Post-crosslinking PMMA waterproof coating and preparation method thereof

Abstract

The present application provides a post-crosslinked PMMA waterproof coating and a preparation method thereof. The post-crosslinked PMMA waterproof coating comprises component A and component B; wherein component A comprises optional additives and the following raw material components in parts by weight: 20-50 parts of PUA resin, 30-60 parts of active diluent, and 4-10 parts of reducing agent; wherein the PUA resin is obtained by reacting oligomer polyol, polyisocyanate, chain extender, hydroxy acrylate monomer, and end capping agent under the condition of polymerization inhibitor, the molar ratio of -NCO in polyisocyanate to -OH in oligomer polyol is 1.1-1.5, and the chain extender has the structure shown in formula 1: R 1 , R 2 , R 4 , R 5 are independently selected from hydrogen or C1-C5 alkyl, R 3 Selected from C1-C5 alkyl, component B includes 15-30 parts of peroxide oxidant.

Description

Technical Field

[0001] The present application belongs to the technical field of waterproof coatings, and in particular relates to a post-crosslinked PMMA elastic waterproof coating and a preparation method thereof. Background Art

[0002] Polymethyl Methacrylate (PMMA) is a high molecular polymer. The name of PMMA waterproof materials comes from the fact that they use acrylate monomers as active diluents. In the system, the initiator and the reducing agent contact each other and react to generate active free radicals. The active free radicals induce the polymerization reaction of acrylate monomers to form polymerized polymers.

[0003] Existing PMMA waterproof coatings are high glass transition temperature coatings, which are used in scenes with low base mobility such as floors and railway tracks, and their use is very limited. When applied to concrete structures, cracking and freezing cracking problems will occur. In addition, existing PMMA waterproof coatings are very susceptible to oxygen attack and may cause incomplete curing. Summary of the invention

[0004] The embodiment of the present application provides a post-cross-linked PMMA waterproof coating and a preparation method thereof. The coating formed by the post-cross-linked PMMA waterproof coating has certain elasticity and flexibility and can effectively cope with a variety of substrates.

[0005] In a first aspect, an embodiment of the present application provides a post-crosslinked PMMA waterproof coating, comprising component A and component B; wherein component A comprises optional additives and the following raw material components in parts by weight: 20-50 parts of PUA resin, 30-60 parts of active diluent, 4-10 parts of reducing agent, and 5-10 parts of air drying agent; wherein the PUA resin is obtained by reacting oligomer polyol, polyisocyanate, chain extender, hydroxyl acrylate monomer, and end capping agent under inhibitor conditions, the molar ratio of -NCO in the polyisocyanate to -OH in the oligomer polyol is 1.1-1.5, and the chain extender comprises the structure shown in Formula 1,

[0006]

[0007] R 1 , R 2 , R 4 , R 5 independently selected from hydrogen or C1-C5 alkyl, R 3 Selected from C1-C5 alkyl;

[0008] Component B includes 15-30 parts of peroxide curing agent.

[0009] According to the embodiment of the first aspect of the present application, the ratio of the amounts of inhibitor, end capping agent, chain extender and hydroxy acrylate monomer calculated based on the amount of NCO remaining after the reaction of oligomer polyol and polyisocyanate is 0.06:(0.1~0.5):(0.1~0.5):1.

[0010] According to an embodiment of the first aspect of the present application, the post-crosslinked PMMA waterproof coating satisfies at least one of the following conditions: the molecular weight of the oligomer polyol is 1000-6000, and the functionality is 2-3; the polyisocyanate includes at least one of TDI, MDI, IPDI, and HMDI; the inhibitor includes at least one of hydroquinone, 2,5-di-tert-butylhydroquinone, and methylhydroquinone; the capping agent includes at least one of benzyl alcohol, n-octanol, hydroxybutyric acid, and isobornyl alcohol; the hydroxyacrylate monomer includes at least one of hydroxyethyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, and hydroxybutyl methacrylate.

[0011] According to the embodiment of the first aspect of the present application, the PUA resin also includes acrylate monomers, and the acrylate monomers account for 20% to 30% of the weight of the entire PUA resin.

[0012] According to an embodiment of the first aspect of the present application, the acrylic ester monomer includes at least one of methyl methacrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, hexyl acrylate, isooctyl acrylate, lauryl acrylate, benzyl acrylate, cyclohexyl acrylate, perfluoroalkyl acrylate, isobornyl acrylate, tetrahydrofuran methyl acrylate, methacrylic acid, and acrylic acid.

[0013] According to an embodiment of the first aspect of the present application, the active diluent includes at least one of methacrylic acid, methyl methacrylate, butyl acrylate, isooctyl acrylate, glycidyl acrylate, hydroxyethyl methacrylate, ethyl acrylate, allyl methacrylate, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate.

[0014] According to an embodiment of the first aspect of the present application, the reducing agent includes at least one of diethanolamine, dimethylethanolamine, N,N-diethylhydroxylamine, N,N-dimethyl-p-toluidine, and N,N-diethylaniline.

[0015] According to an embodiment of the first aspect of the present application, the peroxide curing agent includes at least one of benzoyl peroxide, dicumyl peroxide, and cumene hydroperoxide.

[0016] According to an embodiment of the first aspect of the present application, the optional additives include: air-drying agent, 5-10 parts; filler, 25-45 parts; color paste, 1-2 parts; pH buffer, 0.5-3 parts; plasticizer, 10-20 parts; anti-ultraviolet aging agent, 1-2 parts; antioxidant, 1-2 parts; reducing agent, 4-10 parts; anti-settling agent, 2-5 parts; reinforcing agent, 10-18 parts.

[0017] According to an embodiment of the first aspect of the present application, the optional additives meet at least one of the following conditions: the air-drying agent includes at least one of refined paraffin and semi-refined paraffin; the filler includes at least one of heavy calcium carbonate, light calcium carbonate, talcum powder, barium sulfate, aluminum hydroxide, titanium dioxide, fumed silica, and nano calcium carbonate; the particle size of the filler is 400-2000 mesh; the color paste includes at least one of emerald green, iron red, and orange; the pH buffer includes at least one of tartaric acid, potassium dihydrogen phosphate, and sodium bicarbonate; the plasticizer includes at least one of DOTP, DOP, and acetyl tributyl citrate; the anti-ultraviolet aging agent includes UV-326, At least one of UV-329; antioxidants include 1010, 686; the reducing agent includes at least one of diethanolamine, dimethylethanolamine, N,N-diethylhydroxylamine, N,N-dimethyl-p-toluidine, and N,N-diethylaniline; the anti-settling agent includes A-200 fumed silica; the reinforcing agent includes at least one of 3102 Mitsubishi resin and 950 Mitsubishi resin.

[0018] In a second aspect, the present application provides a method for preparing the above-mentioned post-crosslinked PMMA waterproof coating, comprising the following steps:

[0019] To prepare PUA resin, after the oligomer polyol and polyisocyanate react, a solid acid catalyst, an inhibitor, a capping agent, a chain extender, and a hydroxy acrylate monomer are added in order, and the PUA resin is obtained after further reaction; to prepare component A, materials containing PUA resin, an active diluent, a reducing agent, and an additive are mixed to obtain component A; to prepare component B, materials containing a peroxide curing agent are mixed to obtain component B; to prepare a PMMA-type elastic waterproof coating composition, components A and B are stored independently to obtain a PMMA-type elastic waterproof coating composition.

[0020] According to an embodiment of the second aspect of the present application, the preparation of the chain extender comprises the following steps: reacting a diol with a compound having a structure shown in Formula 2, a solid acid catalyst and a polymerization inhibitor to obtain a chain extender,

[0021]

[0022] Among them, R 1 , R 2 , R 4 , R 5 Independently selected from hydrogen or C1-C5 alkyl;

[0023] The molar ratio of the diol to the compound having the structure shown in Formula 2 is 1:(1-2).

[0024] Compared with the prior art, this application has at least the following beneficial effects:

[0025] The post-crosslinked PMMA waterproof coating provided in the embodiment of the present application adopts a PUA resin with a special structure. The PUA resin with a special structure is obtained by reacting an oligomer polyol, a polyisocyanate, a chain extender, a hydroxyl acrylate monomer, and a capping agent under inhibitor conditions, wherein the molar ratio of -NCO in the polyisocyanate to -OH in the oligomer polyol is 1.1 to 1.5, and a -NCO-terminated polyurethane prepolymer can be obtained; the polyurethane prepolymer reacts with the hydroxyl acrylate monomer and the structure shown in Formula 1 to obtain the PUA resin, wherein the structure shown in Formula 1 contains hydroxyl groups, double bonds, and carboxyl groups, wherein the structure shown in Formula 1 contains a double bond, and the hydrogen on the positive carbon atom in the double bond is easily lost to form a free radical, which combines with oxygen in the air to generate a peroxide, and this peroxide produces a highly active free radical, which promotes the continuation of the next reaction, thereby causing a series of double bond crosslinking reactions, effectively isolating the inhibitory effect of oxygen on the reaction of the acrylate coating, so that it solidifies in the air without becoming sticky. PUA resin can effectively reduce the effect of oxygen inhibition on its curing behavior by introducing double bonds in the structure shown in Formula 1 and oxygen-absorbing functional groups in the PUA resin structure. In addition, it contains double bonds and can be used as a reactive diluent and cross-linking agent. The presence of carboxyl groups in the structure shown in Formula 1 allows the PUA resin to be cross-linked with the reactive diluent after film formation, effectively enhancing the tensile modulus strength of the PMMA coating. For example, when the reactive diluent includes glycidyl acrylate, the carboxyl group can undergo a "carboxyl-epoxy" chemical reaction with the epoxy group to achieve cross-linking after film formation, further increasing the internal cross-linking density and effectively enhancing the tensile modulus strength of the PMMA coating. The polyurethane prepolymer and the hydroxy acrylate monomer form a polyurethane structure with double bonds, which provides reaction points for the subsequent active diluent (such as acrylate) to form chain growth and three-dimensional network cross-linking structure on the molecular structure of the polyurethane. This will produce an elastic PMMA coating with both strength and ductility, which can be better used in various scenarios, such as ground structures and roof structures with large base activity areas; at the same time, considering the construction performance, the construction process usually does not have the working conditions of a high-torque electric mixer, and requires a long low-viscosity slurry. Therefore, polar and large steric hindrance functional groups are introduced at the end of the PUA resin to reduce the viscosity of the resin, promote the floating of the air-drying agent (wax), form an oxygen barrier layer, and improve the surface drying properties. DETAILED DESCRIPTION

[0026] In order to make the invention purpose, technical scheme and beneficial technical effect of the present application clearer, the present application is further described in detail in conjunction with the embodiments below. It should be understood that the embodiments described in this specification are only for explaining the present application, not for limiting the present application.

[0027] For simplicity, only some numerical ranges are explicitly disclosed herein. However, any lower limit can be combined with any upper limit to form an unambiguous range; and any lower limit can be combined with other lower limits to form an unambiguous range, and any upper limit can be combined with any other upper limit to form an unambiguous range. In addition, although not explicitly stated, each point or single value between the range endpoints is included in the range. Thus, each point or single value can be combined with any other point or single value as its own lower limit or upper limit or with other lower limits or upper limits to form an unambiguous range.

[0028] In the description herein, when a composition is described as containing, comprising or including specific components, or when a process is described as containing, comprising or including specific process steps, it is expected that the composition of the present application also consists essentially of or consists of the components, and the process of the present application also consists essentially of or consists of the process steps.

[0029] Unless otherwise expressly stated, the use of the terms "include", "comprising", "containing", and "having" should generally be interpreted as open-ended and non-restrictive. In the description herein, it should be noted that, unless otherwise stated, "above" and "below" are inclusive, and the "multiple" in "one or more" means more than two.

[0030] The above-mentioned summary of the invention of the present application is not intended to describe each disclosed embodiment or each implementation in the present application. The following description more specifically illustrates exemplary embodiments. In many places throughout the application, guidance is provided by a series of examples, which can be used in various combinations. In each example, enumeration is only used as a representative group and should not be interpreted as exhaustive.

[0031] The inventor of this application noticed that the existing PMMA waterproof coating is a high glass transition temperature coating, which is used in places with low base mobility such as floors and railway tracks, and the application scenarios are very limited. Since most buildings are made of concrete structures, concrete structures will shrink and settle during long-term service, that is, the base is highly mobile, which requires the coating covering the building surface to have a certain degree of elasticity and flexibility to prevent stress cracking and frost cracking.

[0032] To this end, the inventors of the present application have conducted extensive research and provided a post-crosslinked PMMA waterproof coating and a preparation method thereof, aiming to improve the elastic modulus so that it has a wider range of applications.

[0033] Post-crosslinking PMMA waterproof coating

[0034] In a first aspect, the present application provides a post-crosslinking PMMA waterproof coating, including component A and component B; wherein:

[0035] Component A includes optional additives and the following raw material components in parts by weight: 20-50 parts of PUA resin, 30-60 parts of active diluent, 4-10 parts of reducing agent, and 5-10 parts of air drying agent;

[0036] The PUA resin is obtained by reacting oligomer polyol, polyisocyanate, chain extender, hydroxy acrylate monomer, and end capping agent under the condition of polymerization inhibitor, the molar ratio of -NCO in polyisocyanate to -OH in oligomer polyol is 1.1 to 1.5, and the chain extender includes the structure shown in Formula 1.

[0037]

[0038] R 1 , R 2 , R 4 , R 5 independently selected from hydrogen or C1-C5 alkyl, R 3 Selected from C1-C5 alkyl;

[0039] Component B includes 15-30 parts of peroxide curing agent.

[0040] PMMA refers to polymethyl methacrylate, a high molecular polymer also known as acrylic or organic glass. It has the advantages of high transparency, low price, and easy machining. It is a commonly used glass substitute material.

[0041] PMMA coating: PMMA coating is mainly composed of acrylic monomers (usually MMA), oxidants, reducing agents and powders. When used, several components are mixed and then applied to the base layer to form a waterproof structure.

[0042] MMA refers to methyl methacrylate, also known as methyl methacrylate, which is an organic compound.

[0043] PUA resin refers to polyurethane acrylate. The molecules of PUA resin contain acrylic functional groups and urethane bonds. The cured adhesive has the high wear resistance, adhesion, flexibility, high peel strength and excellent low temperature resistance of polyurethane, as well as the excellent optical properties and weather resistance of polyacrylate.

[0044] Without intending to be limited by any theory or explanation, the post-crosslinked PMMA waterproof coating provided in the present application adopts a PUA resin with a special structure, which is obtained by reacting oligomer polyols, polyisocyanates, chain extenders, hydroxy acrylate monomers, and end-capping agents with an organic tin catalyst in a solid acid catalyst under the condition of an inhibitor. Among them, the molar ratio of -NCO in the polyisocyanate to -OH in the oligomer polyol is 1.1 to 1.5, and a -NCO-terminated polyurethane prepolymer can be obtained. The polyurethane prepolymer reacts with the hydroxy acrylate monomer and the structure shown in Formula 1, and reacts with the end-capping agent to obtain the PUA resin. The structure shown in Formula 1 contains hydroxyl groups, double bonds, and carboxyl groups; among them, the structure shown in Formula 1 contains double bonds, and the hydrogen on the positive carbon atom in the double bonds is easily lost to form free radicals, which combine with oxygen in the air to generate peroxides. This peroxide produces highly active free radicals, which promote the continuation of the next reaction, thereby causing a series of double bond cross-linking reactions, effectively isolating the inhibitory effect of oxygen on the reaction of acrylate coatings, allowing it to cure in the air without becoming sticky. PUA resin can effectively reduce the effect of oxygen inhibition on its curing behavior and improve surface smoothness by introducing double bonds in the structure shown in Formula 1 and oxygen-absorbing functional groups in the PUA resin structure. In addition, it contains double bonds and can be used as an active diluent and cross-linking agent. The presence of a carboxyl group in the structure shown in Formula 1 allows the PUA resin to be cross-linked with the active diluent after film formation, effectively enhancing the tensile modulus strength of the PMMA coating. For example, when the active diluent includes glycidyl acrylate, the carboxyl group can undergo a "carboxyl-epoxy" chemical reaction with the epoxy group to achieve cross-linking after film formation, further increasing the internal cross-linking density and effectively enhancing the tensile modulus strength of the PMMA coating. The polyurethane prepolymer and the hydroxy acrylate monomer form a polyurethane structure with a double bond, providing a reaction point for the subsequent active diluent (such as acrylate) to form a chain growth and a three-dimensional network cross-linking structure on the molecular structure of the polyurethane. This will result in an elastic PMMA coating that has both strength and ductility, and can be better used in various scenarios, such as ground structures and roof structures with larger base activity areas.

[0045] At the same time, considering the construction performance, the construction process usually does not have the working conditions of a high-torque electric mixer, and requires a low-viscosity working condition with a longer slurry. Therefore, polar and large steric hindrance functional groups are introduced at the end of the PUA resin. For example, benzyl alcohol, n-octanol, hydroxybutyric acid, and isoborneol are used to introduce benzyl, n-octyl, butyric acid, and isoborneol, respectively, to reduce the viscosity of the resin, promote the floating of the air-drying agent (wax), form an oxygen barrier layer, and improve the surface drying properties.

[0046] In the embodiment of the present application, the weight proportion of the PUA resin is 20-50 parts. Exemplarily, the weight proportion of the PUA resin is 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts, or a range consisting of any two of the above values.

[0047] The embodiment of the present application optimizes the monomer ratio of the acrylic acid active diluent, improves the adhesion of the coating to the cement foundation, further reduces the odor and residue of acrylic acid, and reduces the impact on construction personnel and the environment. The weight parts of the active diluent in the embodiment of the present application are 30-60 parts. For example, the weight parts of the active diluent are 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, or a range consisting of any two of the above values.

[0048] Oligomeric polyols are divided into polyether polyols and polyester polyols, which constitute the soft segments of polyurethane molecules. Polyether polyols mainly include polytetramethylene glycol, polyethylene glycol and polypropylene glycol; polyester polyols mainly include polyhexane adipate diol, polycarbonate diol, polybutylene adipate diol and polycaprolactone diol.

[0049] In some embodiments, the oligomer polyol may be selected from polyether diols and polyether triols.

[0050] The polyether diol may refer to a polyether polyol containing two hydroxyl groups in one molecule. As an example, the polyether diol may include but is not limited to polyether polyol DL-2000D or polyether polyol DL-1000.

[0051] The polyether triol may refer to a polyether polyol containing three hydroxyl groups in one molecule. As an example, the polyether triol may include but is not limited to polyether polyol EP330N or polyether polyol MN1000.

[0052] In the embodiments of the present application, the end-capping agent, the chain extender, and the hydroxy acrylate monomer are used as reactants to react with the NCO groups remaining after the reaction of the oligomer polyol and the polyisocyanate to completely consume the NCO groups. The molar ratio of the above-mentioned reactants to the NCO remaining after the reaction of the oligomer polyol and the polyisocyanate is preferably (1 to 1.05):1.

[0053] In some embodiments, in order to completely consume the remaining NCO groups after the reaction of the oligomer polyol and the polyisocyanate, the ratio of the amount of inhibitor, end capping agent, chain extender, and hydroxy acrylate monomer used is 0.06: (0.1 ~ 0.5): (0.1 ~ 0.5): 1, calculated according to the amount of NCO remaining after the reaction of the oligomer polyol and the polyisocyanate.

[0054] Without intending to be limited by any theory or explanation, in the embodiments of the present application, by adjusting the ratio of the amounts of inhibitors, end capping agents, chain extenders, and hydroxy acrylate monomers within the above range, the PUA resin can have a suitable functionality and molecular weight, which facilitates cross-linking of the PUA resin after film formation in the coating system, thereby making the coating film formed by the post-cross-linked PMMA waterproof coating have both elasticity and flexibility.

[0055] In some embodiments, the molecular weight of the oligomer polyol is 1000 to 6000 and the functionality is 2 to 3. For example, the molecular weight of the oligomer polyol is independently selected from 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000 or a range consisting of any two of the above values.

[0056] In some embodiments, the polyisocyanate includes at least one of TDI, MDI, IPDI, HMDI.

[0057] TDI refers to toluene diisocyanate, which has six isomers, namely toluene-2,3-diisocyanate, toluene-2,4-diisocyanate, toluene-2,5-diisocyanate, toluene-2,6-diisocyanate, toluene-3,4-diisocyanate and toluene-3,5-diisocyanate. Among them, toluene-2,4-diisocyanate and toluene-2,6-diisocyanate are the most common isomers. Toluene diisocyanate in industry is usually a mixture of toluene-2,4-diisocyanate and toluene-2,6-diisocyanate.

[0058] MDI refers to diphenylmethane diisocyanate. HMDI refers to dicyclohexylmethane diisocyanate.

[0059] IPDI refers to isophorone diisocyanate, with the chemical formula C 12 H 18 N2O2 is an alicyclic diisocyanate. IPDI is one of the least active varieties among the commonly used diisocyanate products. It has a stable reaction. Its two isocyanate groups have different reactivity of about ten times, which is conducive to the preparation of various prepolymers. In addition, its vapor pressure is low, which makes it safer to use and operate.

[0060] In some embodiments, the polymerization inhibitor includes at least one of hydroquinone, 2,5-di-tert-butylhydroquinone, and methylhydroquinone.

[0061] In some embodiments, the capping agent is a small molecule, including at least one of benzyl alcohol, n-octanol, hydroxybutyric acid, and isobornyl alcohol.

[0062] In some embodiments, the hydroxyacrylate monomer includes at least one of hydroxyethyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, and hydroxybutyl methacrylate.

[0063] In some embodiments, the PUA resin further includes acrylate monomers, and the acrylate monomers account for 20% to 30% of the weight of the entire PUA resin.

[0064] Adding acrylate monomers to PUA resin can reduce the viscosity of PUA resin so that it can later undergo free radical curing reaction with the double bonds on the PUA chain segments (i.e., the hydroxy acrylate structural units before the addition of MMA monomers) and active diluents under the action of oxidants and reductants to form a post-crosslinked PMMA elastic waterproof coating comprising PUA resin, acrylate structural units, and active diluent structural units.

[0065] In some embodiments, the acrylic ester monomer includes at least one of methyl methacrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, hexyl acrylate, isooctyl acrylate, lauryl acrylate, benzyl acrylate, cyclohexyl acrylate, perfluoroalkyl acrylate, isobornyl acrylate, tetrahydrofuranyl methyl acrylate, methacrylic acid, and acrylic acid.

[0066] In some embodiments, the reactive diluent includes at least one of methacrylic acid, methyl methacrylate, butyl acrylate, isooctyl acrylate, glycidyl acrylate, hydroxyethyl methacrylate, ethyl acrylate, allyl methacrylate, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate.

[0067] Since PUA resin is a viscous liquid, adding active diluents to post-cross-linked PMMA coatings can, on the one hand, effectively reduce the viscosity of the PUA resin and facilitate the contact between the PUA resin and the oxidant, reductant and other components; on the other hand, the active diluent itself also participates in free radical polymerization, which is beneficial to promote the curing speed and curing efficiency.

[0068] The active diluent can dissolve or disperse the components in the PMMA elastic waterproof coating composition, and can also participate in free radical curing during the coating film-forming process. When the active diluent includes glycidyl acrylate (GMA), the epoxy group in glycidyl acrylate can react with the carboxyl group in the chain extender to undergo a "carboxyl-epoxy" chemical reaction, preparing for post-film crosslinking, achieving post-film crosslinking, further increasing the internal crosslinking density, and effectively enhancing the tensile modulus strength of the PMMA coating to further improve the tensile strength of the coating.

[0069] The self-crosslinking reaction principle of the carboxyl group of the chain extender (monohydroxyl) and the epoxy group of GMA is shown in the following formula:

[0070]

[0071] In some embodiments, the reducing agent includes at least one of diethanolamine, dimethylethanolamine, N,N-diethylhydroxylamine, N,N-dimethyl-p-toluidine, and N,N-diethylaniline.

[0072] In some embodiments, the peroxide oxidant comprises at least one of benzoyl peroxide, cumene hydroperoxide,

[0073] The embodiments of the present application achieve high conversion rate while reducing reaction heat by optimizing the types and ratios of oxidants and reductants.

[0074] In some embodiments, the optional additives include: air drying agent, 5-10 parts; filler, 25-45 parts; color paste, 1-2 parts; pH buffer, 0.5-3 parts; plasticizer, 10-20 parts; anti-ultraviolet aging agent, 1-2 parts; antioxidant, 1-2 parts; reducing agent, 4-10 parts; anti-settling agent, 2-5 parts; reinforcing agent, 10-18 parts.

[0075] In the examples of the present application, a pH buffer is creatively introduced to ensure the pH stability of the system, reduce the reaction heat and achieve a high conversion rate.

[0076] In some embodiments, the air-drying agent includes at least one of refined paraffin and semi-refined paraffin. Exemplarily, the air-drying agent can be selected from at least one of the numbers 52#, 54#, 56#, 58#, 60#, 62#, and 68#.

[0077] In some embodiments, the filler includes at least one of heavy calcium carbonate, light calcium carbonate, talc, barium sulfate, aluminum hydroxide, titanium dioxide, fumed silica, and nano calcium carbonate.

[0078] In some embodiments, the particle size of the filler is 400-2000 mesh; the color paste includes at least one of emerald green, iron red, and orange.

[0079] In some embodiments, the color paste includes at least one of emerald green, iron red, and orange.

[0080] In some embodiments, the pH buffer comprises at least one of tartaric acid, potassium dihydrogen phosphate, and sodium bicarbonate.

[0081] In some embodiments, the plasticizer includes at least one of DOTP, DOP, and acetyltributyl citrate.

[0082] In some embodiments, the anti-ultraviolet aging agent includes UV-326, At least one of UV-329.

[0083] In some embodiments, the antioxidant comprises 1010, At least one of 686.

[0084] In some embodiments, the reducing agent includes at least one of diethanolamine, dimethylethanolamine, N,N-diethylhydroxylamine, N,N-dimethyl-p-toluidine, and N,N-diethylaniline.

[0085] In some embodiments, the anti-settling agent includes A-200 fumed silica; the reinforcing agent includes at least one of 3102 Mitsubishi resin and 950 Mitsubishi resin.

[0086] Preparation method of post-crosslinking PMMA waterproof coating

[0087] In a second aspect, the present application provides a method for preparing the above-mentioned post-crosslinked PMMA waterproof coating, comprising the following steps:

[0088] To prepare PUA resin, after the oligomer polyol and polyisocyanate react, a catalyst, an inhibitor, a capping agent, a chain extender, and a hydroxy acrylate monomer are added in order, and the PUA resin is obtained after the reaction again;

[0089] Prepare component A by mixing materials containing PUA resin, active diluent, reducing agent and additives to obtain component A;

[0090] Prepare component B by mixing materials containing a peroxide curing agent to obtain component B;

[0091] A PMMA-based elastic waterproof coating composition is prepared, and component A and component B are stored independently to obtain the PMMA-based elastic waterproof coating composition.

[0092] As an example, PUA resin can be prepared by the following steps:

[0093] Put the oligomer polyol into a reactor, heat to 105°C, and vacuum dehydrate for 3 hours. After testing the moisture content to be less than 0.5%, reduce the temperature to 75°C, add polyisocyanate according to the R value (1.1 to 1.5), react for 3 hours, add organic tin catalyst (0.5%), and add inhibitor, small molecule end-capping agent, chain extender A, hydroxy acrylate in sequence (calculated according to the amount of residual NCO, the molar ratio is 0.06: (0.1-0.5): (0.1-0.5): 1), react at 75°C for 2 hours, reduce the temperature to 45°C, add MMA monomer (accounting for 30% of the total weight of PUA resin), discharge the material, and obtain PUA resin.

[0094] The R value refers to the ratio of the amount of isocyanate group (-NCO) to the amount of hydroxyl group (-OH), also known as the isocyanate index.

[0095] As an example, component A can be prepared by the following steps:

[0096] According to the weight percentage, add 20-50 parts of PUA resin to a high-speed disperser, add 25-45 parts of powder, shear and disperse for 30 minutes, add 30-60 parts of active diluent in 2-3 times, shear for 1 hour to disperse evenly, add 5-10 parts of air drying agent, 1-2 parts of color paste, 0.5-3 parts of pH buffer, 10-20 parts of plasticizer, 1-2 parts of anti-ultraviolet aging agent, 1-2 parts of antioxidant, 4-10 parts of reducing agent, 2-5 parts of anti-settling agent, 10-18 parts of reinforcing agent in sequence, shear for 1 hour to disperse evenly, discharge, and obtain PMMA coating component A. The shearing speed is 4000-10000rpm.

[0097] In some embodiments, the preparation of the chain extender comprises the following steps: reacting a diol with a compound having a structure shown in Formula 2, an esterification catalyst and a polymerization inhibitor to obtain a chain extender,

[0098]

[0099] Among them, R 1 , R 2 , R 4 , R 5 Independently selected from hydrogen or C1-C5 alkyl;

[0100] The molar ratio of the diol to the compound having the structure represented by Formula 2 is 1:(1-2).

[0101] In some embodiments, the diol includes at least one of ethylene glycol, propylene glycol, butylene glycol, and diethylene glycol.

[0102] The chain extender obtained by reacting a diol with a compound having a structure shown in Formula 2 may include only a monohydroxy compound, or may include a monohydroxy compound and a dihydroxy compound at the same time. For example, the reaction process when the diol is ethylene glycol and the compound having a structure shown in Formula 2 is nadic anhydride is shown in the following reaction formula:

[0103]

[0104] As an example, the chain extender can be prepared by the following steps: ethylene glycol (or propylene glycol) is put into a reactor, heated to 105°C, vacuumed and dehydrated for 3 hours, and after the moisture content is tested to be less than 5 parts per thousand, nadic anhydride (or methyl nadic anhydride) and a solid acid catalyst and a polymerization inhibitor are put into the reactor, and reacted at 130°C and a vacuum degree of -0.03MPa for 3 hours, and then the chain extender is obtained. In terms of the ratio of the amount of substance, nadic anhydride: ethylene glycol: solid acid catalyst: polymerization inhibitor is 1: (1-2): 0.06: 0.10.

[0105] In some embodiments, the solid acid catalyst includes an esterification catalyst, an organotin catalyst.

[0106] The esterification catalyst includes at least one of beta molecular sieve, strong acid resin, sulfuric acid / zirconium oxide, and tungstic acid / zirconium oxide.

[0107] For example, the strong acid resin may be Rohm and Haas Amberlyst 15WET or D005 macroporous strong acid cationic resin.

[0108] In some embodiments, the organotin catalyst includes at least one of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, and dibutyltin didodecylsulfide.

[0109] In some embodiments, the polymerization inhibitor includes at least one of hydroquinone, 2,5-di-tert-butylhydroquinone, and methylhydroquinone.

[0110] The preparation method of the post-crosslinked PMMA waterproof coating provided in the present application is simple and easy, has low equipment requirements, is well compatible with existing processes, and has great potential for large-scale application.

[0111] Example

[0112] The following examples more specifically describe the disclosure of the present application, which are intended for illustrative purposes only, as it will be apparent to those skilled in the art that various modifications and variations are possible within the scope of the disclosure of the present application. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further processing, and the instruments used in the examples are commercially available.

[0113] The sources of raw materials used in the following examples are as follows:

[0114] Polyether polyol, molecular weight 1000-3000, functionality 2, model: DL2000, Bluestar Dongda Chemical Co., Ltd.;

[0115] Nadic anhydride, Puyang Huicheng Electronic Materials Co., Ltd.;

[0116] Polyisocyanate, MDI50, Wanhua Chemical Co., Ltd.;

[0117] Hydroxylated acrylic acid ester monomer: hydroxyethyl methacrylate, Shanghai Yuanye Biotechnology Co., Ltd.;

[0118] Acrylate monomer (MMA monomer): methyl methacrylate, Yan'an Energy Chemical Company;

[0119] Active diluent: methyl methacrylate, butyl methacrylate, glycidyl acrylate;

[0120] Air drying agent, refined paraffin with a melting point of 50°C; filler, talcum powder; color paste, iron red;

[0121] pH buffer: 5wt.% sodium bicarbonate aqueous solution; Plasticizer: acetyl tributyl citrate;

[0122] Anti-ultraviolet aging agent, UV-326; Antioxidant, 1010;

[0123] Reducing agents, dimethylethanolamine, N,N-diethylhydroxylamine, N,N-dimethyl-p-toluidine;

[0124] Anti-settling agent, fumed silica; reinforcing agent, solid acrylic resin, Mitsubishi 3102;

[0125] Peroxide oxidizing agent, benzoyl peroxide.

[0126] Other raw materials not otherwise specified are common commercially available products.

[0127] Example 1

[0128] A post-crosslinking PMMA waterproof coating comprises the following raw material components in percentage by weight:

[0129] Component A: 45 parts of PUA resin, 30 parts of active diluent (methyl methacrylate), 4 parts of reducing agent (dimethylethanolamine); 5 parts of air drying agent; 35 parts of filler; 1 part of color paste; 1 part of pH buffer; 10 parts of plasticizer; 1 part of anti-ultraviolet aging agent; 1 part of antioxidant; 2 parts of anti-settling agent; 10 parts of reinforcing agent.

[0130] The PUA resin is obtained by reacting polyether polyol, polyisocyanate, chain extender, hydroxy acrylate monomer, and end capping agent under the condition of polymerization inhibitor, and the chain extender has the structure shown below:

[0131]

[0132] Component B includes 20 parts of a peroxide oxidizing agent (benzoyl peroxide).

[0133] Preparation steps of post-crosslinking PMMA waterproof coating:

[0134] Preparation of chain extender: put ethylene glycol into a reactor, heat to 105°C, vacuum dehydrate for 3 hours, test the moisture content to be less than 5%, then put in nadic anhydride, esterification catalyst (beta molecular sieve), and inhibitor (hydroquinone), react for 3 hours at 130°C and vacuum degree of -0.03MPa, and then discharge the material to obtain a chain extender. Calculated by the ratio of the amount of substance, the ratio of nadic anhydride: ethylene glycol: esterification catalyst: inhibitor is 1:2:0.06:0.10.

[0135] Preparation of PUA resin: put the polyether polyol into the reactor, heat it to 105°C, vacuum dehydrate for 3 hours, test the moisture content to be less than 5 parts per thousand, then reduce the temperature to 75°C, add polyisocyanate according to the R value (1.2), react for 3 hours, add organic tin catalyst (dibutyltin dilaurate, 5 parts per thousand), add inhibitor (hydroquinone), small molecule end-capping agent (benzyl alcohol), chain extender, hydroxy acrylate monomer in order (calculated according to the amount of residual NCO, the molar ratio of the substance is 0.06:0.1:0.1:1, react at 75°C for 2 hours, cool to 45°C, add MMA monomer (methyl methacrylate, accounting for 30% of the total weight of the PUA resin), discharge the material, and obtain PUA resin.

[0136] Preparation of component A: Calculated by weight, add 45 parts of PUA resin to a high-speed disperser, add 35 parts of filler, shear and disperse for 30 minutes, add 30 parts of active diluent (methyl methacrylate) in 2-3 times, shear for 1 hour to disperse evenly, add 5 parts of air drying agent, 1 part of color paste, 1 part of pH buffer, 10 parts of plasticizer, 1 part of anti-ultraviolet aging agent, 1 part of antioxidant, 4 parts of reducing agent, 2 parts of anti-settling agent, 10 parts of reinforcing agent in sequence, shear for 1 hour to disperse evenly, discharge, and obtain PMMA coating component A. The shearing speed is 4000rpm.

[0137] Example 2

[0138] A post-crosslinking PMMA waterproof coating comprises the following raw material components in percentage by weight:

[0139] Component A: 45 parts of PUA resin, 32 parts of active diluent (methyl methacrylate), 4.5 parts of reducing agent (N,N-diethylhydroxylamine); 5 parts of air drying agent; 25 parts of filler; 1 part of color paste; 1 part of pH buffer; 10 parts of plasticizer; 1 part of anti-ultraviolet aging agent; 1 part of antioxidant; 2 parts of anti-settling agent; 10 parts of reinforcing agent.

[0140] The PUA resin is obtained by reacting polyether polyol, polyisocyanate, chain extender, hydroxy acrylate monomer, and end capping agent under the condition of polymerization inhibitor, and the chain extender has the structure shown below:

[0141]

[0142] Component B includes 21 parts of a peroxide oxidizing agent (benzoyl peroxide).

[0143] Preparation steps of post-crosslinking PMMA waterproof coating:

[0144] Preparation of chain extender: put ethylene glycol into a reactor, heat to 105°C, vacuum dehydrate for 3 hours, test the moisture content to be less than 5%, then put in nadic anhydride, esterification catalyst (beta molecular sieve), and inhibitor (hydroquinone), react for 3 hours at 130°C and vacuum degree of -0.03MPa, then discharge the material to obtain the chain extender. The ratio of nadic anhydride: ethylene glycol: esterification catalyst: inhibitor is 1:2:0.06:0.10.

[0145] Preparation of PUA resin: put the polyether polyol into the reactor, heat it to 105°C, vacuum dehydrate for 3 hours, test the moisture content to be less than 5 parts per thousand, then reduce the temperature to 75°C, add polyisocyanate according to the R value (1.12), react for 3 hours, add organic tin catalyst (dibutyltin dilaurate, 5 parts per thousand), add inhibitor (hydroquinone), small molecule end-capping agent (benzyl alcohol), chain extender, hydroxy acrylate monomer in order (calculated according to the amount of residual NCO, the molar ratio of the substance is 0.06:0.1:0.1:1, react at 75°C for 2 hours, cool to 45°C, add MMA monomer (methyl methacrylate, accounting for 30% of the total weight of the PUA resin), discharge the material, and obtain PUA resin.

[0146] Preparation of component A: Calculated by weight, add 45 parts of PUA resin to a high-speed disperser, add 25 parts of filler, shear and disperse for 30 minutes, add 32 parts of active diluent (methyl methacrylate) in 2-3 times, shear for 1 hour to disperse evenly, add 5 parts of air drying agent, 1 part of color paste, 1 part of pH buffer, 10 parts of plasticizer, 1 part of anti-ultraviolet aging agent, 1 part of antioxidant, 4.5 parts of reducing agent, 2 parts of anti-settling agent, 10 parts of reinforcing agent in sequence, shear for 1 hour to disperse evenly, discharge, and obtain PMMA coating component A. The shearing speed is 4000rpm.

[0147] Example 3

[0148] A post-crosslinking PMMA waterproof coating comprises the following raw material components in percentage by weight:

[0149] Component A: 45 parts of PUA resin, 30 parts of active diluent (methyl methacrylate), 4.1 parts of reducing agent (N,N-dimethyl-p-toluidine); 5 parts of air drying agent; 30 parts of filler; 1 part of color paste; 1 part of pH buffer; 10 parts of plasticizer; 1 part of anti-ultraviolet aging agent; 1 part of antioxidant; 2 parts of anti-settling agent; 10 parts of reinforcing agent.

[0150] The PUA resin is obtained by reacting polyether polyol, polyisocyanate, chain extender, hydroxy acrylate monomer, and end capping agent under the condition of polymerization inhibitor, and the chain extender has the structure shown below:

[0151]

[0152] Component B includes 22 parts of a peroxide oxidizing agent (benzoyl peroxide).

[0153] Preparation steps of post-crosslinking PMMA waterproof coating:

[0154] Preparation of chain extender: put ethylene glycol into a reactor, heat to 105°C, vacuum dehydrate for 3 hours, test the moisture content to be less than 5%, then put in nadic anhydride, esterification catalyst (beta molecular sieve), and inhibitor (hydroquinone), react for 3 hours at 130°C and vacuum degree of -0.03MPa, then discharge the material to obtain the chain extender. In terms of molar ratio, nadic anhydride: ethylene glycol: esterification catalyst: inhibitor is 1:2:0.06:0.10.

[0155] Preparation of PUA resin: put the polyether polyol into the reactor, heat to 105°C, vacuum dehydrate for 3 hours, test the moisture content below 5 parts per thousand, then reduce the temperature to 75°C, add polyisocyanate according to the R value (1.3), react for 3 hours, add organic tin catalyst (dibutyltin dilaurate, 5 parts per thousand), add inhibitor (hydroquinone), small molecule end-capping agent (benzyl alcohol), chain extender, hydroxy acrylate monomer (calculated according to the amount of residual NCO, the molar ratio is 0.06:0.1:0.1:1), react at 75°C for 2 hours, cool to 45°C, add MMA monomer (methyl methacrylate, accounting for 30% of the total weight of the PUA resin), discharge the material, and obtain PUA resin.

[0156] Preparation of component A: Calculated by weight, add 30 parts of PUA resin to a high-speed disperser, add 30 parts of filler, shear and disperse for 30 minutes, add 30 parts of active diluent (methyl methacrylate) in 2-3 times, shear for 1 hour to disperse evenly, add 5 parts of air drying agent, 1 part of color paste, 1 part of pH buffer, 10 parts of plasticizer, 1 part of anti-ultraviolet aging agent, 1 part of antioxidant, 4.1 parts of reducing agent, 2 parts of anti-settling agent, 10 parts of reinforcing agent in sequence, shear for 1 hour to disperse evenly, discharge, and obtain PMMA coating component A. The shear rate is 4000rpm.

[0157] Example 4

[0158] Compared with Example 1, the only difference is that the active diluent includes methyl methacrylate and butyl methacrylate in a mass ratio of 2:1.

[0159] Example 5

[0160] Compared with Example 1, the only difference is that the reactive diluent comprises methyl methacrylate and glycidyl acrylate in a mass ratio of 10:1.

[0161] Comparative Example 1

[0162] Compared with Example 1, the main difference is that no chain extender is added when preparing the PUA resin.

[0163] Comparative Example 2

[0164] Compared with Example 1, the main difference is that no acrylic acid ester monomer is added when preparing the PUA resin.

[0165] Comparative Example 3

[0166] Compared with Example 1, in the step of preparing the chain extender, an equal amount of nadic anhydride is replaced by maleic anhydride.

[0167] Comparative Example 4

[0168] Compared with Example 1, the main difference is that no pH buffer is added.

[0169] Comparative Example 5

[0170] Compared with Example 1, the main difference is that the peroxide oxidant is replaced by a 20% hydrogen peroxide aqueous solution.

[0171] Comparative Example 6

[0172] Compared with Example 1, the main difference is that when preparing the PUA resin, the molar ratio of -NCO in the polyisocyanate to -OH in the polyether polyol is 2:1.

[0173] Comparative Example 7

[0174] Compared with Example 1, the main difference is that when preparing the PUA resin, the molar ratio of the chain extender and the hydroxy acrylate monomer is 10:1.

[0175] Test Results

[0176] The components A and B in Examples 1-7 and Comparative Examples 1-5 were mixed in the same proportion to form a waterproof structure, and the performance of the waterproof structure was tested. The test method is as follows. The test results are shown in Table 1:

[0177] Tear strength: According to the requirements of GB / T 19250-2013 polyurethane waterproof coating;

[0178] Elongation at break: According to the requirements of GB / T 19250-2013 polyurethane waterproof coating;

[0179] Tensile strength: According to the requirements of GB / T 19250-2013 polyurethane waterproof coating.

[0180] Table 1

[0181] Comparative Cases Tear strength / (N / mm) Elongation at break / (%) Tensile strength / (MPa) Example 1 45 600 4.5 Example 2 42 408 4.1 Example 3 46 650 5.3 Example 4 40 750 3.8 Example 5 48 450 6.0 Comparative Example 1 35 310 1.0 Comparative Example 2 30 893 1.2 Comparative Example 3 15 870 2.9 Comparative Example 4 30 540 3.1 Comparative Example 5 12 870 2.3 Comparative Example 6 80 126 3.4 Comparative Example 7 32 802 3.1

[0182] It can be seen from the above table:

[0183] Comparing Example 1 with Comparative Example 1 and Comparative Example 3, not adding a chain extender or replacing nadic anhydride with maleic anhydride will lead to an enhanced oxygen inhibition effect during coating curing, insufficient chain growth and crosslinking, and a decrease in coating strength, such as tear strength, which decreases from 45 N / mm in Example 1 to 35 N / mm in Comparative Example 1 and 15 N / mm in Comparative Example 3, respectively; such as tensile strength, which decreases from 4.5 MPa in Example 1 to 1.0 MPa in Comparative Example 1 and 1.9 MPa in Comparative Example 3, respectively.

[0184] Comparing Example 1 with Comparative Example 2, without adding methyl methacrylate, an acrylic acid ester hard monomer, the coating as a whole exhibits the properties of pure polyurethane resin, with acceptable tear strength, but insufficient tensile strength.

[0185] Comparative Example 1 and Comparative Example 4, if no pH buffer is added, the curing speed of the acrylate will be reduced, and the problem of incomplete curing will occur, resulting in the loss of tensile strength and tear strength.

[0186] Comparing Example 1 and Comparative Example 5, replacing the peroxide modifier benzoyl peroxide with a 20% aqueous hydrogen peroxide solution will result in a decrease in the tear strength of the coating formed by the coating, reaching 12 N / mm; and an increase in elasticity, with an elongation at break reaching 870%.

[0187] Comparing Example 1 and Comparative Example 6, when the R value is adjusted to 2, the hard segment of the polyurethane increases, causing the tear strength of the coating formed by the paint to rise too quickly, reaching 80N / mm, but the coating loses its elasticity, causing the elongation at break of the coating formed by the paint to decrease to 126%.

[0188] Comparative Example 1 and Comparative Example 7, when the hydroxy acrylate monomer in the capping agent is insufficient, the crosslinking degree between the polyurethane and the reactive diluent will be too low, resulting in a low tear strength of the coating formed by the coating, reaching 32N / mm, and a too large elastic surplus, reaching 802%.

[0189] Comparing Example 1 and Example 2, when the R value is adjusted from 1.2 to 1.12, the tear strength of the coating decreases, the elongation at break also decreases accordingly, and the tensile strength also decreases.

[0190] Comparing Example 1 and Example 3, when the R value is adjusted from 1.2 to 1.3, the tear strength of the coating increases slightly and the elongation at break also increases.

[0191] Comparing Example 1 and Example 4, when the type of active diluent is changed from single methyl methacrylate to methyl methacrylate and butyl methacrylate in a mass ratio of 2:1, the tear strength of the coating decreases, but the elongation at break increases significantly, while the tensile strength decreases significantly.

[0192] Comparing Example 1 and Example 5, when the active diluent is replaced by methyl methacrylate alone with methyl methacrylate and glycidyl acrylate in a mass ratio of 10:1, the tear strength of the coating increases, the elongation at break decreases, and the tensile strength increases significantly. This may be due to the "carboxyl-epoxy" chemical reaction between the epoxy group of glycidyl acrylate in the active diluent and the carboxyl group in the chain extender, which increases the internal crosslink density of the coating and enhances the tensile modulus strength of the PMMA coating, resulting in an increase in tensile strength.

[0193] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A post-crosslinking PMMA waterproof coating, characterized in that: It comprises component A and component B; wherein, The A component includes optional additives and the following raw material components in parts by weight: 20-50 parts of PUA resin, 30-60 parts of active diluent, 4-10 parts of reducing agent; 0.5-3 parts of pH buffer; The PUA resin is obtained by reacting an oligomer polyol, a polyisocyanate, a chain extender, a hydroxy acrylate monomer, and a capping agent under an inhibitor condition, wherein the molar ratio of -NCO in the polyisocyanate to -OH in the oligomer polyol is 1.1-1.5, and the molar ratio of the inhibitor, the capping agent, the chain extender, and the hydroxy acrylate monomer is 0.06: (0.1-0.5): (0.1-0.5): 1, calculated based on the amount of NCO remaining after the reaction of the oligomer polyol and the polyisocyanate. The end-capping agent includes at least one of benzyl alcohol, n-octanol, hydroxybutyric acid, and isobornyl alcohol; the hydroxy acrylate monomer includes at least one of hydroxyethyl acrylate, hydroxybutyl acrylate, hydroxyethyl methacrylate, and hydroxybutyl methacrylate; the PUA resin also includes an acrylate monomer, and the acrylate monomer accounts for 20% to 30% of the weight of the entire PUA resin; The chain extender comprises a structure shown in Formula 1, Formula 1, R 1 , R 2 , R 4 , R 5 are independently selected from hydrogen or C1-C5 alkyl, R 3 Selected from C1~C5 alkyl; prepare PUA resin, react oligomer polyol and polyisocyanate, add solid acid catalyst, inhibitor, end-capping agent, chain extender, hydroxy acrylate monomer in order, and react again to obtain the PUA resin; The B component includes 15-30 parts of a peroxide oxidant, and the peroxide oxidant includes at least one of benzoyl peroxide, dicumyl peroxide, and cumene hydroperoxide.

2. The post-crosslinked PMMA waterproof coating according to claim 1, characterized in that: At least one of the following conditions is met: The molecular weight of the oligomer polyol is 1000-6000 and the functionality is 2-3; The polyisocyanate comprises at least one of TDI, MDI, IPDI, and HMDI; The polymerization inhibitor includes at least one of hydroquinone, 2,5-di-tert-butylhydroquinone and methylhydroquinone.

3. The post-crosslinked PMMA waterproof coating according to claim 1, characterized in that: The acrylic acid ester monomer includes at least one of methyl methacrylate, ethyl acrylate, butyl acrylate, isobutyl acrylate, hexyl acrylate, isooctyl acrylate, lauryl acrylate, benzyl acrylate, cyclohexyl acrylate, perfluoroalkyl acrylate, isobornyl acrylate, tetrahydrofuran methyl acrylate, methacrylic acid, and acrylic acid.

4. The post-crosslinked PMMA waterproof coating according to claim 1, characterized in that: The reactive diluent comprises at least one of methacrylic acid, methyl methacrylate, butyl acrylate, isooctyl acrylate, glycidyl acrylate, hydroxyethyl methacrylate, ethyl acrylate, allyl methacrylate, ethylene glycol dimethacrylate, and trimethylolpropane triacrylate; and / or, The reducing agent includes at least one of diethanolamine, dimethylethanolamine, N,N-diethylhydroxylamine, N,N-dimethyl-p-toluidine, and N,N-diethylaniline.

5. The post-crosslinked PMMA waterproof coating according to claim 1, characterized in that: Optional additives include: Air drying agent, 5-10 parts; Filler, 25-45 parts; Color paste, 1-2 parts; Plasticizer, 10-20 parts; Anti-ultraviolet aging agent, 1-2 parts; Antioxidant, 1-2 parts; Anti-settling agent, 2-5 parts; Reinforcing agent, 10-18 parts.

6. The post-crosslinking PMMA waterproof coating according to claim 5, characterized in that: The optional additives satisfy at least one of the following conditions: The gas drying agent includes at least one of refined paraffin wax and semi-refined paraffin wax; The filler includes at least one of heavy calcium carbonate, light calcium carbonate, talcum powder, barium sulfate, aluminum hydroxide, titanium dioxide, fumed silica, and nano calcium carbonate; the particle size of the filler is 400-2000 mesh; The color paste includes at least one of emerald green, iron red, and orange; The pH buffer comprises at least one of tartaric acid, potassium dihydrogen phosphate and sodium bicarbonate; The plasticizer includes at least one of DOTP, DOP, and acetyl tributyl citrate; The anti-ultraviolet aging agent includes at least one of RIASORB® UV-326 and RIASORB® UV-329; The antioxidant includes at least one of RIANOX® 1010 and RIANOX® 686; The anti-settling agent includes A-200 fumed silica; The reinforcing agent includes at least one of 3102 Mitsubishi resin and 950 Mitsubishi resin.

7. A method for preparing a post-crosslinked PMMA waterproof coating according to any one of claims 1 to 6, characterized in that: The following steps are involved: Prepare component A by mixing materials containing the PUA resin, an active diluent, a reducing agent and an additive to obtain component A; Prepare component B by mixing materials containing a peroxide curing agent to obtain the component B; A PMMA-based elastic waterproof coating composition is prepared, and the component A and the component B are stored independently to obtain the PMMA-based elastic waterproof coating composition.

8. The method for preparing the post-crosslinked PMMA waterproof coating according to claim 7, characterized in that: The preparation of the chain extender comprises the following steps: The diol is reacted with a compound having a structure shown in Formula 2, a solid acid catalyst and a polymerization inhibitor to obtain the chain extender, Formula 2; Among them, R 1 , R 2 , R 4 , R 5 Independently selected from hydrogen or C1~C5 alkyl; The molar ratio of the diol to the compound having the structure shown in Formula 2 is 1:(1-2).

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