Coating process

Abstract

Provided herein is a process for coating at least part of a surface of a swimming pool shell or spa shell. Also provided herein is a coated swimming pool shell or spa shell. Also provided herein are uses of coating compositions for coating at least part of a surface of a swimming pool shell or spa shell, for preventing or retarding surface degradation and / or preventing or retarding loss of colour of swimming pool shell or spa shell surfaces, and for improving the appearance of swimming pool shell or spa shell surfaces.

Description

[0001] COATING PROCESS

[0002] Related Applications

[0003] The present application claims priority from Australian Provisional Patent Application No. 2025900960, the entire contents of which is incorporated herein by this reference.

[0004] Field

[0005] The present disclosure relates to a process for coating at least part of a surface of a swimming pool shell or spa shell. The present disclosure also relates to a coated swimming pool shell or spa shell, and to uses of coating compositions for coating at least part of a surface of a swimming pool shell or spa shell, for preventing or retarding surface degradation and / or preventing or retarding loss of colour of swimming pool shell or spa shell surfaces, and for improving the appearance of swimming pool shell or spa shell surfaces.

[0006] Background

[0007] Many homes contain swimming pools, with over 3.1 million Australians living in a house with a swimming pool and spa, (Roy Morgan, Australian Swimming Pool Ownership March 2023), and in the US there are 10.4 million residential swimming pools (TestHut, Swimming Pool Statistics 2023).

[0008] Swimming pools require regular upkeep and maintenance, with pools being susceptible to issues including cracking, chipping and / or flaking, in some cases resulting in leaks, as well as discolouration, for example associated with exposure to sunlight or high / low temperature. At the same time, swimming pool water contains cleaning chemicals, which create a relatively harsh environment in contact with the pool surface. Such conditions can include long periods of immersion, chlorine and / or salt exposure, pH fluctuations, and exposure to sunlight and heat. These conditions can accelerate coating degradation, and can lead to one or more of discolouration, loss of gloss, blistering, cracking, peeling and / or loss of adhesion of surface coatings.

[0009] Many swimming pools are provided with coatings for aesthetic and / or protective purposes. Typically, such coatings are epoxy-based or chlorinated rubber-based. However, epoxy coatings tend to suffer from discolouration / yellowing on exposure to sunlight and / or high temperatures, and chlorinated rubber-based coatings can have a tendency to flake or crack.In some instances, coatings that perform acceptably in non-immersion building applications can still perform poorly under pool / spa immersion and chemical exposure.

[0010] It would be desirable to provide a coating for a swimming pool shell which provides good performance in respect of one or more of: good adhesion, resistance to chipping, flaking and / or peeling, coating stability, low or no discolouration / yellowing, resistance to sunlight / UV exposure, resistance to high, low and / or variable temperature, and resistance to swimming pool water exposure.

[0011] It would further be desirable to provide processes for preventing, reducing, or delaying degradation of swimming pool shells and spa shells.

[0012] It would further be desirable to provide processes for improving the appearance of aged swimming pool shells and spa shells, for example which can restore the original colour and / or original appearance of the swimming pool shell or spa shell.

[0013] Summary

[0014] In a first aspect, there is provided a process for coating at least part of a surface of a swimming pool shell or spa shell, including:

[0015] applying a polyaspartic-based coating composition to at least part of a surface of a swimming pool shell or spa shell.

[0016] In some embodiments, the polyaspartic-based coating composition is a polyaspartic-polyurea coating composition.

[0017] In some embodiments, the polyaspartic-based coating composition comprises a solvent. In some embodiments, the solvent is dimethyl carbonate,

[0018] In some embodiments, the solvent is dimethyl carbonate in an amount of from 2 to 25% by weight of the composition.

[0019] In some embodiments, the polyaspartic-based coating composition provides a coating having one or more of the following properties when cured for 48 hours at 22°C and 50% relative humidity:

[0020] a. a light transmittance value of at least 80% as assessed in accordance with ASTM D 1746: 2023;

[0021] b. an elongation at break of at least 400% as assessed in accordance with ASTM D2370;

[0022] c. passes a water immersion test with no corrosion and no blistering discernible by eye as assessed in accordance with ISO 2812-2;d. a QUV UV resistance value of at least 90% as assessed in accordance with ASTMD4587;

[0023] e. resistance to salt spray exposure for at least 5000 hours with no corrosion and no blistering discernible by eye, as assessed in accordance with ASTM B177; and

[0024] f. chemical resistance of at least 1,500 methyl ethyl ketone double rubs, as assessed in accordance with ASTM D4752.

[0025] In some embodiments, the polyaspartic-polyurea coating composition is produced from a first composition comprising an isocyanate, and a second composition comprising a polyaspartic ester.

[0026] In some embodiments, the isocyanate is an aliphatic isocyanate.

[0027] In some embodiments, the aliphatic isocyanate is selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate and xylene diisocyanate.

[0028] In some embodiments, the polyaspartic ester is produced from an alkyl maleate and a polyamine.

[0029] In some embodiments, the alkyl maleate is selected from the group consisting of dimethyl maleate or diethyl maleate.

[0030] In some embodiments, the polyaspartic ester is a diethyl aspartate or a dimethyl aspartate. In some embodiments, the polyaspartic-based coating composition is a one-part polyaspartic-polyurea coating composition.

[0031] In some embodiments, the polyaspartic-polyurea coating composition is moisture-curing. In some embodiments, the polyaspartic-based coating composition comprises a polyaspartic-containing isocyanate-functional prepolymer comprising free isocyanate groups; and optionally one or more additives selected from an adhesion promoter, a catalyst, a UV stabiliser, a flow / levelling agent, a defoamer, an anti-mildew agent, and an alkali-resistance additive.

[0032] In some embodiments, the polyaspartic-based coating composition comprises a latent curing agent that hydrolyses in the presence of atmospheric moisture to release amine functionality, optionally wherein the latent curing agent is selected from aldimines, ketimines, oxazolidines, and mixtures thereof.

[0033] In some embodiments, the swimming pool shell is a fibreglass swimming pool shell or spa shell.

[0034] In some embodiment the swimming pool shell or spa shell is a concrete swimming pool shell or spa shell.In some embodiments, the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition at the installation site.

[0035] In some embodiments, the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition in-ground.

[0036] In some embodiments, the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition prior to installation on site.

[0037] In some embodiments, substantially all, or all, of the surface of the swimming pool shell or spa shell which in use is for contacting water, is coated with the polyaspartic-based coating composition.

[0038] In some embodiments, substantially all, or all, of the surface of the swimming pool shell or spa shell which in use is exposed to sunlight, is coated with the polyaspartic-based coating composition.

[0039] In some embodiments, substantially all, or all, of the surface of the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition.

[0040] In some embodiments, following application, the polyaspartic-based coating composition is allowed to cure, such that the at least part of the shell surface is coated with a cured polyaspartic-based coating composition.

[0041] In some embodiments, wherein the polyaspartic-based coating composition is allowed to cure for a time period in the range of from 1 to 12 hours.

[0042] In some embodiments, the polyaspartic-based coating composition is allowed to cure at a temperature in the range of from 5 to 80 °C.

[0043] In some embodiments, multiple coats of the polyaspartic-based coating composition are applied.

[0044] In some embodiments, the polyaspartic-based coating composition comprises one or more of the following:

[0045] - a solvent;

[0046] - a reactive diluent;

[0047] - a filler;

[0048] - an adhesion promoter;

[0049] - a catalyst;

[0050] - a UV stabiliser;

[0051] - a pigment;

[0052] - an anti-slip additive;- coloured cosmetic particles; and

[0053] - glitter and / or shimmer particles.

[0054] In some embodiments, the polyaspartic-based coating composition is spray-coated onto the surface of the swimming pool shell or spa shell.

[0055] In some embodiments, the polyaspartic-based coating composition is applied using a roller and / or brush.

[0056] In some embodiments, prior to applying the polyaspartic-based coating composition, the surface of the swimming pool shell or spa shell is coated with a primer coat.

[0057] In another aspect, there is provided a process for preventing or retarding surface degradation of at least part of a surface of a swimming pool shell or spa shell, comprising applying a polyaspartic-based coating composition to at least a part of a surface of a swimming pool shell or spa pool shell.

[0058] In another aspect, there is provided a process for preventing or retarding loss of colour of at least part of a coloured surface of a swimming pool shell or spa shell, comprising applying a polyaspartic-based coating composition to at least part of a surface of a swimming pool shell or spa pool shell.

[0059] In some embodiments, the swimming pool shell or spa shell is a new swimming pool shell or spa shell.

[0060] In another aspect, there is also provided a process for improving the appearance of at least part of a surface of an aged swimming pool shell or spa shell, comprising applying a polyaspartic-based coating composition to at least part of a surface of an aged swimming pool shell or spa shell.

[0061] In some embodiments, prior to applying the coating composition, the surface of the aged swimming pool shell or spa shell has one or more of a faded appearance, loss of colour, a yellowed appearance, and microcracks.

[0062] In some embodiments, the process restores the original appearance of the swimming pool shell or spa shell.

[0063] In some embodiments, the swimming pool shell or spa shell is a fiberglass swimming pool shell or spa shell.

[0064] In another aspect, there is provided a swimming pool shell or spa shell whose surface is at least partially coated with a polyaspartic-based coating.

[0065] In some embodiments, the surface is at least partially coated with a cured polyaspartic-based coating composition.In another aspect, there is provided use of a polyaspartic-based coating composition for coating at least part of a surface of a swimming pool shell or spa shell.

[0066] In another aspect, there is provided use of a polyaspartic-based coating composition for coating at least part of a surface of a swimming pool shell or a spa shell.

[0067] In another aspect, there is provided use of a polyaspartic-based coating composition for preventing or retarding surface degradation of at least part of a surface of a swimming pool shell or spa shell.

[0068] In another aspect, there is provided use of a polyaspartic-based coating composition for preventing or retarding loss of colour of at least part of a surface of a swimming pool shell or spa shell.

[0069] In another aspect, there is provided use of a polyaspartic-based coating composition as a protective coating for a swimming pool shell or spa shell surface.

[0070] In another aspect, there is provided use of a polyaspartic-based coating composition for improving the appearance of at least part of a surface of an aged swimming pool shell or an aged spa shell.

[0071] In another aspect, there is provided use of a kit for producing a polyaspartic-based coating composition for use in a process as defined herein, or in a use as defined herein, the kit comprising:

[0072] a first composition comprising an isocyanate; and

[0073] a second composition comprising a polyaspartic ester.

[0074] In some embodiments, the first composition and second composition are mixed to form a polyaspartic-based coating composition, and then applied to at least part of the surface of a swimming pool shell or spa shell.

[0075] In another aspect, there is provided a one-part polyaspartic-based coating composition comprising components for forming a polyaspartic-based coating and dimethyl carbonate.

[0076] In some embodiments, the composition comprises components for forming a polyaspartic-polyurea coating composition.

[0077] In some embodiments, the composition comprises from 2 to 25% by weight of dimethyl carbonate.

[0078] Brief Description of the Drawings

[0079] Figure l is a schematic representation of a process in accordance with embodiments of the present disclosure, whereby microcracks in a section of aged pool or spa shell are filled andcovered with a polyaspartic-based coating composition, thereby reducing visual appearance of the microcracks.

[0080] Figure 2 shows a photographic image of a section of aged pool shell, part of which has been treated with a primer polyaspartic-based coating composition.

[0081] Figure 3 shows a photographic image of the section of aged pool shell shown in figure 2, which has been treated with a topcoat polyaspartic-based coating composition.

[0082] Figure 4 shows a photographic image of a section of aged pool shell, part of which has been treated with a polyaspartic-based coating composition.

[0083] Figure 5 shows a photographic image of the section of aged pool shell shown in figure 4, part of which has been treated with a polyaspartic-polyurea coating composition.

[0084] Detailed Description

[0085] Definitions

[0086] Unless specifically defined otherwise, all technical and scientific terms used herein shall be taken to have the same meaning as commonly understood by one of ordinary skill in the art.

[0087] Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, preferred methods and materials are described. For the purposes of the present invention, the following terms are defined below.

[0088] The present disclosure may refer to the contents of certain documents being incorporated herein by reference. In the event of any inconsistent teaching between the teaching of the present disclosure and the contents of those documents, the teaching of the present disclosure takes precedence.

[0089] It is to be understood that if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art.

[0090] As used herein, the term “and / or”, e.g., “X and / or Y” shall be understood to mean either "X and Y" or "X or Y" and shall be taken to provide explicit support for both meanings or for either meaning.

[0091] As used herein, the term about, unless stated to the contrary, refers to + / - 10%, of the designated value.Throughout this specification, unless specifically stated otherwise or the context requires otherwise, reference to a single step, composition of matter, group of steps or group of compositions of matter shall be taken to encompass one and a plurality (i.e. one or more) of those steps, compositions of matter, groups of steps or groups of compositions of matter. Thus, as used herein, the singular forms "a", "an" and "the" include plural aspects unless the context clearly dictates otherwise. For example, reference to "a" includes a single as well as two or more; reference to "an" includes a single as well as two or more; reference to "the" includes a single as well as two or more and so forth.

[0092] Unless otherwise indicated, terms such as "first," "second," etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to a “second” item does not require or preclude the existence of lower-numbered item (e.g., a “first” item) and / or a higher-numbered item (e.g., a “third” item).

[0093] As used herein, the phrase “at least one of’, when used with a list of items, means different combinations of one or more of the listed items may be used and only one of the items in the list may be needed. The item may be a particular object, thing, or category. In other words, “at least one of’ means any combination of items or number of items may be used from the list, but not all of the items in the list may be required. For example, “at least one of item A, item B, and item C” may mean item A; item A and item B; item B; item A, item B, and item C; or item B and item C. In some cases, “at least one of item A, item B, and item C” may mean, for example and without limitation, two of item A, one of item B, and ten of item C; four of item B and seven of item C; or some other suitable combination.

[0094] As used herein, the word “comprise” and other forms of the word, such as “comprising” and “comprises,” means including but not limited to, and is not intended to exclude, for example, other additives, components, integers, or steps.

[0095] Each embodiment of the present disclosure described herein is to be applied mutatis mutandis to each and every other embodiment unless specifically stated otherwise or required otherwise by context.

[0096] Coating Process

[0097] In a first aspect, there is provided a process for coating at least part of a surface of a swimming pool shell or spa shell, including:

[0098] applying a polyaspartic-based coating composition to at least part of a surface of a swimming pool shell or spa shell.The process provides for the application of a particularly effective protective coating to the surface of swimming pool and / or spa shells, providing them with good properties so as to maintain good aesthetic performance and resist degradation such as cracking and discolouration.

[0099] The process may for example comprise applying a polyaspartic-based coating composition to at least part of a surface of a swimming pool shell or spa shell, then allowing that coating composition to cure to provide a solid film.

[0100] Polyaspartic-based Coating Composition

[0101] The process involves use of a polyaspartic-based coating composition.

[0102] Polyaspartic-based coating compositions, and / or the resulting polyaspartic-based coatings when used on swimming pool or spa shells, may have one or more of the following properties:

[0103] High solids content, for example 70-100 wt.%, or 80-100 wt.%, or 90-100 wt.%, or 95-100 wt.%, for example 97 wt% or 98 wt%;

[0104] - Polyaspartic-based coating compositions may be applied at high wet film thickness; - Fast cure, for example within 1-2 hours;

[0105] - Wide temperature range for application;

[0106] Tolerance to application in high humidity, up to 95%;

[0107] Good adhesion properties, for example to polyester (e.g. unsaturated polyester), concrete and / or cement surfaces;

[0108] High flexibility;

[0109] - High elongation properties, for example the cured coating may have an elongation at break of at least 300%, or 400%, or 450%, or 700%, or at least 1000%, for example when assessed in accordance with ASTM D2370;

[0110] - Resistance to cuts and abrasion;

[0111] - Low VOC;

[0112] - Low odour;

[0113] - High gloss and colour;

[0114] - UV stability;

[0115] Temperature stability;

[0116] - Water stability, for example after 7 days of complete water immersion, the coating may in some embodiments show no whitening and no peeling discernible by eye; - Resistance to yellowing;- Resistance to staining;

[0117] Chemical resistance;

[0118] Stability on exposure to chlorine, salts and / or pH fluctuations;

[0119] - High bonding properties to materials, including concrete and fibreglass;

[0120] - Low prevalence of cracking;

[0121] Abrasion resistance; and

[0122] - Ease of cleaning.

[0123] In preferred embodiments, the polyaspartic-based coating composition has good adhesion to one or more of fiberglass (e.g. polyester), concrete and / or cement render surface.

[0124] In preferred embodiments, the polyaspartic-based coating composition, once cured, has good resistance to water exposure and chemical exposure (e.g. chlorine, salts, pH fluctuations).

[0125] In preferred embodiments, the polyaspartic-based coating composition, once cured, has good resistance to yellowing and / or degradation on exposure to sunlight, for example after exposure to UV or sunlight for at least 1000 hours, in some embodiments the coating shows no yellowing and no peeling discernible by eye.

[0126] In some embodiments, the polyaspartic-based coating composition is transparent, or partly transparent, including when cured. In some embodiments, the polyaspartic-based coating composition, including when cured, provides a light transmittance value of at least 50%, 60%, 70%, 80%, 90%, 95%, or 98% as assessed in accordance with ASTM D 1746: 2023.

[0127] In some embodiments, the polyaspartic-based coating composition, once cured, has high scratch resistance, for example a pencil hardness of at least 4H, at least 5H, at least 6H or at least 7H. In some embodiments, pencil hardness is assessed in accordance with ASTM D3363.

[0128] In some embodiments, the polyaspartic-based coating composition, once cured, has high hardness, for example a pendulum hardness of at least 100, 150, or at least 200 seconds (Persoz), and for example about 220 seconds (Persoz). In some embodiments, pendulum hardness is assessed by applying the Persoz method in accordance with ASTM D4366.

[0129] In some embodiments, the polyaspartic-based coating composition, once cured, has high abrasion resistance, for example an abrasion loss of less than 20 mg, less than 15 mg, less than 10 mg, or less than about 5 mg when assessed in accordance with ASTM D4060.

[0130] In some embodiments, the polyaspartic-based coating composition, once cured, has high impact resistance, for example an impact resistance of at least 100, at least 120, or at least 140 in-lbs when assessed in accordance with ASTM D2794.

[0131] In some embodiments, the polyaspartic-based coating composition, once cured, has high chemical resistance. In some embodiments, the coating exhibits chemical resistance to methylethyl ketone (MEK) double rubs of at least 500 rubs, at least 1000 rubs, or greater than 1500 rubs, where chemical resistance is assessed in accordance with ASTM D4752.

[0132] In some embodiments, the polyaspartic-based coating composition, once cured, has high water immersion resistance, for example passing a water immersion test with no corrosion and no blistering discernible by eye after immersion for at least 7 days. In some embodiments, water immersion resistance is assessed in accordance with ISO 2812-2.

[0133] In some embodiments, the polyaspartic-based coating composition, once cured, has high resistance to salt spray exposure, for example resistance for at least 1000 hours, at least 3000 hours, or at least 5000 hours, for example with no corrosion and no blistering discernible by eye. In some embodiments, salt spray resistance is assessed in accordance with ASTM B 177.

[0134] In some embodiments, the polyaspartic-based coating composition, once cured, has high resistance to degradation under UV exposure. In some embodiments, UV resistance is assessed in accordance with ASTM D4587. In some embodiments, UV resistance (as assessed in accordance with ASTM D4587) is at least 0.90, at least 0.95, at least 0.97, or about 0.99.

[0135] In some embodiments, the polyaspartic-based coating composition, once cured, has high gloss retention on weathering. In some embodiments, the coating retains at least 90%, at least 95%, or at least 98% gloss compared with the initial fully cured coating, for example when assessed in accordance with ASTM D523.

[0136] In some embodiments, the polyaspartic-based coating composition, once cured, has temperature resistance in the range of from about -40°C to about 120°C without deformation or physical changes discernible by eye.

[0137] Polyaspartic-based coating compositions contain a polyaspartic component.

[0138] In some embodiments, the polyaspartic-based coating composition is a polyaspartic-polyurea coating composition.

[0139] The term polyaspartic-polyurea can be used to refer to a polyurea coating compositions in which polyaspartic chemistry is used to form a cured film, including polyaspartic polyurea compositions formed using polyaspartic ester chemistry.

[0140] Polyaspartic-based coating compositions may be provided as one-part systems or as multi-part systems. In some embodiments, a multi-part system is provided, such as a two-part system, where the parts are mixed prior to application and curing.

[0141] One-part systems are those where the components are provided in a single composition that cures after application, e.g. under ambient conditions.

[0142] In some embodiments, the polyaspartic-based coating composition is provided as a one-part coating composition. A one-part polyaspartic-based coating composition typically does notrequire mixing of a second or further component to initiate curing, but instead cures by exposure to ambient conditions, for example exposure to humidity, moisture, oxygen, light and / or ambient temperatures after application.

[0143] In some embodiments the one-part polyaspartic-based coating composition is one containing components that cure by reaction with moisture, that is, the coating is moisturecuring. Moisture-curing means that the cure proceeds after application through reaction pathways that are initiated and / or driven by atmospheric moisture. Without being bound by theory, moisture-curing one-part coating compositions can comprise reactive functional groups that undergo reaction after application when exposed to atmospheric moisture, thereby forming a crosslinked network. In some embodiments, one-part systems comprising isocyanate groups can react with water to form an amine with evolution of carbon dioxide, and the amine can then react with isocyanate groups to form urea linkages to progress curing.

[0144] In some embodiments, the rate of curing of moisture-curing compositions is related to substrate moisture content, ambient temperature, dew point, and / or humidity.

[0145] In some embodiments, the coating composition comprises one or more components that contribute to film formation, for example selected from (i) an isocyanate-functional prepolymer and / or polyisocyanate component and (ii) an aspartate-functional (polyaspartic ester) component, wherein cure proceeds after application by formation of a urea-rich and / or urea / urethane polymer network.

[0146] In some embodiments, the isocyanate-functional component comprises an isocyanate-terminated polyurethane prepolymer formed from a polyol component and an excess of an organic polyisocyanate, the prepolymer comprising free isocyanate groups that react after application under ambient conditions.

[0147] In some embodiments, the organic polyisocyanate is an aliphatic or cycloaliphatic polyisocyanate selected from isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), hydrogenated methylenediphenyl diisocyanate (HMDI), and oligomeric derivatives thereof, including isocyanurate- and / or biuret-type oligomers.

[0148] In some embodiments, the polyaspartic ester component is formed by aza-Michael addition between (a) a dialkyl maleate and / or dialkyl fumarate and (b) an amine, diamine or polyamine, thereby converting primary amine groups to sterically hindered secondary amines and providing controlled reactivity with the isocyanate-functional component.

[0149] In some embodiments, the dialkyl maleate comprises diethyl maleate.In some embodiments, the amine, diamine or polyamine used to form the polyaspartic ester component is selected from isophorone diamine, 2-methylpentanediamine, and polyether amines, and mixtures thereof.

[0150] In some embodiments, moisture-curing is achieved at least in part via direct reaction of isocyanate groups with atmospheric moisture to generate amine functionality which subsequently reacts with isocyanate groups to form urea linkages in the cured composition.

[0151] In some embodiments, moisture-curing is provided at least in part by one or more latent curing agents that hydrolyse in the presence of atmospheric moisture to release amines that react with isocyanate groups. In some embodiments the latent curing agents are selected from aldimines, ketimines, oxazolidines and mixtures thereof.

[0152] In some embodiments, the coating composition comprises a dialdimine latent curing agent in combination with a polyurethane prepolymer comprising free isocyanate groups, optionally further comprising an acid catalyst, for example acids selected from carboxylic acids, toluenesulfonic acid, and mixtures thereof.

[0153] In some embodiments, the coating composition further comprises one or more catalysts to adjust curing rate, for example catalysts selected from organotin catalysts, bismuth catalysts and amine-based catalysts.

[0154] In some embodiments, the coating composition further comprises one or more light stabilisers, for example stabilisers selected from hindered amine light stabilizers and benzotriazole UV absorbers, including bis(l,2,2,6,6-pentamethyl-4-piperidyl) sebacate, methyl(l,2,2,6,6-pentamethyl-4-piperidyl) sebacate), and / or hydroxyphenyl benzotriazole UV absorbers.

[0155] In some embodiments, the coating composition further comprises one or more additives, for example additives selected from

[0156] - a solvent;

[0157] - a reactive diluent;

[0158] - a filler;

[0159] - an adhesion promoter;

[0160] - a catalyst;

[0161] - a UV stabiliser;

[0162] - a pigment;

[0163] - an anti-slip additive;

[0164] - coloured cosmetic particles; and

[0165] - glitter and / or shimmer particles- flow / leveling agents;

[0166] - defoamers;

[0167] - anti-mildew agents; and

[0168] - alkali-resistance additives.

[0169] In some embodiments, the polyaspartic-based coating composition is a one-part polyaspartic-polyurea coating composition that is moisture-curing.

[0170] There is also provided a one-part polyaspartic-based coating composition comprising components for forming a polyaspartic-based coating and a suitable solvent, such as dimethyl carbonate.

[0171] In some embodiments, the one-part composition comprises components for forming a polyaspartic-polyurea coating composition and a suitable solvent, such as dimethyl carbonate.

[0172] In some embodiments, the one-part composition comprises from 1 to 40% by weight of a solvent (e.g. dimethyl carbonate), or from 2 to 25% by weight of a solvent (e.g. dimethyl carbonate), or from 5 to 10% by weight of a solvent (e.g. dimethyl carbonate).

[0173] In some embodiments, the polyaspartic-based coating composition is provided as a multipart coating composition, for example a two-part polyaspartic-polyurea coating composition. Typically, polyaspartic-polyureas are produced by reaction of an isocyanate (e.g. a polyisocyanate having more than one isocyanate groups, such as a diisocyanate, e.g. an aliphatic diisocyanate) with amine groups present in a polyaspartic reactant, typically a polyaspartic ester. The polyaspartic reactant may be produced, for example, by reaction of an alkyl maleate (e.g. a dialkyl maleate such as diethyl maleate or dimethyl maleate), with a suitable polyamine, e.g. an aliphatic diamine.

[0174] In some embodiments, prior to applying the coating to the surface of the swimming pool shell or spa shell, the polyaspartic-polyurea coating composition is produced from a first composition comprising an isocyanate, and a second composition comprising a polyaspartic ester (also known as a polyaspartic resin). For example, the first and second compositions may be mixed, and if desired other components added as required, and the mixture then applied to the pool or spa surface.

[0175] Accordingly, there is also provided a kit for use in coating at least part of a surface of a swimming pool shell or spa shell, comprising a first composition comprising an isocyanate, and a second composition comprising a polyaspartic ester. For example, in use, the two components may be combined, and then the resulting polyaspartic-based coating composition then applied to the pool shell or spa shell surface.In some embodiments, the isocyanate is a polyisocyanate. In some embodiments, the polyisocyanate is a diisocyanate. In some other embodiments, the polyisocyanate is a triisocyanate.

[0176] In some embodiments, the isocyanate is an aliphatic isocyanate, e.g. an aliphatic polyisocyanate. In some embodiments, the polyisocyanate is an aliphatic diisocyanate.

[0177] In some embodiments, the aliphatic polyisocyanate is selected from the group consisting of hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI) and xylene diisocyanate (XDI).

[0178] In some embodiments, the polyisocyanate is hexamethylene diisocyanate trimer.

[0179] In some embodiments, the polyaspartic-based coating composition contains from 10 to 50% by weight isocyanate, or from 20 to 30% by weight isocyanate.

[0180] In some embodiments, the polyaspartic ester is produced from an alkyl maleate and a polyamine.

[0181] In some embodiments, the alkyl maleate is selected from the group consisting of dimethyl maleate and diethyl maleate.

[0182] In some embodiments, the polyamine is a diamine.

[0183] In some embodiments, the diamine is an aliphatic diamine.

[0184] Examples of suitable diamines include alkylene diamines, e.g. C2-i2alkylene diamines, such as hexamethylene diamine (HDI), A further example of a suitable diamine is isophorone diamine (IPDI). IPDI may be particularly useful, for example, in situations where high chemical resistance is desired.

[0185] In some embodiments, the polyamine is a triamine, such as di ethylenetri amine.

[0186] In some embodiments, the polyamine is selected from the group consisting of hexamethylene diamine, isophorone diamine, and diethylenetriamine.

[0187] Examples of suitable compositions containing a polyaspartic ester, e.g. for use in mixing with a composition comprising a polyisocyanate, to produce a polyaspartic-polyurea coating composition, include those in the Desmophen® range provided by Covestro, such as Desmophen® NH1420 and Desmophen® NH1520. For many types of application, either of those Desmophen products may be suitable, with Desmophen® NH1520 being preferred in some cases where greater flexibility is required. Further examples of compositions containing a polyaspartic ester (e.g. polyaspartic resins) include Feispartic F220, Feispartic F420 and Feispartic F520.In some embodiments, the polyaspartic-based coating composition contains from 20 to 80% by weight polyaspartic ester, or from 30 to 70% by weight polyaspartic ester, or from 40 to 50% by weight polyaspartic ester, or from 50 to 60% by weight polyaspartic ester.

[0188] In some embodiments, the polyaspartic-based coating composition comprises one or more of the following additional components:

[0189] - a solvent;

[0190] - a reactive diluent;

[0191] - a filler;

[0192] - an adhesion promoter;

[0193] - a catalyst;

[0194] - a UV stabiliser;

[0195] - a pigment;

[0196] - an anti-slip additive;

[0197] - coloured cosmetic particles; and

[0198] - glitter and / or shimmer particles

[0199] In some embodiments, the polyaspartic-based coating composition comprises one or more of the following additional components:

[0200] - a solvent;

[0201] - a reactive diluent;

[0202] - a filler;

[0203] - an adhesion promoter;

[0204] - a catalyst;

[0205] - a UV stabiliser;

[0206] - a pigment;

[0207] - an anti-slip additive;

[0208] - coloured cosmetic particles; and

[0209] - glitter and / or shimmer particles

[0210] - flow / leveling agents;

[0211] - defoamers;

[0212] - anti-mildew agents; and

[0213] - alkali-resistance additives.

[0214] In some embodiments, the polyaspartic-based coating composition has low viscosity. In some embodiments, the polyaspartic-based coating composition has a viscosity of less than200 cP, less than 100 cP, less than 50 cP, less than 20 cP, or less than 10 cP, for example when assessed in accordance with ASTM / ISO2555.

[0215] To reduce the viscosity and aid the application of the polyaspartic-based coating composition, a solvent may be included in the composition. In some embodiments, the polyaspartic-based coating composition comprises a solvent. Solvents may be useful to adjust viscosity, e.g. for applications where a lower viscosity system is required. Greater amounts of solvent may assist in workability and / or in penetrating and filling surfaces with micro-cracks.

[0216] Suitable solvents can include polar solvents having a boiling point at atmospheric pressure that is less than 100°C, or less than 95°C. Examples of suitable solvents include xylene, methyl ethyl ketone (MEK), propylene carbonate, dimethyl carbonate, or an acetate solvent. In some embodiments the polyaspartic-based coating composition comprises dimethyl carbonate. A single solvent may be used. Alternatively, a combination of two or more solvents may be used.

[0217] In some embodiments, the polyaspartic-based coating composition contains from 1 to 40% by weight of a solvent, or from 2 to 25% by weight of a solvent, or from 5 to 10% by weight of a solvent. It is considered that such proportions of solvent assist in producing a hig performing composition, which provides a composition from which solvent can be readily evaporated and the composition has good thickness properties.

[0218] In some embodiments, the polyaspartic-based coating composition contains from 2 to 25 % by weight dimethyl carbonate.

[0219] Inclusion of solvent in the ranges specified may have advantages, including sufficiently rapid, and / or low levels of bubbles, pits or craters forming in the cured coating composition.

[0220] Alternatively, in cases where other components of the composition provide a mixture that is sufficiently free-flowing and provides good coating properties, in some embodiments the composition is substantially free of solvent. In some embodiments, the polyaspartic based-coating composition comprises a reactive diluent, such as polyetheramine. Reactive diluents may be useful, for example, in situation where low volatile organic content (VOC) is desired.

[0221] In some embodiments, the polyaspartic-based coating composition contains from 2 to 25% by weight of a reactive diluent, or from 10 to 15 % by weight of a reactive diluent.

[0222] Inclusion of a solvent or reactive diluent may be of assistance, for example, where penetration of the composition into microcracks is desired.

[0223] In some embodiments, the polyaspartic-based coating composition comprises a solvent and has a low viscosity, for example less than 100 cP, less than 50 cP, less than 20 cP, less than 10 cP, or less than 5 cP, for example when assessed in accordance with ASTM / ISO2555.In some embodiments, the polyaspartic-based coating composition comprises a filler, such as titanium dioxide. Further examples include silica and calcium carbonate.

[0224] In some embodiments, the polyaspartic -based coating composition contains from 2 to 20% by weight filler (e.g. titanium dioxide), or from 5 to 10% by weight filler (e.g. titanium dioxide).

[0225] In some embodiments, the polyaspartic-based coating composition comprises an adhesion promoter. Examples of adhesion promoters include chlorinated polyolefins, silane-based adhesion promoters, and functional silanes such as epoxy silanes or aminosilanes. For example, with fiberglass shells, chlorinated polyolefins or silane-based adhesion promoters such as epoxysilanes and aminosilanes may be preferred. Silane adhesion promoters can improve bonding to oxidized or weathered fiberglass, for example. With concrete shells, functional silanes such as epoxysilanes or urethane silanes may be preferred.

[0226] In some embodiments, the polyaspartic-based coating composition contains from 0.5 to 5% by weight adhesion promoter, or from 1 to 3 % by weight adhesion promoter.

[0227] Whilst in some embodiments, incorporation of a catalyst may not be required if the reaction between the polyisocyanate and polyaspartic ester is sufficiently rapid, in some other embodiments, the polyaspartic-based coating composition comprises a catalyst. Catalysts assist with acceleration of cure time. Examples of catalysts include tin catalysts, such as dibutyltin dilaurate (DBTDL), and amine catalysts, such as tertiary aliphatic amines and ethanolamines.

[0228] In some embodiments, the polyaspartic-based coating composition contains from 0.5 to 1 % by weight of a catalyst.

[0229] In some embodiments, the polyaspartic-based coating composition comprises a UV stabiliser, such as titanium dioxide.

[0230] In some embodiments, the polyaspartic -based coating composition contains from 2 to 20% by weight UV stabiliser (e.g. titanium dioxide, or hindered amine lights stabilisers (HALS)), or from 5 to 10% by weight UV stabiliser (e.g. titanium dioxide or hindered amine lights stabilisers (HALS)).

[0231] In some embodiments, the polyaspartic-based coating composition comprises a pigment. For example, a suitable white pigment may be titanium dioxide.

[0232] In some embodiments, the polyaspartic -based coating composition contains from 2 to 20% by weight pigment (e.g. titanium dioxide), or from 5 to 10% by weight pigment (e.g. titanium dioxide).

[0233] An abrasion resistance additive, such as silica or calcium carbonate, may also be included in the polyaspartic-based coating composition, if desired.It will be appreciated that certain materials have properties such that it may perform more than one function in the composition. A material may be included in the composition in order to fulfil one, or multiple functions, as needed.

[0234] In some embodiments, the polyaspartic-based coating composition may be a selflevelling clear coat, for example it may contain a flow modifier to assist self-levelling and crack filling. Examples of flow modifiers include polyether siloxanes.

[0235] In some embodiments, the polyaspartic-based coating composition contains from 0.5 to 2 weight percent of a flow modifier (e.g. of a polyetheramine).

[0236] In some embodiments, the polyaspartic-based coating composition may be a gloss coating composition, for example to provide an attractive appearance.

[0237] In some embodiments, the polyaspartic-based coating composition may comprise an anti-slip additive. Examples include glass beads, silica, and polymeric particles.

[0238] In some embodiments, the polyaspartic-based coating compositions may contain coloured cosmetic particles, for example to improve aesthetic appearance.

[0239] In some embodiments, the polyaspartic-based coating compositions may contain shimmer / glitter particles, for example to improve aesthetic appearance.

[0240] In embodiments where the polyaspartic-polyurea coating composition is produced from a first composition comprising an isocyanate, and a second composition comprising a polyaspartic ester, any of the above additional components, where present, may be present in either one, or both, of the first and second compositions, Any of the above additional components may also, or instead, be added once the first and second compositions have been combined. For example, if the resulting composition is more viscous than required, solvent may be added to the combined mixture of first and second compositions.

[0241] However, in preferred embodiments, most or even all of the above components may be present in the second composition comprising a polyaspartic ester. The isocyanate curing agent is active and can react with some other materials. Accordingly, in some preferred embodiments, the first composition contains the isocyanate, optionally a solvent and / or diluent, and optionally a stabiliser. In some embodiments, the first composition does not contain any of the following:

[0242] - a reactive diluent;

[0243] - a filler;

[0244] - an adhesion promoter;

[0245] - a catalyst;

[0246] - a UV stabiliser;- a pigment;

[0247] - an anti-slip additive;

[0248] - coloured cosmetic particles; and

[0249] - glitter and / or shimmer particles.

[0250] In some embodiments, the second composition contains one or more of the following: - a solvent;

[0251] - a reactive diluent;

[0252] - a filler;

[0253] - an adhesion promoter;

[0254] - a catalyst;

[0255] - a UV stabiliser;

[0256] - a pigment;

[0257] - an anti-slip additive;

[0258] - coloured cosmetic particles; and

[0259] - glitter and / or shimmer particles.

[0260] It will be appreciated that some of the polyaspartic-based coating compositions disclosed herein, and some of the precursor first and second compositions for mixing, which are adapted for use with coating swimming pool shell and spa shell surfaces, are new. Accordingly, the present disclosure also relates to those compositions in their own right.

[0261] Swimming Pools and Spas

[0262] The process produces a coated swimming pool shell or spa shell, e.g. which has been coated according to the process disclosed herein.

[0263] Accordingly, there is provided a swimming pool shell or spa shell having a surface which is at least partially coated with a polyaspartic-based coating composition as defined herein. Typically, the coated surface or part thereof will be coated with a composition that has been allowed to cure. Accordingly, in some embodiments, the surface is at least partially coated with a cured polyaspartic-based coating composition.

[0264] In some embodiments a swimming pool shell is coated. In some other embodiments, a spa shell is coated.

[0265] The swimming pool shell or spa shell may be of any suitable shape or size.

[0266] Any suitable type of swimming pool shell or spa shell may be coated.

[0267] In some embodiments, the swimming pool shell is a fibreglass swimming pool shell or spa shell.In some embodiments, the swimming pool shell or spa shell is a concrete swimming pool shell or spa shell.

[0268] In some embodiments, the swimming pool shell or spa shell contains a cement render, which is coated.

[0269] Application

[0270] Any suitable approach for coating the surface of the swimming pool or spa shell may be utilised.

[0271] In some embodiments, the process is used for coating a new swimming pool shell or spa shell.

[0272] In some embodiments, the process is used as a preventative process for a new swimming pool shell or spa shell, or for a maintained shell that has not yet substantially degraded.

[0273] In some embodiments, the preventative coating is applied to delay or retard subsequent degradation caused by immersion, chlorine and / or alkali exposure, UV exposure and / or thermal cycling.

[0274] In some other embodiments, the process is used for renovating, maintaining and / or upgrading an existing swimming pool shell or spa shell. In some embodiments, the process is used as a restorative process for an aged swimming pool shell or spa shell surface.

[0275] In some embodiments, the aged surface has microcracks and / or an oxidised appearance that reduces perceived colour and / or gloss.

[0276] In some embodiments, the coating composition is transparent and restores appearance while preserving underlying decorative texture and / or colour.

[0277] In some embodiments, where restoration is non-uniform due to prior repairs, delamination or clear-coated regions, a coloured coating is applied as a subsequent coat to provide a uniform appearance to the pool shell or spa shell surface.

[0278] When used for rejuvenating an existing swimming pool shell or spa shell, the polyaspartic-based coating composition will preferably have one or more of the following: micro-crack penetration and filling properties, colour restoration properties, and / or strong adhesion to the existing surface, e.g. to aged polyester.

[0279] If desired, the polyaspartic-based coating can be applied over existing coatings, for example such as an epoxy, zinc, urethane or polyurea coating.

[0280] In some embodiments, the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition at the installation site. For example, in the case of a fibreglass shell, it may be applied at the site, prior to positioning in its final intended position.Applying the coating composition may also be something which is carried out on site when renovating or maintaining an existing pool.

[0281] In some embodiments, the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition in-ground. For example, in the case of a concrete shell for an in-ground pool, once the concrete shell has been formed and dried, the polyaspartic-based coating may be applied to the formed shell. As another example, where a render coat has been applied to the shell, the polyaspartic-based coating may be applied to a render coat applied to the shell.

[0282] Alternatively, the coating may be applied as part of the manufacturing process, e.g. when producing a fibreglass shell. Thus, in some embodiments, the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition prior to installation on site.

[0283] As much or as little of the surface of the swimming pool or spa shell as is required to be protected, may be coated with the polyaspartic-based coating composition.

[0284] In some embodiments, substantially all, or all, of the surface of the swimming pool shell or spa shell which in use is for contacting water, is coated with the polyaspartic-based coating composition.

[0285] In some embodiments, substantially all, or all, of the surface of the swimming pool shell or spa shell which in use is exposed to sunlight, is coated with the polyaspartic-based coating composition.

[0286] In some embodiments, substantially all, or all, of the surface of the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition.

[0287] The process may include additional steps if required, depending on factors such as the type of swimming pool or spa shell, and whether a new shell is to be coated or whether rejuvenation of an existing pool or spa shell is desired.

[0288] For example, in the case of a fiberglass swimming pool shell or spa shell, the process may include one or more preparatory steps, such as sanding the shell surface to create a rough surface and / or cleaning of the surface with a suitable solvent, such as acetone or / .w-propyl alcohol. If sanding of the surface is carried out, sandpaper of appropriate coarseness may be used (e.g. 180-220 grit or, for restoration of oxidised surfaces, 220-400 grit may be preferred).

[0289] In the case of a concrete shell, or cement render shell, preferably the coating process is carried out after the concrete or cement surface is full cured, for example at least 14 days, or at least 28 days after the concrete or cement has been applied. Preparatory steps for a concrete or cement shell surface may for example include treatment with an acid such as HC1 to etch the surface, and / or grinding the surface, with the aim of improving adhesion.In some embodiments, where the process is performed as a restorative process for an aged fibreglass shell, aggressive grinding is avoided where the aim is to retain and fill existing microcracks with the coating composition.

[0290] In some embodiments, the solvent used for cleaning is selected such that it does not substantially dissolve the surface and / or does not substantially close or obscure surface microcracks to be filled. In cases where suitable coverage and performance can be obtained with a single coat of the composition, the process may be carried out by applying one coat of the polyaspartic-based coating composition. However, in many cases, multiple coats of the composition are applied, for example 2-3 coats. Accordingly, in some embodiments, multiple coats of the polyaspartic-based coating composition are applied. For example, two coats, three coats, or four or more coats may be applied if required.

[0291] For example, where a shell surface contains significant cracks (e.g. in some rejuvenation cases), an additional coat of the composition may be applied (e.g. 3-4 coats).

[0292] In some embodiments, after applying a coat of the composition, a time period of at least 30 minutes, or at least 1 hour, or at least 2 hours, or at least 4 hours, is allowed to elapse before applying the next coat. In some embodiments, a time period in the range of from 1 to 3 hours is allowed to elapse.

[0293] In some embodiments, the coating composition is applied to the surface in an amount of from 0.1 to 1.0 kg / m2, from 0.2 to 0.8 kg / m2, or from 0.2 to 0.4 kg / m2per coat.

[0294] In some embodiments, the polyaspartic-based coating composition is applied to provide a dry film thickness of at least 10 pm, at least 20 pm, at least 30 pm, at least 40 pm, or at least 50 pm, for example from about 35 pm to about 65 pm.

[0295] In some embodiments, the coating composition is applied at a thickness selected to reduce entrapment of air and / or volatile species during cure. Without being bound by theory, solvent or water evaporation from the curing composition, or carbon dioxide evolution from isocyanate-water reaction pathways that occur during curing, can contribute to bubbles, pinholes or craters if gas is trapped in the curing film.

[0296] In some embodiments, bubbles are mitigated by avoiding application to wet substrates, avoiding condensation, controlling film thickness, and / or allowing adequate time between coats for the subsequent coat to become touch dry.

[0297] In some embodiments, microbubbles can escape during cure and form a small crater that subsequently closes over during cure to form an integral film.

[0298] In some embodiments, the cured coating composition contains essentially no bubbles, pits or cracks discernible by eye.In some embodiments, the coating is applied under defined environmental conditions. In some embodiments, the coating is applied when ambient temperature is from about 4°C to about 35°C, for example about 15°C to about 30°C.

[0299] In some embodiments, the coating is applied when ambient relative humidity is from about 20% to about 90%, for example about 40% to about 70%.

[0300] In some embodiments, the coating is applied when the temperature of the pool or spa surface is from about +5°C to about +50°C, from about +10°C to about +40°C, or from about +15°C to about +30°C.

[0301] In some embodiments, the coating is applied when the temperature of the pool or spa surface is greater than or equal to about 1°C, 2°C, 3°C, or 4°C above the atmospheric dew point temperature.

[0302] In some embodiments, the coating is applied when there is an absence of surface condensation, visible water, or when the pool or spa surface is not under reverse moisture pressure.

[0303] Typically following application, the polyaspartic-based coating composition is allowed to cure. Any suitable curing conditions may be used.

[0304] In some embodiments, the polyaspartic-based coating composition is allowed to cure at ambient temperature. In some embodiments, the polyaspartic-based coating composition is cured at a temperature in the range of from 5 to 50°C, or from 15 to 40°C. Any suitable number of coats may be applied. In some embodiments, one coat is applied. In some other embodiments, multiple (e.g. 2, 3, 4 or more) coats are applied.

[0305] In some embodiments, each subsequent coat is applied after the previous coat is surface touch dry. Touch dryness, or tack free, refers to a surface dryness state having an absence of a wet or sticky sensation when the surface of the coat is lightly touched. The coating underneath the touch dry surface can still be soft and curing.

[0306] In some embodiments, touch dryness occurs after about 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 hours at 22°C and 50% relative humidity.

[0307] In some embodiments, full dryness of the coat occurs at about 6, 12, 18, 24, or 36 hours under those conditions. Full dryness refers to a surface that is dry throughout its thickness, but which curing is still taking place and chemical and material properties are developing. Preferably, to allow full curing, after application of the final coat of the polyaspartic-based coating composition, the coated surface is allowed to cure for a time period of at least 24 hours, or at least 48 hours or at least 72 hours. In some embodiments, following application of thefinal coat of the polyaspartic-based coating composition, the coated surface is allowed to cure for a time period in the range of from 1 to 7 days. In some embodiments, a time period of at least 7 days is allowed to elapse before filling the swimming pool shell or spa shell with water.

[0308] In some embodiments, the polyaspartic-based coating composition is fully cured after 48 hours curing at 22°C and 50% relative humidity.

[0309] Any suitable means of application may be used. In some embodiments, the polyaspartic-based coating composition is spray-coated onto the surface of the swimming pool shell or spa shell. Such an approach may for example be particularly suitable for fiberglass shells with relatively smooth surfaces.

[0310] In some other embodiments, the polyaspartic-based coating composition is roller-coated onto the surface of the swimming pool shell or spa shell. In some embodiments, the polyaspartic-based coating composition is applied using a roller and / or brush. Use of rollers and / or brushes may for example be useful on surfaces where the surface is relatively textured / less smooth, for example such as some concrete and / or cement render surfaces.

[0311] Whilst in some embodiments, the use of a primer composition may not be required (for example suitable results may be obtained for some new fiberglass shell surfaces without requiring a primer composition, in some other embodiments, prior to applying the polyaspartic-based coating composition, the surface of the swimming pool shell or spa shell is coated with a primer coat. Applying a primer coat can improve bonding of the polyaspartic-based coating composition to the shell surface.

[0312] Where a primer coat is applied, this is typically applied after any preparatory sanding, etching, grinding and / or cleaning steps have been carried out, if such steps are required.

[0313] A primer composition typically contains one or more of a polyaspartic ester (e.g, Desmophen® NH1420 or Desmophen® NH1520) (e.g. in an amount in the range of from 40-50 % by weight, or from 20-30% by weight), a polyisocyanate (e.g. HDI trimer, isophorone diisocyanate) (e.g. in an amount in the range of from 20-30% by weight, or from 10-20% by weight), an epoxy resin (e.g. a low viscosity epoxy resin such as bisphenol -F or modified Bid-A epoxy) (e.g in an amount in the range of from 30-40% by weight), an adhesion promoter (e.g. a silane such as an epoxy or aminosilane) (e.g. in an amount in the range of from 1-3% by weight), a reactive diluent (e.g. alkyl glycidyl ether) (e.g. in an amount in the range of from 10-15% by weight), a solvent (e.g. acetone, methyl ethyl ketone, propylene carbonate) (e.g. in an amount in the range of from 1-3% by weight, or from 5-10% by weight), a moisture scavenger (e.g. a zeolite-based additive) to assist adhesion in damp conditions (e.g. in an amount in the range of from 0.5-2% by weight), a flow and / or wetting agent (e.g. poly ether siloxane) (e.g. inan amount in the range of from 0.5-2% by weight), and / or a catalyst (e.g. a tin catalyst such as DBTDL or an amine catalyst) (e.g. in an amount in the range of from 0.5-1% by weight).

[0314] In some embodiments, for example where a primer formulation is used in conjunction with a fiberglass pool or spa shell, a polyaspartic-based primer formulation may for example be used.

[0315] In some embodiments, for example where a primer formulation is used in conjunction with a concrete or cement render swimming pool shell or spa shell, a mixture of an epoxy resin and a polyaspartic-based coating composition may be used.

[0316] For concrete / cement render surfaces with high moisture content, or for damp concrete, it may be preferable to apply a moisture-tolerant primer.

[0317] Where a primer coat is applied, preferably the primer coat is allowed to cure for a time period in the range of from 1 to 6 hours, or from 2 to 4 hours. Preferably, the polyaspartic-based coating composition is then applied within 24 hours of applying the primer coat.

[0318] Swimming Pool and Spa Shells

[0319] In another aspect, there is provided a swimming pool shell or spa shell whose surface is at least partially coated with a polyaspartic-based coating. The polyaspartic-based coating may for example be any of the polyaspartic-based coatings discussed herein. The swimming pool shell or spa shell may for example be any of the swimming pool or spa shells discussed herein.

[0320] Typically, the coated surface or part thereof will be coated with a composition that has been allowed to cure. Accordingly, in some embodiments, the surface is at least partially coated with a cured polyaspartic-based coating composition.

[0321] There is also provided a panel for a swimming pool shell, or a panel for a spa shell, which panel has a surface that is at least partially coated with a polyaspartic-based coating composition as defined herein.

[0322] Uses of Polyaspartic-based Coating Composition

[0323] In another aspect, there is provided use of a polyaspartic-based coating composition for coating at least part of a surface of a swimming pool shell or spa shell.

[0324] The poly aspartic-based coating composition may for example be any of the poly aspartic-based coatings discussed herein. The swimming pool shell or spa shell may for example be any of the swimming pool or spa shells discussed herein.As discussed herein, the polyaspartic-based coating composition provides good performance in preventing degradation, or retarding degradation, of the surface of swimming pool shells and spa shells, acting as a protective coating. The polyaspartic-based coating compositions also provides good performance in preventing or retarding loss of colour of a coloured swimming pool shell or spa shell surface, again acting as a protective coating.

[0325] Accordingly, in another aspect, there is provided a process for preventing or retarding surface degradation of at least part of a surface of a swimming pool shell or spa shell, comprising applying a polyaspartic-based coating composition to at least a part of a surface of a swimming pool shell or spa pool shell.

[0326] In another aspect, there is provided a process for preventing or retarding loss of colour of at least part of a coloured surface of a swimming pool shell or spa shell, comprising applying a polyaspartic-based coating composition to at least part of a surface of a swimming pool shell or spa pool shell.

[0327] In another aspect, there is provided use of a polyaspartic-based coating composition for preventing or retarding surface degradation of at least part of a surface of a swimming pool shell or spa shell.

[0328] In another aspect, there is provided use of a polyaspartic-based coating composition for preventing or retarding loss of colour of at least part of a surface of a swimming pool shell or spa shell.

[0329] In another aspect, there is provided use of a polyaspartic-based coating composition as a protective coating for a swimming pool shell or spa shell surface.

[0330] The poly aspartic-based coating composition may for example be any of the poly aspartic-based coatings discussed herein. The swimming pool shell or spa shell may for example be any of the swimming pool or spa shells discussed herein.

[0331] In some embodiments, the swimming pool shell or spa shell is a new swimming pool shell or spa shell.

[0332] In some embodiments, the swimming pool shell or spa shell is a fiberglass swimming pool shell or spa shell.

[0333] In some embodiments, the swimming pool shell or spa shell is a concrete swimming pool shell or spa shell.

[0334] Without being bound by any particular theory, it is considered that, as swimming pool shells and spa shells age, their appearance can diminish due to formation of microcracks in the surface. This is believed to affect refraction of light, and can lead to loss of colour and / or a faded appearance. The polyaspartic-based coating composition provides good performance infilling such microcracks, improving and / or restoring the appearance of the surface, and enabling the original colour to be seen.

[0335] Accordingly, in another aspect, there is also provided a process for improving the appearance of at least part of a surface of an aged swimming pool shell or spa shell, comprising applying a polyaspartic-based coating composition to at least part of a surface of an aged swimming pool shell or spa shell.

[0336] In another aspect, there is provided use of a polyaspartic-based coating composition for improving the appearance of at least part of a surface of an aged swimming pool shell or an aged spa shell.

[0337] The poly aspartic-based coating composition may for example be any of the poly aspartic-based coatings discussed herein. The swimming pool shell or spa shell may for example be any of the swimming pool or spa shells discussed herein.

[0338] In some embodiments, the swimming pool shell or spa shell is at least 2 years old, or at least 5 years old, or at least 10 years old.

[0339] In some embodiments, the swimming pool shell or spa shell is a fiberglass swimming pool shell or spa shell.

[0340] In some embodiments, prior to applying the coating composition, the surface of the aged swimming pool shell or spa shell has one or more of a faded appearance, loss of colour, a yellowed appearance, and microcracks. In some embodiments, the surface of the age swimming pool shell or spa shell contains microcracks.

[0341] In some embodiments, the process restores the original appearance of the swimming pool shell or spa shell. In some embodiments, the process restores the original colour of the swimming pool shell or spa shell. In some embodiments, the polyaspartic-based coating composition does not contain a pigment, and the process restores the original colour of the swimming pool shell or spa shell.

[0342] An exemplary process for coating a pool or spa shell with a polyaspartic-based coating to improve the visual appearance of microcracks in shown in Figure 1. In the image on the left, an untreated pool surface having microcracks is provided. In the centre image, the composition of the present disclosure is being applied to the surface, Without being bound by any particular theory, it is considered that the composition bother covers the surface but also penetrates and at least partially fills the microcracks. In the right image is shown the coated pool surface.

[0343] Examples of polyaspartic-based coating compositions used in the process of the disclosure include the following:

[0344]

[0345]

[0346]

[0347]

[0348] Examples of primer compositions used in embodiments of the process of the disclosure include the following:

[0349]

[0350] For example, a primer formulation such as that above may be particularly beneficial for, e.g. penetration into micro-cracks, colour restoration, and strong adhesion of polyaspartic topcoat.

[0351]

[0352]

[0353] Such a primer formulation may, for example be beneficial for achieving deep penetration into porous concrete, sealing the surface, and improving adhesion of a polyaspartic topcoat.

[0354] Numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. Accordingly, this invention is intended to embrace all alternatives, modifications and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above-described invention.

[0355] The present disclosure is further illustrated by the following non-limiting examples.

[0356] Example 1: Application of polyaspartic-based coating composition to aged pool surface A section of an 11 -year-old fiberglass pool shell was treated with a primer polyaspartic-based coating composition in accordance with the present disclosure, followed by treatment a topcoat composition which is a polyaspartic-based coating composition.

[0357] Figure 2 show the primer-treated section of the pool shell. It shows a control section, separated by a line of primer composition. As is evident from the Figure, treatment with the primer composition immediately returns the original colour to the sample, demonstrating thatthe colour has not faded but rather there are microcracks. The primer composition restores colour by filling microcracks and preventing light refraction over the microcracks.

[0358] Figure 3 shows the section of the pool after treatment with topcoat polyaspartic-based coating composition. Good adhesion of the composition to the aged pool shell surface was observed with good colour restoration.

[0359] Example 2: Application of polyaspartic-based coating composition to aged pool surface A section of an 11 -year-old fiberglass pool shell was treated with a polyaspartic-polyurea coating composition in accordance with the present disclosure.

[0360] Figures 4 and 5 show a treated section of the pool shell next to an untreated section of the pool shell. As is evident from the Figures, treatment with the polyaspartic-polyurea coating composition returns the original colour to the sample, demonstrating that the colour has not faded but rather there are microcracks. The polyaspartic-polyurea coating composition restores colour by filling microcracks and preventing light refraction over the microcracks.

Claims

Claims1. A process for coating at least part of a surface of a swimming pool shell or spa shell, including:applying a polyaspartic-based coating composition to at least part of a surface of a swimming pool shell or spa shell.

2. A process as claimed in claim 1, wherein the polyaspartic-based coating composition is a polyaspartic-polyurea coating composition.

3. A process as claimed in any preceding claim, wherein the polyaspartic-based coating composition comprises a solvent.

4. A process as claimed in any preceding claim, wherein the solvent is dimethyl carbonate, optionally in an amount of from 2 to 25% by weight of the composition.

5. A process as claimed in any preceding claim, wherein the polyaspartic-based coating composition provides a coating having one or more of the following properties when cured for 48 hours at 22°C and 50% relative humidity:a. a light transmittance value of at least 80% as assessed in accordance with ASTMD 1746: 2023;b. an elongation at break of at least 400% as assessed in accordance with ASTM D2370;c. passes a water immersion test with no corrosion and no blistering discernible by eye as assessed in accordance with ISO 2812-2;d. a QUV UV resistance value of at least 90% as assessed in accordance with ASTMD4587;e. resistance to salt spray exposure for at least 5000 hours with no corrosion and no blistering discernible by eye, as assessed in accordance with ASTM B 177; andf. chemical resistance of at least 1,500 methyl ethyl ketone double rubs, as assessed in accordance with ASTM D4752.

6. A process as claimed in claim 2, wherein the polyaspartic-polyurea coating composition is produced from a first composition comprising an isocyanate, and a second composition comprising a polyaspartic ester.

7. A process as claimed in claim 6, wherein the isocyanate is an aliphatic isocyanate.

8. A process as claimed in claim 7, wherein the aliphatic isocyanate is selected from the group consisting of hexamethylene diisocyanate, isophorone diisocyanate and xylene diisocyanate.

9. A process as claimed in any of claims 6 to 8, wherein the polyaspartic ester is produced from an alkyl maleate and a polyamine.

10. A process as claimed in claim 9, wherein the alkyl maleate is selected from the group consisting of dimethyl maleate or diethyl maleate.

11. A process as claimed in any of claims 6 to 10, wherein the polyaspartic ester is a diethyl aspartate or a dimethyl aspartate.

12. A process as claimed in any of claims 1 to 5, wherein the polyaspartic-based coating composition is a one-part polyaspartic-polyurea coating composition.

13. A process as claimed in claim 12, wherein the polyaspartic-polyurea coating composition is moisture-curing.

14. A process as claimed in claim 12 or 13, wherein the polyaspartic-polyurea coating composition comprises a polyaspartic-containing isocyanate-functional prepolymer comprising free isocyanate groups; and optionally one or more additives selected from an adhesion promoter, a catalyst, a UV stabiliser, a flow / levelling agent, a defoamer, an anti-mildew agent, and an alkali-resistance additive.

15. The coating composition of any one of claims 1 to 14, wherein the coating composition comprises a latent curing agent that hydrolyses in the presence of atmospheric moisture to release amine functionality, optionally wherein the latent curing agent is selected from aldimines, ketimines, oxazolidines, and mixtures thereof.

16. A process as claimed in any preceding claim, wherein the swimming pool shell or spa shell is a fiberglass shell.

17. A process as claimed in any preceding claim , wherein the swimming pool shell or spa shell is a concrete shell.

18. A process as claimed in any preceding claim, wherein the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition at the installation site.

19. A process as claimed in any preceding claim, wherein the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition in-ground.

20. A process as claimed in preceding claim, wherein the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition prior to installation on site.

21. A process as claimed in any preceding claim, wherein substantially all, or all, of the surface of the swimming pool shell or spa shell which in use is for contacting water, is coated with the polyaspartic-based coating composition.

22. A process as claimed in any preceding claim, wherein substantially all, or all, of the surface of the swimming pool shell or spa shell which in use is exposed to sunlight, is coated with the polyaspartic-based coating composition.

23. A process as claimed in any preceding claim, wherein substantially all, or all, of the surface of the swimming pool shell or spa shell is coated with the polyaspartic-based coating composition.

24. A process as claimed in any preceding claim, wherein, following application, the polyaspartic-based coating composition is allowed to cure, such that the at least part of the shell surface is coated with a cured polyaspartic-based coating composition.

25. A process as claimed in any preceding claim, wherein the polyaspartic-based coating composition is allowed to cure for a time period in the range of from 1 to 3 hours.

26. A process as claimed in any preceding claim, wherein the polyaspartic-based coating composition is allowed to cure at a temperature in the range of from 5 to 80 °C.

27. A process as claimed in any preceding claim, wherein multiple coats of the polyaspartic- based coating composition are applied.

28. A process as claimed in any preceding claim, wherein the polyaspartic-based coating composition comprises one or more additives selected from:- a reactive diluent;- a filler;- an adhesion promoter;- a catalyst;- a UV stabiliser;- a pigment;- an anti-slip additive;- coloured cosmetic particles; and- glitter and / or shimmer particles.

29. A process as claimed in any preceding claim, wherein the polyaspartic-based coating composition is spray-coated onto the surface of the swimming pool shell or spa shell.

30. A process as claimed in any preceding claim, wherein the polyaspartic-based coating composition is applied using a roller and / or brush.

31. A process as claimed in preceding claim, wherein prior to applying the polyaspartic- based coating composition, the surface of the swimming pool shell or spa shell is coated with a primer coat.

32. A process for preventing or retarding surface degradation of at least part of a surface of a swimming pool shell or spa shell, comprising applying a polyaspartic-based coating composition to at least a part of a surface of a swimming pool shell or spa pool shell.

33. A process for preventing or retarding loss of colour of at least part of a coloured surface of a swimming pool shell or spa shell, comprising applying a polyaspartic-based coating composition to at least part of a surface of a swimming pool shell or spa pool shell.

34. A process as claimed in claim 32 or 33, wherein the swimming pool shell or spa shell is a new swimming pool shell or spa shell.

35. A process for improving the appearance of at least part of a surface of an aged swimming pool shell or spa shell, comprising applying a polyaspartic-based coating composition to at least part of a surface of an aged swimming pool shell or spa shell.

36. A process as claimed in claim 35, wherein prior to applying the coating composition, the surface of the aged swimming pool shell or spa shell has one or more of: a faded appearance, loss of colour, a yellowed appearance, and microcracks.

37. A process as claimed in claim 35 or 36, wherein the process restores the original appearance of the swimming pool shell or spa shell.

38. A process as claimed in any of claims 32 to 37, wherein the swimming pool shell or spa shell is a fiberglass swimming pool shell or spa shell.

39. A swimming pool shell or spa shell whose surface is at least partially coated with a polyaspartic-based coating.

40. A swimming pool shell or spa shell as claimed in claim 39, wherein the surface is as least partially coated with a cured polyaspartic-based coating composition.

41. Use of a polyaspartic-based coating composition for coating at least part of a surface of a swimming pool shell or a spa shell.

42. Use of a polyaspartic-based coating composition for preventing or retarding surface degradation of at least part of a surface of a swimming pool shell or spa shell.

43. Use of a polyaspartic-based coating composition for preventing or retarding loss of colour of at least part of a surface of a swimming pool shell or spa shell.

44. Use of a polyaspartic-based coating composition as a protective coating for a swimming pool shell or spa shell surface.

45. Use of a polyaspartic-based coating composition for improving the appearance of at least part of a surface of an aged swimming pool shell or an aged spa shell.

46. Use of a kit for producing a polyaspartic-based coating composition for use in a process according to any of claims 1 to 38, or in a use according to any of claims 41 to 45, the kit comprising:a first composition comprising an isocyanate; anda second composition comprising a polyaspartic ester.

47. Use according to claim 46, wherein the first composition and second composition are mixed to form a polyaspartic-based coating composition, and then applied to at least part of the surface of a swimming pool shell or spa shell.

48. A one-part polyaspartic-based coating composition comprising components for forming a polyaspartic-based coating and dimethyl carbonate.

49. A one-part polyaspartic based coating composition as claimed in claim 48, whererein the composition comprises components for forming a polyaspartic-polyurea coating composition.

50. A one-part polyaspartic-based coating composition as claimed in claim 48 or 49, wherein, the composition comprises from 2 to 25% by weight of dimethyl carbonate.

Images