CN100582323C - Particulate titanium oxide, method and apparatus for manufacturing the same, and treatment methods using such titanium oxide - Google Patents

Particulate titanium oxide, method and apparatus for manufacturing the same, and treatment methods using such titanium oxide Download PDF

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CN100582323C
CN100582323C CN200480001932A CN200480001932A CN100582323C CN 100582323 C CN100582323 C CN 100582323C CN 200480001932 A CN200480001932 A CN 200480001932A CN 200480001932 A CN200480001932 A CN 200480001932A CN 100582323 C CN100582323 C CN 100582323C
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titanium oxide
oxide particles
polyhedron
synthesis
tube
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CN1723304A (en
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寺田佳弘
上片野充
贺嘉磊
姬野邦治
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Fujikura Ltd
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Abstract

Titanium oxide grains of large specific area and high crystallinity with reduced internal defects, whose high photocatalytic activity as a photocatalyst is promising; and titanium oxide grains which even when heated at high temperature, exhibits low tendency of transformation to rutile crystal structure and exhibits low rate of sintering. As titanium oxide grains for composing a photocatalyst, use is made of those of the shape of a boxy polyhedron. The polyhedron constituting the titanium oxide grains is composed of one or more titanium oxide single-crystal polyhedrons. The crystallinity can be enhanced by causing the flatness ratio of single-crystal polyhedrons to fall within the range of 0.33 to 3.0. It is preferred that the polyhedron be a hexa to decahedron. The rutile transformation ratio R (700 to 24) is to be 7.5% or less while the rutile transformation ratio R (500 to 24) is to be 2.0% or less. Titanium oxide grains of the above configuration are produced through a process comprising feeding titanium tetrachloride vapor and oxygen into a synthetic tube of quartz glass and heating them from the exterior of the synthetic tube by means of an oxyhydrogen flame burner so as to effect thermal oxidation.

Description

氧化钛粒子及其制造方法、制造装置以及使用该氧化钛的处理方法 Titanium oxide particles, method for producing the same, production device, and treatment method using the same

背景技术 Background technique

本发明涉及用于光催化剂等的氧化钛粒子及其制造方法、制造装置以及处理方法,是通过将氧化钛粒子做成新的形状的粒子,可大大提高作为光催化剂时的光催化活性。The present invention relates to titanium oxide particles used in photocatalysts and the like, a production method, a production device, and a treatment method thereof. By making titanium oxide particles into particles of a new shape, the photocatalytic activity of the photocatalyst can be greatly improved.

由氧化钛粒子组成的光催化剂是众所周知的。氧化钛粒子的光催化反应是在氧化钛粒子的表面引起的化学反应,分解对象的化学物质是从吸附在氧化钛粒子的表面开始其反应的。为此,氧化钛粒子的粒径越小越显示高的光催化活性。Photocatalysts composed of titanium oxide particles are well known. The photocatalytic reaction of titanium oxide particles is a chemical reaction caused on the surface of titanium oxide particles, and the chemical substance to be decomposed begins its reaction by being adsorbed on the surface of titanium oxide particles. Therefore, the smaller the particle size of the titanium oxide particles, the higher the photocatalytic activity.

在日本特开平11-267519号公报、日本特开平08-164334号公报、日本特开平07-303835号公报中公开的在先发明中,为此,希望将氧化钛粒子的粒径微细化到数nm级的氧化钛粒子。可是,对于这样的数nm级的氧化钛粒子,在作成浆液时,有时在分散性上产生问题。In the prior inventions disclosed in Japanese Patent Laid-Open No. 11-267519, Japanese Patent Laid-Open No. 08-164334, and Japanese Patent Laid-Open No. 07-303835, it is desired to reduce the particle size of titanium oxide particles to several Nanoscale titanium oxide particles. However, when such titanium oxide particles on the order of several nanometers are made into a slurry, there may be a problem in dispersibility.

另外,作为光催化剂用市售的氧化钛粒子,其粒子形状都是球形的,存在每单位重量的比表面积小,反应性不充分的问题。In addition, titanium oxide particles commercially available as photocatalysts have spherical particle shapes, have a small specific surface area per unit weight, and have a problem of insufficient reactivity.

可是,人们发现氧化钛的光催化作用是通过将光照射在氧化钛粒子上,激发构成氧化钛的电子,产生电子(e-)或空穴(h+),由此产生氧化力或还原力。However, it has been found that the photocatalysis of titanium oxide is by irradiating light on titanium oxide particles, exciting the electrons that make up titanium oxide, generating electrons (e - ) or holes (h + ), thereby generating oxidizing or reducing power .

可是,人们还知道被激发了的电子或空穴的一部分以氧化钛内部的缺陷作为再结合中心进行再结合,这样就降低了光催化活性。However, it is also known that some of the excited electrons or holes are recombined using defects inside titanium oxide as recombination centers, thus reducing the photocatalytic activity.

因此,希望得到内部缺陷少的氧化钛粒子,日本特开2001-276615号公报中公开的在先发明中,提出了显示高的催化活性的大粒径的锐钛矿型单晶。Therefore, it is desired to obtain titanium oxide particles with few internal defects, and the prior invention disclosed in JP-A-2001-276615 proposes an anatase-type single crystal having a large particle size and exhibiting high catalytic activity.

可是,在以往的制造方法中,不能得到结晶性高且粒径小的氧化钛粒子,为了得到内部缺陷少的结晶性高的粒子,只能采用加大粒径,牺牲比表面积的方法。为此,上述日本特开2001-276615号公报中公开的氧化钛粒子,对分解对象的化学物质的吸附量少,作为光催化剂是不利的。However, in conventional production methods, titanium oxide particles with high crystallinity and small particle size cannot be obtained. In order to obtain particles with high crystallinity and few internal defects, only a method of increasing the particle size and sacrificing the specific surface area can be used. For this reason, the titanium oxide particles disclosed in JP 2001-276615 A are disadvantageous as photocatalysts because they have a small amount of adsorption of chemical substances to be decomposed.

另外,在日本特开平10-081517号公报、日本特开平10-095617号公报中提出了作为颜料、遮蔽材料等的用途,除了球形粒子以外还公开了针状、树枝状、海星状、板状等形状的氧化钛粒子。可是,对于这些形状的氧化钛粒子,是脱离氧化钛原来的结晶形状而形成的,其结晶性大大降低,成为接近非结晶的结构,必然存在内部缺陷很多的问题。In addition, in Japanese Patent Application Laid-Open No. 10-081517 and Japanese Patent Laid-Open No. 10-095617, applications as pigments, masking materials, etc. are proposed, and needle-shaped, dendritic, starfish-shaped, and plate-shaped particles are also disclosed in addition to spherical particles. Titanium oxide particles of equal shape. However, titanium oxide particles of these shapes are formed out of the original crystal shape of titanium oxide, and their crystallinity is greatly reduced to a structure close to amorphous, which inevitably has a problem of many internal defects.

因此,迄今尚不知道单位重量的比表面积大、结晶性高且内部缺陷少、适宜作为光催化剂的氧化钛粒子。Therefore, titanium oxide particles having a large specific surface area per unit weight, high crystallinity and few internal defects, and suitable as a photocatalyst have not been known so far.

另外,作为氧化钛粒子的制造方法,已知有日本特开平05-163022号公报公开的液相合成法和日本特开2001-276615号公报公开的气相合成法。可是,对于这些制造方法,不能合成上述的单位重量的比表面积大、结晶性高且内部缺陷少而适宜作为光催化剂的氧化钛粒子。In addition, as methods for producing titanium oxide particles, there are known a liquid phase synthesis method disclosed in JP-A-05-163022 and a gas-phase synthesis method disclosed in JP-A-2001-276615. However, these production methods cannot synthesize titanium oxide particles suitable as photocatalysts having a large specific surface area per unit weight, high crystallinity, and few internal defects.

另外,使氧化钛粒子作为光催化剂发挥实际功能时,需要将氧化钛粒子载持在基材上,使它与分解对象物高效地接触。作为将该氧化钛粒子向基材上载持的方法,如日本特开平07-002522号公报公开的那样,有向含有无机材料的基材直接烧结的方法。该方法是将低熔点玻璃等作为粘合材料使用,加热到该粘合材料软化、熔融的温度,通常加热到700℃左右而进行烧结。In addition, in order to make titanium oxide particles actually function as a photocatalyst, it is necessary to support the titanium oxide particles on a base material so that they can efficiently contact with the object to be decomposed. As a method of supporting the titanium oxide particles on the substrate, there is a method of direct sintering on a substrate containing an inorganic material as disclosed in JP-A-07-002522. In this method, a low-melting-point glass or the like is used as a binder, and the binder is heated to a temperature at which the binder softens and melts, usually at about 700° C. for sintering.

另外,如日本专利3279755号公报公开的那样,有使用合成树脂等有机系粘合材料固定在基材的方法。对于该方法,作为有机系粘合材料需要选用难以被氧化钛分解,而且经500℃左右的数小时加热达到固化的合成树脂。In addition, as disclosed in Japanese Patent No. 3279755, there is a method of fixing to a substrate using an organic adhesive such as a synthetic resin. For this method, it is necessary to select a synthetic resin that is difficult to be decomposed by titanium oxide and cured by heating at about 500° C. for several hours as an organic adhesive material.

可是,对于这些载持方法,由于任何一种都是加热到500℃~700℃左右的温度,所以氧化钛的结晶结构发生了变化。However, in any of these supporting methods, since heating is performed at a temperature of about 500°C to 700°C, the crystal structure of titanium oxide changes.

作为光催化剂来使用的氧化钛是具有锐钛矿型结晶结构的物质,这是因为该锐钛矿型氧化钛的光催化活性比其他的结晶结构的金红石型、板钛矿型优良的缘故。Titanium oxide used as a photocatalyst has an anatase-type crystal structure, and this is because the photocatalytic activity of this anatase-type titanium oxide is superior to that of other crystal structures such as rutile and brookite.

可是,通常所知的是,在载持锐钛矿型结晶结构的氧化钛粒子时,如上所述,在加热到500℃~700℃左右时,结晶结构转变为金红石型,光催化活性降低。However, it is generally known that when titanium oxide particles with an anatase crystal structure are supported, the crystal structure changes to a rutile crystal structure when heated to about 500° C. to 700° C. as described above, and the photocatalytic activity decreases.

另外,在进行该加热时,氧化钛粒子相互烧结,其表面积减少,由于这样的原因,光催化活性也会降低。In addition, when this heating is performed, the titanium oxide particles are sintered with each other to reduce the surface area, and the photocatalytic activity is also reduced due to this reason.

因此,本发明的课题在于提供氧化钛粒子及其制造方法和制造装置,该氧化钛粒子作为光催化剂可期待高的光催化活性,比表面积大,结晶性高且内部缺陷少。另外,还提供氧化钛粒子,该氧化钛粒子即使加热到高温也很少发生向金红石型结晶结构的转变,另外,即使加热也难以进行烧结。进而,还提供使用这样的氧化钛粒子高效地处理有害物质的分解方法等的利用方法。Therefore, an object of the present invention is to provide titanium oxide particles which can be expected to have high photocatalytic activity as a photocatalyst, have a large specific surface area, have high crystallinity, and have few internal defects, as well as a production method and production apparatus thereof. Also provided are titanium oxide particles which rarely undergo transformation to a rutile crystal structure even when heated to a high temperature, and which are difficult to sinter even when heated. Furthermore, utilization methods such as a decomposition method for efficiently treating harmful substances using such titanium oxide particles are also provided.

发明内容 Contents of the invention

为了解决这样的问题,提出以下的方案。In order to solve such a problem, the following proposals are proposed.

本发明的第1种实施方式为氧化钛粒子,其粒径在1nm~500nm,是由1个或更多个单晶多面体所构成的箱型形状的多面体或基本上是箱型形状的多面体形成的。上述基本上是箱型形状的多面体包括多面体的角稍有缺失的形状的多面体、带有圆形的形状的多面体及具有凹凸等而使得形状稍微变化的多面体。The first embodiment of the present invention is titanium oxide particles, the particle size of which is 1 nm to 500 nm, and is formed of a box-shaped polyhedron or substantially box-shaped polyhedron composed of one or more single crystal polyhedrons of. The above-mentioned substantially box-shaped polyhedron includes polyhedrons having slightly missing corners, polyhedrons having rounded shapes, and polyhedrons having irregularities and the like to slightly change the shape.

本发明的第2种实施方式为,第1种实施方式的氧化钛粒子,其单晶多面体的扁平率是0.33~3.0的。A second embodiment of the present invention is the titanium oxide particle of the first embodiment, wherein the flatness of the single crystal polyhedron is 0.33 to 3.0.

本发明的第3种实施方式为,第1种实施方式的氧化钛粒子,其中的多面体是6面体~10面体中的任何1种。A third embodiment of the present invention is the titanium oxide particle of the first embodiment, wherein the polyhedron is any one of hexahedron to decahedron.

本发明的第4种实施方式为,第1~第3中任何一种实施方式的氧化钛粒子,其中,金红石转变率R(700-24)是7.5%或更少、金红石转变率R(500-24)是2.0%或更少。A fourth embodiment of the present invention is the titanium oxide particle according to any one of the first to third embodiments, wherein the rutile conversion rate R(700-24) is 7.5% or less, the rutile conversion rate R(500 -24) is 2.0% or less.

本发明的第5种实施方式为,第1~第4中任何一种实施方式的氧化钛粒子,其粒径是100~500nm。A fifth embodiment of the present invention is that the titanium oxide particles according to any one of the first to fourth embodiments have a particle diameter of 100 to 500 nm.

本发明的第6种实施方式为,第1~第4中任何一种实施方式的氧化钛粒子,其粒径是10~50nm。A sixth embodiment of the present invention is that the titanium oxide particles according to any one of the first to fourth embodiments have a particle diameter of 10 to 50 nm.

本发明的第7种实施方式为,第1~第6中任何一种实施方式的氧化钛粒子,其中,比表面积是3~40m2/g,在内径15mm的密闭容器中加入5体积%醋酸水溶液5毫升和氧化钛粒子50mg,在悬浮的状态下以15mW/cm2的照度照射365nm的紫外光,其每1小时产生的二氧化碳量位于用y=0.8x(x是比表面积,单位为m2/g;y是二氧化碳发生量,单位为μmol/hr。)表示的线的上方区域。A seventh embodiment of the present invention is the titanium oxide particle of any one of the first to sixth embodiments, wherein the specific surface area is 3 to 40 m 2 /g, and 5% by volume of acetic acid is added to a closed container with an inner diameter of 15 mm. 5 milliliters of aqueous solution and 50 mg of titanium oxide particles are irradiated with 365 nm ultraviolet light at an illumination intensity of 15 mW/cm 2 in a suspended state. 2 /g; y is the amount of carbon dioxide produced in μmol/hr.) The area above the line indicated.

本发明的第8种实施方式为,第1~第6中任何一种实施方式的氧化钛粒子,其中,掺杂有硅,比表面积是3~40m2/g,在内径15mm的密闭容器中加入5体积%醋酸水溶液5毫升和氧化钛粒子50mg,在悬浮的状态下以15mW/cm2的照度照射365nm的紫外光,其每1小时产生的二氧化碳量位于用y=0.8x(x是比表面积,单位为m2/g;y是二氧化碳产生量,单位为μmol/hr。)表示的线的上方区域。An eighth embodiment of the present invention is the titanium oxide particle according to any one of the first to sixth embodiments, which is doped with silicon, has a specific surface area of 3 to 40 m 2 /g, and is placed in a closed container with an inner diameter of 15 mm. Add 5 milliliters of 5 volume % acetic acid aqueous solution and 50 mg of titanium oxide particles, and irradiate the ultraviolet light of 365 nm with the illuminance of 15 mW/cm in the state of suspension, and the amount of carbon dioxide that it produces every 1 hour is positioned at with y=0.8x (x is ratio Surface area, in m 2 /g; y is carbon dioxide production, in μmol/hr.) The area above the line indicated.

本发明的第9种实施方式为,第7种实施方式的氧化钛粒子,其中掺杂磷、氮、硅、硼中任一元素。A ninth embodiment of the present invention is the titanium oxide particle according to the seventh embodiment, wherein any one of phosphorus, nitrogen, silicon, and boron is doped.

本发明的第10种实施方式为一种氧化钛粉末,是第1~第8中任何一种实施方式的氧化钛粒子多个集合了的氧化钛粉末,形成该粉末的氧化钛粒子的80%或更高是锐钛矿型结晶。A tenth embodiment of the present invention is a titanium oxide powder, which is a titanium oxide powder in which a plurality of titanium oxide particles according to any one of the first to eighth embodiments are assembled, and 80% of the titanium oxide particles forming the powder are Or higher is anatase crystal.

本发明的第11种实施方式为,第10种实施方式的氧化钛粉末,其中锐钛矿型结晶占90%或更多。An eleventh embodiment of the present invention is the titanium oxide powder of the tenth embodiment, wherein anatase crystals account for 90% or more.

本发明的第12种实施方式为第1种实施方式的氧化钛粒子的制造方法,其特征是,向合成管内供给钛化合物蒸汽和氧,从合成管外部加热。A twelfth embodiment of the present invention is the method for producing titanium oxide particles according to the first embodiment, characterized in that titanium compound vapor and oxygen are supplied into the synthesis tube and heated from the outside of the synthesis tube.

本发明的第13种实施方式为,第12种实施方式的氧化钛粒子的制造方法,其特征是,作为加热源使用氢氧焰灯(酸水素炎バ一ナ)。A thirteenth embodiment of the present invention is the method for producing titanium oxide particles according to the twelfth embodiment, characterized in that an oxyhydrogen flame lamp (acid hydrochloride varna) is used as a heating source.

本发明的第14种实施方式为,第12或第13种实施方式的氧化钛粒子的制造方法,其特征是旋转合成管。A fourteenth embodiment of the present invention is the method for producing titanium oxide particles according to the twelfth or thirteenth embodiment, which is characterized in that the synthesis tube is rotated.

本发明的第15种实施方式为,第12种实施方式的氧化钛粒子的制造方法,其特征是在合成管内部设置将钛化合物蒸汽和氧的混合气体导入到合成管的内壁侧的柱状部件,从外部加热。A fifteenth embodiment of the present invention is the method for producing titanium oxide particles according to the twelfth embodiment, which is characterized in that a columnar member that introduces a mixed gas of titanium compound vapor and oxygen to the inner wall side of the synthesis tube is provided inside the synthesis tube. , heated from the outside.

本发明的第16种实施方式为,第15种实施方式的氧化钛粒子的制造方法,其特征是将合成管和柱状部件的间隔作成0.1~10mm。A sixteenth embodiment of the present invention is the method for producing titanium oxide particles according to the fifteenth embodiment, characterized in that the interval between the synthetic tube and the columnar member is 0.1 to 10 mm.

本发明的第17种实施方式为,第12~第16中任何一种实施方式的氧化钛粒子制造方法,其特征是,生成的氧化钛粒子的回收方法是利用热迁移(サ一モフォレシス)效果,使氧化钛粒子堆积在合成管的下游部分进行回收。A seventeenth embodiment of the present invention is the method for producing titanium oxide particles according to any one of the twelfth to sixteenth embodiments, characterized in that the recovery method of the produced titanium oxide particles utilizes thermal migration (thermophoresis) effect , so that titanium oxide particles are accumulated in the downstream part of the synthesis pipe for recovery.

本发明的第18种实施方式为,第12~第16中任何一种实施方式的氧化钛粒子制造方法,其特征是,生成的氧化钛粒子的回收方法是使用设置在合成管下游侧的袋滤器的方法。An eighteenth embodiment of the present invention is the method for producing titanium oxide particles according to any one of the twelfth to sixteenth embodiments, wherein the recovery method of the generated titanium oxide particles is to use a bag installed on the downstream side of the synthetic pipe filter method.

本发明的第19种实施方式为,第12~第16中任何一种实施方式的氧化钛粒子制造方法,其特征是合成时的合成管的温度在850~1500℃。A nineteenth embodiment of the present invention is the method for producing titanium oxide particles according to any one of the twelfth to sixteenth embodiments, characterized in that the temperature of the synthesis tube during synthesis is 850 to 1500°C.

本发明的第20种实施方式为第1种实施方式的氧化钛粒子的制造装置,其具有合成管、从外部对合成管进行加热的加热源、使合成管绕其轴旋转的旋转驱动部和向合成管内提供钛化合物蒸汽和氧的原料供给部。A twentieth embodiment of the present invention is the production apparatus of titanium oxide particles according to the first embodiment, which has a synthesis tube, a heat source for externally heating the synthesis tube, a rotary drive unit for rotating the synthesis tube around its axis, and A raw material supply unit that supplies titanium compound vapor and oxygen into the synthesis tube.

本发明的第21种实施方式为,第20种实施方式的氧化钛粒子的制造装置,其中,具有对合成管内生成的氧化钛粒子进行回收的袋滤器。A twenty-first embodiment of the present invention is the production apparatus of titanium oxide particles according to the twenty-first embodiment, which includes a bag filter for recovering the titanium oxide particles generated in the synthesis tube.

本发明的第22种实施方式为,第20或第21种实施方式的氧化钛粒子的制造装置,其中,在合成管内部设置将钛化合物蒸汽和氧的混合气体导入到合成管内壁侧的柱状部件。The 22nd embodiment of the present invention is the manufacturing device of titanium oxide particles according to the 20th or 21st embodiment, wherein a column-shaped tube for introducing a mixed gas of titanium compound vapor and oxygen to the inner wall side of the synthesis tube is provided inside the synthesis tube. part.

本发明的第23种实施方式为含有第1~第8中任何一种实施方式的氧化钛粒子的光催化剂。A twenty-third embodiment of the present invention is a photocatalyst containing the titanium oxide particles according to any one of the first to eighth embodiments.

本发明的第24种实施方式为含有第10或第11种实施方式的氧化钛粉末的光催化剂。A twenty-fourth embodiment of the present invention is a photocatalyst containing the titanium oxide powder according to the tenth or eleventh embodiment.

本发明的第25种实施方式为含有第1~第8中任何一种实施方式的氧化钛粒子的涂料。A twenty-fifth embodiment of the present invention is a paint containing the titanium oxide particles according to any one of the first to eighth embodiments.

本发明的第26种实施方式为含有第10或第11种实施方式的氧化钛粉末的涂料。A twenty-sixth embodiment of the present invention is a paint containing the titanium oxide powder according to the tenth or eleventh embodiment.

本发明的第27种实施方式为光催化装置,其中,具有将第1~第8中任何一种实施方式的氧化钛粒子载持在表面的光催化反应体和向该光催化反应体上照射光的光源。A twenty-seventh embodiment of the present invention is a photocatalytic device comprising a photocatalyst reactant having the titanium oxide particles of any one of the first to eighth embodiments supported on the surface, and irradiating the photocatalyst reactant with light source.

本发明的第28种实施方式为分解有害物质的方法,其中,使用第10或第11种实施方式的氧化钛粉末。A twenty-eighth embodiment of the present invention is a method for decomposing harmful substances, wherein the titanium oxide powder of the tenth or eleventh embodiment is used.

本发明的第29种实施方式为,第28种实施方式的分解有害物质的方法,其中,使被处理对象物和氧化钛粒子接触进行分解后,用过滤器分离氧化钛粒子。A twenty-ninth embodiment of the present invention is the method for decomposing harmful substances according to the twenty-eighth embodiment, wherein after the object to be processed is brought into contact with titanium oxide particles to decompose, the titanium oxide particles are separated by a filter.

本发明的第30种实施方式为第29种实施方式的分解有害物质的方法,其中,过滤器是玻璃纤维制的,开孔是2.0μm或更大。A thirtieth embodiment of the present invention is the method for decomposing harmful substances according to the twenty-ninth embodiment, wherein the filter is made of glass fiber and has pores of 2.0 μm or more.

本发明的第31种实施方式为脱臭方法,其中,使用第22或第24种实施方式的光催化剂。A thirty-first embodiment of the present invention is a deodorization method using the photocatalyst of the twenty-second or twenty-fourth embodiment.

本发明的第32种实施方式为杀菌方法,其中,使用第23或第24种实施方式的光催化剂。A thirty-second embodiment of the present invention is a sterilization method using the photocatalyst of the twenty-third or twenty-fourth embodiment.

本发明的第33种实施方式为分解有害物质的方法,其中,使用第23或第24种实施方式的光催化剂。A 33rd embodiment of the present invention is a method for decomposing harmful substances, wherein the photocatalyst of the 23rd or 24th embodiment is used.

本发明的氧化钛粒子,由于是箱型形状的多面体形成的,所以结晶性高,内部缺陷及表面缺陷少,另外,每单位重量的比表面积大。特别优选的是结晶多面体的扁平率是0.33~3.0的范围,其比表面积更大,且结晶性也高。另外,即使加热,也很少发生从高活性的锐钛矿型结晶结构向低活性的金红石型结晶结构的转变,烧结也是难以进行的。Since the titanium oxide particles of the present invention are formed of box-shaped polyhedrons, they have high crystallinity, few internal defects and surface defects, and have a large specific surface area per unit weight. It is particularly preferable that the oblateness of the crystal polyhedron is in the range of 0.33 to 3.0, the specific surface area is larger, and the crystallinity is also high. In addition, even when heated, the transition from the highly active anatase crystal structure to the low active rutile crystal structure rarely occurs, and sintering is also difficult.

为此,含有该氧化钛粒子的光催化剂,由于被激发的电子、空穴的再结合的比例减少,另外,分解对象物质的吸附面积变大,所以具有极高的光催化活性。另外,通过将氧化钛粒子载持在基材时受到的加热处理,也不降低光催化活性。Therefore, the photocatalyst containing the titanium oxide particles has extremely high photocatalytic activity because the ratio of recombination of excited electrons and holes is reduced and the adsorption area of the decomposed substance is increased. In addition, the photocatalytic activity was not lowered by the heat treatment received when the titanium oxide particles were supported on the substrate.

另外,本发明的氧化钛粒子的制造方法及制造装置可高效地制造上述的箱型形状的多面体形成的氧化钛粒子。In addition, the method and apparatus for producing titanium oxide particles of the present invention can efficiently produce the above-mentioned titanium oxide particles formed of box-shaped polyhedrons.

进而,本发明的光催化剂、涂料、光催化装置利用了上述的氧化钛粉末,所以有害物质的分解效率高。另外,脱臭效果、杀菌效果也高。Furthermore, since the photocatalyst, paint, and photocatalytic device of the present invention utilize the above-mentioned titanium oxide powder, the decomposition efficiency of harmful substances is high. In addition, the deodorizing effect and the sterilizing effect are also high.

附图说明 Description of drawings

图1是模式地表示本发明箱型形状多面体的氧化钛粒子的例子的概略立体图。FIG. 1 is a schematic perspective view schematically showing an example of a box-shaped polyhedral titanium oxide particle of the present invention.

图2是模式地表示构成本发明氧化钛粒子的结晶多面体的例子的概略立体图。Fig. 2 is a schematic perspective view schematically showing an example of a crystal polyhedron constituting the titanium oxide particle of the present invention.

图3是表示本发明的氧化钛粒子的表面积和醋酸分解量的关系的图表。Fig. 3 is a graph showing the relationship between the surface area of titanium oxide particles and the amount of acetic acid decomposed in the present invention.

图4是表示本发明的氧化钛粒子的制造装置的一个例子的概略构成图。Fig. 4 is a schematic configuration diagram showing an example of a production apparatus of titanium oxide particles of the present invention.

图5是表示本发明的氧化钛粒子的制造装置的另一个例子的概略构成图。Fig. 5 is a schematic configuration diagram showing another example of the production apparatus of titanium oxide particles of the present invention.

图6是表示本发明的氧化钛粒子的制造装置的另一个例子的要部的概略构成图。Fig. 6 is a schematic configuration diagram showing main parts of another example of the production apparatus of titanium oxide particles of the present invention.

图7是表示本发明的用于分解有害物质的方法的装置的一个例子的概略构成图。Fig. 7 is a schematic configuration diagram showing an example of an apparatus for the method of decomposing harmful substances according to the present invention.

图8是显示由实施例1得到的氧化钛粒子的形状的电子显微镜照片。FIG. 8 is an electron micrograph showing the shape of titanium oxide particles obtained in Example 1. FIG.

图9是表示实施例2的结果的图表。FIG. 9 is a graph showing the results of Example 2. FIG.

图10是显示比较例3中加热后的氧化钛粒子的电子显微镜照片。FIG. 10 is an electron micrograph showing titanium oxide particles after heating in Comparative Example 3. FIG.

图11是表示实施例5中的结果的图表。FIG. 11 is a graph showing the results in Example 5. FIG.

具体实施方式 Detailed ways

(氧化钛粒子)(titanium oxide particles)

以下,详细地说明本发明的氧化钛粒子。Hereinafter, the titanium oxide particles of the present invention will be described in detail.

图1是表示本发明的氧化钛粒子的一个例子的模式图。该例子的氧化钛粒子1是箱型形状,且为10面体。FIG. 1 is a schematic view showing an example of titanium oxide particles of the present invention. The titanium oxide particle 1 of this example has a box shape and is a decahedron.

本发明所说的“箱型形状的多面体”是指可推定正方晶系的氧化钛的结晶面被反映在粒子的外形上的多面体或基本上是箱型形状的多面体。The term "box-shaped polyhedron" in the present invention refers to a polyhedron in which the crystal plane of tetragonal titanium oxide is estimated to be reflected in the particle shape or a substantially box-shaped polyhedron.

另外,该箱型形状的多面体的氧化钛粒子是由1个或多个氧化钛单晶的多面体(单晶多面体)集合构成的,根据单晶的多面体的集合数变化成从6面体到多于六面的多面体形状。对于本发明,这些完全包括在本发明的箱型形状的多面体中。另外,即使是单晶多面体,也存在例如10面体等的不少于6面体的多面体,这些也包括在本发明的多面体中。In addition, the box-shaped polyhedral titanium oxide particles are composed of one or more polyhedrons (single crystal polyhedrons) of single crystals of titanium oxide, and vary from hexahedrons to more than one according to the number of polyhedrons of single crystals. Six-sided polyhedron shape. For the present invention, these are fully included in the box-shaped polyhedron of the present invention. In addition, even if it is a single-crystal polyhedron, there are polyhedrons not less than hexahedral such as a decahedron, and these are also included in the polyhedron of the present invention.

在这些多面体中,最优选的是如图1所示的10面体。Among these polyhedra, the most preferable is the decahedron as shown in FIG. 1 .

另外,作为箱型形状的多面体以6面体为例时,6面体的角稍有缺失的形状或稍微带有圆形的形状的,原来是完全的6面体、但由于热或者机械变形的,这些也被看作是包括在这里的6面体中的基本上是箱型形状的多面体。In addition, when a hexahedron is used as an example of a box-shaped polyhedron, the hexahedron has a slightly missing corner or a slightly rounded shape. It is originally a complete hexahedron, but due to thermal or mechanical deformation, these A substantially box-shaped polyhedron also considered to be included in the hexahedron herein.

进而,例如在10面体的一部分产生处于结晶成长时的缺陷、具有凹凸等而使得形状稍微变化的,只要具有后述的效果,都包括在本发明的10面体中。作为该多面体,6面体~10面体富于结晶性,比具有其他的更多面数的多面体更理想。Furthermore, for example, a portion of the decahedron that has a defect during crystal growth, has unevenness, etc., and slightly changes its shape, as long as it has the effect described later, is included in the decahedron of the present invention. As the polyhedron, a hexahedron to a decahedron is rich in crystallinity and is more preferable than other polyhedrons having a larger number of faces.

一般,氧化钛的结晶形状有锐钛矿型、金红石型、板钛矿型3种,但对于本发明的箱型形状的多面体的氧化钛粒子,该氧化钛粒子是多个集合的粉末状态,构成该粉末的粒子的80%或更多、优选的是90%或更多是锐钛矿型,20%或更少、优选的是10%或更少是由金红石型结晶构成。Generally, there are three types of crystal shapes of titanium oxide: anatase type, rutile type, and brookite type, but for the box-shaped polyhedral titanium oxide particles of the present invention, the titanium oxide particles are in the powder state of a plurality of aggregates, 80% or more, preferably 90% or more, of the particles constituting the powder are of anatase type, and 20% or less, preferably 10% or less are composed of rutile type crystals.

另外,锐钛矿型及金红石型都是属于正方晶体,由于正方晶体的a轴和b轴是等价的,所以即使在6面体以外的多面体中也可确定氧化钛本来的a轴、b轴和c轴。In addition, both the anatase type and the rutile type belong to the square crystal. Since the a-axis and b-axis of the square crystal are equivalent, the original a-axis and b-axis of titanium oxide can be determined even in polyhedrons other than hexahedrons. and c-axis.

图2是表示构成本发明的箱型形状的多面体的氧化钛粒子的单晶多面体2的例子。将从该单晶多面体2的中心到与a轴垂直相交的面或棱的距离作为X,将到与c轴垂直相交的面或棱的距离作为Z,将单晶多面体的扁平率H定义为H=X/Z时,扁平率H是0.33~3.0、优选的是0.6~1.67的单晶多面体构成的氧化钛粒子,光催化活性高,因此是优选的。FIG. 2 shows an example of a single crystal polyhedron 2 of titanium oxide particles constituting the box-shaped polyhedron of the present invention. Taking the distance from the center of the single crystal polyhedron 2 to the face or edge perpendicular to the a-axis as X, and the distance to the face or edge perpendicular to the c-axis as Z, the oblateness H of the single crystal polyhedron is defined as When H=X/Z, the flattening ratio H is 0.33 to 3.0, preferably 0.6 to 1.67, and the titanium oxide particle composed of a single crystal polyhedron is preferable because of its high photocatalytic activity.

另外,在多面体由多个单晶多面体组成时,可认为分割成各个单晶多面体,同样地对于各个单晶多面体算出其扁平率,取它们的平均值就可以。另外,该扁平率的实际测定,是将合成了的氧化钛粒子作为对象用扫描型电子显微镜观察,测定该多面体的尺寸,计算X及Z的值,从这些可以算出扁平率。In addition, when the polyhedron is composed of a plurality of single crystal polyhedrons, it can be considered that it is divided into individual single crystal polyhedrons, and the oblateness of each single crystal polyhedron is similarly calculated, and their average value may be taken. In addition, the actual measurement of the flatness is to observe the synthesized titanium oxide particles with a scanning electron microscope, measure the size of the polyhedron, and calculate the values of X and Z, and the flatness can be calculated from these.

另外,本发明的箱型形状的多面体的氧化钛粒子的尺寸,平均粒径作成1~500nm、优选的是1~200nm、较优选的是1~90nm、更优选的是10~70nm、更进一步优选的是10~50nm,若用粒径分布表示时,占全部粒子的85%的粒径是10nm~100nm,优选的是10nm~40nm。In addition, the box-shaped polyhedral titanium oxide particles of the present invention have an average particle diameter of 1 to 500 nm, preferably 1 to 200 nm, more preferably 1 to 90 nm, more preferably 10 to 70 nm, and even more preferably It is preferably 10 to 50 nm, and when represented by particle size distribution, the particle size accounting for 85% of all particles is 10 nm to 100 nm, preferably 10 nm to 40 nm.

另外,氧化钛粒子的平均粒径可根据使用用途决定适宜的粒径范围,从1~500nm的范围适宜选择。In addition, the average particle diameter of the titanium oxide particles can be determined in an appropriate particle diameter range according to the intended use, and is appropriately selected from the range of 1 to 500 nm.

另外,本发明的氧化钛粒子因加热而向金红石型结晶结构的转变非常小。在本发明中,用金红石转变率R(700-24)及金红石转变率R(500-24)评价向金红石型的转变。In addition, the titanium oxide particles of the present invention undergo very little transformation to the rutile crystal structure by heating. In the present invention, the conversion to the rutile type is evaluated by the rutile conversion ratio R(700-24) and the rutile conversion ratio R(500-24).

所说的金红石转变率R(700-24)是指对于在700℃下被加热24小时的氧化钛粒子,将其加热前的锐钛矿型结晶结构的氧化钛粒子的比例作为A(前)%,将加热后的锐钛矿型结晶结构的氧化钛粒子的比例作为A(后)%,The rutile conversion rate R (700-24) refers to the ratio of titanium oxide particles with anatase crystal structure before heating to titanium oxide particles heated at 700°C for 24 hours as A (before) %, the ratio of the titanium oxide particles of the anatase crystal structure after heating is A (after) %,

用[A(前)-A(后)]/A(前)×100定义的。Defined by [A(front)-A(back)]/A(front)×100.

所说的金红石转变率R(500-24)是指将氧化钛粒子在500℃下加热24小时时的转变率,其它与上述同样地定义。The rutile conversion rate R(500-24) refers to the conversion rate when titanium oxide particles are heated at 500° C. for 24 hours, and the others are defined in the same manner as above.

锐钛矿型结晶结构的氧化钛粒子的比例用X线衍射法从其峰强度测定。The proportion of titanium oxide particles having an anatase crystal structure was determined from the peak intensity thereof by the X-ray diffraction method.

对于本发明的氧化钛粒子,金红石转变率R(700-24)是7.5%或更少、优选的是5.0%或更少,且金红石转变率R(500-24)为2.0%或更少、优选的是1.0%或更少。For the titanium oxide particles of the present invention, the rutile conversion ratio R(700-24) is 7.5% or less, preferably 5.0% or less, and the rutile conversion ratio R(500-24) is 2.0% or less, 1.0% or less is preferred.

另外,本发明的氧化钛粒子,可大幅度地抑制因加热引起的烧结,可以防止由于加热处理引起其比表面积的降低。这可认为是由于氧化钛粒子的结晶性高引起的效果。In addition, the titanium oxide particles of the present invention can significantly suppress sintering due to heating, and can prevent the decrease in specific surface area due to heat treatment. This is considered to be an effect due to the high crystallinity of the titanium oxide particles.

在这样的氧化钛粒子中,由于该多面体是由1个或更多个的单晶多面体构成的,所以结晶性优良,内部缺陷及表面缺陷少。另外,如图1所示,由于粒子形状是箱型或基本上是箱型的,所以与以往的球形的氧化钛粒子相比,每单位重量的比表面积大。In such titanium oxide particles, since the polyhedron is composed of one or more single-crystal polyhedrons, it has excellent crystallinity and few internal defects and surface defects. In addition, as shown in FIG. 1 , since the particle shape is box-shaped or substantially box-shaped, the specific surface area per unit weight is larger than conventional spherical titanium oxide particles.

特别是对于扁平率是0.33~3.0的、尤其是在0.6~1.6的范围内的,可进而成为结晶性高的物质。为此,含有该氧化钛粒子的光催化剂,与以往的比较,可发挥极高的光催化活性。In particular, those with an oblateness of 0.33 to 3.0, especially in the range of 0.6 to 1.6, can further become highly crystalline. Therefore, the photocatalyst containing the titanium oxide particles exhibits extremely high photocatalytic activity compared with conventional ones.

另外,这样的氧化钛粒子中,由于金红石转变率小,通过加热向金红石型结晶结构的转变极小,且抑制了粒子相互的烧结,所以即使通过将该氧化钛粒子载持在基材时的加热处理,也不失去高的催化活性。In addition, in such titanium oxide particles, since the rutile conversion rate is small, the transformation to the rutile crystal structure by heating is extremely small, and the sintering of the particles is suppressed, so even if the titanium oxide particles are supported by the base material, Heat treatment does not lose high catalytic activity.

另外,本发明的氧化钛粒子的表面积比以往的氧化钛粒子小,且具有高结晶性,所以具有高的光催化活性。In addition, the titanium oxide particles of the present invention have a smaller surface area than conventional titanium oxide particles and have high crystallinity, so they have high photocatalytic activity.

即,用BET法测定的比表面积是3~40m2/g的范围,在内径15mm的密闭容器中加入5体积%醋酸水溶液5ml和氧化钛粒子50mg,在悬浮的状态下以15mW/cm2的照度照射365nm的紫外光,每1小时产生的二氧化碳量位于如图3所示的y=0.8x(x是比表面积,单位为m2/g;y是二氧化碳产生量,单位为μmol/hr。)的线的上方区域,优选的是具有40μmol或更高的光催化活性。另外,对掺杂硅的氧化钛粒子,在相同的试验条件下,二氧化碳量位于如图3所示的y=0.8x(x是比表面积,y是二氧化碳产生量。)的线的上方区域,优选的是具有30μmol~45μmol的光催化活性。That is, the specific surface area measured by the BET method is in the range of 3 to 40 m 2 /g, and 5 ml of 5 volume % acetic acid aqueous solution and 50 mg of titanium oxide particles are added to a closed container with an inner diameter of 15 mm, and the surface area is 15 mW/cm 2 in a suspended state. When irradiated with 365nm ultraviolet light, the amount of carbon dioxide produced per hour is located at y=0.8x as shown in Figure 3 (x is the specific surface area in m2 /g; y is the amount of carbon dioxide produced in μmol/hr. ) above the line, preferably has a photocatalytic activity of 40 μmol or higher. In addition, for titanium oxide particles doped with silicon, under the same test conditions, the amount of carbon dioxide is located in the area above the line of y=0.8x (x is the specific surface area, and y is the amount of carbon dioxide produced.) as shown in Figure 3, It is preferable to have photocatalytic activity of 30 μmol to 45 μmol.

对于以往市售的氧化钛粒子,为了得到充分的光催化活性,其表面积作成50m2/g或更多,但它的制造是困难的。与此相对,对于本发明的氧化钛粒子,尽管其表面积小,但也显示出高的催化活性,其制造容易。Conventionally, commercially available titanium oxide particles have a surface area of 50 m 2 /g or more in order to obtain sufficient photocatalytic activity, but their production is difficult. On the other hand, the titanium oxide particle of the present invention exhibits high catalytic activity despite its small surface area, and its production is easy.

为了标定上述光催化活性作为基质使用的醋酸,由于通过光催化作用分解成二氧化碳,通过对产生的二氧化碳量定量可以评价催化活性的程度。如上所述,在内径15mm的密闭容器中加入5体积%醋酸水溶液5ml和氧化钛粒子50mg,在悬浮的状态下以15mW/cm2的照度照射365nm的紫外光,用每1小时产生的二氧化碳量进行比较时,如图3所示,市售的以往产品的氧化钛粒子和本发明的氧化钛粒子,在光催化活性上有很大的差异。In order to calibrate the above-mentioned photocatalytic activity, acetic acid used as a substrate can be evaluated by quantifying the amount of carbon dioxide produced because it is decomposed into carbon dioxide by photocatalysis. As mentioned above, add 5 ml of 5 volume % acetic acid aqueous solution and 50 mg of titanium oxide particles in a closed container with an inner diameter of 15 mm, and irradiate 365 nm ultraviolet light with an illuminance of 15 mW/ cm2 in a suspended state, and use the amount of carbon dioxide produced per hour In comparison, as shown in FIG. 3 , there is a large difference in photocatalytic activity between commercially available conventional titanium oxide particles and the titanium oxide particles of the present invention.

在该实验条件下,由于紫外线照射面积一定,所以氧化钛粒子受到的激发光量是一定的,分解量取决于对分解对象物的吸附能。因此,对于以往的氧化钛粒子的特性,二氧化碳的产生量是与氧化钛粒子的比表面积成正比例。Under the experimental conditions, since the ultraviolet irradiation area is constant, the amount of excitation light received by the titanium oxide particles is constant, and the amount of decomposition depends on the adsorption energy of the object to be decomposed. Therefore, regarding the characteristics of conventional titanium oxide particles, the amount of carbon dioxide generated is proportional to the specific surface area of the titanium oxide particles.

以往的氧化钛粒子,在这次的实验条件下,X轴为比表面积、Y轴为二氧化碳产生量时,在y=0.8x的线上或者下方标绘出特性值。由该结果表明,对于以往的制法,只能制作位于该线下方的特性粒子。For the conventional titanium oxide particles, the characteristic values are plotted on or below the line y=0.8x when the X-axis represents the specific surface area and the Y-axis represents the amount of carbon dioxide generated under the experimental conditions of this time. From this result, it was revealed that only characteristic particles located below this line could be produced in the conventional production method.

可是,在相同图3中,对于以样品A~D表示的本发明的氧化钛粒子,得到位于远离该线的上方的光催化特性,在比表面积3~40m2/g的范围内,每1小时二氧化碳的产生量,对于样品A~C是40μmol或更多。However, in the same Fig. 3, for the titanium oxide particles of the present invention represented by samples A to D, the photocatalytic properties located above the line are obtained, and the specific surface area is in the range of 3 to 40 m 2 /g, per 1 The amount of carbon dioxide produced per hour was 40 µmol or more for samples A to C.

由此表明,本发明的氧化钛粒子具有高光催化活性及高醋酸分解活性,这不是由于以往的比表面积的大小所致的的吸附能的差引起的,而是其他理由,即由于高结晶性的理由引起的。This shows that the titanium oxide particles of the present invention have high photocatalytic activity and high acetic acid decomposition activity. This is not due to the difference in adsorption energy due to the size of the conventional specific surface area, but other reasons, namely, high crystallinity. caused by the reason.

另外,本发明的氧化钛粒子,根据需要也可掺杂其他的元素,例如磷、氮、硅、硼等的元素,进行光催化活性的调整或者光催化活性激发光波长向长波长侧偏移等的特性变更。例如,图3中,作为样品D表示的氧化钛粒子,添加作为掺杂物的硅,来降低氧化钛粒子的光催化活性。In addition, the titanium oxide particles of the present invention may also be doped with other elements as required, such as elements such as phosphorus, nitrogen, silicon, boron, etc., to adjust the photocatalytic activity or to shift the excitation light wavelength of the photocatalytic activity to the long wavelength side. etc. characteristic changes. For example, in FIG. 3 , as the titanium oxide particles shown in Sample D, silicon is added as a dopant to lower the photocatalytic activity of the titanium oxide particles.

(氧化钛粒子的制造)(production of titanium oxide particles)

以下,对于本发明的氧化钛粒子的制造方法及制造装置详细地进行说明。Hereinafter, the manufacturing method and manufacturing apparatus of the titanium oxide particle of this invention are demonstrated in detail.

本发明的箱型形状的多面体的氧化钛粒子的制造,基本上是通过向合成管内供给钛化合物蒸汽和氧,从合成管外部加热而进行的。The box-shaped polyhedral titanium oxide particles of the present invention are basically produced by supplying titanium compound vapor and oxygen into the synthesis tube and heating from the outside of the synthesis tube.

图4是表示本发明的氧化钛粒子的制造装置的一个例子,图中符号11表示合成管。该合成管11是由石英玻璃、氧化铝等的热、化学性质稳定的材料组成的、内径10~200mm的管状物。这些合成管内径若不足10mm,在合成管11内的原料物质的流速变快,反应效率低下;若超过200mm时,合成管11的径向的温度分布变大,氧化钛粒子的粒径分布变大。FIG. 4 shows an example of a production apparatus of titanium oxide particles of the present invention, and reference numeral 11 in the figure denotes a synthesis tube. The synthetic tube 11 is made of thermally and chemically stable materials such as quartz glass and alumina, and is a tube-shaped object with an inner diameter of 10-200 mm. If the internal diameter of these synthetic tubes is less than 10mm, the flow velocity of the raw material in the synthetic tube 11 becomes fast, and the reaction efficiency is low; big.

该合成管11被固定在其两端未被图示的玻璃转盘上,以20~70rpm左右的转速旋转。另外,在合成管11的下方,配置氢氧焰灯12,可从外部加热合成管11。该氢氧焰灯12,可以是1台或更多台,通常是将4~12台并列配置的,但优选的是将合成管11均匀加热,可使粒径分布变小。The synthetic tube 11 is fixed to a glass turntable not shown at both ends thereof, and rotates at a rotational speed of about 20 to 70 rpm. In addition, below the synthesis tube 11, an oxyhydrogen flame lamp 12 is arranged so that the synthesis tube 11 can be heated from the outside. The oxyhydrogen flame lamp 12 may be one or more, and usually 4 to 12 are arranged in parallel. However, it is preferable to uniformly heat the synthesis tube 11 to reduce the particle size distribution.

另外,在用该氢氧焰灯12加热中,优选的是控制火焰的大小、合成管11和氢氧焰灯12的间隔等,以使合成管11的外周的至少3分之1或更多与火焰接触而被加热,由此可进行均匀加热。In addition, in heating with the oxyhydrogen flame lamp 12, it is preferable to control the size of the flame, the interval between the synthetic tube 11 and the oxyhydrogen flame lamp 12, etc. so that at least 1/3 or more of the outer circumference of the synthetic tube 11 It is heated by contact with a flame, thereby enabling uniform heating.

另外,符号13表示鼓泡器,该鼓泡器13的内部充满四氯化钛、硫酸钛等的钛化合物液体,从管14供给的氩气等气体被吹入到钛化合物液中(鼓泡),使钛化合物液气化。此时的钛化合物液的温度,例如对于四氯化钛,从蒸汽压的大小来看,为60℃或更高。为了使得气化了的钛化合物蒸汽不液化,需要经过保温到鼓泡器13的温度或更高的温度,例如对于四氯化钛,经由保温到85℃或更高温度的配管15,从合成管11的一端被送入到其内部。In addition, reference numeral 13 represents a bubbler, and the inside of this bubbler 13 is filled with titanium compound liquids such as titanium tetrachloride and titanium sulfate, and gas such as argon gas supplied from a pipe 14 is blown into the titanium compound liquid (bubbling). ) to gasify the titanium compound liquid. The temperature of the titanium compound liquid at this time is, for example, 60° C. or higher in view of the vapor pressure of titanium tetrachloride. In order not to liquefy the gasified titanium compound vapor, it needs to be kept at the temperature of the bubbler 13 or higher. One end of the tube 11 is fed into its interior.

另外,在合成管11的一端通过管16送入来自未图示的氧瓶等的氧供给源的氧。In addition, oxygen from an oxygen supply source such as an oxygen bottle (not shown) is fed into one end of the synthesis tube 11 through a tube 16 .

在合成管11的另一端连接管17的一端,该管17的另一端连接袋滤器18,来自合成管11的排气被送入到袋滤器18。The other end of the synthesis pipe 11 is connected to one end of a pipe 17 , and the other end of the pipe 17 is connected to a bag filter 18 , and the exhaust gas from the synthesis pipe 11 is sent to the bag filter 18 .

该袋滤器18用于对在合成管11内被合成,随着排气气体流出的氧化钛粒子的一部分或全部进行捕集,可使用具有用空气、氮气等的压缩气体对于过滤器给予冲击而除掉堵孔的氧化钛粒子的机构和机械地击落堵孔物的机构的设备。The bag filter 18 is used to trap part or all of the titanium oxide particles that are synthesized in the synthesis pipe 11 and flow out with the exhaust gas. It is a device that removes the mechanism of titanium oxide particles that block pores and the mechanism that mechanically knocks down pores.

来自袋滤器18的排气通过未图示的排气装置排气到系统外。Exhaust from the bag filter 18 is exhausted to the outside of the system through an exhaust device (not shown).

使用该装置说明制造氧化钛粒子的方法。Using this apparatus, a method for producing titanium oxide particles will be described.

首先,将来自鼓泡器13的钛化合物蒸汽和来自氧供给源的氧导入到旋转的合成管11内,从外部用氢氧焰灯12加热,在合成管11内对四氯化钛等的钛化合物进行加热氧化,合成氧化钛粒子。First, the titanium compound vapor from the bubbler 13 and the oxygen from the oxygen supply source are introduced into the rotating synthetic tube 11, heated from the outside with the oxyhydrogen flame lamp 12, and the titanium tetrachloride and the like are treated in the synthetic tube 11. The titanium compound is heated and oxidized to synthesize titanium oxide particles.

该合成时的合成管11内的反应区域的合成温度控制在850~1500℃,若不足850℃,反应率降低;若在850℃或更高时,达到90%或更高的反应率。另外,超过1500℃时,生成的氧化钛粒子相互开始烧结,生成的氧化钛粒子的比表面积降低。During the synthesis, the synthesis temperature of the reaction zone in the synthesis tube 11 is controlled at 850-1500°C. If it is less than 850°C, the reaction rate will decrease; if it is at 850°C or higher, the reaction rate will reach 90% or higher. In addition, when the temperature exceeds 1500° C., the produced titanium oxide particles start to sinter with each other, and the specific surface area of the produced titanium oxide particles decreases.

另外,关于在合成管11内的钛化合物蒸汽和氧气的流速,流速越快,通过加热区域的时间即结晶成长时间越短,可得到粒径小的氧化钛粒子。可是,若流速过快,由于反应效率大幅度地降低,所以在工业上是不理想的。将四氯化钛作为原料,使用内径32mm、厚度2.5mm的石英玻璃制的合成管11,在将合成温度作成1230℃时,优选的流速是150~1500mm/分钟。In addition, regarding the flow velocity of the titanium compound vapor and oxygen in the synthesis tube 11, the faster the flow velocity, the shorter the time for passing through the heating zone, that is, the crystal growth time, and the titanium oxide particles with a smaller particle size can be obtained. However, if the flow rate is too high, since the reaction efficiency will be greatly reduced, it is unfavorable industrially. Titanium tetrachloride is used as a raw material, and a synthesis tube 11 made of quartz glass with an inner diameter of 32 mm and a thickness of 2.5 mm is used. When the synthesis temperature is 1230° C., the flow rate is preferably 150 to 1500 mm/min.

另外,作为用于合成的加热源使用氢氧焰灯12,该氢氧焰灯的产生热量高,与电加热器相比可局部地加热。因此,可容易地得到生成均匀核所必要的热能,另外,加上加热区域变窄,可控制氧化钛的结晶成长。另外,可以容易得到原子扩散移动所必要的高温,可合成结晶性高的氧化钛粒子。In addition, an oxyhydrogen flame lamp 12 is used as a heating source for the synthesis. The oxyhydrogen flame lamp has a high heat generation and can be locally heated compared with an electric heater. Therefore, the thermal energy necessary to generate uniform nuclei can be easily obtained, and in addition, the heating region can be narrowed, so that the crystal growth of titanium oxide can be controlled. In addition, the high temperature necessary for atomic diffusion and movement can be easily obtained, and titanium oxide particles with high crystallinity can be synthesized.

进而,供给到合成管11内的钛化合物蒸汽和氧的比率,是基于氧化反应的当量决定的,优选的是稍微过剩地供给氧以使氧化反应完全地进行。例如,在使用四氯化钛时,对于1摩尔四氯化钛,优选的是氧为1.05~1.2摩尔左右。Furthermore, the ratio of the titanium compound vapor and oxygen supplied into the synthesis tube 11 is determined based on the equivalent of the oxidation reaction, and it is preferable to supply oxygen in a slight excess so that the oxidation reaction proceeds completely. For example, when titanium tetrachloride is used, it is preferable that oxygen is about 1.05 to 1.2 mol with respect to 1 mol of titanium tetrachloride.

在合成管11内合成的氧化钛粒子随着排气的流动,移动到合成管11的下游侧,但由于不加热合成管11的下游侧,所以其温度低,为数10℃。因此,高温的氧化钛粒子急速地冷却,通过热迁移效果堆积在合成管11的下游部分的壁上。将合成部分的温度局部地加热到1000℃左右,由于下游部分是数10℃,所以热迁移效果有效地作用,可高效地堆积氧化钛粒子。The titanium oxide particles synthesized in the synthesis pipe 11 move to the downstream side of the synthesis pipe 11 along with the flow of the exhaust gas. However, since the downstream side of the synthesis pipe 11 is not heated, its temperature is as low as several 10°C. Therefore, the high-temperature titanium oxide particles are rapidly cooled and deposited on the wall of the downstream portion of the synthesis tube 11 due to the thermal migration effect. The temperature of the synthesis part is locally heated to about 1000°C, and since the temperature of the downstream part is several 10°C, the thermomigration effect works effectively, and titanium oxide particles can be deposited efficiently.

另外,若用水、氮气等气体冷却合成管11的下游部分,氧化钛粒子的堆积效率提高。进而,若将热传导系数大、热交换作用高的氦气供给到合成管11内,可更有效地进行下游部分的冷却、热迁移效果提高,由此堆积效率也提高。In addition, when the downstream portion of the synthesis tube 11 is cooled with water, nitrogen, or other gas, the deposition efficiency of titanium oxide particles is improved. Furthermore, if helium gas having a high heat transfer coefficient and a high heat exchange effect is supplied into the synthetic tube 11, the cooling of the downstream part can be performed more effectively, and the heat transfer effect can be improved, thereby improving the stacking efficiency.

另一方面,存在于排气中的残余氧化钛粒子,随着其流动,送入到袋滤器18中,在此进行回收。该回收时,由于合成的氧化钛粒子是极微细粒子,所以容易堵塞过滤器。因此,具有用上述空气、氮气等的压缩气体对过滤器给予冲击以除掉堵孔的氧化钛粒子的机构和机械地击落堵孔物的机构的设备,对于处理堵塞是适宜的。On the other hand, the residual titanium oxide particles present in the exhaust gas are sent to the bag filter 18 along with the flow, and recovered there. During this recovery, since the synthesized titanium oxide particles are extremely fine particles, the filter is easily clogged. Therefore, a device having a mechanism for impacting the filter with compressed gas such as air or nitrogen to remove blocked titanium oxide particles and a mechanism for mechanically knocking down the plugged objects is suitable for dealing with clogging.

在该合成反应时,通过调整原料浓度、反应温度等的反应条件可变化结晶多面体的各结晶面的结晶成长速度,由此可控制上述扁平率。另外,也可控制多面体的面数。另外,可制造由扁平率0.33~3.0、优选的是0.6~1.67的结晶多面体形成的、光催化剂作用极高的氧化钛粒子。During this synthesis reaction, the crystal growth rate of each crystal plane of the crystal polyhedron can be changed by adjusting the reaction conditions such as the concentration of the raw materials and the reaction temperature, thereby controlling the above-mentioned oblateness. In addition, the number of faces of the polyhedron can also be controlled. In addition, it is possible to produce titanium oxide particles formed of crystal polyhedrons with an oblateness of 0.33 to 3.0, preferably 0.6 to 1.67, and having a very high photocatalytic effect.

进而,通过将反应氛围作成氧化氛围,可将具有锐钛矿型结晶结构的氧化钛粒子控制为95%或更多,通过将反应氛围从氧化氛围适当地变化成还原氛围,可控制其锐钛矿型和金红石型的比率。Furthermore, by making the reaction atmosphere into an oxidizing atmosphere, the titanium oxide particles having an anatase crystal structure can be controlled to 95% or more, and by appropriately changing the reaction atmosphere from an oxidizing atmosphere to a reducing atmosphere, the amount of anatase can be controlled. The ratio of ore type and rutile type.

图5是表示本发明的氧化钛粒子制造装置的另一个例子,对于与图4所示的相同构成部分附加同一符号,省略其说明。FIG. 5 shows another example of the titanium oxide particle manufacturing apparatus of the present invention, and the same components as those shown in FIG. 4 are assigned the same reference numerals, and description thereof will be omitted.

该例的制造装置,是在被合成的氧化钛粒子中添加例如磷、氮、硅、硼等的掺杂物时使用的,增加了用来产生作为掺杂物的化合物蒸汽的另外的鼓泡器21,来自该鼓泡器21的作为掺杂物的化合物蒸汽经过管22与管15合流,然后被送入到合成管11内。The manufacturing apparatus of this example is used when dopants such as phosphorus, nitrogen, silicon, boron, etc. are added to the synthesized titanium oxide particles, and additional bubbling is added to generate the compound vapor as the dopant. From the bubbler 21, the vapor of the compound as a dopant passes through the pipe 22 to join the pipe 15, and then is sent into the synthesis pipe 11.

另外,为了供给成为掺杂物的化合物蒸汽,也可将管22直接与合成管11连接,直接供给到合成管11中。进而,作为加热源,不限于氢氧焰灯,可使用电加热器等局部进行加热,但从上述理由看更优选的是氢氧焰灯。In addition, in order to supply the compound vapor to be a dopant, the pipe 22 may be directly connected to the synthesis pipe 11 and directly supplied to the synthesis pipe 11 . Furthermore, the heating source is not limited to an oxyhydrogen flame lamp, and local heating may be performed using an electric heater or the like, but an oxyhydrogen flame lamp is more preferable from the above reasons.

另外,生成的氧化钛粒子的回收,可以仅是利用热迁移效果使其堆积在合成管的下游部分的方式,也可以是不堆积生成的氧化钛粒子而直接将其送入到袋滤器18中。另外,也可用将原料钛化合物加热气化的方法(烘烤)作成钛化合物蒸汽。In addition, the recovery of the generated titanium oxide particles may be made only by utilizing the effect of thermal migration to accumulate in the downstream part of the synthesis pipe, or it may be directly sent to the bag filter 18 without accumulating the generated titanium oxide particles. . In addition, a titanium compound vapor can also be produced by heating and vaporizing the raw material titanium compound (baking).

按照这样的氧化钛粒子的制造方法可高效地制造上述的箱型形状的多面体的氧化钛粒子。该制造方法是被分类为热氧化法的,但对于以往的在合成室内送入四氯化钛蒸汽和加热氧,在合成室内进行氧化反应的热氧化的方法,仅是生成球状的氧化钛粒子,且仅可得到粒径大的粒子。According to such a method for producing titanium oxide particles, the aforementioned box-shaped polyhedral titanium oxide particles can be efficiently produced. This production method is classified as a thermal oxidation method, but compared to the conventional thermal oxidation method in which titanium tetrachloride vapor and heated oxygen are fed into the synthesis chamber, and the oxidation reaction is carried out in the synthesis chamber, only spherical titanium oxide particles are produced. , and only particles with large particle sizes can be obtained.

与此相对,上述的制造方法,例如可得到平均粒径20nm、占全部粒子的85%的粒子的粒径是10nm~40nm的粒度分布。On the other hand, the above-mentioned production method can obtain, for example, a particle size distribution in which the average particle size is 20 nm and the particle size of 85% of all particles is 10 nm to 40 nm.

图6是表示本发明的氧化钛粒子的制造装置的另一个例子,在该例的制造装置中,除了在合成管11的内部的加热部位设置柱状部件31之外,其他与图4所示的制造装置相同。Fig. 6 shows another example of the manufacturing apparatus of the titanium oxide particle of the present invention, in the manufacturing apparatus of this example, except that columnar member 31 is set at the inner heating part of synthetic tube 11, other is the same as that shown in Fig. 4 The manufacturing apparatus is the same.

该柱状部件31是中空有底圆筒状或实心圆棒状的部件,是由与石英玻璃等形成合成管11的材料在热膨胀率方面接近或相同的材料构成的。如图所示,该柱状部件31离开合成管11的内壁,且与合成管11同轴地配置,与内壁面的间隙为0.1~10mm。该间隔不足0.1mm时,则生成的粒子堵塞该间隙,超过10mm时,增加了温度分布不均匀的区域,设置柱状部件31的意义就没有了。The columnar member 31 is a hollow bottomed cylindrical member or a solid round rod member, and is made of a material that has a thermal expansion coefficient close to or equal to that of the material forming the synthetic tube 11 such as quartz glass. As shown in the figure, the columnar member 31 is separated from the inner wall of the synthetic tube 11 and arranged coaxially with the synthetic tube 11 with a gap of 0.1 to 10 mm from the inner wall surface. If the gap is less than 0.1 mm, the generated particles will clog the gap, and if it exceeds 10 mm, an area with uneven temperature distribution will increase, and the meaning of installing the columnar member 31 will be lost.

另外,该例子的柱状部件31的支持是通过将柱状部件31连接在用于供给原料气体的配管15的顶端部而进行,用玻璃转盘32可旋转地支持配管15。来自配管15的原料气体,从形成在配管15的顶端的孔33送入到合成管11的内部。In this example, the columnar member 31 is supported by connecting the columnar member 31 to the tip of the pipe 15 for supplying the source gas, and the pipe 15 is rotatably supported by the glass turntable 32 . The raw material gas from the pipe 15 is sent into the inside of the synthesis pipe 11 through the hole 33 formed at the tip of the pipe 15 .

对于使用该例的制造装置制造氧化钛粒子的方法进行说明时,通过设置这样的柱状部件31,送入到合成管11内的原料被导入到合成管11的内壁侧,沿着其内壁流动。由于用氢氧焰灯12可将合成管11的内壁部分加热到最高温,原料气体在合成管11内的加热温度高的区域被加热,进行氧化反应。由此,生成的氧化钛粒子成为粒径整齐均匀的粒子。另外,可以得到更多的结晶性高的粒子,减少结晶形状的不均匀,由此可制造催化活性高的氧化钛粒子。用该制造装置,例如可得到平均粒径20nm、占全体粒子的85%的粒子的粒径在10nm~40nm的粒度分布。When describing the method of producing titanium oxide particles using the production apparatus of this example, by providing such a columnar member 31, the raw material fed into the synthesis tube 11 is introduced to the inner wall side of the synthesis tube 11 and flows along the inner wall. Since the inner wall of the synthesis tube 11 can be heated to the highest temperature by the oxyhydrogen flame lamp 12, the raw material gas is heated in the high heating temperature region of the synthesis tube 11 to carry out oxidation reaction. As a result, the produced titanium oxide particles have uniform particle diameters. In addition, more particles with high crystallinity can be obtained, and unevenness in crystal shape can be reduced, whereby titanium oxide particles with high catalytic activity can be produced. With this production apparatus, for example, a particle size distribution in which the average particle diameter is 20 nm and the particle diameters of 85% of the total particles are 10 nm to 40 nm can be obtained.

关于该制造方法的制造条件,原料气体的流速快时,通过加热区域所需要的时间要短,虽然生成粒径小的氧化钛粒子,但反应效率低下。因此,在合成管11的内径36mm、柱状部件31的外径20mm、合成温度1100℃时,优选的是将原料气体的流速控制150~1500mm/分钟左右。Regarding the production conditions of this production method, when the flow rate of the raw material gas is high, the time required to pass through the heating zone is short, and although titanium oxide particles with a small particle size are produced, the reaction efficiency is low. Therefore, when the inner diameter of the synthesis tube 11 is 36 mm, the outer diameter of the columnar member 31 is 20 mm, and the synthesis temperature is 1100° C., it is preferable to control the flow rate of the raw material gas to about 150 to 1500 mm/min.

(氧化钛粒子的应用)(Application of Titanium Oxide Particles)

以下,对于使用上述的氧化钛粒子的各种应用进行说明。Hereinafter, various applications using the above-mentioned titanium oxide particles will be described.

(光催化剂)(catalyst of light)

本发明的光催化剂包含上述的箱型形状的多面体的氧化钛粒子或该氧化钛粒子多个集合而成的氧化钛粉末,将该氧化钛粒子或粉末用适宜的方法涂覆、附着在基材上发挥光催化作用。例如,分散在有机溶剂等的分散剂作成膏状,将该膏涂覆在玻璃、陶瓷、金属、木材、塑料、涂膜等的基材上,加热后通过载持在基材上起到光催化剂的功能。另外,添加低熔点玻璃或各种聚合物等的粘合材料,将其涂覆在基材上,通过加热熔融粘合材料固定在基材上,也起到光催化剂功能。The photocatalyst of the present invention includes the above-mentioned box-shaped polyhedral titanium oxide particles or titanium oxide powder obtained by a plurality of aggregations of the titanium oxide particles, and the titanium oxide particles or powder are coated and adhered to the substrate by an appropriate method. play a photocatalytic role. For example, a dispersant dispersed in an organic solvent or the like is made into a paste, and the paste is coated on substrates such as glass, ceramics, metals, wood, plastics, coatings, etc. Catalyst function. In addition, adding a binder such as low-melting glass or various polymers, coating it on the base material, and then heating and melting the binder and fixing it on the base material can also function as a photocatalyst.

另外,本发明的光催化剂也可作成可见光应答型。例如,在用氩气稀释到规定的浓度的氨气氛围中,将本发明的氧化钛粒子加热规定时间,可作成可见光应答型光催化剂。可见光应答型光催化剂即使是400nm或更大的波长的可见光也发挥光催化活性,即使是来自室内等的荧光灯、电灯等的人工光源的可见光,也可充分利用其光催化活性。In addition, the photocatalyst of the present invention can also be made into a visible light responsive type. For example, the visible light responsive photocatalyst can be prepared by heating the titanium oxide particles of the present invention for a predetermined time in an ammonia gas atmosphere diluted with argon gas to a predetermined concentration. Visible light-responsive photocatalysts exhibit photocatalytic activity even with visible light with a wavelength of 400nm or more, and can fully utilize their photocatalytic activity even with visible light from indoor artificial light sources such as fluorescent lamps and electric lamps.

该光催化剂与以往的含有氧化钛粒子的光催化剂同样地可用于污染物的分解去除、恶臭物质的分解去除、杀菌、灭菌等或超疏水性被膜的形成、表面的防污等,其具体的使用方式与以往的含有氧化钛粒子的光催化剂相同。This photocatalyst can be used for the decomposition and removal of pollutants, the decomposition and removal of malodorous substances, sterilization, sterilization, etc. or the formation of superhydrophobic coatings, antifouling of surfaces, etc., like conventional photocatalysts containing titanium oxide particles. The method of use is the same as that of conventional photocatalysts containing titanium oxide particles.

(涂料)(coating)

本发明的涂料含有上述氧化钛粒子或氧化钛粉末以及用于构成涂膜的树脂成分作为必需成分。The coating material of the present invention contains the above-mentioned titanium oxide particles or titanium oxide powder and a resin component for constituting a coating film as essential components.

该光催化剂涂料的氧化钛粒子的配合量,相对于固形成分总量而言,为0.1~80质量%的范围、优选的是5~20质量%的范围。若氧化钛粒子的配合量比上述范围少,有可能不能充分得到该涂膜的光催化活性。另外,若氧化钛粒子的配合量超过上述范围,涂料的流动性变差,涂覆操作困难,另外,由于树脂成分变少,有可能得不到牢固的涂膜。The compounding quantity of the titanium oxide particle of this photocatalyst coating is the range of 0.1-80 mass % with respect to the solid content total amount, Preferably it is the range of 5-20 mass %. When the compounding quantity of titanium oxide particle is less than the said range, the photocatalytic activity of this coating film may not fully be acquired. In addition, if the compounding amount of titanium oxide particles exceeds the above-mentioned range, the fluidity of the coating material will deteriorate, making the coating work difficult, and since the resin component will decrease, a firm coating film may not be obtained.

配合在该涂料中的树脂成分,作为涂料只要可以形成优良的涂膜就没有特别限制,可以使用以往涂料领域内使用的树脂成分,例如可使用丙烯酸系树脂、醇酸树脂、聚氨酯系树脂等。另外,可使用这些树脂的树脂成分10~40质量%的水溶性乳化液。若使用水溶性乳化液,不需要配合溶剂,对于环境是有利的。The resin component blended in the paint is not particularly limited as long as the paint can form a good coating film. Resin components conventionally used in the paint field can be used, for example, acrylic resins, alkyd resins, polyurethane resins, etc. can be used. In addition, water-soluble emulsions containing 10 to 40% by mass of resin components of these resins can be used. If a water-soluble emulsion is used, no solvent is required, which is beneficial to the environment.

该树脂成分的配合量,相对于固形成分总量而言,为20~99.9质量%的范围、优选的是50~80质量%的范围。The compounding quantity of this resin component is the range of 20-99.9 mass % with respect to solid content total amount, Preferably it is the range of 50-80 mass %.

另外,作为配合在该涂料中的溶剂,可使用适合于溶解所用树脂成分的各种溶剂,例如,可使用水、乙醇、芳香族烃或环式烃等的烃系溶剂、丙酮等的酮类、醋酸乙酯等的酯类等。该溶剂的配合量,相对于光催化剂涂料中的总固形成分100质量份而言,为80~99.5质量份左右。In addition, as a solvent mixed in the paint, various solvents suitable for dissolving the resin components used can be used, for example, water, ethanol, hydrocarbon solvents such as aromatic hydrocarbons or cyclic hydrocarbons, and ketones such as acetone can be used. , Ethyl acetate and other esters. The compounding quantity of this solvent is about 80-99.5 mass parts with respect to 100 mass parts of total solid content in a photocatalyst paint.

在该涂料中,除了上述必须成分之外,在不损坏该涂料的物性、光催化活性的范围内,根据需要可添加颜料、分散稳定剂、紫外线吸收剂、抗氧化剂等的添加物。In addition to the above-mentioned essential components, additives such as pigments, dispersion stabilizers, ultraviolet absorbers, and antioxidants may be added to the paint as needed within the range not impairing the physical properties and photocatalytic activity of the paint.

对于该涂料,通过将其涂覆在金属板、瓷砖等的陶瓷板、玻璃、木材、混凝土等的各种基材上,通过干燥固化可形成具有光催化活性的涂膜。向该光催化剂涂料的基材涂覆的方法,根据基材的形状、材料、大小等可从以往公知的各种涂覆方法中适宜选择,例如,可使用浸渍涂覆、用刷子涂覆、喷涂、电泳涂漆、旋转涂层法、刮刀法等涂覆。This paint can form a photocatalytically active coating film by applying it to various substrates such as metal plates, ceramic plates such as tiles, glass, wood, concrete, etc., and drying and curing. The method of coating the substrate of the photocatalyst coating can be appropriately selected from conventionally known various coating methods according to the shape, material, size, etc. of the substrate, for example, dip coating, brush coating, Spray coating, electrophoretic coating, spin coating method, doctor blade method and other coatings.

对于该涂料,含有具有高的光催化活性的氧化钛粒子,所以通过将其涂覆在适当基材上,可形成具有比以往产品高的光催化活性的涂膜。This paint contains titanium oxide particles with high photocatalytic activity, so by coating it on an appropriate substrate, a coating film with higher photocatalytic activity than conventional products can be formed.

另外,在该涂料中,在氧化钛粒子的光催化活性高时,有时使树脂成分、溶剂等的添加材料本身分解。为此,有时优选使用通过添加硅等的元素而使光催化活性稍微降低的氧化钛粒子。In addition, in this paint, when the photocatalytic activity of the titanium oxide particles is high, additives such as resin components and solvents themselves may be decomposed. For this reason, it may be preferable to use titanium oxide particles whose photocatalytic activity is slightly lowered by adding elements such as silicon.

(光催化装置)(photocatalytic device)

本发明的光催化装置具有其表面有上述氧化钛粒子的光催化反应体,和向该光催化反应体上照射光的光源。The photocatalytic device of the present invention includes a photocatalytic reactant having the titanium oxide particles on its surface, and a light source for irradiating light onto the photocatalytic reactant.

对于光催化反应体的形状、结构没有特别限制,可以是粉体状或悬浮在水等的液体中的状态,但优选的是将含有上述的氧化钛粒子或粉末的涂料涂覆在适当的基材表面而得到的结构体。There are no special restrictions on the shape and structure of the photocatalytic reactant, and it can be in the form of powder or suspended in a liquid such as water, but it is preferable to coat the coating containing the above-mentioned titanium oxide particles or powder on a suitable substrate structure obtained from the surface of the material.

进而,该结构体可作成板状、管状、蜂窝状、粒子状等的各种形状,根据含有有害物的被处理物的性状、供给方法等适宜选择。上述板状、管状、蜂窝状等的结构体可通过在金属板或金属管、金属制蜂窝材的表面涂覆上述涂料进行制作。另外,粒子状的结构体可通过向玻璃珠、合成树脂珠、多孔质陶瓷等的适当的粒径的粒子上涂覆上述涂料进行制作。Furthermore, the structure can be made into various shapes such as plate shape, pipe shape, honeycomb shape, particle shape, etc., and can be appropriately selected according to the properties of the object to be treated containing harmful substances, the supply method, and the like. The plate-like, tubular, and honeycomb-like structures can be produced by coating the surface of a metal plate, metal tube, or metal honeycomb with the aforementioned paint. In addition, the particulate structure can be produced by coating the above-mentioned coating material on particles having an appropriate particle size such as glass beads, synthetic resin beads, and porous ceramics.

用于该光催化装置的光源,优选的是高压水银灯、氙灯、石墨等的人工光源。The light source used for this photocatalytic device is preferably an artificial light source such as a high-pressure mercury lamp, a xenon lamp, or graphite.

该光催化装置的结构可根据含有有害物的被处理物的性状或供给方法等适宜地变更。例如,被处理物是工业废水等的液体时,可在槽内加入板状、管状、蜂窝状、粒子状等的上述光催化反应体,进而在槽内配置光源或使用光纤维从槽外部的光源将光照射在槽内而构成,向槽内加入被处理液,通过光催化反应体分解有害物质。The structure of this photocatalyst can be changed suitably according to the property of the to-be-processed object containing a harmful substance, a supply method, etc. For example, when the object to be treated is a liquid such as industrial wastewater, the above-mentioned photocatalytic reactants in the form of a plate, a tube, a honeycomb, or a particle can be added to the tank, and then a light source is arranged in the tank or an optical fiber is used to transmit the light from the outside of the tank. The light source irradiates the light in the tank, and the liquid to be treated is added into the tank, and the harmful substances are decomposed by the photocatalytic reaction body.

另外,被处理物是排气气体等的气体时,也可在该被处理气体的流路中配置上述光催化反应体和光源,使被处理气体与光催化反应体接触而分解有害物,在配置了光源的槽内填充上述粒子状的光催化反应体,从槽下方吹出被处理气体,形成光催化反应体的流动床,处理被处理气体。In addition, when the object to be treated is gas such as exhaust gas, the above-mentioned photocatalyst reactant and light source can also be arranged in the flow path of the gas to be treated, so that the gas to be treated can be contacted with the photocatalyst reactant to decompose harmful substances. The tank in which the light source is arranged is filled with the particle-shaped photocatalyst reactant, and the gas to be treated is blown out from the bottom of the tank to form a fluidized bed of the photocatalyst reactant to treat the gas to be treated.

按照本发明的光催化装置,具有其表面有上述氧化钛粒子的光催化反应体,和向该光催化反应体上照射光的光源。通过这样的结构,可以高效率分解氮氧化物、污染物质、恶臭成分等的有害物。A photocatalytic device according to the present invention includes a photocatalyst reactant having the above-mentioned titanium oxide particles on its surface, and a light source for irradiating light onto the photocatalyst reactant. With such a structure, harmful substances such as nitrogen oxides, pollutants, and malodorous components can be efficiently decomposed.

(有害物质的分解方法)(Decomposition method of harmful substances)

使用本发明的氧化钛粉末的分解有害物质的方法中,所使用的氧化钛粉末是粒径100~500nm的氧化钛粒子集合而成的粉末,构成该粉末的全部粒子中90%或更多是由锐钛矿型结晶组成,而且氧化钛粒子由箱形形状的10面体等的多面体形成的。In the method for decomposing harmful substances using the titanium oxide powder of the present invention, the titanium oxide powder used is a powder composed of titanium oxide particles with a particle diameter of 100 to 500 nm, and 90% or more of all particles constituting the powder are It consists of anatase crystals, and the titanium oxide particles are formed of polyhedrons such as box-shaped decahedrons.

该方法是将该氧化钛粉末与溶解或分散了有害物质的水、空气等的流体直接接触,在其上照射紫外光等的光,分解流体中的有害物质后,用过滤器过滤流体,分离回收氧化钛粉末的方法。The method is to directly contact the titanium oxide powder with fluids such as water and air in which harmful substances are dissolved or dispersed, irradiate light such as ultraviolet light on it, decompose the harmful substances in the fluid, filter the fluid with a filter, and separate A method for recovering titanium oxide powder.

通常,显示高的光催化活性的氧化钛粒子是小的粒径。为此,将从数nm到数十nm的粒径的氧化钛粒子用于这样的用途。可是,若使用这样的粒径的粒子,分散到水等中时产生凝聚,形成约300nm左右的凝聚体。若将该大小的凝聚体进行过滤,可使用开孔0.1μm左右的过滤器,但对于这样细孔的过滤器会立即堵塞,不能实用。Generally, titanium oxide particles exhibiting high photocatalytic activity have a small particle diameter. For this reason, titanium oxide particles having a particle diameter of several nm to several tens of nm are used for such applications. However, when particles with such a particle diameter are used, aggregation occurs when dispersed in water or the like, and aggregates of about 300 nm are formed. To filter aggregates of this size, a filter with pores of about 0.1 μm can be used, but a filter with such fine pores will be clogged immediately, so it is not practical.

与此相对,在使用本发明中的氧化钛粒子时,尽管选择其粒径为100~500nm之大的进行使用,由于提高了原来的结晶性,显示出优良的催化活性,发挥高的分解能力。另外,凝聚后的凝聚体的大小是2~5μm,所以使用开孔1~2μm的过滤器,可急速过滤,且过滤器也难以堵塞,实用性高。In contrast, when using titanium oxide particles in the present invention, even if the particle size is selected to be as large as 100 to 500 nm, the original crystallinity is improved, excellent catalytic activity is exhibited, and high decomposition ability is exhibited. . In addition, since the size of aggregates after aggregation is 2 to 5 μm, rapid filtration is possible by using a filter with openings of 1 to 2 μm, and the filter is hardly clogged, which is highly practical.

图7是表示用于本发明的有害物质的分解方法的处理装置的例子,该例的装置是将有害物质溶解或分散在水中的液体作为处理对象的。Fig. 7 shows an example of a processing apparatus used in the method for decomposing hazardous substances of the present invention, and the apparatus of this example is a liquid in which hazardous substances are dissolved or dispersed in water as a processing object.

图中符号51是由不锈钢、塑料等组成的处理槽,在该槽51上连接着流入处理对象液的流入管52和流出分解处理后的液体的排出管53。在流入管52的顶端设置预过滤器54,以除去分散在流入液体的粗大的垃圾等,在排出管53的基端设置分离过滤器55,分散在处理对象液体的氧化钛粉末被过滤,分离回收。该分离过滤器55使用由玻璃纤维等制作的过滤器。Reference numeral 51 in the figure is a treatment tank made of stainless steel, plastic, etc., and an inflow pipe 52 for inflowing the liquid to be treated and a discharge pipe 53 for outflowing the decomposed liquid are connected to the tank 51 . A pre-filter 54 is provided at the top of the inflow pipe 52 to remove coarse garbage and the like dispersed in the inflowing liquid, and a separation filter 55 is provided at the base end of the discharge pipe 53 so that the titanium oxide powder dispersed in the liquid to be treated is filtered and separated. Recycle. As the separation filter 55, a filter made of glass fiber or the like is used.

另外,在处理槽51的上部形成收容紫外光灯用凹部56,该凹部56的壁由石英玻璃等的紫外光透过性玻璃构成,成为照射窗,来自收容到凹部56内的高压水银灯、氙灯、杀菌灯、紫外线灯等的紫外光光源57的紫外光从照射窗照射处理槽51内的处理对象液。通过该紫外光分散到处理对象液的氧化钛粒子发挥光催化剂作用,溶解或分散在处理对象液中的有害物质被分解,被无害化。In addition, a recess 56 for accommodating an ultraviolet lamp is formed on the upper portion of the processing tank 51. The wall of the recess 56 is made of ultraviolet light-transmitting glass such as quartz glass, and serves as an irradiation window. The liquid to be treated in the treatment tank 51 is irradiated with ultraviolet light from an ultraviolet light source 57 such as a germicidal lamp or an ultraviolet lamp through an irradiation window. The titanium oxide particles dispersed in the liquid to be treated by the ultraviolet light act as a photocatalyst, and harmful substances dissolved or dispersed in the liquid to be treated are decomposed and rendered harmless.

进而,在处理槽51中形成用于搅拌内部的处理对象液的螺旋桨轴58和磁性搅拌子59,磁性搅拌子59通过设置在处理槽51的底部的磁性搅拌器60而被旋转。Furthermore, a propeller shaft 58 for stirring the liquid to be treated inside and a magnetic stirrer 59 are formed in the treatment tank 51 , and the magnetic stirrer 59 is rotated by a magnetic stirrer 60 provided at the bottom of the treatment tank 51 .

另外,作为氧化钛粒子,使用通过太阳光等的可见光发挥活性的可见光型时,也可以用玻璃等材料构成处理槽51的全部或一部分。In addition, when a visible light type that is activated by visible light such as sunlight is used as titanium oxide particles, all or part of the treatment tank 51 may be made of a material such as glass.

对于使用该例子的处理装置的处理方法,处理对象液中的氧化钛粒子的分散浓度,相对于处理对象液而言是0.5~10重量%,不足0.5重量%时,不能充分分解,若超过10重量%时,均匀粒子的分散困难,氧化钛粒子夹带有害物质而沉降。For the processing method using the processing device of this example, the dispersion concentration of titanium oxide particles in the processing object liquid is 0.5 to 10% by weight relative to the processing object liquid. When it is less than 0.5% by weight, it cannot be fully decomposed. When the weight % is lower, the dispersion of uniform particles is difficult, and the titanium oxide particles entrain harmful substances and settle.

随着分解处理的进行,在分离过滤器55中捕获氧化钛粒子,处理对象液中的氧化钛粒子的分散浓度减少。此时,若进行周知的逆洗涤,可消除分离过滤器55的堵塞,而且处理对象液中的氧化钛粒子的分散浓度也复原。As the decomposition process proceeds, the titanium oxide particles are trapped in the separation filter 55, and the dispersion concentration of the titanium oxide particles in the treatment target liquid decreases. At this time, by performing well-known backwashing, the clogging of the separation filter 55 can be eliminated, and the dispersion concentration of the titanium oxide particles in the liquid to be treated can also be restored.

在这样的分解方法中,在处理对象液中,氧化钛粒子凝聚,成为2μm或更大的凝聚体,所以使用筛孔比较粗的、开孔1μm或更大的分离过滤器55,可有效地进行过滤,大大地提高过滤速度。例如,对于有效面积500cm2、开孔2μm的玻璃纤维制过滤器,可达到每1小时10升或更大的过滤速度。In such a decomposition method, in the treatment object liquid, the titanium oxide particles are aggregated and become aggregates of 2 μm or larger, so using a separation filter 55 with a relatively coarse mesh and an opening of 1 μm or larger can effectively Filtering, greatly improving the filtering speed. For example, a glass fiber filter having an effective area of 500 cm 2 and an opening of 2 μm can achieve a filtration rate of 10 liters or more per hour.

另外,在空气等的气体中溶解或分散有害物质时,将该气体导入到处理槽内,用设置在处理槽内的风扇搅拌气体的同时,强制地使氧化钛粉末浮游成为分散状态,在该状态下可采用照射紫外光等的方法。另外,也可以将上述的涂料涂覆在适当的基材表面作成涂膜的状态,使得溶解或分散有害物质的流体与该涂膜接触,进行光照的方法。In addition, when dissolving or dispersing harmful substances in a gas such as air, the gas is introduced into the treatment tank, and while the gas is stirred by a fan installed in the treatment tank, the titanium oxide powder is forcibly floated into a dispersed state. In this state, a method such as irradiating ultraviolet light can be used. In addition, it is also possible to apply the above-mentioned paint on the surface of a suitable substrate to form a coating film, and make the fluid that dissolves or disperses harmful substances come into contact with the coating film to expose to light.

用本发明的分解有害物质的方法分解的有害物质,可举出氮氧化物(NOx)、污染物质、恶臭成分。作为污染物质和恶臭成分,例如可举出乙醛等的醛类、丁醇等的醇类、醋酸等的羧酸类、酮类、氨或胺类等的含氮化合物、硫化氢或硫醇等的含硫化合物等。The harmful substances decomposed by the method of decomposing harmful substances of the present invention include nitrogen oxides (NO x ), pollutants, and malodorous components. Examples of pollutants and odor components include aldehydes such as acetaldehyde, alcohols such as butanol, carboxylic acids such as acetic acid, ketones, nitrogen-containing compounds such as ammonia and amines, hydrogen sulfide, and mercaptans. and other sulfur-containing compounds.

按照本发明的分解有害物的方法,通过对氧化钛粒子照射光的同时与有害物接触而分解该有害物,可高效地分解氮氧化物(NOx)、污染物质、恶臭成分等有害物。According to the method of decomposing harmful substances of the present invention, harmful substances such as nitrogen oxides (NO x ), pollutants, and malodorous components can be efficiently decomposed by irradiating titanium oxide particles with light and contacting harmful substances to decompose the harmful substances.

以下,用实施例明确地说明本发明的作用效果。Hereinafter, the effects of the present invention will be clearly described using examples.

比较例1Comparative example 1

以四氯化钛蒸汽作为原料,在合成室内与加热保温的氧混合,进行热氧化合成氧化钛粒子。四氯化钛蒸汽用鼓泡器供给,鼓泡温度是85℃。鼓泡气体使用氩气,其流量作成200sccm。反应氧流量是1000sccm,反应氧温度是1000℃。得到的氧化钛粒子的形状是球形。另外,其平均粒径是90nm,粒径分布是,占全体粒子的85%的粒子的粒径是20nm~200nm。Titanium tetrachloride vapor is used as a raw material, mixed with heated oxygen in the synthesis chamber, and then thermally oxidized to synthesize titanium oxide particles. Titanium tetrachloride vapor was supplied by a bubbler, and the bubbling temperature was 85°C. As the bubbling gas, argon gas was used, and the flow rate thereof was set to 200 sccm. The reaction oxygen flow rate is 1000 sccm, and the reaction oxygen temperature is 1000°C. The shape of the obtained titanium oxide particles was spherical. In addition, the average particle diameter is 90 nm, and the particle diameter distribution is such that the particle diameter of the particles accounting for 85% of the whole particles is 20 nm to 200 nm.

实施例1Example 1

使用石英玻璃制的合成管,热源是氢氧焰灯,在合成管内导入四氯化钛蒸汽和氧,通过从合成管外部加热的热氧化法制造氧化钛粒子。用鼓泡供给四氯化钛蒸汽,将鼓泡器温度作成85℃,配管保温温度作成140℃。对于鼓泡气体使用氩气,其流量作成180sccm。反应氧流量作成1000sccm,合成温度作成1230℃。配置6台氢氧焰灯。石英玻璃管的内径是32mm、厚度是2.5mm,将其用55rpm的转速旋转。A synthesis tube made of quartz glass is used, and the heat source is an oxyhydrogen flame lamp. Titanium tetrachloride vapor and oxygen are introduced into the synthesis tube, and titanium oxide particles are produced by a thermal oxidation method heated from the outside of the synthesis tube. Titanium tetrachloride vapor was supplied by bubbling, the temperature of the bubbler was set to 85°C, and the pipe insulation temperature was set to 140°C. Argon was used as the bubbling gas, and its flow rate was set to 180 sccm. The reaction oxygen flow rate was set at 1000 sccm, and the synthesis temperature was set at 1230°C. Equipped with 6 oxyhydrogen flame lamps. The inner diameter of the quartz glass tube was 32 mm and the thickness was 2.5 mm, and it was rotated at 55 rpm.

得到的氧化钛粒子的形状是如图1所示的10面体。其平均粒径是20nm,粒径分布是,占全体粒子的85%的粒子的粒径是10nm~40nm。另外,扁平率是0.33~3.0。The shape of the obtained titanium oxide particles was a decahedron as shown in FIG. 1 . The average particle diameter is 20 nm, and the particle diameter distribution is such that the particle diameter of the particles accounting for 85% of the whole particles is 10 nm to 40 nm. In addition, the flatness ratio is 0.33 to 3.0.

图8是显示在该制造条件下制造的氧化钛粒子的粒子形状的一例的用扫描型电子显微镜拍摄的显微镜照片。FIG. 8 is a micrograph taken with a scanning electron microscope showing an example of the particle shape of titanium oxide particles produced under the production conditions.

另外,在进行X线衍射测定,从峰强度求出锐钛矿型结晶结构的氧化钛粒子的比例(%),结果是95%。In addition, when the X-ray diffraction measurement was performed, the ratio (%) of the titanium oxide particles having the anatase crystal structure was determined from the peak intensity, and it was 95%.

接着,将该氧化钛粒子在氮气氛中、500℃下进行24小时热处理。对热处理后的氧化钛粒子进行X线衍射测定和电子显微镜观察。电子显微镜观察的结果是,粒子没有进行烧结,也没有看到粒子间的颈缩现象。另外,从X线衍射测定的结果可知,从峰强度可以推定锐钛矿型结晶构造的氧化钛粒子的比例(%)。锐钛矿型结晶构造的氧化钛粒子占粒子全体的比例与热处理前相比是没有变化的。Next, the titanium oxide particles were heat-treated at 500° C. for 24 hours in a nitrogen atmosphere. The heat-treated titanium oxide particles were subjected to X-ray diffraction measurement and electron microscope observation. As a result of electron microscope observation, the particles were not sintered, and no necking between particles was observed. In addition, from the results of X-ray diffraction measurement, it was found that the ratio (%) of titanium oxide particles having an anatase crystal structure can be estimated from the peak intensity. The ratio of the titanium oxide particles with the anatase crystal structure to the total particles remained unchanged from that before the heat treatment.

将该氧化钛粒子在氮气氛中、700℃下进行24小时热处理。对于热处理后的氧化钛粒子进行X线衍射测定和电子显微镜观察。电子显微镜观察的结果,粒子没有进行烧结,也没有看到粒子间的颈缩现象。The titanium oxide particles were heat-treated at 700° C. for 24 hours in a nitrogen atmosphere. The heat-treated titanium oxide particles were subjected to X-ray diffraction measurement and electron microscope observation. As a result of electron microscope observation, the particles were not sintered, and the necking phenomenon between the particles was not observed.

另外,从X线衍射测定的结果可知,从峰强度可以推定锐钛矿型结晶构造的氧化钛粒子的比例(%)。锐钛矿型结晶构造的氧化钛粒子占粒子全体的比例与热处理前相比有微小的减少,但是金红石转变率R(700-24)是5.0%。In addition, from the results of X-ray diffraction measurement, it was found that the ratio (%) of titanium oxide particles having an anatase crystal structure can be estimated from the peak intensity. The ratio of titanium oxide particles with an anatase crystal structure to the total particles was slightly decreased compared with that before heat treatment, but the rutile conversion ratio R(700-24) was 5.0%.

实施例2Example 2

将实施例1得到的氧化钛粒子涂覆在石英玻璃板上,进行用紫外线照射的光催化活性的评价。The titanium oxide particles obtained in Example 1 were coated on a quartz glass plate, and the photocatalytic activity was evaluated by ultraviolet irradiation.

评价是用相同条件下的乙醛的分解能力进行的,测定分解后产生的二氧化碳的浓度,并比较与构成氧化钛粒子的多面体的扁平率H的关系。在图9中表示具有各扁平率的氧化钛催化剂的二氧化碳浓度随时间的变化。其结果,多面体的扁平率为1.01及1.58的样品显示了最高的活性,扁平率为0.53及2.16的样品显示稍低的活性。The evaluation was performed using the ability to decompose acetaldehyde under the same conditions, and the concentration of carbon dioxide generated after decomposition was measured to compare the relationship with the oblateness H of the polyhedron constituting the titanium oxide particles. FIG. 9 shows changes with time in the carbon dioxide concentration of titanium oxide catalysts having various flatness ratios. As a result, the samples with the flatness ratios of the polyhedrons of 1.01 and 1.58 showed the highest activity, and the samples with the flatness ratios of 0.53 and 2.16 showed slightly lower activities.

比较例2Comparative example 2

将比较例1得到的氧化钛粒子涂覆在石英玻璃板上,涂覆大肠杆菌,向其照射不可见光,调查大肠杆菌数随时间的变化,结果是达到最初的大肠杆菌数的不多于1%的时间是60分钟。The titanium oxide particles obtained in Comparative Example 1 were coated on a quartz glass plate, coated with Escherichia coli, and irradiated with invisible light to investigate changes in the number of Escherichia coli over time. % time is 60 minutes.

实施例3Example 3

将实施例1得到的氧化钛粒子涂覆在石英玻璃板上,涂覆大肠杆菌,向其照射紫外线灯,调查大肠杆菌数随时间的变化,结果是达到最初的大肠杆菌数的不多于1%或更少的时间是30分钟。The titanium oxide particles obtained in Example 1 were coated on a quartz glass plate, coated with Escherichia coli, and irradiated with an ultraviolet lamp to investigate changes in the number of Escherichia coli over time. % or less of the time is 30 minutes.

实施例4Example 4

使用石英玻璃制的合成管,热源是使用氢氧焰灯,向合成管内导入四氯化钛蒸汽和氧,通过从合成管的外部加热的热氧化法制造氧化钛粒子。四氯化钛蒸汽是以鼓泡形式供给,鼓泡的温度是85℃,鼓泡气体是使用氩气,其流量是180sccm。A synthetic tube made of quartz glass was used, and the heat source was an oxyhydrogen flame lamp. Titanium tetrachloride vapor and oxygen were introduced into the synthetic tube, and titanium oxide particles were produced by a thermal oxidation method heated from the outside of the synthetic tube. Titanium tetrachloride vapor was supplied in the form of bubbling. The bubbling temperature was 85° C., and the bubbling gas was argon gas with a flow rate of 180 sccm.

反应氧流量是1000sccm,合成温度是1230℃。石英玻璃管是内径32mm、厚度是2.5mm,用55rpm的转速使其旋转。The reaction oxygen flow rate is 1000 sccm, and the synthesis temperature is 1230°C. The quartz glass tube has an inner diameter of 32 mm and a thickness of 2.5 mm, and is rotated at a rotation speed of 55 rpm.

对于合成的氧化钛粒子进行X线衍射测定和电子显微镜观察。电子显微镜观察的结果为,其粒子的形状是10面体,氧化钛粒子的平均粒径是60nm,粒径的分布是,占据全体粒子的85%的粒子的粒径是20~100nm。从X线衍射测定的结果可知,从峰强度可以推定锐钛矿型结晶构造的氧化钛粒子的比例(%)。其结果表示在表1。The synthesized titanium oxide particles were subjected to X-ray diffraction measurement and electron microscope observation. As a result of electron microscope observation, the shape of the particles was decahedral, the average particle size of the titanium oxide particles was 60 nm, and the particle size distribution was such that 85% of the total particles had a particle size of 20 to 100 nm. From the results of the X-ray diffraction measurement, it was found that the ratio (%) of the titanium oxide particles having the anatase crystal structure can be estimated from the peak intensity. The results are shown in Table 1.

接着将该氧化钛粒子在氮气氛中、500℃下进行24小时热处理。对于热处理后的氧化钛粒子进行X线衍射测定和电子显微镜观察。电子显微镜观察的结果为,粒子没有进行烧结,也没有看到粒子间的颈缩现象。另外,从X线衍射测定的结果可知,从峰强度可以推定锐钛矿型结晶构造的氧化钛粒子的比例(%)。结果表示在表1,锐钛矿型结晶构造的氧化钛粒子占粒子全体的比例与热处理前比较是没有变化的。Next, the titanium oxide particles were heat-treated at 500° C. for 24 hours in a nitrogen atmosphere. The heat-treated titanium oxide particles were subjected to X-ray diffraction measurement and electron microscope observation. As a result of electron microscope observation, the particles were not sintered, and the necking phenomenon between the particles was not observed. In addition, from the results of X-ray diffraction measurement, it was found that the ratio (%) of titanium oxide particles having an anatase crystal structure can be estimated from the peak intensity. The results are shown in Table 1. The ratio of the titanium oxide particles with the anatase crystal structure to the total particles did not change compared with that before the heat treatment.

另外,将该氧化钛粒子在氮气氛中、700℃下进行24小时热处理。对于热处理后的氧化钛粒子进行X线衍射测定和电子显微镜观察。电子显微镜观察的结果为,粒子没有进行烧结,也没有看到粒子间的颈缩现象。In addition, the titanium oxide particles were heat-treated at 700° C. for 24 hours in a nitrogen atmosphere. The heat-treated titanium oxide particles were subjected to X-ray diffraction measurement and electron microscope observation. As a result of electron microscope observation, the particles were not sintered, and the necking phenomenon between the particles was not observed.

另外,从X线衍射测定的结果可知,从峰强度可以推定锐钛矿型结晶构造的氧化钛粒子的比例(%)。结果表示在表1。锐钛矿型结晶构造的氧化钛粒子占粒子全体的比例与热处理前相比有微小的减少,但是金红石转变率R(700-24)是4.2%。In addition, from the results of X-ray diffraction measurement, it was found that the ratio (%) of titanium oxide particles having an anatase crystal structure can be estimated from the peak intensity. The results are shown in Table 1. The ratio of titanium oxide particles with an anatase crystal structure to the total particles was slightly decreased compared with that before heat treatment, but the rutile conversion ratio R(700-24) was 4.2%.

比较例3Comparative example 3

购入市售的光催化剂用氧化钛粒子进行比较。用于比较的氧化钛粒子是用热水解法合成的粒子,电子显微镜观察的结果为,粒子形状是球形的,其平均粒径是60nm,粒径分布是,占据全体粒子85%的粒子的粒径是20~100nm。从X线衍射测定的结果可知,从峰强度可以推定锐钛矿型结晶构造的氧化钛粒子的比例(%)。其结果表示在表1。Commercially available titanium oxide particles for photocatalysts were purchased for comparison. The titanium oxide particles used for comparison are particles synthesized by thermal hydrolysis. As a result of electron microscope observation, the particle shape is spherical, the average particle diameter is 60nm, and the particle size distribution is that of the particles accounting for 85% of the total particles. The diameter is 20 to 100 nm. From the results of the X-ray diffraction measurement, it was found that the ratio (%) of the titanium oxide particles having the anatase crystal structure can be estimated from the peak intensity. The results are shown in Table 1.

接着将该氧化钛粒子在氮气氛中、700℃下进行24小时热处理。对于热处理后的氧化钛粒子进行X线衍射测定和电子显微镜观察。电子显微镜观察的结果是,粒子进行着烧结,可看到粒子间的颈缩现象。Next, the titanium oxide particles were heat-treated at 700° C. for 24 hours in a nitrogen atmosphere. The heat-treated titanium oxide particles were subjected to X-ray diffraction measurement and electron microscope observation. As a result of electron microscope observation, the particles were sintered, and the phenomenon of necking between the particles was observed.

该加热后的粒子的电子显微镜照片表示在图10。An electron micrograph of the heated particles is shown in FIG. 10 .

从X线衍射测定的结果,从峰强度可以推定锐钛矿型结晶构造的氧化钛粒子的比例(%)。其结果表示在表1。锐钛矿型结晶构造的氧化钛粒子占全体粒子的比例与热处理前相比有大幅度地减少,但是金红石转变率R(700-24)是78.5%。From the results of the X-ray diffraction measurement, the ratio (%) of the titanium oxide particles having the anatase crystal structure can be estimated from the peak intensity. The results are shown in Table 1. The ratio of titanium oxide particles with an anatase crystal structure to the total particles was significantly reduced compared with that before heat treatment, but the rutile transformation ratio R(700-24) was 78.5%.

表1.Table 1.

  热处理前锐钛矿型的比例(%) Proportion of anatase type before heat treatment (%)   500℃、24小时热处理后的锐钛矿型的比例(%) The proportion of anatase type after heat treatment at 500℃ and 24 hours (%)   700℃、24小时热处理后的锐钛矿型的比例(%) The proportion of anatase type after 700℃, 24 hours heat treatment (%)   金红石转变率(%)R(500-24) Rutile conversion rate (%) R (500-24)   金红石转变率(%)R(700-24) Rutile conversion rate (%) R (700-24)  实施例4 Example 4   95.0 95.0   95.0 95.0   91.0 91.0   0.0 0.0   4.2 4.2  比较例3 Comparative example 3   70.0 70.0   - -   15.0 15.0   - -   78.5 78.5

实施例5Example 5

将实施例4制作的氧化钛粒子与低熔点玻璃及粘合剂、溶剂混合,得到氧化钛浆液。该氧化钛浆液均匀地涂覆在石英玻璃板上,在大气中700℃下加热2小时,进行烧结,制作载有氧化钛粒子的玻璃板。对该玻璃板利用紫外线照射而进行光催化活性的评价。评价是用乙醛的分解能力进行的,测定分解后产生的二氧化碳的浓度。The titanium oxide particles produced in Example 4 were mixed with low-melting glass, a binder, and a solvent to obtain a titanium oxide slurry. The titanium oxide slurry was uniformly coated on a quartz glass plate, heated at 700° C. for 2 hours in the air, and sintered to produce a glass plate carrying titanium oxide particles. The photocatalytic activity of this glass plate was evaluated by ultraviolet irradiation. The evaluation was performed using the ability to decompose acetaldehyde, and the concentration of carbon dioxide produced after the decomposition was measured.

为了比较,用比较例3的氧化钛粒子(市售品)制作载有同样的氧化钛粒子的玻璃板,进行同样的评价。图11中表示了二氧化碳浓度随时间的变化。另外,涂覆浆液后在烧结前(没有热处理)的状态下进行同样的实验,其结果也表示在图11。For comparison, a glass plate carrying the same titanium oxide particles was produced using the titanium oxide particles (commercially available) of Comparative Example 3, and the same evaluation was performed. Fig. 11 shows the change of carbon dioxide concentration with time. In addition, the same experiment was carried out in the state before sintering (without heat treatment) after coating the slurry, and the results are also shown in FIG. 11 .

其结果为,用于比较的市售的氧化钛粒子制作的玻璃板,在烧结的前后活性大大地下降,但是用实施例4的氧化钛粒子制作的玻璃板的特性没有变化,显示了高的乙醛分解能力。As a result, the glass plate made of commercially available titanium oxide particles used for comparison had a greatly reduced activity before and after sintering, but the properties of the glass plate made with the titanium oxide particles of Example 4 did not change, showing high Acetaldehyde decomposition ability.

实施例6Example 6

使用图4的氧化钛粒子制造装置,进行氧化钛粒子的制造。在玻璃转盘上设置外径40mm的石英玻璃制的反应合成管,以45rpm旋转。向该管内导入四氯化钛蒸汽50sccm和氧气1200sccm,从反应合成管的外部用氢氧焰灯加热到1300℃,在反应合成管内合成氧化钛粒子。合成了的氧化钛粒子用袋滤器回收。Titanium oxide particles were produced using the titanium oxide particle production apparatus shown in FIG. 4 . A reaction synthesis tube made of quartz glass with an outer diameter of 40 mm was installed on a glass turntable and rotated at 45 rpm. 50 sccm of titanium tetrachloride vapor and 1,200 sccm of oxygen were introduced into the tube, and heated to 1,300° C. with an oxyhydrogen flame lamp from the outside of the reaction synthesis tube to synthesize titanium oxide particles in the reaction synthesis tube. The synthesized titanium oxide particles were recovered with a bag filter.

回收了的氧化钛粒子是十面体,从X线衍射分析(XRD)峰鉴定的结果可知,粉末中的全体粒子的96%是锐钛矿型结晶,另外用BET法测定比表面积,结果是10.2m2/g。The recovered titanium oxide particle is a decahedron. From the results of X-ray diffraction analysis (XRD) peak identification, it can be seen that 96% of the whole particles in the powder are anatase crystals. In addition, the specific surface area is measured by the BET method, and the result is 10.2 m 2 /g.

将得到的氧化钛粒子50mg加入到内径15mm的密闭容器,使其悬浮在5体积%醋酸水溶液的5毫升中,在悬浮的状态下用15mW/cm2的照度照射365nm的紫外线光,用气相色谱法定量分析每小时产生的二氧化碳量时,结果是54μmol。Add 50 mg of the obtained titanium oxide particles to a closed container with an inner diameter of 15 mm, suspend them in 5 ml of 5 volume % acetic acid aqueous solution, and irradiate 365 nm ultraviolet light with an illumination intensity of 15 mW/cm 2 in the suspended state. When the amount of carbon dioxide produced per hour was quantitatively analyzed by the method, the result was 54 μmol.

实施例7Example 7

在玻璃旋盘上设置外径40mm的石英玻璃制的反应合成管,以45rpm旋转。向该管内导入四氯化钛蒸汽20sccm和氧气1200sccm,从反应合成管的外部用氢氧焰灯加热到1300℃,在反应合成管内合成氧化钛粒子。合成了的氧化钛粒子用袋滤器回收。A reaction synthesis tube made of quartz glass with an outer diameter of 40 mm was installed on a glass turntable and rotated at 45 rpm. 20 sccm of titanium tetrachloride vapor and 1,200 sccm of oxygen were introduced into the tube, and heated to 1,300° C. with an oxyhydrogen flame lamp from the outside of the reaction synthesis tube to synthesize titanium oxide particles in the reaction synthesis tube. The synthesized titanium oxide particles were recovered with a bag filter.

回收了的氧化钛粒子是十面体,从X线衍射分析(XRD)峰鉴定的结果可知,粉末中的全体粒子的96%是锐钛矿型结晶,另外用BET法测定比表面积,结果是32.4m2/g。The recovered titanium oxide particle is a decahedron. From the results of X-ray diffraction analysis (XRD) peak identification, it can be seen that 96% of the whole particles in the powder are anatase crystals. In addition, the specific surface area is measured by the BET method, and the result is 32.4 m 2 /g.

将得到的氧化钛粒子50mg加入到内径15mm的密闭容器,使其悬浮在5体积%醋酸水溶液的5毫升中,在悬浮的状态下用15mW/cm2的照度照射365nm的紫外光,用气相色谱法定量分析每小时产生的二氧化碳量,结果是52μmol。Add 50 mg of the obtained titanium oxide particles to a closed container with an inner diameter of 15 mm, suspend it in 5 ml of 5 volume % acetic acid aqueous solution, irradiate 365 nm ultraviolet light with an illumination intensity of 15 mW/cm 2 in the suspended state, and use gas chromatography The amount of carbon dioxide produced per hour was quantitatively analyzed by the method, and the result was 52 μmol.

实施例8Example 8

在玻璃旋盘上设置外径40mm的石英玻璃制的反应合成管,以45rpm旋转。向该管内导入四氯化钛蒸汽30sccm和氧气1200sccm,从反应合成管的外部用氢氧焰灯加热到1300℃,在反应合成管内合成氧化钛粒子。合成了的氧化钛粒子用袋滤器回收。A reaction synthesis tube made of quartz glass with an outer diameter of 40 mm was installed on a glass turntable and rotated at 45 rpm. 30 sccm of titanium tetrachloride vapor and 1200 sccm of oxygen were introduced into the tube, and the reaction synthesis tube was heated to 1300° C. with an oxyhydrogen flame lamp from the outside of the reaction synthesis tube to synthesize titanium oxide particles in the reaction synthesis tube. The synthesized titanium oxide particles were recovered with a bag filter.

回收了的氧化钛粒子是十面体,从X线衍射分析(XRD)峰鉴定的结果可知,粉末中的全体粒子的96%是锐钛矿型结晶,另外用BET法测定比表面积,结果是21.8m2/g。The recovered titanium oxide particle is a decahedron. From the results of X-ray diffraction analysis (XRD) peak identification, it can be seen that 96% of the whole particles in the powder are anatase crystals. In addition, the specific surface area was measured by the BET method, and the result was 21.8 m 2 /g.

将得到的氧化钛粒子50mg加入到内径15mm的密闭容器,使其悬浮在5体积%醋酸水溶液的5毫升中,在悬浮的状态下用15mW/cm2的照度照射365nm的紫外光,用气相色谱法定量分析每小时产生的二氧化碳量,结果是51μmol。Add 50 mg of the obtained titanium oxide particles to a closed container with an inner diameter of 15 mm, suspend it in 5 ml of 5 volume % acetic acid aqueous solution, irradiate 365 nm ultraviolet light with an illumination intensity of 15 mW/cm 2 in the suspended state, and use gas chromatography The amount of carbon dioxide produced per hour was quantitatively analyzed by the method, and the result was 51 μmol.

实施例9Example 9

在玻璃旋盘上设置外径40mm的石英玻璃制的反应合成管,以45rpm旋转。向该管内导入四氯化钛蒸汽40sccm和四氯化硅蒸汽2sccm和氧1200sccm,从反应合成管的外部用氢氧焰灯加热到1300℃,在反应合成管内合成氧化钛粒子。合成的氧化钛粒子用袋滤器回收。A reaction synthesis tube made of quartz glass with an outer diameter of 40 mm was installed on a glass turntable and rotated at 45 rpm. 40 sccm of titanium tetrachloride vapor, 2 sccm of silicon tetrachloride vapor, and 1200 sccm of oxygen were introduced into the tube, and heated to 1300° C. with an oxyhydrogen flame lamp from the outside of the reaction synthesis tube to synthesize titanium oxide particles in the reaction synthesis tube. The synthesized titanium oxide particles were recovered with a bag filter.

回收的氧化钛粒子是十面体,从X线衍射分析(XRD)峰鉴定的结果可知,粉末中的全体粒子的96%是锐钛矿型结晶,另外用BET法测定比表面积,结果是30.1m2/g。The recovered titanium oxide particles are decahedrons. From the results of X-ray diffraction analysis (XRD) peak identification, it can be seen that 96% of the total particles in the powder are anatase crystals. In addition, the specific surface area was measured by the BET method, and the result was 30.1m 2 /g.

将得到的氧化钛粒子50mg加入到内径15mm的密闭容器,使其悬浮在5体积%醋酸水溶液5毫升中,在悬浮的状态下用15mW/cm2的照度照射365nm的紫外光,用气相色谱法定量分析每小时产生的二氧化碳量,结果是36μmol。在原料中添加硅可以有意地控制氧化钛粒子的分解能力。以往产品和本发明产品的比较Add 50 mg of the obtained titanium oxide particles to a closed container with an inner diameter of 15 mm, suspend it in 5 ml of 5 volume % acetic acid aqueous solution, irradiate 365 nm ultraviolet light with an illumination intensity of 15 mW/cm 2 in the suspended state, and use gas chromatography Quantitative analysis of the amount of carbon dioxide produced per hour was 36 μmol. Adding silicon to the raw material can intentionally control the decomposition ability of titanium oxide particles. Comparison of Conventional Products and Products of the Invention

购入市售的氧化钛粒子4种(以下,称为市售粉A~D),分别进行XRD。从XRD峰的鉴定结果可知,4种都是锐钛矿型结晶占95%或更多的氧化钛粉末。用BET测定这些粒子的比表面积。Four types of commercially available titanium oxide particles (hereinafter, referred to as commercially available powders A to D) were purchased, and XRD was performed on each of them. From the identification results of XRD peaks, it can be seen that all four types are titanium oxide powders in which anatase crystals account for 95% or more. The specific surface area of these particles was measured by BET.

将这些的氧化钛粒子50mg分别加入到内径15mm的密闭容器,使其悬浮在5体积%醋酸水溶液5毫升中,在悬浮的状态下用15mW/cm2的照度照射365nm的紫外光,用气相色谱法定量分析每小时产生的二氧化碳量。以得到的二氧化碳量作为y轴,比表面积作为x轴,得到图3所示的结果。50 mg of these titanium oxide particles were added to airtight containers with an inner diameter of 15 mm, suspended in 5 ml of 5 volume % acetic acid aqueous solution, and irradiated with 365 nm ultraviolet light at an illuminance of 15 mW/cm 2 in the suspended state, and analyzed by gas chromatography. Quantitative analysis of the amount of carbon dioxide produced per hour. Taking the amount of carbon dioxide obtained as the y-axis and the specific surface area as the x-axis, the results shown in FIG. 3 were obtained.

将在上述实施例6~9中制作的、测定过比表面积和光催化活性的氧化钛粒子分别作为样品A~D,一起标绘在图3中。The titanium oxide particles produced in Examples 6 to 9 above and whose specific surface area and photocatalytic activity were measured are respectively referred to as samples A to D, and are plotted together in FIG. 3 .

从图3的结果可以看出,作为以往产品的市售粉A~D,在将X轴取为比表面积,Y轴取为二氧化碳产生量时,特性值是标绘在y=0.8x的线上或者下方。从该结果可以明显地看出,用以往的技术时,只能够制作位于该线下方的特性粒子。From the results in Fig. 3, it can be seen that commercially available powders A to D, which are conventional products, have characteristic values plotted on the line y=0.8x when the X-axis is taken as the specific surface area and the Y-axis is taken as the amount of carbon dioxide produced. up or down. From this result, it is clear that only characteristic particles located below this line can be produced with the conventional technology.

另一方面,作为样品A~D所表示的本发明的氧化钛粒子,可以得到远远在该线上方的光催化特性,比表面积在10~40m2/g的范围,每小时的二氧化碳的产生量,对于样品A~C是40μmol或更多。On the other hand, as the titanium oxide particles of the present invention represented by samples A to D, photocatalytic properties far above the line can be obtained, the specific surface area is in the range of 10 to 40 m 2 /g, and the generation of carbon dioxide per hour The amount was 40 μmol or more for samples A to C.

另外,在图3中,作为样品D所表示的氧化钛粒子,通过添加作为掺杂物的硅,可以使得氧化钛粒子的光催化活性下降。In addition, in FIG. 3 , as the titanium oxide particles represented by sample D, by adding silicon as a dopant, the photocatalytic activity of the titanium oxide particles can be reduced.

实施例10Example 10

使用图6的制造装置,制造氧化钛粒子。使用石英玻璃制的合成管,以氢氧焰灯作为热源,向合成管中导入四氯化钛蒸汽和氧,利用从合成管外部加热的热氧化法制造氧化钛粒子。四氯化钛蒸汽是以鼓泡方式供给,鼓泡温度是85℃,配管保温温度是140℃。鼓泡气体使用氩气,其流量是200sccm。反应氧流量是1000sccm,合成温度是1100℃。石英玻璃管外径为40mm、厚度是2mm,柱状部件的外径是20mm,石英玻璃管和柱状部件的间隙是8mm。以55rpm的转速使其旋转。Titanium oxide particles were produced using the production apparatus shown in FIG. 6 . Using a synthetic tube made of quartz glass, using an oxyhydrogen flame lamp as a heat source, titanium tetrachloride vapor and oxygen are introduced into the synthetic tube, and titanium oxide particles are produced by a thermal oxidation method heated from the outside of the synthetic tube. Titanium tetrachloride vapor is supplied by bubbling, the bubbling temperature is 85°C, and the pipe insulation temperature is 140°C. Argon was used as the bubbling gas, and its flow rate was 200 sccm. The reaction oxygen flow rate is 1000 sccm, and the synthesis temperature is 1100°C. The outer diameter of the quartz glass tube is 40 mm, the thickness is 2 mm, the outer diameter of the columnar member is 20 mm, and the gap between the quartz glass tube and the columnar member is 8 mm. Spin it at 55 rpm.

得到的氧化钛粒子的形状是如图1所示的10面体。其平均粒径是20nm,粒径分布是,占据粒子全体的85%的粒子的粒径是10nm~40nm。另外扁平率是0.33~3.0。The shape of the obtained titanium oxide particles was a decahedron as shown in FIG. 1 . The average particle size is 20 nm, and the particle size distribution is such that the particle size of the particles occupying 85% of the whole particles is 10 nm to 40 nm. In addition, the flattening ratio is 0.33 to 3.0.

另外,进行X线衍射测定从峰强度求出锐钛矿型结晶构造的氧化钛粒子的比例(%),结果是95%。In addition, the ratio (%) of titanium oxide particles having an anatase crystal structure was determined from the peak intensity by X-ray diffraction measurement, and it was 95%.

实施例11Example 11

改变实施例1中的制造条件,制造粒径200~350nm、具有十面体形状、粒子全体的97%是锐钛矿型结晶的氧化钛粉末。The production conditions in Example 1 were changed to produce a titanium oxide powder having a particle size of 200 to 350 nm, a decahedral shape, and 97% of the entire particle size being anatase crystals.

在石英玻璃制的处理槽内加入10μmol/L的亚甲蓝水溶液1.5升,向其中投入上述氧化钛粉末15g,搅拌水溶液。向该处理槽由紫外线灯照射波长365nm的紫外光。处理槽的紫外线受光面积是300cm2,用2.5mW/cm2的照度进行照射。1.5 liters of a 10 μmol/L methylene blue aqueous solution was placed in a treatment tank made of quartz glass, 15 g of the above-mentioned titanium oxide powder was put thereinto, and the aqueous solution was stirred. Ultraviolet light having a wavelength of 365 nm was irradiated to the treatment tank from an ultraviolet lamp. The ultraviolet light receiving area of the treatment tank was 300 cm 2 , and it was irradiated with an illuminance of 2.5 mW/cm 2 .

30分钟后,使用面积500cm2、开孔2.0μm的玻璃纤维筛孔制的圆筒型过滤器,用自重过滤,可在25分钟内全量过滤。用水逆洗涤过滤后的过滤器,干燥洗涤液,可以回收13.5g相当于投入氧化钛粉末的90%。After 30 minutes, use a cylindrical filter made of glass fiber mesh with an area of 500 cm 2 and an opening of 2.0 μm to filter by its own weight, and the entire amount can be filtered within 25 minutes. The filtered filter is backwashed with water, and the washing solution is dried to recover 13.5 g equivalent to 90% of the input titanium oxide powder.

用分光光度计定量过滤水溶液中的亚甲蓝的浓度,其结果是0.8μmol/L,用肉眼观察是无色透明的。The concentration of methylene blue in the filtered aqueous solution was quantified with a spectrophotometer, and the result was 0.8 μmol/L, and it was colorless and transparent when observed with the naked eye.

比较例4Comparative example 4

准备市售的氧化钛粉末。该粉末是粒径10~40nm、球形的形状,粒子的全体的90%是锐钛矿型结晶。Commercially available titanium oxide powder was prepared. This powder has a particle diameter of 10 to 40 nm and a spherical shape, and 90% of the whole particles are anatase crystals.

使用该市售氧化钛粉末,与实施例11相同的条件下,进行亚甲蓝水溶液的分解。Using this commercially available titanium oxide powder, under the same conditions as in Example 11, an aqueous solution of methylene blue was decomposed.

但是,处理后的过滤是使用面积500cm2、开孔0.1μm的玻璃纤维筛孔制的圆筒型过滤器进行的。通过120分钟的自重过滤,只有20ml通过过滤。一旦停止过滤进行逆洗涤后,再次试验过滤时,则过滤孔被氧化钛粒子堵塞,过滤速度没有得到改善。However, the filtration after the treatment was performed using a cylindrical filter made of glass fiber mesh with an area of 500 cm 2 and an opening of 0.1 μm. After 120 minutes of gravity filtration, only 20ml passed through the filter. Once the filtration was stopped and backwashing was performed, when the filtration was tested again, the filter pores were clogged with titanium oxide particles, and the filtration rate was not improved.

用分光光度计定量过滤水溶液中的亚甲蓝的浓度,其结果是0.8μmol/L,用肉眼观察是无色透明的。The concentration of methylene blue in the filtered aqueous solution was quantified with a spectrophotometer, and the result was 0.8 μmol/L, and it was colorless and transparent when observed with the naked eye.

比较例5Comparative Example 5

准备载有氧化钛粒子的市售的玻璃珠状的光催化剂。用电子显微镜观察该光催化剂,可以判明其珠径是1mm,珠的表面附着有粒径10~40nm的氧化钛粒子。另外,用X线衍射分析观察氧化钛粒子的结晶形状,由于玻璃珠的影响峰是很广的,但是观察到锐钛矿型和金红石型的峰是同等的强度。A commercially available glass bead photocatalyst carrying titanium oxide particles was prepared. When this photocatalyst was observed with an electron microscope, it was found that the bead diameter was 1 mm, and titanium oxide particles with a particle diameter of 10 to 40 nm adhered to the surface of the bead. In addition, when the crystal shape of titanium oxide particles was observed by X-ray diffraction analysis, the peaks were broad due to the influence of glass beads, but the anatase and rutile peaks were observed to have the same intensity.

使用该光催化剂150g,在与实施例11相同的条件下,进行亚甲蓝水溶液的分解处理。Using 150 g of this photocatalyst, the decomposition treatment of the methylene blue aqueous solution was performed under the same conditions as in Example 11.

30分钟后,使用面积500cm2、开孔2.0μm的玻璃纤维筛孔制的圆筒型过滤器进行自重过滤,结果是15分钟内全量通过过滤。用水逆洗涤过滤后的过滤器,干燥洗涤液,投入的光催化剂的几乎全量可以回收,但是可以看到从玻璃珠脱落的氧化钛粒子,再次使用时,可以预想到分解处理能力的下降。After 30 minutes, self-weight filtration was performed using a cylindrical filter made of glass fiber mesh with an area of 500 cm 2 and an opening of 2.0 μm. As a result, the entire amount passed through the filter within 15 minutes. After backwashing the filtered filter with water and drying the washing solution, almost all of the input photocatalyst can be recovered, but titanium oxide particles falling off from the glass beads can be seen, and when reused, it is expected that the degradation of the decomposition capacity will be reduced.

用分光光度计定量过滤水溶液中的亚甲蓝的浓度,其结果是4.6μmol/L,用肉眼观察是蓝色透明的。The concentration of methylene blue in the filtered aqueous solution was quantified with a spectrophotometer, and the result was 4.6 μmol/L, which was blue and transparent when observed with the naked eye.

实施例12Example 12

制作石英玻璃制的处理槽,其容量是1.5升,上部设置带搅拌叶的轴,内部可搅拌,用泵可以流入和排出一定量的水溶液。在处理槽上设置流入管和排出管,流入管安装预过滤器,排出管上安装面积500cm2、开孔2.0μm的玻璃纤维筛孔制的圆筒状分离过滤器。A treatment tank made of quartz glass is made, with a capacity of 1.5 liters. A shaft with stirring blades is installed on the upper part, and the inside can be stirred, and a certain amount of aqueous solution can be flowed in and discharged by a pump. An inflow pipe and a discharge pipe were installed on the treatment tank. A pre-filter was installed on the inflow pipe, and a cylindrical separation filter made of glass fiber mesh with an area of 500 cm 2 and an opening of 2.0 μm was installed on the discharge pipe.

处理槽内充满水,进而投入与实施例11使用的氧化钛粉末相同的粉末15g,从流入管以0.5升/小时的流量流入浓度10μmol/L的亚甲蓝水溶液。The treatment tank was filled with water, and 15 g of the same powder as the titanium oxide powder used in Example 11 was added, and an aqueous solution of methylene blue with a concentration of 10 μmol/L flowed in from the inflow pipe at a flow rate of 0.5 liter/hour.

充分时间流入的亚甲蓝水溶液,在从排出管排出的水溶液的亚甲蓝浓度与流入的亚甲蓝水溶液的浓度相同的时刻,开始对处理槽照射来自紫外线灯的365nm的紫外光。处理槽的紫外线受光面积是300cm2,用2.5mW/cm2的照度进行照射。进行中为了防止分离过滤器的堵塞,每45分钟停止泵,将泵逆方向运转后,以0.5升/小时的流量进行5分钟的逆洗涤。The methylene blue aqueous solution flowing in for a sufficient time starts to irradiate the treatment tank with 365nm ultraviolet light from the ultraviolet lamp when the methylene blue concentration of the aqueous solution discharged from the discharge pipe is the same as the concentration of the methylene blue aqueous solution flowing in. The ultraviolet light receiving area of the treatment tank was 300 cm 2 , and it was irradiated with an illuminance of 2.5 mW/cm 2 . In order to prevent clogging of the separation filter, the pump is stopped every 45 minutes, and after the pump is operated in the reverse direction, reverse washing is performed at a flow rate of 0.5 liters/hour for 5 minutes.

每间隔一定的时间从排出管采取排出的水溶液,测定亚甲蓝浓度,结果是,在照射1小时后其浓度成为稳定状态,为3.6μmol/L。The aqueous solution discharged from the discharge pipe was collected at regular intervals, and the concentration of methylene blue was measured. As a result, the concentration became stable at 3.6 μmol/L after 1 hour of irradiation.

产业上的利用领域Industrial field of use

本发明的氧化钛粒子可以作为光催化剂,使用于对有害物质的分解、脱臭、杀菌等用途。The titanium oxide particle of the present invention can be used as a photocatalyst for decomposition of harmful substances, deodorization, sterilization, and the like.

Claims (31)

1.一种氧化钛粒子,其粒径为1nm~500nm,由1个或更多个单晶多面体所构成的箱型形状的多面体或基本上是箱型形状的多面体形成,上述基本上是箱型形状的多面体包括多面体的角稍有缺失的形状的多面体、带有圆形的形状的多面体及具有凹凸等而使得形状稍微变化的多面体;所述多面体是6面体~10面体中的任何1种;金红石转变率R(700-24)是7.5%或更低,金红石转变率R(500-24)是2.0%或更低。1. A titanium oxide particle having a particle diameter of 1 nm to 500 nm, formed of a box-shaped polyhedron or substantially a box-shaped polyhedron composed of one or more single crystal polyhedrons, the above-mentioned is basically a box-shaped polyhedron. The polyhedron of the type shape includes a polyhedron of a shape in which corners of the polyhedron are slightly missing, a polyhedron of a shape with a circle, and a polyhedron of a shape slightly changed by concavities and convexities; the polyhedron is any one of hexahedrons to decahedrons ; The rutile conversion rate R(700-24) is 7.5% or less, and the rutile conversion rate R(500-24) is 2.0% or less. 2.权利要求1所述的氧化钛粒子,其单晶多面体的扁平率是0.33~3.0。2. The titanium oxide particle according to claim 1, wherein the flatness of the single crystal polyhedron is 0.33 to 3.0. 3.权利要求1所述的氧化钛粒子,其粒径是100~500nm。3. The titanium oxide particle according to claim 1, which has a particle diameter of 100 to 500 nm. 4.权利要求1所述的氧化钛粒子,其粒径是10~50nm。4. The titanium oxide particle according to claim 1, which has a particle diameter of 10 to 50 nm. 5.权利要求1所述的氧化钛粒子,其中,比表面积是3~40m2/g,在内径15mm的密闭容器中加入5体积%醋酸水溶液5毫升和氧化钛粒子50mg,使其在悬浮的状态下以15mW/cm2的照度照射365nm的紫外光,每1小时产生的二氧化碳量位于用y=0.8x表示的线的上方的区域,其中,x是比表面积,单位为m2/g;y是二氧化碳产生量,单位为μmol/hr。5. The titanium oxide particles according to claim 1, wherein the specific surface area is 3 to 40 m 2 /g, and 5 ml of 5 volume % acetic acid aqueous solution and 50 mg of titanium oxide particles are added to a closed container with an inner diameter of 15 mm to make it suspended in the airtight container. When irradiated with 365nm ultraviolet light at an illuminance of 15mW/cm 2 under normal conditions, the amount of carbon dioxide produced per hour is located in the area above the line represented by y=0.8x, where x is the specific surface area, and the unit is m 2 /g; y is the amount of carbon dioxide produced in μmol/hr. 6.权利要求1所述的氧化钛粒子,其中,掺杂有硅,比表面积是3~40m2/g,在内径15mm的密闭容器中加入5体积%醋酸水溶液5毫升和氧化钛粒子50mg,在悬浮的状态下以15mW/cm2的照度照射365nm的紫外光,每1小时产生的二氧化碳量位于用y=0.8x表示的线的上方的区域,其中,x是比表面积,单位为m2/g;y是二氧化碳产生量,单位为μmol/hr。6. The titanium oxide particle according to claim 1, wherein it is doped with silicon and has a specific surface area of 3 to 40 m 2 /g, and 5 ml of 5 vol% acetic acid aqueous solution and 50 mg of titanium oxide particles are added to a closed container with an inner diameter of 15 mm, Irradiate 365nm ultraviolet light with an illuminance of 15mW/ cm2 in a suspended state, and the amount of carbon dioxide produced per hour is located in the area above the line represented by y=0.8x, where x is the specific surface area, and the unit is m2 /g; y is the amount of carbon dioxide produced in μmol/hr. 7.权利要求5所述的氧化钛粒子,其中掺杂磷、氮、硅、硼中任一元素。7. The titanium oxide particle according to claim 5, wherein any element of phosphorus, nitrogen, silicon, and boron is doped. 8.一种氧化钛粉末,是权利要求1所述的氧化钛粒子多个集合而成的氧化钛粉末,构成该粉末的氧化钛粒子全体的80%或更多是锐钛矿型结晶。8. A titanium oxide powder obtained by aggregating a plurality of titanium oxide particles according to claim 1, wherein 80% or more of the total titanium oxide particles constituting the powder are anatase crystals. 9.权利要求8所述的氧化钛粉末,其中锐钛矿型结晶占据90%或更多。9. The titanium oxide powder according to claim 8, wherein the anatase type crystals occupy 90% or more. 10.一种制造权利要求1所述的氧化钛粒子的方法,其特征是,向合成管内供给钛化合物蒸汽和氧,从合成管外部加热。10. A method for producing titanium oxide particles according to claim 1, wherein titanium compound vapor and oxygen are supplied into the synthesis tube and heated from the outside of the synthesis tube. 11.权利要求10所述的氧化钛粒子的制造方法,其特征是,使用氢氧焰灯作为加热源。11. The method for producing titanium oxide particles according to claim 10, wherein an oxyhydrogen flame lamp is used as a heating source. 12.权利要求10所述的氧化钛粒子的制造方法,其特征是,旋转合成管。12. The method for producing titanium oxide particles according to claim 10, wherein the synthesis tube is rotated. 13.权利要求10所述的氧化钛粒子的制造方法,其特征是,在合成管内部设置将钛化合物蒸汽和氧的混合气体导入到合成管的内壁侧的柱状部件,从外部加热。13. The method for producing titanium oxide particles according to claim 10, wherein a columnar member for introducing a mixed gas of titanium compound vapor and oxygen to the inner wall side of the synthesis tube is provided inside the synthesis tube and heated from the outside. 14.权利要求13所述的氧化钛粒子的制造方法,其特征是,将合成管和柱状部件的间隔作成0.1~10mm。14. The method for producing titanium oxide particles according to claim 13, wherein the distance between the synthetic tube and the columnar member is 0.1 to 10 mm. 15.权利要求10所述的氧化钛粒子的制造方法,其特征是,生成的氧化钛粒子的回收方法是利用热迁移效果,在合成管的下游部分堆积氧化钛粒子而回收的。15. The method for producing titanium oxide particles according to claim 10, characterized in that the produced titanium oxide particles are recovered by accumulating the titanium oxide particles in the downstream part of the synthetic tube by utilizing the thermal migration effect. 16.权利要求10所述的氧化钛粒子的制造方法,其特征是,生成的氧化钛粒子的回收方法是使用设置在合成管的下游侧的袋滤器的方法。16. The method for producing titanium oxide particles according to claim 10, wherein the recovery method of the generated titanium oxide particles is a method using a bag filter installed on the downstream side of the synthesis pipe. 17.权利要求10所述的氧化钛粒子的制造方法,其特征是,合成时的合成管的温度在850~1500℃。17. The method for producing titanium oxide particles according to claim 10, wherein the temperature of the synthesis tube during synthesis is 850 to 1500°C. 18.一种制造权利要求1所述的氧化钛粒子的装置,其中,具有合成管、从其外部加热该合成管的加热源、使合成管绕其轴旋转的旋转驱动部以及向合成管中供给钛化合物蒸汽和氧的原料供给部。18. An apparatus for producing the titanium oxide particles according to claim 1, comprising a synthesis tube, a heating source for heating the synthesis tube from the outside, a rotary drive unit for rotating the synthesis tube around its axis, and Raw material supply part for supplying titanium compound vapor and oxygen. 19.权利要求18所述的氧化钛粒子的制造装置,其中,具有对在合成管内生成的氧化钛粒子进行回收的袋滤器。19. The apparatus for producing titanium oxide particles according to claim 18, comprising a bag filter for recovering the titanium oxide particles produced in the synthesis tube. 20.权利要求18或19所述的氧化钛粒子的制造装置,其中在合成管内部设置将钛化合物蒸汽和氧的混合气体导入到合成管的内壁侧的柱状部件。20. The apparatus for producing titanium oxide particles according to claim 18 or 19, wherein a columnar member for introducing a mixed gas of titanium compound vapor and oxygen to the inner wall side of the synthesis tube is provided inside the synthesis tube. 21.一种光催化剂,其中,含有权利要求1所述的氧化钛粒子。21. A photocatalyst comprising the titanium oxide particles according to claim 1. 22.一种光催化剂,其中,含有权利要求8所述的氧化钛粉末。22. A photocatalyst containing the titanium oxide powder according to claim 8. 23.一种涂料,其中,含有权利要求1所述的氧化钛粒子。23. A paint containing the titanium oxide particles according to claim 1. 24.一种涂料,其中,含有权利要求8所述的氧化钛粉末。24. A paint containing the titanium oxide powder according to claim 8. 25.一种光催化装置,其中,具有将权利要求1所述的氧化钛粒子载持在表面的光催化反应体和向该光催化反应体上照射光的光源。25. A photocatalytic device comprising a photocatalytic reactant having the titanium oxide particles according to claim 1 carried on its surface, and a light source for irradiating light onto the photocatalytic reactant. 26.一种分解有害物质的方法,其中,使用权利要求8所述的氧化钛粉末。26. A method for decomposing harmful substances, wherein the titanium oxide powder according to claim 8 is used. 27.权利要求26所述的分解有害物质的方法,其中,使氧化钛粒子与被处理对象物接触进行分解后,用过滤器分离氧化钛粒子。27. The method for decomposing harmful substances according to claim 26, wherein after the titanium oxide particles are brought into contact with the object to be processed to decompose, the titanium oxide particles are separated by a filter. 28.权利要求27所述的有害物质的分解方法,其中,过滤器是玻璃纤维制的,开孔为2.0μm或更大。28. The method for decomposing harmful substances according to claim 27, wherein the filter is made of glass fiber and has openings of 2.0 [mu]m or more. 29.一种脱臭方法,其中,使用权利要求21所述的光催化剂。29. A deodorization method using the photocatalyst according to claim 21. 30.一种杀菌方法,其中,使用权利要求21所述的光催化剂。30. A sterilizing method using the photocatalyst according to claim 21. 31.一种分解有害物质的方法,其中,使用权利要求21所述的光催化剂。31. A method for decomposing harmful substances, wherein the photocatalyst according to claim 21 is used.
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