High-temperature protective covering material

Abstract

The protective coating includes a binder component mixture having a reactive mixture portion and a filler mixture portion, the reactive mixture portion including an epoxy resin portion and an epoxy silane portion, the epoxy silane portion being present in an amount between about 10% by weight of the reactive mixture portion and about 40% by weight of the reactive mixture portion, and the protective coating includes a curing component having one or more amine curing compounds, the amine curing compound of the curing component including unmodified diaminocyclohexane (DACH) present in an amount between about 70% by weight and about 100% by weight of the curing component.

Description

[Technical Field]

[0001] Related Applications This application claims priority to U.S. Provisional Patent Application No. 62 / 848,423, filed May 15, 2019, entitled "High Temperature Protective Coating," the contents of which are incorporated herein by reference.

[0002] Background technology FIELD OF THE INVENTION The present invention relates to coatings for commercial and industrial products, and in particular to protective coatings suitable for high temperature applications. [Background technology]

[0003] Traditional protective coating technology has helped protect underlying substrates by using various organic resins, such as epoxies, urethanes, and polyesters. Traditional protective coatings typically contain an active binder and a curing component. One type of traditional protective coating is epoxy resin-based coatings, which are well-known for their adhesion to substrates such as metals, durability, strength, corrosion protection, and chemical resistance. Furthermore, traditional epoxy coatings based on bisphenol A resins are limited to service temperatures below 80°C. These coatings can be modified to use bisphenol F resins, which can increase the service temperature capability of the coatings to approximately 100°C.

[0004] However, conventional protective coatings are often unsuitable for high temperature applications because they are destroyed when exposed to temperatures above these mentioned temperatures. Summary of the Invention

[0005] Summary of the Invention The present invention relates to a protective coating comprising a resin component mixture and a separate curing component. The resin component mixture can include a reactive mixture portion and a filler mixture portion. The reactive mixture portion includes an epoxy resin component and an epoxy silane, with the epoxy silane portion being present in an amount of about 10% by weight of the reactive mixture portion and about 40% by weight of the reactive mixture portion. The curing component can include one or more amine curing compounds, such as unmodified diaminocyclohexane (DACH). The DACH can be present in an amount between about 70% and about 100% by weight of the curing component. The use of a phenolic novalac resin with an appropriate unmodified cycloaliphatic curing agent can increase the crosslinking ability and glass transition temperature of the coating, achieving service temperatures above 130°C and approaching 200°C. Furthermore, the protective coating of the present invention can help protect against erosion / corrosion, abrasion, impact, and chemical attack. The protective coating is durable, strong, and exhibits excellent adhesion to metals and other types of substrates, and is corrosion- and chemical-resistant. The use of high amounts of epoxy silane in this invention allows for the formation of an epoxy-silicone hybrid matrix that has higher temperature service capabilities than traditional protective coatings that employ epoxy resins alone.

[0006] The present invention relates to a protective coating comprising a binder component mixture having a reactive mixture portion and a filler mixture portion, the reactive mixture portion comprising an epoxy resin portion and an epoxy silane portion, the epoxy silane portion being present in an amount of about 10% by weight of the active mixture portion and about 40% by weight of the reactive mixture portion, the coating further comprising a curing component having one or more amine curing compounds.

[0007] The epoxy resin portion of the reactive mixture portion is present in an amount between about 60% by weight of the reactive mixture portion and about 90% by weight of the reactive mixture portion. The reactive mixture portion consists essentially of the epoxy resin portion and the epoxy silane portion, the epoxy resin portion of the reactive mixture portion being present in an amount between about 60% by weight of the reactive mixture portion and about 90% by weight of the reactive mixture portion, and the epoxy silane portion of the reactive mixture portion being present in an amount between about 10% by weight of the reactive mixture portion and about 40% by weight of the reactive mixture portion. The epoxy resin portion of the reactive mixture portion can include a multifunctional phenolic novalac epoxy resin. Furthermore, the reactive mixture portion of the resin component mixture can be present in an amount between about 30% by weight and about 45% by weight of the resin component mixture.

[0008] The filler mixture portion can include any combination of a thickener component, a pigment component, an anti-crater component, a water-repellent component, a dry component, an additive component, and a filler component, wherein the thickener component includes silica, the pigment component includes titanium dioxide, the anti-crater component includes a polyacrylate material, the water-repellent component includes a silicone-modified polyacrylate, the dry component includes aluminum oxide, the additive component includes feldspar, and the filler component includes calcium carbonate.

[0009] According to the teachings of the present invention, the amine curing compound of the curing component includes one or more amine compounds, preferably multiple amine compounds. The amine curing compound of the curing component can include diaminocyclohexane (DACH), preferably unmodified diaminocyclohexane (DACH). The DACH is present in an amount between about 70% and about 100% by weight of the curing component. When multiple amine compounds are used, the additional amine curing agent can include DETA, TETA, Ancamine® 2903, or Ancamine® 2904.

[0010] Additionally, the weight ratio of the resin component mixture to the curing component can be between about 14:1 and about 20:1, and is preferably about 16.8:1.

[0011] According to another aspect of the present invention, the protective coating comprises a binder component mixture having a reactive mixture portion and a filler mixture portion, the reactive mixture portion comprising an epoxy resin portion and an epoxy silane portion, the epoxy silane portion being present in an amount of about 10% by weight of the reactive mixture portion and about 40% by weight of the reactive mixture portion, and a curing component having one or more amine curing compounds, the amine curing compound of the curing component comprising unmodified diaminocyclohexane (DACH) present in an amount between about 70% by weight and about 100% by weight of the curing component.

[0012] The weight ratio of the resin component mixture to the curing component is between about 14:1 and about 20:1, preferably about 16.8:1. Additionally, the stoichiometric ratio can be between about 0.9 and about 1.1, preferably about 1.0. BEST MODE FOR CARRYING OUT THE INVENTION

[0013] The present invention relates to protective coatings, and more particularly to high-temperature protective coatings that help protect the surface of a substrate. The protective coatings can help protect against erosion / corrosion, abrasion, impact, and chemical attack. The protective coatings of the present invention are durable, strong, exhibit excellent adhesion to metal and other types of substrates, and are corrosion- and chemical-resistant.

[0014] The high-temperature protective coating of the present invention includes a protective coating formulation consisting of two major parts or components: a Part A resin binder component mixture and a separate Part B curing component. The Part A and Part B components are not premixed, but rather are formed as separate components or mixtures that are mixed immediately prior to use. The protective coating may include other materials, ingredients, or solutions as known in the art. The Part A resin component mixture can include or consist of a reactive mixture portion and a filler mixture portion. Thus, unless otherwise specified, the weight percentages of the various components described herein are set forth relative to the weight percentages forming or comprising each particular mixture portion, also referred to as the resin matrix percentage.

[0015] The resin component mixture of Part A of the protective coating formulation of the present invention can comprise or consist of a reactive prepolymer or polymer, such as an epoxy resin, and a silane coupling agent, such as an epoxy silane, as the primary or major resin binder portion or component of the mixture. The epoxy resin can preferably be a multifunctional phenolic novalak epoxy resin, having a functionality ranging from about 2.5 to about 4.0. The novalak epoxy resin has a higher viscosity than the epoxy silane. Specifically, the higher the functionality of the novalak epoxy resin, the higher the overall viscosity. According to one embodiment of the present invention, the active mixture portion of the resin component mixture of Part A contains only two active ingredients, such as a reactive polymer or prepolymer and a silane coupling agent.

[0016] In conventional protective coatings, epoxy silanes, if used at all, are typically present in amounts less than 1% by weight of the reactive organic components. In the present invention, epoxy silanes are present in much higher amounts, such as between about 10% and about 40% by weight of the reactive organic components. The recited ranges are intended to encompass any and all selected amounts within the recited ranges. Thus, one characteristic of current protective coating formulations is the use of relatively large or high amounts of epoxy silanes as binders. The relatively low viscosity of the epoxy silanes helps compensate for the relatively high viscosity of the novalac epoxy resins.

[0017] An advantage of using a high amount of epoxy silane in accordance with the teachings of the present invention is that it allows for the formation of an epoxy-silicone hybrid matrix that has superior heat resistance and high temperature service capability compared to conventional protective coatings that employ epoxy resins alone. Additionally, the relatively low viscosity of the epoxy silane reduces the overall viscosity of the protective coating, advantageously allowing for the addition of a relatively high amount of solid filler to the protective coating, resulting in high penetration resistance.

[0018] Within the resin component blend in Part A, the filler blend component or portion serves to provide a stable blend suitable for the intended purpose of the coating. This filler blend portion provides selected functions and properties, such as appropriate viscosity for easy application by brushing, troweling, or spraying to achieve the desired thickness with vertical sag resistance, while simultaneously reducing the weight percentage of more expensive components to reduce the overall cost of the blend. The appropriate filler selection and blending can provide improved compressive strength, improved erosion and abrasion resistance, improved penetration resistance, improved chemical resistance (reducing chemical uptake in immersion service), and improved stiffness. The filler blend portion can include, or be a combination of, thickening or reinforcing components or fillers such as silica, preferably fumed silica; pigment components such as any type of titanium dioxide (e.g., TiO or TiO); and mineral fillers such as ground feldspar, preferably Minspar, Minex (nepheline syenite), barium sulfate, and calcium carbonate. The filler may also include ceramic materials such as aluminum oxide, preferably aluminum oxide 400, and silicon carbide, preferably SiC 400. The formulation may also include one or more liquid additives, which are typically non-reactive but provide important morphological and cosmetic properties. Examples of suitable additives include anti-crater components such as polyacrylate materials, preferably BYK 354; water-repellent (e.g., cleaning effect) components such as silicone-modified polyacrylates, preferably BYK-Silclean 3700; dry components such as silica gel or aluminum oxide, preferably aluminum oxide BR 400; additives such as ground feldspar, preferably Minspar 3; and fillers such as calcium carbonate. The active mixture portion of the resin component mixture in Part A preferably ranges between about 30 and about 45 percent by weight. The aforementioned fillers and additives are non-reactive components. Typically, fillers are solid components and are used in relatively large amounts (e.g., between about 1 percent and about 50 percent by weight), while additives are liquid components and are typically less than 2 percent by weight.

[0019] The Part B curing component of the protective coating formulation of the present invention can include one or more amine curing compounds or amine curing agents, and preferably includes multiple different amine curing agents (e.g., a blend of curing agents). According to one embodiment, the amine curing component can consist solely of diaminocyclohexane (DACH) or can include DACH in combination with one or more other amine curing agents. The DACH of the present invention is preferably unmodified diaminocyclohexane (DACH). Typically, DACH is used in physical blends with other amines or in adducts in chemically modified forms to adjust the rate of cure and achieve the desired cure state. Thus, the Part B curing component can comprise a relatively high proportion of unmodified diaminocyclohexane (DACH), in an amount of about 70 weight percent or more of the curing component (e.g., resin matrix), and can include as much as 100% of the curing component (e.g., resin matrix) when a single amine material is used. Alternatively, when DACH is combined with one or more other amines, the amount of DACH may range between about 70 and about 99 weight percent of the curing components. These recited ranges are intended to encompass any and all selected amounts within the recited ranges. DACH can optionally be combined or mixed with one or more other amines, such as commercial amine formulations (up to about 30%), to optimize the coating cure rate. According to one embodiment, unmodified DACH can be combined with modified aliphatic, cycloaliphatic, or aromatic amine or polyamine curing agents, such as Ancamine® 2903 or 2904, diethylenetriamine (DETA), or triethylenetetramine (TETA). Depending on the type and combination of fillers, the weight ratio of the resin component mixture in Part A to the curing component in Part B can be between about 14:1 and about 20:1, preferably about 16.8:1. Furthermore, the corresponding stoichiometric ratio can range from about 0.9 to about 1.1.

[0020] DACH curing agents with their associated high crosslinking capabilities result in tightly crosslinked structures when combined with the resin component mixtures (e.g., epoxy-silane formulations) of the present invention. The amount of DACH curing agent used in the protective coatings of the present invention has a relatively low viscosity, between about 5 cps and about 10 cps, lowering the overall viscosity of the protective coating mixture and thus allowing the addition of relatively high amounts of solid fillers, which results in high penetration resistance. The result is a binder system with high penetration resistance and service temperatures up to about 200°C, yet can be sprayed with minimal solvent use. That is, mixing Part A of the resin component mixture with Part B of the curing component at a stoichiometric ratio of about 1.0 results in a highly crosslinkable system capable of producing coatings with glass transition temperatures, Tg (e.g., a measure of the thermal resistance of the coating), of about 220°C. The mixed viscosity of the protective coating is low enough to accommodate the use of large amounts of high-viscosity novalac resin, allowing the incorporation and loading of other functional fillers to maximize penetration resistance. This feature is important in a variety of applications that involve high temperature aqueous environments.

[0021] The protective coatings of the present invention thus utilize an epoxy silane mixture as a significant percentage of the overall binder composition. This relatively high percentage of epoxy silane results in the formation of an epoxy-silicone hybrid matrix that has superior heat resistance and high service temperature capabilities compared to the epoxy matrix alone. Furthermore, the low viscosity of the epoxy silane mixture reduces the viscosity of the overall resin mixture, thereby allowing for greater loading of functional fillers for superior penetration resistance.

[0022] Another aspect of the protective coating of the present invention is the use of DACH as the main component of the curing component in Part B. DACH is typically sold by commercial vendors in modified or diluted form to make the curing agent user-friendly in terms of cure speed, flow behavior, appearance, working time, etc. Benzyl alcohol is also typically used in commercial products for the same reasons. The inventors have discovered that by directly using unmodified DACH rather than a modified form, they can create a protective coating with high crosslinking ability and very low viscosity.

[0023] The present invention also relates to a method of coating or treating the surface of a substrate with the protective coating of the present invention. As used herein, the term "coating" is intended to include any type of coating in any form (e.g., liquid, semi-liquid, or solid) that can be applied to the surface of an object. The coating can be applied to a portion of a surface, to all of a surface, and can be applied in one or more layers. As used herein, the term "substrate" is intended to include any object of any type and made of any suitable material, having one or more surfaces. Examples of types of materials to which the protective coating of the present invention can be applied include metal and concrete. The coating can be applied to the surface of the substrate according to known techniques, such as by brushing, troweling, spraying, rolling, pouring, painting, etc. The coating can be applied to the surface in one or more layers.

[0024] Epoxy resin-based coatings are used as protective coatings in industrial environments, typically with service conditions below 80°C. The glass transition temperature (Tg), a measure of the coating's heat resistance, generally ranges from 80 to 90°C. By selecting a novalac epoxy resin instead of a bisphenol A epoxy resin and using an appropriate curing agent, the Tg can be increased to between about 120°C and about 130°C following high-temperature curing. The glass transition temperature can be further increased to about 200°C by combining the resin component mixture (e.g., the binder component) with a DACH curing component.

[0025] The protective coating of the present invention has a glass transition temperature of 220°C after a high-temperature cure of approximately 180°C. High-temperature cure can be achieved in the field (e.g., at the time of use) after sufficient initial cure to render the product ready for use. Typical curing of this coating prior to use is approximately 23°C for approximately two days. This relatively high transition temperature allows for use temperatures of approximately 190°C or higher, making the protective coating of the present invention suitable for use in high-temperature environments such as the oil and gas industry. The epoxy-silicone hybrid resin blend, the active ingredient in this protective coating formulation, provides increased thermal capability over conventional epoxy resin-based coatings. Additionally, the use of a diaminocyclohexane (DACH) curing agent in its unmodified state further enhances the crosslinking and thermal capability of the coating. The coating also utilizes approximately 31% by volume of a filler to improve penetration resistance.

[0026] The following are merely examples of specific components and associated amounts of the high temperature protective coating of the present invention and should not be construed in a limiting sense. Example 1

[0027] Example 1 The protective coating formulation of the present invention can include the following general components: The resin component mixture, Part A, can include a reactive mixture component, preferably in liquid form, including an epoxy silane and an epoxy resin, such as epoxy phenol novalac 3 (EPN3). The novalac epoxy resin can have a functionality ranging from about 2.4 to about 4.0. The filler mixture portion of the resin component can include additives, such as polyacrylate additives, e.g., BYK 354, or silicon-containing additives, e.g., BYK Silclean 3700, to improve the easy-cleaning properties of the protective coating. The protective coating can also include additional functional fillers, which constitute the filler mixture portion of the protective coating. The filler mixture portion can include silica, e.g., fumed silica, titanium dioxide (TiO or TiO), aluminum oxide BR 400 or other similar components, Minspar 3 or other similar components, and calcium carbonate or other similar components. A preferred formulation of the protective coating is as follows:

[0028] [Table 1]

[0029] [Table 2]

[0030] Those skilled in the art will readily appreciate that other fast-setting agents such as DETA, TETA, Ancamine® 2904, etc., can be used in place of Ancamine® 2903.

[0031] Additionally, the weight ratio of part A to part B can be about 16.8 to 1. Furthermore, the corresponding stoichiometric ratio is about 1.0, and the weight ratio may vary from about 14:1 to about 20:1, and the stoichiometric ratio may vary from about 0.9 to about 1.1.

Claims

1. a binder component mixture having a reactive mixture portion and a filler mixture portion, the reactive mixture portion including an epoxy resin portion and an epoxy silane portion, the epoxy silane portion being present in an amount of 10% by weight of the reactive mixture portion and 40% by weight of the reactive mixture portion; and a curing component having one or more amine curing compounds, the one or more amine curing compounds comprising unmodified diaminocyclohexane (DACH) present in an amount between 70% and 100% by weight of the curing component.

2. 10. The protective coating of claim 1, wherein the epoxy resin portion of the reactive mixture portion is present in an amount between 60% by weight of the reactive mixture portion and 90% by weight of the reactive mixture portion.

3. 10. The protective coating of claim 1, wherein the reactive mixture portion consists essentially of the epoxy resin portion and the epoxy silane portion, the epoxy resin portion of the reactive mixture portion being present in an amount between 60% by weight of the reactive mixture portion and 90% by weight of the reactive mixture portion, and the epoxy silane portion of the reactive mixture portion being present in an amount between 10% by weight of the reactive mixture portion and 40% by weight of the reactive mixture portion.

4. 10. The protective coating of claim 1, wherein the epoxy resin portion of the reactive mixture portion comprises a multifunctional phenolic novalac epoxy resin.

5. 10. The protective coating of claim 1, wherein the reactive mixture portion of the binder component mixture is present in an amount between 30% and 45% by weight of the binder component mixture.

6. 10. The protective coating of claim 1, wherein the filler mixture portion comprises any combination of a thickener component, a pigment component, an anti-crater component, a water repellent component, a drying component, an additive component, and a filler component.

7. 7. The protective coating of claim 6, wherein the thickener component comprises silica, the pigment component comprises titanium dioxide, the anti-crater component comprises a polyacrylate material, the water-repellent component comprises a silicone-modified polyacrylate, the dry component comprises aluminum oxide, the additive component comprises feldspar, and the filler component comprises calcium carbonate.

8. 10. The protective coating of claim 1, wherein the amine curing compound of the curing component comprises a plurality of amine compounds.

9. 10. The protective coating of claim 1, wherein the amine-curing compound comprises another amine curing agent.

10. 10. The protective coating of claim 9, wherein the other amine curing agent comprises DETA or TETA.

11. 10. The protective coating of claim 1, wherein the weight ratio of the binder component mixture to the curing component is 16.8:

1.

12. a binder component mixture having a reactive mixture portion and a filler mixture portion, the reactive mixture portion including an epoxy resin portion and an epoxy silane portion, the epoxy silane portion being present in an amount of 10% by weight of the reactive mixture portion and 40% by weight of the reactive mixture portion; and a curing component having one or more amine curing compounds, the amine curing compound of the curing component comprising unmodified diaminocyclohexane (DACH) present in an amount between 70% and 100% by weight of the curing component.

13. 13. The protective coating of claim 12, wherein the reactive mixture portion of the binder component mixture is present in an amount between 30% and 45% by weight of the binder component mixture.

14. 13. The protective coating of claim 12, wherein the filler mixture portion comprises any combination of a thickener component, a pigment component, an anti-crater component, a water repellent component, a dry component, an additive component, and a filler component.

15. 10. The protective coating of claim 9, wherein the amine-curing compound comprises another amine curing agent, the other amine curing agent comprising DETA or TETA.

16. 13. The protective coating of claim 12, wherein the weight ratio of the binder component mixture to the curing component is between 14:1 and 20:

1.

17. 17. The protective coating of claim 16, wherein the stoichiometric ratio is between 0.9 and 1.1.

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