Low voc anti-dwell biobased white latex and method of making

Abstract

This invention relates to the field of adhesive technology, specifically disclosing a low-VOC, anti-settling, and foam-suppressing bio-based white latex and its preparation method. It is prepared from raw materials comprising the following parts by weight: 80-120 parts bio-based starch; 30-50 parts nano-sized inorganic filler; 10-20 parts vinyl acetate; 8-10 parts polyvinyl alcohol; 5-10 parts modified etherified cellulose; 3-8 parts hydrated acrylic amide solution; 2-5 parts sodium carbonate; 150-200 parts deionized water; 1-3 parts emulsifier; 0.5-1.5 parts inorganic initiator; and 2-4 parts bio-based plasticizer. This invention effectively solves the technical defects of existing white latexes, such as high dependence on petroleum-based materials, high VOC content, high cost, easy sedimentation and stratification, and incomplete degassing, through reasonable raw material ratios, optimized preparation processes, and vacuum degassing technology. It achieves a synergistic balance between environmental friendliness, economy, and stability in use. Test results fully demonstrate that this technical solution has significant beneficial effects and meets industry development trends and industrial production needs.

Description

Technical Field

[0001] This invention belongs to the field of adhesive technology, specifically relating to a low-VOC anti-settling and anti-foaming bio-based white latex and its preparation method. Background Technology

[0002] White glue, also known as polyvinyl acetate emulsion adhesive, is widely used in wood processing, furniture assembly, building decoration, paper bonding, and packaging due to its excellent bonding performance, convenient application, good compatibility, and moderate cost. It is one of the most widely used water-based adhesives in industrial production and daily life. With increasingly stringent global environmental policies, low VOC, formaldehyde-free, and environmentally friendly products have become the core development trend of the adhesive industry. At the same time, companies are placing higher demands on production cost control and product storage stability.

[0003] Current traditional white glue production technology has many insurmountable defects:

[0004] Current white glue mainly uses vinyl acetate as its core raw material, which is a petroleum-based product. This not only results in high production costs but also makes it easy for VOC content to exceed standards during production and use. Although some technologies have attempted to use ordinary starch as a small substitute, most of these are short-chain starches without suitable nanofillers and protective colloid systems. The proportion of bio-based substitution is low, and significant reductions in VOCs and costs cannot be achieved.

[0005] Traditional processes often use polyvinyl alcohol as a single protective colloid. Even after adding starch and inorganic fillers, the emulsion is still prone to problems such as sedimentation, stratification, and clumping, which seriously affect the product's performance and shelf life, making it difficult to meet the needs of long-term storage and industrial applications.

[0006] Existing technologies lack efficient physical degassing methods and rely heavily on chemical defoamers. As a result, residual gases in the emulsion cannot be effectively removed, which not only exacerbates VOC emissions but also leads to excessive bubbles during construction, affecting the bonding density and surface finish.

[0007] Conventional processes use strong alkaline chemical additives such as sodium hydroxide to adjust the pH value of the system, which poses safety hazards and harmful residues, increases the environmental burden, and reduces the stability of the emulsion system.

[0008] In summary, existing white glue technologies generally suffer from problems such as high dependence on petroleum-based materials, high VOC content, high cost, easy sedimentation and stratification, incomplete degassing, and non-environmentally friendly pH adjustment. They cannot simultaneously achieve comprehensive performance of low VOC, low cost, anti-settling, anti-foaming, and high stability, making it difficult to meet the dual requirements of current green manufacturing and industrial production. Summary of the Invention

[0009] The purpose of this invention is to provide a low-VOC anti-settling and anti-foaming bio-based white latex and its preparation method, so as to solve the problems mentioned in the background art, such as high dependence on petroleum-based materials, high VOC, high cost, easy sedimentation and stratification, and incomplete degassing of existing white latex.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] A low-VOC, anti-settling, and foam-suppressing bio-based white latex is prepared from raw materials comprising the following parts by weight: 80-120 parts bio-based starch; 30-50 parts nano-sized inorganic filler; 10-20 parts vinyl acetate; 8-10 parts polyvinyl alcohol; 5-10 parts modified etherified cellulose; 3-8 parts hydrated acrylic amide solution; 2-5 parts sodium carbonate; 150-200 parts deionized water; 1-3 parts emulsifier; 0.5-1.5 parts inorganic initiator; and 2-4 parts bio-based plasticizer.

[0012] Preferably, the bio-based starch is long-chain corn starch or long-chain cassava starch; the nano-scale inorganic filler is nano-scale light calcium carbonate or nano-scale talc; the polyvinyl alcohol is polyvinyl alcohol 1788 or polyvinyl alcohol 1799; the modified etherified cellulose is modified hydroxyethyl cellulose or modified hydroxypropyl methyl cellulose; the acrylamide hydrate is acrylamide hydrate or methacrylamide hydrate; and the acidic sodium carbonate is sodium bicarbonate or potassium bicarbonate.

[0013] Preferably, the inorganic initiator is ammonium persulfate or sodium persulfate; the bio-based plasticizer is bio-based citrate or bio-based epoxidized soybean oil.

[0014] Preferably, the hydrated acrylic acid solution is diluted to a mass concentration of 20%-30% before use; the sodium carbonate is in powder form; and the polyvinyl alcohol is in 60-80 mesh particles.

[0015] A method for preparing a low-VOC, anti-settling, and anti-foaming bio-based white latex includes the following steps:

[0016] S1. Add the formulated amount of polyvinyl alcohol and modified etherified cellulose to a portion of deionized water, heat to 85-90℃ to dissolve, and form a protective colloidal system.

[0017] S2. Add the remaining deionized water, emulsifier, hydrated acrylic amide and sodium carbonate to the protective colloid system. After stirring evenly, add a portion of vinyl acetate and a portion of inorganic initiator dropwise for the initial polymerization. Then raise the temperature and add the remaining vinyl acetate and the remaining inorganic initiator dropwise simultaneously. Cure at a constant temperature to obtain the basic emulsion.

[0018] S3. While the polymerization reaction is underway, prepare starch solution and nano-sized inorganic filler aqueous solution respectively;

[0019] S4. Perform a first vacuum degassing treatment on the base emulsion obtained in step S2.

[0020] S5. The starch solution and nano-sized inorganic filler aqueous solution prepared in S3 are added to the degassed base emulsion in S4 in sequence, and the mixture is heated to gelatinize. Then, a bio-based plasticizer is added.

[0021] S6: The mixed emulsion obtained in S5 is subjected to a second vacuum degassing treatment, and after cooling, preservatives and defoamers are added to obtain the low-VOC anti-settling and foam-suppressing bio-based white emulsion.

[0022] Preferably, in step S1, the dissolution time is more than 1 hour; in step S2, the dripping time of the base vinyl acetate is 15-20 minutes; the dripping time of the remaining vinyl acetate and the remaining inorganic initiator is 2 hours; and the constant temperature curing is curing at 82°C for 30 minutes.

[0023] Preferably, the first vacuum degassing process in S4 and the second vacuum degassing process in S6 are both performed using a vacuum adsorption pump, and the vacuuming time for each is 10-15 minutes independently.

[0024] Preferably, in step S5, the starch gelatinization temperature is 74-75℃, the gelatinization and maturation time is 30 minutes, and the emulsion temperature is lowered to below 70℃ before adding the aqueous solution of nano-sized inorganic filler.

[0025] Preferably, in step S3, the starch solution is prepared by adding long-chain corn starch to process water and stirring at 300-450 rpm until no dry powder remains; the nano-sized inorganic filler aqueous solution is prepared by adding nano-sized inorganic filler to process water and dispersing it evenly at 500-600 rpm.

[0026] Compared with the prior art, the beneficial effects of the present invention are:

[0027] This invention innovatively uses long-chain corn starch (bio-based starch) and nano-scale inorganic fillers to largely replace petroleum-based raw materials such as vinyl acetate, with bio-based raw materials accounting for over 50%, eliminating the introduction of harmful substances such as formaldehyde and benzene compounds. Simultaneously, non-toxic and environmentally friendly polyvinyl alcohol is selected as a protective colloid, combined with bio-based citrate ester to replace the traditional dibutyl phthalate plasticizer, further reducing environmental impact. A dual vacuum degassing process is implemented using a self-developed vacuum adsorption pump to reduce VOC content, minimize emulsion bubbles, and improve the product's environmental and performance characteristics.

[0028] Furthermore, this invention reduces costs through raw material structure optimization. For example, the unit price of bio-based raw materials (long-chain corn starch, nano-grade light calcium carbonate) is much lower than that of vinyl acetate, and the substitution ratio is high. Secondly, the optimized protective colloidal system (synergistic effect of polyvinyl alcohol and anti-settling additives) significantly reduces the amount of emulsifiers, crosslinking agents and other additives, thus reducing additive costs. Thirdly, the low-temperature polymerization process reduces production energy consumption and has a significant competitive advantage in the market.

[0029] This invention utilizes a synergistic anti-sedimentation system formed by polyvinyl alcohol, modified etherified cellulose, and acrylamide hydrate (AM). This system effectively addresses the industry pain point of easy sedimentation and stratification when using polyvinyl alcohol alone as a protective colloid and adding bio-based raw materials. It exhibits excellent anti-sedimentation and anti-stratification properties, significantly improved product stability, extended shelf life, and greatly enhanced reliability.

[0030] This invention abandons traditional toxic and harmful chemical additives, using food-grade sodium carbonate (an inorganic weakly alkaline regulator) to adjust the pH value of the emulsion, stabilizing it at 7.2-7.8. It leaves no harmful additive residues and avoids the potential safety hazards associated with traditional regulators such as sodium hydroxide. Furthermore, the product's appearance, non-volatile matter, viscosity, and pH value all meet relevant industry standards, ensuring stable product quality and fulfilling practical application requirements.

[0031] In summary, this invention addresses the technical pain points of existing white glue, namely the imbalance between environmental protection and cost, insufficient performance and stability, and limited applicability. Leveraging its core advantages of environmental friendliness, low cost, and high applicability, it can be widely applied in fields such as environmentally friendly decoration, furniture manufacturing, green packaging, handicrafts, biomass fuels, and agriculture and horticulture. In the decoration and furniture sector, the product price is 15%-20% lower than traditional environmentally friendly white glue of the same specifications, offering a significant cost-performance advantage. In the packaging and cultural and creative industries, the product is biodegradable, leaves no harmful residues, and meets EU standards. The technical solution of this invention has a standardized process and controllable parameters, enabling large-scale production without large-scale modifications to existing production equipment. It provides a replicable and scalable technical paradigm for the green transformation of the traditional white glue industry, possessing strong industrial application value and promising prospects for promotion. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] Example 1:

[0034] A method for preparing a low-VOC, anti-settling, and anti-foaming bio-based white latex is as follows:

[0035] The raw material ratio is as follows (parts by weight): 80 parts long-chain corn starch, 30 parts nano-grade light calcium carbonate, 10 parts vinyl acetate, 8 parts polyvinyl alcohol, 5 parts modified hydroxyethyl cellulose, 3 parts acrylic amide hydrate, 2 parts sodium carbonate, 150 parts deionized water, 1 part emulsifier (OP-10), 0.5 parts ammonium persulfate, and 2 parts bio-based citrate.

[0036] Preparation method:

[0037] (1) PVA dissolution: Add 120 parts of deionized water to the dissolution vessel, start stirring, add 8 parts of polyvinyl alcohol and 5 parts of modified hydroxyethyl cellulose, turn on the jacket steam, raise the temperature to 85°C, keep it at the temperature for 1.5 hours until the PVA is completely dissolved and there are no particles, then transfer the material to the polymerization vessel.

[0038] (2) Preparation of materials for polymerization reactor: Add 30 parts of supplemental water to the polymerization reactor, adjust the temperature inside the reactor to 68°C, and stir at 65%. Add 1 part of emulsifier, 3 parts of acrylic amide hydrate, and 2 parts of sodium carbonate in sequence, and stir to disperse evenly.

[0039] (3) Adding VAC as a base: Add 4 parts of vinyl acetate (40% of the total amount) and add it at a uniform rate within 15 minutes. Observe the foam state throughout the process.

[0040] (4) Addition of initiator in the early stage: After the addition is completed, add 0.2 parts of ammonium persulfate (40% of the total amount).

[0041] (5) Polymerization heating: When the temperature starts to rise due to the polymerization reaction, slowly raise the temperature to 72°C.

[0042] (6) Adding the remaining VAC and initiator: After the temperature stabilizes, add 6 parts of the remaining vinyl acetate, with a total adding time of 2 hours; add 0.25 parts of ammonium persulfate (50% of the total amount) at the same constant rate; add 0.05 parts of the remaining ammonium persulfate (10% of the total amount) within 15 minutes after the remaining vinyl acetate is added.

[0043] (7) First cooking: After the addition is completed, the temperature is raised to 82°C and cooked at a constant temperature for 30 minutes.

[0044] (8) Starch solution preparation (conducted simultaneously): Add 50 parts of process water to the disperser, and slowly add 80 parts of long-chain corn starch while stirring at 300 rpm. Stir until there is no dry powder or lumps, and set aside.

[0045] (9) First vacuuming: After the first curing is completed, turn on the cooling water to cool down to 72°C, and start the vacuum adsorption pump to evacuate for 10 minutes.

[0046] (10) Starch addition: After breaking the vacuum, the starch solution is pumped into the polymerization reactor. The stirring frequency is adjusted to 40%. After the material is pumped out, the disperser reactor wall is rinsed with the remaining process water and all of it is flushed into the polymerization reactor.

[0047] (11) Starch gelatinization: Adjust the stirring frequency back to 65%, raise the temperature to 74°C, turn off the steam, let the system rise naturally to 75°C, and maintain the temperature for 30 minutes. The temperature should not exceed 77°C throughout the process.

[0048] (12) Preparation of light calcium aqueous solution (conducted simultaneously): Add 25 parts of process water into the disperser, and add 30 parts of nano-sized light calcium while stirring at 500 rpm, and disperse evenly at high speed.

[0049] (13) Addition of light calcium: After starch gelatinization is completed, the temperature is lowered to below 70°C, and the light calcium aqueous solution is pumped into the polymerization reactor and stirred evenly.

[0050] (14) Addition of bio-based citrate: Add 2 parts of bio-based citrate and stir to disperse evenly.

[0051] (15) Second vacuuming: Start the vacuum adsorption pump and vacuum again for 10 minutes.

[0052] (16) Cooling and post-processing: After the sample is tested and found to be qualified, the material is put into a cooling kettle and cooled to 25-35℃. Preservatives and defoamers are added, stirred evenly, filtered and packaged to obtain the finished white latex product.

[0053] Example 2:

[0054] A method for preparing a low-VOC, anti-settling, and anti-foaming bio-based white latex is as follows:

[0055] Raw material ratio (parts by mass):

[0056] 100 parts long-chain corn starch, 40 parts nano-grade light calcium carbonate, 15 parts vinyl acetate, 9 parts polyvinyl alcohol, 7.5 parts modified hydroxyethyl cellulose, 5.5 parts acrylic amide hydrate, 3.5 parts sodium carbonate, 175 parts deionized water, 2 parts emulsifier (OP-10), 1 part ammonium persulfate, and 3 parts bio-based citrate.

[0057] Preparation method:

[0058] The process is basically the same as in Example 1, with the following main parameters adjusted: PVA dissolution temperature: 88℃, dissolution time: 1 hour; VAC dripping time: 18 minutes; VAC ratio: 40% of the total vinyl acetate (i.e., 6 parts); first vacuuming time: 12 minutes; second vacuuming time: 12 minutes; starch gelatinization temperature is raised to 75℃ and kept at a constant temperature for 30 minutes; the remaining parameters are the same as in Example 1.

[0059] Example 3:

[0060] A method for preparing a low-VOC, anti-settling, and anti-foaming bio-based white latex is as follows:

[0061] Raw material ratio (parts by mass):

[0062] 120 parts long-chain corn starch, 50 parts nano-grade light calcium carbonate, 20 parts vinyl acetate, 10 parts polyvinyl alcohol, 10 parts modified hydroxyethyl cellulose, 8 parts acrylic amide hydrate, 5 parts sodium carbonate, 200 parts deionized water, 3 parts emulsifier (OP-10), 1.5 parts ammonium persulfate, and 4 parts bio-based citrate.

[0063] Preparation method: basically the same as in Example 1, with the main parameters adjusted as follows:

[0064] PVA dissolution temperature: 90℃, dissolution time: 1 hour; VAC dripping time: 20 minutes;

[0065] VAC ratio for the base layer: 40% of the total vinyl acetate (i.e., 8 parts); Polymerization reaction temperature: maintain a stable 72℃; First curing temperature: 82℃, curing time: 30 minutes; First vacuuming time: 15 minutes;

[0066] Starch gelatinization: Heat to 75°C and maintain the temperature for 30 minutes, with the maximum temperature not exceeding 77°C; Second vacuuming time: 15 minutes; Other parameters are the same as in Example 1.

[0067] To ensure the smooth progress of the preparation process and avoid the impact of process abnormalities on product quality, the following abnormal situation handling measures are formulated:

[0068] 1. Adding VAC solution: Stop dripping immediately, add defoamer, and continue after the foam subsides. Do not force feeding.

[0069] 2. Risk of vacuum backflow: If the liquid level exceeds the warning line, immediately slightly open the funnel valve to allow air in, stop the pump, check, and then resume operation.

[0070] 3. Starch clumping: Increase the speed of the disperser, feed the material in batches, and prohibit the concentrated dumping of dry powder. If clumping has occurred, extend the mixing time.

[0071] 4. Light calcium carbonate settling: Increase the dispersion speed, extend the dispersion time, and strengthen stirring after adding the mixture to the reactor. With the help of the protective colloidal system, ensure uniform dispersion.

[0072] 5. Poor dispersion of citrate esters: Slow down the feeding speed, extend the stirring time, and avoid pouring in large quantities at once.

[0073] 6. Overheating: Immediately turn off the steam, fully open the cooling water, stop feeding materials, check the temperature control system, and resume operation only after the temperature has returned to normal.

[0074] 7. Incomplete PVA dissolution: Extend the dissolution time and increase the stirring speed to ensure that PVA is completely dissolved, so as to avoid undissolved particles affecting the protective colloid effect and thus causing emulsion separation.

[0075] To verify the effectiveness of the embodiments of the present invention, the following experiment was designed:

[0076] Experimental group: The raw materials were prepared using the technical solution of this invention, and the proportions of the raw materials were selected according to the median of the above-mentioned range, as in Example 2. The finished product was obtained through the above preparation steps.

[0077] Control group: Traditional white glue, with raw materials mainly consisting of 80 parts vinyl acetate, 9 parts polyvinyl alcohol (protective colloid, the same amount as the experimental group), 175 parts deionized water, 2 parts emulsifier, and 1 part initiator. No bio-based raw materials or anti-settling additives were added, vacuum degassing was not used, and the pH value was adjusted with sodium hydroxide.

[0078] Test items and test methods

[0079] VOC content testing: Gas chromatography was used, with the following detection conditions: column temperature 80-200℃, heating rate 10℃ / min, detector temperature 250℃, and nitrogen as the carrier gas. The VOC content of the two groups of samples was detected.

[0080] Cost testing: The total cost of raw materials, energy consumption, and processes during the preparation of the two sets of samples was statistically analyzed, and the cost per unit mass of product was calculated.

[0081] Stability test: The two groups of samples were placed in a constant temperature environment of 25℃ and left to stand for 30 days to observe whether the emulsion showed sedimentation or stratification; at the same time, the viscosity change rate of the emulsion was tested (viscosity test was performed using a rotational viscometer at a temperature of 25℃ and a rotation speed of 60r / min).

[0082] Bubble content test: The volumetric method was used to detect the percentage of bubble volume in the two groups of samples.

[0083] Safety testing: The pH value and residual amount of harmful additives in the two groups of samples were tested to determine whether they met environmental and safety standards.

[0084] Test Results and Analysis

[0085] The test results are shown in the table below:

[0086] VOC content: The VOC content of the experimental group was 15-25 g / L, while that of the control group was 80-95 g / L. The VOC content of the experimental group was reduced by more than 70% compared with that of the control group. The main reason is that this invention uses long-chain corn starch and nano-sized inorganic fillers to replace vinyl acetate in a large proportion. At the same time, the residual gas is effectively extracted by the self-developed vacuum adsorption pump. The dual effect achieves a significant reduction in VOC content, which meets the low VOC environmental protection requirements. In addition, the polyvinyl alcohol protective colloid does not increase VOC emissions, ensuring environmental performance.

[0087] Production cost: The unit mass cost of the experimental group was 1.8-2.2 yuan / kg, while that of the control group was 3.5-4.0 yuan / kg. The cost of the experimental group was more than 35% lower than that of the control group. This was due to the fact that the cost of bio-based raw materials (long-chain corn starch and nano-grade light calcium) was lower than that of vinyl acetate and the substitution ratio was high. At the same time, the process was simple and energy consumption costs were reduced. Polyvinyl alcohol was used as a conventional raw material, and the amount was adjusted to 8-10 parts, which further reduced the raw material cost burden.

[0088] Stability: After 30 days of standing, the experimental group showed no sedimentation or stratification, with a viscosity change rate of ≤5%; the control group showed obvious stratification and sedimentation after 15 days of standing, with a viscosity change rate of ≥20%. This indicates that the polyvinyl alcohol (protective colloid) in this invention works synergistically with the modified etherified cellulose and acrylic amide hydrate (AM), effectively solving the problem of easy sedimentation and stratification of emulsions when polyvinyl alcohol is used alone as a protective colloid in traditional methods, thus significantly improving the stability of the emulsion and extending its shelf life.

[0089] Bubble content: The bubble volume ratio in the experimental group was ≤0.5%, while that in the control group was 3.0%-4.5%, proving that the self-developed vacuum adsorption pump can effectively remove residual gas from the emulsion, reduce bubbles, improve product performance, and protect the colloidal system from negatively affecting the degassing effect.

[0090] Safety: The experimental group had a pH value of 7.2-7.8 and no harmful additive residues, meeting environmental and safety standards. The control group had trace amounts of harmful residues due to the use of sodium hydroxide to adjust the pH value, resulting in slightly lower safety. Polyvinyl alcohol, as a non-toxic and environmentally friendly protective colloid, further enhances the safety of the product.

[0091] In summary, the technical solution of this invention effectively solves the technical defects of existing white glue through reasonable raw material ratio (including polyvinyl alcohol protective colloid), optimized preparation process and vacuum degassing technology, and achieves a synergistic balance of environmental protection, economy and use stability. The test results fully demonstrate that the technical solution has significant beneficial effects and is in line with industry development trends and industrial production needs.

[0092] Furthermore, to further verify the product quality and environmental performance of the white latex of this invention, it was tested and verified by a professional testing institution. The specific test results are as follows:

[0093] Professional testing evidence

[0094] I. The content of harmful substances is far below the GB 18582-2020 standard.

[0095] (I) According to the testing and inspection by Suzhou Huace Testing Technology Co., Ltd., the polyvinyl acetate emulsion (named Innovation No. I White Emulsion) of this invention meets and exceeds the standard of GB 18582-2020 "Limits of Hazardous Substances in Wall Coatings for Buildings". The specific test information is as follows:

[0096] 1. Testing Unit: Suzhou Huace Testing Technology Co., Ltd.;

[0097] 2. Sample name submitted for testing: Bio-based white latex sample;

[0098] 3. Test results: The total volatile matter content in this bio-based white latex sample was 24 g / L, which is far below the limit of 50 g / L for total volatile matter content in GB18582-2020 standard. Its environmental performance is better than the national standard, and the polyvinyl alcohol protective colloid did not have a negative impact on environmental indicators.

[0099] (ii) All other indicators meet the relevant quality standards for white latex.

[0100] According to tests conducted by professional testing institutions, the polyvinyl acetate emulsion described in this invention meets the relevant industry standards in terms of four indicators: appearance, non-volatile matter, viscosity (30℃), and pH value. The product quality is stable, and the polyvinyl alcohol protective colloid effectively ensures the basic performance of the emulsion, meeting the needs of practical applications.

[0101] The above two professional test results further confirm that the white latex of this invention can not only effectively solve the defects of the existing technology, but also that the product's environmental performance and quality meet the relevant standards, and some indicators are better than the national standards, thus possessing strong industrial application value and promotion prospects.

[0102] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0103] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A low-VOC, anti-settling, and anti-foaming bio-based white latex, characterized in that, It is prepared from raw materials containing the following parts by weight: 80-120 parts of bio-based starch; 30-50 parts of nano-sized inorganic filler; 10-20 parts of vinyl acetate; 8-10 parts of polyvinyl alcohol; 5-10 parts of modified etherified cellulose; 3-8 parts of hydrated acrylic amide; 2-5 parts of sodium carbonate; 150-200 parts of deionized water; 1-3 parts of emulsifier; 0.5-1.5 parts of inorganic initiator; and 2-4 parts of bio-based plasticizer.

2. The bio-based white latex according to claim 1, characterized in that: The bio-based starch is long-chain corn starch or long-chain cassava starch; the nano-scale inorganic filler is nano-scale light calcium carbonate or nano-scale talc; the polyvinyl alcohol is polyvinyl alcohol 1788 or polyvinyl alcohol 1799; the modified etherified cellulose is modified hydroxyethyl cellulose or modified hydroxypropyl methyl cellulose; the acrylamide hydrate is acrylamide hydrate or methacrylamide hydrate; and the acidic sodium carbonate is sodium bicarbonate or potassium bicarbonate.

3. The bio-based white latex according to claim 1, characterized in that: The inorganic initiator is ammonium persulfate or sodium persulfate; the bio-based plasticizer is bio-based citrate or bio-based epoxidized soybean oil.

4. The bio-based white latex according to claim 1, characterized in that: The hydrated acrylic amide solution is diluted to a mass concentration of 20%-30% before use; the sodium carbonate is in powder form; and the polyvinyl alcohol is in 60-80 mesh particles.

5. A method for preparing a low-VOC, anti-settling, and anti-foaming bio-based white latex, comprising preparing the bio-based white latex according to any one of claims 1-4, characterized in that: Includes the following steps: S1. Add the formulated amount of polyvinyl alcohol and modified etherified cellulose to a portion of deionized water, heat to 85-90℃ to dissolve, and form a protective colloidal system. S2. Add the remaining deionized water, emulsifier, hydrated acrylic amide and sodium carbonate to the protective colloid system. After stirring evenly, add a portion of vinyl acetate and a portion of inorganic initiator dropwise for the initial polymerization. Then raise the temperature and add the remaining vinyl acetate and the remaining inorganic initiator dropwise simultaneously. Cure at a constant temperature to obtain the basic emulsion. S3. While the polymerization reaction is underway, prepare starch solution and nano-sized inorganic filler aqueous solution respectively; S4. Perform a first vacuum degassing treatment on the base emulsion obtained in step S2. S5. The starch solution and nano-sized inorganic filler aqueous solution prepared in S3 are added to the degassed base emulsion in S4 in sequence, and the mixture is heated to gelatinize. Then, a bio-based plasticizer is added. S6: The mixed emulsion obtained in S5 is subjected to a second vacuum degassing treatment, and after cooling, preservatives and defoamers are added to obtain the low-VOC anti-settling and foam-suppressing bio-based white emulsion.

6. The preparation method according to claim 5, characterized in that: In S1, the dissolution time is more than 1 hour; in S2, the dripping time of the base vinyl acetate is 15-20 minutes; the dripping time of the remaining vinyl acetate and the remaining inorganic initiator is 2 hours; the constant temperature curing is curing at 82°C for 30 minutes.

7. The preparation method according to claim 5, characterized in that: The first vacuum degassing process in S4 and the second vacuum degassing process in S6 are both carried out using a vacuum adsorption pump, and the vacuuming time for each process is 10-15 minutes.

8. The preparation method according to claim 5, characterized in that: In step S5, the starch gelatinization temperature is 74-75℃, the gelatinization and maturation time is 30 minutes, and the emulsion temperature is reduced to below 70℃ before adding the aqueous solution of nano-sized inorganic filler.

9. The preparation method according to claim 5, characterized in that: In S3, the starch solution is prepared by adding long-chain corn starch to process water and stirring at 300-450 rpm until no dry powder remains; the nano-sized inorganic filler aqueous solution is prepared by adding nano-sized inorganic filler to process water and dispersing it evenly at 500-600 rpm.