JPH0551210A - Production of photochromic fine titanium dioxide powder - Google Patents
Production of photochromic fine titanium dioxide powderInfo
- Publication number
- JPH0551210A JPH0551210A JP29185691A JP29185691A JPH0551210A JP H0551210 A JPH0551210 A JP H0551210A JP 29185691 A JP29185691 A JP 29185691A JP 29185691 A JP29185691 A JP 29185691A JP H0551210 A JPH0551210 A JP H0551210A
- Authority
- JP
- Japan
- Prior art keywords
- titanium dioxide
- fine powder
- photochromic
- granular
- sample
- 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.)
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- Inorganic Compounds Of Heavy Metals (AREA)
- Pigments, Carbon Blacks, Or Wood Stains (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、フォトクロミック性演
色体用材料に好適なフォトクロミック性二酸化チタン微
粉末の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a photochromic titanium dioxide fine powder suitable for a photochromic color rendering material.
【０００２】[0002]
【発明の技術的背景とその問題点】物質に紫外線などの
光をあてると色が変わり、光の照射を止めると元に戻る
現象、すなわち光照射を受けて吸収スペクトルに可逆的
な変化を起こす現象をフォトクロミズムといい、この現
象を利用した、化粧料、塗料などにおける調光性素子、
センサー素子、表示素子、光遮蔽素子などの機能性素材
として種々の適用展開が期待されているところで、フォ
トクロミック性材料としては、種々の有機系もしくは無
機系の化合物が使用されている。一般にたとえばスピロ
ピラン系、スピロオキサジン系などで代表される有機系
フォトクロミック性化合物は、着色体の吸光度が高く、
また着色体と消色体の吸収波長の差が大きく、さらに着
色体の吸収波長が置換基により比較的任意に変えられ易
いことなどから、鮮やかな演色性が期待され、近年機能
性素材として注目されつつある。しかしながら前記有機
系フォトクロミック性化合物は、光に対する劣化が起こ
り易く、その結果、繰り返し使用による演色性能の低下
や、演色性能の持続安定性の低下がさけられずその改善
が望まれている。TECHNICAL BACKGROUND AND PROBLEMS OF THE INVENTION A phenomenon in which a substance changes its color when exposed to light such as ultraviolet rays and returns to its original state when the light irradiation is stopped, that is, a reversible change occurs in the absorption spectrum upon light irradiation. The phenomenon is called photochromism, and it is a dimming element in cosmetics, paints, etc. that uses this phenomenon.
Various applications are expected as functional materials such as sensor elements, display elements, and light shielding elements, and various organic or inorganic compounds are used as photochromic materials. In general, organic photochromic compounds represented by, for example, spiropyran-based and spirooxazine-based compounds have high absorbance of a colored body,
In addition, since the difference in absorption wavelength between the colored body and the decolored body is large and the absorption wavelength of the colored body can be relatively easily changed by a substituent, a bright color rendering property is expected, and it has recently attracted attention as a functional material. Is being done. However, the organic photochromic compound is apt to be deteriorated by light, and as a result, deterioration of color rendering performance due to repeated use and deterioration of continuous stability of color rendering performance are unavoidable, and improvement thereof is desired.
【０００３】しかして、本発明者等は、かねてより、フ
ォトクロミックセンターを形成する元素をドープした、
たとえばチタン酸ストロンチウムなどのペロブスカイト
型系酸化物や二酸化チタンなどのフォトクロミック性無
機化合物が、対光劣化性に優れていることに着目し、と
りわけ白色性と安全性に優れたフォトクロミック性二酸
化チタンの開発につき種々の検討を進めてきている。通
常、二酸化チタンにフォトクロミックセンターを形成さ
せるには鉄や、モリブデン、ニッケルなどの遷移金属イ
オンをドープすることが知られているが、演色効果を高
めようとすると鉄イオンなどの添加金属イオン量を多く
する必要があり、その結果、添加金属イオンによる着色
が大きくなったり、さらに、添加金属イオンをドープす
る加熱処理過程で二酸化チタン粒子の粒子内、粒子間の
焼結によって粗大粒子化が起こり易く、そのものを使用
した種々のフォトクロミック性組成物系での分散性がい
ちじるしく損なわれ、所望の演色効果がもたらされなく
なる。本発明者等は、前記問題点の解決を図るべくさら
に種々検討をすすめた結果、特定の粒子形状の酸化鉄微
粉末を乾式系で二酸化チタンと混合処理した後、フォト
クロミック性を発現し、かつ、ルチル化転移温度未満で
加熱することによって、意外にも、鉄イオンのドープが
均一におこなわれ易く、このため、比較的少量の鉄源で
かつ比較的低温での加熱処理で十分なフォトクロミック
センターを付与し得るとともに、焼結や粒子成長による
粗大粒子化を実質的にもたらすことなく、分散性の良好
なフォトクロミック性二酸化チタン微粉末を形成し得る
ことの知見を得、本発明を完成したものであるHowever, the present inventors have long been doped with an element forming a photochromic center,
For example, we focused on the fact that perovskite-type oxides such as strontium titanate and photochromic inorganic compounds such as titanium dioxide have excellent photodegradability, and in particular, developed a photochromic titanium dioxide with excellent whiteness and safety. We are proceeding with various studies. In order to form a photochromic center in titanium dioxide, it is generally known to dope transition metal ions such as iron, molybdenum and nickel, but when trying to enhance the color rendering effect, the amount of added metal ions such as iron ions should be controlled. It is necessary to increase the amount, and as a result, the coloring due to the added metal ions becomes large, and further, during the heat treatment process of doping the added metal ions, coarse particles are likely to be formed due to the sintering of the particles of titanium dioxide particles and between the particles. , The dispersibility in various photochromic composition systems using the same is markedly impaired, and the desired color rendering effect cannot be obtained. The present inventors, as a result of further various studies in order to solve the above problems, after the iron oxide fine powder of a specific particle shape is mixed with titanium dioxide in a dry system, the photochromic property is developed, and Surprisingly, by heating below the rutile transition temperature, iron ions are likely to be uniformly doped. Therefore, a photochromic center with a relatively small amount of iron source and a heat treatment at a relatively low temperature is sufficient. The present invention has been completed with the knowledge that a photochromic titanium dioxide fine powder having good dispersibility can be formed without substantially causing coarsening due to sintering or particle growth. Is
【０００４】[0004]
【発明の構成】本発明は、以下に示されるフォトクロミ
ック性二酸化チタン微粉末の製造方法に関する。 （１）アナターゼ型二酸化チタン微粉末と粒状形状の酸
化鉄微粉末とを乾式混合し、次いで該混合物を、フォト
クロミック性を発現し、かつ、アナターゼ型二酸化チタ
ンがルチル型二酸化チタンへ転移する温度未満で加熱処
理するフォトクロミック性二酸化チタン微粉末の製造方
法。 （２）粒状形状の酸化鉄微粉末が、粒状形状のマグネタ
イトを加熱処理して得られる平均粒子径が０，０５〜
０．５μｍのα−Ｆｅ２Ｏ３微粉末である前（１）項記
載のフォトクロミック性二酸化チタン微粉末の製造方
法、および （３）粒状形状の酸化鉄微粉末が、針状含水酸化鉄を加
熱処理して得られる平均粒子径が０，０５〜０．５μｍ
の粒状形状のα−Ｆｅ２Ｏ３微粉末である前（１）項記
載のフォトクロミック性二酸化チタン微粉末の製造方法
である。The present invention relates to a method for producing the photochromic titanium dioxide fine powder shown below. (1) Dry-mixing anatase-type titanium dioxide fine powder and granular iron oxide fine powder, and then expressing the mixture at a temperature below the temperature at which anatase-type titanium dioxide is transformed into rutile-type titanium dioxide and which exhibits photochromic properties. A method for producing a fine powder of photochromic titanium dioxide, which is heat-treated with. (2) The granular iron oxide fine powder has an average particle size of 0.05 to 0.5 obtained by heat-treating granular magnetite.
The method for producing the photochromic titanium dioxide fine powder according to item (1), which is 0.5 μm α-Fe 2 O 3 fine powder, and (3) the granular iron oxide fine powder contains acicular iron-containing hydrous oxide. Average particle size obtained by heat treatment is 0.05 to 0.5 μm
The method for producing a photochromic titanium dioxide fine powder according to the above item (1), which is the α-Fe 2 O 3 fine powder having a granular shape.
【０００５】本発明において、アナターゼ型二酸化チタ
ン微粉末としては種々の方法によって製造されるものを
使用することができるが、例えば硫酸チタン溶液や四塩
化チタン溶液を、加熱加水分解したりあるいはアルカリ
で中和したりして含水二酸化チタンを生成させ後、焼
成、粉砕してアナターゼ型結晶を主体とする二酸化チタ
ン微粉末とする。このものは、平均粒子径が０．０５〜
１μｍ程度、好ましくは０．１〜０．５μｍ程度であっ
て、粒度分布の揃ったものであるのが望ましい。また粒
状酸化鉄は、その粒子の軸比（最長粒子径／最短粒子
径）が１．５以下の一般に粒状形状といわれる酸化鉄を
意味し、平均粒子径（平均の最長粒子径）は０．０５〜
０．５μｍのものが二酸化チタンに均一にドープするう
えから望ましい。これらの酸化鉄は種々の方法によって
製造されるものを使用することが出来るが、たとえば、
（１）第一鉄塩溶液をアルカリで中和、酸化して粒状形
状のマグネタイト（Ｆｅ３Ｏ４）を生成し、乾燥後微粉
末としたもの、（２）前記（１）の粒状Ｆｅ３Ｏ４を非
還元性雰囲気中で焼成して粒状形状のヘマタイト（α−
Ｆｅ２Ｏ３）微粉末としたもの、（３）第一鉄塩溶液を
アルカリで中和、酸化して針状の含水酸化鉄（たとえば
α−ＦｅＯＯＨ、γ−ＦｅＯＯＨなど）を生成後、この
ものを非還元性雰囲気中で焼成して粒状形状のα−Ｆｅ
２Ｏ３微粉末としたもの、（４）第二鉄塩溶液を、一般
的には１００℃以上の温度下、アルカリで中和し、熟成
して粒状形状のα−Ｆｅ２Ｏ３を生成し、乾燥後微粉末
としたものなどを挙げることができる。前記したように
粒状酸化鉄は粒度分布の揃った微粉末とするために、二
酸化チタン微粉末と混合するに先立って、たとえば、擂
潰機、エッジランナーミル、リングローラーミルなどの
圧密型粉砕機で粉砕しておくと、二酸化チタン粒子表面
で少量の鉄イオンが効率的にドープするため、高明度で
高演色度のフォトクロミック性二酸化チタンを一層有利
に得ることができる。In the present invention, as the anatase type titanium dioxide fine powder, those produced by various methods can be used. For example, titanium sulfate solution or titanium tetrachloride solution is hydrolyzed by heating or with an alkali. After neutralization or the like to generate hydrous titanium dioxide, it is fired and pulverized to obtain titanium dioxide fine powder mainly composed of anatase type crystals. This has an average particle size of 0.05-
It is about 1 μm, preferably about 0.1 to 0.5 μm, and it is desirable that the particle size distribution is uniform. Further, the granular iron oxide means iron oxide generally referred to as a granular shape having an axial ratio (longest particle diameter / shortest particle diameter) of 1.5 or less, and an average particle diameter (average longest particle diameter) of 0. 05-
A material having a thickness of 0.5 μm is desirable for uniformly doping titanium dioxide. As these iron oxides, those produced by various methods can be used.
(1) Neutralizing and oxidizing a ferrous salt solution with an alkali to produce magnetite (Fe 3 O 4 ) in the form of particles, which is dried and made into a fine powder, (2) The granular Fe 3 of the above (1) O 4 is fired in a non-reducing atmosphere to form granular hematite (α-
Fe 2 O 3 ) finely divided powder, (3) a ferrous salt solution is neutralized with an alkali and oxidized to form acicular hydrous iron oxide (eg, α-FeOOH, γ-FeOOH). Of α-Fe in a granular form by firing the product in a non-reducing atmosphere
2 O 3 fine powder, (4) ferric salt solution is neutralized with alkali generally at a temperature of 100 ° C. or higher, and aged to produce α-Fe 2 O 3 in a granular form. However, a fine powder after drying can be used. As described above, the granular iron oxide is made into a fine powder having a uniform particle size distribution, and therefore, before being mixed with the titanium dioxide fine powder, for example, a compaction type crusher such as a crusher, an edge runner mill, or a ring roller mill. If a small amount of iron ions are efficiently doped on the surface of the titanium dioxide particles, the photochromic titanium dioxide having high brightness and high color rendering can be more advantageously obtained.
【０００６】本発明において、アナターゼ型二酸化チタ
ン微粉末と鉄イオン源としての粒状形状の酸化鉄微粉末
とを乾式混合するには、種々の乾式方式の粉砕機、混合
機を使用することによりおこない得る。前記粒状形状の
酸化鉄微粉末の混合割合は、アナターゼ型二酸化チタン
微粉末の重量基準に対して、０．１〜５％、好ましくは
０．５〜２％である。該酸化鉄の混合割合が前記範囲よ
り小さきに過ぎると所望のフォトクロミック性特性がも
たらされず、また前記範囲より多きに過ぎると鉄イオン
による着色が大きくなったり、粒子内、粒子間の焼結に
よる粗大粒子化が起こり易かったりする。なお、後記比
較例に示すように前記において、乾式混合に代えて湿式
混合をおこなう場合は、而後の加熱処理過程で粒子焼結
等が惹起し易く所望のフォトクロミック性二酸化チタン
の微粉末が得られ難い。In the present invention, dry mixing of the anatase type titanium dioxide fine powder and the granular iron oxide fine powder as an iron ion source is carried out by using various dry type pulverizers and mixers. obtain. The mixing ratio of the granular iron oxide fine powder is 0.1 to 5%, preferably 0.5 to 2%, based on the weight of the anatase type titanium dioxide fine powder. If the mixing ratio of the iron oxide is less than the above range, the desired photochromic properties are not provided, and if it is more than the above range, coloring due to iron ions becomes large, or the particles become coarse due to sintering between particles or between particles. Particle formation is likely to occur. Incidentally, as shown in Comparative Examples below, in the case of performing wet mixing instead of dry mixing, fine powder of the desired photochromic titanium dioxide is easily obtained in which particle sintering or the like easily occurs in the subsequent heat treatment process. hard.
【０００７】本発明において、前記混合物の加熱処理温
度は、フォトクロミック性を発現し、かつ、アナターゼ
型結晶が、ルチル型結晶へ実質的に転移する温度未満の
温度範囲にする必要があり、好ましくは転移温度より１
０〜１２０℃、さらに好ましくは３０〜１００℃低く設
定するのが望ましい。該加熱処理温度は、粒状形状の酸
化鉄微粉末の種類、添加量、加熱処理装置の型式、大き
さなどによっても異なり一概には言えないが、通常６７
０〜７８０℃、好ましくは６９０〜７６０℃程度であ
る。加熱温度が前記範囲より、低きに過ぎると、鉄イオ
ンのドープ化が進まず所望のフォトクロミック性を付与
することができず、一方高きに過ぎると粒子内、粒子間
焼結が惹起して分散性がいちじるしく損なわれるととも
に、所望のフォトクロミック性が得られなくなる。な
お、前記所望のフォトクロミック性とは、ΔＬで表示し
た演色度が４．５以上である場合をいう。In the present invention, the heat treatment temperature of the mixture is required to be in a temperature range below the temperature at which the photochromic property is exhibited and the anatase type crystal is substantially transformed into the rutile type crystal. 1 from the transition temperature
It is desirable to set the temperature to 0 to 120 ° C., more preferably 30 to 100 ° C. lower. The heat treatment temperature varies depending on the type and amount of the granular iron oxide fine powder, the type of heat treatment apparatus, the size, etc., and cannot be generally stated, but is usually 67.
It is 0 to 780 ° C, preferably about 690 to 760 ° C. If the heating temperature is lower than the above range, the desired photochromic property cannot be imparted without the progress of iron ion doping, while if the heating temperature is too high, intra-particle and inter-particle sintering will be induced and dispersed. As a result, the desired photochromic properties cannot be obtained while the properties are significantly impaired. The desired photochromic property means that the color rendering index represented by ΔL is 4.5 or more.
【０００８】本発明で得られるフォトクロミック性二酸
化チタンは、種々の演色体素子用の機能性素材としてき
わめて好適な物であって、たとえば該演色体素子の基体
表面に塗布して成膜化したり、あるいは基体中へ充填し
たりして用いることができる。The photochromic titanium dioxide obtained in the present invention is extremely suitable as a functional material for various color rendering element, for example, it is coated on the surface of the base of the color rendering element to form a film, Alternatively, it can be used by filling it into a substrate.
【０００９】[0009]
実施例１ ６０℃に保持した水２０００ｍｌに硫酸第一鉄（ＦｅＳ
Ｏ４・７Ｈ２Ｏ）１８０ｇを投入して溶解した。この水
溶液に４００ｇ／ｌの水酸化ナトリウム溶液１３２ｍｌ
を徐々に添加し６０分間攪拌混合を続けた。次いで１ｌ
／分の速度で３時間空気を吹き込んだ後、沈澱生成物を
ろ過、水洗、乾燥して平均粒子径０．１５μｍの粒状Ｆ
ｅ３Ｏ４（電子顕微鏡観察による：以下同じ）を得た。
この粒状Ｆｅ３Ｏ４を大気中５００℃で２時間加熱して
平均粒子径０．２０μｍの粒状α−Ｆｅ２Ｏ３とした
後、擂潰機で粉砕した。このようにして得られたα−Ｆ
ｅ２Ｏ３微粉末１ｇと、硫酸法により製造された比表面
積１０．２ｍ２／ｇ、平均粒子径０．２２μｍのアナタ
ーゼ型二酸化チタン微粉末１００ｇを擂潰機に入れよく
混合した。次いでこの混合物を大気中７５０℃で４時間
加熱処理して、本発明のフォトクロミック性二酸化チタ
ン（試料Ａ）を得た。Example 1 Ferrous sulfate (FeS) was added to 2000 ml of water kept at 60 ° C.
O 4 · 7H 2 O) 180g was charged with dissolved. 132 ml of 400 g / l sodium hydroxide solution in this aqueous solution
Was gradually added and stirring and mixing were continued for 60 minutes. Then 1 liter
After blowing air for 3 hours at a speed of 1 / min, the precipitated product was filtered, washed with water, and dried to give granular F having an average particle size of 0.15 μm.
e 3 O 4 (by electron microscope observation: the same hereinafter) was obtained.
The granular Fe 3 O 4 was heated in the atmosphere at 500 ° C. for 2 hours to obtain granular α-Fe 2 O 3 having an average particle diameter of 0.20 μm, and then pulverized with a crusher. Α-F thus obtained
1 g of e 2 O 3 fine powder and 100 g of anatase-type titanium dioxide fine powder having a specific surface area of 10.2 m 2 / g and an average particle diameter of 0.22 μm produced by a sulfuric acid method were put in a grinder and mixed well. Next, this mixture was heat-treated in the air at 750 ° C. for 4 hours to obtain a photochromic titanium dioxide of the present invention (Sample A).
【００１０】実施例２ 実施例１において、粒状Ｆｅ３Ｏ４を大気中６００℃で
２時間加熱処理して平均粒子径０．２２μｍの粒状α−
Ｆｅ２Ｏ３としたことのほかは、実施例１と同様に処理
して、本発明のフォトクロミック性二酸化チタン（試料
Ｂ）を得た。Example 2 In Example 1, granular Fe 3 O 4 was heat-treated in air at 600 ° C. for 2 hours to obtain granular α-having an average particle size of 0.22 μm.
A photochromic titanium dioxide (Sample B) of the present invention was obtained by the same process as in Example 1 except that Fe 2 O 3 was used.
【００１１】実施例３ 実施例１において、混合物を大気中７００℃で４時間加
熱処理したことのほかは、実施例１と同様に処理して、
本発明のフォトクロミック性二酸化チタン（試料Ｃ）を
得た。Example 3 The same treatment as in Example 1 was carried out except that in Example 1, the mixture was heat-treated at 700 ° C. for 4 hours in air.
A photochromic titanium dioxide (Sample C) of the present invention was obtained.
【００１２】実施例４ 実施例１に記載した方法で粒状Ｆｅ３Ｏ４を得、この粒
状Ｆｅ３Ｏ４を擂潰機で粉砕した微粉末１ｇを平均粒子
径０．２２μｍのアナターゼ型二酸化チタン微粉末１０
０ｇと混合した。次いでこの混合物を大気中７５０℃で
４時間加熱処理して、本発明のフォトクロミック性二酸
化チタン（試料Ｄ）を得た。Example 4 Granular Fe 3 O 4 was obtained by the method described in Example 1, and 1 g of fine powder obtained by pulverizing the granular Fe 3 O 4 with a crusher was used as anatase titanium dioxide having an average particle diameter of 0.22 μm. Fine powder 10
Mixed with 0 g. Next, this mixture was heat-treated in the atmosphere at 750 ° C. for 4 hours to obtain a photochromic titanium dioxide of the present invention (Sample D).
【００１３】比較例１ 実施例１において、混合物の加熱温度を６５０℃とした
ことのほかは、実施例１と同様に処理して比較試料（試
料Ｅ）を得た。Comparative Example 1 A comparative sample (Sample E) was prepared in the same manner as in Example 1 except that the heating temperature of the mixture was 650 ° C.
【００１４】比較例２ 実際例１において、混合物の加熱温度を８５０℃とした
ことのほかは、実施例１と同様に処理して比較試料（試
料Ｆ）を得た。Comparative Example 2 A comparative sample (Sample F) was prepared in the same manner as in Example 1 except that the heating temperature of the mixture was 850 ° C.
【００１５】比較例３ 実施例１において、粒状α−Ｆｅ２Ｏ３１ｇとアナター
ゼ型二酸化チタン１００ｇを水に懸濁させてスラリーと
し、このものをホモミキサーを用いて十分に湿式混合し
た後、乾燥し、解砕した混合物を用いたことのほかは、
実施例１と同様に処理して比較試料（試料Ｇ）を得た。Comparative Example 3 In Example 1, 1 g of granular α-Fe 2 O 3 and 100 g of anatase type titanium dioxide were suspended in water to form a slurry, which was thoroughly wet-mixed with a homomixer, Other than using the dried and crushed mixture,
The sample was treated in the same manner as in Example 1 to obtain a comparative sample (Sample G).
【００１６】比較例４ ６０℃に保持した水２０００ｍｌに硫酸第一鉄（ＦｅＳ
Ｏ４・７Ｈ２Ｏ）６０ｇと硫酸第二鉄（Ｆｅ２（Ｓ
Ｏ４）３・８．６Ｈ２Ｏ）１２０ｇを投入して溶解し
た。この水溶液に４００ｇ／ｌの水酸化ナトリウム溶液
１１０ｍｌを徐々に添加し６０分間攪拌混合した後、沈
澱生成物をろ過、水洗、乾燥して平均粒子径０．０１μ
ｍの粒状Ｆｅ３Ｏ４を得た。この粒状Ｆｅ３Ｏ４を大気
中４５０℃で２時間加熱処理して平均粒子径０．０２μ
ｍの粒状α−Ｆｅ２Ｏ３とした後、擂潰機で粉砕した。
このようにして得られたα−Ｆｅ２Ｏ３微粉末１ｇと、
硫酸法により製造された比表面積１０．２ｍ２／ｇ、平
均粒子径０．２２μｍのアナターゼ型二酸化チタン微粉
末１００ｇを擂潰機に入れよく混合した。次いでこの混
合物を大気中７５０℃で４時間加熱処理して比較試料
（試料Ｈ）を得た。Comparative Example 4 Ferrous sulfate (FeS) was added to 2000 ml of water kept at 60 ° C.
O 4 · 7H 2 O) 60g ferric sulfate (Fe 2 (S
O 4) was dissolved 3 · 8.6H 2 O) was charged 120 g. 110 ml of 400 g / l sodium hydroxide solution was gradually added to this aqueous solution, and the mixture was stirred and mixed for 60 minutes, and then the precipitated product was filtered, washed with water and dried to obtain an average particle diameter of 0.01 μm.
m granular Fe 3 O 4 was obtained. This granular Fe 3 O 4 was heat-treated in air at 450 ° C. for 2 hours to obtain an average particle diameter of 0.02 μm.
After being made into granular α-Fe 2 O 3 of m, it was pulverized by a crusher.
1 g of the α-Fe 2 O 3 fine powder thus obtained,
100 g of anatase type titanium dioxide fine powder having a specific surface area of 10.2 m 2 / g and an average particle diameter of 0.22 μm, which was produced by the sulfuric acid method, was put into a crusher and mixed well. Then, this mixture was heat-treated in the air at 750 ° C. for 4 hours to obtain a comparative sample (Sample H).
【００１７】実施例５ ５０℃に保持した水２０００ｍｌに硫酸第一鉄（ＦｅＳ
Ｏ４．７Ｈ２Ｏ）５５６ｇを投入して溶解した。この水
溶液に４００ｇ／ｌの水酸化ナトリウム溶液１１２ｍｌ
を徐々に添加し６０分間攪拌混合を続けた。次いで１ｌ
／分の速度で５時間空気を吹き込んだ後、沈澱生成物を
ろ過、水洗、乾燥して平均長軸径０．５μｍ、軸比１０
の針状α−ＦｅＯＯＨを得た。この針状α−ＦｅＯＯＨ
を大気中８００℃で２時間加熱処理して平均粒子径０．
１５μｍの粒状α−Ｆｅ２Ｏ３とした後、擂潰機で粉砕
した。このようにして得られたα−Ｆｅ２Ｏ３微粉末１
ｇと、硫酸法により製造された比表面積１０．２ｍ２／
ｇ、平均粒子径０．２２μｍのアナターゼ型二酸化チタ
ン微粉末１００ｇを擂潰機に入れよく混合した。次いで
この混合物を大気中７５０℃で４時間加熱処理して、本
発明のフォトクロミック性二酸化チタン（試料Ｉ）を得
た。Example 5 Ferrous sulfate (FeS) was added to 2000 ml of water kept at 50 ° C.
O 4 . 7H 2 O) (556 g) was added and dissolved. 112 ml of 400 g / l sodium hydroxide solution in this aqueous solution
Was gradually added and stirring and mixing were continued for 60 minutes. Then 1 liter
After blowing air for 5 hours at a speed of / min, the precipitated product was filtered, washed with water and dried to have an average major axis diameter of 0.5 μm and an axial ratio of 10
To obtain needle-shaped α-FeOOH. This needle-shaped α-FeOOH
Is heat-treated at 800 ° C. for 2 hours in the air to have an average particle size of 0.
It was made into 15 μm granular α-Fe 2 O 3 and then pulverized with a crusher. Α-Fe 2 O 3 fine powder 1 thus obtained
g and a specific surface area of 10.2 m 2 / produced by the sulfuric acid method
100 g of anatase type titanium dioxide fine powder having an average particle diameter of 0.22 μm was put in a crusher and mixed well. Then, this mixture was heat-treated in the atmosphere at 750 ° C. for 4 hours to obtain a photochromic titanium dioxide (Sample I) of the present invention.
【００１８】実施例６ 実施例５において、針状α−ＦｅＯＯＨを大気中７５０
℃で２時間加熱処理して平均粒子径０．１５μｍのほぼ
粒状のα−Ｆｅ２Ｏ３としたことのほかは、実施例５と
同様に処理して、本発明のフォトクロミック性二酸化チ
タン（試料Ｊ）を得た。Example 6 In Example 5, needle-like α-FeOOH was added to 750 in air.
The photochromic titanium dioxide of the present invention (sample) was treated in the same manner as in Example 5 except that it was heated at 0 ° C. for 2 hours to obtain almost granular α-Fe 2 O 3 having an average particle diameter of 0.15 μm. J) was obtained.
【００１９】実施例７ 実施例５において、α−Ｆｅ２Ｏ３微粉末を１．７５ｇ
としたことのほかは、実施例５と同様に処理して、本発
明のフォトクロミック性二酸化チタン（試料Ｋ）を得
た。Example 7 In Example 5, 1.75 g of α-Fe 2 O 3 fine powder was used.
Other than the above, the same treatment as in Example 5 was carried out to obtain a photochromic titanium dioxide (Sample K) of the present invention.
【００２０】比較例５ 実施例５において、混合物の加熱温度を６５０℃とした
ことのほかは、実施例５と同様に処理して比較試料（試
料Ｌ）を得た。Comparative Example 5 A comparative sample (Sample L) was prepared in the same manner as in Example 5, except that the heating temperature of the mixture was 650 ° C.
【００２１】比較例６ 実施例５において、混合物の加熱温度を８００℃とした
ことのほかは、実施例５と同様に処理して比較試料（試
料Ｍ）を得た。Comparative Example 6 A comparative sample (Sample M) was prepared in the same manner as in Example 5, except that the heating temperature of the mixture was 800 ° C.
【００２２】比較例７ 実施例５において、混合物の加熱温度を８５０℃とした
ことのほかは、実施例５と同様に処理して比較試料（試
料Ｎ）を得た。Comparative Example 7 A comparative sample (Sample N) was prepared in the same manner as in Example 5, except that the heating temperature of the mixture was 850 ° C.
【００２３】比較例８ 実施例５において、針状α−ＦｅＯＯＨを大気中７００
℃で２時間加熱処理して、平均長軸径０．５μｍで、ほ
ぼ針状のα−Ｆｅ２Ｏ３としたことのほかは、実施例５
と同様に処理して比較試料（試料Ｏ）を得た。Comparative Example 8 In Example 5, needle-shaped α-FeOOH was added to the air at 700
Example 5 except that heat treatment was performed at 0 ° C. for 2 hours to obtain α-Fe 2 O 3 having an average major axis diameter of 0.5 μm and a substantially needle shape.
A comparative sample (Sample O) was obtained by the same treatment as described above.
【００２４】比較例９ 実施例５に記載した方法で針状α−ＦｅＯＯＨを得、こ
の針状α−ＦｅＯＯＨを擂潰機で粉砕した微粉末１ｇを
平均粒子径０．２２μｍのアナターゼ型二酸化チタン微
粉末１００ｇと混合した。次いでこの混合物を大気中７
５０℃で４時間加熱処理して比較試料（試料Ｐ）を得
た。Comparative Example 9 Acicular α-FeOOH was obtained by the method described in Example 5, and 1 g of fine powder obtained by crushing the acicular α-FeOOH with a crusher was used as anatase titanium dioxide having an average particle diameter of 0.22 μm. Mixed with 100 g of fine powder. This mixture is then placed in the atmosphere 7
A comparative sample (Sample P) was obtained by heat treatment at 50 ° C. for 4 hours.
【００２５】比較例１０ 実施例５に記載した方法で針状α−ＦｅＯＯＨを得、こ
の針状α−ＦｅＯＯＨを擂潰機で粉砕した微粉末１ｇを
平均粒子径０．２２μｍのアナターゼ型二酸化チタン微
粉末１００ｇと混合した。次いでこの混合物を大気中８
００℃で４時間加熱処理して比較試料（試料Ｑ）を得
た。Comparative Example 10 Acicular α-FeOOH was obtained by the method described in Example 5, and 1 g of fine powder obtained by pulverizing the acicular α-FeOOH with a crusher was anatase type titanium dioxide having an average particle diameter of 0.22 μm. Mixed with 100 g of fine powder. This mixture is then placed in the atmosphere 8
A comparative sample (Sample Q) was obtained by heat treatment at 00 ° C. for 4 hours.
【００２６】比較例１１ 実施例５において、針状α−ＦｅＯＯＨを大気中９５０
℃で２時間加熱処理して、平均粒子径１μｍの粒状α−
Ｆｅ２Ｏ３としたことのほかは、実施例５と同様に処理
して比較試料（試料Ｒ）を得た。COMPARATIVE EXAMPLE 11 In Example 5, needle-shaped α-FeOOH was added to the atmosphere at 950
Heat treatment for 2 hours at 0 ° C to obtain granular α- with an average particle diameter of 1 μm.
A comparative sample (Sample R) was obtained by treating in the same manner as in Example 5 except that Fe 2 O 3 was used.
【００２７】前記実施例および比較例の試料Ａ〜Ｒにつ
いて、比表面積（ＢＥＴ法）を測定するとともに、Ｘ線
回折を行いアナターゼ型結晶の（１０１）面の回折強度
を１００として、ルチル型結晶の（１１０）面の回折強
度との比より、ルチル化度を表示した。The specific surface areas (BET method) of the samples A to R of the examples and comparative examples were measured, and X-ray diffraction was performed to determine the diffraction intensity of the (101) plane of the anatase type crystal as 100, and the rutile type crystal was obtained. The degree of rutile formation was displayed from the ratio with the diffraction intensity of the (110) plane.
【００２８】また前記各試料について試料４ｇとウレタ
ン樹脂（固形分３０％）７．１ｍｌとメチルエチルケト
ン／トルエン混合溶媒（１／１）６．４ｍｌをペイント
シェーカーで１時間振盪後、得られた塗液をポリエチレ
ンテレフタレートのフィルム（７５μｍ）上にドクター
ブレード（１２５μｍ）で塗布し室温で２４時間乾燥し
て塗布板を作成した。得られた各試料の塗布板につい
て、光源ＨＯＹＡ ＵＶ Ｌｉｇｈｔ Ｓｏｕｒｃｅ
（ＨＬＳ−２００ｕ）を用いて、３０ｍＷ／ｃｍ２の強
度でＵＶ光を塗膜面に照射し照射前後のＬ値（明度）を
測定し（色差計：日本電色製）、その差（ΔＬ値）を求
めた（数値が大きい程フォトクロミック性が良い。）。
さらに塗布板の光沢度（６０°−６０°）を目視観察
し、Ａ：粗粒なし、Ｂ：粗粒ほとんどなし、Ｃ：粗粒若
干あり、Ｄ：粗粒多い、で表示した。これらの結果を表
１および表２で示す。For each of the above samples, 4 g of the sample, 7.1 ml of urethane resin (solid content 30%) and 6.4 ml of methyl ethyl ketone / toluene mixed solvent (1/1) were shaken for 1 hour on a paint shaker, and the obtained coating liquid was obtained. Was coated on a polyethylene terephthalate film (75 μm) with a doctor blade (125 μm) and dried at room temperature for 24 hours to prepare a coated plate. Regarding the obtained coated plate of each sample, the light source HOYA UV Light Source was used.
(HLS-200u), UV light was applied to the surface of the coating film at an intensity of 30 mW / cm 2 , and the L value (brightness) before and after the irradiation was measured (color difference meter: manufactured by Nippon Denshoku), and the difference (ΔL Value) was calculated (the larger the value, the better the photochromic property).
Further, the glossiness (60 ° -60 °) of the coated plate was visually observed, and it was indicated by A: no coarse particles, B: almost no coarse particles, C: some coarse particles, and D: many coarse particles. The results are shown in Tables 1 and 2.
【００２９】[0029]
【表１】 [Table 1]
【００３０】[0030]
【表２】 [Table 2]
【００３１】[0031]
【発明の効果】本発明は、変色前の明度が高くかつ光照
射による演色性に優れ、しかも媒体系での分散性にきわ
めて優れた特性を有するフォトクロミック性微粉末を、
比較的簡素な手段でもって経済的に製造することができ
るものであり、フォトクロミック性演色体用材料の適用
拡大を図る上で甚だ意義の大きいものである。INDUSTRIAL APPLICABILITY The present invention provides a photochromic fine powder having high brightness before discoloration, excellent color rendering properties by light irradiation, and extremely excellent dispersibility in a medium system.
It can be economically produced by a relatively simple means, and is of great significance in expanding the application of photochromic color rendering material.
Claims (3)
状の酸化鉄微粉末を乾式混合し、次いで該混合物を、フ
ォトクロミック性を発現し、かつ、アナターゼ型二酸化
チタンがルチル型二酸化チタンへ転移する温度未満で加
熱処理するフォトクロミック性二酸化チタン微粉末の製
造方法。1. Anatase-type titanium dioxide fine powder and iron oxide fine powder in the form of particles are dry-mixed, and then the mixture is exposed to photochromic properties and at a temperature at which the anatase-type titanium dioxide is converted to rutile-type titanium dioxide. A method for producing a photochromic titanium dioxide fine powder, which is heat-treated at a temperature of less than 1.
グネタイトを加熱処理して得られる平均粒子径が０．０
５〜０．５μｍのα−Ｆｅ２Ｏ３微粉末である請求項１
記載のフォトクロミック性二酸化チタン微粉末の製造方
法。2. An iron oxide fine powder having a granular shape has an average particle diameter of 0.0 obtained by heat-treating granular magnetite.
A fine powder of α-Fe 2 O 3 having a particle size of 5 to 0.5 μm.
A method for producing the fine powder of photochromic titanium dioxide described.
鉄を加熱処理して得られる平均粒子径が０．０５〜０．
５μｍの粒状形状のα−Ｆｅ２Ｏ３微粉末である請求項
１記載のフォトクロミック性二酸化チタン微粉末の製造
方法。3. An iron oxide fine powder in the form of particles having an average particle diameter of 0.05 to 0.
Claim 1 photochromic titanium dioxide fine powder production method of wherein the α-Fe 2 O 3 fine powders of granulated shape of 5 [mu] m.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29185691A JPH0551210A (en) | 1991-08-20 | 1991-08-20 | Production of photochromic fine titanium dioxide powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29185691A JPH0551210A (en) | 1991-08-20 | 1991-08-20 | Production of photochromic fine titanium dioxide powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0551210A true JPH0551210A (en) | 1993-03-02 |
Family
ID=17774310
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29185691A Pending JPH0551210A (en) | 1991-08-20 | 1991-08-20 | Production of photochromic fine titanium dioxide powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0551210A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004024832A1 (en) * | 2002-08-07 | 2004-03-25 | Ishihara Sangyo Kaisha, Ltd. | Titanium dioxide pigment and method for producing the same, and resin composition using the same |
| CN104151874A (en) * | 2014-07-10 | 2014-11-19 | 池州市英派科技有限公司 | Wear-resistant reinforced modified nano titanium dioxide and preparation method thereof |
| JP2016155902A (en) * | 2015-02-23 | 2016-09-01 | 共同印刷株式会社 | Photochromic brilliant pigment and production method of the same |
| JP2020059803A (en) * | 2018-10-10 | 2020-04-16 | 共同印刷株式会社 | Photochromic pigment and production method of the same |
| JP2020059805A (en) * | 2018-10-10 | 2020-04-16 | 共同印刷株式会社 | Mixed photochromic pigment and production method of the same |
-
1991
- 1991-08-20 JP JP29185691A patent/JPH0551210A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004024832A1 (en) * | 2002-08-07 | 2004-03-25 | Ishihara Sangyo Kaisha, Ltd. | Titanium dioxide pigment and method for producing the same, and resin composition using the same |
| CN1298790C (en) * | 2002-08-07 | 2007-02-07 | 石原产业株式会社 | Titanium dioxide pigment, its preparation and resin composition using the same |
| US7371276B2 (en) | 2002-08-07 | 2008-05-13 | Ishihara Sangyo Kaisha, Ltd. | Titanium dioxide pigment and method for producing the same and resin composition using the same |
| CN104151874A (en) * | 2014-07-10 | 2014-11-19 | 池州市英派科技有限公司 | Wear-resistant reinforced modified nano titanium dioxide and preparation method thereof |
| CN104151874B (en) * | 2014-07-10 | 2015-10-28 | 池州市英派科技有限公司 | Modified nano-titanium dioxide of a kind of wear-resisting enhancing and preparation method thereof |
| JP2016155902A (en) * | 2015-02-23 | 2016-09-01 | 共同印刷株式会社 | Photochromic brilliant pigment and production method of the same |
| JP2020059803A (en) * | 2018-10-10 | 2020-04-16 | 共同印刷株式会社 | Photochromic pigment and production method of the same |
| JP2020059805A (en) * | 2018-10-10 | 2020-04-16 | 共同印刷株式会社 | Mixed photochromic pigment and production method of the same |
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