Multi-component water-based coating systems which can be applied as an aerosol

Abstract

This invention relates to a multi-component water-based coating system that can be applied in aerosol form. It also describes a coating film obtained by applying the multi-component water-based coating system to a road surface in aerosol form, and the use of the coating film in horizontal road markings.

Description

Technical Field

[0001] This invention relates to a multi-component water-based coating system that can be applied in aerosol form. It also describes a coating film obtained by applying the multi-component water-based coating system to a road surface in aerosol form, and the use of the coating film in horizontal road markings. Background Technology

[0002] Horizontal road markings originated in the early 20th century and have served various purposes: from optical orientation tools to traffic flow regulators; from informing drivers of impending dangers to driving restrictions.

[0003] Therefore, horizontal road markings play a major role in reducing the number of deaths and injuries on the road.

[0004] Therefore, both road users and road management authorities require road markings to be efficient and durable. From the user's perspective, color and brightness contrast with the road surface are characteristics that should be maximized (Horberry et al., Transportation Research Part F: Traffic Psychology and Behaviour, 2006, 9(1):77-87). Road managers' choice of road marking material types depends on many factors, including expected duration, required visibility, price, and local regulations.

[0005] Horizontal road markings are typically made up of a coating containing or excessively deposited (drip-type) reflective material (most commonly, glass beads).

[0006] Besides durability and functionality, ease of application and impact on human health and the environment are also key considerations in road marking selection. Horizontal road marking paint systems can be categorized as: two-component materials based on epoxy resins, polyurethanes, or unsaturated acrylics, which cure due to a chemical reaction at the application site; thermoplastic powders based on hydrocarbon or alkyd resins, which require heat for application to road surfaces; paints that dry after evaporation from a solvent medium; and water-based paints that cure at the application site due to the loss of a neutralizing agent (e.g., ammonia).

[0007] Thermoplastic materials are essentially solvent-free, and although some of the resins required to produce these materials come from renewable natural resources, the need for dual heating (production-application) significantly increases their environmental impact.

[0008] Some two-component systems also require heating and have toxicity issues related to the use of epoxy resins, isocyanates, or acrylic monomers, as well as hazardous issues due to the use of organic peroxides as in-situ reaction catalysts.

[0009] In the case of solvent-based coatings (solvent-based), these products traditionally include various types of organic adhesives soluble in organic solvents: alkyd adhesives, alkyd adhesives combined with chlorinated rubber, or acrylic adhesives. The solvent phase of this system allows a large amount of VOCs (volatile organic compounds) to be released into the atmosphere.

[0010] These exhaled environmental impacts are significantly aggravated by the photochemical decomposition of these substances in the atmosphere.

[0011] During the decomposition of these substances in the atmosphere, VOCs interact with nitrogen oxides (NOx), significantly increasing ozone formation. Ground-level ozone is a significant lung irritant and is recognized worldwide as one of the main pollutants contributing to smog.

[0012] On average, solvent-based paints used for road markings exhibit poor stability over time, and these products can indeed show problems with deposition and increased viscosity. Applying solvent-based products produces a coating thickness of no more than 400 µm. In fact, thicker films tend to form a skin layer that slows down coating evaporation, thus requiring a much longer drying time, even under favorable conditions.

[0013] Solvent-based coatings can be applied at room temperatures ranging from 5°C to 40°C and at surface temperatures below 50°C. The drying of these coatings is greatly affected by air, surface temperature, the structure of the film being applied, and the mixture of solvents used.

[0014] Conversely, compared to other materials, water-based coatings significantly reduce the impact on human health and the environment.

[0015] Therefore, environmental concerns have led paint manufacturers to favor water-based products.

[0016] In the early 1980s, the first water-based coating product was launched in the United States.

[0017] These products are very similar to solvent-based coatings. Their sizing is solely related to the loss of the solvent phase (water), which automatically leads to drying (varnish coatings). However, they suffer from long drying times and concurrent erosion resistance issues, which are heavily influenced by weather conditions.

[0018] Therefore, in the 1990s, a so-called "quick-set" technology was introduced, which introduces ammonia into the polymer to form the binder portion of these water-based coating products. The polymer irreversibly solidifies as the pH drops due to ammonia evaporation.

[0019] International patent application WO2022 / 112958, filed in the name of the applicant, describes a fast-curing waterborne coating composition that can withstand adverse environmental conditions such as snowfall and heavy rain, while maintaining the abrasion resistance, excellent visibility and anti-slip properties that can be obtained using conventional solvent-based or thermoplastic products, but with low environmental impact.

[0020] This innovation has shown significant effectiveness in improving the film-forming rate of coatings; however, for rates exceeding 800 g / m², it remains effective. 2 The amount of paint product applied is unfavorable.

[0021] In tenders requiring coating durability over time (2 / 4 years), applications exceeding 800 g / m² are required. 2 The coating products are used to produce high-thickness coatings.

[0022] International patent application PCT / IB2023 / 055322, filed in the applicant's name, describes a process that allows for the formation of high-thickness films (≥ 800 g / m²). 2 A new type of water-based product with coating durability that extends over time (2 / 4 years and longer).

[0023] In particular, international patent application PCT / IB2023 / 055322 describes a spraying system characterized by each component being selected from the following, expressed as a percentage by weight relative to the total weight of the components: 1) The acrylic acid content is between 55% and 75%, preferably 60-70%; 2) The epoxy component is between 15% and 30%, preferably 17-22%; and 3) The epoxy polyamine component is between 3% and 18%, preferably 10-15%.

[0024] Public opinion, particularly the growing environmental awareness of government organizations representing public opinion, has sparked a process of "finding alternatives," which is increasingly attracting the attention of contractors and operators in the industry.

[0025] Therefore, the necessity of providing new water-based coating products is obvious. Summary of the Invention

[0026] The object of this invention is to provide a new water-based coating product that allows the formation of a low-thickness film (between 200 µm and 400 µm) and can be applied in the form of an aerosol.

[0027] Another object of the present invention is to provide new coating products that have high reflectivity and durability against road wear.

[0028] Advantageously, applying a "thin" but high-performance coating significantly reduces the cost of horizontal road markings and significantly reduces the environmental impact of the system.

[0029] The main objective described above is achieved by the multi-component water-based coating system according to claim 1, the use of the multi-component water-based coating system according to claim 16 in horizontal road markings, the coating according to claim 17, and the method for reducing curing time according to claim 19. Attached Figure Description

[0030] Figure 1 A diagram of the application system according to the invention using two aerosol dispensers, the two aerosol dispensers causing the product streams to cross, thereby depositing onto the surface.

[0031] Figure 2 A diagram of an alternative application system according to the invention using a single aerosol dispenser, the single aerosol dispenser being fed a ternary mixture generated between arrivals at the dispenser.

[0032] Figure 3 This figure compares the reference coating composition (dashed line) according to International Patent Application WO2022 / 112958 with the multi-component coating system of Example 1 of the present invention (solid line).

[0033] Figure 4 This figure compares the reference coating composition (dashed line) according to International Patent Application WO2022 / 112958 with the multi-component coating system of Example 4 of the present invention (solid line).

[0034] Figure 5 The figure compares the reference coating composition (dashed line) according to International Patent Application WO2022 / 112958 with the multi-component coating system of Example 6 of the present invention (solid line).

[0035] definition Unless otherwise defined, all technical terms, symbols, and other scientific terms used herein are intended to have the meaning commonly understood by one of ordinary skill in the art to which this disclosure pertains. In some instances, terms with commonly understood meanings are defined herein for clarity and / or for timely reference; therefore, the inclusion of such definitions in this disclosure should not be construed as representing a material difference from the meaning commonly understood in the art.

[0036] The terms “approximately” and “about” used in this article refer to the range of experimental error inherent in performing experimental measurements.

[0037] The terms “contains,” “has,” “includes,” and “contains” are intended to be open-ended terms (i.e., meaning “includes but not limited to”) and are also considered to be support for terms such as “consist essentially of,” “consisting essentially of,” “consist of,” or “consisting of.”

[0038] The terms “consist essentially of” and “consisting essentially of” are intended to be semi-closed terms, meaning that other components that affect the novel features of the invention are not included (therefore optional excipients may be included).

[0039] The terms “consists of” and “consisting of” are intended to be closed terms.

[0040] The term "acrylic polymer" is intended to refer to either pure acrylic polymer or styrene-modified acrylic polymer.

[0041] The term "anionic stabilization" is intended to indicate that the polymer carries an anionic charge in the chain (e.g., R-COO). - The functional group of the anion, wherein the charge of the anion is counteracted by the cation (e.g., NH4). + Neutralization. After neutralization, the anionic functional groups impart sufficient polarity to the system, which is essential for stabilizing suspensions of polymer colloidal particles. The release of counteracting cations (volatile bases) destabilizes the colloidal suspension and subsequently coagulates, thus initiating particle aggregation.

[0042] The term "volatile alkali" is intended to indicate an alkali that evaporates in sufficient quantities under dry air conditions to be released.

[0043] The term "epoxy polyamine component or epoxy polyamine adduct" is intended to indicate a polymer containing at least four of the following blocks: - The bifunctional epoxy block determines the linear skeleton of the final compound; a typical example is the diglycidyl ether of bisphenol A and F, such as resins like Ankarez. Araldite Bekopox Epikote Epiox Eponac Eposir Epotec Epon ; - Alkylamines with straight or branched C1-C6 aliphatic chains that introduce hydrophobic properties; - Polyetheramines (based on propylene oxide (PO), ethylene oxide (EO), or combinations thereof) that incorporate hydrophilic properties, a typical example being Jeffamine. Polyetheramine; - Chain terminator, wherein the chain terminator may be an amino or amide-amino chain terminator.

[0044] In this context, the term "C1-C6 alkyl" refers to a branched or straight-chain hydrocarbon containing one to six carbon atoms. Examples of C1-C6 groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, and n-hexyl.

[0045] The term "high-boiling-point glycol ether" is intended to indicate compounds with boiling points between 225°C and 250°C.

[0046] The term "self-crosslinking functional group" is intended to indicate the reactive functional group of the polymer required for the curing / crosslinking process (polymerization / condensation) of the polymer without the need for further addition of reagents.

[0047] The term "minimum film-forming temperature" is intended to refer to the lowest film-forming temperature (MFFT) of a coating or paint, and is the lowest temperature at which a product condenses into a homogeneous and transparent film when applied to a substrate.

[0048] The two main international standards used to measure MFFT are: ASTM-D2354 - Standard test method for minimum film-forming temperature (MFFT) of emulsifiers.

[0049] ISO 2115:1996: Plastics—Polymer dispersions—Determination of white point temperature and minimum film-forming temperature.

[0050] The term "multi-component coating system" is intended to refer to a coating system consisting of two or more components that are mixed together during use.

[0051] The term "high thickness" is intended to indicate 800 g / m or greater. 2 Preferably between 800 g / m 2 With 2000 g / m 2 The thickness between.

[0052] The term "low thickness" is intended to indicate a thickness equal to or less than 400 µm, preferably between 200 µm and 400 µm.

[0053] The term "hardener component" is intended to indicate a chemical product added to a coating (a two-component or multi-component product) to induce a chemical curing reaction (polymerization). Detailed Implementation

[0054] The object of this invention is represented by a multi-component water-based coating system, the multi-component water-based coating system comprising: - An acrylic component comprising an aqueous emulsion of an acrylic polymer, the aqueous emulsion of the acrylic polymer being stabilized with a volatile base anion at an alkaline pH and containing self-crosslinking functional groups, preferably, the acrylic component being supplemented with a high-boiling-point ethylene glycol ether, and the amount of the acrylic component relative to the total weight of the component being between 76% by weight and 90% by weight, preferably between 77% by weight and 82% by weight; - A hardener component comprising liquid epoxy resin or water-soluble polyisocyanate resin or a mixture thereof, wherein the amount of the hardener component is between 5% by weight and 15% by weight, preferably between 8% by weight and 14% by weight, relative to the total weight of the components. - The amount of the epoxy polyamine component relative to the total weight of the components is between 5% by weight and 14% by weight, preferably between 7% by weight and 10% by weight, and more preferably, the epoxy polyamine component contains polythiol.

[0055] Preferably, the minimum film-forming temperature (MFFT) of the acrylic polymer is between 0°C and 40°C, and more preferably between 10°C and 20°C.

[0056] Preferably, the acrylic polymer is anionicly stabilized at an alkaline pH between 8 and 11.

[0057] Preferably, the acrylic polymer is in the form of anionic colloid.

[0058] Preferably, the volatile base that can be used in this invention is selected from ammonia, morpholine, 2-methylaminoethanol, 2-dimethylaminoethanol, N-methylmorpholine, and ethylenediamine. More preferably, ammonia.

[0059] Self-crosslinking functional groups are obtained by introducing monomers or external reagents into the chain according to the following scheme, wherein the monomers or external reagents have reactivity attributable to Michael synthesis (diketoyl groups with amines or diketoyl groups with hydrazides):

[0060] Preferably, the most widely used reaction system for the functionalization of acrylic polymers is the diacetone-acrylamide and adipic acid dihydrazide (DAAM-ADH) system (diacetone-acrylamide, DAAM, and adipic acid dihydrazide (ADH)).

[0061] The diketone functional group of an acrylic polymer (e.g., DAAM) reacts with an amine or hydrazine (e.g., ADH) added externally to the polymer.

[0062] In a preferred embodiment, the acrylic polymer containing self-crosslinking functional groups further comprises a polyamine polymer having a coagulant function. The polyamine polymer has properties different from those of epoxy polyamine adducts; preferably, the polyamine polymer is polymerized from a mixture of monomers comprising at least one acid monomer and at least one amine monomer.

[0063] The acid monomers suitable for preparing polyamine polymers are acrylic acid, methacrylic acid, and mixtures thereof.

[0064] Some amino monomers suitable for preparing polyamine polymers include alkylaminoalkyl esters or amides of unsaturated acids (such as acrylic acid or methacrylic acid).

[0065] Polyamine polymers can be mixed with acrylic polymers, or the two polymers can be crosslinked together.

[0066] Examples of polyamine polymers that can be used in this invention and are commercially available are described in European patent applications EP0409459, EP0811663 and EP0832949, the contents of which are hereby incorporated by reference in their entirety.

[0067] While the inventors do not wish to be bound by any explanatory theory, it is believed that the loss of ammonia due to evaporation upon contact with air triggers the reactivity of the coagulant polymer, which neutralizes the stable anionic charge on the colloidal surface through protonation. The coagulant polymer causes a rapid loss of sensitivity to water during the initial drying stage (early rain resistance).

[0068] Preferred examples of acrylic polymers that can be used in this invention and are commercially available include the following products:

[0069]

[0070] Preferred acrylic polymers are E5, E17, E25, E30, E31, E34 and E35.

[0071] In a preferred embodiment, the acrylic component is added together with a high-boiling-point glycol ether.

[0072] For the purposes of this invention, the following high-boiling-point ethylene glycol ethers (illustrated only, but not limited to): diethylene glycol monobutyl ether (DB), dipropylene glycol n-butyl ether (DPnB), propylene glycol phenyl ether (PPh), and tripropylene glycol monomethyl ether (TPM) may be used.

[0073] Preferred examples of high-boiling-point glycol ethers that can be used in this invention and are commercially available are DB and DPnB.

[0074] In the coating system according to the present invention, high-boiling-point glycol ethers function as coagulants.

[0075] Advantageously, the addition of a coagulant helps the polymer form a film in colloidal form and adequately regulates the drying time of the applied coating.

[0076] Coagulation causes the polymer to precipitate and separate from the aqueous medium, which remains free to evaporate. The coagulated polymer reaches the intercolloidal distance (between particles) required for the coagulation process to occur more quickly.

[0077] The direct consequence of this acceleration is a faster loss of water sensitivity (erosion resistance). Full settling and the final properties of the membrane still depend on the intrinsic reactivity of the polymer expressed during the crosslinking process.

[0078] In a preferred embodiment, the liquid epoxy resin according to the invention is in the form of an emulsion or is emulsifiable.

[0079] Epoxy resins can be obtained by the condensation of epichlorohydrin and bisphenol.

[0080] The ratio of these two components determines the extension of the epoxy chain and the residual reactive glycidyl group, i.e., the chain terminator.

[0081] The smallest unit produced by this condensation reaction (polymerization) is a diglycidyl ether of bisphenol F or A.

[0082]

[0083] Bisphenol A diglycidyl ether

[0084] Bisphenol F diglycidyl ether A more detailed description of the chemiphysical properties that distinguish the epoxy resin in the “waterborne dispersion / emulsion” is provided in document “3.2.2 Waterborne Two-Component Epoxy Coatings”. Water-borne two-component epoxy paints Pages 200-206; Vincentz Network 2012 report.

[0085] In another preferred embodiment, the liquid epoxy resin according to the invention comprises a molecular structure containing one to three bisphenol groups in the chain and diglycidyl ether ends with the following structural formula:

[0086] The chemical reactivity of these polymers depends directly on the amount of ethylene oxide groups (glycidyl ethers) present in the chain.

[0087] This quantity is typically expressed in epoxy resin equivalent (EEW), which is expressed in grams per equivalent of solid resin.

[0088] Examples of commercially available epoxy resins suitable for the purposes of this invention in aqueous dispersions are as follows: Olin epoxy resin: DER™ 913, EEW 167 - 193 Olin epoxy resin: DER™ 915, EEW 475-500 Olin epoxy resin: DER™ 917, EEW 193 - 204 SIR: WD 733 / 67, EEW 185 - 195 Huntsman: Araldite PZ 756-1 / 67, EEW 270 - 295 Huntsman: Araldite PZ 3961-1, EEW 450 - 510 Huntsman: Araldite PY 33757, EEW 172 - 182 Huntsman: Araldite PZ 323, EEW 222 - 250 Huntsman: Araldite PY 3961-1, EEW 450 - 510 Evonik: ANCAREZ AR555, EEW 500 - 550 Hexion: EPI-REZ™ Resin 7510-W-60, EEW 462 - 536 Hansen: EPI-REZ™ Resin 7723-W-53, EEW 185 - 215 Hansen: EPI-REZ™ 6520-WH-53, EEW 500 - 600 In another preferred embodiment, the epoxy resin equivalent (EEW) of the liquid epoxy resin according to the invention, expressed as grams / equivalents based on solid resin, is between 170 and 300, more preferably between 200 and 250.

[0089] More preferably, the epoxy resin suitable for the purposes of this invention in the aqueous dispersion is: Olin epoxy resin: DER™ 917, EEW 193 - 204 SIR: WD 733 / 67, EEW 185 - 195 Huntsman: Araldite PZ 756-1 / 67, EEW 270 - 295 Hansen: EPI-REZ™ Resin 7723-W-53, EEW 185 - 215 In another preferred embodiment, the water-soluble polyisocyanate resin used in this invention is the resin described in patent US9975985B2.

[0090] Examples of commercially available products relating to water-soluble polyisocyanate resins suitable for the purposes of this invention are as follows: - Phosphate-based hydrophilic polyisocyanates; as described in EP2212368B1

[0091] - Aminosulfonic acid modified polyisocyanates; as described in EP3045485B1

[0092]

[0093] - Polyacrylate-modified polyisocyanate; as described in EP1788008B1

[0094] - Other hydrophilic polyisocyanates

[0095] In a preferred embodiment, liquid epoxy resin and water-soluble polyisocyanate resin are present in the curing agent component in a 1:1 ratio.

[0096] For the purposes of this invention, epoxy polyamine adducts having a structure that can be represented as shown in the following diagram can be used as epoxy polyamine components:

[0097] Specifically:

[0098] Where n is between 1 and 15, R1, R2, R3e, and R4 are the same or different, and are independently selected from H, alkyl, amine, or amide groups.

[0099] AR is mainly composed of aromatic diphenyl groups, wherein R is composed of =C(-CH3)2 (bisphenol A)o da-CH2- (bisphenol F), and the aromatic diphenyl groups are combined with a small percentage of straight-chain or branched alkyl groups.

[0100] In the structure under discussion, the H groups of HNR1R2 and HNR3R4 are presented, which will react with the adjacent ethylene oxide group to produce an "adduct": R1R2N-adduct-NR3R4.

[0101] Specifically:

[0102] Epoxy polyamine adducts can be prepared by the following: a) at least one biepoxide compound, preferably a diglycidyl ether of bisphenol A and F; b) At least one alkylamine, said at least one alkylamine having a straight-chain or branched C1-C6 aliphatic chain; c) At least one polyetheramine based on propylene oxide (PO), ethylene oxide (EO), or a combination thereof; d) At least one amino or amide-amino chain terminator.

[0103] Typical examples of biepoxide compounds are diglycidyl ethers of bisphenol A and F, such as resins like Ankarez. Araldite Bekopox Epikote Epiox Eponac Eposir Epotec Epon .

[0104] Polyethoxylated or polypropoxylated amines that can be used (e.g., Jeffamine) Some examples are: Polyoxyethylene monoamine (diamine or polyamine)

[0105] Polyoxypropylene diamine (or polyamine)

[0106] Polyoxyethylene / propylene diamine (or polyamine)

[0107] Epoxy polyamine adducts are described in the following references: 1) Binder systems for waterborne two-pack products for car refinishes application. Progress in Organic Coatings 48 (2003) 153-160.

[0108] 2) EP 1 280 842 B1; 3) OD / Coatings Manual 2011, Appendix “C”, Page 5: Curing Agent for Epoxies; “Polyamine adducts”.

[0109] Preferred examples of epoxy polyamine adducts that can be used in this invention and are commercially available include the following products:

[0110]

[0111] Preferred epoxy polyamine adducts are PA30, PA31, PA32, PA35, PA40, PA42, PA44, and PA46. PA30, PA35, PA40, and PA46 are the epoxy polyamine adducts that produce optimal results.

[0112] In a preferred embodiment, the epoxy polyamine component contains polythiol.

[0113] The polythiol according to the present invention is a molecular structure derived from the esterification reaction of thiocarboxylic acids and polyols.

[0114] The condensation (esterification) of mercaptocarboxylic acids with the hydroxyl groups of polyols produces a molecular structure with reactive -SH (thiol group or thioalkyl) terminals.

[0115] Examples of commercially available molecular structures that can be used in this innovation are:

[0116] Trimethylolpropane tris(3-mercaptopropionate)

[0117] Pentaerythritol tetra(3-mercaptopropionate)

[0118] 2-Hydroxymethyl-2-methyl-1,3-propanediol tris(3-mercaptopropionate) The chemical reactivity of these polymers depends directly on the amount of available thiol groups present in the chain.

[0119] The amount of available thiol groups present is expressed as a percentage (by weight) based on the overall molecular structure.

[0120] In a preferred embodiment, based on the overall molecular structure, the available thiol value of the polythiol molecular structure (suitable for the purposes of this invention) is between 7% by weight and 27% by weight.

[0121] Examples of commercially available polythiol molecular structures that can be used in this innovation are:

[0122] Based on the overall molecular structure, the preferred polythiol molecular structure has a percentage of available thiols ranging from 12% to 27% by weight.

[0123] More preferably, the polythiol that can be used in this innovation is:

[0124] In the coating system according to the present invention, the epoxy polyamine component has the function of making polythiol emulsifiable.

[0125] The epoxy polyamine adducts of the present invention possess specific properties that function as surfactants / emulsifiers. The hydrophobic component (bisphenol) of its molecular structure is facilitated by hydrophilic polyether chains (e.g., Jeffamine). The hydrophilic polyamine group and the hydrophilic polyamine group are balanced, so that the final molecule achieves hydrophilic-lipophilic balance (HLB).

[0126] Epoxy polyamine adducts draw polythiols (insoluble in water) into aqueous emulsions, thereby delivering them to their final products.

[0127] By introducing a second hardener with thiol (thioalkyl) properties into the reaction system, deep polymer crosslinking is accelerated (curing time), and the resulting product can be classified in the category of "fast-drying waterborne systems," which is typical of paint products used in the workplace for applying horizontal road markings.

[0128] The polythiol and epoxy components require catalysis (Lewis base) to fully utilize the high polymerization rate. The basic catalysis (tertiary amine) already present in this invention is provided by the epoxy amine component, which is used in combination with the high-boiling-point glycol ether.

[0129] The thiol anion is a much stronger nucleophile than the starting thiol and is significantly more reactive. The presence of the thiol anion in the system is obtained through the association of thiols in the presence of basic catalysis (tertiary amine-ammonium ion).

[0130]

[0131] According to the present invention, the water-based coating system may contain one or more components selected from the following: pigments, fillers, antibacterial agents and other specific additives.

[0132] Preferably, one or more components are added to the acrylic component.

[0133] Pigments are crucial for the desired coloring of the final coating. Pigments can be selected based on both their formulation and application characteristics and their behavior / performance characteristics within the final coating. For formulation / production, micronized pigments that can be dispersed in aqueous media without significant shear stress are preferred. Regarding final performance, alkaline materials exhibiting excellent color reproduction and retention during exposure to external reagents are preferred. Examples of pigments that can be used in this invention include titanium dioxide, namely Yellow 65 (CAS 652-34-3); Aryl Yellow 74 (CAS 6358-31-2); Anthrone Red 168 (CAS 4378-61-4); Phthalocyanine Green 7 (CAS 1328-53-6); and Phthalocyanine Blue 15 (CAS 147-14-8).

[0134] Chain extenders of various properties are selected to optimize the rheological and physical properties of the coating and, where possible, control the costs determined by dyeing. Preferred chain extenders for rheology adjustment are micronized minerals with low oil absorption. Specific gravity and particle size will affect the product's settling and abrasion resistance in the can. Other chain extenders that can positively influence the coating's duration include micronized silicates, which partially interfere with polymer film formation. Examples of chain extenders that can be used in this invention are carbonates (CaCO3), barium sulfate, and silicates such as kaolin, mica, talc, and silica.

[0135] The coating system according to the invention may include additional specific additives, the purpose of which is to optimize the coating product during the production process and to optimize its behavior during the application and drying stages. Examples of specific additives are dispersing additives, defoaming additives, anionic and nonionic surfactants, and rheology modifiers.

[0136] Dispersing additives such as chain extenders and polyacrylates in the pigment dispersion stage.

[0137] Surfactants of various properties are used to regulate the surface tension of a system, thereby helping the dispersant to “wet” the chain extender during dispersion and improving the applicability of the product on the surface to be coated (surface wetting).

[0138] It can be used as a defoaming additive in all processes that can stabilize foam generation.

[0139] Antimicrobial agents are additives designed to prevent the development of bacterial contamination (such as mold). The selection of appropriate additives is preferably based on the properties of the binder and is tested in stability tests of the canned product over time.

[0140] Examples of commercially available antimicrobial agents include: 1-(3-chloroallyl)-3,5,7-triaza-1-azamonoadamantane chloride in combination with a stabilizer (sodium bicarbonate), namely DOWICIL 75 from Dow Chemical Company, or a 20% aqueous solution of dipropylene glycol containing 1,2-benzisothiazolin-3-one, namely Proxel GXL from Lonza.

[0141] In a preferred embodiment, the multi-component water-based coating system according to the present invention contains water in the range of 20% to 40% by weight. Preferably, the content is between 25% and 35% by weight.

[0142] Another object of the present invention is represented by the use of the multi-component water-based coating system according to the invention for horizontal road markings.

[0143] Another object of the present invention is represented by a coating film obtained by applying a multi-component water-based coating system according to the present invention to a road surface in the form of an aerosol, followed by evaporation of the aqueous medium.

[0144] Another object of the present invention is represented by a method for reducing the curing time of horizontal road markings on a road surface, the method comprising: i. Mix the three components of the water-based coating system according to the present invention; ii. Apply a layer of the water-based coating composition thus obtained to the road surface in the form of an aerosol; or i. Mixing the acrylic component according to the invention with the epoxy polyamine component, and atomizing the resulting mixture; simultaneously atomizing the hardener component according to any one of the inventions; ii. The atomized components obtained in the previous step are mixed, and a layer of the atomized mixture is applied to the road surface in the form of an aerosol; and iii. Evaporate the aqueous medium from the layer to form the wear-resistant horizontal road markings on the road surface.

[0145] Preferably, the mixing of the atomized components in alternative step ii is achieved in the "aerosol" stream.

[0146] The solution requires vehicles (trucks, vans, or motorized sprayers) used for applying road marking coatings to be equipped with two separate tanks and two volumetric pumps. Component "A" (acrylic acid) and component "B" (epoxyamine) are mixed in the first tank, while component "C" (epoxy resin) is introduced into the second tank. Two proven functional alternatives for application are: 1) Two aerosol dispensers (spray guns) are used to cross the product flow for deposition. On the surface ( Figure 1 ).

[0147] The mixture of components A + B is pumped from the first tank toward the main distributor and applied to the substrate through the main distributor. Component C is pumped from the second tank toward the second distributor. The latter directs its jet onto the jet generated by the main distributor. The mixing, occurring in the form of an "aerosol" stream, has proven satisfactory.

[0148] The coating system "1" is easy to use because it requires no operator intervention in cleaning pipes or valves in a specific manner. The equipment is complex and cumbersome to engineer because the self-propelled vehicle needs to carry two complete binary coating systems. This solution is ideally suited for large vehicles.

[0149] 2) Using a single aerosol dispenser, the single aerosol dispenser feeds between the same dispenser. The resulting ternary mixture ( Figure 2 ).

[0150] The mixture of components A + B is pumped from the first tank toward the main distributor and applied to the substrate through the main distributor. Component C is pumped from the second tank toward a valve (premix) located on a conduit that carries mixture A + B to the distributor. The latter directly applies the mixture of the three components.

[0151] The "reactive" mixture remains in the short section from the "premix" valve to the dispenser for a few seconds without causing clogging problems. In this case, the premixing that occurs within the valve also proves satisfactory.

[0152] The application system "2" requires careful maintenance of the final section from the premixing valve to the dispenser. Each time an application operation is stopped for more than the in-vessel life of the ternary mixture, the operator needs to intervene by carefully cleaning this section. The equipment engineering is simpler and less cumbersome because component "C" will be added in a relatively small dose and will not require a large-volume pump and head, nor a second dispenser tangential to the first dispenser for self-propelled vehicles (trucks). In this case, the solution can be used for relatively small vehicles.

[0153] Comparison of application tests using the two different application methods showed no significant differences. Evaluation and characterization of the two produced coatings yielded similar results.

[0154] In a preferred embodiment, by inserting a system for moving heated air into the application process of the present invention, a traffic resistance time close to that obtained with a "thermoplastic" coating product is achieved, wherein the heated air contacts the surface of a coating applied with a low thickness.

[0155] The drying rate of the applied road marking coating represents the "performance theme," which directly impacts the cost-effectiveness of the construction process on road sections. The shorter the drying time of the road marking coating, the higher the productivity of the application process.

[0156] To accelerate drying, the present invention requires an energy supply; however, the heat involved is much lower than that required for the application of "thermoplastic" coating products and can be sustained by renewable energy (electricity).

[0157] The multi-component water-based coating system according to the present invention preferably contains a water content between 20% by weight and 40% by weight. More preferably, the water content is between 25% by weight and 35% by weight.

[0158] During the drying phase, water leaves the coating through evaporation. The duration of the evaporation process is a function of ambient temperature, relative humidity, and air movement over the coating surface.

[0159] According to drying tests conducted by the inventors, it is understood that the drying process achieved by applying the innovative product EXP00C49 does not require the complete loss of water to make it suitable for driving on a car.

[0160] This fact allows for the use of external renewable energy sources to accelerate the drying process, which influence the surface of the coating, temperature, and air movement. The result is an improvement in the time required to produce a road marking coating suitable for use by vehicles.

[0161] After the coating product is applied, glass beads, preferably glass beads of different particle sizes, can be deposited on the surface. The purpose of the glass beads is to reflect the tangential light of the headlights of vehicles traveling along the road in this way, so as to improve the poor visibility of horizontal road markings in the dark.

[0162] The theoretical principle of retroreflectivity induced by glass beads on marking coating stripes has been extensively and thoroughly described in the following literature: 1952 Pocock BW, Rhodes CC: The principle of glass bead reflection ( Principles of glass-bead reflectorization). Highway Research Committee Bulletin ( Highway Research Board Bulletin )》, 57, 1952, 32-48 .

[0163] Further theoretical analysis shows that glass beads with a refractive index (RI) of 1.5 and 59% of their diameter embedded in the coating allow for the highest retroreflection when the angle between the incident and reflected light is between 0° and 3°.

[0164] The glass beads are preferably spherical in shape and have a smooth surface. Recycled glass is preferably used.

[0165] In a preferred embodiment, the refractive index of the glass beads is between 1.45 and 2.2, preferably between 1.5 and 2.

[0166] In another preferred embodiment, the average diameter of the glass beads is between about 100 μm and 850 μm.

[0167] In another preferred embodiment, 50% to 80%, preferably 50% to 60%, of the glass bead diameter is embedded in the coating.

[0168] Glass beads are typically prepared in a vertical furnace by flame quenching at approximately 1200°C from recycled, ground window glass (refractive index RI equal to 1.5), and can yield a white marking coating with an initial RL of approximately 350 mcd / m² / lx.

[0169] An example of a commercially available glass bead suitable for the purposes of this invention is the product Echostar. : 63-212, 125-710, 125-850, 125-1180, 212-1180, 212-1400, 300-600.

[0170] The following examples are intended to further illustrate the invention, but do not limit the invention.

[0171] Example Material Table 1 - Composition of coating products according to international patent application WO2022 / 112958 (reference)

[0172]

[0173] Table 2 - Composition of the multi-component coating products according to the present invention

[0174]

[0175]

[0176]

[0177]

[0178]

[0179]

[0180]

[0181]

[0182]

[0183]

[0184] method Standard tests for the abrasion resistance of coating products using TABER equipment (ASTM D4060). Use TABER (Test method for the wear resistance of organic coatings using an abrasion tester) . The coating product is applied to a special board, which, after undergoing a complete drying process, is placed on a machine that performs controlled abrasion using a C17 type abrasion wheel (coarse abrasion machine) with a total additional weight of 500 g added to the horizontal axis.

[0185] Each wear test lasted for 5,000 revolutions.

[0186] Weight loss observed after testing each sample was reported as a percentage relative to the standard coating (glass beads).

[0187] Retroreflectivity (RL) (EN 1436 standard, ASTM E 1710) The retroreflectometer simulates the nighttime retroreflection (RL) conditions of horizontal road markings encountered by a driver of a motor vehicle when available illumination is provided by vehicle headlights, i.e., nighttime type headlights. The instrument is capable of measuring the nighttime retroreflectance (RL) of horizontal road markings on a perfect scale.

[0188] The observation angle of 2.29° corresponds to a vehicle observation distance of 30 m under normal conditions. The illumination angle is 1.24°.

[0189] Figure 3 The relationship between the number of wear cycles the coating underwent and the detected residual retroreflectivity value was depicted. Each wear test (cycle) lasted for 5,000 revolutions.

[0190] The figure compares a reference coating composition (dashed line) according to international patent application WO2022 / 112958 with a multi-component coating system (solid line) according to Example 1 of the present invention.

[0191] The figures clearly illustrate that the multi-component coating system of the present invention maintains high reflectivity retention and extended coating durability over time under road wear, even when applied at a thickness of up to 400 µm.

[0192] Compared with the reference coating composition (dashed line) according to International Patent Application WO2022 / 112958, the same results were also obtained using the multi-component coating systems (solid line) according to Examples 4 and 6 of the present invention. Figure 4-5 ).

[0193] Surprisingly, the inventors have thus discovered that the multi-component water-based coating system of the present invention has significant advantages: - Installation advantages: The application system is simple and fast (low labor costs).

[0194] - Environmental Management: Water-based system. It requires no washing solvents, produces no toxic / hazardous waste, and generates no atmospheric emissions harmful to workers and the environment.

[0195] - Even at very low thicknesses, it achieves retroreflectivity durability over time that is difficult to achieve with thermoplastic technology, even at high thicknesses.

[0196] - Cost-effectiveness: The cost of applying a thin layer using this method is significantly lower than the cost of applying a thicker layer. The durability of the coating performance allows for a significant extension of road marking repair time, directly impacting the final cost.

Claims

1. A multi-component water-based coating system comprising: - an acrylic component comprising an aqueous emulsion of acrylic polymers, stabilized with a volatile base anion at basic pH and containing self-crosslinking functional groups, preferably the acrylic component is added with a high-boiling glycol ether, the amount of the acrylic component is between 76 and 90 wt%, preferably between 77 and 82 wt%, relative to the total weight of the component; - a hardener component comprising a liquid epoxy resin or a water-soluble polyisocyanate resin or a mixture thereof, the amount of the hardener component is between 5 and 15 wt%, preferably between 8 and 14 wt%, relative to the total weight of the component; - an epoxy polyamine component, the amount of the epoxy polyamine component is between 5 and 14 wt%, preferably between 7 and 10 wt%, relative to the total weight of the component, more preferably the epoxy polyamine component is added with a polythiol.

2. The coating system according to claim 1, characterized in that The amount of polythiol added to the epoxy polyamine component is between 1 and 15 wt%, preferably 5-10 wt%, relative to the total weight of the component.

3. The coating system according to any of the preceding claims, characterized in that The minimum film formation temperature of the acrylic polymers is between 0 and 40°C, preferably between 10 and 20°C.

4. The coating system according to any of the preceding claims, characterized in that The basic pH is between 8 and 11.

5. The coating system according to any of the preceding claims, characterized in that The volatile base is selected from the group comprising ammonia, morpholine, 2-methylaminoethanol, 2-dimethylaminoethanol, N-methylmorpholine and ethylenediamine, preferably ammonia.

6. The coating system according to any of the preceding claims, characterized in that The self-crosslinking functional groups contain diketone groups that react with amine or hydrazide outside the polymer.

7. The coating system according to any of the preceding claims, characterized in that The high-boiling glycol ether is selected from the group comprising diethylene glycol monobutyl ether (DB), dipropylene glycol n-butyl ether (DPnB), propylene glycol phenyl ether (PPh), tripropylene glycol monomethyl ether (TPM), preferably DB and DPnB.

8. The coating system according to any of the preceding claims, characterized in that The liquid epoxy resin is an emulsion or in emulsifiable state.

9. The coating system according to any of the preceding claims, characterized in that The liquid epoxy resin consists of a molecular structure of the following formula: 。 10. The coating system according to any of the preceding claims, characterized in that The epoxy resin equivalent weight (EEW) of the liquid epoxy resin is between 170 and 300, preferably between 200 and 250, as expressed in g / eq based on the solid resin.

11. The coating system according to any of the preceding claims, characterized in that The epoxy polyamine component is prepared from: a) at least one bis-epoxide compound, preferably diglycidyl ethers of bisphenol A and F; b) at least one alkylamine having a linear or branched C1-C6 aliphatic chain; c) at least one polyetheramine based on propylene oxide (PO), ethylene oxide (EO) or a combination thereof; d) at least one amino or amide-amino chain terminator.

12. The coating system according to any of the preceding claims, characterized in that The polythiol is selected from trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetra(3-mercaptopropionate) or 2-hydroxymethyl-2-methyl-1,3-propanediol tris(3-mercaptopropionate).

13. The coating system according to any of the preceding claims, characterized in that The amount of free thiol groups of the polythiol is between 7 and 27 wt%, based on the overall polythiol structure.

14. The coating system according to any of the preceding claims, characterized in that The amount of water contained by the coating system is between 20 and 40 wt%, preferably between 25 and 35 wt%.

15. The coating system according to any of the preceding claims, characterized in that The coating system further comprises one or more components selected from the group consisting of pigments, chain extenders, antibacterial agents, dispersants, defoamers, anionic and nonionic surfactants, and rheology modifiers.

16. Use of a multi-component water-based coating system according to any one of the preceding claims for use in horizontal road markings.

17. A coating film obtained by applying a multi-component water-based coating system according to any one of claims 1 to 15 to a road surface in the form of an aerosol, followed by evaporation of the aqueous medium.

18. The coated film according to claim 17, characterized by The thickness of the coating is between 200 µm and 400 µm.

19. A method for reducing the curing time of horizontal road markings on a road surface, the method comprising: i. Mixing the three components of the water-based coating system according to any one of claims 1 to 15; ii. Apply a layer of the water-based coating composition thus obtained to the road surface in the form of an aerosol; or i. Mixing the acrylic component according to any one of claims 1 to 15 with the epoxy polyamine component, and atomizing the resulting mixture; while atomizing the hardener component according to any one of claims 1 to 15; ii. The atomized components obtained in the previous step are mixed, and a layer of the atomized mixture is applied to the road surface in the form of an aerosol; and iii. Evaporate the aqueous medium from the layer to form the wear-resistant horizontal road markings on the road surface.

20. The method of claim 19, further comprising the step of applying glass beads over the layer in step ii).

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