JP2011102216A - Color-developing flake material and method for producing the same - Google Patents
Color-developing flake material and method for producing the same Download PDFInfo
- Publication number
- JP2011102216A JP2011102216A JP2009258232A JP2009258232A JP2011102216A JP 2011102216 A JP2011102216 A JP 2011102216A JP 2009258232 A JP2009258232 A JP 2009258232A JP 2009258232 A JP2009258232 A JP 2009258232A JP 2011102216 A JP2011102216 A JP 2011102216A
- Authority
- JP
- Japan
- Prior art keywords
- fine particles
- inorganic fine
- inorganic
- flake body
- substrate
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Oxygen, Ozone, And Oxides In General (AREA)
- Silicon Compounds (AREA)
Abstract
Description
本発明は、微粒子の周期構造に基づく構造性発色を示すフレーク状の発色粉体（発色フレーク体）とその製造方法に関する。 The present invention relates to a flaky colored powder (colored flake body) that exhibits structural color development based on the periodic structure of fine particles and a method for producing the same.
可視光の波長程度の周期を有する微細な周期構造により、発色が生じることが知られている。この発色は、周期構造による光の回折および干渉に基づいており、一般に構造性発色（構造色）と呼ばれる。構造色は、独特の光沢感があり、見る角度に応じて色が変化する特徴を持つ。また、光の回折・干渉に基づく発色であるために退色しないなど、構造色を示す色材は有用であり、今後のさらなる応用が期待される。微細な周期構造は、薄膜の積層（多層膜）または溝、突起もしくは微粒子の配列で作ることができる。そのうち、微粒子の周期構造に基づく構造色は、微粒子構造色と呼ばれる（非特許文献１を参照）。 It is known that color development occurs due to a fine periodic structure having a period of about the wavelength of visible light. This color development is based on light diffraction and interference by a periodic structure, and is generally called structural color development (structural color). The structural color has a unique glossiness, and the color changes depending on the viewing angle. In addition, a coloring material showing a structural color, such as no color fading because it is colored based on diffraction and interference of light, is useful, and further application in the future is expected. A fine periodic structure can be made of a thin film stack (multilayer film) or an array of grooves, protrusions or fine particles. Among these, the structural color based on the periodic structure of the fine particles is called the fine particle structural color (see Non-Patent Document 1).
微粒子の周期構造を有し、これに基づく構造色を示す色材は、通常、膜状であり、基板上に作製される。例えば特許文献１には、ポリスチレンあるいはシリカなどからなる、ミクロンオーダーの粒径を有する微粒子を基板上に六方最密充填させた単層微粒子膜であって、オパール様回折発色を示す膜が開示されている。特許文献１によれば、この膜は、微粒子の懸濁液を基板に塗布し乾燥させることで形成され、微粒子の六方最密充填は、懸濁液に含まれる溶媒が蒸発する際に微粒子に作用する毛管力によって進行する。特許文献１に記載されている当該膜の作製方法を考えると、当該膜では、基板に対する微粒子の付着力ならびに微粒子同士の接合力が弱い。基板に対する付着力が弱いことは、微粒子が基板から剥がれやすく、形成した膜を粉末の色材に加工しやすいという利点となる（実際、特許文献１には、単層微粒子膜が基板から容易に剥がれることが記載されている）。しかし一方で、微粒子同士の接合力が弱いことは、構造色の元となる微粒子の周期構造が崩れやすく、発色が容易に失われることを意味する。 A coloring material having a periodic structure of fine particles and exhibiting a structural color based on the periodic structure is usually in the form of a film and is produced on a substrate. For example, Patent Document 1 discloses a single-layer fine particle film made of polystyrene, silica, or the like and having a micron-order particle size and packed in a hexagonal close-packed manner on a substrate, and exhibits opal-like diffraction coloring. ing. According to Patent Document 1, this film is formed by applying a suspension of fine particles to a substrate and drying, and the hexagonal closest packing of fine particles is applied to the fine particles when the solvent contained in the suspension evaporates. It progresses by acting capillary force. Considering the method for producing the film described in Patent Document 1, the film has a weak adhesion force of fine particles to the substrate and a bonding force between the fine particles. The weak adhesion to the substrate is advantageous in that the fine particles are easily peeled off from the substrate, and the formed film is easily processed into a powder coloring material. It is described that it will peel off). On the other hand, the weak bonding force between the fine particles means that the periodic structure of the fine particles, which is the source of the structural color, is easily broken and the color development is easily lost.
特許文献２には、ポリスチレンあるいはシリカなどからなる真球状微粒子を、当該微粒子が三次元的な周期性を有するように基板上に集積させるとともに、真球状微粒子の間隙に樹脂を充填させた、オパール構造を有するフォトニック結晶膜、ならびに当該結晶膜を粉砕して得たフォトニック結晶粉末が開示されている。この粉末は、充填された樹脂によって真球状微粒子の周期構造が保持されているため、安定した構造色を示す。しかし、真球状微粒子の周期構造を保持したまま当該微粒子の間隙に充填できる樹脂が限られることが問題である。また、特許文献２に開示されている方法では、樹脂の充填を、真球状微粒子の集積の後に別工程として実施しなければならず、製造コストの問題がある。 Patent Document 2 discloses an opal in which spherical fine particles made of polystyrene, silica, or the like are accumulated on a substrate so that the fine particles have a three-dimensional periodicity, and a resin is filled in a gap between the spherical fine particles. A photonic crystal film having a structure and a photonic crystal powder obtained by pulverizing the crystal film are disclosed. This powder exhibits a stable structural color since the periodic structure of the spherical particles is held by the filled resin. However, there is a problem that the resin that can be filled in the gaps between the fine particles while maintaining the periodic structure of the spherical fine particles is limited. Further, in the method disclosed in Patent Document 2, filling of the resin has to be performed as a separate process after the accumulation of the spherical fine particles, and there is a problem of manufacturing cost.
また、特許文献２には、フォトニック結晶膜を粉砕して得たフォトニック結晶粉末をマイカなどのフレーク状の基体に付着させることで、構造色を示す発色フレーク体が得られることが記載されている。しかし、この方法では、それ自体は構造色を示さないフレーク状の基体が必要になることから、必ずしも良好な構造色が得られるとは限らない。また、当該基体へのフォトニック結晶粉末の付着工程が必要であることから、製造コストも問題である。 Patent Document 2 describes that a colored flake body showing a structural color can be obtained by attaching a photonic crystal powder obtained by pulverizing a photonic crystal film to a flake-like substrate such as mica. ing. However, this method requires a flaky substrate that does not exhibit a structural color, so that a good structural color is not always obtained. In addition, since a process of attaching the photonic crystal powder to the substrate is necessary, the manufacturing cost is also a problem.
なお、特許文献２には、ポリマーからなる真球状微粒子を、当該微粒子が三次元的な周期性を有するように基板上に集積させた後、真球状微粒子の間隙に樹脂の代わりにチタニアゾルを充填し、これを加熱することで真球状微粒子を熱分解するとともにチタニアゾルを酸化チタンとして、真球状の空孔からなる周期構造が酸化チタンのマトリクス中に形成された、逆オパール構造を有するフォトニック結晶膜が得られることが記載されている。 In Patent Document 2, true spherical fine particles made of a polymer are accumulated on a substrate so that the fine particles have a three-dimensional periodicity, and then a titania sol is filled in the gap between the true spherical fine particles instead of a resin. By heating this, the spherical particles are pyrolyzed and the titania sol is made of titanium oxide, and a periodic structure consisting of spherical holes is formed in the titanium oxide matrix, and the photonic crystal has an inverted opal structure. It is described that a film is obtained.
本発明は、無機微粒子の周期構造、具体的には最密充填構造、を有し、当該構造に入射した光の回折および干渉による構造性発色を示すフレーク状の発色粉体（発色フレーク体）であって、無機微粒子間の接合力が強く、基板上に形成された膜ではなくフレーク体でありながら無機微粒子の周期構造が良好に保持されることで安定した発色を示す発色フレーク体と、その製造方法の提供とを目的とする。 The present invention relates to a flake-like colored powder (colored flake body) having a periodic structure of inorganic fine particles, specifically a close-packed structure, and showing structural color development by diffraction and interference of light incident on the structure. And the coloring force flakes exhibiting stable color development because the bonding force between the inorganic fine particles is strong, and the periodic structure of the inorganic fine particles is well maintained while being a flake rather than a film formed on the substrate, It aims at providing the manufacturing method.
本発明の発色フレーク体は、単分散の粒径分布を示す球状の無機微粒子が最密充填された構造を有し、前記構造において、隣り合う前記無機微粒子は、当該無機微粒子同士の接触点にて互いに接合されるとともに、当該無機微粒子間に空隙を有し、前記構造に入射した光の回折および干渉による構造性発色を示す。 The colored flake body of the present invention has a structure in which spherical inorganic fine particles having a monodispersed particle size distribution are closely packed, and in the structure, the adjacent inorganic fine particles are at contact points between the inorganic fine particles. Are bonded to each other and have voids between the inorganic fine particles, and exhibit structural coloration by diffraction and interference of light incident on the structure.
本発明の発色フレーク体の製造方法（第１の製造方法）は、単分散の粒径分布を示す球状の無機微粒子と、焼成後に無機酸化物となる、金属アルコキシド、金属塩および金属酸化物コロイドから選ばれる少なくとも１種の金属化合物と、水および／またはアルコールと、を含み、前記少なくとも１種の金属化合物と前記無機微粒子との混合比が、前記少なくとも１種の金属化合物について焼成後の無機酸化物換算で、金属化合物：無機微粒子＝１：１０〜１：１０００（重量比）である溶液を、基板の表面に塗布し、乾燥させることによって、前記無機微粒子が最密充填された構造を有し、当該構造において、隣り合う前記無機微粒子が、当該無機微粒子同士の接触点にて前記少なくとも１種の金属化合物によって互いに接合されるとともに、当該無機微粒子間に空隙を有する塗布膜を前記基板上に形成し、前記形成した塗布膜を前記基板から剥離し、フレーク体とした後に当該フレーク体を焼成することで、前記少なくとも１種の金属化合物を無機酸化物として、前記無機微粒子が最密充填された構造を有し、当該構造において、隣り合う前記無機微粒子が、当該無機微粒子同士の接触点にて前記無機酸化物によって互いに接合されるとともに、当該無機微粒子間に空隙を有し、前記構造に入射した光の回折および干渉による構造性発色を示す発色フレーク体を得る方法である。 The method for producing a colored flake body of the present invention (first production method) includes spherical inorganic fine particles having a monodispersed particle size distribution, metal alkoxide, metal salt, and metal oxide colloid that become an inorganic oxide after firing. At least one metal compound selected from the group consisting of water and / or alcohol, and the mixing ratio of the at least one metal compound and the inorganic fine particles is inorganic after firing for the at least one metal compound. By applying a solution of metal compound: inorganic fine particles = 1: 10 to 1: 1000 (weight ratio) on the surface of the substrate in terms of oxide, and drying, a structure in which the inorganic fine particles are closely packed is obtained. In the structure, the adjacent inorganic fine particles are joined to each other by the at least one metal compound at a contact point between the inorganic fine particles. A coating film having voids between the inorganic fine particles is formed on the substrate, the formed coating film is peeled from the substrate to form a flake body, and then the flake body is baked, whereby the at least one metal It has a structure in which the compound is made of an inorganic oxide and the inorganic fine particles are closely packed, and in the structure, the adjacent inorganic fine particles are joined to each other by the inorganic oxide at a contact point between the inorganic fine particles. A method of obtaining a colored flake body having voids between the inorganic fine particles and exhibiting structural color development due to diffraction and interference of light incident on the structure.
別の側面から見た本発明の発色フレーク体の製造方法（第２の製造方法）は、単分散の粒径分布を示す球状の無機微粒子と、有機ポリマーと、前記有機ポリマーの溶媒と、を含み、前記有機ポリマーと前記無機微粒子との混合比が、重量比にして、有機ポリマー：無機微粒子＝１：３〜１：１０００である溶液を、基板の表面に塗布し、乾燥させることによって、前記無機微粒子が最密充填された構造を有し、当該構造において、隣り合う前記無機微粒子が、当該無機微粒子同士の接触点にて前記有機ポリマーによって互いに接合されるとともに、当該無機微粒子間に空隙を有する塗布膜を前記基板上に形成し、前記形成した塗布膜を前記基板から剥離し、フレーク体とした後に当該フレーク体を焼成することで、前記無機微粒子が最密充填された構造を有し、当該構造において、隣り合う前記無機微粒子が、当該無機微粒子同士の接触点にて互いに接合されるとともに、当該無機微粒子間に空隙を有し、前記構造に入射した光の回折および干渉による構造性発色を示す発色フレーク体を得る方法である。 According to another aspect of the present invention, a method for producing a colored flake body (second production method) includes spherical inorganic fine particles having a monodispersed particle size distribution, an organic polymer, and a solvent for the organic polymer. A solution in which the mixing ratio of the organic polymer and the inorganic fine particles is a weight ratio of organic polymer: inorganic fine particles = 1: 3 to 1: 1000 is applied to the surface of the substrate and dried. The inorganic fine particles have a structure in which the inorganic fine particles are closely packed, and in the structure, the adjacent inorganic fine particles are joined to each other by the organic polymer at a contact point between the inorganic fine particles, and voids are formed between the inorganic fine particles. And forming the flake body after the formed coating film is peeled from the substrate to form a flake body, whereby the inorganic fine particles are closely packed. In the structure, adjacent inorganic fine particles are bonded to each other at a contact point between the inorganic fine particles, and there are voids between the inorganic fine particles. This is a method for obtaining a colored flake body exhibiting structural color development by diffraction and interference.
本発明の発色フレーク体は、無機微粒子が最密充填された構造に基づく構造性発色（構造色）を示すが、当該構造において、無機微粒子同士は、隣り合う無機微粒子同士の接触点にて互いに接合されている。本発明の発色フレーク体は、無機微粒子間の接合力が強く、基板上に形成された膜ではなくフレーク体でありながら無機微粒子の周期構造が良好に保持されることで安定した発色を示す。 The colored flake body of the present invention exhibits structural color development (structural color) based on a structure in which inorganic fine particles are closely packed. In this structure, the inorganic fine particles are mutually connected at the contact point between adjacent inorganic fine particles. It is joined. The colored flake body of the present invention has a strong bonding force between the inorganic fine particles, and exhibits stable color development because the periodic structure of the inorganic fine particles is well maintained despite being a flake body rather than a film formed on the substrate.
また、本発明の発色フレーク体は、無機微粒子が最密充填された構造において、無機微粒子間に空隙、即ち空気層、を有する。この場合、無機微粒子間に無機物または有機物が充填されている場合に比べて、無機微粒子と無機微粒子間の部分（＝空隙）との屈折率差が大きくなる。このため、本発明の発色フレーク体では、無機微粒子の粒径および粒径分布、ならびに無機微粒子が最密充填された部分の厚さなどにもよるが、得られる構造色の明度がより高く、鮮明な構造色となる。 Further, the colored flake body of the present invention has a void, that is, an air layer, between the inorganic fine particles in a structure in which the inorganic fine particles are closely packed. In this case, the refractive index difference between the inorganic fine particles and the portion (= void) between the inorganic fine particles is larger than when the inorganic fine particles are filled with an inorganic substance or an organic substance. Therefore, in the colored flake body of the present invention, although depending on the particle size and particle size distribution of the inorganic fine particles and the thickness of the portion in which the inorganic fine particles are closely packed, the lightness of the resulting structural color is higher, Clear structural color.
本発明の発色フレーク体の製造方法では、無機微粒子が最密充填された構造を、無機微粒子と当該微粒子のバインダー（少なくとも１種の金属化合物または有機ポリマー）とを含む溶液を塗布、乾燥させ、フレーク体とした後にさらに焼成して形成しているが、このとき、バインダーと無機微粒子との混合比を所定の範囲とした溶液を用いる。この範囲は、無機微粒子が最密充填された構造が形成されるとともに、当該構造において、隣り合う無機微粒子同士が、当該無機微粒子同士の接触点にてバインダーによって互いに接合され、当該無機微粒子間に空隙が形成される範囲である。この混合比の範囲では、無機微粒子間にバインダーが充填される混合比に比べて、無機微粒子に対するバインダーの量が大幅に少ない。これにより、本発明の発色フレーク体の製造方法では、特許文献２に開示の方法とは異なり、無機微粒子の周期構造の形成と、当該無機微粒子同士の接合とを一つの工程で実施できる。即ち、本発明の発色フレーク体の製造方法では、無機微粒子間の接合力が強く、基板上に形成された膜ではなくフレーク体でありながら無機微粒子の周期構造が良好に保持されることで安定した発色を示す発色フレーク体を、より低コストで製造することが可能となる。 In the method for producing a colored flake body of the present invention, a structure in which inorganic fine particles are closely packed is coated with a solution containing inorganic fine particles and a binder (at least one metal compound or organic polymer) of the fine particles, and dried. The flake body is formed by further firing, and at this time, a solution having a mixing ratio of the binder and the inorganic fine particles in a predetermined range is used. In this range, a structure in which inorganic fine particles are closely packed is formed, and in the structure, adjacent inorganic fine particles are joined to each other by a binder at a contact point between the inorganic fine particles, This is the range in which voids are formed. In the range of the mixing ratio, the amount of the binder with respect to the inorganic fine particles is significantly smaller than the mixing ratio in which the binder is filled between the inorganic fine particles. Thereby, unlike the method disclosed in Patent Document 2, in the method for producing a colored flake body of the present invention, the formation of a periodic structure of inorganic fine particles and the bonding of the inorganic fine particles can be performed in one step. That is, in the method for producing a colored flake body of the present invention, the bonding strength between the inorganic fine particles is strong, and the periodic structure of the inorganic fine particles is stably maintained while being a flake body rather than a film formed on the substrate. It is possible to produce a colored flake body exhibiting the developed color at a lower cost.
また、無機微粒子に対するバインダーの量が少ないことにより、バインダーとして有機ポリマーを用いる場合にも、当該ポリマーの選択の自由度が向上する。 In addition, since the amount of the binder with respect to the inorganic fine particles is small, the degree of freedom in selecting the polymer is improved even when an organic polymer is used as the binder.
図１に、本発明の発色フレーク体の一例を示す。図１に示す発色フレーク体１は、その表面の拡大部分に示すように、無機微粒子２が六方最密充填された構造を有する。この構造において、隣り合う無機微粒子２ａ、２ｂは、無機微粒子２ａ、２ｂ同士の接触点３にて互いに接合されている。また、この構造において、隣り合う無機微粒子２間には空隙（空気層）４が存在する。換言すれば、隣り合う無機微粒子２の間は、バインダーによって充填されていない。発色フレーク体１は、無機微粒子２の上記構造に入射した光の回折および干渉による構造色を示す。 FIG. 1 shows an example of the colored flake body of the present invention. The colored flake body 1 shown in FIG. 1 has a structure in which inorganic fine particles 2 are packed in a hexagonal close-packed manner as shown in the enlarged portion of the surface. In this structure, adjacent inorganic fine particles 2a and 2b are joined to each other at a contact point 3 between the inorganic fine particles 2a and 2b. In this structure, a gap (air layer) 4 exists between the adjacent inorganic fine particles 2. In other words, the space between the adjacent inorganic fine particles 2 is not filled with the binder. The colored flake body 1 exhibits a structural color due to diffraction and interference of light incident on the structure of the inorganic fine particles 2.
無機微粒子２は、球状であり、単分散の粒径分布を示す。無機微粒子２は必ずしも真球である必要はないが、明度が高く鮮明な構造色が得られることから、できるだけ真球に近いことが好ましい。 The inorganic fine particles 2 are spherical and exhibit a monodispersed particle size distribution. The inorganic fine particle 2 is not necessarily a true sphere, but is preferably as close to a true sphere as possible since a bright and clear structural color can be obtained.
本明細書では、無機微粒子２の粒径の変動係数（ＣＶ値）が１０％以下の場合、当該微粒子は単分散の粒径分布を示す、とする。無機微粒子２の粒径のＣＶ値は、８％以下が好ましい。無機微粒子２の粒径のＣＶ値は、レーザー回折式粒度分布測定法などの公知の方法により求めることができる。 In this specification, when the variation coefficient (CV value) of the particle size of the inorganic fine particles 2 is 10% or less, the fine particles exhibit a monodispersed particle size distribution. The CV value of the particle size of the inorganic fine particles 2 is preferably 8% or less. The CV value of the particle size of the inorganic fine particles 2 can be determined by a known method such as a laser diffraction particle size distribution measurement method.
無機微粒子２の平均粒径は特に限定されず、得たい構造色の波長に応じて調整できる。可視光域の構造色を得るためには、無機微粒子２の平均粒径を可視光の波長と同程度あるいは当該波長よりも若干小さくするとよい。可視光域の構造色が得られる無機微粒子２の平均粒径は、例えば、１００〜８００ｎｍであり、１５０〜７００ｎｍが好ましく、２００〜６００ｎｍがより好ましい。なお、本明細書において、無機微粒子２の平均粒径とは、当該微粒子の粒径分布において、粒径が小さい側からの体積累積が５０％に相当する粒径Ｄ５０をいう。ＣＶ値を求める際の平均粒径の値にも、このＤ５０を用いた。 The average particle diameter of the inorganic fine particles 2 is not particularly limited and can be adjusted according to the wavelength of the structural color desired to be obtained. In order to obtain a structural color in the visible light region, the average particle diameter of the inorganic fine particles 2 is preferably set to be the same as or slightly smaller than the wavelength of visible light. The average particle diameter of the inorganic fine particles 2 from which a structural color in the visible light region is obtained is, for example, 100 to 800 nm, preferably 150 to 700 nm, and more preferably 200 to 600 nm. In the present specification, the average particle size of the inorganic fine particles 2 refers to a particle size D50 corresponding to 50% volume accumulation from the smaller particle size in the particle size distribution of the fine particles. This D50 was also used for the average particle size when determining the CV value.
無機微粒子２を構成する材料は特に限定されないが、金属酸化物などの無機酸化物が適当である。無機微粒子２は、得たい構造色の光に対して透明であることが好ましく、この場合、明度がより高く鮮明な構造色が得られる。無機微粒子２は、例えば、シリカ、チタニア、アルミナ、ジルコニアおよびセリアから選ばれる少なくとも１種の無機酸化物からなり、シリカからなることが好ましい。 Although the material which comprises the inorganic fine particle 2 is not specifically limited, Inorganic oxides, such as a metal oxide, are suitable. The inorganic fine particles 2 are preferably transparent to the light of the structural color desired to be obtained. In this case, a clear structural color with higher brightness is obtained. The inorganic fine particles 2 are made of, for example, at least one inorganic oxide selected from silica, titania, alumina, zirconia, and ceria, and are preferably made of silica.
図１に示す発色フレーク体１は、無機微粒子２が六方最密充填された構造を有するが、無機微粒子２の最密充填方法は六方最密充填に限られず、例えば、立方最密充填であってもよい。なお、発色フレーク体１は、その表面だけではなく厚さ方向にも（即ち、三次元的に）無機微粒子２が最密充填された構造を有する。ただし、例えば、発色フレーク体１のエッジ部などにおいて、無機微粒子２の最密充填構造が部分的に壊れていることがある。 The colored flake body 1 shown in FIG. 1 has a structure in which inorganic fine particles 2 are packed in a hexagonal close-packed manner. However, the close-packing method of the inorganic fine particles 2 is not limited to the hexagonal close-packed packing. May be. The colored flake body 1 has a structure in which the inorganic fine particles 2 are packed not only in the surface but also in the thickness direction (that is, three-dimensionally). However, for example, the close-packed structure of the inorganic fine particles 2 may be partially broken in the edge portion of the colored flake body 1 or the like.
図１に示す発色フレーク体１は基板を有さないが、本発明の発色フレーク体は、必要であれば、フレーク状の基板の表面に無機微粒子２の最密充填構造体が付着した構造を有していてもよい。 Although the colored flake body 1 shown in FIG. 1 does not have a substrate, the colored flake body of the present invention has a structure in which a close-packed structure of inorganic fine particles 2 is attached to the surface of a flaky substrate if necessary. You may have.
隣り合う無機微粒子２は、当該無機微粒子同士の接触点にて、例えば無機酸化物によって互いに接合されていてもよい。この場合、無機微粒子２間の接合力がより強くなるとともに、発色フレーク体１の耐熱性が高くなる。このような発色フレーク体１は、例えば、後述する第１の製造方法により形成できる。 Adjacent inorganic fine particles 2 may be joined to each other by, for example, an inorganic oxide at a contact point between the inorganic fine particles. In this case, the bonding strength between the inorganic fine particles 2 becomes stronger and the heat resistance of the colored flake body 1 becomes higher. Such a colored flake body 1 can be formed by, for example, a first manufacturing method described later.
無機微粒子２を接合する無機酸化物は、隣り合う無機微粒子２同士を接触点３にて接合できる限り特に限定されないが、例えば、シリカ、アルミナ、チタニア、ジルコニアおよびセリアから選ばれる少なくとも１種の無機酸化物である。隣り合う無機微粒子２が無機酸化物によって互いに接合されている場合、無機酸化物と同一の材料から無機微粒子２がなることが好ましい。この場合、無機微粒子２ならびに当該微粒子同士を接合する無機酸化物の屈折率が互いに同一となり、明度がさらに高く鮮明な構造色が得られる。なお、この効果は、本発明の発色フレーク体において無機微粒子２間にバインダーが充填されておらず、空隙（空気層）４が存在するが故に得ることができる。無機微粒子２間にバインダーが充填されている場合、無機微粒子２とバインダーとの間である程度以上の屈折率差がある状態としなければ、構造色を得ることができない。 The inorganic oxide for joining the inorganic fine particles 2 is not particularly limited as long as adjacent inorganic fine particles 2 can be joined at the contact point 3. For example, at least one inorganic substance selected from silica, alumina, titania, zirconia and ceria is used. It is an oxide. When adjacent inorganic fine particles 2 are joined to each other by an inorganic oxide, the inorganic fine particles 2 are preferably made of the same material as the inorganic oxide. In this case, the inorganic fine particles 2 and the inorganic oxide joining the fine particles have the same refractive index, and a brighter and clearer structural color can be obtained. This effect can be obtained because the colored flake body of the present invention is not filled with the binder between the inorganic fine particles 2 and the voids (air layer) 4 exist. When a binder is filled between the inorganic fine particles 2, a structural color cannot be obtained unless there is a certain difference in refractive index between the inorganic fine particles 2 and the binder.
無機酸化物は、例えば、金属アルコキシド、金属塩および金属酸化物コロイドから選ばれる少なくとも１種の金属化合物を焼成して形成できる。 The inorganic oxide can be formed, for example, by firing at least one metal compound selected from metal alkoxides, metal salts, and metal oxide colloids.
隣り合う無機微粒子２が無機酸化物によって互いに接合されている場合においても、本発明の発色フレーク体では無機微粒子２間に空隙が存在しているため、無機微粒子２に比べて無機酸化物の量が少ない。この場合、発色フレーク体が含む無機酸化物と無機微粒子との比は、重量比にして、例えば、無機酸化物：無機微粒子＝１：１０〜１：１０００であり、１：３０〜１：５００が好ましく、１：５０〜１：５００がより好ましい。 Even when adjacent inorganic fine particles 2 are joined to each other by an inorganic oxide, the colored flakes of the present invention have voids between the inorganic fine particles 2, so that the amount of inorganic oxide compared to the inorganic fine particles 2 is large. Less is. In this case, the weight ratio of the inorganic oxide and the inorganic fine particles contained in the colored flake body is, for example, inorganic oxide: inorganic fine particles = 1: 10 to 1: 1000, and 1:30 to 1: 500. Is preferable, and 1:50 to 1: 500 is more preferable.
隣り合う無機微粒子２が無機酸化物によって互いに接合されている場合、無機微粒子２間の間隙が無機酸化物によって充填されていない限り、隣り合う無機微粒子２の接触点だけではなく、無機微粒子２間の空隙４の一部に無機酸化物が存在していてもよい。 When the adjacent inorganic fine particles 2 are joined to each other by the inorganic oxide, as long as the gap between the inorganic fine particles 2 is not filled with the inorganic oxide, not only the contact point between the adjacent inorganic fine particles 2 but also between the inorganic fine particles 2. An inorganic oxide may be present in a part of the gap 4.
本発明の発色フレーク体の厚さは特に限定されず、例えば、０．８〜１０００μｍであり、１〜５００μｍが好ましい。 The thickness of the colored flake body of the present invention is not particularly limited, and is, for example, 0.8 to 1000 μm, preferably 1 to 500 μm.
本発明の発色フレーク体は、無機微粒子の周期構造による構造色を示す粉体であり、色素あるいは顔料を混入して発色させた粉体とは異なり、明度が高く鮮やかで効果的な発色を示す。また、微粒子間の接合力が強く、製造時および使用時において無機微粒子の周期構造が壊れにくく、安定して発色を維持できる。 The colored flake body of the present invention is a powder exhibiting a structural color due to the periodic structure of inorganic fine particles, and unlike a powder colored by mixing a dye or pigment, it has a high brightness and shows a vivid and effective color development. . Further, the bonding force between the fine particles is strong, and the periodic structure of the inorganic fine particles is not easily broken at the time of production and use, and the color development can be maintained stably.
本発明の発色フレーク体は、化粧品、塗料、樹脂フィルムを含む樹脂成形品などに、混合・配合でき、混合・配合の際にも発色フレーク体における無機微粒子の周期構造が壊れにくい。このため、本発明の発色フレーク体を混合・配合したこれら製品は、本発明の発色フレーク体が示す構造色に基づく効果的な発色を安定して示す。また、隣り合う無機微粒子が無機酸化物によって互いに接合されている場合、本発明の発色フレーク体は高い耐熱性、耐候性を有し、高温雰囲気下あるいは屋外における使用によっても、色調変化を受けにくい。さらにこの場合、高温で溶融する樹脂への練り込みなども可能となる。 The colored flake body of the present invention can be mixed and blended with cosmetics, paints, resin molded products including resin films, and the like, and the periodic structure of inorganic fine particles in the colored flake body is not easily broken during mixing and blending. Therefore, these products in which the colored flake bodies of the present invention are mixed and blended stably exhibit effective color development based on the structural color exhibited by the colored flake bodies of the present invention. In addition, when adjacent inorganic fine particles are bonded to each other by an inorganic oxide, the colored flake body of the present invention has high heat resistance and weather resistance, and hardly undergoes a change in color tone even when used in a high temperature atmosphere or outdoors. . Further, in this case, kneading into a resin that melts at a high temperature is possible.
本発明の発色フレーク体は、例えば、本発明の発色フレーク体の製造方法により得ることができる。 The colored flake body of the present invention can be obtained, for example, by the method for producing the colored flake body of the present invention.
第１の製造方法では、単分散の粒径分布を示す球状の無機微粒子と、焼成後に無機酸化物となる、金属アルコキシド、金属塩および金属酸化物コロイドから選ばれる少なくとも１種の金属化合物と、水および／またはアルコールとを含む溶液Ａを用いる。 In the first production method, spherical inorganic fine particles having a monodispersed particle size distribution, and at least one metal compound selected from metal alkoxides, metal salts and metal oxide colloids, which become inorganic oxides after firing, Solution A containing water and / or alcohol is used.
無機微粒子は、本発明の発色フレーク体の説明において上述した無機微粒子である。 The inorganic fine particles are the inorganic fine particles described above in the description of the colored flake body of the present invention.
少なくとも１種の金属化合物は、焼成後に無機酸化物となって、隣り合う無機微粒子同士をその接触点にて互いに接合させる。この金属化合物は、形成したい無機酸化物に応じて選択できる。 The at least one metal compound becomes an inorganic oxide after firing, and bonds adjacent inorganic fine particles to each other at the contact point. This metal compound can be selected according to the inorganic oxide to be formed.
金属アルコキシドは、例えば、シリコン、アルミニウム、チタンおよびジルコニウムから選ばれる少なくとも１種の金属のメトキシド、エトキシドあるいはプロポキシドである。金属塩は、例えば、ケイ酸ナトリウム、硝酸アルミニウム、四塩化チタンである。金属酸化物コロイドは、例えば、シリカコロイド、アルミナコロイド、チタニアコロイド、ジルコニアコロイド、セリアコロイドである。金属酸化物コロイドにおけるコロイド粒子の平均粒径は、無機微粒子の平均粒径よりも小さいことが好ましく、例えば、１００ｎｍ以下、好ましくは５０ｎｍ以下、より好ましくは３０ｎｍ以下である。 The metal alkoxide is, for example, methoxide, ethoxide or propoxide of at least one metal selected from silicon, aluminum, titanium and zirconium. Examples of the metal salt include sodium silicate, aluminum nitrate, and titanium tetrachloride. The metal oxide colloid is, for example, a silica colloid, an alumina colloid, a titania colloid, a zirconia colloid, or a ceria colloid. The average particle size of the colloidal particles in the metal oxide colloid is preferably smaller than the average particle size of the inorganic fine particles, for example, 100 nm or less, preferably 50 nm or less, more preferably 30 nm or less.
溶液Ａにおける上記少なくとも１種の金属化合物と無機微粒子との混合比は、上記少なくとも１種の金属化合物について、当該化合物を焼成して得られる無機酸化物換算で、重量比にして、金属化合物（焼成後の無機酸化物換算）：無機微粒子＝１：１０〜１：１０００であり、当該比は、金属化合物（焼成後の無機酸化物換算）：無機微粒子＝１：３０〜１：５００が好ましく、１：５０〜１：５００がより好ましい。 The mixing ratio of the at least one metal compound and the inorganic fine particles in the solution A is a weight ratio in terms of an inorganic oxide obtained by firing the compound with respect to the at least one metal compound. Inorganic oxide after firing): Inorganic fine particles = 1: 10 to 1: 1000, and the ratio is preferably a metal compound (in terms of inorganic oxide after firing): Inorganic fine particles = 1: 30 to 1: 500. 1: 50-1: 500 is more preferable.
溶液Ａは、溶媒として水および／またはアルコールを含む。アルコールは、例えば、エタノール、メタノール、１−プロパノール、２−プロパノールである。 Solution A contains water and / or alcohol as a solvent. The alcohol is, for example, ethanol, methanol, 1-propanol, or 2-propanol.
上記少なくとも１種の金属化合物が金属アルコキシドである場合、溶液Ａは、当該アルコキシドの加水分解を起こすための水と、水および金属アルコキシドの相溶性を向上させるためのアルコールとの双方を含む必要がある。また、この場合、溶液Ａが、加水分解反応の触媒として酸またはアルカリを含むことが好ましい。 When the at least one metal compound is a metal alkoxide, the solution A needs to contain both water for causing hydrolysis of the alkoxide and alcohol for improving the compatibility of water and the metal alkoxide. is there. In this case, the solution A preferably contains an acid or an alkali as a catalyst for the hydrolysis reaction.
溶液Ａにおける溶媒の量は適宜調整できる。溶液Ａにおける無機微粒子の含有率は２０〜９０重量％程度が好ましい。溶液Ａにおける水とアルコールとの混合比は、適宜調整できる。 The amount of the solvent in the solution A can be adjusted as appropriate. The content of the inorganic fine particles in the solution A is preferably about 20 to 90% by weight. The mixing ratio of water and alcohol in the solution A can be adjusted as appropriate.
第１の製造方法では、溶液Ａを基板の表面に塗布し、乾燥させる。これによって、無機微粒子が最密充填された構造を有し、当該構造において、隣り合う無機微粒子が、当該無機微粒子同士の接触点にて上記少なくとも１種の金属化合物によって互いに接合されるとともに、当該無機微粒子間に空隙を有する塗布膜が基板上に形成される。 In the first manufacturing method, the solution A is applied to the surface of the substrate and dried. This has a structure in which inorganic fine particles are closely packed, and in the structure, adjacent inorganic fine particles are joined to each other by the at least one metal compound at a contact point between the inorganic fine particles, and A coating film having voids between the inorganic fine particles is formed on the substrate.
基板への溶液Ａの塗布方法は特に限定されず、ロールコーター、バーコーター、スプレーコーター、フローコーター、アプリケーターなどの各種のコーターを用いた塗布、あるいはディッピング法による塗布を行えばよい。溶液Ａの塗布は、乾燥後の厚さにして０．８〜１０００μｍ程度となるように実施することが好ましい。乾燥後の厚さが過度に小さいと、基板から塗布膜を剥離する際の当該膜の強度が小さく、粉々に砕けてフレーク体が得られない。また、膜の厚さ方向に無機微粒子の重なりが少ない状態となり、構造色の発色が弱くなる。一方、乾燥後の厚さが過度に大きいと、得られた発色フレーク体を塗料などに混合・配合した際に、塗装面が平滑にならないなどの問題が生じる。 The method for applying the solution A onto the substrate is not particularly limited, and application using various coaters such as a roll coater, bar coater, spray coater, flow coater, applicator, or application by dipping may be performed. The application of the solution A is preferably carried out so that the thickness after drying is about 0.8 to 1000 μm. If the thickness after drying is excessively small, the strength of the film when the coating film is peeled off from the substrate is small, and the flake body cannot be obtained by breaking into pieces. Further, there is little overlap of inorganic fine particles in the thickness direction of the film, and the structural color is weakened. On the other hand, when the thickness after drying is excessively large, there arises a problem that the coated surface is not smooth when the obtained colored flakes are mixed and blended with a paint or the like.
基板は、表面が平滑である限り特に限定されず、例えば、ガラス基板、金属基板、セラミクス基板、ポリマー基板である。なお、無機微粒子と上記少なくとも１種の金属化合物と溶媒とを混合した後、３０〜８０℃で１〜２４時間養生した溶液Ａを基板の表面に塗布することが好ましい。 The substrate is not particularly limited as long as the surface is smooth, and is, for example, a glass substrate, a metal substrate, a ceramic substrate, or a polymer substrate. In addition, after mixing the inorganic fine particles, the at least one metal compound and the solvent, it is preferable to apply the solution A cured at 30 to 80 ° C. for 1 to 24 hours on the surface of the substrate.
基板の表面に塗布した溶液Ａの乾燥方法は特に限定されない。ただし、あまりに早く乾燥させた場合、無機微粒子が最密充填された構造が形成されにくいため、比較的ゆっくりと乾燥させる（溶液の塗布厚にもよるが、例えば、１〜６０分かけて乾燥させる）ことが好ましい。 The drying method of the solution A applied to the surface of the substrate is not particularly limited. However, if it is dried too quickly, it is difficult to form a structure in which the inorganic fine particles are closely packed, so that it is dried relatively slowly (depending on the coating thickness of the solution, for example, it is dried over 1 to 60 minutes). Is preferred.
次に、基板の表面に形成した塗布膜を基板から剥離し、フレーク体とした後に当該フレーク体を焼成する。これにより、無機微粒子を接合している上記少なくとも１種の金属化合物が無機酸化物となって、無機酸化物によって、互いの接触点にて無機微粒子が接合された本発明の発色フレーク体が得られる。 Next, the coating film formed on the surface of the substrate is peeled from the substrate to form a flake body, and then the flake body is baked. As a result, the colored flake body of the present invention in which the at least one metal compound bonded with the inorganic fine particles becomes an inorganic oxide and the inorganic fine particles are bonded at the contact points with each other by the inorganic oxide is obtained. It is done.
塗布膜の剥離は、例えば、ブラシ、スクレーパー、エアーの吹きつけなどにより行えばよい。このとき、塗布膜は断片的に切断され、フレーク体となる。 The coating film may be peeled off by, for example, a brush, a scraper, or air blowing. At this time, the coating film is cut into pieces to form flake bodies.
フレーク体の焼成は、上記少なくとも１種の金属化合物が無機酸化物となる条件で実施すればよく、例えば、３００〜１２００℃程度の温度において、５分〜１２時間行えばよい。 The flake body may be fired under the condition that the at least one metal compound becomes an inorganic oxide, for example, at a temperature of about 300 to 1200 ° C. for 5 minutes to 12 hours.
得られた本発明の発色フレーク体は、必要に応じて、粉砕および分級してもよい。 The obtained colored flake body of the present invention may be pulverized and classified as necessary.
第２の製造方法では、単分散の粒径分布を示す球状の無機微粒子と、有機ポリマーと、当該有機ポリマーの溶媒とを含む溶液Ｂを用いる。 In the second production method, a solution B containing spherical inorganic fine particles showing a monodispersed particle size distribution, an organic polymer, and a solvent for the organic polymer is used.
無機微粒子は、本発明の発色フレーク体の説明において上述した無機微粒子である。 The inorganic fine particles are the inorganic fine particles described above in the description of the colored flake body of the present invention.
有機ポリマーは、例えば、ポリビニルアルコール、ポリビニルピロリドン、メチルセルロース、カルボキシメチルセルロース、アクリル樹脂エマルジョン、ウレタン樹脂エマルジョンおよびエポキシ樹脂エマルジョンから選ばれる少なくとも１種である。発色フレーク体の製造が容易となることから、有機ポリマーが水溶性であることが好ましい。 The organic polymer is at least one selected from, for example, polyvinyl alcohol, polyvinyl pyrrolidone, methyl cellulose, carboxymethyl cellulose, acrylic resin emulsion, urethane resin emulsion, and epoxy resin emulsion. The organic polymer is preferably water-soluble because the colored flakes can be easily produced.
溶媒は、有機ポリマーを溶解するとともに、溶液Ｂを基板の表面に塗布し、乾燥させることが可能である限り特に限定されない。溶媒として水を使用できることから、有機ポリマーは、ポリビニルアルコール、ポリビニルピロリドンなどの水溶性ポリマーであることが好ましい。 The solvent is not particularly limited as long as the organic polymer can be dissolved and the solution B can be applied to the surface of the substrate and dried. Since water can be used as the solvent, the organic polymer is preferably a water-soluble polymer such as polyvinyl alcohol or polyvinyl pyrrolidone.
溶液Ｂにおける有機ポリマーと無機微粒子との混合比は、重量比にして、有機ポリマー：無機微粒子＝１：３〜１：１０００であり、当該比は、有機ポリマー：無機微粒子＝１：５〜１：５００が好ましく、１：１０〜１：５００がより好ましい。 The mixing ratio of the organic polymer and the inorganic fine particles in the solution B is, as a weight ratio, organic polymer: inorganic fine particles = 1: 3 to 1: 1000, and the ratio is organic polymer: inorganic fine particles = 1: 5 to 1. : 500 is preferable, and 1:10 to 1: 500 is more preferable.
溶液Ｂにおける溶媒の量は適宜調整できる。溶液Ｂにおける無機微粒子の含有率は２０〜９０重量％程度が好ましい。 The amount of the solvent in the solution B can be adjusted as appropriate. The content of inorganic fine particles in the solution B is preferably about 20 to 90% by weight.
第２の製造方法では、溶液Ｂを基板の表面に塗布し、乾燥させる。これによって、無機微粒子が最密充填された構造を有し、当該構造において、隣り合う無機微粒子が、当該無機微粒子同士の接触点にて有機ポリマーによって互いに接合されるとともに、当該無機微粒子間に空隙を有する塗布膜が基板上に形成される。 In the second manufacturing method, the solution B is applied to the surface of the substrate and dried. This has a structure in which inorganic fine particles are closely packed, in which the adjacent inorganic fine particles are joined to each other by an organic polymer at the contact point between the inorganic fine particles, and voids are formed between the inorganic fine particles. Is formed on the substrate.
基板への溶液Ｂの塗布方法は、基板への溶液Ａの塗布方法と同様であればよい。 The method for applying the solution B to the substrate may be the same as the method for applying the solution A to the substrate.
基板の表面に塗布した溶液Ｂの乾燥方法は、基板の表面に塗布した溶液Ａの乾燥方法と同様であればよい。 The method for drying the solution B applied to the surface of the substrate may be the same as the method for drying the solution A applied to the surface of the substrate.
次に、基板の表面に形成した塗布膜を基板から剥離し、フレーク体とした後に当該フレーク体を焼成する。これにより、本発明の発色フレーク体が得られる。 Next, the coating film formed on the surface of the substrate is peeled from the substrate to form a flake body, and then the flake body is baked. Thereby, the colored flake body of the present invention is obtained.
塗布膜の基板からの剥離は、例えば、ブラシ、スクレーパー、エアーの吹きつけなどにより行えばよい。このとき、塗布膜は断片的に切断され、フレーク体となる。 The coating film may be peeled from the substrate by, for example, a brush, a scraper, or air blowing. At this time, the coating film is cut into pieces to form flake bodies.
フレーク体の焼成は、例えば、有機ポリマーが熱分解する温度近傍（２５０〜４５０℃）でフレーク体を熱処理した後、さらに処理温度を上げて、４００〜１２００℃で熱処理することで実施できる。なお、熱処理の昇温条件が比較的ゆっくりであり、無機微粒子が互いに熱融着する温度に至るまでに有機ポリマーの分解がほぼ完了する条件であれば、熱処理を２段階に分けて行う必要は必ずしもない。また、焼成によって有機ポリマーが完全に失われる条件である必要はなく、無機微粒子が互いに点接触している部分に有機ポリマーが僅かに残留していたとしても、残留ポリマーが無機微粒子と空隙との間の屈折率差に影響を及ぼすことはほぼなく、構造色の発色に大きな影響を与えない。 The calcination of the flake body can be carried out, for example, by heat-treating the flake body in the vicinity of the temperature at which the organic polymer is thermally decomposed (250 to 450 ° C.), and further raising the treatment temperature and heat treating at 400 to 1200 ° C. In addition, if the temperature raising conditions of the heat treatment are relatively slow and the decomposition of the organic polymer is almost completed before reaching the temperature at which the inorganic fine particles are thermally fused to each other, the heat treatment needs to be performed in two stages. Not necessarily. Moreover, it is not necessary that the organic polymer is completely lost by firing. Even if the organic polymer is slightly left in the portion where the inorganic fine particles are in point contact with each other, the residual polymer is not formed between the inorganic fine particles and the voids. There is almost no effect on the difference in refractive index between them, and the color of the structural color is not greatly affected.
以下、実施例により、本発明をさらに詳細に説明する。本発明は、以下の実施例に限定されない。 Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to the following examples.
（実施例１）
内容積５００ｍＬのビーカーを用いて、５０℃程度の加熱条件下で、ポリビニルアルコール（クラレ製、ポバールＰＶＡ−１１７）２．５ｇを水９７．５ｇにゆっくりと溶解させた。溶解後、加熱を止め、得られたポリビニルアルコール水溶液に球状のシリカ微粒子（日本触媒製、シーホスターＫＥ−Ｗ３０、平均粒径３００ｎｍ、水分散液（固形分濃度２０重量％））２５０ｇを加え、全体を十分に混合した。加えたシリカ微粒子のＣＶ値を、レーザー回折式粒度分布測定装置（日機装製、マイクロトラックＨＲＡ）を用いて別途測定したところ、６％であった。
Example 1
Using a beaker having an internal volume of 500 mL, 2.5 g of polyvinyl alcohol (manufactured by Kuraray, Poval PVA-117) was slowly dissolved in 97.5 g of water under heating conditions of about 50 ° C. After dissolution, heating was stopped, and 250 g of spherical silica fine particles (manufactured by Nippon Shokubai Co., Ltd., Seahoster KE-W30, average particle size of 300 nm, aqueous dispersion (solid content concentration: 20% by weight)) were added to the resulting aqueous polyvinyl alcohol solution. Were mixed well. The CV value of the added silica fine particles was measured separately using a laser diffraction particle size distribution analyzer (manufactured by Nikkiso, Microtrac HRA), and found to be 6%.
このようにして作製した混合溶液を塗布液として、アプリケーターを用いて、当該塗布液を１０ｃｍ×２０ｃｍのガラス基板上に塗布厚約６００μｍで塗布した。次に、６０℃に保持した乾燥機を用いて、塗布膜を１時間乾燥させた。乾燥後の塗布膜の厚さは約２００μｍであった。次に、乾燥後の塗布膜をスクレーパーを用いてガラス基板から剥離し、フレーク状の粉体（フレーク体）を得た。次に、得られた粉体をアルミナるつぼに収容し、焼成炉を用いて室温から６５０℃まで４時間かけて昇温し、その後、焼成炉を６５０℃に保持して、１時間焼成した。 The mixed solution thus prepared was used as a coating solution, and the coating solution was applied to a 10 cm × 20 cm glass substrate with a coating thickness of about 600 μm using an applicator. Next, the coating film was dried for 1 hour using a drier maintained at 60 ° C. The thickness of the coating film after drying was about 200 μm. Next, the coating film after drying was peeled off from the glass substrate using a scraper to obtain a flaky powder (flake body). Next, the obtained powder was placed in an alumina crucible and heated from room temperature to 650 ° C. over 4 hours using a baking furnace, and then the baking furnace was held at 650 ° C. and baked for 1 hour.
焼成によって得られた粉体を光学顕微鏡で観察したところ、フレーク（薄片）の形態を有していた。また、粉体を指につけて擦り合わせてから光学顕微鏡で再度観察したところ、先程と同様の大きさおよび形態を維持しており、擦り合わせによっても破壊されない強度を有することが確認された。蛍光灯を用いて、粉体の色調を目視により観察したところ、干渉色が見られ、見られた色は、観察する角度（光源に対する角度）によって緑色から赤色に変化した。 When the powder obtained by baking was observed with the optical microscope, it had the form of flakes (flakes). Further, when the powder was put on a finger and rubbed together, it was observed again with an optical microscope. As a result, it was confirmed that the same size and shape as before were maintained, and the strength was not broken by rubbing. When the color tone of the powder was visually observed using a fluorescent lamp, an interference color was observed, and the observed color changed from green to red depending on the observation angle (angle with respect to the light source).
得られた粉体の表面を走査型電子顕微鏡（ＳＥＭ）により観察した結果を図２に示す。また、得られた粉体の一部を削りとって露出させた当該粉体の断面をＳＥＭにより観察した結果を図３に示す。図２、３に示すように、粉体の表面および断面のいずれにおいても、シリカ微粒子が最密充填されている構造が確認できた。 The result of having observed the surface of the obtained powder with the scanning electron microscope (SEM) is shown in FIG. Moreover, the result of having observed the cross section of the said powder exposed by shaving off part of the obtained powder by SEM is shown in FIG. As shown in FIGS. 2 and 3, a structure in which silica fine particles are closely packed can be confirmed on both the surface and the cross section of the powder.
（実施例２）
内容積１Ｌのビーカーを用いて、水５０ｇと濃度６０重量％の硝酸０．５ｇとの混合物を調製した後に、当該ビーカー内にエタノール５０ｇを加えて混合し、さらにシリコンメトキシド２．５ｇを加えて、全体を３０分間攪拌、混合した。得られた混合溶液をビーカーから密閉可能な容器に移し、密閉した状態および５０℃で６時間養生した。
(Example 2)
After preparing a mixture of 50 g of water and 0.5 g of nitric acid having a concentration of 60% by weight using a 1 L beaker, add 50 g of ethanol into the beaker and mix, and then add 2.5 g of silicon methoxide. The whole was stirred and mixed for 30 minutes. The obtained mixed solution was transferred from the beaker to a sealable container, and cured at 50 ° C. for 6 hours in a sealed state.
次に、養生後のシリコンメトキシド溶液に球状のシリカ微粒子（日本触媒製、シーホスターＫＥ−Ｗ３０、平均粒径３００ｎｍ、水分散液（固形分濃度２０重量％））５００ｇを加え、全体を十分に混合した。このようにして作製した混合溶液を塗布液として、バーコーターを用いて、当該塗布液を２０ｃｍ角のガラス基板上に塗布厚約２０μｍで塗布した。次に、１００℃に保持した乾燥機を用いて、塗布膜を１０分間乾燥させた。乾燥後の塗布膜の厚さは約１０μｍであった。次に、乾燥後の塗布膜をスクレーパーを用いてガラス基板から剥離し、フレーク状の粉体（フレーク体）を得た。次に、得られた粉体をアルミナるつぼに収容し、焼成炉を用いて室温から８００℃まで５時間かけて昇温し、その後、焼成炉を８００℃に保持して、１時間焼成した。 Next, 500 g of spherical silica particles (manufactured by Nippon Shokubai Co., Ltd., Seahoster KE-W30, average particle size 300 nm, aqueous dispersion (solid content concentration 20 wt%)) 500 g is added to the silicon methoxide solution after curing, and the whole is fully Mixed. Using the mixed solution thus prepared as a coating solution, the coating solution was applied on a 20 cm square glass substrate with a coating thickness of about 20 μm using a bar coater. Next, the coating film was dried for 10 minutes using a drier kept at 100 ° C. The thickness of the coating film after drying was about 10 μm. Next, the coating film after drying was peeled off from the glass substrate using a scraper to obtain a flaky powder (flake body). Next, the obtained powder was housed in an alumina crucible and heated from room temperature to 800 ° C. over 5 hours using a firing furnace, and then the firing furnace was held at 800 ° C. and fired for 1 hour.
焼成によって得られた粉体を光学顕微鏡で観察したところ、フレーク（薄片）の形態を有していた。また、粉体を指につけて擦り合わせてから再び光学顕微鏡で観察したところ、先程と同様の大きさおよび形態を維持しており、擦り合わせによっても破壊されない強度を有することが確認された。蛍光灯を用いて、粉体の色調を目視により観察したところ、干渉色が見られ、見られた色は、観察する角度（光源に対する角度）によって緑色から赤色に変化した。なお、得られた粉体において、シリカ微粒子同士を接合する無機酸化物が当該微粒子と同じシリカからなり、微粒子および無機酸化物の屈折率が同一であるにも関わらず構造色が観察されていることから、シリカ微粒子間には無機酸化物が充填されているのではなく、空隙（空気層）が存在していると考えられる。 When the powder obtained by baking was observed with the optical microscope, it had the form of flakes (flakes). Further, when the powder was put on a finger and rubbed, it was observed again with an optical microscope. As a result, it was confirmed that the same size and form as before were maintained, and the strength was not broken by rubbing. When the color tone of the powder was visually observed using a fluorescent lamp, an interference color was observed, and the observed color changed from green to red depending on the observation angle (angle with respect to the light source). In the obtained powder, the inorganic oxide joining the silica fine particles is made of the same silica as the fine particles, and the structural color is observed even though the refractive indexes of the fine particles and the inorganic oxide are the same. Therefore, it is considered that a void (air layer) is not present between the silica fine particles but filled with an inorganic oxide.
（比較例１）
シリコンメトキシドを加えなかった以外は実施例２と同様にして、水、硝酸、エタノールおよび球状のシリカ微粒子を含む塗布液を得た。次に、得られた塗布液を、バーコーターを用いて、２０ｃｍ角のガラス基板上に塗布厚約２０μｍで塗布した。次に、１００℃に保持した乾燥機を用いて、塗布膜を１０分間乾燥させた。乾燥後の塗布膜の厚さは約１０μｍであった。次に、乾燥後の塗布膜をスクレーパーを用いてガラス基板から剥離し、フレーク状の粉体（フレーク体）を得た。次に、得られた粉体をアルミナるつぼに収容し、焼成炉を用いて室温から３００℃まで２時間かけて昇温し、その後、焼成炉を３００℃に保持して、１時間焼成した。
(Comparative Example 1)
A coating solution containing water, nitric acid, ethanol and spherical silica fine particles was obtained in the same manner as in Example 2 except that silicon methoxide was not added. Next, the obtained coating solution was applied to a 20 cm square glass substrate with a coating thickness of about 20 μm using a bar coater. Next, the coating film was dried for 10 minutes using a drier kept at 100 ° C. The thickness of the coating film after drying was about 10 μm. Next, the coating film after drying was peeled off from the glass substrate using a scraper to obtain a flaky powder (flake body). Next, the obtained powder was housed in an alumina crucible and heated from room temperature to 300 ° C. over 2 hours using a firing furnace, and then fired for 1 hour while maintaining the firing furnace at 300 ° C.
焼成によって得られた粉体を指につけて軽く擦ったところ、強度が著しく低く、簡単にバラバラとなった。 When the powder obtained by baking was applied to a finger and rubbed lightly, the strength was remarkably low and it easily fell apart.
本発明の発色フレーク体は、化粧品、塗料、樹脂フィルムを含む樹脂成形品などに、混合・配合でき、混合・配合の際にも発色フレーク体における無機微粒子の周期構造が壊れにくい。このため、本発明の発色フレーク体を混合・配合したこれら製品は、本発明の発色フレーク体が示す構造色に基づく効果的な発色を安定して示す。 The colored flake body of the present invention can be mixed and blended with cosmetics, paints, resin molded products including resin films, and the like, and the periodic structure of inorganic fine particles in the colored flake body is not easily broken during mixing and blending. Therefore, these products in which the colored flake bodies of the present invention are mixed and blended stably exhibit effective color development based on the structural color exhibited by the colored flake bodies of the present invention.
１ 発色フレーク体
２ 無機微粒子
３ 接触点
４ 空隙（空気層）
1 Colored flake body 2 Inorganic fine particles 3 Contact point 4 Air gap (air layer)
Claims (5)
前記構造において、隣り合う前記無機微粒子は、当該無機微粒子同士の接触点にて互いに接合されるとともに、当該無機微粒子間に空隙を有し、
前記構造に入射した光の回折および干渉による構造性発色を示す発色フレーク体。 It has a structure in which spherical inorganic fine particles showing a monodisperse particle size distribution are closely packed,
In the structure, the adjacent inorganic fine particles are bonded to each other at a contact point between the inorganic fine particles, and have a gap between the inorganic fine particles,
A colored flake that exhibits structural coloration due to diffraction and interference of light incident on the structure.
焼成後に無機酸化物となる、金属アルコキシド、金属塩および金属酸化物コロイドから選ばれる少なくとも１種の金属化合物と、
水および／またはアルコールと、を含み、
前記少なくとも１種の金属化合物と前記無機微粒子との混合比が、前記少なくとも１種の金属化合物について焼成後の無機酸化物換算で、金属化合物：無機微粒子＝１：１０〜１：１０００（重量比）である溶液を、
基板の表面に塗布し、乾燥させることによって、前記無機微粒子が最密充填された構造を有し、当該構造において、隣り合う前記無機微粒子が、当該無機微粒子同士の接触点にて前記少なくとも１種の金属化合物によって互いに接合されるとともに、当該無機微粒子間に空隙を有する塗布膜を前記基板上に形成し、
前記形成した塗布膜を前記基板から剥離し、フレーク体とした後に当該フレーク体を焼成することで、前記少なくとも１種の金属化合物を無機酸化物として、
前記無機微粒子が最密充填された構造を有し、当該構造において、隣り合う前記無機微粒子が、当該無機微粒子同士の接触点にて前記無機酸化物によって互いに接合されるとともに、当該無機微粒子間に空隙を有し、
前記構造に入射した光の回折および干渉による構造性発色を示す発色フレーク体を得る、発色フレーク体の製造方法。 Spherical inorganic fine particles exhibiting a monodisperse particle size distribution;
At least one metal compound selected from metal alkoxides, metal salts and metal oxide colloids, which become inorganic oxides after firing;
Water and / or alcohol,
The mixing ratio of the at least one metal compound and the inorganic fine particles is calculated in terms of the inorganic oxide after firing for the at least one metal compound: metal compound: inorganic fine particles = 1: 10 to 1: 1000 (weight ratio) ) Solution
The structure has a structure in which the inorganic fine particles are closely packed by applying to the surface of the substrate and drying, and in the structure, the adjacent inorganic fine particles are the at least one kind at the contact point between the inorganic fine particles. Forming a coating film on the substrate that is bonded to each other by the metal compound and has voids between the inorganic fine particles,
The formed coating film is peeled from the substrate to form a flake body, and then the flake body is baked, whereby the at least one metal compound is used as an inorganic oxide.
The inorganic fine particles have a structure in which the inorganic fine particles are closely packed, and in the structure, adjacent inorganic fine particles are joined to each other by the inorganic oxide at a contact point between the inorganic fine particles, and between the inorganic fine particles. Have voids,
A method for producing a colored flake body, which obtains a colored flake body exhibiting structural color development due to diffraction and interference of light incident on the structure.
有機ポリマーと、
前記有機ポリマーの溶媒と、を含み、
前記有機ポリマーと前記無機微粒子との混合比が、重量比にして、有機ポリマー：無機微粒子＝１：３〜１：１０００である溶液を、
基板の表面に塗布し、乾燥させることによって、前記無機微粒子が最密充填された構造を有し、当該構造において、隣り合う前記無機微粒子が、当該無機微粒子同士の接触点にて前記有機ポリマーによって互いに接合されるとともに、当該無機微粒子間に空隙を有する塗布膜を前記基板上に形成し、
前記形成した塗布膜を前記基板から剥離し、フレーク体とした後に当該フレーク体を焼成することで、
前記無機微粒子が最密充填された構造を有し、当該構造において、隣り合う前記無機微粒子が、当該無機微粒子同士の接触点にて互いに接合されるとともに、当該無機微粒子間に空隙を有し、
前記構造に入射した光の回折および干渉による構造性発色を示す発色フレーク体を得る、発色フレーク体の製造方法。 Spherical inorganic fine particles exhibiting a monodisperse particle size distribution;
An organic polymer;
A solvent for the organic polymer,
A solution in which the mixing ratio of the organic polymer and the inorganic fine particles is, as a weight ratio, organic polymer: inorganic fine particles = 1: 3 to 1: 1000,
By applying to the surface of the substrate and drying, it has a structure in which the inorganic fine particles are closely packed, and in the structure, the adjacent inorganic fine particles are brought into contact with the inorganic fine particles by the organic polymer. Formed on the substrate is a coating film bonded to each other and having voids between the inorganic fine particles,
By peeling the formed coating film from the substrate and making the flake body, the flake body is baked,
The inorganic fine particles have a structure in which the inorganic fine particles are closely packed, and in the structure, the adjacent inorganic fine particles are bonded to each other at a contact point between the inorganic fine particles, and have a gap between the inorganic fine particles,
A method for producing a colored flake body, which obtains a colored flake body exhibiting structural color development due to diffraction and interference of light incident on the structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009258232A JP2011102216A (en) | 2009-11-11 | 2009-11-11 | Color-developing flake material and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2009258232A JP2011102216A (en) | 2009-11-11 | 2009-11-11 | Color-developing flake material and method for producing the same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2011102216A true JP2011102216A (en) | 2011-05-26 |
Family
ID=44192739
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2009258232A Pending JP2011102216A (en) | 2009-11-11 | 2009-11-11 | Color-developing flake material and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2011102216A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012039494A1 (en) * | 2010-09-24 | 2012-03-29 | 京セラ株式会社 | Opal and method of production therefor |
| WO2016031492A1 (en) * | 2014-08-29 | 2016-03-03 | 住友化学株式会社 | Porous layer, separator obtained by layering porous layer, and non-aqueous electrolyte secondary battery containing porous layer or separator |
| WO2016157741A1 (en) * | 2015-03-31 | 2016-10-06 | Canon Kabushiki Kaisha | Particle assembly |
| WO2016157742A1 (en) * | 2015-03-31 | 2016-10-06 | Canon Kabushiki Kaisha | Particle assembly |
| CN112537757A (en) * | 2020-11-20 | 2021-03-23 | 浙江瑞成新材料股份有限公司 | Inorganic sheet material and method for producing same |
-
2009
- 2009-11-11 JP JP2009258232A patent/JP2011102216A/en active Pending
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2012039494A1 (en) * | 2010-09-24 | 2012-03-29 | 京セラ株式会社 | Opal and method of production therefor |
| JP5047402B2 (en) * | 2010-09-24 | 2012-10-10 | 京セラ株式会社 | Opal and its manufacturing method |
| WO2016031492A1 (en) * | 2014-08-29 | 2016-03-03 | 住友化学株式会社 | Porous layer, separator obtained by layering porous layer, and non-aqueous electrolyte secondary battery containing porous layer or separator |
| JP5976947B2 (en) * | 2014-08-29 | 2016-08-24 | 住友化学株式会社 | Porous layer, separator formed by laminating porous layer, and nonaqueous electrolyte secondary battery including porous layer or separator |
| JPWO2016031492A1 (en) * | 2014-08-29 | 2017-04-27 | 住友化学株式会社 | Porous layer, separator formed by laminating porous layer, and nonaqueous electrolyte secondary battery including porous layer or separator |
| US9865856B2 (en) | 2014-08-29 | 2018-01-09 | Sumitomo Chemical Company, Limited | Porous layer, separator formed by laminating porous layer, and non-aqueous electrolyte secondary battery including porous layer or separator |
| WO2016157741A1 (en) * | 2015-03-31 | 2016-10-06 | Canon Kabushiki Kaisha | Particle assembly |
| WO2016157742A1 (en) * | 2015-03-31 | 2016-10-06 | Canon Kabushiki Kaisha | Particle assembly |
| CN112537757A (en) * | 2020-11-20 | 2021-03-23 | 浙江瑞成新材料股份有限公司 | Inorganic sheet material and method for producing same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20220002554A1 (en) | Structurally colored materials with spectrally selective absorbing components and methods for making the same | |
| Wang et al. | Structural coloration pigments based on carbon modified ZnS@ SiO2 nanospheres with low-angle dependence, high color saturation, and enhanced stability | |
| US6818051B2 (en) | Pigments | |
| CN109021481B (en) | Colored inverse opal structure photonic crystal plastic film with bright pearlescent color and luster, and preparation method and application thereof | |
| JP2011102216A (en) | Color-developing flake material and method for producing the same | |
| WO2020221227A1 (en) | High-refractive index microsphere mie scattering-based schemochrome coating | |
| CN107614627B (en) | Bright pigment, method for producing same, pigment-containing composition, and pigment-containing coated body | |
| TW200840804A (en) | SiO2 slurry for the production of quartz glass as well as the application of the slurry | |
| Clough et al. | Photonic Paints: Structural Pigments Combined with Water‐Based Polymeric Film‐Formers for Structurally Colored Coatings | |
| CN108325481A (en) | Photonic crystal decorative coveringn of color tunable and preparation method thereof | |
| CN110016269A (en) | A kind of reflection heat-insulating type texture paint and preparation method thereof | |
| CN102535255A (en) | Energy-saving temperature-adjusting wall paper and preparation method thereof | |
| CN109897204A (en) | A kind of large area water writes colorless and transparent crystal film with photon of colour developing and preparation method thereof | |
| CN107201690B (en) | A method of utilizing microballoon preparation structure color coating | |
| US20240180790A1 (en) | Method for generation of opalescence in dental restorations | |
| JP2018203843A (en) | Particle aggregate | |
| Zhang et al. | Designing composite films of SiO2/TiO2/PDMS with long lasting invariable colors and enhanced mechanical robustness | |
| JP5721503B2 (en) | Decorative product and manufacturing method thereof | |
| CN107497649A (en) | The preparation method of the non crystalline structure color coating of color addition | |
| CN104955782B (en) | Glass plate and its manufacture method with low reflectance coating | |
| US9994714B2 (en) | Silica protected pigments for use in artist media | |
| US20180237957A1 (en) | Method for preparing inverse opal colloidal crystal fibers | |
| JP2016190909A (en) | Particle assembly | |
| JP2016190178A (en) | Particle assembly | |
| KR100932851B1 (en) | Method for producing spherical colloidal crystals with milky light effect |