Water-based road marking paint for cold regions and preparation method thereof

Abstract

The application relates to the technical field of traffic paint, in particular to a water-based marking paint for cold region road surfaces and a preparation method thereof. The application takes HDI polymer as a core, carries out grafting reaction with a multi-amino silane coupling agent to obtain a modified amine curing agent, and is matched with an acrylic acid epoxy hybrid emulsion with good weather resistance as a film-forming material, so that the prepared water-based marking paint has better flexibility and low-temperature anti-cracking property under the premise of not reducing wear resistance, water resistance and adhesion, has good resistance to saturated sodium chloride solution and can resist corrosion of deicing salt.

Description

Technical Field

[0001] This application relates to the field of traffic coating technology, and in particular to a water-based road marking coating for cold regions and its preparation method. Background Technology

[0002] Currently, there are two development directions for road marking paints. One is to increase the solids content of the paint to create hot-melt marking paints, thereby reducing VOCs. The other is to replace volatile organic solvents with water to create water-based marking paints. The disadvantage of hot-melt marking paints is that, due to construction considerations, they cannot be made into a thermosetting system. Thick coats can affect driving, while thin coats are prone to peeling. Hot-melt paints require heating to 180-220℃ to melt before application at high temperatures, resulting in high costs and safety risks.

[0003] Water-based road marking paints, using water as a carrier, solve the problem of excessively high VOCs in normal-temperature road marking paints. They can also be formulated as room-temperature self-drying two-component paints, eliminating the need for high-temperature application. However, water-based marking paints suffer from issues such as water absorption after film formation and poor wet adhesion. After being soaked in rainwater, they are prone to blistering due to water absorption and expansion, leading to peeling under the mechanical friction of pedestrians and vehicles. Furthermore, on cold northern highways, such as those in seasonally frozen soil areas according to JTG / T D31-06-2017, winter road temperatures are typically below -20°C. The two-component cured coating is prone to cracking due to cold shrinkage, resulting in peeling under the mechanical friction of vehicles. Therefore, it is necessary to specially adjust the formula and design water-based marking paints for cold northern roads, possessing advantages such as wear resistance, water resistance, de-icing salt resistance, good adhesion, and low-temperature crack resistance. Summary of the Invention

[0004] To address the problems of existing technologies, this application designs a polyamine curing agent with a special structure, which is used in combination with an acrylic-epoxy hybrid emulsion with good weather resistance. The resulting water-based road marking paint has better flexibility and low-temperature crack resistance without reducing wear resistance, water resistance, and adhesion.

[0005] To achieve the above technical objectives, the technical solution adopted in this application is as follows: In a first aspect, a water-based road marking paint includes components A and B, wherein component A includes: epoxy-modified acrylic emulsion, pigments, fillers, and additives; Component B includes: grafted modified amine curing agent, tetraethyl orthosilicate, and polyethylene glycol; The epoxy-modified acrylic emulsion is selected from acrylic-epoxy hybrid emulsions; The pigment is selected from at least one of titanium dioxide, medium chrome yellow, titanium nickel yellow, and iron oxide yellow; The filler is selected from at least one of quartz powder, calcium carbonate, kaolin, wollastonite powder, talc powder, bentonite, barium sulfate, and mica powder; The additive is selected from at least one of rheology modifiers, dispersants, wetting agents, defoamers, antifreeze agents, preservatives, and pH adjusters; The grafted modified amine curing agent is obtained by reacting a polyaminosilane coupling agent with a dimer or trimer of hexamethylene diisocyanate at room temperature; Preferably, the polyaminosilane coupling agent molecule contains at least two primary or secondary amino groups, and at least one primary amino group; More preferably, the polyaminosilane coupling agent is selected from at least one of N-aminoethyl-3-aminopropyltrimethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, diethylenetriaminopropyltrimethoxysilane, and diethylenetriaminopropylmethyldimethoxysilane. Preferably, the grafted modified amine curing agent is obtained by reacting a trimer of a polyaminosilane coupling agent and hexamethylene diisocyanate at room temperature; The polyethylene glycol is selected from polyethylene glycol with a molecular weight of 400-1000; The molar ratio of epoxy groups in the epoxy-modified acrylic emulsion to NH groups in the grafted amine curing agent is (1.10-1.25):1. The amount of tetraethyl orthosilicate used is 15-25 wt% of the grafted modified amine curing agent.

[0006] Furthermore, by weight, component A comprises: 90-110 parts by weight of epoxy-modified acrylic emulsion, 10-30 parts by weight of pigment, 40-60 parts by weight of filler, and 0.5-5 parts by weight of additives; component B comprises: 5-25 parts by weight of graft-modified amine curing agent, 0.5-6.5 parts by weight of tetraethyl orthosilicate, and 0.5-3 parts by weight of polyethylene glycol.

[0007] Secondly, the preparation method of the water-based road marking paint mentioned above includes: mixing epoxy modified acrylic emulsion and additives in a uniform manner, then adding pigments and fillers in a uniform manner, and finally grinding to a fineness of ≤60μm to obtain component A of the water-based road marking paint. The grafted modified amine curing agent, tetraethyl orthosilicate and polyethylene glycol were mixed evenly to obtain component B of the water-based road marking paint.

[0008] Thirdly, the above-mentioned water-based road marking paint is used in the painting of road markings in seasonally frozen soil areas.

[0009] The beneficial effects of the above-mentioned technical solution proposed in this application are as follows: the design and synthesis of a modified amine curing agent containing secondary amine groups is prepared by grafting HDI polymer with a polyaminosilane coupling agent. This modified amine curing agent is then used as a film-forming substance in combination with a weather-resistant epoxy-modified acrylic emulsion. The prepared water-based road marking paint has better flexibility and low-temperature crack resistance without reducing wear resistance, water resistance and adhesion. It also has good resistance to saturated sodium chloride solution and can resist de-icing salt corrosion. Detailed Implementation

[0010] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present invention. It should be noted that the terminology used herein is only for describing specific implementation methods and is not intended to limit the exemplary implementation methods according to the present invention.

[0011] Unless otherwise specified, the experimental conditions used in the examples are generally in accordance with conventional conditions in the art or the conditions recommended by the reagent company. Unless otherwise specified, the materials and reagents used in the examples can be purchased commercially.

[0012] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings: The terms "and / or," "or / and," and "and / or" as used herein include any one of two or more of the related listed items, as well as any and all combinations of the related listed items. These arbitrary and all combinations include any two related listed items, any more related listed items, or a combination of all related listed items. It should be noted that when at least three items are connected by at least two conjunctions selected from "and / or," "or / and," and "and / or," it should be understood that in this application, the technical solution undoubtedly includes technical solutions connected by "logical AND," and also undoubtedly includes technical solutions connected by "logical OR." For example, "A and / or B" includes three parallel solutions: A, B, and A+B. For example, the technical solution of "A, and / or, B, and / or, C, and / or, D" includes any one of A, B, C, and D (that is, a technical solution that is connected by "logical OR"), as well as any and all combinations of A, B, C, and D, that is, combinations of any two or three of A, B, C, and D, and also combinations of all four of A, B, C, and D (that is, a technical solution that is connected by "logical AND").

[0013] In this application, the terms "multiple", "various", "multiple times", "multi-dimensional", etc., unless otherwise specified, refer to a quantity greater than or equal to 2. For example, "one or more" means one or more than or equal to two.

[0014] In this application, "optionally," "optionally," and "optional" mean that something is optional, that is, it means that it is selected from either "with" or "without." If there are multiple "optional" entries in a technical solution, unless otherwise specified, and there are no contradictions or mutual constraints, each "optional" entry shall be independent.

[0015] In this application, the technical features described in an open-ended manner include both closed technical solutions composed of the listed features and open technical solutions composed of the listed features.

[0016] Example 1

[0017] Weigh 50.5 g (0.1 mol) of HDI trimer and dissolve it in 50 mL of acetone. Add 73.4 g (0.33 mol) of N-aminoethyl-3-aminopropyltrimethoxysilane to the reaction vessel. Under continuous nitrogen purging and stirring, add the acetone-dissolved HDI trimer dropwise to the reaction vessel over 30 minutes. Continue stirring and reacting at room temperature for 2 hours. Remove the acetone solvent by vacuum distillation. The resulting product was measured by infrared spectroscopy at 2250-2260 cm⁻¹. -1 The -NCO characteristic peak disappears, thus yielding the grafted modified amine curing agent. The theoretical active hydrogen equivalent (AHEW) is 390.

[0018] Example 2

[0019] N-aminoethyl-3-aminopropylmethyldimethoxysilane was used instead of N-aminoethyl-3-aminopropyltrimethoxysilane in Example 1, at a dosage of 68.1 g (0.33 mol). The remaining reactants and operating procedures were the same as in Example 1. The theoretical AHEW was 374.

[0020] Example 3

[0021] Diethylenetriaminepropyltrimethoxysilane was used instead of N-aminoethyl-3-aminopropyltrimethoxysilane in Example 1, at a dosage of 87.6 g (0.33 mol). The remaining reactants and operating procedures were the same as in Example 1. The theoretical AHEW was 217.

[0022] Example 4

[0023] Diethylenetriaminepropylmethyldimethoxysilane was used instead of N-aminoethyl-3-aminopropyltrimethoxysilane in Example 1, at a dosage of 82.3 g (0.33 mol). The remaining reactants and operating procedures were the same as in Example 1. The theoretical AHEW was 209.

[0024] Example 5

[0025] The water-based road marking paint is divided into components A and B. By weight, component A includes: 100 parts by weight of Uacryl 4080A acrylic-epoxy hybrid emulsion (epoxy equivalent 1100, solid content 50%, Lian Gu New Materials), 18 parts by weight of titanium dioxide, 12 parts by weight of kaolin, 15 parts by weight of wollastonite powder, 12 parts by weight of talc powder, 5 parts by weight of mica powder, 0.1 parts by weight of rheology modifier RHEOBYK-420, 0.4 parts by weight of dispersant Additive LF-750, 0.1 parts by weight of defoamer BYK-024, 0.5 parts by weight of antifreeze propylene glycol, and 0.3 parts by weight of preservative 1,2-benzisothiazolin-3-one. Component B comprises: 15.5 parts by weight of the grafted modified amine curing agent prepared in Example 1, 3 parts by weight of tetraethyl orthosilicate, and 0.8 parts by weight of polyethylene glycol 600 (PEG-600); The preparation method of water-based road marking paint involves dispersing the water-based emulsion and various additives in the prescribed amount at 1000 rpm until uniform. After stirring for 10 minutes, various pigments and fillers in the prescribed amount are added, and stirring is continued at 1000 rpm for 20 minutes. Subsequently, the mixture is ground in a sand mill until the fineness is ≤60μm. After filtration, component A of the water-based road marking paint is obtained. Component B is a pre-mixed mixture of the grafted modified amine curing agent, PEG-600, and tetraethyl orthosilicate prepared in Example 1, which is then sealed and stored. Components A and B are mixed again before the paint is used.

[0026] Example 6

[0027] The water-based road marking paint uses 15.5 parts by weight of the grafted modified amine curing agent prepared in Example 2 to replace the grafted modified amine curing agent prepared in Example 1. The remaining components and preparation method are the same as in Example 5.

[0028] Example 7

[0029] The water-based road marking paint uses 8.5 parts by weight of the grafted modified amine curing agent prepared in Example 3 instead of the grafted modified amine curing agent prepared in Example 1. The amount of tetraethyl orthosilicate is 1.7 parts by weight, and the remaining components and preparation method are the same as in Example 5.

[0030] Example 8

[0031] The water-based road marking paint uses 8.5 parts by weight of the grafted modified amine curing agent prepared in Example 4 instead of the grafted modified amine curing agent prepared in Example 1. The amount of tetraethyl orthosilicate is 1.7 parts by weight, and the remaining components and preparation method are the same as in Example 5.

[0032] Comparative Example 1 The water-based road marking paint uses 2.2 parts by weight of diethylenetriaminepropylmethyldimethoxysilane prepared in Example 4 to replace the grafted modified amine curing agent prepared in Example 1. The amount of tetraethyl orthosilicate is 0.4 parts by weight, and the remaining components and preparation method are the same as in Example 5.

[0033] Comparative Example 2 The water-based road marking paint, with tetraethyl orthosilicate removed from component B of the formula, has the same components and preparation method as in Example 5.

[0034] Test section Referring to the standard JT / T 280-2022 for road marking paint, the coating's water resistance, resistance to saturated NaCl solution immersion, adhesion, and low-temperature crack resistance were tested. The water resistance and resistance to saturated NaCl solution immersion were tested for 120 hours each, and the low-temperature crack resistance test was conducted at -25℃. The rest of the tests were the same as those in the JT / T 280-2022 standard.

[0035] The flexibility of the coating was tested using the cylindrical shaft bending method, in accordance with the standard GB / T 1731-2020.

[0036] The abrasion resistance of the coating was tested using the rotating rubber grinding wheel method, in accordance with the standard GB / T 1768-2006.

[0037] The test results of the water-based road marking paints prepared in Examples 5-8 and Comparative Examples 1-2 are listed in Table 1.

[0038] Table 1

[0039] Analysis of the data in Table 1 shows that using the grafted modified amine curing agent prepared in Examples 1-4 improves the adhesion, flexibility, and low-temperature crack resistance of water-based road marking paint. The amine curing agent contains -NH and trimethoxy / dimethoxy silane groups that can crosslink with epoxy groups. Hydrolysis generates Si-OH, which can dehydrate and condense with the hydroxyl groups on the surface of pigments and fillers inside the paint film, and also form Si-O-Si chemical bonds with the hydroxyl groups on the surface of cementitious substrates, forming a strong covalent interface between the organic and inorganic phases, directly improving adhesion to level 1. The grafted modified amine curing agent also contains flexible aliphatic segments. After grafting, a flexible skeleton is introduced into the curing agent molecule, resulting in a higher crosslinking density but sufficient flexible segments, balancing strength and toughness. While ensuring wear resistance and water resistance, it improves adhesion, flexibility, and low-temperature crack resistance. In Comparative Example 1, using a polyamine silane coupling agent alone as a curing agent, the crosslinking network is too rigid, leading to decreased coating adhesion and stress concentration during low-temperature testing, resulting in cracks. Comparative Example 2 did not contain tetraethyl orthosilicate, and lacked the hydrolysis-condensation process with the siloxane in the grafted modified amine curing agent to form a denser cross-linked structure. Although the coating flexibility was improved, the wear resistance and resistance to saturated NaCl solution were reduced.

[0040] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of them. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention. Although the specific embodiments of the present invention have been described above, they are not intended to limit the protection scope of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A water-based road marking paint, characterized in that, Includes components A and B; Component A includes: epoxy-modified acrylic emulsion, pigments, fillers, and additives; Component B includes: grafted modified amine curing agent, tetraethyl orthosilicate, and polyethylene glycol; The epoxy-modified acrylic emulsion is selected from acrylic-epoxy hybrid emulsions; The pigment is selected from at least one of titanium dioxide, medium chrome yellow, titanium nickel yellow, and iron oxide yellow; The filler is selected from at least one of quartz powder, calcium carbonate, kaolin, wollastonite powder, talc powder, bentonite, barium sulfate, and mica powder; The additive is selected from at least one of rheology modifiers, dispersants, wetting agents, defoamers, antifreeze agents, preservatives, and pH adjusters; The grafted modified amine curing agent is obtained by reacting a polyaminosilane coupling agent with a dimer or trimer of hexamethylene diisocyanate at room temperature; The polyethylene glycol is selected from polyethylene glycol with a molecular weight of 400-1000; The molar ratio of epoxy groups in the epoxy-modified acrylic emulsion to NH groups in the grafted amine curing agent is (1.10-1.25):

1. The amount of tetraethyl orthosilicate used is 15-25 wt% of the grafted modified amine curing agent.

2. The water-based road marking paint according to claim 1, characterized in that, The polyaminosilane coupling agent molecule contains at least two primary or secondary amino groups, and at least one primary amino group.

3. The water-based road marking paint according to claim 1, characterized in that, The polyaminosilane coupling agent is selected from at least one of N-aminoethyl-3-aminopropyltrimethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, diethylenetriaminepropyltrimethoxysilane, and diethylenetriaminepropylmethyldimethoxysilane.

4. The water-based road marking paint according to claim 1, characterized in that, The grafted modified amine curing agent is obtained by reacting a trimer of a polyaminosilane coupling agent and hexamethylene diisocyanate at room temperature.

5. The water-based road marking paint according to claim 1, characterized in that, By weight, component A comprises: 90-110 parts by weight of epoxy-modified acrylic emulsion, 10-30 parts by weight of pigment, 40-60 parts by weight of filler, and 0.5-5 parts by weight of additives; component B comprises: 5-25 parts by weight of graft-modified amine curing agent, 0.5-6.5 parts by weight of tetraethyl orthosilicate, and 0.5-3 parts by weight of polyethylene glycol.

6. A method for preparing a water-based road marking paint as described in any one of claims 1-5, characterized in that, After mixing the epoxy-modified acrylic emulsion and additives in the formula evenly, the pigments and fillers in the formula are added and mixed evenly. Finally, the mixture is ground to a fineness of ≤60μm to obtain component A of the water-based road marking paint. The grafted modified amine curing agent, tetraethyl orthosilicate and polyethylene glycol were mixed evenly to obtain component B of the water-based road marking paint.

7. The use of the water-based road marking paint as described in any one of claims 1-5 in the application of road markings in seasonally frozen areas.

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