Patent Application
20080240479
Many polymer/plastic materials have desirable bulk properties such as low density, low cost, good strength, and ease of processing that have allowed them to become integral components of countless consumer goods and devices. However, many plastics that have ideal bulk properties for certain applications are lacking in their surface properties, such as, for example, abrasion resistance and wetting. As a result, it may be desirable to coat a polymer/plastic to modify its surface so that its favorable bulk properties can be exploited for various uses.
In many instances, various devices are designed to prevent water from entering interior portions of the devices in order to maintain proper functionality. Manufacturers often design devices to be used in environments where water or other liquid materials may come into contact with the devices and components of the devices. Devices and device components may have various protective coverings to protect interior portions of the devices and components. Often, the protective covering is made from multiple parts, resulting in various seams and openings that may expose interior portions to damage from liquids. Many devices also require small openings or interstices in the protective cover in order to allow air or other gases to flow freely between the interior and exterior of the device while preventing liquids from passing through the cover. For example, a battery used in powering an electronic device may be susceptible to damage from moisture, and may nonetheless require an external source of oxygen to operate. Additionally, devices may contain a liquid material that is intended to be contained within the device for an extended time until the liquid is dispensed. An ink jet cartridge, for example, often contains a liquid ink solution that is contained within the cartridge for extended periods.
According to at least one embodiment, a method may comprise depositing a first silane onto a surface, the first silane comprising a functional linking group and a silane group, and depositing a second silane onto the first silane, the second silane comprising a hydrophobic aliphatic group and a silane group.
In certain embodiments, a composition of matter may comprise the reaction product of a substrate comprising a hydroxyl group, a first silane comprising a functional linking group and a silane group, and a second silane comprising a hydrophobic aliphatic group and a silane group.
In various embodiments, a coating composition may comprise a first silane bonded to the surface, the first silane comprising a silane group, and a second silane bonded to the first silane by a siloxane linkage, the second si ane comprising a hydrophobic aliphatic group.
In certain embodiments, an article may comprise a first portion having a surface, a first silane bonded to the surface of the first portion, the first silane comprising a silane group, and a second silane bonded to the first silane by a siloxane linkage, the second silane comprising a hydrophobic aliphatic group.
In additional embodiments, a hearing aid device may comprise a first component, the first component having a surface portion, a coating composition bonded to the surface portion of the first component, the coating composition comprising an adhesion layer bonded to the surface portion of the first component, and a hydrophobic layer bonded to the adhesion layer.
In at least one embodiment, a method may comprise depositing an adhesion promoting compound onto a surface, the adhesion promoting compound comprising a functional linking group and at least one of a silane functional group and a germanium functional group. The method may also comprise depositing a hydrophobic layer forming compound onto the adhesion promoting compound, the hydrophobic layer forming compound comprising a hydrophobic aliphatic group and at least one of a silane functional group and a germanium functional group.
In various embodiments, a composition of matter may comprise the reaction product of a substrate comprising a hydroxyl group, an adhesion promoting composition comprising an adhesion promoting compound, the adhesion promoting compound comprising a functional linking group and at least one of a silane functional group and a germanium functional group, and a hydrophobic layer forming composition comprising a hydrophobic layer forming compound, the hydrophobic layer forming compound comprising a hydrophobic aliphatic group and at least one of a silane functional group and a germanium functional group.
Features from any of the above-mentioned embodiments may be used in combination with one another in accordance with the general principles described herein. These and other embodiments, features, and advantages will be more fully understood upon reading the following detailed description in conjunction with the accompanying drawings and claims.
The accompanying drawings illustrate a number of exemplary embodiments and are a part of the specification. Together with the following description, these drawings demonstrate and explain various principles of the instant disclosure.
Throughout the drawings, identical reference characters and descriptions indicate similar, but not necessarily identical, elements. While the exemplary embodiments described herein are susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, the exemplary embodiments described herein are not intended to be limited to the particular forms disclosed. Rather, the instant disclosure covers all modifications, equivalents, and alternatives falling within the scope of the appended claims.
The silane compositions presented in the instant disclosure may be deposited on an article to provide the article with various properties. Methods of applying the compositions to various articles are also presented in the instant disclosure. The compositions and methods discussed herein may also provide various other features and advantages.
Substrate 22 may comprise any material or combination of materials suitable for deposition of a silane compound as described below. Examples of materials suitable for forming substrate 22 include, without limitation, polymer materials, metallic materials, composite materials, silicon-based materials, semiconducting materials, insulating materials, or a combination of the foregoing. Surface 24 of substrate 22 may comprise an external and/or internal portion of substrate 22 and/or article 20.
Coating 26 may be formed on portions of completed article assemblies, article sub-assemblies, individual articles, device components, and/or shell components. Coating 26 may have a substantially consistent thickness respective to surface 24. Alternatively, coating 26 may be applied to surface 24 intermittently and/or in a specific pattern. Additionally, coating 26 may be applied to surface 24 only on desired portions of surface 24, such as, for example, portions of surface 24 contacting or in close proximity to a seam, hole, interstice, or other opening defined in surface 24 or adjacent to surface 24. Coating 26 may provide surface 24 with various properties, including, for example, increased hydrophobicity, increased oleophobicity, increased abrasion resistance, increased protection from staining, and/or increased protection from discoloration. Coating 26 may additionally provide portions of surface 24 and/or substrate 22 with gas permeability while providing surface 24 with liquid impermeability. Additionally, coating 26 may comprise an ultra-thin transparent layer, enabling coating 26 to be formed on surface 24 with little to no impact on functionality or aesthetics of article 20.
Adhesion promoting layer 28 may be formed on surface 24. In certain embodiments, adhesion promoting layer 28 may be bonded to surface 24. Adhesion promoting layer 28 may act as an adhesion promoter to bond and secure additional compounds to substrate 24. Adhesion promoting layer 28 may comprise a first silane having at least two reactive groups. In addition, the first silane and/or the adhesion promoting layer 28 may comprise mixtures of various silane compounds. Adhesion promoting layer 28 may also comprise additional compounds in addition to the first silane. The additional compounds in adhesion promoting layer 28 may impart various desirable properties to adhesion promoting layer 28, such as, for example, microbial resistance, without preventing adhesion promoting layer 28 and/or the first silane from acting as an adhesion promoter.
In certain embodiments, adhesion promoting layer 28 may comprise a germanium based compound in addition to or in place of a silane compound (e.g. the first silane). Germanium based compounds may function as adhesion promoters in a manner similar to analogous silicon compounds. Accordingly, silicon compounds listed below as examples of the first silane may be substituted or replaced with an analogous germanium compound.
The first silane may be capable of forming polymers containing siloxane (Si—O—Si) linkages. In at least one embodiment, the first silane may comprise at least one of an isocyanate group, an acyl chloride group, an epoxide group, a glycidyl group, an amino group, a methyl ester group, an isothiocyanato group, a carboxyl group, an activated carboxyl group, an alkyl chloride group, an alkyl bromide group, an alkyl iodide group, a benzyl chloride group, a benzyl bromide group, a chlorosilane group (e.g., —SiCl3), a methoxysilane group (e.g., —Si(OCH3)3), an ethoxysilane group (e.g., —Si(OCH2CH3)3), and/or any other suitable reactive functional group, without limitation.
The first silane may also comprise at least one silane group. In an exemplary embodiment, the silane group on the first silane may be represented by formula (I):
where R1, R2, and R3 may each be, independently, P, Cl, Br, I, H, OH, a methoxy group, an ethoxy group, an isopropoxy group, an alkoxy group, an acetoxy group, a methyl group, an alkyl group, a perfluoroalkyl group, a partially fluorinated alkyl group, a dimethylamino group, a dialkylamino group, an ethylamino group, a monoalkylamino group, an amino group, a phenyl group, or a methoxyethoxyethoxy group.
In at least one embodiment, the first silane may be represented by formula (II):
where X may be an isocyanate group, an acyl chloride group, an epoxide group, a glycidyl group, an amino group, a methyl ester group, an isothiocyanato group, a carboxyl group, an activated carboxyl group, an alkyl chloride group, an alkyl bromide group, an alkyl iodide group, a benzyl chloride group, a benzyl bromide group, a chlorosilane group (e.g., —SiCl3), a methoxysilane group (e.g., —Si(OCH3)3), an ethoxysilane group (e.g., —Si(OCH2CH3)3), and/or any other suitable reactive functional group, without limitation. In formula (II), n may be an integer from 0-32. In additional embodiments, n may be an integer from 1-18. In at least one embodiment, n may be an integer from 3-4. Additionally, in formula (II), R1, R2, and R3 may be as defined above for formula (I).
Representative examples of the first silane include, without limitation, 3-isocyanatopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 4-isocyanatobutyltriethoxysilane, 4-isocyanatobutyltrimethoxysilane, 3-isocyanatopropyldimethylchlorosilane, (isocyanatomethyl)methyldimethoxysilane, 3-thiocyanatopropyltriethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 4-aminobutyltriethoxysilane, 4-aminobutyltrimethoxysilane, (aminoethylaminomethyl)phenethyl-trimethoxysilane, N-(2-Aminoethyl)-3-aminoisobutyl-methyldimethoxysilane, N-methylaminopropyltrimethoxysilane, N-methylaminopropyltriethoxysilane, N-methylaminopropylmethyldimethoxysilane, N-methylaminopropylmethyldiethoxysilane, N-ethylaminoisobuyltrimethoxysilane, (N,N-diethyl-3-aminopropyl)trimethoxysilane, (N,N-diethyl-3-aminopropyl)triethoxysilane, n-butylaminopropyltrimethoxysilane, 11-aminoundecyltriethoxysilane, 11-aminoundecyltrimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyldimethylethoxysilane, 3-aminopropyldimethylmethoxysilane, 3-aminopropyltris(methoxyethoxyethoxy)silane, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-amino ethyl)-3-aminopropyltri ethoxysilane, (amino ethylaminomethyl)phenethyltrimethoxysilane, (amino ethylaminomethyl)phenethyltriethoxysilane, N-(2-aminoethyl)-3-aminoisobutylmethyldimethoxysilane, N-(2-aminoethyl)-3-aminoisobutylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminoisobutyldimethylmethoxysilane, N-(2-aminoethyl)-3-aminoisobutyldimethylethoxysilane, (3-glycidoxypropyl)trimethoxysilane, (3-glycidoxypropyl)triethoxysilane, (3-glycidoxypropyl)methyldimethoxysilane, (3-glycidoxypropyl)methyldiethoxysilane, (3-glycidoxypropyl)dimethylethoxysilane, (3-glycidoxybutyl)trimethoxysilane, (3-glycidoxybutyl)triethoxysilane, SiCl4, Si(CH3)Cl3, Si(CH3)2Cl2, Si(OCH3)4, Si(CH3)(OCH3)3, Si(CH3)2(OCH3)2, Si(OCH2CH3)4, Si(CH3)(OCH2CH3)3, Si(CH3)2(OCH2CH3)2, Si(N(CH3)2)4, SiH(N(CH3)2)3, and Si(CH3)(N(CH3)2)3, SiCl(N(CH3)2)3, Si(CH3)H(N(CH3)2)2.
Additional examples of the first silane that may be capable of binding to surface 24 through, for example, siloxane or other end group linkages, include, without limitation, bis(dimethylaminodimethylsilyl)ethane, bis(dimethylamino)vinylmethylsilane, 3-mercaptopropyltriethoxysilane, acetoxyethyltrimethoxysilane, bis(chloromethyl)dichlorosilane, bis(chloromethyl)methylchlorosilane, bis(dichlorosilyl)methane, bis(methyldichlorosilyl)ethane, bis(trichlorosilyl)hexane, bis(trichlorosilyl)methane, bis(trichlorosilyl)octane, 1,3-bis(trichlorosilyl)propane, bis(triethoxysilyl)ethane, 2-bromoethyltrichlorosilane, 1-chloroethyltrichlorosilane, hexachlorodisilane, methyltrichlorosilane, hexadecyltrichlorosilane, tetrabromosilane, trichloromethyltrichlorosilane, tris(trichlorosilylethyl)methylsilane, and tris(p-trichlorosilylpropylphenyl)amine, bis(methyl dichloro silyl)butane.
Hydrophobic layer 30 may be formed on adhesion promoting layer 28. In certain embodiments, hydrophobic layer 30 may be bonded to adhesion promoting layer 28. The hydrophobic layer 30 may act as a hydrophobic and/or oleophobic layer. Additionally, the second silane may act as a hydrophobic and/or oleophobic compound. Hydrophobic layer 30 may comprise a second silane having at least one perfluorinated aliphatic group and at least one silane group. Hydrophobic layer 30 may also comprise additional compounds in addition to the second silane. The additional compounds in hydrophobic layer 30 may impart various desirable properties to hydrophobic layer 30, such as, for example, microbial resistance, without preventing hydrophobic layer 30 and/or the second silane from acting as a hydrophobic and/or oleophobic layer or compound.
In order to impart hydrophobic characteristics to coating 26, the second silane may comprise long alkyl chains, partially fluorinated alkyl chains, and/or alkyl chains that have regions that are perfluorinated, any of which may be straight or branched. For example, the second silane may comprise alkyl chains having the general formulas CF3(CF2)n(CH2)mSiR1R2R3 and/or CF2H(CF2)n(CH2)mSiR1R2R3, where n and m are integers (n≧0, and m≧0). In addition, the second silane and/or the hydrophobic layer 30 may comprise mixtures of alkyl, perfluoroalkyl, or partially fluorinated alkyl chains.
The second silane may be capable of bonding to the first silane through, for example, a siloxane (Si—O—Si) linkage. Additionally, the second silane may be capable of forming polymers containing siloxane linkages. In an exemplary embodiment, the silane group on the second silane may be represented by formula (III):
where R4, R5, and R6 may each be, independently, F, Cl, Br, I, H, OH, a methoxy group, an ethoxy group, an isopropoxy group, an alkoxy group, an acetoxy group, a methyl group, an alkyl group, a perfluoroalkyl group, a partially fluorinated alkyl group, a dimethylamino group, a dialkylamino group, an ethylamino group, a monoalkylamino group, an amino group, a phenyl group, or a methoxyethoxyethoxy group.
In at least one embodiment, the second silane may be represented by formula (IV):
where n may be an integer from 0-32, and R4, R5, and R6 may be as defined above for formula (III). In additional embodiments, n may be an integer from 1-16. In at least one embodiment, n may be an integer from 5-9.
Representative examples of the second silane include, without limitation, (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane, (tridecafluoro-1,1,2,2-tetrahydrooctyl)methyldichlorosilane, (tridecafluoro-1,1,2,2-tetrahydrooctyl)trimethoxysilane, (tridecafluoro-1,1,2,2-tetrahydrooctyl)triethoxysilane, (tris(tridecafluoro 1,1,2,2-tetrahydrooctyl)dimethylsiloxy)chlorosilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl)trichlorosilane, triethoxy(1H,1H,2H,2H-perfluorooctyl)silane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl)triethoxysilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl)trimethoxysilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl)methyldichlorosilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl)dimethylchlorosilane, perfluorododecyl-1H,1H,2H,2H-triethoxysilane-perfluorotetradecyl-1H,1H,2H,2H-triethoxysilane mixture, 1,8-bis(trichlorosilylethyl)hexadecylfluorooctane, n-octadecyldimethylchlorosilane, n-octadecyldimethylmethoxysilane, n-octadecylmethoxydichlorosilane, n-octadecylmethyldichlorosilane, n-octadecylmethoxydichlorosilane, n-octadecylmethyldiethoxysilane, n-octadecyltrichlorosilane, n-octadecyltriethoxysilane, n-octadecyltrimethoxysilane, n-octadecyldimethyl(dimethylamino)silane, n-triacontyldimethylchlorosilane, n-triacontyltrichlorosilane, n-hexadecyltrichlorosilane, n-hexadecyltrimethoxysilane, n-hexadecyltriethoxysilane, n-dodecyltrichlorosilane, n-dodecyltrimethoxysilane, n-dodecyltriethoxysilane, n-dodecylmethyldichlorosilane, n-octyltrichlorosilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, n-octylmethyldichlorosilane, and n-octyldimethylchliorosilane. The second silane may also include compounds according to the general formula CH3(CH2)nCHRCH2SiCl3, where R═CH3(CH2)m, and n and m are integers (n≧0, and m≧0). The second silane may also include compounds according to the general formula CH3(CH2)nCHRSiCl3, where R═CH3(CH2)m, and n and m are integers (n≧0, and m≧0). The second silane may also include compounds according to the general formula CH3(CH2)nCHRSi(OCH3)3, where R═CH3(CH2)m, and n and m are integers (n≧0, and m≧0).
In certain embodiments, adhesion promoting layer 28 may comprise a germanium compound in addition to or in place of a silane compound. Germanium compounds may function as hydrophobic and/or oleophobic compositions in a manner similar to analogous silicon compounds. Accordingly, silicon compounds listed above as examples of the first silane may be substituted with analogous germanium compounds, in which the Si atom is replaced with a Ge atom.
In at least one embodiment, the adhesion promoting layer 28 may comprise a germanium compound that acts as an adhesion promoter. The germanium compound in the adhesion promoting layer 28 may comprise at least one of an isocyanate group, an acyl chloride group, an epoxide group, a glycidyl group, an amino group, a methyl ester group, an isothiocyanato group, a carboxyl group, an activated carboxyl group, an alkyl chloride group, an alkyl bromide group, an alkyl iodide group, a benzyl chloride group, a benzyl bromide group, a chlorosilane group (e.g., —SiCl3), a methoxysilane group (e.g., —Si(OCH3)3), an ethoxysilane group (e.g., —Si(OCH2CH3)3), and/or any other suitable reactive functional group, without limitation. The germanium compound in the adhesion promoting layer 28 may also comprise at least one germanium group. In an exemplary embodiment, the germanium group on the germanium compound in the adhesion promoting layer 28 may be represented by formula (V):
where R7, R8, and R9 may each be, independently, F, Cl, Br, I, H, OH, a methoxy group, an ethoxy group, an isopropoxy group, an alkoxy group, an acetoxy group, a methyl group, an alkyl group, a perfluoroalkyl group, a partially fluorinated alkyl group, a dimethylamino group, a dialkylamino group, an ethylamino group, a monoalkylamino group, an amino group, a phenyl group, or a methoxyethoxyethoxy group.
In at least one embodiment, the germanium compound in the adhesion promoting layer 28 may be represented by formula (VI):
where X may be an isocyanate group, an acyl chloride group, an epoxide group, a glycidyl group, an amino group, a methyl ester group, an isothiocyanato group, a carboxyl group, an activated carboxyl group, an alkyl chloride group, an alkyl bromide group, an alkyl iodide group, a benzyl chloride group, a benzyl bromide group, a chlorosilane group (e.g., —SiCl3), a methoxysilane group (e.g., —Si(OCH3)3), an ethoxysilane group (e.g., —Si(OCH2CH3)3), and/or any other suitable reactive functional group, without limitation. In formula (VI), n may be an integer from 0-32. In additional embodiments, n may be an integer from 1-18. In at least one embodiment, n may be an integer from 3-4. Additionally, in formula (VI), R7, R8, and R9 may be as defined above for formula (V).
In certain embodiments, hydrophobic layer 30 may comprise a germanium compound in addition to or in place of a silane compound. Germanium compounds may function as hydrophobic and/or oleophobic compositions in a manner similar to analogous silicon compounds. Accordingly, silicon compounds listed above as examples of the second silane may be substituted with analogous germanium compounds, in which the Si atom is replaced with a Ge atom.
The germanium compound in hydrophobic layer 30 may be capable of bonding to a silane (e.g., the first silane) or a germanium compound through, for example, a siloxane (Si—O—Si) linkage, a Ge—O—Si linkage, and/or a Ge—O—Ge linkage, The germanium compound in adhesion promoting layer 28 may also be capable of bonding to a silane (e.g., the first silane) or a germanium compound through, for example, a siloxane linkage, Ge—O—Si linkage, and/or a Ge—O—Ge linkage. Additionally, the germanium compound in hydrophobic layer 30 may be capable of forming polymers containing siloxane linkages, Ge—O—Si linkages, and/or Ge—O—Ge linkages. In an exemplary embodiment, the silane group on the second silane may be represented by formula (VII):
where R10, R11, and R12 may each be, independently, F, Cl, Br, I, H, OH, a methoxy group, an ethoxy group, an isopropoxy group, an alkoxy group, an acetoxy group, a methyl group, an alkyl group, a perfluoroalkyl group, a partially fluorinated alkyl group, a dimethylamino group, a dialkylamino group, an ethylamino group, a monoalkylamino group, an amino group, a phenyl group, or a methoxyethoxyethoxy group.
In at least one embodiment, the second silane may be represented by formula (VIII):
where n may be an integer from 0-32, and R10, R11, and R12 may be as defined above for formula (VII). In additional embodiments, n may be an integer from 1-16. In at least one embodiment, n may be an integer from 5-9.
During or following 106, in which the first silane may be deposited onto surface 24, the first silane may become bonded to surface 24. In at least one embodiment, the first silane may become covalently bonded to surface 24 through, for example, a carbamate (i.e., urethane) linkage, an ester linkage, an ether linkage, an amide linkage, and/or a C—O—Si linkage. For example, a surface, such as a surface of a polymer substrate, may comprise a hydroxyl group.
In at least one example, a carbamate linkage may be formed between the first silane and surface 24 by a reaction between a hydroxyl group on surface 24 and an isocyanate group on the first silane. In an additional embodiment, an ester linkage may be formed between the first silane and surface 24 by a reaction between a hydroxyl group on surface 24 and an acyl chloride group on the first silane. In certain embodiments, an ether linkage may be formed between the first silane and surface 24 by a reaction between a hydroxyl group on surface 24 and an alkyl or benzyl chloride group on the first silane. In an additional embodiment, an ether linkage may be formed between the first silane and surface 24 by a reaction between a hydroxyl group on surface 24 and an epoxy or glycidyl group on the first silane. In an additional embodiment, an ester linkage may be formed between the first silane and surface 24 by a reaction between a hydroxyl group on surface 24 and a methyl ester group on the first silane. In an additional embodiment, a Si—O—C linkage may be formed between the first silane and surface 24 by a reaction between a hydroxyl group on surface 24 and a Si—Cl group, a Si—OCH3 group, a Si—OCH2CH3 group, a Si—N(CH3)2 group, or a similar reactive group, on the first silane. In an additional embodiment, an amide linkage may be formed between the first silane and surface 24 by a reaction between a carboxyl group on surface 24 and an amine group on the first silane. In an additional embodiment, an ionic linkage may be formed between the first silane and surface 24 by a reaction between a carboxyl group on surface 24 and a primary amine group on the first silane to form an ion pair of the —COO− and —NH3+ groups. In an additional embodiment, an imine linkage may be formed between the first silane and surface 24 by a reaction between a carbonyl group on surface 24 and an amine group on the first silane.
Alternatively, a siloxane linkage and/or a Si—O—C linkage may be formed between the first silane and a surface of a silicon oxide based substrate by, for example, a reaction between a silane group on the first silane and a silanol (Si—OH) group on surface 24. An Al—O—Si linkage may also be formed between the first silane and a surface of an aluminum oxide based substrate by, for example, a reaction between a silane group on the first silane and an AlOH group on surface 24.
During 114, in which the second silane may be deposited onto the first silane, the second silane may be in a solid, liquid, or gaseous state. Deposition of the second silane onto surface 24 may be conducted using any suitable method, including for example, immersing surface 24 in a liquid comprising the second silane and/or exposing surface 24 to a vapor comprising the second silane. In certain embodiments, the second silane may be contained in a solution comprising a solvent. In various embodiments, the second silane film may be deposited under a pressure ranging from a few torr to above atmospheric pressure.
During or following 114, in which the second silane may be deposited onto the first silane, the second silane may become bonded to the first silane. In at least one embodiment, the second silane may become covalently bonded to the first silane through, for example, a siloxane (Si—O—Si) linkage. A siloxane linkage may be formed by a reaction between a silane group on the second silane and a silane group on the first silane. Prior to 114, a silane group on the first silane may be hydrolyzed to form a siloxyl (Si—OH) group. Subsequently, the siloxyl group on first silane may react with a silane group on the second silane to form a siloxane linkage.
In certain embodiments, prior to depositing the first silane onto surface 24, surface 24 may be oxidized. For example, as illustrated in
In at least one embodiment, surface 24 may be oxidized by exposing surface 24 to an oxygen plasma. Surface 24 may also be oxidized by exposing surface 24 to a water plasma. In an additional embodiment, surface 24 may also be oxidized by exposing surface 24 to a plasma that contains oxygen and water. In an additional embodiment, surface 24 may be oxidized by exposing surface 24 to an argon plasma, and subsequently exposing the surface to air or an oxygen containing gaseous composition. In an additional embodiment, surface 24 may be oxidized by exposing surface 24 to a helium plasma, and subsequently exposing the surface to the air. In an additional embodiment, surface 24 may be oxidized by exposing surface 24 to an ultraviolet (UV) light. In an additional embodiment, surface 24 may be oxidized by exposing surface 24 to a solution containing an oxidizing agent.
In various embodiments, the first silane may be vaporized prior to being deposited on surface 24. For example, as illustrated in
The first silane may be vaporized through any suitable method, including, for example, increasing the temperature and/or reducing the pressure of the first silane. In certain embodiments, a carrier solvent may be used to transport the first silane into a heated vacuum chamber, where the first silane may be vaporized. Substrate 22 may be present in a heated vacuum chamber in which the first silane may be vaporized.
Vapor deposition of the first silane may enable effective deposition and/or reaction of the first silane with surface 24, while reducing or eliminating the use of solvents to carry the first silane to desired portions of surface 24. Accordingly, vapor deposition of the first silane may effectively minimize solvent and/or other waste products in comparison with a solution based delivery system. Additionally, vapor deposition of the first silane may reduce or eliminate any need for cleaning surface 24 and the deposited first silane prior to 114, in which a second silane may deposited onto the first silane.
In at least one embodiment, the first silane may be hydrolyzed during or following deposition of the first silane onto surface 24. For example, as illustrated in
Alternatively, hydrolysis may be promoted by water derived in-part or exclusively from the substrate material and/or reaction by-products. For example, in a case where surface 24 comprises a surface of a polymeric substrate, vaporized water may be produced from a decomposition or reaction of the polymeric substrate during method 100. Additionally, water may be present in the substrate itself, and may be released during method 100. The vaporized water may in turn hydrolyze the first silane.
During hydrolysis of the first silane, at least one silanol group (i.e., a Si—O—H group) may be formed on the first silane at the location of the silane group. The silanol group may act as an adhesion promoter for the second silane, providing a highly reactive site at which the second silane may bond to the first silane.
Hydrolysis of the first silane may lead to condensation between molecular components of the first silane, forming siloxane bonds between adjacent molecular components. The siloxane bonds between adjacent molecular components may result in cross-linking of the first silane deposited onto surface 24. Siloxane linkages between adjacent molecular components of the first silane may add structural robustness to the first silane deposited on surface, enabling formation of an ultra-thin adhesion promoting layer 28, which is relatively stable and abrasion resistant, on surface 24.
In various embodiments, exposing the first silane to the vaporized water may result in hydrolysis of at least one unreacted isocyanate group on the first silane, producing an amine group (i.e., —NH2). An amine group on the first silane may act as a Brønsted-Lowry base, accepting protons and forming ionic bonds with carboxyl groups that may be present on surface 24. At elevated temperature, the amine group that has accepted a proton from a carboxyl group at the surface may form an amide linkage, with concomitant loss of water. The amine group may also form ionic bonds with silanol groups on the second silane deposited on the first silane. The amine group may also form ionic bonds with silanol groups in the adhesion promoting layer 28.
In additional embodiments, the second silane may be vaporized prior to being deposited on the first silane and/or adhesion promoting layer 28. For example, as illustrated in
The second silane may be vaporized through any suitable method, including, for example, increasing the temperature and/or reducing the pressure of the second silane. In certain embodiments, a carrier solvent may be used to transport the second silane into a heated vacuum chamber, where the second silane may be vaporized. Substrate 22 may be present in a heated vacuum chamber in which the second silane may be vaporized.
Vapor deposition of the second silane may enable effective deposition and/or reaction of the second silane with the first silane while reducing or eliminating the use of solvents to carry the second silane to desired portions of the adhesion promoting layer 28. Accordingly, vapor deposition of the second silane may effectively minimize solvent and/or other waste products in comparison with a solution based delivery system. Additionally, vapor deposition of the second silane may reduce or eliminate any need for cleaning surface 24 and the deposited second silane following deposition of the second silane.
In various embodiments, after depositing the first silane onto surface 24, the first silane may be cross-linked. For example, as illustrated in
Cross-linking of the first silane may be performed at any suitable time following deposition of the first silane on the substrate, including, for example, prior to or following deposition of the second silane on the first silane. Cross-linking of the first silane may be promoted through any suitable method, including, for example hydrolysis of the first silane. As described above, at 108, the first silane may be hydrolyzed. Hydrolysis of the first silane may lead to condensation between molecular components of the first silane, forming siloxane bonds between adjacent molecular components. The siloxane bonds between adjacent molecular components may result in cross-linking of the first silane deposited on surface 24. Siloxane linkages between adjacent molecular components of the first silane may add structural robustness to the first silane deposited on surface, enabling formation of an ultra-thin adhesion promoting layer 28, which is relatively stable and abrasion resistant, on surface 24.
In additional embodiments, a cross-linking compound may be used to promote and/or increase cross-linking between molecular components of the first silane. Examples of cross-linking compounds suitable for use in cross-linking the first silane include, without limitation, bis(trichlorosilyl)hexane and tetrakis(trichlorosilyethyl)-silane. The cross-linking compound may be bonded to molecular components of the first silane through any suitable means, including, for example, through hydrolysis. A cross-linking compound may promote increased branching between molecular components of the first silane, and may increase stability and abrasion resistance in adhesion promoting layer 28. In certain embodiments, polymerizable groups such as, for example, vinyl groups, may be introduced onto the first silane, and polymerization of the polymerizable groups may then be induced.
In various embodiments, after depositing the second silane onto surface 24, the second silane may be cross-linked. For example, as illustrated in
Cross-linking of the second silane may be promoted through any suitable method, including, for example hydrolysis of the second silane. In certain embodiments, the second silane may be hydrolyzed by exposing the second silane to vaporized water during or following deposition of the second silane onto the first silane. Alternatively, hydrolysis may be promoted by water derived in-part or exclusively from the substrate material and/or reaction by-products. For example, in a case where surface 24 comprises a surface of a polymeric substrate, vaporized water may be produced from a decomposition or reaction of the polymeric substrate during method 100. Additionally, water may be present in the substrate itself, and may be released during method 100.
Hydrolysis of the second silane may lead to condensation between individual molecular components of the second silane, as well as between molecular components of the second silane and the first silane. The condensation may lead to the formation of siloxane bonds between adjacent molecular components. The siloxane bonds between adjacent molecular components may result in cross-linking of the second silane deposited onto surface 24. The siloxane bonds between adjacent molecular components may also result in cross-linking between the second silane and the first silane. Siloxane linkages between adjacent molecular components of the second silane and/or the first silane may add structural robustness to the coating composition, enabling an ultra-thin coating, which is relatively stable and abrasion resistant, to be deposited onto surface 24.
In additional embodiments, a cross-linking compound may be used to promote and/or increase cross-linking between molecular components of the second silane. Examples of cross-linking compounds suitable for use in cross-linking the second silane include, without limitation, bis(trichlorosilyl)hexane and tetrakis(trichlorosilyethyl)-silane. The cross-linking compound may be bonded to molecular components of the second silane through any suitable means, including, for example, through hydrolysis. A cross-linking compound may promote increased branching between molecular components of the second silane, and may increase stability and abrasion resistance in a coating of the second silane. In certain embodiments, polymerizable groups such as, for example, vinyl groups, may be introduced onto the second silane, and polymerization of the polymerizable groups may then be induced.
In certain embodiments, after depositing the first silane onto surface 24 and/or after depositing the second silane onto the first silane, the first silane and/or the second silane may be cured. For example, as illustrated in
Curing of the first silane and/or the second silane may be conducted using any suitable method, including, for example, exposing the first silane and/or the second silane to heat or radiation. In an exemplary embodiment, a coating comprising the first silane and the second silane may be cured by exposing the coating to an elevated temperature for a suitable period of time.
In an additional embodiment, as illustrated in
In an additional embodiment, as illustrated in
Hearing aid device 200 may comprise coating 26 on, near, or adjacent to any suitable portion, including external and internal portions of hearing aid device 200. Additionally, any suitable component or portion thereof may comprise coating 26. Coating 26 may be formed on, near, or adjacent to any portion of hearing aid device 200 that may having an opening between an exterior portion and an interior portion of hearing aid device 200. Examples of portions of hearing aid device 200 that coating 26 may be formed on, near, or adjacent to include, without limitation, device cover 202, microphone cover 204, volume control 206, battery door 208, tubing 210, ear hook 212, program button 214, in-the-ear dome 216, ear mold 218, sound port 220, battery compartment 222, and/or battery 224.
The following examples are for illustrative purposes only and are not meant to be limiting on the scope of the appended claims.
Reagents used in the following examples include: (Tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane (≧−97%, Aldrich), 3-isocyanatopropyltriethoxysilane (95%, Gelest, Morrisville, Pa.), triethoxy(1H,1H,2H,2H-perfluorooctyl)silane (98%, Aldrich), m-cresol (97%, Aldrich), and nylon 6/6 pellets (Aldrich, Cat. No. 181129). An “aqueous salt/acid” solution employed herein is a formulation for artificial sweat, which was 0.34 M NaCl, 0.08 M urea, 0.33 M NH4Cl, 0.04 M CH3COOH and 0.12 M lactic acid. The solution was adjusted to pH 4.7 with 2 M NaOH.
Substrates used in the following examples included silicon substrates, reinforced nylon substrates, and spin-coated nylon substrates. Silicon substrates used in the examples included silicon wafers (test grade, n-type, <1-0-0> orientation, 2-6 Ω-cm) from UniSil Corporation, California. The silicon wafers were cleaved into ca, 1.5×1.5 cm pieces. Prior to performing any surface chemistry on the silicon substrates, the silicon substrates were cleaned with an aqueous 2% sodium dodecyl sulfate (“SDS”) solution and water without sonication.
Reinforced nylon substrates used in the following examples included FDA grade reinforced nylon 6/6 surfaces containing 35% chopped glass fiber by weight (⅛- 3/16″ long). The FDA grade reinforced nylon surfaces contained FDA compliant additives (e.g., colorants) and no UV or high flow additives. Aldrich indicated the melting point of the nylon 6/6 they provided was 263° C., and its glass transition temperature was 45° C. Prior to performing any surface chemistry on the reinforced nylon substrates, the reinforced nylon substrates were sonicated in an SDS solution for 5 minutes. They were then sonicated in deionized water for 10 minutes. This water was changed three times during sonication.
Spin-coated nylon substrates used in the following examples included substrates prepared by spin-coating a solution of nylon 6/6 pellets in m-cresol onto surfaces of native oxide coated silicon wafers using the following program conditions (on an instrument from Laurell Technologies Corporation, model WS-400B-6NPP/LITE): 1000 rpm (10 seconds) followed by 5000 rpm (90 seconds). An initial concentration of the nylon 6/6 solution was <3% (w/w), but this nylon 6/6 solution was diluted in m-cresol until the spin-coating process obtained a film thickness of approximately 170 Å. The spin-coated nylon substrates were then baked in a vacuum oven at 100° C. for 2 hours at reduced pressure to drive off m-cresol.
Time-of-flight secondary ion mass spectrometry (“TOF-SIMS”) was performed with an ION-TOF (TOF-SIMS IV) instrument with a two-lens, monoisotopic 69Ga+ gun as a primary ion source. X-ray photoelectron spectroscopy (“XPS”) was performed with an SSX-100 instrument from Surface Sciences using an Al Kα source and a hemispherical analyzer. An electron flood gun was employed for charge compensation of the reinforced nylon samples, and this charge compensation was further enhanced by placing a fine Ni mesh ca. 0.5-1.0 mm above the surface of the glass reinforced polymer. No charge compensation was necessary for the silicon or spin-coated nylon on silicon samples. Water contact angles were measured with a Ramé-Hart (model 100-00) contact angle goniometer. Spectroscopic ellipsometry was performed with an M-2000 instrument from the J.A. Woollam Co., Inc. The wavelength range was 190.5-989.4 nm, and the angle of incidence was fixed at 75′. Silicon oxide, hydrocarbon, deposited silane films, and spin coated nylon were modeled using the same optical constants of silicon oxide that were found in the instrument software.
Plasma cleaning/treatment of silicon substrates was performed by exposing the silicon substrates to an air plasma in a plasma cleaner (model PDC-32G from Harrick Plasma, Ithaca, N.Y.) at medium power (10.5 W applied to the RF coil) for 30 seconds. An advancing water contact angle (θa(H2O)) for a silicon substrate surface was measured to be 40° prior to plasma cleaning/treatment. Following plasma cleaning/treatment, an average advancing water contact angle for a surface of silicon substrate prepared according to this example was measured to be <15°.
Advancing water contact angle may be used as a measure of surface hydrophobicity. A higher advancing water contact angle for a surface may indicate that the surface has a higher degree of hydrophobicity. A decrease in water contact angle for a surface following plasma cleaning/treatment may indicate an increase in oxygen content (e.g., —OH content) of the surface. A decrease in water contact angle for a surface following plasma cleaning/treatment may also indicate removal of hydrocarbon contamination from the surface as a result of the plasma cleaning/treatment.
Plasma cleaning/treatment of reinforced nylon substrates was performed by exposing the reinforced nylon substrates to an air plasma in a plasma cleaner (model PDC-32G from Harrick Plasma, Ithaca, N.Y.) at medium power (10.5 W applied to the RF coil) for 30 seconds.
An average advancing water contact angle for surfaces of three reinforced nylon substrates was measured to be 69° prior to plasma cleaning/treatment. Following plasma cleaning/treatment, an average advancing water contact angle for surfaces of five reinforced nylon substrates prepared according to this example was measured to be 32°.
Prior to plasma cleaning/treatment of a reinforced nylon substrate prepared according to this example, an X-ray photoelectron spectrum (“XP spectrum”) for the reinforced nylon substrate surface, obtained using XPS, was dominated by signals from oxygen (O1s), nitrogen (N1s), and carbon (C1s). Following plasma cleaning/treatment of the reinforced nylon substrate, O1s, N1s, and C1s signals still dominated the XP spectrum for the reinforced nylon substrate surface. However, a peak ratio of O1s to C1s for the reinforced nylon substrate surface increased significantly, from a ratio of 0.14 prior to plasma cleaning/treatment to a ratio of 0.28 following plasma cleaning/treatment, which indicates an increase in oxygen (e.g., —OH) content of the reinforced nylon substrate surface following plasma cleaning/treatment. Additionally, the C1s narrow scan of the XP spectrum for the reinforced nylon substrate surface showed a notable increase in a peak representing oxidized (i.e., chemically shifted) carbon, further indicating an increase in oxygen content of the reinforced nylon substrate following plasma cleaning/treatment.
The O−/C− ratio in a negative ion TOF-SIMS spectrum of a reinforced nylon substrate surface prepared according to this example was 0.09 prior to plasma cleaning/treatment and was 0.21 following plasma cleaning/treatment, indicating an increase in oxygen content of the reinforced nylon substrate surface as a result of the plasma cleaning/treatment.
Plasma cleaning/treatment of spin-coated nylon substrates was performed by exposing the spin-coated nylon substrates to an air plasma in a plasma cleaner (model PDC-32G from Harrick Plasma, Ithaca, N.Y.) at medium power (10.5 W applied to the RF coil) for 30 seconds.
An average advancing water contact angle for surfaces of five spin-coated nylon substrates was measured to be 60° prior to plasma cleaning/treatment. Following plasma cleaning/treatment, an average advancing water contact angle for surfaces of six spin-coated nylon substrates prepared according to this example was measured to be 34°.
Following plasma cleaning/treatment according to Example 1, silicon substrates were dehydrated in a vacuum oven at 100° C. at reduced pressure. The vacuum for the vacuum oven was provided by a rotary vane pump. The vacuum oven contained a dry ice/acetone-cooled glass trap that prevented back-streaming of oil from the rotary vane pump and prevented both solvents and reagents from entering the rotary vane pump. After introducing the silicon substrates into the oven, the rotary vane pump was turned on for 3 minutes to attain a pressure of 15 Torr, and the valve to the rotary vane pump was then closed. The surfaces were allowed to dehydrate under these conditions for 30 minutes. The rotary vane pump was then turned on again for 3 minutes to pump off water vapors, after which the valve to the rotary vane pump was again closed.
An aliquot of 250 μL of 3-isocyanatopropyltriethoxysilane (“NCO-silane”) was then injected into the vacuum oven through a septum. The NCO-silane evaporated rapidly after being injected into the vacuum oven. The surfaces were allowed to react with the vapors of the NCO-silane under essentially static conditions for 30 minutes to form a silicon substrate having NCO-silane deposited on it (“NCO-silane/silicon substrate”). The valve to the rotary vane pump was then opened to pump off unreacted NCO-silane. Following plasma cleaning/treatment, an average advancing water contact angle for three NCO-silane/silicon substrates prepared according to this example was measured to be 82°.
Prior to deposition of NCO-silane on a silicon substrate, no N1s signal could be observed in an XP spectrum of the silicon substrate surface. Following deposition of NCO-silane on the silicon substrate to form an NCO-silane/silicon substrate surface according to this example, a small N1s signal was observable in an XP spectrum of the NCO-silane/silicon substrate surface. Spectroscopic ellipsometry of the NCO-silane/silicon substrate surface indicated that a layer having a thickness of 9.5 Å was present on the silicon substrate surface.
The procedure described for Example 4 was essentially followed with the exception that a reinforced nylon substrate prepared according to Example 2 was used instead of a silicon substrate to form a reinforced nylon substrate having NCO-silane deposited on it (“NCO-silane/reinforced nylon substrate”). Following deposition of NCO-silane, an average advancing water contact angle for five NCO-silane/reinforced nylon substrates prepared according to this example was measured to be 87°.
The procedure described for Example 4 was essentially followed with the exception that a spin-coated nylon substrate prepared according to Example 3 was used instead of a silicon substrate to form a spin-coated nylon substrate having NCO-silane deposited on it (“NCO-silane/spin-coated nylon substrate”). Following NCO silane deposition and plasma cleaning/treatment, the average advancing water contact angle for six NCO-silane/spin-coated nylon substrates prepared according to this example was measured to be 82°.
NCO-silane/silicon substrates prepared according to Example 4 were left in a vacuum oven, and a Petri dish containing 5 ml of water was introduced into the vacuum oven. The door to the oven was closed and the NCO-silane/silicon substrates were allowed to hydrolyze at atmospheric pressure and 100° C. for 30 minutes to form NCO-silane/silicon substrates having hydrolyzed surfaces (“hydrolyzed NCO-silane/silicon substrates”).
NCO-silane/reinforced nylon substrates prepared according to Example 5 were left in a vacuum oven, and a Petri dish containing 5 ml of water was introduced into the vacuum oven. The door to the oven was closed and the NCO-silane/reinforced nylon substrates were allowed to hydrolyze at atmospheric pressure and 100° C. for 30 minutes to form NCO-silane/reinforced nylon substrates having hydrolyzed surfaces (“hydrolyzed NCO-silane/reinforced nylon substrates”).
NCO-silane/spin-coated nylon substrates prepared according to Example 6 were left in a vacuum oven, and a Petri dish containing 5 ml of water was introduced into the vacuum oven. The door to the oven was closed and the NCO-silane/spin-coated nylon substrates were allowed to hydrolyze at atmospheric pressure and 100° C. for 30 minutes to form NCO-silane/spin-coated nylon substrates having hydrolyzed surfaces (“hydrolyzed NCO-silane/spin-coated nylon substrates”).
Hydrolyzed NCO-silane/silicon substrates prepared according to Example 7 were placed in a desiccator along with an open vial of (tridecafluoro-1,1,2,2-tetrahydrooctyl)tri chlorosilane (“Rf-silane”) for 16 hours. The hydrolyzed NCO-silane/silicon substrates were then removed from the desiccator and cured in an oven at 80° C. for 1 hour to form NCO-silane/silicon substrates having Rf-silane deposited on their surfaces (“Rf-NCO-silane/silicon substrates”). Spectroscopic ellipsometry indicated that an average surface thickness of hydrolyzed NCO-silane/silicon substrates was 29.1 Å prior to exposure to Rf-silane and was 78.2 Å following exposure to Rf-silane to form Rf-NCO-silane/silicon substrates according to this example. The notable increase in thickness of the surfaces following exposure to Rf-silane may indicate cross-linking of Rf-silane molecules into a polymeric thin film on the substrate surfaces.
Hydrolyzed NCO-silane/reinforced nylon substrates prepared according to Example 8 were placed in a desiccator along with an open vial of Rf-silane for 16 hours. The hydrolyzed NCO-silane/reinforced nylon substrates were then removed from the desiccator and cured in an oven at 80° C. for 1 hour to form NCO-silane/reinforced nylon substrates having Rf-silane deposited on their surfaces (“Rf-NCO-silane/reinforced nylon substrates”).
An XPS analysis of an Rf-NCO-silane/reinforced nylon substrate prepared according to this example showed that an F1s signal, with its accompanying F Auger peaks, was the dominant signal in the XP spectrum. A split carbon signal was observed and indicated the presence of i) carbon bonded to carbon and/or hydrogen and/or mildly oxidized carbon at lower binding energy, and ii) carbon in CF2 groups at higher binding energy, where each F atom bonded to a C atom is known to shift the C1s signal by ca. 2.9 eV, and secondarily shift carbon atoms by ca. 0.7 eV. No N 1s signal was observable in the XP spectrum, indicating that the Rf-silane may have formed a film that was free from pinhole defects and/or that was relatively thick in all places. A small oxygen signal was also present in the XP spectrum, which would be expected from Si—O linkages.
Hydrolyzed NCO-silane/spin-coated nylon substrates prepared according to Example 9 were placed in a desiccator along with an open vial of Rf-silane for 16 hours. The hydrolyzed NCO-silane/spin-coated nylon substrates were then removed from the desiccator and cured in an oven at 80° C. for 1 hour to form NCO-silane/spin-coated nylon substrates having Rf-silane deposited on their surfaces (“Rf-NCO-silane/spin-coated nylon substrates”). Spectroscopic ellipsometry indicated that a surface thickness of a hydrolyzed NCO-silane/spin-coated nylon substrate was 125.9 Å prior to exposure to Rf-silane and was 272.3 Å following exposure to Rf-silane to form a Rf-NCO-silane/spin-coated nylon substrate according to this example. The notable increase in thickness of the surfaces following exposure to Rf-silane may indicate crosslinking of Rf-silane molecules into a polymeric thin film on the substrate surfaces.
An abrasion apparatus for testing abrasion resistance consisted of an electrical drill (Craftsman, Model No. 315.101160) that was clamped vertically relative to a bench top. A commercially available polishing disk (Craftsman), which is designed to be used with an electric drill, was attached to the chuck of the drill, and a piece of abrasive felt (15 cm×14.7 cm) was pasted onto the polishing disk. When the drill was turned on, it caused the felt disk to rotate parallel to the bench top. A sample holder was made from two rectangular strips of plywood joined end-to-end with a steel hinge. The end of one of the rectangular strips was clamped to a stand, and a sample was attached to the end of the other rectangular strip with double-sided tape. The sample was then placed on the felt wheel 4.5 cm from its center, and remained in contact with the felt wheel as the felt wheel rotated. A brass cylinder weighing 164 g was placed directly above the sample on the wood strip. The rotational speed of the drill was controlled with a powerstat and the felt was also marked on its edge so as to count the number of cycles during the abrasion tests.
Additionally, a reinforced nylon substrate was plasma cleaned/treated according to Example 2. Following plasma cleaning/treatment, the reinforced nylon substrate was hydrolyzed with a similar surface that had been treated with the NCO silane, and then placed in a desiccator along with an open vial of (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane for 16 hours. The reinforced nylon substrate was then removed from the desiccator and cured in an oven at 80° C. for 1 hour to form reinforced nylon substrates having Rf-silane deposited on its surface, with no NCO-silane between the Rf-silane and the surface of the reinforced nylon substrate.
An Rf-NCO-silane/reinforced nylon substrate prepared according to Example 11 and the reinforced nylon substrate containing Rf-Silane and no NCO-silane were each tested using the abrasion apparatus. After more than 430 cycles in the abrasion testing apparatus, the advancing water contact angle of the surface of the Rf-NCO-silane/reinforced nylon substrate prepared according to Example 11 was 10° higher than the advancing water contact angle of the surface of the reinforced nylon substrate containing Rf-Silane and no NCO-silane.
An XP spectrum of the substrate surfaces following abrasion testing indicated that the ratio of C:F for the Rf-NCO-silane/reinforced nylon substrate prepared according to Example 11 was 43:57, while the C:F ratio for the reinforced nylon substrate containing Rf-Silane and no NCO-silane was 49:51, indicating a higher concentration of Rf-silane on the surface of the Rf-NCO-silane/reinforced nylon substrate prepared according to Example 11. The narrow scan of the XP spectra shows a peak for C attached to F atoms is comparatively larger in intensity for the surface of Rf-NCO-silane/reinforced nylon substrate prepared according to Example 11, further indicating a higher concentration of Rf-silane on the surface.
TOF-SIMS analysis in both the negative and positive ion modes was performed on silicon oxide, reinforced nylon, and spin-coated nylon substrates after treatment with the NCO-silane, and again after treatment with the Rf-silane TOF-SIMS analysis, which has an information depth of only about 2 nm, is typically more surface sensitive than XPS analysis, which probes at least 10 nm into a material. Positive ion TOF-SIMS spectra of a Rf-NCO-silane/silicon substrate prepared according to Example 10, a Rf-NCO-silane/reinforced nylon substrate prepared according to Example 11, and a Rf-NCO-silane/spin-coated nylon substrate prepared according to Example 10 each showed a series of peaks that are characteristic of a perfluorinated hydrocarbon. The two largest peaks in the TOF-SIMS spectra were identified as the CF+ and CF3+ peaks. The negative ion spectra from the Rf-NCO-silane/silicon substrate, the Rf-NCO-silane/reinforced nylon substrate, and the Rf-NCO-silane/spin-coated nylon substrate were dominated by a single F− peak, and also showed an F2− peak, which is typically less than 5% intense as the F− signal.
Plasma treated silicon substrates and spin-coated nylon substrates, each having no NCO-silane deposited on the surfaces, were hydrolyzed. Silicon substrates and spin-coated nylon substrates with NCO-silane deposited on their surfaces were also hydrolyzed. Each of the substrates in this example were then placed in a desiccator along with an open vial of Rf-silane for 16 hours, after which they were cured in an oven at 80° C. for 1 hour.
Spectroscopic ellipsometry indicated that surfaces of the silicon substrates having no NCO-silane deposited on them had an average coating thickness of 116.7 Å, and surfaces of the spin-coated substrates having no NCO-silane deposited on them had an average coating thickness of 232.7 Å. Spectroscopic ellipsometry indicated that surfaces of the silicon substrates with NCO-silane deposited on them had an average coating thickness of 48.0 Å, and surfaces of the spin-coated substrates having NCO-silane deposited on them had an average coating thickness of 67.0 Å. Accordingly, the spectroscopic ellipsometry analysis indicates that the surfaces coated with the NCO-silane were considerably thinner than the surfaces that were not treated with the NCO.
Reinforced nylon substrates were cleaned/treated in O2 plasma using a YES 1224 P Chemical Vapor Deposition System manufactured by Yield Engineering Systems, Inc., California (“YES System”). Various time periods were used. Table 1 shows advancing water contact angles for reinforced nylon substrates exposed to O2 plasma for various time periods according to this example.
Silicon substrates were cleaned/treated in O2 plasma for 6 minutes using the YES System. The silicon substrates were then exposed to NCO-silane vapor for 10 minutes at a temperature of 100° C. to form an NCO-silane/silicon substrate. An advancing water contact angle for an NCO-silane/silicon substrate prepared according to this example was measured to be 55°. Spectroscopic ellipsometry of a silicon substrate surface and an NCO-silane/silicon substrate surface prepared according to this example indicated an increase in the thickness of the silicon substrate surface of 11.8 Å as a result of the NCO-silane deposition.
Reinforced nylon substrates were cleaned/treated in O2 plasma for 6 minutes using the YES System. The reinforced nylon substrates were then exposed to NCO-silane vapor for 10 minutes at a temperature of 100° C. to form an NCO-silane/reinforced nylon substrate. An advancing water contact angle for an NCO-silane/reinforced nylon substrate prepared according to this example was measured to be 76°.
Following preparation of NCO-silane/silicon substrates according to Example 17, 3 mL of water was introduced into a chamber in the YES system to produce water vapor in the chamber. The NCO-silane/silicon substrates were hydrolyzed by exposing them to the water vapor in the chamber for 30 minutes at a temperature of 100° C. The NCO-silane/silicon substrates were then exposed to Rf-NCO-silane vapor for 15 minutes at a temperature of 100° C. to form Rf-NCO-silane/silicon substrates. An advancing water contact angle for an Rf-NCO-silane/silicon substrate prepared according to this example was measured to be 125°.
Following preparation of NCO-silane/reinforced nylon substrates according to Example 18, 3 mL of water was introduced into a chamber containing the NCO-silane/reinforced nylon substrates in the YES system to produce water vapor in the chamber. The NCO-silane/reinforced nylon substrates were hydrolyzed by exposing them to the water vapor in the chamber for 30 minutes at a temperature of 100° C. The NCO-silane/reinforced nylon substrates were then exposed to Rf-silane vapor for 15 minutes at a temperature of 100° C. to form Rf-NCO-silane/reinforced nylon substrates. An average advancing water contact angle for Rf-NCO-silane/reinforced nylon substrates prepared according to this example was measured to be 155°.
The preceding description has been provided to enable others skilled in the art to best utilize various aspects of the exemplary embodiments described herein. This exemplary description is not intended to be exhaustive or to be limited to any precise form disclosed. Many modifications and variations are possible without departing from the spirit and scope of the instant disclosure. The embodiments described herein are in all respects illustrative and not restrictive.
Unless otherwise noted, the terms “a” or “an,” as used in the specification and claims, are to be construed as meaning “at least one of.” In addition, for ease of use, the words “including” and “having,” as used in the specification and claims, are interchangeable with and have the same meaning as the word “comprising.”
This application claims the priority benefit of U.S. Provisional Application No. 60/849,233, filed Oct. 3, 2006, the disclosure of which is incorporated, in its entirety, by this reference.
| Number | Date | Country | |
|---|---|---|---|
| 60849233 | Oct 2006 | US |
