Thermosetting bio-based polyurethane antibacterial powder coating and preparation method thereof

Abstract

The invention discloses a thermosetting bio-based polyurethane antibacterial powder coating which comprises the following components in parts by weight: 3-100 parts of rosin-based modified polyol, 0-80 parts of toughened resin, 5-35 parts of a curing agent, 0.001-1 part of a catalyst, 30-100 parts of modified red mud powder, 0.5-3 parts of a flatting agent, 0.2-2 parts of a nano antibacterial agent and 0-20 parts of pigment, wherein the rosin-based modified polyol is one or more of hydrogenated rosin alcohol, hydrogenated rosin acid (1-chloro-2-hydroxy) propyl ester, acrylpimaric acid di (1-chloro-2-hydroxy) propyl ester, acrylpimaric alcohol, maleopimaric alcohol and maleopimaric acid tri (1-chloro-2-hydroxy) propyl ester. According to the thermosetting bio-based polyurethane antibacterial powder coating and the preparation method thereof, the hardness, the adhesive force, the heat resistance, the flexibility, the hydrophobicity and the like of an existing polyurethane powder coating can be improved, the comprehensive performance of the existing antibacterial powder coating is improved, and the service life of the coating is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of antibacterial powder coatings, and in particular to a thermosetting bio-based polyurethane antibacterial powder coating and a preparation method thereof. Background Art

[0002] Powder coating is a solid powdered synthetic resin coating composed of solid resin, pigment, filler and additives. It uses air as a dispersion medium and has the characteristics of no solvent pollution, 100% film formation and low energy consumption. With the continuous improvement of the coating industry's requirements for low content of volatile organic compounds (VOCs) in recent years, the application of powder coatings has received more and more attention, and breakthroughs have been made in the field of use. In order to protect the health of the people, high-efficiency, long-lasting and environmentally friendly antibacterial powder coatings are used on the surfaces of various furniture, appliances and daily necessities in the living environment. By cutting off the transmission channels of bacteria and viruses and avoiding or reducing the transmission channels of pathogens, antibacterial coatings are increasingly popular among consumers. However, due to the limitations of the application process of antibacterial materials in coatings, the upgrading of antibacterial powder coating production equipment and resin performance, the research and development and production of antibacterial powder coatings are still in the primary development stage and urgently need breakthroughs.

[0003] At present, vigorously developing low-carbon, green and environmentally friendly materials has become an important development direction of the chemical industry. Among them, replacing petroleum-based materials with biomass raw materials is one of the important ways to develop new green high-performance materials. Rosin has been used as a bio-based material for a long time. It is a mixture of tricyclic diterpene resin acids with hydrogenated phenanthrene structures, mainly including rosin acid, pimaric acid, and a small amount of fatty acids and neutral substances. Since the hydrogenated phenanthrene ring structure of rosin acid is similar to some petroleum-based aliphatic and aromatic compounds, it has great potential in replacing petroleum-based compounds to synthesize polyurethane.

[0004] Therefore, using rosin as the main raw material in the preparation of coatings has broad development prospects. Summary of the invention

[0005] In view of this, the present invention provides a thermosetting bio-based polyurethane antibacterial powder coating and a preparation method thereof, so as to improve the adhesion, hardness, heat resistance, hydrophobicity, anticorrosion and other comprehensive properties of the thermosetting polyurethane antibacterial powder coating.

[0006] The present invention includes the following technical solutions: A thermosetting bio-based polyurethane antibacterial powder coating, comprising:

[0007] 3-100 parts of rosin-based modified polyol, 0-80 parts of toughening resin, 5-35 parts of curing agent, 0.001-1 parts of catalyst, 30-100 parts of modified red mud powder, 0.5-3 parts of leveling agent, 0.2-2 parts of nano antibacterial agent, 0-20 parts of pigment;

[0008] The rosin-based modified polyol is one or more of hydrogenated rosin alcohol, hydrogenated rosin acid (1-chloro-2-hydroxy) propyl ester, propylene pimaric acid di(1-chloro-2-hydroxy) propyl ester, propylene pimaric alcohol, maleopimaric alcohol, and maleopimaric acid tri(1-chloro-2-hydroxy) propyl ester.

[0009] Preferably, the toughening resin is a mixture of one or more of a polyol, a carboxyl-terminated polyester resin, and an acrylate resin, wherein the polyol is preferably one or more of poly(1,3-propylene succinate) diol (PPSu), poly(butylene succinate) diol (PBSu), poly(1,3-propylene sebacate) diol (PPSe), and poly(butylene sebacate) diol (PBSe).

[0010] Preferably, the curing agent is a mixture of one or more of diisocyanate, triisocyanate, tetraisocyanate and triglycidyl isocyanurate.

[0011] Preferably, the catalyst is a mixture of one or more of stannous octoate, dibutyltin dilaurate, and bismuth isooctanoate.

[0012] The present invention also provides a method for preparing the thermosetting bio-based polyurethane antibacterial powder coating.

[0013] (1) firstly, the rosin-based modified polyol and the toughening resin are fully mixed, and then a curing agent is added and mixed to obtain a resin premix;

[0014] (2) adding the resin premix into a mixer, and then sequentially adding the modified red mud powder, the leveling agent, the nano antibacterial agent, the pigment component, and finally adding the catalyst, fully mixing, then pre-crushing for 2 to 10 minutes, and then mixing for another 5 to 20 minutes to obtain a uniformly mixed raw material;

[0015] (3) feeding the uniformly mixed raw materials obtained in step (2) into an extruder, heating and reacting and extruding, tableting, cooling, and then crushing into flakes in two stages, wherein the reaction extrusion temperature is 65 to 180° C., wherein the first stage reaction temperature is 65 to 110° C.; and the second stage reaction temperature is 110 to 180° C.;

[0016] (4) The crushed flakes in step (3) are placed in an ACM mill for grinding, and after cyclone separation and screening, an antibacterial powder coating with an average particle size of 35-40 μm is obtained. The present invention also provides a method for preparing the thermosetting bio-based polyurethane antibacterial powder coating, firstly, the rosin-based modified polyol and the toughening resin are fully mixed, and then a curing agent is added and mixed to obtain a resin premix;

[0017] The invention provides a thermosetting bio-based polyurethane antibacterial powder coating and a preparation method thereof. The method uses rosin as a main raw material and converts the carboxyl groups in the molecular structure of the polyol into hydroxyl groups to prepare a polyol containing a hydrogen phenanthrene ring structure. The polyol can be used as a polyurethane modification raw material for powder coatings. The hydrogen phenanthrene ring structure of the rosin structure is introduced into the polyurethane macromolecule, which can improve the hardness, adhesion, heat resistance, flexibility and hydrophobicity of the existing polyurethane powder coating, improve the comprehensive performance of the existing antibacterial powder coating, extend the service life of the coating, and further promote the technical level of bio-based green coatings and sustainable development. It is the trend of future coating development and has broad development prospects.

[0018] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0021] Figure 1 Schematic diagram of the preparation of hydrogenated rosin acid (1-chloro-2-hydroxy) propyl ester, acrylopimaric acid di(1-chloro-2-hydroxy) propyl ester, and maleopimaric acid tri(1-chloro-2-hydroxy) propyl ester provided by the present invention;

[0022] Figure 2 This is a schematic diagram of the preparation of propylene pinamarin and maleic pinamarin provided by the present invention. DETAILED DESCRIPTION

[0023] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of methods consistent with some aspects of the present invention as detailed in the appended claims.

[0024] In order to solve the increasingly prominent problem of the contradiction between population, resources and environment, promote the development of bio-based green high-performance coatings, and improve the adhesion, hardness, heat resistance, hydrophobicity, anti-corrosion and other comprehensive properties of existing thermosetting polyurethane antibacterial powder coatings on the basis of simplifying the production process and reducing the production cost, and extend the service life of thermosetting polyurethane antibacterial powder coatings; the present invention provides a thermosetting bio-based polyurethane antibacterial powder coating, which is polymerized from rosin-based modified polyols, toughening resins, curing agents, catalysts, modified red mud powder, leveling agents, nano antibacterial agents, and pigments. Specifically, the components are as follows by mass:

[0025] a) 3 to 100 parts of rosin-based modified polyol component, preferably 5 to 30 parts;

[0026] b) 0 to 80 parts of toughening resin component, preferably 25 to 60 parts;

[0027] c) 5 to 35 parts of the curing agent component, preferably 10 to 25 parts;

[0028] d) the catalyst component is 0.001 to 1 part, preferably 0.01 to 0.5 part;

[0029] e) the modified red mud powder component is 30 to 100 parts, preferably 60 to 90 parts;

[0030] f) 0.5 to 3 parts of the leveling agent component, preferably 0.7 to 1.6 parts;

[0031] g) 0.2 to 2 parts of the nano antibacterial agent component, preferably 0.3 to 0.8 parts;

[0032] h) 0 to 20 parts of the pigment component, preferably 1 to 5 parts;

[0033] The rosin-based modified polyol is one or more of hydrogenated rosin alcohol, hydrogenated rosin acid (1-chloro-2-hydroxy) propyl ester, propylene pimaric acid di(1-chloro-2-hydroxy) propyl ester, propylene pimaric alcohol, maleopimaric alcohol, and maleopimaric acid tri(1-chloro-2-hydroxy) propyl ester.

[0034] Specifically, the preparation method of the hydrogenated rosin acid (1-chloro-2-hydroxy) propyl ester, di(1-chloro-2-hydroxy) propyl acrylpimaric acid, and tri(1-chloro-2-hydroxy) propyl maleopimaric acid is as follows: dissolving a rosin derivative in a non-water-soluble solvent, adding epichlorohydrin, adding a promoter, and reacting at 40 to 130° C. for 0.5 to 60 hours. After the reaction is completed, deionized water is added, and after sufficient shaking, the reaction is allowed to stand for stratification, the water layer is removed, and the oil-containing layer liquid is subjected to high vacuum rotary evaporation to obtain the corresponding hydrogenated rosin acid (1-chloro-2-hydroxy) propyl ester, di(1-chloro-2-hydroxy) propyl acrylpimaric acid, and tri(1-chloro-2-hydroxy) propyl maleopimaric acid.

[0035] Furthermore, the rosin derivative is hydrogenated rosin, propylene pimaric acid, maleopimaric acid, or maleopimaric anhydride, and the mass ratio of carboxyl group to epichlorohydrin in the structure of the rosin derivative 1 is 1:1.05-1.50, preferably 1:1.10-1.20;

[0036] Furthermore, the amount of the non-water-soluble solvent is 3 to 200 wt% of the mass of the rosin derivative, preferably 10 to 50 wt%; the amount of the accelerator added is 0.5 to 3.5 wt% of the total mass of the rosin derivative and epichlorohydrin, preferably 0.8 to 1.5 wt%;

[0037] Furthermore, in order to improve the reaction conversion rate, the promoter is preferably added in multiple times, the best number of additions being 3-4 times, with the first addition being 1 / 2 of the total promoter amount, and the remaining additions being 1 / 2 of the remaining promoter amount, until all the promoter is added.

[0038] Furthermore, the non-aqueous solvent is preferably a mixture of one or more of toluene, xylene, ethyl acetate, butyl acetate, dichloromethane, dichloroethane, chloroform, carbon tetrachloride, trichloroethylene, and dichloroethylene.

[0039] Further, the accelerator is a mixture of one or more of tetrabutylammonium bromide, tetrabutylammonium chloride, tetrabutylammonium hydrogen sulfate, tetrabutylammonium fluoride, and tetrabutylammonium hydroxide, wherein tetrabutylammonium bromide and tetrabutylammonium chloride are preferred;

[0040] The preparation method of the propylene pinamarin and maleic pinamarin is:

[0041] Dissolve propylene pimaric acid or maleopimaric acid in a solvent, and slowly add a reducing agent under the protection of an inert gas at low temperature. After the reducing agent is added, react for 0.5 to 12 hours, and then heat to 40 to 80°C to react for 6 to 60 hours. After the reaction is completed, quench the excess reducing agent with a quenching agent, then add deionized water and shake thoroughly, filter, and vacuum filter at 40 to 60°C to constant weight. Add a non-aqueous solvent to the constant weight filtrate, shake thoroughly, stand and separate, remove the water layer, and perform high vacuum rotary evaporation on the oil-containing layer liquid to obtain a viscous liquid product with a polyol structure - propylene pimaric alcohol or maleopimaric alcohol.

[0042] The solvent is preferably a mixed solvent of one or more of anhydrous tetrahydrofuran, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, ethyl ether, ethyl butyl ether, dihexyl ether, dipentyl ether, and 3-methylfuran; the inert gas is preferably one or a mixed gas of nitrogen or argon; the reducing agent is preferably a mixture of one or more of lithium aluminum hydride, sodium borohydride, potassium borohydride, or dibutylaluminum hydride; and the quencher is one or more of water, sodium hydroxide aqueous solution, sodium carbonate aqueous solution, sodium bicarbonate aqueous solution, hydrochloric acid solution, or ethyl sulfuric acid solution.

[0043] The low temperature condition can be achieved by a liquid nitrogen quick freezing method, or by maintaining a temperature condition of -10°C to 15°C through a temperature control device.

[0044] The toughening resin is a mixture of one or more of a polyol, a carboxyl-terminated polyester resin, and an acrylate resin. The polyol is preferably one or more of poly(1,3-propylene glycol succinate) diol (PPSu), poly(butylene glycol succinate) diol (PBSu), poly(1,3-propylene glycol sebacate) diol (PPSe), and poly(butylene glycol sebacate) diol (PBSe).

[0045] The curing agent is a mixture of one or more of diisocyanate, triisocyanate, tetraisocyanate, and triglycidyl isocyanurate. Preferably, triglycidyl isocyanurate, 4,4-diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, 4,4',4"-triphenylmethane triisocyanate, dimethyltriphenylmethane tetraisocyanate, and tetraisocyanatosilane are used.

[0046] The catalyst is preferably a mixture of one or more of stannous octoate, dibutyltin dilaurate and bismuth isooctanoate.

[0047] The modified red mud powder is prepared by washing red mud with sulfuric acid until the pH value is 9.2-9.4, then mixing with fatty alcohol polyoxyethylene ether ammonium sulfate, diethanolamide stearic acid glycerol monoester, sodium fatty acid methyl ester sulfonate, and N-trimethyl chitosan for modification, and then grinding. Preferably, the particle size of the modified red mud powder is greater than 300 meshes.

[0048] The leveling agent is PV88 leveling agent.

[0049] The nano antibacterial agent is a mixture of one or more nano silver ions and nano silver-zinc composite ions.

[0050] The pigment is transparent blue or phthalocyanine green.

[0051] A thermosetting bio-based polyurethane antibacterial powder coating and a preparation method thereof, comprising the following steps:

[0052] (1) firstly, the rosin-based modified polyol and the toughening resin are fully mixed, and then a curing agent is added and mixed to obtain a resin premix;

[0053] (2) adding the resin premix into a mixer, then sequentially adding the modified red mud powder, the leveling agent, the nano antibacterial agent, the pigment component, and finally adding the catalyst component, fully mixing, then pre-crushing for 2 to 10 minutes, and then mixing for 5 to 20 minutes to obtain a uniformly mixed raw material;

[0054] (3) feeding the uniformly mixed raw materials obtained in step (2) into an extruder, heating and reaction extruding, tableting, cooling, and then crushing into flakes in two stages, wherein the reaction extrusion temperature is 65 to 180° C., wherein the first stage reaction temperature is 65 to 110° C., preferably 70 to 110° C.; the second stage reaction temperature is 110 to 180° C., preferably 150 to 170° C.;

[0055] (4) The crushed flakes in step (3) are placed in an ACM grinder for grinding, and after cyclone separation and screening, an antibacterial powder coating with an average particle size of 35-40 μm is obtained.

[0056] The raw material information involved in the embodiments of the present invention is as follows:

[0057] (1) Acrylopimaric Acid:

[0058] Preparation of acrylpimaric acid was based on the literature (Wan Guoyun, Wang Zhenguo, Su Jianxiong. Preparation of acrylic rosin polyester fiberglass from rosin [J]. Plastics Industry, 1987, (01): 30-32+2.)

[0059] Rosin and acrylic acid were added into a three-necked flask at a mass ratio of 4:25, and heated to 170°C for 2 hours under nitrogen protection to isomerize the abietic resin acid in the rosin to generate L-pimaric acid. The temperature was then raised to 225°C for 2 hours. Since the conjugated double bond of L-pimaric acid is S-cis, it has high reactivity, so it undergoes a Diels-Alder reaction with the dienophile acrylic acid to obtain a light yellow transparent solid propylene pimaric acid.

[0060] (2) Maleopimaric acid and maleopimaric anhydride:

[0061] Maleopimaric acid and maleopimaric anhydride are prepared by Diels-Alder reaction of rosin and maleic acid or maleic anhydride. According to the literature (Yin Hongmei, Guo Hong, Xu Feng, et al. Synthesis and application of maleopimaric acid [J]. Journal of Shenyang Institute of Chemical Technology, 1998, (02): 15-21.)

[0062] Add a certain amount of rosin and maleic anhydride into a three-necked flask, heat to 180℃ and react for 4-5 hours, and cool to a light yellow solid. Treat the powder with carbon tetrachloride for 2-3 times to remove the unreacted rosin, and then treat it with water for several times to remove the unreacted maleic anhydride to obtain a white powder product. The rosin and maleopimaric acid in the carbon tetrachloride treatment solution can be recovered.

[0063] (3) Modified red mud powder:

[0064] Provided by Guangxi Fubaoxin Technology Co., Ltd.

[0065] According to the method disclosed in patent CN 111440515 A, the specific preparation method of modified red mud powder is as follows:

[0066] 1) washing the red mud with sulfuric acid at a concentration of 10-20wt% to a pH value of 9.2-9.4, then washing the acid-washed red mud with water, and after the water washing, the red mud is tested to have a pH value of 7.9-8.1, and then filtered to obtain clean red mud, which is then dried to a water content of ≤3.6%;

[0067] 2) grinding the clean red mud obtained in step 1) into ultrafine powder, and sieving to obtain clean red mud powder with a size larger than 300 mesh;

[0068] 3) adding modifier a to the clean red mud powder obtained in step 2), wherein the modifier a is composed of fatty alcohol polyoxyethylene ether ammonium sulfate and diethanolamide stearic acid glyceryl monoester, the amount of the modifier a added is 2.8-3.5% of the mass of the clean red mud powder, the mass ratio of the fatty alcohol polyoxyethylene ether ammonium sulfate and diethanolamide stearic acid glyceryl monoester is 5.2-7.8:2.9-4.6, the temperature is controlled to 70-75° C., and the mixture is stirred at a speed of 600-900 r / min for 30-50 min to obtain a mixture a;

[0069] 4) adding the mixture a obtained in step 3) and the modifier b into a mixer, wherein the modifier b is composed of sodium fatty acid methyl ester sulfonate and N-trimethyl chitosan, the amount of the modifier b added is 4.6-5.7% of the mass of the clean red mud powder, the mass ratio of the sodium fatty acid methyl ester sulfonate to N-trimethyl chitosan is 4.3-5.4:1.8-2.5, the temperature is controlled to 78-86° C., and the mixture is stirred at a speed of 900-1300 r / min for 32-45 min to obtain a mixture b;

[0070] 5) The mixture b obtained in step 4) is dried at a temperature of 50-53° C. to a moisture content of ≤1.5%, and then ultrafine ground and sieved to obtain modified red mud powder with a mesh size greater than 300.

[0071] Bio-based raw materials such as rosin derivatives - hydrogenated rosin, propylene pimaric acid, maleic pimaric acid, etc. are used as raw materials for further modification to prepare rosin-based polyol derivatives, which are used as bio-based modified components of thermosetting polyurethane antibacterial powder coatings to prepare high-performance thermosetting bio-based polyurethane antibacterial powder coatings. Compared with ordinary thermosetting polyurethane antibacterial powder coatings, the thermosetting bio-based polyurethane antibacterial powder coating provided by the present invention not only applies bio-based materials to polyurethane modification to prepare bio-based polyurethane powder coatings, which have excellent green and environmental protection properties, but also introduces the bulky ternary phenanthrene ring structure of rosin into the polymer main chain, and blends it with other polyurethane materials for use, which can further improve the hardness, heat resistance, hydrophobicity and other comprehensive properties of the polyurethane antibacterial powder coating, and extend the service life of the antibacterial powder coating; in addition, experiments show that the thermosetting bio-based polyurethane antibacterial powder coating modified with rosin-based polyol derivatives has better antibacterial properties than unmodified powder coatings, and the antibacterial durability is further improved, and the comprehensive performance of the antibacterial powder coating is significantly improved, indicating that after the introduction of the rosin-based polyol derivatives, the modified polymer and the antibacterial agent have a synergistic antibacterial effect.

[0072] The present invention has important scientific significance and practical application prospects for further promoting the coordinated improvement of greening and functionalization of high-performance polyurethane powder coatings.

[0073] The present invention is further explained below in conjunction with specific embodiments, but is not intended to limit the protection scope of the present invention.

[0074] Example 1

[0075] First, 3 parts by weight of hydrogenated rosin alcohol and 80 parts by weight of carboxyl-terminated polyester resin were fully mixed in a mixer, and then 0.5 parts by weight of hexamethylene diisocyanate and 6.5 parts by weight of triglycidyl isocyanurate were added and mixed to obtain a resin premix; the resin premix was added to the mixer, and then 60 parts by weight of modified red mud powder, 3 parts by weight of PV88 leveling agent, 2 parts by weight of nano silver-zinc composite ion antibacterial agent, and 20 parts by weight of transparent blue pigment were added to the mixer containing the resin premix in sequence, and finally 0.00 The method comprises the following steps: adding 1 part of dibutyltin dilaurate catalyst, fully mixing, pre-crushing for 2 minutes, and then mixing for 5 minutes to obtain a uniformly mixed raw material; putting the uniformly mixed raw material into an extruder, and heating and reacting and extruding in two stages, wherein the reaction temperature of the first stage is 100°C; and the reaction temperature of the second stage is 110°C; the extruded material is tableted, cooled, and then crushed into flakes, and the crushed flakes are placed in an ACM grinder for grinding, and after cyclone separation and screening, an antibacterial powder coating with an average particle size of 40um is obtained.

[0076] Example 2

[0077] First, 50 parts by weight of hydrogenated rosin acid (1-chloro-2-hydroxy) propyl ester and 50 parts by weight of propylene pimaric acid di(1-chloro-2-hydroxy) propyl ester are fully mixed in a mixer, and then 15 parts by weight of 4,4-diphenylmethane diisocyanate and 20 parts by weight of toluene diisocyanate curing agent are added and mixed to obtain a resin premix; the resin premix is ​​added to the mixer, and then 100 parts by weight of modified red mud powder, 2 parts by weight of PV88 leveling agent, 0.2 parts by weight of nano silver ion antibacterial agent, and 10 parts by weight of phthalocyanine green pigment are added to the mixer containing the resin premix in sequence, and finally After adding 0.5 parts by weight of dibutyltin dilaurate and 0.5 parts by weight of bismuth isooctanoate catalyst, the mixture was fully mixed, and then pre-crushed for 10 minutes, and then mixed for 20 minutes to obtain a uniformly mixed raw material; the uniformly mixed raw material was put into an extruder, and heated and reacted and extruded in two stages, wherein the reaction temperature of the first stage was 65° C.; the reaction temperature of the second stage was 180° C.; the extruded material was tableted, cooled, and then crushed into flakes, and the crushed flakes were placed in an ACM grinder for grinding, and after cyclone separation and screening, an antibacterial powder coating with an average particle size of 35 μm was obtained.

[0078] Example 3

[0079] First, 10 parts by weight of di(1-chloro-2-hydroxy)propyl acrylopimarate, 20 parts by weight of tri(1-chloro-2-hydroxy)propyl maleopimarate, 20 parts by weight of maleopimarol and 45 parts by weight of carboxyl-terminated polyester resin were fully mixed in a mixer, and then 5 parts by weight of hexamethylene diisocyanate, 7 parts by weight of 4,4',4"-triphenylmethane triisocyanate and 7 parts by weight of triglycidyl isocyanurate curing agent were added and mixed to obtain a resin premix; the resin premix was added into the mixer, and then 70 parts by weight of modified red mud powder, 1 part by weight of PV88 leveling agent were added into the mixer containing the resin premix in sequence; agent, 0.5 parts by weight of nano silver ion antibacterial agent, and finally 0.3 parts by weight of stannous octoate and 0.5 parts by weight of bismuth isooctanoate catalyst are added, and the mixture is fully mixed, and then pre-crushed for 5 minutes, and then mixed for 10 minutes to obtain a uniformly mixed raw material; the prepared uniformly mixed raw material is put into an extruder, and heated and reacted and extruded in two stages, wherein the reaction temperature of the first stage is 105° C.; the reaction temperature of the second stage is 150° C.; the extruded material is tableted, cooled, and then crushed into flakes, and the crushed flakes are placed in an ACM grinder for grinding, and after cyclone separation and screening, an antibacterial powder coating with an average particle size of 38 μm is obtained.

[0080] Example 4

[0081] First, 5 parts by weight of maleopimarol, 15 parts by weight of tri(1-chloro-2-hydroxy)propyl maleopimarate and 40 parts by weight of carboxyl-terminated polyester resin are fully mixed in a mixer, and then 2 parts by weight of hexamethylene diisocyanate, 4 parts by weight of triphenylmethane tetraisocyanate, 6 parts by weight of triglycidyl isocyanurate and 3 parts by weight of tetraisocyanatosilane curing agent are added and mixed to obtain a resin premix; the resin premix is ​​added into the mixer, and then 30 parts by weight of modified red mud powder, 0.5 parts by weight of PV88 leveling agent and 0.3 parts by weight of nano silver ion are added into the mixer containing the resin premix in sequence; The invention discloses an antibacterial agent, 1.5 parts by weight of transparent blue and 0.5 parts by weight of phthalocyanine green pigment, and finally 0.6 parts by weight of bismuth isooctanoate catalyst, and then the mixture is fully mixed, and then pre-crushed for 10 minutes, and then mixed for 8 minutes to obtain a uniformly mixed raw material; the uniformly mixed raw material is put into an extruder, and heated and reacted and extruded in two stages, wherein the reaction temperature of the first stage is 90° C.; the reaction temperature of the second stage is 170° C.; the extruded material is tableted, cooled, and then crushed into flakes, and the crushed flakes are placed in an ACM grinder for grinding, and after cyclone separation and screening, an antibacterial powder coating with an average particle size of 37 μm is obtained.

[0082] Example 5

[0083] First, 10 parts by weight of di(1-chloro-2-hydroxy)propyl acrylopimarate and 60 parts by weight of carboxyl-terminated polyester resin are fully mixed in a mixer, and then 2 parts by weight of hexamethylene diisocyanate and 10 parts by weight of triglycidyl isocyanurate curing agent are added and mixed to obtain a resin premix; the resin premix is ​​added to the mixer, and then 70 parts by weight of modified red mud powder, 1.6 parts by weight of PV88 leveling agent, 0.4 parts by weight of nano silver ion antibacterial agent, and 3 parts by weight of transparent blue pigment are added to the mixer containing the resin premix in sequence. , and finally, after adding 0.05 parts by weight of bismuth isooctanoate catalyst, fully mixing, then pre-crushing for 6 minutes, and then mixing for 12 minutes to obtain a uniformly mixed raw material; the prepared uniformly mixed raw material is put into an extruder, and heated and reacted and extruded in two stages, wherein the reaction temperature of the first stage is 95° C.; the reaction temperature of the second stage is 110° C.; the extruded material is tableted, cooled, and then crushed into flakes, and the crushed flakes are placed in an ACM grinder for grinding, and after cyclone separation and screening, an antibacterial powder coating with an average particle size of 38 μm is obtained.

[0084] Comparative Example 1

[0085] The difference between this comparative example and Example 4 is that in this comparative example, 5 parts by mass of maleopimarol and 15 parts by mass of tri(1-chloro-2-hydroxy)propyl maleopimarate are replaced by 20 parts by mass of terminal carboxyl polyester resin, and 2 parts by mass of hexamethylene diisocyanate, 4 parts by mass of triphenylmethane tetraisocyanate and 3 parts by mass of tetraisocyanatosilane curing agent are replaced by 3 parts by mass of triglycidyl isocyanurate.

[0086] Comparative Example 2

[0087] The difference between this comparative example and Example 5 is that in this comparative example, 10 parts by mass of di(1-chloro-2-hydroxy)propyl acrylpimarate is replaced by 10 parts by mass of terminal carboxyl polyester resin, and 2 parts by mass of hexamethylene diisocyanate curing agent is replaced by 0.5 parts by mass of triglycidyl isocyanurate curing agent.

[0088] The pencil hardness, adhesion, antibacterial performance and artificial weathering resistance of the antibacterial powder coatings prepared in Examples 1-5 and Comparative Examples 1 and 2 were tested, wherein the pencil hardness was tested using GB / T6739-1998; the adhesion was tested using GB / T9286-2021ISO2409; the antibacterial performance was tested using GB / T 21866-2008; and the artificial weathering resistance was tested using GB / T1865-1997ASTMG151. The results are shown in Table 1 below.

[0089] Table 1 Performance test results of antibacterial powder coatings prepared in Examples 1-5 and Comparative Examples 1 and 2

[0090]

[0091]

[0092] Those skilled in the art will readily appreciate other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art that are not disclosed by the present invention. The specification and examples are to be considered exemplary only, and the true scope and spirit of the present invention are indicated by the following claims.

[0093] It should be understood that the present invention is not limited to what has been described above and that various modifications and changes may be made without departing from its scope. The scope of the present invention is limited only by the appended claims.

Claims

1. A thermosetting bio-based polyurethane antibacterial powder coating, characterized in that: include: 3-100 parts of rosin-based modified polyol, 0-80 parts of toughening resin, 5-35 parts of curing agent, 0.001-1 parts of catalyst, 30-100 parts of modified red mud powder, 0.5-3 parts of leveling agent, 0.2-2 parts of nano antibacterial agent, 0-20 parts of pigment; The rosin-based modified polyol is one or more of hydrogenated rosin alcohol, hydrogenated rosin acid (1-chloro-2-hydroxy) propyl ester, propylene pimaric acid di(1-chloro-2-hydroxy) propyl ester, propylene pimaric alcohol, maleopimaric alcohol, and maleopimaric acid tri(1-chloro-2-hydroxy) propyl ester.

2. A thermosetting bio-based polyurethane antibacterial powder coating according to claim 1, characterized in that: The toughening resin is a mixture of one or more of a polyol, a carboxyl-terminated polyester resin, and an acrylate resin, wherein the polyol is preferably one or more of poly(1,3-propylene succinate) diol (PPSu), poly(butylene succinate) diol (PBSu), poly(1,3-propylene sebacate) diol (PPSe), and poly(butylene sebacate) diol (PBSe).

3. The thermosetting bio-based polyurethane antibacterial powder coating according to claim 1, characterized in that: The curing agent is a mixture of one or more of diisocyanate, triisocyanate, tetraisocyanate and triglycidyl isocyanurate.

4. The thermosetting bio-based polyurethane antibacterial powder coating according to claim 1, characterized in that: The catalyst is a mixture of one or more of stannous octoate, dibutyltin dilaurate and bismuth isooctanoate.

5. The method for preparing the thermosetting bio-based polyurethane antibacterial powder coating according to claims 1-4, characterized in that: (1) firstly, the rosin-based modified polyol and the toughening resin are fully mixed, and then a curing agent is added and mixed to obtain a resin premix; (2) adding the resin premix into a mixer, and then sequentially adding the modified red mud powder, the leveling agent, the nano antibacterial agent, the pigment component, and finally adding the catalyst, fully mixing, then pre-crushing for 2 to 10 minutes, and then mixing for another 5 to 20 minutes to obtain a uniformly mixed raw material; (3) feeding the uniformly mixed raw materials obtained in step (2) into an extruder, heating and reacting and extruding, tableting, cooling, and then crushing into flakes in two stages, wherein the reaction extrusion temperature is 65 to 180° C., wherein the first stage reaction temperature is 65 to 110° C.; and the second stage reaction temperature is 110 to 180° C.; (4) The crushed flakes in step (3) are placed in an ACM grinder for grinding, and after cyclone separation and screening, an antibacterial powder coating with an average particle size of 35-40 μm is obtained.

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