Antiseptic and mildew-proof liquid for wood surface and preparation method thereof

Abstract

The present application relates to the technical field of preservatives, in particular to a preservative and mildew-proof liquid for wood surface and a preparation method thereof; in order to improve the long-term storage performance of wood, the present application adds and prepares bacteriostatic waterborne polyurethane; the present application carries out guanidination treatment on chitosan oligosaccharide molecules, generates guanidino groups in chitosan oligosaccharide molecules and introduces reactive amino groups; then further modifies 3-thiophene boronic acid, mixes it with guanidination chitosan oligosaccharide for reaction, and prepares modified chitosan oligosaccharide compounds with chitosan oligosaccharide, guanidino groups and thiophene ring structure; and prepares waterborne polyurethane emulsion with bacteriostatic performance, and in order to further enhance the penetration performance and antibacterial performance of the prepared preservative and mildew-proof liquid, the present application further adds a surfactant and ammoniacal copper quaternary ammonium salt ACQ for mixing, and finally prepares a preservative and mildew-proof liquid with long-term retention characteristics.

Description

Technical Field

[0001] This invention relates to the field of preservative technology, specifically to a preservative and antifungal liquid for wood surfaces and its preparation method. Background Technology

[0002] In recent years, fast-growing wood has gradually become a commonly used material in the home decoration and construction industry due to its rapid growth, high yield, and low price. However, compared with woods such as mahogany, fast-growing wood is flammable, corrosive, and not resistant to storage. It is also susceptible to mold and other privacy issues, causing storage pressure. Therefore, it is necessary to study the anti-mold and anti-corrosion technology for fast-growing wood to solve the industry's pain points. Summary of the Invention

[0003] The purpose of this invention is to provide an anti-corrosion and anti-mildew liquid for wood surfaces and its preparation method, so as to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for preparing an anti-corrosion and anti-mildew liquid for wood surfaces, comprising the following steps:

[0005] S1. Preparation of antibacterial aqueous polyurethane emulsion;

[0006] S11. Dissolve chitosan oligosaccharide in hydrochloric acid solution, stir and mix for 10-15 min to obtain chitosan oligosaccharide solution, further add 2-amino-2-cyanoacetamide to it, heat to 85-90℃, stir and react for 3-6 h, stop heating, evaporate under vacuum at 60℃ to constant weight to obtain guanidyl-modified chitosan oligosaccharide compound.

[0007] S12. Disperse the guanidinated chitosan oligosaccharide compound prepared in step S11 into DMF, shake and mix for 15-20 min, and then cool to 5-15℃ to obtain a guanidinated chitosan oligosaccharide solution;

[0008] Under a nitrogen atmosphere, 3-thiopheneboronic acid was dispersed in dimethyl sulfoxide and mixed by shaking for 15-30 min. Then, a dimethyl sulfoxide solution containing anhydrous ferrous chloride was added dropwise over 0.5-1 h. After the addition was complete, the temperature was raised to 95-105 °C and reacted for 10-15 min. The mixture was then evaporated under vacuum at 60-80 °C to constant weight. The resulting product was then dispersed again in carbon tetrachloride and cooled to 5-15 °C. This product was then added dropwise to a guanidyl-modified chitosan oligosaccharide solution over 1-2 h. After the addition was complete, the temperature was raised to 80-90 °C and the reaction was continued for 2-4 h. The mixture was then evaporated under vacuum to constant weight to obtain the modified chitosan oligosaccharide compound.

[0009] S13. Mix triisocyanate (methyl)silicon with DMF, heat to 55-65℃ under nitrogen atmosphere, add DMF solution containing modified chitosan oligosaccharide compound dropwise, continue heating to 115-120℃ after the addition is completed, react for 1.5-2h, and then remove excess solvent by rotary evaporation to obtain modified isocyanate.

[0010] S14. After vacuum drying polytetrahydrofuran diol for 0.5-1 h, add modified isocyanate, heat to 75-80℃, react for 0.5-2 h, add acetone and 1,6-hexanediol, continue the reaction for 1-1.5 h, add N-methyldiethanolamine, react for 1.5-3 h, cool to 45-50℃, add hydrochloric acid dropwise to adjust the pH of the solution to neutral, add deionized water, emulsify and disperse for 0.5-1 h to obtain antibacterial waterborne polyurethane emulsion;

[0011] S2. Mix the antibacterial waterborne polyurethane emulsion prepared in step S1 with surfactant and deionized water. After high-speed shear mixing for 15-30 min, add ammonia-soluble copper quaternary ammonium salt ACQ and continue mixing for 30-45 min to obtain an anti-corrosion and anti-mildew liquid for wood surfaces.

[0012] To improve the long-term storage performance of wood, it is necessary to fix the effective components of the anti-mold and preservative liquid on the wood for a long time, and avoid factors such as volatilization or moisture leaching, which would reduce the content of anti-mold and preservative components on the wood surface and thus reduce the anti-mold and preservative effect. Therefore, this invention adds antibacterial waterborne polyurethane to the anti-mold and preservative liquid. This invention first uses chitosan oligosaccharide as a reaction raw material. The positive charge on its molecule can combine with the negative charge on the cell membrane of bacteria, fungi and other microorganisms, thereby causing leakage of cell components and preventing microbial proliferation. Then, this application also performs guanidinolation treatment on the chitosan oligosaccharide molecule, using 2-amino-2-cyanoacetamide to react with it, thereby generating guanidino groups and introducing reactive amino groups into the chitosan oligosaccharide molecule.

[0013] Based on this, the present invention further modified 3-thiopheneboronic acid and reacted it with guanidinolated chitosan oligosaccharide. In this process, due to the relatively strong bond energy between boron and oxygen in the borate group (-B(OH)2) of 3-thiopheneboronic acid, and the attraction of the sulfur atom in the thiophene ring to the electrons in the borate group, the nucleophilic substitution of the borate group is weak, which makes it difficult for the borate group to react directly with the amino group in the guanidinolated chitosan oligosaccharide. Therefore, the present invention first subjected 3-thiopheneboronic acid to acylation treatment, and then reacted it with the amino group to prepare a modified chitosan oligosaccharide compound with chitosan oligosaccharide, guanidino group and thiophene ring structure.

[0014] Subsequently, the present invention further reacts the prepared modified chitosan oligosaccharide compound with triisocyanate (methyl)silicon to introduce the modified chitosan oligosaccharide compound with antibacterial properties into the isocyanate compound. Then, the present invention reacts it with substances such as polytetrahydrofurandiol to finally prepare an antibacterial waterborne polyurethane emulsion.

[0015] To further enhance the penetration and antibacterial properties of the preservative and antifungal liquid prepared by this invention, a surfactant and ammoniacal copper quaternary ammonium salt (ACQ) are added and mixed, followed by high-speed emulsification and shearing. This reduces the number of emulsion droplets generated in the preservative and antifungal liquid prepared by this invention, thereby improving its penetration performance. Furthermore, as the water in the preservative and antifungal liquid evaporates, the solid components will coat the wood surface, thus preventing the loss of antibacterial components and maintaining its antibacterial properties for a long time.

[0016] Furthermore, in step S11, the weight-average molecular weight of chitosan oligosaccharide is 1000-3000 Da.

[0017] Furthermore, in step S11, the mass ratio of chitosan oligosaccharide to 2-amino-2-cyanoacetamide is 10:(0.7-1) by weight.

[0018] Furthermore, in step S12, the mass ratio of guanidylchitosan oligosaccharide compound, 3-thiopheneboronic acid, and anhydrous ferrous chloride is 10:(0.8-1):(1.3-1.8) by weight.

[0019] Furthermore, in step S13, the mass ratio of triisocyanate (methyl)silicon to modified chitosan oligosaccharide compound is 1:(2.6-5.1).

[0020] Furthermore, in step S14, the weight-average molecular weight of the polytetrahydrofuran diol is 2000-3000.

[0021] Furthermore, in step S14, the mass ratio of polytetrahydrofuran diol, modified isocyanate, acetone, 1,6-hexanediol, and N-methyldiethanolamine is 15:(12-18):(0.1-0.2):(0.05-0.08):(0.1-0.15).

[0022] Furthermore, in step S14, the mass ratio of polytetrahydrofuran diol to deionized water is 15:(250-300).

[0023] Furthermore, in step S2, the anti-corrosion and anti-mildew liquid on the wood surface, by weight, includes the following components: 280-300 parts of antibacterial waterborne polyurethane emulsion, 200-250 parts of deionized water, 0.9-1.5 parts of surfactant, and 0-10 parts of ammonia-soluble copper quaternary ammonium salt ACQ.

[0024] The surfactant is any one of the nonionic surfactants.

[0025] Compared with the prior art, the beneficial effects achieved by the present invention are:

[0026] To improve the long-term storage performance of wood, this invention adds and prepares an antibacterial waterborne polyurethane. The invention guanidinolates chitosan oligosaccharide molecules by reacting them with 2-amino-2-cyanoacetamide to generate a guanidinium group and introduce a reactive amino group into the chitosan oligosaccharide molecules. Subsequently, 3-thiophene boric acid is further modified and reacted with the guanidinolate chitosan oligosaccharide to prepare a modified chitosan oligosaccharide compound possessing chitosan oligosaccharide, guanidinium, and thiophene ring structures. This modified compound is then reacted with isocyanate, polytetrahydrofuran glycol, and other substances to prepare an antibacterial waterborne polyurethane emulsion. Furthermore, to further enhance the penetration and antibacterial properties of the preservative and antifungal liquid prepared in this invention, a surfactant and ammoniacal copper quaternary ammonium salt (ACQ) are added, ultimately preparing a preservative and antifungal liquid with long-lasting properties. Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] The chitosan oligosaccharide used in this application is YXL2240 type chitosan oligosaccharide provided by Shanghai Yingxin Laboratory Equipment Co., Ltd., with a MW of 1000 kDa; the 2-amino-2-cyanoacetamide, triisocyanate (methyl)silicon, and polytetrahydrofurandiol used are provided by Shanghai Aladdin Biochemical Technology Co., Ltd., wherein the polytetrahydrofurandiol Mn=2000; the 3-thiophene boric acid used is provided by Shanghai Haohong Biomedical Technology Co., Ltd.; the surfactant used is ZY-1465 alkynyl alcohol polyether surfactant provided by Shanghai Ziyi Chemical Co., Ltd.; and the ammonia-soluble copper quaternary ammonium salt ACQ used is ZB-03 type wood preservative ACQ provided by Jinan Zhongbei Fine Chemical Co., Ltd.

[0029] Example 1. A method for preparing a preservative and antifungal liquid for wood surfaces, comprising the following steps:

[0030] S1. Preparation of antibacterial aqueous polyurethane emulsion;

[0031] S11. By weight, 1 part of chitosan oligosaccharide was dissolved in a hydrochloric acid solution, and the mixture was stirred for 10 min to obtain a chitosan oligosaccharide solution. Further, 0.7 parts of 2-amino-2-cyanoacetamide were added to the solution, the temperature was raised to 85°C, the mixture was stirred for 3 h, the heating was stopped, and the mixture was evaporated under vacuum at 60°C to constant weight to obtain a guanidyl-modified chitosan oligosaccharide compound.

[0032] S12. By weight, 10 parts of the guanidinized chitosan oligosaccharide compound prepared in step S11 are dispersed in DMF, shaken and mixed for 15 min, and then cooled to 5°C to obtain a guanidinized chitosan oligosaccharide solution.

[0033] Under a nitrogen atmosphere, 0.8 parts of 3-thiopheneboronic acid were dispersed in dimethyl sulfoxide and mixed by shaking for 15 min. Then, a dimethyl sulfoxide solution containing 1.3 parts of anhydrous ferrous chloride was added dropwise over a period of 0.5 h. After the addition was completed, the temperature was raised to 95 °C and reacted for 10 min. The mixture was then evaporated under vacuum at 60 °C to constant weight. The resulting product was dispersed again in carbon tetrachloride and cooled to 5 °C. It was then added dropwise to a guanidyl-modified chitosan oligosaccharide solution over a period of 1 h. After the addition was completed, the temperature was raised to 80 °C and the reaction was continued for 2 h. The mixture was then evaporated under vacuum to constant weight to obtain the modified chitosan oligosaccharide compound.

[0034] S13. By weight, 1 part of triisocyanate (methyl)silicon is mixed with DMF. Under a nitrogen atmosphere, the temperature is raised to 55-65℃, and a DMF solution containing 2.6 parts of modified chitosan oligosaccharide compound is added dropwise. After the addition is completed, the temperature is raised to 115℃ and the reaction is carried out for 1.5 hours. Then, the excess solvent is removed by rotary evaporation to obtain the modified isocyanate.

[0035] S14. By weight, 15 parts of polytetrahydrofuran diol were vacuum dried for 0.5-1 h, and then 12 parts of modified isocyanate were added. The mixture was heated to 75°C and reacted for 0.5 h. Then, 0.1 parts of acetone and 0.05 parts of 1,6-hexanediol were added, and the mixture was reacted for another 1 h. Then, 0.1 parts of N-methyldiethanolamine were added, and the mixture was reacted for another 1.5 h. The mixture was then cooled to 45°C, and hydrochloric acid was added dropwise to adjust the pH of the solution to neutral. Finally, 250 parts of deionized water were added, and the mixture was emulsified and dispersed for 0.5 h to obtain an antibacterial waterborne polyurethane emulsion.

[0036] S2. Mix 280 parts of the antibacterial waterborne polyurethane emulsion prepared in step S1 with 0.9 parts of surfactant and 200 parts of deionized water. After high-speed shear mixing for 15 minutes, continue mixing for 30 minutes to obtain an anti-corrosion and anti-mildew liquid for wood surfaces.

[0037] Example 2. A method for preparing a preservative and antifungal liquid for wood surfaces, comprising the following steps:

[0038] Compared with Example 1, this example increases the amount of modified chitosan oligosaccharide compound added in step S13;

[0039] S1. Preparation of antibacterial aqueous polyurethane emulsion;

[0040] S11. By weight, 1 part of chitosan oligosaccharide was dissolved in a hydrochloric acid solution, and the mixture was stirred for 10 min to obtain a chitosan oligosaccharide solution. Further, 0.7 parts of 2-amino-2-cyanoacetamide were added to the solution, the temperature was raised to 85°C, the mixture was stirred for 3 h, the heating was stopped, and the mixture was evaporated under vacuum at 60°C to constant weight to obtain a guanidyl-modified chitosan oligosaccharide compound.

[0041] S12. By weight, 10 parts of the guanidinized chitosan oligosaccharide compound prepared in step S11 are dispersed in DMF, shaken and mixed for 15 min, and then cooled to 5°C to obtain a guanidinized chitosan oligosaccharide solution.

[0042] Under a nitrogen atmosphere, 0.8 parts of 3-thiopheneboronic acid were dispersed in dimethyl sulfoxide and mixed by shaking for 15 min. Then, a dimethyl sulfoxide solution containing 1.3 parts of anhydrous ferrous chloride was added dropwise over a period of 0.5 h. After the addition was completed, the temperature was raised to 95 °C and reacted for 10 min. The mixture was then evaporated under vacuum at 60 °C to constant weight. The resulting product was dispersed again in carbon tetrachloride and cooled to 5 °C. It was then added dropwise to a guanidyl-modified chitosan oligosaccharide solution over a period of 1 h. After the addition was completed, the temperature was raised to 80 °C and the reaction was continued for 2 h. The mixture was then evaporated under vacuum to constant weight to obtain the modified chitosan oligosaccharide compound.

[0043] S13. By weight, 1 part of triisocyanate (methyl)silicon is mixed with DMF. Under a nitrogen atmosphere, the temperature is raised to 55-65℃, and a DMF solution containing 5.1 parts of modified chitosan oligosaccharide compound is added dropwise. After the addition is completed, the temperature is raised to 115℃ and the reaction is carried out for 1.5 hours. Then, the excess solvent is removed by rotary evaporation to obtain the modified isocyanate.

[0044] S14. By weight, 15 parts of polytetrahydrofuran diol were vacuum dried for 0.5-1 h, and then 12 parts of modified isocyanate were added. The mixture was heated to 75°C and reacted for 0.5 h. Then, 0.1 parts of acetone and 0.05 parts of 1,6-hexanediol were added, and the mixture was reacted for another 1 h. Then, 0.1 parts of N-methyldiethanolamine were added, and the mixture was reacted for another 1.5 h. The mixture was then cooled to 45°C, and hydrochloric acid was added dropwise to adjust the pH of the solution to neutral. Finally, 250 parts of deionized water were added, and the mixture was emulsified and dispersed for 0.5 h to obtain an antibacterial waterborne polyurethane emulsion.

[0045] S2. Mix 280 parts of the antibacterial waterborne polyurethane emulsion prepared in step S1 with 0.9 parts of surfactant and 200 parts of deionized water. After high-speed shear mixing for 15 minutes, continue mixing for 30 minutes to obtain an anti-corrosion and anti-mildew liquid for wood surfaces.

[0046] Example 3. A method for preparing an anti-corrosion and anti-mildew liquid for wood surfaces, comprising the following steps:

[0047] Compared with Example 1, this example increases the amount of 2-amino-2-cyanoacetamide added in step S11;

[0048] S1. Preparation of antibacterial aqueous polyurethane emulsion;

[0049] S11. By weight, 1 part of chitosan oligosaccharide was dissolved in a hydrochloric acid solution. After stirring and mixing for 10 min, a chitosan oligosaccharide solution was obtained. Then, 1 part of 2-amino-2-cyanoacetamide was added to the solution, the temperature was raised to 85°C, and the reaction was stirred for 3 h. After heating was stopped, the solution was evaporated under vacuum at 60°C to constant weight to obtain the guanidinolated chitosan oligosaccharide compound.

[0050] S12. By weight, 10 parts of the guanidinized chitosan oligosaccharide compound prepared in step S11 are dispersed in DMF, shaken and mixed for 15 min, and then cooled to 5°C to obtain a guanidinized chitosan oligosaccharide solution.

[0051] Under a nitrogen atmosphere, 0.8 parts of 3-thiopheneboronic acid were dispersed in dimethyl sulfoxide and mixed by shaking for 15 min. Then, a dimethyl sulfoxide solution containing 1.3 parts of anhydrous ferrous chloride was added dropwise over a period of 0.5 h. After the addition was completed, the temperature was raised to 95 °C and reacted for 10 min. The mixture was then evaporated under vacuum at 60 °C to constant weight. The resulting product was dispersed again in carbon tetrachloride and cooled to 5 °C. It was then added dropwise to a guanidyl-modified chitosan oligosaccharide solution over a period of 1 h. After the addition was completed, the temperature was raised to 80 °C and the reaction was continued for 2 h. The mixture was then evaporated under vacuum to constant weight to obtain the modified chitosan oligosaccharide compound.

[0052] S13. By weight, 1 part of triisocyanate (methyl)silicon is mixed with DMF. Under a nitrogen atmosphere, the temperature is raised to 55-65℃, and a DMF solution containing 2.6 parts of modified chitosan oligosaccharide compound is added dropwise. After the addition is completed, the temperature is raised to 115℃ and the reaction is carried out for 1.5 hours. Then, the excess solvent is removed by rotary evaporation to obtain the modified isocyanate.

[0053] S14. By weight, 15 parts of polytetrahydrofuran diol were vacuum dried for 0.5-1 h, and then 12 parts of modified isocyanate were added. The mixture was heated to 75°C and reacted for 0.5 h. Then, 0.1 parts of acetone and 0.05 parts of 1,6-hexanediol were added, and the mixture was reacted for another 1 h. Then, 0.1 parts of N-methyldiethanolamine were added, and the mixture was reacted for another 1.5 h. The mixture was then cooled to 45°C, and hydrochloric acid was added dropwise to adjust the pH of the solution to neutral. Finally, 250 parts of deionized water were added, and the mixture was emulsified and dispersed for 0.5 h to obtain an antibacterial waterborne polyurethane emulsion.

[0054] S2. Mix 280 parts of the antibacterial waterborne polyurethane emulsion prepared in step S1 with 0.9 parts of surfactant and 200 parts of deionized water. After high-speed shear mixing for 15 minutes, continue mixing for 30 minutes to obtain an anti-corrosion and anti-mildew liquid for wood surfaces.

[0055] Example 4. A method for preparing a preservative and mildew-preventing liquid for wood surfaces, comprising the following steps:

[0056] Compared with Example 1, this example increases the amount of ammonia-soluble copper quaternary ammonium salt ACQ added in step S2;

[0057] S1. Preparation of antibacterial aqueous polyurethane emulsion;

[0058] S11. By weight, 1 part of chitosan oligosaccharide was dissolved in a hydrochloric acid solution, and the mixture was stirred for 10 min to obtain a chitosan oligosaccharide solution. Further, 0.7 parts of 2-amino-2-cyanoacetamide were added to the solution, the temperature was raised to 85°C, the mixture was stirred for 3 h, the heating was stopped, and the mixture was evaporated under vacuum at 60°C to constant weight to obtain a guanidyl-modified chitosan oligosaccharide compound.

[0059] S12. By weight, 10 parts of the guanidinized chitosan oligosaccharide compound prepared in step S11 are dispersed in DMF, shaken and mixed for 15 min, and then cooled to 5°C to obtain a guanidinized chitosan oligosaccharide solution.

[0060] Under a nitrogen atmosphere, 0.8 parts of 3-thiopheneboronic acid were dispersed in dimethyl sulfoxide and mixed by shaking for 15 min. Then, a dimethyl sulfoxide solution containing 1.3 parts of anhydrous ferrous chloride was added dropwise over a period of 0.5 h. After the addition was completed, the temperature was raised to 95 °C and reacted for 10 min. The mixture was then evaporated under vacuum at 60 °C to constant weight. The resulting product was dispersed again in carbon tetrachloride and cooled to 5 °C. It was then added dropwise to a guanidyl-modified chitosan oligosaccharide solution over a period of 1 h. After the addition was completed, the temperature was raised to 80 °C and the reaction was continued for 2 h. The mixture was then evaporated under vacuum to constant weight to obtain the modified chitosan oligosaccharide compound.

[0061] S13. By weight, 1 part of triisocyanate (methyl)silicon is mixed with DMF. Under a nitrogen atmosphere, the temperature is raised to 55-65℃, and a DMF solution containing 2.6 parts of modified chitosan oligosaccharide compound is added dropwise. After the addition is completed, the temperature is raised to 115℃ and the reaction is carried out for 1.5 hours. Then, the excess solvent is removed by rotary evaporation to obtain the modified isocyanate.

[0062] S14. By weight, 15 parts of polytetrahydrofuran diol were vacuum dried for 0.5-1 h, and then 12 parts of modified isocyanate were added. The mixture was heated to 75°C and reacted for 0.5 h. Then, 0.1 parts of acetone and 0.05 parts of 1,6-hexanediol were added, and the mixture was reacted for another 1 h. Then, 0.1 parts of N-methyldiethanolamine were added, and the mixture was reacted for another 1.5 h. The mixture was then cooled to 45°C, and hydrochloric acid was added dropwise to adjust the pH of the solution to neutral. Finally, 250 parts of deionized water were added, and the mixture was emulsified and dispersed for 0.5 h to obtain an antibacterial waterborne polyurethane emulsion.

[0063] S2. Mix 280 parts of the antibacterial waterborne polyurethane emulsion prepared in step S1 with 0.9 parts of surfactant and 200 parts of deionized water. After high-speed shear mixing for 15 min, add 10 parts of ammonia-soluble copper quaternary ammonium salt ACQ and continue mixing for 30 min to obtain an anti-corrosion and anti-mildew liquid for wood surfaces.

[0064] Example 5. A method for preparing a preservative and antifungal liquid for wood surfaces, comprising the following steps:

[0065] S1. Preparation of antibacterial aqueous polyurethane emulsion;

[0066] S11. By weight, 1 part of chitosan oligosaccharide was dissolved in a hydrochloric acid solution. After stirring and mixing for 10 min, a chitosan oligosaccharide solution was obtained. Then, 1 part of 2-amino-2-cyanoacetamide was added to the solution, the temperature was raised to 85°C, and the reaction was stirred for 3 h. After heating was stopped, the solution was evaporated under vacuum at 60°C to constant weight to obtain the guanidinolated chitosan oligosaccharide compound.

[0067] S12. By weight, 10 parts of the guanidinized chitosan oligosaccharide compound prepared in step S11 are dispersed in DMF, shaken and mixed for 15 min, and then cooled to 5°C to obtain a guanidinized chitosan oligosaccharide solution.

[0068] Under a nitrogen atmosphere, 1 part of 3-thiopheneboronic acid was dispersed in dimethyl sulfoxide and mixed by shaking for 15 min. Then, a solution of dimethyl sulfoxide containing 1.8 parts of anhydrous ferrous chloride was added dropwise over a period of 0.5 h. After the addition was completed, the temperature was raised to 95 °C and reacted for 10 min. The mixture was then evaporated under vacuum at 60 °C to constant weight. The resulting product was dispersed again in carbon tetrachloride and cooled to 5 °C. Then, it was added dropwise to a guanidyl-modified chitosan oligosaccharide solution over a period of 1 h. After the addition was completed, the temperature was raised to 80 °C and the reaction was continued for 2 h. The mixture was then evaporated under vacuum to constant weight to obtain the modified chitosan oligosaccharide compound.

[0069] S13. By weight, 1 part of triisocyanate (methyl)silicon is mixed with DMF. Under a nitrogen atmosphere, the temperature is raised to 55-65℃, and a DMF solution containing 5.1 parts of modified chitosan oligosaccharide compound is added dropwise. After the addition is completed, the temperature is raised to 115℃ and the reaction is carried out for 1.5 hours. Then, the excess solvent is removed by rotary evaporation to obtain the modified isocyanate.

[0070] S14. By weight, 15 parts of polytetrahydrofuran glycol were vacuum dried for 0.5-1 h, and then 18 parts of modified isocyanate were added. The mixture was heated to 75°C and reacted for 0.5 h. Then, 0.2 parts of acetone and 0.08 parts of 1,6-hexanediol were added, and the mixture was reacted for another 1 h. Then, 0.15 parts of N-methyldiethanolamine were added, and the mixture was reacted for another 1.5 h. The mixture was then cooled to 45°C, and hydrochloric acid was added dropwise to adjust the pH of the solution to neutral. Finally, 300 parts of deionized water were added, and the mixture was emulsified and dispersed for 0.5 h to obtain an antibacterial waterborne polyurethane emulsion.

[0071] S2. Mix 300 parts of the antibacterial waterborne polyurethane emulsion prepared in step S1 with 1.5 parts of surfactant and 250 parts of deionized water. After high-speed shear mixing for 15 minutes, add 10 parts of ammonia-soluble copper quaternary ammonium salt ACQ and continue mixing for 30 minutes to obtain an anti-corrosion and anti-mildew liquid for wood surfaces.

[0072] Comparative Example 1. A method for preparing a preservative and mildew-preventing liquid for wood surfaces, comprising the following steps:

[0073] Compared with Example 1, the chitosan oligosaccharide in this comparative example was not modified by guanidinization.

[0074] S1. Preparation of antibacterial aqueous polyurethane emulsion;

[0075] S11. Disperse 10 parts by weight of chitosan oligosaccharide into DMF, shake and mix for 15 min, then cool to 5°C to obtain chitosan oligosaccharide solution;

[0076] Under a nitrogen atmosphere, 0.8 parts of 3-thiopheneboronic acid were dispersed in dimethyl sulfoxide and mixed by shaking for 15 min. Then, a dimethyl sulfoxide solution containing 1.3 parts of anhydrous ferrous chloride was added dropwise over a period of 0.5 h. After the addition was completed, the temperature was raised to 95 °C and reacted for 10 min. The mixture was then evaporated under vacuum at 60 °C to constant weight. The resulting product was dispersed again in carbon tetrachloride and cooled to 5 °C. It was then added dropwise to a chitosan oligosaccharide solution over a period of 1 h. After the addition was completed, the temperature was raised to 80 °C and the reaction was continued for 2 h. The mixture was then evaporated under vacuum to constant weight to obtain the modified chitosan oligosaccharide compound.

[0077] S12. By weight, 1 part of triisocyanate (methyl)silicon is mixed with DMF. Under a nitrogen atmosphere, the temperature is raised to 55-65℃, and a DMF solution containing 2.6 parts of modified chitosan oligosaccharide compound is added dropwise. After the addition is completed, the temperature is raised to 115℃ and the reaction is carried out for 1.5 hours. Then, the excess solvent is removed by rotary evaporation to obtain the modified isocyanate.

[0078] S13. By weight, 15 parts of polytetrahydrofuran glycol were vacuum dried for 0.5-1 h, and then 12 parts of modified isocyanate were added. The mixture was heated to 75°C and reacted for 0.5 h. Then, 0.1 parts of acetone and 0.05 parts of 1,6-hexanediol were added, and the mixture was reacted for another 1 h. Then, 0.1 parts of N-methyldiethanolamine were added, and the mixture was reacted for another 1.5 h. The mixture was then cooled to 45°C, and hydrochloric acid was added dropwise to adjust the pH of the solution to neutral. Finally, 250 parts of deionized water were added, and the mixture was emulsified and dispersed for 0.5 h to obtain an antibacterial waterborne polyurethane emulsion.

[0079] S2. Mix 280 parts of the antibacterial waterborne polyurethane emulsion prepared in step S1 with 0.9 parts of surfactant and 200 parts of deionized water. After high-speed shear mixing for 15 minutes, continue mixing for 30 minutes to obtain an anti-corrosion and anti-mildew liquid for wood surfaces.

[0080] Comparative Example 2. A method for preparing an anti-corrosion and anti-mildew liquid for wood surfaces, comprising the following steps:

[0081] Compared to Example 1, this example involves treating 3-thiopheneboronic acid with anhydrous ferrous chloride;

[0082] S1. Preparation of antibacterial aqueous polyurethane emulsion;

[0083] S11. By weight, 1 part of chitosan oligosaccharide was dissolved in a hydrochloric acid solution, and the mixture was stirred for 10 min to obtain a chitosan oligosaccharide solution. Further, 0.7 parts of 2-amino-2-cyanoacetamide were added to the solution, the temperature was raised to 85°C, the mixture was stirred for 3 h, the heating was stopped, and the mixture was evaporated under vacuum at 60°C to constant weight to obtain a guanidyl-modified chitosan oligosaccharide compound.

[0084] S12. By weight, 10 parts of the guanidinized chitosan oligosaccharide compound prepared in step S11 are dispersed in DMF, shaken and mixed for 15 min, and then cooled to 5°C to obtain a guanidinized chitosan oligosaccharide solution.

[0085] Under a nitrogen atmosphere, 0.8 parts of 3-thiopheneboric acid were dispersed in carbon tetrachloride, cooled to 5°C, and then added dropwise to a guanidyl-modified chitosan oligosaccharide solution over a period of 1 hour. After the addition was completed, the temperature was raised to 80°C and the reaction was continued for 2 hours. The mixture was then vacuum evaporated to constant weight to obtain the modified chitosan oligosaccharide compound.

[0086] S13. By weight, 1 part of triisocyanate (methyl)silicon is mixed with DMF. Under a nitrogen atmosphere, the temperature is raised to 55-65℃, and a DMF solution containing 2.6 parts of modified chitosan oligosaccharide compound is added dropwise. After the addition is completed, the temperature is raised to 115℃ and the reaction is carried out for 1.5 hours. Then, the excess solvent is removed by rotary evaporation to obtain the modified isocyanate.

[0087] S14. By weight, 15 parts of polytetrahydrofuran diol were vacuum dried for 0.5-1 h, and then 12 parts of modified isocyanate were added. The mixture was heated to 75°C and reacted for 0.5 h. Then, 0.1 parts of acetone and 0.05 parts of 1,6-hexanediol were added, and the mixture was reacted for another 1 h. Then, 0.1 parts of N-methyldiethanolamine were added, and the mixture was reacted for another 1.5 h. The mixture was then cooled to 45°C, and hydrochloric acid was added dropwise to adjust the pH of the solution to neutral. Finally, 250 parts of deionized water were added, and the mixture was emulsified and dispersed for 0.5 h to obtain an antibacterial waterborne polyurethane emulsion.

[0088] S2. Mix 280 parts of the antibacterial waterborne polyurethane emulsion prepared in step S1 with 0.9 parts of surfactant and 200 parts of deionized water. After high-speed shear mixing for 15 minutes, continue mixing for 30 minutes to obtain an anti-corrosion and anti-mildew liquid for wood surfaces.

[0089] Comparative Example 3. A method for preparing a preservative and antifungal liquid for wood surfaces, comprising the following steps:

[0090] Compared with Comparative Example 1, this comparative example added the ammonia-soluble copper quaternary ammonium salt ACQ in step S2;

[0091] S1. Preparation of antibacterial aqueous polyurethane emulsion;

[0092] S11. Disperse 10 parts by weight of chitosan oligosaccharide into DMF, shake and mix for 15 min, then cool to 5°C to obtain chitosan oligosaccharide solution;

[0093] Under a nitrogen atmosphere, 0.8 parts of 3-thiopheneboronic acid were dispersed in dimethyl sulfoxide and mixed by shaking for 15 min. Then, a dimethyl sulfoxide solution containing 1.3 parts of anhydrous ferrous chloride was added dropwise over a period of 0.5 h. After the addition was completed, the temperature was raised to 95 °C and reacted for 10 min. The mixture was then evaporated under vacuum at 60 °C to constant weight. The resulting product was dispersed again in carbon tetrachloride and cooled to 5 °C. It was then added dropwise to a chitosan oligosaccharide solution over a period of 1 h. After the addition was completed, the temperature was raised to 80 °C and the reaction was continued for 2 h. The mixture was then evaporated under vacuum to constant weight to obtain the modified chitosan oligosaccharide compound.

[0094] S12. By weight, 1 part of triisocyanate (methyl)silicon is mixed with DMF. Under a nitrogen atmosphere, the temperature is raised to 55-65℃, and a DMF solution containing 2.6 parts of modified chitosan oligosaccharide compound is added dropwise. After the addition is completed, the temperature is raised to 115℃ and the reaction is carried out for 1.5 hours. Then, the excess solvent is removed by rotary evaporation to obtain the modified isocyanate.

[0095] S13. By weight, 15 parts of polytetrahydrofuran glycol were vacuum dried for 0.5-1 h, and then 12 parts of modified isocyanate were added. The mixture was heated to 75°C and reacted for 0.5 h. Then, 0.1 parts of acetone and 0.05 parts of 1,6-hexanediol were added, and the mixture was reacted for another 1 h. Then, 0.1 parts of N-methyldiethanolamine were added, and the mixture was reacted for another 1.5 h. The mixture was then cooled to 45°C, and hydrochloric acid was added dropwise to adjust the pH of the solution to neutral. Finally, 250 parts of deionized water were added, and the mixture was emulsified and dispersed for 0.5 h to obtain an antibacterial waterborne polyurethane emulsion.

[0096] S2. Mix 280 parts of the antibacterial waterborne polyurethane emulsion prepared in step S1 with 0.9 parts of surfactant and 200 parts of deionized water. After high-speed shear mixing for 15 min, add 10 parts of ammonia-soluble copper quaternary ammonium salt ACQ and continue mixing for 30 min to obtain an anti-corrosion and anti-mildew liquid for wood surfaces.

[0097] Comparative Example 4. A method for preparing an anti-corrosion and anti-mildew liquid for wood surfaces, comprising the following steps:

[0098] Compared with Comparative Example 2, this comparative example added the ammonia-soluble copper quaternary ammonium salt ACQ in step S2;

[0099] S1. Preparation of antibacterial aqueous polyurethane emulsion;

[0100] S11. By weight, 1 part of chitosan oligosaccharide was dissolved in a hydrochloric acid solution, and the mixture was stirred for 10 min to obtain a chitosan oligosaccharide solution. Further, 0.7 parts of 2-amino-2-cyanoacetamide were added to the solution, the temperature was raised to 85°C, the mixture was stirred for 3 h, the heating was stopped, and the mixture was evaporated under vacuum at 60°C to constant weight to obtain a guanidyl-modified chitosan oligosaccharide compound.

[0101] S12. By weight, 10 parts of the guanidinized chitosan oligosaccharide compound prepared in step S11 are dispersed in DMF, shaken and mixed for 15 min, and then cooled to 5°C to obtain a guanidinized chitosan oligosaccharide solution.

[0102] Under a nitrogen atmosphere, 0.8 parts of 3-thiopheneboric acid were dispersed in carbon tetrachloride, cooled to 5°C, and then added dropwise to a guanidyl-modified chitosan oligosaccharide solution over a period of 1 hour. After the addition was completed, the temperature was raised to 80°C and the reaction was continued for 2 hours. The mixture was then vacuum evaporated to constant weight to obtain the modified chitosan oligosaccharide compound.

[0103] S13. By weight, 1 part of triisocyanate (methyl)silicon is mixed with DMF. Under a nitrogen atmosphere, the temperature is raised to 55-65℃, and a DMF solution containing 2.6 parts of modified chitosan oligosaccharide compound is added dropwise. After the addition is completed, the temperature is raised to 115℃ and the reaction is carried out for 1.5 hours. Then, the excess solvent is removed by rotary evaporation to obtain the modified isocyanate.

[0104] S14. By weight, 15 parts of polytetrahydrofuran diol were vacuum dried for 0.5-1 h, and then 12 parts of modified isocyanate were added. The mixture was heated to 75°C and reacted for 0.5 h. Then, 0.1 parts of acetone and 0.05 parts of 1,6-hexanediol were added, and the mixture was reacted for another 1 h. Then, 0.1 parts of N-methyldiethanolamine were added, and the mixture was reacted for another 1.5 h. The mixture was then cooled to 45°C, and hydrochloric acid was added dropwise to adjust the pH of the solution to neutral. Finally, 250 parts of deionized water were added, and the mixture was emulsified and dispersed for 0.5 h to obtain an antibacterial waterborne polyurethane emulsion.

[0105] S2. Mix 280 parts of the antibacterial waterborne polyurethane emulsion prepared in step S1 with 0.9 parts of surfactant and 200 parts of deionized water. After high-speed shear mixing for 15 min, add 10 parts of ammonia-soluble copper quaternary ammonium salt ACQ and continue mixing for 30 min to obtain an anti-corrosion and anti-mildew liquid for wood surfaces.

[0106] Testing: According to LY / T 1283, the anti-mildew and anti-corrosion liquid prepared in Examples 1-5 and Comparative Examples 1-4 was used to treat the 20*20*10mm straight-grained Populus tomentosa samples, and Cladosporium clavatum and Cladosporium velutipes were inoculated on them respectively, and their corrosion resistance was tested.

[0107] After being treated and dried with the anti-mildew and anti-corrosion liquid prepared in Examples 1-5 and Comparative Examples 1-4, the samples of Populus tomentosa were immersed in distilled water for 24 hours, then dried to constant weight. In accordance with LY / T 1283, Cladosporium cladosporium and Cladosporium velutipes were inoculated on them respectively, and their corrosion resistance was tested.

[0108] Masson pine wood was prepared into 20*20*20mm samples. The water absorption of the samples treated with the anti-mildew and anti-corrosion liquids prepared in Examples 1-5 and Comparative Examples 1-4 was tested according to GB / T 1934.1-2009.

[0109] Another control group was set up, which did not receive any antiseptic or antifungal treatment;

[0110] The test results are shown in the table below:

[0111]

[0112] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing an anti-corrosion and anti-mildew liquid for wood surfaces, characterized in that, Includes the following steps: S1. Preparation of antibacterial aqueous polyurethane emulsion; S11. Dissolve chitosan oligosaccharide in hydrochloric acid solution, stir and mix for 10-15 min to obtain chitosan oligosaccharide solution, further add 2-amino-2-cyanoacetamide to it, heat to 85-90℃, stir and react for 3-6 h, stop heating, evaporate under vacuum at 60℃ to constant weight to obtain guanidyl-modified chitosan oligosaccharide compound. S12. Disperse the guanidinated chitosan oligosaccharide compound prepared in step S11 into DMF, shake and mix for 15-20 min, and then cool to 5-15℃ to obtain a guanidinated chitosan oligosaccharide solution; Under a nitrogen atmosphere, 3-thiopheneboronic acid was dispersed in dimethyl sulfoxide and mixed by shaking for 15-30 min. Then, a dimethyl sulfoxide solution containing anhydrous ferrous chloride was added dropwise over 0.5-1 h. After the addition was complete, the temperature was raised to 95-105 °C and reacted for 10-15 min. The mixture was then evaporated under vacuum at 60-80 °C to constant weight. The resulting product was then dispersed again in carbon tetrachloride and cooled to 5-15 °C. This product was then added dropwise to a guanidyl-modified chitosan oligosaccharide solution over 1-2 h. After the addition was complete, the temperature was raised to 80-90 °C and the reaction was continued for 2-4 h. The mixture was then evaporated under vacuum to constant weight to obtain the modified chitosan oligosaccharide compound. S13. Mix triisocyanate (methyl)silicon with DMF, heat to 55-65℃ under nitrogen atmosphere, add DMF solution containing modified chitosan oligosaccharide compound dropwise, continue heating to 115-120℃ after the addition is completed, react for 1.5-2h, and then remove excess solvent by rotary evaporation to obtain modified isocyanate. S14. After vacuum drying polytetrahydrofuran diol for 0.5-1 h, add modified isocyanate, heat to 75-80℃, react for 0.5-2 h, add acetone and 1,6-hexanediol, continue the reaction for 1-1.5 h, add N-methyldiethanolamine, react for 1.5-3 h, cool to 45-50℃, add hydrochloric acid dropwise to adjust the pH of the solution to neutral, add deionized water, emulsify and disperse for 0.5-1 h to obtain antibacterial waterborne polyurethane emulsion; S2. Mix the antibacterial waterborne polyurethane emulsion prepared in step S1 with surfactant and deionized water. After high-speed shear mixing for 15-30 min, add ammonia-soluble copper quaternary ammonium salt ACQ and continue mixing for 30-45 min to obtain an anti-corrosion and anti-mildew liquid for wood surfaces. In step S12, the mass ratio of guanidylchitosan oligosaccharide compound, 3-thiopheneboronic acid, and anhydrous ferrous chloride is 10:(0.8-1):(1.3-1.8) by weight.

2. The method for preparing an anti-corrosion and anti-mildew liquid for wood surfaces according to claim 1, characterized in that: In step S11, the weight-average molecular weight of chitosan oligosaccharide is 1000-3000 Da.

3. The method for preparing a preservative and mildew-preventing liquid for wood surfaces according to claim 1, characterized in that: In step S11, the mass ratio of chitosan oligosaccharide to 2-amino-2-cyanoacetamide is 10:(0.7-1) by weight.

4. The method for preparing a preservative and mildew-preventing liquid for wood surfaces according to claim 1, characterized in that: In step S13, the mass ratio of triisocyanate (methyl)silicon to modified chitosan oligosaccharide compound is 1:(2.6-5.1).

5. The method for preparing a preservative and mildew-preventing liquid for wood surfaces according to claim 1, characterized in that: In step S14, the weight-average molecular weight of the polytetrahydrofuran diol is 2000-3000.

6. The method for preparing a preservative and mildew-preventing liquid for wood surfaces according to claim 1, characterized in that: In step S14, the mass ratio of polytetrahydrofuran diol, modified isocyanate, acetone, 1,6-hexanediol, and N-methyldiethanolamine is 15:(12-18):(0.1-0.2):(0.05-0.08):(0.1-0.15).

7. The method for preparing a preservative and antifungal liquid for wood surfaces according to claim 1, characterized in that: In step S14, the mass ratio of polytetrahydrofuran diol to deionized water is 15:(250-300).

8. The method for preparing a preservative and mildew-preventing liquid for wood surfaces according to claim 1, characterized in that: In step S2, the anti-corrosion and anti-mildew liquid on the wood surface, by weight, includes the following components: 280-300 parts of antibacterial waterborne polyurethane emulsion, 200-250 parts of deionized water, 0.9-1.5 parts of surfactant, and 0-10 parts of ammoniacal copper quaternary ammonium salt ACQ. The surfactant is any one of the nonionic surfactants.

9. An anti-corrosion and anti-mildew liquid prepared by the method of any one of claims 1-8 for use on wood surfaces.

Images