JP3945664B2 - Method for producing water-repellent silicon oxide film - Google Patents

Description

表１より、本実施例のいずれの皮膜においても、その表面では、撥水性に寄与するＦ／ＳｉおよびＦ／Ｃ値が減少していること、親水性の増加に寄与するＯ／Ｆ値が増加していること、並びに皮膜の無機化を示すＣ／Ｓｉ値が減少していることがそれぞれ確認された。この測定結果からも明らかなように、本実施例で得られた皮膜の表面は、実施例５の皮膜の表面よりも親水化していることがわかる。これは、成膜途中で反応容器内に導入するガスを酸素からＦＡＳ−１７／Ａｒに切り替える際、プラズマ雰囲気中に残存する酸素がＦＡＳ−１７の分解および皮膜中への極性基（水素基等）の生成を促進したためと考えられる。それゆえ、本実施例の皮膜の接触角が低下したものと考えられる。
【００８３】
次に、７０℃の基板温度で得られた皮膜と、３００℃の基板温度で得られた皮膜とについて、それぞれ皮膜の深さ方向の化学組成を分析した。それらの分析結果をそれぞれ図１１および図１２に示す。図１１および図１２において、図中の記号△は炭素、○はシリコン、●は酸素、□はフッ素を示す。なお、皮膜の深さ方向の化学組成変化はＸＰＳのＡｒイオンエッチング（２．０ｋＶ、３０ｍＡ）により測定した。この測定では、エッチング深さはエッチング時間に比例して大きくなる。
【００８４】
図１１から明らかなように、７０℃の基板温度で得られた皮膜では、エッチング時間が約１２０分を越えたあたりから、フッ素および炭素濃度の著しい減少が観察され、反対に、シリコンおよび酸素濃度の増加が確認された。一方、図１２から明らかなように、３００℃の基板温度で得られた皮膜では、エッチング時間が約３０分を越えたあたりから、同様の傾向が観察された。
【００８５】
以上の化学組成の分析結果から、７０℃の基板温度で得られた皮膜の方が３００℃の基板温度で得られたものよりも撥水層の厚さが大きいことがわかる。即ち、１００℃以下の基板温度で得られた皮膜の方が２００℃以上の基板温度で得られたものよりも撥水層の厚さが大きい。このように選択する基板温度によって、その撥水層の質および厚さが異なってき、ひいては皮膜の撥水性および硬度が異なってくる。
【００８６】
最後に、本実施例で得られた皮膜の可視光透過率について測定した。その測定の結果、いずれの皮膜においても、可視光領域での透過率が９０％以上で、未処理のガラス基板と変わらないことがわかった。図１３に、２００℃の基板温度で得られた皮膜の可視光透過率の測定結果を一例として示した。なお測定にあたっては、リファレンスに空気を使用した。
【００８７】
以上の評価により、本実施例の硬質撥水性酸化シリコン皮膜は、撥水性に優れかつ硬度が大きく、さらに可視光の透過率も大きいことが明らかとなった。
（比較例１）
傾斜層３００および撥水層を形成しない以外は、実施例９と同様にして４種類の皮膜を形成した。
【００８８】
これらの皮膜はいずれも膜中にＳｉ−Ｏ−Ｓｉの結合をもち、そのシリコンおよび酸素濃度がそれぞれ、３０ａｔ．％および６０ａｔ．％であることがわかった。さらに、これらの硬質酸化シリコン皮膜は、いずれもホウ珪酸ガラスに匹敵する硬さをもつことがわかった。さらに緻密な皮膜であることも確認された。
（実施例１０）
ＴＭＳの代わりにヘキサメチルジシラン（以下、ＨＭＤＳと称する）を用いる他は、実施例９と同様にして４種類の硬質撥水性酸化シリコン皮膜を作製した。
【００８９】
また、これらの硬質撥水性酸化シリコン皮膜では、いずれも実施例９で同じ基板温度条件で得られたものとほぼ同じ接触角および硬度をそれぞれもつことがわかった。しかし、実施例９での撥水層の成膜速度は、約１０〜２５ｎｍ／ｍｉｎであったのに対し、本実施例のものでは約７０〜１００ｎｍ／ｍｉｎと非常に大きかった。
（実施例１１）
ＦＡＳ−１７ガスのキャリアガスとしてＡｒガスの代わりにＨ₂ガスを使用して、このＦＡＳ−１７ガス中に水素ガスを含ませる他は、実施例９と同様にして４種類の硬質撥水性酸化シリコン皮膜を作製した。
【００９０】
これらの撥水性酸化シリコン皮膜では、いずれも実施例９で同じ基板温度条件で得られたものよりも高い撥水性をそれぞれもつことがわかった。特に、基板温度２００℃以上では単独の撥水膜と同様の接触角が得られた。また、ＸＰＳ測定の結果、いずれの撥水層の酸素含有量も、実施例９でそれぞれで得られたものと比べて大幅に低下していることが確認された。
（実施例１２）
ＴＭＳの代わりにＨＭＤＳを用いる他は、実施例１１と同様にして４種類の硬質撥水性酸化シリコン皮膜を作製した。
【００９１】
これらの硬質撥水性酸化シリコン皮膜について、それぞれの接触角を測定した。その測定結果を図１４に示す。比較のために、実施例７および実施例１０で得られたものの測定結果についても図１４に併せて示した。
図１４より、本実施例のいずれの皮膜も優れた撥水性をもち、特に実施例１０の同じ基板温度の条件で得られた皮膜よりも高い撥水性をそれぞれもつことがわかった。この結果より、キャリアガスにＨ₂ガスを用いたほうが、アルゴンガスを用いるよりも高い撥水性が得られることがわかる。
【００９２】
ただし、２００℃以下の基板温度で得られた皮膜は、実施例７の同じ基板温度の条件で得られた皮膜よりもそれぞれ撥水性でやや劣ることがわかった。しかしながら、硬度についてはここでは図示しないが、いずれも実施例７の同じ基板温度条件で得られた皮膜よりも高いことがわかった。
【００９３】
【発明の効果】
上記撥水性酸化シリコン皮膜は、撥水性、耐摩耗性および耐擦傷性に優れるため、これらのような性能に劣る製品等に用いることにより、これらの製品の撥水性、耐摩耗性および耐擦傷性を向上させることができる。
また、上記撥水性酸化シリコン皮膜は、撥水性の持久性および耐候性に優れるため、摩耗頻度が大きい環境下や雪や氷の付着の著しい環境下などで使用される製品等に用いることにより、これらの製品の撥水性の持久性および耐候性を向上させることができる。
【００９４】
本発明の撥水性酸化シリコン皮膜の製造方法により、撥水性および耐摩耗性に優れる撥水性酸化シリコン皮膜を、容易に、低温でかつ母材と密着性良く形成することができるため、製造コスト等を低減することができ、また、耐熱温度の低い製品においても、品質を低下させることなく、撥水性、耐摩耗性および耐擦傷性に優れた撥水性酸化シリコン皮膜を製造することができる。
【００９５】
具体的には、３００℃以下の低温で硬質な撥水性酸化シリコン皮膜が作製できるため、耐熱性、耐摩耗性の低い材料の表面硬質、高機能化に有効な方法である。特に、１００℃以下の低温でこうした皮膜を作製できることから、プラスチックのような材料に適用できる。
また、フッ素が皮膜中に均一に分散した形態の撥水性酸化シリコン皮膜を、容易に、低温でかつ密着性良く形成することができるため、撥水性の持久性および耐候性に優れた撥水性酸化シリコン皮膜を、低コストで、かつ耐熱温度の低い製品においても、品質を低下させることなく製造することができる。
【００９６】
また、任意のフッ素含有量の撥水性酸化シリコン皮膜を、容易に、低温でかつ密着性良く形成することができるため、撥水性に優れた撥水性酸化シリコン皮膜を、低コストで、かつ耐熱温度の低い製品においても、品質を低下させることなく製造することができる。
さらに、母材上に有機塗料等を用いて描かれた文字、絵画等の上に、透光性に優れた撥水性酸化シリコン皮膜を低温で形成できるため、文字、絵画の変色、劣化等を生じさせることなく、撥水性酸化シリコン皮膜を形成できる。
【００９７】
上記硬質撥水性酸化シリコン皮膜は、撥水性および耐摩耗性に極めて優れ、かつ機械的強度にも優れるため、撥水性、耐摩耗性の低い材料に用いることによってその性能を改善することができる。
【図面の簡単な説明】
【図１】この図は、本実施例で使用した皮膜形成装置を示す概略図である。
【図２】この図は、実施例１で得られた撥水性酸化シリコン皮膜の水滴との静的接触角を示すグラフである。
【図３】この図は、実施例２で得られた撥水性酸化シリコン皮膜について、赤外線吸収分析法（ＩＲ）により赤外線の透過率を測定した結果を示す図である。
【図４】この図は、実施例２で得られた４種類の撥水性酸化シリコン皮膜の水滴との静的接触角を示すグラフである。
【図５】この図は、実施例３で得られた４種類の撥水性酸化シリコン皮膜の水滴との静的接触角を示すグラフである。
【図６】この図は、実施例４で得られた４種類の撥水性酸化シリコン皮膜の水滴との静的接触角を示すグラフである。
【図７】この図は、実施例５で得られた４種類の撥水性酸化シリコン皮膜の水滴との静的接触角を示すグラフである。
【図８】この図は、実施例９の撥水性酸化シリコン皮膜の作製過程を模式的に示した図である。
【図９】この図は、実施例５および実施例９で得られた撥水性酸化シリコン皮膜の水滴との静的接触角をそれぞれ示すグラフである。
【図１０】この図は、実施例９および比較例１で得られた撥水性酸化シリコン皮膜の硬度をそれぞれ示すグラフである。
【図１１】この図は、実施例９で得られた撥水性酸化シリコン皮膜のひとつの深さ方向の組成変化を示す図である。
【図１２】この図は、実施例９で得られた撥水性酸化シリコン皮膜のひとつの深さ方向の組成変化を示す図である。
【図１３】この図は、実施例９で得られた撥水性酸化シリコン皮膜について、それらの可視光透過率の一例を示すグラフである。
【図１４】この図は、実施例７、実施例１０および実施例１２で得られた撥水性酸化シリコン皮膜、もしくは硬質撥水性酸化シリコン皮膜の水滴との静的接触角をそれぞれ示すグラフである。
【符号の説明】
１：皮膜形成装置 ２：反応容器 ４：基板 ６：堆積容器 ８：マイクロ波電源 １０：ロータリーポンプ １２：シリコン化合物供給源 １４：フッ素化合物供給源 １６：開口端部分 １８：天井部分 ２０：基板ホルダー ２２：導波管 ２４：キャビティー ２６：スタブチューナー ２７：プランジャー ２８：低温プラズマ ２９：アルゴンガス供給源 ３０：ニードルバルブ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water-repellent silicon oxide film having water repellency, abrasion resistance and scratch resistance, a method for producing the water-repellent silicon oxide film, and a hard water-repellent silicon oxide film.
[0002]
[Prior art]
Conventionally, water-repellent treatment by surface modification such as forming a water-repellent film for the purpose of repelling water on the surface of glass products, resin products, metal products, semiconductor products, wood products, fibers, building materials, etc. Has been made.
Such water-repellent films include Teflon and surface science Vol. 14, no. 9, fluorine-containing SiO disclosed in pp 540-545, 1993₂Thin films are known.
[0003]
Teflon has a water droplet static contact angle of 108 ° and is excellent in water repellency, but has a problem of poor wear resistance. Meanwhile, the fluorine-containing SiO₂The thin film is formed by a sol-gel method using a coating solution prepared by mixing tetraethoxysilane and fluoroalkylsilane in a liquid state, and a glass substrate, containing silicon oxide as a main component and containing fluorine. Therefore, it is known as a material that is excellent in abrasion resistance because it contains silicon oxide as a main component and that has excellent water repellency because it contains fluorine.
[0004]
However, the formation of a water-repellent silicon oxide film using this sol-gel method requires a solvent such as ethanol during the preparation of the coating solution, and uses tetraethoxysilane and fluoroalkylsilane in a liquid state. If it is high, it is difficult to adjust the concentration of the coating solution. Furthermore, since a high-temperature heat treatment at 350 ° C. or higher is required after the coating solution is applied to the surface, a product having a low heat-resistant temperature has a problem that the quality is deteriorated by the high-temperature heat treatment. Also, with this method, fluorine concentrates near the surface of the film as the solvent evaporates during drying and curing, so that a water-repellent silicon oxide film in a form in which fluorine is uniformly dispersed in the film can be obtained. It was difficult. This water-repellent silicon oxide film in a form in which fluorine is concentrated in the vicinity of the surface has a problem that the water repellency is lowered if the fluorine-concentrated portion is scraped off due to abrasion or the like.
[0005]
[Problems to be solved by the invention]
[0006]
  The present invention has been made in view of the above circumstances,Provided is a method for easily producing a water-repellent silicon oxide film having excellent water repellency, abrasion resistance and scratch resistance without requiring preparation of a coating solution and high-temperature heat treatment, at low temperature and with good adhesion to a base material. Aimed at.
[0007]
[Means for Solving the Problems]
The present inventor uses a silicon compound gas containing a silicon compound and a fluorine compound gas containing a fluorine compound, and decomposes the silicon compound and the fluorine compound in a gas phase to thereby produce a silicon-containing decomposition reaction product and a fluorine-containing decomposition reaction product. A silicon-containing decomposition reaction product and a fluorine-containing decomposition reaction product were produced in such a manner that at least one of them contained oxygen and at least one of them contained carbon. And it discovered that the water-repellent silicon oxide film formed by depositing these silicon-containing decomposition products and fluorine-containing decomposition reaction products on the base material was excellent in water repellency, abrasion resistance and scratch resistance, and The present inventors have found that a water-repellent silicon oxide film having such properties can be easily formed at a low temperature and with good adhesion to a base material, and the present invention has been achieved.
[0009]
  That is,In the method for producing a water-repellent silicon oxide film of the present invention, at least one of a silicon compound and a fluorine compound contains oxygen, and at least one of the silicon compound and the fluorine compound uses a compound containing carbon. Containing silicon compoundContainsGas,Along with carrier gas including hydrogen gasFluorine compound containing the fluorine compoundContainsA raw material gas preparation step in which each gas is a raw material gas, and a silicon-containing decomposition reaction product obtained by decomposing the silicon compound and the fluorine compound contained in the raw material gas in a gas phase. At least one of the fluorine-containing decomposition reaction product contains oxygen, and at least one of the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product contains carbon, the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction. The silicon-containing decomposition reaction product generation step for generating a product, and the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product generated in the decomposition reaction product generation step are deposited on a base material. Silicon oxide bonded to the oxygen contained in at least one of the decomposition reaction product and the fluorine-containing decomposition reaction product, and the fluorine-containing decomposition reaction of the silicon And wherein the film forming step of forming a film containing a said fluorine and said carbon bound to the carbon contained in at least one, of the fluorine-containing decomposition reaction, in that it consists of.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
  Water-repellent silicon oxide film of the present inventionAn embodiment of the manufacturing method of the present invention, together with a water-repellent silicon oxide film and a hard water-repellent silicon oxide film,Each will be described below.
(Water repellent silicon oxide film)
  RepellentThe aqueous silicon oxide film is composed of a silicon-containing decomposition reaction product produced by decomposing a silicon compound in the gas phase and a fluorine-containing decomposition reaction product produced by decomposing the fluorine compound in the gas phase. It is a film. A silicon compound and a fluorine compound are compounds in which at least one of these compounds contains oxygen, and at least one of these compounds contains carbon. Silicon is contained in the form of silicon oxide bonded to oxygen contained in at least one of these decomposition products, and fluorine is contained in the form bonded to carbon contained in at least one of these decomposition products.
[0012]
The silicon compound used at this time is not particularly limited in its kind, but is preferably an organic silicon compound. Organosilicon compounds are preferred because they are often in a gaseous state at room temperature and are easily decomposed in the gas phase. Organic silicon is preferable because it contains not only silicon but also carbon, which can be used for bonding with fluorine.
[0013]
The organosilicon compound used at this time is preferably an organoalkoxysilane. Organoalkoxysilane is easy to evaporate due to its high vapor pressure, and can be supplied stably without heating or using carrier gas, etc. Cost can be reduced.
[0014]
  Also,Organosilicon compoundAs tetramethylsilane ((CH₃)₄Si), tetraethoxysilane (Si (OC₂H₅)₄), Tetramethoxysilane (Si (OCH₃)₄), Methyltrimethoxysilane (CH₃Si (OCH₃)₃), Dimethyldimethoxysilane ((CH₃)₂Si (OCH₃)₂), Trimethylmethoxysilane ((CH₃)₃Si (OCH₃)), Hexamethyldisilane ((CH₃)₆Si₂) And hexamethyldisiloxane ((CH₃)₆OSi₂).
[0015]
  These aboveOrganosilicon compoundIs preferred because of its low boiling point and high vapor pressure. Among organoalkoxysilanes, tetraethoxysilane, tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, and trimethylmethoxysilane are preferable because they contain oxygen and can be bonded to silicon to form silicon oxide. Furthermore, a water-repellent silicon oxide film made of a silicon-containing decomposition reaction product formed from tetraethoxysilane, tetramethoxysilane, or methyltrimethoxysilane is preferable because of excellent scratch resistance.
[0016]
The fluorine compound is not particularly limited in its kind, but is preferably a silicon compound having a perfluoroalkyl group. A silicon compound having a perfluoroalkyl group is preferable because it has a low boiling point and a high vapor pressure. In addition, since silicon is included, silicon is preferably combined with oxygen to form silicon oxide. Further, a surface having a low surface free energy such as polytetrafluoroethylene (PTFE) is formed, and properties such as water repellency, lubricity and mold release are improved, and oil repellency is also exhibited.
[0017]
The silicon compound having a perfluoroalkyl group is fluoroalkylsilane (C_nF_{2n + 1}CH₂CH₂Si (OCH_Three)_Three(Where n is an arbitrary positive integer)) is desirable. Among silicon compounds having a perfluoroalkyl group, C_nF_{2n + 1}CH₂CH₂Si (OCH_Three)_ThreeFor example C_nF_{2n + 1}CH₂CH₂SiCl_ThreeThe hydrolysis rate is low even when compared with, and chemically reacts with the surface of the base material to form a durable and low surface energy film.
[0018]
Further, the value of n of this fluoroalkylsilane is desirably 8 or more. Those having such a value of n are more preferable among fluoroalkylsilanes since they are particularly excellent in water repellency.
Furthermore, the silicon compound is tetramethylsilane, and the fluorine compound is a fluoroalkylsilane (CF having an n value of 8)._Three(CF₂)₇CH₂CH₂Si (OCH_Three)_ThreeIn addition, it is desirable that the static contact angle of the water droplet is 150 ° or more.
Tetramethylsilane does not contain oxygen, but fluoroalkylsilane preferably contains oxygen and can be bonded to silicon to form silicon oxide. Further, in the water-repellent silicon oxide film, the contact angle with water droplets is further increased, and the super-water repellency can be imparted by setting the static contact angle of water droplets to 150 ° or more.
[0019]
  RepellentIn the case of the aqueous silicon oxide film, the film shape, film area, film thickness and the like are not particularly limited, and can be arbitrarily selected depending on the application.
  RepellentIn the case of an aqueous silicon oxide film, the coexistence form of the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product is not particularly limited, but the silicon-containing decomposition reaction product does not contain silicon oxide in which silicon and oxygen are bonded. In addition, when the fluorine-containing decomposition reaction product does not contain fluorine and carbon bonded to each other, the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product chemically react with each other to generate silicon oxide or fluorine and carbon combined with each other. A coated film.
[0020]
  Also,In the water-repellent silicon oxide film, it is desirable that the silicon oxide has a bonded form represented by Si—O—Si. This silicon oxide has a high bonding force, increases the hardness of the film, and improves the wear resistance and scratch resistance.
  Also,In the water-repellent silicon oxide film, it is desirable that the fluorine and the carbon form a functional group having a C—F bond. Since the fluorine atom F has a small atomic radius and high electronegativity, the C—F bond energy is large and the bond distance is short. Therefore, there is only a very weak interaction within the molecule. For this reason, interaction with water which is a polar molecule becomes weak, and water repellency improves.
[0021]
  At this time, the functional group having a C—F bond is CF₃A functional group represented by-or / and -CF₂The functional group represented by-is desirable. Since the surface covered with these functional groups has a low critical surface tension (surface energy), the water repellency is further improved.
  further,The water-repellent silicon oxide film preferably contains a functional group composed of carbon and hydrogen having high hydrophobicity. Water repellent silicon oxide film is perfect in the tissueOroWhen the structure is long and has a rigid functional group such as an alkyl group, the structure form of the film has many gaps and it is difficult to make a dense structure form. This is not preferable because it causes a decrease in water repellency. Therefore, the water repellency can be improved by filling such a gap with a functional group having high hydrophobicity. In particular, many functional groups composed of carbon and hydrogen are highly hydrophobic and chemically stable.
[0022]
  Such a functional group is preferably a methyl group. Since the methyl group is highly hydrophobic and structurally small, it can easily fill the gaps in the film structure, and can form a very dense structure. Furthermore, it is very stable chemically.
  Also,In the water-repellent silicon oxide film, it is desirable that fluorine and carbon bonded to each other are uniformly dispersed in the film. As a result, even if the portion that becomes the surface of the film is repeatedly scraped off due to abrasion or the like, the portion that becomes the new surface always has a form in which fluorine and carbon bonded to each other are uniformly contained, and water repellency is maintained.
[0023]
Further, the content of fluorine contained in the film is not particularly limited, but it is desirable that fluorine is contained in 10 to 50 at%. Thereby, a film with low surface energy can be formed, and water repellency can be improved. At this time, if the fluorine content is less than 10 at%, the surface energy is not sufficiently lowered and sufficient water repellency cannot be obtained. Moreover, when fluorine exceeds 50 at%, hardness will become small and abrasion resistance will fall.
[0024]
Further, the visible light transmittance is not particularly limited, but the visible light transmittance is preferably 90 to 95%. This water-repellent silicon oxide film is excellent in translucency and can be used for materials requiring translucency, such as transparent plastics such as polycarbonate, transparent glass, and the like.
(Method for producing water-repellent silicon oxide film)
Next, embodiments of the method for producing a water-repellent silicon oxide film of the present invention will be described below. This manufacturing method includes three steps, that is, a raw material gas preparation step, a decomposition reaction product generation step, and a film formation step.
[0025]
  In the raw material gas preparation step, at least one of the silicon compound and the fluorine compound contains oxygen, and at least one of the silicon compound and the fluorine compound uses a compound containing carbon, and the silicon compound containing the silicon compound is used.ContainsGas and fluorine compound containing the fluorine compoundContainsGas and preparing each gas as a raw material gas.
[0026]
  Silicon compounds used in this processContainsThe gas can be prepared by vaporizing a silicon compound in a liquid state at room temperature.ContainsThe concentration of the silicon compound in the gas, the gas temperature, the gas pressure and the like are not particularly limited, but can be selected according to the application. Similarly, fluorine compoundsContainsThe gas can be prepared by vaporizing a fluorine compound in a liquid state at room temperature.ContainsThe concentration of the fluorine compound in the gas, the gas temperature, the gas pressure and the like are not particularly limited, but can be selected according to the application. When the boiling point of the silicon compound and / or fluorine compound used is high, it can be evaporated and vaporized by using an inert gas such as argon gas as a carrier gas or heating.
[0027]
  ThisFluorine compoundsContainsGas,Hydrogen gasFluorine compound with carrier gas containingIt is desirable to include. This hydrogen gas reacts with F atoms generated by decomposition from C—F bonds in the fluoroalkylsilane in a subsequent decomposition reaction product generation step, and is exhausted from the vacuum in the form of HF. Therefore, the etching of the film is suppressed. This also reduces the amount of oxygen taken into the film during the film formation process. Therefore, a water-repellent silicon oxide film having a low oxygen content can be obtained.
[0028]
In the decomposition reaction product generation step, at least one of the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product contains oxygen by causing the silicon compound and the fluorine compound contained in the source gas to decompose in the gas phase. And at least one of the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product produces the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product in a form containing carbon.
[0029]
This step is performed in an atmosphere in which an impurity gas such as air is hardly present by pre-vacuum using a vacuum pump such as a rotary pump.
The method for decomposing and reacting the silicon compound and fluorine compound contained in the source gas in the gas phase is not particularly limited, but the decomposing reaction can be performed using plasma, high heat, light or the like. Since plasma, high heat, light, and the like have high energy, the silicon compound and fluorine compound contained in the source gas can be decomposed by this high energy.
[0030]
When plasma is used at this time, the state of plasma temperature and the like is not particularly limited, but it is desirable that at least one of the silicon compound and the fluorine compound is decomposed in the gas phase using low temperature plasma. It is preferable to cause both the silicon compound and the fluorine compound to undergo a decomposition reaction in the gas phase using low-temperature plasma. If the product that forms the water-repellent silicon oxide film has a low heat-resistant temperature, the use of high-temperature plasma may reduce the quality of the product due to the high heat of this plasma. Therefore, care should be taken such that the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product are deposited at a position not affected by this. However, when using low-temperature plasma, such a precaution is not necessary, so that an arbitrary product can be placed at an arbitrary position to deposit a silicon-containing decomposition reaction product and a fluorine-containing decomposition reaction product. It is.
[0031]
  Moreover, although the generation method of low temperature plasma is not specifically limited, it is desirable to generate it by vacuum discharge using microwaves and / or high frequencies. Thereby, plasma with low gas temperature but high electron temperature can be obtained.
  In this process, silicon compoundContainsGas and fluorine compoundsContainsIt is desirable to produce a silicon-containing decomposition reaction product and a fluorine-containing decomposition reaction product in a mixed form of gas. This makes it possible to carry out the same operation in the same container, thus simplifying the apparatus for forming the water-repellent silicon oxide film, improving the work efficiency, and the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction. It is easy to produce a product.
[0032]
  At this time, silicon compoundContainsGases and fluorine compoundsContainsThe total pressure, partial pressure ratio, etc. of the gas are not particularly limited, but the silicon-containing decomposition reaction product, the fluorine-containing decomposition reaction product, and the production rate are determined in accordance with the total pressure, partial pressure ratio, etc. The total pressure, the partial pressure ratio, etc. can be selected according to the desired production rate of the decomposition reaction product.
  At this time, the formation of the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product is the silicon compoundContainsGas and the fluorine compoundContainsThe total pressure with the gas is preferably 10 Pa or higher. By generating a silicon-containing decomposition reaction product and a fluorine-containing decomposition reaction product under this pressure, uniform nucleation is performed in a low-temperature plasma, grain growth becomes remarkable, and the water-repellent silicon oxide film formed in the film forming process The unevenness of the surface becomes large.
[0033]
In the film forming step, the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product generated in the decomposition reaction product generation step are deposited on a base material, whereby the silicon is decomposed into the silicon-containing decomposition reaction product and the fluorine. Silicon oxide bonded to oxygen contained in at least one of the contained decomposition reaction products, and fluorine and carbon bonded to carbon contained in at least one of the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product And forming a film containing
[0034]
In this step, since the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product are deposited on the base material at the molecular level, a film can be formed with good adhesion to the base material.
Also, when the silicon-containing decomposition reaction product does not contain silicon oxide in which silicon and oxygen are bonded, or when the fluorine-containing decomposition reaction product does not contain fluorine and carbon bonded to each other, the silicon-containing decomposition reaction product and fluorine The decomposition reaction product can be deposited on the base material and chemically reacted with each other to produce silicon oxide or fluorine and carbon bonded to each other in the film.
[0035]
In this step, the temperature of the surface on which the base material film is formed is not particularly limited, but at least the surface on which the base material film is formed is heated to bring the surface temperature to 50 to 350 ° C. It is desirable. Thereby, since a thermal decomposition reaction advances, a film | membrane becomes densified and the hardness of the film | membrane obtained becomes large.
Further, the material of the base material used in this step is not particularly limited, but a material made of at least one of glass material, resin material, metal material, semiconductor material, wood, fiber, and building material is desirable. Many products that require water repellency, abrasion resistance, and scratch resistance are made of these materials, and are desirable forms.
[0036]
Also, the shape and size of the base material are not particularly limited, and the base material is fixed or moved in one, two, or three dimensions according to the shape and size of the base material. By depositing the decomposition reaction product and fluorine-containing decomposition reaction product, a water-repellent silicon oxide film can be formed on a base material having an arbitrary shape and size.
[0037]
The movement form of the generated silicon-containing decomposition reaction product and fluorine-containing decomposition reaction product to the surface of the base material is not particularly limited, but is deposited on the base material by being moved by an air current or the like. be able to.
Although there is no particular limitation on the base material installation mode, the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product are generated most, and the base material is installed at a position where the moving distance is as short as possible. It is desirable to deposit cracking reactants and fluorine-containing cracking reactants. At this time, the direction in which the film grows on the surface of the base material is not particularly limited, but the surface direction of the base material surface is selected according to the moving direction of the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product, By depositing the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product, a film can be grown in an arbitrary direction with respect to the base material surface.
[0038]
Specifically, for example, when low-temperature plasma is used, by installing a base material near the end of the low-temperature plasma, the movement distance between the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product generated in the plasma is increased. It can be deposited in almost no state. At this time, if it is installed at a position away from the vicinity of the end of the low temperature plasma, the movement distance between the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product generated in the plasma becomes long, and it is attached to the container etc. In addition, the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product cannot be deposited on the base material.
[0039]
  In the decomposition reaction product generation step, the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product can each be generated at an arbitrary generation rate.,In the film forming step, the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product can be deposited at a desired deposition rate, respectively, and a film can be formed at an arbitrary film formation rate.
(Hard water repellent silicon oxide film)
  HardAs described above, the quality water-repellent silicon oxide film is composed of at least two layers of a water-repellent layer and a hard layer, and each layer is disposed on the substrate so that the water-repellent layer is located on the outermost surface of the film. This water repellent layer is a layer having high water repellency. On the other hand, this hard layer is a layer having high hard performance.
[0040]
  Therefore, the hard water-repellent silicon oxide film has a structure in which the water-repellent layer is lined with the hard layer, and high water repellency and high hardness can be obtained. Furthermore, since both layers have a silicon oxide compound as a main component, they have high matching with each other, and the adhesion between these layers is high. This water repellent layer also,Like the water repellent silicon oxide film, it is desirable that fluorine and carbon bonded to each other are uniformly dispersed in the film.
[0041]
In addition, any layer can have high visible light transmittance. Therefore, high transparency of visible light can be obtained with the present hard water-repellent silicon oxide film.
The thickness of each layer is not particularly limited, but the thickness of each layer is appropriately selected so that the hard layer is not too thin or the water repellent layer is not too thick. It is preferable to do. If the hard layer is too thin, sufficient hard performance cannot be obtained. On the other hand, if the water repellent layer is too thick, this prevents the hard layer from exhibiting the hard performance.
[0042]
  HardA quality water-repellent silicon oxide film can be produced by first forming a hard layer on a substrate and forming a water-repellent layer on the hard layer. At this time, the hard layerofA known forming means can be used for the formation. Moreover, the formation means by the manufacturing method of the water repellent silicon oxide film of this invention can be used for formation of a water repellent layer.
[0043]
At this time, the hard water-repellent silicon oxide film may be formed by combining the water-repellent layer uniformly containing the fluorine and the carbon and the hard layer, but high consistency is obtained. That's not perfect integrity.
Therefore, in the present hard water-repellent silicon oxide film, the water-repellent layer is inclined at the boundary surface between the hard layer and the content concentration of the carbon and the fluorine gradually decreases in the boundary direction. It is desirable to have a graded layer that is nearly zero. This graded layer provides almost perfect consistency at the interface with the hard layer. Therefore, the adhesion of these layers becomes extremely high.
[0044]
[Action]
  the aboveSince the water-repellent silicon oxide film contains silicon oxide, it has excellent wear resistance and scratch resistance. In addition, since it contains a bond of fluorine and carbon, it is excellent in water repellency. In addition, it is formed without preparation of coating solution, etc., and consists of molecular level decomposition reaction products generated from the minimum necessary raw materials, so there are few impurities contained in the film, there is no uneven composition, etc. For the reason, it is superior in water repellency than the conventional water-repellent silicon oxide film.
[0045]
This water-repellent silicon oxide film in which fluorine and carbon bonded to each other are uniformly dispersed in the film is excellent in water repellency durability and weather resistance. Moreover, what contains 10-50 at% of fluorine is excellent in water repellency. Furthermore, what has the transmittance | permeability of visible light 90-95% is excellent in translucency.
According to the method for producing a water-repellent silicon oxide film of the present invention, a water-repellent silicon oxide film excellent in water repellency and wear resistance can be easily formed at a low temperature and with good adhesion to a base material. In the film formation step, the silicon-containing decomposition product and the fluorine-containing decomposition product can be simultaneously deposited on the base material at an arbitrary deposition rate, and a water-repellent silicon oxide film having an arbitrary film thickness can be formed. Therefore, it is possible to form a film in which fluorine is uniformly dispersed in the film, a film having an arbitrary fluorine content, a film having an arbitrary transmittance, and the like. Specifically, one containing 10 to 50 at% fluorine or one having a visible light transmittance of 90 to 95% can be produced.
[0046]
  the aboveIn the hard water-repellent silicon oxide film, the water-repellent layer exhibits high water-repellent performance, and the hard layer exhibits high hard performance, so that high water-repellency and high hardness can be obtained. Further, since these layers are bonded with high adhesion and are difficult to peel off from each other, high mechanical strength can be obtained. Furthermore, by using a layer having a high visible light transmittance for any of the layers, a high visible light transmittance can be obtained.
[0047]
【Example】
  Hereinafter, the present invention will be described specifically by way of examples.Examples 1 to 7 and Examples 9 and 10 are reference examples.
Example 1
  For the formation of the water-repellent silicon oxide film of this example, tetramethylsilane (manufactured by Kanto Chemical Co., Inc.) is used as the silicon compound, and fluoroalkylsilane having an n value of 8 as the fluorine compound (hereinafter referred to as FAS-17) ( CF₃(CF₂)₇CH₂CH₂Si (OCH₃)₃) (Manufactured by Shin-Etsu Chemical; KBM7803) was used, and a Si substrate (size: 30 × 30 × 0.5 mm) was used as a base material.
[0048]
Further, as the film forming apparatus, a microwave plasma CVD apparatus capable of generating a low temperature plasma by causing vacuum discharge by microwaves was used. In this apparatus, the raw material gas is caused to undergo a chemical reaction by microwave plasma, and a reaction product generated by this chemical reaction is deposited on the surface of the substrate or the like placed below to deposit it. It is the film formation apparatus which employ | adopted the downstream system which forms. FIG. 1 shows a schematic diagram of the film forming apparatus 1.
[0049]
  This film forming apparatus 1 is composed of a silicon compound.ContainsGases and fluorine compoundsContainsA reaction vessel 2 in which a gas is decomposed, a deposition vessel 6 in which a substrate 4 is installed and a decomposition reaction product generated in the reaction vessel 2 is deposited on the substrate 4, and a microwave power source 8 capable of generating microwaves The vacuum pumping rotary pump 10, the silicon compound supply source 12 that can supply the silicon compound, and the fluorine compound supply source 14 that can supply the fluorine compound are the main components.
[0050]
The reaction vessel 2 is formed of a cylindrical quartz tube (size; length: 270 mm, inner diameter: 51 mm, outer diameter: 57 mm) with one end closed and the other end opened, and the open end portion 16 covers the ceiling portion 18 of the deposition vessel 6. It is connected through. The inside of the reaction vessel 2 communicates with the inside of the deposition vessel 6 through this open end portion 16.
In the deposition container 6, a substrate holder 20 is provided in the container, and the substrate 4 can be placed on the substrate holder 20. In the substrate holder 20, the substrate 4 can be installed at a position of 100 to 450 mm from the central portion of the reaction vessel 2.
[0051]
The microwave power source 8 is connected to the reaction vessel 2 through the waveguide 22, and a microwave having a predetermined output generated by the microwave power source 8 can be sent into the reaction vessel 2 through the waveguide 22. At this time, the reaction vessel 2 is fixed to the cavity 24 of the waveguide 22 in the vicinity of the center thereof, and the incident wave and the reflected wave of the microwave are adjusted by the slice tab tuner 26 and the plunger 27 attached to the waveguide 22. Thus, a microwave having a certain strength can be sent into the reaction vessel 2. Note that the cavity 24 not only connects and fixes the microwave power source 8 and the sli tab tuner 26 but also plays a role of efficiently transmitting the microwave passing through the waveguide 22 to the reaction vessel. A vacuum discharge is generated in the reaction vessel 2 by this microwave, and a stable low-temperature plasma 28 can be generated in the reaction vessel 2.
[0052]
  The rotary pump 10, the silicon compound supply source 12, and the fluorine compound supply source 14 are connected to the deposition container 6, and the reaction container 2 directly connected to the deposition container 6 is brought to a maximum vacuum of 1 Pa by the rotary pump 10. The silicon compound in the deposition vessel 6 by the silicon compound source 12 and the fluorine compound source 14.ContainsGases and fluorine compoundsContainsGas can be supplied.
[0053]
  In the silicon compound supply source 12, a silicon compound in a liquid state is placed in a container, and the silicon compound is evaporated and vaporized to thereby generate a silicon compound.ContainsGas can be supplied. Moreover, in the fluorine compound supply source 14, a fluorine compound in a liquid state is placed in a container, and the fluorine compound is evaporated and vaporized to thereby generate a fluorine compound.ContainsGas can be supplied. When the boiling point of the fluorine compound is high, the fluorine compound in a liquid state in the container can be heated and evaporated and vaporized at a predetermined heating temperature using a ribbon heater wound around and attached to the outside of the container. Further, the fluorine compound supply source 14 is provided with a pipe so that the carrier gas can be introduced from the carrier gas supply source 29. The fluorine compound supply source 14 is introduced into the container through the fluorine compound in a liquid state, and is introduced into the deposition container 6 from the introduction pipe. Can be moved to. This carrier gas acts as a gas that stabilizes the vacuum discharge and is a fluorine compound.ContainsBy promoting the transport of the gas, the fluorine compound in a gaseous state can be stably supplied. In this example, argon gas was used as the carrier gas.
[0054]
  These silicon compoundsContainsGases and fluorine compoundsContainsThe gases are respectively introduced into the deposition containers 6 through the introduction pipes, and are filled in the reaction container 2 through the deposition containers 6 in a mixed gas state. At this time, silicon compoundContainsGases and fluorine compoundsContainsThe amount of gas introduced can be adjusted by needle valves 30 and 30 attached to the respective introduction pipes. And by adjusting each introduction amount, silicon compoundContainsGases and fluorine compoundsContainsThe gas can be adjusted to a desired partial pressure, and the pressure in the reaction vessel 2 can be set to a predetermined pressure.
[0055]
  Silicon compound in reaction vessel 2ContainsGases and fluorine compoundsContainsIn the gas, the silicon compound and the fluorine compound are decomposed by low-temperature plasma, and a silicon-containing decomposition reaction product and a fluorine-containing decomposition reaction product are generated. The generated silicon-containing decomposition reaction product and fluorine-containing decomposition reaction product can be moved and deposited on the substrate 4 in the deposition container 6.
[0056]
Further, the substrate temperature is about 80 ° C. at the maximum due to the radiant heat of the low-temperature plasma 28 or the like when no external heating is performed. Therefore, a resistance heating device (not shown) capable of heating the substrate temperature in a temperature range of 100 to 400 ° C. is attached to the substrate holder 20, and the substrate temperature can be arbitrarily controlled within this temperature range.
In this embodiment, the substrate 4 is set at a position 100 mm from the vicinity of the center of the low temperature plasma 28, and the reaction vessel 2 and the deposition vessel 6 are evacuated to 1 Pa by the rotary pump 10, and then the evacuation speed by the rotary pump 10 is increased. Tetramethylsilane gas was introduced into the reaction vessel 2 from the silicon compound supply source 12 while adjusting, and the pressure in the reaction vessel 2 was maintained almost constant at a predetermined pressure. Subsequently, the fluorine compound supply source 14 is heated by a ribbon heater at about 70 to 80 ° C. to evaporate and vaporize the FAS-17 in a liquid state in the container, and this FAS-17 gas is put into the reaction container 2. Introduced and mixed with the previously introduced tetramethylsilane gas, the total pressure of the mixed gas was set to a predetermined pressure. At this time, 20 to 50 sccm of argon gas was used as the carrier gas.
[0057]
The microwave power source 8 is set to 300 W to cause a vacuum discharge, and the vacuum discharge is maintained at this output to generate a low temperature plasma 28, thereby forming a water-repellent silicon oxide film while maintaining the substrate temperature substantially constant at 50 ° C. For 15 minutes.
At this time, the predetermined pressure of the tetramethylsilane gas is selected from 12.5 Pa, 15.0 Pa, 20.0 Pa, 25.0 Pa, and the partial pressure of the FAS-17 gas is set in accordance with the predetermined pressure of the tetramethylsilane gas. Are selected from 12.5 Pa, 15.0 Pa, 20.0 Pa, 25.0 Pa, and the total pressure of the mixed gas is 25.0 Pa, 30.0 Pa, 40.0 Pa, 50.0 Pa, and four types of water-repellent silicon oxide films Was made.
[0058]
These water-repellent silicon oxide films were evaluated for film thickness, contact angle and visible light transmittance. In addition, each measurement was performed using the following means. In addition, evaluation was performed in the same manner for other examples described later.
The film thickness was measured using a surface roughness meter (manufactured by Mitsutoyo, Surftest SV-600). Water repellency was measured with a contact angle meter (Kyowa Interface Science, CA-X150 type) in an atmosphere at 25 ° C. by a droplet method using a static contact angle of distilled water (droplet diameter of about 2 mmφ). Visible light transmittance was measured using a double beam spectrophotometer (manufactured by Shimadzu Corporation, UV-3101PC).
[0059]
FIG. 2 shows static contact angles with water droplets of the four types of water-repellent silicon oxide films obtained. FIG. 2 shows that the static contact angle of these water-repellent silicon oxide films with water droplets is 115 to 160 °. The static contact angle with the water droplets exceeds 108 ° of the static contact angle with the Teflon water droplets, and it can be seen that the obtained four types of water-repellent silicon oxide films are very excellent in water repellency. In particular, a water-repellent silicon oxide film produced with a total mixed gas pressure of 50.0 Pa has a static contact angle with a water droplet of 160 ° and has a very high water repellency (super water repellency) exceeding 150 °. I understood.
[0060]
Further, FIG. 2 shows that the film formation rate of these water-repellent silicon oxide films is 25 to 120 nm / min, and the film formation rate increases as the total pressure of the mixed gas increases.
Further, it was found that the water-repellent silicon oxide film produced with the total pressure of the mixed gas being 25.0 Pa and 30.0 Pa has a visible light transmittance of 93% and is excellent in light-transmitting property.
(Example 2)
Trimethylmethoxysilane (manufactured by Kanto Chemical) is used as the silicon compound, the predetermined pressure of trimethylmethoxysilane is 25.0 Pa, the partial pressure of fluoroalkylsilane is 25.0 Pa, and the total pressure of the mixed gas is 50.0 Pa. In the same manner as in Example 1, except that the substrate temperature was selected from 50 ° C., 100 ° C., 200 ° C., and 300 ° C., four types of water-repellent silicon oxide films having different substrate temperatures were produced. These substrate temperatures were measured with an alumel-chromel thermocouple. Unless otherwise noted, the following substrate temperatures were all measured by this measuring means.
[0061]
At this time, with respect to the water-repellent silicon oxide film produced at a substrate temperature of 50 ° C., the infrared transmittance was measured by infrared absorption analysis (IR), the infrared absorption spectrum was obtained from the transmittance, and the bonding form in the film was examined. . The measurement results are shown in FIG. In FIG. 3, the horizontal axis represents the wave number of infrared rays, and the vertical axis represents the transmittance.
According to FIG. 3, infrared absorption peaks due to stretching vibration between Si—O—Si bonds are confirmed in the vicinity of wave numbers of 1070 / cm, 800 / cm, and 460 to 410 / cm. From the fact that the infrared absorption peak due to the stretching vibration between the bonds was confirmed near the wave number of 850 / cm, it was found that silicon oxide was contained in the film. CF_Three-, -CF₂-Infrared absorption peaks due to stretching vibrations between C-F bonds were confirmed near the wave numbers of 1260-1200 / cm and 1120 / cm, indicating that fluorine and carbon were bonded to each other and C- It was found that it was contained in the film in the form of F bonds.
[0062]
The static contact angle is shown in FIG. From FIG. 4, it can be seen that the static contact angle of these water-repellent silicon oxide films with water droplets is 102 to 110 °, and any water-repellent silicon oxide film has excellent water repellency.
(Example 3)
Four types of water-repellent silicon oxide films were prepared in the same manner as in Example 2 except that dimethyldimethoxysilane (manufactured by Kanto Chemical) was used as the silicon compound.
[0063]
FIG. 5 shows static contact angles with water droplets of the four types of water-repellent silicon oxide films obtained at this time. From FIG. 5, it can be seen that the static contact angle of these water-repellent silicon oxide films with water droplets is 95 to 100 °, and that any water-repellent silicon oxide film has excellent water repellency.
(Example 4)
Four types of water-repellent silicon oxide films were prepared in the same manner as in Example 2 except that methyltrimethoxysilane (manufactured by Kanto Chemical) was used as the silicon compound.
[0064]
FIG. 6 shows static contact angles with water droplets of the four types of water-repellent silicon oxide films obtained at this time. FIG. 6 shows that the static contact angle of these water-repellent silicon oxide films with water droplets is 90 to 94 °, and that any water-repellent silicon oxide film has excellent water repellency.
Further, as a result of a scratch test using a stainless steel chip, it was found that the chip was excellent in scratch resistance.
(Example 5)
Four types of water-repellent silicon oxide films were prepared in the same manner as in Example 2 except that tetramethoxysilane (hereinafter referred to as TMS) (manufactured by Kanto Chemical) was used as the silicon compound.
[0065]
FIG. 7 shows static contact angles with water droplets of the four types of water-repellent silicon oxide films obtained at this time. From FIG. 7, it can be seen that the static contact angle of these water-repellent silicon oxide films with water droplets is 80 to 93 °, and that any water-repellent silicon oxide film has excellent water repellency.
Further, as a result of a scratch test using a stainless steel chip, it was found that the chip was excellent in scratch resistance.
(Example 6)
Four types of water-repellent silicon oxide films were prepared in the same manner as in Example 2 except that tetraethoxysilane (manufactured by Kanto Chemical) was used as the silicon compound.
[0066]
  Although the static contact angles with water droplets of the four types of water-repellent silicon oxide films obtained at this time are not shown, they may have static contact angles with water droplets substantially the same as the water-repellent silicon oxide film of Example 5. As can be seen, all the water-repellent silicon oxide films have excellent water repellency.
  Further, as a result of a scratch test using a stainless steel chip, it was found that the chip was excellent in scratch resistance.
(Example 7)
  As a silicon compound,Except for using hexamethyldisilane (hereinafter referred to as HMDS),2In the same manner, a water-repellent silicon oxide film was produced.
[0067]
  This water repellent silicon oxide filmEach contact angle was measured. The measurement results are shown in FIG.
(Example 8)
  H instead of Ar gas as carrier gas for FAS-17 gas₂Example 1 except that hydrogen is included in the FAS-17 gas using a gas.2In the same manner, a water-repellent silicon oxide film was produced.
[0068]
These water-repellent silicon oxide films were all found to have higher water repellency than films using argon. In particular, a contact angle similar to that of a single water-repellent film was obtained at a substrate temperature of 200 ° C. or higher. Moreover, as a result of XPS measurement, it was confirmed that the oxygen content in the upper layer was significantly reduced as compared with the case where argon was used.
Example 9
In this example, a hard water-repellent silicon oxide film composed of a water-repellent layer and a hard layer and arranged on the substrate so that the surface of the water-repellent layer is the outermost surface was produced.
In this film, the water-repellent layer has an inclined layer at the boundary portion with the hard layer, in which the concentration of carbon and fluorine gradually decreases toward the boundary direction and becomes almost zero at the boundary surface.
[0069]
  In this embodiment, a hard layer is first formed on a substrate and then this is done.HardA gradient layer was formed on the layer, and then a water-repellent layer was formed on the gradient layer to produce a hard water-repellent silicon oxide film. The hard layer was formed by using TMS gas and oxygen gas as source gases and subjecting these source gases to gas phase reaction. In addition, the water repellent layer was formed by using FAS-17 gas and TMS gas as source gases and subjecting these source gases to gas phase reaction. FIG. 8 schematically shows a series of these layer formation processes.
[0070]
The procedure for producing the hard water-repellent silicon oxide film of this example will be described below with reference to FIGS. Note that the microwave plasma CVD apparatus shown in FIG. 1 was used for forming these layers. Prior to the production of the hard water-repellent silicon oxide film, a silicon wafer (10 mm × 10 mm × 0.5 mm) was prepared as a substrate, and this substrate was placed at a position about 100 mm away from the plasma center. Further, the substrate was exposed to oxygen plasma (20 Pa) for about 5 minutes to remove impurities on the substrate surface in advance.
[0071]
First, after the reaction vessel 6 was evacuated to 1 Pa by the rotary pump 10, the silicon compound supply source 12 for TMS gas was kept at room temperature, and the vapor was introduced into the reaction vessel 6. At this time, TMS gas was introduced from about 10 mm above the substrate 4 and oxygen gas was introduced from above the quartz tube 2. After introducing these source gases, film formation was carried out with the film formation conditions set as follows.
[0072]
Total pressure and microwave output were kept constant at 50 Pa and 300 W, respectively. Oxygen partial pressure ratio (O₂As (Pa) / total pressure (Pa)), 80%, which is known to obtain the optimum hardness by the inventors' research, was adopted. The substrate temperature was kept constant at the temperature described later. The film formation time was selected so that the film thickness was 1.0 μm or more.
Thus, the hard layer 100 was formed on the substrate as shown in FIG. This hard layer 100 is the same as the film obtained in Comparative Example 1 described later.
[0073]
Next, while maintaining the previously held substrate temperature, the supply of oxygen gas was gradually reduced by the needle valve 30, and instead, FAS-17 was introduced into the reaction vessel 6 using Ar as the carrier gas. Here, the fluorine compound supply source 14 for FAS-17 was kept at about 70 ° C., and the vapor was introduced into the reaction vessel 6. In order to avoid condensation of the FAS-17 vapor, the gas introduction pipe was also maintained at about 70 ° C. On the other hand, the Ar flow rate was controlled to 20 sccm by a mass flow controller. Thus, as shown in FIG. 8B, the inclined layer 200 was formed on the hard layer 100.
[0074]
Subsequently, the needle valve 30 was adjusted so that the total pressure was 50 Pa and the partial pressure ratio of TMS and FAS-17 / Ar was 25 Pa: 25 Pa, and film formation was performed for 1 to 5 minutes. Thus, as shown in FIG. 8C, the water repellent layer 300 was formed on the inclined layer 200.
In this embodiment, the condition in which the substrate temperature is not controlled (about 70 ° C.) and the condition in which the substrate temperature is controlled almost constant in the temperature range up to 350 ° C. such as 100 ° C., 200 ° C., and 300 ° C. by external resistance heating 4 types of hard water-repellent silicon oxide films were prepared. Hereinafter, unless otherwise specified, the four types refer to these types of substrate temperatures.
[0075]
All of these hard water-repellent silicon oxide films had a film thickness of about 1.0 μm or more. It was also found that these films had good adhesion to both the substrate / film and the hard layer / gradient layer. This was confirmed by the fact that peeling at the boundary (interface) between the substrate / film and the hard layer / gradient layer was not observed in the cross-cut peel test. Next, the contact angle and hardness were evaluated as follows.
[0076]
First, the contact angle measurement results are shown in FIG. For comparison, the contact angle of the water-repellent silicon oxide film of Example 5 is also shown in FIG.
From FIG. 9, it can be seen that all have a high contact angle of 100 ° or more. However, it is slightly inferior to that of Example 5. It can also be seen that the lower the substrate temperature, the higher the contact angle.
[0077]
Next, the measurement result of hardness is shown in FIG. Here, the ultra micro hardness was measured using a dynamic ultra micro hardness meter (manufactured by Shimadzu Corporation, DUH-200). A Knoop indenter was used as the indenter, and the maximum load was set to 0.50 gf.
FIG. 10 shows that all the films have high hardness. In particular, it can be seen that those obtained at a substrate temperature of 200 ° C. or higher have the same hardness as the film of Comparative Example 1, and the hardness is extremely high.
[0078]
  On the other hand, it was confirmed that those obtained at a substrate temperature of 100 ° C. or lower had a lower hardness than those obtained at a substrate temperature of 200 ° C. or higher. This is considered to be due to the difference in the thickness of the water repellent layer. It is known that the former formation rate is very fast, about 60 to 100 nm / min, compared to the latter. Here, since each film-forming time is the same, a thick water-repellent layer is formed in the former compared with the latter. Therefore, what was obtained at a substrate temperature of 100 ° C. or lower isHardIt is thought that the hardness was reduced because the hardness of the layer was not reflected.
[0079]
Therefore, when the film was formed at a substrate temperature of 100 ° C. or lower and the water-repellent layer was formed for 1 minute, and the film formation time was shorter than the previous one, the substrate having a hardness of 200 ° C. or higher was obtained. The value was almost the same as that obtained at temperature. The hardness of these films was also shown in FIG. 10 (Δ mark in the figure). Although the contact angle at this time slightly decreased as the film-forming time of the water-repellent layer was shortened, it exhibited 105-112 ° and water repellency as high as PTFE (108 °).
[0080]
As described above, the hard water-repellent oxide film of this example is slightly inferior in contact angle to the water-repellent oxide silicon film of Example 5, but has excellent water repellency and extremely high hardness. all right. It was also found that the contact angle and hardness differ depending on the substrate temperature during film formation. Therefore, in order to find out the reason why the film of this example is slightly inferior in contact angle as compared with that of Example 5 and the reason why the contact angle and hardness differ depending on the substrate temperature, the chemical bonding state and the chemistry in these films The composition was evaluated as follows.
[0081]
First, about the film | membrane of a present Example and the film | membrane of Example 5, the chemical bonding state of those surface parts was measured. The analysis results are shown in Table 1. Note that XPS (manufactured by Shimadzu Corporation, ESCA1000) and FTIR (manufactured by JASCO, FT / TR5300) were used for analysis of the chemical bonding state.
[0082]
[Table 1]

From Table 1, in any film of this Example, the F / Si and F / C values that contribute to water repellency are decreased on the surface, and the O / F value that contributes to an increase in hydrophilicity. It was confirmed that the increase and the C / Si value indicating the mineralization of the film decreased. As is apparent from the measurement results, it can be seen that the surface of the film obtained in this example is more hydrophilic than the surface of the film of Example 5. This is because, when the gas introduced into the reaction vessel is switched from oxygen to FAS-17 / Ar during film formation, oxygen remaining in the plasma atmosphere decomposes FAS-17 and polar groups (hydrogen groups, etc.) into the film. ). Therefore, it is considered that the contact angle of the film of this example was lowered.
[0083]
  Next, the chemical composition in the depth direction of the film was analyzed for each of the film obtained at the substrate temperature of 70 ° C. and the film obtained at the substrate temperature of 300 ° C. The analysis results are shown in FIGS. 11 and 12, respectively.11 and 12, symbols Δ in the drawings indicate carbon, ◯ indicates silicon, ● indicates oxygen, and □ indicates fluorine.The chemical composition change in the depth direction of the film was measured by XPS Ar ion etching (2.0 kV, 30 mA). In this measurement, the etching depth increases in proportion to the etching time.
[0084]
As is clear from FIG. 11, in the film obtained at the substrate temperature of 70 ° C., a significant decrease in the fluorine and carbon concentrations was observed after the etching time exceeded about 120 minutes, and conversely, the silicon and oxygen concentrations Increase was confirmed. On the other hand, as apparent from FIG. 12, in the film obtained at the substrate temperature of 300 ° C., the same tendency was observed after the etching time exceeded about 30 minutes.
[0085]
From the analysis results of the above chemical composition, it can be seen that the film obtained at the substrate temperature of 70 ° C. has a larger thickness of the water repellent layer than that obtained at the substrate temperature of 300 ° C. That is, the film obtained at a substrate temperature of 100 ° C. or lower has a greater thickness of the water-repellent layer than that obtained at a substrate temperature of 200 ° C. or higher. The quality and thickness of the water-repellent layer differ depending on the substrate temperature selected in this way, and the water repellency and hardness of the film differ accordingly.
[0086]
Finally, the visible light transmittance of the film obtained in this example was measured. As a result of the measurement, it was found that in any film, the transmittance in the visible light region was 90% or more, which was not different from an untreated glass substrate. In FIG. 13, the measurement result of the visible light transmittance of the film obtained at the substrate temperature of 200 ° C. is shown as an example. In the measurement, air was used as a reference.
[0087]
From the above evaluation, it has been clarified that the hard water-repellent silicon oxide film of this example is excellent in water repellency, has high hardness, and has high visible light transmittance.
(Comparative Example 1)
Four types of films were formed in the same manner as in Example 9 except that the inclined layer 300 and the water repellent layer were not formed.
[0088]
Each of these films has Si—O—Si bonds in the film, and the silicon and oxygen concentrations thereof are 30 at. % And 60 at. %. Furthermore, it has been found that these hard silicon oxide films all have a hardness comparable to that of borosilicate glass. It was also confirmed that the film was dense.
(Example 10)
Four types of hard water-repellent silicon oxide films were prepared in the same manner as in Example 9 except that hexamethyldisilane (hereinafter referred to as HMDS) was used instead of TMS.
[0089]
Further, it was found that these hard water-repellent silicon oxide films each have substantially the same contact angle and hardness as those obtained in Example 9 under the same substrate temperature conditions. However, the film forming rate of the water repellent layer in Example 9 was about 10 to 25 nm / min, whereas in the present example, it was very high at about 70 to 100 nm / min.
(Example 11)
H instead of Ar gas as carrier gas for FAS-17 gas₂Four types of hard water-repellent silicon oxide films were prepared in the same manner as in Example 9 except that hydrogen was included in the FAS-17 gas using a gas.
[0090]
It was found that each of these water-repellent silicon oxide films had higher water repellency than that obtained in Example 9 under the same substrate temperature conditions. In particular, a contact angle similar to that of a single water-repellent film was obtained at a substrate temperature of 200 ° C. or higher. Moreover, as a result of XPS measurement, it was confirmed that the oxygen content of any water-repellent layer was significantly reduced as compared with those obtained in Example 9.
(Example 12)
Four types of hard water-repellent silicon oxide films were prepared in the same manner as in Example 11 except that HMDS was used instead of TMS.
[0091]
The contact angle of each of these hard water-repellent silicon oxide films was measured. The measurement results are shown in FIG. For comparison, the measurement results obtained in Example 7 and Example 10 are also shown in FIG.
From FIG. 14, it was found that any of the films of this example had excellent water repellency, and in particular, had higher water repellency than the film obtained in Example 10 under the same substrate temperature conditions. From this result, the carrier gas is H₂It can be seen that higher water repellency can be obtained by using gas than by using argon gas.
[0092]
However, the film obtained at a substrate temperature of 200 ° C. or lower was found to be slightly inferior in water repellency and slightly inferior to the film obtained under the same substrate temperature conditions as in Example 7. However, although not shown here, the hardness was found to be higher than the film obtained in Example 7 under the same substrate temperature conditions.
[0093]
【The invention's effect】
  the aboveSince the water-repellent silicon oxide film is excellent in water repellency, abrasion resistance and scratch resistance, the water repellency, abrasion resistance and scratch resistance of these products can be improved by using them in products with poor performance. Can be improved.
  Also,the aboveSince the water-repellent silicon oxide film has excellent water repellency and weather resistance, these products can be used in products that are used in environments with high wear frequency or in environments where snow or ice adheres significantly. The durability and weather resistance of water repellency can be improved.
[0094]
By the method for producing a water-repellent silicon oxide film of the present invention, a water-repellent silicon oxide film excellent in water repellency and wear resistance can be easily formed at low temperature and with good adhesion to a base material, so that production costs, etc. In addition, even in a product having a low heat-resistant temperature, a water-repellent silicon oxide film excellent in water repellency, abrasion resistance and scratch resistance can be produced even in a product having a low heat-resistant temperature.
[0095]
  Specifically, 300℃Since a hard water-repellent silicon oxide film can be produced at the following low temperatures, it is an effective method for increasing the surface hardness and functionality of materials with low heat resistance and wear resistance. In particular, since such a film can be produced at a low temperature of 100 ° C. or lower, it can be applied to materials such as plastics.
  In addition, a water-repellent silicon oxide film in which fluorine is uniformly dispersed in the film can be easily formed at a low temperature and with good adhesion, so that the water-repellent oxidation has excellent water repellency and weather resistance. The silicon film can be manufactured without reducing the quality even in a low-cost product with a low heat-resistant temperature.
[0096]
In addition, a water-repellent silicon oxide film having an arbitrary fluorine content can be easily formed at a low temperature and with good adhesion. Even a low product can be manufactured without degrading the quality.
In addition, a water-repellent silicon oxide film with excellent translucency can be formed at low temperature on letters and pictures drawn using organic paints on the base material. A water-repellent silicon oxide film can be formed without causing it.
[0097]
  the aboveSince the hard water-repellent silicon oxide film is extremely excellent in water repellency and wear resistance, and is excellent in mechanical strength, its performance can be improved by using it for a material having low water repellency and wear resistance.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a film forming apparatus used in this example.
FIG. 2 is a graph showing a static contact angle with a water droplet of the water repellent silicon oxide film obtained in Example 1.
FIG. 3 is a graph showing the results of measuring the infrared transmittance of the water-repellent silicon oxide film obtained in Example 2 by infrared absorption analysis (IR).
4 is a graph showing static contact angles with water droplets of four types of water-repellent silicon oxide films obtained in Example 2. FIG.
5 is a graph showing static contact angles with water droplets of four types of water-repellent silicon oxide films obtained in Example 3. FIG.
6 is a graph showing static contact angles with water droplets of four types of water-repellent silicon oxide films obtained in Example 4. FIG.
7 is a graph showing static contact angles with water droplets of the four types of water-repellent silicon oxide films obtained in Example 5. FIG.
FIG. 8 is a view schematically showing a process for producing a water-repellent silicon oxide film of Example 9.
FIG. 9 is a graph showing static contact angles with water droplets of the water-repellent silicon oxide film obtained in Example 5 and Example 9, respectively.
FIG. 10 is a graph showing the hardness of the water-repellent silicon oxide film obtained in Example 9 and Comparative Example 1, respectively.
FIG. 11 is a view showing a composition change in one depth direction of the water repellent silicon oxide film obtained in Example 9. FIG.
12 is a view showing a composition change in one depth direction of the water repellent silicon oxide film obtained in Example 9. FIG.
13 is a graph showing an example of the visible light transmittance of the water repellent silicon oxide film obtained in Example 9. FIG.
FIG. 14 is a graph showing static contact angles with water droplets of the water-repellent silicon oxide films or hard water-repellent silicon oxide films obtained in Example 7, Example 10, and Example 12, respectively. .
[Explanation of symbols]
1: Film formation device 2: Reaction vessel 4: Substrate 6: Deposition vessel 8: Microwave power supply 10: Rotary pump 12: Silicon compound supply source 14: Fluorine compound supply source 16: Open end portion 18: Ceiling portion 20: Substrate holder 22: Waveguide 24: Cavity 26: Stub tuner 27: Plunger 28: Low temperature plasma 29: Argon gas supply source 30: Needle valve

Claims (7)

At least one of the silicon compound and the fluorine compound contains oxygen, and at least one of the silicon compound and the fluorine compound uses a compound containing carbon, respectively, a silicon compound-containing gas containing the silicon compound, and a carrier gas containing hydrogen gas And a fluorine compound-containing gas containing the fluorine compound, and a raw material gas preparation step using each as a raw material gas,
By decomposing the silicon compound and the fluorine compound contained in the source gas in the gas phase, at least one of the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product contains oxygen, and the silicon-containing decomposition reaction A decomposition reaction product generating step of generating the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product in a form in which at least one of the reactant and the fluorine-containing decomposition reaction product contains carbon;
The silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product are deposited on the base material by depositing the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product generated in the decomposition reaction product generation step. Silicon oxide bonded to the oxygen contained in at least one, and the fluorine and carbon bonded to the carbon contained in at least one of the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product. A film forming process for forming a film;
A method for producing a water-repellent silicon oxide film, comprising: The method for producing a water-repellent silicon oxide film according to claim 1, wherein in the decomposition reaction product generation step, at least one of the silicon compound and the fluorine compound is decomposed in a gas phase using low-temperature plasma. The method for producing a water-repellent silicon oxide film according to claim 2 , wherein the low-temperature plasma is generated by vacuum discharge using at least one of microwave, high frequency, low frequency, direct current, and alternating current. The water-repellent oxidation according to claim 1, wherein in the decomposition reaction product generation step, the silicon compound-containing gas and the fluorine compound-containing gas are mixed to generate the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product. Silicon film manufacturing method. In the decomposition reaction product generation step, the generation of the silicon-containing decomposition reaction product and the fluorine-containing decomposition reaction product is performed under a total pressure of 10 Pa or more of the silicon compound-containing gas and the fluorine compound-containing gas. Item 5. A method for producing a water-repellent silicon oxide film according to Item 4. The method for producing a water-repellent silicon oxide film according to claim 1, wherein in the film forming step, at least a surface portion of the base material on which the film is formed is set to a temperature of 50 to 350 ° C. The method for producing a water-repellent silicon oxide film according to claim 1, wherein the base material is made of at least one of glass material, resin material, metal material, semiconductor material, wood, fiber, and building material.

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