An acrylate emulsion, its preparation method and use

Abstract

The application discloses an acrylate emulsion and a preparation method and application thereof, and the emulsion is prepared by emulsion polymerization of raw material components including the following mass percentages: a) 15-70 wt% of butyl acrylate, b) 1.3-10 wt% of an olefinically unsaturated monomer containing an acetoacetic ester functional group, c) 0.5-5 wt% of an unsaturated hydrophilic monomer, d) 0.2-5% of a reactive silane coupling agent, e) 10-40% of styrene, f) 1-20% of maleic anhydride, g) 1-40% of other olefinically unsaturated monomers, and h) 10-20% of an amine type post-crosslinking monomer. The emulsion is mainly applied to building interior wall coatings, and the emulsion has a relatively low MFFT without adding a film forming aid, and the coating prepared from the emulsion has excellent scrub resistance and freeze-thaw stability, low VOC content and good environmental protection performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building coatings, in particular to an acrylate emulsion for interior wall coatings, a preparation method and application thereof. BACKGROUND

[0002] Water-based acrylic emulsion gradually becomes the mainstream of building material coating resins due to its excellent environmental protection and low cost, and the building interior wall coating pays more attention to the scrub resistance and frost resistance indexes, and the key factor affecting these indexes is the selection of emulsion. Most coatings on the market choose to add a small amount of antifreeze to improve the antifreeze performance of the emulsion, but the antifreeze generally contains a large amount of VOC and has a strong odor, which greatly affects the odor of the coating.

[0003] In addition, the minimum film formation temperature (MFFT) of the coating emulsion is also an important index for evaluating the performance of the emulsion, and most coating manufacturers will add solvents as film forming additives in the coating. The film forming additive not only increases the cost of the coating, but also introduces a large amount of VOC. Therefore, the development of an emulsion with low MFFT, high frost resistance and high film forming property, which meets the performance requirements, has become the focus of emulsion manufacturers under the current green and environmental protection trend.

[0004] Patent CN108285505A discloses a zero-addition odor-free interior wall emulsion and a preparation method thereof, which mainly solves the freeze-thaw stability of the emulsion paint by coating a layer of styrene shell on the outer layer of the latex particle, but this method also enhances the hydrophobicity of the surface of the latex particle and thins the hydration, which is not conducive to the freeze-thaw stability of the emulsion paint, and the rigidity of the surface of the latex particle is enhanced, which makes the low-temperature thick coating of the emulsion paint prone to cracking.

[0005] Patent CN109651551B introduces a method of using carboxyl and amine groups to crosslink to improve the film forming ability of the emulsion and using the steric hindrance of the carboxyl group to improve the frost resistance, but it is difficult to ensure the integrity of the carboxyl group during the neutralization process of the emulsion, so this method requires very precise control of the feeding conditions to have an effect, and the use of crosslinking to improve the film forming ability is limited, and the glass transition temperature of the emulsion itself cannot be designed too high, which greatly affects the scrubbing performance.

[0006] Therefore, in the field, it is desirable to develop an acrylate emulsion with good film forming property and frost resistance, and at the same time, with ultra-low odor, excellent scrubbing resistance and freeze-thaw stability. SUMMARY

[0007] In view of the above problems in the prior art, the present application provides an acrylate low-odor emulsion and a preparation method thereof without adding film forming additives and antifreeze, which has ultra-low odor, excellent scrubbing resistance and freeze-thaw stability.

[0008] This invention has discovered that, by utilizing the characteristic of maleic anhydride reacting with amines to generate amide groups, maleic anhydride can be copolymerized and introduced into the polymer first. Then, amines can be used to react with it via ring-opening to generate two adjacent amide structures (one maleic anhydride generates two adjacent amides). The adjacent amides can form strong hydrogen bonds. This structure can greatly improve the film-forming ability and antifreeze ability of the emulsion. Furthermore, because the two adjacent amides in this structure are close together, the hydrogen bonding force is extremely strong, further enhancing film-forming properties and antifreeze ability. The main principle is shown in Formula 1 (where R represents an electron-donating conjugated group, and m, n, and L are 10-100).

[0009]

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] This invention provides an acrylic emulsion, prepared by emulsion polymerization from raw material components comprising the following mass percentages:

[0012] a) 15-70 wt% butyl acrylate, for example 20%, 30%, 40%, 50%, 60%, 70%, preferably 40-60%;

[0013] b) 1.3-10 wt% of an olefinic unsaturated monomer containing an acetoacetate functional group, for example 2%, 5%, 8%, 10%, preferably 2-4%;

[0014] c) 0.5-5 wt% of unsaturated hydrophilic monomers, such as 1%, 2%, 3%, 4%, 5%, preferably 2-5%;

[0015] d) 0.2-5% of a reactive silane coupling agent, such as 0.5%, 1%, 3%, 5%, preferably 0.5-2%;

[0016] e) 10-40% styrene, for example 10%, 20%, 30% or 40%, preferably 10-30%;

[0017] f) 1-20% maleic anhydride, for example 5%, 10%, 15%, 20%, preferably 10-15%;

[0018] g) 1-40% of other olefinic unsaturated monomers, such as 5%, 10%, 20%, 30%, 40%, preferably 5-10%;

[0019] h) 10-20% amine-based post-crosslinking monomers, for example 10%, 15%, 20%, preferably 10-15%;

[0020] The total mass of a), b), c), d), e), f), g), and h is 100%.

[0021] In addition, unless otherwise specified, all percentages mentioned in this invention are mass percentages.

[0022] In this invention, the olefinic unsaturated monomer containing the acetoacetate functional group in component b) is selected from one or more of ethyl acetoacetate (meth)acrylate, propoxy acetoacetate (meth)acrylate, butoxy acetoacetate (meth)acrylate, vinyl acetoacetate, and allyl acetoacetate, preferably one or more of ethyl acetoacetate (meth)acrylate and allyl acetoacetate.

[0023] In this invention, the unsaturated hydrophilic monomer of component c) is selected from one or more unsaturated monomers having hydrophilic groups of carboxyl, hydroxyl, amide, sulfonic acid, phosphate, urea, sulfonate, sulfate or phosphate groups, preferably one or more of acrylic acid, methacrylic acid, hydroxyethyl acrylate, acrylamide, methacrylamide ethyl ethylene urea, vinylalkoxy phosphate, and sodium 2-acrylamido-2-methylpropanesulfonate.

[0024] In this invention, the reactive silane coupling agent of component d) is selected from one or more of vinyl silane coupling agents and epoxy silane coupling agents, preferably one or more of vinyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and γ-glycidoxypropyltrimethoxysilane.

[0025] In this invention, the other olefinic unsaturated monomers in component g) are selected from olefinic unsaturated monomers containing 2-5 double bonds, preferably one or more of divinylbenzene, ethylene glycol dimethacrylate, trimethylolpropionic acid trimethacrylate, and allyl methacrylate, and more preferably divinylbenzene.

[0026] In this invention, the component h) amine post-crosslinking monomer is selected from functional amines containing conjugated electron-donating functional groups, wherein the conjugated electron-donating functional groups are selected from groups containing benzene rings, cyclopentadiene, etc.; preferably selected from one or more of aniline, furfurylamine, benzylamine, phenethylamine and aniline derivatives, and more preferably aniline and / or furfurylamine.

[0027] In a preferred embodiment, the acrylate emulsion of the present invention does not contain film-forming aids, and preferably also does not contain antifreeze agents. Currently, coating emulsions often add solvents as film-forming aids to ensure their scrub resistance, antifreeze properties, and other indicators, while simultaneously adding antifreeze agents to improve antifreeze performance. Common film-forming aids include ethylene glycol butyl ether, propylene glycol butyl ether, diethylene glycol butyl ether, and Taxanol, while common antifreeze agents include ethylene glycol, propylene glycol, and FT-100. In the acrylate emulsion of the present invention, by combining specific types of monomer components a)-h), a polymer with excellent film-forming properties is obtained through emulsion polymerization of butyl acrylate, an olefinic unsaturated monomer containing acetoacetate functional groups, an unsaturated hydrophilic monomer, a reactive silane coupling agent, styrene, maleic anhydride, other olefinic unsaturated monomers, and amine post-crosslinking monomers. This polymer can achieve good film-forming effects and a low MFFT (minimum molding temperature) even without the addition of film-forming aids or very little film-forming aid.

[0028] The acrylate emulsion described in this invention is obtained by emulsion polymerization, which is a polymerization method known in the prior art. Those skilled in the art can use any feasible method to prepare it.

[0029] Preferably, the raw materials for preparing the acrylate emulsion according to the present invention may also optionally include emulsifiers, initiators, neutralizers, post-treatment agents, pH adjusters, alcohol solvents, water, etc.

[0030] In this invention, the emulsifier is selected from one or more of sodium dodecyl sulfate, sodium p-styrene sulfonate, sodium dodecylbenzene sulfonate, alcohol ether sulfosuccinate, alkyl alcohol ether sulfate, and alkyl alcohol ether phosphate, preferably sodium dodecyl sulfate and / or sodium dodecylbenzene sulfonate;

[0031] Preferably, the total amount of the emulsifier is 1-5% of the total mass of components a)-h), for example 1%, 2%, 3%, 4%, 5%, preferably 1-2%.

[0032] In this invention, the initiator is selected from one or more of sodium persulfate, potassium persulfate, and ammonium persulfate, preferably sodium persulfate and / or potassium persulfate;

[0033] Preferably, the total amount of the initiator is 0.2-0.6% of the total mass of components a)-h), for example, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, and more preferably 0.2-0.4%.

[0034] In this invention, the neutralizing agent is selected from one or more of sodium bicarbonate, diethylenetriamine, diethanolamine, and ethanolamine, with sodium bicarbonate being preferred;

[0035] Preferably, the amount of neutralizing agent is 0.1-4% of the total mass of monomer components a)-h), for example 0.1%, 0.2%, 0.3%, 0.5%, 1.0%, 2.0%, 3.0%, and more preferably 0.1-0.3%.

[0036] In this invention, the post-treatment agent includes an oxidant and / or a reducing agent. The oxidant is selected from one or more of tert-butyl hydroperoxide, hydrogen peroxide, sodium persulfate, potassium persulfate, and ammonium persulfate, preferably tert-butyl hydroperoxide and / or hydrogen peroxide. The reducing agent is selected from one or more of sodium bisulfite, sodium metabisulfite, and vitamin C, preferably sodium bisulfite and / or sodium metabisulfite.

[0037] Preferably, the total amount of the post-treatment agent is 0.15-0.6% of the total mass of components a)-h), for example, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, and more preferably 0.2-0.4%.

[0038] In this invention, the pH adjuster is selected from one or more of sodium bicarbonate, diethylenetriamine, diethanolamine, and ethanolamine, preferably diethylenetriamine and / or ethanolamine;

[0039] Preferably, the endpoint of adding the pH adjuster is to adjust the pH to 7-9.

[0040] In this invention, the alcohol solvent is selected from one or more of ethanol, n-butanol, and isobutanol, with ethanol being preferred;

[0041] Preferably, the total amount of the alcohol solvent is 0.01-0.5% of the total mass of monomer components a)-h), for example, 0.01%, 0.015%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, and more preferably 0.01-0.3%.

[0042] In this invention, the total amount of water used is 1-1.5 times the total mass of components a) and h), for example, 1.1 times, 1.2 times, 1.3 times, or 1.4 times, preferably 1-1.3 times.

[0043] The present invention also provides a method for preparing the above-mentioned acrylate emulsion, comprising the following steps:

[0044] 1) Mix components a), b), c), d), e), f), g), h), a portion of water, alcohol solvent, and a portion of emulsifier to prepare a pre-emulsion;

[0045] 2) Dissolve part of the initiator in water to obtain the dropwise initiator; dissolve the remaining initiator in water to obtain the bottom initiator;

[0046] 3) Mix the remaining emulsifier with the remaining water and neutralizer and add it to the reactor. Stir thoroughly and heat to 80-90℃. Add part of the pre-emulsion and stir until uniform. Then add all the initiator from the bottom of the reactor and react for 10-20 minutes to obtain the seed emulsion.

[0047] 4) Control the temperature inside the reactor to 80-90℃, continue to add the remaining pre-emulsion and all the added initiator to the seed emulsion, add the material for 2-4 hours, and then keep warm for 20-60 minutes, such as 20, 40 or 60 minutes.

[0048] 5) Cool the reactor to 70-80℃ and gradually add the post-treatment agent into the reactor over 20-60 minutes, for example, 30, 40 or 50 minutes. The feeding time is 2-4 hours. Then keep it at the temperature for 30-60 minutes, for example, 40 or 50 minutes.

[0049] 6) Cool down to below 45℃, add pH adjuster to adjust the pH of the system to 7-9, strip at 55-80℃, filter and discharge.

[0050] In step 1) of the preparation method of the present invention, the amount of emulsifier added is 90-99.5% of the total mass of the emulsifier, such as 95% or 98%.

[0051] The amount of water added is 25-35% of the total water mass, such as 25wt%, 30wt%, or 35wt%.

[0052] In step 2) of the preparation method of the present invention, 25-50% (e.g., 35%, 40%, 45%) of the total mass of the initiator is mixed and dissolved with 1-6% (e.g., 2%, 4%, 6%) of the total mass of water to obtain a dropwise initiator; then the remaining initiator is mixed and dissolved with 1-6% (e.g., 2%, 4%, 6%) of the total mass of water to obtain a bottom-of-bottle initiator. In the above preparation process, the addition of the initiator is well known in the art, and it is added in two steps to prepare the dropwise initiator and the bottom-of-bottle initiator, for example, the ratio of the two additions can be 1:2-2:1, for example 1.5:1; this feeding method is a commonly used feeding method in the art, and will not be described in detail here.

[0053] In step 3) of the preparation method of the present invention, the mass of the pre-emulsion used to prepare the seed emulsion is 1-8% of the total mass of the pre-emulsion, for example, 2%, 4%, 5%, or 6%.

[0054] The present invention also provides an application of the acrylate emulsion described above in the preparation of coatings.

[0055] The acrylic emulsion of this invention has good film-forming effect and low MFFT even without the addition of film-forming aids. It has the advantages of excellent scrub resistance and freeze-thaw stability, low VOC content and good environmental performance, and is especially suitable for use in the field of building interior wall coatings.

[0056] The present invention prepares an acrylate emulsion with the following characteristics: solid content of 46-49%, pH of 7-9, emulsion particle size of 90-160 nm, and MFFT of 10-40 °C.

[0057] Compared with the prior art, the advantages of the technical solution of the present invention are as follows:

[0058] 1. By introducing maleic anhydride and reacting it with amine to generate two closely adjacent amide groups, the two amide bonds are fixed in adjacent positions and a strong hydrogen bond is formed. Through the cross-linking effect of hydrogen bond, the film-forming ability of the paint film is significantly improved, and the scrub resistance is also improved due to the cross-linking structure.

[0059] 2. Due to the formation of hydrogen bonds, a specific steric structure is formed between the amide bonds, which prevents the latex particles from being squeezed and broken at low temperatures, further improving the freeze-thaw resistance of the emulsion. Given that the freeze resistance in existing coatings is mainly obtained by introducing antifreeze agents, and antifreeze agents are the main source of VOCs in coatings, since the emulsion of this invention does not require the addition of antifreeze agents, the VOC content in the coating is further reduced.

[0060] 3. By using post-polymerization stripping, the residual VOC in the emulsion was reduced, further improving the odor level;

[0061] 4. The synthesis process is simple, easy to operate, low in cost, low in VOC content, and high in safety. Detailed Implementation

[0062] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0063] The raw materials used in the following embodiments are shown in Table 1. Unless otherwise specified, all other raw materials are common commercially available materials:

[0064] Table 1

[0065]

[0066] The following embodiments employ the following processing procedure:

[0067] Stripping: The emulsion is preheated to 55°C in a buffer vessel and then passed into a stripping tower for stripping (stripping temperature 55°C). The emulsion is fed from the top of the tower, while air and steam are fed from the bottom. The two feed countercurrently and mix rapidly for a short time. The steam and air, carrying VOC components, separate from the emulsion through the vacuum exhaust pipe, and the emulsion is discharged from the bottom. During stripping, the relative flow rates of air, steam, and emulsion are 1:0.5:10.

[0068] Odor Assessment (Smell Level): Odor was assessed based on olfactory perception. Ten participants were selected to evaluate the odor inside the polymer latex can. The assessment results were graded from 1 to 5, as shown in Table 2.

[0069] Table 2

[0070] Rank Unpleasant odour 5 None 4 Slight 3 Little 2 Moderate 1 Strong

[0071] Low-Temperature Cohesion Assessment (LTC): A putty was applied to an A4-sized high-density asbestos-free fiberboard. The substrate conformed to NAF (asbestos-free) standards in JC / T412.1-2006. After drying, the surface was sanded smooth. A film was then applied to the A4-sized putty board using a 400µm film-forming tool and immediately placed in a 3°C low-temperature chamber. After 4 hours, the surface cracking of the coating was observed and compared. The degree of cracking was rated from 1 to 5, as shown in Table 3.

[0072] Table 3

[0073] Severe Rank 5 Degree of cracking 4 None 3 Slight 2 Little 1 Moderate Strong Severe

[0074] Scrub resistance evaluation of paint film: The scrub resistance of the paint film was tested according to GB / T 9266-2009;

[0075] Freeze-thaw stability assessment: The freeze-thaw stability of latex paint was determined according to GB / T 9268-2008;

[0076] Formaldehyde purification efficiency assessment: The formaldehyde purification efficiency of the paint film was tested according to JC / T 1074-2008.

[0077]

Example 1

[0078] Preparation of acrylate emulsion:

[0079] 1) At room temperature and pressure, add 9.8g of emulsifier SDS, 10g of emulsifier SSS, and 480g of deionized water to an emulsification tank and stir thoroughly to dissolve. Then, add 180g of styrene (component e), 180g of maleic anhydride (component f), 180g of benzylamine (component h), 660g of BA (component a), 40g of AAEM (component b), 15g of AA (component c), 5g of A171 (component d), 100g of LMA (component g), and 2g of ethanol in sequence to prepare a pre-emulsion.

[0080] 2) Mix 1.6g of initiator APS with 40g of water thoroughly to obtain a dropwise initiator solution; mix the remaining 2.4g of initiator APS with 24g of water thoroughly to obtain a bottom initiator.

[0081] 3) Add the remaining 0.2g of emulsifier SDS, 900g of water, and 2g of sodium bicarbonate to the bottom of the reactor, stir thoroughly to dissolve, heat to 85℃, add 50g of pre-emulsion, and after stirring evenly, add all the initiator from the bottom of the reactor and react for 10 minutes to obtain the seed emulsion.

[0082] 4) Keep the seed emulsion temperature at 85℃, and add the remaining pre-emulsion and all the initiator dropwise over 4 hours, then keep warm for 20 minutes.

[0083] 5) After the heat preservation is completed, cool down to 75℃, and at the same time start adding 2.5g t-BHP and 40g 5% sodium bisulfate aqueous solution. Add for 2 hours, and then keep warm for about 30 minutes.

[0084] 6) Cool down to below 45°C, add 180g of pH adjuster diethylenetriamine to adjust the pH to about 8, then cool down to 55°C for stripping. After stripping, cool down to below 45°C and filter the material through a 100-mesh filter to obtain acrylate emulsion.

[0085] The prepared acrylate emulsion had a solid content of 48%, a pH of 7.6, a particle size of 143 nm, and an MFFT test result at 12 °C.

[0086] The prepared emulsion was used to prepare latex paint (coating) according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested.

[0087] Table 4

[0088]

[0089]

[0090] The test time for the interior wall testing items specified in GB / T 9756-2009 is superior to this national standard. See Table 5 for details.

[0091]

Example 2

[0092] Preparation of acrylate emulsion:

[0093] 1) At room temperature and pressure, 16.6g of emulsifier alcohol ether sulfosuccinate, 10.2g of emulsifier alkyl alcohol ether phosphate, and 480g of deionized water were added to an emulsification tank and stirred thoroughly to dissolve. Then, 580g of styrene (component e), 40g of maleic anhydride (component f), 246g of furfurylamine (component h), 273g of BA (component a), 23g of AAEM (component b), 60g of A174 (component d), 150g of LMA (component g), 67g of AA (component c), and 2g of ethanol were added sequentially and mixed to prepare a pre-emulsion.

[0094] 2) Mix 1.6g of potassium persulfate initiator with 80g of water thoroughly to obtain a dropwise initiator solution; mix the remaining 4.8g of potassium persulfate initiator with 80g of water thoroughly to obtain a bottom initiator.

[0095] 3) Add the remaining 0.2g of emulsifier alcohol ether sulfosuccinate, 900g of water and 4g of sodium bicarbonate to the bottom of the reactor, stir thoroughly to dissolve, heat to 85℃, add 50g of pre-emulsion, and after stirring evenly, add all the initiator from the bottom of the reactor and react for 10 minutes to obtain seed emulsion.

[0096] 4) Keep the seed emulsion temperature at 85℃, and add the remaining pre-emulsion and all the initiator dropwise. The initiator dropwise addition time is 3 hours, and then keep warm for 10 minutes.

[0097] 5) After the heat preservation is completed, cool down to 75℃, and at the same time start adding 4gt-BHP and 40g of 10% hydrogen peroxide solution. Add for 2 hours, and then keep warm for about 20 minutes.

[0098] 6) Cool down to below 45°C, add 180g of pH adjuster diethanolamine to adjust the pH to about 8.0, then cool down to 55°C for stripping. After stripping, cool down to below 45°C and filter the material through a 100-mesh filter to obtain acrylate emulsion.

[0099] The prepared emulsion had a solid content of 48%, a pH of 7.6, a particle size of 143 nm, and an MFFT test temperature of 26 °C.

[0100] Referring to Example 1, the prepared emulsion was used to prepare latex paint according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested.

[0101] The test time for the interior wall testing items specified in GB / T 9756-2009 is superior to this national standard. See Table 5 for details.

[0102]

Example 3

[0103] Preparation of acrylate emulsion:

[0104] 1) At room temperature and pressure, 39g of emulsifier alcohol ether sulfosuccinate, 1.2g of emulsifier alkyl alcohol ether phosphate, and 660g of deionized water were added to an emulsification tank and stirred thoroughly to dissolve. Then, 210g of styrene (component e), 200g of maleic anhydride (component f), 244g of furfurylamine (component h), 831g of BA (component a), 123g of AAEM (component b), 30g of A174 (component d), 450g of LMA (component g), 67g of AA (component c), and 2g of ethanol were added sequentially and mixed to prepare a pre-emulsion.

[0105] 2) Mix 4.9 g of potassium persulfate initiator with 80 g of water thoroughly to obtain a dropwise initiator solution; mix the remaining 7.1 g of potassium persulfate initiator with 48 g of water thoroughly to obtain a bottom initiator.

[0106] 3) Add the remaining 0.2g of emulsifier alcohol ether sulfosuccinate, 1600g of water and 4g of sodium bicarbonate to the bottom of the reactor, stir thoroughly to dissolve, heat to 85℃, add 50g of pre-emulsion, and after stirring evenly, add all the initiator from the bottom of the reactor and react for 10 minutes to obtain the seed emulsion.

[0107] 4) Keep the seed emulsion temperature at 85℃, and add the remaining pre-emulsion and all the initiator dropwise. The initiator dropwise addition time is 2 hours, and then keep warm for 10 minutes.

[0108] 5) After the heat preservation is completed, cool down to 75℃, and at the same time start adding 3gt-BHP and 40g of 10% hydrogen peroxide. Add for 2 hours, and then keep warm for about 20 minutes.

[0109] 6) Cool down to below 45°C, add 280g of pH adjuster diethanolamine to adjust the pH to about 7, then cool down to 55°C for stripping. After stripping, cool down to below 45°C and filter the material through a 100-mesh filter to obtain acrylate emulsion.

[0110] The prepared emulsion had a solid content of 48%, a pH of 7.2, a particle size of 140 nm, and was tested by MFFT at 15 °C.

[0111] Referring to Example 1, the prepared emulsion was used to prepare latex paint according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested.

[0112] The test time for the interior wall testing items specified in GB / T 9756-2009 is superior to this national standard. See Table 5 for details.

[0113]

Example 4

[0114] Preparation of acrylate emulsion:

[0115] Prepared according to the method and raw material dosage in Example 3, with the only difference being that component h is replaced with aniline, component b is replaced with AAAL, and component d is replaced with A171.

[0116] The prepared emulsion had a solid content of 48%, a pH of 8, a particle size of 140 nm, and was tested at 15 °C using MFFT.

[0117] The emulsion prepared in Example 1 was used to prepare latex paint according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested. The results are shown in Table 5.

[0118]

Example 5

[0119] Preparation of acrylate emulsion:

[0120] Prepared according to the method and raw material dosage in Example 3, with the only difference being that component h is replaced with phenylethylamine and component b is replaced with AAAL.

[0121] The prepared emulsion had a solid content of 48%, a pH of 8, a particle size of 130 nm, and an MFFT test temperature of 15 °C.

[0122] The emulsion prepared in Example 1 was used to prepare latex paint according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested. The results are shown in Table 5.

[0123] Comparative Example 1

[0124] Emulsion O was prepared according to the method and raw material dosage in Example 1, except that component f) maleic anhydride was replaced with acrylic acid. The final emulsion had a solid content of 48%, a pH of 8, a particle size of 150 nm, and an MFFT of 40 °C.

[0125] The prepared emulsion was used to prepare latex paint according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested. The results are shown in Table 5.

[0126] Comparative Example 2

[0127] Emulsion 1 was prepared according to the method and raw material dosage in Example 1, with the only difference being that the amine chain extender was replaced with sodium hydroxide. The final emulsion had a solid content of 48%, a pH of 7.5, a particle size of 120 nm, and an MFFT of 39°C.

[0128] The prepared emulsion was used to prepare latex paint according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested. The results are shown in Table 5.

[0129] Comparative Example 3

[0130] Emulsion 2 was prepared according to the method and raw material dosage in Example 1, with the only difference being that the amine chain extender was replaced with vinyl dianhydride. The final emulsion had a solid content of 48%, a pH of 7, a particle size of 130 nm, and an MFFT of 43 °C.

[0131] The prepared emulsion was used to prepare latex paint according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested. The results are shown in Table 5.

[0132] Comparative Example 4

[0133] Emulsion 3 was prepared according to the method and raw material dosage in Example 1, except that component a) butyl acrylate BA was not added, the final emulsion had a solid content of 45%, a pH of 8, a particle size of 130 nm, and an MFFT of 63 °C.

[0134] The prepared emulsion was used to prepare latex paint according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested. The results are shown in Table 5.

[0135] Comparative Example 5

[0136] Emulsion 4 was prepared according to the method and raw material dosage in Example 1, with the only difference being that the post-crosslinking monomer was placed at the bottom of the vessel. The final emulsion had a solid content of 48%, a pH of 7, a particle size of 110 nm, and an MFFT of 43 °C.

[0137] The prepared emulsion was used to prepare latex paint according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested. The results are shown in Table 5.

[0138] Comparative Example 6

[0139] Emulsion 5 was prepared according to the method and raw material dosage in Example 1, with the only difference being that component f) maleic anhydride was not added, the final emulsion had a solid content of 48%, a pH of 8, a particle size of 120 nm, and an MFFT of 40 °C.

[0140] The prepared emulsion was used to prepare latex paint according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested. The results are shown in Table 5.

[0141] Comparative Example 7

[0142] Emulsion 6 was prepared according to the method and raw material dosage in Example 1, with the only difference being that no component h) amine chain extender was added. The final emulsion had a solid content of 47%, a pH of 8.5, a particle size of 150 nm, and an MFFT of 40 °C.

[0143] The prepared emulsion was used to prepare latex paint according to the formula in Table 4, and the properties of the latex paint or paint film, such as scrub resistance, LTC, and freeze-thaw resistance, were tested. The results are shown in Table 5.

[0144] Table 5

[0145]

[0146] As shown in Table 5, the performance test results of the latex paint prepared by the emulsions obtained in Examples 1-5 all meet the requirements for children's room paints in GB / T34676-2017 Interior Wall Coatings for Children's Room Decoration, and the film-forming properties and freeze-thaw stability are significantly improved.

[0147] The test results above show that...

[0148] The specific sequence of hydrogen bonds in the formulation of this invention has a synergistic enhancing effect on the low-temperature film-forming properties, scrub resistance, and freeze-thaw stability of the emulsion, and the VOC content is low and the emulsion has a low odor.

[0149] The test results from the examples and comparative examples show that the scrubbing ability and freeze resistance of the emulsion were significantly improved by introducing maleic anhydride. However, after reducing the amount of maleic anhydride and post-crosslinking monomers required for the formation of the emulsion, the film-forming properties and freeze resistance of the coating were affected.

[0150] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. An acrylate emulsion, characterized in that, Prepared by emulsion polymerization from raw material components comprising the following mass percentages: a) 15-70% butyl acrylate; b) 1.3-10% of an ethylenically unsaturated monomer containing acetoacetate functional groups; c) 0.5-5% of an unsaturated hydrophilic monomer; d) 0.2-5% of a reactive silane coupling agent; e) 10-40% of styrene; f) 1-20% of maleic anhydride; g) 1-40% of other ethylenically unsaturated monomers; h) 10-20% of an amine-based post-crosslinking monomer; wherein the total mass of a), b), c), d), e), f), g), h) is 100%; said component c) is selected from one or more of unsaturated monomers having carboxyl, hydroxyl, amide, phosphate, ureido or phosphate salt hydrophilic groups; said component g) is selected from one or more of divinyl benzene, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, allyl methacrylate; said component h) is selected from one or more of aniline, furfuryl amine, benzyl amine, phenethyl amine and aniline derivatives; said method for preparing the acrylate emulsion comprises the following steps: 1) mixing component a), component b), component c), component d), component e), component f), component g), component h), part of the water, alcohol solvent, part of the emulsifier to prepare a pre-emulsion; 2) dissolving part of the initiator with part of the water to obtain a dropwise initiator; dissolving the remaining initiator with part of the water to obtain a bottom initiator; 3) mixing the remaining emulsifier with the remaining water and neutralizing agent, then adding into the reaction kettle, stirring thoroughly and then heating to 80-90°C; adding part of the pre-emulsion, stirring uniformly, then adding all the bottom initiator, reacting for 10-20 min to prepare a seed emulsion; 4) controlling the temperature in the reaction kettle at 80-90°C, continuing to add the remaining pre-emulsion and all the dropwise initiator to the seed emulsion, adding for 2-4 h, then maintaining for 20-60 min; 5) cooling the reaction kettle to 70-80°C, then gradually adding the post-treatment agent to the reaction kettle within 20-60 min, adding for 2-4 h, then maintaining for 30-60 min; 6) cooling to below 45°C, adding a pH adjusting agent to adjust the pH of the system to 7-9, stripping at 55-85°C, and filtering the product; in step 1), the amount of emulsifier added is 90-99.5% of the total mass of the emulsifier; the amount of water added is 25-35% of the total mass of the water; in step 2), 25-50% of the total mass of the initiator is dissolved with 1-6% of the total mass of the water to obtain a dropwise initiator; then the remaining initiator is dissolved with 1-6% of the total mass of the water to obtain a bottom initiator; in step 3), the mass of the pre-emulsion used to prepare the seed emulsion is 1-8% of the total mass of the pre-emulsion.

2. The acrylate emulsion according to claim 1, characterized in that, Prepared by emulsion polymerization from raw material components comprising the following mass percentages: a) 40-60% butyl acrylate; b) 2-4% of an ethylenically unsaturated monomer containing acetoacetate functional groups; c) 2-5% of an unsaturated hydrophilic monomer; d) 0.5-2% of a reactive silane coupling agent; e) 10-30% of styrene; f) 10-15% of maleic anhydride; g) 20-30% of other ethylenically unsaturated monomers; h) 10-15% of amine-based post-crosslinking monomers; wherein the total weight of a), b), c), d), e), f), g), h) is 100%.

3. The acrylate emulsion according to claim 1, characterized in that, The component b) is selected from one or more of acetoacetoxy (meth) acrylate, acetoacetoxy propoxy (meth) acrylate, acetoacetoxy butoxy (meth) acrylate, acetoacetyl vinyl ester, acetoacetyl allyl ester.

4. The acrylate emulsion according to claim 3, characterized in that, The component b) is selected from one or more of acetoacetoxy (meth) acrylate, acetoacetyl allyl ester.

5. The acrylate emulsion according to claim 1, characterized in that, The component c) is selected from one or more of acrylic acid, methacrylic acid, hydroxyethyl acrylate, acrylamide, methacrylamide ethyl ethylene urea, vinyl alkoxyl phosphate, sodium 2-acrylamido-2-methylpropane sulfonate.

6. The acrylate emulsion according to claim 1, characterized in that, The component d) is selected from one or more of vinyl silane coupling agent, epoxy silane coupling agent.

7. The acrylate emulsion according to claim 6, characterized in that, The component d) is selected from one or more of vinyl trimethoxysilane, gamma-methacryloyloxy propyl trimethoxysilane, gamma-glycidoxy propyl trimethoxysilane.

8. The acrylate emulsion according to claim 1, characterized in that, The raw materials for preparation also optionally include emulsifiers, initiators, alcohol solvents, water, post-treatment agents, pH adjusters; The emulsifiers are selected from one or more of sodium dodecyl sulfate, sodium p-styrene sulfonate, sodium dodecyl benzene sulfonate, alcohol ether sulfosuccinate, alkyl alcohol ether sulfate, alkyl alcohol ether phosphate; The initiators are selected from one or more of sodium persulfate, potassium persulfate, ammonium persulfate; The neutralizing agents are selected from one or more of sodium bicarbonate, diethylene triamine, diethanol amine, ethanol amine; The post-treatment agents include oxidizing agents and / or reducing agents, the oxidizing agents are selected from one or more of tert-butyl peroxide, hydrogen peroxide, sodium persulfate, potassium persulfate, ammonium persulfate; the reducing agents are selected from one or more of sodium bisulfite, sodium metabisulfite, vitamin C; The pH adjusters are selected from one or more of diethylene triamine, diethanol amine, ethanol amine; The alcohol solvents are selected from one or more of ethanol, n-butanol, isobutanol.

9. The acrylate emulsion according to claim 8, characterized in that, The total amount of the emulsifiers is 1-5% of the total mass of components a)-h).

10. The acrylate emulsion according to claim 9, characterized in that, The total amount of the emulsifiers is 1-2% of the total mass of components a)-h).

11. The acrylate emulsion according to claim 8, characterized in that, The total amount of the initiators is 0.2-0.6% of the total mass of components a)-h).

12. The acrylate emulsion according to claim 11, characterized in that, The total amount of the initiators is 0.2-0.4% of the total mass of components a)-h).

13. The acrylate emulsion according to claim 8, characterized in that, The amount of the neutralizing agents is 0.1-4% of the total mass of monomer components a)-h).

14. The acrylate emulsion according to claim 13, characterized in that, The amount of the neutralizing agents is 0.1-0.3% of the total mass of monomer components a)-h).

15. The acrylate emulsion according to claim 8, characterized in that, The total amount of the post-treatment agents is 0.15-0.6% of the total mass of components a)-h).

16. The acrylate emulsion according to claim 15, characterized in that, The total amount of the post-treatment agents is 0.2-0.4% of the total mass of components a)-h).

17. The acrylate emulsion according to claim 8, characterized in that, The end point of the amount of the pH adjusters added is adjusted to a pH of 7-9.

18. The acrylate emulsion according to claim 8, characterized in that, The total amount of the alcohol solvents is 0.01-0.5% of the total mass of monomer components a)-h).

19. The acrylate emulsion according to claim 18, characterized in that, The total amount of the alcohol solvent is 0.01-0.3% of the total mass of monomer components a)-h).

20. The acrylate emulsion of claim 8, wherein, The total amount of water is 1-1.5 times the total mass of components a)-h).

21. The acrylate emulsion according to claim 20, characterized in that, The total amount of water is 1-1.3 times the total mass of components a)-h).

22. A process for the preparation of the acrylate emulsion according to any one of claims 1 to 21, characterized in that, The method comprises the following steps: 1) mixing component a), component b), component c), component d), component e), component f), component g), component h), part of water, alcohol solvent, and part of emulsifier to prepare a pre-emulsion; 2) dissolving part of the initiator in part of water to obtain a dropwise added initiator, and dissolving the remaining initiator in part of water to obtain a bottom initiator; 3) mixing the remaining emulsifier with the remaining water and neutralizing agent, and then adding them into a reaction kettle, and then stirring thoroughly and heating to 80-90°C; adding part of the pre-emulsion, and then stirring uniformly, and then adding all of the bottom initiator, and then reacting for 10-20 min to prepare a seed emulsion; 4) controlling the temperature in the reaction kettle to be 80-90°C, and then continuously adding the remaining pre-emulsion and all of the dropwise added initiator into the seed emulsion, and then adding for 2-4 h, and then maintaining the temperature for 20-60 min; 5) cooling the reaction kettle to 70-80°C, and then gradually adding the post-treatment agent into the reaction kettle within 20-60 min, and then adding for 2-4 h, and then maintaining the temperature for 30-60 min; 6) cooling to below 45°C, and then adding a pH adjusting agent to adjust the pH of the system to 7-9, and then stripping at 55-85°C, and then filtering the product.

23. The method of claim 22, wherein, In step 1), the amount of the emulsifier added is 90-99.5% of the total mass of the emulsifier; and the amount of water added is 25-35% of the total mass of water. In step 2), 25-50% of the total mass of the initiator is mixed and dissolved with 1-6% of the total mass of water to obtain the dropwise added initiator; and then the remaining initiator is mixed and dissolved with 1-6% of the total mass of water to obtain the bottom initiator. In step 3), the mass of the pre-emulsion used to prepare the seed emulsion is 1-8% of the total mass of the pre-emulsion.

24. Use of the acrylate emulsion of any one of claims 1-21 or the acrylate emulsion prepared by the method of claim 22 or 23 in a coating.

Images