One-component self-repairing waterborne polyurethane waterproof material and preparation method thereof

Abstract

The application provides a single-component self-repairing water-based polyurethane waterproof material and a preparation method thereof, and belongs to the technical field of building materials.The single-component self-repairing water-based polyurethane waterproof material comprises a modified water-based polyurethane dispersion, a neoprene emulsion, a microbial self-repairing agent powder, an additive, a pigment and filler, and water.The single-component self-repairing water-based polyurethane waterproof material is provided with the neoprene emulsion with good aging resistance and corrosion resistance in the water-based polyurethane waterproof material, so that the single-component self-repairing water-based polyurethane waterproof material not only has a waterproof layer with excellent tensile strength, elongation, peeling strength and low-temperature flexibility, but also has excellent weather resistance for long-time outdoor exposure, and can realize automatic repair for some small cracks appearing in the later period.

Description

Technical Field

[0001] This invention belongs to the field of building materials technology, specifically relating to a single-component self-healing waterborne polyurethane waterproof material and its preparation method. Background Technology

[0002] Water-based polyurethane waterproof coating is an environmentally friendly high-molecular polymer elastic waterproof material. The product is non-toxic and odorless, with excellent adhesion and impermeability. It exhibits strong adhesion to mortar, cementitious surfaces, stone, and metal products. The product is chemically stable, can withstand long-term sunlight exposure, and possesses high strength, high elongation, good elasticity, and excellent waterproofing performance. This material is suitable for national key projects and general waterproofing projects, such as roofs, corrugated steel sheets, basements, civil defense projects, kitchens and bathrooms, culverts, tunnels, bridges, and water tanks. It can also be used for corrosion protection of metal pipes, workshop floors, and water tanks. Its characteristics include: single-component waterproofing, cold application, non-toxic and harmless; application to damp, dry, or non-wet substrates; a tough and highly elastic coating; strong adhesion to brick, mortar, concrete, metal, foam board, and insulation layers; safe and simple construction with a short construction period.

[0003] Since most of the roof waterproofing layer is exposed to the atmosphere, it will age and crack after long-term exposure to wind and sun, which will have a significant impact on the waterproofing effect. Later repairs will be difficult and costly. If some small cracks are not properly repaired, they will further aggravate the phenomenon of water accumulation and leakage.

[0004] Patent document CN114410209A describes a dual self-healing composite anti-corrosion coating formed by modifying graphene oxide sheets with TiO2 nanocapsules loaded with corrosion inhibitors and multi-branched waterborne polyurethane (WPU). However, it is expensive, and cracks remain on the surface after self-healing, posing a risk of secondary cracking.

[0005] Patent document CN112876690A uses metal oxides such as iron oxide nanoparticles as reinforcing fillers and utilizes the excellent self-healing and stimulus-response properties of metal-organic ligand coordination bonds to obtain a high-strength, fast-self-healing waterborne polyurethane composite material. However, this reduces the flexibility of the coating itself and makes it prone to cracking. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention provides a single-component self-healing waterborne polyurethane waterproofing material and its preparation method, as well as a slurry and its preparation method. The single-component self-healing waterborne polyurethane waterproofing material and its preparation method of this invention incorporate a chloroprene rubber emulsion with good aging and corrosion resistance into the waterborne polyurethane waterproofing. This results in a waterproof layer with excellent tensile strength, elongation, peel strength, and low-temperature flexibility, while also exhibiting excellent weather resistance for prolonged outdoor exposure and the ability to automatically repair minor cracks that appear later.

[0007] To solve the above problems, the present invention is achieved through the following technical solution:

[0008] The first objective of this invention is:

[0009] A single-component self-healing waterborne polyurethane waterproof material is provided, comprising the following components in parts by weight:

[0010] The mixture consists of 35-45 parts modified waterborne polyurethane dispersion, 5-10 parts chloroprene rubber latex, 1-3 parts microbial self-healing agent powder, 0.5-3.5 parts additives, 35-45 parts pigments and fillers, and 6-9 parts water.

[0011] The microbial self-healing agent powder comprises the following components in parts by weight:

[0012] Molecular sieve 1-3 parts, microbial inoculum 4-6 parts;

[0013] The microbial inoculum is one or a combination of Bacillus licheniformis and Bacillus subtilis, with a cell diameter of 2-5 μm;

[0014] The molecular sieve has a diameter of 1 mm to 2 mm;

[0015] The additives are one or a combination of several of the following: cellulose, pH adjuster, dispersant, wetting agent, defoamer, bactericide, film-forming aid, thickener, and preservative.

[0016] Bacillus and / or Bacillus subtilis in the coating are awakened under water conditions, begin to multiply, and promote the reaction of surrounding calcium ions to generate calcium carbonate precipitation, which fills the cracks and thus plays a repair role.

[0017] A further optimization of the single-component self-healing waterborne polyurethane waterproofing material of the present invention is as follows:

[0018] The microbial self-healing agent powder comprises the following preparation steps:

[0019] S1. Glucose was selected as the culture medium for microbial inoculum and cultured for 24 hours at 35-40℃, pH between 6.5 and 7.5, and dissolved oxygen concentration above 20%.

[0020] In a vacuum environment, a culture medium containing microbial bacterial solution is mixed with a molecular sieve and adsorbed for 48 to 72 hours to prepare microbial self-healing particles.

[0021] After drying the microbial self-healing particles in an environment of 40℃~60℃ for 48 hours, they were ground and sieved to prepare a microbial self-healing agent powder of 250 mesh~350 mesh.

[0022] A further optimization of the single-component self-healing waterborne polyurethane waterproofing material of the present invention is as follows:

[0023] The modified waterborne polyurethane dispersion is a modified waterborne polyurethane dispersion modified with a silane coupling agent, wherein the silane coupling agent is one or a combination of several of vinyl silane coupling agents, epoxy silane coupling agents, and amino silane coupling agents.

[0024] A further optimization of the single-component self-healing waterborne polyurethane waterproofing material of the present invention is as follows:

[0025] The glass transition temperature range of the chloroprene rubber emulsion is -45℃ to -25℃, the molecular weight of the emulsion is 100,000 to 150,000, and the relative density is 1.05 to 1.2.

[0026] A further optimization of the single-component self-healing waterborne polyurethane waterproofing material of the present invention is as follows:

[0027] The molecular sieves mentioned are zeolite molecular sieves and ZSM molecular sieves, and their structures include type A, type X, and type Y; the diameter of the molecular sieves is 1 mm to 2 mm.

[0028] The second objective of this invention is:

[0029] A method for preparing the aforementioned single-component self-healing waterborne polyurethane waterproof material is provided, comprising the following preparation steps:

[0030] S1. Weigh out the water according to the proportion and add it accurately, then turn on low-speed stirring;

[0031] S2. Slowly add cellulose while stirring at 500 rpm and stir thoroughly for 10 minutes;

[0032] S3. Add pH adjuster, dispersant, defoamer, modified waterborne polyurethane dispersion and chloroprene rubber latex in sequence while stirring at 500 rpm, and stir thoroughly for 5 min;

[0033] S4. Adjust the rotation speed to 1200 rpm, accurately add pigments and fillers, and stir thoroughly for 30 minutes;

[0034] S5. Reduce the rotation speed to 500 rpm, add the wetting agent, bactericide, film-forming aid, preservative, thickener, and microbial self-healing agent powder in sequence, and stir thoroughly for 20 minutes to obtain the single-component self-healing waterborne polyurethane waterproof material.

[0035] The single-component self-healing waterborne polyurethane waterproof material of the present invention achieves the following:

[0036] (1) The addition of chloroprene rubber emulsion and water-based polyurethane emulsion to the formula improves the aging resistance, oil resistance and chemical corrosion resistance of the waterproof coating.

[0037] (2) Add self-healing additives (microbial self-healing powder: composed of microorganisms, molecular sieve carriers and nutrients, which calcify and deposit at cracks under water conditions) to the formula to repair the fine cracks in the waterproof coating, reduce the difficulty of repair and reduce the repair cost.

[0038] The single-component self-healing waterborne polyurethane waterproofing material of the present invention ensures the waterproofing effect of the coating while shortening the self-healing time of cracks.

[0039] The single-component self-healing waterborne polyurethane waterproof material of the present invention has the following technical features:

[0040] (1) The waterproof layer formed by the waterproof material of the present invention can repair the cracks and maintain the waterproof effect by calcifying and settling the self-healing microorganisms added to it in a water-cultured state when small cracks appear.

[0041] (2) The waterproof material of the present invention has good weather resistance and can maintain good tensile strength and ductility under extreme conditions.

[0042] (3) The waterproof material of the present invention has a low water absorption rate and is not prone to water absorption, swelling, bubbling and other phenomena when exposed to the outdoors for a long time.

[0043] (4) The waterproof material of the present invention has excellent mechanical properties and low-temperature flexibility. The waterproof layer formed by the waterproof material has high tensile strength, high adhesion between the base layer and the waterproof layer, and is not easy to fall off.

[0044] (5) The waterproof material of the present invention is simple to operate, has low maintenance cost, dries quickly, and reduces the impact of climate on construction progress. Detailed Implementation

[0045] To make the application, technical solution, and advantages of this invention clearer, the invention is described in detail with reference to specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Any simple modifications to the preparation method of this invention based on the inventive concept are within the scope of protection of this invention.

[0046] Example

[0047] A method for preparing a single-component self-healing waterborne polyurethane waterproof material includes the following preparation steps:

[0048] S1. Weigh out the water according to the proportion and add it accurately, then turn on low-speed stirring;

[0049] S2. Slowly add cellulose while stirring at 500 rpm and stir thoroughly for 10 minutes;

[0050] S3. Add pH adjuster, dispersant, defoamer, modified waterborne polyurethane dispersion and chloroprene rubber latex in sequence while stirring at 500 rpm, and stir thoroughly for 5 min;

[0051] S4. Adjust the rotation speed to 1200 rpm, accurately add pigments and fillers, and stir thoroughly for 30 minutes;

[0052] S5. Reduce the rotation speed to 500 rpm, add the wetting agent, bactericide, film-forming aid, preservative, thickener, and microbial self-healing agent powder in sequence, and stir thoroughly for 20 minutes to obtain the single-component self-healing waterborne polyurethane waterproof material.

[0053] Example 1 (Phase 1)

[0054] One-component waterborne polyurethane waterproofing materials were prepared using the components shown in Table 1 below. Each component, by weight, is included in the following experimental groups:

[0055] Table 1

[0056] Raw material name Comparative Example 1 Example 1# Example 2# pure water 9.2 8.2 6.2 Cellulose 0.1 0.1 0.1 pH adjuster 0.05 0.05 0.05 dispersant 1.2 1.2 1.2 wetting agent 0.2 0.2 0.2 Defoamer 0.8 0.8 0.8 Chloroprene rubber latex 0 5 10 Titanium dioxide 5 5 5 filler 37.5 37.5 37.5 bactericide 0.2 0.2 0.2 Film-forming aids 0.5 0.5 0.5 Modified waterborne polyurethane dispersion 45 41 38 Thickener 0.05 0.05 0.05 preservative 0.2 0.2 0.2 Total 100 100 100

[0057] Mechanical property testing:

[0058] Performance tests were conducted using the above comparative and example examples in accordance with standard T / CWA 206-2021.

[0059] Table 2 Mechanical Performance Tests

[0060]

[0061]

[0062] As can be seen from the results in Table 2, the waterborne polyurethane waterproof material of the present invention (without adding self-healing additive microbial self-healing agent powder) exhibits good mechanical properties. The higher the proportion of chloroprene rubber latex, the better the mechanical properties and the lower the water absorption rate.

[0063] Example 2 (Phase Two)

[0064] Single-component waterborne polyurethane waterproofing materials were prepared using the components shown in Table 3 below. Each experimental group included the following components by weight:

[0065] Table 3

[0066] Raw material name Comparative Example 2 Example 3# Example 4# pure water 9.2 8.2 6.2 Cellulose 0.1 0.1 0.1 Microbial self-healing powder 0 1 3 pH adjuster 0.05 0.05 0.05 dispersant 1.2 1.2 1.2 wetting agent 0.2 0.2 0.2 Defoamer 0.8 0.8 0.8 Chloroprene rubber latex 8 8 8 Titanium dioxide 5 5 5 filler 37.5 37.5 37.5 bactericide 0.2 0.2 0.2 Film-forming aids 0.5 0.5 0.5 Modified waterborne polyurethane dispersion 37 37 37 Thickener 0.05 0.05 0.05 preservative 0.2 0.2 0.2 Total 100 100 100

[0067] Self-healing test:

[0068] The above embodiments are performed according to the molding standard 7.4.2 of GB / T 23445-2009, and cured to the appropriate age. A 0.3 mm diameter iron needle is used to puncture the surface, resulting in a pinhole density of 10 holes / cm². 2 The water curing time was 3 days, 7 days, 14 days, and 28 days, with a water pressure of 0.2 MPa, and an impermeability test was conducted.

[0069] Table 4 Self-healing test results

[0070] Test Project Comparative Example 2 Example 3# Example 4# 3D water permeability permeable permeable permeable 3D water flow status Larger smaller smaller 7-day water permeability permeable permeable impermeable 7-day water flow status Larger smaller —— 14-day water permeability permeable impermeable impermeable 14-day water flow status Larger —— —— 28-day water permeability permeable impermeable impermeable 28-day water flow status Larger —— ——

[0071] As shown in Table 4, Examples 3# and 4# exhibited significant self-healing effects under water-based conditions; with 3% self-healing additive, the repair time was shorter and the effect was more pronounced. Comparative Example 2, despite the addition of neoprene latex (without self-healing additive / microbial self-healing agent powder), still showed significant water permeability.

[0072] Example 3 (Phase Three)

[0073] Single-component waterborne polyurethane waterproofing materials were prepared using the components shown in Table 5 below. Each experimental group included the following components by weight:

[0074] Table 5

[0075]

[0076]

[0077] Permeability test:

[0078] The above comparative examples and embodiments were cured to the appropriate age according to the molding standard 7.4.2 in GB / T 23445-2009. A 0.3 mm diameter iron needle was used to puncture the surface, with a needle density of 10 holes per square centimeter. Water curing times were 3 days, 7 days, 14 days, and 28 days, followed by water impermeability tests.

[0079] Table 6 Self-healing test results

[0080] Test Project Comparative Example 3 Example 5# Comparative Example 4 Example 6# 3D water permeability permeable permeable permeable permeable 3D water flow status Larger smaller Larger smaller 7-day water permeability permeable permeable permeable permeable 7-day water flow status Larger smaller Larger smaller 14-day water permeability permeable permeable permeable impermeable 14-day water flow status Larger smaller Larger —— 28-day water permeability permeable impermeable permeable impermeable 28-day water flow status Larger —— Larger ——

[0081] The conclusions drawn from the test results in Table 6 are as follows:

[0082] Comparative Examples 3 and 4 lacked self-healing capabilities without the addition of self-healing additives; Examples 5 and 6, after the addition of self-healing additives, both exhibited self-healing effects, with the formulation containing chloroprene rubber latex showing a shorter self-healing cycle and more pronounced effects.

[0083] In summary, the embodiments of the present invention are merely preferred examples and are not intended to limit the present invention in any way. Any changes, modifications, and evolutions made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content shall be considered equivalent examples of the present invention. Furthermore, any changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention shall still fall within the protection scope of the present invention.

[0084] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] Experimental methods not specified in this invention are generally performed under conventional conditions or as recommended by the manufacturer.

[0086] Unless otherwise stated, the various optimized technical solutions in this invention can be combined with each other.

[0087] Unless otherwise stated, percentages and parts are weight percentages and weight parts.

[0088] Experimental methods not specified in the instructions and examples are generally performed under standard conditions or as recommended by the manufacturer.

[0089] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as are familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be used in the methods of this invention.

Claims

1. A single-component self-healing waterborne polyurethane waterproof material, characterized in that: It comprises the following components in parts by weight: The mixture consists of 35-45 parts modified waterborne polyurethane dispersion, 5-10 parts chloroprene rubber latex, 1-3 parts microbial self-healing agent powder, 0.5-3.5 parts additives, 35-45 parts pigments and fillers, and 6-9 parts water. The microbial self-healing agent powder comprises the following components in parts by weight: Molecular sieve 1-3 parts, microbial inoculum 4-6 parts; The microbial inoculum is one or a combination of Bacillus licheniformis and Bacillus subtilis, with a cell diameter of 2-5 μm; The molecular sieve has a diameter of 1 mm to 2 mm; The aforementioned additives are one or a combination of several of the following: cellulose, pH adjuster, dispersant, wetting agent, defoamer, bactericide, film-forming aid, thickener, and preservative. The microbial self-healing agent powder comprises the following preparation steps: S1. Glucose was selected as the culture medium for microbial inoculum and cultured for 24 hours at 35-40℃, pH between 6.5 and 7.5, and dissolved oxygen concentration above 20%. In a vacuum environment, a culture medium containing microbial bacterial solution is mixed with a molecular sieve and adsorbed for 48 to 72 hours to prepare microbial self-healing particles. After drying the microbial self-healing particles in an environment of 40℃~60℃ for 48 hours, they were ground and sieved to prepare a microbial self-healing agent powder of 250 mesh~350 mesh.

2. The single-component self-healing waterborne polyurethane waterproof material according to claim 1, characterized in that: The modified waterborne polyurethane dispersion is a modified waterborne polyurethane dispersion modified with a silane coupling agent, wherein the silane coupling agent is one or a combination of several of vinyl silane coupling agents, epoxy silane coupling agents, and amino silane coupling agents.

3. The single-component self-healing waterborne polyurethane waterproof material according to claim 1, characterized in that: The glass transition temperature range of the chloroprene rubber emulsion is -45℃ to -25℃, the molecular weight of the emulsion is 100,000 to 150,000, and the relative density is 1.05 to 1.

2.

4. The single-component self-healing waterborne polyurethane waterproof material according to claim 1, characterized in that: The molecular sieves mentioned are zeolite molecular sieves and ZSM molecular sieves, and their structures include type A, type X, and type Y; the diameter of the molecular sieves is 1 mm to 2 mm.

5. A method for preparing the single-component self-healing waterborne polyurethane waterproof material according to claim 1, characterized in that: It includes the following preparation steps: S1. Weigh out the water according to the specified ratio and add it accurately, then turn on low-speed stirring; S2. Slowly add cellulose while stirring at 500 rpm and stir thoroughly for 10 minutes; S3. Add the pH adjuster, dispersant, defoamer, modified waterborne polyurethane dispersion, and chloroprene rubber latex sequentially while stirring at 500 rpm, and stir thoroughly for 5 minutes. S4. Adjust the rotation speed to 1200 rpm, accurately add pigments and fillers, and stir thoroughly for 30 minutes; S5. Reduce the rotation speed to 500 rpm, add the wetting agent, bactericide, film-forming aid, preservative, thickener, and microbial self-healing agent powder in sequence, and stir thoroughly for 20 minutes to obtain the single-component self-healing waterborne polyurethane waterproof material.

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