JP2010222703A - Method for modifying solid surface, and surface-modified base material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for modifying a solid surface, and to provide a surface-modified base material. <P>SOLUTION: Regarding the method for modifying a solid surface, the surface of a base material is coated with organic molecules composed of an annular, branched or straight-chain structure via covalent bonding so as to form a molecular film, thus interaction between the liquid and the surface of the solid is remarkably suppressed, and a difference between a progress contact angle (θ<SB>A</SB>) and a retreat contact angle (θ<SB>R</SB>), (θ<SB>A</SB>-θ<SB>R</SB>, hysteresis) is reduced, thus, the sliding-down of droplets-water gliding properties, water resistance and the removability of droplets from the surface of the solid are improved so as to obtain corrosion resistance or corrosion preventability, and the surface is modified into the one exhibiting water repellency having hysteresis of 5° or super-water repellency. The base material is obtained by performing the surface modification. In this way, the method for modifying a solid surface which can modify a solid surface into a surface having extremely reduced hysteresis, and the base material in which salt water hardly remains on the surface owing to an extremely narrow dynamic contact angle, and which exhibits excellent corrosion resistance are obtainable. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

The present invention relates to a method for modifying a solid surface and a surface-modified substrate, and more specifically, an organic molecule having a cyclic, branched, or straight chain structure is covalently bonded to a solid surface. By coating and forming a molecular film, the interaction between the liquid and the solid surface is remarkably suppressed, and the difference (θ _A −θ _R , hysteresis) between the advancing contact angle (θ _A ) and the receding contact angle (θ _R ) Method for improving the surface of a solid and improving the anti-corrosion or anti-corrosion properties by improving the drop sliding / sliding water resistance, water resistance, and droplet removal from the solid surface It is about.

  The present invention provides a metal, metal oxide film, metal oxide, alloy, semiconductor, polymer, ceramics, and glass substrate surface that exhibits “no hysteresis” water repellency and super water repellency, which is difficult with conventional methods. New technologies for surface treatment of solid surfaces that can improve the anti-corrosion or anti-corrosion properties by improving the sliding and water-sliding properties, water resistance, and droplet removability from the solid surface. Provide new products.

  The adsorption phenomenon of organic molecules on the solid surface is not only a basic research field in surface science such as molecular orientation, density, kinetics of surface chemical reaction, elucidation of reaction specificity, but also improvement of antiseptic and adhesion, It is recognized as an important research theme in the field of practical surface treatment such as hydrophobization / hydrophilization.

  Recently, research on a self-assembled monolayer (SAM) formed by chemisorption of organic molecules has greatly advanced, and has attracted attention not only in the basics but also in industrial applications. The self-assembled monolayer can be arbitrarily designed with respect to the membrane structure, the functionality of the solid surface, the reactivity, etc. by selecting the organic molecules constituting the membrane according to the purpose.

For example, by coating a self-assembled monolayer terminated with a functional group such as NH ₂ group or CHO group, a highly reactive surface can be formed, whereas a CH ₃ group or CF ₃ group can be formed. If a self-assembled monolayer terminated with such an inert functional group is used, the surface energy can be lowered and the surface can be hydrophobized.

Representative examples of combinations of organic molecules and substrates that form self-assembled monolayers include surfaces of metal single crystals and GaAs, organosulfur compounds such as thiols, and Si (natural oxide film [SiO ₂ ]) surfaces. Also well known are examples of glass surfaces and organosilane compounds (R ′ _n SiX _4-n , n = 1, 2, 3, generally X = Cl, OR group). In particular, since self-assembled monolayers of organosilane compounds were reported in 1980 by a group of Prof. Sagiv et al. In Israel (Non-Patent Document 1), research in this field has been energetically conducted around the world. It has been broken.

Since organic silane forms a strong siloxane (Si—O—Si) bond with an oxide surface such as SiO ₂ , it forms a self-assembled monolayer excellent in mechanical strength and chemical stability. Compared with the formation of self-assembled monolayers on Si and glass surfaces, there are few studies on the formation of self-assembled monolayers on the surface of polymers, metals, metal oxide films, metal oxides, and alloys, and biomolecules such as cells Many of them are intended to suppress the adhesion of the resin and to improve the antiseptic properties and wear resistance by reducing the surface energy / hydrophobizing.

  In general, the polymer surface is chemically inert, and the polymer surface modified and activated by plasma or the like is very unstable, and the type of polar groups generated by activation is not uniform. Therefore, since it is randomly oriented, it is difficult to form a high-density / highly oriented self-assembled monolayer. There is also a problem that high temperature processing is difficult due to the low heat resistance of the polymer substrate.

  On the other hand, on the metal (including metal oxide film), metal oxide, and alloy surfaces, in addition to the organic silane compound, phosphonic acid (for example, Non-Patent Document 2), long-chain alkyl fatty acid (for example, Non-Patent Document 3), It has been reported to form a self-assembled monolayer.

  As described above, it is possible to control the surface characteristics of various solids, particularly “wetting”, depending on the type of terminal functional group of the molecule used for forming the self-assembled monolayer. The wettability of a solid surface is generally measured by the contact angle and evaluated by its size. The larger the value, the worse the wettability (hydrophobic / water repellent), and the smaller the contact angle, the better the wettability (hydrophilic).

  For example, when a self-assembled monolayer is formed on a glass surface using a fluorine-based silane coupling agent exhibiting water repellency, the surface becomes very hydrophobic, and the resulting water droplet contact angle is 117 °. The water droplet contact angle is a value measured in a state where the water droplet is stationary on a horizontal plane, that is, a “static contact angle”. Although this surface exhibits high water repellency, water adheres to the solid surface and is inferior in scattering properties, water slidability, and water droplet removal properties. This phenomenon is greatly related to the dynamic wettability of the surface.

When the advancing contact angle (θ _A ) and the receding contact angle (θ _R ), that is, “dynamic contact angle” are measured, a difference, that is, a so-called hysteresis (θ _A −θ _R ) is generated between the two values. If this value is small or zero, the water droplets will easily slide down the surface with only a slight tilt of the substrate without significant changes. The cause of this hysteresis is thought to be due to the so-called “pinning effect” in which water droplets interact with polar functional groups on the surface due to the low coverage and low regularity structure of the formed self-assembled monolayer. (Non-Patent Document 4).

  In previous studies on the formation of self-assembled monolayers, changes in the wettability of the substrate surface before and after the formation of self-assembled monolayers have been mainly evaluated using static contact angles. However, the importance of “dynamic wettability” has recently been recognized in various engineering fields. The dynamic behavior of water at the material surface is particularly important as a guide for "droplet removal performance".

Until now, a few surface treatment techniques have been proposed to reduce the above-described hysteresis and improve the water drop sliding property. McCarthy et al. Fixed tris (trimethylsiloxy) silylethylenedimethylsilane on a silicon substrate with a covalent bond (siloxane bond, Si—O—Si), and the silicon surface became hydrophobized, and the advancing contact angle (θ _A ) The receding contact angle (θ _R ) was 104 ° / 103 °, respectively (Non-patent Document 5).

Further, when dimethyldichlorosilane was immobilized on a silicon substrate, the silicon surface was similarly hydrophobized, and the advancing contact angle (θ _A ) and receding contact angle (θ _R ) were 104 ° / 103 °, respectively ( Non-patent document 6).

  In this way, reports of obtaining extremely small hysteresis are all limited to silicon substrates, and there are no examples of developing hysteresis on other solid surfaces, especially surfaces of practical substrates such as metals and polymers. There are no surfaces with very little hysteresis.

For example, Hintze et al. Have different molecular chain lengths on the surface of an Al alloy (2024-T3) (decyl group [R ′ = CH ₃ [CH ₂ ] ₉ , octadecyl group [R ′ = CH ₃ [CH ₂ ] ₁₇ ]. Although a self-assembled monolayer of organosilane (X═OCH ₂ CH ₃ , n = 1) was formed, the hysteresis was large.

That is, even if any molecule is used, a highly hydrophobic surface (static contact angle 113-117 °) can be obtained, but in the measurement of the dynamic water droplet contact angle, the forward (θ _A ) / backward contact angle (θ _Since the difference (hysteresis) of _{R 2} is as large as 50-70 °, corrosion due to liquid residue has been observed (Non-patent Document 7).

  As described above, for the formation of self-assembled monolayers, there are various reports, however, only the static contact angle has been a problem because of the lack of recognition for dynamic wettability. Actually, it has been recognized that the elimination of hysteresis and the surface of extremely small hysteresis are still groping and realization thereof is very difficult.

J. et al. Sagiv; Am. Chem. Soc. , 102, 92 (1980) J. et al. A. DeRose, E .; Hoque, B.M. Bhushan and H.M. J. et al. Mathieu; Surf. Sci. 602, 1360 (2008) C. O. Timmons and A.M. W. Zisman, J. et al. Phys. Chem. , 69, 984 (1965) Gao, L .; McCarthy, T .; J. et al. Langmuir, 23, 3762 (2007) Fadeev, A.M. McCarthy, T .; J. et al. Langmuir, 15, 7328 (1999) Fadeev, A.M. McCarthy, T .; J. et al. Langmuir, 16, 7268 (2000) P. E. Hintze and L. M.M. Calle; Electrochimica Acta, 51, 1761 (2006)

  Under such circumstances, the present inventor, in view of the above-mentioned prior art, has earnestly researched with the goal of developing a surface treatment technology for a practical base material capable of forming a polymer surface and a metal surface without hysteresis. As a result, the surface of the base material is washed with oxygen plasma, ultraviolet light, ozone, or the like to make it hydrophilic. Preferably, the polymer base material is coated with a silicon oxide film on the surface in advance, or a metal base material. Then, after washing with light or hydrothermal treatment, organic molecules having a cyclic, branched, or straight chain structure are attached to the surface of these base materials from the gas phase to form a molecular film having a thickness of 3 nm or less. Therefore, a surface with extremely low hysteresis can be realized not only on a silicon substrate but also on surfaces of practical metals such as aluminum, titanium oxide, and polymer base material. Found, it has led to the completion of the present invention.

  The present invention significantly suppresses the interaction between the liquid and the solid surface by attaching organic molecules to the solid surface from the gas phase and immobilizing the molecular film of the organic molecules by chemical bonding to form a molecular film. A method for modifying a solid surface and a surface modification, in which a hysteresis which is a difference between an advancing contact angle and a receding contact angle can be modified to a solid surface exhibiting water repellency and super water repellency of 5 ° or less An object of the present invention is to provide a finished substrate.

  The present invention controls the “dynamic wettability” to suppress the interaction between the liquid droplet and the solid surface, for example, ensuring visibility by improving raindrop removability of glass for automobiles and building materials, controlling dirt adhesion, μ The object is to provide a solid surface modification method and a surface-modified base material that are particularly effective in controlling water flow such as TAS and biochip, and controlling micro water droplets such as water-soluble inkjet nozzles. is there.

The present invention for solving the above-described problems comprises the following technical means.
(1) A method for modifying a solid surface, wherein after the solid surface has been previously hydrophilized, organic molecules having a cyclic, branched or straight chain structure are fixed to the solid surface by chemical bonding from a gas phase atmosphere. By forming an organic molecular film, the interaction between the liquid and the solid surface is suppressed, and the hysteresis, which is the difference between the advancing contact angle and the receding contact angle, is less than 5 ° for water repellency and super water repellency. A method for modifying a solid surface, comprising modifying the surface to be shown.
(2) The method for modifying a solid surface according to (1), wherein the advancing contact angle and the receding contact angle are in the range of 30 to 170 °, respectively.
(3) The method for modifying a solid surface according to (1) or (2) above, wherein the treatment temperature when immobilizing the organic molecules is 50 to 180 ° C. and the treatment time is at least 24 hours.
(4) The organic molecule is terminated with 1 to 3 reactive functional groups selected from a hydroxyl group, a hydrogen group, a vinyl group, an alkoxy group, a chloro group, a carboxyl group, an aldehyde group, an isocyanate group, and an amino group. The method for modifying a solid surface according to any one of (1) to (3), wherein is terminated.
(5) The organic molecule is terminated with one or more kinds of inert functional groups selected from a methyl group, a fluoroalkyl group, and a hydrogen group, according to any one of (1) to (4) above Method for modifying the surface of a solid.
(6) From the above (1), which is a polymer substrate, and the surface of the substrate is coated with a silicon oxide thin film (nanoporous silicon oxide thin film) having a film thickness of 0.5 nm to 1 micron. The method for modifying a solid surface according to any one of 5).
(7) The above (1), wherein the solid surface is a solid surface selected from among metals, metal oxide films, metal oxides, alloys, semiconductors, polymers, ceramics (containing mesoporous ceramics), and glass substrates. ) To (6).
(8) cyclic, branched, or linear on a solid surface selected from among metals, metal oxide films, metal oxides, alloys, semiconductors, polymers, ceramics (including mesoporous ceramics), and glass substrates An organic molecule having a structure is immobilized through a chemical bond, the thickness of the organic molecule is more than 0 to 3 nm, and a hysteresis that is a difference between an advancing contact angle and a receding contact angle is 5 ° or less. A surface-modified substrate characterized by exhibiting water repellency and super water repellency.
(9) The organic molecule is terminated with 1 to 3 reactive functional groups selected from a hydroxyl group, a hydrogen group, a vinyl group, an alkoxy group, a chloro group, a carboxyl group, an aldehyde group, an isocyanate group, and an amino group. The surface-modified substrate according to (8), wherein is terminated.
(10) The surface-modified group according to (7), wherein the organic molecule is terminated with one or more kinds of inert functional groups selected from a methyl group, a fluoroalkyl group, and a hydrogen group. Wood.
(11) The surface-modified base material according to (8), wherein the organic molecule is immobilized through a chemical bond with a solid surface hydroxyl group or oxygen-containing polar group.
(12) The surface-modified base material according to (8), wherein the needle-like structure having a height of 5 to 50 nm is formed on the surface of the base material.
(13) The advancing contact angle and the receding contact angle are each in the range of 30 ° to 170 °, and the hysteresis, which is the difference between the advancing contact angle and the receding contact angle, exhibits water repellency and super water repellency of 5 ° or less. The surface-modified base material according to any one of (8) to (12).

Next, the present invention will be described in more detail.
In the present invention, after the surface of various base materials such as polymers and metals is previously removed with impurities such as plasma, ultraviolet rays, ozone, etc. and hydrophilized, the surface of the polymer base material is previously coated with a silicon oxide film. Alternatively, in the case of a metal such as aluminum, after light washing or hydrothermal treatment, organic molecules having a cyclic, branched or linear structure are attached to the surface of these substrates from the gas phase, and the film thickness exceeds 0. By forming a molecular film of ˜3 nm, it has the greatest feature in forming a surface having extremely small hysteresis that can remarkably suppress the interaction with the droplet.

  In the present invention, the advancing contact angle and the receding contact angle are each in the range of 30 ° to 170 °, and the treatment temperature when immobilizing the organic molecules is 50 to 180 ° C., and the treatment time is at least 24 hours. And 1 to 3 reactive functions selected from the group consisting of a hydroxyl group, a hydrogen group, a vinyl group, an alkoxy group, a chloro group, a carboxyl group, an aldehyde group, an isocyanate group, and an amino group. The organic molecule is terminated with one or more inert functional groups selected from a methyl group, a fluoroalkyl group and a hydrogen group, and a polymer. A preferred embodiment is a base material in which the surface of the base material is coated with a silicon oxide thin film (nanoporous silicon oxide thin film) having a film thickness of 0.5 nm to 1 micron.

  The present invention relates to a surface-modified base material, which is formed on a solid surface selected from a metal, a metal oxide film, a metal oxide, an alloy, a semiconductor, a polymer, a ceramic, and a glass base material. Or an organic molecule having a linear structure is immobilized through a chemical bond, the thickness of the organic molecule is more than 0 to 3 nm, and there is hysteresis that is the difference between the receding contact angle and the advancing contact angle. It exhibits water repellency of 5 ° or less and super water repellency.

  In the present invention, the organic molecule is immobilized through a chemical bond between a solid surface hydroxyl group or an oxygen-containing polar group, and is a metal substrate, on the surface of the substrate, Hysteresis in which a needle-like structure having a height of 5 to 50 nm is formed, the advancing contact angle and the receding contact angle are each in the range of 30 ° to 170 °, and the difference between the advancing contact angle and the receding contact angle Exhibiting water repellency of 5 ° or less and super water repellency is a preferred embodiment.

  As a base material that can be used in the present invention, an appropriate material such as a metal, a metal oxide film, a metal oxide, an alloy, a semiconductor, a polymer, ceramics, and glass can be arbitrarily used. As the shape of these base materials, a base material having an arbitrary shape such as a plate shape, a powder shape, or a tube shape can be used.

  In the present invention, the substrate surface is hydrophilized by previously treating the substrate surface with oxygen plasma, vacuum ultraviolet light, ozone, etc. to remove organic substances attached to the substrate surface. In this case, preferably, vacuum ultraviolet light having a wavelength of 172 nm or less is used. In the polymer base material, it is preferable to previously coat the surface with a silicon oxide film.

  In the case of a metal substrate, for example, an aluminum substrate, it is preferable to treat with hot water for 5 minutes or more. Specific examples of the substrate include a polymer coated with silicon, glass, aluminum (including aluminum oxide), titanium oxide, and silicon oxide (including nanoporous silicon oxide) as a suitable substrate.

  Subsequently, the hydroxyl group or oxygen-containing polar functional group on the substrate surface is reacted with a reactive functional group of a cyclic, branched, or linear organic molecule. The reaction method is not particularly limited. Preferably, a reaction by a gas phase method is used, which does not require an expensive reaction apparatus, a long processing time, and a high processing temperature, and can be processed with a small amount of raw materials. .

  When processing for attaching organic molecules to the metal substrate from the gas phase, for example, the processing temperature is preferably about 50 to 180 ° C., and the processing time is preferably 24 to 72 hours or more. The thickness of the molecular film to be attached depends on the length of the organic molecule to be used, and can be arbitrarily controlled in the range from over 0 to about 3 nm. When the terminal of an organic molecule having a cyclic, branched or straight chain structure is terminated with an inert functional group such as a methyl group or a fluoroalkyl group, a hydrophobic surface is formed.

  By forming a molecular film of organic molecules having a cyclic, branched or linear structure of 3 nm or less on the surface of the substrate by the above-described method, an effect of suppressing the interaction with the droplets can be obtained. This phenomenon appears only when a molecular film of organic molecules having a cyclic, branched, or linear structure is formed on a smooth substrate surface. In particular, in the aluminum substrate after the hot water treatment, not only a low hysteresis surface is formed, but also the water repellency is remarkably improved.

  This phenomenon appears only when an uneven structure formed on the substrate surface and a molecular film of organic molecules having a cyclic, branched, or straight chain structure are formed. The raw material used for forming the molecular film is preferably liquid and has a high vapor pressure. In the case of a solid, it is desirable that the melting point is low and a sufficient vapor pressure can be obtained when liquefied. By using the method for modifying a solid surface of the present invention, it is possible to improve the dynamic wettability of the surface of a practical metal, polymer, or ceramic substrate, which was difficult with the conventional method.

  In the present invention, to suppress the interaction between the liquid and the solid surface means that the surface of the treatment substrate described above suppresses the interaction with the droplet, and the reason why the interaction can be suppressed is as follows. For example, in the case of branched organic molecules, the branched organic molecular film plays a role like an “umbrella” and suppresses interaction with unreacted polar functional groups on the substrate surface. This organic molecule is presumed to be due to the chemical effect that the cyclic organic molecule is deposited in a layered manner to suppress the interaction with the polar functional group of the base. In addition, in a metal substrate such as aluminum that has been subjected to hydrothermal treatment, it is presumed that in addition to these chemical effects, the physical effect of forming an air layer due to the uneven surface structure worked synergistically.

  When a self-assembled monomolecular film is formed on a glass surface using a fluorine-based silane coupling agent exhibiting water repellency, the surface becomes very hydrophobic, and the resulting water droplet contact angle is 117 °. Although this surface exhibits high water repellency, water adheres to the solid surface and is inferior in scattering properties, water slidability, and water droplet removal properties. It was a big issue.

  In contrast, in the present invention, organic molecules having a film thickness of 3 nm or less are formed by immobilizing organic molecules having a cyclic, branched or linear structure on a smooth substrate surface by a vapor phase method. The interaction between the solid / liquid interface is suppressed, the hysteresis of the surface of the treated substrate is extremely reduced, and the effect of improving the removability of droplets from the solid surface is obtained, thereby It becomes possible to solve the above-mentioned unsolved problems.

  As described above, these phenomena are caused by chemical reactions in which, for example, the organic molecules having a branch structure immobilized on the surface of the base material serve as an umbrella and suppress the interaction with the polar functional group on the base. It is presumed that it appears due to the effect, and in the case of organic molecules with a cyclic structure, the molecules are deposited in layers, so that the surface is sufficiently covered with the molecules of the cyclic structure and interacts with the polar functional group of the base. It is presumed to appear due to the chemical effect of suppression.

  Regarding the organic molecules used in the present invention, as described above, it is desirable that the liquid has a high vapor pressure, and the solid has a low melting point, so that a sufficient vapor pressure can be obtained when liquefied. It is desirable to be. Moreover, it is desirable that one functional group having a low surface energy such as fluorocarbon or methyl group is contained. Since fluorocarbon and methyl groups have low surface energy, the resulting substrate surface can be effectively hydrophobized.

  Moreover, in order to obtain a strong chemical bond with the substrate surface, it is desirable that at least one reactive functional group is contained. Without the reactive functional group, sufficient adhesion cannot be obtained at the interface between the substrate surface and the adsorbed organic molecules. The film thickness is desirably 3 nm or less in order to prevent changes in the shape and optical characteristics of the substrate surface.

The following effects are exhibited by the present invention.
(1) By forming a molecular film of organic molecules having a cyclic, branched or linear structure of 3 nm or less on a smooth substrate surface, the solid / liquid interface interaction is suppressed, and the surface of the treated substrate The effect of the extremely small hysteresis is obtained.
(2) According to the present invention, the interaction between the liquid and the solid surface on the surface of the polymer, metal, or ceramic substrate is remarkably suppressed, and the hysteresis that is the difference between the advancing contact angle (θ _A ) and the receding contact angle (θ _R ) Therefore, it is possible to greatly improve the sliding property of the droplet and the removability of the droplet from the sample surface.
(3) By using, for example, a perfluoroalkyl group-terminated molecule as the organic molecule, it is possible to obtain a solid surface that also has water repellency and oil repellency in addition to water repellency.

FIG. 1 shows the molecular structure of 1,3,5,7-tetramethylcyclotetrasiloxane, which is a cyclic organosilicon hydride according to Examples 1 and 2. FIG. 2 shows bis (tridecafluoro-1,1,2,2-tetrahydrooctylsiloxy) methylchlorosilane (a) and bis (tridecafluoro 1), which are branched organic silanes according to Examples 3 and 4. , 1,2,2-tetrahydrooctylsiloxy) methylsilane (b). FIG. 3 shows an atomic force microscope image of the aluminum surface after 10 minutes of hot water treatment according to Examples 6 and 7. FIG. 4 shows the state of water droplets on a substrate composed of 1H, 1H, 2H, 2H-perfluorodecyl isocyanate molecular film / hot water treated aluminum according to Example 7. FIG. 5 shows the results relating to the water resistance of the samples according to Example 8 and Comparative Example 4. FIG. 6 is a graph of branched organic silanes, [bis (nonafluorohexyldimethylsiloxy) methyl] silylethyldimethylchlorosilane (a), bis (nonafluorohexyldimethylsiloxy) methylsilane (b) according to Examples 9 and 10. The molecular structure is shown. FIG. 7 shows the molecular structures of branched organic silane, di-t-butylmethylsilane (a) and di-t-butylmethylchlorosilane (b) according to Examples 11 and 12. FIG. 8 shows the molecular structure of a branched organosilane and tri-t-pentoxysilanol according to Example 13. FIG. 9 shows the molecular structures of branched organic silane, tri-t-butoxysilanol (a) and tri-t-butylsilane (b) according to Examples 14 and 15. FIG. 10 shows the results relating to the salt spray resistance test of the samples according to Examples 4, 6, and 7 and Comparative Example 5.

  Next, the present invention will be specifically described based on examples. However, the following examples show preferred examples of the present invention, and the present invention is not limited to the examples. Absent.

After cleaning silicon, aluminum, titanium oxide, copper, iron, stabilized zirconia, glass slide, and quartz substrate by exposure to vacuum ultraviolet light with a wavelength of 172 nm under 1000 Pa for 30 minutes, cyclic organosilicon hydride Is chemically bonded to the substrate surface from the gas phase using the vapor of 1,3,5,7-tetramethylcyclotetrasiloxane ([C ₄ H ₁₆ O ₄ Si ₄ ], made by Gelest) Chemical adsorption was carried out by immobilization with The treatment temperature was 80 ° C. and the treatment time was 72 hours. The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the water droplets on the surface after treatment are 103 ° / 99 ° (silicon), 103 ° / 101 ° (aluminum), 104 ° / 103 ° (titanium oxide). ), 104 ° / 102 ° (copper) 102 ° / 100 ° (iron), 104 ° / 102 °, 103 ° / 101 ° (stabilized zirconia), 103 ° / 102 ° (slide glass), 102 ° / 99 ° (quartz).

After cleaning silicon, aluminum, titanium oxide, magnesium alloy, copper, iron, stabilized zirconia, glass slide, and quartz substrate by exposing to vacuum ultraviolet light having a wavelength of 172 nm under 1000 Pa for 30 minutes, the above-described ring The organosilicon hydride 1,3,5,7-tetramethylcyclotetrasiloxane was chemically adsorbed by performing a treatment for fixing it from the gas phase to the substrate surface by a chemical bond. The treatment temperature was 180 ° C. and the treatment time was 72 hours. The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the water droplets on the treated surface are 166 ° / 164 ° (silicon), 168 ° / 164 ° (aluminum), 163 ° / 161 ° (titanium oxide). ), 162 ° / 158 ° (magnesium alloy), 165 ° / 162 ° (copper), 164 ° / 162 ° (iron), 164 ° / 161 ° (stabilized zirconia), 166 ° / 164 ° (slide glass), It became 165 ° / 163 ° (quartz).

The silicon substrate was washed by exposure to vacuum ultraviolet light having a wavelength of 172 nm under 1000 Pa for 30 minutes, and then bis (tridecafluoro-1,1,2,2-tetrahydrooctylsiloxy, which is a branched organic silane. ) Using chemical vapor of methylchlorosilane (C ₂₁ H ₂₃ ClF ₂₆ O ₂ Si ₃ , manufactured by Gelest), the molecule was chemically adsorbed by performing a process of immobilizing the molecule on the substrate surface by a chemical bond from the gas phase. . The treatment temperature was 70 ° C. and 150 ° C., and the treatment time was 72 hours. The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the water droplets on the treated surface were 109 ° / 105 ° at 70 ° C. and 110 ° / 107 ° at 150 ° C. Further, the advancing contact angle (θ _A ) and receding contact angle (θ _R ) of n-hexadecane (oil) were 61 ° / 59 ° at 70 ° C. and 62 ° / 60 ° at 150 ° C.

A silicon and aluminum base material was washed by exposure to vacuum ultraviolet light having a wavelength of 172 nm at 1000 Pa for 30 minutes, and then bis (tridecafluoro-1,1,2,2-tetrahydro, which is a branched organic silane. Octylsiloxy) methylsilane (C ₂₁ H ₂₄ F ₂₆ O ₂ Si ₃ , manufactured by Gelest) vapor is used to perform chemical adsorption by performing a process of immobilizing the molecule from the gas phase to the substrate surface by chemical bonding. It was. The processing temperature was 150 ° C. and the processing time was 72 hours. The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the water droplets on the treated surface were 110 ° / 107 ° (silicon) and 109 ° / 107 ° (aluminum). Further, the advancing contact angle (θ _A ) and receding contact angle (θ _R ) of n-hexadecane (oil) were 64 ° / 63 ° (silicon) and 52 ° / 50 ° (aluminum).

Acrylic substrate (Delagrass (registered trademark) A manufactured by Asahi Kasei Co., Ltd.) is a cyclic organosilicon hydride on the surface of a substrate that has been hydrophilized by exposure to vacuum ultraviolet light with a wavelength of 172 nm under atmospheric pressure for 30 minutes. 1,3,5,7-tetramethylcyclotetrasiloxane ([C ₄ H ₁₆ O ₄ Si ₄ ], manufactured by Gelest) was used to chemisorb the molecules from the gas phase. The treatment temperature was 80 ° C. and the treatment time was 1 hour. The sample surface was again irradiated with vacuum ultraviolet light at 1000 Pa for 30 minutes using the same light source.

Further, on the surface of the sample, bis (tridecafluoro1,1,2,2-tetrahydrooctylsiloxy) methylchlorosilane (C ₂₁ H ₂₃ ClF ₂₆ O ₂ Si ₃ , manufactured by Gelest), which is a branched organic silane, is formed. Chemical adsorption was performed by performing a treatment of immobilizing the molecules from the gas phase on the substrate surface by chemical bonds using vapor. The treatment temperature was 70 ° C. and the treatment time was 72 hours. The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the treated surface were 108 ° / 105 °.

After the aluminum substrate was treated in hot water for 10 minutes, it was washed by exposure to vacuum ultraviolet light having a wavelength of 172 nm under 1000 Pa for 30 minutes, which is a linear organic silane (heptadecafluoro-1, 1 2,2-tetrahydrodecyl) trimethoxysilane (FAS: CF ₃ [CF ₂ ] ₇ CH ₂ CH ₂ Si [OCH ₃ ] ₃ , manufactured by Gelest) is used to vaporize FAS from the gas phase to the substrate surface Chemical adsorption was carried out by carrying out a process of immobilizing them with chemical bonds. The processing temperature was 150 ° C. and the processing time was 72 hours. The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the treated surface were 170 ° / 167 °.

The aluminum substrate is treated in hot water for 10 minutes, and then washed by exposure to vacuum ultraviolet light having a wavelength of 172 nm at 1000 Pa for 30 minutes to obtain linear organic molecules 1H, 1H, 2H. , 2H-perfluorodecyl isocyanate (PFI: CF ₃ [CF ₂ ] ₇ CH ₂ CH ₂ N═C═O, manufactured by Aldrich) is used to chemically bond PFI to the substrate surface from the gas phase. Chemical adsorption was carried out by carrying out the immobilization process. The processing temperature was 150 ° C. and the processing time was 72 hours. The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the treated surface were 167 ° / 165 °.

  The aluminum base material produced in Example 4 was immersed in Milli-Q water at room temperature.

The silicon substrate was washed by exposure to vacuum ultraviolet light having a wavelength of 172 nm under 1000 Pa for 30 minutes, and then a branched organic silane, [bis (nonafluorohexyldimethylsiloxy) methyl] silylethyldimethylchlorosilane (C ₂₁ H ₃₃ ClF ₁₈ O ₂ Si ₄ (manufactured by Gelest) was used to chemisorb the molecules from the gas phase (treatment temperatures were 70 ° C., 150 ° C., treatment time was 72 hours). The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the water droplets on the treated surface were 108 ° / 106 ° at 70 ° C. and 109 ° / 107 ° at 150 ° C. Further, the advancing contact angle (θ _A ) and receding contact angle (θ _R ) of n-hexadecane (oil) were 51 ° / 49 ° at 70 ° C. and 52 ° / 50 ° at 150 ° C.

The silicon substrate was cleaned by exposure to vacuum ultraviolet light having a wavelength of 172 nm under 1000 Pa for 30 minutes, and then a branched organic silane, bis (nonafluorohexyldimethylsiloxy) methylsilane (C ₁₇ H ₂₄ F ₁₈ O ₂ Si ₃ and made by Gelest), the molecules were chemisorbed from the gas phase (treatment temperature was 150 ° C., treatment time was 72 hours). The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the water droplets on the surface after the treatment were 109 ° / 107 °. Further, the advancing contact angle (θ _A ) and receding contact angle (θ _R ) of hexadecane (oil) were 51 ° / 48 °.

The silicon substrate was cleaned by exposure to vacuum ultraviolet light having a wavelength of 172 nm under 1000 Pa for 30 minutes, and then a vapor of a branched organic silane, di-t-butylmethylsilane (C ₉ H ₂₂ Si, manufactured by Gelest). Was used to chemisorb the molecules from the gas phase (treatment temperature was 70 ° C., treatment time was 72 hours). The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the water droplets on the treated surface were 111 ° / 109 °.

The silicon substrate was cleaned by exposure to vacuum ultraviolet light with a wavelength of 172 nm under 1000 Pa for 30 minutes, and then a vapor of a branched organic silane, di-t-butylmethylchlorosilane (C ₉ H ₂₁ ClSi, manufactured by Gelest). Was used to chemisorb the molecules from the gas phase (treatment temperature was 70 ° C., treatment time was 72 hours). The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the water droplets on the surface after the treatment were 108 ° / 106 °.

After cleaning the silicon substrate by exposing it to vacuum ultraviolet light having a wavelength of 172 nm under 1000 Pa for 30 minutes, a branched organic silane, tri-t-pentoxysilanol (C ₁₅ H ₃₄ O ₄ Si, manufactured by Gelest) The molecules were chemisorbed from the gas phase using the vapor (treatment temperature was 70 ° C., treatment time was 72 hours). The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the water droplets on the surface after the treatment were 104 ° / 102 °. Further, the advancing contact angle (θ _A ) and receding contact angle (θ _R ) of n-hexadecane (oil) were 41 ° / 39 °.

After cleaning the silicon substrate by exposing it to vacuum ultraviolet light having a wavelength of 172 nm under 1000 Pa for 30 minutes, a branched organic silane, tri-t-butoxysilanol (C ₁₂ H ₂₈ O ₄ Si, manufactured by Gelest) Using steam, the molecules were chemisorbed from the gas phase (treatment temperature was 80 ° C., treatment time was 72 hours). The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the water droplets on the surface after the treatment were 97 ° / 95 °.

After cleaning the silicon substrate by exposing it to vacuum ultraviolet light having a wavelength of 172 nm under 1000 Pa for 30 minutes, a vapor of a branched organic silane, tri-t-butylsilane (C ₁₂ H ₂₈ Si, manufactured by Gelest) is used. Then, the molecules were chemically adsorbed from the gas phase (the processing temperature was 80 ° C. and the processing time was 72 hours). The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the water droplets on the surface after the treatment were 100 ° / 99 °.

  A salt spray test (JIS 2371; salt water (5 wt%) at 35 ° C. for 1000 hours) was carried out using the aluminum base material produced in Examples 4, 6, and 7.

Comparative Example 1
After washing the silicon, aluminum, and titanium oxide base materials by exposing them to vacuum ultraviolet light having a wavelength of 172 nm at 1000 Pa for 30 minutes, linear organosilane (heptadecafluoro-1, 1, 2,. FAS was chemisorbed from the vapor phase using the vapor of 2-tetrahydrodecyl) trimethoxysilane (FAS: CF ₃ [CF ₂ ] ₇ CH ₂ CH ₂ Si [OCH ₃ ] ₃ , manufactured by Gelest). The processing temperature was 150 ° C. and the processing time was 72 hours. The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the treated surface are 120 ° / 110 ° (silicon), 125 ° / 110 ° (aluminum), 121 ° / 110 ° (titanium oxide). became.

Comparative Example 2
After cleaning the silicon, aluminum, and titanium oxide base materials by exposing them to vacuum ultraviolet light having a wavelength of 172 nm at 1000 Pa for 30 minutes, perfluoroisocyanate (PFI: CF ₃ [CF ₂ ] ₇ CH ₂ CH ₂ N═C═O, manufactured by Aldrich), PFI was chemisorbed from the gas phase. The processing temperature was 150 ° C. and the processing time was 72 hours. The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the treated surface are 118 ° / 108 ° (silicon), 125 ° / 103 ° (aluminum), 120 ° / 102 ° (titanium oxide). became.

Comparative Example 3
Bis (tridecafluoro 1), which is a branched organic silane, is formed on the surface of an acrylic substrate (made by Asahi Kasei, Delaglass) exposed to vacuum ultraviolet light having a wavelength of 172 nm at 1000 Pa for 30 minutes to make it hydrophilic. , 1,2,2-tetrahydrooctylsiloxy) methylchlorosilane (C ₂₁ H ₂₃ ClF ₂₆ O ₂ Si ₃ , manufactured by Gelest) was used to chemisorb the molecules from the gas phase. The treatment temperature was 70 ° C. and the treatment time was 72 hours. The advancing contact angle (θ _A ) and receding contact angle (θ _R ) of the treated surface were 87 ° / 15 °.

Comparative Example 4
The aluminum base material produced in Comparative Example 1 was immersed in Milli-Q water at room temperature.

Comparative Example 5
A salt spray test (JIS 2371; salt water (5 wt%) at 35 ° C. for 1000 hours) was performed using an untreated aluminum substrate.

  When the sample surfaces prepared in the above 16 examples and the five comparative examples are relatively evaluated, a smooth substrate is obtained in the comparison between the examples 1, 3, 4, 9-15 and the comparative examples 1 and 2. On the surface, it was found that only a substrate on which a molecular film was formed using cyclic or branched organic molecules realized a hydrophobic surface with a small hysteresis of the water droplet contact angle.

  In Example 2, although it was a smooth substrate surface, it was found that a superhydrophobic surface having a small hysteresis was formed due to a difference in reaction temperature. This is because, at high temperatures, 1,3,5,7-tetramethylcyclotetrasiloxane, which is a cyclic organosilicon hydride, undergoes a uniform nucleation reaction in the gas phase, and particles preferentially precipitate on the substrate surface. This is because an uneven structure is introduced on the surface.

  When the samples prepared in Example 5 and Comparative Example 3 were evaluated relatively, the polymer substrate could not realize sufficient hydrophobicity with the sample coated with the molecular film directly on the substrate. It was found that only when the surface was previously coated with a silicon oxide film, a hydrophobic surface with small hysteresis of the water droplet contact angle was realized. When Examples 6 and 7 were compared with Comparative Example 3, it was found that when the metal (aluminum) surface had irregularities, a superhydrophobic surface having a small hysteresis was formed regardless of the molecular structure.

  Furthermore, when the results of Example 8 and Comparative Example 3 are evaluated relatively, the organic silane molecules having a branched structure have a very small change in dynamic contact angle despite the same fluorine-based molecular film. I understood. This result proves that the branched organic silane molecules on the surface play a role of umbrella and efficiently suppress the interaction with water.

  Furthermore, when the results of Examples 4, 6, and 7 and Comparative Example 5 were relatively evaluated, the untreated aluminum substrate was corroded in about 96 hours, and the surface was turned white. On the other hand, the aluminum surface treated with the fluorine-based organosilane molecule having a branch structure and the aluminum surface subjected to super water repellency maintained a metallic luster despite the salt spray test for one month. Since these surfaces have a very small difference in dynamic contact angle, salt water hardly remains on the surfaces. Therefore, it is considered that excellent corrosion resistance was exhibited.

  As described above in detail, the present invention relates to a method for modifying a solid surface and a surface-modified substrate, and according to the present invention, a smooth substrate surface having a ring shape of 3 nm or less, By forming a molecular film of organic molecules having a straight chain structure, the interaction between the solid / liquid interface is suppressed, and the effect that the hysteresis on the surface of the treated substrate is extremely reduced can be obtained.

  This phenomenon appears, for example, due to the chemical effect that the branched organic molecules immobilized on the substrate surface suppress the interaction with the underlying polar functional group, and the cyclic organic molecules It appears due to the chemical effect of suppressing the interaction with the polar functional group of the base.

The present invention makes it possible to remarkably suppress the interaction between a liquid and a solid surface on the surface of a polymer, metal, or ceramic substrate, which has been difficult with the prior art, and advancing contact angle (θ _A ) and receding contact angle ( Provided is a new surface modification technique for a solid surface that reduces the difference (hysteresis) of θ _R ), and can greatly improve the sliding property of the droplet and the removal property of the droplet from the sample surface. Useful as a thing.

Claims (13)

  A method for modifying a solid surface, wherein the solid surface is previously hydrophilized, and then organic molecules having a cyclic, branched, or linear structure are immobilized on the solid surface by chemical bonding from a gas phase atmosphere. By forming an organic molecular film in the surface, the interaction between the liquid and the solid surface is suppressed, and the hysteresis that is the difference between the advancing contact angle and the receding contact angle is 5 ° or less on the surface exhibiting water repellency and super water repellency. A method for modifying a solid surface, comprising modifying the solid surface.   The method for modifying a solid surface according to claim 1, wherein the advancing contact angle and the receding contact angle are each in the range of 30 to 170 °.   The method for modifying a solid surface according to claim 1 or 2, wherein the treatment temperature for immobilizing the organic molecules is 50 to 180 ° C and the treatment time is at least 24 hours.   The organic molecule is terminated with 1 to 3 reactive functional groups selected from hydroxyl group, hydrogen group, vinyl group, alkoxy group, chloro group, carboxyl group, aldehyde group, isocyanate group and amino group. The solid surface modification method according to any one of claims 1 to 3.   The solid surface modification according to any one of claims 1 to 4, wherein the organic molecule is terminated with one or more kinds of inert functional groups selected from a methyl group, a fluoroalkyl group, and a hydrogen group. Method.   It is a polymer base material, Comprising: The surface of this base material is coat | covered with the silicon oxide thin film (nanopore silicon oxide thin film) with a film thickness of 0.5 nm-1 micron in any one of Claim 1 to 5 The method for modifying a solid surface as described.   The solid surface is a solid surface selected from metals, metal oxide films, metal oxides, alloys, semiconductors, polymers, ceramics (containing mesoporous ceramics), and glass substrates, The method for modifying a solid surface according to any one of the above.   A solid surface selected from metals, metal oxide films, metal oxides, alloys, semiconductors, polymers, ceramics (including mesoporous ceramics), and glass substrates has a cyclic, branched, or linear structure. An organic molecule is immobilized through a chemical bond, the film thickness of the organic molecule is more than 0 to 3 nm, and the water repellent property having a hysteresis of 5 ° or less, which is a difference between the advancing contact angle and the receding contact angle, A surface-modified base material characterized by exhibiting super water repellency.   The organic molecule is terminated with 1 to 3 reactive functional groups selected from hydroxyl group, hydrogen group, vinyl group, alkoxy group, chloro group, carboxyl group, aldehyde group, isocyanate group and amino group. The surface-modified substrate according to claim 8.   The surface-modified substrate according to claim 7, wherein the organic molecule is terminated with one or more kinds of inert functional groups selected from a methyl group, a fluoroalkyl group, and a hydrogen group.   The surface-modified base material according to claim 8, wherein the organic molecule is immobilized via a chemical bond with a hydroxyl group on the solid surface or an oxygen-containing polar group.   The surface-modified substrate according to claim 8, which is a metal substrate, and a needle-like structure having a height of 5 to 50 nm is formed on the surface of the substrate.   The advancing contact angle and the receding contact angle are in the range of 30 ° to 170 °, respectively, and the hysteresis that is the difference between the advancing contact angle and the receding contact angle exhibits water repellency and super water repellency of 5 ° or less. To 12. The surface-modified base material according to any one of 1 to 12.