Vegetable oil-based polyurethane anticorrosive paint

Abstract

The invention discloses a vegetable oil-based polyurethane anticorrosive paint, which relates to the technical field of anticorrosive paints, comprises a primer, an intermediate paint and a finish paint, and is prepared from the following raw materials: modified vegetable oil polyol, isocyanate, a catalyst, a pigment, a coloring agent, a filler, an anti-settling agent and a mixed solvent. The preparation process of the vegetable oil-based polyurethane anticorrosive paint is simple and easy to operate; the vegetable oil polyol is used for replacing the traditional petrochemical-based polyol, so that the use of non-renewable petrochemical-based polyol is avoided, the method is green and environment-friendly, and the cost is reduced. Meanwhile, the prepared plant oil-based polyurethane anticorrosive primer, intermediate paint and finish paint are matched for use, can be widely applied to anticorrosive scenes in the industrial fields of steel structures, process pipelines, storage tanks, ladder platforms and the like, and can replace petrochemical epoxy zinc-rich primer, epoxy micaceous iron intermediate paint and polyurethane / acrylate finish paint; the adhesive force is improved by 2.5 times or more, the VOC content is reduced by 50% or more, and the biochar content is 30% or more.

Description

Technical Field

[0001] The invention relates to the technical field of anti-corrosion coatings, in particular to a vegetable oil-based polyurethane anti-corrosion coating. Background Art

[0002] Polyurethane is a multifunctional polymer material obtained by the polymerization and addition reaction of polyols and isocyanates. It is known as the "fifth plastic" and is widely used in industries and construction due to its excellent performance. There are two major raw materials for the production of polyurethane - polyols and isocyanates. There are relatively few types of isocyanate products, mainly MDI, TDI, HDI and PAPI, etc. The other type of monomer polyols has a wide variety of varieties and different qualities, and its downstream applications are diversified, so there is room for further research.

[0003] At present, polyols and isocyanates are mainly derived from petroleum resources. With the depletion of petroleum resources and the intensification of environmental problems, the preparation of polyols or isocyanates from green renewable biomass resources and the synthesis of bio-based polyurethanes have become one of the important directions for the development of my country's strategic emerging materials industry and biomass industry. Compared with petroleum-based polyurethane raw materials, bio-based polyurethane raw materials are less toxic, more abundant in sources, cheaper, and more diverse in structure, which is conducive to the expansion of industrial production scale and the reduction of production costs, and can effectively improve the comprehensive performance of polyurethane materials.

[0004] Research on bio-based polyurethanes mainly focuses on the preparation of bio-based polyols, bio-based isocyanates, and bio-based chain extenders. Among them, the use of bio-based chain extenders to prepare polyurethanes has limited effect on improving the bio-based content of polyurethanes and is not a research focus. Bio-based isocyanates can be divided into aliphatic isocyanates, aromatic isocyanates, symmetrical and asymmetrical isocyanates. At present, aliphatic isocyanate products modified by dimer acid have been developed, but the application field of polyurethanes prepared by this isocyanate is narrow.

[0005] Polyurethane materials based on bio-based polyols have been extensively studied and have great application prospects. The raw materials of bio-based polyols come from a wide range of sources, mainly including cellulose, vegetable oils, sugars, and natural phenols. Vegetable oil is an important source of bio-based polyols. Compared with petroleum-based polyols, vegetable oil polyols have the advantages of abundant raw material resources, low energy consumption, low greenhouse gas emissions, and good physical and chemical stability. They are excellent substitutes for petroleum-based polyols and have good applications in polyurethane foams, adhesives, coatings, potting compounds, structural adhesives and other products. At present, in the field of coatings, the development of bio-based polyols derived from vegetable oils is relatively slow, especially in anti-corrosion coatings. At present, the polyurethane coatings developed using bio-based polyols are difficult to coordinate in terms of hardness, toughness, and anti-corrosion.

[0006] The long-chain groups in the vegetable oil structure replace the repeating units of traditional petrochemical polyol polyethers or polyesters. The basic mother nucleus of triglycerides in the structure has a star-shaped spatial conformation, which gives downstream polyurethane more functional properties and application space. However, vegetable oil polyols often have performance defects. There are two main reasons:

[0007] First, the epoxidation-ring-opening reaction process of vegetable oil is uncontrollable. During the functional group transformation process, multiple epoxy groups and ester groups often participate in multiple side reaction processes. As a result, the designed molecular structure is difficult to construct through traditional chemical methods, which greatly limits the quality of polyols. It often needs to be mixed with traditional petrochemical polyols to have a certain application effect.

[0008] Second, compared with petrochemical polyether polyols, vegetable oil polyols have secondary hydroxyl groups, large steric hindrance, and poor reactivity and system miscibility with isocyanates. The reaction mechanism of vegetable oil polyols and isocyanates is different from that of traditional petrochemical-based polyether polyols and isocyanates, and the rate control steps are different, resulting in the unsuitability of the controlled polymerization technology of traditional petrochemical-based polyurethane anticorrosive coatings for vegetable oil-based polyurethanes. Affected by multiple functional groups in the structure of vegetable oil polyols, it is difficult to balance reaction selectivity and conversion rate, and the process controllability is poor, resulting in poor molecular uniformity, high viscosity, and large differences between the macroscopic indicators and the microscopic indicators of a single molecule of the resulting polyurethane material.

[0009] Therefore, it is necessary to start from two aspects: First, in the case that the vegetable oil components are not single and the structure-activity relationship is unclear, the quality of polyol products should be controlled through reaction process control and macro-indicator regulation, and its key technical indicators such as hydroxyl value and viscosity should be controlled within a certain range to meet the requirements of downstream anti-corrosion scenarios. Second, develop catalysts suitable for the polymerization of vegetable oil polyols and petrochemical-based isocyanates, complete the formula design and optimization, and then prepare bio-based polyurethane anti-corrosion coatings whose performance indicators meet the requirements of petrochemical-based anti-corrosion coatings, and have excellent performance in terms of adhesion, VOC and biocarbon content. Summary of the invention

[0010] In view of the deficiencies in the prior art, the present invention provides a plant oil-based polyurethane anti-corrosion coating.

[0011] In order to optimize the performance of downstream vegetable oil-based polyurethane anticorrosive coatings, the present invention uses vegetable oil polyols to replace the original petrochemical-based polyethers or polyester polyols. By studying the polymerization mechanism of vegetable oil polyols and isocyanates, the differences in molecular structure and physical property parameters between vegetable oil polyols and petrochemical-based polyols are studied, and ionic liquid tertiary amine catalysts are developed to solve the problems of poor reactivity of vegetable oil polyols and isocyanates and poor solubility of the system. The mutual influence between the molecular structure, key technical parameters (hydroxyl value and viscosity, etc.) of vegetable oil polyols and the performance (adhesion, salt spray resistance) of polyurethane anticorrosive coatings is systematically studied, the relationship between polyols and material structure-activity is mastered, and vegetable oil polyols suitable for anticorrosive coatings are developed, and their key technical parameters are determined. According to the specific anticorrosion scene requirements such as steel structures and industrial pipelines, the formulation design and optimization of vegetable oil-based polyurethane anticorrosive coatings are carried out, and finally a vegetable oil-based polyurethane anticorrosive coating with good economy and stable performance is developed.

[0012] To achieve the above object, the present invention is implemented by the following technical scheme: a plant oil-based polyurethane anticorrosive coating, comprising a primer, an intermediate paint and a topcoat, wherein the primer comprises component A and component B, the intermediate paint comprises component C and component B, and the topcoat comprises component D and component B;

[0013] By weight:

[0014] The component A comprises: 20-30 parts of vegetable oil polyol, 0.1-0.5 parts of ionic liquid tertiary amine catalyst, 5-15 parts of anti-rust pigment, 5-20 parts of coloring powder, 10-25 parts of inert filler, 0.5-5 parts of aminosilane resin, 1-5 parts of anti-settling agent, and 10-20 parts of mixed solvent;

[0015] The B component comprises: 100 parts of isocyanate;

[0016] The C component comprises: 15-25 parts of vegetable oil polyol, 0.1-0.5 parts of ionic liquid tertiary amine catalyst, 3-15 parts of anti-rust pigment, 5-20 parts of coloring powder, 10-25 parts of inert filler, 0.5-5 parts of aminosilane resin, 1-5 parts of anti-settling agent, and 10-20 parts of mixed solvent;

[0017] The D component comprises: 40-70 parts of vegetable oil polyol, 0.1-0.5 parts of ionic liquid tertiary amine catalyst, 5-20 parts of coloring powder, 1-5 parts of auxiliary agent, 5-20 parts of inert filler, 0.5-5 parts of aminosilane resin, 1-5 parts of anti-settling agent and 10-20 parts of mixed solvent.

[0018] Preferably, the anti-rust pigment is one of strontium phosphate yellow, high-purity zinc phosphate, nano zinc oxide, and aluminum tripolyphosphate; the coloring powder is one of titanium dioxide, red iron oxide, phthalocyanine blue, and carbon black; the inert filler is one of talcum powder and barium sulfate; the anti-settling agent is one of bentonite and fumed silica; the auxiliary agent is at least one of a defoaming agent, a dispersant, a leveling agent, and an antioxidant.

[0019] Preferably, the mass ratio of component A to component B is 5-15, and the mixing time is 5-15 min; the mass ratio of component C to component B is 5-15, and the mixing time is 5-15 min; the mass ratio of component D to component B is 5-15, and the mixing time is 5-15 min.

[0020] Preferably, the vegetable oil polyol is at least one of soybean oil polyol, sunflower oil polyol, cottonseed oil polyol, peanut oil polyol, coconut oil polyol, palm oil polyol, sesame oil polyol and corn oil polyol.

[0021] Preferably, the vegetable oil polyol is soybean oil polyol or cottonseed oil polyol; the soybean oil polyol and cottonseed oil polyol are prepared by reacting epoxidized soybean oil and epoxidized cottonseed oil as raw materials, respectively, with fluoroboric acid, methanesulfonic acid, phosphoric acid or phosphotungstic acid as catalyst, and cyclohexanediol, cyclohexanedimethanol, cyclohexanediethanol or mannitol as ring-opening reagent, the amount of the catalyst is 0.5-2‰ of the mass of the epoxidized soybean oil or epoxidized cottonseed oil, the molar ratio of the ring-opening reagent to the epoxidized soybean oil or epoxidized cottonseed oil is 2-6, the reaction temperature of the reaction is 60-100°C, and the reaction time is 5-10h.

[0022] Preferably, the vegetable oil polyol has a hydroxyl value of 250-400 mgKOH / g, a viscosity of 500-800 mPa·s, and an epoxy value of 0-1.

[0023] Preferably, the ionic liquid tertiary amine catalyst is an imidazole / pyridinium quaternary ammonium salt ionic liquid catalyst, and the added amount of the ionic liquid tertiary amine catalyst is 1-5‰ of the mass of the vegetable oil polyol.

[0024] Preferably, the isocyanate is at least one of diphenylmethane diisocyanate polymer, hexamethylene diisocyanate trimer, isophorone diisocyanate, and polymethylene polyphenyl isocyanate.

[0025] Preferably, the preparation methods of component A, component C and component D all include the following steps: weighing the formulated amount of raw materials and throwing them into a pull cylinder, stirring and dispersing at high speed for 15-30 minutes, then entering the grinding process, controlling the outlet temperature of the sand mill to be below 50°C, grinding for more than three times or not less than 4 hours, until the fineness is less than 20μm, entering the color adjustment process, adjusting the color of the paint to meet the requirements of the standard color card, controlling the color difference value ΔE to not exceed 2%, adding an appropriate amount of solvent, adjusting the product viscosity to less than 160s for coating 4 cups, and finally filtering to obtain the product.

[0026] Preferably, the preparation method of the B component comprises the following steps: weighing a formula amount of isocyanate, mixing, and vacuum dehydrating to obtain the component.

[0027] In a specific application, the plant oil-based polyurethane anticorrosive coating of the present invention is used in combination with a primer, an intermediate paint and a topcoat, and is applied to ordinary anticorrosion of steel structures and metal pipes, and the applicable temperature is -20°C-120°C. The non-volatile content of the primer is ≥70%, the VOC content is ≤250g / L, the adhesion is ≥8MPa, and the biocarbon content is ≥50%. The non-volatile content of the intermediate paint is ≥70%, the VOC content is ≤250g / L, the adhesion is ≥8MPa, and the biocarbon content is ≥50%. The non-volatile content of the topcoat is ≥60%, the VOC content is ≤300g / L, the adhesion is ≥8MPa, and the biocarbon content is ≥30%.

[0028] The present invention discloses a plant oil-based polyurethane anticorrosive coating, which has the following beneficial effects:

[0029] 1. The present invention uses vegetable oil polyols to replace traditional petrochemical-based polyether or polyester polyols. Compared with petrochemical-based polyols, vegetable oil polyols have the advantages of abundant raw material resources, low energy consumption, low greenhouse gas emissions, and good physical and chemical stability. The molecular structure of vegetable oil polyols is rich in triglycerides, epoxy groups, hydroxyl groups, ester groups, cyclic hydrocarbons, and ether bonds, and the bio-based polyurethane materials prepared therefrom have rich properties and strong controllability. Based on the study of the key technical parameters of vegetable oil polyols and the structure-activity relationship of polyurethane material performance, the hydroxyl value and viscosity range of vegetable oil polyols for vegetable oil-based polyurethane anticorrosive coatings are optimized and limited, thereby improving the technical performance of vegetable oil-based polyurethane anticorrosive coatings.

[0030] 2. Based on the research on the polymerization reaction mechanism of vegetable oil polyols and isocyanates, the present invention adopts a new type of ionic liquid tertiary amine catalyst to catalyze the polymerization process of vegetable oil polyols and isocyanic acid, thereby improving the reaction activity and system miscibility, thereby meeting the requirements of anti-corrosion coatings for curing time, adhesion and corrosion resistance.

[0031] 3. Aiming at the different requirements of anti-corrosion primers, intermediate paints and topcoats for steel structures and industrial pipelines, the present invention completes the formula design optimization of primers, intermediate paints and topcoats. By adopting the formula and preparation method of the present invention, the prepared plant oil-based polyurethane anti-corrosion primers, intermediate paints and topcoats have performance indicators that meet those of similar petrochemical-based products, are far superior to similar petrochemical-based products in terms of adhesion, salt water resistance, VOC content and other indicators, and the biocarbon content is above 30%.

[0032] 4. The vegetable oil-based polyurethane anticorrosive primer, intermediate paint and topcoat prepared by the present invention can replace epoxy zinc-rich primer, epoxy iron red intermediate paint and polyurethane / acrylic topcoat, and their comprehensive performance is better than that of similar petrochemical-based coatings after being used in combination. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The relevant determination method of the prepared vegetable oil-based polyurethane anticorrosive coating of the present invention is as follows:

[0035] (1) Measure the non-volatile content of the coating according to GB / T 1725-2007;

[0036] (2) Measure the adhesion of the coating according to GB / T 5210-2006 (pull-off method);

[0037] (3) Determine the surface drying and through drying time of the coating according to GB / T 1728-2020;

[0038] (4) Determine the impact resistance of the coating according to GB / T 1732-2020;

[0039] (5) Determine the acid resistance, alkali resistance and salt water resistance of the topcoat according to GB / T 9274-1988;

[0040] (6) Determine the neutral salt spray resistance of the coating according to GB / T 1771-2007;

[0041] (7) Determine the artificial weathering resistance of the topcoat according to GB / T 1865-2009;

[0042] (8) The biochar content of the coating was determined according to ASTM D6866.

[0043] Embodiment 1: A plant oil-based polyurethane anticorrosive coating, comprising a primer, an intermediate paint and a topcoat, wherein the primer comprises component A and component B, the intermediate paint comprises component C and component B, and the topcoat comprises component D and component B;

[0044] By weight:

[0045] The component A comprises: 25 parts of vegetable oil polyol, 0.2 parts of ionic liquid tertiary amine catalyst, 15 parts of anti-rust pigment, 15 parts of coloring powder, 20 parts of inert filler, 4 parts of aminosilane resin, 4 parts of anti-settling agent, and 16.8 parts of mixed solvent;

[0046] The B component comprises: 100 parts of diphenylmethane diisocyanate polymer;

[0047] The C component comprises: 20 parts of vegetable oil polyol, 0.3 parts of pyridine quaternary ammonium salt ionic liquid catalyst, 12 parts of anti-rust pigment, 18 parts of coloring powder, 23 parts of inert filler, 4 parts of aminosilane resin, 3 parts of anti-settling agent, and 19.7 parts of mixed solvent;

[0048] The D component comprises: 55 parts of vegetable oil polyol, 0.4 parts of pyridinium quaternary ammonium salt ionic liquid catalyst, 15 parts of coloring powder, 3 parts of auxiliary agent, 10 parts of inert filler, 2 parts of aminosilane resin, 2 parts of anti-settling agent and 12.6 parts of mixed solvent.

[0049] The anti-rust pigment is strontium phosphate yellow; the coloring powder is titanium dioxide; the inert filler is talcum powder; the anti-settling agent is bentonite; and the auxiliary agents are defoaming agents and dispersants.

[0050] The vegetable oil polyol is a cottonseed oil polyol, with a hydroxyl value of 300 mgKOH / g, a viscosity of 544 mPa·s, and an epoxy value of 0.5. The cottonseed oil polyol is prepared by using epoxidized cottonseed oil as a raw material, fluoroboric acid as a catalyst, and cyclohexanediol as a ring-opening reagent, the amount of the catalyst is 1‰ of the added mass of the epoxidized cottonseed oil, the molar ratio of the ring-opening reagent to the epoxidized cottonseed oil is 4, the reaction temperature is 90°C, and the reaction time is 6 hours.

[0051] The preparation methods of the components A, C and D all include the following steps: weighing a formula amount of raw materials and throwing them into a pull cylinder, stirring and dispersing them at high speed for 20 minutes, then entering a grinding process, controlling the outlet temperature of the sand mill to be below 50° C., grinding until the fineness is less than 20 μm, entering a color adjustment process, adjusting the color of the coating to meet the requirements of the standard color card, controlling the color difference value ΔE to not exceed 2%, adding an appropriate amount of solvent, adjusting the product viscosity to less than 160 seconds for coating 4 cups, and finally filtering to obtain the coating.

[0052] The preparation method of the B component comprises the following steps: weighing a formula amount of isocyanate, mixing, and vacuum dehydrating to obtain the component.

[0053] The component A and the component B are mixed and stirred at a mass ratio of 10 for 10 minutes, and polymerized to obtain a plant oil-based polyurethane anti-corrosion primer. The plant oil-based polyurethane anti-corrosion primer is sprayed on a steel plate substrate. The spraying is performed once, and the dry film thickness is 25 um. After standing for 48 hours, the non-volatile matter content, VOC, adhesion, acid resistance, alkali resistance, salt water resistance, neutral salt spray resistance, artificial weathering resistance and biocarbon content are tested in a laboratory environment.

[0054] The C component and the B component are mixed and stirred for 15 minutes according to a mass ratio of 10, and polymerized to obtain a plant oil-based polyurethane anti-corrosion intermediate paint. The plant oil-based polyurethane anti-corrosion intermediate paint is sprayed on a steel plate substrate. The spraying is performed once, and the dry film thickness is 50 um. After standing for 48 hours, the non-volatile matter content, VOC, adhesion, acid resistance, alkali resistance, salt water resistance, neutral salt spray resistance, artificial weathering resistance and biocarbon content are tested in a laboratory environment.

[0055] The D component and the B component are mixed and stirred at a mass ratio of 5 for 10 minutes, and polymerized to obtain a plant oil-based polyurethane anti-corrosion topcoat. The plant oil-based polyurethane anti-corrosion topcoat is sprayed on a steel plate substrate. The spraying is performed once, and the dry film thickness is 50 um. After standing for 48 hours, the non-volatile matter content, VOC, adhesion, acid resistance, alkali resistance, salt water resistance, neutral salt spray resistance, artificial weathering resistance and biocarbon content are tested in a laboratory environment.

[0056] The performance indicators of the vegetable oil-based polyurethane anticorrosive primer, intermediate paint and topcoat described in Example 1 are shown in Table 1.

[0057] Table 1 Main performance indicators of vegetable oil-based polyurethane anticorrosive primer, intermediate paint and topcoat in Example 1

[0058]

[0059]

[0060] From the data in Table 1, it can be seen that the plant oil-based polyurethane anti-corrosion primer, intermediate paint and topcoat of the present invention have a non-volatile matter content increased by 25.8%, a VOC content reduced by more than 50.8%, an adhesion increased by more than 2.5 times, a biocarbon content of more than 30%, and other indicators meet the requirements of similar petrochemical-based products.

[0061] Embodiment 2: A vegetable oil-based polyurethane anticorrosive coating, comprising a primer, an intermediate paint and a topcoat, wherein the primer comprises component A and component B, the intermediate paint comprises component C and component B, and the topcoat comprises component D and component B;

[0062] By weight:

[0063] The component A comprises: 20 parts of vegetable oil polyol, 0.5 parts of ionic liquid tertiary amine catalyst, 5 parts of anti-rust pigment, 20 parts of coloring powder, 10 parts of inert filler, 5 parts of aminosilane resin, 1 part of anti-settling agent, and 20 parts of mixed solvent;

[0064] The B component comprises: 100 parts of hexamethylene diisocyanate trimer;

[0065] The C component comprises: 15 parts of vegetable oil polyol, 0.5 parts of ionic liquid tertiary amine catalyst, 3 parts of anti-rust pigment, 20 parts of coloring powder, 10 parts of inert filler, 5 parts of aminosilane resin, 1 part of anti-settling agent, and 20 parts of mixed solvent;

[0066] The D component comprises: 40 parts of vegetable oil polyol, 0.5 parts of ionic liquid tertiary amine catalyst, 5 parts of coloring powder, 5 parts of auxiliary agent, 5 parts of inert filler, 5 parts of aminosilane resin, 1 part of anti-settling agent and 20 parts of mixed solvent.

[0067] The anti-rust pigment is high-purity zinc phosphate; the coloring powder is red iron oxide; the inert filler is barium sulfate; the anti-settling agent is fumed silica; and the auxiliary agents are a leveling agent and an antioxidant.

[0068] The vegetable oil polyol is soybean oil polyol, with a hydroxyl value of 250 mgKOH / g, a viscosity of 500 mPa·s, and an epoxy value of 0.2. The soybean oil polyol uses epoxidized soybean oil as a raw material, methanesulfonic acid as a catalyst, and cyclohexanedimethanol as a ring-opening reagent, the amount of the catalyst is 0.5‰ of the added mass of the epoxidized soybean oil, the molar ratio of the ring-opening reagent to the epoxidized soybean oil is 2, the reaction temperature is 60°C, and the reaction time is 5 hours.

[0069] The preparation methods of the components A, C and D all include the following steps: weighing a formula amount of raw materials and throwing them into a pull cylinder, stirring and dispersing them at high speed for 15 minutes, then entering a grinding process, controlling the outlet temperature of the sand mill to be below 50° C., grinding until the fineness is less than 20 μm, entering a color adjustment process, adjusting the color of the coating to meet the requirements of the standard color card, controlling the color difference value ΔE to not exceed 2%, adding an appropriate amount of solvent, adjusting the product viscosity to less than 160 seconds for coating 4 cups, and finally filtering to obtain the coating.

[0070] The preparation method of the B component comprises the following steps: weighing a formula amount of isocyanate, mixing, and vacuum dehydrating to obtain the component.

[0071] The component A and the component B are mixed and stirred at a mass ratio of 10 for 10 minutes, and polymerized to obtain a plant oil-based polyurethane anti-corrosion primer. The plant oil-based polyurethane anti-corrosion primer is sprayed on a steel plate substrate. The spraying is performed once, and the dry film thickness is 25 um. After standing for 48 hours, the non-volatile matter content, VOC, adhesion, acid resistance, alkali resistance, salt water resistance, neutral salt spray resistance, artificial weathering resistance and biocarbon content are tested in a laboratory environment.

[0072] The C component and the B component are mixed and stirred for 15 minutes according to a mass ratio of 10, and polymerized to obtain a plant oil-based polyurethane anti-corrosion intermediate paint. The plant oil-based polyurethane anti-corrosion intermediate paint is sprayed on a steel plate substrate. The spraying is performed once, and the dry film thickness is 50 um. After standing for 48 hours, the non-volatile matter content, VOC, adhesion, acid resistance, alkali resistance, salt water resistance, neutral salt spray resistance, artificial weathering resistance and biocarbon content are tested in a laboratory environment.

[0073] The D component and the B component are mixed and stirred at a mass ratio of 5 for 10 minutes, and polymerized to obtain a plant oil-based polyurethane anti-corrosion topcoat. The plant oil-based polyurethane anti-corrosion topcoat is sprayed on a steel plate substrate. The spraying is performed once, and the dry film thickness is 50 um. After standing for 48 hours, the non-volatile matter content, VOC, adhesion, acid resistance, alkali resistance, salt water resistance, neutral salt spray resistance, artificial weathering resistance and biocarbon content are tested in a laboratory environment.

[0074] The performance indicators of the vegetable oil-based polyurethane anticorrosive primer, intermediate paint and topcoat described in Example 2 are shown in Table 2.

[0075] Table 2 Main performance indicators of vegetable oil-based polyurethane anticorrosive primer, intermediate paint and topcoat in Example 2

[0076]

[0077]

[0078] Embodiment 3: A plant oil-based polyurethane anticorrosive coating, comprising a primer, an intermediate paint and a topcoat, wherein the primer comprises component A and component B, the intermediate paint comprises component C and component B, and the topcoat comprises component D and component B;

[0079] By weight:

[0080] The component A comprises: 30 parts of vegetable oil polyol, 0.1 parts of ionic liquid tertiary amine catalyst, 15 parts of anti-rust pigment, 5 parts of coloring powder, 25 parts of inert filler, 0.5 parts of aminosilane resin, 5 parts of anti-settling agent, and 10 parts of mixed solvent;

[0081] The B component comprises: 100 parts of isophorone diisocyanate;

[0082] The C component comprises: 25 parts of vegetable oil polyol, 0.1 parts of ionic liquid tertiary amine catalyst, 15 parts of anti-rust pigment, 5 parts of coloring powder, 25 parts of inert filler, 0.5 parts of aminosilane resin, 5 parts of anti-settling agent, and 10 parts of mixed solvent;

[0083] The D component comprises: 70 parts of vegetable oil polyol, 0.1 parts of ionic liquid tertiary amine catalyst, 20 parts of coloring powder, 1 part of auxiliary agent, 20 parts of inert filler, 0.5 parts of aminosilane resin, 5 parts of anti-settling agent and 10 parts of mixed solvent.

[0084] The anti-rust pigment is nano zinc oxide; the coloring powder is carbon black; the inert filler is talcum powder; the anti-settling agent is bentonite; and the auxiliary agents are defoaming agents and antioxidants.

[0085] The vegetable oil polyol is cottonseed oil polyol, with a hydroxyl value of 400 mgKOH / g, a viscosity of 800 mPa·s, and an epoxy value of 0.9. The cottonseed oil polyol uses epoxidized cottonseed oil as a raw material, phosphoric acid as a catalyst, and mannitol as a ring-opening reagent, the amount of the catalyst is 2‰ of the added mass of the epoxidized cottonseed oil, the molar ratio of the ring-opening reagent to the epoxidized cottonseed oil is 6, the reaction temperature is 100°C, and the reaction time is 10 hours.

[0086] The preparation methods of the components A, C and D all include the following steps: weighing a formula amount of raw materials and throwing them into a pull cylinder, stirring and dispersing at high speed for 30 minutes, then entering a grinding process, controlling the outlet temperature of the sand mill to be below 50° C., grinding until the fineness is less than 20 μm, entering a color adjustment process, adjusting the color of the coating to meet the requirements of the standard color card, controlling the color difference value ΔE to not exceed 2%, adding an appropriate amount of solvent, adjusting the product viscosity to less than 160 seconds for coating 4 cups, and finally filtering to obtain the coating.

[0087] The preparation method of the B component comprises the following steps: weighing a formula amount of isocyanate, mixing, and vacuum dehydrating to obtain the component.

[0088] The component A and the component B are mixed and stirred at a mass ratio of 10 for 10 minutes, and polymerized to obtain a plant oil-based polyurethane anti-corrosion primer. The plant oil-based polyurethane anti-corrosion primer is sprayed on a steel plate substrate. The spraying is performed once, and the dry film thickness is 25 um. After standing for 48 hours, the non-volatile matter content, VOC, adhesion, acid resistance, alkali resistance, salt water resistance, neutral salt spray resistance, artificial weathering resistance and biocarbon content are tested in a laboratory environment.

[0089] The C component and the B component are mixed and stirred for 15 minutes according to a mass ratio of 10, and polymerized to obtain a plant oil-based polyurethane anti-corrosion intermediate paint. The plant oil-based polyurethane anti-corrosion intermediate paint is sprayed on a steel plate substrate. The spraying is performed once, and the dry film thickness is 50 um. After standing for 48 hours, the non-volatile matter content, VOC, adhesion, acid resistance, alkali resistance, salt water resistance, neutral salt spray resistance, artificial weathering resistance and biocarbon content are tested in a laboratory environment.

[0090] The D component and the B component are mixed and stirred at a mass ratio of 5 for 10 minutes, and polymerized to obtain a plant oil-based polyurethane anti-corrosion topcoat. The plant oil-based polyurethane anti-corrosion topcoat is sprayed on a steel plate substrate. The spraying is performed once, and the dry film thickness is 50 um. After standing for 48 hours, the non-volatile matter content, VOC, adhesion, acid resistance, alkali resistance, salt water resistance, neutral salt spray resistance, artificial weathering resistance and biocarbon content are tested in a laboratory environment.

[0091] The performance indicators of the vegetable oil-based polyurethane anticorrosive primer, intermediate paint and topcoat described in Example 3 are shown in Table 3.

[0092] Table 3 Main performance indicators of vegetable oil-based polyurethane anticorrosive primer, intermediate paint and topcoat in Example 3

[0093] Test items Primer Intermediate paint Topcoat Petrochemical-based similar products Non-volatile matter content (after mixing A and B), % ≥ 86.1 85.6 75.0 60 VOC(g / L)(after mixing A and B) 221 228 249 500 / 500 / 550 Adhesion (pull-off method) / MPa 17 14 13 6 <![CDATA[Acid resistance (50 g / L H 2 SO 4 )]]> / / 168h no abnormality 168h no abnormality Alkali resistance (20g / L NaOH) / / 168h no abnormality 168h no abnormality Salt water resistance (3% NaCl solution) qualified qualified qualified qualified Neutral salt spray resistance / / 1000h 1000h Artificial weathering resistance / / 1000h 1000h Biomass carbon content% 57.8 54.6 35.7 0

[0094] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A vegetable oil-based polyurethane anticorrosive coating, characterized in that: The method comprises a primer, an intermediate paint and a topcoat, wherein the primer comprises component A and component B, the intermediate paint comprises component C and component B, and the topcoat comprises component D and component B; By weight: The component A comprises: 20-30 parts of vegetable oil polyol, 0.1-0.5 parts of ionic liquid tertiary amine catalyst, 5-15 parts of anti-rust pigment, 5-20 parts of coloring powder, 10-25 parts of inert filler, 0.5-5 parts of aminosilane resin, 1-5 parts of anti-settling agent, and 10-20 parts of mixed solvent; The B component comprises: 100 parts of isocyanate; The C component comprises: 15-25 parts of vegetable oil polyol, 0.1-0.5 parts of ionic liquid tertiary amine catalyst, 3-15 parts of anti-rust pigment, 5-20 parts of coloring powder, 10-25 parts of inert filler, 0.5-5 parts of aminosilane resin, 1-5 parts of anti-settling agent, and 10-20 parts of mixed solvent; The D component comprises: 40-70 parts of vegetable oil polyol, 0.1-0.5 parts of ionic liquid tertiary amine catalyst, 5-20 parts of coloring powder, 1-5 parts of auxiliary agent, 5-20 parts of inert filler, 0.5-5 parts of aminosilane resin, 1-5 parts of anti-settling agent and 10-20 parts of mixed solvent.

2. The vegetable oil-based polyurethane anticorrosive coating according to claim 1, characterized in that: The anti-rust pigment is one of strontium phosphate yellow, high-purity zinc phosphate, nano zinc oxide, and aluminum tripolyphosphate; the coloring powder is one of titanium dioxide, red iron oxide, phthalocyanine blue, and carbon black; the inert filler is one of talcum powder and barium sulfate; the anti-settling agent is one of bentonite and fumed silica; the auxiliary agent is at least one of a defoaming agent, a dispersant, a leveling agent, and an antioxidant.

3. The vegetable oil-based polyurethane anticorrosive coating according to claim 1 or 2, characterized in that: The mass ratio of component A to component B is 5-15, and the mixing time is 5-15 minutes; the mass ratio of component C to component B is 5-15, and the mixing time is 5-15 minutes; the mass ratio of component D to component B is 5-15, and the mixing time is 5-15 minutes.

4. The vegetable oil-based polyurethane anticorrosive coating according to claim 1 or 2, characterized in that: The vegetable oil polyol is at least one of soybean oil polyol, sunflower oil polyol, cottonseed oil polyol, peanut oil polyol, coconut oil polyol, palm oil polyol, sesame oil polyol and corn oil polyol.

5. The vegetable oil-based polyurethane anticorrosive coating according to claim 4, characterized in that: The vegetable oil polyol is soybean oil polyol or cottonseed oil polyol; the soybean oil polyol and cottonseed oil polyol are prepared by reaction with epoxidized soybean oil and epoxidized cottonseed oil as raw materials, respectively, with fluoroboric acid, methanesulfonic acid, phosphoric acid or phosphotungstic acid as catalyst, and with cyclohexanediol, cyclohexanedimethanol, cyclohexanediethanol or mannitol as ring-opening reagent, the amount of the catalyst is 0.5-2‰ of the mass of the epoxidized soybean oil or epoxidized cottonseed oil, the molar ratio of the ring-opening reagent to the epoxidized soybean oil or epoxidized cottonseed oil is 2-6, the reaction temperature of the reaction is 60-100°C, and the reaction time is 5-10h.

6. The vegetable oil-based polyurethane anticorrosive coating according to claim 1 or 2, characterized in that: The vegetable oil polyol has a hydroxyl value of 250-400 mgKOH / g, a viscosity of 500-800 mPa•s, and an epoxy value of 0-1.

7. The vegetable oil-based polyurethane anticorrosive coating according to claim 1 or 2, characterized in that: The ionic liquid tertiary amine catalyst adopts an imidazole / pyridinium quaternary ammonium salt ionic liquid catalyst, and the added amount of the ionic liquid tertiary amine catalyst is 1-5‰ of the mass of the vegetable oil polyol.

8. The vegetable oil-based polyurethane anticorrosive coating according to claim 1 or 2, characterized in that: The isocyanate is at least one of diphenylmethane diisocyanate polymer, hexamethylene diisocyanate trimer, isophorone diisocyanate, and polymethylene polyphenyl isocyanate.

9. The vegetable oil-based polyurethane anticorrosive coating according to claim 1 or 2, characterized in that: The preparation methods of the components A, C and D all include the following steps: weighing a formula amount of raw materials and throwing them into a pull cylinder, stirring and dispersing them at high speed for 15-30 minutes, then entering a grinding process, controlling the outlet temperature of the sand mill to be below 50°C, grinding for more than three times or not less than 4 hours, until the fineness is less than 20 μm, entering a color adjustment process, adjusting the color of the coating to meet the requirements of the standard color card, controlling the color difference value ΔE to not exceed 2%, adding an appropriate amount of solvent, adjusting the product viscosity to less than 160 seconds for coating 4 cups, and finally filtering to obtain the coating.

10. The vegetable oil-based polyurethane anticorrosive coating according to claim 1 or 2, characterized in that: The preparation method of the B component comprises the following steps: weighing a formula amount of isocyanate, mixing, and vacuum dehydrating to obtain the component.

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