Single component hydrophobic coating
阅读说明：本技术 单组分疏水涂层 (Single component hydrophobic coating ) 是由 D·N·沃特斯 E·S·莱因哈特 C·库驰科 S·D·赫尔灵 于 2020-01-28 设计创作，主要内容包括：一种涂料组合物包含由反应物混合物制备的聚合物,所述反应物包含(a)氟化聚硅氧烷和(b)烷氧基硅烷官能树脂。所述烷氧基硅烷官能树脂包含聚氨酯树脂或丙烯酸树脂。还公开了至少部分涂有所述涂料组合物的基材。还公开了一种通过使至少部分涂有所述涂料组合物的基材与极性流体接触使得极性流体冷凝在涂布基材的至少一部分上来冷凝极性流体的方法。(A coating composition includes a polymer prepared from a mixture of reactants including (a) a fluorinated polysiloxane and (b) an alkoxysilane-functional resin. The alkoxysilane-functional resin comprises a polyurethane resin or an acrylic resin. Also disclosed are substrates at least partially coated with the coating composition. Also disclosed is a method of condensing a polar fluid by contacting a substrate at least partially coated with the coating composition with the polar fluid such that the polar fluid condenses on at least a portion of the coated substrate.)
1. A coating composition comprising a polymer prepared from a mixture of reactants comprising (a) a fluorinated polysiloxane; and (b) an alkoxysilane functional resin, wherein the alkoxysilane functional resin comprises a polyurethane resin or an acrylic resin.
2. The coating composition of claim 1, wherein the reactant mixture further comprises (c) a metal alkoxide.
3. The coating composition of claim 1, further comprising a hydrophobic additive and/or a hydrophilic additive.
4. The coating composition of claim 3, wherein the surface active coating composition comprises a hydrophobic additive, wherein the hydrophobic additive comprises a fluorinated treated silica, a fluorinated silane treated particle, a hydrophobic treated metal oxide, a rare earth metal oxide, or a combination thereof.
5. The coating composition of claim 1, wherein the fluorinated polysiloxane comprises polytrifluoropropylmethylsiloxane.
6. The coating composition of claim 1, further comprising a coupling agent.
7. The coating composition of claim 6, wherein the coupling agent comprises a silane, an alkoxysilane, a fluoroalkylsilane, an aminopropyltriethoxysilane, or some combination thereof.
8. The coating composition of claim 3, wherein the hydrophilic additive and/or hydrophobic additive comprises at least 1 wt% of the coating composition, based on the total solids weight of the coating composition.
9. The coating composition of claim 2, wherein the metal alkoxide comprises at least 0.5 weight percent of the coating composition based on a total solids weight of the coating composition.
10. The coating composition of claim 1, wherein the coating is hydrophobic when applied to a substrate and cured to form a coating.
11. The coating composition of claim 1, wherein the coated substrate exhibits a water contact angle of at least 140 ° when applied to a substrate and cured to form a coating.
12. The coating composition of claim 3, wherein when applied to a substrate and cured to form a coating, the coating comprises a hydrophobic portion and a hydrophilic portion, the hydrophobic portion comprising at least a fluorinated portion of a polymer, the hydrophilic portion comprising a hydrophilic additive.
13. The coating composition of claim 3, wherein the coating composition comprises a hydrophilic additive, wherein the hydrophilic additive comprises nanoscale particles comprising titanium dioxide, aminopropylsilane treated silica particles, untreated silica particles, or some combination thereof.
14. The coating composition of claim 1, wherein the alkoxysilane-functional resin comprises at least 4 alkoxy groups bonded to silicon atoms.
15. The coating composition of claim 1, wherein when cured, a coating formed from the coating composition exhibits a hardness value that is greater than the hardness value of an identical coating prepared from a coating composition that does not comprise an alkoxysilane-functional resin.
16. The coating composition of claim 1, further comprising a thermally conductive material comprising metal flakes, metal powder, electrically conductive carbon, or some combination thereof.
17. A substrate at least partially coated with the coating composition of claim 1.
18. The substrate of claim 17, wherein the coating has a film thickness of at most 3 mils when the coating composition is cured to form a coating.
19. The substrate of claim 17, wherein the substrate comprises a surface of a component in an HVAC system.
20. A method of condensing a polar fluid, the method comprising:
contacting a substrate at least partially coated with a coating composition comprising a polymer prepared from a mixture of reactants comprising (a) a fluorinated polysiloxane with a polar fluid such that the polar fluid condenses on at least a portion of the coated substrate; and (b) an alkoxysilane functional resin, wherein the alkoxysilane functional resin comprises a polyurethane resin or an acrylic resin.
Technical Field
The present invention relates to a coating composition, a substrate coated with the coating composition and a method of condensing a polar fluid by contacting the substrate at least partially coated with the coating composition with the polar fluid.
Background
Coating compositions that are applied to a substrate and cured to form a coating are used in various industries to promote condensation of water or other polar fluids from the surrounding air onto the coating. Examples include coating compositions for use on ventilation shafts or heating, ventilation, and air conditioning (HVAC) systems, e.g., condenser tubes thereof. The efficiency of the heat exchanger can be improved by rapidly condensing water from the air in these coated areas and then rapidly removing water droplets from the coated surfaces by gravity and/or forced air flowing over the heat exchanger surfaces. Accordingly, there is a need to provide coated surfaces with high water contact angles and low hysteresis values to facilitate more efficient and cost effective operation of heat exchangers.
Disclosure of Invention
The present invention relates to coating compositions comprising a polymer prepared from a mixture of reactants comprising (a) a fluorinated polysiloxane and (b) an alkoxysilane-functional resin. The alkoxysilane-functional resin comprises a polyurethane resin or an acrylic resin.
The invention also relates to a method of condensing a polar fluid, the method comprising: contacting a substrate at least partially coated with the coating composition with a polar fluid such that the polar fluid condenses on at least a portion of the coated substrate. The coating composition comprises a polymer prepared from a mixture of reactants comprising (a) a fluorinated polysiloxane and (b) an alkoxysilane-functional resin. The alkoxysilane-functional resin comprises a polyurethane resin or an acrylic resin.
Detailed Description
For the purposes of the following detailed description, it is to be understood that the invention may assume various alternative variations and step sequences, except where expressly specified to the contrary. Moreover, other than in any operating examples, or where otherwise indicated, all numbers expressing, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques.
Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
Moreover, it should be understood that any numerical range recited herein is intended to include all sub-ranges subsumed therein. For example, a range of "1 to 10" is intended to include all sub-ranges between (and including) the recited minimum value of 1 and the recited maximum value of 10, i.e., having a minimum value of 1 or greater and a maximum value of 10 or less.
In this application, the use of the singular includes the plural and plural encompasses singular, unless expressly stated otherwise. In addition, in this application, the use of "or" means "and/or" unless explicitly stated otherwise, even though "and/or" may be explicitly used in certain instances. Further, in this application, the use of "a" or "an" means "at least one" unless explicitly stated otherwise. For example, "an" alkoxysilane-functional resin, "a" fluorinated polysiloxane, and the like, refers to one or more of these items. Further, as used herein, the term "polymer" means prepolymers, oligomers, and both homopolymers and copolymers. The terms "resin" and "polymer" are used interchangeably.
As used herein, the transitional term "comprising" (and other equivalent terms, such as "comprises" and "comprising") is "open-ended" and is open-ended to the inclusion of unspecified content. Although described in terms of "comprising," the terms "consisting essentially of … …" and "consisting of … …" are also within the scope of the invention.
The present invention can be directed to a coating composition comprising a polymer prepared from a mixture of reactants comprising (a) a fluorinated polysiloxane and (b) an alkoxysilane-functional resin, wherein the alkoxysilane-functional resin can comprise a polyurethane resin or an acrylic resin. A coating composition may refer to a coating composition that, when applied to a substrate and cured, causes water (or other polar fluid) from the surrounding environment to condense onto the substrate. The coating composition, when applied to a substrate and cured, can help the coated substrate exhibit other advantageous properties, such as ease of cleaning, self-cleaning, anti-fouling, and/or anti-fogging (e.g., promoting condensation of water in the form of a film rather than droplets).
The polymer may be prepared from a mixture comprising a fluorinated polysiloxane. As used herein, the term "polysiloxane" refers to a polymer having a backbone or main chain containing one or more Si-O-Si bonds. The polysiloxane may comprise a single polysiloxane or a mixture of polysiloxanes. The polysiloxane may have the general structure of formula I:
in formula I, n can range from at least 1 to a maximum of 1,000 or 1 to 100, and each RaAnd RbIndependently represent a group selected from hydrogen, hydroxyl, substituted or unsubstituted hydrocarbon groups, and mixtures thereof. Each individual RaThe radicals being able to react with other radicals RaThe radicals being identical or different and each individual RbThe radicals being able to react with other radicals RbThe groups may be the same or different. The fluorinated polysiloxane may have the general structure of formula I, wherein at least one RbThe groups contain fluorinated groups. RbAn alkyl chain which may be one or more carbons, wherein one or more fluoro groups are attached to one or more carbons in the alkyl chain. The fluoro group may be bonded to the terminal carbon or other along the alkyl chainCarbon attachment. Suitable fluorinated polysiloxanes include, but are not limited to, polytrifluoropropylmethylsiloxane, a polymer as shown in formula II. The fluorinated polysiloxane may be silanol terminated.
The polymer component (a) may comprise at least two polysiloxanes, a first fluorinated polysiloxane and a second polysiloxane, which are different from each other. The fluorinated polysiloxane can be present in the coating composition in an amount of 5 wt.% or more, such as 10 wt.% or more, 20 wt.% or more, 30 wt.% or more, 40 wt.% or more, or 50 wt.% or more, based on the total solids weight of the coating composition. The fluorinated polysiloxane can be present in the coating composition in an amount of 80 wt.% or less, such as 75 wt.% or less, based on the total solids weight of the coating composition. The fluorinated polysiloxane can be present in the coating composition in an amount of 5 to 80 weight percent, 10 to 75 weight percent, 20 to 75 weight percent, 30 to 75 weight percent, 40 to 75 weight percent, 50 to 80 weight percent, or 50 to 75 weight percent based on the total solids weight of the coating composition. The fluorinated polysiloxane can impart hydrophobicity (by virtue of the hydrophobic moieties present in the polymer) to a cured coating prepared by including the fluorinated polysiloxane in a coating composition. The hydrophobic portion is defined as the portion of the coating composition that exhibits a Water Contact Angle (WCA) of at least 90 ° using Kruss droplet shape analysis. As reported herein, Kruss droplet shape analysis was performed on a Kruss droplet shape analyzer (DSA100) according to ASTM test method D7334.
The polymer may be prepared from a mixture comprising alkoxysilane-functional resins. The alkoxysilane-functional resin comprises at least one pendant and/or terminal alkoxysilane group. A "pendant group," also referred to as a "side chain," is a branch of the polymer backbone and is not part of the backbone, and a "terminal group" refers to a functional group located at an end of the polymer backbone. The term "silane" refers to a compound derived from SiH4And the term "alkoxy" refers to-An O-alkyl group. Further, "alkoxysilane" means an alkoxysilane compound having at least one bond to a silicon atom. The alkoxysilane may also include a plurality of alkoxy groups bonded to the silicon atom. The alkoxysilane may include two alkoxy groups or three alkoxy groups bonded to the silicon atom. Thus, the alkoxysilane may have one, two or three alkoxy groups. Alkoxy groups that may be bonded to a silicon atom include, but are not limited to, those having C1To C20Carbon chain, C1To C10Carbon chain, C1To C6Carbon chain or C1To C4Alkoxy groups of carbon chains. Suitable alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, sec-butoxy, isobutoxy, tert-butoxy, pentyloxy, isopentyloxy, and combinations thereof.
The alkoxysilane-functional resin may include a specific polymer structure, such as a linear polymer including pendant and/or terminal alkoxysilane groups. The alkoxysilane-functional resin may be a branched polymer comprising pendant and/or terminal alkoxysilane groups. The alkoxysilane functional resin may contain a total of at least 2 silicon atom-bonded alkoxy groups, such as at least 3, at least 4, at least 6, or at least 9 silicon atom-bonded alkoxy groups.
The alkoxysilane-functional resin may comprise a polyurethane resin. As used herein, the term "polyurethane resin" refers to a polymer that includes at least one urethane linkage. The polyurethane resin may be formed according to any method known in the art, such as by reacting at least one polyisocyanate with one or more compounds having functional groups reactive with the isocyanate functional groups of the polyisocyanate. The reactive functional group can be an active hydrogen-containing functional group such as a hydroxyl group, a thiol group, an amine group, and an acid group such as a carboxylic acid group. The hydroxyl groups can react with isocyanate groups to form urethane linkages. The primary or secondary amine groups may react with isocyanate groups to form urea linkages. Typically, the reaction mixture comprises at least one hydroxyl-functional reactive compound, such as a polyol for forming carbamate functional groups. Typically, the compound having functional groups reactive with the isocyanate functional groups of the polyisocyanate includes at least one compound having two or more active hydrogen-containing functional groups per molecule, such as functional groups selected from those described above.
Suitable reactive compounds include polyols, polyisocyanates, carboxylic acid group-containing compounds, diols containing carboxylic acid groups, polyamines, polythiols, and/or other compounds having reactive functional groups such as hydroxyl groups, thiol groups, amine groups, and carboxylic acids. The reactive compound may include an alkoxysilane group to impart alkoxysilane functionality to the polyurethane resin.
Isocyanate functional polyurethane prepolymers may be formed by reacting a stoichiometric excess of a polyisocyanate with one or more of the above reactive compounds, such as a polyol. The isocyanate functional polyurethane prepolymer may be reacted with additional reactive compounds including alkoxysilanes to produce alkoxysilane functional polyurethanes. The additional reactive compound may be an alkoxysilane-functional primary or secondary amine that reacts with the polyurethane prepolymer to form a urea linkage. The alkoxysilane-functional reactive compound may include terminal alkoxysilane groups to produce a polyurethane having terminal alkoxysilane groups.
The alkoxysilane-functional resin may comprise an acrylic resin. As used herein, the term "acrylic resin" refers to a polymer formed from at least one acrylic monomer. The acrylic resin may be formed by using any number of acrylic monomers according to any method known in the art, including alkyl (meth) acrylates such as ethyl (meth) acrylate, methyl (meth) acrylate, and butyl (meth) acrylate; functional acrylates, such as hydroxyethyl (meth) acrylate; cyclic and polycyclic (meth) acrylic acids such as benzyl (meth) acrylate, cyclohexyl (meth) acrylate, and isobornyl (meth) acrylate; and acrylamides, such as N-butoxymethylacrylamide. The acrylic monomer may be an alkoxysilane-functional acrylic monomer. Acid-functional (meth) acrylic acid and alkyl (meth) acrylates may each be used. Mixtures of (meth) acrylic resins may also be used. It is to be understood that (meth) acrylic and similar terms refer to both methacrylic and acrylic.
The alkoxysilane-functional acrylic resin may be a polymer formed from at least one alkoxysilane-functional acrylic monomer. The alkoxysilane-functional acrylic resin may be a polymer formed from at least one isocyanate-functional acrylic monomer and/or epoxy-functional acrylic monomer, which is further reacted to form the alkoxysilane-functional acrylic resin. The isocyanate functional acrylic residue may be reacted with an alkoxysilane functional compound, such as an alkoxysilane functional amine, having functional groups reactive with isocyanate functional groups. The epoxy functional acrylic residue may be reacted with an alkoxysilane functional compound, such as an alkoxysilane functional amine or an alkoxysilane functional thiol, having a functional group reactive with the epoxy functional group. The alkoxysilane-functional acrylic resin may be a polymer formed from a hydroxy-functional acrylic resin reacted with an alkoxysilane-functional compound having a functional group reactive with the hydroxy-functional group, such as an alkoxysilane-functional isocyanate.
The polymer may further comprise (c) a metal alkoxide. "alkoxide" refers to the conjugate base of an alcohol (Y-OH), where Y may be C1-C10Straight or branched chain alkyl. The metal alkoxide can comprise a multivalent metal. Suitable metal alkoxides include zirconium alkoxides (such as zirconium butoxide or zirconium methoxide), titanium alkoxides, tantalum alkoxides, hafnium alkoxides, aluminum alkoxides, zirconium isopropoxide isopropanol, or mixtures thereof.
The metal alkoxide may be present in the coating composition in an amount of at least 0.5 wt.%, at least 1 wt.%, or at least 2 wt.%, based on the total solids weight of the coating composition. The metal alkoxide may be present in the coating composition in an amount of less than 20 wt.%, such as less than 15 wt.%, less than 10 wt.%, or less than 5 wt.%, based on the total solids weight of the coating composition. The metal alkoxide may be present in the coating composition in an amount of from 0.5 to 20 weight percent, for example, from 0.5 to 5 weight percent, from 0.5 to 10 weight percent, from 0.5 to 15 weight percent, from 1 to 20 weight percent, from 1 to 10 weight percent, from 1 to 5 weight percent, from 2 to 20 weight percent, from 2 to 10 weight percent, or from 2 to 5 weight percent, based on the total solids weight of the coating composition.
PolymerisationThe composition may also comprise hydrophobic and/or hydrophilic additives. As used herein, a "hydrophobic additive" is an additive that increases the water contact angle of the cured coating composition. As used herein, a "hydrophilic additive" is an additive that reduces the water contact angle of the cured coating composition. The additive may be a hydrophilic additive, which may not be a reactant for forming the polymer. The hydrophilic additive may be added after the preparation of the polymer as described previously. The hydrophilic additive can impart hydrophilicity (create hydrophilic moieties) to a cured coating prepared by including the hydrophilic additive in a coating composition. The hydrophilic portion is defined as the portion of the coating composition that exhibits a WCA of less than 90 ° using Kruss droplet shape analysis. Suitable hydrophilic additives include titanium dioxide (TiO)2) Nano-sized particles of aminopropylsilane treated silica, untreated silica and/or mixtures thereof. "nanosize" means TiO having an average particle size of no more than 100 nanometers according to ASTM F1877-162And (3) granules.
The hydrophilic additive may be present in the coating composition in an amount of at least 1 wt.%, at least 10 wt.%, at least 15 wt.%, at least 20 wt.%, or at least 25 wt.%, based on the total solids weight of the coating composition. The hydrophilic additive may be present in the coating composition in an amount of less than 50 wt.%, less than 40 wt.%, or less than 35 wt.%, based on the total solids weight of the coating composition. The hydrophilic additive may be present in the coating composition in an amount of 10 to 50 weight percent, 15 to 40 weight percent, 20 to 35 weight percent, or 25 to 35 weight percent based on the total solids weight of the coating composition. The hydrophilic additive may be added to the coating composition in an amount effective to render the entire coating hydrophobic when applied to a substrate and cured. Hydrophilic coatings are defined as the entire cured coating showing a WCA of less than 90 ° using Kruss droplet shape analysis. A hydrophobic coating is defined as the entire cured coating showing a WCA of at least 90 ° using Kruss droplet shape analysis. A superhydrophobic coating is defined as the entire cured coating that shows a WCA of at least 150 ° using Kruss droplet shape analysis. As used herein, the term "entire coating" refers to the properties of the coating when considered as a whole, and not any one portion of the coating.
The hydrophilic additive may be added to the coating composition in an amount effective such that when coated on a substrate and cured, the entire cured coating exhibits a WCA of at least 100 °, at least 110 °, at least 120 °, at least 130 °, at least 140 °, or at least 150 °. An effective amount of a hydrophilic additive may be added to the coating composition such that when applied to a substrate and cured, the entire coating is superhydrophobic. The hydrophilic additive may be added to the coating composition in an amount effective such that when applied to a substrate and cured, the entire cured coating exhibits a WCA of at least 150 ° and a hysteresis of no more than 25 ° or no more than 10 °. As used herein, hysteresis is defined as the difference in advancing and receding contact angles of a drop of liquid (such as water) on a plane at an angle of 0 ° to 90 ° relative to the horizontal. Hysteresis can be measured using Kruss droplet shape analysis.
The additive may be a hydrophobic additive, which may not be a reactant to form a polymer. As previously mentioned, the hydrophobic additive may be added after the polymer is prepared. The hydrophobic additive can impart hydrophobicity (create hydrophobic portions) to a cured coating prepared by including the hydrophobic additive in a coating composition. The hydrophobic portion is defined as the portion of the coating composition that exhibits a WCA of at least 90 ° using Kruss droplet shape analysis. Suitable hydrophobic additives include fluorinated treated particles, such as fluorinated treated silica, fluorinated silane treated particles, such as fluorinated silane treated silica, hydrophobically treated metal oxides, rare earth metal oxides, or mixtures thereof.
The hydrophobic additive may be present in the coating composition in an amount of at least 1 wt.%, at least 3 wt.%, at least 5 wt.%, at least 10 wt.%, or at least 15 wt.%, based on the total solids weight of the coating composition. The hydrophobic additive may be present in the coating composition in an amount of less than 30 wt.%, less than 25 wt.%, less than 20 wt.%, or less than 18 wt.%, based on the total solids weight of the coating composition. The hydrophobic additive may be present in the coating composition in an amount of 3 to 30 weight percent, 5 to 25 weight percent, 10 to 20 weight percent, or 15 to 20 weight percent based on the total solids weight of the coating composition. An effective amount of a hydrophobic additive may be added to the coating composition such that when applied to a substrate and cured, the entire coating is hydrophobic. An effective amount of a hydrophobic additive may be added to the coating composition such that when applied to a substrate and cured, the entire cured coating exhibits a WCA of at least 100 °, at least 110 °, at least 120 °, at least 130 °, at least 140 °, or at least 150 °. The hydrophobic additive may be added to the coating composition in an amount effective such that when applied to a substrate and cured, the entire cured coating is superhydrophobic. The hydrophobic additive may be added to the coating composition in an amount effective such that when applied to a substrate and cured, the entire cured coating exhibits a WCA of at least 150 ° and a hysteresis of no more than 25 ° or no more than 10 °.
The coating composition may further comprise a coupling agent. The coupling agent may comprise a functional group, such as a hydroxyl, methoxy, or ethoxy group, that is reactive with the substrate, such as aluminum, to provide or enhance adhesion between the coating composition and the substrate. The coupling agent may comprise silane, alkoxysilane, fluoroalkylsilane, aminopropyltriethoxysilane, and/or mixtures thereof. The coupling agent may be an alkoxysilane such as 3-aminopropyltriethoxysilane. Other coupling agents may be included in the coating composition based on the composition of the substrate and/or other components included in the coating composition.
The alkoxysilane-functional resin may be reacted with itself or a coupling agent to form a crosslinked polymer network. The use of a coupling agent serves to increase the crosslink density of the crosslinked polymer network. The use of coupling agents, such as aminopropyltriethoxysilane, can also be used to accelerate the cure response of the coating composition. The crosslinked polymer network may have a mass of 1.5 to 3.5mmole/cm, as measured by ASTM F2214-023The crosslinking density of (a).
The coating composition may further comprise a thermally conductive material. The thermally conductive material may comprise a metallic material or a conductive carbonaceous material. The thermally conductive material may comprise metal flakes, metal powder, conductive carbon, or some combination thereof. The thermally conductive material may comprise copper, graphene, zinc cerium, or some combination thereof.
Any of the coating compositions described herein can comprise additional materials. Suitable additional materials that may be used with the coating composition of the present invention include: colorants (e.g., pigments and/or dyes), plasticizers, abrasion resistant particles, corrosion inhibiting additives, fillers including, but not limited to, clays, inorganic minerals, antioxidants, hindered amine light stabilizers, UV light absorbers and stabilizers, surfactants, flow and surface control agents, thixotropic agents, organic co-solvents, reactive diluents, catalysts, reaction inhibitors, and other common adjuvants.
After the coating composition is prepared, the coating composition can be applied to a substrate and cured to form a coating. The substrate may be any suitable material. The substrate may be metallic or non-metallic. The metal substrate may include, but is not limited to, tin, steel (including stainless steel, electro galvanized steel, cold rolled steel, hot dipped galvanized steel, etc.), aluminum alloys, zinc-aluminum alloys, steel coated with zinc-aluminum alloys, or aluminized steel. The metal substrate may further comprise a metal pretreatment coating or a conversion coating. Suitable pretreatment coatings or conversion coatings include, but are not limited to, zinc phosphate, iron phosphate, or chromate-containing pretreatments. Other suitable pretreatment coatings or conversion coatings include, but are not limited to, thin film pretreatment coatings, such as zirconium or titanium containing pretreatments. The metal pretreatment coating may also include a sealer, such as a chromate or non-chromate sealer.
The non-metallic substrate may comprise a polymeric material. Suitable polymeric materials for the substrate may comprise plastics, polyesters, polyolefins, polyamides, cellulose, polystyrene, polyacrylic acid, poly (ethylene naphthalate), polypropylene, polyethylene, nylon, EVOH, polylactic acid, other "green" polymeric substrates, poly (ethylene terephthalate) (PET), polycarbonate acrylonitrile butadiene styrene (PC/ABS) or polyamides. Other non-metallic substrates may include glass, wood veneer, wood composite, particle board, medium density fiberboard, cement, stone, paper, cardboard, textiles, leather (both synthetic and natural), and the like. The non-metallic substrate may also include a treatment coating applied prior to applying the coating, which increases the adhesion of the coating to the substrate.
The substrate may be part of an HVAC system or other system that includes a heat exchanger, which includes a metal, such as aluminum, an aluminum alloy, or stainless steel. The substrate can be a surface of a condenser tube of an HVAC system such that the condenser tube is coated with the coating composition and the coated condenser tube can condense water onto a surface thereof. Alternatively, the substrate may be glass, such that the glass coated by the coating composition renders the glass self-cleaning or easy to clean.
The coating composition may be applied to a component of an HVAC system or other system that includes a heat exchanger, and may be formulated and/or applied to avoid over-insulation of the component. The degree to which a coating formed from the applied coating composition insulates a part can be expressed by the heat flow resistance (R-value) of the coating. The R value of the coated substrate and/or the uncoated substrate and/or the coating itself can be determined. The R value can be determined using the following formula:
R＝l//λ
where R is the resistance to heat flow, l is the thickness of the material in meters, and λ is the thermal conductivity of the material in W/mK, such that R has units of square meters Kelvin per Watt (m)2K/W)。
To minimize the R-value of the coating, the thermally conductive materials previously described can be included to increase the thermal conductivity of the material, thereby reducing the R-value of the coating and/or the coated substrate.
To minimize the R-value of the coating, the thickness of the coating can be minimized, thereby reducing the R-value of the coating and/or the coated substrate. The thickness of the coating may be up to 3 mils, such as up to 2 mils, or up to 1 mil. The thickness of the coating can range from 0.5 to 3 mils, such as 0.5 to 2.5 mils, 0.5 to 2 mils, 0.5 to 1.5 mils, 0.5 to 1 mil, 1 to 3 mils, 1 to 2.5 mils, 1 to 2 mils, or 1 to 1.5 mils.
The coating composition is applied to a substrate to render the substrate surface active. Application of the coating composition to a substrate, such as a metal substrate, provides a coated surface of the substrate that is capable of condensing a polar fluid (e.g., water) from the ambient air onto the surface of the coated substrate. Application of the coating composition to a substrate, such as glass, can provide a coated glass surface that is easy to clean or self-cleaning.
The coating compositions described herein can be applied by any means known in the art, such as electrocoating, spraying, electrostatic spraying, dipping, rolling, brushing, and the like. The coating composition can be applied to the substrate by spraying, such as by using a siphon feed spray gun. The coating composition can be sprayed onto the substrate in a variety of different thicknesses (e.g., using different numbers of passes).
The coating composition, when applied to a substrate and cured to form a coating, may have about 30N/mm at 24 hours2And may have a hardness value of 150N/mm when fully cured2The maximum hardness value of (a), as measured by using a FISCOPE HM2000, the FISCOPE HM2000 is a specialized microhardness measuring instrument that analyzes mechanical and elastic properties of materials by means of nanoindentation. The coating composition may exhibit a hardness value that is greater than the hardness value of an identical coating prepared from a coating composition that does not include the alkoxysilane-functional resin.
The coating composition, when applied to a substrate and cured to form a coating, can render the coated substrate hydrophobic. The coating composition, when applied to a substrate and cured to form a coating, can render the coated substrate hydrophobic, thereby exhibiting a WCA of at least 140 °. The coating composition, when applied to a substrate and cured to form a coating, can render the coated substrate superhydrophobic. The coating composition, when applied to a substrate and cured to form a coating, can render the coated substrate hydrophobic such that it exhibits a WCA of at least 150 ° and a hysteresis of no more than 25 °.
When the coating composition is applied to a substrate and cured to form a coating, the cured coating can comprise at least one hydrophobic portion (comprising at least one fluorinated portion of the polymer) and at least one hydrophilic portion (comprising a hydrophilic additive). The hydrophobic portion may exhibit a WCA of at least 90 °, while the hydrophilic portion may exhibit a WCA of less than 90 °. It should be understood that while the cured coating may comprise at least one hydrophobic portion and at least one hydrophilic portion, the entire coating may be hydrophobic such that the entire cured coating exhibits a hydrophobic WCA as measured by Kruss droplet shape analysis.
The coating composition may comprise a plurality of hydrophobic portions and a plurality of hydrophilic portions when applied to a substrate and cured to form a coating. The coating composition may comprise alternating hydrophobic and hydrophilic portions. Alternating hydrophobic and hydrophilic portions may mean that at least one hydrophobic portion is located between at least two hydrophilic portions that are not in direct contact with each other and/or at least one hydrophilic portion is located between at least two hydrophobic portions that are not in direct contact with each other. It should be understood that while the cured coating may contain alternating hydrophobic and hydrophilic portions, the entire coating may be hydrophobic such that the entire cured coating exhibits a WCA that is hydrophobic.
The invention further comprises the subject matter of the following clauses:
clause 1: a coating composition comprising a polymer prepared from a mixture of reactants comprising (a) a fluorinated polysiloxane; and (b) an alkoxysilane functional resin, wherein the alkoxysilane functional resin comprises a polyurethane resin or an acrylic resin.
Clause 2: the coating composition according to clause 1, wherein the mixture of reactants further comprises (c) a metal alkoxide.
Clause 3: the coating composition according to clause 1 or 2, further comprising a hydrophobic additive and/or a hydrophilic additive.
Clause 4: the coating composition according to clause 3, wherein the surface active coating composition comprises a hydrophobic additive, wherein the hydrophobic additive comprises a fluorinated treated silica, a fluorinated silane treated particle, a hydrophobic treated metal oxide, a rare earth metal oxide, or some combination thereof.
Clause 5: the coating composition according to any one of the preceding clauses wherein the fluorinated polysiloxane comprises polytrifluoropropylmethylsiloxane.
Clause 6: the coating composition according to any one of the preceding clauses further comprising a coupling agent.
Clause 7: the composition of clause 6, wherein the coupling agent comprises silane, alkoxysilane, fluoroalkylsilane, aminopropyltriethoxysilane, or some combination thereof.
Clause 8: the coating composition according to any of clauses 3 to 7, wherein the hydrophilic additive and/or the hydrophobic additive comprises at least 1 wt.% of the surface active coating composition, based on the total solids weight of the surface active coating composition.
Clause 9: the coating composition according to any of clauses 2 to 8, wherein the metal alkoxide comprises at least 0.5 wt.% of the surface active coating composition based on the total solids weight of the surface active coating composition.
Clause 10: the coating composition according to any one of the preceding clauses wherein the coating is hydrophobic when applied to a substrate and cured to form a coating.
Clause 11: the coating composition according to any one of the preceding clauses wherein the coated substrate exhibits a water contact angle of at least 140 ° when applied to a substrate and cured to form a coating.
Clause 12: the coating composition according to any of clauses 3 to 11, wherein when applied to a substrate and cured to form a coating, the coating comprises a hydrophobic portion comprising at least a fluorinated portion of the polymer and a hydrophilic portion comprising a hydrophilic additive.
Clause 13: the coating composition according to any of clauses 3 to 12, wherein the surface active coating composition comprises a hydrophilic additive, wherein the hydrophilic additive comprises nanoscale particles comprising titanium dioxide, aminopropylsilane treated silica particles, untreated silica particles, or some combination thereof.
Clause 14: the coating composition according to any one of the preceding clauses wherein the alkoxysilane-functional resin includes at least 4 alkoxy groups bonded to silicon atoms.
Clause 15: the coating composition according to clause 14, wherein the alkoxysilane-functional resin includes at least 6 alkoxy groups bonded to silicon atoms.
Clause 16: the coating composition according to clause 14 or 15, wherein the alkoxysilane-functional resin comprises at least 9 alkoxy groups bonded to silicon atoms.
Clause 17: the coating composition according to any of the preceding clauses wherein, when cured, a coating formed from the surface active coating composition exhibits a hardness value that is greater than the hardness value of an identical coating prepared from a coating composition that does not comprise the alkoxysilane-functional resin.
Clause 18: the coating composition according to any of the preceding clauses wherein the hardness value when fully cured is less than or equal to 150N/mm2。
Clause 19: the coating composition according to any one of the preceding clauses wherein the crosslink density when cured is from 1.5 to 3.5mmole/cm3。
Clause 20: the coating composition according to any one of the preceding clauses wherein the coated substrate exhibits a water contact angle of at least 150 ° and a hysteresis of no more than 25 ° when applied to a substrate and cured to form a coating.
Clause 21: the coating composition according to any one of the preceding clauses wherein the coating is superhydrophobic when applied to a substrate and cured to form a coating.
Clause 22: the coating composition according to any one of the preceding clauses further comprising a crosslinker.
Clause 23: the coating composition according to any of clauses 2 to 22, wherein the metal alkoxide comprises 0.5 to 10 weight percent of the coating composition based on the total solids weight of the coating composition.
Clause 24: the coating composition according to clause 23, wherein the metal alkoxide comprises 0.5 to 5 weight percent of the coating composition based on the total solids weight of the coating composition.
Clause 25: the coating composition according to any of clauses 1 to 24, further comprising a thermally conductive material comprising metal flakes, metal powder, electrically conductive carbon, or some combination thereof.
Clause 26: a substrate at least partially coated with the coating composition of any of the preceding clauses.
Clause 27: the substrate of clause 26, wherein the substrate comprises metal or glass.
Clause 28: the substrate according to clause 26 or 27, wherein the substrate comprises a surface of a component in an HVAC system.
Clause 29: the substrate of any of clauses 26 to 28, wherein the coating has a film thickness of at most 3 mils when the coating composition is cured to form the coating.
Clause 30: a method of condensing a polar fluid, comprising: contacting the substrate of any of clauses 26 to 29 with a polar fluid such that the polar fluid condenses on at least a portion of the coated substrate.
Clause 31: the method according to clause 30, wherein the polar fluid comprises water.
The following examples are provided to illustrate the general principles of the present invention. The invention should not be considered limited to the particular examples given. All parts and percentages in the examples are by weight unless otherwise indicated.
Example 1
Water contact Angle of Room temperature-curable coating compositions
The coating compositions were prepared from the components listed in table 1.
TABLE 1
Components
Weight of solution
Solid body
Weight% of solids
FMS-9922 silanol terminated polytrifluoropropylmethylsiloxane1
8.4
8.4
21.7％
Nano TiO 22-P25,Aeroxide2
12.6
12.6
32.6％
3-aminopropyltriethoxysilane3
2.0
2.0
5.2％
Acetic acid n-butyl ester4
47.8
0
0.0％
Zirconium Butanol5
1.4
1.4
3.6％
Dibutyl tin diacetate6
0.25
0.25
0.6％
Alkoxysilanes carbamates7
24.15
14
36.2％
96.60
38.65
100.0％
1Available from Gelest corporation (Morise Vial, Pa)
2The grain diameter is 25nm, and the self-winning wound can be obtainedIndustrial group (German Essen)
3Available from Gelest corporation (Morise Vial, Pa)
4Available from Fisher Scientific (New Hampshire Hanputon)
5Available from Sigma Aldrich (St. Louis, Mo.)
6Available from Sigma Aldrich (St. Louis, Mo.)
7Alkoxysilane-functional urethane resins prepared by reacting polyfunctional isocyanate trimer (52%), 1, 4-butanediol (3.8%) and n-butyl-3-aminopropyltrimethoxysilane (44.2%) (solids content).
A total of 8.4 grams of FMS-9922 silanol-terminated polytrifluoropropylmethylsiloxane and 47.8 grams of n-butyl acetate were charged to a suitable reaction vessel equipped with a pneumatic motor containing a Cowles dispersing blade first set at 125 rpm. TiO is reacted for 15 minutes2P25 aeroxide nanoscale particles (13.04 g) (from the winning industry group (egsen, germany)) and the average particle size reported by the manufacturer to be 25nm were slowly added to the reaction vessel. The speed of the pneumatic motor was increased to 1600rpm and the particles were dispersed in the mixture for 30 minutes. After 30 minutes, the speed of the pneumatic motor was set to 125rpm and 2.0 grams of 3-aminopropyltriethoxysilane, 1.4 grams of zirconium butoxide, 0.25 grams of dibutyltin diacetate and 24.15 grams of alkoxysilane functional urethane were added to the mixture over 10 minutes and the mixture was allowed to stir at 125rpm for an additional 10 minutes. The mixture was then sprayed (using X-Bond 4000 from PPG industries (PA pittsburgh) onto pre-treated aluminium panels and allowed to cure for 24 hours at room temperature. The coating thickness was about 0.3 mm. The next day, the WCA and hysteresis of the test panels were analyzed using a Kruss droplet shape analyzer (DSA100) using a Kruss droplet shape according to ASTM test method D7334. The WCA of the coating was 154.5. The coating showed a hysteresis of 20.4 °. The hardness of the coatings was also tested using the FISCOPE HM2000, a professional method for analysing the mechanical and elastic properties of materials by means of nanoindentationMicrohardness measuring instrument. The microhardness of the coating was measured to be 104.6N/mm2。
Example 2
Water contact angle of room temperature-curable coating composition free of metal alkoxide
The coating compositions were prepared from the components listed in table 2.
TABLE 2
Components
Weight of solution
Solid body
Weight% of solids
FMS-9922 silanol terminated polytrifluoropropylmethylsiloxane1
15.4
15.4
41.3％
Nano TiO 22-P25,Aeroxide2
12.6
12.6
33.8％
3-aminopropyltriethoxysilane3
2.0
2.0
5.4％
Acetic acid n-butyl ester4
53
0
0.0％
Dibutyl tin diacetate5
0.25
0.25
0.7％
Alkoxysilanes carbamates6
12.07
7
18.8％
95.32
37.25
100.0％
1-6See table 1.
A total of 15.4 grams of FMS-9922 silanol-terminated polytrifluoropropylmethylsiloxane and 53.0 grams of n-butyl acetate were charged to a suitable reaction vessel equipped with a pneumatic motor containing a Cowles dispersing blade first set at 125 rpm. TiO is reacted for 15 minutes2-P25 aeroxide nanoparticles (12.6 g) (average particle size 25nm according to ASTM F1877-16) were slowly added to the reaction vessel. The speed of the pneumatic motor was increased to 1600rpm and the particles were dispersed in the mixture for 30 minutes. After 30 minutes, the speed of the pneumatic motor was set to 125rpm and 2.0 g of 3-aminopropyltriethoxysilane, 0.25 g of dibutyltin diacetate and 12.1 g of alkoxysilane-functional urethane were added to the mixture over 10 minutes and the mixture was stirred at 125rpm for a further 10 minutes. The mixture was then mixed using X-Bond 4000The material was sprayed onto a pre-treated aluminum plate and allowed to cure at room temperature for 24 hours. The coating thickness was about 0.3 mm. The next day, the test panels were analyzed for WCA and hysteresis using a Kruss droplet shape. The WCA of the coating was 158.1. The coating showed a hysteresis of 26.2 °. The hardness of the coating was also tested using a FISCOPE HM2000, a professional microhardness measuring instrument that analyzes the mechanical and elastic properties of materials by means of nanoindentation. The microhardness of the coating was measured to be 16.1N/mm2。
Example 3
Water contact Angle of Room temperature-curable coating compositions
The coating compositions were prepared from the components listed in table 3.
TABLE 3
Components
Weight of solution
Solid body
Weight% of solids
FMS-9922 silanol terminated polytrifluoropropylmethylsiloxane1
9.8
9.8
22.8％
Nano TiO 22-P25,Aeroxide2
12.9
12.9
30.0％
3-aminopropyltriethoxysilane3
2.3
2.3
5.3％
Acetic acid n-butyl ester4
48.8
0.0
0.0％
Zirconium Butanol5
1.4
1.4
3.2％
Dibutyl tin diacetate6
0.26
0.26
0.6％
Acrylic acid silane8
24.47
16.4
38.1％
99.93
43.2
100.0％
1-6See table 1.
8By reacting an acrylic polyol (84%), trimethoxysilyl isocyanate functional silane (16%) and ethylSilane functional acrylic resins prepared by reacting alkenyltrimethoxysilane (solids content).
A total of 9.8 grams of FMS-9922 silanol-terminated polytrifluoropropylmethylsiloxane and 48.8 grams of n-butyl acetate were charged to a suitable reaction vessel equipped with a pneumatic motor containing a Cowles dispersing blade first set at 125 rpm. TiO is reacted for 15 minutes2-P25 aeroxide nanoparticles (12.9 g) (average particle size 25nm according to ASTM F1877-16) were slowly added to the reaction vessel. The speed of the pneumatic motor was increased to 1600rpm and the particles were dispersed in the mixture for 30 minutes. After 30 minutes, the speed of the pneumatic motor was set to 125rpm and 2.3 grams of 3-aminopropyltriethoxysilane, 1.4 grams of zirconium butoxide, 0.26 grams of dibutyltin diacetate and 24.47 grams of silane functional acrylic acid were added to the mixture over 10 minutes and the mixture was stirred at 125rpm for an additional 10 minutes. The mixture was then sprayed onto a pre-treated aluminum plate using X-Bond 4000 and allowed to cure for 24 hours at room temperature. The coating thickness was about 0.3 mm. The next day, the test panels were analyzed for WCA and hysteresis using a Kruss droplet shape. The WCA of the coating was 154.2. The coating showed a hysteresis of 1.8 °. The Fischer microhardness of the fully cured coating was measured at 92.04N/mm2。
While specific embodiments of the invention have been described above for purposes of illustration, it will be evident to those skilled in the art that numerous variations of the details of the present invention may be made without departing from the invention as defined in the appended claims.