Odor-removing formaldehyde-absorbing pure acrylic emulsion as well as raw material composition, preparation method and application thereof

Abstract

The invention discloses an odorless formaldehyde-absorbing pure acrylic emulsion as well as a raw material composition, a preparation method and application thereof. The odorless formaldehyde-absorbing pure acrylic emulsion comprises the following components in parts by weight: 173-301 parts of a monomer, 20-26 parts of an emulsifier, 2.8-4.1 parts of an initiator and 10-30 parts of a multifunctional monomer, wherein the multifunctional monomer is selected from acetoacetoxyethyl methacrylate and / or adipic acid dihydrazide. The preparation method comprises the following steps: selecting a specific emulsifier and a multifunctional monomer methylacrylic acid acetoacetoxyethyl ester and / or adipic acid dihydrazide with a formaldehyde absorption function; meanwhile, more methyl methacrylate monomers are used, the methyl methacrylate monomers are difficult to hydrolyze in the polymerization process to produce methanol, then a specific dropwise adding reaction process strategy is combined, and finally oxidation-reduction post-treatment and steam stripping process treatment are performed, so that the odor of the emulsion is further reduced, and the prepared emulsion is ultralow in VOC (volatile organic compound) and residual monomer content. The pure acrylic emulsion has an excellent formaldehyde absorption effect and is durable.

Description

Technical Field

[0001] The invention belongs to the technical field of pure acrylic emulsion preparation, and specifically relates to a pure acrylic emulsion with no odor and formaldehyde absorption, a raw material composition thereof, and a preparation method and application thereof. Background Art

[0002] With the improvement of living standards, people have higher and higher requirements for living environment. Traditional oil-based paints can no longer meet people's needs for odor-free and environmentally friendly paints, and have gradually been replaced by water-based paints on the market. One of the important components of water-based paints is acrylate polymers and their modified polymers. The paints prepared entirely with acrylates as raw materials are pure acrylic emulsions. Most of the commonly used pure acrylic emulsions on the market have high VOC content. When they are configured as architectural paints for indoor use, they will cause high VOC content and strong odor indoors, which will have a serious impact on human health and also cause environmental pollution. In addition, indoor home decoration will continue to release toxic formaldehyde, which is extremely harmful to the human body. Therefore, the market urgently needs to develop a pure acrylic emulsion that is odor-free and absorbs formaldehyde. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a pure acrylic emulsion with odor-free and formaldehyde-absorbing properties, a raw material composition thereof, a preparation method thereof and an application thereof. The pure acrylic emulsion with odor-free and formaldehyde-absorbing properties has ultra-low VOC and residual monomer content, and has excellent formaldehyde-absorbing effect and durability.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0005] In one aspect, the present invention provides a raw material composition of a pure acrylic emulsion for odorless formaldehyde absorption, which comprises the following components in parts by weight: 173 to 301 parts of a monomer, 20 to 26 parts of an emulsifier, 2.8 to 4.1 parts of an initiator, and 10 to 30 parts of a multifunctional monomer;

[0006] Wherein, the multifunctional monomer is selected from acetoacetoxyethyl methacrylate and / or adipic acid dihydrazide.

[0007] In some embodiments, the monomers include 2 to 6 parts of methacrylic acid, 90 to 130 parts of butyl acrylate, 0 to 40 parts of isooctyl acrylate, 80 to 120 parts of methyl methacrylate, and 1 to 5 parts of a silane coupling agent monomer;

[0008] In some embodiments, the emulsifier includes an anionic emulsifier and a nonionic emulsifier;

[0009] In some embodiments, the initiator is selected from one of sodium persulfate, ammonium persulfate, and potassium persulfate.

[0010] In some embodiments, the silane coupling agent monomer is selected from at least one of vinyl trimethoxy silane, vinyl triethoxy silane or gamma-glycidoxypropyl trimethoxy silane;

[0011] In some embodiments, the anionic emulsifier is an APEO-free sulfonate emulsifier selected from sodium dodecylbenzene sulfonate, such as BASF's LDBS-23 emulsifier;

[0012] In some embodiments, the nonionic emulsifier is a water-soluble fatty alcohol ethoxylate emulsifier that does not contain APEO and has an HLB value of 13 to 15, for example, Clariant emulsifier Emulsogen LCN 118;

[0013] This application has specially screened the emulsifier, taking into account the environmental protection of the emulsifier itself, while considering the full progress of the monomer polymerization reaction and the performance of the emulsion. On the one hand, the anionic emulsifier adopts a sulfonate emulsifier that does not contain APEO, and specifically selects branched alkyl alcohol ether sulfonate, such as BASF's LDBS-23 emulsifier. This emulsifier can provide excellent wetting and dispersibility, and can make each monomer fully dispersed, especially after compounding with a silane coupling agent, it is helpful for the polymerization and greatly reduces residual monomers. On the other hand, the non-ionic emulsifier adopts a water-soluble fatty alcohol ethoxylate emulsifier that does not contain APEO, and the HLB value is 13 to 15. For example, Clariant's emulsifier Emulsogen LCN118 is used. This type of emulsifier improves the stability of the emulsion through emulsification, dispersion, surface activity and volatility control. For example, it can form hydrogen bonds or other interaction forces with VOC molecules to slow down the volatilization rate of VOC.

[0014] In some embodiments, the weight percentage of the anionic emulsifier is 18 to 22 parts;

[0015] In some embodiments, the weight proportion of the nonionic emulsifier is 2 to 4 parts;

[0016] In some embodiments, the raw material composition of the odorless formaldehyde-absorbing pure acrylic emulsion further includes 400 to 600 parts of water;

[0017] In some embodiments, the raw material composition of the odorless formaldehyde-absorbing pure acrylic emulsion further includes 1 to 4 parts of an oxidant;

[0018] In some embodiments, the raw material composition of the odorless formaldehyde-absorbing pure acrylic emulsion further includes 0.5 to 2 parts of a reducing agent.

[0019] In some embodiments, the oxidant is tert-butyl hydroperoxide or hydrogen peroxide;

[0020] In some embodiments, the reducing agent is VCNa and / or VC.

[0021] In another aspect, the present invention provides a method for preparing a pure acrylic emulsion with a clean odor and formaldehyde absorption, which at least comprises:

[0022] (1) mixing water and part of the emulsifier, adding the monomer, the multifunctional monomer and the initial initiator and stirring to obtain a pre-emulsion;

[0023] (2) mixing water and remaining emulsifier in a reaction kettle to obtain a bottom material;

[0024] (3) When the temperature in the reactor rises to 83-84° C., a reaction initiator is added, and the pre-emulsion is dripped, and the dripping speed of the pre-emulsion is controlled. In the initial stage of the reaction, the dripping speed is 1.5-2.5 times that of the stable stage of the reaction, and then the pre-emulsion is dripped at a uniform speed;

[0025] (4) After the reaction is completed, a post-initiator is added dropwise, and then a redox agent is added dropwise for post-treatment.

[0026] The dripping process of the present application is a key step. Compared with the seed emulsion method, the present application adds the reaction initiator to the bottom material of the kettle at one time, and then drips the pre-emulsion. The reaction is first carried out at a dripping speed of 1.5 to 2.5 times that of the reaction stabilization stage, and more preferably at a dripping speed of 2 times. Under this condition, the pre-emulsion containing each monomer raw material begins to gradually polymerize in the reactor to form micelles. In the initial stage of the reaction, the dripping speed increases, and micelles can be quickly formed in a shorter time, increasing the contact frequency between the surfactant molecules and the oil phase or the water phase, reducing the aggregation and deposition of oil droplets, accelerating the mixing and reaction rate of the reactants, promoting the progress of the chemical reaction, and helping to form more cross-linked or gel structures in the early stage. At the same time, the oil droplets in the emulsion are more uniform and fine, and the fine oil droplets have a larger surface area, which better interacts with the surfactant and enhances the stability of the emulsion. Then, the dripping speed is reduced until the stable reaction ends, and finally the synthesis of the emulsion is controlled, which helps the stable polymerization of each monomer, helps to reduce residual monomers, and improves the scrub resistance of the emulsion.

[0027] In addition, the present application finally utilizes the effects of oxidants and reductants to undergo redox reactions with organic matter in the emulsion, thereby decomposing the organic matter into smaller molecules, reducing volatility and residues, and the redox post-treatment helps to eliminate or reduce the odor in the emulsion by degrading the organic matter. After reducing the content of organic matter, the long-term stability of the emulsion is improved.

[0028] In step (1), the amount of the emulsifier is 40-70% of the total amount of the emulsifier;

[0029] In step (1), the weight proportion of water is 180 to 220 parts;

[0030] In step (1), the mixing time is 10 to 20 minutes;

[0031] In step (1), the amount of the initially added initiator is 40 to 70% of the total amount of the initiator;

[0032] In step (1), the stirring time is 20 to 60 minutes;

[0033] In step (2), the weight proportion of water is 280 to 320 parts;

[0034] In step (2), the mixing time is 10 to 20 minutes;

[0035] In step (3), the amount of the reaction initiator is 30-60% of the total amount of the initiator;

[0036] In step (3), the dropping time is 3 to 4 hours;

[0037] In step (3), the dropping temperature is 83-85°C;

[0038] In step (3), the initial reaction time is 15 to 25 minutes, preferably, the initial reaction time is 20 minutes;

[0039] After step (4), step (5) of stripping treatment is further performed, specifically: stripping is performed at a temperature of 50 to 60° C. and a pressure of -70 to -90 KPa.

[0040] After step (5), the temperature is lowered to below 45° C., the material is filtered through a 200-mesh filter cloth, and the pH is adjusted to 7-9 with liquid alkali.

[0041] The initially added initiator, the reaction initiator and the later added initiator are all added in the form of aqueous solution.

[0042] The third aspect of the present invention further provides a pure acrylic emulsion with a clean taste and formaldehyde absorption, which is prepared by the above-mentioned method for preparing the pure acrylic emulsion with a clean taste and formaldehyde absorption.

[0043] The fourth aspect of the present invention also provides a use of the above-mentioned odorless formaldehyde-absorbing pure acrylic emulsion in indoor furniture decoration.

[0044] The reagents and raw materials used in the present invention are commercially available.

[0045] The positive and progressive effects of the present invention are:

[0046] The present invention selects a specific emulsifier and a multifunctional monomer, and the multifunctional monomer is acetoacetoxyethyl methacrylate and / or adipic acid dihydrazide, which has the function of absorbing formaldehyde. At the same time, the preparation process of the pure acrylic emulsion of the present invention uses a large amount of methyl methacrylate monomer, which is difficult to hydrolyze to produce methanol during the polymerization process. Combined with a specific drop reaction process strategy, the odor of the emulsion is further reduced through redox post-treatment and stripping process treatment, and ultra-low VOC and residual monomer content are prepared, and the pure acrylic emulsion with excellent formaldehyde absorption effect and long-lasting odor-free formaldehyde absorption is obtained. DETAILED DESCRIPTION

[0047] The present invention is described in detail below in conjunction with the embodiments, and the technical scheme of the present invention is clearly and completely described to facilitate the understanding of the present invention by those skilled in the art. The described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. At the same time, the raw materials mentioned below that are not described in detail are all commercially available products; the process steps or preparation methods not mentioned in detail are process steps or preparation methods known to those skilled in the art.

[0048] The present invention provides a method for preparing a pure acrylic emulsion with a clean taste and formaldehyde absorption, comprising the following steps:

[0049] a) Prepare a pre-emulsion: weigh 200 parts of deionized water, 9-11 parts of BASF's LDBS-23 emulsifier, 1-2 parts of Clariant's emulsifier Emulsogen LCN 118, stir for 10-20 minutes, add 2-6 parts of methacrylic acid, 90-130 parts of butyl acrylate, 0-40 parts of isooctyl acrylate, 80-120 parts of methyl methacrylate, 1-5 parts of silane coupling agent, 10-30 parts of multifunctional monomer, 1.5-2 parts of sodium persulfate solution (1 part of sodium persulfate is dissolved in every 10 parts of water), stir to obtain a pre-emulsion.

[0050] b) Prepare the bottom material of the kettle: weigh 300 parts of deionized water, 9 to 11 parts of BASF's LDBS-23 emulsifier and 1 to 2 parts of Clariant's emulsifier Emulsogen LCN 118, and stir for 10 to 20 minutes.

[0051] c) When the temperature in the autoclave rises to 83-84°C, add 1-1.5 parts of sodium persulfate solution (1 part of sodium persulfate is dissolved in every 10 parts of water), and at the same time, add the pre-emulsified solution dropwise. The total dropwise addition time is 3-4 hours. In the first 15-25 minutes, the dropwise addition speed is twice that of the reaction stabilization stage, and then the dropwise addition speed is uniform. The reaction temperature is controlled at 83-85°C.

[0052] d) After the addition is completed, continue to add an appropriate amount of post-initiator 0.3-0.6 parts of sodium persulfate solution (1 part of sodium persulfate is dissolved in every 10 parts of water) for 0.5-1.5 hours, and keep warm for 0.5-1.5 hours. After the insulation is completed, cool to 65-75°C, and at the same time, add an appropriate amount of hydrogen peroxide 1-4 parts of solution (2 parts of H2O2 are dissolved in every 15 parts of water) and an appropriate amount of vitamin C solution 0.5-2 parts (1 part of VC is dissolved in every 15 parts of water) for 0.5-1.5 hours. Keep warm for 0.5-1.5 hours.

[0053] e) After the insulation is completed, steam stripping is carried out at a temperature of 50-60°C and a pressure of -70 to -90Kpa for about 3-5 hours, the temperature is lowered to below 45°C, the material is filtered through a 200-mesh filter cloth, and the pH is adjusted to 7-9 with liquid alkali to obtain a pure propylene emulsion with no odor and formaldehyde absorption.

[0054] The following are specific examples.

[0055] Example 1

[0056] Preparation of odorless formaldehyde absorbing pure acrylic emulsion, the raw material formula is shown in Table 1, and the specific steps are as follows:

[0057] a) Preparing a pre-emulsion, weighing 200 g of deionized water, 10 g of BASF's LDBS-23 emulsifier, and 1.5 g of Clariant's emulsifier Emulsogen LCN 118, stirring for 15 minutes, adding 5 g of methacrylic acid, 100 g of butyl acrylate, 20 g of isooctyl acrylate, 110 g of methyl methacrylate, 4 g of silane coupling agent A-171, 20 g of acetoacetoxyethyl methacrylate, and 1.8 g of sodium persulfate to prepare a solution, stirring for 30 minutes to obtain a pre-emulsion.

[0058] b) Prepare the bottom material of the kettle: weigh 300 g of deionized water, 10 g of BASF's LDBS-23 emulsifier and 1.5 g of Clariant's emulsifier Emulsogen LCN 118, and stir for 10 minutes.

[0059] c) When the temperature in the autoclave rises to 84°C, add 1.2 g of sodium persulfate to prepare the solution, and at the same time, drop the pre-emulsified liquid. The total dropwise addition time is 3.5 hours. In the first 20 minutes, the dropwise addition speed is twice that of the reaction stabilization stage, and then the dropwise addition speed is uniform. The reaction temperature is controlled at 83-85°C.

[0060] d) After the addition is completed, 0.5 g of sodium persulfate as the initiator is continued to be added dropwise for 1 hour and kept warm for 1 hour. After the insulation is completed, the temperature is lowered to 70° C., and 2 g of hydrogen peroxide solution and 1 g of vitamin C solution are added dropwise at the same time. The addition time is 1 hour and the temperature is kept warm for 1 hour.

[0061] e) After the insulation is completed, steam stripping is carried out at a temperature of 60°C and a pressure of -70Kpa for about 3 hours, the temperature is lowered to below 45°C, the material is filtered through a 200-mesh filter cloth, and the pH is adjusted to 7-9 with liquid alkali to obtain a pure propylene emulsion with no odor and formaldehyde absorption.

[0062] Example 2

[0063] The preparation of the odorless formaldehyde-absorbing pure acrylic emulsion, the raw material formula is shown in Table 1, and the preparation method is the same as that in Example 1.

[0064] The specific steps are:

[0065] a) Pre-emulsion was prepared by weighing 180 g of deionized water, 9 g of BASF's LDBS-23 emulsifier, and 1 g of Clariant's emulsifier Emulsogen LCN 118, stirring for 15 minutes, adding 2 g of methacrylic acid, 90 g of butyl acrylate, 120 g of methyl methacrylate, 1 g of silane coupling agent A-171, 10 g of acetoacetoxyethyl methacrylate, and 1.5 g of sodium persulfate to prepare a solution, stirring for 30 minutes to obtain a pre-emulsion.

[0066] b) Prepare the bottom material of the kettle: weigh 320 g of deionized water, 11 g of BASF's LDBS-23 emulsifier and 2 g of Clariant's emulsifier Emulsogen LCN 118, and stir for 10 minutes.

[0067] c) When the temperature in the autoclave rises to 84°C, add 1g of sodium persulfate to prepare the solution, and at the same time, add the pre-emulsified liquid dropwise. The total dropping time is 3.5h. In the first 20min, the dropping speed is twice that of the reaction stabilization stage, and then the dropping speed is uniform. The reaction temperature is controlled at 83-85°C.

[0068] d) After the addition is completed, continue to add 0.3g of sodium persulfate solution as the rear initiator, the addition time is 1 hour, and keep warm for 1 hour. After the insulation is completed, cool to 70°C, and simultaneously add 1g of hydrogen peroxide solution and 0.5g of vitamin C solution (1g VC dissolved in 15g of water), the addition time is 1 hour and keep warm for 1 hour.

[0069] e) After the insulation is completed, steam stripping is carried out at a temperature of 55°C and a pressure of -80Kpa for about 4 hours, the temperature is lowered to below 45°C, the material is filtered through a 200-mesh filter cloth, and the pH is adjusted to 7-9 with liquid alkali to obtain a pure propylene emulsion with no odor and formaldehyde absorption.

[0070] Example 3

[0071] The preparation of the odorless formaldehyde-absorbing pure acrylic emulsion, the raw material formula is shown in Table 1, and the preparation method is the same as that in Example 1.

[0072] The specific steps are:

[0073] a) Preparing a pre-emulsion, weighing 220 g of deionized water, 11 g of BASF's LDBS-23 emulsifier, and 2 g of Clariant's emulsifier Emulsogen LCN 118, stirring for 15 minutes, adding 6 g of methacrylic acid, 130 g of butyl acrylate, 40 g of isooctyl acrylate, 80 g of methyl methacrylate, 5 g of silane coupling agent A-171, 30 g of acetoacetoxyethyl methacrylate, and 2 g of sodium persulfate to prepare a solution, stirring for 30 minutes to obtain a pre-emulsion.

[0074] b) Prepare the bottom material of the kettle by weighing 280 g of deionized water, 9 g of BASF's LDBS-23 emulsifier and 1 g of Clariant's emulsifier Emulsogen LCN 118, and stirring for 10 minutes.

[0075] c) When the temperature in the autoclave rises to 84°C, add 1.5 g of sodium persulfate to prepare the solution, and at the same time, add the pre-emulsified liquid dropwise. The total dropping time is 3.5 hours. In the first 20 minutes, the dropping speed is twice that of the reaction stabilization stage, and then the dropping speed is uniform. The reaction temperature is controlled at 83-85°C.

[0076] d) After the addition is completed, 0.6 g of sodium persulfate as the rear initiator is continued to be added dropwise for 1 hour and the mixture is kept warm for 1 hour. After the warming is completed, the temperature is lowered to 70° C. and 4 g of hydrogen peroxide solution and 2 g of vitamin C solution are added dropwise at the same time. The addition time is 1 hour and the mixture is kept warm for 1 hour.

[0077] e) After the insulation is completed, steam stripping is carried out at a temperature of 50°C and a pressure of -90Kpa for about 5 hours, the temperature is lowered to below 45°C, the material is filtered through a 200-mesh filter cloth, and the pH is adjusted to 7-9 with liquid alkali to obtain a pure propylene emulsion with no odor and formaldehyde absorption.

[0078] Table 1 Examples 1 to 3 Pure Acrylic Emulsion Formula (Unit: g)

[0079]

[0080]

[0081] The present invention also provides the following comparative examples.

[0082] Comparative Example 1

[0083] With reference to Example 1, the type of emulsifier was changed, LDBS-23 emulsifier was replaced by Solvay's A102 emulsifier, and emulsifier LCN 118 was replaced by Clariant 1309. The rest was the same as Example 1.

[0084] Comparative Example 2

[0085] With reference to Example 1, the seed emulsion method was adopted for preparation, that is, in step c), about 5% by weight of the pre-emulsion was first added to the reactor for reaction, and then the remaining pre-emulsion was added dropwise, and the rest was the same as in Example 1.

[0086] Comparative Example 3

[0087] Taking Example 1 as a reference, in step e), no stripping process operation is performed, and the rest is the same as Example 1.

[0088] Comparative Example 4

[0089] Taking Example 1 as a reference, no multifunctional monomer was added. The rest was the same as Example 1.

[0090] Comparative Example 5

[0091] Taking Example 1 as a reference, acetoacetoxyethyl methacrylate was replaced by glycidyl methacrylate, and the rest was the same as Example 1.

[0092] Comparative Example 6

[0093] With reference to Example 1, the types of macromonomers were changed: the hard monomer methyl methacrylate was replaced by styrene and the amount was kept unchanged; the soft monomer isooctyl acrylate was replaced by butyl acrylate and the amount was kept unchanged, and the rest were the same as Example 1.

[0094] Product performance testing

[0095] The products prepared in the examples and comparative examples were tested, and the test standards or methods were as follows:

[0096] 1. Solid content: Tested according to 4.3 of GB / T 20623-2006.

[0097] 2. Viscosity: The test was conducted using Brookfield LV 25°C, 2#, 60rpm.

[0098] 3. Residual order: measured according to Appendix A of GB / T 20623-2006.

[0099] 4. VOC: The test is carried out according to the standard GB / T 18582-2020.

[0100] 5. The specific method for evaluating the odor level is as follows: put the lotion in a clean frosted wide-mouth bottle, with the liquid level at half the height of the bottle body, cover it with a glass cover, and let it stand for 24 hours. Five odor assessors will evaluate the odor intensity level. The odor intensity level is divided into 0-5 levels, with 0 being no odor. Level 1 is perceptible, no disturbing odor, and slight intensity. Level 2 is clearly perceptible, no disturbing odor, and medium intensity. Level 3 is clearly perceptible, with disturbing odor and greater intensity. Level 4 is clearly perceptible, with strong disturbing odor and great intensity. Level 5 is unbearable odor.

[0101] 6. Scrub resistance test: The emulsion is used to prepare interior wall latex paint. The specific formula of the interior wall latex paint is shown in Table 2. The emulsion addition amount is 9%. The scrub resistance of the interior wall latex paint is tested according to standard GB / T 9756-2018.

[0102] 7. Formaldehyde absorption efficiency and formaldehyde absorption persistence: The detection method is implemented in accordance with standard JC / T 1074-2021.

[0103] Table 2 Composition of interior wall latex paint

[0104] Components specific ingredients Percentage Pure acrylic emulsion Emulsion obtained in the embodiment / comparative example 90 Wetting Agents Dow X-405 1.5 antifreeze Sinopec Propylene Glycol 8 Multifunctional Conditioner Dow AMP-95 1.5 Powder Titanium dioxide 50 Powder Kaolin 100 Powder talcum powder 50 Powder Heavy Calcium 300 Defoaming agent Nopco NXZ 2.5 Film-forming aids Eastman alcohol ester 12 12 Thickener Rohm and Haas Alesun RM-8W 1 Fungicides Rohm and Haas LXE 1.5 water Deionized water 38

[0105] Function tests were performed on the products prepared in Examples 1 to 3 and Comparative Examples 1 to 6. The results are shown in Tables 3 and 4.

[0106] Table 3 Performance test results

[0107]

[0108]

[0109] Table 4 Performance test results

[0110] Test items Residuals / ppm VOC / ppm Odor level Scrub resistance / number of times Example 1 32 980 0 1521 Example 2 44 1190 0 1434 Example 3 38 1060 0 1482 Comparative Example 1 58 1410 2 1236 Comparative Example 2 65 1490 2 1189 Comparative Example 3 72 2470 4 1375 Comparative Example 4 36 1020 0 1502 Comparative Example 5 81 1640 3 1688 Comparative Example 6 383 1330 4 1214

[0111] As can be seen from Table 3, the odorless formaldehyde-absorbing pure acrylic emulsion obtained in the embodiment of the present invention has suitable solid content and viscosity, and the VOC content and residual formaldehyde content are relatively low. The VOC content is reduced to below 1200ppm, and the total residual formaldehyde content is reduced to below 50ppm. The emulsion reaches a level of odorlessness (or slightly perceptible), meeting the requirements of high-quality emulsions. At the same time, after being used in the preparation of interior wall latex paint, it has excellent scrub resistance and excellent formaldehyde absorption efficiency and durability.

[0112] The effects of the products obtained in the comparative examples are not as good as those in the embodiments, and the results are not ideal.

[0113] Compared with the examples, the type of emulsifier was changed in comparative example 1, and the prepared emulsion had a solid content of 48.2%, a viscosity of 289, a residual monomer of 58 ppm, a VOC of 1410 ppm, and an odor level of 2.

[0114] Comparative Example 2 was prepared by the seed emulsion method. The prepared emulsion had a solid content of 48.2%, a viscosity of 386, a residual monomer of 65 ppm, a VOC of 1490 ppm, an odor level of 2, and an odor level of 2.

[0115] In Comparative Example 3, no steam stripping process was performed, and the prepared emulsion had a solid content of 48.2%, a viscosity of 364, a residual monomer of 72 ppm, a VOC of 2470 ppm, and an odor level of 4.

[0116] In Comparative Example 4, no multifunctional monomer was added, and the prepared emulsion had a solid content of 48.2%, a viscosity of 362, a formaldehyde absorption efficiency of 0 (and the emulsion itself contained 5 ppm of formaldehyde), and a formaldehyde absorption durability of 0.

[0117] In Comparative Example 5, the type of multifunctional monomer was changed, and the prepared emulsion had a solid content of 48.2%, a viscosity of 368, a formaldehyde absorption efficiency of 0 (and the emulsion itself contained 5 ppm of formaldehyde), and a formaldehyde absorption durability of 0.

[0118] In Comparative Example 6, the type of macromonomer was changed, and the prepared emulsion had a solid content of 48.2%, a viscosity of 624, a residual monomer of 383 ppm, a VOC of 1330 ppm, and an odor level of 4.

[0119] Finally, it should be noted that in the present invention, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also includes other elements that are not explicitly listed, or also includes elements that are inherent to such process, method, article or apparatus.

[0120] Although the present disclosure has been disclosed above through the description of the specific embodiments of the present disclosure, it should be understood that those skilled in the art can design various modifications, improvements or equivalents to the present disclosure within the spirit and scope of the attached scheme. These modifications, improvements or equivalents should also be considered to be included in the scope of protection claimed by the present disclosure.

Claims

1. A raw material composition of a pure acrylic emulsion with a clean taste and formaldehyde absorption, characterized in that: The invention comprises the following components in parts by weight: 173 to 301 parts of monomer, 20 to 26 parts of emulsifier, 2.8 to 4.1 parts of initiator and 10 to 30 parts of multifunctional monomer; Wherein, the multifunctional monomer is selected from acetoacetoxyethyl methacrylate and / or adipic acid dihydrazide.

2. The raw material composition of the odorless formaldehyde-absorbing pure acrylic emulsion according to claim 1, characterized in that: The monomers include 2 to 6 parts of methacrylic acid, 90 to 130 parts of butyl acrylate, 0 to 40 parts of isooctyl acrylate, 80 to 120 parts of methyl methacrylate and 1 to 5 parts of silane coupling agent monomer; and / or, the emulsifier comprises an anionic emulsifier and a nonionic emulsifier; And / or, the initiator is selected from one of sodium persulfate, ammonium persulfate and potassium persulfate.

3. The raw material composition of the odorless formaldehyde-absorbing pure acrylic emulsion according to claim 2, characterized in that: The silane coupling agent monomer is selected from at least one of vinyl trimethoxy silane, vinyl triethoxy silane or gamma-glycidoxypropyl trimethoxy silane; And / or, the anionic emulsifier is a sulfonate emulsifier that does not contain APEO, selected from sodium dodecylbenzene sulfonate, such as BASF's LDBS-23 emulsifier; And / or, the nonionic emulsifier is a water-soluble fatty alcohol ethoxylate emulsifier that does not contain APEO and has an HLB value of 13 to 15, for example, Clariant emulsifier Emulsogen LCN 118; And / or, the weight proportion of the anionic emulsifier is 18 to 22 parts; And / or, the weight proportion of the nonionic emulsifier is 2 to 4 parts.

4. The raw material composition of the odorless formaldehyde-absorbing pure acrylic emulsion according to claim 1, characterized in that: The raw material composition of the odorless formaldehyde-absorbing pure acrylic emulsion further includes 400 to 600 parts of water; And / or, the raw material composition of the odorless formaldehyde-absorbing pure acrylic emulsion further comprises 1 to 4 parts of an oxidant; And / or, the raw material composition of the odorless formaldehyde-absorbing pure acrylic emulsion further includes 0.5 to 2 parts of a reducing agent.

5. The raw material composition of the odorless formaldehyde-absorbing pure acrylic emulsion according to claim 4, characterized in that: The oxidant is tert-butyl hydroperoxide or hydrogen peroxide; And / or, the reducing agent is VCNa and / or VC.

6. A method for preparing a pure acrylic emulsion with a clean taste and formaldehyde absorption, characterized in that: The raw materials of the odorless formaldehyde-absorbing pure acrylic emulsion include the raw material composition of the odorless formaldehyde-absorbing pure acrylic emulsion as claimed in any one of claims 1 to 5, and the method includes the following steps: (1) mixing water and part of the emulsifier, adding the monomer, the multifunctional monomer and the initial initiator and stirring to obtain a pre-emulsion; (2) mixing water and remaining emulsifier in a reaction kettle to obtain a bottom material; (3) When the temperature in the reactor rises to 83-84° C., a reaction initiator is added, and the pre-emulsion is dripped, and the dripping speed of the pre-emulsion is controlled. In the initial stage of the reaction, the dripping speed is 1.5-2.5 times that of the stable stage of the reaction, and then the pre-emulsion is dripped at a uniform speed; (4) After the reaction is completed, a post-initiator is added dropwise, and then a redox agent is added dropwise for post-treatment.

7. The method for preparing the odorless formaldehyde-absorbing pure acrylic emulsion according to claim 6, characterized in that: The preparation method satisfies at least one of the following conditions: In step (1), the amount of the emulsifier is 40-70% of the total amount of the emulsifier; In step (1), the weight proportion of water is 180 to 220 parts; In step (1), the mixing time is 10 to 20 minutes; In step (1), the amount of the initially added initiator is 40 to 70% of the total amount of the initiator; In step (1), the stirring time is 20 to 60 minutes; In step (2), the weight proportion of water is 280 to 320 parts; In step (2), the mixing time is 10 to 20 minutes; In step (3), the amount of initiator added to the reaction is 30-60% of the total amount of the initiator; In step (3), the dropping time is 3 to 4 hours; In step (3), the dropping temperature is 83-85°C; In step (3), the initial reaction time is 15 to 25 minutes, preferably, the initial reaction time is 20 minutes; After step (4), step (5) of stripping treatment is further performed, specifically: stripping is performed at a temperature of 50 to 60° C. and a pressure of -70 to -90 KPa.

8. The method for preparing the odorless formaldehyde-absorbing pure acrylic emulsion according to claim 7, characterized in that: The preparation method satisfies at least one of the following conditions: After step (5), the temperature is lowered to below 45°C, the material is filtered through a 200-mesh filter cloth, and the pH is adjusted to 7-9 with liquid alkali; The initially added initiator, the reaction initiator and the later added initiator are all added in the form of aqueous solution.

9. A pure acrylic emulsion with a clean taste and formaldehyde absorption, characterized in that: The invention discloses a pure acrylic emulsion for absorbing formaldehyde and having no odor.

10. Use of the odorless formaldehyde-absorbing pure acrylic emulsion as claimed in claim 9 in indoor furniture decoration.

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