Water-based polymer dispersion

Abstract

A water-based vinyl-acetate copolymer dispersion containing an acrylate monomer. The water-based dispersion is resistant to biological degradation.

Description

Technical Field

[0001] This invention relates to water-based polymer dispersions, particularly to biologically resistant vinyl ester-ethylene copolymer dispersions. Background Technology

[0002] Ao Chen, Hui Peng, Idriss Blakey & Andrew K. Whittaker (2016): BiocidalPolymers: A Mechanistic Overview, Polymer Reviews, DOI: 10.1080 / 15583724.2016.1223131 discloses a PDMAEMA polymer, which is a polymer of dimethylaminoethyl methacrylate, and is resistant to biodegradation.

[0003] CN101044176B discloses a copolymer with acrylic acid as the main monomer, wherein the d1 comonomer may contain ethyl methacrylate (2-dimethylamino)methacrylate. This copolymer can be used in cosmetics and pharmaceuticals. Its main uses are as an adhesive, film-forming agent, surfactant compound, or for modifying the rheological properties of aqueous systems.

[0004] CN1328296C discloses a multifunctional copolymer with acrylamide as the main monomer, which is used as a film-forming agent in the field of cosmetic hair treatment. The comonomers of this copolymer may contain ethylene, vinyl acetate, and ethyl (2-dimethylamino)methacrylate. However, no copolymer with ethylene and vinyl acetate as the main monomers is disclosed. Summary of the Invention

[0005] This invention provides a water-based polymer dispersion resistant to biological degradation.

[0006] This dispersion is odorless to the human olfactory system and exhibits stable storage performance and long-term resistance to biological degradation. The residual monomer content in this dispersion is less than 1000 ppm, preferably less than 500 ppm, and more preferably less than 300 ppm.

[0007] This invention provides a water-based polymer dispersion comprising... Component i) A copolymer, said copolymer being prepared by monomer polymerization comprising vinyl ester, ethylene and monomer A according to formula (1), (1) Wherein R1 is H or C1-C4 alkyl; R2 is C1-C4 alkylene; R3 and R4 are C1-C4 alkyl. Component iv) Water, The amount of monomer A is 0.10 to 5 wt%, preferably 0.40 to 5 wt%, more preferably 0.40 to 3 wt%, more preferably 0.40 to 2 wt%, for example 0.20 wt%, 0.30 wt%, 0.45 wt%, 0.65 wt%, 0.85 wt%, 1.05 wt%, 1.25 wt%, 1.45 wt%, 1.65 wt%, 1.85 wt%, 2.25 wt%, 2.45 wt%, 2.65 wt%, based on the total weight of vinyl ester and ethylene monomer as 100 wt%. The total amount of vinyl ester and ethylene is greater than 80% by weight, preferably greater than 85% by weight, preferably greater than 90% by weight, more preferably greater than 95% by weight, more preferably greater than 97% by weight, more preferably greater than 98% by weight, more preferably greater than 98.5% by weight, based on the total weight of the copolymer of component i) as 100% by weight.

[0008] According to the above-described water-based polymer dispersion, the vinyl ester is selected from one or more of vinyl acetate, vinyl butyrate, vinyl propionate, vinyl pentanoate, vinyl 2-ethylhexanoate, 1-methyl vinyl acetate, and vinyl laurate, preferably vinyl acetate.

[0009] As described above, in the aqueous polymer dispersion, in monomer A, R1 is H or C1-C2 alkyl; R2 is C1-C3 alkylene; R3 and R4 are C1-C2 alkyl, preferably R1 is H or methyl; R2 is ethylene or propylene; and R3 and R4 are methyl.

[0010] As described above, in the water-based polymer dispersion, monomer A is selected from one or more of (2-dimethylamino)ethyl methacrylate, (2-dimethylamino)ethyl acrylate, dimethylaminopropyl methacrylate, and 3-(dimethylamino)propyl acrylate.

[0011] As described above, the application of the water-based polymer dispersion in the field of anti-biological degradation is preferably in the field of polymer emulsion anti-biological degradation.

[0012] A water-based dispersion resistant to biological degradation, comprising the water-based polymer dispersion described above.

[0013] A composition comprising a product obtained by drying an aqueous polymer dispersion as described above. Preferred drying processes are dehydration and / or solvent removal processes; more preferred drying processes are spray drying processes.

[0014] According to the water-based polymer dispersion described above, wherein component i) the copolymer is prepared by using component iii) polyvinyl alcohol and / or hydroxyethyl cellulose as a protective colloid.

[0015] According to the water-based polymer dispersion described above, it contains 39-60% by weight of component i), said component i) being a copolymer prepared by monomer polymerization comprising vinyl ester, ethylene and monomer A according to formula (1), 0.6-4% by weight of component iii) protective colloid, and 39-60% by weight of the component (iv) water, The total weight of the water-based polymer dispersion is taken as 100% by weight.

[0016] According to the water-based polymer dispersion described above, it contains 49-60% by weight of component i), said component i) being a copolymer prepared by monomer polymerization comprising vinyl ester, ethylene and monomer A according to formula (1), 0.9-3% by weight of component iii) protective colloid, and 39-50% by weight of the component (iv) water, The total weight of the water-based polymer dispersion is taken as 100% by weight.

[0017] According to the water-based polymer dispersion described above, its pH value is less than or equal to 5, preferably between 3 and 5, such as 3.5, 3.8, 4.0, 4.2, 4.3, 4.5, and 4.8.

[0018] According to the water-based polymer dispersion described above, its pH value is greater than 5, preferably between 5 and 9, such as 5.5, 5.8, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5.

[0019] The water-based polymer dispersion described above, wherein the total amount of vinyl acetate and ethylene is greater than 85% by weight, preferably greater than 90% by weight, more preferably greater than 95% by weight, more preferably greater than 97% by weight, more preferably greater than 98% by weight, more preferably greater than 98.5% by weight, based on the total weight of component i) copolymer as 100% by weight.

[0020] The water-based polymer dispersion described above, wherein the total amount of vinyl acetate, ethylene and monomer A is greater than 85% by weight, preferably greater than 90% by weight, more preferably greater than 95% by weight, more preferably greater than 97% by weight, more preferably greater than 98% by weight, more preferably greater than 99% by weight, more preferably greater than 99.5% by weight, more preferably greater than 99.9% by weight, based on the total weight of the copolymer of component i) as 100% by weight.

[0021] According to the water-based polymer dispersion described above, the amounts of "biocide" and "antibiotic" are less than 800 ppm, preferably less than 500 ppm, more preferably less than 200 ppm, more preferably less than 100 ppm, and even more preferably less than 50 ppm.

[0022] The water-based polymer dispersions described above are essentially free of "biocides" and "antibiotics".

[0023] The term "resistance to biological degradation" mentioned in this invention refers to the effect of killing or inhibiting the growth of microorganisms.

[0024] Microorganisms typically include prokaryotes such as bacteria, actinomycetes, spirochetes, mycoplasmas, rickettsiae, and chlamydia; eukaryotes such as fungi, algae, protozoa; and viruses and subviral organisms.

[0025] Preferably, the term "resistance to biological degradation" as used in this invention refers to the effect of killing or inhibiting the growth of bacteria and algae; more preferably, it refers to the effect of killing or inhibiting the growth of microorganisms that contaminate the polymer emulsion.

[0026] When aqueous polymer dispersions or polymer emulsions are contaminated with microorganisms, it can lead to a range of effects, including changes in color, odor, viscosity, pH, and visible surface growth. It is known in the art that aqueous polymer dispersions or polymer emulsions are susceptible to contamination by a variety of microorganisms.

[0027] In this invention, the microorganisms found to contaminate water-based polymer dispersions or polymer emulsions are selected from one or more of the following: Aeromonas hydrophila ( Aeromonas hydrophilia ), Alcaligenes faecalis ( Alcaligenes faecalis ), Corynebacterium ammoniagenes ( Corynebacterium ammoniagenes) Enterobacter aerogenes ( Enterobacter aerogenes ), Proteus vulgaris ( Proteus vulgaris Providencia retaliculata ( ), Providencia rettgeri ), Pseudomonas schrenckii ( Pseudomonas stutzeri ), Pseudomonas putida ( Pseudomonas putida ), Pseudomonas aeruginosa ( Pseudomonas aeruginosa ), Escherichia coli ( Escherichia coli Staphylococcus aureus ( Staphylococcus aereus ), Klebsiella pneumoniae ( Klebsiella pneumoniae Shewanella putrefactive bacteria ( Shewanella putrefaciens ), Serratia liquefied Serratia liquefaciens Acinetobacter baumannii ( Acinetobacter baumannii Burkholderia cepacia (), Burkholderia epacian Elizabethan bacillus meningitidis ( Chryseobacterium meningosepticum ), Sphingomyelin Bacillus ( Sphingobacterium spiritivorum ), Roldstonei ( Ralstonia pickettii ), liquefied glucosamine acetic acid bacteria ( Gluconoacetobacter liquefaciens ), Glucono-acetic acid bacteria ( Gluconoacetobacter ), white ground mold ( Geotrichum candidum Aspergillus ( ) Aspergillus species ), Sporothrix ( Sporothrix species ), green Trichoderma ( Trichoderma viride Cladosporium ( ) Cladosporium species ), red yeast ( Rhodoturula glutinis ), Candida albicans ( Candida guillermondi ), Penicillium ( Penicillium species ), Tropical Candida ( Candida tropicalis ), brewer's yeast ( Saccharomyces cerevisiae Candida albicans ( Candida albicans ), dark red yeast ( Rhodotorula rubra ) and Vacuoliviride algae.

[0028] As used herein, the phrase "inhibit and control growth" is defined as meaning that the project under discussion reduces the concentration of a broad spectrum of microorganisms by at least 1 log10 over a period of time, as measured by shake-flask method, droplet challenge test, and / or aerosol challenge test. Preferably, it reduces the microbial concentration by a factor of 3 log10 (i.e., a reduction of 10 colony-forming units per gram of material (CFU / g)) over 1, 4, or 7 days. 3 Most preferably, it reduces the microbial concentration by a factor of 4 log10 or more within 1 day, 4 days, or 7 days.

[0029] The term "biocides" is a general term used to describe chemical agents (such as pesticides, which are usually broad-spectrum) that inactivate living microorganisms.

[0030] The term "antibiotic" refers to an organic chemical substance, either synthetic or of natural origin, most commonly used at low concentrations to treat infectious diseases in humans, animals, and plants by preventing or inhibiting the growth of microorganisms.

[0031] Examples of antibiotics include therapeutic drugs such as penicillin, while biocides are disinfectants or antibacterial agents such as iodine.

[0032] Antibiotics typically have a single target and a highly specific mode of action, thus interacting with receptors in the cell membrane or the cell's metabolic or nucleic acid functions to inhibit enzymatic or metabolic processes, much like a "lock and key" to kill microorganisms. Biocides, on the other hand, have multiple targets and modes of action, which can include physical disruption and permanent damage to the outer cell membrane of bacteria and microorganisms. The difference between antibiotics and biocides is like trying to open a door with a key and a hammer.

[0033] In this invention, the biocide is selected from one or more of the following: Biguanides (e.g., chlorhexidine, alexiidine, polyhexamethylene biguanide and related salts). Reagents that release halogens (e.g., iodine, povidone-iodine, sodium hypochlorite, N-haloamines, etc.). Stabilizing oxidants such as chlorine dioxide, Stabilize peroxides (e.g., urea peroxide, mannitol peroxide). Contains metallic substances and their oxides (such as silver, copper, selenium, etc., in particulate form or incorporated into a carrier matrix such as zeolite or polymer). Sulfides (e.g., sodium metabisulfite) Bisphenols (such as triclosan, hexachlorophenol, etc.) Quaternary ammonium compounds (such as benzalkonium chloride, cetrimonium bromide, hexadecylpyridine chloride, quaternized cellulose and other quaternized polymers). Various "naturally occurring" reagents (such as polyphenols, citric acid, chitosan, anatase TiO2, tourmaline, bamboo extract, neem oil, etc. in green or black tea extracts). 1,2-Benzisothiazolin-3-one (BIT), 5-chloro-2-methyl-4-isothiazolin-3-one (CIT), 2-methyl-4-isothiazolin-3-one (MIT). 1,2-Dibromo-2,4-dicyanobutane (DBDCB), 2,2-dibromo-3-hydantoinamide (DBNPA), 2-bromo-2-nitro-1,3-propanediol (BNPD), aldehyde derivatives, formaldehyde-releasing reagents, hydantoin and chlorinated aromatic hydrocarbons.

[0034] Preferably, the biocide is selected from one or more of 1,2-benzisothiazolin-3-one (BIT), 5-chloro-2-methyl-4-isothiazolin-3-one (CIT), and 2-methyl-4-isothiazolin-3-one (MIT).

[0035] According to the aqueous polymer dispersion described above, the amount of anionic surfactant and / or cationic surfactant in the aqueous polymer dispersion is less than 1 wt%, preferably less than 0.5 wt%, more preferably less than 0.1 wt%, based on the total weight of vinyl acetate and ethylene monomer as 100 wt%.

[0036] According to the aqueous polymer dispersion described above, the amount of vinyl ester present in the aqueous polymer dispersion is 70 to 95% by weight, preferably 70 to 90% by weight, more preferably 70 to 85% by weight, most preferably 71-75% by weight or 81 to 85% by weight, and the amount of ethylene present is 5 to 30% by weight, preferably 10 to 25% by weight, more preferably 15 to 30% by weight, most preferably 25 to 29% by weight or 15 to 19% by weight, based on the total weight of vinyl acetate and ethylene monomer.

[0037] Polyvinyl alcohol According to the present invention, polyvinyl alcohol may be medium molecular weight polyvinyl alcohol, low molecular weight polyvinyl alcohol, or a combination thereof, preferably comprising at least one medium molecular weight polyvinyl alcohol and at least one low molecular weight polyvinyl alcohol.

[0038] As used herein, the term "medium molecular weight polyvinyl alcohol" refers to polyvinyl alcohol with a Hoppler viscosity of 10 to 35 mPa·s in a 4% by weight aqueous solution, measured at 20°C according to DIN 53015. The term "low molecular weight polyvinyl alcohol" refers to polyvinyl alcohol with a Hoppler viscosity of 3 to 10 mPa·s in a 4% by weight aqueous solution, measured at 20°C according to DIN 53015. Typically, the degree of hydrolysis for medium molecular weight polyvinyl alcohol is 85 to 99 mol%, and for low molecular weight polyvinyl alcohol it is 75 to 90 mol%.

[0039] Suitable medium molecular weight polyvinyl alcohols may be PVOH 25 / 88 and / or PVOH 117, but are not limited to these. Suitable low molecular weight polyvinyl alcohols may be PVOH 04 / 88, but are not limited to these.

[0040] According to the invention, the amount of polyvinyl alcohol used is suitably 2 to 8% by weight, preferably 2 to 6% by weight, for example 2% by weight, 3% by weight, 4% by weight, 5% by weight or 6% by weight, based on the total weight of vinyl acetate and ethylene monomer.

[0041] In some embodiments of the invention, the polyvinyl alcohol comprises a medium molecular weight polyvinyl alcohol and a low molecular weight polyvinyl alcohol, wherein the former has a degree of hydrolysis of 85 to 99 mol% and the latter has a degree of hydrolysis of 75 to 90 mol%.

[0042] In other embodiments of the invention, the polyvinyl alcohol comprises two medium molecular weight polyvinyl alcohols and one low molecular weight polyvinyl alcohol, wherein the first medium molecular weight polyvinyl alcohol has a degree of hydrolysis of 85 to 95 mol% and a Hoppler viscosity of 20 to 30 mPa·s in a 4 wt% aqueous solution at 20°C according to DIN 53015; the second medium molecular weight polyvinyl alcohol has a degree of hydrolysis of 95 to 99 mol% and a Hoppler viscosity of 10 to 20 mPa·s in a 4 wt% aqueous solution at 20°C according to DIN 53015; and the low molecular weight polyvinyl alcohol has a degree of hydrolysis of 75 to 90 mol% and a Hoppler viscosity of 3 to 10 mPa·s in a 4 wt% aqueous solution at 20°C according to DIN 53015.

[0043] Redox initiators According to the present invention, copolymerization is initiated by a redox initiator. Suitable oxidants may be one or more selected from sodium persulfate, potassium persulfate, ammonium persulfate, hydrogen peroxide, tert-butyl peroxide (e.g., tert-butyl hydrogen peroxide), potassium peroxydisulfate, tert-butyl peroxypentanoate, cumene hydroperoxide, and azobisisobutyronitrile, preferably one or a combination of sodium persulfate, potassium persulfate, ammonium persulfate, hydrogen peroxide, and tert-butyl peroxide. According to the present invention, the amount of oxidant used is suitably 0.1 to 2% by weight, preferably 0.2 to 1% by weight, based on the total weight of the vinyl ester and ethylene monomer.

[0044] Suitable reducing agents are selected from one or more of alkali metal or ammonium sulfites, bisulfites (e.g., sodium sulfite), hyposulfite derivatives (e.g., formaldehyde-zinc hyposulfite or formaldehyde-sodium hyposulfite), sulfinic acids or their salts (e.g., 2-hydroxy-2-sulfinyl acetate, disodium 2-hydroxy-2-sulfinyl acetate, zinc 2-hydroxy-2-sulfinyl acetate, or disodium 2-hydroxy-2-sulfinyl propionate), ascorbic acid or its salts (e.g., sodium ascorbate), isoascorbic acid or its salts (e.g., sodium isoascorbate), and tartaric acid, preferably one or more of sulfinic acids or their salts, ascorbic acid or its salts, and isoascorbic acid or its salts. Sulfinic acids or their salts may also be commercially available, such as Bruggolite® FF6, Bruggolite® FF6M, or Bruggolite® FF7 supplied by Brüggemann Chemical, Germany. According to the invention, the amount of reducing agent used is suitably 0.02 to 2% by weight, preferably 0.05 to 1% by weight, based on the total weight of vinyl ester and ethylene monomer.

[0045] Other comonomers In this invention, other comonomers refer to one or more monomers other than vinyl acetate, ethylene and monomer A according to formula (1) that can be free radical polymerized.

[0046] Examples of other comonomers in this invention include: halogenated ethylene, such as vinyl chloride; olefins having two or more carbon atoms, such as propylene; olefinically unsaturated carboxylic acids and their derivatives, such as fumaric acid, maleic acid, maleic anhydride, acrylamide, and acrylonitrile; pre-crosslinked or post-crosslinked comonomers, such as divinyl adipate, diallyl maleate, allyl methacrylate, triallyl cyanurate, acrylamide glycolic acid (AGA), methyl methacrylamidoglycolate (MAGME), and N-hydroxy... Methacrylamide (NMA), N-hydroxymethyl methacrylamide (NMMA), N-hydroxymethyl allyl carbamate, isobutoxy ether or ester of N-hydroxymethyl acrylamide, isobutoxy ether or ester of N-hydroxymethyl methacrylamide, isobutoxy ether or ester of N-hydroxymethyl allyl carbamate; epoxy functional comonomers such as glycidyl methacrylate (GAM) and glycidyl acrylate; and silicone functional comonomers such as vinyltrialkoxysilane and vinylmethyldialkoxysilane.

[0047] According to the present invention, the amount of other comonomers may be 10% by weight or less, for example 5% by weight or less, 2% by weight or less, 1% by weight or less, 0.5% by weight or less, 0.1% by weight or less or 0.01% by weight or less, based on the total weight of vinyl ester and ethylene monomers as 100% by weight.

[0048] According to the present invention, the amount of other comonomers may be 10% by weight or less, for example 5% by weight or less, 2% by weight or less, 1% by weight or less, 0.5% by weight or less, 0.1% by weight or less or 0.01% by weight or less, based on the total weight of vinyl acetate and ethylene monomers as 100% by weight.

[0049] According to the present invention, water-based polymer dispersions can be prepared by solution, dispersion, or suspension polymerization methods, with dispersion polymerization being preferred. The polymerization method can be divided into three stages: (1) before polymerization initiation, (2) during polymerization, and (3) after polymerization.

[0050] According to the present invention, the pre-polymerization initiation stage refers to the stage before the polymerization of monomers is initiated by an initiator. The post-polymerization stage refers to the stage where the reaction between vinyl ester and ethylene monomers is largely completed and the residual vinyl ester monomer content is 2% by weight or less (based on the total weight of vinyl ester monomers), or even 1% by weight or 5,000 ppm or less.

[0051] The initial materials added to the reactor before polymerization initiation include: a) At least partly, suitably, 40 to 100% by weight of the total ethylene, preferably 50 to 85% by weight of ethylene; b) At least partially, suitably 40 to 90% by weight of the total vinyl ester, preferably 30 to 85% by weight of the vinyl ester; and optionally, c) At least partially, suitably at least 20% by weight, preferably at least 50% by weight, and more preferably 100% by weight of the total weight of polyvinyl alcohol.

[0052] In some embodiments of the invention, the initial material prepared prior to polymerization initiation comprises 50 to 80% by weight of vinyl ester, 50 to 75% by weight of ethylene, and 100% by weight of polyvinyl alcohol, based on their total amounts.

[0053] Prior to polymerization initiation, once the initial materials are prepared and loaded into the reactor, their pH needs to be adjusted to less than 6, preferably less than 5, and more preferably 3 to 4. Organic or inorganic acids, preferably phosphoric acid or formic acid, are typically used for pH adjustment. A catalyst, such as ferrous ammonium sulfate, may also be added to the initial materials in the reactor to initiate and catalyze the polymerization reaction.

[0054] According to the invention, polymerization is typically carried out at 20 to 150°C, preferably 50 to 120°C. The pressure in the reactor is generally stable during polymerization, which is achieved by controlling the addition of ethylene and can be set at different levels to meet the pressure requirements of different formulations. Suitable pressures during polymerization are typically between 2 and 100 bar, preferably between 40 and 80 bar.

[0055] During aggregation The initial materials are typically heated to a temperature 10 to 40°C lower than the desired temperature, and the reactor is further heated to the reaction temperature by the heat released from the polymerization reaction before the remaining monomers are metered and fed, while the redox initiator is fed.

[0056] Monomer A is preferred in " During aggregation "Added in stages, and preferably in " During aggregation The stage is added to the reactor dropwise.

[0057] According to the present invention, after the vinyl ester-ethylene polymerization is completed, an antifoaming agent may optionally be added to the dispersion. Suitable antifoaming agents may be one or a combination of mineral oil-based antifoaming agents, higher fatty alcohol-based antifoaming agents, polyether-based antifoaming agents, and silicone-based antifoaming agents, preferably mineral oil-based antifoaming agents, wherein the mineral oil-based antifoaming agent is a defoaming agent with mineral oil (such as white oil, diesel oil, or kerosene) as a carrier and hydrophobic substances (such as fatty acid / fatty acid metal soaps, fatty acid amides, and higher fatty alcohols) as active antifoaming components. The amount of antifoaming agent may be 2% by weight or less, for example, 1% by weight or less, 0.5% by weight or less, or 0.2% by weight or less, based on the total weight of the vinyl ester and ethylene monomers as 100% by weight.

[0058] Detailed description of the preferred implementation scheme The present invention is further illustrated by the following embodiments, but is not limited thereto. Any experimental methods not specified in the following embodiments are selected according to conventional methods and conditions or product instructions.

[0059] Resistance to biological degradation test Aseptic examination Approximately 10 μg of each sample was screened on NA (nutrient agar) and PDA (potato dextrose agar) and incubated at 30°C / 25°C for 2–5 days to check for bacterial or fungal contamination. The detection limit of this method is approximately 100 CFU / g or 100 CFU / ml.

[0060] After passing sterility testing, the samples were used for wet challenge testing.

[0061] Wet Challenge Test Inoculate samples weekly with a mixed microbial suspension (containing bacteria and yeast) or an acetic acid bacterial suspension, using 1 ml of inoculum per 50 g sample. Shake or mix with a stirrer. Incubate samples at 30 ± 2 °C. After incubation, shake or thoroughly mix each sample and determine the presence of viable or growing bacteria. Routine incubation periods are 1, 4, and 7 days. Evaluation of streak plates is the same as for sterility testing.

[0062] The samples were tested in three rounds, each lasting seven days, with scores given on days 1, 4, and 7. A score of 0 on day 7 was considered a pass for that round. A score of 4 or higher on day 7 was considered a fail for that round.

[0063] If the score on day 7 of each of the three rounds of testing is 0, then it is recorded as follows: Through 3 rounds of testing If the score on day 7 of the first two rounds is 0, then it is recorded as... Through 2 rounds of testing If the score is 0 only on day 7 of the first round, then it is recorded as... Through 1 round of testing try .

[0064] Table 1

[0065] Table 2

[0066] Algae Challenge Experiment (1) Preparation of BG11 culture medium: Mix 1.7 g of BG11 culture medium (Haibo Biotechnology) with 1000 ml of distilled water and heat to dissolve; autoclave at about 121°C; then cool to room temperature (25°C) for later use.

[0067] (2) In a glass test tube, mix 100±5 g of BG11 culture medium and 10 g of the inoculated emulsion sample thoroughly. The inoculum concentration was 250 cells / mL, and the algal species was V algae, belonging to Vacuoliviride, Stramenopiles, Eustigmatophyceae.

[0068] (3) Place the test tubes obtained in step (2) into an artificial climate chamber (25°C), connect the air inlet and outlet pipes, adjust the bubbling rate, and start culturing in the artificial climate chamber.

[0069] (4) Continue culturing, observe with the naked eye every day to see if algae grow and record it; when algae are visible to the naked eye (the culture medium turns green, or there is green precipitate at the bottom of the test tube), record the number of days of culturing at this time.

[0070] Table 3

[0071] Table 4

[0072] Table 5

[0073] In Table 5, RT refers to the time when the sample was inoculated at room temperature and then subjected to a wet challenge test.

[0074] 50℃ 2w refers to the sample being stored at 50°C for 2 weeks prior to inoculation and wet challenge testing.

[0075] In Table 4, in each of the embodiments Ex.1-2, 6 and C.Ex.3-5, 7-8, the water-based ethylene-vinyl acetate base polymer dispersions used are almost identical, comprising 39-60% by weight of component i), i.e., a copolymer prepared by polymerization of vinyl acetate, ethylene and optional comonomers; 0.6-4% by weight of component iii) polyvinyl alcohol; and 39-60% by weight of component iv) water, wherein only the optional comonomers differ.

[0076] In Ex. 1-2, 6 and C. Ex. 3-5, 1 pphm or 0.4 pphm of comonomer is added during polymerization. Ethyl (2-dimethylamino)methacrylate and ethyl (2-dimethylamino)acrylate belong to monomer A of this invention, while N-[3-(dimethylamino)propyl]methacrylamide and methacrylamidopropyltrimethylammonium chloride do not belong to monomer A.

[0077] The products in Table 1 remained homogeneous and stable after being stored at 50°C for two weeks. This indicates good stability.

[0078] As used herein, the term “pphm” refers to the number of parts per hundred major monomers, that is, the number of parts per hundred vinyl acetate and ethylene.

[0079] C.Ex.7 does not contain comonomers. After polymerization, 200 ppm of the isothiazolinone complex was added to a water-based ethylene-vinyl acetate polymer dispersion to obtain product C.Ex.7. The isothiazolinone complex is a mixture of CIT, MIT, and BIT. The dosage was 200 ppm, based on 100% by weight of the water-based polymer dispersion. Product C.Ex.8 showed good antibacterial activity but poor antialgae activity.

[0080] Furthermore, in C.Ex.8, ethyl (2-dimethylamino)methacrylate was polymerized separately to obtain the homopolymer PDMAEMA. PDMAEMA was then added to an aqueous ethylene-vinyl acetate-based polymer dispersion to obtain the C.Ex.8 product, wherein the amount of ethyl (2-dimethylamino)methacrylate was 1 pphm. After storage at 50°C for 2 weeks, the C.Ex.8 product underwent phase separation, and a homogeneous and stable aqueous dispersion could not be obtained.

Claims

1. A water-based polymer dispersion comprising... Component i) A copolymer, said copolymer being prepared by monomer polymerization comprising vinyl ester, ethylene and monomer A according to formula (1), (1) Wherein R1 is H or C1-C4 alkyl; R2 is C1-C4 alkylene; R3 and R4 are C1-C4 alkyl. Component iv) Water, The amount of monomer A is 0.10 to 5% by weight, preferably 0.40 to 5% by weight, more preferably 0.40 to 3% by weight, and even more preferably 0.40 to 2% by weight, based on the total weight of vinyl ester and ethylene monomer as 100% by weight. The total amount of vinyl ester and ethylene is greater than 80% by weight, preferably greater than 85% by weight, preferably greater than 90% by weight, more preferably greater than 95% by weight, more preferably greater than 97% by weight, more preferably greater than 98% by weight, more preferably greater than 98.5% by weight, based on the total weight of the copolymer of component i) as 100% by weight.

2. The water-based polymer dispersion according to claim 1, wherein the vinyl ester is selected from one or more of vinyl acetate, vinyl butyrate, vinyl propionate, vinyl pentanoate, vinyl 2-ethylhexanoate, 1-methyl vinyl acetate, and vinyl laurate, preferably the vinyl ester is vinyl acetate.

3. The water-based polymer dispersion according to claim 1 or 2, wherein in monomer A, R1 is H or C1-C2 alkyl; R2 is C1-C3 alkylene; R3 and R4 are C1-C2 alkyl, preferably R1 is H or methyl; R2 is ethylene or propylene; and R3 and R4 are methyl.

4. The water-based polymer dispersion according to any one of claims 1-3, wherein the monomer A is one or more selected from (2-dimethylamino)ethyl methacrylate, (2-dimethylamino)ethyl acrylate, dimethylaminopropyl methacrylate and 3-(dimethylamino)propyl acrylate.

5. The water-based polymer dispersion according to any one of claims 1-4, wherein the amount of "biocide" and "antibiotic" is less than 800 ppm, preferably less than 500 ppm, more preferably less than 200 ppm, more preferably less than 100 ppm, and even more preferably less than 50 ppm.

6. The water-based polymer dispersion according to any one of claims 1-5, wherein the total amount of vinyl acetate, ethylene and monomer A is greater than 85% by weight, preferably greater than 90% by weight, more preferably greater than 95% by weight, more preferably greater than 97% by weight, more preferably greater than 98% by weight, more preferably greater than 99% by weight, more preferably greater than 99.5% by weight, more preferably greater than 99.9% by weight, based on the total weight of the copolymer of component i) as 100% by weight.

7. The water-based polymer dispersion according to any one of claims 1-6, comprising: 39-60% by weight of component i), said component i) being a copolymer prepared by monomer polymerization comprising vinyl ester, ethylene and monomer A according to formula (1), 0.6-4% by weight of component iii) protective colloid, and 39-60% by weight of the component (iv) water, The total weight of the water-based polymer dispersion is taken as 100% by weight.

8. The water-based polymer dispersion according to any one of claims 1-7 is preferably used in the field of anti-biological degradation of polymer emulsions.

9. A water-based dispersion resistant to biological degradation, comprising a water-based polymer dispersion according to any one of claims 1-7.

10. A composition comprising a product obtained by drying a water-based polymer dispersion according to any one of claims 1-7.

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