A deodorant interior wall emulsion, its preparation method and application

Abstract

The application discloses a deodorizing interior wall emulsion and a preparation method and application thereof, and belongs to the technical field of polymer emulsion, and aims to solve the problem that the existing interior wall emulsion is difficult to consider low VOC, high scrubbing resistance and freeze-thaw stability at the same time. The method comprises the following steps: first, preparing a pre-emulsion containing deionized water, an emulsifier and main monomers, preparing an initiator and a reducing agent solution, adding the remaining pre-emulsion, the initiator and the reducing agent solution drop by drop after seed reaction, then eliminating and treating through two-stage and more than two-stage oxidation-reduction, and finally adjusting pH and filtering to obtain the product. The application improves the polymer molecular weight through low-temperature oxidation-reduction polymerization to enhance the film performance and freeze-thaw stability, uses special functional monomers to reduce the freezing point through surface enrichment, matches long carbon chain monomers and crosslinking monomers to ensure low-temperature film forming property, and combines multi-stage post-elimination and stripping process to reduce VOC, SVOC and residual monomer content.

Description

Technical Field

[0001] This invention belongs to the field of polymer emulsion technology, specifically relating to an odor-neutralizing interior wall emulsion, its preparation method, and its application. Background Technology

[0002] With the rapid development of the construction industry, the use of interior wall coatings has increased dramatically, and their environmental performance has received increasing attention. Currently, various odor-free products are available on the market, and the content of volatile organic compounds (VOCs) has been effectively controlled. However, as people's requirements for indoor air quality and health and safety continue to rise, and environmental regulations become increasingly stringent, restrictions on semi-volatile organic compounds (SVOCs) in interior wall coatings are becoming increasingly strict. SVOCs mainly originate from high-boiling-point film-forming aids and antifreeze agents. These substances have low volatility and can be released persistently indoors, affecting human health in the long term. Currently, manufacturers are actively optimizing the formulations of high-end interior wall coatings to reduce the use of SVOCs, and the industry's technological research and development and product upgrades are actively moving towards a "zero SVOC" standard.

[0003] Therefore, developing a high-performance, odor-neutralizing interior wall emulsion that does not require the addition of film-forming aids and antifreeze agents has become a pressing technical problem to be solved in this field. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an odor-neutralizing interior wall emulsion, its preparation method, and its application. This emulsion can produce an interior wall coating with low VOC, low SVOC, low residual ions, high scrub resistance, and excellent freeze-thaw stability without the need for additional film-forming aids and antifreeze agents.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing an odor-neutralizing interior wall emulsion, comprising the following steps:

[0007] (1) Preparation of pre-emulsion: Mix part of deionized water and part of reactive emulsifier, stir for 20-30 minutes, then add the main monomer, hydrophilic monomer and crosslinking monomer, and continue stirring for 20-30 minutes to obtain pre-emulsion; the crosslinking monomer includes ethyl acetoacetate methacrylate, silane coupling agent and crosslinking monomer containing flexible segments;

[0008] (2) Preparation of initiator and reducing agent solutions: Dissolve the initiator and reducing agent separately in deionized water to prepare at least two sets of initiator and reducing agent solutions;

[0009] (3) Seed reaction and dropwise polymerization: Add the remaining deionized water, remaining reactive emulsifier and buffer to the reactor, and heat to 70-75℃; first add 5-15% of the total amount of the pre-emulsion obtained in step (1), and add the first set of initiator and reducing agent solutions, and keep warm for 20-40 minutes; then simultaneously add the remaining pre-emulsion and the second set of initiator and reducing agent solutions, with a dropwise addition time of 220-250 minutes; when 1 / 4 of the pre-emulsion has been added, add the special functional monomer, stir for 5 minutes and continue to add until the end;

[0010] (4) Post-treatment: After the addition is completed, heat to 75-85℃ and keep warm for 50-70 minutes; then carry out at least two stages of oxidation-reduction elimination treatment and stripping process in sequence;

[0011] (5) Discharge: Cool down to below 45°C, add neutralizing agent to adjust pH to 7-8.5, filter, and the odor-free interior wall emulsion is obtained.

[0012] Optionally, in step (1), the pre-emulsion comprises the following components in parts by weight:

[0013] 8-15 parts deionized water, 0.2-1 part reactive emulsifier, 40-45 parts main monomer, 0.5-2.5 parts hydrophilic monomer, and 2-4 parts crosslinking monomer;

[0014] And / or, in step (2), in the first set of initiator and reducing agent solutions, the amount of initiator is 5-20% of the total weight of the initiator and the amount of reducing agent is 5-20% of the total weight of the reducing agent; in the second set of initiator and reducing agent solutions, the amount of initiator is 80-95% of the total weight of the initiator and the amount of reducing agent is 80-95% of the total weight of the reducing agent.

[0015] Optionally, the reactive emulsifier is selected from at least one of sodium 2-acrylamido-2-methylpropanesulfonate, 1-allyloxy-3-alkylphenoxy-2-polyoxyethylene sulfate, vinyl polyoxyethylene alkyl ether ammonium sulfate, and sodium allyl succinic ester sulfonate.

[0016] And / or, the main monomer is selected from at least one of styrene, methyl methacrylate, isooctyl acrylate, butyl acrylate, isodecanyl methacrylate, tridecyl methacrylate, and laurate methacrylate;

[0017] And / or, the hydrophilic monomer is selected from at least one of acrylic acid, methacrylic acid, β-CEA, acrylamide, and methacrylamide;

[0018] And / or, the silane coupling agent is selected from at least one of vinyltrimethoxysilane, vinyltriethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane;

[0019] And / or, the crosslinking monomer containing the flexible segment is selected from at least one of ethylene glycol dimethacrylate, dibutyl itaconic acid, 1,6-hexanediol diacrylate, glycidyl methacrylate, and trimethylolpropane trimethacrylate.

[0020] And / or, the special functional monomer is selected from at least one of polyethylene glycol acrylate, polypropylene glycol acrylate, and betaine acrylates.

[0021] Optionally, in step (4), the post-redox elimination treatment includes at least two stages:

[0022] Elimination after the first stage: Cool down to 70-80℃, add oxidant and reducing agent dropwise over 30-50 minutes, and keep warm for 20-30 minutes;

[0023] Elimination after the second stage: Cool down to 60-70℃, add oxidant and reducing agent dropwise over 50-70 minutes, and keep warm for 20-30 minutes;

[0024] And / or, in step (4), the stripping process is carried out at a temperature of 60-70℃ and a pressure of -70 to -90Kpa, and the stripping time is 3-5 hours.

[0025] Optionally, the raw materials used in the preparation method include the following components in parts by weight:

[0026] 48-52 parts deionized water, 0.05-0.2 parts buffer, 0.3-1.5 parts reactive emulsifier, 40-45 parts main monomer, 0.5-2.5 parts hydrophilic monomer, 2-4 parts crosslinking monomer, 0.5-2.5 parts special functional monomer, 0.08-0.3 parts initiator, 0.08-0.3 parts oxidant, 0.1-0.4 parts reducing agent, and 0.5-1.5 parts neutralizing agent.

[0027] In a second aspect, the present invention provides an odor-neutralizing interior wall emulsion prepared by the above method.

[0028] In a third aspect, the present invention provides the application of the above-mentioned odor-neutralizing interior wall emulsion in the preparation of interior wall coatings.

[0029] In a fourth aspect, the present invention provides an interior wall coating comprising the above-mentioned odor-neutralizing interior wall emulsion.

[0030] The beneficial effects of this invention are as follows:

[0031] (1) This invention employs a low-temperature oxidation-reduction polymerization system, which significantly increases the molecular weight of the polymer, thereby improving the hardness, toughness, and scrub resistance of the paint film. Simultaneously, the high molecular weight enhances the latex particles' resistance to compression during freezing, indirectly improving the coating's freeze-thaw stability.

[0032] (2) This invention selects special functional monomers containing hydrophilic groups (such as -EO, -PO, -OH, quaternary ammonium salts, carboxylic acid groups, etc.) and uses a post-addition process to enrich them on the surface of latex particles. These groups can lower the freezing point through hydrogen bonding, greatly improving the freeze-thaw resistance of the emulsion, thus eliminating the need for external antifreeze agents.

[0033] (3) By using a combination of long-chain acrylic monomers and ethyl acetoacetate methacrylate, the present invention effectively improves the flexibility and low-temperature film-forming properties of latex particles, achieving the goal of eliminating the need for external film-forming aids.

[0034] (4) This invention uses crosslinking monomers containing flexible segments, which improves the crosslinking density of the coating film while ensuring its low-temperature film-forming properties. At the same time, the introduction of silane coupling agents and reactive emulsifiers improves the adhesion of the coating film to the substrate, water resistance and low-temperature scrub resistance.

[0035] (5) The present invention adopts a multi-stage post-elimination process and a stripping process, which greatly reduces the residual monomer and VOC content of the emulsion, ensuring the clean taste and environmental protection characteristics of the product. Detailed Implementation

[0036] The present invention will be described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited thereto.

[0037] Unless otherwise specified, all raw materials used in the embodiments and comparative examples of this invention are commercially available.

[0038] Example 1

[0039] A method for preparing an odor-neutralizing interior wall emulsion includes the following steps:

[0040] a. Preparation of pre-emulsion: Add 4g of vinyl polyoxyethylene alkyl ether ammonium sulfate emulsifier and 125g of deionized water to a pre-emulsion bottle and stir for 25 minutes; add 145g of styrene, 255g of butyl acrylate, 20g of tridecyl methacrylate, 25g of ethyl acetoacetate methacrylate, 10g of acrylic acid, 4g of acrylamide, 5g of ethylene glycol dimethacrylate, and 2.5g of vinyltriethoxysilane, and continue stirring for 25 minutes to obtain the pre-emulsion for later use.

[0041] b. Preparation of the reaction vessel: Add 0.6g of vinyl polyoxyethylene alkyl ether ammonium sulfate emulsifier, 1g of sodium bicarbonate and 270g of deionized water to a 2L four-necked flask, stir and heat to 73℃.

[0042] c. Preparation of initiator and reducing agent solution:

[0043] Dissolve 0.002g of ferrous sulfate in 2g of deionized water to obtain solution ①;

[0044] Dissolve 0.4g of sodium persulfate in 6g of deionized water to obtain solution ②;

[0045] Dissolve 0.4g of sodium bisulfite in 6g of deionized water to obtain solution ③;

[0046] Dissolve 0.8g of sodium persulfate in 10g of deionized water to make solution ④;

[0047] Dissolve 0.8g of sodium bisulfite in 10g of deionized water to make solution ⑤.

[0048] d. Seed reaction and dropwise polymerization: After the reactor temperature stabilizes at 73℃, add 10% of the pre-emulsion; after 2 minutes, add solutions ①, ②, and ③ in sequence; after the emulsion in the reactor turns blue and the temperature stabilizes, keep it at this temperature for 30 minutes; then start adding the remaining pre-emulsion, solution ④, and solution ⑤ dropwise simultaneously for 240 minutes; when 1 / 4 of the pre-emulsion has been added, add 15g of polyethylene glycol acrylate, stir for 5 minutes, and continue adding until finished; after the addition is complete, raise the temperature to 82-84℃ and keep it at this temperature for 60 minutes.

[0049] e. Post-elimination process ①: Cool down to 75℃, dissolve 0.4g of tert-butyl hydrogen peroxide and 0.28g of sodium bisulfite in 5g of deionized water respectively, and then add the dissolved oxidant and reducing agent dropwise at the same time over 30 minutes, and keep warm for 20 minutes.

[0050] f. Post-elimination process ②: Cool to 65-67℃, dissolve 0.95g of tert-butyl hydrogen peroxide and 0.68g of FF6M in 15g of deionized water respectively, and then add the dissolved oxidant and reducing agent dropwise simultaneously over a period of 60 minutes, and keep warm for 30 minutes.

[0051] g. Stripping process: After the heat preservation is completed, stripping is carried out at 70℃ and -90Kpa pressure for 3-5 hours.

[0052] h. Discharge: Cool to below 45℃, neutralize with ethanolamine and adjust pH to 7-8.5, filter to obtain odor-free interior wall emulsion.

[0053] Example 2

[0054] The difference between this embodiment and Example 1 is that the types and amounts of monomers used in the preparation of the pre-emulsion are different:

[0055] a. Preparation of pre-emulsion: Add 4g of vinyl polyoxyethylene alkyl ether ammonium sulfate emulsifier and 125g of deionized water to a pre-emulsion bottle and stir for 25 minutes; add 140g of styrene, 260g of butyl acrylate, 20g of laurate methacrylate, 25g of ethyl acetoacetate methacrylate, 10g of acrylic acid, 4g of acrylamide, 5g of ethylene glycol dimethacrylate, and 2.5g of vinyltrimethoxysilane, and continue stirring for 25 minutes to obtain the pre-emulsion for later use.

[0056] Steps b to h are the same as in Example 1.

[0057] Example 3

[0058] The difference between this embodiment and Example 1 is that in the preparation of the pre-emulsion, 10g of acrylic acid and 4g of acrylamide are replaced with 14g of methacrylic acid, and 5g of ethylene glycol dimethacrylate is replaced with 5g of 1,6-hexanediol diacrylate; the special functional monomer added in the dropping stage is replaced with 15g of betaine acrylate instead of 15g of polyethylene glycol acrylate. The remaining steps are the same as in Example 1.

[0059] Example 4

[0060] a. Preparation of pre-emulsion: Add 2.8g of sodium 2-acrylamido-2-methylpropanesulfonate and 120g of deionized water to a pre-emulsion bottle and stir for 20 minutes; add 170g of styrene, 230g of butyl acrylate, 15g of isodecyl methacrylate, 20g of ethyl acetoacetate methacrylate, 8g of acrylic acid, 3g of methacrylamide, 8g of trimethylolpropane trimethacrylate, and 3g of γ-methacryloyloxypropyltrimethoxysilane, and continue stirring for 25 minutes to obtain the pre-emulsion for later use.

[0061] b. Preparation of the reaction vessel: Add 0.5g of sodium 2-acrylamido-2-methylpropanesulfonate, 0.15g of sodium carbonate and 280g of deionized water to a 2L four-necked flask, stir and heat to 72℃.

[0062] c. Preparation of initiator and reducing agent solution:

[0063] Dissolve 0.003g of ferrous sulfate in 2g of deionized water to obtain solution ①;

[0064] Dissolve 0.3g of potassium persulfate in 5g of deionized water to make solution ②;

[0065] Dissolve 0.3g of isoascorbic acid in 5g of deionized water to prepare solution ③;

[0066] Dissolve 1.0g of potassium persulfate in 12g of deionized water to make solution ④;

[0067] Dissolve 1.0g of isoascorbic acid in 12g of deionized water to make solution ⑤.

[0068] d. Seed reaction and dropwise polymerization: After the reactor temperature stabilizes, add 8% of the pre-emulsion; after 2 minutes, add solution ①, solution ②, and solution ③ in sequence; after holding at the temperature for 25 minutes, start to add the remaining pre-emulsion, solution ④, and solution ⑤ dropwise simultaneously, with a dropwise addition time of 230 minutes; when 1 / 4 of the pre-emulsion has been added, add 8g of polypropylene glycol acrylate, stir for 5 minutes, and continue to add dropwise; after the dropwise addition is completed, raise the temperature to 80℃ and hold at that temperature for 55 minutes.

[0069] e. Post-elimination process ①: Cool down to 78℃, dissolve 0.3g of hydrogen peroxide and 0.25g of sodium formaldehyde sulfoxylate in 5g of deionized water respectively, and then add them dropwise at the same time over 40 minutes, and keep warm for 25 minutes.

[0070] f. Post-elimination process ②: Cool down to 68℃, dissolve 0.8g hydrogen peroxide and 0.6g FF6M in 15g deionized water respectively, and then add them dropwise at the same time over a period of 65 minutes, and keep warm for 25 minutes.

[0071] g. Stripping process: After the heat preservation is completed, stripping is carried out at 65℃ and -80Kpa pressure for 4 hours.

[0072] h. Discharge: Cool to below 45℃, neutralize with diethanolamine and adjust pH to 8.0, filter to obtain odor-free interior wall emulsion.

[0073] Example 5

[0074] a. Preparation of pre-emulsion: Add 3g of sodium allyl succinate sulfonate and 110g of deionized water to a pre-emulsion bottle and stir for 30 minutes; add 120g of methyl methacrylate, 150g of isooctyl acrylate, 140g of butyl acrylate, 15g of ethyl acetoacetate methacrylate, 5g of β-CEA, 6g of acrylamide, 10g of glycidyl methacrylate, and 4g of vinyltrimethoxysilane, and continue stirring for 20 minutes to obtain the pre-emulsion for later use.

[0075] b. Preparation of the reaction vessel: Add 0.7g of sodium allyl succinate sulfonate, 0.6g of sodium bicarbonate and 260g of deionized water to a 2L four-necked flask, stir and heat to 75℃.

[0076] c. Preparation of initiator and reducing agent solution:

[0077] Dissolve 0.001g of ferrous sulfate in 1g of deionized water to obtain solution ①;

[0078] Dissolve 0.5g of ammonium persulfate in 8g of deionized water to make solution ②;

[0079] Dissolve 0.5g of sodium bisulfite in 8g of deionized water to make solution ③;

[0080] Dissolve 1.2g of ammonium persulfate in 15g of deionized water to make solution ④;

[0081] Dissolve 1.2g of sodium bisulfite in 15g of deionized water to make solution ⑤.

[0082] d. Seed reaction and dropwise polymerization: After the reactor temperature stabilizes, add 12% pre-emulsion; after 2 minutes, add solution ①, solution ②, and solution ③ in sequence; after holding at the temperature for 35 minutes, start adding the remaining pre-emulsion, solution ④, and solution ⑤ simultaneously over a period of 250 minutes; when 1 / 4 of the pre-emulsion has been added, add 5g of acrylate betaine, stir for 5 minutes, and continue adding; after the addition is complete, raise the temperature to 78℃ and hold for 65 minutes.

[0083] e. Post-elimination process ①: Cool down to 72℃, dissolve 0.5g of tert-butyl hydrogen peroxide and 0.35g of FF6M in 6g of deionized water respectively, and then add them dropwise at the same time over a period of 45 minutes, and keep warm for 30 minutes.

[0084] f. Post-elimination process ②: Cool down to 62℃, dissolve 1.0g of tert-butyl hydroperoxide and 0.8g of isoascorbic acid in 18g of deionized water respectively, and then add them dropwise at the same time over a period of 55 minutes, and keep warm for 30 minutes.

[0085] g. Stripping process: After the heat preservation is completed, stripping is carried out at 62℃ and -85Kpa for 4.5 hours.

[0086] h. Discharge: Cool to below 45℃, neutralize with N,N-dimethylethanolamine and adjust pH to 7.5, filter to obtain odor-free interior wall emulsion.

[0087] Example 6

[0088] a. Preparation of pre-emulsion: Add 1.0g of 1-allyloxy-3-alkylphenoxy-2-polyoxyethylene sulfate and 160g of deionized water to a pre-emulsion bottle and stir for 25 minutes; add 160g of styrene, 250g of butyl acrylate, 15g of ethyl acetoacetate methacrylate, 4.0g of methacrylic acid, 8g of dibutyl itaconic acid, and 3g of vinyltriethoxysilane, and continue stirring for 30 minutes to obtain the pre-emulsion for later use.

[0089] b. Preparation of the reaction vessel: Add 0.4g of 1-allyloxy-3-alkylphenoxy-2-polyoxyethylene sulfate, 0.1g of sodium bicarbonate and 300g of deionized water to a 2L four-necked flask, stir and heat to 70℃.

[0090] c. Preparation of initiator and reducing agent solution:

[0091] Dissolve 0.001g of ferrous sulfate in 2g of deionized water to obtain solution ①;

[0092] Dissolve 0.06g of ammonium persulfate in 2g of deionized water to prepare solution ②;

[0093] Dissolve 0.04g of sodium bisulfite in 13g of deionized water to make solution ③;

[0094] Dissolve 0.22g of ammonium persulfate in 13g of deionized water to make solution ④;

[0095] Dissolve 0.22g of sodium bisulfite in 13g of deionized water to prepare solution ⑤;

[0096] d. Seed reaction and dropwise polymerization: After the reactor temperature stabilizes, add 5% of the pre-emulsion; after 2 minutes, add solution ①, solution ②, and solution ③ in sequence; after keeping warm for 20 minutes, start to add the remaining pre-emulsion, solution ④, and solution ⑤ dropwise simultaneously for 220 minutes; when 1 / 4 of the pre-emulsion has been added, add 8.0g of polyethylene glycol acrylate, stir for 5 minutes, and continue to add dropwise; after the addition is complete, raise the temperature to 75℃ and keep warm for 50 minutes.

[0097] e. Post-elimination process ①: Cool down to 70℃, dissolve 0.15g tert-butyl hydroperoxide and 0.2g isoascorbic acid in 15g deionized water respectively, and then add them dropwise at the same time over 30 minutes, and keep warm for 20 minutes.

[0098] f. Post-elimination process ②: Cool down to 60℃, dissolve 0.2g of tert-butyl hydrogen peroxide and 0.25g of FF6M in 15g of deionized water respectively, and then add them dropwise simultaneously over a period of 50 minutes, followed by 20 minutes of heat preservation.

[0099] g. Stripping process: After the heat preservation is completed, stripping is carried out for 3 hours at a temperature of 60℃ and a pressure of -70Kpa.

[0100] h. Discharge: Cool to below 45℃, neutralize with ethanolamine and adjust pH to 7.0, filter to obtain odor-free interior wall emulsion.

[0101] Comparative Example 1

[0102] Referring to Example 1, the temperature during the reaction process was adjusted, that is, the temperature of the reaction vessel in step (d) when taking seeds and during the reaction process was adjusted from the original 73°C to 85°C, and the rest of the operation was the same as in Example 1.

[0103] Comparative Example 2

[0104] Referring to Example 1, the vinyl polyoxyethylene alkyl ether ammonium sulfate emulsifier in steps (a) and (b) was replaced with SDBS emulsifier from Nanjing Qicheng New Materials Co., Ltd., and the remaining operations were the same as in Example 1.

[0105] Comparative Example 3

[0106] Referring to Example 1, the ethylene glycol dimethacrylate in step (a) was replaced with allyl methacrylate, and the rest of the operation was the same as in Example 1.

[0107] Comparative Example 4

[0108] Referring to Example 1, the polyethylene glycol acrylate in step (d) was removed, and the rest of the operation was the same as in Example 1.

[0109] Comparative Example 5

[0110] Referring to Example 1, the ethyl acetoacetate methacrylate in step (a) was replaced with butyl acrylate, and the rest of the operation was the same as in Example 1.

[0111] Comparative Example 6

[0112] Referring to Example 1, step (e) is removed, and no stripping is performed; the operation is the same as in Example 1.

[0113] Application examples

[0114] The emulsions prepared in Examples 1-6 and Comparative Examples 1-6 were formulated into interior wall latex paints according to Table 1. Based on GB / T 9780-2013 "Test Method for Scrub Resistance of Architectural Coatings", GB / T9209-2016 "Test Method for Freeze-Thaw Cycles of Architectural Coatings", GB / T 9756.1-2018 "Synthetic Resin Emulsion Interior Wall Coatings" and industry practice, the formulated latex particles were subjected to low-temperature thick coating tests, freeze-thaw stability tests, room-temperature scrub resistance tests, and low-temperature scrub resistance tests.

[0115] Table 1

[0116]

[0117]

[0118] Table 2

[0119]

[0120] The above coatings were tested, and the test results are shown in Table 2. The odorless interior wall emulsions prepared in Examples 1-6 of this invention exhibit excellent comprehensive performance without the need for added film-forming aids and antifreeze agents: In terms of environmental friendliness, the VOC content is only 226-345 ppm and the SVOC content is only 142-197 ppm; in terms of low-temperature film formation, no cracking occurred in thick coatings (200μm, 600μm) at low temperatures, meeting the requirements for low-temperature construction; in terms of freeze-thaw stability, all passed three freeze-thaw cycle tests, demonstrating excellent resistance to extrusion of the latex particles; in terms of scrub resistance, the number of scrub cycles at room temperature reaches 8000-12500, and the number of scrub cycles at low temperatures reaches 2000-3100, with a good balance between film hardness and toughness. Example 1 (the best example) exhibits the best comprehensive performance, with a room temperature scrub resistance of 12500 and a low temperature scrub resistance of 3100.

[0121] By comparing the comparative examples and the embodiments, the necessity of the key technical features of the present invention can be further verified: Comparative Example 1 increased the polymerization temperature, resulting in a decrease in freeze-thaw resistance and low-temperature scrub resistance; Comparative Example 2 replaced the reactive emulsifier with a common emulsifier, resulting in a decrease in scrub resistance; Comparative Example 3 replaced the crosslinking monomer containing flexible segments with a rigid crosslinking monomer, resulting in cracking during low-temperature film formation; Comparative Example 4 removed the special functional monomer, resulting in the failure of freeze-thaw stability; Comparative Example 5 replaced the core crosslinking monomer ethyl acetoacetate with a common monomer, resulting in cracking during both low-temperature film formation and scrub resistance; Comparative Example 6 omitted the post-elimination and stripping processes, resulting in a significant increase in VOCs and loss of the odor-free properties.

[0122] In summary, the low-temperature polymerization system, reactive emulsifier, specific crosslinking monomers (including core monomers and flexible segments), special functional monomers, and post-processing technology of this invention are key to achieving high performance and environmental friendliness of emulsions, and none of them can be omitted.

[0123] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. The application of a low-odor interior wall emulsion in the preparation of interior wall coatings, characterized in that, The preparation method of the odor-free interior wall emulsion includes the following steps: (1) Preparation of pre-emulsion: Mix deionized water and reactive emulsifier and stir for 20-30 minutes, then add the main monomer, hydrophilic monomer and crosslinking monomer, and continue stirring for 20-30 minutes to obtain the pre-emulsion; the crosslinking monomer includes ethyl acetoacetate methacrylate, silane coupling agent and crosslinking monomer containing flexible segments; (2) Preparation of initiator and reducing agent solutions: Dissolve the initiator and reducing agent separately in deionized water to prepare at least two sets of initiator and reducing agent solutions; (3) Seed reaction and dropwise polymerization: Add deionized water, reactive emulsifier and buffer to the reactor and heat to 70-75℃; first add 5-15% of the total amount of pre-emulsion obtained in step (1), and add the first set of initiator and reducing agent solution, and keep warm for 20-40 minutes; then add the remaining pre-emulsion and the second set of initiator and reducing agent solution dropwise at the same time, and the dropwise addition time is 220-250 minutes; when 1 / 4 of the pre-emulsion has been added, add the special functional monomer, stir for 5 minutes and continue to add dropwise until the end; (4) Post-treatment: After the addition is completed, heat to 75-85℃ and keep warm for 50-70 minutes; then carry out at least two stages of oxidation-reduction elimination treatment and stripping process in sequence; (5) Discharge: Cool down to below 45°C, add neutralizing agent to adjust pH, filter, and the odor-free interior wall emulsion is obtained; In step (1), the pre-emulsion comprises the following components in parts by weight: 8-15 parts deionized water, 0.2-1 part reactive emulsifier, 40-45 parts main monomer, 0.5-2.5 parts hydrophilic monomer, and 2-4 parts crosslinking monomer; In step (2), in the first set of initiator and reducing agent solutions, the amount of initiator is 5-20% of the total weight of the initiator, and the amount of reducing agent is 5-20% of the total weight of the reducing agent; in the second set of initiator and reducing agent solutions, the amount of initiator is 80-95% of the total weight of the initiator, and the amount of reducing agent is 80-95% of the total weight of the reducing agent. The reactive emulsifier is selected from at least one of sodium 2-acrylamido-2-methylpropanesulfonate, 1-allyloxy-3-alkylphenoxy-2-polyoxyethylene sulfate, vinyl polyoxyethylene alkyl ether ammonium sulfate, and sodium allyl succinic ester sulfonate. The main monomer is selected from at least one of styrene, methyl methacrylate, isooctyl acrylate, butyl acrylate, isodecyl methacrylate, tridecyl methacrylate, and laurate methacrylate; The hydrophilic monomer is selected from at least one of acrylic acid, methacrylic acid, β-CEA, acrylamide, and methacrylamide; The silane coupling agent is selected from at least one of vinyltrimethoxysilane, vinyltriethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane; The crosslinking monomer containing flexible segments is selected from at least one of ethylene glycol dimethacrylate, dibutyl itaconic acid, 1,6-hexanediol diacrylate, and trimethylolpropane trimethacrylate. The special functional monomer is selected from at least one of polyethylene glycol acrylate and polypropylene glycol acrylate; The raw materials used in the preparation method include the following components in parts by weight: 48-52 parts deionized water, 0.05-0.2 parts buffer, 0.3-1.5 parts reactive emulsifier, 40-45 parts main monomer, 0.5-2.5 parts hydrophilic monomer, 1-2.5 parts ethyl acetoacetate methacrylate, 0.2-0.4 parts silane coupling agent, 0.5-1 part crosslinking monomer containing flexible segments, 0.5-2.5 parts special functional monomer, 0.08-0.3 parts initiator, 0.08-0.3 parts oxidant, 0.1-0.4 parts reducing agent, and 0.5-1.5 parts neutralizing agent.

2. The application of the odor-neutralizing interior wall emulsion according to claim 1 in the preparation of interior wall coatings, characterized in that, In step (4), the post-oxidation and post-reduction elimination treatment includes at least two stages: Elimination after the first stage: Cool down to 70-80℃, add oxidant and reducing agent dropwise over 30-50 minutes, and keep warm for 20-30 minutes; Elimination after the second stage: Cool down to 60-70℃, add oxidant and reducing agent dropwise over 50-70 minutes, and keep warm for 20-30 minutes; In step (4), the stripping process is carried out at a temperature of 60-70℃ and a pressure of -70 to -90Kpa, and the stripping time is 3-5 hours.

3. An interior wall coating, characterized in that, The product includes an odor-neutralizing interior wall emulsion, and the preparation method of the odor-neutralizing interior wall emulsion includes the following steps: (1) Preparation of pre-emulsion: Mix deionized water and reactive emulsifier and stir for 20-30 minutes, then add the main monomer, hydrophilic monomer and crosslinking monomer, and continue stirring for 20-30 minutes to obtain the pre-emulsion; the crosslinking monomer includes ethyl acetoacetate methacrylate, silane coupling agent and crosslinking monomer containing flexible segments; (2) Preparation of initiator and reducing agent solutions: Dissolve the initiator and reducing agent separately in deionized water to prepare at least two sets of initiator and reducing agent solutions; (3) Seed reaction and dropwise polymerization: Add deionized water, reactive emulsifier and buffer to the reactor and heat to 70-75℃; first add 5-15% of the total amount of pre-emulsion obtained in step (1), and add the first set of initiator and reducing agent solution, and keep warm for 20-40 minutes; then add the remaining pre-emulsion and the second set of initiator and reducing agent solution dropwise at the same time, and the dropwise addition time is 220-250 minutes; when 1 / 4 of the pre-emulsion has been added, add the special functional monomer, stir for 5 minutes and continue to add dropwise until the end; (4) Post-treatment: After the addition is completed, heat to 75-85℃ and keep warm for 50-70 minutes; then carry out at least two stages of oxidation-reduction elimination treatment and stripping process in sequence; (5) Discharge: Cool down to below 45°C, add neutralizing agent to adjust pH, filter, and the odor-free interior wall emulsion is obtained; In step (1), the pre-emulsion comprises the following components in parts by weight: 8-15 parts deionized water, 0.2-1 part reactive emulsifier, 40-45 parts main monomer, 0.5-2.5 parts hydrophilic monomer, and 2-4 parts crosslinking monomer; In step (2), in the first set of initiator and reducing agent solutions, the amount of initiator is 5-20% of the total weight of the initiator, and the amount of reducing agent is 5-20% of the total weight of the reducing agent; in the second set of initiator and reducing agent solutions, the amount of initiator is 80-95% of the total weight of the initiator, and the amount of reducing agent is 80-95% of the total weight of the reducing agent. The reactive emulsifier is selected from at least one of sodium 2-acrylamido-2-methylpropanesulfonate, 1-allyloxy-3-alkylphenoxy-2-polyoxyethylene sulfate, vinyl polyoxyethylene alkyl ether ammonium sulfate, and sodium allyl succinic ester sulfonate. The main monomer is selected from at least one of styrene, methyl methacrylate, isooctyl acrylate, butyl acrylate, isodecyl methacrylate, tridecyl methacrylate, and laurate methacrylate; The hydrophilic monomer is selected from at least one of acrylic acid, methacrylic acid, β-CEA, acrylamide, and methacrylamide; The silane coupling agent is selected from at least one of vinyltrimethoxysilane, vinyltriethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane; The crosslinking monomer containing flexible segments is selected from at least one of ethylene glycol dimethacrylate, dibutyl itaconic acid, 1,6-hexanediol diacrylate, and trimethylolpropane trimethacrylate. The special functional monomer is selected from at least one of polyethylene glycol acrylate and polypropylene glycol acrylate; The raw materials used in the preparation method include the following components in parts by weight: 48-52 parts deionized water, 0.05-0.2 parts buffer, 0.3-1.5 parts reactive emulsifier, 40-45 parts main monomer, 0.5-2.5 parts hydrophilic monomer, 1-2.5 parts ethyl acetoacetate methacrylate, 0.2-0.4 parts silane coupling agent, 0.5-1 part crosslinking monomer containing flexible segments, 0.5-2.5 parts special functional monomer, 0.08-0.3 parts initiator, 0.08-0.3 parts oxidant, 0.1-0.4 parts reducing agent, and 0.5-1.5 parts neutralizing agent.

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