JP5082179B2 - Silica-coated mixed crystal oxide particles, process for producing the same, and cosmetics using the same - Google Patents

Description

【０１０５】
（式中、Ｒ¹は炭素数１〜４のアルキル基またはフェニル基、Ｒ²は水素基または炭素数1〜４のアルキル基またはフェニル基、Ｘは炭素数1〜４のアルコキシル基、ｎは０〜２の整数である。）
アルキルアルコキシシラン類を疎水性付与剤として表面処理する場合には、液相法が特に好ましい。
【０１０６】
すなわち、前記の方法に従って混晶酸化物粒子粒子のシリカ被覆を行った後、シリカ被覆混晶酸化物粒子粒子を分離することなく、疎水性付与剤を添加し、必要に応じて水、有機溶媒、アルカリを添加し、水／有機溶媒比が０．１〜１０の範囲で、かつ該アルキルアルコキシシランに由来する珪素濃度が０．０００１〜５モル／リットルの範囲である組成物を形成し、アルキルアルコキシシランの反応生成物を該シリカ被覆混晶酸化物粒子粒子の表面に選択的に沈着せしめることにより表面処理することができる。
この方法は、乾燥工程がないので、シリカ被覆混晶酸化物粒子の分散性や小さい一次粒径を損なうことがなく、中間の固体分離工程を省略でき、工業的に有利である。
【０１０７】
アルキルアルコキシシラン類による表面疎水化シリカ被覆混晶酸化物粒子の製造方法における疎水化組成物は、水／有機溶媒比が容量比で０．１〜１０の範囲であり、かつアルキルアルコキシシランに由来する珪素濃度が０．０００１〜５モル／リットルの範囲である。本組成物における珪素濃度、水、水／有機溶媒比、アルカリ、有機溶媒、温度、ｐＨ、及び分離精製工程に関しては、シリカ被膜形成組成物における記述がそのまま適用できる。また、本組成物は、シリカ被膜形成終了後の前記シリカ被膜形成用組成物に、珪酸を産生する前駆体の替りにアルキルアルコキシシラン類を添加することにより得られるが、必ずしも組成や条件を同一にする必要はない。例えば、珪酸を産生する前駆体に比べて該アルキルアルコキシシランの反応速度が異なる場合には、必要に応じてアルカリ、水、または溶媒を添加してもよく、上記の制限範囲内において実用的な反応速度を与えるような水／有機溶媒比、珪素濃度、ｐＨ、温度等の反応条件を選択することができる。
【０１０８】
疎水性付与剤の被覆量は、該疎水性付与剤が原料のシリカ被覆混晶酸化物粒子の表面を完全に被覆できる最小被覆量以上であればよい。この量は、下記式（２）
【０１０９】
【化２】

【０１１０】
によって算出することができる。疎水性付与剤の添加量が過多になるとシリカ被覆混晶酸化物粒子粒子の表面以外に析出する分が増えるので、経済的でない。
【０１１１】
疎水性付与剤の分子量、シリカ被覆混晶酸化物粒子粒子の比表面積に依存するので一概には決められないが、通常、シリカ被覆混晶酸化物粒子粒子に対して３０質量％以下が好ましく、さらに好ましくは２０質量％以下である。
【０１１２】
以下、本発明の第二の側面について説明する。本発明の化粧料に用いることができるシリカ被覆混晶酸化物粒子粒子のシリカ膜厚は、好ましくは０．１〜２５ｎｍである。０．１ｎｍ以下では、十分な光触媒活性の抑制効果がありかつ使用感が良好な化粧料が得られない場合があり、２５ｎｍ以上では、十分な紫外線遮蔽能を持つ化粧料が得られない場合があり、また経済的でない。
【０１１３】
本発明のシリカ被覆混晶酸化物粒子粒子のテトラリン自動酸化法による光触媒活性度は、６０Ｐａ／ｍｉｎ．以下であり、好ましくは５０Ｐａ／ｍｉｎ．以下、さらに好ましくは４５Ｐａ／ｍｉｎ．以下である。６０Ｐａ／ｍｉｎ．を越えると、十分な光触媒活性の抑制効果が得られず、保存安定性の良好な化粧料が得られない場合がある。
【０１１４】
本発明のシリカ被覆混晶酸化物粒子粒子のサンセットイエロ−法により測定される色素退色速度は、０．１以下であり、好ましくは、０．０６以下、さらに好ましくは０．０２以下である。０．１を越えると、光触媒活性の抑制効果が十分でなく、保存安定性の高い化粧料が得られない場合がある。
【０１１５】
本発明のシリカ被覆混晶酸化物粒子粒子の一次粒径は、好ましくは１〜１００ｎｍである。この範囲を外れると、良好な使用感と透明感、高い紫外線遮蔽能を合わせ持つ化粧料が得られない場合がある。なお、本発明でいう一次粒子、二次粒子は、久保輝一郎他編『粉体』ｐ５６〜６６，１９７９年発行、により定義されているものである。
【０１１６】
本発明のシリカ被覆混晶酸化物粒子粒子のガラス平板法により測定される粉体動摩擦係数は、０．５５以下であり、好ましくは０．５以下、さらに好ましくは０．４５以下である。０．５５を越えると、良好な使用感を有する化粧料が得られない場合がある。
【０１１７】
本発明のシリカ被覆混晶酸化物粒子は、一次粒径が小さく、凝集性が低くさらに分散性が良好なので、高い紫外線遮蔽能と高い可視光透過性を有する。また、緻密で実用的なシリカ被膜で被覆されているので、光触媒活性の抑制効果が高く、他の化粧料配合成分を変性させることが少なく、触感や滑り性が良好である。
【０１１８】
従って、シリカ被覆混晶酸化物粒子を配合することにより、保存安定性が良く、安全で、透明感及び使用感に優れた紫外線遮蔽用化粧料が得られる。表面疎水化シリカ被覆混晶酸化物粒子の場合は、油性化粧料、Ｗ／Ｏ乳化型の化粧料及び水・汗による化粧崩れが少ない撥水型化粧料に用いることが好ましい。
【０１１９】
以下に第三の側面について説明する。
本発明の化粧料は、前記のシリカ被覆混晶酸化物粒子を含有するとともに、化粧料に配合可能な通常の原料を使用し、通常の製法により製造することができる。
【０１２０】
本発明の化粧料は、粉末及び油分を含有するものであれば、特に限定されるものではなく、粉末を溶剤や溶液に分散したものも含むものとする。例えば、白粉、ファンデーション、パウダー、頬紅、アイシャドー、口紅、アイライナー、マスカラ、アイブロー、クリーム、エッセンス、ローション、化粧水、乳液、ムース等が挙げられる。特に、表面疎水化シリカ被覆混晶酸化物粒子の場合には、油性化粧料、Ｗ／Ｏ乳化型の化粧料及び水・汗による化粧崩れが少ない撥水型化粧料が好ましい。
【０１２１】
本発明の化粧料を構成するものとして、粉末成分と油分がある。このうち、粉末成分を構成するものには、シリカ被覆混晶酸化物粒子の他に体質顔料（例えば、マイカ、タルク、カオリン、炭酸カルシウム、炭酸マグネシウム、無水珪酸、酸化アルミニウム、硫酸バリウム等。）、白色顔料（例えば、二酸化チタン、酸化亜鉛等。）、及び着色顔料（例えば、ベンガラ、黄酸化鉄、黒酸化鉄、酸化クロム、群青、紺青、カーボンブラック等。）があり、これらを適宜配合することができる。また、使用感をさらに向上させる為に、球状粉末（例えばナイロン粉末、ポリメタクリル酸メチル粉末等。）を用いることもできる。
【０１２２】
本発明の化粧料に配合される油分としては、流動パラフィン、スクワラン、ヒマシ油、ジイソステアリン酸グリセリル、トリイソステアリン酸グルセリル、トリ−２−エチルヘキサン酸グリセリル、ミリスチン酸イソプロピル、トリイソステアリン酸グリセリル、ジメチルポリシロキサン、メチルフェニルポリシロキサン、ワセリン、マレイン酸ジイソステアリル、精製ラノリン等が挙げられる。本発明の化粧料に対する油分の配合量は、好ましくは１〜３５質量％、より好ましくは３〜３０質量％、さらに好ましくは１０〜２５質量％である。
【０１２３】
また油分中には、有機系の紫外線吸収剤を配合してもよい。有機系の紫外線吸収剤とは、紫外線を吸収して熱、振動、蛍光、ラジカル等にエネルギー変換し、皮膚を保護するような機能を有する有機化合物を指す。
【０１２４】
本発明の化粧料に使用できる紫外線吸収剤としては、特に制限はないが、例えば、ベンゾフェノン系、サリチル酸系、ＰＡＢＡ系、ケイ皮酸系、ジベンゾイルメタン系、ウロカニン酸系等の紫外線吸収剤が挙げられる。その配合量は０．１〜１０質量％の範囲であるが、該吸収剤の紫外線吸収能によって適切な配合量にすることが望ましい。本発明に用いるシリカ被覆混晶酸化物粒子は、有機系の紫外線吸収剤と併用しても、該吸収剤の分解が抑制され、高い紫外線遮蔽能を有する化粧料とすることができる。
【０１２５】
本発明の化粧料には、既存の乳化剤を一般的な濃度で添加することもできる。例えば、化粧品原料基準第二版注解、日本公定書教会編、１９８４（薬事日報社）、化粧品原料基準外成分規格、厚生省薬務局審査課監修、１９９３（薬事日報社）、化粧品原料基準外成分規格追補、厚生省薬務局審査課監修、１９９３（薬事日報社）、化粧品種別許可基準、厚生省薬務局審査課監修、１９９３（薬事日報社）、及び化粧品原料辞典、平成３年（日光ケミカルズ）等、に記載されている全ての乳化剤が使用できる。また、トコフェリルリン酸エステル類も乳化剤として使用できる。
【０１２６】
本発明の化粧料には、紫外線による炎症を防止するため、既存の抗炎症成分または消炎成分を安全性上支障がない限り、併用又は混用することもできる。本発明の化粧料に添加できる消炎成分としてはアニリン誘導体型消炎剤、サリチル酸誘導体型消炎剤、ピラゾロン誘導体型消炎剤、インドメタシン系消炎剤、メフェナム酸系消炎剤、抗ヒスタミン剤、抗アレルギー剤、抗炎酵素剤等が挙げられる。
【０１２７】
本発明におけるシリカ被覆混晶酸化物粒子を含有する化粧料において、抗酸化作用を持つ物質である抗酸化剤を併用すると、紫外線によるフリーラジカルの発生量を抑制することにより極めて光毒性の低い化粧料が得られる。
【０１２８】
本発明の化粧料に抗酸化剤としては、特に制限はないが、例えば、ビタミンＡ、β−カロチン、アスタキサンチン、ビタミンＢ、ビタミンＣ、Ｌ−アスコルビン酸−２−リン酸マグネシウム、Ｌ−アスコルビン酸−２−リン酸ナトリウム、Ｌ−アスコルビン酸−２−リン酸ナトリウムマグネシウム、Ｌ−アスコルビン酸−２−グルコシド−６−パルミチン酸塩、Ｌ−アスコルビン酸−２−リン酸−６−パルミチン酸塩、Ｌ−アスコルビン酸−２−リン酸−５，６−ベンジリデン、天然ビタミンＥ、ｄｌ−α−トコフェロール、ｄｌ−α−トコフェリル酢酸エステル、ｄｌ−α−トコフェリルリン酸ナトリウム、ユビキノン及びこれらのビタミン誘導体、システイン、グルタチオン、グルタチオンペルオキシターゼ、ＳＯＤ、カタラーゼ、クエン酸、リン酸、ポリフェノール、カテキン、茶抽出物、コウジ酸、核酸、ハイドロキノン、アルブチン等が挙げられる。これらの群より選択される一種又は二種以上の抗酸化剤を配合することができる。
【０１２９】
なお、本発明にかかる化粧料には、化粧料に一般的に配合される上記以外の成分、例えば油脂類、ロウ類、炭化水素、脂肪酸類、アルコール類、多価アルコール類、糖類、エステル類、金属石けん、水溶性高分子化合物、界面活性剤、酸化防止剤、殺菌・防腐剤、ビタミン、ホルモン、色材等を配合することができる。
【０１３０】
本発明の化粧料におけるシリカ被覆混晶酸化物粒子の配合量は、好ましくは化粧料に対して１〜５０質量％であり、より好ましくは３〜４０質量％、さらに好ましくは５〜３０質量％の範囲である。
【０１３１】
本発明の化粧料において、比表面積の大きな超微粒子混結晶酸化物が良好に分散しているシリカ被覆混晶酸化物粒子を用いる場合、特に高い紫外線遮蔽能を有することができ、また添加量を低減することができる。また、一次粒径が小さく、緻密で実用的なシリカ被膜で被覆された金属酸化物ゾル及び／又は表面疎水化シリカ被覆金属酸化物ゾルを用いる含有しているので、高濃度に配合した場合にも、きしみ感や伸びの悪さがなく、使用感に優れている。
【０１３２】
さらに、本発明の化粧料は、粒径の小さい金属酸化物粒子が良好に分散しているシリカ被覆金属酸化物ゾル及び／又は表面疎水化シリカ被覆金属酸化物ゾルを用いるので、可視光透過性が良好で、透明感のある化粧仕上がりが得られる。
また、金属酸化物微粒子の表面が、緻密で、実用的なシリカ被膜で被覆されているので、金属酸化物による光触媒活性が十分抑制され、化粧料の他の配合成分を変性させず、保存安定性に優れている。
【０１３３】
有機系紫外線吸収剤を含有することが可能であり、より高い紫外線遮蔽能を達成できる。さらに、抗酸化剤を含有することにより活性酸素等の発生が極めて低くでき、人体に対する安全性を高められる。
【０１３４】
本発明においてシリカ膜の膜厚、屈折率は、シリカ被覆混晶酸化物粒子を合成する際に系内に浸せきしたシリコンウエハー上に形成されるシリカ膜を用いて測定することができる。このシリコンウエハーには、シリカ被覆混晶酸化物粒子中の混晶酸化物粒子粒子上と同じシリカ被膜が形成される。シリカ膜の屈折率は、エリプソメーター（ＵＬＶＡＣ製；ＬＡＳＳＥＲ ＥＬＬＩＰＳＯＭＥＴＥＲ ＥＳＭ−１Ａ）により測定できる。膜厚測定には段差計を用いることができる。シリカ被覆混晶酸化物粒子粒子のシリカ膜の透過赤外吸収スペクトルは、日本分光製ＦＴ−ＩＲ−８０００により測定することができる。
【０１３５】
シリカ被覆混晶酸化物粒子の１次粒径及びシリカ膜厚は、透過型電子顕微鏡像より求めることができる。全アルカリ金属含有量は、シリカ被覆混晶酸化物粒子を硫弗酸に溶解し、炎光分析により測定する。
【０１３６】
シリカ被覆混晶酸化物粒子の光触媒活性度すなわち初期酸素消費速度は、テトラリン自動酸化法（清野学著、酸化チタン−物性と応用技術、技報堂出版、ｐ．１９６−１９７，１９９１年）により測定することができる。測定条件は、温度４０℃、テトラリン２０ｍｌ、固形分濃度１０％の混晶酸化物粒子０．０２ｇとする。
【０１３７】
本発明のシリカ被覆混晶酸化物粒子の有機系紫外線吸収剤の分解速度、粉体動摩擦係数、色素退色速度は、それぞれ本明細書中に記載されたパラソール法、ガラス平板法、サンセットイエロ−法により測定される。
【０１３８】
【実施例】
以下、本発明の実施例について詳細に説明する。但し、本発明はこれにより限定されるものではない。
【０１３９】
（実施例１）
（混晶酸化物粒子１の製造）
金属亜鉛３．８ｋｇ／時と９００℃に加熱した窒素ガス２５Ｎｍ³／時（Ｎは標準状態を示す。以下、同じ）とを亜鉛気化器に供給し、Ｚｎ原料ガスを得た。これを、Ｚｎ原料ガス加熱器で１０００℃まで加熱した。
一方、水蒸気３体積％、酸素９７体積％の組成を持つ酸化性ガス２５Ｎｍ³／時を酸化性ガス加熱器で加熱した。加熱されたガスの温度は反応器への導入口において１０３０℃であった。
【０１４０】
またテトラエトキシシラン７００ｇ／時を窒素と共に３００℃まで加熱した。
以上のＺｎ原料ガス、酸化性ガス、テトラエトキシシランを含む窒素ガスを反応器に導入した。
流速はＺｎ原料ガスが１００ｍ／秒、酸化性ガスが９０ｍ／秒、テトラエトキシランを含む窒素ガスが４０ｍ／秒であった。反応させた後、バッグフィルターにおいて粉体を捕集した。
【０１４１】
得られた粉体は、白色で、ＱＵＡＮＴＡＣＨＲＯＭＥ社製のモノソーブ型装置を用いてＢＥＴ一点法にて比表面積を測定したところ４２ｍ²／ｇであり、株式会社リガク製の蛍光Ｘ線分析装置Ｘ−ｒａｙ Ｓｐｅｃｔｒｏｍｅｔｅｒ Ｓｉｍｕｌｔｉｘ １０を用いて分析したところシリカ成分を４質量％含んでいた。
この粉体を株式会社リガク製の回折Ｘ線装置２０００／ＰＣ型を使用し、３０ｋＶ、３０ｍＡの条件で、ＣｕＫα線を用いて２θ＝１０°〜８０°の範囲を２°／分の速度でスキャンし、結晶形を調べた。
【０１４２】
その結果、結晶性酸化亜鉛に特有の格子面（１００）、（００２）、（１０１）に相当する２θ＝３１．８°、３４．５°、３６．３°にピークを持ち、かつ結晶性シリカに特有の格子面（１０１）に相当する２θ＝２２°付近にもピークをもつＸＲＤチャートを示す粉体であった。
【０１４３】
さらに耐熱性を調べる為、サンプルを磁製坩堝に分取し、８００℃の電気炉に入れ、１時間保持した後、ただちに取り出し室温にまで放冷した。この粉体の比表面積を再び前述のＢＥＴ１点法で測定した。加熱前後の比表面積比、すなわち、（熱処理後の比表面積／熱処理前の比表面積）を算出したところ、７９％となった。
【０１４４】
さらに透過型電子顕微鏡（ＴＥＭ）観察による一次粒子は異方性のテトラポッド状及び針状の粒子と等方性粒子に分別され、３００個を目処にし、ＴＥＭ写真に写っている全部の粒子を数えた。その結果、全個数に占めるテトラポッド状及び針状の粒子の割合は８３％であった。
【０１４５】
また、テトラポッド状粒子、針状粒子および等方性粒子のそれぞれの一次粒子についてＥＤＸにより測定スポット径５ｎｍで元素分析をしたところ、各形状の粒子ともにＺｎ、Ｓｉが存在していることが確認された。これを各形状の粒子それぞれについて、複数箇所実施したが、いずれもＺｎ、Ｓｉが検出された。
【０１４６】
（シリカ被覆混晶酸化物粒子１の製造）
５０Ｌ反応器に脱イオン水１８．２５Ｌ、エタノール（純正化学株式会社製）２２．８Ｌおよび２５質量％アンモニア水１２４ｍＬ（大盛化工社製）を混合し、その中に、上記混晶酸化物粒子の製造１にて製造した混晶酸化物粒子１．７４Ｋｇを分散させ、懸濁液１を調製した。次に、テトラエトキシシラン（ＧＥ東芝シリコーン社製）１．６２Ｌ、エタノール１．２６Ｌを混合し、溶液１を調製した。
【０１４７】
撹拌している懸濁液１に、溶液１を９時間かけて一定速度で加えた後、１２時間熟成した。成膜、熟成は４５℃にて行った。その後、固形分を遠心濾過にて分離し、５０℃で１２時間真空乾燥し、さらに８０℃で１２時間温風乾燥し、さらにジェットミルにより粉砕することによりシリカ被覆混晶酸化物粒子１を得た。
【０１４８】
（実施例２）
（混晶酸化物粒子２の製造）
金属亜鉛６ｋｇ／時と９００℃に加熱した窒素ガス２５Ｎｍ³／時とを亜鉛気化器に供給し、Ｚｎ原料ガスを得た。これを、さらにＺｎ原料ガス加熱器で１０００℃まで加熱した。
一方、水蒸気３体積％、酸素９７体積％の組成を持つ酸化性ガス２５Ｎｍ³／時を酸化性ガス加熱器で加熱した。加熱されたガスの温度は反応器への導入口において１０３０℃であった。
【０１４９】
またテトラエトキシシラン１０ｋｇ／時を窒素と共に３００℃まで加熱した。
以上のＺｎ原料ガス、酸化性ガス、テトラエトキシシランを含む窒素ガスを反応器に導入した。流速は、Ｚｎ原料ガスが１００ｍ／秒、酸化性ガスが９０ｍ／秒、テトラエトキシランを含む窒素ガスが５０ｍ／秒であった。反応させた後、バッグフィルターにおいて粉体を捕集した。
【０１５０】
得られた白色粉体を実施例１と同様に分析した。
その結果、比表面積３７ｍ²／ｇであり、シリカ成分２６質量％含んでいた。結晶形は、実施例１と同じ２θの位置にピークを持つ粉体であった。加熱前後の比表面積比は８５％であった。
【０１５１】
（シリカ被覆混晶酸化物粒子２の製造）
５０Ｌ反応器に脱イオン水１８．２５Ｌ、エタノール（純正化学株式会社製）２２．８Ｌおよび２５質量％アンモニア水１２４ｍＬ（大盛化工社製）を混合し、その中に、上記混晶酸化物粒子１を１．９６Ｋｇ分散させ、懸濁液２を調製した。次に、テトラエトキシシラン（ＧＥ東芝シリコーン社製）０．８１Ｌ、エタノール１．９３Ｌを混合し、溶液２を調製した。
【０１５２】
撹拌している懸濁液２に、溶液２を４．５時間かけて一定速度で加えた後、１２時間熟成した。成膜、熟成は４５℃にて行った。その後、固形分を遠心濾過にて分離し、５０℃で１２時間真空乾燥し、さらに８０℃で１２時間温風乾燥し、さらにジェットミルにより粉砕することによりシリカ被覆混晶酸化物粒子２を得た。
【０１５３】
（実施例３）
（混晶酸化物粒子３の製造）
濃度１００体積％のガス状四塩化チタン９．４Ｎｍ³／時間（Ｎは標準状態を意味する。以下同じ）及び濃度１００体積％のガス状四塩化珪素２．４Ｎｍ³／時間を含有するガスを混合後１，０００℃に、８Ｎｍ³／時間の酸素及び２０Ｎｍ³／時間の水蒸気の混合ガスを１，０００℃にそれぞれ予熱して、同軸平行流ノズルを用いて、それぞれ流速４９ｍ／秒、６０ｍ／秒で反応管に導入した。同軸平行流ノズルの内管径は２０ｍｍとし、内管に混合ハロゲン化金属を含有するガスを導入した。
【０１５４】
反応管の内径は１００ｍｍであり、反応温度１，３００℃における管内流速は計算値で１０ｍ／秒であった。反応管内の高温滞留時間が０．３秒以下となるように、反応後冷却空気を反応管に導入し、その後、テフロン製バグフィルターを用いて製造された超微粒子粉末を捕集した。その後、オーブンにて空気雰囲気下、５００℃×１時間加熱し、脱塩処理を実施した。
【０１５５】
得られた混晶酸化物粒子は、ＢＥＴ比表面積が８８ｍ²／ｇ、平均真比重３．７ｇ／ｃｃ、平均一次粒子径０．０１８μｍ、塩素が０．０１％であり、ＸＰＳによって明らかにチタン−酸素−珪素結合が認められた。
８００℃×１時間後のＢＥＴ比表面積減少率は２％であった。
【０１５６】
（シリカ被覆混晶酸化物粒子３の製造）
５０Ｌ反応器に脱イオン水４．２Ｌ、エタノール（純正化学株式会社製）１９．３Ｌおよび２５質量％アンモニア水０．７５Ｌ（大盛化工社製）を混合し、その中に、上記混晶酸化物粒子３を１．０５ｋｇを分散させ、懸濁液３を調製した。次に、テトラエトキシシラン（ＧＥ東芝シリコーン社製）０．９７Ｌ、エタノール１．０５Ｌを混合し、溶液３を調製した。
【０１５７】
撹拌している懸濁液３に、溶液３を６時間かけて一定速度で加えた後、１２時間熟成した。成膜、熟成は２５℃にて行った。その後、固形分を遠心濾過にて分離し、５０℃で１２時間真空乾燥し、さらに８０℃で１２時間温風乾燥し、さらにジェットミルにより粉砕することによりシリカ被覆混晶酸化物粒子３を得た。
【０１５８】
（実施例４）
（混晶酸化物粒子４の製造）
ガス状四塩化チタン８．３Ｎｍ³／時間とガス状三塩化アルミニウム２．４Ｎｍ³／時間と窒素６Ｎｍ³／時間を含有するガスを混合後９００℃に、８Ｎｍ³／時間の酸素及び２０Ｎｍ³／時間の水蒸気の混合ガスを１，０００℃にそれぞれ予熱して、同軸平行流ノズルを用いて、それぞれ流速６３ｍ／秒、６０ｍ／秒で反応管に導入した。同軸平行流ノズルの内管径は２０ｍｍとし、内管に混合ハロゲン化金属を含有するガスを導入した。
【０１５９】
反応管の内径は１００ｍｍであり、反応温度１，２００℃における管内流速は計算値で１０ｍ／秒であった。反応管内の高温滞留時間が０．３秒以下となるように、反応後冷却空気を反応管に導入し、その後、テフロン製バグフィルターを用いて製造された超微粒子粉末を捕集した。その後、オブンにて空気雰囲気下、５００℃×１時間加熱し、脱塩処理を実施した。
【０１６０】
得られた混晶酸化物粒子は、ＢＥＴ比表面積が４８ｍ²／ｇ、平均真比重３．９ｇ／ｃｃ、平均一次粒子径０．０３２μｍ、塩素が０．１％であり、ＸＰＳによって明らかにチタン−酸素−アルミニウム結合が認められた。
８００℃×１時間後のＢＥＴ比表面積減少率は５％であった。
【０１６１】
（シリカ被覆混晶酸化物粒子４の製造）
５０Ｌ反応器に脱イオン水４．２Ｌ、エタノール（純正化学株式会社製）１９．３Ｌおよび２５質量％アンモニア水０．７５Ｌ（大盛化工社製）を混合し、その中に、上記混晶酸化物粒子４を１．０５ｋｇを分散させ、懸濁液４を調製した。次に、テトラエトキシシラン（ＧＥ東芝シリコーン社製）０．４４Ｌ、エタノール１．３５Ｌを混合し、溶液４を調製した。
【０１６２】
撹拌している懸濁液４に、溶液４を６時間かけて一定速度で加えた後、１２時間熟成した。成膜、熟成は２５℃にて行った。その後、固形分を遠心濾過にて分離し、５０℃で１２時間真空乾燥し、さらに８０℃で１２時間温風乾燥し、さらにジェットミルにより粉砕することによりシリカ被覆混晶酸化物粒子４を得た。
【０１６３】
ＫＢｒ法により、実施例１〜４で得られたシリカ被覆混晶酸化物粒子の透過赤外吸収スペクトルを測定したところ、いずれの金属酸化物粒子も１０００〜１２００ｃｍ-1にＳｉ−Ｏ−Ｓｉ伸縮振動由来の吸収が観測され、２８００〜３０００ｃｍ-1にＣ−Ｈ伸縮振動由来の吸収は観測されず、生成した被膜はシリカであると同定された。
さらに、シリカ膜厚、赤外吸収スペクトルの吸収ピーク強度の比Ｉ、シリカ膜の屈折率を測定した。結果を表１にまとめた。
【０１６４】
（光触媒活性度の測定・テトラリン自動酸化法）
実施例１〜４で得られたシリカ被覆混晶酸化物粒子を被験物質としてテトラリン自動酸化法による光触媒活性度を測定した。結果を表１にまとめて示す。本発明のシリカ被覆混晶酸化物粒子のいずれもが６０Ｐａ／ｍｉｎ以下であり、従来のシリカ被覆金属酸化物粉と同等の光触媒活性の抑制を示す。
【０１６５】
（色素退色速度の測定・サンセットイエロ−法）
実施例１〜４で得られたシリカ被覆混晶酸化物粒子を被験物質としてサンセットイエロ−法により色素退色速度を測定した。すなわち、化粧料用の色素であるサンセットイエロ−を９８質量％グリセリンに色素濃度が０．０２質量％となるように溶解した。被験物質を０．０６７質量％となるように分散させ、該分散液に紫外線照射（紫外線強度１．６５ｍＷ／ｃｍ²）した。光路長１ｍｍでサンセットイエロ−の最大吸収波長である４９０ｎｍの吸光度を経時的に分光光度計（ＳＨＩＭＡＤＺＵ ＵＶ−１６０）で測定し、該吸光度の減少速度（ΔＡ₄₉₀／ｈ）を計算した。結果は表１に示す。
【０１６６】
本発明に用いられるシリカ被覆混晶酸化物粒子の色素退色速度は、いずれも０．１０（ΔＡ₄₉₀／ｈ）以下であり、従来のシリカ被覆金属酸化物粉と同等の色素退色速度を示している。本発明のシリカ被覆混晶酸化物粒子は、従来のシリカ被覆金属酸化物粉が有する低い色素分解性を維持しており、保存安定性の高い化粧料を提供できる。
【０１６７】
（有機系紫外線吸収剤の分解速度の測定・パラソール法）
実施例１〜４で得られたシリカ被覆混晶酸化物粒子を被験物質としてパラソール法により有機系紫外線吸収剤の分解速度を測定した。すなわち、４−ｔｅｒｔ−ブチル−４’−メトキシジベンゾイルメタン（パラソール１７８９）のポリエチレングリコール３００溶液（パラソール１７８９濃度として０．０４５質量％）に被験物質を分散させ、各々固形分１質量％のスラリーとした。スラリー１．５ｇをガラス容器に入れ、紫外線照射（１．６５ｍＷ／ｃｍ2）した後、１ｇを分取し、イソプロピルアルコール２ｍＬ、ヘキサン２ｍＬ、蒸留水３ｍＬを順次添加した。
【０１６８】
攪拌してヘキサン相にパラソール１７８９を抽出し、ヘキサン相の光路長１ｍｍでの吸光度（３４０ｎｍ）を分光光度計（ＳＨＩＭＡＤＺＵ ＵＶ−１６０）で経時的に（紫外線照射０、５及び１０時間後の３点）測定した。３４０ｎｍの吸光度の減少速度（ΔＡ₃₄₀／ｈ）を求めた。結果を表１にまとめて示す。
【０１６９】
本発明に用いることができるシリカ被覆混晶酸化物粒子のいずれもが０．０１（ΔＡ₃₄₀／ｈ）以下であり、有機紫外線吸収剤の分解性が低いものであった。従って、シリカ被覆混晶酸化物粒子を含有した化粧料は、有機系紫外線遮蔽材との併用が可能であり、紫外線防御能を長期にわたり維持することができる。
【０１７０】
（粉体動摩擦係数の測定・ガラス平板法）
実施例１〜４で得られたシリカ被覆混晶酸化物粒子を被験物質としてガラス平板法により粉体動摩擦係数を測定した。すなわち、１００×２００ｍｍのガラス板上に被験物質の粉体を１０ｍｇ／ｃｍ² となるように分散させ、このガラス板を表面性状測定装置（ＨＥＩＤＯＮ）の試験台に載せ、荷重２２．２ｇ／ｃｍ²、移動速度２００ｍｍ／ｍｉｎ．、移動距離２０ｍｍの条件で動摩擦係数を測定した。結果を表１に示す。
【表１】

【０１７１】
本発明のシリカ被覆混晶酸化物粒子の粉体動摩擦係数のいずれもが０．５５０以下であり、従来のシリカ被覆金属酸化物粉よりもさらに低い動摩擦係数を示している。このことは、本発明のシリカ被覆混晶酸化物粒子を含有した化粧料は、従来よりも、さらに優れた使用感を有することが示唆している。
【０１７２】
（実施例５〜８）日焼け止め乳液
定法により下記処方の日焼け止め乳液を製造した。すなわち、精製水にポリエチレングリコールを加え、加熱溶解後、被験物質、ビーガムを加え、ホモミキサーで均一に分散し、７０℃に保つ（水相）。他の成分を混合し、加熱溶解して７０℃に保つ（油相）。水相に油相を加え、ホモミキサーで均一に乳化分散し、乳化後かき混ぜながら３５℃まで冷却した。被験物質には、実施例１〜４で製造したシリカ被覆混晶酸化物粒子を用いた。その使用に当たっては、乳液のオイル相側へ分散させるため、さらにその表面を処理粉体重量に対してジメチルポリシロキサンが３質量％となるように疎水化処理を施した。（以下この疎水化処理品を、「シリコーン処理シリカ被覆混晶酸化物粒子」と表現する。）
【０１７３】
日焼け止め乳液の処方
シリコーン処理シリカ被覆混晶酸化物粒子 ７．０質量％
ステアリン酸 ２．０質量％
セチルアルコール １．０質量％
ワセリン ５．０質量％
シリコン油 ２．０質量％
流動パラフィン １０．０質量％
グリセリンモノステアリン酸エステル（自己乳化型） １．０質量％
ポリオキシエチレン(25モル)モノオレイン酸エステル １．０質量％
ポリエチレングリコール１５００ ５．０質量％
ビーガム ０．５質量％
精製水 ６５．２質量％
香料 ０．１質量％
防腐剤 ０．２質量％
【０１７４】
また比較例として、シリカ被覆混晶酸化物粒子の代わりに従来表面処理酸化チタン（石原産業社製ＴＴＯ−Ｓ−１）及び従来酸化亜鉛（住友大阪セメント社製ＺｎＯ３５０）を用いて日焼け止め乳液を調製した（比較例１、２）。
【０１７５】
さらに、実施例１のシリカ被覆混晶酸化物粒子１において混晶酸化物粒子１の代わりに酸化亜鉛（昭和タイタニウム株式会社製ＵＦＺ４０）を使用したシリカ被覆酸化亜鉛を用いて日焼け止め乳液を調製し比較例３とし、実施例４のシリカ被覆混晶酸化物粒子４において混晶酸化物粒子４の代わりに酸化チタン（昭和タイタニウム株式会社製Ｆ４）を使用したシリカ被覆酸化チタンを用いて日焼け止め乳液を調製し比較例４とした。（官能試験）
【０１７６】
実施例５〜８及び比較例１〜４で製造した日焼け止め乳液の使用感及び仕上がりの透明感を２０から４０歳台の女性５０人を用いた官能試験で評価した。５０人の被験者によって各々のファンデーションの使用感が、
極めて良い：５点 良い：３点 普通：２点 悪い：１点 極めて悪い：０点の基準により採点された。次いで、５０人の評価点数を集計した合計点数により、下記の基準に基づく５段階で使用感を判定した。
【０１７７】
２５０〜２００点：極めて良い（＋＋）
２００〜１５０点：良い （＋ ）
１５０〜１００点：普通 （＋−）
１００〜 ５０点：悪い （− ）
５０〜 ０点：極めて悪い（−−）
【０１７８】
結果を表２に示す。
【表２】

【０１７９】
本発明のシリカ被覆混晶酸化物粒子を配合した日焼け止め乳液の使用感及び透明感は、いずれも極めて良い（＋＋）である。
本発明のシリカ被覆混晶酸化物粒子を含有する日焼け止め乳液は、特に透明感が向上していることが明らかである。
【０１８０】
（実施例９〜１２）ファンデーション
定法により下記処方のファンデーションを製造した。被験物質として、それぞれ実施例１〜４で得られたシリカ被覆混晶酸化物粒子を用いた。
【０１８１】
ファンデーションの処方
シリカ被覆混晶酸化物粒子 １５．０質量％
マイカ １５．０質量％
タルク １０．０質量％
亜鉛華 １５．０質量％
酸化鉄（赤） １．５質量％
酸化鉄（黄） ３．４質量％
グリセリン １０．０質量％
精製水 ３０．０質量％
香料 ０．１質量％
【０１８２】
また比較例として、シリカ被覆混晶酸化物粒子の代わりに従来表面処理酸化チタン（石原産業社製ＴＴＯ−Ｓ−１）及び従来酸化亜鉛（住友大阪セメント社製ＺｎＯ３５０）を用いてファンデーションを調製した（比較例５、６）。
【０１８３】
さらに、実施例１のシリカ被覆混晶酸化物粒子１において混晶酸化物粒子１の代わりに酸化亜鉛（昭和タイタニウム製ＵＦＺ４０）を使用したシリカ被覆酸化亜鉛を用いてファンデーションを調製し比較例７とした。
また、実施例４のシリカ被覆混晶酸化物粒子４において混晶酸化物粒子４の代わりに酸化チタン（昭和タイタニウム製Ｆ４）を使用したシリカ被覆酸化チタンを用いてファンデーションを調製し比較例８とした。
【０１８４】
（官能試験）
実施例９〜１２で製造したファンデーションの使用感及び仕上がりの透明感を、前記の方法に従い、官能試験で評価した。
【０１８５】
結果を表３に示す。
【表３】

【０１８６】
本発明のシリカ被覆混晶酸化物粒子を配合したファンデーションの使用感及び透明感は、いずれも極めて良い（＋＋）である。
本発明のシリカ被覆混晶酸化物粒子を含有するファウンデーションは、特に透明感が向上していることが明らかである。
【０１８７】
（実施例１３）化粧水
定法により下記処方の化粧水を製造した。
【０１８８】
化粧水の処方
シリカ被覆混晶酸化物粒子１ ３．０質量％
エチルアルコール ３９．６質量％
１，３−ブチレングリコール ９．５質量％
ヒマシ油 ４．９質量％
メチルパラベン ０．２質量％
精製水 ４２．８質量％
【０１８９】
上記の化粧水について官能試験を実施したところ、良い使用感及び極めて良い透明感という評価を得た。
【０１９０】
（実施例１４）乳液
定法により下記処方の乳液を製造した。
【０１９１】
乳液の処方
シリコーン処理シリカ被覆混晶酸化物粒子３ ３．０質量％
アボガド油 １１．０質量％
ベヘニルアルコール ０．６質量％
ステアリン酸 ０．４質量％
グリセリン脂肪酸エステル ０．９質量％
ポリオキシエチレンソルビタン脂肪酸エステル １．１質量％
ポリオキシエチレンアルキルエーテル ０．４質量％
１，３−ブチレングリコール １０．１質量％
メチルパラベン ０．２質量％
香料 ０．４質量％
精製水 ７１．９質量％
【０１９２】
上記の化粧水について官能試験を実施したところ、極めて良い使用感及び極めて良い透明感という評価を得た。
【０１９３】
（実施例１５）クリーム
定法により下記処方のクリームを製造した。
【０１９４】
クリームの処方
シリコーン処理シリカ被覆混晶酸化物粒子１ ３．５質量％
スクワラン １５．２質量％
ステアリン酸 ７．８質量％
ステアリルアルコール ６．０質量％
ミツロウ １．９質量％
プロピレングリコールモノステアレート ３．１質量％
ポリオキシエチレンセチルエーテル １．１質量％
１，３−ブチレングリコール １１．９質量％
メチルパラベン ０．２質量％
香料 ０．４質量％
精製水 ４１．９質量％
【０１９５】
上記のクリームについて官能試験を実施したところ、極めて良い使用感及び極めて良い透明感という評価であった。
【０１９６】
（実施例１６）パック
被験物質として実施例３で得られたシリカ被覆混晶酸化物粒子を用いて、常法により下記の処方でパックを製造した。
【０１９７】
パックの処方
シリカ被覆混晶酸化物粒子３ ７．０質量％
ポリビニルアルコール １４．５質量％
カルボキシメチルセルロースナトリウム ４．８質量％
１，３−ブチレングリコール ２．９質量％
エチルアルコール １０．０質量％
メチルパラベン ０．１質量％
精製水 ６０．７質量％
【０１９８】
上記のパックについて官能試験を実施したところ、良い使用感と透明感という評価であった。
【０１９９】
（実施例１７）口紅
被験物質として実施例１のシリカ被覆混晶酸化物粒子（使用に当たっては、さらにその表面を、ジメチルポリシロキサンが処理粉体重量に対して３質量％となるように疎水化処理を施した。）を用いて、常法により下記の処方で口紅を製造した。
【０２００】
シリコーン処理シリカ被覆混晶酸化物粒子１ ３．０質量％
シリコン油 ２７．０質量％
ヒマシ油 １８．３質量％
ヘキサデシルアルコール ２５．２質量％
ラノリン ３．９質量％
ミツロウ ４．８質量％
オゾケライト ３．４質量％
キャンデリラロウ ６．２質量％
カルナウバロウ ２．１質量％
メチルパラベン ０．１質量％
赤色色素 ４．８質量％
香料 ０．１質量％
精製水 １．１質量％
【０２０１】
上記の口紅について官能試験を実施したところ、極めて良い使用感及び透明感という評価であった。
【０２０２】
（実施例１８〜２１）両用ファンデーション
実施例１〜４で得られたシリカ被覆混晶酸化物粒子（使用に当たっては、さらにその表面を、ジメチルポリシロキサンが処理粉体重量に対して３質量％となるように疎水化処理を施した。）を被験物質に用いて、定法により下記処方の両用ファンデーションを製造した。
【０２０３】
両用ファンデーションの処方
シリコーン処理シリカ被覆混晶酸化物粒子 ６．０質量％
シリコーン処理タルク １９．０質量％
シリコーン処理マイカ ３９．６質量％
シリコーン処理酸化鉄（赤） １．０質量％
シリコーン処理酸化鉄（黄） ３．０質量％
シリコーン処理酸化鉄（黒） ０．３質量％
シリコーン処理チタニア １５．０質量％
ステアリン酸亜鉛 ０．２質量％
ナイロンパウダー ２．０質量％
スクアラン ４．０質量％
固形パラフィン ０．５質量％
ジメチルポリシロキサン ４．０質量％
トリイソオクタン酸グリセリン ５．０質量％
酸化防止剤 ０．２質量％
防腐剤 ０．１質量％
香料 ０．１質量％
【０２０４】
実施例１８〜２１の両用ファンデーションについて官能試験を実施して、使用感及び透明感を評価した。本発明によるシリカ被覆混晶酸化物粒子を含有するファンデーションは、いずれも極めて良い使用感と極めて良い透明感を示した。
【０２０５】
（実施例２２〜２５） Ｗ／Ｏ日焼止めクリーム
実施例１〜４で得られたシリカ被覆混晶酸化物粒子（使用に当たっては、さらにその表面を、ジメチルポリシロキサンが処理粉体重量に対して３質量％となるように疎水化処理を施した。）を被験物質に用いて、下記処方のＷ／Ｏ日焼止めクリームを製造した。
【０２０６】
（１）２−エチルヘキサン酸グリセリル １２．０質量％、（２）４−ｔｅｒｔ−ブチル−４´−メトキシジベンゾイルメタン ５．０質量％、（３）イソステアリン酸ポリグリセリル １．０質量％、（４）セスキオレイン酸ソルビタン ２．０質量％、（５）デカメチルポリシロキサン １０．０質量％、（６）有機変性ベントナイト ０．２質量％、（７）スクワラン ５．０質量％、（８）パラメトキシケイ皮酸２−エチルヘキシル ８．０質量％、（９）シリコーン処理シリカ被覆混晶酸化物粒子 １０．０質量％、（１０）香料 ０．１質量％、（１１）パラオキシ安息香酸メチル ０．３質量％、（１２）エデト酸二ナトリウム ０．１質量％、（１３）精製水 ４６．３質量％
【０２０７】
（１）〜（８）を加熱溶解し、（９）（１０）を添加して均一に分散し、（１１）〜（１３）を徐々に添加して乳化し、充分攪拌してから３０℃まで冷却してＷ／Ｏ日焼止めクリームを得た。
【０２０８】
（実施例２６〜２９） Ｏ／Ｗ日焼止めクリーム
実施例１〜４で得られたシリカ被覆混晶酸化物粒子（使用に当たっては、さらにその表面を、ジメチルポリシロキサンが処理粉体重量に対して３質量％となるように疎水化処理を施した。）を被験物質に用いて、下記処方のＯ／Ｗ日焼止めクリームを製造した。
【０２０９】
（１）スクワラン ５．０質量％、（２）２−エチルヘキサン酸グリセリル １０．０質量％、（３）マイクロクリスタンワックス １．０質量％、（４）ステアリルアルコール ２．０質量％、（５）パラオキシ安息香酸ブチル ０．１質量％、（６）４−ｔｅｒｔ−ブチル−４´−メトキシジベンゾイルメタン １．０質量％、（７）パラメトキシケイ皮酸２−エチルヘキシル ３．０質量％、（８）シリコーン処理シリカ被覆混晶酸化物粒子 ５．０質量％、（９）香料 ０．２質量％、（１０）パラオキシ安息香酸メチル ０．１質量％、（１１）１，３−ブチレングリコール ７．０質量％、（１２）精製水 ６５．６質量％
【０２１０】
（１）〜（７）を加熱溶解し、（８）（９）を添加して均一に分散し、（１０）〜（１２）を徐々に添加して乳化し、充分攪拌してから３０℃まで冷却してＯ／Ｗ日焼け止めクリームを得た。
【０２１１】
（実施例３０〜３３） 口紅
実施例１〜４で得られたシリカ被覆混晶酸化物粒子（使用に当たっては、さらにその表面を、ジメチルポリシロキサンが処理粉体重量に対して３質量％となるように疎水化処理を施した。）を被験物質に用いて、下記処方の口紅を製造した。
【０２１２】
（１）パラフィンワックス １０．０質量％、（２）マイクロクリスタリンワックス １０．０質量％、（３）シリコーン処理シリカ被覆混晶酸化物粒子 ３．０質量％、（４）２−エチルヘキサン酸グリセリル ４６．４質量％、（５）パラメトキシケイ皮酸２−エチルヘキシル ５．０質量％、（６）４−ｔｅｒｔ−ブチル−４´−メトキシジベンゾイルメタン ３．０質量％、（７）リンゴ酸ジイソステアリル １５．０質量％、（８）赤色２０１号 ２．０質量％、（９）赤色２０２号 ２．０質量％、（１０）青色１号 ０．５質量％、（１１）ベンガラ ３．０質量％、（１２）香料 ０．１質量％
【０２１３】
（１）〜（１１）を加熱溶解し、（１２）を添加して均一に分散し、３０℃まで冷却して口紅を得た。
【０２１４】
（実施例３４〜３７）パウダーファンデーション
実施例１〜４で得られたシリカ被覆混晶酸化物粒子を被験物質に用いて、下記処方のパウダーファンデーションを製造した。
【０２１５】
（１）マイカ ３６．０質量％、（２）タルク ２０．０質量％、（３）シリカ被覆混晶酸化物粒子 ６．０質量％、（４）パラメトキシケイ皮酸２−エチルヘキシル ５．０質量％、（５）４−ｔｅｒｔ−ブチル−４´−メトキシジベンゾイルメタン １０．０質量％、（６）ステアリン酸亜鉛 ４．０質量％、（７）黄酸化鉄 ３．０質量％、（８）ベンガラ ０．８質量％、（９）黒酸化鉄 ０．２質量％、（１０）スクワラン ５．０質量％、（１１）２−エチルヘキサン酸グリセリル ８．７質量％、（１２）モノイソステアリン酸ソルビタン １．０質量％、（１３）パラオキシ安息香酸ブチル ０．２質量％、（１４）香料 ０．１質量％
【０２１６】
（１０）〜（１３）を加熱溶解したのち（１４）を混合し、室温に冷却して油相とする。（１）〜（９）を混合機にてよく攪拌し、さらに油相を添加しよく混合する。これを粉砕機に通し粉砕したものを金皿にプレスし目的のパウダーファンデーションを得た。
【０２１７】
実施例２５〜３７の処方中のシリカ被覆混晶酸化物粒子を、従来表面処理酸化チタン（石原産業社製ＴＴＯ−Ｓ−１）及び従来酸化亜鉛（住友大阪セメント社製ＺｎＯ３５０）に変更して調製した化粧料を比較例として、１ヶ月後の経時安定性を目視にて判断した。
【０２１８】
比較例はいずれも４−ｔｅｒｔ−ブチル−４´−メトキシジベンゾイルメタンの析出が観察されたのに対して、実施例２５〜３７のシリカ被覆混晶酸化物粒子を配合した化粧料はいずれも４−ｔｅｒｔ−ブチル−４´−メトキシジベンゾイルメタンの析出が無く経時安定性の優れた化粧料であった。
【０２１９】
実施例２５〜３７で得られた化粧料は、経時安定性および温度安定性をに優れたものであった。つまり、本発明の化粧料は、従来の４−ｔｅｒｔ−ブチル−４´−メトキシジベンゾイルメタンを配合した化粧料に比較して経時安定性の著しく向上したものであって、各種香・化粧料に好適に使用可能なものである。
【０２２０】
【発明の効果】
本発明によれば、緻密で実用的なシリカ膜で被覆され、かつ分散性及び透明性が向上したシリカ被覆混晶酸化物粒子及びその経済的な製造法が提供され、さらにシリカ被覆混晶酸化物粒子が良好に分散し、特に透明感と保存安定性に優れた紫外線遮蔽用化粧料が提供される。[0001]
BACKGROUND OF THE INVENTION
The present invention has a BET specific surface area of 10 to 200 m. ² The surface of mixed crystal oxide particles containing primary particles in a mixed crystal state at / g is coated with a dense and practical silica thin film having a specific infrared absorption spectrum peak, and has good dispersibility. The present invention relates to silica-coated mixed crystal oxide particles suitable for use in cosmetics, particularly UV shielding cosmetics, and a method for producing the same. Further, the present invention relates to a cosmetic containing the silica-coated mixed crystal oxide particles having excellent use feeling during makeup and whitening prevention effect, high ultraviolet shielding ability, and excellent storage stability.
[0002]
[Prior art]
In the ultraviolet shielding cosmetics, metal oxides such as titanium oxide, zinc oxide, and cerium oxide are widely used as inorganic ultraviolet shielding materials having excellent ultraviolet shielding ability and high safety.
[0003]
However, when these metal oxides are blended in cosmetics as they are, there is a problem that the feeling of use at the time of makeup deteriorates or there is a problem that the human body is adversely affected by the photocatalytic activity possessed by the metal oxides. The surface is coated with an inorganic substance having no function. Metal oxides coated with alumina, silica, etc. are commercially available, but no product has been known that can satisfy both the suppression of photocatalytic activity by coating and the good feeling of use when blended in cosmetics.
[0004]
We have previously made 1150-1250 cm ^-1 And 1000-1100cm ^-1 Of the peak intensity of the infrared absorption spectrum of I (I = I ₁ / I ₂ : In the formula I ₁ 1150-1250cm ^-1 Maximum absorption peak intensity in the range I ₂ Is 1000-1100cm ^-1 Represents the maximum absorption peak intensity within the range. ) Is 0.2 or more, and a silica-coated metal oxide having a silica film having a refractive index of 1.435 or more, a method for producing the same, and a cosmetic containing the same are disclosed. The photocatalytic activity measured by a tetralin auto-oxidation method coated with a 100 nm silica film was 60 Pa / min. It was shown that by containing the following silica-coated metal oxide, an ultraviolet shielding cosmetic material having a good feeling of use, a high effect of suppressing photocatalytic activity, and excellent storage stability was obtained.
[0005]
In recent years, cosmetics for shielding ultraviolet rays have been required to have good usability and transparency in addition to high ultraviolet shielding ability. Therefore, a metal oxide used as an ultraviolet shielding material is desired to have a smaller primary particle size and better dispersibility than the conventional one so as to give a good feeling of use and transparency when blending cosmetics. It is supposed to be. The silica-coated metal oxide based on the inventors' invention has excellent characteristics such as suppression of photocatalytic activity and feeling of use, but in order to increase transparency when blended with cosmetics, further finer particles are formed. And improvement of dispersibility was desired.
[0006]
However, when the metal oxide powder with a small primary particle size is suspended in a solvent, it is difficult to achieve high dispersion because it flocculates, and ultrasonic dispersion treatment is performed before or during the silica coating reaction. In addition, there is a problem in terms of economy because a crushing process using a wet bead mill or a homogenizer is required, or an extra step than usual is required.
[0007]
[Problems to be solved by the invention]
The present invention is a silica-coated mixed crystal oxide particle that is rich in dispersibility, has excellent visible light transparency and ultraviolet shielding ability, and has a sufficiently low photocatalytic activity, and an economical production method thereof, An object of the present invention is to provide a UV-shielding cosmetic containing silica-coated mixed crystal oxide particles and having particularly excellent visible light transparency.
[0008]
[Means for Solving the Problems]
As a result of intensive studies in view of the above situation, the present inventors have found that the BET specific surface area is 10 to 200 m. ² Even better dispersibility by coating the surface of mixed crystal oxide particles containing primary particles in a mixed crystal state at a / g with a dense and practical silica thin film having a specific infrared absorption spectrum peak And silica-coated mixed crystal oxide particles (first object) suitable for use in cosmetics, particularly UV shielding cosmetics excellent in visible light transparency, and a production method (second object) It was.
[0009]
Further, the cosmetic comprising the silica-coated mixed crystal oxide particles is excellent in use feeling and transparency during makeup, has a high ultraviolet shielding ability, and has excellent storage stability (third purpose). It was a thing.
[0010]
In order to achieve the first object of the present invention, the surface of the silica-coated mixed crystal oxide particle has a specific infrared absorption spectrum absorption peak ratio, and the mixed crystal oxide particle has a complicated shape. Disclosed is a silica-coated mixed crystal oxide particle that is coated with a practical, dense silica film that has good coverage and good coverage even at a very thin film thickness.
[0011]
Here, “dense” means that the formed silica film has a refractive index of 1.435 or more. In general, the denseness and refractive index of silica films are considered to have a positive correlation (for example, C. JEFFEREY BRINKER, Saul-GEL SCIENCE, 581-583, ACADEMIC PRESS (1990)). The resulting silica film has a refractive index of 1.435 or more when fired, but it is less than 1.435 unless fired and has a low density. However, in the present invention, this value is achieved without firing.
[0012]
The term “practical” as used herein means that the silica has a strong covering power on the base material, does not substantially peel off the coating, and has a suitable hydrophilic property. The hydrophilicity of the silica membrane is 1150-1250 cm ^-1 And 1000-1100cm ^-1 Of the absorption peak intensity of the infrared absorption spectrum of I (I = I ₁ / I ₂ : In the formula I ₁ 1150-1250cm ^-1 Maximum absorption peak intensity in the range I ₂ Is 1000-1100cm ^-1 Represents the maximum absorption peak intensity within the range. ).
[0013]
I ₁ Is the absorption of bending vibration of SiOH, and I ₂ Is absorption of stretching vibration of Si-O-Si, and I ₁ / I ₂ The higher the value, the higher the hydrophilicity. “Moderate hydrophilicity” in the present invention means a case where this value is 0.2 or more. A silica film obtained by a normal sol-gel method has an I value of 0.2 or more unless fired, but the denseness is reduced as described above. On the other hand, if the baking is performed, the density is improved, but the I value is less than 0.2, the hydrophilicity is lowered, and the hydrophilicity is not appropriate.
[0014]
As described above, the silica coating of the present invention has an appropriate hydrophilicity, so that it cannot be obtained unless it is fired while maintaining good surface properties (moist feeling, slipperiness) when blended in cosmetics. It has a dense and strong coating and maintains a high ability to suppress the photocatalytic activity of the mixed crystal oxide particles even with a very thin film thickness of about 0.1 nm.
[0015]
In order to achieve the second object of the present invention, the BET specific surface area is 10 to 200 m. ² In order of mixed crystal oxide particles containing primary particles in a mixed crystal state at / g, a) a silicic acid or a precursor capable of producing silicic acid, b) an alkali, c) an organic solvent, and, if necessary, d) water. Regardless of whether the water / organic solvent ratio after addition is in the range of 0.1 to 10 and the silicon concentration is in the range of 0.0001 to 5 mol / liter, the surface of the mixed crystal oxide particles is added. There is provided a method for producing silica-coated mixed crystal oxide particles characterized by depositing silica to form a silica film.
[0016]
In order to achieve the third object of the present invention, it is desirable to add silica-coated mixed crystal oxide particles in which the surface of the mixed crystal oxide particles is coated with silica having a silica film thickness of 0.1 to 25 nm. The present inventors have found that a cosmetic material having the following characteristics can be obtained, and have completed the third aspect of the present invention.
[0017]
That is, according to the third aspect of the present invention, the mixed crystal oxide particles are 10 to 200 m. ² The present invention relates to the provision of a cosmetic containing mixed crystal oxide particles having a BET specific surface area of / g and containing primary particles in a mixed crystal state.
[0018]
Further, in the third aspect of the present invention, the silica-coated mixed crystal oxide particles measured by a tetralin auto-oxidation method with respect to the cosmetic containing silica-coated mixed crystal oxide particles having a silica film thickness of 0.1 to 25 nm. Has a photocatalytic activity of 60 Pa / min. Hereinafter, preferably 45 Pa / min. In the following, the dye fading rate (ΔABS) of the silica-coated mixed crystal oxide particles measured by the sunset yellow method ₄₉₀ / Hr) is 0.1 or less, preferably 0.06 or less, and the dynamic friction coefficient of the silica-coated mixed crystal oxide particles measured by the glass plate method is 0.550 or less, preferably 0.500 or less. It relates to providing cosmetics.
[0019]
Furthermore, the third aspect of the present invention relates to providing the cosmetic containing an antioxidant and the cosmetic containing an ultraviolet absorber.
[0020]
That is, the present invention relates to the following matters.
[1] BET specific surface area of 10 to 200 m ² A silica-coated mixed crystal oxide particle characterized in that the surface of a mixed crystal oxide particle containing primary particles in a mixed crystal state at / g is coated with dense thin-film silica.
[2] The silica-coated mixed crystal oxide particle according to [1], wherein the silica film has a thickness of 0.1 to 25 nm.
[3] The photocatalytic activity measured by the tetralin auto-oxidation method is 60 Pa / min. The silica-coated mixed crystal oxide particle according to the above [1] or [2], characterized in that:
[0021]
[4] Silica coating is 1150 to 1250 cm ^-1 And 1000-1100cm ^-1 Of the absorption peak intensity of the infrared absorption spectrum of I (I = I ₁ / I ₂ : In the formula I ₁ 1150-1250cm ^-1 Maximum absorption peak intensity in the range I ₂ Is 1000-1100cm ^-1 Represents the maximum absorption peak intensity within the range. ) Is 0.2 or more and the refractive index is 1.435 or more, the silica-coated mixed crystal oxide particles according to any one of the above [1] to [3].
[5] Dye fading rate (ΔABS) measured by the sunset yellow method ₄₉₀ The silica-coated mixed crystal oxide particles according to any one of [1] to [4], wherein / hr) is 0.1 or less.
[6] The silica-coated mixed crystal oxide particle according to any one of [1] to [5], wherein a dynamic friction coefficient measured by a glass plate method is 0.550 or less.
[0022]
[7] In a gas phase production method for producing a metal oxide by oxidizing a mixed gas containing a metal halide with an oxidizing gas at a high temperature, the metal halide includes chloride, bromide, iodine, titanium, silicon and aluminum. [1] to [6], wherein the mixed gas containing at least two kinds of compounds selected from the group consisting of compounds and an oxidizing gas are preheated to 500 ° C. or higher and reacted. ] The silica-coated mixed crystal oxide particles according to any one of the above. [8] At least two or more compounds selected from the group consisting of chlorides, bromides, and iodides of titanium, silicon and aluminum are vaporized and mixed in a gaseous state, with the mixed gas containing a metal halide. The silica-coated mixed crystal oxide particle according to the above [7], which is a particle.
[9] The mixed crystal oxide particles according to any one of the above [1] to [8], wherein the mixed crystal oxide particles are mixed crystal oxide particles containing a mixed crystal having a titanium-oxygen-silicon bond in the primary particles. The silica-coated mixed crystal oxide particles described.
[0023]
[10] The mixed crystal oxide particle according to any one of the above [1] to [8], wherein the mixed crystal oxide particle is a mixed crystal oxide containing a mixed crystal having a titanium-oxygen-aluminum bond in the primary particle. Silica-coated mixed crystal oxide particles.
[11] Lattice planes (100), (002), (101) in which the mixed crystal oxide particles include crystal structures of zinc oxide and silica, and are X-ray crystallographically characteristic diffraction peaks of crystalline zinc oxide. And any one of the above [1] to [6], characterized in that it is a composite oxide mainly composed of zinc oxide having a diffraction peak on the lattice plane (101), which is a diffraction peak peculiar to crystalline silica. The silica-coated mixed crystal oxide particles according to claim 1.
[12] The silica-coated mixed crystal oxide particles as described in [11] above, wherein the mixed crystal oxide particles contain each crystal structure of zinc oxide and silica in the primary particles.
[0024]
[13] The silica described in [11] or [12], wherein the mixed crystal oxide particles are mixed crystal oxide particles containing a mixed crystal having a zinc-oxygen-silicon bond in the primary particles. Coated mixed crystal oxide particles.
[14] In a gas phase reaction in which mixed crystal oxide particles oxidize gaseous zinc in the presence of oxygen and water vapor, a Zn source gas containing gaseous zinc in an inert gas, and oxygen and water vapor It is a composite oxide produced by introducing an oxidizing gas into a reactor, causing an oxidation reaction of zinc in the reactor, introducing a silicon-containing composition into the reaction zone, and oxidizing it. The silica-coated mixed crystal oxide particles according to any one of [11] to [13].
[15] The silica-coated mixed crystal oxide particle according to any one of the above [1] to [14], wherein the BET specific surface area reduction rate after heating at 800 ° C. for 1 hour is 30% or less.
[0025]
[16] The silica-coated mixed crystal oxide particle according to any one of [1] to [15], wherein the surface of the silica coating is hydrophobized with a hydrophobicity imparting agent.
[17] The above [16], wherein the hydrophobicity-imparting agent is one or more hydrophobicity-imparting agents selected from the group consisting of silicone oils, alkoxysilanes, silane coupling agents, and higher fatty acid salts. The silica-coated mixed crystal oxide particles described in 1.
[18] A) BET specific surface area of 10 to 200 m ² Mixed crystal oxide particles containing primary particles in a mixed crystal state at / g, b) silicic acid containing no organic group and halogen, or precursor capable of producing silicic acid, c) alkali, d) organic solvent, and f) water. Regardless of the order, the water / organic solvent ratio after addition is in the range of 0.1 to 10 and the silicon concentration is in the range of 0.0001 to 5 mol / liter. The method for producing silica-coated mixed crystal oxide particles according to any one of [1] to [17], wherein a dense thin-film silica is selectively formed.
[0026]
[19] In a mixture of a) alkali, b) organic solvent and c) water, d) a BET specific surface area of 10 to 200 m ² Mixed crystal oxide particles containing primary particles in a mixed crystal state at / g, and further, e) a silicic acid not containing an organic group and a halogen or a precursor capable of producing the silicic acid, f) an organic solvent, and if necessary And f) a mixture of water is added so that the water / organic solvent ratio after addition is in the range of 0.1 to 10 and the silicon concentration is in the range of 0.0001 to 5 mol / liter, The method for producing silica-coated mixed crystal oxide particles according to any one of [1] to [17], wherein dense thin-film silica is selectively formed on the surface of the mixed crystal oxide particles.
[20] The silica-coated mixed crystal oxide particle according to [18] or [19], wherein the alkali is at least one selected from the group consisting of ammonia, ammonium carbonate, ammonium hydrogen carbonate, ammonium formate, and ammonium acetate. Production method.
[0027]
[21] The organic solvent according to any one of [18] to [20], wherein the organic solvent is at least one selected from the group consisting of methanol, ethanol, propanol, pentanol, tetrahydrofuran, 1,4-dioxane and acetone. A method for producing silica-coated mixed crystal oxide particles.
[22] Silica-coated mixed crystal oxide particles produced by the production method according to any one of [18] to [21].
[23] A cosmetic comprising the silica-coated mixed crystal oxide particles according to any one of [1] to [17] and [22].
[0028]
[24] The cosmetic as described in [23] above, which contains an antioxidant.
[25] The cosmetic according to [23] or [24] above, which contains an organic ultraviolet absorber.
[26] An ultraviolet protection cosmetic comprising the cosmetic according to any one of [23] to [25].
[27] The UV-preventive cosmetic according to [26] above, which is a W / O or O / W emulsion or cream, foundation or gel.
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
First, the silica-coated mixed crystal oxide particles (first side) and the production method (second side) that can be suitably used for the cosmetic of the present invention (third side) will be described.
[0030]
In the cosmetic of the present invention, the surface of the mixed crystal oxide particles is 1150 to 1250 cm. ^-1 And 1000-1100cm ^-1 Of the absorption peak intensity of the infrared absorption spectrum of I (I = I ₁ / I ₂ : I ₁ 1150-1250cm ^-1 Maximum absorption peak intensity in the range I ₂ Is 1000-1100cm ^-1 Represents the maximum absorption peak intensity within the range. ) Is 0.2 or more, and silica-coated mixed crystal oxide particles coated with a silica film having a refractive index of 1.435 or more can be used.
[0031]
The silica-coated mixed crystal oxide particles that can be used in the cosmetic of the present invention are mixed with the mixed crystal oxide particles in order of silicic acid or a precursor capable of producing silicic acid, an alkali, an organic solvent, and water as necessary. Regardless of whether the water / organic solvent ratio after addition is within the range of 0.1 to 10 by volume and the silicon concentration is within the range of 0.0001 to 5 mol / liter, the mixed crystal oxide is added. It is obtained by a method in which silica is deposited on the surface of particle particles to form a silica coating.
[0032]
Particularly preferably, mixed crystal oxide particles are added to a mixture of alkali, organic solvent and water as required, and further, silicic acid or a precursor capable of producing silicic acid, an organic solvent, and water as necessary. The mixed solution was added so that the water / organic solvent ratio after addition was in the range of 0.1 to 10 and the silicon concentration was in the range of 0.0001 to 5 mol / liter. It is obtained by a method in which silica is deposited on the surface to form a silica film.
[0033]
The mixed crystal oxide particles used as the raw material for the silica-coated mixed crystal oxide particles of the present invention will be described.
In a vapor phase production method for producing a metal oxide by oxidizing a metal halide at high temperature with an oxidizing gas, the metal halide is at least selected from the group consisting of titanium, silicon and aluminum chlorides, bromides, and iodides. A mixed gas containing two or more kinds of compounds (hereinafter also referred to as “mixed metal halide gas”), wherein the mixed metal halide gas and the oxidizing gas are each preheated to 500 ° C. or more and reacted. BET specific surface area of 10 to 200 m ² It is an ultrafine oxide containing primary particles in a mixed crystal state at / g.
[0034]
Furthermore, the BET specific surface area is 10 to 200 m. ² / G and mixed crystal oxide particles including a mixed crystal in which a titanium-oxygen-silicon bond is present in a primary particle or a mixed crystal in which a titanium-oxygen-aluminum bond is present.
The mixed metal halide gas may be a gas mixture obtained by vaporizing at least two or more compounds selected from the group consisting of chloride, bromide, and iodide of titanium, silicon and aluminum alone.
[0035]
As a mode of supplying the mixed metal halide gas to the reaction tube, it is preferable to use a gas mixture obtained by vaporizing one kind of the metal halide alone. As the oxidizing gas, oxygen or water vapor or a mixed gas containing these is used.
[0036]
The titanium, silicon and aluminum chlorides, bromides and iodides used in the present invention are not limited, but any metal halide capable of generating the metal halide gas when preheated to at least 500 ° C. or more may be used. TiCl _Four , TiBr _Four , SiCl _Four AlCl _Three Is particularly preferred.
[0037]
In the present invention, the mixed metal halide gas and the oxidizing gas must be preheated to at least 500 ° C. or higher, preferably 650 ° C. or higher, more preferably 800 ° C. or higher before reacting. When the preheating temperature of the mixed metal halide gas and oxidizing gas is lower than 500 ° C., the generation of uniform nuclei is low and the reactivity is low, so that it is difficult to form ultrafine particles, and the residual chlorine after desalting increases. .
[0038]
In the present invention, each of the mixed metal halide gas and the oxidizing gas is desirably supplied to the reaction tube at a flow rate of 10 m / second or more, preferably 30 m / second or more, and 600 ° C. is set in the reaction tube. These gases are preferably reacted so that the time during which the gas stays and reacts under a high temperature condition exceeding the above (hereinafter also referred to as “high temperature residence time”) is within 1.0 seconds.
[0039]
The flow rate when the mixed metal halide gas and oxidizing gas are introduced into the reaction tube is preferably 10 m / second or more in view of the reaction. This is because by increasing the flow velocity, mixing of both gases is promoted. If the introduction temperature of the gas into the reaction tube is 500 ° C. or higher, the reaction is completed simultaneously with the mixing, so that the generation of uniform nuclei is promoted, and the zone in which the grown particles are formed under the control of CVD can be shortened. it can.
[0040]
The source gas is preferably introduced into the reaction tube so that the gas introduced into the reaction tube is sufficiently mixed. If the gas is sufficiently mixed, the fluid state of the gas in the reaction tube is not particularly limited. However, for example, a fluid state in which turbulent flow occurs is preferable. Moreover, a swirl flow may exist.
[0041]
The flow rate of the gas supplied into the reaction tube is preferably large in order to completely mix the gases, and in particular, the average flow rate is preferably 5 m / second or more. If the flow rate of the gas in the reaction tube is 5 m / second or more, mixing in the reaction tube can be sufficiently performed.
[0042]
This reaction in the reaction tube is an exothermic reaction, and the reaction temperature is higher than the sintering temperature of the produced ultrafine titanium oxide. Although there is heat radiation from the reaction apparatus, the produced fine particles are sintered and become grown particles unless they are rapidly cooled after the reaction. In the present invention, the high temperature residence time exceeding 600 ° C. in the reaction tube is preferably set to 1.0 second or less and then rapidly cooled.
[0043]
As a means for rapidly cooling the particles after the reaction, introduction of a large amount of cooling air, gas such as nitrogen, or spraying of water into the mixture after the reaction is employed.
[0044]
Further, the mixed metal halide gas used as a raw material is used in 100% by volume of the mixed metal halide gas, or preferably diluted with an inert gas to be 10% by volume or more and less than 100%, more preferably 20% by volume. More than 100% by volume can be charged. When a gas having a mixed metal halide gas concentration (total concentration of metal halide gas) of 10% by volume or more is used as a raw material, the generation of uniform nuclei increases or the reactivity increases. As the inert gas, one that does not react with the mixed metal halide and is not oxidized should be selected. Specifically, nitrogen, argon, etc. are mentioned as preferable dilution gas.
[0045]
The mixed crystal oxide particles of the present invention have a BET specific surface area of 10 to 200 m. ² The average primary particle diameter is 0008 μm to 0.1 μm, preferably 0.015 μm to 0.1 μm.
[0046]
The mixed crystal oxide particles of the present invention are composite oxides mainly composed of zinc oxide, each containing a crystal structure of zinc oxide and silica, and a diffraction peak peculiar to crystalline zinc oxide in X-ray crystallography. Is a complex oxide characterized by having diffraction peaks on the lattice planes (100), (002), (101) and the lattice plane (101), which is a diffraction peak peculiar to crystalline silica. Each of the crystalline structures of silica and silica is a composite oxide included in the primary particles of the composite oxide.
[0047]
In a reaction in which zinc vapor is oxidized in an atmosphere containing oxygen and water vapor, an inert gas containing zinc vapor (hereinafter also referred to as “Zn source gas”) and a gas containing oxygen and water vapor (hereinafter referred to as “oxidative”). Gas ") is introduced into the reactor to oxidize zinc. Into the reaction field, for example, a silicon-containing composition containing organosilane, silicon halide or the like (hereinafter sometimes referred to as “Si raw material”) is introduced by spraying in a liquid state, preferably in a gaseous state, and Si. The raw material is oxidized to obtain the composite oxide of the present invention. At this time, the Si raw material may contain an inert gas as a carrier gas.
[0048]
The oxidizing gas may be obtained by combusting a combustible gas such as propane or hydrogen with an excess combustion supporting gas of oxygen or air, and includes a nozzle for introducing the oxidizing gas and a Zn source gas. There may be a plurality of nozzles to be introduced and nozzles to introduce the Si raw material.
[0049]
The oxide thus obtained is a mixed crystal oxide in which crystalline silica is uniformly dispersed in the crystalline zinc oxide particles, and the main component is zinc oxide having excellent dispersibility. The main component here is the most abundant component among the constituent components, and the component of 50% by mass or more is the main component.
[0050]
This composite oxide has a strong diffraction peak on the lattice planes (100), (002), and (101) peculiar to crystalline zinc oxide in X-ray crystallography, and is a synthesis of zinc oxide that becomes very high in temperature. Since silica is formed in the reaction field, it is possible to obtain particles having a strong diffraction peak on the lattice plane (101) peculiar to crystalline silica in terms of X-ray crystallography.
[0051]
Further, this composite oxide can be confirmed by local component analysis (EDX) to be a composite oxide in which silica crystallites are uniformly dispersed in zinc oxide crystallites. In the conventional composite oxide, since the second component is added after the core material is synthesized, the second component has a core-shell structure surrounding the first component, or the first component particle and the second component. It was a simple mixed powder in which the component particles were present individually.
[0052]
As in the composite oxide of the present invention, in all particles, the crystalline second component (silica) is uniformly dispersed in the crystalline first component (zinc oxide). It is a complex oxide having diffraction peaks of both silica and zinc oxide.
[0053]
Regardless of the shape of these particles, it is confirmed by local component analysis (EDX) that the Si component is uniformly present in the Zn component.
It is also possible to supply an inert gas to the zinc vaporizer simultaneously with the raw metal zinc. Examples of the inert gas include nitrogen, helium, and argon.
[0054]
Next, the Zn source gas is introduced into the reactor from the zinc vaporizer through the Zn source gas heater. The temperature at which the Zn source gas is introduced into the reactor is 900 to 1800 ° C, preferably 900 to 1500 ° C, and more preferably 950 to 1300 ° C. The speed | rate which introduce | transduces Zn raw material gas into a reactor is 10-250 m / sec, Preferably it is 50-150 m / sec.
[0055]
The temperature at which the oxidizing gas is introduced into the reactor is 900 to 1800 ° C, preferably 900 to 1500 ° C, more preferably 950 to 1300 ° C. The oxygen concentration of the oxidizing gas is 5% by volume to 100% by volume, preferably 50% by volume to 100% by volume.
[0056]
The silicon-containing composition is vaporized together with an inert gas as a carrier gas and introduced into the reactor. The silicon-containing composition is a composition containing organosilane or silicon halide.
[0057]
The temperature at which the Si raw material is introduced into the reactor is 50 ° C. or more and 1200 ° C. or less, preferably the boiling point or more and the decomposition temperature or less of the silicon-containing composition. For example, when tetraethoxysilane is used, an introduction temperature of 170 ° C. or higher and 400 ° C. or lower which is gaseous without being decomposed is preferable.
[0058]
The supply amount of the Si raw material is such that the Si content in the obtained composite oxide is preferably 5% by mass or more and less than 50% by mass, particularly preferably 5% by mass or more and less than 35% by mass in terms of silica. Amount.
[0059]
The introduction flow rate of the Si raw material is very important in determining the silica distribution in the composite oxide particles. When a coaxial parallel flow nozzle is used, the flow rate of introduction as a gaseous Si raw material is adjusted to a range of 30% to 300%, preferably 80% to 150%, of the Zn raw material gas flow rate. Silica can be uniformly dispersed in the product particles.
[0060]
Further, by setting the introduction flow rate to a flow rate exceeding 150% of the Zn raw material gas flow rate, it is possible to make more silica unevenly distributed in the vicinity of the surface than the particle central portion. When the nozzle to be used is not a coaxial nozzle, the same effect can be obtained if the direction of introduction is directed to the downstream side and the reaction zone of the Si raw material is located downstream of the zinc reaction zone.
[0061]
Regarding the particle shape, the ratio of tetrapod-like and needle-like particles can be increased by reducing the amount of the silicon-containing composition to be introduced. The proportion of tetrapod-like and needle-like particles affects the dispersibility of the complex oxide in the medium, and is preferably 5 to 95% by number, particularly preferably 40 to 90% by number.
[0062]
As long as the Zn source gas, the oxidizing gas, and the Si source are within the above-mentioned conditions, the oxidation reaction proceeds rapidly in any introduction mode such as coaxial parallel flow, cross flow, and oblique alternating current.
[0063]
These oxidation reactions proceed in a high temperature reactor. In order to suppress the particle growth more completely, the high temperature residence time may be controlled by a method such as rapid cooling at a specific position.
Further, the mixed crystal oxide particles of the present invention have a BET specific surface area reduction rate of 30% or less after heating at 800 ° C. for 1 hour in the evaluation of the BET specific surface area reduction rate after heating as an index of sintering resistance. Have
[0064]
Silicic acid used in the composition for forming a silica coating is, for example, orthosilicic acid and its silica as shown in the section of “silicic acid” in the Chemical Dictionary (Kyoritsu Shuppan Co., Ltd. Examples of the polymer include metasilicic acid, mesosilicic acid, mesotrisilicic acid, and mesotetrasilicic acid.
[0065]
The composition containing silicic acid is a precursor capable of producing silicic acid, such as tetraalkoxysilane (Si (OR)). _Four In the formula, R is a hydrocarbon group, specifically, tetramethoxysilane, tetraethoxysilane, tetra n-propoxysilane, tetraisopropoxysilane, tetra n-butoxysilane or the like. ), Water, an alkali, and an organic solvent are added to and stirred, and the hydrolysis reaction proceeds. This method is preferable because it is easy to handle or operate and practical. Of these, tetraethoxysilane is a preferred material.
[0066]
In addition, water, alkali, and organic solvent are added to tetrahalogenated silane and hydrolyzed, alkali and organic solvent are added to water glass, or water glass is treated with a cation exchange resin to obtain alkali, A composition containing silicic acid can also be obtained by using a method of adding an organic solvent.
[0067]
Tetraalkoxysilane, tetrahalogenated silane, water glass, etc. used as a precursor capable of producing silicic acid are not particularly limited and may be industrially used or widely used as reagents, but preferably have higher purity. Is suitable. Furthermore, the composition for forming a silica film of the present invention may contain an unreacted material of the above-mentioned silicic acid raw material.
[0068]
The amount of silicic acid is not particularly limited, but is preferably in the range of 0.0001 to 5 mol / liter as the silicon concentration. If the silicon concentration is less than 0.0001 mol / liter, the formation rate of the silica film is very slow and not practical. If it exceeds 5 mol / liter, silica particles may be formed in the composition without forming a coating on the surface of the metal oxide.
[0069]
The silicon concentration can be calculated from the amount of silicic acid raw material, for example, tetraethoxysilane, but the composition can also be measured by atomic absorption analysis. For the measurement, the spectrum of silicon having a wavelength of 251.6 nm is used as an analysis line, and the frame is preferably made of acetylene / nitrous oxide.
[0070]
The water used in the composition for forming a silica film is not particularly limited, but is preferably water from which particles have been removed by filtration or the like. If particles are contained in water, it is not preferable because they are mixed as impurities in the product.
[0071]
Water is preferably used in such an amount that the water / organic solvent ratio is in the range of 0.1 to 10 by volume ratio. If it is out of this range, film formation may not be possible or the film formation speed may be extremely reduced. More preferably, the water / organic solvent ratio is in the range of 0.1 to 0.5 by volume ratio. When the water / organic solvent ratio is in the range of 0.1 to 0.5, the type of alkali used is not limited. In a range outside this range, that is, when the water / organic solvent ratio is 0.5 or more, it is preferable to form a film using an alkali not containing an alkali metal, for example, ammonia, ammonium hydrogen carbonate, ammonium carbonate or the like.
[0072]
The alkali used in the composition for forming a silica film is not particularly limited. For example, inorganic alkalis such as ammonia, sodium hydroxide and potassium hydroxide; inorganic alkali salts such as ammonium carbonate, ammonium hydrogen carbonate, sodium carbonate and sodium hydrogen carbonate Organic alkalis such as monomethylamine, dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, pyridine, aniline, choline, tetramethylammonium hydroxide, guanidine; ammonium formate, ammonium acetate, monomethylamine formate, dimethylamine acetate, lactic acid Organic acid alkali salts such as pyridine, guanidinoacetic acid and aniline acetate can be used.
[0073]
One or a combination of two or more from these groups can be used. Among these, ammonia, ammonium carbonate, ammonium hydrogen carbonate, ammonium formate, ammonium acetate, sodium carbonate, and sodium hydrogen carbonate are particularly preferable.
The purity of the alkali used in the present composition is not particularly limited, and may be industrially used or widely used as a reagent, but higher purity is preferable.
[0074]
In order to increase the film formation rate, it is effective to increase the temperature during film formation. In this case, it is preferable to use an alkali and an organic solvent that hardly volatilize and decompose at the film forming temperature.
[0075]
For example, in the case of sodium carbonate, the alkali can be added with a small amount of about 0.002 mol / liter, but a large amount of about 1 mol / liter may be added. However, it is not preferable to add a solid alkali in an amount exceeding the solubility because it is mixed as an impurity in the silica-coated mixed crystal oxide particles.
[0076]
By using an alkali not containing an alkali metal as a main component, silica-coated mixed crystal oxide particles having a low alkali metal content can be produced. Among these, ammonia, ammonium carbonate, and ammonium hydrogen carbonate are particularly preferable because of high film formation speed and ease of residue removal.
[0077]
The organic solvent used for the film-forming composition is preferably such that the composition forms a uniform solution. For example, alcohols such as methanol, ethanol, propanol and pentanol; ethers and acetals such as tetrahydrofuran and 1,4-dioxane; aldehydes such as acetaldehyde; ketones such as acetone, diacetone alcohol and methyl ethyl ketone; ethylene glycol, Polyhydric alcohol derivatives such as propylene glycol and diethylene glycol can be used. Among these, alcohols are preferable, and ethanol is particularly preferable. As an organic solvent, 1 type selected from these groups, or 2 or more types can be mixed and used.
[0078]
There is no restriction | limiting in particular in the purity of the organic solvent used by this composition, Although what is used widely industrially or widely as a reagent may be used, Preferably the thing of higher purity is suitable.
[0079]
A general solution preparation method can be applied to the preparation of the composition for forming a silica film. For example, a method of adding and stirring tetraethoxysilane after sufficiently dispersing the mixed crystal oxide particles by adding and stirring alkali, water, and an organic solvent to a predetermined amount of the mixed crystal oxide particles. However, even if any of these mixing orders is repeated first or a plurality of times, a film can be formed. When mixing water and tetraethoxysilane, it is preferable to dilute both with an organic solvent from the viewpoint of controllability of the reaction.
[0080]
The composition for forming a silica film thus prepared is a stable composition, and substantially no coating or precipitation occurs before contacting with the mixed crystal oxide particle. By bringing the mixed crystal oxide particle particles into contact with the composition, a silica coating is selectively formed on the surface of the mixed crystal oxide particle particles.
[0081]
As used herein, “selective” means that the formation of a film accompanying silica deposition proceeds only on the surface of the mixed crystal oxide particle particles, and does not cause silica particle formation due to uniform nucleation in the solution. This means that the silica film thickness and silica content of the silica-coated mixed crystal oxide particles can be controlled.
[0082]
Basically, a silica film forming composition containing mixed crystal oxide particles is added to and kept at a predetermined temperature to selectively deposit silica on the surface of the mixed crystal oxide particles. A film can be formed. A method of forming a silica film by adding mixed crystal oxide particles after preparing a film forming composition in advance, or adding other raw material components after previously suspending the mixed crystal oxide particles in a solvent. Thus, a film forming composition may be used, and a method of forming a silica film may be used. That is, the order in which the raw material of the film-forming composition and the mixed crystal oxide particles are added is not particularly limited, and any film can be formed first.
[0083]
Among these methods, after preparing a suspension with mixed crystal oxide particles, an organic solvent, water and an alkali, and adding tetraalkoxysilane diluted with the organic solvent over time, a silica film with good denseness can be obtained. This is preferable because it can be formed and an industrially useful continuous process can be constructed.
[0084]
Furthermore, when mixed crystal oxide particles are added to a mixed liquid of an organic solvent, water and alkali, and tetraalkoxysilane diluted with water in some cases is added thereto over time, a silica film with good denseness is obtained. This is preferable because an industrially useful continuous process can be constructed.
[0085]
Since the silica film grows by deposition on the surface of the mixed crystal oxide particles, the film thickness can be increased by increasing the film formation time. Of course, when most of the silicic acid or its precursor in the film-forming composition is consumed due to the formation of the film, the film formation rate decreases, but the silicic acid or its precursor corresponding to the consumption is added in sequence. By doing so, the silica film can be continuously formed at a practical film formation rate.
[0086]
In particular, the mixed crystal oxide particles are retained for a predetermined time in the film-forming composition to which silicic acid corresponding to the desired silica film thickness is added, the silica film is formed, and the silica-coated mixed crystal oxide particles are taken out of the system. Then, an organic solvent, volatile alkali, etc. can be collect | recovered by a separation / purification process, and it can use for the film formation of the next mixed crystal oxide particle, and can build a process with high economical efficiency and productivity.
[0087]
Although the temperature at the time of film formation is not specifically limited, Preferably it is the range of 10 to 100 degreeC, More preferably, it is the range of 20 to 50 degreeC. The higher the temperature, the higher the film forming rate. However, if the temperature is too high, it becomes difficult to keep the solution composition constant due to volatilization of the components in the composition. On the other hand, if the temperature is too low, the film formation rate becomes slow, which is not practical.
[0088]
Moreover, the pH at the time of film formation should just be alkaline pH. However, the pH is preferably such that the mixed crystal oxide particles do not gel. Moreover, when silica-coated mixed crystal oxide particles whose solubility increases depending on the pH, it is preferable to control the pH of the film-forming composition.
[0089]
For example, in the production of a silica-coated product of ultrafine mixed crystal oxide containing zinc oxide as a main component, it is preferable to reduce the alkali addition amount and control the pH during film formation to 11 or less. When the pH exceeds 11, the yield of the silica-coated product may decrease. Furthermore, since the film formation rate decreases due to a decrease in the amount of alkali, it is preferable to maintain a practical film formation rate by increasing the film formation temperature or increasing the silicon concentration.
[0090]
After the coating is formed, unreacted raw materials, alkalis and organic solvents are removed and concentrated as necessary to obtain silica-coated mixed crystal oxide particles. As the method, a general separation method such as evaporation, distillation, membrane separation or the like can be used.
[0091]
The silica-coated sol medium of the present invention is not particularly limited, but is usually selected from dermatologically harmless media. For example, water, natural oil, or silicone oil is used. The change from the aqueous system to another medium can be performed by general solvent replacement, membrane separation, or the like.
[0092]
Moreover, silica-coated mixed crystal oxide particle particles can be obtained by solid-liquid separation of the silica-coated mixed crystal oxide particle sol, followed by drying. As a solid / liquid separation method, general separation methods such as filtration, centrifugal sedimentation, and centrifugal separation can be used. As a drying method, a general drying method such as natural drying, warm air drying, vacuum drying, spray drying, or the like can be used. If the particles aggregate due to drying, they can be crushed. Since the silica-coated mixed crystal oxide particles of the present invention have a strong covering power of the silica coating on the surface of the mixed crystal oxide particle particles as the base material, the silica coating is destroyed by pulverization and the effect of suppressing the photocatalytic activity is reduced And the feeling of use does not deteriorate. The pulverization method is not particularly limited, and a jet mill, a high-speed rotary mill, or the like can be used.
[0093]
The silica film obtained by the above production method is 1150 to 1250 cm. ^-1 And 1000-1100cm ^-1 Of the absorption peak intensity of the infrared absorption spectrum of I (I = I ₁ / I ₂ : I ₁ 1150-1250cm ^-1 Maximum peak intensity within the absorption range, I ₂ Is 1000-1100cm ^-1 Represents the maximum absorption peak intensity within the range. ) Is 0.2 or more and the refractive index is 1.435 or more.
[0094]
That is, the silica film is a dense and practical silica film that cannot be obtained without firing while maintaining the surface properties (moist feeling, slipperiness) of the original silica film. Furthermore, the above silica film is good for the complicated shape of the mixed crystal oxide particle particles of the base material, and even if it is a thin film of about 0.1 nm, it has good coverage and the ability to conceal photocatalytic activity. high. Moreover, since it can be set as a silica film with an extremely low alkali metal content, a silica film that does not dissolve in a high-temperature and high-humidity atmosphere and does not change the physical properties of the silica-coated mixed crystal oxide particles can be obtained.
[0095]
In the cosmetic of the present invention, surface-hydrophobized silica-coated mixed crystal oxide particles obtained by further surface-treating the silica-coated mixed crystal oxide particles with a hydrophobicity imparting agent can also be used.
[0096]
As a method for surface-treating the silica-coated mixed crystal oxide particles with a hydrophobicity imparting agent, a known method can be used. In the present invention, it is preferable to use a wet method from the viewpoint that the dispersibility of the silica-coated mixed crystal oxide particles and the small primary particle diameter are not impaired. For example, in the wet method, a hydrophobicity imparting agent, a solution thereof, a reaction catalyst, or the like is added to a liquid in which silica-coated mixed crystal oxide particles are dispersed in water, an organic solvent, or a mixed solvent. Method can be used.
[0097]
Further, the silica-coated mixed crystal oxide particles can be directly hydrophobized using a dry method or a spray method. In the dry method, a method of spraying a hydrophobicity-imparting agent or an organic solvent solution of the hydrophobicity-imparting agent onto the silica-coated mixed crystal oxide particle particles stirred by a mixer such as a V-type mixer or a Henschel mixer Can be added, and further mixed, uniformly adhered to the surface of the powder, dried, and if necessary, heated in order to adhere firmly. In addition, in the spray method, a method of spraying a hydrophobicity imparting agent or a solution thereof onto the silica-coated mixed crystal oxide particle particles having a high temperature to coat the surface can be used.
[0098]
The hydrophobicity-imparting agent used in the present invention is not particularly limited, and examples thereof include higher fatty acids such as wax, higher fatty acid triglycerides, higher fatty acids, higher fatty acid polyvalent metal salts, and polyvalent metal salts of higher aliphatic sulfates; Alcohol or derivatives thereof; organic fluoro compounds such as perfluoro- or partially fluorinated higher fatty acids and higher alcohols; organic silicon compounds such as silicone oils, organic alkoxysilanes, organic chlorosilanes, and silazanes can be used. Higher fatty acid polyvalent metal salts, silicone oil, silane coupling agents, and alkoxysilanes are preferably used, but alkoxysilanes and silane coupling agents are particularly preferably used from the viewpoint of practical effects.
[0099]
The silicone oil used in the present invention is not particularly limited, and examples thereof include dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, and cyclic polydimethylsiloxane. Further, modified silicone oils such as alkyl-modified, polyether-modified, amino-modified, mercapto-modified, epoxy-modified and fluorine-modified may be used.
[0100]
There are no particular restrictions on the chlorosilanes used in the present invention, but trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, methyldichlorosilane, dimethylvinylchlorosilane, methylvinyldichlorosilane, triphenylchlorosilane, methyldiphenylchlorosilane, diphenyldisilane. Examples include chlorosilane, methylphenyldichlorosilane, and phenyltrichlorosilane.
[0101]
Silazanes used in the present invention are not particularly limited, and examples include hexamethyldisilazane, N, N′-bis (trimethylsilyl) urea, N-trimethylsilylacetamide, dimethyltrimethylsilylamine, diethyltrimethylsilylamine, and trimethylsilylimidazole. .
[0102]
The organoalkoxysilanes used in the present invention are not particularly limited. For example, vinyltrichlorosilane, vinyltris (β-methoxyethoxy) silane, vinyltrimethoxysilane, vinyltriethoxysilane, γ- (methacryloyloxypropyl) Trimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidyloxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, N-β (aminoethyl) γ-aminopropyl Trimethoxysilane, N-β (aminoethyl) γ-aminopropylmethyldietoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane and γ Silane coupling agents such as chloropropyltrimethoxysilane and methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, methyldimethoxysilane, methyldiethoxysilane, dimethylethoxy Examples include silane, dimethylvinylmethoxysilane, dimethylvinylethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, diphenyldimethoxysilane, and diphenyldiethoxysilane. Also, alkoxysilanes having perfluorinated or partially fluorinated alkyl groups can be used.
[0103]
In particular, an alkylalkoxysilane represented by the following formula (1) is preferably used.
[0104]
[Chemical 1]

[0105]
(Wherein R ¹ Is an alkyl group having 1 to 4 carbon atoms or a phenyl group, R ² Is a hydrogen group, an alkyl group having 1 to 4 carbon atoms or a phenyl group, X is an alkoxyl group having 1 to 4 carbon atoms, and n is an integer of 0 to 2. )
When surface treatment is performed using alkylalkoxysilanes as hydrophobicity imparting agents, the liquid phase method is particularly preferable.
[0106]
That is, after the silica coating of the mixed crystal oxide particle particles is performed according to the above method, the hydrophobicity imparting agent is added without separating the silica coated mixed crystal oxide particle particles, and water or an organic solvent is added if necessary. Adding an alkali to form a composition in which the water / organic solvent ratio is in the range of 0.1 to 10 and the silicon concentration derived from the alkylalkoxysilane is in the range of 0.0001 to 5 mol / liter; Surface treatment can be performed by selectively depositing the reaction product of the alkylalkoxysilane on the surface of the silica-coated mixed crystal oxide particle.
Since this method does not have a drying step, it does not impair the dispersibility of the silica-coated mixed crystal oxide particles and the small primary particle size, and an intermediate solid separation step can be omitted, which is industrially advantageous.
[0107]
The hydrophobizing composition in the method for producing surface-hydrophobized silica-coated mixed crystal oxide particles using alkylalkoxysilanes has a water / organic solvent ratio in the range of 0.1 to 10 in terms of volume ratio, and is derived from alkylalkoxysilane. The concentration of silicon is 0.0001 to 5 mol / liter. Regarding the silicon concentration, water, water / organic solvent ratio, alkali, organic solvent, temperature, pH, and separation / purification step in the present composition, the description in the silica film-forming composition can be applied as it is. The composition can be obtained by adding alkylalkoxysilanes to the silica film-forming composition after completion of silica film formation, instead of the precursor that produces silicic acid, but the composition and conditions are not necessarily the same. There is no need to make it. For example, when the reaction rate of the alkylalkoxysilane is different from that of a precursor that produces silicic acid, an alkali, water, or a solvent may be added if necessary, and is practical within the above-mentioned limit range. Reaction conditions such as water / organic solvent ratio, silicon concentration, pH, temperature, etc. that give reaction rate can be selected.
[0108]
The coating amount of the hydrophobicity-imparting agent may be at least the minimum coating amount that allows the hydrophobicity-imparting agent to completely cover the surface of the silica-coated mixed crystal oxide particles. This amount is expressed by the following formula (2)
[0109]
[Chemical 2]

[0110]
Can be calculated. If the added amount of the hydrophobicity-imparting agent is excessive, the amount of precipitation on the surface other than the surface of the silica-coated mixed crystal oxide particle particles increases, which is not economical.
[0111]
Since it depends on the molecular weight of the hydrophobicity-imparting agent and the specific surface area of the silica-coated mixed crystal oxide particle particles, it cannot be determined unconditionally. Usually, it is preferably 30% by mass or less based on the silica-coated mixed crystal oxide particle particles, More preferably, it is 20 mass% or less.
[0112]
The second aspect of the present invention will be described below. The silica film thickness of the silica-coated mixed crystal oxide particle particles that can be used in the cosmetic of the present invention is preferably 0.1 to 25 nm. If it is 0.1 nm or less, there may be a case where a cosmetic having a sufficient photocatalytic activity suppressing effect and a good feeling of use cannot be obtained, and if it is 25 nm or more, a cosmetic having a sufficient ultraviolet shielding ability may not be obtained. Yes and not economical.
[0113]
The photocatalytic activity of the silica-coated mixed crystal oxide particles of the present invention by a tetralin auto-oxidation method is 60 Pa / min. Or less, preferably 50 Pa / min. Hereinafter, more preferably 45 Pa / min. It is as follows. 60 Pa / min. If it exceeds 1, a sufficient photocatalytic activity suppressing effect cannot be obtained, and a cosmetic with good storage stability may not be obtained.
[0114]
The dye fading speed measured by the sunset yellow method of the silica-coated mixed crystal oxide particles of the present invention is 0.1 or less, preferably 0.06 or less, more preferably 0.02 or less. . If it exceeds 0.1, the effect of suppressing the photocatalytic activity is not sufficient, and a cosmetic with high storage stability may not be obtained.
[0115]
The primary particle size of the silica-coated mixed crystal oxide particle of the present invention is preferably 1 to 100 nm. If it is out of this range, a cosmetic having both a good feeling of use and transparency, and a high ultraviolet shielding ability may not be obtained. The primary particles and secondary particles referred to in the present invention are those defined by Kuichiro Teruichiro et al., “Powder”, p. 56-66, published in 1979.
[0116]
The powder dynamic friction coefficient measured by the glass plate method of the silica-coated mixed crystal oxide particles of the present invention is 0.55 or less, preferably 0.5 or less, more preferably 0.45 or less. If it exceeds 0.55, a cosmetic material having a good feeling in use may not be obtained.
[0117]
Since the silica-coated mixed crystal oxide particles of the present invention have a small primary particle size, low cohesiveness and good dispersibility, they have high ultraviolet shielding ability and high visible light transmittance. In addition, since it is coated with a dense and practical silica coating, it has a high effect of suppressing photocatalytic activity, hardly modifies other cosmetic ingredients, and has good tactile sensation and slipperiness.
[0118]
Therefore, by blending the silica-coated mixed crystal oxide particles, a UV-shielding cosmetic material having good storage stability, safety, and excellent transparency and usability can be obtained. In the case of the surface-hydrophobized silica-coated mixed crystal oxide particles, it is preferably used for oil-based cosmetics, W / O emulsion type cosmetics, and water-repellent type cosmetics that are less likely to collapse by water and sweat.
[0119]
The third aspect will be described below.
The cosmetic of the present invention contains the above silica-coated mixed crystal oxide particles and can be produced by an ordinary production method using an ordinary raw material that can be blended in the cosmetic.
[0120]
The cosmetic of the present invention is not particularly limited as long as it contains powder and oil, and includes those obtained by dispersing powder in a solvent or solution. Examples include white powder, foundation, powder, blusher, eye shadow, lipstick, eyeliner, mascara, eyebrow, cream, essence, lotion, lotion, emulsion, mousse and the like. In particular, in the case of surface-hydrophobized silica-coated mixed crystal oxide particles, oil-based cosmetics, W / O emulsified cosmetics, and water-repellent cosmetics that are less likely to collapse by water / sweat are preferred.
[0121]
As a constituent of the cosmetic of the present invention, there are a powder component and an oil component. Among these, constituents of the powder component include extender pigments (for example, mica, talc, kaolin, calcium carbonate, magnesium carbonate, anhydrous silicic acid, aluminum oxide, barium sulfate, etc.) in addition to silica-coated mixed crystal oxide particles. , White pigments (eg, titanium dioxide, zinc oxide, etc.) and colored pigments (eg, bengara, yellow iron oxide, black iron oxide, chromium oxide, ultramarine blue, bitumen, carbon black, etc.) can do. In order to further improve the feeling of use, spherical powder (for example, nylon powder, polymethyl methacrylate powder, etc.) can also be used.
[0122]
Oils to be blended in the cosmetic of the present invention include liquid paraffin, squalane, castor oil, glyceryl diisostearate, glyceryl triisostearate, glyceryl tri-2-ethylhexanoate, isopropyl myristate, glyceryl triisostearate, dimethylpoly Examples include siloxane, methylphenyl polysiloxane, petrolatum, diisostearyl maleate, and purified lanolin. The blending amount of oil in the cosmetic of the present invention is preferably 1 to 35% by mass, more preferably 3 to 30% by mass, and still more preferably 10 to 25% by mass.
[0123]
Moreover, you may mix | blend an organic type ultraviolet absorber in oil. The organic ultraviolet absorber refers to an organic compound having a function of protecting the skin by absorbing ultraviolet rays and converting the energy into heat, vibration, fluorescence, radicals and the like.
[0124]
The ultraviolet absorber that can be used in the cosmetic of the present invention is not particularly limited, and examples thereof include ultraviolet absorbers such as benzophenone series, salicylic acid series, PABA series, cinnamic acid series, dibenzoylmethane series, and urocanic acid series. Can be mentioned. The blending amount is in the range of 0.1 to 10% by mass, but it is desirable to make the blending amount appropriate depending on the ultraviolet absorbing ability of the absorbent. Even when the silica-coated mixed crystal oxide particles used in the present invention are used in combination with an organic ultraviolet absorber, decomposition of the absorber is suppressed, and a cosmetic having high ultraviolet shielding ability can be obtained.
[0125]
An existing emulsifier can be added to the cosmetic of the present invention at a general concentration. For example, Cosmetic Material Standards Second Edition Annotation, Japan Official Church Church, 1984 (Pharmaceutical Daily Report), Cosmetic Raw Material Standards Non-Standard, Supervised by Ministry of Health and Welfare Pharmaceutical Affairs Bureau Examination Division, 1993 (Pharmaceutical Daily Report), Cosmetic Raw Material Non-Standard Components Standards supplement, supervised by the Ministry of Health and Welfare Pharmacy Examination Division, 1993 (Pharmaceutical Daily), permission standards by cosmetic type, supervision by the Ministry of Health and Welfare Pharmacy Examination Division, 1993 (Pharmaceutical Daily), and Cosmetic Raw Material Dictionary, 1991 (Nikko Chemicals) Etc. All emulsifiers described in etc. can be used. Tocopheryl phosphates can also be used as emulsifiers.
[0126]
In the cosmetic of the present invention, in order to prevent inflammation due to ultraviolet rays, an existing anti-inflammatory component or anti-inflammatory component can be used in combination or mixed as long as there is no problem in safety. Anti-inflammatory ingredients that can be added to the cosmetics of the present invention include aniline derivative anti-inflammatory agents, salicylic acid derivative anti-inflammatory agents, pyrazolone derivative anti-inflammatory agents, indomethacin anti-inflammatory agents, mefenamic acid anti-inflammatory agents, antihistamines, anti-allergic agents, anti-inflammatory enzymes Agents and the like.
[0127]
In the cosmetic containing silica-coated mixed crystal oxide particles in the present invention, when an antioxidant, which is a substance having an antioxidative action, is used in combination, makeup with extremely low phototoxicity is achieved by suppressing the amount of free radicals generated by ultraviolet rays. A fee is obtained.
[0128]
The antioxidant of the cosmetic composition of the present invention is not particularly limited. For example, vitamin A, β-carotene, astaxanthin, vitamin B, vitamin C, L-ascorbic acid-2-magnesium phosphate, L-ascorbic acid 2-sodium phosphate, L-ascorbic acid-2-sodium magnesium phosphate, L-ascorbic acid-2-glucoside-6-palmitate, L-ascorbic acid-2-phosphate-6-palmitate, L-ascorbic acid-2-phosphate-5,6-benzylidene, natural vitamin E, dl-α-tocopherol, dl-α-tocopheryl acetate, dl-α-tocopheryl sodium phosphate, ubiquinone and their vitamin derivatives , Cysteine, glutathione, glutathione peroxidase, SOD, catalase, citrus , Phosphoric acid, polyphenol, catechin, tea extract, kojic acid, nucleic acid, hydroquinone, arbutin, and the like. One or more antioxidants selected from these groups can be blended.
[0129]
The cosmetics according to the present invention include components other than those generally added to cosmetics, such as oils and fats, waxes, hydrocarbons, fatty acids, alcohols, polyhydric alcohols, saccharides and esters. Metal soap, water-soluble polymer compounds, surfactants, antioxidants, bactericides / preservatives, vitamins, hormones, coloring materials, and the like can be blended.
[0130]
The amount of the silica-coated mixed crystal oxide particles in the cosmetic of the present invention is preferably 1 to 50% by mass, more preferably 3 to 40% by mass, and further preferably 5 to 30% by mass with respect to the cosmetic. Range.
[0131]
In the cosmetic of the present invention, when using silica-coated mixed crystal oxide particles in which ultrafine mixed crystal oxide having a large specific surface area is well dispersed, it can have a particularly high ultraviolet shielding ability, and the addition amount can be Can be reduced. In addition, since it contains a metal oxide sol and / or surface hydrophobized silica-coated metal oxide sol that has a small primary particle size and is coated with a dense and practical silica coating, However, there is no squeaky feeling or poor elongation, and it is excellent in use feeling.
[0132]
Furthermore, since the cosmetic of the present invention uses a silica-coated metal oxide sol and / or a surface-hydrophobized silica-coated metal oxide sol in which metal oxide particles having a small particle diameter are well dispersed, visible light transmittance is achieved. And a transparent finish is obtained.
In addition, since the surface of the metal oxide fine particles is covered with a dense and practical silica coating, the photocatalytic activity of the metal oxide is sufficiently suppressed, and other compounding ingredients of cosmetics are not denatured and stable in storage. Excellent in properties.
[0133]
An organic ultraviolet absorber can be contained, and higher ultraviolet shielding ability can be achieved. Furthermore, by containing an antioxidant, the generation of active oxygen and the like can be made extremely low, and safety for the human body can be improved.
[0134]
In the present invention, the thickness and refractive index of the silica film can be measured using a silica film formed on a silicon wafer immersed in the system when the silica-coated mixed crystal oxide particles are synthesized. On this silicon wafer, the same silica film as that on the mixed crystal oxide particles in the silica-coated mixed crystal oxide particles is formed. The refractive index of the silica film can be measured by an ellipsometer (manufactured by ULVAC; LASSER ELIPSOMETER ESM-1A). A step gauge can be used for the film thickness measurement. The transmission infrared absorption spectrum of the silica film of silica-coated mixed crystal oxide particle particles can be measured by FT-IR-8000 manufactured by JASCO Corporation.
[0135]
The primary particle diameter and the silica film thickness of the silica-coated mixed crystal oxide particles can be determined from a transmission electron microscope image. The total alkali metal content is measured by dissolving the silica-coated mixed crystal oxide particles in hydrofluoric acid and analyzing with flame.
[0136]
The photocatalytic activity of the silica-coated mixed crystal oxide particles, that is, the initial oxygen consumption rate, is measured by a tetralin auto-oxidation method (Kiyono Manabu, Titanium oxide-physical properties and applied technology, Gihodo Shuppan, p.196-197, 1991). be able to. The measurement conditions are a temperature of 40 ° C., 20 ml of tetralin, and 0.02 g of mixed crystal oxide particles having a solid content concentration of 10%.
[0137]
The decomposition rate, the powder dynamic friction coefficient, and the dye fading rate of the organic ultraviolet absorbent of the silica-coated mixed crystal oxide particles of the present invention are the parasol method, glass plate method, and sunset yellow described in this specification, respectively. Measured by the method.
[0138]
【Example】
Examples of the present invention will be described in detail below. However, the present invention is not limited thereby.
[0139]
Example 1
(Production of mixed crystal oxide particles 1)
Metallic zinc 3.8kg / hr and nitrogen gas heated to 900 ° C 25Nm ^Three / H (N represents a standard state; hereinafter the same) was supplied to a zinc vaporizer to obtain a Zn source gas. This was heated to 1000 ° C. with a Zn source gas heater.
On the other hand, an oxidizing gas having a composition of 3% by volume of water vapor and 97% by volume of oxygen is 25 Nm. ^Three / Hour was heated with an oxidizing gas heater. The temperature of the heated gas was 1030 ° C. at the inlet to the reactor.
[0140]
Further, 700 g / hour of tetraethoxysilane was heated to 300 ° C. together with nitrogen.
The above-described Zn source gas, oxidizing gas, and nitrogen gas containing tetraethoxysilane were introduced into the reactor.
The flow rates were 100 m / sec for Zn source gas, 90 m / sec for oxidizing gas, and 40 m / sec for nitrogen gas containing tetraethoxylane. After the reaction, the powder was collected in a bag filter.
[0141]
The obtained powder was white and its specific surface area was measured by a BET single point method using a monosorb type device manufactured by QUANTACHROME. ² It was / g and was analyzed using a fluorescent X-ray analyzer X-ray Spectrometer Simultix 10 manufactured by Rigaku Corporation, and contained 4% by mass of a silica component.
Using this powder, a diffraction X-ray apparatus 2000 / PC type manufactured by Rigaku Corporation, and using CuKα rays under the conditions of 30 kV and 30 mA, a range of 2θ = 10 ° to 80 ° at a rate of 2 ° / min. Scanned and examined for crystal form.
[0142]
As a result, there are peaks at 2θ = 31.8 °, 34.5 °, and 36.3 ° corresponding to lattice planes (100), (002), and (101) peculiar to crystalline zinc oxide, and the crystallinity. It was a powder showing an XRD chart having a peak also in the vicinity of 2θ = 22 ° corresponding to the lattice plane (101) peculiar to silica.
[0143]
In order to further check the heat resistance, the sample was taken into a magnetic crucible, placed in an electric furnace at 800 ° C., held for 1 hour, immediately taken out and allowed to cool to room temperature. The specific surface area of this powder was again measured by the BET 1-point method described above. The specific surface area ratio before and after heating, that is, (specific surface area after heat treatment / specific surface area before heat treatment) was calculated to be 79%.
[0144]
Furthermore, the primary particles obtained by observation with a transmission electron microscope (TEM) are classified into anisotropic tetrapod-like and needle-like particles and isotropic particles. I counted. As a result, the ratio of tetrapod-like and needle-like particles in the total number was 83%.
[0145]
In addition, elemental analysis of each primary particle of tetrapod-like particles, needle-like particles, and isotropic particles by EDX with a measurement spot diameter of 5 nm confirmed that Zn and Si exist in each shape of the particles. It was done. This was carried out at a plurality of locations for each shape particle, and Zn and Si were detected in all cases.
[0146]
(Production of silica-coated mixed crystal oxide particles 1)
A 50 L reactor was mixed with 18.25 L of deionized water, 22.8 L of ethanol (manufactured by Junsei Chemical Co., Ltd.) and 124 mL of 25% by mass ammonia water (manufactured by Daisei Kako Co., Ltd.), and the mixed crystal oxide particles were mixed therein. 1. Suspension 1 was prepared by dispersing 1.74 kg of the mixed crystal oxide particles produced in Production 1. Next, 1.62 L of tetraethoxysilane (GE Toshiba Silicone) and 1.26 L of ethanol were mixed to prepare Solution 1.
[0147]
The solution 1 was added to the stirring suspension 1 at a constant rate over 9 hours, and then aged for 12 hours. Film formation and aging were performed at 45 ° C. Thereafter, the solid content is separated by centrifugal filtration, vacuum-dried at 50 ° C. for 12 hours, further dried in warm air at 80 ° C. for 12 hours, and further pulverized by a jet mill to obtain silica-coated mixed crystal oxide particles 1. It was.
[0148]
(Example 2)
(Production of mixed crystal oxide particles 2)
Nitrogen gas 25kg Nm heated to 900kg with metal zinc 6kg / h ^Three / Hour was supplied to the zinc vaporizer to obtain Zn source gas. This was further heated to 1000 ° C. with a Zn source gas heater.
On the other hand, an oxidizing gas having a composition of 3% by volume of water vapor and 97% by volume of oxygen is 25 Nm. ^Three / Hour was heated with an oxidizing gas heater. The temperature of the heated gas was 1030 ° C. at the inlet to the reactor.
[0149]
Further, 10 kg / hour of tetraethoxysilane was heated to 300 ° C. together with nitrogen.
The above-described Zn source gas, oxidizing gas, and nitrogen gas containing tetraethoxysilane were introduced into the reactor. The flow rates were 100 m / sec for Zn source gas, 90 m / sec for oxidizing gas, and 50 m / sec for nitrogen gas containing tetraethoxylane. After the reaction, the powder was collected in a bag filter.
[0150]
The obtained white powder was analyzed in the same manner as in Example 1.
As a result, specific surface area 37m ² / G and contained 26% by mass of a silica component. The crystal form was a powder having a peak at the same 2θ position as in Example 1. The specific surface area ratio before and after heating was 85%.
[0151]
(Production of silica-coated mixed crystal oxide particles 2)
A 50 L reactor was mixed with 18.25 L of deionized water, 22.8 L of ethanol (manufactured by Junsei Chemical Co., Ltd.) and 124 mL of 25% by mass ammonia water (manufactured by Daisei Kako Co., Ltd.), and the mixed crystal oxide particles were mixed therein. Suspension 2 was prepared by dispersing 1.96 kg of 1. Next, tetraethoxysilane (GE Toshiba Silicones Co., Ltd.) 0.81 L and ethanol 1.93 L were mixed to prepare Solution 2.
[0152]
The solution 2 was added to the stirring suspension 2 at a constant rate over 4.5 hours, and then aged for 12 hours. Film formation and aging were performed at 45 ° C. Thereafter, the solid content is separated by centrifugal filtration, vacuum-dried at 50 ° C. for 12 hours, further dried in warm air at 80 ° C. for 12 hours, and further pulverized by a jet mill to obtain silica-coated mixed crystal oxide particles 2. It was.
[0153]
(Example 3)
(Production of mixed crystal oxide particles 3)
Gaseous titanium tetrachloride with a concentration of 100% by volume 9.4Nm ^Three / Time (N means standard state; the same applies hereinafter) and gaseous silicon tetrachloride with a concentration of 100% by volume 2.4 Nm ^Three After mixing the gas containing / time to 1,000 ° C., 8 Nm ^Three / Hour of oxygen and 20 Nm ^Three A gas mixture of water vapor / hour was preheated to 1,000 ° C. and introduced into the reaction tube at a flow rate of 49 m / second and 60 m / second, respectively, using a coaxial parallel flow nozzle. The inner diameter of the coaxial parallel flow nozzle was 20 mm, and a gas containing a mixed metal halide was introduced into the inner pipe.
[0154]
The inner diameter of the reaction tube was 100 mm, and the flow rate in the tube at a reaction temperature of 1,300 ° C. was 10 m / sec as a calculated value. After the reaction, cooling air was introduced into the reaction tube so that the high-temperature residence time in the reaction tube was 0.3 seconds or less, and then ultrafine powder produced using a Teflon bag filter was collected. Then, it desalted by heating in an air atmosphere at 500 ° C. for 1 hour.
[0155]
The obtained mixed crystal oxide particles have a BET specific surface area of 88 m. ² / G, an average true specific gravity of 3.7 g / cc, an average primary particle diameter of 0.018 μm, chlorine of 0.01%, and a titanium-oxygen-silicon bond was clearly observed by XPS.
The BET specific surface area reduction rate after 1 hour at 800 ° C. was 2%.
[0156]
(Production of silica-coated mixed crystal oxide particles 3)
A 50 L reactor was mixed with 4.2 L of deionized water, 19.3 L of ethanol (manufactured by Junsei Chemical Co., Ltd.) and 0.75 L of 25% by mass ammonia water (manufactured by Daisei Kako). A suspension 3 was prepared by dispersing 1.05 kg of the product particles 3. Next, 0.97 L of tetraethoxysilane (GE Toshiba Silicone) and 1.05 L of ethanol were mixed to prepare a solution 3.
[0157]
Solution 3 was added to stirring suspension 3 at a constant rate over 6 hours, and then aged for 12 hours. Film formation and aging were performed at 25 ° C. Thereafter, the solid content is separated by centrifugal filtration, vacuum-dried at 50 ° C. for 12 hours, further dried in warm air at 80 ° C. for 12 hours, and further pulverized by a jet mill to obtain silica-coated mixed crystal oxide particles 3. It was.
[0158]
Example 4
(Production of mixed crystal oxide particles 4)
Gaseous titanium tetrachloride 8.3Nm ^Three / Hour and gaseous aluminum trichloride 2.4Nm ^Three / Hour and nitrogen 6Nm ^Three After mixing the gas containing / hour, to 900 ° C, 8Nm ^Three / Hour of oxygen and 20 Nm ^Three A gas mixture of water vapor / hour was preheated to 1,000 ° C. and introduced into the reaction tube at a flow rate of 63 m / second and 60 m / second, respectively, using a coaxial parallel flow nozzle. The inner diameter of the coaxial parallel flow nozzle was 20 mm, and a gas containing a mixed metal halide was introduced into the inner pipe.
[0159]
The inner diameter of the reaction tube was 100 mm, and the flow rate in the tube at a reaction temperature of 1,200 ° C. was 10 m / sec as a calculated value. After the reaction, cooling air was introduced into the reaction tube so that the high-temperature residence time in the reaction tube was 0.3 seconds or less, and then ultrafine powder produced using a Teflon bag filter was collected. Then, desalting was performed by heating at 500 ° C. for 1 hour in an air atmosphere.
[0160]
The obtained mixed crystal oxide particles have a BET specific surface area of 48 m. ² / G, average true specific gravity 3.9 g / cc, average primary particle size 0.032 μm, chlorine 0.1%, and a titanium-oxygen-aluminum bond was clearly observed by XPS.
The BET specific surface area reduction rate after 1 hour at 800 ° C. was 5%.
[0161]
(Production of silica-coated mixed crystal oxide particles 4)
A 50 L reactor was mixed with 4.2 L of deionized water, 19.3 L of ethanol (manufactured by Junsei Chemical Co., Ltd.) and 0.75 L of 25% by mass ammonia water (manufactured by Daisei Kako). A suspension 4 was prepared by dispersing 1.05 kg of the product particles 4. Next, 0.44 L of tetraethoxysilane (GE Toshiba Silicone) and 1.35 L of ethanol were mixed to prepare Solution 4.
[0162]
The solution 4 was added to the stirring suspension 4 at a constant rate over 6 hours, and then aged for 12 hours. Film formation and aging were performed at 25 ° C. Thereafter, the solid content is separated by centrifugal filtration, vacuum-dried at 50 ° C. for 12 hours, further dried in warm air at 80 ° C. for 12 hours, and further pulverized by a jet mill to obtain silica-coated mixed crystal oxide particles 4. It was.
[0163]
When the transmission infrared absorption spectrum of the silica-coated mixed crystal oxide particles obtained in Examples 1 to 4 was measured by the KBr method, all the metal oxide particles were stretched to 1000 to 1200 cm @ -1 in Si-O-Si stretch. Absorption due to vibration was observed, absorption due to C—H stretching vibration was not observed at 2800 to 3000 cm −1, and the produced coating was identified as silica.
Furthermore, the silica film thickness, the ratio I of the absorption peak intensity of the infrared absorption spectrum, and the refractive index of the silica film were measured. The results are summarized in Table 1.
[0164]
(Measurement of photocatalytic activity, tetralin auto-oxidation method)
The photocatalytic activity by the tetralin auto-oxidation method was measured using the silica-coated mixed crystal oxide particles obtained in Examples 1 to 4 as test substances. The results are summarized in Table 1. All of the silica-coated mixed crystal oxide particles of the present invention are 60 Pa / min or less, and show the same suppression of photocatalytic activity as conventional silica-coated metal oxide powders.
[0165]
(Measurement of dye fading rate / Sunset yellow method)
The dye fading rate was measured by the sunset yellow method using the silica-coated mixed crystal oxide particles obtained in Examples 1 to 4 as test substances. That is, Sunset Yellow, which is a pigment for cosmetics, was dissolved in 98% by mass of glycerin so that the pigment concentration was 0.02% by mass. The test substance is dispersed so as to be 0.067% by mass, and the dispersion is irradiated with ultraviolet rays (ultraviolet intensity: 1.65 mW / cm ² )did. Absorbance at 490 nm, which is the maximum absorption wavelength of sunset yellow with an optical path length of 1 mm, was measured over time with a spectrophotometer (SHIMADZU UV-160), and the rate of decrease in absorbance (ΔA ₄₉₀ / H) was calculated. The results are shown in Table 1.
[0166]
The dye fading rate of the silica-coated mixed crystal oxide particles used in the present invention is 0.10 (ΔA ₄₉₀ / H) or less, showing a dye fading rate equivalent to that of a conventional silica-coated metal oxide powder. The silica-coated mixed crystal oxide particles of the present invention maintain the low pigment decomposability of conventional silica-coated metal oxide powders, and can provide cosmetics with high storage stability.
[0167]
(Measurement of decomposition rate of organic UV absorbers, parasol method)
Using the silica-coated mixed crystal oxide particles obtained in Examples 1 to 4 as test substances, the decomposition rate of the organic ultraviolet absorber was measured by the parasol method. That is, a test substance is dispersed in a polyethylene glycol 300 solution of 4-tert-butyl-4′-methoxydibenzoylmethane (parasol 1789) (concentration of parasol 1789 is 0.045% by mass), and each slurry has a solid content of 1% by mass. It was. After putting 1.5 g of the slurry into a glass container and irradiating with ultraviolet rays (1.65 mW / cm 2), 1 g was taken, and 2 mL of isopropyl alcohol, 2 mL of hexane, and 3 mL of distilled water were sequentially added.
[0168]
The mixture was stirred to extract parasol 1789 in the hexane phase, and the absorbance (340 nm) at an optical path length of 1 mm of the hexane phase was measured with a spectrophotometer (SHIMADZU UV-160) over time (3 after UV irradiation 0, 5 and 10 hours). Point) measured. Decrease rate of absorbance at 340 nm (ΔA ₃₄₀ / H). The results are summarized in Table 1.
[0169]
Any of the silica-coated mixed crystal oxide particles that can be used in the present invention is 0.01 (ΔA ₃₄₀ / H) or less, and the decomposability of the organic ultraviolet absorber was low. Therefore, the cosmetic containing silica-coated mixed crystal oxide particles can be used in combination with an organic ultraviolet shielding material, and can maintain the ultraviolet protection ability for a long time.
[0170]
(Measurement of powder dynamic friction coefficient, glass plate method)
The powder dynamic friction coefficient was measured by the glass plate method using the silica-coated mixed crystal oxide particles obtained in Examples 1 to 4 as test substances. That is, 10 mg / cm of the test substance powder on a 100 × 200 mm glass plate. ² The glass plate was placed on a test table of a surface texture measuring device (HEIDON), and the load was 22.2 g / cm. ² , Moving speed 200 mm / min. The dynamic friction coefficient was measured under the condition of a moving distance of 20 mm. The results are shown in Table 1.
[Table 1]

[0171]
All of the powder dynamic friction coefficients of the silica-coated mixed crystal oxide particles of the present invention are 0.550 or less, indicating a lower dynamic friction coefficient than the conventional silica-coated metal oxide powder. This suggests that the cosmetic material containing the silica-coated mixed crystal oxide particles of the present invention has an even better feeling than before.
[0172]
(Examples 5-8) Sunscreen latex
A sunscreen emulsion having the following formulation was produced by a conventional method. That is, polyethylene glycol is added to purified water, and after dissolution by heating, a test substance and bee gum are added, and dispersed uniformly with a homomixer and kept at 70 ° C. (aqueous phase). The other ingredients are mixed, dissolved by heating and kept at 70 ° C. (oil phase). The oil phase was added to the aqueous phase, and the mixture was uniformly emulsified and dispersed with a homomixer. The emulsion was cooled to 35 ° C. with stirring. As the test substance, silica-coated mixed crystal oxide particles produced in Examples 1 to 4 were used. In its use, in order to disperse it to the oil phase side of the emulsion, the surface was further hydrophobized so that dimethylpolysiloxane was 3% by mass with respect to the weight of the treated powder. (Hereinafter, this hydrophobized product is expressed as “silicone-treated silica-coated mixed crystal oxide particles”.)
[0173]
Sunscreen latex prescription
Silicone-treated silica-coated mixed crystal oxide particles 7.0% by mass
Stearic acid 2.0% by mass
Cetyl alcohol 1.0 mass%
Vaseline 5.0% by mass
Silicon oil 2.0% by mass
Liquid paraffin 10.0% by mass
Glycerin monostearate (self-emulsifying) 1.0% by mass
Polyoxyethylene (25 mol) monooleate 1.0% by mass
Polyethylene glycol 1500 5.0% by mass
Bee gum 0.5% by mass
Purified water 65.2% by mass
Fragrance 0.1% by mass
Preservative 0.2% by mass
[0174]
In addition, as a comparative example, a sunscreen emulsion using conventional surface-treated titanium oxide (TTO-S-1 manufactured by Ishihara Sangyo Co., Ltd.) and conventional zinc oxide (ZnO350 manufactured by Sumitomo Osaka Cement Co., Ltd.) instead of silica-coated mixed crystal oxide particles Prepared (Comparative Examples 1 and 2).
[0175]
Furthermore, a sunscreen emulsion was prepared using silica-coated zinc oxide using zinc oxide (UFZ40 manufactured by Showa Titanium Co., Ltd.) instead of mixed crystal oxide particles 1 in silica-coated mixed crystal oxide particles 1 of Example 1. As Comparative Example 3, sunscreen emulsion using silica-coated titanium oxide using titanium oxide (F4 manufactured by Showa Titanium Co., Ltd.) instead of mixed crystal oxide particles 4 in silica-coated mixed crystal oxide particles 4 of Example 4. Was prepared as Comparative Example 4. (Sensory test)
[0176]
The feeling of use of the sunscreen emulsions produced in Examples 5 to 8 and Comparative Examples 1 to 4 and the transparency of the finish were evaluated by a sensory test using 50 women aged 20 to 40 years. The feeling of use of each foundation by 50 subjects
Very good: 5 points Good: 3 points Normal: 2 points Bad: 1 point Very bad: Scored on a 0-point basis. Next, the feeling of use was determined in five stages based on the following criteria based on the total score obtained by counting the evaluation scores of 50 people.
[0177]
250-200 points: very good (++)
200-150 points: Good (+)
150-100 points: Normal (+-)
100-50 points: Bad (-)
50-0 points: Extremely bad (-)
[0178]
The results are shown in Table 2.
[Table 2]

[0179]
The feeling of use and transparency of the sunscreen emulsion containing the silica-coated mixed crystal oxide particles of the present invention are both very good (++).
It is clear that the sunscreen emulsion containing the silica-coated mixed crystal oxide particles of the present invention has particularly improved transparency.
[0180]
(Examples 9 to 12) Foundation
The foundation of the following prescription was manufactured by the usual method. The silica-coated mixed crystal oxide particles obtained in Examples 1 to 4 were used as test substances, respectively.
[0181]
Foundation prescription
Silica-coated mixed crystal oxide particles 15.0% by mass
Mica 15.0% by mass
Talc 10.0% by mass
Zinc flower 15.0% by mass
Iron oxide (red) 1.5% by mass
Iron oxide (yellow) 3.4% by mass
Glycerin 10.0% by mass
Purified water 30.0% by mass
Fragrance 0.1% by mass
[0182]
As a comparative example, a foundation was prepared using conventional surface-treated titanium oxide (TTO-S-1 manufactured by Ishihara Sangyo Co., Ltd.) and conventional zinc oxide (ZnO350 manufactured by Sumitomo Osaka Cement Co., Ltd.) instead of silica-coated mixed crystal oxide particles. (Comparative Examples 5 and 6).
[0183]
Further, in the silica-coated mixed crystal oxide particles 1 of Example 1, a foundation was prepared using silica-coated zinc oxide using zinc oxide (UFZ40 manufactured by Showa Titanium) instead of the mixed crystal oxide particles 1, and Comparative Example 7 and did.
Also, in the silica-coated mixed crystal oxide particles 4 of Example 4, a foundation was prepared using silica-coated titanium oxide using titanium oxide (F4 manufactured by Showa Titanium) instead of the mixed crystal oxide particles 4, and Comparative Example 8 and did.
[0184]
(Sensory test)
The feeling of use and the finished transparency of the foundations produced in Examples 9 to 12 were evaluated by a sensory test according to the above methods.
[0185]
The results are shown in Table 3.
[Table 3]

[0186]
The feeling of use and the transparency of the foundation containing the silica-coated mixed crystal oxide particles of the present invention are both very good (++).
It is clear that the foundation containing the silica-coated mixed crystal oxide particles of the present invention has particularly improved transparency.
[0187]
(Example 13) Lotion
A lotion having the following formulation was produced by a conventional method.
[0188]
Prescription for lotion
Silica-coated mixed crystal oxide particles 1 3.0% by mass
Ethyl alcohol 39.6% by mass
1,3-butylene glycol 9.5% by mass
Castor oil 4.9% by mass
Methylparaben 0.2% by mass
42.8% by mass of purified water
[0189]
When the sensory test was implemented about said lotion, evaluation that it was good use feeling and very good transparency was obtained.
[0190]
(Example 14) Latex
The emulsion of the following prescription was manufactured by the usual method.
[0191]
Milk formula
Silicone-treated silica-coated mixed crystal oxide particles 3 3.0% by mass
Avocado oil 11.0% by mass
Behenyl alcohol 0.6% by mass
Stearic acid 0.4% by mass
Glycerin fatty acid ester 0.9% by mass
Polyoxyethylene sorbitan fatty acid ester 1.1% by mass
Polyoxyethylene alkyl ether 0.4% by mass
1,3-butylene glycol 10.1% by mass
Methylparaben 0.2% by mass
Fragrance 0.4% by mass
Purified water 71.9% by mass
[0192]
When the sensory test was implemented about said lotion, the evaluations of a very good feeling of use and a very good transparency were obtained.
[0193]
(Example 15) Cream
A cream having the following formulation was produced by a conventional method.
[0194]
Cream formula
Silicone-treated silica-coated mixed crystal oxide particles 1 3.5% by mass
Squalane 15.2% by mass
Stearic acid 7.8% by mass
Stearyl alcohol 6.0% by mass
Beeslow 1.9% by mass
Propylene glycol monostearate 3.1% by mass
Polyoxyethylene cetyl ether 1.1% by mass
1,3-butylene glycol 11.9% by mass
Methylparaben 0.2% by mass
Fragrance 0.4% by mass
41.9% by mass of purified water
[0195]
When the sensory test was implemented about said cream, it was evaluation of a very good feeling of use and a very good transparency.
[0196]
(Example 16) Pack
Using the silica-coated mixed crystal oxide particles obtained in Example 3 as a test substance, a pack was produced according to the following formulation by a conventional method.
[0197]
Pack prescription
Silica-coated mixed crystal oxide particles 3 7.0% by mass
Polyvinyl alcohol 14.5% by mass
Sodium carboxymethylcellulose 4.8% by mass
1,3-butylene glycol 2.9% by mass
Ethyl alcohol 10.0% by mass
Methylparaben 0.1% by mass
Purified water 60.7% by mass
[0198]
When the sensory test was conducted on the above pack, the evaluation was good feeling of use and transparency.
[0199]
(Example 17) Lipstick
Silica-coated mixed crystal oxide particles of Example 1 as test substances (in use, the surface was further hydrophobized so that dimethylpolysiloxane was 3% by mass with respect to the weight of the treated powder.) Lipsticks were produced by the conventional method using the following formula.
[0200]
Silicone-treated silica-coated mixed crystal oxide particles 1 3.0% by mass
Silicon oil 27.0% by mass
Castor oil 18.3% by mass
Hexadecyl alcohol 25.2% by mass
Lanolin 3.9% by mass
Beeswax 4.8% by mass
Ozokerite 3.4% by mass
Candelilla wax 6.2% by mass
Carnauba wax 2.1% by mass
Methylparaben 0.1% by mass
4.8% by mass of red pigment
Fragrance 0.1% by mass
Purified water 1.1% by mass
[0201]
When a sensory test was performed on the above lipstick, the evaluation was extremely good feeling of use and transparency.
[0202]
(Examples 18 to 21) Dual-use foundation
Silica-coated mixed crystal oxide particles obtained in Examples 1 to 4 (in use, the surface was further hydrophobized so that dimethylpolysiloxane was 3% by mass with respect to the weight of the treated powder. ) Was used as a test substance to prepare a dual-use foundation having the following formulation by a conventional method.
[0203]
Prescription for amphibious foundation
Silicone-treated silica-coated mixed crystal oxide particles 6.0% by mass
Silicone-treated talc 19.0% by mass
Silicone-treated mica 39.6% by mass
Silicone-treated iron oxide (red) 1.0% by mass
Silicone-treated iron oxide (yellow) 3.0% by mass
Silicone-treated iron oxide (black) 0.3% by mass
Silicone-treated titania 15.0% by mass
Zinc stearate 0.2% by mass
Nylon powder 2.0% by mass
Squalane 4.0% by mass
Solid paraffin 0.5% by mass
Dimethylpolysiloxane 4.0% by mass
Glycerin triisooctanoate 5.0% by mass
Antioxidant 0.2% by mass
Preservative 0.1% by mass
Fragrance 0.1% by mass
[0204]
The sensory test was implemented about the amphibious foundation of Examples 18-21, and usability | use_condition and transparency were evaluated. The foundations containing the silica-coated mixed crystal oxide particles according to the present invention all showed a very good feeling of use and a very good transparency.
[0205]
(Examples 22 to 25) W / O sunscreen cream
Silica-coated mixed crystal oxide particles obtained in Examples 1 to 4 (in use, the surface was further hydrophobized so that dimethylpolysiloxane was 3% by mass with respect to the weight of the treated powder. .) Was used as a test substance to produce a W / O sunscreen cream having the following formulation.
[0206]
(1) Glyceryl 2-ethylhexanoate 12.0% by mass, (2) 4-tert-butyl-4′-methoxydibenzoylmethane 5.0% by mass, (3) 1.0% by mass of polyglyceryl isostearate, ( 4) sorbitan sesquioleate 2.0 mass%, (5) decamethylpolysiloxane 10.0 mass%, (6) organically modified bentonite 0.2 mass%, (7) squalane 5.0 mass%, (8) 2-Methyl paramethoxycinnamate 8.0% by mass, (9) Silicone-treated silica-coated mixed crystal oxide particles 10.0% by mass, (10) Fragrance 0.1% by mass, (11) Methyl paraoxybenzoate 0 .3% by mass, (12) 0.1% by mass of disodium edetate, (13) 46.3% by mass of purified water
[0207]
(1) to (8) are dissolved by heating, (9) and (10) are added and uniformly dispersed, (11) to (13) are gradually added and emulsified, and after sufficient stirring, 30 ° C. To obtain a W / O sunscreen cream.
[0208]
(Examples 26 to 29) O / W sunscreen cream
Silica-coated mixed crystal oxide particles obtained in Examples 1 to 4 (in use, the surface was further hydrophobized so that dimethylpolysiloxane was 3% by mass with respect to the weight of the treated powder. .) Was used as a test substance to produce an O / W sunscreen cream having the following formulation.
[0209]
(1) Squalane 5.0% by mass, (2) Glyceryl 2-ethylhexanoate 10.0% by mass, (3) Microcristan wax 1.0% by mass, (4) Stearyl alcohol 2.0% by mass, (5 ) 0.1% by mass of butyl paraoxybenzoate, (6) 1.0% by mass of 4-tert-butyl-4′-methoxydibenzoylmethane, (7) 3.0% by mass of 2-ethylhexyl paramethoxycinnamate, (8) Silicone-treated silica-coated mixed crystal oxide particles 5.0% by mass, (9) Fragrance 0.2% by mass, (10) Methyl paraoxybenzoate 0.1% by mass, (11) 1,3-butylene glycol 7.0% by mass, (12) 65.6% by mass of purified water
[0210]
(1) to (7) are dissolved by heating, (8) and (9) are added and dispersed uniformly, (10) to (12) are gradually added and emulsified, and after sufficient stirring, 30 ° C. To obtain an O / W sunscreen cream.
[0211]
(Examples 30 to 33) Lipstick
Silica-coated mixed crystal oxide particles obtained in Examples 1 to 4 (in use, the surface was further hydrophobized so that dimethylpolysiloxane was 3% by mass with respect to the weight of the treated powder. ) Was used as a test substance to produce a lipstick having the following formulation.
[0212]
(1) Paraffin wax 10.0% by mass, (2) Microcrystalline wax 10.0% by mass, (3) Silicone-treated silica-coated mixed crystal oxide particles 3.0% by mass, (4) Glyceryl 2-ethylhexanoate 46.4% by mass, (5) 2-ethylhexyl paramethoxycinnamate 5.0% by mass, (6) 4-tert-butyl-4′-methoxydibenzoylmethane 3.0% by mass, (7) malic acid Diisostearyl 15.0% by mass, (8) Red No. 201 2.0% by mass, (9) Red No. 202 2.0% by mass, (10) Blue No. 1 0.5% by mass, (11) Bengala 3 0.0% by mass, (12) Fragrance 0.1% by mass
[0213]
(1) to (11) were dissolved by heating, (12) was added and dispersed uniformly, and cooled to 30 ° C. to obtain a lipstick.
[0214]
(Examples 34 to 37) Powder foundation
Using the silica-coated mixed crystal oxide particles obtained in Examples 1 to 4 as test substances, powder foundations having the following formulation were produced.
[0215]
(1) Mica 36.0% by mass, (2) Talc 20.0% by mass, (3) Silica-coated mixed crystal oxide particles 6.0% by mass, (4) 2-ethylhexyl paramethoxycinnamate 5.0 Mass%, (5) 4-tert-butyl-4′-methoxydibenzoylmethane 10.0 mass%, (6) zinc stearate 4.0 mass%, (7) yellow iron oxide 3.0 mass%, ( 8) Bengala 0.8% by mass, (9) Black iron oxide 0.2% by mass, (10) Squalane 5.0% by mass, (11) Glyceryl 2-ethylhexanoate 8.7% by mass, (12) Mono Sorbitan isostearate 1.0 mass%, (13) Butyl paraoxybenzoate 0.2 mass%, (14) Fragrance 0.1 mass%
[0216]
After (10) to (13) are dissolved by heating, (14) is mixed and cooled to room temperature to obtain an oil phase. (1) to (9) are thoroughly stirred in a mixer, and an oil phase is further added and mixed well. This was pulverized through a pulverizer and pressed into a metal pan to obtain the desired powder foundation.
[0217]
The silica-coated mixed crystal oxide particles in the formulations of Examples 25 to 37 were changed to conventional surface-treated titanium oxide (TTO-S-1 manufactured by Ishihara Sangyo Co., Ltd.) and conventional zinc oxide (ZnO350 manufactured by Sumitomo Osaka Cement Co., Ltd.). Using the prepared cosmetic as a comparative example, the temporal stability after one month was judged visually.
[0218]
In all of the comparative examples, precipitation of 4-tert-butyl-4'-methoxydibenzoylmethane was observed, whereas all the cosmetics containing the silica-coated mixed crystal oxide particles of Examples 25 to 37 were used. 4-tert-Butyl-4′-methoxydibenzoylmethane did not precipitate and was a cosmetic with excellent temporal stability.
[0219]
The cosmetics obtained in Examples 25 to 37 were excellent in stability with time and temperature stability. That is, the cosmetic of the present invention has significantly improved temporal stability as compared with a cosmetic containing conventional 4-tert-butyl-4′-methoxydibenzoylmethane, and has various fragrances and cosmetics. Can be suitably used.
[0220]
【Effect of the invention】
According to the present invention, silica-coated mixed crystal oxide particles coated with a dense and practical silica film and improved in dispersibility and transparency and an economical production method thereof are provided. Provided is a UV shielding cosmetic material in which product particles are well dispersed, and in particular, excellent in transparency and storage stability.

Claims (17)

A silica-coated mixed crystal oxide particle characterized in that the surface of a mixed crystal oxide particle having a BET specific surface area of 10 to 200 m @ 2 / g and containing primary particles in a mixed crystal state is coated with dense thin-film silica.
In a vapor phase production method in which mixed crystal oxide particles produce a metal oxide by high-temperature oxidation of a mixed gas containing a metal halide with an oxidizing gas, as the metal halide, chlorides of titanium, silicon and aluminum And a mixed gas containing at least two kinds of compounds selected from the group consisting of bromide and iodide, and an oxidizing gas, each of which is preheated to 500 ° C. or higher and reacted to produce a silica-coated mixture. Crystalline oxide particles. A mixed gas containing a metal halide is a gas mixture obtained by vaporizing at least two kinds of compounds selected from the group consisting of chloride, bromide and iodide of titanium, silicon and aluminum, respectively, and then vaporizing them alone. The silica-coated mixed crystal oxide particle according to claim 1 , wherein A silica-coated mixed crystal oxide particle characterized in that the surface of a mixed crystal oxide particle having a BET specific surface area of 10 to 200 m @ 2 / g and containing primary particles in a mixed crystal state is coated with dense thin-film silica.
A silica-coated mixed crystal oxide particle, wherein the mixed crystal oxide particle is a mixed crystal oxide containing a mixed crystal having a titanium-oxygen-aluminum bond in a primary particle. A silica-coated mixed crystal oxide particle characterized in that the surface of a mixed crystal oxide particle having a BET specific surface area of 10 to 200 m @ 2 / g and containing primary particles in a mixed crystal state is coated with dense thin-film silica.
Lattice planes (100), (002), (101) in which the mixed crystal oxide particles include crystal structures of each of zinc oxide and silica and are diffraction peaks peculiar to crystalline zinc oxide in X-ray crystallography, A silica-coated mixed crystal oxide particle, which is a composite oxide mainly composed of zinc oxide having a diffraction peak on a lattice plane (101) which is a diffraction peak peculiar to crystalline silica. 5. The silica-coated mixed crystal oxide particle according to claim 4 , wherein the mixed crystal oxide particle contains each crystal structure of zinc oxide and silica in the primary particle. 6. The silica-coated mixed crystal oxide particle according to claim 4 , wherein the mixed crystal oxide particle is a mixed crystal oxide particle containing a mixed crystal having a zinc-oxygen-silicon bond in a primary particle. . A silica-coated mixed crystal oxide particle characterized in that the surface of a mixed crystal oxide particle having a BET specific surface area of 10 to 200 m @ 2 / g and containing primary particles in a mixed crystal state is coated with dense thin-film silica.
In a gas phase reaction in which mixed crystal oxide particles oxidize gaseous zinc in the presence of oxygen and water vapor, a Zn source gas containing gaseous zinc in an inert gas, and an oxidizing gas containing oxygen and water vapor Is a composite oxide produced by introducing a silicon-containing composition into the reaction zone and introducing a silicon-containing composition into the reaction zone to oxidize zinc in the reactor. Mixed crystal oxide particles. A) a mixed crystal oxide particle having a BET specific surface area of 10 to 200 m 2 / g and containing primary particles in a mixed crystal state; b) a silicic acid containing no organic group and halogen or a precursor capable of producing the silicic acid; c) an alkali; D) Organic solvent and e) Water are added so that the water / organic solvent ratio after addition is in the range of 0.1 to 10 and the silicon concentration is in the range of 0.0001 to 5 mol / liter regardless of the order. A method for producing silica-coated mixed crystal oxide particles, wherein a dense thin-film silica is selectively formed on the surface of the mixed crystal oxide particles ,
A method in which the mixed crystal oxide particles are produced by the following method (1) or (2).
(1) As a metal halide, a mixed gas containing at least two compounds selected from the group consisting of chloride, bromide and iodide of titanium, silicon and aluminum, and an oxidizing gas are preheated to 500 ° C. or more, respectively. To react after manufacturing
(2) A Zn source gas containing gaseous zinc in an inert gas and an oxidizing gas containing oxygen and water vapor are respectively introduced into the reactor, and the zinc is oxidized in the reactor, and the reaction zone Produced by introducing and oxidizing a silicon-containing composition B) Add mixed crystal oxide particles containing primary particles in a mixed crystal state with a BET specific surface area of 10-200 m @ 2 / g to a mixed solution of alkali, b) organic solvent and c) water. Silicic acid not containing an organic group and halogen or a precursor capable of producing the silicic acid, f) an organic solvent and, if necessary, f) a mixed liquid comprising water, the water / organic solvent ratio after addition is 0.1 to 0.1 The silica is characterized in that it is added in a range of 10 and the silicon concentration is in the range of 0.0001 to 5 mol / liter to selectively form a dense thin-film silica on the surface of the mixed crystal oxide particles. A method for producing coated mixed crystal oxide particles , comprising:
A method in which the mixed crystal oxide particles are produced by the following method (1) or (2).
(1) As a metal halide, a mixed gas containing at least two compounds selected from the group consisting of chloride, bromide and iodide of titanium, silicon and aluminum, and an oxidizing gas are preheated to 500 ° C. or more, respectively. To react after manufacturing
(2) A Zn source gas containing gaseous zinc in an inert gas and an oxidizing gas containing oxygen and water vapor are respectively introduced into the reactor, and the zinc is oxidized in the reactor, and the reaction zone Produced by introducing and oxidizing a silicon-containing composition The method for producing silica-coated mixed crystal oxide particles according to claim 8 or 9 , wherein the alkali is at least one selected from the group consisting of ammonia, ammonium carbonate, ammonium hydrogen carbonate, ammonium formate and ammonium acetate. The silica-coated mixed crystal oxide according to any one of claims 8 to 10 , wherein the organic solvent is at least one selected from the group consisting of methanol, ethanol, propanol, pentanol, tetrahydrofuran, 1,4-dioxane and acetone. Particle production method. A silica-coated mixed crystal oxide particle produced by the production method according to claim 8 . A cosmetic comprising the silica-coated mixed crystal oxide particles according to any one of claims 1 to 7 and claim 12 . The cosmetic according to claim 13 , comprising an antioxidant. The cosmetic according to claim 13 or 14 , comprising an organic ultraviolet absorber. An anti-ultraviolet cosmetic comprising the cosmetic according to any one of claims 13 to 15 . The anti-UV cosmetic according to claim 16 , which is a W / O or O / W emulsion or cream, foundation or gel.