An interlayer release agent for polyurethane coating, and a preparation method and application thereof

Abstract

This invention relates to a polyurethane coating, its preparation method, and its application. The polyurethane coating comprises the following components: maleic anhydride-modified polyurethane, silane-modified polyurethane, maleic anhydride-modified adhesive, and solvent. The maleic anhydride-modified polyurethane is obtained by reacting raw materials including polyol, maleic anhydride, isocyanate, and catalyst. The silane-modified polyurethane is obtained by reacting raw materials including polyol, silane coupling agent, isocyanate, and catalyst. The adhesive is selected from one or more combinations of petroleum resin, asphalt, rosin resin, terpene resin, styrene-butadiene rubber, and butyl rubber. The maleic anhydride-modified adhesive is obtained by reacting raw materials including maleic anhydride, adhesive, and initiator. This polyurethane coating can be used as a primer for concrete substrates or as an interlayer separator between polyurethane coatings and asphalt roofing membranes. This coating can prevent the migration of plasticizers and other additives in traditional polyurethane coatings, improving the compatibility and adhesion performance between traditional polyurethane coatings and asphalt roofing membranes.

Description

Technical Field

[0001] This invention relates to an interlayer release agent for polyurethane coatings, its preparation method, and its application. Background Technology

[0002] To achieve good waterproofing performance, traditional self-adhesive bitumen waterproofing membranes are typically coated with a polyurethane waterproofing coating. However, conventional polyurethane is made from polyether and isocyanate as raw materials, and is usually compounded with plasticizers, powder materials, additives, and solvents. It has high polarity, while self-adhesive bitumen membranes are generally non-polar. This significant difference in polarity leads to weak adhesion between the two materials, resulting in insufficient interfacial bonding. This is particularly problematic in systems like sidewalls and sloping roofs, where poor bonding can easily lead to interface damage and loss of adhesion, causing the membrane to detach during backfilling.

[0003] In addition, plasticizers, solvents, and small molecules in traditional polyurethane coatings can easily migrate to the coating surface, which has a negative effect on the adhesion of asphalt membranes. This can lead to delamination of the membrane and coating when the membrane is exposed for a long time or in extreme environments, affecting the waterproofing effect and shortening the service life of the material. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an interlayer release agent for polyurethane coatings, addressing the shortcomings and deficiencies of existing technologies. This interlayer release agent can prevent the migration of plasticizers and other additives in traditional polyurethane coatings, exhibits good adhesion to polyurethane, and simultaneously forms a high-strength bond with asphalt roofing membranes. This improves the compatibility and adhesion performance between traditional polyurethane coatings and asphalt roofing membranes, while maintaining the excellent waterproof properties of the polyurethane coating.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0006] A polyurethane coating comprising the following components: maleic anhydride-modified polyurethane, silane-modified polyurethane, maleic anhydride-modified adhesive, and solvent; wherein the maleic anhydride-modified polyurethane is obtained by reacting raw materials comprising polyol, maleic anhydride, isocyanate, and catalyst; wherein the silane-modified polyurethane is obtained by reacting raw materials comprising polyol, silane coupling agent, isocyanate, and catalyst; wherein the adhesive is selected from one or more combinations of petroleum resin, asphalt, rosin resin, terpene resin, styrene-butadiene rubber, and butyl rubber; and wherein the maleic anhydride-modified adhesive is obtained by reacting raw materials comprising maleic anhydride, adhesive, and initiator.

[0007] Traditional polyurethane coatings are highly polar, while asphalt waterproof membranes are non-polar. This difference in polarity results in insufficient adhesion between the two, making it easy for the polyurethane coating to peel off the waterproof membrane. Furthermore, plasticizers and other additives in traditional polyurethane coatings tend to migrate to the coating surface, further exacerbating the delamination between the coating and the membrane layers. The inventors of this application discovered through research that by placing a polyurethane interlayer spacer layer (formed from the polyurethane coating of this application) with intermediate polarity between the traditional polyurethane coating and the asphalt waterproof membrane, it can achieve a strong bond with the traditional polyurethane coating. In addition, it contains non-polar segments, exhibiting good affinity with the non-polar asphalt waterproof membrane, thereby significantly increasing the peel strength between the two. This optimizes the compatibility and adhesion performance between the two membranes, significantly improving the delamination and peeling problems between the asphalt waterproof membrane and the polyurethane coating. Furthermore, the specific composition of the polyurethane coating of this application can microscopically repair and densify the surface defects of traditional polyurethane coatings, thereby isolating harmful substances such as plasticizers in traditional polyurethane coatings from migrating outwards, while maintaining the excellent waterproof properties of polyurethane itself.

[0008] The matrix adhesive in the maleic anhydride-modified adhesive is non-polar, which facilitates bonding with non-polar bitumen waterproof membranes. Furthermore, the adhesive itself typically acts as a tackifier, increasing bond strength. The silane coupling agent component in the silane-modified polyurethane improves the compatibility between the bitumen waterproof membrane and the polyurethane. Additionally, the maleic anhydride-modified polyurethane, maleic anhydride-modified adhesive, and silane-modified polyurethane undergo further reaction after mixing, further improving the polarity of the polyurethane chain segments. This application, through the compounding of maleic anhydride-modified polyurethane, maleic anhydride-modified adhesive, and silane-modified polyurethane, achieves sufficient microphase fusion of polar and non-polar materials. It also exhibits strong repair and isolation capabilities for micropores on traditional polyurethane coating surfaces, preventing the release of harmful substances and demonstrating excellent and sustained adhesion to traditional polyurethane coatings, waterproof bitumen membranes, and other substrates.

[0009] In some embodiments, the mass ratio of the maleic anhydride-modified polyurethane, the silane-modified polyurethane, the maleic anhydride-modified adhesive, and the solvent is 10-35:10-30:12-25:28-40.

[0010] In some embodiments, the polyol is selected from polyether polyols or polyester polyols.

[0011] The polyether polyol can be one or more of the following: 2000d, 1000d, 3050d, and 330Nd from Dongda Chemical Co., Ltd.

[0012] In some embodiments, the isocyanate is selected from one or more combinations of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), and 4,4'-dicyclohexylmethane diisocyanate (HMDI).

[0013] In some embodiments, the silane coupling agent is selected from one or more combinations of WD50, KH550, KH560, KH570 and propyltriethoxysilane (IPTS).

[0014] In some embodiments, the catalyst is selected from one or more combinations of organotin NEOSTANN U-303, butyltin dilaurate, stannous octoate, zinc isooctanoate, bismuth isooctanoate, bismuth neodecanoate, and zinc neodecanoate. Organotin NEOSTANN U-303 is manufactured by Nitto Chemical Corporation and is composed of the reaction product of tetraethyl silicate and bis(acetyloxy)dibutyltinane.

[0015] In some embodiments, the initiator is selected from azo initiators or organic peroxide initiators. An example of an organic peroxide initiator is dicumyl peroxide.

[0016] In some embodiments, the solvent is selected from one or more combinations of aromatic hydrocarbons, dimethyl carbonate, and butyl acetate.

[0017] In some embodiments, the mass ratio of the polyol, maleic anhydride, isocyanate and catalyst in the raw materials of the maleic anhydride-modified polyurethane is 60-70:2-6:22-40:0.01-0.05.

[0018] In some embodiments, the mass ratio of the polyol, silane coupling agent, isocyanate and catalyst in the raw materials of the silane-modified polyurethane is 65-75:3-7:17-25:0.01-0.05.

[0019] In some embodiments, the mass ratio of maleic anhydride, gum, and initiator in the raw material of the maleic anhydride modified gum is 15-25:75-85:0.05-0.15.

[0020] In some embodiments, the polyurethane coating further includes a catalyst.

[0021] In some embodiments, the mass ratio of the maleic anhydride-modified polyurethane to the catalyst is 10-35:0.05-0.1.

[0022] In some embodiments, the polyurethane coating further includes solvents, dispersants, defoamers, dehydrating agents, and catalysts.

[0023] In some embodiments, the mass ratio of the maleic anhydride-modified polyurethane, silane-modified polyurethane, maleic anhydride-modified adhesive, solvent, dispersant, defoamer, dehydrating agent, and catalyst is 10-35:10-30:12-25:30-40:0.1-0.3:0.1-0.3:1-3:0.05-0.1.

[0024] In some embodiments, the dispersant is selected from one or both of F108 coating dispersant and 9250 dispersant.

[0025] In some embodiments, the defoamer is selected from one or more combinations of BYK-066N defoamer, 5500 defoamer, and silicone defoamer.

[0026] In some embodiments, the dehydrating agent is selected from vinyltrimethoxysilane A-171.

[0027] In some embodiments, the catalyst is selected from one or more combinations of organotin NEOSTANN U-303, butyltin dilaurate, stannous octoate, zinc isooctanoate, bismuth isooctanoate, bismuth neodecanoate, and zinc neodecanoate.

[0028] The present invention further provides a method for preparing the above-mentioned polyurethane coating, the method comprising the step of mixing and dispersing the maleic anhydride modified polyurethane, silane modified polyurethane, maleic anhydride modified adhesive and other raw materials to obtain the polyurethane coating.

[0029] In some embodiments, the method further includes the step of preparing the maleic anhydride-modified polyurethane: adding the polyol to a reaction vessel, heating to dehydrate, then adding maleic anhydride and a catalyst, and adding isocyanate dropwise to react, testing the NCO content of the system, and when the NCO content of the system is less than 6.1%, the reaction is complete, and the maleic anhydride-modified polyurethane is obtained.

[0030] In some embodiments, the dripping time is 10-40 minutes.

[0031] In some implementations, the temperature is heated to 80-130°C.

[0032] In some implementations, the water content is reduced to less than 0.05% by mass.

[0033] In some embodiments, the method further includes the step of preparing the silane-modified polyurethane: adding the polyol to a reaction vessel, heating to dehydrate, then adding a silane coupling agent and a catalyst, and adding isocyanate dropwise to react, testing the NCO content of the system, and when the NCO content of the system is less than 4.9%, the reaction is complete, and the silane-modified polyurethane is obtained.

[0034] In some embodiments, the dripping time is 10-40 minutes.

[0035] In some implementations, the temperature is heated to 80-130°C.

[0036] In some implementations, the water content is reduced to less than 0.05% by mass.

[0037] In some embodiments, the method further includes the step of preparing the maleic anhydride-modified gel: adding the gel to a reaction vessel, heating it to a higher temperature, adding maleic anhydride and an initiator, and reacting to obtain the maleic anhydride-modified gel.

[0038] The present invention further provides the use of the aforementioned polyurethane coating as an interlayer release agent between polyurethane coatings and bitumen rolls.

[0039] The present invention further provides the use of the aforementioned polyurethane coating as a primer for concrete substrates. The polyurethane coating of this application can also be used as a primer, and it has very good adhesion to concrete substrates, even damp surfaces. The bond strength between the polyurethane coating and the concrete substrate is higher than 2.5 MPa.

[0040] The present invention further provides a waterproof laminate comprising a substrate layer, a polyurethane coating, and an asphalt waterproof membrane layer, and further comprising an interlayer spacer layer located between the polyurethane coating and the asphalt waterproof membrane layer, the interlayer spacer layer being formed of the aforementioned polyurethane coating.

[0041] The present invention further provides a method for preparing the aforementioned waterproof laminate, the method comprising the following steps: forming the polyurethane coating on the substrate layer, coating the polyurethane coating of the present application onto the polyurethane coating, and bonding it to the asphalt waterproof membrane layer to form the interlayer spacer layer, thereby obtaining the waterproof laminate.

[0042] Preferably, the bitumen waterproof membrane is selected from SBS waterproof membrane or APP waterproof membrane. These two types of waterproof membranes do not have a release liner on their surface and can be directly bonded to the interlayer spacer layer.

[0043] Preferably, the bitumen waterproof membrane is selected from wet-laid waterproof membranes or self-adhesive polymer-modified bitumen waterproof membranes. Both types of waterproof membranes have a release liner on their surface. This release liner needs to be removed to expose the adhesive layer before it is bonded to the interlayer spacer layer.

[0044] Furthermore, the substrate layer is a building surface.

[0045] Preferably, the building surface is a roof, a garage roof, or a basement side wall.

[0046] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art:

[0047] This application significantly enhances the bond strength between traditional polyurethane coatings and bitumen waterproof membranes by compounding maleic anhydride-modified polyurethane, maleic anhydride-modified adhesive, and silane-modified polyurethane, enabling traditional polyurethane to maintain good waterproof sealing performance even in complex and variable environments.

[0048] This application utilizes a compound of maleic anhydride-modified polyurethane, maleic anhydride-modified adhesive, and silane-modified polyurethane to achieve a polyurethane with both soft and hard grafting modifications. This modified polyurethane forms a bond with the waterproof bitumen membrane, which helps the resulting material maintain its bond strength in weakly acidic / weakly alkaline environments, making it less prone to peeling and detachment.

[0049] When the polyurethane coating of this application is used as an interlayer spacer, it can improve the overall durability and sealing performance of the composite waterproof layer composed of traditional polyurethane coating and waterproof asphalt membrane, making it widely applicable to waterproofing treatment of roofs, underground structures and bridges.

[0050] The polyurethane coating of this application has excellent bonding with various polar or non-polar coatings, concrete, etc., and is particularly suitable for application in the roll-coating composite waterproofing of basement side walls, and has excellent weather resistance and anti-corrosion effect.

[0051] The polyurethane coating of this application has excellent and sustained adhesion to traditional polyurethane coatings and other substrates. Its peel strength with self-adhesive asphalt rolls is higher than 2.0 N / mm. It is not afraid of water immersion and can be submerged in water for a long time. It is suitable for new strength requirements and can be used for roll-coated composite waterproofing in underground engineering.

[0052] The polyurethane coating of this application can also be used as a primer. It exhibits excellent adhesion to concrete substrates, even damp surfaces, with the bond strength between the polyurethane coating and the concrete substrate exceeding 2.5 MPa. This polyurethane coating is suitable for waterproofing various substrates and complex surfaces, and possesses excellent water resistance, maintaining a bond strength of over 80% after immersion in water. Detailed Implementation

[0053] The technical solutions of the present invention will be described in detail below with reference to specific embodiments, so that those skilled in the art can better understand and implement the technical solutions of the present invention, but the present invention is not limited to the scope of the examples described.

[0054] Unless otherwise specified, all raw materials in the following examples were commercially available or prepared using conventional methods in the art. TDI, MDI, HMDI, and IPDI were purchased from Wanhua Chemical; polyether 2000, polyether 1000, 330N, and 3050 were purchased from Shandong Lanxing and Dongda Chemical, respectively; defoamer was BYK Chemical 066N; dispersant was Deqian 9250; catalyst was organotin NEOSTANNU-303; dehydrating agent was vinyltrimethoxysilane A-171; No. 70 asphalt and petroleum resin were purchased from Sinopec; and solvent was Hualun No. 150 aromatic solvent.

[0055] Example 1

[0056] This example provides a polyurethane coating that can be used as a primer or interlayer spacer. Its raw material composition (parts by weight) is shown in Table 1, and the preparation method is as follows:

[0057] 1) Preparation of maleic anhydride modified polyurethane: Polyether polyol polyether 2000 was added to the reactor and heated to 110℃ for more than 2 hours to dehydrate. The moisture content was tested until it was below 0.05%. Then the reactor was cooled to 80℃, and maleic anhydride and the catalyst organotin NEOSTANN U-303 were added at once. The mixture was stirred for 20 minutes. Then TDI was added dropwise to the reactor within 20 minutes. The mixture was stirred and kept at the temperature for 2 hours. The NCO content was tested by di-n-butylamine titration. When it reached 5.5%, the reaction was considered complete. Stirring was stopped and the material was discharged.

[0058] The mass ratio of polyether polyol, isocyanate TDI, maleic anhydride and catalyst is 65:22:3:0.01.

[0059] 2) Preparation of silane-modified polyurethane: Polyether polyol polyether 2000 was added to the reactor and heated to 110℃ for more than 2 hours to dehydrate. The moisture content was tested until it was below 0.05%. Then the reactor was cooled to 80℃, and silane coupling agent KH550 and catalyst NEOSTANN U-303 were added at once. The mixture was stirred for 20 minutes. Then TDI was added dropwise to the reactor within 20 minutes. The mixture was stirred and kept at the temperature for 2 hours. The NCO content was tested by di-n-butylamine titration. When it reached 4.5%, the reaction was considered complete. Stirring was stopped and the material was discharged.

[0060] The mass ratio of polyether polyol, isocyanate TDI, silane coupling agent and catalyst is 70:17.3:5:0.01.

[0061] 3) Preparation of maleic anhydride modified rubber: Add No. 70 asphalt and petroleum resin to a kneader, then heat to 90℃ and add maleic anhydride and initiator dicumyl peroxide. Dehydrate, knead and react under vacuum of -0.1MPa for 2-4 hours until the moisture content is below 0.1%. Stir for 30 minutes and then discharge.

[0062] The mass ratio of No. 70 asphalt, petroleum resin, maleic anhydride, and initiator is 40:40:20:0.1.

[0063] 4) Add the raw materials in Table 1 to the reactor, mix, degas, disperse and react to obtain a polyurethane coating that can be used as a primer or interlayer spacer.

[0064] Examples 2-5

[0065] This example provides a polyurethane coating that can be used as a primer or interlayer spacer, which is basically the same as Example 1, except that its raw material composition is different from that of Example 1. Its specific composition is shown in Table 1.

[0066] Example 6

[0067] This example provides a polyurethane coating that can be used as a primer or interlayer spacer, which is basically the same as in Example 1, except that the type of silane coupling agent in step 2) is replaced with KH560.

[0068] Example 7

[0069] This example provides a polyurethane coating that can be used as a primer or interlayer spacer, which is basically the same as in Example 1, except that the type of adhesive in step 3) is replaced with a terpene resin.

[0070] Comparative Example 1

[0071] This example provides a polyurethane coating that can be used as a primer or interlayer spacer, which is basically the same as Example 1, except that the polyurethane in step 2) is not modified with silane, that is, no silane coupling agent is added in step 2).

[0072] Comparative Example 2

[0073] This example provides a polyurethane coating that can be used as a primer or interlayer spacer, which is basically the same as Example 1, except that the polyurethane in step 1) is not modified with maleic anhydride, that is, maleic anhydride is not added in step 1).

[0074] Comparative Example 3

[0075] This example provides a polyurethane coating that can be used as a primer or interlayer spacer, which is basically the same as in Example 1, except that the adhesive in step 3) is not modified with maleic anhydride, that is, maleic anhydride and initiator are not added in step 3).

[0076] Table 1. Raw material composition of polyurethane coatings in each embodiment.

[0077]

[0078] Performance tests were conducted on the polyurethane coatings of Examples 1-7 and Comparative Examples 1-3. The test methods followed the standards JC / T2254 Interlayer Treatment Agent for Sprayed Polyurea / Q / 320584PBT049 Interlayer Treatment Agent for Coatings. The bond strength refers to the bond strength with the concrete substrate layer, and after immersion in water, the test was conducted according to standard GB16777. The peel strength with asphalt roofing membrane was tested as follows: First, conventional polyurethane was coated onto the concrete substrate layer, then the polyurethane coating of this application was applied over the conventional polyurethane coating, and then the asphalt roofing membrane was bonded to it, specifically according to the standards JC / T2254 Interlayer Treatment Agent for Sprayed Polyurea / Q / 320584PBT049 Interlayer Treatment Agent for Coatings; immersion in water and heat treatment were conducted according to the standards Q / 320584PBT049 Interlayer Treatment Agent for Coatings. The test results are shown in Table 2.

[0079] Table 2 Performance results of polyurethane coatings in each example and comparative example

[0080]

[0081]

[0082] The peel strength of the asphalt roofing membrane may be slightly improved after immersion and heat treatment compared to the untreated membrane. This is because the water pressure during immersion and the heat melting effect during heat treatment promote better adhesion between the two materials, thus increasing the peel strength.

[0083] As can be seen from Table 2, this application significantly enhances the bond strength between traditional polyurethane coatings and asphalt waterproof membranes by compounding maleic anhydride-modified polyurethane, maleic anhydride-modified adhesive, and silane-modified polyurethane, and also increases its bond strength as a primer for concrete substrates.

[0084] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They are not intended to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

[0085] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

Claims

1. A polyurethane coating, characterized by: The polyurethane coating comprises the following components: maleic anhydride modified polyurethane, silane modified polyurethane, maleic anhydride modified colloid and solvent; the maleic anhydride modified polyurethane is obtained by reaction of raw materials comprising polyol, maleic anhydride, isocyanate and catalyst; the silane modified polyurethane is obtained by reaction of raw materials comprising polyol, silane coupling agent, isocyanate and catalyst; the colloid is selected from the group consisting of one or more combinations of petroleum resin, asphalt, rosin resin, terpene resin, styrene butyl glue and butyl glue; the maleic anhydride modified colloid is obtained by reaction of raw materials comprising maleic anhydride, colloid and initiator; the mass ratio of the maleic anhydride modified polyurethane, silane modified polyurethane, maleic anhydride modified colloid and solvent is 10-35:10-30:12-25:28-40; in the raw materials of the maleic anhydride modified polyurethane, the mass ratio of the polyol, maleic anhydride, isocyanate and catalyst is 60-70:2-6:22-40:0.01-0.05; in the raw materials of the silane modified polyurethane, the mass ratio of the polyol, silane coupling agent, isocyanate and catalyst is 65-75:3-7:17-25:0.01-0.05; in the raw materials of the maleic anhydride modified colloid, the mass ratio of the maleic anhydride, colloid and initiator is 15-25:75-85:0.05-0.

15.

2. The polyurethane coating according to claim 1, characterized in that: The polyol is selected from the group consisting of polyether polyol or polyester polyol; and / or, the isocyanate is selected from the group consisting of one or more combinations of toluene diisocyanate TDI, diphenyl methane diisocyanate MDI, hexamethylene diisocyanate HDI, isophorone diisocyanate IPDI and 4,4'-dicyclohexyl methane diisocyanate HMDI.

3. The polyurethane coating of claim 1, wherein: The silane coupling agent is selected from the group consisting of one or more combinations of WD50, KH550, KH560, KH570 and isocyanate propyl triethoxysilane IPTS; and / or, the catalyst is selected from the group consisting of one or more combinations of organic tin NEOSTANN U-303, butyl tin dilaurate, stannous octoate, zinc isooctoate, bismuth isooctoate, bismuth neodecanoate and zinc neodecanoate; and / or, the initiator is selected from the group consisting of azo initiator or organic peroxide initiator; and / or, the solvent is selected from the group consisting of one or more combinations of aromatic hydrocarbon, dimethyl carbonate and butyl acetate.

4. The polyurethane coating of claim 1, wherein: The polyurethane coating further comprises dispersant, defoaming agent, water removing agent and catalyst.

5. The polyurethane coating according to claim 4, characterized in that: The mass ratio of the maleic anhydride modified polyurethane, silane modified polyurethane, maleic anhydride modified colloid, solvent, dispersant, defoaming agent, water removing agent and catalyst is 10-35:10-30:12-25:30-40:0.1-0.3:0.1-0.3:1-3:0.05-0.

1.

6. The polyurethane coating of claim 4, wherein: The dispersant is selected from one or both of f108 coating dispersant and 9250 dispersant; and / or, the defoaming agent is selected from a combination of one or more of BYK-066N defoaming agent, 5500 defoaming agent, and silicone defoaming agent; and / or, the water-removing agent is selected from vinyl trimethoxysilane A-171; and / or, the catalyst is selected from a combination of one or more of organic tin NEOSTANN U-303, butyl tin dilaurate, stannous octoate, zinc isooctoate, bismuth isooctoate, bismuth neodecanoate, and zinc neodecanoate.

7. A process for the preparation of a polyurethane coating as claimed in any one of claims 1 to 6, characterized in that: The method comprises the step of mixing and dispersing the maleic anhydride modified polyurethane, the silane modified polyurethane, the maleic anhydride modified colloid, and other raw materials to obtain the polyurethane coating.

8. The method of claim 7, wherein: The method further comprises the step of preparing the maleic anhydride modified polyurethane: adding the polyol into a reaction kettle, heating to dehydrate, then adding maleic anhydride and a catalyst, and adding isocyanate dropwise to react, and testing the NCO content of the system, when the NCO content of the system is less than 6.1%, the reaction is complete, and the maleic anhydride modified polyurethane is obtained; and / or, the method further comprises the step of preparing the silane modified polyurethane: adding the polyol into a reaction kettle, heating to dehydrate, then adding silane coupling agent and a catalyst, and adding isocyanate dropwise to react, and testing the NCO content of the system, when the NCO content of the system is less than 4.9%, the reaction is complete, and the silane modified polyurethane is obtained; and / or, the method further comprises the step of preparing the maleic anhydride modified colloid: adding the colloid into a reaction kettle, adding maleic anhydride and an initiator after heating to warm, and reacting to obtain the maleic anhydride modified colloid.

9. Use of the polyurethane coating of any one of claims 1-6 as an interlayer separator between a polyurethane coating and a bitumen sheet.

10. Use of the polyurethane coating of any one of claims 1-6 as a primer for a concrete base.

11. A waterproofing laminate comprising a substrate layer, a polyurethane coating layer, and an asphaltic waterproofing membrane layer, characterized in that: The waterproof layer stack further comprises an interlayer separator layer between the polyurethane coating layer and the bitumen waterproof sheet layer, and the interlayer separator layer is formed by the polyurethane coating of any one of claims 1-6.

12. The method of producing a waterproof laminate according to claim 11, characterized by: The preparation method comprises the steps of: forming the polyurethane coating layer on the base material layer, coating the polyurethane coating of any one of claims 1-6 on the polyurethane coating layer, and bonding to the bitumen waterproof sheet layer to form the interlayer separator layer, to obtain the waterproof layer stack.

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