Weather-resistant single-component polyurethane waterproof coating, preparation method thereof and waterproof structure comprising weather-resistant single-component polyurethane waterproof coating on underground engineering facade

Abstract

The invention provides a weather-resistant single-component polyurethane waterproof coating and a preparation method thereof, and a waterproof structure comprising the weather-resistant single-component polyurethane waterproof coating on an underground engineering facade. The waterproof coating is prepared from the following components in parts by weight: 80 to 400 parts of polyether polyol, 20 to 70 parts of isocyanate, 0 to 30 parts of plasticizer, 350 to 550 parts of solid filler, 0.05 to 2 parts of catalyst, 0.5 to 5 parts of crosslinking improving aid and 0 to 150 parts of solvent. The preparation method comprises the following steps: mixing polyether polyol, a plasticizer, a solid filler and a pigment, and performing vacuum dehydration to obtain a first mixture; adding a cross-linking improving aid into the first mixture, performing first stirring to obtain a second mixture, and reacting isocyanate with the second mixture to obtain a reactant; stirring reactants, a catalyst and a solvent for the second time; the waterproof structure of the underground engineering facade is composed of a waterproof coating and puncture-resistant geotechnical cloth, and the waterproof coating is formed by coating weathering-resistant single-component polyurethane waterproof paint.

Description

Technical Field

[0001] The present invention belongs to the technical field of waterproofing, and in particular relates to a weathering-resistant single-component polyurethane waterproof coating and a preparation method thereof, as well as a waterproof structure comprising the same on the facade of an underground project. Background Art

[0002] One-component polyurethane waterproof coating is a waterproof coating with excellent performance and convenient construction. It is widely used in various fields such as construction, roads and bridges.

[0003] For many years, the use of one-component polyurethane waterproof coatings in underground projects has been limited by problems: (1) After applying one-component polyurethane waterproof coatings on the side walls of underground projects, if the protective layer is not constructed in time, the coating film of the waterproof coating will be exposed to the natural environment for a period of time. The coating film will be greatly affected by natural weathering, causing the coating film performance to deteriorate, the surface to discolor and produce micro cracks, resulting in poor waterproofing effects; (2) If backfilling is performed without constructing a protective layer, the backfilling process will damage the coating and cause waterproofing failure; (3) Using a protective layer to protect the coating increases the construction process compared to other waterproof materials that do not require protection, increases the project cost, and hinders the application and promotion of one-component polyurethane waterproof coatings.

[0004] Therefore, it is urgent to propose a weathering-resistant single-component polyurethane waterproof coating and a preparation method thereof, and a protection-free waterproof structure for the facade of an underground project.

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

[0006] The purpose of the present invention is to provide a weather-resistant one-component polyurethane waterproof coating and a preparation method thereof, as well as a waterproof structure including the same on the facade of an underground project, so as to solve the above-mentioned problems.

[0007] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0008] The first aspect of the present invention provides a weather-resistant one-component polyurethane waterproof coating, which comprises, by weight, 80 to 400 parts of polyether polyol, 20 to 70 parts of cross-linking agent isocyanate, 0 to 30 parts of plasticizer, 350 to 550 parts of solid filler, 0.05 to 2 parts of catalyst, 0.5 to 5 parts of cross-linking improvement auxiliary agent and 0 to 150 parts of solvent.

[0009] Optionally, the polyether polyol is a polyether diol and / or polyether triol having a molecular weight of 1000-5000;

[0010] Preferably, the cross-linking agent isocyanate includes at least one of toluene diisocyanate, diphenylmethane diisocyanate, and isophorone diisocyanate;

[0011] Preferably, the plasticizer includes one or more of diisononyl phthalate, diisodecyl phthalate, and chlorinated paraffin;

[0012] Preferably, the solid filler comprises at least one of barium sulfate, heavy calcium carbonate, talc, bentonite, and kaolin;

[0013] Preferably, the mesh size of the solid filler is 400 to 1250 mesh;

[0014] Preferably, the catalyst comprises at least one of organotin, organobismuth, and DMDEE;

[0015] Preferably, the solvent includes at least one of 100#, 150#, and 200# solvent oil.

[0016] Optionally, the weather-resistant one-component polyurethane waterproof coating further includes a pigment; preferably, the pigment includes at least one of titanium dioxide, lithopone, zinc chloride, red iron oxide, carbon black, zinc sulfide, and cobalt green.

[0017] Preferably, the cross-linking improving agent is a hydroxyl-terminated polymer having multiple branches;

[0018] More preferably, the cross-linking improving agent has a molecular weight of 800 to 1500 and a functionality of 6 to 12.

[0019] A second aspect of the present invention provides a method for preparing the weather-resistant one-component polyurethane waterproof coating, the method comprising the following steps:

[0020] S1: uniformly mixing the polyether polyol, plasticizer, solid filler and pigment in a certain proportion, and vacuum dehydrating the mixture to obtain a first mixture;

[0021] S2: adding the crosslinking improving agent to the first mixture obtained in S1 and performing a first stirring to obtain a second mixture, and then reacting the crosslinking agent isocyanate with the second mixture to obtain a reactant;

[0022] S3: The reactants, catalyst and solvent are stirred for a second time to obtain the weathering-resistant one-component polyurethane waterproof coating.

[0023] Optionally, the preparation method satisfies one or more of the following conditions:

[0024] a. The vacuum dehydration conditions include: a temperature of 105-115 ℃, a vacuum degree controlled below 0.092MPa;

[0025] b. The water content of the first mixture is controlled below 0.03%;

[0026] c. The first stirring speed is 400 to 800 r / min for 40 to 60 min;

[0027] d. The first stirring temperature is 85 to 95 ° C;

[0028] e. The reaction temperature is 75-85°C.

[0029] Preferably, the preparation method of the cross-linking improving agent comprises: dissolving carboxymethyl butylene oxide and boron trichloride complex in dichloromethane solvent, and synthesizing the cross-linking improving agent through cationic self-condensation ring-opening polymerization at -50°C to 30°C.

[0030] The general formula of the cross-linking improving auxiliary agent poly 3-ethyl-3-hydroxymethyl butylene oxide synthesized by the present invention is: [-O-CH2-C(CH2OH)(C2H5)-O-] n , wherein n is 6 to 12 or any integer therebetween; the molecular weight of the obtained poly 3-ethyl-3-hydroxymethyl butylene oxide is 800 to 1500. The epoxy ring of the monomer 3-ethyl-3-hydroxymethyl butylene oxide of the polymer is located in a four-membered ring, wherein the carbon number 3 has two substituents: an ethyl group (C2H5) and a hydroxymethyl group (CH2OH).

[0031] In order to avoid adverse effects such as loss of control of molecular cross-linking degree and phase separation, the present invention synthesizes a cross-linking improvement auxiliary agent by precisely controlling the polymerization temperature. Compared with commonly used terminal hydroxyl polyethers, the cross-linking improvement auxiliary agent of the present invention is a polyhydroxy compound with a small molecular weight, a large number of -OH groups, and higher reactivity. During the synthesis process of the polyurethane prepolymer, the cross-linking improvement auxiliary agent preferentially reacts with one of the isocyanate groups to form a hard segment with a denser structure, and then the other isocyanate group of the isocyanate reacts with the terminal hydroxyl polyether to generate a prepolymer. The newly generated hard segment gives the prepolymer higher mechanical properties, so the mechanical properties of the prepared weathering-resistant single-component polyurethane waterproof coating are significantly improved.

[0032] The third aspect of the present invention provides a waterproof structure for an underground engineering facade, which is composed of a waterproof coating and a puncture-resistant geotextile. The waterproof coating includes a waterproof coating formed by coating the weather-resistant single-component polyurethane waterproof coating.

[0033] Preferably, the waterproof coating comprises: a first waterproof coating and a second waterproof coating, which are sequentially arranged from the inside out with the puncture-resistant geotextile as the base; the first waterproof coating comprises an inner surface of the first waterproof coating arranged on the surface of the puncture-resistant geotextile, and an outer surface of the first waterproof coating connected to the second waterproof coating; the second waterproof coating is the surface of the waterproof facade;

[0034] Preferably, at least one of the inner surface of the first waterproof coating, the outer surface of the first waterproof coating, and the second waterproof coating is formed by uniformly coating the weather-resistant single-component polyurethane waterproof coating.

[0035] Optionally, the puncture-resistant geotextile comprises at least one of polyester filaments, glass fiber filaments, and polyester staple fibers;

[0036] Preferably, the puncture-resistant geotextile has a unit weight of 100 to 400 g / m2.

[0037] Beneficial effects of the present invention:

[0038] The present invention adjusts the coating formula by adding a specific cross-linking improvement additive, so that the bonding strength of the single-component polyurethane waterproof coating reaches 2.5 MPa, solves the problem of weak bonding ability, and at the same time improves the aging and weathering resistance; the waterproof coating has a significant improvement in tensile strength, elongation at break, and bonding strength.

[0039] The preparation method provided by the invention has cheap and readily available raw materials, simple operating steps, safe and easily controllable conditions, and is conducive to industrial promotion and use.

[0040] The waterproof structure of the underground engineering facade provided by the present invention is a composite structure of a weather-resistant single-component polyurethane waterproof coating and a puncture-resistant geotextile, which solves the technical defects in backfilling in a composite manner; at the same time, due to the strong aging and weathering resistance of the coating, the problem of coating aging caused by untimely backfilling is avoided; and by using geotextile as a flexible buffer layer to disperse the backfill stress, the problems of insufficient puncture resistance and easy debonding due to lateral pressure of the soil are solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 A schematic cross-sectional view of the waterproof structure of the underground engineering facade provided in Example 5;

[0043] Figure 2 This is a graph showing comparative observation results of the weather-resistant one-component polyurethane waterproof coating provided in Example 1 on the day of surface drying and 60 days after surface drying;

[0044] Figure 3 This is a graph showing the comparative observation results of the weather-resistant one-component polyurethane waterproof coating provided in Comparative Example 1 on the day of surface drying and 60 days after surface drying;

[0045] Figure 4 This is a graph showing the comparative observation results of the weather-resistant one-component polyurethane waterproof coating provided in Comparative Example 2 on the day of surface drying and 60 days after surface drying;

[0046] Figure 5 This is a graph showing the comparative observation results of the weather-resistant one-component polyurethane waterproof coating provided in Comparative Example 3 on the day of surface drying and 60 days after surface drying;

[0047] Figure numerals: 1-puncture-resistant geotextile; 2-inner surface of the first waterproof coating; 3-outer surface of the first waterproof coating; 4-second waterproof coating. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0049] It should be noted that the sources of the raw materials used in the embodiments of the present invention are as follows:

[0050] Polyether polyols: DL-2000D (functionality 2, number average molecular weight 2000), DL-4000 (functionality 2, number average molecular weight 4000), EP-330NG (functionality 3, number average molecular weight 5000) were purchased from Sinochem Dongda (Zibo) Co., Ltd.

[0051] The crosslinking enhancer is prepared by dissolving carboxymethyl butylene oxide monomer and boron trichloride complex initiator in dichloromethane solvent and synthesizing the crosslinking enhancer via cationic self-condensation ring-opening polymerization at temperatures ranging from -50°C to 30°C. The hydroxyl value is determined by the phthalic anhydride method, and the molecular weight of the crosslinking enhancer is determined to be 800-1500, and the functionality is 6-12.

[0052] Other raw materials not otherwise specified are common commercially available products.

[0053] Example 1

[0054] This embodiment provides a weather-resistant one-component polyurethane waterproof coating and a preparation method thereof, the components of which are shown in Table 1 below:

[0055] Table 1 Composition of weather-resistant one-component polyurethane waterproof coating provided in Example 1

[0056]

[0057] The preparation method is as follows:

[0058] S1: The polyether polyols DL-2000, DL-4000, EP-330NG, chlorinated paraffin, barium sulfate, heavy calcium carbonate, and pigment in Table 1 were mixed, heated to 105° C. with stirring, and dehydrated under a vacuum condition of 0.085 MPa for 2 hours to obtain a first mixture having a water content of less than 0.03%;

[0059] S2: The first mixture obtained in S1 was cooled to 85° C., the crosslinking improving agent prepared in the present invention was added, and the mixture was stirred at a speed of 800 r / min for 40 min to obtain a second mixture, which was then cooled to 75° C., isocyanate was added, and the mixture was reacted under stirring for 2 h.

[0060] S3: Cool the reactants obtained in S2 to below 65° C., add the catalyst and solvent listed in Table 1, continue stirring for 20 minutes, and discharge the reactants to obtain a weather-resistant one-component polyurethane waterproof coating.

[0061] Example 2

[0062] The difference from Example 1 is that 60 parts of the polyether polyol DL-4000 component is replaced by polyether polyol DL-2000, that is, the polyether polyol used in this example is 260 parts of DL-2000 and 40 parts of EP-330NG.

[0063] Example 3

[0064] The difference from Example 1 is that the polyether polyol used in this example is a single polyether polyol with a specification of DL-2000 and a weight of 300 parts.

[0065] Example 4

[0066] This embodiment provides a weather-resistant one-component polyurethane waterproof coating and a preparation method thereof, the components of which are shown in Table 2 below:

[0067] Table 2 Composition of weather-resistant one-component polyurethane waterproof coating provided in Example 4

[0068] Component name Specifications Parts by weight polyether polyols DL-4000 260 polyether polyols EP-330NG 40 Solid filler barium sulfate 1250 mesh 400 Solid filler heavy calcium carbonate 1250 mesh 150 pigment Iron oxide red 5 Isocyanates TDI-80 40 Cross-linking improving agent self made 2 Catalyst organotin T-12 1.5 catalyst DMDEE 1.5

[0069] Example 5

[0070] The weather-resistant one-component polyurethane waterproof coating prepared in Examples 1-4 is used to make a waterproof structure for the facade of an unprotected underground project. The waterproof structure of the facade consists of a waterproof coating and a puncture-resistant geotextile, such as Figure 1As shown, its waterproof structure specifically includes: a first waterproof coating layer and a second waterproof coating layer 4 arranged in sequence from the inside out with a puncture-resistant geotextile 1 as the base; the first waterproof coating layer includes a first waterproof coating inner surface 2 arranged on the surface of the puncture-resistant geotextile, and a first waterproof coating outer surface 3 connected to the second waterproof coating layer; the second waterproof coating layer 4 is the surface of the waterproof facade;

[0071] In this embodiment, the puncture-resistant geotextile is polyester staple fiber with a unit weight of 350 g / m2; the first waterproof coating and the second waterproof coating both include the weather-resistant single-component polyurethane waterproof coating prepared in Examples 1-4.

[0072] Example 6

[0073] The difference from Example 5 is that in this embodiment, the puncture-resistant geotextile is polyester filament with a unit weight of 400 g / m2.

[0074] Comparative Example 1

[0075] This comparative example provides a one-component polyurethane waterproof coating and its preparation method. The formulation of the waterproof coating differs from that of Example 1 in that the self-prepared crosslinking agent in Example 1 is replaced with 4,4'-diaminodiphenylmethane, a conventional method. The preparation steps for the waterproof coating are the same as those in Example 1.

[0076] Comparative Example 2

[0077] This comparative example differs from Example 1 in that no crosslinking-improving agent is added. The corresponding preparation method differs from Example 1 only in that the step of adding the homemade crosslinking-improving agent in S2 is omitted, and the isocyanate is directly added to the first mixture prepared in S1 for reaction. The preparation steps of the waterproof coating are the same as those in Example 1.

[0078] Comparative Example 3

[0079] The difference from Example 1 is that the cross-linking improving auxiliary agent used in this comparative example has a synthesis temperature of 80° C. and a molecular weight of 1000.

[0080] The weathering resistance of the single-component polyurethane waterproof coating provided in the examples and comparative examples was tested. The weathering resistance of the coating was tested by exposing the coating to an outdoor environment and observing the discoloration and cracking of the coating. The weathering resistance test results of the single-component polyurethane waterproof coating prepared in Example 1 and the single-component polyurethane waterproof coating prepared in Comparative Examples 1-3 after application and after 60 days of surface drying are shown in the following table. Figure 2-5 shown; among them, Figure 2 This is a graph showing the comparative observation results of the weather-resistant one-component polyurethane waterproof coating provided in Example 1 on the day of surface drying and 60 days after surface drying. Figure 2 The left picture shows the observation results of the surface drying on the day. Figure 2The right graph is the observation result graph of the film coated with the weather-resistant single-component polyurethane waterproof coating after 60 days of surface drying. Figure 3 The comparative observation result graph of the film coated with the weather-resistant single-component polyurethane waterproof coating provided for Comparative Example 1 is shown in the following table, which is observed on the day of surface drying and after 60 days of surface drying. Figure 3 The left graph is the observation result graph of the film coated with the weather-resistant single-component polyurethane waterproof coating on the day of surface drying. Figure 3 The right graph is the observation result graph of the film coated with the weather-resistant single-component polyurethane waterproof coating after 60 days of surface drying. Figure 4 The comparative observation result graph of the film coated with the weather-resistant single-component polyurethane waterproof coating provided for Comparative Example 2 is shown in the following table, which is observed on the day of surface drying and after 60 days of surface drying. Figure 4 The left graph is the observation result graph of the film coated with the weather-resistant single-component polyurethane waterproof coating on the day of surface drying. Figure 4 The right graph is the observation result graph of the film coated with the weather-resistant single-component polyurethane waterproof coating after 60 days of surface drying. Figure 5 The comparative observation result graph of the film coated with the weather-resistant single-component polyurethane waterproof coating provided for Comparative Example 3 is shown in the following table, which is observed on the day of surface drying and after 60 days of surface drying. Figure 5 The left graph is the observation result graph of the film coated with the weather-resistant single-component polyurethane waterproof coating on the day of surface drying. Figure 5 The right graph is the observation result graph of the film coated with the weather-resistant single-component polyurethane waterproof coating after 60 days of surface drying. Figure 2-5 As can be seen from the above table, the film coated with the weather-resistant single-component polyurethane waterproof coating does not have any discoloration and cracking phenomenon within 60 days, while the ordinary single-component polyurethane waterproof coating has obvious discoloration and cracking phenomenon within 60 days, which indicates that the addition of the crosslinking improvement aid provided in the application improves the weather resistance of the single-component polyurethane waterproof coating.

[0081] The weather-resistant single-component polyurethane waterproof coating provided in the application has improved weather resistance and corresponding improved aging resistance:

[0082] On the basis of the requirements of the current national standards GB / T 19250-2013 “Polyurethane Waterproof Coating” and GB 55030-2012 “General Specification for Waterproofing of Building and Municipal Engineering”, the alkali and acid treatment is extended from the original 168h to 336h, and the aging time is doubled, which still meets the standard requirements, and the specific results are shown in the following Table 3:

[0083] Table 3: Performance test results of polyurethane waterproof coating

[0084]

[0085]

[0086] Please note that the technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above embodiments only express several implementation methods of the present application. The description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of this application, several variations and improvements can be made, which all fall within the scope of protection of this application. Therefore, the scope of protection of the patent in this application shall be based on the attached claims.

Claims

1. A weather-resistant one-component polyurethane waterproof coating, characterized in that: The weather-resistant single-component polyurethane waterproof coating comprises, by weight, 80 to 400 parts of polyether polyol, 20 to 70 parts of cross-linking agent isocyanate, 0 to 30 parts of plasticizer, 350 to 550 parts of solid filler, 0.05 to 2 parts of catalyst, 0.5 to 5 parts of cross-linking improvement auxiliary agent and 0 to 150 parts of solvent.

2. The weather-resistant one-component polyurethane waterproof coating according to claim 1, characterized in that: The polyether polyol is a polyether diol and / or polyether triol having a molecular weight between 1000 and 5000; Preferably, the cross-linking agent isocyanate includes at least one of toluene diisocyanate, diphenylmethane diisocyanate, and isophorone diisocyanate; Preferably, the plasticizer includes one or more of diisononyl phthalate, diisodecyl phthalate, and chlorinated paraffin; Preferably, the solid filler comprises at least one of barium sulfate, heavy calcium carbonate, talc, bentonite, and kaolin; Preferably, the mesh size of the solid filler is 400 to 1250 mesh; Preferably, the catalyst comprises at least one of organotin, organobismuth, and DMDEE; Preferably, the solvent includes at least one of 100#, 150#, and 200# solvent oil.

3. The weather-resistant one-component polyurethane waterproof coating according to claim 1, characterized in that: The weather-resistant one-component polyurethane waterproof coating further includes a pigment; Preferably, the pigment includes at least one of titanium dioxide, lithopone, zinc chloride, red iron oxide, carbon black, zinc sulfide, and cobalt green.

4. The weather-resistant one-component polyurethane waterproof coating according to claim 1 or 3, characterized in that: The cross-linking improving agent is a hydroxyl-terminated polymer with multiple branches; Preferably, the molecular weight of the cross-linking improving agent is 800-1500 and the functionality is 6-12.

5. A method for preparing the weather-resistant one-component polyurethane waterproof coating according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: S1: uniformly mixing the polyether polyol, plasticizer, solid filler and pigment in a certain proportion, and vacuum dehydrating the mixture to obtain a first mixture; S2: adding the crosslinking improving agent to the first mixture obtained in S1 and performing a first stirring to obtain a second mixture, and then reacting the crosslinking agent isocyanate with the second mixture to obtain a reactant; S3: The reactants, catalyst and solvent are stirred for a second time to obtain the weathering-resistant one-component polyurethane waterproof coating.

6. The preparation method according to claim 5, characterized in that The preparation method satisfies one or more of the following conditions: a. The vacuum dehydration conditions include: a temperature of 105-115 ℃, a vacuum degree controlled below 0.092MPa; b. The water content of the first mixture is controlled below 0.03%; c. The first stirring speed is 400 to 800 r / min for 40 to 60 min; d. The first stirring temperature is 85 to 95 ° C; e. The reaction temperature is 75-85°C.

7. The preparation method according to claim 5 or 6, characterized in that: The preparation method of the cross-linking improving auxiliary agent comprises: dissolving carboxymethyl butylene oxide and boron trichloride complex in dichloromethane solvent, and synthesizing the cross-linking improving auxiliary agent through cationic self-condensation ring-opening polymerization at -50°C to 30°C.

8. A waterproof structure for an underground engineering facade, comprising a waterproof coating and a puncture-resistant geotextile, characterized in that: The waterproof coating comprises a waterproof coating formed by coating the weather-resistant single-component polyurethane waterproof coating according to claims 1 to 4.

9. The waterproof structure of the underground engineering facade according to claim 8, characterized in that: The waterproof structure of the underground engineering facade comprises: a first waterproof coating and a second waterproof coating arranged in sequence from the inside out, with the puncture-resistant geotextile as a base; the first waterproof coating comprises an inner surface of the first waterproof coating arranged on the surface of the puncture-resistant geotextile, and an outer surface of the first waterproof coating connected to the second waterproof coating; the second waterproof coating is the surface of the waterproof facade; Preferably, at least one of the inner surface of the first waterproof coating, the outer surface of the first waterproof coating, and the second waterproof coating is formed by uniformly coating the weather-resistant single-component polyurethane waterproof coating.

10. The waterproof structure of underground engineering facade according to claim 8 or 9, characterized in that: The puncture-resistant geotextile comprises at least one of polyester filaments, glass fiber filaments, and polyester staple fibers; Preferably, the puncture-resistant geotextile has a unit weight of 100 to 400 g / m2.

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