity are excellent. More excellent zinc oxide-based fine particles.
the aboveWhen the zinc source is at least one selected from the group consisting of zinc oxide, zinc hydroxide and zinc acetate, the zinc oxide crystal formation reaction during the heating process is inhibited. It is easy to control the size and shape of crystals and fine particles.the aboveWhen the monocarboxylic acid is a saturated fatty acid having a boiling point of 200 ° C. or lower under normal pressure, the amount of monocarboxylic acid in the reaction system can be easily controlled and the zinc oxide crystallinity is exhibited. It is easy to strictly control the precipitation reaction of the metal oxide coprecipitate.
[0271]
the aboveIn the method for producing zinc oxide-based fine particles, a zinc source and a monocarboxylic acid are added in a medium comprising at least an alcohol and at least one selected from the group consisting of a group IIIB metal element and a group IVB metal element When maintaining at a temperature of 100 ° C. or higher in the presence of a compound containing an element, (1) a polymer is allowed to coexist in this system, or (2) a carboxyl group, an amino group, a quaternary ammonio group, an amide in the molecule. Groups, imide bonds, alcoholic and / or phenolic hydroxyl groups, carboxylic acid ester bonds, urethane groups, urethane bonds, ureido groups, ureylene bonds, isocyanate groups, epoxy groups, phosphate groups, metal hydroxyl groups, metal alkoxy groups and sulfones Addition having at least one atomic group selected from the group consisting of acid groups, one or more, and a molecular weight of less than 1000 Or coexist things, ▲ 3 ▼ or coexistence of carbon dioxide and / or carbonate source, ▲ 4 ▼ sometimes or the coexistence of lactic acid source.
[0272]
When the system is kept at a temperature of 100 ° C. or higher, if a polymer is allowed to coexist, zinc oxide-based fine particles obtained by combining the single particles with the polymer are obtained.
When the system is maintained at a temperature of 100 ° C. or higher, if the compound having the specific functional group described above coexists, the surface treatment of the fine particles becomes possible and the particle size can be controlled.
When the system is kept at a temperature of 100 ° C. or higher, if carbon dioxide and / or a carbonic acid source is present, fine particles having excellent water dispersibility and fine (0.05 μm or less) are easily obtained.
When the system is maintained at a temperature of 100 ° C. or higher, if a lactic acid source is present, single particles made of a metal oxide coprecipitate are made primary particles, and secondary particles are formed by aggregating the primary particles. It is easy to obtain zinc oxide fine particles in the form of
[0273]
The coating composition of the present invention comprises the zinc oxide-based fine particles of the present invention and a binder component capable of forming a film that binds the zinc oxide-based fine particles, with respect to the total solid weight of both of them. Since the fine particles are contained in a proportion of 0.1 to 99% by weight and the binder component in a ratio of 1 to 99.9% by weight, it has an ultraviolet shielding ability and an infrared shielding ability including heat rays, and the conductivity is controlled. A painted product can be formed. In this case, the total solid weight of the zinc oxide-based fine particles and the binder component is preferably 1 to 80% by weight, and the remainder is preferably a solvent.
The coated product of the present invention comprises one base material selected from the group consisting of a resin molded product, glass and paper, and a coating film formed on the surface thereof. The zinc-based fine particles and the binder component for binding the zinc oxide-based fine particles are 0.1 to 99% by weight of the zinc oxide-based fine particles and 1 to 99.9% by weight of the binder component with respect to the total weight of both. Therefore, it has ultraviolet shielding ability and infrared shielding ability including heat rays, and the conductivity is controlled. In this case, the resin molded product is, for example, at least one selected from the group consisting of a plate, a sheet, a film, and a fiber.
[0274]
The resin composition of the present invention comprises the above-described zinc oxide-based fine particles of the present invention and a resin capable of forming a continuous phase in which the zinc oxide-based fine particles are dispersed, with respect to the total solid weight of the two. Since the zinc-based fine particles are contained in a proportion of 0.1 to 99% by weight and the resin in a proportion of 1 to 99.9% by weight, they have ultraviolet shielding ability and infrared shielding ability including heat rays, and the conductivity is controlled. A resin molded product can be formed.
Since the resin molded product of the present invention is obtained by molding the resin composition of the present invention into any shape selected from the group consisting of a plate, a sheet, a film and a fiber, It has infrared shielding ability including heat rays, and conductivity is controlled.
[Brief description of the drawings]
FIG. 1 is a diagram showing a spectral transmittance curve of a coated product.
FIG. 2 is a diagram showing an X-ray diffraction pattern of powder.
FIG. 3 shows an X-ray diffraction pattern of powder.
FIG. 4 is a diagram showing a spectral transmittance curve of a coated product.

Claims (1)

At least one additive element selected from the group consisting of Group IIIB metal elements and Group IVB metal elements and zinc are used as metal components, and the zinc content is the number of zinc atoms relative to the total number of atoms of the metal components. The metal oxide coprecipitate, which is expressed by a ratio of 80 to 99.9% and shows zinc oxide crystallinity as viewed from X-ray diffraction, has at least a main component, and has infrared shielding properties defined below. Zinc oxide-based fine particles that are 20% or more.
[Definition of infrared shielding properties of fine particles]
A dried film (coating amount: 3 g / m ^{2 in} terms of fine particles) is formed on the substrate to obtain a coated product. The light transmittance (%) for the wavelength of 2 μm of the dry film, that is, the value obtained by subtracting the light transmittance (%) for the wavelength of 2 μm of the coated product from the light transmittance (%) of the base material for the wavelength of 2 μm, It is defined as the infrared shielding property of fine particles.
Infrared shielding property of fine particles (%) = [light transmittance (%) of substrate to wavelength 2 μm] − [light transmittance (%) of coated product to wavelength 2 μm]

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