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CN-122011908-A - Nontoxic environment-friendly water-based protective coating and preparation method thereof

CN122011908ACN 122011908 ACN122011908 ACN 122011908ACN-122011908-A

Abstract

The invention relates to a nontoxic environment-friendly water-based protective coating and a preparation method thereof, belonging to the technical field of coatings, the coating comprises the components of siloxane-bio-based polyester composite emulsion, cyclodextrin-sodium phytate-ketimine composite cross-linking agent, composite nano reinforcing slurry, talcum powder, hydrophilic fumed silica, sodium glycinate and deionized water. The siloxane-bio-based polyester composite emulsion is prepared from D4, tetramethyl ammonium hydroxide, AGE, trimethylolpropane triglycidyl ether mixed solution, bio-based polyester polyol, an emulsifying agent and isomeric decaol polyoxyethylene ether. The cyclodextrin-sodium phytate-ketimine composite cross-linking agent is prepared from beta-cyclodextrin, epichlorohydrin, sodium phytate, ketimine and the like. The composite nano reinforced slurry is prepared by modifying and dispersing lithium magnesium silicate and nano silicon dioxide through NDZ-201 titanate, KH550, sodium glycolate, sodium polyacrylate and the like. The paint realizes no toxicity and low emission, and improves the adhesive force and the medium permeation resistance.

Inventors

  • CHEN YUN
  • ZHU HUIMING

Assignees

  • 中华制漆（深圳）有限公司

Dates

Publication Date
20260512
Application Date
20260313

Claims (10)

  1. 1. The nontoxic environment-friendly water-based protective coating is characterized by comprising, by mass, 60-65 parts of siloxane-bio-based polyester composite emulsion, 4-6 parts of cyclodextrin-sodium phytate-ketimine composite cross-linking agent, 7-11 parts of composite nano reinforcing slurry, 4-7 parts of talcum powder, 0.9-1.3 parts of hydrophilic fumed silica, 0.2-0.4 part of sodium glycinate and 18-24 parts of deionized water; The silicone-bio-based polyester composite emulsion is prepared by adding tetramethyl ammonium hydroxide into D4 for reflux reaction at 90-95 ℃, dropwise adding AGE and trimethylolpropane triglycidyl ether mixed solution at 65-70 ℃, preserving heat at 65-70 ℃, reacting at 80-85 ℃, adding bio-based polyester polyol, reacting at 85-90 ℃, adding emulsifying agent and isomeric decanol polyoxyethylene ether for shearing at 40-45 ℃, dropwise adding deionized water to prepare a product with the solid content of 40-45 wt%, wherein the bio-based polyester polyol is prepared by adding PDO, SA, MA for heat preservation at 155-165 ℃, adding tetrabutyl titanate for reacting at 195-205 ℃, adding hydroquinone and phenothiazine at 145-155 ℃, and stirring; The cyclodextrin-sodium phytate-ketimine composite cross-linking agent is prepared by dissolving beta-cyclodextrin in deionized water, adjusting pH to 11-12 at 40-45 ℃ for activation, dropwise adding epichlorohydrin for reaction at 55-60 ℃, adding 20-22wt% of sodium phytate aqueous solution at 45-50 ℃ for reaction at 65-70 ℃, adding ketimine at 50-55 ℃ for stirring, neutralizing with sodium glycinate at 35-40 ℃ to pH 7-8, and filtering; The composite nano reinforced slurry is prepared by adding magnesium lithium silicate and nano silicon dioxide into a mixer, diluting NDZ-201 titanate with absolute ethyl alcohol, spraying the diluted NDZ-201 titanate into the mixer for stirring, pre-hydrolyzing KH550 with an aqueous solution of ethyl alcohol, spraying the diluted KH550 into the mixer for stirring, adding a mixed solution of sodium glycolate, sodium polyacrylate and deionized water, ball milling, curing and filtering.
  2. 2. The nontoxic environment-friendly water-based protective coating according to claim 1, wherein the siloxane-bio-based polyester composite emulsion is prepared by adding tetramethyl ammonium hydroxide into the emulsion D4, carrying out reflux reaction for 3-4 hours at 80-85 ℃, dropwise adding mixed solution of AGE and trimethylolpropane triglycidyl ether at 65-70 ℃, carrying out heat preservation for 1.5 hours at 65-70 ℃, carrying out reaction for 1-1.5 hours at 80-85 ℃, adding bio-based polyester polyol into the emulsion D4, carrying out reaction for 2.5-3 hours at 85-90 ℃, carrying out reaction for 2.5-3 hours at 80-45 ℃, adding emulsifying agent into the emulsion D4, carrying out reflux reaction for 40-45 hours at 90-95 ℃, carrying out reflux reaction for 3-4 hours at 65-70 ℃, dropwise adding mixed solution of AGE and trimethylolpropane triglycidyl ether at 65-70 ℃, carrying out heat preservation for 1.5 hours at 80-85 ℃, adding bio-polyester polyol into the emulsion D4 to obtain a product, and carrying out reflux reaction for 1-1.5 hours at 80-90 ℃, adding the emulsion D4 to obtain a product, and carrying out reflux reaction for 800-1000 rpm; The bio-based polyester polyol is prepared by mixing PDO, SA, MA, tetrabutyl titanate, hydroquinone and phenothiazine (145-155), 115-120, 95-100, 0.4-0.6, 0.2-0.4 and 0.05-0.1) in a mass ratio, keeping the temperature of PDO, SA, MA at 155-165 ℃ for 1-1.5 h, adding tetrabutyl titanate, reacting for 4-6 h at 195-205 ℃, adding hydroquinone and phenothiazine at 145-155 ℃ and stirring.
  3. 3. The non-toxic and environment-friendly water-based protective coating according to claim 2, wherein the preparation method of the siloxane-bio-based polyester composite emulsion comprises the following steps: 1, keeping the temperature of 145-155 parts of PDO, 115-120 parts of SA and 95-100 parts of MA at 155-165 ℃ for 1-1.5 hours, adding 0.4-0.6 part of tetrabutyl titanate, and reacting at 195-205 ℃ for 4-6 hours, adding 0.2-0.4 part of hydroquinone and 0.05-0.1 part of phenothiazine at 145-155 ℃, and stirring to obtain bio-based polyester polyol; The preparation method comprises the steps of stirring 25-30 parts by mass of D4 at 80-85 ℃, adding 0.12-0.18 part by mass of tetramethylammonium hydroxide, carrying out reflux reaction at 90-95 ℃ for 3-4 hours to obtain hydroxyl-terminated polysiloxane, dropwise adding 10-14 parts by mass of mixed solution of AGE and 4-5 parts by mass of trimethylolpropane triglycidyl ether at 65-70 ℃, carrying out heat preservation at 65-70 ℃ for 1.5-2 hours, carrying out reaction at 80-85 ℃ for 1-1.5 hours, adding 6-9 parts by mass of bio-based polyester polyol, carrying out reaction at 85-90 ℃ for 2.5-3 hours, adding 1.5-2.0 parts by mass of emulsifier and 0.2-0.4 part by mass of isomeric dodecanol polyoxyethylene ether at 800-1000 rpm, carrying out shearing, dropwise adding 40-45 parts by mass of deionized water, cooling to 25-30 ℃, regulating the solid content to 40-45 wt%, and filtering to obtain the silicone-bio-based polyester composite emulsion.
  4. 4. The nontoxic environment-friendly water-based protective coating is characterized in that the cyclodextrin-sodium phytate-ketimine composite cross-linking agent is beta-cyclodextrin, epichlorohydrin, 20-22wt% of sodium phytate aqueous solution, ketimine is added according to the mass ratio of (12-15): (3-3.5): (8-10): (2.5-3.5), the beta-cyclodextrin is dissolved in deionized water, pH is adjusted to 11-12 at 40-45 ℃ for activation, epichlorohydrin is added dropwise for reacting for 4.5-5 hours at 55-60 ℃, 20-22wt% of sodium phytate aqueous solution is added at 45-50 ℃ for reacting for 3.5-4 hours at 65-70 ℃, ketimine is added at 50-55 ℃ for stirring for 1-1.5 hours, sodium glycinate is used for neutralizing to pH 7-8 at 35-40 ℃, and the water-based protective coating is prepared through filtration.
  5. 5. The nontoxic environment-friendly water-based protective coating is characterized in that the preparation method of the cyclodextrin-sodium phytate-ketimine compound cross-linking agent comprises the steps of adding 12-15 parts by mass of beta-cyclodextrin into 90-100 parts by mass of deionized water, stirring and dissolving at 60-70 ℃, reducing to 40-45 ℃, adjusting pH to 11-12 for activation, dropwise adding 3-3.5 parts by mass of epichlorohydrin, reacting at 55-60 ℃ for 4.5-5 hours, obtaining an epoxy modified beta-cyclodextrin solution, reducing to 45-50 ℃, adding 8-10 parts by weight of 20-22 wt% sodium phytate aqueous solution, keeping pH >9, reacting at 65-70 ℃ for 3.5-4 hours, reducing to 50-55 ℃, adding 2.5-3.5 parts by mass of ketimine, stirring for 1-1.5 hours, reducing to 35-40 ℃, neutralizing with sodium glycinate to pH 7-8, and filtering to obtain the cyclodextrin-sodium phytate-ketimine compound cross-linking agent.
  6. 6. The nontoxic environment-friendly water-based protective coating is characterized in that the preparation method of ketimine comprises the steps of carrying out reflux reaction on 80-90 parts by mass of IPDA, 95-105 parts by mass of MIBK and 5-10 parts by mass of toluene at 105-115 ℃ for 5.5-6.5 hours, and carrying out reduced pressure distillation to obtain ketimine with a solid content of more than 98 wt%.
  7. 7. The nontoxic environment-friendly water-based protective coating is characterized in that the composite nano reinforcing slurry is prepared by adding (25-35) magnesium lithium silicate, nano silicon dioxide, NDZ-201 titanate, KH550, sodium glycolate, sodium polyacrylate and deionized water (4-6), (2-3), 1.0-1.5, 1.2-1.8) and 0.3-0.6 (65-70) into a mixer, diluting NDZ-201 titanate with absolute ethyl alcohol, spraying the diluted NDZ-201 titanate into the mixer, stirring, spraying the pre-hydrolyzed KH550 with an aqueous ethanol solution, stirring, adding a mixed solution of sodium glycolate, sodium polyacrylate and deionized water, ball milling for 3-3.5 hours, stirring and curing for 5.5-6.5 hours at 25-35 ℃, and filtering.
  8. 8. The nontoxic environment-friendly water-based protective coating is characterized in that the preparation method of the composite nano reinforcing slurry comprises the steps of adding 25-35 parts by mass of magnesium lithium silicate and 4-6 parts by mass of nano silicon dioxide into a mixer, diluting 2-3 parts by mass of NDZ-201 titanate by absolute ethyl alcohol, spraying mist into the mixer for stirring, spraying 1.0-1.5 parts by mass of KH550 by aqueous ethanol solution for prehydrolysis, spraying mist into the mixer for stirring, adding a mixed solution of 1.2-1.8 parts by mass of sodium glycolate, 0.3-0.6 part by mass of sodium polyacrylate and 65-70 parts by mass of deionized water, ball milling for 3-3.5 hours to obtain slurry with the particle size D90 of 500nm, stirring and curing at 25-35 ℃ for 5.5-6.5 hours, and filtering to obtain the composite nano reinforcing slurry.
  9. 9. The method for preparing the nontoxic environment-friendly water-based protective coating as claimed in claim 1, which is characterized by comprising the following steps: Adding sodium glycinate into deionized water according to a coating formula, stirring, adding hydrophilic fumed silica, stirring, adding talcum powder and composite nano reinforcing slurry, stirring, adding siloxane-bio-based polyester composite emulsion, stirring, adding cyclodextrin-sodium phytate-ketimine composite cross-linking agent, stirring, vacuum defoaming, and filtering to obtain the coating.
  10. 10. The preparation method of the nontoxic environment-friendly water-based protective coating is characterized by comprising the steps of adding deionized water into a coating formula, stirring for 3-5 min at 200-300 rpm, adding hydrophilic fumed silica, stirring for 8-12 min at 400-600 rpm, adding talcum powder and composite nano reinforcing slurry, stirring for 15-20 min at 600-800 rpm, adding silicone-bio-based polyester composite emulsion, stirring for 15-20 min at 600-800 rpm, adding cyclodextrin-sodium phytate-ketimine composite cross-linking agent, stirring for 10-15 min at 600-800 rpm, defoaming for 5-10 min at-0.07 MPa under vacuum, and filtering for 100-150 meshes to obtain the coating.

Description

Nontoxic environment-friendly water-based protective coating and preparation method thereof Technical Field The invention belongs to the technical field of coatings, and particularly relates to a nontoxic environment-friendly water-based protective coating and a preparation method thereof. Background Along with the popularization of the stricter and green manufacturing concepts of environmental protection, the traditional solvent type coating is gradually replaced by the environmental friendly type coating due to the defects of high emission of volatile organic compounds, great irritation, inflammability, explosiveness and the like. The water-based protective coating takes water as a main dispersion medium, contains no or only a very small amount of organic solvent, has the advantages of low toxicity, no smell, no pollution, safe construction, convenient storage and transportation and the like, is widely applied to the fields of metal corrosion prevention, building decoration, rail transit, ship engineering, mechanical equipment and the like, and becomes the main stream development direction of a modern protective coating system. The current water-based protective coating mainly uses water-based acrylic acid, water-based epoxy, water-based polyurethane, water-based alkyd and a modified copolymerization system thereof as core base materials, and forms a film through the modes of emulsion polymerization, physical dispersion, crosslinking solidification and the like, so that the functions of corrosion prevention, rust prevention, decoration and protection of a foundation can be realized in a conventional environment. Compared with the traditional solvent type product, the water-based paint is obviously upgraded on environmental protection indexes, and can meet the use requirements of most indoor and conventional outdoor scenes. However, the existing water-based protective coating is limited by the characteristics of the water-based system, and short plates which are difficult to ignore still exist in the comprehensive performance, so that the requirements of severe working conditions such as high-end equipment, heavy corrosion environment, long-acting service and the like cannot be completely matched. The most prominent problems of the current water-based protective coating are concentrated on insufficient protection stability. The water volatilization rate is slow, so that the early water resistance of the coating is poor, the phenomena of blushing, back-sticking, foaming and the like are easy to occur when the coating meets water, and the construction efficiency and the film forming quality are seriously affected. Meanwhile, the interface wetting capability of the water-based resin and the substrate is weak, and the chemical bonding is insufficient, so that the adhesive force of the coating is low, the problems of peeling, cracking and other failure easily occur under the conditions of cold and hot circulation, mechanical vibration and salt spray erosion, and the protection service life is greatly shortened. In terms of corrosion resistance and medium resistance, tiny pores are easy to remain in the cured aqueous coating to form a permeation channel of water vapor, chloride ions and acid-base mediums, dense blocking is difficult to realize, and substrate corrosion and coating bulge and shedding are easy to occur after long-term service. In conclusion, the existing water-based protective coating is difficult to cooperatively balance in terms of environmental protection, adhesive force and corrosion resistance, and cannot meet the dual requirements of high-end scenes on non-toxicity, high protection and long-acting stability. Therefore, development of a novel water-based protective coating is needed, and improvement of performance indexes is considered while non-toxicity and environmental protection are ensured. Disclosure of Invention Aiming at the problem that the environmental protection safety and the excellent protection performance of the water-based protective coating in the prior art are difficult to be compatible, the invention provides the nontoxic environment-friendly water-based protective coating and the preparation method thereof, and the compactness, the adhesive force and the medium permeation resistance of the coating are improved on the basis of realizing nontoxic low emission by optimizing a resin structure, adopting a non-assistant film forming technology, adopting interface enhancement modification and adopting a nontoxic crosslinking system design, so that the unification of the environmental protection performance and the protection performance is truly achieved, and the requirements of high-end green protection in multiple fields are met. The specific technical scheme is as follows: The nontoxic environment-friendly water-based protective coating comprises, by mass, 60-65 parts of siloxane-bio-based polyester composite emulsion, 4-6 parts of cyclodextrin-sodium phytate-ketimine composit