A solvent-free environment-friendly single-component polyurethane waterproof coating and a preparation method thereof

Abstract

The present application relates to polyurethane coating technical field, specifically, it is a kind of solvent-free environment-friendly single-component polyurethane waterproof coating and its preparation method. According to mass fraction, the raw material of waterproof coating includes the following components: 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, defoaming agent 0.3-0.4 parts, anti-settling agent 0.2-0.3 parts;Among them, the modified powder is obtained by modifying the mixture of powder and rheological auxiliary agent by organosilane.The product solid content is more than 99.5%, environmental protection is high, viscosity is low, easy to construction, mechanical property is good, and after aging treatment, performance does not appear attenuation, and good aging resistance.The product is smooth after curing after construction on concrete, the film inside is dense and bubble-free, and the surface is free of shrinkage, which can achieve good waterproof effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyurethane coating, in particular to a solvent-free environment-friendly single-component polyurethane waterproof coating and a preparation method thereof. BACKGROUND

[0002] The solvent-free polyurethane waterproof coating is prepared by reacting isocyanate, polyether polyol as main raw materials, various additives and fillers, and is a high solid content waterproof coating without volatile solvent. The single-component and solvent-free characteristics make the coating have good environmental performance, simple construction, fast curing speed and excellent comprehensive performance.

[0003] The single-component solvent-free polyurethane waterproof coating is widely used in various waterproof engineering, including but not limited to indoor waterproof engineering of basements, bathrooms, kitchens and balconies of industrial and civil buildings, roof waterproof engineering including flat roof and slope roof, underground engineering such as subway, tunnel and comprehensive pipe gallery, and engineering with high environmental requirements or poor ventilation such as hospitals and schools.

[0004] However, most of the solvent-free polyurethane waterproof coatings on the market have the following shortcomings: due to the absence of solvent, the viscosity is large and the construction efficiency is low; when used on a flat interface, there are no bubbles in the waterproof film after curing, but when applied on concrete, there are many honeycomb pores in the film after curing, and due to poor leveling and permeability, the coating cannot completely enter the voids of the concrete, resulting in defects and incomplete phenomenon on the surface of the film, and bubbles in the film; the content of free TDI is high, which is not environmentally friendly; the curing speed is slow in winter; the overall performance is low, and the performance decays a lot after aging.

[0005] Therefore, the present application is proposed. SUMMARY

[0006] The first object of the present application is to provide a solvent-free environment-friendly single-component polyurethane waterproof coating to solve the technical problems of large viscosity of the existing solvent-free single-component polyurethane waterproof coating, which is not conducive to construction, and / or many bubbles in the film and serious surface shrinkage when applied on concrete, and / or poor mechanical properties and aging resistance. The solvent-free single-component polyurethane waterproof coating provided by the present application has high environmental performance, a solid content of more than 99.5%, low viscosity, easy construction, good mechanical properties, and no decay of mechanical properties after aging treatment. When applied on concrete, the coating film is smooth and flat after curing, the film is dense and bubble-free, the surface has no shrinkage, and good waterproof effect can be achieved.

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

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

[0009] The solvent-free environment-friendly single-component polyurethane waterproof coating, by mass fraction, comprises the following components:

[0010] 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, defoaming agent 0.3-0.4 parts, anti-settling agent 0.2-0.3 parts;

[0011] The modified powder is obtained by modifying the mixture of the powder and the rheological auxiliary agent with organosilane.

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

[0013] Mix the powder and the rheological auxiliary agent, 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, and obtain the modified powder.

[0014] Preferably, the powder comprises at least one of heavy calcium carbonate, high-light 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 auxiliary agent comprises at least one of CRAYVALLAC SL and MT-1.

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

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

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

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

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

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

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

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

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

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

[0028] The double-end vinyl silicone oil, the photoinitiator solution and the mercapto alcohol are stirred and reacted under ultraviolet lamp irradiation for 0.5-1.5 h, and the solvent is evaporated to obtain the chain extender.

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

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

[0031] Preferably, the amount of the photoinitiator solution is 0.5wt%-1.5wt% of the double-end vinyl silicone oil.

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

[0033] Preferably, the amount of the mercapto alcohol is 3wt%-6wt% of the double-end vinyl silicone oil.

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

[0035] S1. After the polypropylene ether glycol is dehydrated, it is reacted with p-phenylene diisocyanate to obtain an intermediate product;

[0036] S2. KH540 and KH550 are stirred and mixed under vacuum heating for 15-25 min, the intermediate product is added, and stirring and reaction are carried out under vacuum heating for 2-4 h to obtain the anti-settling agent.

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

[0038] Preferably, the substance amount ratio of the polypropylene oxide 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.

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

[0040] A preparation method of the solvent-free environment-friendly single-component polyurethane waterproof coating as in any one of the preceding embodiments, comprising the following steps:

[0041] S1. mixing and vacuum dewatering the polyol, the plasticizer and the modified powder;

[0042] S2. adding MDI at 78-80 DEG C, stirring and reacting under vacuum for 1-2h, adding the first catalyst and IPDI, stirring and reacting under vacuum for 1-2h, adding the chain extender, and stirring and reacting under vacuum for 20-40min;

[0043] S3. cooling to below 70 DEG C, adding the second catalyst, the defoaming agent and the anti-settling agent, and stirring at a speed of 1500-1800r / min for 20-40min, to obtain the product.

[0044] Compared with the prior art, the present application has the following beneficial effects:

[0045] The modified powder has better compatibility with the waterproof coating system, can significantly reduce the viscosity of the coating, and reduce the construction difficulty; the self-defoaming effect of the modified powder and the chain extender together improves the bubble and shrinkage problems of the coating film after curing; the anti-settling agent can form a stable chemical action with the coating system, and cooperates with the modified powder to ensure that the coating does not settle within one year. The chain extender and the anti-settling agent prepared by the present application can also improve the aging resistance of the coating; the addition of the modified polysiloxane defoaming agent reduces the content of free NCO in the system through process control, and the mechanical properties are excellent. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0047] Figure 1 The coating film quality photo after construction on the concrete of Example 1;

[0048] Figure 2A photograph of the coating film quality after the application of Example 2 on concrete;

[0049] Figure 3 A photograph of the coating film quality after the application of Example 3 on concrete;

[0050] Figure 4 A photograph of the coating film quality after the application of Comparative Example 1 on concrete;

[0051] Figure 5 A photograph of the coating film quality after the application of Comparative Example 3 on concrete;

[0052] Figure 6 A photograph of the coating film quality after the application of Comparative Example 8 on concrete;

[0053] Figure 7 A photograph of the coating film quality after the application of Comparative Example 9 on concrete;

[0054] Figure 8 A photograph of the coating film quality after the application of Comparative Example 10 on concrete. DETAILED DESCRIPTION

[0055] The technical solutions of the present application will be described clearly and completely in combination with the drawings and specific embodiments, but those skilled in the art will understand that the following described embodiments are part of the embodiments of the present application, rather than all the embodiments, and are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts are within the scope of protection of the present application. The specific conditions are not specified in the embodiments, and are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not specified by the manufacturer, and are conventional products that can be obtained by market purchase.

[0056] The first aspect of the present application provides a solvent-free environment-friendly single-component polyurethane waterproof coating, and the raw materials include the following components in mass fraction:

[0057] 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, defoaming agent 0.3-0.4 parts, anti-settling agent 0.2-0.3 parts;

[0058] The modified powder is obtained by modifying the mixture of the powder and the rheological auxiliary agent with organosilane.

[0059] The solvent-free single-component polyurethane waterproof coating provided by the application has a solid content of 99.5% or more, no free TDI, high environmental protection, a viscosity of 15000 cp (23 DEG C) or less, easy construction, and performance meeting the requirements of GB / T19250-2017 type II polyurethane waterproof coating and T / CWA209-2022, and after various aging treatments, the performance such as tensile strength, elongation at break, and bonding strength retention rate after water immersion treatment does not decrease, and the anti-aging performance is good. After the product is applied on concrete, the coating film is smooth and flat after curing, the film is dense and bubble-free, and the surface is free of shrinkage holes, so that good waterproof effect can be achieved.

[0060] The addition of the rheological aid in the powder can reduce the viscosity of the product and improve the anti-settling effect, and improve the bubble and shrinkage phenomena after curing of the product, and after modification by the organic silane, a coating is formed on the surface of the powder, which can improve the compatibility of the powder with the system, reduce the viscosity of the system and improve the leveling performance, avoid the formation of bubbles and shrinkage, prevent the agglomeration between the 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 limitedly, for example, the mass fraction of the polyol can be any one value or a range value composed of any two point values in 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts; the mass fraction of the plasticizer can be any one value or a range value composed of any two point values in 10 parts, 12 parts, 13 parts, 15 parts; the mass fraction of the isocyanate can be any one value or a range value composed of any two point values in 9 parts, 9.5 parts, 10 parts, 10.5 parts, 11 parts; the mass fraction of the chain extender can be any one value or a range value composed of any two point values in 1 part, 1.2 parts, 1.5 parts, 1.8 parts, 2 parts; the mass fraction of the catalyst can be any one value or a range value composed of any two point values in 0.07 parts, 0.08 parts, 0.09 parts; the mass fraction of the defoaming agent can be any one value or a range value composed of any two point values in 0.3 parts, 0.32 parts, 0.35 parts, 0.38 parts, 0.4 parts; and the mass fraction of the anti-settling agent can be any one value or a range value composed of any two point values in 0.2 parts, 0.22 parts, 0.25 parts, 0.28 parts, 0.3 parts.

[0062] In some specific embodiments of the application, the preparation method of the modified powder comprises the following steps:

[0063] The powder and rheological additive are mixed and placed in a high-speed stirring tank, a modified liquid containing organosilane is added, and stirring is carried out at a speed of 1600-1700 r / min for 15-25 min; heating to 80-85℃ under vacuum, and continue to stir at a speed of 1600-1700 r / min until the solvent is completely volatilized, to obtain a modified powder. Typically but not limited to, for example, the stirring speed during organosilane modification can be any one value or a range value composed of two point values selected from 1600 r / min, 1620 r / min, 1650 r / min, 1680 r / min, and 1700 r / min; the stirring time can be any one value or a range value composed of two point values selected from 15 min, 18 min, 20 min, 23 min, and 25 min.

[0064] In some embodiments of the present application, the powder used includes at least one of heavy calcium carbonate, high light barium, and wollastonite.

[0065] In some embodiments of the present application, the oil absorption value of the powder used is less than 18 g / 100 g, and an excessively high oil absorption value will increase the viscosity of the product and increase the difficulty of construction.

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

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

[0068] In some embodiments of the present application, the weight ratio of the powder to the rheological additive is 100:0.5-0.6, for example, it can be any one value or a range value composed of two point values selected from 100:0.5, 100:0.52, 100:0.55, 100:0.58, and 100:0.6.

[0069] In some embodiments of the present application, the modified liquid includes methyltrimethoxysilane, 3-(2,3-epoxypropoxy) propyl trimethoxysilane, and a solvent in a mass ratio of 1:1-3:7-8, for example, the mass ratio of methyltrimethoxysilane, 3-(2,3-epoxypropoxy) propyl trimethoxysilane, and a solvent can be any one value or a range value composed of two point values selected from 1:1:7, 1:1:8, 1:2:7, 1:2:8, 1:3:7, and 1:3:8; as an example, the solvent for preparing the modified liquid can be ethyl acetate.

[0070] In some embodiments of the present application, the modified liquid is added in an amount of 15wt%-25wt% of the powder, for example, 15wt%, 18wt%, 20wt%, 22wt%, 25wt% or a range between any two of them.

[0071] In some embodiments of the present application, the polyols used include polyether glycol, polytetrahydrofuran ether glycol, polycarbonate glycol and glycerol-based polyether polyol; for example, the polyether glycol can be DL-1000D or a combination of DL-1000D and DL-2000D; the polytetrahydrofuran ether glycol can be PTMEG2000; the polycarbonate glycol can be WHP-CD200; and the glycerol-based polyether polyol can be EP-330NG. By selecting a suitable combination of polyols, the product can still have a high curing speed in a low-temperature and low-humidity environment, and the mechanical properties of the product can be improved.

[0072] In some preferred embodiments of the present application, the polyols used include DL-1000D, DL-2000D, PTMEG2000, WHP-CD200 and EP-330NG in 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 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 between any two of them. 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 and DL-1000D and EP-330NG synergistically act to significantly improve the low-temperature curing speed of the coating film and the mechanical properties of the product.

[0073] In some embodiments of the present application, the plasticizer used includes at least one of plasticizer LF-70 (blue sail chemical) and plasticizer T60 (Jiangsu Shengkai), both of which are environmentally friendly plasticizers, which is conducive to improving the environmental friendliness of the waterproof coating.

[0074] In some embodiments of the present application, the isocyanate used includes 7-8 parts of MDI (diphenyl methane diisocyanate) and 2-3 parts of IPDI (isophorone diisocyanate), MDI has good mechanical properties, IPDI has good weather resistance, and the combination of the two can improve the mechanical properties and aging resistance of the product. The present application does not use toluene diisocyanate (TDI), has low volatile organic content, no free TDI, and high environmental protection.

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

[0076] In some embodiments of the present application, the catalyst used 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, for example, can be at least one of Valikat ZB1001, Valikat ZB8, Guangzhou Youyun BX-EM14, and Guangzhou Youyun BX-EM23; the second catalyst includes at least one of dimorpholine diethyl ether and triethylene diamine. The first catalyst can promote the progress of the synthesis reaction, and at the same time, can also promote the curing and film formation during the use of the coating; the second catalyst mainly promotes the reaction of the product with moisture during the use of the coating, improves the curing and film formation speed, and the combination of the two has better effect.

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

[0078] In some embodiments of the present application, the chain extender used is a polymerization product of a double-end vinyl silicone oil and a mercapto alcohol, and the preparation method of the chain extender includes the following steps:

[0079] The double-end vinyl silicone oil, the photoinitiator solution, and the mercapto alcohol are stirred and reacted under the irradiation of an ultraviolet lamp for 0.5-1.5 h, and the solvent is evaporated to obtain the chain extender.

[0080] The application takes a double-end vinyl silicone oil as a main chain raw material, and a mercapto alcohol is subjected to a polymerization reaction under the presence of a photoinitiator and the irradiation of a UV lamp to obtain a chain extender containing a siloxane bond and a hydroxyl group, which can not only extend the chain, but also has a defoaming effect, the chain extender prepared by the application can improve the problems of bubbles and shrinkage holes after the curing of a coating film by jointly acting with modified powder, and the chain extender prepared by the application can also significantly improve the aging resistance of a product.

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

[0082] In some specific embodiments of the application, the used photoinitiator solution comprises benzoin dimethyl ether and a solvent, for example, the used solvent can be at least one of ethyl acetate, butyl acetate, acetone, wherein the mass fraction of benzoin dimethyl ether in the photoinitiator solution is 10 %-15 %, for example, it can be any point value or a range value composed of any two point values in 10 %, 12 %, 14 %, 15 %.

[0083] In some specific embodiments of the application, the amount of the photoinitiator solution is 0.5wt %-1.5wt % of the double-end vinyl silicone oil, for example, it can be any point value or a range value composed of any two point values in 0.5wt %, 0.8wt %, 1wt %, 1.2wt %, 1.5wt %.

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

[0085] In some specific embodiments of the application, the amount of the mercapto alcohol is 3wt %-6wt % of the double-end vinyl silicone oil, for example, it can be any point value or a range value composed of any two point values in 3wt %, 4wt %, 5wt %, 6wt %.

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

[0087] S1. After vacuum dehydration of a polypropylene ether diol, an intermediate product is obtained by reacting with p-phenylene diisocyanate;

[0088] S2. KH540 and KH550 are stirred and mixed under vacuum heating for 15-25 min, the intermediate product prepared in step S1 is added, and stirring reaction is carried out under vacuum heating for 2-4 h to obtain the anti-settling agent.

[0089] The present application adopts p-phenylene diisocyanate with symmetry to react with polypropylene ether glycol to generate intermediate product containing -NCO group, and the -NCO group on the intermediate product further reacts with the amino group in KH540 and KH550 to form urea bond, so as to obtain the anti-settling agent. The anti-settling agent prepared by the present application can obviously improve the aging resistance of the product; and the anti-settling agent formed by the reaction of the intermediate product and the silane coupling agent can form stable chemical action with the coating system, and the synergistic effect with the modified powder can ensure that the coating does not settle within one year.

[0090] In some embodiments of the present application, in step S2, the intermediate product is slowly added to avoid gelation caused by too fast feeding, thereby affecting the anti-settling effect, and the feeding time is preferably not less than 4 min, for example, can be any point value or a range value composed of any two point values in 4 min, 5 min, 6 min, 7 min, 8 min.

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

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

[0093] In some embodiments of the present application, in step S2, the temperature of stirring mixing and stirring reaction is 75-85℃, for example, can be any point value or a range value composed of any two point values in 75℃, 78℃, 80℃, 82℃, 85℃.

[0094] The second aspect of the present application provides a preparation method of the solvent-free environment-friendly single-component polyurethane waterproof coating described in any one of the preceding embodiments, comprising the following steps:

[0095] S1. mixing and vacuum dewatering of polyol, plasticizer and modified powder;

[0096] S2. adding MDI at 78-80℃, stirring and reacting under vacuum for 1-2h, adding first catalyst and IPDI, stirring and reacting under vacuum for 1-2h, adding chain extender, stirring and reacting under vacuum for 20-40min;

[0097] S3. cooling to below 70℃, adding second catalyst, defoaming agent and anti-settling agent, stirring at a speed of 1500-1800r / min for 20-40min, and obtaining.

[0098] The method has simple process, mild conditions, and is convenient for batch production, the polyurethane coating is prepared from MDI and IPDI, has high environmental protection, and has good mechanical properties and weather resistance; the addition of the chain extender and the anti-settling agent prepared in the application can significantly improve the aging resistance of the product; the modified powder has better compatibility with the waterproof coating system, and can significantly reduce the viscosity of the product; the modified powder and the chain extender prepared in the application jointly act, and can improve the bubble and shrinkage problem of the coating film after curing; the modified powder and the anti-settling agent prepared in the application synergistically act, and can ensure that the coating does not settle within one year; after the defoaming agent is added and high-speed stirring, the defoaming agent is promoted to react with free NCO and volatilize, the content of free NCO in the system can be reduced, and the mechanical properties of the product can be improved.

[0099] After the defoaming agent is added, the stirring speed is 1500-1800r / min, the purpose is to promote the volatilization of free NCO, for example, the stirring speed after the defoaming agent is added can be any one value or a range value composed of two point values in 1500r / min, 1600r / min, 1700r / min and 1800r / min; the stirring time after the defoaming agent is added can be any one value or a range value composed of two point values in 20min, 25min, 30min, 35min and 40min. In other stirring mixing and stirring reaction processes, the stirring speed is not particularly limited, as long as the materials can be uniformly mixed.

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

[0101] Some embodiments of the application will be described in detail below with reference to specific application examples. The raw materials used in the examples, such as those not specifically described, can be purchased on the market.

[0102] Examples 1-5

[0103] The raw material composition of the solvent-free environment-friendly one-component polyurethane waterproof coating in examples 1-5 is 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)propyl trimethoxysilane, ethyl acetate in a ratio of 1:2:7 to make a modification liquid;

[0110] Put 50 parts of heavy calcium carbonate (oil absorption value 17 g / 100 g), 50 parts of high light barium (oil absorption value 16 g / 100 g), 0.5 parts of CRAYVALLAC SL into a high-speed stirring tank, add 20 parts of modification liquid, high-speed stirring at 1600 r / min for 20 min, open high temperature 80-85℃, vacuum, continue high-speed stirring at 1600 r / min for 20 min, collect after ethyl acetate is completely evaporated, seal the obtained modified powder and package 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 benzoin dimethyl ether ethyl acetate solution with a mass fraction of 10% into the reaction kettle, place the reaction system under ultraviolet lamp irradiation, add 4 parts of 4-mercapto-1-butanol, stir for 1 h, stop irradiation, heat to 80℃, vacuum stirring for 20 min, collect after ethyl acetate is completely evaporated, pour out the product, seal and store, 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 benzoin dimethyl ether ethyl acetate solution with a mass fraction of 12% into the reaction kettle, place the reaction system under ultraviolet lamp irradiation, add 5 parts of 6-mercapto-1-hexanol, stir for 1 h, stop irradiation, heat to 80℃, vacuum stirring for 20 min, collect after ethyl acetate is completely evaporated, pour out the product, seal and store, obtain chain extender B for standby.

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

[0116] 1 mol of polyether polyol DL-4000D is dehydrated under vacuum and at 120℃ for 2 h, then cooled to 80℃, and 1.2 mol of p-phenylene diisocyanate is added. The reaction is carried out under vacuum and at 78-80℃ for 2 h to obtain an intermediate product.

[0117] Pour 0.2 mol of 3-aminopropyl trimethoxysilane (KH540) and 0.4 mol of 3-aminopropyl triethoxysilane (KH550) into the reaction kettle, heat at 80℃, vacuum, and stir for 20 min, then slowly add the intermediate product, which takes 5 min. Heat at 80℃, vacuum, and stir for 3 h to obtain the anti-settling agent, which is poured out and sealed for standby.

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

[0119] S1. The polyols, plasticizers, and modified powders were added to the reaction kettle according to the proportions, stirred and dispersed, the materials were uniformly mixed, the temperature was controlled at 100°C, and the materials were stirred and dehydrated under vacuum for 1h;

[0120] S2. The temperature was lowered to 78-80°C, MDI was added, the temperature was controlled at 78-80°C, and the reaction was stirred under vacuum for 1.5h, the first catalyst was added, IPDI was gradually added, the temperature was controlled at 78-80°C, and the reaction was stirred under vacuum for 1.5h, the chain extender was added, the temperature was controlled at 78-80°C, and the reaction was stirred under vacuum for 0.5h;

[0121] S3. The temperature was lowered to below 70°C, the second catalyst, defoaming agent, and anti-settling agent were added, the mixture was stirred at 1500r / min for 30min under vacuum, and the kettle was discharged for filling.

[0122] Comparative Example 1

[0123] Comparative Example 1 is similar to Example 1, except that no chain extender was added, and the other conditions were the same as in Example 1.

[0124] Comparative Example 2

[0125] Comparative Example 2 is similar to Example 2, except that no anti-settling agent was added, and the other conditions were the same as in Example 2.

[0126] Comparative Example 3

[0127] Comparative Example 3 is similar to Example 3, except that no rheological aid CRAYVALLAC SL was added when preparing the modified powders, and the other conditions were the same as in Example 3.

[0128] Comparative Example 4

[0129] Comparative Example 4 is similar to Example 4, except that no defoaming agent was added, and the other conditions were the same as in Example 4.

[0130] Comparative Example 5

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

[0132] Comparative Example 6

[0133] Comparative Example 6 is similar to Example 2, except that the addition order of MDI and IPDI was exchanged, and the other conditions were the same as in Example 2.

[0134] Comparative Example 7

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

[0136] Comparative Example 8

[0137] Comparative Example 8 is similar to Example 4, the only difference is that when preparing the modified powder, the modified liquid is not modified, and a mixture of 50 parts of heavy calcium carbonate, 50 parts of high light barium, and 0.5 parts of CRAYVALLAC SL is directly used instead of the modified powder in Example 4, and the rest of the conditions are the same as Example 4.

[0138] Comparative Example 9

[0139] Comparative Example 9 is similar to Example 1, the only difference is that the chain extender A is replaced by the commercially available chain extender 1,6-hexanediol, and the rest of the conditions are the same as Example 1.

[0140] Comparative Example 10

[0141] Comparative Example 10 is similar to Example 2, the only difference is that according to the ratio of 3:7, methyltrimethoxysilane and ethyl acetate are mixed to prepare the modified liquid, that is, 3-(2,3-epoxypropoxy) propyl trimethoxysilane is not added in the modified liquid, and the rest of the conditions are the same as Example 2.

[0142] Comparative Example 11

[0143] Comparative Example 11 is similar to Example 3, the only difference is that according to the ratio of 3:7, 3-(2,3-epoxypropoxy) propyl trimethoxysilane and ethyl acetate are mixed to prepare the modified liquid, that is, methyltrimethoxysilane is not added in the modified liquid, and the rest of the conditions are the same as Example 3.

[0144] Test Example

[0145] The performance of the products in each example and each comparative example is detected respectively, and the detection method is as follows:

[0146] After the product is kept at 23°C for 24h, the viscosity is tested by using Brookfield DV2T type viscometer;

[0147] The rest of the product performance is carried out according to the method specified in T / CWA209-2022 "Solvent-free polyurethane waterproof coating".

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

[0149] Table 2

[0150]

[0151]

[0152] From the results in Table 2, it can be seen that according to the ratio and production process specified in the present application, the solid content of the solvent-free environmentally friendly single-component polyurethane waterproof coating obtained is all above 99.5%, 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 80℃ heat treatment for 14d, alkali treatment and acid treatment, the tensile strength and elongation at break do not show attenuation, the adhesion strength retention rate after water immersion treatment is above 100%, indicating that the product has good anti-aging performance. The coating film after construction on concrete is dense, bubble-free and shrinkage-free. The 1mm coating film completely solidifies in 12h or less under low temperature and low humidity conditions of 5℃ and 20% RH, which can ensure the efficiency during winter construction. No sedimentation occurs after standing for one year, indicating that the product does not need to be stirred in advance when used within one year, avoiding affecting the efficiency and air bubbles generated by stirring affecting the construction quality. The adhesion strength does not show attenuation under standard test conditions after one year, and the product can be used normally, with high construction safety.

[0153] Figure 1 、 Figure 2 and Figure 3 are respectively the coating film quality photos of the coating in Example 1, Example 2 and Example 3 after construction on concrete, and the coating film is dense, bubble-free and shrinkage-free.

[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 Comparative Example 1 does not add the chain extender prepared in the present application, causing the anti-aging performance to decrease, the adhesion strength to decrease under standard test conditions after one year, and air bubbles and shrinkage to easily occur, indicating that the chain extender prepared in the present application can improve the anti-aging performance of the product and improve the air bubble and shrinkage phenomenon after solidification; Comparative Example 2 does not add the anti-settling agent prepared in the present application, causing the anti-aging performance to decrease, the adhesion strength to decrease under standard test conditions after one year, and obvious sedimentation to occur after one year, indicating that the anti-settling agent prepared in the present application can improve the anti-aging performance of the product and has excellent anti-settling effect; Comparative Example 3 does not add CRAYVALLAC SL in the modified powder, causing the viscosity to increase and the anti-settling effect to decrease, and air bubbles and shrinkage to occur after solidification of the product; Comparative Example 4 does not add the modified polysiloxane defoaming agent, which is not conducive to promoting the emission of free NCO in the system, and the mechanical properties under standard conditions decrease.

[0158] By Figure 4 and Figure 5 It can be seen that the coating film of the coating in Comparative Example 1 and Comparative Example 3 after construction on the concrete has many bubbles and serious shrinkage.

[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 is changed to a commercially available anti-settling aid ECO-6500, and slight settlement occurs after one year, and the aging resistance performance decreases, which shows that the anti-settling effect of the anti-settling agent prepared in the application is better. In Comparative Example 6, the feeding order of MDI and IPDI in the production process is changed, and the mechanical properties under standard conditions decrease, and the tensile strength does not meet the performance requirements of type II polyurethane waterproof coating specified in GB / T19250-2013. In Comparative Example 7, the amount of DL-2000D is changed to 9 parts, and PTMEG2000 and WHP-CD200 are not added, and the low-temperature curing speed is obviously slower, and the mechanical properties under standard conditions decrease. In Comparative Example 8, the mixture of the modified liquid, the powder and the rheological additive is not modified, and then the viscosity is obviously increased, which is not conducive to construction, and the coating film after construction on the concrete has bubbles and serious shrinkage, which affects the waterproof effect, and slight settlement occurs after one year. Combined with Comparative Example 2 and Comparative Example 5, it shows that the anti-settling agent prepared in the application and the modified powder jointly have good anti-settling effect.

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

[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 by a commercially available chain extender 1,6-hexanediol, and the product aging resistance performance decreases, and the coating film after construction on the concrete has many bubbles; in Comparative Examples 10 and 11, only one of 3-(2,3-epoxypropoxy) propyl trimethoxysilane and methyl trimethoxysilane is added in the modified liquid, and the coating film after construction on the concrete has a small amount of bubbles, and slight settlement occurs after one year, which shows that a single silane coupling agent has poor effect.

[0169] ByFigure 7 It can be seen that the coating film of the coating in Comparative Example 9 has many bubbles and no shrinkage holes after application on the concrete. Figure 8 It can be seen that the coating film of the coating in Comparative Example 10 has a small amount of bubbles and no shrinkage holes after application on the concrete.

[0170] Although the present application has been illustrated and described with reference to specific embodiments, it is to be understood that the above-described embodiments are merely illustrative of the principles of the present application and are not intended to limit its scope. It is to be understood that various modifications can be made to the embodiments described above without departing from the spirit and scope of the present application. It is to be understood that such modifications are intended to fall within the scope of the present application.

Claims

1. A solvent-free, environmentally friendly, one-component polyurethane waterproof coating, characterized in that, By mass, the raw materials comprise the following components: 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 polyols comprise DL-1000D, DL-2000D, PTMEG2000, WHP-CD200, and EP-330NG in a mass ratio of 6:0-3:2-6:2-4:12-16; the isocyanate comprises 7-8 parts of MDI and 2-3 parts of IPDI; the catalyst comprises 0.02-0.03 parts of a first catalyst and 0.05-0.06 parts of a second catalyst. The preparation method of the modified powder includes the following steps: The powder and rheology modifier are mixed, and a modification liquid containing organosilane is added. The mixture is stirred at 1600-1700 r / min for 15-25 min. The solvent is evaporated by heating to obtain the modified powder. The rheology modifier includes at least one of CRAYVALLACSL and MT-1. The modification liquid includes methyltrimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane and solvent in a mass ratio of 1:1-3:7-8. The preparation method of the chain extender includes the following steps: The chain extender is obtained by stirring the double-ended vinyl silicone oil, photoinitiator solution and mercapto alcohol under ultraviolet light for 0.5-1.5 h, and then evaporating to remove the solvent. The method for preparing the anti-settling agent includes the following steps: (1) The polyoxypropylene ether diol was dehydrated and then reacted with terephthalic diisocyanate to obtain an intermediate product; (2) KH540 and KH550 are stirred and mixed under vacuum heating for 15-25 min, the intermediate product is added, and the reaction is carried out under vacuum heating for 2-4 h to obtain the anti-settling agent. The preparation method of the solvent-free, environmentally friendly, single-component polyurethane waterproof coating includes the following steps: S1. The polyol, the plasticizer, and the modified powder are mixed and then vacuum dehydrated; S2. Add the MDI at 78-80℃ and stir under vacuum for 1-2 hours. Then add the first catalyst and the IPDI and stir under vacuum for 1-2 hours. Then add the chain extender and stir under vacuum for 20-40 minutes. S3. Cool down to below 70°C, add the second catalyst, the defoamer, and the anti-settling agent, and stir at 1500-1800 r / min for 20-40 min to obtain the final product.

2. The solvent-free, environmentally friendly, single-component polyurethane waterproof coating according to claim 1, characterized in that, When preparing the modified powder, at least one of the following characteristics is satisfied: (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 18g / 100g; (3) The moisture content of the powder is less than 0.5‰; (4) The weight ratio of the powder to the rheology modifier is 100:0.5-0.6; (5) The modified liquid accounts for 15wt%-25wt% of the powder.

3. The solvent-free, environmentally friendly, single-component polyurethane waterproof coating according to claim 1, characterized in that, It meets at least one of the following characteristics: (1) The plasticizer includes at least one of LF-70 and T60; (2) The first catalyst includes a bismuth-zinc composite catalyst, and the second catalyst includes at least one of dimorpholine diethyl ether and triethylenediamine; (3) The defoamer is a modified polysiloxane compound.

4. The solvent-free, environmentally friendly, single-component polyurethane waterproof coating according to claim 1, characterized in that, When preparing the chain extender, at least one of the following characteristics is satisfied: (1) The mass percentage of vinyl groups in the double-ended 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 used is 0.5wt%-1.5wt% of the double-ended vinyl silicone oil; (4) The mercapto alcohol includes at least one of 4-mercapto-1-butanol and 6-mercapto-1-hexanol; (5) The amount of the mercapto alcohol is 3wt%-6wt% of the double-ended vinyl silicone oil.

5. The solvent-free, environmentally friendly, single-component polyurethane waterproof coating according to claim 1, characterized in that, When preparing the anti-settling agent, at least one of the following characteristics is satisfied: (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 terephthalic diisocyanate, the KH540 and the KH550 is 1:1.1-1.4:0.1-0.4:0.2-0.5; (3) In step (2), the temperature of stirring and mixing is 75-85℃, and the temperature of stirring reaction is 75-85℃.

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