Solvent-free environment-friendly single-component polyurethane waterproof coating and preparation method thereof

Abstract

The invention relates to the technical field of polyurethane coatings, in particular to a solvent-free environment-friendly single-component polyurethane waterproof coating and a preparation method thereof. The waterproof coating is prepared from the following raw material components in parts by mass: 25 to 30 parts of polyol, 10 to 15 parts of a plasticizer, 52 to 56 parts of modified powder, 9 to 11 parts of isocyanate, 1 to 2 parts of a chain extender, 0.07 to 0.09 part of a catalyst, 0.3 to 0.4 part of a de-foaming agent and 0.2 to 0.3 part of an anti-settling agent, wherein the modified powder is obtained by modifying a mixture of powder and a rheological additive with organosilane. The solid content of the product is 99.5% or above, and the product is high in environmental protection property, low in viscosity, easy to construct, good in mechanical property, free of performance attenuation after aging treatment and good in aging resistance. After the product is constructed on concrete, a coating film is flat and smooth after being cured, the interior of the film is compact and free of bubbles, the surface is free of shrinkage cavities, and a good waterproof effect can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of polyurethane coatings, and in particular, to a solvent-free environmentally friendly one-component polyurethane waterproof coating and a preparation method thereof. Background Art

[0002] The solvent-free polyurethane waterproof coating is made by reacting isocyanate and polyether polyol as the main raw materials, with various additives and fillers, and is a high-solid-content waterproof coating without volatile solvents. Its characteristics are one-component and solvent-free, so it has the advantages of good environmental performance, simple construction, fast curing speed, and excellent comprehensive performance.

[0003] The one-component solvent-free polyurethane waterproof coating is widely applicable to various waterproof projects, including but not limited to: indoor waterproof projects such as basements, bathrooms, kitchens, balconies, etc. of industrial and civil buildings; roof waterproof projects, including flat roofs, pitched roofs, etc.; underground projects such as subways, tunnels, utility tunnels, etc.; projects with high environmental protection requirements or poor ventilation, such as hospitals, schools, etc.

[0004] However, most of the solvent-free polyurethane waterproof coatings sold on the market at present have the following disadvantages: due to the absence of solvents added, the viscosity is too large and the construction efficiency is low; when used on a flat interface, there are no air bubbles inside the waterproof film after curing, but when constructed on concrete, after curing, there are many honeycomb pores inside the film, and due to poor leveling and permeability, the coating cannot completely enter the voids of the concrete, resulting in defects and incomplete surfaces on the film, and air bubbles inside the film; the free TDI content is high and it is not environmentally friendly; the curing speed is slow in winter; the overall performance is low, and after aging, the performance decays significantly.

[0005] In view of this, the present invention is specifically proposed. Summary of the Invention

[0006] The first object of the present invention is to provide a solvent-free environmentally friendly one-component polyurethane waterproof coating to solve the technical problems that the existing solvent-free one-component polyurethane waterproof coating has a large viscosity and is not conducive to construction, and / or has many air bubbles inside the film and serious surface shrinkage holes when constructed on concrete, and / or has poor mechanical properties and anti-aging properties. The solvent-free one-component polyurethane waterproof coating provided by the present invention has high environmental protection, a solid content of more than 99.5%, low viscosity, is easy to construct, has good mechanical properties, and the mechanical properties do not decay after aging treatment. When constructed on concrete, the coating film is smooth and flat after curing, the inside of the film is dense and bubble-free, and there are no shrinkage holes on the surface, and a good waterproof effect can be achieved.

[0007] The second object of the present invention is to provide a preparation method of the solvent-free environmentally friendly one-component polyurethane waterproof coating as described above.

[0008] In order to achieve the above objects of the present invention, the following technical solutions are specifically adopted:

[0009] A solvent-free environmentally friendly one-component polyurethane waterproof coating, calculated by mass fraction, the raw materials include the following components:

[0010] 25-30 parts of polyol, 10-15 parts of plasticizer, 52-56 parts of modified powder, 9-11 parts of isocyanate, 1-2 parts of chain extender, 0.07-0.09 parts of catalyst, 0.3-0.4 parts of defoamer, 0.2-0.3 parts of anti-settling agent;

[0011] Among them, the modified powder is obtained by modifying a mixture of powder and rheological aid with organosilane.

[0012] Preferably, the preparation method of the modified powder includes the following steps:

[0013] Mix the powder and the rheological aid, add the modification liquid containing the organosilane, and stir at a speed of 1600-1700 r / min for 15-25 min; heat to volatilize the solvent to obtain the modified powder.

[0014] Preferably, the powder includes at least one of heavy calcium carbonate, high-gloss barium, and wollastonite.

[0015] Preferably, the oil absorption value of the powder is less than 18 g / 100 g.

[0016] Preferably, the water content of the powder is less than 0.5‰.

[0017] Preferably, the rheological aid includes at least one of CRAYVALLAC SL and MT-1.

[0018] Preferably, the weight ratio of the powder to the rheological aid is 100:0.5-0.6.

[0019] Preferably, the modification liquid includes methyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane and a solvent with a mass ratio of 1:1-3:7-8.

[0020] Preferably, the modification liquid accounts for 15 wt%-25 wt% of the powder.

[0021] Preferably, the polyol includes polyether diol, polytetrahydrofuran ether diol, polycarbonate diol and glycerol-based polyether polyol.

[0022] More preferably, the polyol includes DL-1000D, DL-2000D, PTMEG2000, WHP-CD200 and EP-330NG with a mass ratio of 6:0-3:2-6:2-4:12-16.

[0023] Preferably, the plasticizer includes at least one of LF-70 and T60.

[0024] Preferably, the isocyanate includes 7-8 parts of MDI and 2-3 parts of IPDI.

[0025] Preferably, the catalyst includes 0.02-0.03 parts of a first catalyst and 0.05-0.06 parts of a second catalyst. The first catalyst includes a bismuth-zinc composite catalyst, and the second catalyst includes at least one of dimorpholine diethyl ether and triethylenediamine.

[0026] Preferably, the defoamer is a modified polysiloxane compound.

[0027] Preferably, the preparation method of the chain extender includes the following steps:

[0028] Stir and react vinyl-terminated silicone oil, a photoinitiator solution, and mercapto alcohol under ultraviolet lamp irradiation for 0.5-1.5 h, and evaporate to remove the solvent to obtain the chain extender.

[0029] Preferably, the mass percentage of vinyl in the vinyl-terminated silicone oil is (1±0.2)%.

[0030] Preferably, the photoinitiator solution includes benzoin dimethyl ether and a solvent. Among them, the mass fraction of benzoin dimethyl ether is 10%-15%.

[0031] Preferably, the dosage of the photoinitiator solution is 0.5 wt%-1.5 wt% of the vinyl-terminated silicone oil.

[0032] Preferably, the mercapto alcohol includes at least one of 4-mercapto-1-butanol and 6-mercapto-1-hexanol.

[0033] Preferably, the dosage of the mercapto alcohol is 3 wt%-6 wt% of the vinyl-terminated silicone oil.

[0034] Preferably, the preparation method of the anti-settling agent includes the following steps:

[0035] S1. Dehydrate polypropylene glycol ether diol and react it with p-phenylene diisocyanate to obtain an intermediate product;

[0036] S2. Stir and mix KH540 and KH550 under vacuum heating for 15-25 min, add the intermediate product, and keep stirring and reacting under vacuum heating for 2-4 h to obtain the anti-settling agent.

[0037] Preferably, the polypropylene glycol ether diol includes at least one of DL-4000D, DL-3000D, and DL-2000D.

[0038] Preferably, the molar ratio of the polypropylene glycol ether diol, the terephthalic diisocyanate, the KH540, and the KH550 is 1: 1.1-1.4: 0.1-0.4: 0.2-0.5.

[0039] Preferably, in step S2, the temperature of the stirring and mixing is 75-85 °C, and the temperature of the stirring reaction is 75-85 °C.

[0040] A method for preparing a solvent-free environmentally friendly one-component polyurethane waterproof coating as described in any one of the foregoing embodiments, comprising the following steps:

[0041] S1. Mix a polyol, a plasticizer, and a modified powder and perform vacuum dehydration.

[0042] S2. Add MDI at 78-80 °C, stir and react under vacuum for 1-2 h, add a first catalyst and IPDI, stir and react under vacuum for 1-2 h, and add a chain extender and stir and react under vacuum for 20-40 min.

[0043] S3. Cool down to below 70 °C, add a second catalyst, an antifoaming agent, and an anti-settling agent, and stir at a speed of 1500-1800 r / min for 20-40 min to obtain the product.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0045] After the powder of the present invention is modified, it has better compatibility with the waterproof coating system, can significantly reduce the viscosity of the coating, and reduce the construction difficulty; the self-anti-foaming effect of the modified powder and the chain extender acts together to improve the problems of air bubbles and shrinkage holes after the film is cured; the anti-settling agent can form a stable chemical action with the coating system, and cooperate with the modified powder to ensure that no settlement occurs in the coating within one year. The chain extender and anti-settling agent prepared by the present invention can also improve the aging resistance of the coating; adding a modified polysiloxane antifoaming agent, through process control, reduces the free NCO content in the system, and has excellent mechanical properties. Description of the Drawings

[0046] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0047] Figure 1 It is a photograph of the film quality after construction of Example 1 on concrete;

[0048] Figure 2Photograph of the film quality after construction on concrete in Example 2;

[0049] Figure 3 Photograph of the film quality after construction on concrete in Example 3;

[0050] Figure 4 Photograph of the film quality after construction on concrete in Comparative Example 1;

[0051] Figure 5 Photograph of the film quality after construction on concrete in Comparative Example 3;

[0052] Figure 6 Photograph of the film quality after construction on concrete in Comparative Example 8;

[0053] Figure 7 Photograph of the film quality after construction on concrete in Comparative Example 9;

[0054] Figure 8 Photograph of the film quality after construction on concrete in Comparative Example 10. Detailed implementation manners

[0055] The technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and specific implementation manners. However, those skilled in the art will understand that the following described embodiments are some embodiments of the present invention, rather than all embodiments, and are only used to illustrate the present invention, and should not be construed as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present invention. For those conditions not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. For those reagents or instruments without indicating the manufacturer, they are all conventional products that can be obtained through commercial purchase.

[0056] The first aspect of the present invention provides a solvent-free environmentally friendly one-component polyurethane waterproof coating. By mass, the raw materials include the following components:

[0057] 25 - 30 parts of polyol, 10 - 15 parts of plasticizer, 52 - 56 parts of modified powder, 9 - 11 parts of isocyanate, 1 - 2 parts of chain extender, 0.07 - 0.09 parts of catalyst, 0.3 - 0.4 parts of defoamer, 0.2 - 0.3 parts of anti-settling agent;

[0058] Among them, the modified powder is obtained by modifying the mixture of powder and rheological aid with organosilane.

[0059] The solvent-free one-component polyurethane waterproof coating provided by the present invention has a solid content of more than 99.5%, no free TDI, high environmental protection, a viscosity below 15,000 cp (23 °C), is easy to construct, and its performance meets the requirements of Type II polyurethane waterproof coating in GB / T 19250-2017 and T / CWA 209-2022. After various aging treatments, the performance such as tensile strength, elongation at break, and retention rate of bond strength after immersion treatment does not show attenuation, and it has good aging resistance. After the product is constructed on concrete, the coating film is smooth and flat after curing, the film interior is dense and bubble-free, and there are no shrinkage holes on the surface, achieving a good waterproof effect.

[0060] Adding a rheological aid to the powder in the present invention can reduce the viscosity of the product and improve the anti-settling effect, and improve the bubble and shrinkage hole phenomena after the product cures. After being modified by organosilane, a coating is formed on the surface of the powder, which can improve the compatibility between the powder and the system, reduce the viscosity of the system and improve the leveling performance, and avoid the formation of bubbles and shrinkage holes; it can also prevent agglomeration between powder particles, enhance the bonding force between the powder and the coating matrix, and improve the stability of the system.

[0061] In some embodiments, typically but not restrictively, for example, the mass fraction of the polyol can be any value among 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts or a range value composed of any two of these values; the mass fraction of the plasticizer can be any value among 10 parts, 12 parts, 13 parts, 15 parts or a range value composed of any two of these values; the mass fraction of the isocyanate can be any value among 9 parts, 9.5 parts, 10 parts, 10.5 parts, 11 parts or a range value composed of any two of these values; the mass fraction of the chain extender can be any value among 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts or a range value composed of any two of these values; the mass fraction of the catalyst can be any value among 0.07 parts, 0.08 parts, 0.09 parts or a range value composed of any two of these values; the mass fraction of the defoamer can be any value among 0.3 parts, 0.32 parts, 0.35 parts, 0.38 parts, 0.4 parts or a range value composed of any two of these values; the mass fraction of the anti-settling agent can be any value among 0.2 parts, 0.22 parts, 0.25 parts, 0.28 parts, 0.3 parts or a range value composed of any two of these values.

[0062] In some specific embodiments of the present invention, the preparation method of the modified powder includes the following steps:

[0063] Mix the powder material and the rheological aid, place them in a high-speed stirring tank, add the modified liquid containing silane, and stir at a speed of 1600 - 1700 r / min for 15 - 25 min; heat to 80 - 85 °C under vacuum conditions and continue to stir at a speed of 1600 - 1700 r / min until the solvent completely evaporates to obtain the modified powder material. Typically but not restrictively, for example, the stirring speed during silane modification can be any value among 1600 r / min, 1620 r / min, 1650 r / min, 1680 r / min, 1700 r / min or a range value composed of any two of these values; the stirring time can be any value among 15 min, 18 min, 20 min, 23 min, 25 min or a range value composed of any two of these values.

[0064] In some specific embodiments of the present invention, the powder material used includes at least one of heavy calcium carbonate, high-gloss barium, and wollastonite.

[0065] In some specific embodiments of the present invention, the oil absorption value of the powder material used is less than 18 g / 100 g. An excessive oil absorption value will cause an increase in the viscosity of the product and increase the construction difficulty.

[0066] In some specific embodiments of the present invention, the water content of the powder material used is less than 0.5‰. Using a powder material with a low water content can shorten the dehydration time and improve production efficiency.

[0067] In some specific embodiments of the present invention, the rheological aid used includes at least one of CRAYVALLAC SL and MT-1.

[0068] In some specific embodiments of the present invention, the weight ratio of the powder material to the rheological aid is 100:0.5 - 0.6. For example, it can be any value among 100:0.5, 100:0.52, 100:0.55, 100:0.58, 100:0.6 or a range value composed of any two of these values.

[0069] In some specific embodiments of the present invention, the modified liquid includes methyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane and a solvent with a mass ratio of 1:1 - 3:7 - 8. For example, the mass ratio of methyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane and the solvent can be any value among 1:1:7, 1:1:8, 1:2:7, 1:2:8, 1:3:7, 1:3:8 or a range value composed of any two of these values; as an example, the solvent for preparing the modified liquid can be ethyl acetate.

[0070] In some specific embodiments of the present invention, the addition amount of the modification liquid is 15wt%-25wt% of the powder material. For example, it can be any value among 15wt%, 18wt%, 20wt%, 22wt%, 25wt% or a range value composed of any two of these values.

[0071] In some specific embodiments of the present invention, the polyols used include polyether diols, polytetrahydrofuran ether diols, polycarbonate diols, and glycerol-based polyether polyols. As an example, the polyether diol can be DL-1000D or a combination of DL-1000D and DL-2000D; the polytetrahydrofuran ether diol can be PTMEG2000; the polycarbonate diol can be WHP-CD200; the glycerol-based polyether polyol can be EP-330NG. By selecting a suitable combination of polyols, it is possible to ensure that the product still has a high curing speed in a low-temperature and low-humidity environment and can improve the mechanical properties of the product.

[0072] In some preferred embodiments of the present invention, the polyols used include DL-1000D, DL-2000D, PTMEG2000, WHP-CD200, and EP-330NG with a mass ratio of 6:0-3:2-6:2-4:12-16. For example, the mass ratio of DL-1000D, DL-2000D, PTMEG2000, WHP-CD200, and EP-330NG can be any value among 6:0:6:3:14, 6:2:3:3:14, 6:3:3:3:14, 6:1:5:3:14, 6:0:5:4:12, 6:2:4:2:16 or a range value composed of any two of these values. Among them, DL-1000D has a low molecular weight, good flexibility and reactivity, PTMEG2000 has excellent mechanical properties, WHP-CD200 has good dispersibility and compatibility, and PTMEG2000, WHP-CD200, DL-1000D, and EP-330NG act synergistically to significantly improve the low-temperature curing speed of the coating film and the mechanical properties of the product.

[0073] In some specific embodiments of the present invention, the plasticizers used include at least one of plasticizer LF-70 (Blue Sail Chemical Industry) and plasticizer T60 (Jiangsu Shengkai). Both plasticizers are environmentally friendly plasticizers, which is beneficial to improving the environmental protection of the waterproof coating.

[0074] In some specific embodiments of the present invention, the isocyanates used include 7-8 parts of MDI (diphenylmethane diisocyanate) and 2-3 parts of IPDI (isophorone diisocyanate). MDI has good mechanical properties, and IPDI has good weather resistance. When used in combination, they can improve the mechanical properties and anti-aging properties of the product. Toluene diisocyanate (TDI) is not used in the present invention, resulting in a low content of volatile organic compounds, no free TDI, and high environmental friendliness.

[0075] In some embodiments, typically but not restrictively, for example, the mass fraction of MDI can be any value among 7 parts, 7.2 parts, 7.5 parts, 7.8 parts, 8 parts or a range value composed of any two of these values; the mass fraction of IPDI can be any value among 2 parts, 2.2 parts, 2.5 parts, 2.8 parts or a range value composed of any two of these values.

[0076] In some specific embodiments of the present invention, the catalysts used include 0.02-0.03 parts of a first catalyst and 0.05-0.06 parts of a second catalyst. The first catalyst includes a bismuth-zinc composite catalyst, such as at least one of Umicore Valikat ZB1001, Umicore Valikat ZB8, Guangzhou Yourun BX-EM14, and Guangzhou Yourun BX-EM23; the second catalyst includes at least one of dimorpholine diethyl ether and triethylenediamine. The first catalyst can promote the synthesis reaction and also promote film formation during the use of the coating. The second catalyst mainly promotes the reaction between the product and moisture during the use of the coating, improving the film formation speed. The combination of the two has a better effect.

[0077] In some specific embodiments of the present invention, the defoamer used is a modified polysiloxane compound. Adding the modified polysiloxane defoamer can reduce the content of free NCO in the system and improve the mechanical properties. As an example, the defoamer used includes at least one of DEFOART-2346 and BYK024.

[0078] In some specific embodiments of the present invention, the chain extender used is a polymerization product of bis(vinyl-terminated) silicone oil and mercapto alcohol. The preparation method of the chain extender includes the following steps:

[0079] Stir and react bis(vinyl-terminated) silicone oil, a photoinitiator solution, and mercapto alcohol under ultraviolet lamp irradiation for 0.5-1.5 h, and evaporate to remove the solvent to obtain the chain extender.

[0080] In the present invention, a double-ended vinyl silicone oil is used as the main chain raw material to carry out a polymerization reaction with mercapto alcohol in the presence of a photoinitiator and under the irradiation of an ultraviolet lamp. The obtained chain extender contains silicon-oxygen bonds and hydroxyl groups, which can not only extend the chain but also have the effect of defoaming. The chain extender prepared in the present invention and the modified powder act together to improve the problems of bubbles and shrinkage holes after the film is cured; the chain extender prepared in the present invention can also significantly improve the aging resistance of the product.

[0081] In some specific embodiments of the present invention, the mass percentage of vinyl in the double-ended vinyl silicone oil used is (1±0.2)%.

[0082] In some specific embodiments of the present invention, the photoinitiator solution used includes benzoin dimethyl ether and a solvent. As an example, the solvent used can be at least one of ethyl acetate, butyl acetate, and acetone. Among them, the mass fraction of benzoin dimethyl ether in the photoinitiator solution is 10%-15%, for example, it can be any value among 10%, 12%, 14%, 15% or a range value composed of any two of these values.

[0083] In some specific embodiments of the present invention, the dosage of the photoinitiator solution is 0.5wt%-1.5wt% of the double-ended vinyl silicone oil, for example, it can be any value among 0.5wt%, 0.8wt%, 1wt%, 1.2wt%, 1.5wt% or a range value composed of any two of these values.

[0084] In some specific embodiments of the present invention, the mercapto alcohol used includes at least one of 4-mercapto-1-butanol and 6-mercapto-1-hexanol.

[0085] In some specific embodiments of the present invention, the dosage of the mercapto alcohol is 3wt%-6wt% of the double-ended vinyl silicone oil, for example, it can be any value among 3wt%, 4wt%, 5wt%, 6wt% or a range value composed of any two of these values.

[0086] In some specific embodiments of the present invention, the preparation method of the anti-settling agent used includes the following steps:

[0087] S1. Vacuum dehydrate polypropylene glycol ether diol and react it with p-phenylene diisocyanate to obtain an intermediate product;

[0088] S2. Stir and mix KH540 and KH550 under vacuum heating for 15-25 min, add the intermediate product prepared in step S1, and keep stirring and reacting under vacuum heating for 2-4 h to obtain the anti-settling agent.

[0089] In the present invention, symmetric p-phenylene diisocyanate is used to react with polypropylene glycol ether diol to generate an intermediate product containing -NCO groups. The -NCO groups on the intermediate product further react with the amino groups in KH540 and KH550 to form urea bonds, thus obtaining an anti-settling agent. The anti-settling agent prepared by the present invention can significantly improve the aging resistance of the product; moreover, the anti-settling agent formed by the reaction of the intermediate product with the silane coupling agent can form a stable chemical interaction with the coating system, and its synergistic effect with the modified powder can ensure that the coating will not settle within one year.

[0090] In some specific embodiments of the present invention, in step S2, the intermediate product is slowly added to avoid gel formation due to too fast feeding, which may affect the anti-settling effect. Preferably, the feeding time is not less than 4 min. For example, it can be any value among 4 min, 5 min, 6 min, 7 min, 8 min or a range value composed of any two of these values.

[0091] In some specific embodiments of the present invention, the polypropylene glycol ether diol used includes at least one of DL-4000D, DL-3000D, and DL-2000D.

[0092] In some specific embodiments of the present invention, the molar ratio of polypropylene glycol ether diol, p-phenylene diisocyanate, KH540, and KH550 is 1:1.1 - 1.4:0.1 - 0.4:0.2 - 0.5.

[0093] In some specific embodiments of the present invention, in step S2, the temperatures of both the stirring and mixing and the stirring reaction are 75 - 85 °C. For example, it can be any value among 75 °C, 78 °C, 80 °C, 82 °C, 85 °C or a range value composed of any two of these values.

[0094] The second aspect of the present invention provides a preparation method of the solvent-free environmentally friendly one-component polyurethane waterproof coating described in any one of the foregoing embodiments, including the following steps:

[0095] S1. Mix polyol, plasticizer, and modified powder and perform vacuum dehydration.

[0096] S2. Add MDI at 78 - 80 °C, stir and react under vacuum for 1 - 2 h, add the first catalyst and IPDI, stir and react under vacuum for 1 - 2 h, add the chain extender, and stir and react under vacuum for 20 - 40 min.

[0097] S3. Cool down to below 70 °C, add the second catalyst, defoamer, and anti-settling agent, and stir at a speed of 1500 - 1800 r / min for 20 - 40 min to obtain the product.

[0098] The method of the present invention has a simple process, mild conditions, and is convenient for batch production. Polyurethane coatings are prepared using MDI and IPDI, which are highly environmentally friendly and have good mechanical properties and weather resistance. Adding the chain extender and anti-settling agent prepared by the present invention can significantly improve the anti-aging performance of the product; the modified powder has better compatibility with the waterproof coating system, which can significantly reduce the viscosity of the product; the combined action of the modified powder and the chain extender prepared by the present invention can improve the problems of bubbles and shrinkage holes after the film is cured; the synergistic effect of the modified powder and the anti-settling agent prepared by the present invention can ensure that the coating does not settle within one year; after adding the defoaming agent and stirring at high speed, promoting the action of the defoaming agent and free NCO and the volatilization of free NCO can reduce the content of free NCO in the system and improve the mechanical properties of the product.

[0099] In the present invention, after adding the defoaming agent, stirring is carried out at a rotation speed of 1500 - 1800 r / min, and the purpose is to promote the volatilization of free NCO. For example, the rotation speed after adding the defoaming agent can be any one value among 1500 r / min, 1600 r / min, 1700 r / min, 1800 r / min or a range value composed of any two of these values; the stirring time after adding the defoaming agent can be any one value among 20 min, 25 min, 30 min, 35 min, 40 min or a range value composed of any two of these values. In other stirring and mixing and stirring reaction processes, the stirring speed has no special limitation as long as the materials can be evenly mixed.

[0100] In some embodiments of the present invention, the vacuum state during the reaction process or solvent volatilization process refers to a vacuum degree in the container of -0.095 MPa to -0.1 MPa.

[0101] The following combines specific application examples to make a detailed description of some embodiments of the present invention. The raw material substances used in the examples can be obtained through commercial purchase without special instructions.

[0102] Examples 1 - 5

[0103] By mass, the raw material compositions of the solvent-free environmentally friendly one-component polyurethane waterproof coatings in Examples 1 - 5 are shown in Table 1.

[0104] Table 1

[0105]

[0106]

[0107] Preparation of raw materials:

[0108] (1) Preparation of modified powder

[0109] Mix methyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, and ethyl acetate in a ratio of 1:2:7 to prepare a modification liquid;

[0110] Put 50 parts of heavy calcium carbonate (oil absorption value 17 g / 100 g), 50 parts of high-gloss barium (oil absorption value 16 g / 100 g), and 0.5 part of CRAYVALLAC SL into a high-speed stirring tank, add 20 parts of the modification liquid, stir at a high speed of 1600 r / min for 20 min, turn on the high temperature of 80 - 85 °C, evacuate, continue to stir at a high speed of 1600 r / min for 20 min, collect after ethyl acetate is completely evaporated, and seal and package the obtained modified powder for standby.

[0111] (2) Preparation of chain extender A

[0112] Add 100 parts of double-end vinyl silicone oil VSO-100 with a vinyl mass percentage of 1.05% and 1 g of an ethyl acetate solution of benzoin dimethyl ether with a mass fraction of 10% into a reaction kettle, place the reaction system under ultraviolet light irradiation, add 4 parts of 4-mercapto-1-butanol, stir and react for 1 h, stop irradiation, raise the temperature to 80 °C, stir under vacuum for 20 min, collect after ethyl acetate is completely evaporated, pour out the product, seal and store it to obtain chain extender A for standby.

[0113] (3) Preparation of chain extender B

[0114] Add 100 parts of double-end vinyl silicone oil JP-01V-100 with a vinyl mass percentage of 1.0% and 1 g of an ethyl acetate solution of benzoin dimethyl ether with a mass fraction of 12% into a reaction kettle, place the reaction system under ultraviolet light irradiation, add 5 parts of 6-mercapto-1-hexanol, stir and react for 1 h, stop irradiation, raise the temperature to 80 °C, stir under vacuum for 20 min, collect after ethyl acetate is completely evaporated, pour out the product, seal and store it to obtain chain extender B for standby.

[0115] (4) Preparation of anti-settling agent

[0116] After dehydrating 1 mol of polyether polyol DL-4000D under vacuum at 120 °C for 2 h, cool it to 80 °C, add 1.2 mol of p-phenylene diisocyanate, and react under vacuum at 78 - 80 °C for 2 h to obtain an intermediate product;

[0117] Pour 0.2 mol of 3-aminopropyltrimethoxysilane (KH540) and 0.4 mol of 3-aminopropyltriethoxysilane (KH550) into a reaction kettle, heat at 80 °C, evacuate, stir for 20 min, then slowly add the intermediate product, and the feeding time is 5 min. After heating at 80 °C, evacuating, and stirring and reacting for 3 h, obtain the anti-settling agent, pour it out, seal and store it for standby.

[0118] The preparation process of the solvent-free environmentally friendly one-component polyurethane waterproof coating in Examples 1-5 is as follows:

[0119] S1. Add polyol, plasticizer, and modified powder according to the ratio into the reaction kettle, stir and disperse to mix the materials evenly, control the temperature at 100 °C, and stir and dehydrate under vacuum for 1 h;

[0120] S2. Cool down to 78 - 80 °C, add MDI, control the temperature at 78 - 80 °C, stir and react under vacuum for 1.5 h, add the first catalyst, gradually add IPDI, control the temperature at 78 - 80 °C, stir and react under vacuum for 1.5 h, add the chain extender, control the temperature at 78 - 80 °C, and stir and react under vacuum for 0.5 h;

[0121] S3. Lower the temperature below 70 °C, add the second catalyst, defoamer, and anti-settling agent, stir at a speed of 1500 r / min for 30 min under vacuum, and discharge from the kettle for filling.

[0122] Comparative Example 1

[0123] Comparative Example 1 is similar to Example 1, with the only difference being that the chain extender is not added, and the other conditions are the same as those in Example 1.

[0124] Comparative Example 2

[0125] Comparative Example 2 is similar to Example 2, with the only difference being that the anti-settling agent is not added, and the other conditions are the same as those in Example 2.

[0126] Comparative Example 3

[0127] Comparative Example 3 is similar to Example 3, with the only difference being that when preparing the modified powder, the rheology aid CRAYVALLAC SL is not added, and the other conditions are the same as those in Example 3.

[0128] Comparative Example 4

[0129] Comparative Example 4 is similar to Example 4, with the only difference being that the defoamer is not added, and the other conditions are the same as those in Example 4.

[0130] Comparative Example 5

[0131] Comparative Example 5 is similar to Example 1, with the only difference being that the anti-settling agent is replaced with an equal amount of commercially available anti-settling aid ECO-6500 (polyurea compound), and the other conditions are the same as those in Example 1.

[0132] Comparative Example 6

[0133] Comparative Example 6 is similar to Example 2, with the only difference being that the feeding order of MDI and IPDI is exchanged, and the other conditions are the same as those in Example 2.

[0134] Comparative Example 7

[0135] Comparative Example 7 is similar to Example 3, and the only difference is that the addition amount of DL-2000D in the polyol is changed to 9 parts, PTMEG2000 and WHP-CD200 are not added, and the other conditions are the same as those in Example 3.

[0136] Comparative Example 8

[0137] Comparative Example 8 is similar to Example 4, and the only difference is that when preparing the modified powder, instead of using the modified liquid for modification, a mixture of 50 parts of heavy calcium carbonate, 50 parts of high-gloss barium, and 0.5 part of CRAYVALLAC SL is directly used to replace the modified powder in Example 4, and the other conditions are the same as those in Example 4.

[0138] Comparative Example 9

[0139] Comparative Example 9 is similar to Example 1, and the only difference is that the chain extender A is replaced with a commercially available chain extender 1,6-hexanediol, and the other conditions are the same as those in Example 1.

[0140] Comparative Example 10

[0141] Comparative Example 10 is similar to Example 2, and the only difference is that a modified liquid is prepared by mixing methyltrimethoxysilane and ethyl acetate in a ratio of 3:7, that is, 3-(2,3-epoxypropoxy)propyltrimethoxysilane is not added to the modified liquid, and the other conditions are the same as those in Example 2.

[0142] Comparative Example 11

[0143] Comparative Example 11 is similar to Example 3, and the only difference is that a modified liquid is prepared by mixing 3-(2,3-epoxypropoxy)propyltrimethoxysilane and ethyl acetate in a ratio of 3:7, that is, methyltrimethoxysilane is not added to the modified liquid, and the other conditions are the same as those in Example 3.

[0144] Test Example

[0145] The product performances in each example and each comparative example were respectively detected, and the detection methods are as follows:

[0146] For the detection of viscosity, after the product was kept at a constant temperature of 23°C for 24 hours, it was tested with a Brookfield DV2T type viscometer;

[0147] The other product performances were carried out according to the methods specified in T / CWA209-2022 "Solvent-Free Polyurethane Waterproof Coating".

[0148] The detection results in Examples 1-5 are shown in Table 2.

[0149] Table 2

[0150]

[0151]

[0152] It can be seen from the results in Table 2 that according to the ratio and production process specified in the present invention, the solid content of the solvent-free environmentally friendly one-component polyurethane waterproof coating obtained is above 99.5%, and the performance not only meets the requirements of T / CWA209-2022 "Solvent-free Polyurethane Waterproof Coating", but also meets the performance of Type II polyurethane waterproof coating specified in GB / T19250-2013. After heat treatment at 80°C for 14d, alkali treatment, and acid treatment, there was no attenuation in tensile strength and elongation at break, and the bonding strength retention rate after immersion treatment was above 100%, indicating that the product has good anti-aging properties. After construction on concrete, the coating film is dense, bubble-free, and shrinkage-free. The time taken for a 1mm coating to be completely cured under low temperature and low humidity conditions of 5°C and 20%RH does not exceed 12h, which can ensure efficiency during winter construction. No sedimentation occurred after standing for one year, indicating that when the product is used within one year, it is not necessary to stir in advance to avoid affecting efficiency and bubbles generated by stirring that affect construction quality. After one year, there was no decrease in the bonding strength under standard test conditions, and the product can be used normally, with high construction safety.

[0153] Figure 1 , Figure 2 and Figure 3 The following are photos of the coating quality after the coatings in Example 1, Example 2 and Example 3 were applied on concrete. The coatings are dense, without bubbles or shrinkage cavities.

[0154] The test results in Comparative Examples 1-4 are shown in Table 3.

[0155] Table 3

[0156]

[0157] From the results in Table 3, it can be seen that in Comparative Example 1, the chain extender prepared by the present invention is not added, which causes the aging resistance to decrease. After one year, the bonding strength under the standard test conditions decreases, and bubbles and shrinkage holes are easily generated, indicating that the chain extender prepared by the present invention can improve the aging resistance of the product and improve the bubbles and shrinkage holes after curing; in Comparative Example 2, the anti-settling agent prepared by the present invention is not added, which causes the aging resistance to decrease. After one year, the bonding strength under the standard test conditions decreases, and obvious sedimentation occurs after one year, indicating that the anti-settling agent prepared by the present invention can improve the aging resistance of the product and has excellent anti-settling effect; in Comparative Example 3, CRAYVALLAC SL is not added to the modified powder, which causes the viscosity to increase and the anti-settling effect to decrease. After the product is cured, bubbles and shrinkage holes are generated; in Comparative Example 4, no modified polysiloxane defoamer is added, which is not conducive to promoting the volatilization of free NCO in the system, and the mechanical properties under standard conditions are reduced.

[0158] Depend on Figure 4 and Figure 5 It can be seen that the coating films of Comparative Examples 1 and 3 after being applied on concrete have many bubbles and severe shrinkage cavities.

[0159] The test results in Comparative Examples 5-8 are shown in Table 4.

[0160] Table 4

[0161]

[0162] In comparative example 5, the anti-settling agent was changed to the commercially available anti-settling agent ECO-6500. After one year, slight sedimentation occurred and the aging resistance decreased. This shows that the anti-settling agent prepared by the present invention has better anti-settling effect. Comparative example 6 changed the order of adding MDI and IPDI in the production process. The mechanical properties under standard conditions decreased, and the tensile strength did not meet the performance requirements of type II polyurethane waterproof coatings specified in GB / T19250-2013. Comparative example 7 changed the addition amount of DL-2000D to 9 parts, without adding PTMEG2000 and WHP-CD200, the low-temperature curing speed was significantly slowed down, and the mechanical properties under standard conditions decreased. Comparative example 8 did not use a modifying liquid to modify the mixture of powder and rheological additives, then the viscosity increased significantly, which was not conducive to construction, and after the construction on the concrete was completed, the coating had bubbles and serious shrinkage holes, which affected the waterproof effect. Slight sedimentation occurred after one year. Combined with comparative examples 2 and 5, it is shown that the anti-settling agent prepared by the present invention works together with the modified powder to have a good anti-settling effect.

[0163] Depend on Figure 6 It can be seen that the coating film of the coating in Comparative Example 8 after construction on concrete has bubbles and severe shrinkage cavities.

[0164] The test results in Comparative Examples 9-11 are shown in Table 5.

[0165] Table 5

[0166]

[0167]

[0168] From the results in Table 5, it can be seen that in Comparative Example 9, the chain extender A is replaced with the commercially available chain extender 1,6-hexanediol, and the aging resistance of the product decreases, and there are many bubbles in the coating after the construction on the concrete is completed; in Comparative Examples 10 and 11, only one of 3-(2,3-epoxypropoxy)propyltrimethoxysilane and methyltrimethoxysilane is added to the modified liquid. After the construction on the concrete is completed, there are a small number of bubbles in the coating, and slight sedimentation occurs after 1 year, indicating that a single silane coupling agent is not effective.

[0169] Depend onFigure 7 It can be seen that after the coating in Comparative Example 9 is applied to concrete, there are many bubbles and no shrinkage holes in the coating film; Figure 8 It can be seen that after the coating in Comparative Example 10 is applied to concrete, there are a small number of bubbles and no shrinkage holes in the coating film.

[0170] Although the present invention has been illustrated and described with specific embodiments, it should be realized that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; those of ordinary skill in the art should understand that: without departing from the spirit and scope of the present invention, the technical solutions recorded in the foregoing embodiments may be modified, or some or all of the technical features may be equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such replacements and modifications within the scope of the present invention are included in the appended claims.

Claims

1. A solvent-free, environmentally friendly, one-component polyurethane waterproof coating, characterized in that: The raw materials include the following components by mass: Polyol 25-30 parts, plasticizer 10-15 parts, modified powder 52-56 parts, isocyanate 9-11 parts, chain extender 1-2 parts, catalyst 0.07-0.09 parts, defoamer 0.3-0.4 parts, anti-settling agent 0.2-0.3 parts; The modified powder is obtained by modifying a mixture of powder and a rheological additive through organic silane.

2. The solvent-free, environment-friendly, one-component polyurethane waterproof coating according to claim 1, characterized in that: The preparation method of the modified powder comprises the following steps: The powder and the rheological additive are mixed, and the modified liquid containing the organosilane is added, and stirred at a rotation speed of 1600-1700 r / min for 15-25 minutes; and heated to volatilize the solvent to obtain the modified powder.

3. The solvent-free, environment-friendly, one-component polyurethane waterproof coating according to claim 2, characterized in that: Meet at least one of the following characteristics: (1) The powder includes at least one of heavy calcium carbonate, high-gloss barium, and wollastonite; (2) The oil absorption value of the powder is less than 18 g / 100 g; (3) The water content of the powder is less than 0.5‰; (4) the rheological additive comprises at least one of CRAYVALLAC SL and MT-1; (5) The weight ratio of the powder to the rheological additive is 100:0.5-0.6; (6) The modified liquid comprises methyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane and a solvent in a mass ratio of 1:1-3:7-8; (7) The modified liquid accounts for 15wt%-25wt% of the powder.

4. The solvent-free, environment-friendly, one-component polyurethane waterproof coating according to claim 1, characterized in that: The polyols include polyether diols, polytetramethylene ether diols, polycarbonate diols and glycerol-based polyether polyols; Preferably, the polyol comprises DL-1000D, DL-2000D, PTMEG2000, WHP-CD200 and EP-330NG in a mass ratio of 6:0-3:2-6:2-4:12-16.

5. The solvent-free, environment-friendly, one-component polyurethane waterproof coating according to claim 1, characterized in that: Meet at least one of the following characteristics: (1) The plasticizer includes at least one of LF-70 and T60; (2) the isocyanate comprises 7-8 parts of MDI and 2-3 parts of IPDI; (3) The catalyst comprises 0.02-0.03 parts of a first catalyst and 0.05-0.06 parts of a second catalyst, wherein the first catalyst comprises a bismuth-zinc composite catalyst, and the second catalyst comprises at least one of dimorpholine diethyl ether and triethylenediamine; (4) The defoaming agent is a modified polysiloxane compound.

6. The solvent-free, environment-friendly, one-component polyurethane waterproof coating according to claim 1, characterized in that: The preparation method of the chain extender comprises the following steps: The double-terminal vinyl silicone oil, the photoinitiator solution and the mercapto alcohol are stirred and reacted for 0.5-1.5 hours under ultraviolet light, and the solvent is evaporated to obtain the chain extender.

7. The solvent-free, environment-friendly, one-component polyurethane waterproof coating according to claim 6, characterized in that: Meet at least one of the following characteristics: (1) The mass percentage of vinyl in the double-terminated vinyl silicone oil is (1±0.2)%; (2) The photoinitiator solution comprises benzoin dimethyl ether and a solvent, wherein the mass fraction of the benzoin dimethyl ether is 10%-15%; (3) The amount of the photoinitiator solution is 0.5wt%-1.5wt% of the double-terminal vinyl silicone oil; (4) the mercapto alcohol comprises at least one of 4-mercapto-1-butanol and 6-mercapto-1-hexanol; (5) The amount of the mercapto alcohol used is 3wt%-6wt% of the double-terminal vinyl silicone oil.

8. The solvent-free, environment-friendly, one-component polyurethane waterproof coating according to claim 1, characterized in that: The preparation method of the anti-settling agent comprises the following steps: S1. dehydrating polypropylene oxide ether diol and reacting it with p-phenylene diisocyanate to obtain an intermediate product; S2. KH540 and KH550 are stirred and mixed under vacuum heating for 15-25 minutes, the intermediate product is added, and the vacuum heating state is maintained and stirred for reaction for 2-4 hours to obtain the anti-settling agent.

9. The solvent-free, environment-friendly, one-component polyurethane waterproof coating according to claim 8, characterized in that: Meet at least one of the following characteristics: (1) The polyoxypropylene ether diol includes at least one of DL-4000D, DL-3000D, and DL-2000D; (2) the molar ratio of the polyoxypropylene ether diol, the p-phenylene diisocyanate, the KH540 and the KH550 is 1:1.1-1.4:0.1-0.4:0.2-0.5; (3) In step S2, the temperature of the stirring and mixing is 75-85°C, and the temperature of the stirring reaction is 75-85°C.

10. The method for preparing the solvent-free, environment-friendly, one-component polyurethane waterproof coating according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. The polyol, plasticizer and modified powder are mixed and vacuum dehydrated; S2. Add MDI at 78-80°C, stir and react for 1-2h under vacuum, then add the first catalyst and IPDI, stir and react for 1-2h under vacuum, then add the chain extender and stir and react for 20-40min under vacuum; S3. Cool down to below 70°C, add the second catalyst, defoaming agent and anti-settling agent, and stir at a speed of 1500-1800r / min for 20-40min.

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