Preparation method of polyurethane water-based flame-retardant coating for metal
By using ammonium phosphate APP, melamine, and triazine-forming flame retardant system in polyurethane water-based flame retardant coatings, and adding aqueous rust-proof agents of silicate matrix, the problem of poor smoke release and flame retardant effects in the flame retardant process of existing coatings is solved, and efficient flame retardant and rust-proof effects are achieved, which is suitable for metal surface coating.
Patent Information
- Application Number
- CN202310757827.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-10-13
- Publication Date
- 2025-04-15
AI Technical Summary
The existing polyurethane water-based flame retardant coatings will release a large amount of smoke during the flame retardant process, and the oxygen content in the smoke is low, which poses a risk of suffocation; its flame retardant effect is poor and the carbonization time is short; it cannot add an anti-rust layer to the metal surface to resist water droplet corrosion and copper sulfate oxidation.
A flame retardant system consisting of a mixture of ammonium polyphosphate APP, melamine and triazine carbon-forming agent is used, and a water-based anti-rust agent with silicate as the matrix is added to the water-based polyurethane coating. Through efficient stirring and grinding technology, a polyurethane water-based flame retardant coating for metals with excellent flame retardant effect and anti-rust performance is prepared.
It significantly reduces the amount of smoke released by the paint during combustion, improves the flame retardant effect and carbonization time, ensures the anti-rust effect of the metal surface, extends the service life of the metal, and is suitable for sanitary sensitive areas.
Smart Images
Figure FT_1 
Figure FT_2 
Figure FT_3
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of polyurethane water-based flame-retardant coatings, and in particular to a method for preparing polyurethane water-based flame-retardant coatings for metals. Background Art
[0002] Polyurethane water-based flame retardant coatings have been a hot topic in recent years due to environmental protection. Waterborne polyurethane is a polyurethane resin containing hydrophilic groups in the molecular chain of polyurethane. It has a strong affinity with water and can be dispersed in water to form a stable system using a specific process. The flame retardancy of waterborne polyurethane is one of the important directions of waterborne polyurethane functionalization.
[0003] The existing technology has the following problems: Existing polyurethane water-based flame retardant coatings release a large amount of smoke during the flame retardant process. At the same time, the oxygen content in the smoke is low, which easily poses a risk of suffocation. Moreover, the flame retardant system used in non-expandable water-based polyurethane flame retardant coatings has a poor flame retardant effect and a fast carbonization time when burned. And when used to coat metal surfaces, it is impossible to add an anti-rust layer to the metal to resist water droplet corrosion and copper sulfate oxidation. Summary of the invention
[0004] The present invention provides a method for preparing a polyurethane water-based flame-retardant coating for metal to solve the problems raised in the above background technology.
[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: A method for preparing a polyurethane water-based flame-retardant coating for metal, the method comprising the following steps: S1 weighing the raw materials of the polyurethane water-based flame-retardant coating according to a weight ratio, then placing a beaker in a constant temperature water bath for preheating, then adding the raw materials in sequence for stirring, and adding the stirred and mixed raw materials into an emulsion for slurry mixing; During the stirring and slurrying process S2, the weight of the silicate, organic base, borate, complexing agent and tungstate are weighed, each group of raw materials is put into water, heated and stirred, orthosilicate and surfactant are added and stirred, and then cooled to obtain a water-based rust inhibitor; S3 grinds the slurry obtained in S1 with a conical grinder, adds emulsion, defoamer and leveling agent, stirs at high speed, and adds water-based rust inhibitor until it is evenly dispersed to prepare a water-based polyurethane flame retardant coating.
[0006] The further improvement of the technical solution of the present invention is that: the step S1 comprises: S11 according to the ratio of raw materials to formula / mass part 1, specifically waterborne polyurethane: 125 parts, ammonium polyphosphate APP: 30 parts, melamine: 18 parts, triazine carbonizing agent: 9 parts, titanium dioxide: 3 parts, distilled water: 50 parts; S12: preheating distilled water in a constant temperature water bath, controlling the speed of the stirrer at 300 r / min, and sequentially adding ammonium polyphosphate APP, melamine, triazine carbonizing agent and titanium dioxide into the beaker; After the S13 raw material is added, the stirring rate is increased to 1000 r / min-1300 r / min. After stirring for 30 minutes, the aqueous polyurethane emulsion is added to prepare the slurry. After continuous stirring for 50 minutes, the slurry is obtained.
[0007] The further improvement of the technical solution of the present invention is that the step S2 comprises: S21 adding silicate, organic base, borate, complexing agent and tungstate to water again, raising the temperature to 50°C to 90°C and stirring for 40min to 60min to fully mix the mixed solution; S22 The silicate is sodium silicate and potassium silicate, the organic base is triethanolamine, diethanolamine and triethylamine, the borate is triethanolamine borate, the complexing agent is ethylenediaminetetraacetic acid, the tungstate is sodium tungstate, the surfactant is sodium dodecyl sulfate, and the orthosilicate is tetraethyl orthosilicate; After the stirring in S23 is completed, 3 ml of tetraethyl orthosilicate and 0.3 g of activator sodium dodecyl sulfate are added, and the mixture is stirred for 10 min and then cooled to room temperature to obtain a water-based rust inhibitor.
[0008] The further improvement of the technical solution of the present invention is that the step S3 comprises: S31 adding the emulsion into the conical grinder, and adding the remaining polyurethane emulsion and 0.05% of the defoaming agent and 0.1% of the leveling agent into the conical grinder and grinding to a fineness of less than 70um, and then adding into the agitator; S32 was stirred in a stirrer at 1500 r / min for 30 min, a water-based rust inhibitor was added, and after continuous high-speed stirring for 10 min, the solid content was adjusted to 50% with distilled water to prepare a water-based polyurethane flame-retardant coating.
[0009] Due to the adoption of the above technical solution, the present invention has the following technical advances compared with the prior art: The present invention provides a method for preparing a polyurethane water-based flame-retardant coating for metal. The flame-retardant system composed of ammonium polyphosphate APP, melamine and a triazine carbonizing agent is used to prepare a polyurethane water-based flame-retardant coating for metal. Compared with the flame-retardant system composed of aluminum hydroxide AI(OH)3 and magnesium hydroxide Mg(OH)2 used in general water-based polyurethane coatings, the flame-retardant effect is better and the carbonization time is more lasting. The carbonization time of the former is more than 1 times that of the latter.
[0010] The invention provides a method for preparing a polyurethane water-based flame-retardant coating for metal. The flame-retardant polyurethane coating prepared by using ammonium polyphosphate APP, melamine and a triazine carbonizing agent releases significantly less smoke when burning than a traditional flame-retardant polyurethane, has a limiting oxygen index of more than 28 (ASTMD2863 standard test result), reaches the Vo level (UL94 standard test result), has a good flame-retardant effect, and has excellent environmental protection characteristics. It has a very low odor and is suitable for on-site construction, and can be used in hygienic sensitive areas.
[0011] The present invention provides a method for preparing a polyurethane water-based flame-retardant coating for metal. By adding a silicate-based water-based rust inhibitor into the water-based polyurethane coating, the copper sulfate oxidation resistance and water drop corrosion resistance of the metal can be better protected, the anti-rust effect of the metal can be improved, and the service life of the metal can be increased. At the same time, the anti-rust time is long, and the metal can be rust-proofed for a long time after coating. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a schematic diagram of the process of the present invention; Figure 2 is the weight portion of the water-based flame retardant coating of the present invention; Figure 3 It is the weight part of the water-based rust inhibitor of the present invention. Implementation
[0013] The present invention is further described in detail below in conjunction with embodiments: Example
[0014] like Figure 1-3 As shown, the present invention provides a method for preparing a polyurethane water-based flame-retardant coating for metal, comprising the following steps: S1 weighing the raw materials of the polyurethane water-based flame-retardant coating according to a weight ratio, then putting a beaker in a constant temperature water bath for preheating, then adding the raw materials in sequence for stirring, adding the raw materials after stirring and mixing to an emulsion for slurry adjustment, S2 weighing the weight of silicate, organic base, borate, complexing agent and tungstate during the stirring and slurry adjustment process, adding each group of raw materials into water, heating and stirring, stirring and receiving, adding orthosilicate and surfactant, continuing to stir and cool to obtain a water-based rust inhibitor, S3 grinding the slurry obtained in S1 with a conical grinder, adding an emulsion, a defoamer and a leveling agent, stirring at a high speed, and adding the water-based rust inhibitor until it is evenly dispersed to prepare a water-based polyurethane flame-retardant coating.
[0015] In this embodiment, by adopting a flame retardant system composed of ammonium phosphate APP, melamine, and triazine carbonizing agent, and adding a silicate-based water-based rust inhibitor during the mixing process, the flame retardant effect of the metal is increased while the metal's resistance to copper sulfate oxidation and water droplet corrosion is improved. In addition, the smoke released during the flame retardant process can also be greatly reduced, avoiding the generation of a large amount of toxic gases during the flame retardant process. The prepared polyurethane water-based flame retardant coating for metal has excellent environmental protection characteristics, very low odor, is suitable for on-site construction, and can be used in hygiene-sensitive areas. Example
[0016] like Figure 1-3 As shown, on the basis of Example 1, the present invention provides a technical solution: Preferably, step S1 includes S11 according to the ratio of raw materials to formula / mass parts 1, specifically water-based polyurethane: 125 parts, ammonium polyphosphate APP: 30 parts, melamine: 18 parts, triazine carbon former: 9 parts, titanium dioxide: 3 parts, distilled water: 50 parts, S12 first add distilled water to a beaker in a constant temperature water bath for preheating, use a stirrer to control the speed at 300r / min, and add ammonium polyphosphate APP, melamine, triazine carbon former and titanium dioxide to the beaker in sequence, S13 increase the stirring rate to 1000r / min~1300r / min after the raw materials are added, stir for 30min, add water-based polyurethane emulsion for slurrying, and continue stirring for 50min to obtain slurry.
[0017] In this embodiment, the raw materials are weighed according to weight: 125 parts of water-based polyurethane, 30 parts of ammonium polyphosphate APP, 18 parts of melamine, 9 parts of triazine carbonizing agent, 3 parts of titanium dioxide, and 50 parts of distilled water. After weighing, distilled water is first added to a beaker in a constant temperature water bath for preheating, and then ammonium polyphosphate APP, melamine, triazine carbonizing agent and TiO2 are added in sequence with low-speed stirring. After the addition, the stirring rate is increased to 1000r / min~1300r / min to evenly disperse the components, and part of the water-based polyurethane emulsion is added to adjust the slurry. Example
[0018] like Figure 1-3As shown, on the basis of Example 1, the present invention provides a technical solution: preferably, step S2 includes S21 adding silicate, organic base, borate, complexing agent and tungstate to water again, raising the temperature to 50°C~90°C and stirring for 40min~60min to fully mix the mixed solution, S22 the silicate is sodium silicate and potassium silicate, the organic base is triethanolamine, diethanolamine and triethylamine, the borate is triethanolamine borate, the complexing agent is ethylenediaminetetraacetic acid, the tungstate is sodium tungstate, the surfactant is sodium dodecyl sulfate, and the orthosilicate is tetraethyl orthosilicate, S23 after the stirring is completed, add 3ml of tetraethyl orthosilicate and 0.3g of activator sodium dodecyl sulfate, continue stirring for 10min and then cool to room temperature to obtain a water-based rust inhibitor.
[0019] In this embodiment, silicate (sodium silicate), organic base (triethanolamine), borate (triethanolamine borate), complexing agent (ethylenediaminetetraacetic acid) and tungstate (sodium tungstate) are added to water, heated and stirred, and a mixed solution is prepared. Silicate, organic base, borate, complexing agent and tungstate are added to water, heated and stirred, and the temperature is raised to 50°C~90°C for stirring, so that the dissolution rate of each component can be accelerated, and the components can be mixed more evenly, wherein the acidic component and the alkaline component can react partially or completely to make the rust inhibitor more stable, and the stirring time is 40 to 60 minutes to make the mixed solution fully mixed and the mixed solution stable, and orthosilicate (tetraethyl orthosilicate) and surfactant (sodium dodecyl sulfate) are added to the obtained mixed solution, stirred, and cooled to prepare a water-based rust inhibitor, which uses silicate as a matrix, has a good rust prevention effect, and a long rust prevention time. Example
[0020] like Figure 1-3 As shown, on the basis of Example 1, the present invention provides a technical solution: Preferably, step S3 includes S31 adding slurry into a conical grinder, and adding the remaining polyurethane latex and 0.05% of a defoaming agent and 0.1% of a leveling agent into the conical grinder and grinding to a fineness of less than 70um, and adding into a stirrer, S32 stirring at 1500r / min in the stirrer for 30min, adding a water-based rust inhibitor, and continuously stirring at a high speed for 10min, and adjusting the solid content to 50% with distilled water to prepare a water-based polyurethane flame retardant coating.
[0021] In this embodiment, the mixture is ground with a conical mill to a fineness of less than 70 um, the remaining emulsion and 0.05% of a defoaming agent and 0.1% of a leveling agent are added, and after stirring for 30 minutes, a water-based rust inhibitor is added and continued to be stirred at a high speed to disperse evenly, and the solid content is adjusted to 50% with distilled water to prepare a water-based polyurethane flame retardant coating.
[0022] The working principle of the preparation method of the polyurethane water-based flame-retardant coating for metal is described in detail below.
[0023] like Figure 1-3 As shown, the raw materials are weighed according to weight, including 125 parts of waterborne polyurethane, 30 parts of ammonium polyphosphate APP, 18 parts of melamine, 9 parts of triazine carbon former, 3 parts of titanium dioxide and 50 parts of distilled water. After weighing, distilled water is first added to a beaker for preheating in a constant temperature water bath, and then ammonium polyphosphate APP, melamine, triazine carbon former and TiO2 are added in sequence with low-speed stirring. After the addition, the stirring rate is increased to 1000r / min-1300r / min to uniformly disperse the components, add part of the waterborne polyurethane emulsion, adjust the slurry, and add silicate (sodium silicate), organic base (triethanolamine), borate (triethanolamine borate), complexing agent (ethylenediaminetetraacetic acid) and tungstate (sodium tungstate) to the water again during the stirring preparation process, and the temperature is raised and stirred to obtain a mixed solution. Silicate, organic base, borate, complexing agent and tungstate are added to the water. , heating and stirring, raising the temperature to 50°C~90°C and stirring, thereby accelerating the dissolution rate of each component and making the components more evenly mixed, wherein the acidic component and the alkaline component can partially or completely react to make the rust inhibitor more stable, stirring for 40 to 60 minutes to make the mixed solution fully mixed and stable, adding orthosilicate (tetraethyl orthosilicate) and surfactant (sodium dodecyl sulfate) to the prepared mixed solution, stirring and cooling, preparing a water-based rust inhibitor, the water-based rust inhibitor uses silicate as a matrix, has good rust prevention effect, and a long rust prevention time, finally grinding with a conical mill to a fineness of less than 70um, adding the remaining emulsion and 0.05% defoaming agent and 0.1% leveling agent, stirring for 30 minutes, adding the water-based rust inhibitor and continuing to stir at high speed to disperse evenly, adjusting the solid content to 50% with distilled water, and preparing a water-based polyurethane flame retardant coating.
[0024] The above generally describes the present invention in detail, but it is obvious to a person skilled in the art that some modifications or improvements can be made to the present invention. Therefore, modifications or improvements that do not depart from the spirit of the present invention are within the scope of protection of the present invention.
Claims
1. A method for preparing a polyurethane water-based flame-retardant coating for metal, characterized in that: The preparation method comprises the following steps: S1 weighing the raw materials of the polyurethane water-based flame retardant coating according to the weight ratio, then putting a beaker into a constant temperature water bath for preheating, then adding the raw materials in sequence for stirring, and adding the stirred and mixed raw materials into the emulsion for slurry mixing; During the stirring and slurrying process S2, the weight of the silicate, organic base, borate, complexing agent and tungstate are weighed, each group of raw materials is put into water, heated and stirred, orthosilicate and surfactant are added and stirred, and then cooled to obtain a water-based rust inhibitor; S3 grinds the slurry obtained in S1 with a conical grinder, adds emulsion, defoamer and leveling agent, stirs at high speed, and adds water-based rust inhibitor until it is evenly dispersed to prepare a water-based polyurethane flame retardant coating.
2. The method for preparing a polyurethane water-based flame-retardant coating for metal according to claim 1, characterized in that: The step S1 comprises: S11 according to the ratio of raw materials to formula / mass parts 1, specifically waterborne polyurethane: 125 parts, ammonium polyphosphate APP: 30 parts, melamine: 18 parts, triazine carbonizing agent: 9 parts, titanium dioxide: 3 parts, distilled water: 50 parts; S12: preheating distilled water in a constant temperature water bath, controlling the speed of the stirrer at 300 r / min, and sequentially adding ammonium polyphosphate APP, melamine, triazine carbonizing agent and titanium dioxide into the beaker; After the S13 raw material is added, the stirring rate is increased to 1000 r / min-1300 r / min. After stirring for 30 minutes, the aqueous polyurethane emulsion is added to prepare the slurry. After continuous stirring for 50 minutes, the slurry is obtained.
3. The method for preparing a polyurethane water-based flame-retardant coating for metal according to claim 1, characterized in that: The step S2 comprises: S21, adding silicate, organic base, borate, complexing agent and tungstate to water again, raising the temperature to 50°C to 90°C and stirring for 40min to 60min to fully mix the mixed solution; S22 The silicate is sodium silicate and potassium silicate, the organic base is triethanolamine, diethanolamine and triethylamine, the borate is triethanolamine borate, the complexing agent is ethylenediaminetetraacetic acid, the tungstate is sodium tungstate, the surfactant is sodium dodecyl sulfate, and the orthosilicate is tetraethyl orthosilicate; After S23 stirring is completed, 3 ml of tetraethyl orthosilicate and 0.3 g of activator sodium dodecyl sulfate are added, stirring is continued for 10 min and then cooled to room temperature to obtain a water-based rust inhibitor.
4. The method for preparing a polyurethane water-based flame-retardant coating for metal according to claim 1, characterized in that: The step S3 comprises: S31, adding the emulsion into the conical grinder, and adding the remaining polyurethane emulsion, 0.05% of the defoamer and 0.1% of the leveling agent into the conical grinder, grinding to a fineness of less than 70 um, and adding into the agitator; S32 was stirred in a stirrer at 1500 r / min for 30 min, a water-based rust inhibitor was added, and after continuous high-speed stirring for 10 min, the solid content was adjusted to 50% with distilled water to prepare a water-based polyurethane flame retardant coating.