Bionic raw lacquer prepared from protocatechuic acid and preparation method thereof

Abstract

The invention relates to the technical field of coatings, in particular to bionic raw lacquer prepared from protocatechuic acid and a preparation method of the bionic raw lacquer. According to the specific technical scheme, the method for preparing the bionic raw lacquer from protocatechuic acid comprises the following steps: (1) uniformly mixing protocatechuic acid, an alkylation modifier and a catalyst in a nitrogen atmosphere, carrying out a heating reaction, and after the reaction is completed, washing and drying an organic phase to obtain alkylation modified protocatechuic acid; (2) adding an emulsifier into the aqueous solution of the alkylated modified protocatechuic acid, and uniformly stirring to obtain an alkylated protocatechuic acid emulsion; adding a catalyst into the alkylated protocatechuic acid emulsion, dropwise adding a hydrogen peroxide solution, and reacting to obtain an alkylated protocatechuic acid emulsion polymer; and (3) uniformly mixing the alkylated protocatechuic acid emulsion polymer with a drier or a photoinitiator to obtain the product. The problems that in the prior art, natural raw lacquer resources are limited, and the curing rate of micromolecule bionic raw lacquer monomers is low are solved.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a bionic paint prepared by using protocatechuic acid and a preparation method thereof. Background Art

[0002] Lacquer is a natural paint harvested from the bark of the lacquer tree (Toxicodendron vernicifluum). Its main film-forming substance, lacquer phenol, is a derivative of catechol with a long side carbon chain. Lacquer has excellent weather resistance, corrosion resistance, adhesion, and is environmentally friendly and non-toxic. It is often called the "king of paints." Because of the high durability of lacquer, objects made from it (such as lacquerware, lacquer paintings, etc.) can be used for hundreds of years without losing their original luster and structure.

[0003] Although raw lacquer is a high-quality natural coating, the distribution area of ​​lacquer trees is limited, the growth cycle of lacquer trees is long, and the amount of lacquer liquid that can be collected each year is limited. The collection and processing of lacquer liquid is also very time-consuming and labor-intensive. The collection process has a certain impact on the lacquer tree itself. Excessive collection may lead to the depletion of lacquer trees, which in turn affects the ecological environment. Therefore, the development of bionic lacquer (or artificial raw lacquer) to replace natural raw lacquer can not only alleviate resource pressure, improve production efficiency, and reduce costs, but also help expand the application scope of raw lacquer in the industrial field, which has important economic, environmental and social significance.

[0004] In the field of bionic lacquer research, many research groups at home and abroad have designed and synthesized a variety of "artificial lacquer phenol monomers". It has been reported that the raw materials for preparing bionic lacquer phenol mainly include catechol and its derivatives, protocatechuic aldehyde, eugenol, etc. Most of their structures are similar to natural lacquer phenol, with catechol units and long alkyl chains. There are also studies on replacing long alkyl chains with perfluoroalkyl chains to enhance hydrophobic properties.

[0005] In the study of catechol and its derivatives, Huang Zhandao, Lan Hongyun and others used catechol and tung oil as raw materials and oxalic acid as catalyst to synthesize urushiol analogs through Friedel-Strauss alkylation reaction, and investigated their film-forming properties [Coating Industry, 2005, (2): 28-30+62-63]. The results showed that the obtained urushiol analogs were difficult to form films by themselves, but could be cured by heat or dried under the catalysis of copper complexes. The obtained films had good hardness, adhesion, impact resistance, as well as excellent thermal stability and acid and organic solvent resistance. Starting from catechol, Wei Zengfeng, Zhang Aidong and others first introduced a piperazine fragment at the ortho position of the phenolic hydroxyl group through the Mannich reaction. Subsequently, they used a condensation reaction to connect a long-chain fatty acid fragment to the other nitrogen atom of the piperazine fragment to prepare a series of urushiol analogs [RSC Advances, 2019, 9 (43): 24904-24914]. Miyakoshi et al. used n-butyl lithium to deprotonate the ortho position of catechol derivatives, and then reacted with long-chain halogenated hydrocarbons to obtain urushiol analogs [Talanta, 2007, 71(4): 1536-1540]. However, the water-oxygen sensitivity of metal organic reagents makes the synthesis process more complicated, which restricts its reaction scale and practicality.

[0006] In the study of protocatechuic aldehyde, based on the fact that the aldehyde group can dock with the carbon anion equivalent and introduce a long chain structure, Ruiz-Molina et al. introduced a long alkyl chain at the aldehyde end of the protocatechuic aldehyde derivative with the phenolic hydroxyl group protected in advance through the Wittig reaction, and then hydrogenated the generated carbon-carbon double bond, and then removed the hydroxyl protecting group to obtain a series of urushiol analogs with different carbon numbers containing saturated straight-chain long alkyl groups [ACS Applied Materials & Interfaces, 2014, 6 (20): 17616-17625]. These compounds can be polymerized in the presence of ammonia and air to produce a hydrophobic coating. Zhang Yuchi et al. obtained urushiol-like compounds through the imidization reaction of protocatechuic aldehyde and oleylamine. Then, the mixture with xylene was evenly coated on a glass plate and a cured film was obtained by heating. The test results show that the cured film has good thermal stability, the highest initial decomposition temperature is above 300°C, and its hardness can reach 3H [A lacquer phenol-like compound, its preparation method and application: CN111205199B[P], 2022-11-18].

[0007] In the study of eugenol, Watanabe et al. synthesized a series of urushiol analogs by docking thiols containing long alkyl chains with the allyl double bonds of eugenol through thiol-ene reactions [ACS Applied Bio Materials, 2018, 1(3): 808-813]. The double bonds of eugenol and its derivatives may also be docked with long alkyl chains through metal organic reactions to form intermediates with similar structures to urushiol [Synthesis, 2012, 44(22): 3534-3542]. In general, metal organic catalysts are usually expensive, and their water and oxygen sensitivity restricts the practicality of these synthetic methods.

[0008] In summary, although the above method can be used to prepare various bionic lacquer materials, the standard consideration of practicality requires that the raw materials need to be cheap, readily available and abundant in resources, and the reaction route should be as simple and easy to operate as possible, so that it can be conveniently scaled up for production and put into practical application. In addition, the above research mainly focuses on the synthesis methodology of lacquer phenol-like monomers. Although various lacquer phenol-like small molecules can be directly used to prepare cured paint films, the curing rate is still slow due to the low functionality of the monomers, and it is allergenic to the human body and is not easy to construct. At present, imitating the refining process of natural raw lacquer, emulsion polymerization of lacquer phenol-like molecules is carried out to obtain highly reactive and easy-to-process lacquer phenol-like prepolymers, and then the regulation of curing reaction and paint film performance has not received due attention.

[0009] As people pay more attention to the natural environment, environmentally friendly and safe water-based coatings have become an important research direction in the coatings industry. As a typical water-based coating, emulsion coatings are environmentally friendly, pollution-free, not easy to yellow, and have good durability. With the continuous development of manufacturing technology, the types of emulsifiers are constantly enriched. By utilizing the role of reactive emulsifiers, the water resistance and corrosion resistance of emulsion coatings can be greatly improved. Domestic and foreign scholars have conducted in-depth research on the emulsion polymerization of cardanol. Ladmiral et al. used sodium dodecyl sulfate as a surfactant and persulfate as an initiator to study the free radical aqueous emulsion homopolymerization and copolymerization of cardanol-derived methacrylic acid monomers and methyl methacrylate, and obtained a stable latex with a particle size between 25-75nm, in which the glass transition temperature of the homopolymer is suitable for coating applications [European Polymer Journal, 2017, 93: 785-794]. Demchuk et al. used high oleic soybean oil and cardanol as raw materials to synthesize free radical copolymer vinyl latex. The addition of cardanol-based fragments increased the Young's modulus of the film, while the plant oil-based units helped make the film softer. The cross-linked latex film showed good hardness, water resistance, solvent resistance and metal adhesion properties [ACSSustainable Chemistry&Engineering, 2019, 7:9613-9621].

[0010] In summary, predecessors have achieved a series of scientific research results in the emulsion polymerization of urushiol-like phenols. Most of the emulsion types are water-in-oil type. The results are mainly concentrated in the aspects of emulsion preparation technology, optimization of polymerization reaction and improvement of coating performance, and the performance of the prepared coatings has been evaluated. However, most of the modified urushiol-like phenols have failed to retain their original phenolic hydroxyl or unsaturated side chain structural characteristics, and the proportion of oil phase in the emulsion is limited. Therefore, under high solid content, the presence of water may make the emulsion unstable and difficult to maintain high solid content. It is still difficult to prepare biomimetic lacquers with robust mechanical properties and high solid content by using simple, effective, low-cost and environmentally friendly methods. Summary of the invention

[0011] In view of the shortcomings of the prior art, the present invention provides a bionic lacquer prepared by using protocatechuic acid and a preparation method thereof, which solves the problems of limited natural lacquer resources and slow curing rate of small molecule bionic lacquer monomers in the prior art.

[0012] To achieve the above objectives, the present invention is implemented through the following technical solutions:

[0013] The invention discloses a method for preparing bionic paint by using protocatechuic acid, comprising the following steps:

[0014] (1) Preparation of alkylated protocatechuic acid

[0015] Protocatechuic acid, an alkylation modifier and a catalyst are mixed uniformly under a nitrogen atmosphere, and then heated to react. After the reaction is completed, the organic phase is washed and dried to obtain alkylated modified protocatechuic acid;

[0016] (2) Preparation of alkylated protocatechuic acid emulsion polymer

[0017] The emulsifier is added to the aqueous solution of alkylated modified protocatechuic acid, and the mixture is stirred evenly to obtain an alkylated protocatechuic acid emulsion; a catalyst is added to the alkylated protocatechuic acid emulsion, and a hydrogen peroxide solution is added dropwise. After the reaction is completed, an alkylated protocatechuic acid emulsion polymer is obtained;

[0018] (3) Preparation of protocatechuic acid-based biomimetic paint

[0019] The alkylated protocatechuic acid emulsion polymer is homogenized with a drying agent or a photoinitiator to obtain the polymer.

[0020] Preferably, in step (1), the alkylation modifier is any one of N-methylallylamine, 4-pentene-1-amine, 1,2-dimethyl-4-pentenylamine, 1-amino-10-undecene, 9-octadeceneamine, methylbutenol, 2,7-octadienol, 5-decene-1-ol, dodecadienol, and 15-hexadecenol; and the catalyst is any one of sulfuric acid, hydrochloric acid, acetic anhydride, phosphoric acid, p-toluenesulfonic acid, aluminum chloride, and boron trifluoride.

[0021] Preferably, in step (2), the emulsifier is any one of Tween 20, Tween 80, glyceryl monostearate, sodium dodecyl sulfate, sodium stearate, sodium dodecylbenzene sulfonate, cetyltrimethylammonium chloride, cetyltrimethylammonium bromide, gum arabic, and guar gum; and the catalyst is any one of ferrous sulfate heptahydrate, ferrocene, disalicylicylaldehyde ethylenediamine cobalt, disalicylicylaldehyde ethylenediamine iron, titanium dioxide, bauxite, catalase, lipase, sulfonic acid, phosphoric acid, manganese sulfate, nickel sulfate, cobalt sulfate, cobalt hydroxide, and manganese hydroxide.

[0022] Preferably, in step (3), the drying agent is any one of cobalt triacetate, cobalt naphthenate, cobalt stearate, cobalt isooctanoate, zinc oxide, zinc stearate, manganese 2-ethylhexanoate, manganese stearate, ferric sulfate, benzotriazole compounds, calcium oxide, calcium chloride, benzoyl peroxide, soybean peroxidase, and polyphenol oxidase; the photoinitiator is any one of 2-hydroxy-2-methyl-1-phenylacetone, 1-hydroxy-cyclohexyl benzophenone, 2-hydroxy-2-methyl-1-p-hydroxyethyl ether phenylacetone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-ethoxy-phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 4-p-toluenethiodibenzophenone.

[0023] Preferably, in step (1), the reaction temperature is 80-150° C., and the reaction is carried out at a constant temperature for 1-8 hours; the molar ratio of protocatechuic acid to the alkylation modifier is 1:1-8:1, and the amount of the catalyst added is 1.0%-5.0% of the mass of protocatechuic acid.

[0024] Preferably, in step (1), the organic phase is washed with saturated brine and then washed multiple times with a saturated calcium chloride hot solution at a temperature of 60 to 90° C. After washing, it is dried with anhydrous magnesium sulfate.

[0025] Preferably, in step (2), the mass ratio of water to alkylated modified protocatechuic acid in the aqueous solution of alkylated modified protocatechuic acid is 1:9 to 1:1, the amount of the emulsifier added is 1.0% to 5.0% of the mass of the alkylated modified protocatechuic acid, the amount of the catalyst added is 1.0% to 5.0% of the mass of the alkylated protocatechuic acid emulsion, and the amount of hydrogen peroxide added is 0.1% to 2.0% of the mass of the alkylated protocatechuic acid emulsion.

[0026] Preferably, in step (3), the added amount of the drying agent or the photoinitiator is 1.0% to 5.0% of the mass of the alkylated protocatechuic acid emulsion polymer.

[0027] Correspondingly, a bionic paint is prepared by a method for preparing bionic paint using protocatechuic acid.

[0028] Preferably, the method for using the bionic paint is: after applying the bionic paint containing a drying agent, place it in an air environment at 25 to 80°C for 3 to 72 hours to obtain a heat-curing protocatechuic acid-based bionic paint coating; or, after applying the bionic paint containing a photoinitiator, irradiate it under ultraviolet light with a main wavelength of 365nm for 30 to 90 seconds to obtain a UV-curing protocatechuic acid-based bionic paint coating.

[0029] The present invention has the following beneficial effects:

[0030] 1. The present invention provides a method for preparing a bionic lacquer which is simple and economical. Protocatechuic acid is used as a raw material. From the perspective of molecular design, the catechol anchoring group is retained to promote adhesion to different surfaces, and long-chain unsaturated groups are grafted to promote system reactivity and paint film flexibility. Furthermore, by imitating the oxidative polymerization process of natural lacquer, oil-in-water emulsion polymerization is used to achieve orderly assembly of protocatechuic acid from microscopic to macroscopic scales, thereby preparing a new type of bionic lacquer with high solid content to meet the needs of the modern coatings industry.

[0031] 2. The present invention simulates the structure of natural raw lacquer, uses abundant protocatechuic acid as raw material, grafts long unsaturated carbon chains to improve the activity of monomers, and utilizes water-in-oil emulsion polymerization to realize the orderly assembly of modified protocatechuic acid to prepare high-solid content bionic raw lacquer coatings. The present invention is conducive to solving the problem of shortage of natural raw lacquer resources, enriching the types of raw lacquer resources, and expanding the application of raw lacquer in the fields of special coatings.

[0032] 3. The new emulsion bionic lacquer synthesized by the present invention has the characteristics of low viscosity, good solubility, rich active functional groups, fast drying, good compatibility with nanoparticles, etc., which effectively solves the problems of high viscosity and slow curing of natural lacquer. The bionic lacquer coating prepared by the technology of the present invention has good fluidity and adhesion, making it easier to operate during the coating process and reducing the difficulty of construction.

[0033] 4 The process of the present invention is simple to operate, green and environmentally friendly, the product does not contain VOCs, has low production cost and high safety, and can become a new technology for industrial production of bionic paint coatings, which is conducive to expanding the application of protocatechuic acid in the field of coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is the infrared spectrum of the protocatechuic acid-based biomimetic paint prepared in Example 1;

[0035] Figure 2 This is a microscopic image of the alkylated protocatechuic acid emulsion polymer prepared in Example 1. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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.

[0037] Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0038] The invention discloses a method for preparing bionic paint by using protocatechuic acid, comprising the following steps:

[0039] (1) Preparation of alkylated protocatechuic acid

[0040] Add protocatechuic acid to a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel, add an alkylation modifier and a catalyst of 1.0% to 5.0% by mass of protocatechuic acid to the above four-necked flask according to a molar ratio of protocatechuic acid to alkylation modifier of 1:1 to 8:1, introduce nitrogen as a protective atmosphere, stir to mix evenly, heat to 80 to 150°C, and react at a constant temperature for 1 to 8 hours to obtain a crude product of alkylated protocatechuic acid. Transfer the crude product to a separating funnel, shake and let stand, separate the water phase, wash the organic phase with saturated salt water, and then wash it twice with a saturated calcium chloride hot solution at a temperature of 60 to 90°C each time. Discard the lower liquid, transfer the organic layer to a dry conical flask and dry it with anhydrous magnesium sulfate to obtain the product alkylated protocatechuic acid.

[0041] Wherein, the alkylation modifier is any one of N-methylallylamine, 4-pentene-1-amine, 1,2-dimethyl-4-penteneamine, 1-amino-10-undecene, 9-octadeceneamine, methylbutenol, 2,7-octadienol, 5-decene-1-ol, dodecadienol, and 15-hexadecenol.

[0042] The catalyst is any one of sulfuric acid, hydrochloric acid, acetic anhydride, phosphoric acid, p-toluenesulfonic acid, aluminum trichloride, and boron trifluoride.

[0043] (2) Preparation of alkylated protocatechuic acid emulsion polymer

[0044] Under room temperature, an emulsifier is added to a mixed solution of water and alkylated protocatechuic acid, and the mixture is stirred for 1 to 2 hours using a stirrer, and the rotation speed is controlled at 300 to 2000 r / min to obtain an emulsion. The mass ratio of water to alkylated protocatechuic acid is 1:9 to 1:1, and the amount of the emulsifier added is 1.0% to 5.0% of the mass of the alkylated protocatechuic acid.

[0045] In the alkylated protocatechuic acid emulsion, 1.0% to 5.0% of the catalyst by mass of the emulsion is added, and 0.1% to 2.0% of the 30% hydrogen peroxide solution by mass of the emulsion is added dropwise, and a constant temperature magnetic stirrer is used to react at room temperature for 1 to 12 hours to obtain an alkylated protocatechuic acid emulsion polymer.

[0046] Wherein, the emulsifier is any one of Tween 20 (polysorbate 20), Tween 80 (polysorbate 80), glyceryl monostearate, sodium lauryl sulfate, sodium stearate, sodium dodecylbenzene sulfonate, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, gum arabic, and guar gum.

[0047] The catalyst is any one of ferrous sulfate heptahydrate, ferrocene, disalicylicylaldehyde ethylenediamine cobalt, disalicylicylaldehyde ethylenediamine iron, titanium dioxide, bauxite, catalase, lipase, sulfonic acid, phosphoric acid, manganese sulfate, nickel sulfate, cobalt sulfate, cobalt hydroxide, and manganese hydroxide.

[0048] (3) Preparation of protocatechuic acid-based biomimetic paint

[0049] The alkylated protocatechuic acid emulsion polymer is uniformly mixed with a drying agent or a photoinitiator to obtain the emulsion polymer, wherein the addition amount of the drying agent or the photoinitiator is 1.0% to 5.0% of the mass of the alkylated protocatechuic acid emulsion polymer.

[0050] Wherein, the drying agent is any one of cobalt triacetate, cobalt naphthenate, cobalt stearate, cobalt isooctanoate, zinc oxide, zinc stearate, manganese 2-ethylhexanoate, manganese stearate, ferric sulfate, benzotriazole compounds, calcium oxide, calcium chloride, benzoyl peroxide, soybean peroxidase, and polyphenol oxidase.

[0051] The photoinitiator includes but is not limited to any one of 2-hydroxy-2-methyl-1-phenylpropanone, 1-hydroxy-cyclohexyl benzophenone, 2-hydroxy-2-methyl-1-p-hydroxyethyl ether phenylpropanone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-ethoxy-phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide and 4-p-toluenethiodibenzophenone.

[0052] The method for using the bionic paint prepared by the present invention is as follows: the bionic paint containing a drying agent is uniformly coated on a glass sheet or a tinplate sheet by a coating device, and the sheet is placed in an air environment at 25 to 80°C for 3 to 72 hours to obtain a heat-curing protocatechuic acid-based bionic paint coating; or the bionic paint containing a photoinitiator is uniformly coated on a glass sheet or a tinplate sheet by a coating device, and the sheet is placed under ultraviolet light with a main wavelength of 365nm for irradiation for 30 to 90 seconds to obtain an ultraviolet light-curing protocatechuic acid-based bionic paint coating.

[0053] The present invention will be further described below in conjunction with specific embodiments.

[0054] In the present invention, the equipment and method for characterizing the protocatechuic acid-based biomimetic paint coating are as follows:

[0055] Preparation of membrane: According to GB / T 1727-1992 “General preparation method for coating film”, the prepared protocatechuic acid-based bionic paint was coated on a clean glass sheet or a sandpaper-polished tinplate sheet, and the experiment was carried out in air.

[0056] Conventional physical and mechanical properties: The prepared samples were evenly coated on tinplate sheets, and the conventional physical and mechanical properties and corrosion resistance of the cured film were tested using the following national standards. The drying time of the paint film was measured according to GB / T 1728-1989, the adhesion was measured according to GB / T 1720-1979, the impact resistance was measured according to GB / T 1732-1993, the hardness was measured according to GB / T 6739-2006, the alkali resistance and acid resistance were measured according to GB / T 1763-1979, and the salt spray resistance was measured according to GB / T 1771-1991.

[0057] The infrared spectrum of the samples was measured using a NICOLET6700 FT-IR spectrometer.

[0058] The microstructure of the emulsion was observed using an optical microscope.

[0059] Example 1

[0060] A method for preparing bionic paint using protocatechuic acid comprises the following steps:

[0061] (1) Add protocatechuic acid to a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel. Add 4-pentene-1-amine and 1.0% concentrated sulfuric acid by mass of protocatechuic acid to the four-necked flask in a molar ratio of protocatechuic acid to 4-pentene-1-amine of 1:1, introduce nitrogen as a protective atmosphere, stir to mix evenly, heat to 80°C, and react at constant temperature for 8 hours to obtain a crude product of alkylated protocatechuic acid. Transfer the crude product to a separating funnel, shake and let stand, separate the water phase, wash the organic phase with saturated brine, and then wash twice with a saturated calcium chloride hot solution at a temperature of 60°C each time. Discard the lower liquid, transfer the organic layer to a dry conical flask and dry it with anhydrous magnesium sulfate to obtain the product of alkylated protocatechuic acid.

[0062] (2) At room temperature, polysorbate 80 was added to a mixed solution of water and alkylated protocatechuic acid, wherein the mass ratio of water to alkylated modified protocatechuic acid in the mixed solution was 1:9, and the amount of polysorbate 80 added was 1.0% of the mass of the alkylated protocatechuic acid. The mixture was stirred for 1 h using a stirrer at a speed of 300 r / min to obtain an emulsion.

[0063] (3) Add 1% of ferrous sulfate heptahydrate by weight of the emulsion to the alkylated protocatechuic acid emulsion, and simultaneously dropwise add 0.1% of a 30% hydrogen peroxide solution, and react at room temperature for 12 h using a constant temperature magnetic stirrer to obtain an alkylated protocatechuic acid emulsion polymer.

[0064] (4) Take the alkylated protocatechuic acid emulsion polymer and 1.0% by weight of cobalt cyclohexaneate, mix them and stir them evenly.

[0065] (5) The bionic paint sample containing cobalt cyclohexane prepared in step (4) is evenly coated on a glass sheet or a tinplate sheet using a coating applicator, and placed in an air environment at 25° C. for 72 hours to obtain a protocatechuic acid-based bionic paint coating.

[0066] The infrared spectrum of the protocatechuic acid-based biomimetic paint prepared in Example 1 is as follows: Figure 1 As shown, the results show that 3357cm -1 The peak at 3009cm is attributed to the stretching vibration of OH and NH; -1 The peak at 2924 cm is attributed to the CH stretching vibration of the aromatic ring; -1 and 2853cm -1 The positions correspond to the CH2 antisymmetric stretching vibration and the CH2 symmetric stretching vibration respectively; 1589cm -1 The position is attributed to the antisymmetric stretching vibration of the ester COO; 1487 cm -1 、1456cm -1 and 1349cm -1 The aromatic ring skeleton vibration occurs at 1265cm -1 The position corresponds to the C-OH stretching vibration or the out-of-plane swinging vibration of CH2 in phenols; 1154 cm -1 and 999cm -1 The position corresponds to the CH in-plane bending vibration; 911cm -1 The ester COO out-of-plane bending vibration corresponds to 778 cm -1 and 692cm -1 The positions correspond to the out-of-plane bending vibration of the CH of the aromatic ring or the angular vibration of the COO of the ester group. The above results are consistent with the composition structure of bionic paint.

[0067] Microscopic image of the alkylated protocatechuic acid emulsion polymer prepared in Example 1 Figure 2 As shown, the black area is the water phase and the white area is the oil phase.

[0068] Example 2

[0069] A method for preparing bionic paint using protocatechuic acid comprises the following steps:

[0070] (1) Add protocatechuic acid to a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel. Add 1-amino-10-undecene and acetic anhydride (5.0% by mass of protocatechuic acid) to the four-necked flask at a molar ratio of 8:1 between protocatechuic acid and 1-amino-10-undecene. Pass nitrogen as a protective atmosphere, stir to mix evenly, heat to 150°C, and react at constant temperature for 1 hour to obtain a crude product, alkylated protocatechuic acid. Transfer the crude product to a separating funnel, shake and let stand, separate the water phase, wash the organic phase with saturated brine, and then wash twice with a saturated calcium chloride hot solution at 90°C each time. Discard the lower liquid, transfer the organic layer to a dry conical flask and dry it with anhydrous magnesium sulfate to obtain the product, alkylated protocatechuic acid.

[0071] (2) At room temperature, glyceryl monostearate was added to a mixed solution of water and alkylated protocatechuic acid, wherein the mass ratio of water to alkylated modified protocatechuic acid in the mixed solution was 1:1, and the amount of glyceryl monostearate added was 5.0% of the mass of the alkylated protocatechuic acid. The mixture was stirred for 2 h with a stirrer at a speed of 2000 r / min to obtain an emulsion.

[0072] (3) Add 5.0% of ferrocene by weight of the emulsion to the alkylated protocatechuic acid emulsion, and simultaneously dropwise add 2.0% of a 30% hydrogen peroxide solution, and react at room temperature for 1 hour using a constant temperature magnetic stirrer to obtain an alkylated protocatechuic acid emulsion polymer.

[0073] (4) Take the alkylated protocatechuic acid emulsion polymer and 5.0% by weight of cobalt stearate, mix them and stir them evenly.

[0074] (5) The bionic paint sample containing the drying agent prepared in step (4) is evenly coated on a glass sheet or a tinplate sheet using a coating applicator, and placed in an 80° C. air environment for 3 h to obtain a protocatechuic acid-based bionic paint coating.

[0075] Example 3

[0076] A method for preparing bionic paint using protocatechuic acid comprises the following steps:

[0077] (1) Add protocatechuic acid to a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel. Add 9-octadeceneamine and 2.5% phosphoric acid by mass of protocatechuic acid to the four-necked flask in a molar ratio of protocatechuic acid to 9-octadeceneamine of 4:1, introduce nitrogen as a protective atmosphere, stir to mix evenly, heat to 110°C, and react at a constant temperature for 4.5 hours to obtain a crude product, alkylated protocatechuic acid. Transfer the crude product to a separating funnel, shake and let stand, separate the water phase, wash the organic phase with saturated brine, and then wash twice with a saturated calcium chloride hot solution at a temperature of 75°C each time. Discard the lower liquid, transfer the organic layer to a dry conical flask and dry it with anhydrous magnesium sulfate to obtain the product alkylated protocatechuic acid.

[0078] (2) At room temperature, sodium dodecyl sulfate was added to a mixed solution of water and alkylated protocatechuic acid, wherein the mass ratio of water to alkylated modified protocatechuic acid in the mixed solution was 1:5, and the amount of sodium dodecyl sulfate added was 3.0% of the mass of the alkylated protocatechuic acid. The mixture was stirred for 1.5 hours with a stirrer at a speed of 1000 r / min to obtain an emulsion.

[0079] (3) Add 3.0% of the mass of the emulsion of disalicylic aldehyde ethylenediamine cobalt to the alkylated protocatechuic acid emulsion, and simultaneously dropwise add 1.0% of a 30% hydrogen peroxide solution, and react at room temperature for 6 hours using a constant temperature magnetic stirrer to obtain an alkylated protocatechuic acid emulsion polymer.

[0080] (4) Take the alkylated protocatechuic acid emulsion polymer and 3.0% by weight of zinc stearate, mix them and stir them evenly.

[0081] (5) The bionic paint sample containing the drying agent prepared in step (4) is evenly coated on a glass sheet or a tinplate sheet using a coating device, and placed in an air environment at 55° C. for 36 hours to obtain a protocatechuic acid-based bionic paint coating.

[0082] Example 4

[0083] A method for preparing bionic paint using protocatechuic acid comprises the following steps:

[0084] (1) Add protocatechuic acid to a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel. Add 2,7-octadienol and p-toluenesulfonic acid (2.0% by mass of protocatechuic acid) to the above four-necked flask in a molar ratio of protocatechuic acid to 2,7-octadienol of 2:1, introduce nitrogen as a protective atmosphere, stir to mix evenly, heat to 90°C, and react at constant temperature for 7 hours to obtain a crude product, alkylated protocatechuic acid. Transfer the crude product to a separating funnel, shake and let stand, separate the water phase, wash the organic phase with saturated brine, and then wash twice with a saturated calcium chloride hot solution at a temperature of 70°C each time. Discard the lower liquid, transfer the organic layer to a dry conical flask and dry it with anhydrous magnesium sulfate to obtain the product alkylated protocatechuic acid.

[0085] (2) At room temperature, sodium stearate was added to a mixed solution of water and alkylated protocatechuic acid, wherein the mass ratio of water to alkylated protocatechuic acid in the mixed solution was 1:8, and the amount of sodium stearate added was 2.0% of the mass of the alkylated protocatechuic acid. The mixture was stirred for 1.2 hours with a stirrer at a speed of 400 r / min to obtain an emulsion.

[0086] (3) Add 1.0% to 5.0% of the mass of the emulsion of disalicylic aldehyde ethylenediamine iron to the alkylated protocatechuic acid emulsion, and simultaneously dropwise add 0.4% of a 30% hydrogen peroxide solution, and react at room temperature for 10 hours using a constant temperature magnetic stirrer to obtain an alkylated protocatechuic acid emulsion polymer.

[0087] (4) Take the alkylated protocatechuic acid emulsion polymer and 2.0% by weight of soybean peroxidase, mix them and stir them evenly.

[0088] (5) The bionic paint sample containing a drying agent prepared in step (4) is evenly coated on a glass sheet or a tinplate sheet using a coating device, and placed in an air environment at 40° C. for 60 hours to obtain a protocatechuic acid-based bionic paint coating.

[0089] Example 5

[0090] A method for preparing bionic paint using protocatechuic acid comprises the following steps:

[0091] (1) Add protocatechuic acid to a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel. Add dodecadienol and aluminum chloride (4.0% by mass of protocatechuic acid) to the four-necked flask in a molar ratio of protocatechuic acid to dodecadienol of 6:1, introduce nitrogen as a protective atmosphere, stir to mix evenly, heat to 120°C, and react at a constant temperature for 3.5 hours to obtain a crude product, alkylated protocatechuic acid. Transfer the crude product to a separating funnel, shake and let stand, separate the water phase, wash the organic phase with saturated brine, and then wash twice with a saturated calcium chloride hot solution at 80°C each time. Discard the lower liquid, transfer the organic layer to a dry conical flask and dry it with anhydrous magnesium sulfate to obtain the product, alkylated protocatechuic acid.

[0092] (2) At room temperature, cetyl trimethyl ammonium bromide was added to a mixed solution of water and alkylated protocatechuic acid, wherein the mass ratio of water to alkylated protocatechuic acid in the mixed solution was 1:6, and the amount of cetyl trimethyl ammonium bromide added was 3.5% of the mass of the alkylated protocatechuic acid. The mixture was stirred for 1.8 hours with a stirrer at a speed of 1200 r / min to obtain an emulsion.

[0093] (3) Add 3.5% manganese sulfate by weight of the emulsion to the alkylated protocatechuic acid emulsion, and simultaneously dropwise add 1.2% of a 30% hydrogen peroxide solution, and react at room temperature for 4 h using a constant temperature magnetic stirrer to obtain an alkylated protocatechuic acid emulsion polymer.

[0094] (4) Take the alkylated protocatechuic acid emulsion polymer and 4.0% by weight of 2-hydroxy-2-methyl-1-phenylpropanone, mix them and stir them evenly.

[0095] (5) The bionic paint sample containing a photoinitiator prepared in step (4) is evenly coated on a glass sheet or a tinplate sheet using a coating apparatus, and irradiated under ultraviolet light with a main wavelength of 365 nm for 90 seconds to obtain a protocatechuic acid-based bionic paint coating.

[0096] Example 6

[0097] A method for preparing bionic paint using protocatechuic acid comprises the following steps:

[0098] (1) Add protocatechuic acid to a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer, and a dropping funnel. Add 15-hexadecenol and 4.5% of the mass of protocatechuic acid to the four-necked flask in a molar ratio of protocatechuic acid to 15-hexadecenol of 7:1, introduce nitrogen as a protective atmosphere, stir to mix evenly, heat to 140°C, and react at constant temperature for 2 hours to obtain a crude product of alkylated protocatechuic acid. Transfer the crude product to a separating funnel, shake and let stand, separate the water phase, wash the organic phase with saturated brine, and then wash twice with a saturated calcium chloride hot solution at a temperature of 85°C each time. Discard the lower liquid, transfer the organic layer to a dry conical flask and dry it with anhydrous magnesium sulfate to obtain the product of alkylated protocatechuic acid.

[0099] (2) At room temperature, gum arabic was added to a mixed solution of water and alkylated protocatechuic acid, wherein the mass ratio of water to alkylated protocatechuic acid in the mixed solution was 1:8, and the amount of gum arabic added was 4.0% of the mass fraction of alkylated protocatechuic acid. The mixture was stirred for 2 h using a stirrer at a speed of 1500 r / min to obtain an emulsion.

[0100] (3) Add 4.0% nickel sulfate by weight of the emulsion to the alkylated protocatechuic acid emulsion, and simultaneously dropwise add 1.5% of a 30% hydrogen peroxide solution, and react at room temperature for 3 h using a constant temperature magnetic stirrer to obtain an alkylated protocatechuic acid emulsion polymer.

[0101] (4) Take the alkylated protocatechuic acid emulsion polymer and 4.5% by weight of 2-hydroxy-2-methyl-1-p-hydroxyethyl ether phenyl acetone, mix them and stir them evenly.

[0102] (5) The bionic paint sample containing a photoinitiator prepared in step (4) is evenly coated on a glass sheet or a tinplate sheet using a coating apparatus, and then irradiated under ultraviolet light with a main wavelength of 365 nm for 30 seconds to obtain a protocatechuic acid-based bionic paint coating.

[0103] The present invention uses a 50 μm applicator to apply the bionic lacquer coating and natural lacquer coating prepared in Examples 1-6 on a glass plate and a tinplate sheet, respectively, and dry and solidify. At the same time, the natural lacquer coating is placed in a temperature and humidity control box for drying (T=30°C, RH=80%). The physical and mechanical properties and anti-corrosion properties of the bionic lacquer film and the natural lacquer film after curing are measured, and the results are shown in Table 1. The physical and mechanical properties and corrosion resistance of the bionic lacquer are better, and the results of the present invention are suitable for universal promotion and application.

[0104] Table 1 Drying time of paint film and test results of physical and mechanical properties and corrosion resistance

[0105]

[0106]

[0107] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for preparing bionic paint using protocatechuic acid, characterized in that: The following steps are involved: (1) Preparation of alkylated protocatechuic acid Protocatechuic acid, an alkylation modifier and a catalyst are mixed uniformly under a nitrogen atmosphere, and then heated to react. After the reaction is completed, the organic phase is washed and dried to obtain alkylated modified protocatechuic acid; (2) Preparation of alkylated protocatechuic acid emulsion polymer The emulsifier is added to the aqueous solution of alkylated modified protocatechuic acid, and the mixture is stirred evenly to obtain an alkylated protocatechuic acid emulsion; a catalyst is added to the alkylated protocatechuic acid emulsion, and a hydrogen peroxide solution is added dropwise. After the reaction is completed, an alkylated protocatechuic acid emulsion polymer is obtained; (3) Preparation of protocatechuic acid-based biomimetic paint The alkylated protocatechuic acid emulsion polymer is homogenized with a drying agent or a photoinitiator to obtain the polymer.

2. The method for preparing bionic paint using protocatechuic acid according to claim 1, characterized in that: In step (1), the alkylation modifier is any one of N-methylallylamine, 4-pentene-1-amine, 1,2-dimethyl-4-pentenylamine, 1-amino-10-undecene, 9-octadeceneamine, methylbutenol, 2,7-octadienol, 5-decene-1-ol, dodecadienol, and 15-hexadecenol; and the catalyst is any one of sulfuric acid, hydrochloric acid, acetic anhydride, phosphoric acid, p-toluenesulfonic acid, aluminum chloride, and boron trifluoride.

3. The method for preparing bionic paint using protocatechuic acid according to claim 1, characterized in that: In step (2), the emulsifier is any one of Tween 20, Tween 80, glyceryl monostearate, sodium dodecyl sulfate, sodium stearate, sodium dodecylbenzene sulfonate, hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, gum arabic, and guar gum; the catalyst is any one of ferrous sulfate heptahydrate, ferrocene, disalicylicylaldehyde ethylenediamine cobalt, disalicylicylaldehyde ethylenediamine iron, titanium dioxide, bauxite, catalase, lipase, sulfonic acid, phosphoric acid, manganese sulfate, nickel sulfate, cobalt sulfate, cobalt hydroxide, and manganese hydroxide.

4. The method for preparing bionic paint using protocatechuic acid according to claim 1, characterized in that: In step (3), the drying agent is any one of cobalt triacetate, cobalt cyclohexane, cobalt stearate, cobalt isooctanoate, zinc oxide, zinc stearate, manganese 2-ethylhexanoate, manganese stearate, ferric sulfate, benzotriazole compounds, calcium oxide, calcium chloride, benzoyl peroxide, soybean peroxidase, and polyphenol oxidase; the photoinitiator is any one of 2-hydroxy-2-methyl-1-phenylacetone, 1-hydroxy-cyclohexyl benzophenone, 2-hydroxy-2-methyl-1-p-hydroxyethyl ether phenylacetone, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, 2,4,6-trimethylbenzoyl-ethoxy-phenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 4-p-toluenethiodiphenylphosphine oxide.

5. A method for preparing bionic paint using protocatechuic acid according to claim 1 or 2, characterized in that: In step (1), the reaction temperature is 80-150° C., and the reaction is carried out at a constant temperature for 1-8 hours; the molar ratio of protocatechuic acid to the alkylation modifier is 1:1-8:1, and the amount of the catalyst added is 1.0%-5.0% of the mass of the protocatechuic acid.

6. The method for preparing bionic paint using protocatechuic acid according to claim 1, characterized in that: In step (1), the organic phase is washed with saturated brine and then washed multiple times with a saturated calcium chloride hot solution at a temperature of 60 to 90° C. After washing, it is dried with anhydrous magnesium sulfate.

7. A method for preparing bionic paint using protocatechuic acid according to claim 1 or 3, characterized in that: In step (2), the mass ratio of water to alkylated modified protocatechuic acid in the aqueous solution of alkylated modified protocatechuic acid is 1:9 to 1:1, the amount of the emulsifier added is 1.0% to 5.0% of the mass of the alkylated modified protocatechuic acid, the amount of the catalyst added is 1.0% to 5.0% of the mass of the alkylated protocatechuic acid emulsion, and the amount of hydrogen peroxide added is 0.1% to 2.0% of the mass of the alkylated protocatechuic acid emulsion.

8. A method for preparing bionic paint using protocatechuic acid according to claim 1 or 4, characterized in that: In step (3), the added amount of the drying agent or the photoinitiator is 1.0% to 5.0% of the mass of the alkylated protocatechuic acid emulsion polymer.

9. A bionic paint prepared by the method for preparing bionic paint using protocatechuic acid as claimed in any one of claims 1 to 8.

10. The bionic paint prepared by using protocatechuic acid according to claim 9, characterized in that: The method for using the bionic paint is as follows: after applying the bionic paint containing a drying agent, the paint is placed in an air environment at 25 to 80° C. for 3 to 72 hours to obtain a heat-curing protocatechuic acid-based bionic paint coating; or, after applying the bionic paint containing a photoinitiator, the paint is irradiated under ultraviolet light with a main wavelength of 365 nm for 30 to 90 seconds to obtain an ultraviolet-curing protocatechuic acid-based bionic paint coating.

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