JP2005187936A - Thin film manufacturing method, optical component manufacturing method, and film deposition apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a condition of depositing an anti-fouling layer by using an organosilicon compound containing fluorine. <P>SOLUTION: In the thin film manufacturing method, the pressure in a chamber CH3 is set so that the λ/Lm of the free mean path λ of organosilicon compound containing fluorine to the maximum distance Lm between a vapor deposition source 59 installed in the chamber CH3 and a workpiece 40 becomes ≥ 0.2% when depositing a thin film on a surface of the workpiece 40 in the chamber CH3 with the organosilicon compound containing fluorine as the vapor deposition source 59. The anti-fouling layer appropriate in film thickness, free from step irregularity and excellent in anti-fouling property and durabilitycan be manufactured thereby. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method for producing a fluorine-containing organosilicon compound thin film on the surface of a silicon-containing compound, and more particularly to a method for producing a fluorine-containing organosilicon compound thin film on the surface of an optical component.

  The spectacle lens is provided with an antireflection film on its surface in order to suppress light reflection and increase light transmission, and further, an antifouling layer having water repellency is provided on the surface of this antireflection film. It has been. This antifouling layer is provided in order to prevent stains due to dirt, fingerprints, sweat, cosmetics, etc. adhering to the user when used, or to easily wipe off the stains.

Japanese Patent Laid-Open No. 9-258003 JP 2004-145283 A

  Surface treatment with a fluorine-containing organosilicon compound is employed when a surface requiring high water repellency or an antifouling surface as described above is formed. Patent Document 1 and Patent Document 2 disclose an example of a fluorine-containing organosilicon compound having excellent antifouling properties. It is said that the fluorine-containing organosilicon compound has a higher antifouling property when the molecular weight is larger, whereas it is said that the film strength tends to be lowered when the molecular weight is too large. For this reason, the molecular weight of the fluorine-containing organosilicon compound used for the surface treatment is desirably 500 or more and about tens of thousands or less.

  An example of the fluorine-containing organosilicon compound used when forming the antifouling layer of the lens is KP-801M manufactured by Shin-Etsu Chemical Co., Ltd. and has a molecular weight of 498. An example of a fluorine-containing organosilicon compound having a higher fluorine content and a higher molecular weight is KY-130 manufactured by Shin-Etsu Chemical Co., Ltd., and the molecular weight is estimated to be 2000 to 3000. In addition, Daikin's OPTOOL DSX has a molecular weight in the range of 4000 to 5000.

  The surface treatment of the fluorine-containing organosilicon compound is more effective if the outermost layer is a layer containing silicon such as glass. This is because the fluorine-containing organosilicon compound is bonded to a silanol group on the glass surface to form a siloxane bond. However, this reaction requires hydrolysis and dehydration and condensation polymerization. For this reason, the surface treatment of the fluorine-containing organosilicon compound usually includes a post-process for annealing in a high humidity atmosphere. When the film is thick, it is necessary to anneal for a long time in order to obtain the film strength, and it is difficult to obtain a certain film strength. Also, it is desirable that the film thickness is thin so as not to hinder the performance of the lens. If the film thickness is large, an operation of wiping off the excess film is necessary, and if the film strength is low, the film is peeled off in the process. There is also a problem.

  On the other hand, the process for forming a siloxane bond is a process that does not have a high reaction rate but proceeds at room temperature if there is a suitable humidity. For this reason, if the film is sufficiently thin, the wiping operation is not necessary, and therefore, there is a possibility that the film can be put to practical use only by securing an appropriate aging period after forming the fluorine-containing organosilicon compound. However, when manufacturing a thin film, in order to secure the yield, it is necessary to make the film thickness tolerance of the manufacturing process sufficiently small with respect to the required film thickness.

  When manufacturing thin films by vapor deposition, the pressure in the chamber can be a parameter that affects film thickness tolerance. It is expected that the film thickness tolerance can be reduced by making the chamber high vacuum, but the higher the vacuum, the higher the equipment cost of the chamber and the higher the running cost. Therefore, it is necessary to ascertain the conditions necessary to obtain an appropriate film thickness tolerance. The conditions are necessary for economically producing a thin film of fluorine-containing organosilicon compound having a small difference in film thickness, high water repellency or antifouling properties, and high durability. Accordingly, an object of the present invention is to provide conditions for economically forming a fluorine-containing organosilicon compound suitable for forming an antifouling layer.

  Furthermore, at present, there is not only one type of fluorine-containing organosilicon compound suitable for forming an antifouling layer, and it will continue to be a fluorine-containing organosilicon compound having a different molecular weight and suitable for producing an antifouling layer. There is ample potential for developing fluorine-containing organosilicon compounds. It is unclear whether it is most economical to deposit under the same conditions for fluorine-containing organosilicon compounds having different physical properties such as molecular weight, and in many cases they may be different. Therefore, an object of the present invention is to provide conditions for forming an economical, highly durable and high performance thin film made of fluorine-containing organosilicon compounds having different physical properties.

  The present invention provides a method for producing a thin film having a film forming step for forming a thin film on a surface of a silicon-containing compound of a workpiece by using a fluorine-containing organosilicon compound as a vapor deposition source, wherein the film forming step is installed in a chamber. Of thin film in which the chamber pressure is set so that the ratio of the mean free path λ of the fluorine-containing organosilicon compound to the maximum distance Lm between the deposited vapor deposition source and the workpiece, that is, λ / Lm is 0.2% or more Provide a method. In the film forming step, it is more preferable to set the pressure so that the ratio λ / Lm of the mean free path to the maximum distance is 1.0% or more.

  The mean free path is expressed by the following formula (3).

λ = 1 / (√2 · π · n · d ² ) (3)
Where λ is the mean free path [m], n is the number of molecules in 1 m ³ [pieces / m ³ ], and d is the diameter of the molecule [m].

  The above conditions were found by evaluating the results of the inventors' experiments based on the mean free path. By performing vapor deposition under these conditions, by using a fluorine-containing organosilicon compound with different physical properties, it is possible to check the appearance of the workpiece placed within the maximum distance from the vapor deposition source within a range where the amount of vapor deposition does not become excessive. It is possible to manufacture a thin film that does not show a difference in the deposition amount. Therefore, according to the present invention, it is possible to stably produce a thin film of fluorine-containing organosilicon compounds having different physical property values within a range where the film thickness is not insufficient. For this reason, according to the present invention, a relatively low cost fluorine-containing organosilicon compound having a molecular weight of about 500 is used, and a fluorine-containing organosilicon compound having an excellent antifouling property and having a molecular weight of several thousand or more has high durability. Thin films can be manufactured economically with good yield.

  That is, according to the present invention, it is possible to stably produce a thin film using a high-molecular fluorine-containing organosilicon compound having a molecular weight of about 1000 to 10,000, not limited to a fluorine-containing organosilicon compound having a molecular weight of about 500. it can. An example of the polymer fluorine-containing organosilicon compound is represented by the following general formula (1) and / or general formula (2).

In the general formula (1), Rf ¹ is a perfluoroalkyl group, X is hydrogen, bromine, or iodine, Y is hydrogen or a lower alkyl group, Z is fluorine or a trifluoromethyl group, and R ¹ is a hydroxyl group Alternatively, a hydrolyzable group, R ² represents hydrogen or a monovalent hydrocarbon group. a, b, c, d, e are integers of 0 or more, a + b + c + d + e is an integer of at least 1, and the order of presence of each repeating unit delimited by a, b, c, d, e is It is not limited. f represents 0, 1, or 2; g represents any one of 1, 2, and 3. h represents an integer of 1 or more.

一般式（２）において、式中、Ｒf²は、式：−（Ｃ_kＦ_2k）Ｏ−（前記式中、ｋは１〜６の整数である）で表される単位を含み、分岐を有しない直鎖状のパーフルオロポリアルキレンエーテル構造を有する２価の基を表す。Ｒ³は炭素原子数１〜８の一価炭化水素基であり、Ｘは加水分解性基またはハロゲン原子を表す。ｐは０、１、２のいずれかを表す。ｎは１〜５の整数を表す。ｍ及びｒは２または３を表す。

In the general formula (2), Rf ² includes a unit represented by the formula: — (C _k F _2k ) O— (wherein k is an integer of 1 to 6), and has a branch. It represents a divalent group having a linear perfluoropolyalkylene ether structure that is not present. R ³ is a monovalent hydrocarbon group having 1 to 8 carbon atoms, and X represents a hydrolyzable group or a halogen atom. p represents 0, 1, or 2; n represents an integer of 1 to 5. m and r represent 2 or 3.

さらに、本発明者らは、上記の条件により成膜することにより、同一のフッ素含有有機ケイ素化合物を用いた場合であっても撥水性をさらに向上できることを見出した。したがって、本発明の薄膜の製造方法は、より撥水性が優れており、また、防汚性が優れている薄膜を製造できるという顕著な効果を奏するものである。

Furthermore, the present inventors have found that the water repellency can be further improved by forming a film under the above conditions even when the same fluorine-containing organosilicon compound is used. Therefore, the method for producing a thin film of the present invention has a remarkable effect that a thin film having more excellent water repellency and excellent antifouling property can be produced.

One embodiment of a film forming apparatus that realizes the manufacturing method of the present invention includes a first chamber for generating a thin film on a surface of a silicon-containing compound of a workpiece using a fluorine-containing organosilicon compound as a deposition source, and a first chamber. The pressure in the first chamber is set so that the ratio λ / Lm of the mean free path of the fluorine-containing organosilicon compound with respect to the maximum distance between the vapor deposition source installed in the workpiece and the workpiece is 0.2% or more. A film forming apparatus having a vacuum generating apparatus. More preferably, the vacuum generator can set the pressure in the first chamber so that the ratio of the mean free path to the maximum distance is 1.0% or more. If the molecular weight is about 500, this condition can be achieved by setting the inside of the chamber to about 10 ⁰ to 10 ⁻¹ Pa, and can often be achieved with a Roots pump. If the molecular weight is about several thousand, this condition can be achieved by setting the inside of the chamber to about 10 ⁻² to 10 ⁻³ Pa, and can be sufficiently achieved by using a turbo molecular pump. A configuration capable of maintaining a vacuum of 2 is sufficient.

As can be seen from the above equation (3), the mean free path is increased by reducing the factor n (number of molecules in 1 m ³ ). For this reason, the upper limit of the mean free path with respect to the maximum distance between the vapor deposition source and the workpiece is particularly limited by improving the capacity of the vacuum pump and making the chamber capable of withstanding a high vacuum and lowering the pressure in the chamber. It is not a thing. However, reducing the pressure in the chamber unnecessarily, that is, raising the degree of vacuum more than necessary, reduces the economic effect and is not intended by the present invention. Therefore, the vacuum is such that the mean free path is the same as the maximum distance between the deposition source and the workpiece, that is, the ratio λ / Lm of the mean free path to the maximum distance between the deposition source and the workpiece is 1 (100%) or more. In the present invention, the degree is almost useless, and the ratio λ / Lm of the mean free path to the maximum distance between the vapor deposition source and the work does not need to be 2 (200%) or more. For the purpose of economically producing a thin film with good yield, the ratio λ / Lm of the mean free path to the maximum distance between the deposition source and the work is more preferably about 50% or less, and about 10% or less. Even if it exists, it is preferable enough. High vacuum does not lead to a decrease in yield or performance of the thin film, so there is no need to actively control the upper limit of the ratio of mean free path to the maximum distance between the deposition source and the workpiece. This is as described above.

  A thin film of a fluorine-containing organosilicon compound is strongly bonded to a material containing silicon. Therefore, the present invention is suitable for a method of manufacturing an optical component having a film forming process for generating a thin film on an optical substrate having a surface of a silicon-containing compound using a fluorine-containing organosilicon compound as a deposition source. The optical substrate includes a wide variety of lenses, prisms, filters, mirrors, optical switches, and the like.

Even if the fluorine-containing organosilicon compound thin film is a non-glass workpiece, a strong film can be formed if the surface of the workpiece is formed of a layer containing silicon. A layer containing silicon dioxide as a main component is an example, and since it is transparent, the present invention can be applied by coating on a plastic optical substrate. The layer containing silicon dioxide as a main component does not need to be a single layer, and an example thereof is an antireflection film. For example, it is a multilayer film made of SiO ₂ and ZrO ₂ . Further, when the glass substrate is provided with an antireflection film, the surface is a layer mainly composed of silicon dioxide, which is suitable for the production method of the present invention. Even in the case where the substrate is hard-coated, in the case of an optical element, an antireflection film is formed on the surface thereof, which is suitable for the manufacturing method of the present invention.

  As described above, in the present invention, the ratio of the mean free path of the fluorine-containing organosilicon compound as the vapor deposition source is used as an index, and the chamber pressure is set, thereby using the fluorine-containing organosilicon compound having different physical property values to achieve high performance. The thin film can be manufactured economically with good yield. Therefore, the present invention can provide a manufacturing method and a film forming apparatus suitable for manufacturing an antifouling film on the surface of an optical element such as a lens.

  1A and 1B show an outline of a support device 80 on which a workpiece is mounted. The support device 80 includes a disc-shaped dome 81 that is convexly curved upward, and a plurality of workpieces 40 are arranged concentrically on the dome 81 and can be rotated while holding the arrangement. . In the support device 80 shown in FIG. 1A, a plurality of substrates 40 serving as eyeglass lenses as workpieces can be set concentrically around the rotating shaft 82 in 1 to 4 steps.

  FIG. 2 shows a schematic configuration of a film forming apparatus 50 that coats the surface of a substrate (work) 40 mounted on the support apparatus 80. The film forming apparatus 50 includes three chambers CH1, CH2, and CH3 through which the support device 80 can pass. These chambers CH <b> 1 to CH <b> 3 are connected and can pass through with the support device 80 holding the substrate 40. The chambers CH1 to CH3 can be sealed with each other, and the internal pressures of the chambers CH1 to CH3 can be controlled by the vacuum generators 52, 53, and 54, respectively.

  The chamber CH1 is an entrance or a gate chamber, and after introducing the support device 80 from the outside, degassing is performed by holding the interior of the chamber CH1 below a certain pressure for a certain time. The chamber CH1 is provided with a vacuum generator 52 including a rotary pump 52a, a roots pump 52b, and a cryopump 52c.

The chamber CH2 is a second chamber in which an antireflection film (AR film) 43 is formed. For this reason, inside the chamber CH2, AR film deposition sources 55a and 55b, an electron gun 56 for depositing the AR film deposition source 55, and an openable / closable shutter 57 for adjusting the deposition amount are provided. The AR film 43 employs a structure in which a thin film mainly composed of silicon dioxide and a thin film of another member, for example, one or more of TiO ₂ , Nb ₂ O ₃ , Ta ₂ O ₅ and ZrO ₂ are laminated. Is done. For this reason, at least two film deposition sources 55a and 55b are prepared. The chamber CH2 is maintained at an appropriate pressure by a vacuum generating device 53 including a rotary pump 53a, a roots pump 53b, and a cryopump 53c.

  The chamber CH3 is a first chamber that forms an antifouling outermost surface layer by depositing a fluorine-containing organosilicon compound. Therefore, an evaporation source 59 impregnated with a fluorine-containing organosilicon compound, a heater (halogen lamp) 68, and a correction plate 67 are installed inside the chamber. The correction plate 67 is a fixed type, and the amount of vapor deposition emitted toward the support device 80 can be adjusted by adjusting the opening degree. The chamber CH3 is maintained at an appropriate pressure by a vacuum generator 54 including a rotary pump 54a, a roots pump 54b, and a turbo molecular pump 54c.

  FIG. 3 shows a process for forming a thin film on the workpiece 40 in the film forming apparatus 50. The support device 80 on which the workpiece 40 is set is introduced into the chamber CH1 and degassed (ST1). In the case of a plastic lens, the work 40 in which the hard coat layer 42 is previously formed on the plastic substrate 41 is set on the support device 80. In the case of a glass lens, the workpiece 40 on which no hard coat layer is formed is set on the support device 80.

  Next, the support device 80 is guided to the chamber CH2, and an antireflection film (AR film) 43 is formed on the surface of the workpiece 40 (ST2). In this process, a plurality of thin films are stacked, and a thin film mainly composed of silicon dioxide is formed as the uppermost layer 43a.

  Subsequently, the support device 80 is guided to the chamber CH3, and the antifouling layer 44 made of a fluorine-containing organosilicon compound is formed on the surface of the workpiece 40 (film formation step, ST3).

  After the antifouling layer 44 is formed, the chamber CH3 is gradually returned to atmospheric pressure, and the workpiece 40 is taken out together with the support device 80. The workpiece 40 is put into a constant temperature and humidity chamber (not shown) and annealed in an atmosphere of appropriate humidity and temperature. Alternatively, aging is performed by leaving in a room for a predetermined time (ST4).

  FIG. 4 shows an enlarged view of the relationship between the support device 80 on which the workpiece 40 is mounted and the vapor deposition source 59 in the chamber CH3. Although the dome 81 of the support device 80 in which the workpieces 40 are arranged is curved and the difference in the distance from the vapor deposition source 59 is reduced, the vapor deposition distance L1 between the respective workpieces 40a to 40d and the vapor deposition source 59. ~ L4 is different. In this apparatus, the vapor deposition distance L1 of the first dome work 40a is 287 mm, the vapor deposition distance L2 of the second dome work 40b is 263 mm, and the third dome work in order from the rotating shaft 82 to the outside. The vapor deposition distance L3 of 40c is 257 mm, and the vapor deposition distance L4 of the work 40d at the fourth stage of the dome is 278 mm. Therefore, in the film forming apparatus 50 of this example, the maximum distance Lm between the vapor deposition source 59 and the workpiece 40 is 287 mm, and the condition in which the vapor deposition amount is not uniform in this range is for producing a uniform thin film. Desired.

  Hereinafter, an example in which an antifouling layer is formed on the surface of the spectacle lens using the film forming apparatus 50 will be described.

(Example 1)
A plastic lens for eyeglasses (Seiko Epson Co., Ltd .: Seiko Super Sovereign) having a hard coat layer 42 formed on a plastic substrate 41 is set as the work 40 on the support device 80, degassed in the chamber CH1, and then the chamber. In CH2, SiO ₂ and ZrO ₂ layers were alternately deposited, and an antireflection film 43 composed of these layers was formed. The uppermost layer of the antireflection film 43 is a SiO ₂ layer. After that, the antifouling layer 44 was formed by moving the support device 80 to the chamber CH3. The process up to the chamber CH3 is common to the examples and comparative examples described below, and will not be described below.

  In Example 1, a fluorine-containing organosilicon compound (KY-130, hereinafter referred to as Sample 1) manufactured by Shin-Etsu Chemical Co., Ltd. was used as the vapor deposition source 59. The molecular weight M of the sample 1 is estimated to be in the range of 2000 to 3000, and the molecular diameter n is estimated to be 2 nm. Sample 1 contains a composition represented by the following general formula (2).

一般式（２）において、式中、Ｒf²は、式：−（Ｃ_kＦ_2k）Ｏ−（前記式中、ｋは１〜６の整数である）で表される単位を含み、分岐を有しない直鎖状のパーフルオロポリアルキレンエーテル構造を有する２価の基を表す。Ｒ³は炭素原子数１〜８の一価炭化水素基であり、Ｘは加水分解性基またはハロゲン原子を表す。ｐは０、１、２のいずれかを表す。ｎは１〜５の整数を表す。ｍ及びｒは２または３を表す。

In the general formula (2), Rf ² includes a unit represented by the formula: — (C _k F _2k ) O— (wherein k is an integer of 1 to 6), and has a branch. It represents a divalent group having a linear perfluoropolyalkylene ether structure that is not present. R ³ is a monovalent hydrocarbon group having 1 to 8 carbon atoms, and X represents a hydrolyzable group or a halogen atom. p represents 0, 1, or 2; n represents an integer of 1 to 5. m and r represent 2 or 3.

  Sample 1 was diluted with a fluorine-based solvent (Sumitomo 3M Co., Ltd .: Novec HFE-7200) to prepare a 3% solids concentration solution, impregnated with 1 g of porous ceramic pellets, and dried. The chamber 59 was set as the vapor deposition source 59.

The chamber CH3 was deposited using the turbo molecular pump 54c so that the pressure was maintained in the range of 2.0 to 3.0 × 10 ⁻² Pa. The mean free path λ in this pressure range is 8.5 to 12.8 mm, and the ratio λ / Lm to the maximum deposition distance Lm (287 mm) is 3.0 to 4.4%.

  During film formation, the halogen lamp was used as the heater 68 to heat the pellets of the vapor deposition source 59 to 600 ° C. to evaporate the fluorine-containing organosilicon compound. The deposition time is 5 minutes. After the deposition was completed, the inside of the chamber (vapor deposition machine) CH3 was gradually returned to atmospheric pressure, the work 40 was taken out, put into a constant temperature and humidity chamber set at 60 ° C. and 60% RH, and annealed by holding for 2 hours. .

(Example 2)
In Example 2, the same sample 1 as in Example 1 was used as the evaporation source 59, pellets made of porous ceramics were prepared under the same conditions, and set as the evaporation source 59 in the chamber CH3. The chamber CH3 was deposited using the turbo molecular pump 54c so that the pressure was maintained in the range of 6.0 to 7.0 × 10 ⁻² Pa. The mean free path λ in this pressure range is 3.6 to 4.3 mm, and the ratio λ / Lm to the maximum deposition distance Lm is 1.3 to 1.5%. The film forming conditions and the subsequent annealing conditions were the same as in Example 1.

(Example 3)
In Example 3, as the vapor deposition source 59, the same sample 1 as in Example 1 was used, and a 3% solid concentration solution was prepared using the same solvent. The chamber 59 was set as the vapor deposition source 59. The chamber CH3 was deposited by using a turbo molecular pump 54c so that the pressure was maintained in the range of 1.0 to 2.0 × 10 ⁻¹ Pa. The mean free path λ in this pressure range is 1.3 to 2.6 mm, and the ratio λ / Lm to the maximum deposition distance Lm is 0.4 to 0.9%. The film forming conditions and the subsequent annealing conditions were the same as in Example 1.

Example 4
In Example 4, a fluorine-containing organosilicon compound (OPTOOL DSX, hereinafter referred to as Sample 2) manufactured by Daikin Industries, Ltd. was used as the vapor deposition source 59. The molecular weight M of the sample 2 is in the range of 4000 to 5000, and the molecular diameter n is estimated to be 4 nm. Sample 2 contains a composition represented by the following general formula (1).

ただし、一般式（１）において、式中、Ｒf¹はパーフルオロアルキル基、Ｘは水素、臭素、またはヨウ素、Ｙは水素または低級アルキル基、Ｚはフッ素またはトリフルオロメチル基、Ｒ¹は水酸基または加水分解可能な基、Ｒ²は水素または１価の炭化水素基を表す。ａ、ｂ、ｃ、ｄ、ｅは０以上の整数で、ａ＋ｂ＋ｃ＋ｄ＋ｅは少なくとも１以上の整数であり、ａ、ｂ、ｃ、ｄ、ｅでくくられた各繰り返し単位の存在順序は、式中において限定されない。ｆは０、１、２のいずれかを表す。ｇは１、２、３のいずれかを表す。ｈは１以上の整数を表す。

In the general formula (1), Rf ¹ is a perfluoroalkyl group, X is hydrogen, bromine, or iodine, Y is hydrogen or a lower alkyl group, Z is fluorine or a trifluoromethyl group, and R ¹ is a hydroxyl group Alternatively, a hydrolyzable group, R ² represents hydrogen or a monovalent hydrocarbon group. a, b, c, d, e are integers of 0 or more, a + b + c + d + e is an integer of at least 1, and the order of presence of each repeating unit delimited by a, b, c, d, e is It is not limited. f represents 0, 1, or 2; g represents any one of 1, 2, and 3. h represents an integer of 1 or more.

Sample 2 was diluted in a fluorine-based solvent (Daikin Kogyo Co., Ltd .: demnum solvent) to prepare a 3% solid content solution, and 1 g of this was impregnated into a porous ceramic pellet and dried. Set to chamber CH3 as source 59. The chamber CH3 was deposited using the turbo molecular pump 54c so that the pressure was maintained in the range of 1.0 to 2.0 × 10 ⁻² Pa. The mean free path λ of the sample 2 in this pressure range is 3.2 to 6.4 mm, and the ratio λ / Lm to the maximum deposition distance Lm is 1.1 to 2.2%.

  During film formation, the silane compound was evaporated by heating the pellet of the vapor deposition source 59 to 630 ° C. by the heater 68. The deposition time is 5 minutes. After completion of vapor deposition, the inside of the chamber (vapor deposition machine) CH3 was gradually returned to atmospheric pressure, the work 40 was taken out, put into a constant temperature and humidity chamber set at 60 ° C. and 90% RH, and annealed by holding for 2 hours. .

(Comparative Example 1)
In Comparative Example 1, sample 1 was used as a deposition source 59, diluted to the same solvent as in Example 1 to prepare a 3% solid content solution, impregnated with 2 g of porous ceramic pellets, and dried. This was set as the vapor deposition source 59 in the chamber CH3. The amount of impregnation was increased to ensure the amount of evaporation at low vacuum. The chamber CH3 was deposited using a rotary pump 54a and a roots pump 54b so that the pressure was maintained in the range of ^1.0 to 2.0 × 10 ⁰ Pa.

  The average free path λ of the sample 1 in this pressure range is 0.1 to 0.3 mm, and the ratio λ / Lm to the maximum deposition distance Lm is 0.04 to 0.10%.

  During film formation, the silane compound was evaporated by heating the pellet of the vapor deposition source 59 to 600 ° C. by the heater 68. The deposition time is 5 minutes. After vapor deposition, annealing was performed under the same conditions as in Example 1.

(Comparative Example 2)
In Comparative Example 2, a sample 2 was used as the vapor deposition source 59 and diluted with the same solvent as in Example 4 to prepare a 3% solids concentration solution. This was impregnated with 2 g of porous ceramic pellets and dried. This was set as the vapor deposition source 59 in the chamber CH3. Also in this example, the amount of impregnation was increased in order to ensure the amount of evaporation at a low degree of vacuum. The chamber CH3 was deposited using a rotary pump 54a and a roots pump 54b so that the pressure was maintained in the range of 1.0 to 3.0 × 10 ⁰ Pa. The average free path λ of the sample 2 in this pressure range is 0.02 to 0.1 mm, and the ratio λ / Lm to the maximum deposition distance Lm is 0.01 to 0.02%.

  During film formation, the silane compound was evaporated by heating the pellet of the vapor deposition source 59 to 630 ° C. by the heater 68. The deposition time is 5 minutes. After the deposition, annealing was performed under the same conditions as in Example 4.

  FIG. 5 collectively shows the results of evaluating the workpiece 40 on which the antifouling layer (water repellent film) 44 is formed under the above conditions. First, by evaluating the appearance of the lens after vapor deposition (after annealing), the appropriateness and inappropriateness of the vapor deposition amount and the difference in vapor deposition amount (step unevenness) in the respective works 40a to 40d are evaluated. Appropriate or unsuitable for the amount of deposition, the appearance of the lens after annealing is observed in a dark box to check for the occurrence of water droplets. When the amount of deposition is excessive, it is utilized that water repellent molecules that form an antifouling layer on the lens surface cause uneven distribution due to water droplets condensed on the surface and remain as water droplet traces. In the table, “◯” indicates that there is no trace of water droplets and the deposition amount is appropriate. “X” indicates that water-drop-like dirt is generated, and indicates that the deposition amount is excessive.

  The unevenness of the stage is evaluated by evaluating the appearance of the lens after annealing in a dark box, wiping the surface of the lens with lens paper, and observing the wiping trace. The greater the amount of deposition, the greater the amount wiped with lens paper, and the stronger the wiping mark. If the deposition amount is appropriate or insufficient, no wiping marks will be made. In the table, “◯” indicates that there is almost no wiping trace or water droplet trace of the work at each stage of the dome, and a film having an appropriate thickness is uniformly deposited without unevenness. On the other hand, “x” indicates that a strong wiping trace or a water droplet trace remains on a part of the workpiece, and the amount of deposition is different in each dome.

  Also, the performance of the antifouling layer is evaluated by contact angle, ink repelling property, and ink wiping property. In addition, after these tests are first performed, artificial aging is performed, and then the same evaluation is performed to verify durability. In this example, cotton cloth is used, and the durability is evaluated by reciprocating the convex surface (surface) of the lens 5000 times while applying a load of 200 g and evaluating the performance of the antifouling layer before and after that.

  The contact angle shows the result of measuring the contact angle of pure water by a droplet method using a contact angle meter (Kyowa Kagaku Co., Ltd .: CA-D type). Thereby, the water repellency of the antifouling layer can be evaluated.

  The ink repelling property is determined based on the following criteria by drawing a straight line of about 4 cm on the convex surface of the lens with a black oil marker (Zebra Co., Ltd .: Himackey Care). “○” indicates that the ink is a single line or dot, “△” indicates that the ink is partially repelled, and “×” indicates that the ink can be clearly drawn with a line. Show. In terms of ink repelling property, the state of the ink having wettability higher than that of water is observed, and the surface state of the antifouling layer can be determined in more detail. If the ink repelling property is good, it is considered that the surface of the antifouling layer is stable and the surface energy is low. On the other hand, if the ink repelling property is poor, the surface of the antifouling layer is rough and the surface energy is considered high.

  The ink wiping property indicates the ease of wiping by drawing a line in the same manner as the method shown for ink repelling property, leaving the mark for 5 minutes, and then wiping the mark with wipe paper (Crecia: Kay Dry). It is a thing. “◯” indicates that it can be completely removed by wiping 10 times or less, “Δ” indicates that it can be completely removed by wiping 11 to 20 times, and “×” indicates that after 20 times of wiping. This indicates that there is a part that cannot be removed. The ink wiping property indicates the remaining state of the fluorine-containing organosilicon compound on the surface of the workpiece, and is an especially important evaluation value in the durability test.

  As can be seen from the evaluation results in FIG. 5, in Comparative Examples 1 and 2, the amount of deposition on the second and third dome is excessive, and the amount of deposition on the first and fourth dome is appropriate in terms of appearance. Since the contact angle before a test is less than 100 degrees, it turns out that the amount of vapor deposition is insufficient. Therefore, it is clear that step unevenness has occurred. Before the durability test, the ink wiping property is good, but the ink repelling property is not good. After the durability test, both the contact angle, the ink repelling property, and the wiping property are deteriorated, and as a comprehensive evaluation, the conditions of Comparative Examples 1 and 2 are not conditions that can be used as a product manufacturing method.

  On the other hand, in Examples 1, 2, and 4, the deposition amount is appropriate over each stage of the dome, and no unevenness is observed. Even after the durability test, the contact angle, ink repelling property and ink wiping property are good. Therefore, the comprehensive evaluation with respect to the workpieces of Examples 1, 2, and 4 is good, and the conditions of Examples 1, 2, and 4 are conditions that can be used as a product manufacturing method.

  In Example 3, the contact angle and ink repellency after the durability test of the four-step dome are lowered.

  However, the ink wiping property is sufficiently good. Therefore, the comprehensive evaluation with respect to the workpiece of Example 3 is good, and it can be said that the conditions of Example 3 are also conditions that can be used as a manufacturing method of a product. However, the conditions of Examples 1, 2 and 4 are more suitable as a method for manufacturing a product.

  When such an evaluation result is applied to the ratio λ / Lm of the mean free process λ with respect to the maximum deposition distance Lm, a layer having an appropriate film thickness is uniformly obtained when the ratio λ / Lm is 0.4% or more. Further, the performance and durability of the manufactured antifouling film are good. On the other hand, when the ratio λ / Lm is 0.1% or less, there is unevenness, the film thickness becomes excessive, and the manufactured antifouling film has low durability. Therefore, the ratio λ / Lm of the mean free path λ with respect to the maximum deposition distance Lm is one of the parameters that should be managed in order to produce an antifouling film having an appropriate film thickness, and its lower limit is 0.2. It turns out that it is good to think that it exists in about%.

  Furthermore, from the evaluation shown in FIG. 5, the ratio λ / Lm of the mean free path λ to the maximum deposition distance Lm is not only an important factor for producing an antifouling layer having an appropriate film thickness, but also contains fluorine. It is also revealed for the first time in this specification that this is an important factor for producing a highly durable antifouling layer with an organosilicon compound. That is, from the evaluation shown in FIG. 5, the ratio λ / Lm is required to be about 0.2% or more from the viewpoint of durability of the antifouling layer formed by vapor deposition. Furthermore, comparing the evaluation of Example 3 with Examples 1, 2, and 4, it can be seen that the ratio λ / Lm is more preferably 1.0% or more.

  The relationship between the ratio λ / Lm of the mean free path λ with respect to the maximum deposition distance Lm and the water repellency of the antifouling layer can be qualitatively explained with reference to the residual gas concentration. The residual gas concentration Cg contained during film formation is expressed by the following equation (4).

Cg = 4.37 × 10 ⁻⁴ × (P / √ (Mg · T)) × (M / (ρ · d)) (4)
Where P: residual gas pressure [Pa], Mg: molecular weight [g / mol] of residual gas, T: temperature [K], M; molecular weight [g / mol] of evaporate, ρ: density of film [g / mol] cm ³ ], d; vapor deposition rate [cm / s].

  This equation (4) indicates that the amount of residual gas taken into the thin film increases as the pressure increases and the molecular weight of the vapor deposition material increases. Vapor deposition at a low ratio λ / Lm in Comparative Examples 1 and 2 corresponds to a state where the residual gas pressure is high in Equation (4). Furthermore, samples 1 and 2 have a molecular weight of 2000 or more in order to obtain high water repellency, and a sample having a larger molecular weight than conventional fluorine-containing organosilicon compounds. Therefore, it is considered that the fluorine-containing organosilicon compound film formed has many vacancies and is a so-called “gasaga” film. For this reason, since the film | membrane of the fluorine-containing organosilicon compound manufactured on the conditions of Comparative Examples 1 and 2 also has few bonding points with the layer which has silicon dioxide as a main component on the surface of the lens which is the workpiece | work 40, it is a siloxane bond. It is thought that the durability is lowered due to the relatively small quantity of In addition, since the amount of deposition tends to be excessive, the film becomes thicker. Even if annealing is performed under the same conditions, the amount of water at the interface between the fluorine-containing organosilicon compound and the layer containing silicon dioxide as a main component is insufficient, resulting in a reaction due to annealing. The speed is slow, and the number of siloxane bonds is considered to be relatively small in this respect as well. The low durability of the fluorine-containing organosilicon compound antifouling film is prominent in the ink wiping property after the durability test, and the antifouling film is peeled off and the remaining amount of the work surface is small. Not only the wiping performance but also the wiping performance is degraded.

  The films produced in Comparative Examples 1 and 2 are considered to have reduced antifouling properties from the viewpoint of surface energy. This is because it is necessary to reduce the surface energy as much as possible in order to develop water repellency and antifouling properties, and this surface energy is strongly influenced by the orientation of the water repellent molecules. For example, the surface energy when the water repellent molecules are vertically aligned is 6 dyn / cm, but increases to 18 to 20 dyn / cm when the alignment direction is inclined. A small ratio λ / Lm means that the mean free path λ is short and the collision between molecules is frequently repeated. Therefore, it is considered that the orientation direction of the molecules is considerably disturbed at the stage where the water repellent molecules are entangled with each other by the time they reach the surface of the workpiece 40 and adhere to the surface of the workpiece 40.

  The increase in surface energy is remarkably exhibited in the ink resilience. The workpieces manufactured under the conditions of Comparative Examples 1 and 2 show no difference in the contact angle with water compared to the workpiece 40 manufactured under the conditions of Examples 1 to 4. However, the repelling property of ink with high wettability and low surface energy shows a significant difference before the endurance test. The workpieces of Comparative Examples 1 and 2 have the same water repellent property but poor ink repellent property. Therefore, even though the surface energy is small because it is a fluorine-containing compound, the film surface orientation state is low. From the point of view, the surface energy is not small.

  The workpieces manufactured under the conditions of Examples 1 to 4 are excellent in ink repelling property and wiping property before and after the durability test, and exhibit sufficient performance as a product. Therefore, it is considered that the workpiece 40 manufactured under the conditions of Examples 1 to 4 is superior to Comparative Examples 1 and 2 in terms of residual gas concentration and surface energy. In Example 3, although the ink resilience after the durability test is slightly lowered, the ratio λ / Lm is almost borderline, so that the durability of the film is slightly lower than the other examples. Is considered to be a factor.

  Thus, from the evaluation results shown in FIG. 5, by setting the ratio λ / Lm to 0.2% or more, the surface is dense and highly durable, and the molecular arrangement of the fluorine-containing organosilicon compound is arranged. It turns out that an antifouling layer with small energy can be manufactured. Further, by setting the ratio λ / Lm to 0.2% or more, the deposition amount can be properly maintained, and unevenness of steps can be prevented. Therefore, the film thickness of the antifouling layer made of a fluorine-containing organosilicon compound is about 10 nm or Below that, there is a possibility that it can be controlled by vapor deposition. Being able to control to a desired film thickness by vapor deposition means that the step of wiping off the excessive film thickness after vapor deposition can be omitted, and furthermore, an annealing step (ST4 in FIG. 3) that ensures the strength of the film for wiping. This suggests that it can be omitted. Therefore, by setting the ratio λ / Lm within the range of the present invention, an antifouling film having no unevenness and having excellent durability and antifouling properties can be stably produced with a fluorine-containing organosilicon compound, and annealing can also be performed. It is possible to provide a manufacturing method that can omit the steps and can more economically manufacture the work on which the antifouling film is formed.

  In the above example, the fluorine-containing organosilicon compound is formed after forming the hard coat and the antireflection film on the surface of the plastic lens. However, the fluorine-containing organic silicon compound is directly formed on the surface of the glass lens. Even when an organosilicon compound is formed, the present invention can be applied because the substantial conditions do not change. The same applies to the case of forming an antifouling layer with a fluorine-containing organosilicon compound after forming an antireflection film on the surface of the glass lens. If the interface with the antifouling layer is a silicon-containing compound layer, silane Membranes can be formed by taking advantage of the bond strength with compounds. The present invention is suitable for the surface treatment of an optical element in which performance deterioration due to surface contamination is expected, but can also be applied to other applications where it is desired to form a water-repellent surface.

Fig.1 (a) is a top view which shows the outline | summary of the dome-type support apparatus which supports a workpiece | work, FIG.1 (b) is sectional drawing. It is a figure which shows the outline | summary of the film-forming apparatus. It is a figure which shows the process in which an antireflection film and an antifouling film | membrane are manufactured on the surface of a workpiece | work with the film-forming apparatus of FIG. It is a figure which expands and shows the relationship between the workpiece | work and vapor deposition source in the chamber for vapor deposition of the film-forming apparatus. It is a figure which shows the evaluation of the workpiece | work formed into a film on several conditions.

Explanation of symbols

40 Workpiece 41 Lens body, 42 Hard coat layer, 43 Antireflection film 44 Antifouling layer (water repellent film)
50 Deposition device, 54 Vacuum generation device 59 Deposition source 80 Support device

Claims (15)

A method for producing a thin film having a film forming step for forming a thin film on a surface of a silicon-containing compound of a workpiece, using a fluorine-containing organosilicon compound as a deposition source,
In the film forming step, the chamber pressure is set such that the ratio of the mean free path of the fluorine-containing organosilicon compound to the maximum distance between the vapor deposition source and the workpiece installed in the chamber is 0.2% or more. A method for manufacturing a thin film.   2. The thin film manufacturing method according to claim 1, wherein in the film forming step, the pressure is set so that a ratio of the mean free path to the maximum distance is 1.0% or more. The method for producing a thin film according to claim 1, wherein the fluorine-containing organosilicon compound is represented by the following general formula (1) and / or general formula (2).
In the general formula (1), Rf ¹ is a perfluoroalkyl group, X is hydrogen, bromine, or iodine, Y is hydrogen or a lower alkyl group, Z is fluorine or a trifluoromethyl group, and R ¹ is a hydroxyl group Alternatively, a hydrolyzable group, R ² represents hydrogen or a monovalent hydrocarbon group. a, b, c, d, e are integers of 0 or more, a + b + c + d + e is an integer of at least 1, and the order of presence of each repeating unit delimited by a, b, c, d, e is It is not limited. f represents 0, 1, or 2; g represents any one of 1, 2, and 3. h represents an integer of 1 or more.

In the general formula (2), Rf ² includes a unit represented by the formula: — (C _k F _2k ) O— (wherein k is an integer of 1 to 6), and has a branch. It represents a divalent group having a linear perfluoropolyalkylene ether structure that is not present. R ³ is a monovalent hydrocarbon group having 1 to 8 carbon atoms, and X represents a hydrolyzable group or a halogen atom. p represents 0, 1, or 2; n represents an integer of 1 to 5. m and r represent 2 or 3.

  The method for producing a thin film according to claim 1, wherein the fluorine-containing organosilicon compound has a molecular weight in the range of about 1000 to 10,000.   2. The method for producing a thin film according to claim 1, wherein the surface of the workpiece is a layer mainly composed of silicon dioxide. A method of manufacturing an optical component having a film forming step of forming a thin film using a fluorine-containing organosilicon compound as an evaporation source on an optical substrate having a surface of a silicon-containing compound,
In the film forming step, the chamber pressure is set such that the ratio of the mean free path of the fluorine-containing organosilicon compound to the maximum distance between the vapor deposition source and the workpiece installed in the chamber is 0.2% or more. Manufacturing method of optical parts.   7. The method of manufacturing an optical component according to claim 6, wherein in the film forming step, the pressure is set so that a ratio of the mean free path to the maximum distance is 1.0% or more. The method for producing an optical component according to claim 6, wherein the fluorine-containing organosilicon compound is represented by the following general formula (1) and / or general formula (2).
In the general formula (1), Rf ¹ is a perfluoroalkyl group, X is hydrogen, bromine, or iodine, Y is hydrogen or a lower alkyl group, Z is fluorine or a trifluoromethyl group, and R ¹ is a hydroxyl group Alternatively, a hydrolyzable group, R ² represents hydrogen or a monovalent hydrocarbon group. a, b, c, d, e are 0 or an integer of 1 or more, a + b + c + d + e is an integer of 1 or more, and the order in which each repeating unit delimited by a, b, c, d, e is represented by the formula It is not limited in the inside. f represents 0, 1, or 2; g represents any one of 1, 2, and 3. h represents an integer of 1 or more.

In the general formula (2), Rf ² includes a unit represented by the formula: — (C _k F _2k ) O— (wherein k is an integer of 1 to 6), and has a branch. It represents a divalent group having a linear perfluoropolyalkylene ether structure that is not present. R ³ is a monovalent hydrocarbon group having 1 to 8 carbon atoms, and X represents a hydrolyzable group or a halogen atom. p represents 0, 1, or 2; n represents an integer of 1 to 5. m and r represent 2 or 3.

  7. The method for producing an optical product according to claim 6, wherein the molecular weight of the fluorine-containing organosilicon compound is in the range of about 1000 to 10,000.   7. The method of manufacturing an optical component according to claim 6, wherein the surface of the optical substrate is a layer mainly composed of silicon dioxide.   11. The method of manufacturing an optical component according to claim 10, wherein the layer mainly composed of silicon dioxide forms a part of an antireflection film formed on the optical substrate.   12. The method of manufacturing an optical component according to claim 11, wherein the antireflection film is formed on a hard coat film formed on the optical substrate. A first chamber for forming a thin film on the surface of the silicon-containing compound of the workpiece using a fluorine-containing organosilicon compound as a deposition source;
The first chamber so that the ratio of the mean free path of the fluorine-containing organosilicon compound to the maximum distance between the vapor deposition source and the workpiece installed in the first chamber is 0.2% or more. A film forming apparatus having a vacuum generating apparatus for setting the pressure inside the apparatus.   14. The film forming apparatus according to claim 13, wherein the vacuum generating apparatus sets the pressure in the first chamber so that a ratio of the mean free path to the maximum distance is 1.0% or more. The workpiece according to claim 13, wherein the workpiece is an optical substrate, and has a second chamber for forming an antireflection film having a layer mainly composed of silicon dioxide on the optical substrate.
The film forming apparatus, wherein the first chamber is connected to the second chamber.

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