Waterproof coating containing methyl 3-methoxypropionate

Abstract

The invention discloses a waterproof coating containing methyl 3-methoxypropionate, which belongs to the field of research and development of new chemical materials and comprises an anchoring composition and a waterproof composition, the waterproof composition is a composition which takes a methyl 3-methoxypropionate compound as a solvent; the anchoring composition comprises the following components in parts by weight: 30-40 parts of corncob carbon catalyst residues, 40-45 parts of an acrylic emulsion, 5-6 parts of a silane coupling agent, 2-4 parts of fumed silica, 5-7 parts of propylene glycol, 5-6 parts of a thermosensitive cross-linking agent, 2-3 parts of a polycarboxylate dispersant and the balance of deionized water. The corncob carbon catalyst residue is used as a core substance to form an anchoring component, and the anchoring component is sprayed between an old coating and a new waterproof layer, so that the problem that the old coating swells due to the fact that methyl 3-methoxypropionate in the waterproof layer permeates into the old coating can be avoided.

Description

Technical Field

[0001] The invention belongs to the field of research and development of new chemical materials and relates to a waterproof coating containing methyl 3-methoxypropionate. Background Art

[0002] 3-Methoxymethyl propionate solvent has a mild odor and evaporates completely, leaving no residual odor on the coating surface. It can increase the leveling, gloss, and transparency of the coating. Therefore, 3-Methoxymethyl propionate is widely used as a solvent in waterproof, anti-corrosion and other coatings.

[0003] At present, waterproof coatings using methyl 3-methoxypropionate as a solvent take advantage of the advantages of methyl methoxypropionate, and have good leveling and glossiness. In addition, due to the volatility of methyl 3-methoxypropionate, the coating cures quickly. However, in actual use, it is found that when waterproof coatings using methyl 3-methoxypropionate as a solvent are used in the renovation of old coatings, methyl 3-methoxypropionate has a strong polarity and can easily cause the old coating to swell, affecting the renovation effect. Summary of the Invention

[0004] The purpose of the present invention is to provide a waterproof coating containing methyl 3-methoxypropionate, which solves the problem that when a waterproof coating using methyl 3-methoxypropionate as a solvent is used in the renovation process of an old coating, methyl 3-methoxypropionate has a strong polarity and easily causes the old coating to swell, thereby affecting the renovation effect.

[0005] The technical solution adopted in the present invention is as follows:

[0006] A waterproof coating containing methyl 3-methoxypropionate, comprising an anchoring composition and a waterproof composition; the waterproof composition is a composition using a methyl 3-methoxypropionate complex as a solvent;

[0007] The anchoring composition comprises the following components in parts by weight: 30-40 parts of corn cob carbon catalyst residue, 40-45 parts of acrylic emulsion, 5-6 parts of silane coupling agent, 2-4 parts of fumed silica, 5-7 parts of propylene glycol, 5-6 parts of heat-sensitive crosslinking agent, 2-3 parts of polycarboxylate dispersant, and the balance is deionized water.

[0008] The present invention uses corn cob carbon catalyst residue as a core material to form an anchoring component. The anchoring component is sprayed between the old coating and the new waterproof layer to prevent methyl 3-methoxypropionate in the waterproof layer from penetrating into the old coating and causing the old coating to swell.

[0009] The corn cob carbon catalyst residue utilized in the present invention is the residue generated by the corn cob carbon catalyst in the process of preparing methyl 3-methoxypropionate. The process for preparing methyl 3-methoxypropionate using the corn cob carbon catalyst is disclosed in the patent document No. 202411206332.5; 202411206332.5 is prepared by removing hemicellulose from corn cobs, then subjecting them to high-temperature pyrolysis and carbonization, and then mixing them with concentrated sulfuric acid and heating and sulfonating them to form a corn cob carbon catalyst. When the corn cob carbon catalyst is used to catalyze acetic acid and methanol to prepare methyl acetate, the yield of methyl acetate can be effectively increased, and the catalytic activity of the corn cob carbon catalyst decreases after repeated use, and it needs to be sulfonated again to increase its activity; in order to achieve the recycling of the corn cob carbon catalyst and avoid waste, the corn cob carbon catalyst is generally subjected to re-sulfonation treatment at present;

[0010] Although corn cob carbon catalyst can be reused, it needs to be sulfonated again. Sulfonation treatment requires the use of concentrated sulfuric acid for heating and sulfonation. Concentrated sulfuric acid has a high safety risk in use. Repeated sulfonation treatment increases the usage rate of concentrated sulfuric acid, thereby increasing the safety risk.

[0011] Therefore, in the preparation process and use method of the corn cob carbon catalyst disclosed in 202411206332.5, in order to improve the recycling of the corn cob carbon catalyst, the present invention performs energy conversion (the corn cob carbon catalyst is ultimately converted into a coating component) while reducing safety risks. In the process of preparing a waterproof coating with methyl 3-methoxypropionate as a solvent, the present invention has developed a preparation method for an anchoring layer that can directly utilize corn cob carbon catalyst residues. This solves the problem that when waterproof coatings with methyl 3-methoxypropionate as a solvent are used for renovation of old coatings, methyl 3-methoxypropionate has strong polarity and easily causes swelling of the old coating, affecting the renovation effect. The recycling of the corn cob carbon catalyst is achieved. The present application is for the application field of preparing methyl 3-methoxypropionate. While realizing the conversion of methyl 3-methoxypropionate, the energy conversion of the corn cob carbon catalyst is simultaneously realized, and methyl 3-methoxypropionate and corn cob carbon catalyst residue in the process of preparing methyl 3-methoxypropionate are converted into finished coatings.

[0012] In the process of preparing the anchoring layer, the corncob carbon catalyst residue does not need to be activated or treated, and can be directly used in combination with other components.

[0013] Furthermore, the 3-methoxypropionic acid methyl ester complex comprises 3-methoxypropionic acid methyl ester and propylene glycol methyl ether acetate, and the mass ratio of 3-methoxypropionic acid methyl ester to propylene glycol methyl ether acetate is 2-4:1.

[0014] Furthermore, the waterproof composition comprises the following components in parts by weight: 40-50 parts of NCO-terminated polyurethane prepolymer, 20-25 parts of methyl 3-methoxypropionate complex, 20-25 parts of filler, 1.5-2.5 parts of aminosilane, 1-2 parts of phosphate adhesion promoter, 0.2-0.4 parts of organic bismuth, and 1-3 parts of dispersant.

[0015] Furthermore, the corncob carbon catalyst residue is obtained by the following method:

[0016] A1. After crushing and sieving corn cobs, stir and mix with dilute sulfuric acid and heat to remove hemicellulose, then perform high-temperature pyrolysis and carbonization, and finally mix with concentrated sulfuric acid and heat to sulfonate to obtain a corn cob carbon catalyst;

[0017] A2. Add acetic acid, methanol, and the corncob carbon catalyst into a first reactor to react. After the reaction is completed, separate the methyl acetate obtained by the reaction by distillation. The fraction is the methyl acetate product, and the remainder is the corncob carbon catalyst residue.

[0018] Furthermore, the filler comprises the following components in parts by weight: 8-10 parts of nano titanium dioxide, 4-5 parts of hydrophobic fumed silica, 4-5 parts of nano modified calcium carbonate, and 4-5 parts of polytetrafluoroethylene powder.

[0019] Furthermore, the nano-modified calcium carbonate is nano-calcium carbonate wrapped with stearic acid, and the amount of stearic acid added is 3% of the mass of the nano-calcium carbonate.

[0020] Furthermore, the silane coupling agent is KH-560 silane coupling agent.

[0021] Furthermore, the heat-sensitive cross-linking agent is trimethylolpropane trimethacrylate.

[0022] Furthermore, the thickness ratio of the anchoring layer formed by the anchoring composition to the waterproof layer formed by the waterproof composition is 1:1.5-2.

[0023] Furthermore, the anchoring composition comprises the following components in parts by weight: 40 parts of corn cob carbon catalyst residue, 45 parts of acrylic emulsion, 6 parts of silane coupling agent, 4 parts of fumed silica, 7 parts of propylene glycol, 3 parts of polycarboxylate dispersant, 6 parts of thermosensitive crosslinking agent, and the balance is deionized water;

[0024] The waterproof composition comprises the following components in parts by weight: 50 parts of NCO-terminated polyurethane prepolymer, 25 parts of methyl 3-methoxypropionate complex, 25 parts of filler, 2.5 parts of aminosilane, 2 parts of phosphate adhesion promoter, 0.4 parts of organic bismuth, and 3 parts of polymer block copolymer dispersant;

[0025] The mass ratio of methyl 3-methoxypropionate to propylene glycol methyl ether acetate is 3:1.

[0026] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0027] 1. In a waterproof coating containing methyl 3-methoxypropionate of the present invention, an anchoring component forms an anchoring layer, and the waterproof component forms a waterproof layer as a new waterproof layer. The anchoring component is mainly composed of corn cob carbon catalyst residue, which includes a porous carbon skeleton, residual sulfonic acid groups, and organic residues. The porous structure has high adsorption properties, and the multi-level pore structure of the porous carbon skeleton forms a complex structure similar to a "honeycomb-channel" structure, forming a tortuous path. When the porous structure has a physical adsorption effect on the waterproof layer, the "honeycomb-channel" complex structure prolongs the migration path of the methyl 3-methoxypropionate solvent in the waterproof layer, thereby increasing the time that the old coating is in contact with the methyl 3-methoxypropionate solvent. During this time period, as the anchoring layer solidifies, the methyl 3-methoxypropionate solvent that has penetrated into the anchoring layer is locked by the network cross-linked structure formed by the solidification, thereby preventing the methyl 3-methoxypropionate solvent in the new coating from fully contacting the old coating, thereby effectively preventing the old coating from swelling during the renovation process.

[0028] 2. The waterproof composition of the present invention uses an NCO-terminated polyurethane prepolymer as its core material. Heat is released during the curing process, which is equivalent to heating the anchoring layer. The heat-sensitive crosslinking agent in the anchoring layer triggers a crosslinking reaction. The crosslinking reaction forms a network structure, which simultaneously wraps and locks the corncob charcoal catalyst residue. The porous structure formed by the corncob charcoal catalyst residue is sealed, effectively preventing the 3-methoxypropionic acid methyl ester solvent that has infiltrated the corncob charcoal catalyst residue layer from further migration.

[0029] 3. The acrylic emulsion, silane coupling agent, propylene glycol, dispersant, and corncob carbon catalyst residue in the anchoring layer of the present invention ensure that the anchoring layer has a high connection strength with the waterproof layer and the old coating while ensuring that the 3-methoxypropionic acid methyl ester solvent in the waterproof layer is blocked from penetrating.

[0030] 4. The waterproof composition of the present invention uses the NCO-terminated polyurethane prepolymer as the core material, which can improve the curing speed and permeation barrier ability of the anchoring layer on the one hand, and can also form a uniform coating with high waterproof performance in combination with other components.

[0031] 5. A particle filling gradation is formed between the filler in the waterproof composition of the present invention and the corn cob carbon catalyst residue in the anchoring layer, which improves the density of the entire coating and has higher waterproof performance. The overall coating formed by combining the anchoring layer and the waterproof layer has a better waterproof effect than a single waterproof layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort, among which:

[0033] Figure 1 This is a practical application diagram of the present invention for renovation of old polyurethane waterproof coatings. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present invention and are not intended to limit the present invention. That is, the embodiments described herein are only some embodiments of the present invention, not all embodiments. Generally, the components of the embodiments of the present invention described and illustrated in the drawings herein may be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but is merely intended to represent selected embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative work are within the scope of protection of the present invention.

[0036] It should be noted that relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0037] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0038] Example 1

[0039] A preferred embodiment of the present invention provides a waterproof coating containing methyl 3-methoxypropionate, comprising an anchoring composition and a waterproof composition; the waterproof composition is a composition using a methyl 3-methoxypropionate complex as a solvent;

[0040] The anchoring composition comprises the following components in parts by weight: 30 parts of corn cob carbon catalyst residue, 40 parts of acrylic emulsion, 5 parts of silane coupling agent, 2 parts of fumed silica, 5 parts of propylene glycol, 5 parts of heat-sensitive crosslinking agent, 2 parts of polycarboxylate dispersant, and the balance is deionized water.

[0041] The 3-methoxypropionic acid methyl ester complex comprises 3-methoxypropionic acid methyl ester and propylene glycol methyl ether acetate, and the mass ratio of 3-methoxypropionic acid methyl ester to propylene glycol methyl ether acetate is 2:1.

[0042] The waterproof composition comprises the following components in parts by weight: 40 parts of NCO-terminated polyurethane prepolymer, 20 parts of methyl 3-methoxypropionate complex, 20 parts of filler, 1.5 parts of aminosilane, 1 part of phosphate adhesion promoter, 0.2 parts of organic bismuth, and 1 part of dispersant.

[0043] The corncob carbon catalyst residue is obtained by the following method:

[0044] A1. After crushing and sieving corn cobs, stir and mix with dilute sulfuric acid and heat to remove hemicellulose, then perform high-temperature pyrolysis and carbonization, and finally mix with concentrated sulfuric acid and heat to sulfonate to obtain a corn cob carbon catalyst;

[0045] A2. Add acetic acid, methanol, and the corncob carbon catalyst into a first reactor to react. After the reaction is completed, separate the methyl acetate obtained by the reaction by distillation. The fraction is the methyl acetate product, and the remainder is the corncob carbon catalyst residue.

[0046] The filler comprises the following components in parts by weight: 8 parts of nano titanium dioxide, 4 parts of hydrophobic fumed silica, 4 parts of nano modified calcium carbonate, and 4 parts of polytetrafluoroethylene powder.

[0047] The nano-modified calcium carbonate is nano-calcium carbonate wrapped with stearic acid, and the added amount of stearic acid is 3% of the mass of the nano-calcium carbonate.

[0048] The silane coupling agent is KH-560 silane coupling agent.

[0049] The heat-sensitive crosslinking agent is trimethylolpropane trimethacrylate.

[0050] The thickness ratio of the anchoring layer formed by the anchoring composition to the waterproof layer formed by the waterproof composition is 1:1.5.

[0051] The waterproof coating containing methyl 3-methoxypropionate is prepared by the following method:

[0052] S1. Preparing an anchoring composition: grinding corn cob carbon catalyst residue to obtain corn cob carbon catalyst residue powder, dispersing the corn cob carbon catalyst residue powder in deionized water to obtain a suspension, sequentially adding an acrylic emulsion and propylene glycol to the suspension under stirring, mixing uniformly, and then adding a silane coupling agent. After continuing to stir uniformly, a polycarboxylate dispersant, fumed silica, and a heat-sensitive crosslinking agent are sequentially added, and mixing uniformly to obtain an anchoring composition;

[0053] S2. Preparing a waterproof composition: adding a methyl 3-methoxypropionate complex to a stirred tank, stirring evenly, heating to 40° C., and then slowly adding a terminal NCO polyurethane prepolymer under stirring, stirring at a speed of 200-300 rpm until mixed evenly to obtain a uniform mixed solution; adding aminosilane, phosphate adhesion promoter, organic bismuth catalyst and dispersant to the mixed solution in sequence, continuing stirring for 30-45 minutes, and then slowly adding filler, and high-speed dispersing at 500-800 rpm for 1-2 hours to obtain a uniform waterproof composition; wherein the filler includes multiple components, and the multiple components need to be mixed evenly in advance to obtain the mixed particles before adding to the stirred tank;

[0054] S3. Subpackaging: The anchoring composition and the waterproofing composition are packaged separately and stored in a sealed manner away from light;

[0055] When the above-mentioned waterproof coating is used to renovate the old coating, the old coating can be an epoxy or polyurethane coating. The spraying method for renovating the old coating is to first clean and polish the surface of the old coating, and then evenly spray the anchoring composition on the surface of the old coating. After the surface is dry for 15-20 minutes, the waterproof composition is evenly sprayed again and naturally solidified to complete the renovation of the old coating.

[0056] Example 2

[0057] In this embodiment, based on the embodiment 1, the anchoring composition comprises the following components in parts by weight: 35 parts of corn cob carbon catalyst residue, 43 parts of acrylic emulsion, 6 parts of silane coupling agent, 3 parts of fumed silica, 6 parts of propylene glycol, 6 parts of heat-sensitive crosslinking agent, 3 parts of polycarboxylate dispersant, and the balance is deionized water;

[0058] The waterproof composition comprises the following components in parts by weight: 45 parts of NCO-terminated polyurethane prepolymer, 23 parts of methyl 3-methoxypropionate complex, 23 parts of filler, 2 parts of aminosilane, 2 parts of phosphate adhesion promoter, 0.3 parts of organic bismuth, and 2 parts of dispersant.

[0059] The filler comprises the following components in parts by weight: 9 parts of nano titanium dioxide, 5 parts of hydrophobic fumed silica, 5 parts of nano modified calcium carbonate, and 4 parts of polytetrafluoroethylene powder.

[0060] Example 3

[0061] In this embodiment, based on the embodiment 1, the anchoring composition comprises the following components in parts by weight: 40 parts of corn cob carbon catalyst residue, 45 parts of acrylic emulsion, 6 parts of silane coupling agent, 4 parts of fumed silica, 7 parts of propylene glycol, 3 parts of polycarboxylate dispersant, 6 parts of thermosensitive crosslinking agent, and the balance is deionized water;

[0062] The waterproof composition comprises the following components in parts by weight: 50 parts of NCO-terminated polyurethane prepolymer, 25 parts of methyl 3-methoxypropionate complex, 25 parts of filler, 2.5 parts of aminosilane, 2 parts of phosphate adhesion promoter, 0.4 parts of organic bismuth, and 3 parts of polymer block copolymer dispersant;

[0063] The filler comprises the following components in parts by weight: 10 parts of nano titanium dioxide, 5 parts of hydrophobic fumed silica, 5 parts of nano modified calcium carbonate, and 5 parts of polytetrafluoroethylene powder.

[0064] Example 4

[0065] In this embodiment, based on the embodiment 3, the mass ratio of methyl 3-methoxypropionate to propylene glycol methyl ether acetate in the methyl 3-methoxypropionate complex is 3:1.

[0066] Example 5

[0067] In this embodiment, based on the embodiment 3, the mass ratio of methyl 3-methoxypropionate to propylene glycol methyl ether acetate in the methyl 3-methoxypropionate complex is 4:1.

[0068] Example 6

[0069] In this embodiment, based on the embodiment 4, the thickness ratio of the anchoring layer formed by the anchoring composition to the waterproof layer formed by the waterproof composition is 1:1.7.

[0070] Example 7

[0071] In this embodiment, based on the embodiment 4, the thickness ratio of the anchoring layer formed by the anchoring composition to the waterproof layer formed by the waterproof composition is 1:2.

[0072] Figure 1 This is a practical application diagram of the waterproof coating within the scope of this embodiment for renovating the polyurethane waterproof coating (old coating). The coating surface is smooth and flat, without bubbles, wrinkles, etc. From the coating surface condition, it can be seen that when the present invention renovates the polyurethane waterproof coating (old coating), the renovated layer will not have abnormal coating conditions and can be used for the renovation of the polyurethane waterproof coating.

[0073] Comparative Example 1

[0074] This comparative example is based on Example 1. The waterproof coating containing methyl 3-methoxypropionate provided in this comparative example does not include an anchoring composition, but only includes a waterproof composition. The waterproof composition includes the following components in parts by weight: 40 parts of terminal NCO polyurethane prepolymer, 20 parts of methyl 3-methoxypropionate complex, 20 parts of filler, 1.5 parts of aminosilane, 1 part of phosphate adhesion promoter, 0.2 parts of organic bismuth, and 1 part of dispersant; the methyl 3-methoxypropionate complex includes methyl 3-methoxypropionate and propylene glycol methyl ether acetate, and the mass ratio of methyl 3-methoxypropionate and propylene glycol methyl ether acetate is 2:1.

[0075] The preparation method of the waterproof component comprises the following steps: adding a methyl 3-methoxypropionate complex to a stirring kettle, stirring evenly, heating to 40° C., slowly adding a terminal NCO polyurethane prepolymer under stirring, and stirring at a speed of 200-300 rpm until the mixture is evenly mixed to obtain a uniform mixed liquid; sequentially adding an aminosilane, a phosphate adhesion promoter, an organic bismuth catalyst, and a dispersant to the mixed liquid, continuing stirring for 30-45 minutes, and then slowly adding a filler, and dispersing at a high speed of 500-800 rpm for 1-2 hours to obtain a uniform waterproof composition; wherein the filler comprises multiple components, and the multiple components need to be mixed evenly in advance to obtain the mixed particles, and then added to the stirring kettle.

[0076] Comparative Example 2

[0077] This comparative example is based on Example 1. In this comparative example, the anchoring layer of a waterproof coating containing methyl 3-methoxypropionate does not include corn cob carbon catalyst residue.

[0078] Comparative Example 3

[0079] This comparative example is based on Example 1, and the anchoring layer of the waterproof coating containing methyl 3-methoxypropionate provided in this comparative example does not include acrylic emulsion.

[0080] Comparative Example 4

[0081] This comparative example is based on Example 1. In this comparative example, the anchoring layer of a waterproof coating containing methyl 3-methoxypropionate does not include a silane coupling agent.

[0082] Comparative Example 5

[0083] This comparative example is based on Example 1, and the anchoring layer of the waterproof coating containing methyl 3-methoxypropionate provided in this comparative example does not include propylene glycol.

[0084] Comparative Example 6

[0085] This comparative example is based on Example 1. In this comparative example, the anchoring layer of a waterproof coating containing methyl 3-methoxypropionate does not include a thermosensitive crosslinking agent.

[0086] Comparative Example 7

[0087] This comparative example is based on Example 1, and the 3-methoxypropionic acid methyl ester complex in the waterproof composition of this comparative example only includes 3-methoxypropionic acid methyl ester and does not include propylene glycol methyl ether acetate.

[0088] Comparative Example 8

[0089] This comparative example is based on Example 4, and in this comparative example, the thickness ratio of the anchoring layer formed by the anchoring composition to the waterproof layer formed by the waterproof composition is 1:1.

[0090] Comparative Example 9

[0091] This comparative example is based on Example 4, and in this comparative example, the thickness ratio of the anchoring layer formed by the anchoring composition to the waterproof layer formed by the waterproof composition is 1:2.5.

[0092] Test Example 1

[0093] The swelling of the waterproof coatings prepared in Examples 1-7 and Comparative Examples 1-9 was detected when sprayed on the surfaces of the polyurethane waterproof coating (existing coating) and the epoxy waterproof coating (existing coating). The thickness of the polyurethane waterproof coating and the epoxy waterproof coating were both 200 μm. The waterproof coatings prepared in Examples 1-7 and Comparative Examples 1-9 were used as test samples. The test samples were sprayed on the polyurethane waterproof coating and the epoxy waterproof coating to a thickness of 120 μm. The occurrence of the "bottoming" phenomenon (surface bubbling, wrinkles, or detachment from the substrate) was observed. The results are shown in Table 1.

[0094] Table 1 Swelling detection

[0095]

[0096]

[0097] Test Example 2

[0098] Based on Test Example 1, the polyurethane waterproof coating and the epoxy waterproof coating were used as the base layer, and the waterproof coating prepared in Examples 1-7 and Comparative Examples 1-9 was used as the surface layer. The composite coating obtained by the spraying method given in Examples 1-7 and Comparative Examples 1-9 was tested for water resistance, salt spray resistance, acid resistance, and alkali resistance; the test results are shown in Table 2.

[0099] Water resistance: According to GB / T 1733-1993 "Determination of water resistance of paint films", after soaking in water for 96 hours, observe whether the coating has abnormal phenomena such as blistering and shedding;

[0100] Acid resistance: Test in accordance with GB / T 9274-1988 "Paints and varnishes - Determination of resistance to liquid media". After immersing in 5% hydrochloric acid solution for 96 hours, observe whether the coating shows any abnormal phenomena such as blistering or shedding.

[0101] Alkali resistance: Test according to GB / T 9265-2009 "Determination of Alkali Resistance of Architectural Coatings". After soaking in 5% sodium hydroxide solution for 96 hours, observe whether the coating has any abnormal phenomena such as blistering or shedding.

[0102] Salt spray resistance: Tested in accordance with GB / T 1771-2007 "Paints and varnishes - Determination of resistance to neutral salt spray". After 1000 hours of salt spray testing in a salt spray test chamber, observe whether the coating shows any abnormalities such as blistering or shedding.

[0103] Table 2 Performance test of composite coating

[0104]

[0105]

[0106] Test Example 3

[0107] The bonding strength (Q1) between the anchoring layer alone (without waterproof layer) and the polyurethane waterproof layer, and the bonding strength (Q2) between the waterproof layer + anchoring layer composite layer as a whole and the polyurethane waterproof layer in Examples 1-3 were tested. The results are shown in Table 3.

[0108] Q1: Spray the anchoring composition onto a substrate sprayed with a polyurethane waterproof coating (existing coating, high-strength polyurethane waterproof coating, with a bonding strength greater than 2.5 MPa). After curing, perform a 180° peel test using a tensile testing machine (such as GB / T 16777-2008 standard) and record the maximum peel force.

[0109] Q2. Spray the anchoring composition onto a substrate sprayed with a polyurethane waterproof coating (existing coating). Allow the surface to dry for 15 minutes before spraying the waterproof composition. After curing, perform a 180° peel test using a tensile testing machine (e.g., GB / T 16777-2008 standard) and record the maximum peel force between the waterproof layer + anchoring layer composite layer and the polyurethane waterproof layer.

[0110] Table 3 Test results of bonding strength between layers

[0111] Adhesive strength Q1 (MPa) Adhesive strength Q2 (MPa) Example 1 1.5-1.6 2.7-2.8 Example 2 1.7-1.8 3.0-3.1 Example 3 2.0-2.1 3.2-3.3

[0112] During the bonding strength test, when the waterproof layer + anchoring layer composite layer is peeled off from the polyurethane waterproof layer as a whole, the waterproof layer + anchoring layer composite layer is still in an integral structure, and the waterproof layer + anchoring layer composite layer has a strong bonding strength; as shown in Table 3, the waterproof layer in the present invention has the function of strengthening the bonding ability of the anchoring layer; the bonding strength between the waterproof layer + anchoring layer composite layer as a whole and the polyurethane waterproof layer (old coating) in the present invention meets the bonding strength requirements of the waterproof coating.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made by any technician familiar with the field within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A waterproof coating containing methyl 3-methoxypropionate, characterized in that: It includes an anchoring composition and a waterproofing composition; the waterproofing composition is a composition using a 3-methoxypropionic acid methyl ester complex as a solvent; The anchoring composition comprises the following components in parts by weight: 30-40 parts of corn cob carbon catalyst residue, 40-45 parts of acrylic emulsion, 5-6 parts of silane coupling agent, 2-4 parts of fumed silica, 5-7 parts of propylene glycol, 5-6 parts of heat-sensitive crosslinking agent, 2-3 parts of polycarboxylate dispersant, and the balance is deionized water.

2. The waterproof coating containing methyl 3-methoxypropionate according to claim 1, characterized in that: The 3-methoxypropionic acid methyl ester complex comprises 3-methoxypropionic acid methyl ester and propylene glycol methyl ether acetate, and the mass ratio of 3-methoxypropionic acid methyl ester to propylene glycol methyl ether acetate is 2-4:

1.

3. The waterproof coating containing methyl 3-methoxypropionate according to claim 2, characterized in that: The waterproof composition comprises the following components in parts by weight: 40-50 parts of NCO-terminated polyurethane prepolymer, 20-25 parts of methyl 3-methoxypropionate complex, 20-25 parts of filler, 1.5-2.5 parts of aminosilane, 1-2 parts of phosphate adhesion promoter, 0.2-0.4 parts of organic bismuth, and 1-3 parts of dispersant.

4. The waterproof coating containing methyl 3-methoxypropionate according to claim 1, characterized in that: The corncob carbon catalyst residue is obtained by the following method: A1. After crushing and sieving corn cobs, stir and mix with dilute sulfuric acid and heat to remove hemicellulose, then perform high-temperature pyrolysis and carbonization, and finally mix with concentrated sulfuric acid and heat to sulfonate to obtain a corn cob carbon catalyst; A2. Add acetic acid, methanol, and the corncob carbon catalyst into a first reactor to react. After the reaction is completed, separate the methyl acetate obtained by the reaction by distillation. The fraction is the methyl acetate product, and the remainder is the corncob carbon catalyst residue.

5. The waterproof coating containing methyl 3-methoxypropionate according to claim 3, characterized in that: The filler comprises the following components in parts by weight: 8-10 parts of nano titanium dioxide, 4-5 parts of hydrophobic fumed silica, 4-5 parts of nano modified calcium carbonate, and 4-5 parts of polytetrafluoroethylene powder.

6. The waterproof coating containing methyl 3-methoxypropionate according to claim 5, characterized in that: The nano-modified calcium carbonate is nano-calcium carbonate wrapped with stearic acid, and the added amount of stearic acid is 3% of the mass of the nano-calcium carbonate.

7. The waterproof coating containing methyl 3-methoxypropionate according to claim 1, characterized in that: The silane coupling agent is KH-560 silane coupling agent.

8. The waterproof coating containing methyl 3-methoxypropionate according to claim 1, characterized in that: The heat-sensitive crosslinking agent is trimethylolpropane trimethacrylate.

9. The waterproof coating containing methyl 3-methoxypropionate according to claim 1, characterized in that: The thickness ratio of the anchoring layer formed by the anchoring composition to the waterproof layer formed by the waterproof composition is 1:1.5-2.

10. The waterproof coating containing methyl 3-methoxypropionate according to claim 3, characterized in that: The anchoring composition comprises the following components in parts by weight: 40 parts of corn cob carbon catalyst residue, 45 parts of acrylic emulsion, 6 parts of silane coupling agent, 4 parts of fumed silica, 7 parts of propylene glycol, 3 parts of polycarboxylate dispersant, 6 parts of heat-sensitive crosslinking agent, and the balance is deionized water; The waterproof composition comprises the following components in parts by weight: 50 parts of NCO-terminated polyurethane prepolymer, 25 parts of methyl 3-methoxypropionate complex, 25 parts of filler, 2.5 parts of aminosilane, 2 parts of phosphate adhesion promoter, 0.4 parts of organic bismuth, and 3 parts of polymer block copolymer dispersant; The mass ratio of methyl 3-methoxypropionate to propylene glycol methyl ether acetate is 3:1.

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