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

Abstract

The invention provides a single-component self-repairing waterborne polyurethane waterproof material and a preparation method thereof, and belongs to the technical field of building materials. The single-component self-repairing waterborne polyurethane waterproof material is prepared from modified waterborne polyurethane dispersoid, chloroprene rubber emulsion, microbial self-repairing agent powder, auxiliaries, pigment filler and water. According to the single-component self-repairing waterborne polyurethane waterproof material disclosed by the invention, the chloroprene rubber emulsion with relatively good aging resistance and corrosion resistance is added into the waterborne polyurethane waterproof material, so that the single-component self-repairing waterborne polyurethane waterproof material disclosed by the invention not only has a waterproof layer with excellent tensile strength, elongation percentage, peel strength and low-temperature flexibility, but also has a waterproof layer with low-temperature flexibility; meanwhile, the weather resistance of long-time outdoor exposure is excellent, and some fine cracks appearing in the later period can be automatically repaired.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and specifically relates to a single-component self-repairing waterborne polyurethane waterproof material and a preparation method thereof. Background Art

[0002] Waterborne polyurethane waterproof coating is an environmentally friendly polymer elastic waterproof material. The product is non-toxic and tasteless, has good bonding and impermeability, and has strong adhesion to mortar cement base stone surface and stone, metal products. The chemical properties of the product are stable, can withstand long-term sunlight, high strength, large elongation, good elasticity, and good waterproof effect. This material is suitable for national key projects and general waterproof projects, such as roofs, color steel tiles, basements, civil air defense projects, kitchens and bathrooms, culverts, tunnels, bridges, pools and other projects. It can also be used for metal pipes, workshop floors, pools and other projects. The material features: single-component waterproof, cold construction, non-toxic and harmless; can be constructed on wet, no water or dry base surfaces, the coating is tough and elastic; it has strong adhesion to masonry, mortar, concrete, metal, foam board, insulation layer, etc.; the construction is safe and simple, and the construction period is short.

[0003] Since most of the roof waterproofing layers are exposed to the atmosphere, they will age and crack after being exposed to wind and sun for a long time, which will have a great impact on the waterproofing effect. It is difficult and costly to repair them at a later stage. If some small cracks are not repaired properly, the phenomenon of water accumulation and leakage will be further aggravated.

[0004] Patent document CN114410209A discloses a double self-healing composite anti-corrosion coating formed by TiO2 nanocapsules modified with corrosion inhibitors and multi-branched waterborne polyurethane WPU. However, the coating is relatively expensive, and there are traces of cracks on the surface after self-healing, posing a risk of secondary cracking.

[0005] Patent document CN112876690A uses metal oxides such as ferroferric oxide nanoparticles as reinforcing fillers and utilizes the excellent self-healing and stimulus-responsive 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] In order to solve the technical problems mentioned above, the present invention provides a one-component self-repairing waterborne polyurethane waterproof material and a preparation method thereof, a slurry and a preparation method thereof. The one-component self-repairing waterborne polyurethane waterproof material and a preparation method thereof of the present invention add a chloroprene rubber emulsion with good aging resistance and corrosion resistance to the waterborne polyurethane waterproof material, so that the one-component self-repairing waterborne polyurethane waterproof material of the present invention not only has excellent tensile strength, elongation, peel strength and low-temperature flexible waterproof layer, but also has excellent weather resistance that can be exposed outdoors for a long time, and can automatically repair some small cracks that appear later.

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

[0008] The first invention object of the present invention is:

[0009] Provided is a one-component self-repairing waterborne polyurethane waterproof material, comprising the following components in parts by weight:

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

[0012] The microbial self-repairing agent powder comprises the following components in parts by weight:

[0013] 1-3 parts of molecular sieve, 4-6 parts of microbial culture liquid;

[0014] The microbial liquid is one or a combination of Bacillus licheniformis and Bacillus subtilis, and the diameter of the bacterial cell is 2 to 5 μm;

[0015] The molecular sieve has a diameter of 1 mm to 2 mm;

[0016] The auxiliary agent is one or a combination of cellulose, pH regulator, dispersant, wetting agent, defoamer, bactericide, film-forming auxiliary agent, thickener and preservative.

[0017] The Bacillus and / or Bacillus subtilis in the paint are awakened under water conditions, begin to multiply and promote the reaction of surrounding calcium ions, generate calcium carbonate precipitation, fill the cracks, and thus play a repairing role.

[0018] The one-component self-repairing waterborne polyurethane waterproof material of the present invention is further optimized as follows:

[0019] The microbial self-repairing agent powder comprises the following preparation steps:

[0020] S1. Glucose is selected as the culture medium for microbial culture, and cultured for 24 hours at 35-40°C, pH value between 6.5 and 7.5, and dissolved oxygen concentration in the culture medium above 20%;

[0021] In a vacuum environment, a culture medium containing a microbial liquid is mixed with a molecular sieve and adsorbed for 48 to 72 hours to prepare microbial self-repairing particles;

[0022] The microbial self-repairing particles were dried in an environment of 40°C to 60°C for 48 hours, and then ground and sieved to prepare microbial self-repairing agent powder of 250-350 meshes.

[0023] The one-component self-repairing waterborne polyurethane waterproof material of the present invention is further optimized as follows:

[0024] The modified waterborne polyurethane dispersion is a modified waterborne polyurethane dispersion modified by a silane coupling agent, wherein the silane coupling agent is one or a combination of vinyl silane coupling agent, epoxy silane coupling agent and amino silane coupling agent.

[0025] The one-component self-repairing waterborne polyurethane waterproof material of the present invention is further optimized as follows:

[0026] The glass transition temperature range of the chloroprene rubber emulsion is: -45 DEG C to -25 DEG C, the emulsion molecular weight is: 100,000 to 150,000, and the relative density is: 1.05 to 1.2.

[0027] The one-component self-repairing waterborne polyurethane waterproof material of the present invention is further optimized as follows:

[0028] The molecular sieve is a zeolite molecular sieve or a ZSM molecular sieve, and its structure includes type A, type X and type Y; the diameter of the molecular sieve is 1 mm to 2 mm.

[0029] The second object of the present invention is:

[0030] A method for preparing the above-mentioned one-component self-repairing waterborne polyurethane waterproof material is provided, which comprises the following preparation steps:

[0031] S1. Weigh and add water in proportion and start stirring at low speed;

[0032] S2. Slowly add cellulose under stirring at 500 rpm and stir thoroughly for 10 min;

[0033] S3. Add pH adjuster, dispersant, defoamer, modified aqueous polyurethane dispersion, chloroprene rubber emulsion in sequence under stirring at 500 rpm and stir well for 5 min;

[0034] S4. Adjust the speed to 1200 rpm, accurately add pigments and fillers, and stir thoroughly for 30 minutes;

[0035] 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 one-component self-healing waterborne polyurethane waterproof material.

[0036] The one-component self-repairing waterborne polyurethane waterproof material of the present invention is:

[0037] (1) The chloroprene rubber emulsion and the water-based polyurethane emulsion are added to the formula to improve the aging resistance, oil resistance and chemical corrosion resistance of the waterproof coating;

[0038] (2) Adding self-repairing additives to the formula (microbial self-repairing agent powder: composed of microorganisms, molecular sieve carriers and nutrients, which are calcified and deposited in the cracks by microorganisms under water) can repair the fine cracks in the waterproof coating, reduce the difficulty of repair and reduce the cost of repair.

[0039] The one-component self-repairing waterborne polyurethane waterproof material of the present invention not only ensures the waterproof effect of the coating, but also shortens the self-repairing time of the cracks.

[0040] The one-component self-repairing waterborne polyurethane waterproof material of the present invention has the following technical features:

[0041] (1) When fine cracks appear in the waterproof layer formed by the waterproof material of the present invention, the self-repairing microorganisms added therein by the carrier calcify and settle in a water-grown state, thereby repairing the cracks and maintaining the waterproof effect.

[0042] (2) The waterproof material of the present invention has good weather resistance and can maintain good tensile strength and ductility under extreme environments.

[0043] (3) The waterproof material of the present invention has a low water absorption rate and is not prone to water absorption, swelling, bubbling, etc. when exposed outdoors for a long time.

[0044] (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, and the base layer and the waterproof layer have high adhesion and are not easy to fall off.

[0045] (5) The waterproof material of the present invention has simple construction operation, low maintenance cost, fast drying speed, and reduces the impact of climate on construction progress. DETAILED DESCRIPTION

[0046] In order to make the application, technical scheme and advantages of the present invention clearer, the present invention is described in detail in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not limited to the present invention. All simple improvements to the preparation method of the present invention under the premise of the present invention are within the protection scope of the present invention.

[0047] Example

[0048] A method for preparing a one-component self-repairing waterborne polyurethane waterproof material, comprising the following preparation steps:

[0049] S1. Weigh and add water in proportion and start stirring at low speed;

[0050] S2. Slowly add cellulose under stirring at 500 rpm and stir thoroughly for 10 min;

[0051] S3. Add pH adjuster, dispersant, defoamer, modified aqueous polyurethane dispersion, chloroprene rubber emulsion in sequence under stirring at 500 rpm and stir well for 5 min;

[0052] S4. Adjust the speed to 1200 rpm, accurately add pigments and fillers, and stir thoroughly for 30 minutes;

[0053] 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 one-component self-healing waterborne polyurethane waterproof material.

[0054] Example 1 (Phase 1)

[0055] The one-component waterborne polyurethane waterproof material was prepared using the components shown in Table 1 below, wherein each component is calculated by weight, and each experimental group includes the following components:

[0056] Table 1

[0057] 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 Adjusters 0.05 0.05 0.05 Dispersants 1.2 1.2 1.2 Wetting Agents 0.2 0.2 0.2 Defoaming agent 0.8 0.8 0.8 Neoprene latex 0 5 10 Titanium dioxide 5 5 5 filler 37.5 37.5 37.5 Fungicides 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

[0058] Mechanical properties test:

[0059] The performance tests were carried out using the comparative examples and embodiments described above in accordance with standard T / CWA 206-2021.

[0060] Table 2 Mechanical properties test

[0061]

[0062]

[0063] It can be seen from the results in Table 2 that the water-based polyurethane waterproof material of the present invention (without adding the self-repairing additive microbial self-repairing agent powder) has better performance in terms of mechanical properties. The higher the proportion of chloroprene rubber emulsion, the better the mechanical properties and the lower the water absorption rate.

[0064] Example 2 (Phase 2)

[0065] The one-component waterborne polyurethane waterproof material was prepared using the components shown in Table 3 below, wherein each component was calculated by weight, and each experimental group included the following components:

[0066] Table 3

[0067] 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 agent powder 0 1 3 pH Adjusters 0.05 0.05 0.05 Dispersants 1.2 1.2 1.2 Wetting Agents 0.2 0.2 0.2 Defoaming agent 0.8 0.8 0.8 Neoprene latex 8 8 8 Titanium dioxide 5 5 5 filler 37.5 37.5 37.5 Fungicides 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

[0068] Self-healing test:

[0069] The above embodiment refers to the molding standard 7.4.2 of GB / T 23445-2009 standard and is cured to the appropriate age. A 0.3 mm diameter iron needle is used to poke through the surface, and the pinhole density is: 10 holes / cm 2 The water curing time is 3 days, 7 days, 14 days and 28 days, the water pressure is 0.2MPa, and a watertightness test is carried out.

[0070] Table 4 Self-repair test results

[0071] Test items Comparative Example 2 Example 3# Example 4# 3d water permeability permeable permeable permeable 3d water flow state Larger Smaller Smaller 7d water seepage permeable permeable impermeable 7d water flow status Larger Smaller —— 14d water seepage permeable impermeable impermeable 14d water flow status Larger —— —— 28d water seepage permeable impermeable impermeable 28d water flow status Larger —— ——

[0072] From the test results in Table 4, the self-repairing effect of Example 3# and Example 4# in water-based state is obvious; when the self-repairing additive is 3%, the repair time is short and the effect is obvious. Although the comparative example 2 has the addition of chloroprene rubber emulsion (without the self-repairing additive microbial self-repairing agent powder), it still has obvious water permeability.

[0073] Example 3 (Phase 3)

[0074] The one-component waterborne polyurethane waterproof material was prepared using the components shown in Table 5 below, wherein each component was calculated by weight, and each experimental group included the following components:

[0075] Table 5

[0076]

[0077]

[0078] Water penetration test:

[0079] The comparative examples and embodiments were cured to the appropriate age according to the molding standard 7.4.2 of GB / T 23445-2009. A 0.3 mm diameter iron needle was used to poke through the surface with a pinhole density of 10 per square centimeter. The water curing time was 3 days, 7 days, 14 days, and 28 days, and a water-tightness test was performed.

[0080] Table 6 Self-repair test results

[0081] Test items Comparative Example 3 Example 5# Comparative Example 4 Example 6# 3d water permeability permeable permeable permeable permeable 3d water flow state Larger Smaller Larger Smaller 7d water seepage permeable permeable permeable permeable 7d water flow status Larger Smaller Larger Smaller 14d water seepage permeable permeable permeable impermeable 14d water flow status Larger Smaller Larger —— 28d water seepage permeable impermeable permeable impermeable 28d water flow status Larger —— Larger ——

[0082] The conclusions drawn from the test results in Table 6 are as follows:

[0083] Comparative Examples 3 and 4 do not have self-repairing ability when no self-repairing additives are added; after adding self-repairing additives, Examples 5# and 6# can both have self-repairing effects. The formula containing chloroprene rubber emulsion has a short self-repairing period and a more obvious effect.

[0084] To sum up, the embodiments of the present invention are only preferred examples of the present invention and do not limit the present invention in any form. Any equivalent changes made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the disclosed technical content are regarded as equivalent examples of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

[0085] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described 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.

[0086] The experimental methods without specific conditions in the present invention are usually carried out under conventional conditions or conditions recommended by the manufacturer.

[0087] Unless otherwise stated, the various optimization technical solutions in the present invention can be combined with each other.

[0088] Unless otherwise indicated, percentages and parts are by weight.

[0089] Experimental methods without specific conditions specified in the instructions and examples are usually carried out under conventional conditions or conditions recommended by the manufacturers.

[0090] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any method and material similar or equivalent to the described content can be applied to the method of the present invention.

Claims

1. A one-component self-repairing waterborne polyurethane waterproof material, Features: It includes the following components in parts by weight: 35-45 parts of modified waterborne polyurethane dispersion, 5-10 parts of chloroprene rubber latex, 1-3 parts of microbial self-repairing agent powder, 0.5-3.5 parts of additives, 35-45 parts of pigments and fillers, and 6-9 parts of water; The microbial self-repairing agent powder comprises the following components in parts by weight: 1-3 parts of molecular sieve, 4-6 parts of microbial culture liquid; The microbial liquid is one or a combination of Bacillus licheniformis and Bacillus subtilis, and the diameter of the bacterial cell is 2 to 5 μm; The molecular sieve has a diameter of 1 mm to 2 mm; The auxiliary agent is one or a combination of cellulose, pH regulator, dispersant, wetting agent, defoamer, bactericide, film-forming auxiliary agent, thickener and preservative.

2. The one-component self-repairing waterborne polyurethane waterproof material according to claim 1, Features: The microbial self-repairing agent powder comprises the following preparation steps: S1. Glucose is selected as the culture medium for microbial culture and cultured for 24 hours at 35-40°C, pH value between 6.5 and 7.5, and dissolved oxygen concentration in the culture medium above 20%; In a vacuum environment, a culture medium containing a microbial liquid is mixed with a molecular sieve and adsorbed for 48 to 72 hours to prepare microbial self-repairing particles; The microbial self-repairing particles were dried in an environment of 40°C to 60°C for 48 hours, and then ground and sieved to prepare microbial self-repairing agent powder of 250-350 meshes.

3. The one-component self-repairing waterborne polyurethane waterproof material according to claim 1, Features: The modified waterborne polyurethane dispersion is a modified waterborne polyurethane dispersion modified by a silane coupling agent, wherein the silane coupling agent is one or a combination of vinyl silane coupling agent, epoxy silane coupling agent and amino silane coupling agent.

4. The one-component self-repairing waterborne polyurethane waterproof material according to claim 1, Features: The glass transition temperature range of the chloroprene rubber emulsion is: -45 DEG C to -25 DEG C, the emulsion molecular weight is: 100,000 to 150,000, and the relative density is: 1.05 to 1.

2.

5. The one-component self-repairing waterborne polyurethane waterproof material according to claim 1, Features: The molecular sieve is a zeolite molecular sieve or a ZSM molecular sieve, and its structure includes type A, type X and type Y; the diameter of the molecular sieve is 1 mm to 2 mm.

6. A method for preparing the one-component self-repairing waterborne polyurethane waterproof material according to claim 1, Features: It comprises the following preparation steps: S1. Weigh and add water in proportion and start stirring at low speed; S2. Slowly add cellulose under stirring at 500 rpm and stir thoroughly for 10 min; S3. Add pH adjuster, dispersant, defoamer, modified aqueous polyurethane dispersion, chloroprene rubber emulsion in sequence under stirring at 500 rpm and stir well for 5 min; S4. Adjust the 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 one-component self-healing waterborne polyurethane waterproof material.

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