Environmental condition curing type high-temperature protective coating

Abstract

An ambient condition curable coating composition comprises a mixture of: a polysiloxane having an Mw of at least 10,000, as determined by gel permeation chromatography using a polystyrene standard; (b) an alkoxy functional polysiloxane; and (c) an inorganic corrosion inhibitor; a process for preparing a corrosion resistant coating comprising (i) applying the coating composition to a substrate, and (ii) curing component (b) under ambient conditions; and a substrate at least partially coated with the coating composition.

Description

[0001] This application is a divisional application of Chinese patent application No. 201980084106.5, filed on December 17, 2019, entitled "Environmentally Curable High-Temperature Protective Coating". Technical Field

[0002] This invention relates to silicone coating compositions, coatings formed therefrom, and methods for forming such coatings. Background Technology

[0003] Silicone polymers have been used in anti-corrosion coatings. Typically, such silicone polymers are applied to a substrate, air-dried, and then cured at a high temperature of 175–200°C (350–400°F). During use at temperatures exceeding 350°C (660°F), such coatings tend to become porous, thereby reducing their protective effect on the substrate. Summary of the Invention

[0004] The present invention includes an ambient curable coating composition comprising a mixture of the following components, said components being (a) a polysiloxane, as determined by gel permeation chromatography using a polystyrene standard, having a Mw of at least 10,000; (b) an alkoxy polysiloxane; and (c) an inorganic corrosion inhibitor; a method for preparing the coating comprising (i) applying the coating composition to a substrate, and (ii) curing component (b) under ambient conditions; and a substrate at least partially coated with the coating composition. Attached Figure Description

[0005] Figure 1 These are a set of photographs of the coated separators tested in Examples 1-10. Detailed Implementation

[0006] For the purposes of the following detailed description, it should be understood that the invention may take various alternative variations and sequences of steps unless the contrary is expressly indicated. Furthermore, except in any operational instance, or where otherwise indicated, all figures representing the amount of ingredients as used, for example, in this specification and claims, should be understood to be modified in all cases by the term “about.” Therefore, unless otherwise indicated, the numerical parameters set forth in the following specification and appended claims are approximations that may vary depending on the desired characteristics the invention intends to achieve. To a minimum, and without attempting to limit the application of the principle of equivalence within the scope of the claims, each numerical parameter should be interpreted at least according to the number of significant figures reported and by applying general rounding techniques.

[0007] Although the numerical ranges and parameters illustrating the broad scope of the invention are approximate, the numerical values ​​described in specific examples should be reported as precisely as possible. However, any numerical value inherently contains some error that is necessarily caused by the standard deviation found in its corresponding test measurement.

[0008] Additionally, it should be understood that any range of numbers stated herein is intended to include all subranges contained therein. For example, the range “1 to 10” is intended to include all subranges between the minimum value 1 and the maximum value 10 (and including the endpoints), that is, a minimum value equal to or greater than 1 and a maximum value equal to or less than 10.

[0009] In this application, unless otherwise specifically stated, the use of the singular includes the plural and the plural encompasses the singular. Furthermore, in this application, unless otherwise specifically stated, the use of “or” means “and / or,” even if “and / or” is explicitly used in certain circumstances. Additionally, in this application, unless otherwise specifically stated, the use of “a / an” means “at least one.” For example, “a” polymer, “a” crosslinking agent, etc., refer to any one or more of these articles.

[0010] As used herein, the transitional term “comprising” (and other similar terms such as “containing” and “including”) is “open-ended” and open to include unspecified substances. Although described with the term “comprising”, the terms “consistently composed of” and “composed of” are also within the scope of this invention.

[0011] The silicone coating compositions of the present invention are curable under environmental conditions, such as at ambient temperatures, including temperatures in the range of 2-60°C (including room temperature, for example 20-25°C), and at relative humidity in the range of 1-100%. The environmentally curable coating compositions comprise: (a) a polysiloxane with a molecular weight (Mw) of at least 10,000, at least 20,000, at least 100,000, or at least 200,000 (all Mws disclosed herein were determined by gel permeation chromatography calibrated using polystyrene standards), (b) an alkoxy polysiloxane, and (c) an inorganic corrosion inhibitor, and optionally a curing agent.

[0012] Polysiloxane

[0013] A polysiloxane (a) having a Mw of at least 10,000, such as at least 20,000, at least 100,000, or at least 200,000, relative to other polymer components, may be referred to herein as a "high-Mw polysiloxane". Suitable polysiloxanes have the formula (I):

[0014] (I)

[0015] Each R1 is independently hydroxyl or alkyl, aryl, or alkoxy having up to six carbon atoms, and the choice of n results in the polysiloxane having a molecular weight of at least 10,000. Such high-Mw polysiloxanes are commercially available, such as SILRES REN 50, SILRES REN 60, and SILRES REN 80 from Wacker Chemical Corporation (Adrian, MI), or DOWSIL RSN-0805, DOWSIL RSN-0806, and DOWSIL RSN-0808 from Dow Chemical Company (Midland, MI), or SILIKOPHEN P50 / X and SILIKOPHEN P80 / X from Evonik Corporation (Parsippany, NJ).

[0016] Alkoxy polysiloxane

[0017] The alkoxy polysiloxane (b) used in this invention comprises a polysiloxane different from that of polysiloxane (a), having the general formula (II):

[0018] (II)

[0019] Each R2 group can be hydrogen, alkyl, or alkoxy, and each R3 group can be alkoxy or acetoxy. R2 and R3 each have up to six carbon atoms, and the choice of m results in the alkoxy polysiloxane having a molecular weight of up to 8,000. Such alkoxy polysiloxanes are commercially available, such as SILRES MSE 100 from Wacker Chemical Corporation (Adrian, Michigan) and DOWSIL 2403 from Dow Chemical Company (Midland, Michigan). For example, the R2 group can be the methyl group in a methoxy-functionalized methyl polysiloxane. Alkoxy polysiloxanes are moisture-curable, meaning they are further polymerized and / or crosslinked in the presence of moisture available in the ambient atmosphere. Typically, water (i.e., in moisture form) available in the ambient atmosphere and present in the curable coating composition is used to further polymerize and / or crosslink the polysiloxane. The water hydrolyzes the alkoxy groups on the polysiloxane, producing free hydroxyl groups. In the subsequent condensation reaction between the free hydroxyl groups, the polysiloxane is considered to be cured. This reaction mechanism can be described as a hydrolysis-condensation mechanism, in which the reaction is typically catalyzed by alkyl titanate esters (hydrolysis reaction) and strong bases (condensation reaction).

[0020] Inorganic corrosion inhibitors

[0021] The coating compositions of the present invention comprise inorganic corrosion inhibitors, such as magnesium oxide, zinc phosphate, metal-modified zinc phosphate, metal-modified phosphosilicates and / or metal-modified borosilicates, wherein the metals include calcium, barium, strontium, molybdenum, magnesium and / or aluminum, and “metal-modified” refers to metal additives contained therein. “Corrosion inhibitor” means a component that improves corrosion resistance compared to a coating composition that is otherwise identical except for the absence of a corrosion inhibitor. Corrosion resistance is the coating’s resistance to reaction with the underlying substrate or other degradation of the underlying substrate caused by adverse conditions in the surrounding environment.

[0022] curing agent

[0023] When present, curing agents may include organometallic compounds such as alkyl titanates, for example tetrabutyl titanate; acids (such as sulfonic acids, phosphoric acids, boric acids); zinc compounds; acetylacetonates; and various other basic compounds.

[0024] The amount of polysiloxane (a) present in the coating composition (where all percentages mentioned herein are based on a ready-to-use complete coating composition including the solvent) may be 1 wt% (weight %) or higher, or 2 wt% or higher, or its presence may be 20 wt% or lower, or 5 wt% or lower, or 12 wt% or lower. The wt% range of polysiloxane (a) present in the coating composition is 1-20, such as 2-15 or 2-12, or another range using combinations of these endpoints. The amount of alkoxy polysiloxane (b) present in the coating composition may be 2 wt% or higher, or 3 wt% or higher, or 5 wt% or higher, or its presence may be 40 wt% or lower, or 30 wt% or lower, or 25 wt% or lower. The wt% range of alkoxy polysiloxane (b) present in the coating composition is 2-40, such as 3-30 or 5-25, or another range using combinations of these endpoints. The amount of the inorganic corrosion inhibitor (c) present in the coating composition may be 1 wt% or higher, or 2 wt% or higher, or 4 wt% or higher, or its presence may be 35 wt% or lower, or 25 wt% or lower, or 20 wt% or lower. The wt% range of the coating composition in (c) present in the coating composition may be 1-35, such as 2-25 or 4-20. The amount of the optionally used curing agent present in the coating composition may be 0.05 wt% or higher, or 0.1 wt% or higher, or 0.2 wt% or higher, or its presence may be 5 wt% or lower, or 3 wt% or lower, or 2 wt% or lower, or its presence may be in the range of 0.05-5, such as 0.1-3 or 0.2-2, or another range using combinations of these endpoints.

[0025] The environmentally curable coating composition of the present invention can be prepared as a "two-component" system, wherein the first component comprises a blend of (a) an alkoxy polysiloxane, (b) an inorganic corrosion inhibitor, and (c), and the second component comprises a curing agent. Additional high-Mw polysiloxane (a) may be present in the second component. The inorganic corrosion inhibitor (c) may alternatively be present in the second component or in both components. Subsequently, the first and second components are mixed together before application to a substrate. The environmentally curable coating composition of the present invention can also be prepared as a "one-component" system, wherein all components are mixed together before application to a substrate.

[0026] This invention will be described herein with reference to a two-component system for general shelf life, because curing of the coating composition only begins after all materials are combined, so by maintaining the separation of the second component from the first component, the system can stably (will not cure) maintain its properties for a longer period of time. However, this is not intended as a limitation, as single-component systems are also included in this invention, even when their shelf life (the period before curing) is relatively short.

[0027] The substrate to which the coating composition of the present invention can be applied can be made of any suitable material, specifically, of materials (such as metals) that can undergo degradation in certain environments, such as blistering, cracking, adhesion failure, and / or corrosion. Suitable metallic substrates for use with the present invention can comprise ferrous or nonferrous materials such as tin, aluminum, steel such as stainless steel, tin-plated steel, chromium-passivated steel, galvanized steel, or coiled steel, or other coiled metals, and any metallic alloys thereof. Such substrates can be used in corrosive environments, thus requiring corrosion control and thermal insulation at temperatures from low temperatures to 1000℉ (540°C), commonly referred to as coating under insulation (CUI). Industries where such corrosive environments are found include the aerospace, power, manufacturing, petrochemical, pulp and paper, and military industries. Such substrates can be at least part of components of industrial, chemical, and / or process equipment. Non-limiting examples include reactors, exhaust stacks, reformers, distillation columns, pipelines, containers (including storage tanks for materials such as industrial liquids, hydrocarbon fuels and liquefied natural gas), valves, heat exchangers, boilers and / or aircraft engines.

[0028] Without wishing to be bound by any particular theory, it is believed that in the coating composition of the present invention, high-Mw polysiloxanes and alkoxy polysiloxanes form a mixed polysiloxane, wherein the high-Mw polysiloxane provides flexibility and contributes to the temperature resistance of the resulting coating, while the alkoxy polysiloxane allows for environmental curing and contributes to the temperature resistance of the resulting coating. Furthermore, it is believed that the inorganic corrosion inhibitor contributes to the “self-healing” aspect of the resulting coating, because the porosity generated by conventional silicone coatings at high temperatures (above 350°C) is minimized or avoided due to the presence of the inorganic corrosion inhibitor, through interaction with the polysiloxane. In this way, the high-Mw polysiloxane, alkoxy polysiloxane, and inorganic corrosion inhibitor form a protective organometallic coating on the substrate. Those skilled in the art will understand that the selection of specific compounds (a) the polysiloxane having at least 10,000 Mw, (b) the alkoxy polysiloxane, and (c) the inorganic corrosion inhibitor, as determined by gel permeation chromatography, will depend on the specific application of the coating composition. For example, if the coating composition is intended to be used on a metal substrate, a person skilled in the art can select specific components of (a), (b), and (c) according to the environment of the end use to achieve the desired corrosion resistance, adhesion to the substrate, and / or heat resistance.

[0029] The coating composition may include one or more other components, including, but not limited to, monoepoxides and diepoxides; dehumidifiers; pigments, such as barrier pigments (e.g., MIOX mica iron oxide and / or leafing aluminum) and borate pigments (e.g., BUSAN 11-M2 multifunctional pigment, available from Buckmar Laboratories, Inc., Memphis, TN); aggregates; rheology modifiers; plasticizers; defoamers; adhesion promoters; suspending agents; thixotropic agents; catalysts; pigment wetting agents; asphalt and tar extenders; antisettling agents; diluents; UV stabilizers; degassing agents; dispersing agents; solvents; surfactants; inorganic desiccants; or any mixtures thereof. Suitable inorganic desiccants (materials that readily absorb water from the coating composition and become hydrated) include metallic desiccants such as manganese, zirconium, cerium, rare earth metals, cobalt, zinc, calcium, lithium, barium, and copper. The selection of suitable solvents in the coating compositions used in this invention should be as known to those skilled in the art and includes, but is not limited to, blends of toluene, xylene, dimethyl carbonate, and aromatic 150 solvents.

[0030] Those skilled in the art of resin coating compositions will understand that other common components of this kind can be incorporated into coating compositions. A coating composition may include up to 50% by weight of such components.

[0031] For example, the coating composition of the present invention may contain, but is not limited to, the components listed in Table 1. In use, the components of part A are combined together and the components of part B are combined together, and then part A and part B are combined, wherein part A and part B each total 100%.

[0032] Table 1

[0033]

[0034] The coating compositions of the present invention can be applied to a substrate by various methods. For example, the coating compositions disclosed herein can be formulated and applied using conventional air spraying equipment, airless spraying equipment, air-assisted airless spraying equipment, electrostatic spraying equipment, brushes, or rollers. The compositions can be used as protective coatings for steel, aluminum, concrete, and other substrates, with a dry film thickness ranging from 25 micrometers to two millimeters.

[0035] The coating compositions described herein can be applied to the surface to be treated using conventional techniques such as spraying or brushing, and the applied film thickness can be from 50 to 400 micrometers, or at most 1.5 millimeters. If necessary, multiple layers of the coating composition can be applied to the surface to be protected. For example, for metal substrates, such as in the chemical industry, a dry film thickness of 75 to 350 micrometers can be applied, thereby providing the desired level of protection to the underlying surface. On other surface structures, a coating of appropriate thickness can be applied to provide the desired level of protection. After the coating composition is applied to at least one surface of the substrate, it can be cured under ambient conditions until fully cured, or alternatively, it can be cured at a high temperature exceeding ambient temperature to 150°C–200°C, for example, by placing the coated substrate in a drying or curing oven. The substrate can be removed from the oven after the coating composition has fully cured, or after the coating composition has partially cured, after which the partially cured coating composition can continue to cure on the substrate at ambient temperature until full curing is achieved.

[0036] Surfaces suitable for use with the compositions provided herein may include any material that is desired to be substantially solid. For example, types of surfaces that can be treated with the compositions disclosed herein include glass; glass fibers; carbon fiber composites; basalt fiber composites; siloxane and ceramic fibers; ceramics such as silicon nitride, silicon carbide, silicon dioxide, alumina, zirconium oxide, etc.; metals such as iron, stainless steel, galvanized steel, zinc, aluminum, nickel, copper, magnesium and their alloys, silver and gold, etc.; plastics such as polymethyl methacrylate, polyurethane, polycarbonate, polyesters containing polyethylene terephthalate, polyimide, polyamide, epoxy resin, ABS polymer, polyethylene, polypropylene, polyoxymethylene; porous mineral materials such as concrete, clay bricks, marble, basalt, asphalt, fertile soil, terracotta tiles; organic materials such as wood, leather, parchment, paper and textiles; and coated surfaces such as plastic latex paint, acrylic coatings, epoxy coatings, melamine resins, polyurethane resins and alkyd resin coatings. Surfaces or substrates covered herein also include at least two layers of material. One layer of material may include, for example, glass, metal, ceramic, plastic, wood, or composite material. Other material layers constituting the surface or substrate may include polymer layers, monomer layers, organic compound layers, inorganic compound layers, organometallic compound layers, continuous layers, porous layers, and nanoporous layers.

[0037] This invention also relates to, but is not limited to, the following provisions.

[0038] Clause 1 relates to an environmentally curable coating composition comprising a mixture of (a) a polysiloxane, as determined by gel permeation chromatography using a polystyrene standard, having a Mw of at least 10,000; (b) an alkoxy polysiloxane; and (c) an inorganic corrosion inhibitor. Clause 2 relates to a coating composition according to Clause 1, further comprising a curing agent for curing component (b) by wet curing. Clause 3 relates to a coating composition according to Clause 1 or Clause 2, wherein the Mw of component (a) is at least 100,000. Clause 4 relates to a coating composition according to Clause 1 or Clause 2, wherein the Mw of component (a) is at least 200,000. Clause 5 relates to a coating composition according to any one of Clauses 1 to 4, wherein component (a) comprises an alkylaryl polysiloxane. Clause 6 relates to a coating composition according to any one of Clauses 1 to 5, wherein component (b) comprises an alkoxy-functionalized alkyl polysiloxane. Clause 7 relates to a coating composition according to any one of Clauses 1 to 6, wherein the inorganic corrosion inhibitor (c) comprises magnesium oxide, zinc phosphate, metal-modified zinc phosphate, metal-modified phosphosilicate, and / or metal-modified borosilicate, wherein the metal comprises calcium, barium, strontium, molybdenum, magnesium, and / or aluminum. Clause 8 relates to a method of preparing a coating, the method comprising: (i) applying a coating composition according to any one of Clauses 1 to 7 to a substrate; and (ii) curing component (b) under ambient conditions. Clause 9 relates to a method according to Clause 8, the method further comprising, prior to step (i), preparing a mixture of reactants comprising a first component and a second component, the first component comprising a polysiloxane (a) and an alkoxy-functionalized polysiloxane (b), and the second component comprising an inorganic corrosion inhibitor (c); and mixing the first component and the second component. Clause 10 relates to a method according to Clause 8 or Clause 9, wherein the second component further comprises an additional polysiloxane (a). Clause 11 relates to a method according to any one of Clauses 8 to 10, the method further comprising the additional step of curing the alkoxy-functional polysiloxane component (b) at a temperature of at least 200℉. Clause 12 relates to a substrate at least partially coated with a coating composition according to any one of Clauses 1 to 7. Clause 13 relates to a substrate according to Clause 12, wherein the substrate is metallic. Clause 14 relates to an industrial processing assembly comprising a substrate according to Clause 12 or Clause 13. Clause 15 relates to an industrial processing assembly according to Clause 14, wherein the assembly comprises a reactor, exhaust chimney, reformer, distillation column, pipe, valve, heat exchanger, boiler or storage tank, or aircraft engine. Clause 16 relates to a coating composition according to any one of Clauses 1 to 7, wherein the polysiloxane (a) is present in an amount of 1-20%, 2-15%, or 2-12% by weight.Clause 17 relates to a coating composition according to any one of Clauses 1 to 7, Clause 16, or Clause 17, wherein the predetermined amount of the inorganic corrosion inhibitor is 1-35%, 2-25%, or 4-20% by weight. Clause 19 relates to a coating composition according to any one of Clauses 1 to 7 or Clauses 16 to 18, wherein the coating composition further comprises a curing agent for wet curing the alkoxy polysiloxane (b), the amount of which is 0.05-5%, 0.1-3%, or 0.2-2% by weight.

[0039] The following examples illustrate the invention, but these examples should not be construed as limiting the invention to its details. Unless otherwise indicated, all parts and percentages in the examples and throughout this specification are by weight.

[0040] Example

[0041] The following formulations are prepared from the listed and described components.

[0042] Example 1

[0043]

[0044]

[0045] 1 Methylphenyl polysiloxane, Mw >100,000, purchased from Wacker Chemical Corporation (Adrian, Michigan).

[0046] 2 Vinylalkoxysilane, purchased from Wacker Chemical Corporation (Adrian, Michigan).

[0047] 3 Titanate coupling agent, purchased from Kenrich Petrochemicals, Inc. (Bayonne, NJ)

[0048] 4 Wetting agent, purchased from BYK USA Inc. (Wellingford, CT, Connecticut)

[0049] 5 Rheology modifier, purchased from Elementis Specialties (East Windsor, NJ)

[0050] 6 Micronized mica, purchased from Imerys Talc America, Inc. (Houston, TX)

[0051] 7 MIOX, purchased from Kish Company (Mentor, OH)

[0052] 8 Methyl polysiloxane, purchased from Wacker Chemical Corporation (Adrian, Michigan).

[0053] 9 Zinc phosphate, purchased from ICL Specialty Products, Inc. (Hammond, IN)

[0054] 10 Mineral packing material, purchased from Vanderbilt Minerals (Norwalk, CT, Connecticut)

[0055] Comparison Example 2

[0056]

[0057]

[0058] Comparison Example 3

[0059]

[0060]

[0061] 11 Methylphenyl polysiloxane, Mw 2000-4000, purchased from Dow Chemical Company (Midland, Michigan).

[0062] Comparison Example 4

[0063]

[0064]

[0065] Example 5

[0066]

[0067]

[0068] 12 Methylphenyl polysiloxane, Mw >20,000, purchased from Wacker Chemical Corporation (Adrian, Michigan).

[0069] Example 6

[0070]

[0071]

[0072] 13 Methylphenyl polysiloxane, Mw >200,000, purchased from Dow Chemical Company (Midland, Michigan).

[0073] 14 Methyl polysiloxane, purchased from Dow Chemical Company (Midland, Michigan).

[0074] Example 7

[0075]

[0076]

[0077] 15 Strontium phosphate silicate, purchased from The Cary Company (Addison, IL)

[0078] Example 8

[0079]

[0080]

[0081] 16 Zinc aluminum phosphate, purchased from ICL Specialty Products Inc. (Hamond, Indiana).

[0082] Example 9

[0083]

[0084] Example 10

[0085]

[0086] For Examples 1-8 (two-component systems), two parts A and one part B (by volume) were mixed using a mechanical stirrer. For Example 9 (also a two-component system), 93.3 parts A and one part B (by volume) were mixed using a mechanical stirrer. For Example 10 (a one-component system), all components were mixed under mechanical stirring. The mixtures from Examples 1-10 were applied directly to the metal of a carbon steel partition using an HVLP air spray gun with a 1.7 mm tip opening to produce a coating with a dry film thickness of 10-12 mils on the partition under ambient conditions.

[0087] test

[0088] The following tests were performed on the coatings of Examples 1-10.

[0089] Accelerated Thermal Cycling Corrosion Testing: Based on the ASTM B117 salt spray test, the accelerated thermal cycling corrosion testing method utilizes a programmable oven and salt spray chamber. The B117 salt spray test is an ASTM standardized corrosion test method used to examine the corrosion resistance of materials and surface coatings. It is an accelerated corrosion test that induces corrosive erosion on coated samples to evaluate the suitability of coatings used as protective surface treatments. After a predetermined time period, the presence of corrosion products (rust or other oxides) is evaluated. The test duration depends on the corrosion resistance of the coating; generally, the more corrosion-resistant the coating, the longer the test period before corrosion / rust appears.

[0090] The test consisted of intermittent salt spray exposure following thermal cycling loading. Each cycle consisted of 3 days of dry heat cycling exposure from ambient temperature to 800℉ (427°C). During the drying cycle, the partition was quenched in cold water at the end of each day. After the 3-day drying cycle, the partition was placed in a B117 salt spray chamber and held for 3 days. After each cycle, the partition was inspected (rating for rust according to ASTM D610 and blistering / cracking according to ASTM D1654-08). The test continued until blistering / cracking / peeling, corrosion, and / or rusting appeared. Higher cycle counts prior to the appearance of such degradation indicate improved corrosion resistance. Pull-off adhesion and heat resistance were tested according to ASTM D4541-17 and ASTM 2485-18, respectively. Test results are reported in Table 2, and images of the tested partitions are reported in [Table missing]. Figure 1 middle. Figure 1 The partitions shown demonstrate poor corrosion resistance in Comparative Example 2 (without corrosion inhibitor), Comparative Example 3 (low-Mw polysiloxane and without corrosion inhibitor), and Comparative Example 4 (low-Mw polysiloxane and with corrosion inhibitor). It should be understood that when a low-Mw polysiloxane is used instead of the high-Mw polysiloxane of this invention, the presence of a corrosion inhibitor is insufficient to provide suitable corrosion resistance. A comparison of Example 1 with commercially available products is reported in Table 3.

[0091] Table 2

[0092]

[0093] Table 3

[0094] Benchmark test results of thermal cycling corrosion test

[0095]

[0096] 18 HEAT-FLEX HI-TEMP 1200 purchased from Sherwin-Williams

[0097] 19 INTERBOND 1202UPC purchased from AkzoNobel

[0098] 20 THERMALINE HEAT SHIELD purchased from Carboline

[0099] While specific embodiments of the invention have been described above for illustrative purposes, those skilled in the art will readily recognize that various changes can be made to the details of the invention without departing from the invention as defined in the appended claims.

Claims

1. An ambient condition-curable coating composition, said composition comprising a mixture of components comprising: (a) an alkylaryl polysiloxane present in said curable coating composition in an amount of 1 to 20 weight percent based on the total weight of the coating composition, having a Mw of at least 20,000 as determined by gel permeation chromatography using polystyrene standards; (b) an alkoxy-functional polysiloxane present in said curable coating composition in an amount of 2 to 40 weight percent based on the total weight of the coating composition; and (c) an inorganic corrosion inhibitor present in said curable coating composition in an amount of 1 to 35 weight percent based on the total weight of the coating composition, wherein said coating composition is curable using water at ambient temperatures in the range of 2°C to 60°C, and wherein said coating composition is free of any mono- or di-epoxide.

2. The coating composition of claim 1 further comprising a curing agent selected from the group consisting of alkyl titanates, sulfonic acids, phosphoric acids, boric acids, zinc compounds, and acetylacetonates.

3. The coating composition of claim 1 wherein the Mw of the alkylaryl polysiloxane is at least 100,000.

4. The coating composition of claim 1 wherein the Mw of the alkylaryl polysiloxane is at least 200,000.

5. The coating composition of claim 1 wherein component (b) comprises an alkoxy- functional alkyl polysiloxane.

6. The coating composition of claim 1 wherein the inorganic corrosion inhibitor (c) comprises magnesium oxide, zinc phosphate, metal-modified zinc phosphate, metal-modified phosphosilicates, and / or metal-modified borosilicates, wherein the metal comprises calcium, barium, strontium, molybdenum, magnesium, and / or aluminum.

7. A substrate at least partially coated with the coating composition of claim 1.

8. The substrate of claim 7 wherein the substrate is a metal.

9. An industrial process component, said component comprising the substrate of claim 8.

10. The industrial process component of claim 9 wherein the component comprises a reactor, an exhaust stack, a reformer, a distillation column, a pipe, a valve, a heat exchanger, a boiler or storage tank, or an aircraft engine.

11. An ambient condition-curable coating composition, said composition comprising a mixture of components comprising: (a) an alkylaryl polysiloxane having a molecular weight (Mw) of at least 20,000 as determined by gel permeation chromatography using polystyrene standards; (b) an alkoxy-functional polysiloxane; (c) an inorganic corrosion inhibitor; and (d) a curing agent; wherein said coating composition is curable by crosslinking the alkoxy-functional polysiloxane using water at ambient temperatures in the range of 2°C to 60°C, and wherein said coating composition is free of any mono- or di-epoxide.

12. The coating composition of claim 11 wherein the Mw of the alkylaryl polysiloxane (a) is at least 100,000.

13. The coating composition of claim 11, wherein the alkylaryl polysiloxane (a) has a Mw of at least 200,000.

14. The coating composition of claim 11, wherein component (b) comprises an alkoxy functional alkyl polysiloxane.

15. The coating composition of claim 11, wherein the inorganic corrosion inhibitor (c) comprises magnesium oxide, zinc phosphate, metal-modified zinc phosphate, metal-modified phosphosilicate, and / or metal-modified borosilicate, wherein the metal comprises calcium, barium, strontium, molybdenum, magnesium, and / or aluminum.

16. An ambient condition-curable two-part coating composition comprising: A. a first part comprising: a. an alkylaryl polysiloxane having a molecular weight (Mw) of at least 20,000 as determined by gel permeation chromatography using polystyrene standards; b. an alkoxy functional polysiloxane; and c. a curing agent selected from the group consisting of alkyl titanates, sulfonic acids, phosphoric acids, boric acids, zinc compounds, and acetylacetonates; and B. a second part separate from the first part, the second part comprising: a. an inorganic corrosion inhibitor; and b. an additional polysiloxane having a molecular weight (Mw) of at least 20,000 as determined by gel permeation chromatography using polystyrene standards; wherein the coating composition is curable by crosslinking the alkoxy functional polysiloxane using water at ambient temperatures ranging from 2°C to 60°C when the first part is combined with the second part; and wherein the coating composition is free of any mono- or di-epoxide.

17. A method of making a coating, the method comprising: (i) applying the coating composition of any one of claims 1 to 6 to a substrate; and (ii) crosslinking the alkoxy functional polysiloxane using water at ambient conditions.

18. The method of claim 17, further comprising making a mixture of reactants comprising a first part and a second part, the first part comprising polysiloxane (a) and alkoxy functional polysiloxane (b) and the second part comprising inorganic corrosion inhibitor (c); and mixing the first part and the second part.

19. The method of claim 17, wherein the second part further comprises additional polysiloxane (a).

20. The method of claim 17, further comprising an additional step (iii) of curing the alkoxy functional polysiloxane component (b) at a temperature of at least 200°F.

21. A substrate at least partially coated with the coating composition of claims 11 to 16.

22. The substrate of claim 21, wherein the substrate is a metal.

23. An industrial processing assembly, the assembly comprising the substrate of claims 21 or 22.

24. The industrial processing assembly of claim 23, wherein the assembly comprises a reactor, an exhaust stack, a reformer, a distillation column, a pipe, a valve, a heat exchanger, a boiler or storage tank, or an aircraft engine.

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