Environment-friendly waterproof adhesive for furniture wood board and preparation method of environment-friendly waterproof adhesive

Abstract

The invention relates to an environment-friendly waterproof adhesive for furniture wood boards and a preparation method thereof, and belongs to the technical field of adhesives. The preparation method comprises the following steps: fermenting and degrading lignin, then adding a phenolic compound, stirring under an alkaline condition, finally adding formaldehyde, heating, preserving heat, and cooling to obtain the environment-friendly waterproof adhesive for the furniture wood board. White rot fungi and bacillus subtilis can effectively degrade lignin during fermentation, ether bonds in lignin are broken, steric hindrance of a molecular structure is reduced, more active sites are formed, meanwhile, phenolic compounds are added, the content of phenolic hydroxyl groups is increased, the active sites are further increased, and the content of lignin is increased. And after being combined with formaldehyde, the environment-friendly adhesive with high adhesion and good waterproofness is obtained.

Description

Technical Field

[0001] The invention belongs to the technical field of adhesives and relates to an environmentally friendly waterproof adhesive for furniture wood panels and a preparation method thereof. Background Art

[0002] Adhesive is a material that is widely used due to its excellent bonding properties. Its effectiveness comes from its own cohesive force and the bonding force it generates on the surface of heterogeneous materials. The two work together to form a stable adhesion effect. These substances show good temperature resistance, stability and economy, so they are used in many fields, including the construction industry, the wood industry, etc. In the wood processing industry, adhesives play a vital role. The amount of adhesives used in the wood industry is second only to the wood itself. With the growing demand for wood and artificial boards in modern society, as well as the demand for high-quality The demand for adhesives is increasing, and the wood adhesive industry has shown a rapid development trend in recent years.

[0003] Petroleum resources are often used as the main raw material for wood adhesives, which not only show excellent bonding effects, but also have excellent water resistance. However, during use, petroleum-based adhesives may release harmful substances such as volatile organic compounds, benzene, toluene, xylene and formaldehyde. These emissions not only pollute the environment, but also pose potential risks to human health.

[0004] Lignin is a biomass resource with a wide range of potential applications. It can be naturally degraded through biological processes, thereby reducing harmful gas emissions and lowering 50 million tons of lignin are separated, and only about 2% of lignin is further developed into value-added products such as water reducers, dispersants and surfactants. As the most abundant natural phenolic polymer in nature, lignin has long been considered as a potential raw material for synthesizing phenolic resin adhesives instead of phenol. Due to the structural similarity between lignin and phenol, researchers use lignin to replace phenol, but the phenolic hydroxyl groups in lignin mostly exist in the form of phenolic ethers, which cannot form phenolic anions under alkaline conditions, thereby inducing the hydroxymethylation reaction of the ortho-position of the phenolic hydroxyl group with formaldehyde; the number of ortho-position and para-position sites of the phenolic hydroxyl group in the lignin unit is small, and all para-positions are blocked by side chains; the cross-linked network formed by the condensation of lignin biosynthetic precursors and the steric hindrance effect generated thereby limit the accessibility of lignin to formaldehyde or phenol. Therefore, the environmentally friendly waterproof adhesive for furniture wood panels and the preparation method thereof provided by the present invention can effectively solve the above problems. Summary of the invention

[0005] The invention relates to an environmentally friendly waterproof adhesive for furniture wood panels and a preparation method thereof, and belongs to the technical field of adhesives. The invention discloses a preparation method for an environmentally friendly waterproof adhesive for furniture wood panels, which is as follows: firstly, lignin is fermented and degraded, then a phenolic compound is added and stirred under alkaline conditions, and finally, formaldehyde is added to raise the temperature, keep the temperature, and cool to obtain the environmentally friendly waterproof adhesive for furniture wood panels. White rot fungi and Bacillus subtilis can effectively degrade lignin during fermentation, break the ether bonds in lignin, reduce the steric hindrance of the molecular structure and form more active sites. At the same time, the addition of phenolic compounds increases the content of phenolic hydroxyl groups and further increases the active sites. After combining with formaldehyde, an environmentally friendly adhesive with high adhesion and waterproof properties is obtained.

[0006] The purpose of the present invention can be achieved through the following technical solutions: The invention discloses an environmentally friendly waterproof adhesive for furniture wood panels, which comprises the following raw materials: biomass lignin, phenolic compounds, and formaldehyde aqueous solution, wherein the phenolic compound is catechin.

[0007] A method for preparing an environmentally friendly waterproof adhesive for furniture wood boards, the method comprising the following steps: (1) mixing biomass lignin and liquid culture solution into a mixed solution, adding composite bacteria for aerobic fermentation, heating and sterilizing to obtain a fermentation solution and centrifuging, removing the supernatant, and drying the solid to form a powder; (2) stirring and mixing the powder, catechins, distilled water and 2 / 3 of the sodium hydroxide solution, then heating and keeping the temperature, and then adding 1 / 3 of the sodium hydroxide solution and stirring for 2-4 minutes; (3) Then, 1 / 2 of the formaldehyde aqueous solution is added, and the mixture is heated and kept warm. Then, the sodium hydroxide solution and the remaining formaldehyde aqueous solution are added and stirred at a constant temperature. The viscosity is measured using a viscometer. The mixture is cooled to room temperature and then discharged to obtain an environmentally friendly waterproof adhesive for furniture wood panels.

[0008] Furthermore, the biomass lignin in step (1) is agricultural waste straw, cotton stalks, and sulfonate lignin remaining as a byproduct of industry and papermaking industry, and the mass ratio of the biomass lignin to the liquid culture medium is 1-5:15-20.

[0009] Furthermore, in the step (1), the liquid culture solution is composed of peptone, sodium acetate and distilled water in a mass ratio of 7-9:0.5-1:50-60, and the composite bacteria accounts for 3-5wt% of the mass of the mixed solution, wherein the composite bacteria is composed of white rot fungi and Bacillus subtilis in a mass ratio of 1:1.

[0010] Furthermore, in step (1), the fermentation temperature and time are 25-30°C and 24-48h respectively, the temperature and time of the heating sterilization are 140-150°C and 20-30min respectively, the rotation speed of the centrifugal separation is 500-800r / min, and the temperature and time of the drying are 70-80°C and 1-2h respectively.

[0011] Furthermore, the mass ratio of the powder, catechins, distilled water and sodium hydroxide solution in step (2) is 5:5:2-3:1-2, the mass fraction of the sodium hydroxide solution in step (2) and step (3) is 35-40%, and the insulation temperature and time are 80-85° C. and 2-2.5 h, respectively.

[0012] Furthermore, the volume ratio of the total volume of the formaldehyde aqueous solution in step (3) to the distilled water in step (2) is 1:4-5, the volume ratio of the total volume of the formaldehyde aqueous solution to the sodium hydroxide solution is 20:1-2, and the mass fraction of the formaldehyde aqueous solution is 40%.

[0013] Furthermore, in the step (3), the temperature and time of heating and heat preservation are 90-95° C. and 60-90 min respectively, the time of constant temperature stirring is 15-20 min, and the viscosity is 2-3 Pa·s.

[0014] Beneficial effects of the present invention: The present invention uses white rot fungi and Bacillus subtilis to form a composite fungus. The enzymes and active substances produced by the two during fermentation degrade biomass lignin. Due to the rupture of ether bonds, the spatial steric hindrance of lignin molecules is reduced, so that more active sites are exposed; at the same time, the addition of catechins increases the content of phenolic hydroxyl groups and further increases the active sites, thereby forming a dense cross-linked network structure, greatly improving the bonding strength and waterproofness of the adhesive, and at the same time increasing the polarity, thereby improving the bonding efficiency with the formaldehyde solution. Therefore, the present invention can obtain an environmentally friendly adhesive with high adhesion and good waterproofness. DETAILED DESCRIPTION

[0015] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with embodiments.

[0016] The Bacillus subtilis of the present invention is deposited with CGMCC No.1.15792, and its effective viable count is 1*10 6 CFU / mL, white rot fungi were purchased from Shanghai Xuanya Biotechnology Co., Ltd., and the effective viable count was 1*10 6 CFU / mL, sulfonate lignin is sodium sulfonate lignin.

[0017] The invention discloses an environmentally friendly waterproof adhesive for furniture wood panels, which comprises the following raw materials: biomass lignin, phenolic compounds, and formaldehyde aqueous solution, wherein the phenolic compound is catechin.

[0018] A method for preparing an environmentally friendly waterproof adhesive for furniture wood boards, the method comprising the following steps: (1) mixing biomass lignin and liquid culture solution into a mixed solution, adding composite bacteria for aerobic fermentation, heating and sterilizing to obtain a fermentation solution and centrifuging, removing the supernatant, and drying the solid to form a powder; (2) stirring and mixing the powder, catechins, distilled water and 2 / 3 of the sodium hydroxide solution, then heating and keeping the temperature, and then adding 1 / 3 of the sodium hydroxide solution and stirring for 2 minutes; (3) Then, 1 / 2 of the formaldehyde aqueous solution is added, and the mixture is heated and kept warm. Then, the sodium hydroxide solution and the remaining formaldehyde aqueous solution are added and stirred at a constant temperature. The viscosity is measured using a viscometer. The mixture is cooled to room temperature and then discharged to obtain an environmentally friendly waterproof adhesive for furniture wood panels.

[0019] The biomass lignin in step (1) is agricultural waste straw, cotton stalks, and residual byproduct sulfonate lignin from industry and papermaking industry. The mass ratio of the biomass lignin to the liquid culture medium is 1:15.

[0020] In the step (1), the liquid culture solution is composed of peptone, sodium acetate and distilled water in a mass ratio of 7:0.5:50, the composite bacteria accounts for 3wt% of the mass of the mixed solution, and the composite bacteria is composed of white rot fungi and Bacillus subtilis in a mass ratio of 1:1.

[0021] In the step (1), the fermentation temperature and time are 25° C. and 24 h respectively, the temperature and time of the heating sterilization are 140° C. and 20 min respectively, the rotation speed of the centrifugal separation is 500 r / min, and the temperature and time of the drying are 70° C. and 1 h respectively.

[0022] The mass ratio of the powder, catechins, distilled water and sodium hydroxide solution in step (2) is 5:5:2:1, the mass fraction of the sodium hydroxide solution in step (2) and step (3) is 35%, and the insulation temperature and time are 80° C. and 2 h, respectively.

[0023] The volume ratio of the total volume of the formaldehyde aqueous solution in step (3) to the distilled water in step (2) is 1:4, the volume ratio of the total volume of the formaldehyde aqueous solution to the sodium hydroxide solution is 20:1, and the mass fraction of the formaldehyde aqueous solution is 40%.

[0024] The temperature and time of heating and heat preservation in the step (3) are 90° C. and 60 min respectively, the time of constant temperature stirring is 15 min, and the viscosity is 2 Pa·s.

[0025] The peptone was purchased from Guangdong Mingtong Biotechnology Co., Ltd., CAS No.: 73049-73-7.

[0026] The invention discloses an environmentally friendly waterproof adhesive for furniture wood panels, which comprises the following raw materials: biomass lignin, phenolic compounds, and formaldehyde aqueous solution, wherein the phenolic compound is catechin.

[0027] A method for preparing an environmentally friendly waterproof adhesive for furniture wood boards, the method comprising the following steps: (1) mixing biomass lignin and liquid culture solution into a mixed solution, adding composite bacteria for aerobic fermentation, heating and sterilizing to obtain a fermentation solution and centrifuging, removing the supernatant, and drying the solid to form a powder; (2) stirring and mixing the powder, catechins, distilled water and 2 / 3 of the sodium hydroxide solution, then heating and keeping the temperature, and then adding 1 / 3 of the sodium hydroxide solution and stirring for 3 minutes; (3) Then, 1 / 2 of the formaldehyde aqueous solution is added, and the mixture is heated and kept warm. Then, the sodium hydroxide solution and the remaining formaldehyde aqueous solution are added and stirred at a constant temperature. The viscosity is measured using a viscometer. The mixture is cooled to room temperature and then discharged to obtain an environmentally friendly waterproof adhesive for furniture wood panels.

[0028] The biomass lignin in step (1) is agricultural waste straw, cotton stalks, and residual byproduct sulfonate lignin from industry and papermaking industry. The mass ratio of the biomass lignin to the liquid culture medium is 2:17.

[0029] In the step (1), the liquid culture solution is composed of peptone, sodium acetate and distilled water in a mass ratio of 8:0.8:55, and the composite bacteria accounts for 4wt% of the mass of the mixed solution, wherein the composite bacteria is composed of white rot fungi and Bacillus subtilis in a mass ratio of 1:1.

[0030] In the step (1), the fermentation temperature and time are 28° C. and 32 h respectively, the temperature and time of the heating sterilization are 145° C. and 25 min respectively, the rotation speed of the centrifugal separation is 650 r / min, and the temperature and time of the drying are 75° C. and 1.5 h respectively.

[0031] The mass ratio of the powder, catechins, distilled water and sodium hydroxide solution in step (2) is 5:5:2.5:1.5, the mass fraction of the sodium hydroxide solution in step (2) and step (3) is 37%, and the insulation temperature and time are 83° C. and 2 h, respectively.

[0032] The volume ratio of the total volume of the formaldehyde aqueous solution in step (3) to the distilled water in step (2) is 1:4.5, the volume ratio of the total volume of the formaldehyde aqueous solution to the sodium hydroxide solution is 20:1.5, and the mass fraction of the formaldehyde aqueous solution is 40%.

[0033] The temperature and time of heating and heat preservation in the step (3) are 92° C. and 75 min respectively, the time of constant temperature stirring is 18 min, and the viscosity is 2 Pa·s.

[0034] The peptone was purchased from Guangdong Mingtong Biotechnology Co., Ltd., CAS No.: 73049-73-7.

[0035] The invention discloses an environmentally friendly waterproof adhesive for furniture wood panels, which comprises the following raw materials: biomass lignin, phenolic compounds, and formaldehyde aqueous solution, wherein the phenolic compound is catechin.

[0036] A method for preparing an environmentally friendly waterproof adhesive for furniture wood boards, the method comprising the following steps: (1) mixing biomass lignin and liquid culture solution into a mixed solution, adding composite bacteria for aerobic fermentation, heating and sterilizing to obtain a fermentation solution and centrifuging, removing the supernatant, and drying the solid to form a powder; (2) stirring and mixing the powder, catechins, distilled water and 2 / 3 of the sodium hydroxide solution, then heating and keeping the temperature, and then adding 1 / 3 of the sodium hydroxide solution and stirring for 4 minutes; (3) Then, 1 / 2 of the formaldehyde aqueous solution is added, and the mixture is heated and kept warm. Then, the sodium hydroxide solution and the remaining formaldehyde aqueous solution are added and stirred at a constant temperature. The viscosity is measured using a viscometer. The mixture is cooled to room temperature and then discharged to obtain an environmentally friendly waterproof adhesive for furniture wood panels.

[0037] The biomass lignin in step (1) is agricultural waste straw, cotton stalks, and residual byproduct sulfonate lignin from industry and papermaking industry. The mass ratio of the biomass lignin to the liquid culture medium is 5:20.

[0038] In the step (1), the liquid culture solution is composed of peptone, sodium acetate and distilled water in a mass ratio of 9:1:60, and the composite bacteria accounts for 5wt% of the mass of the mixed solution, wherein the composite bacteria is composed of white rot fungi and Bacillus subtilis in a mass ratio of 1:1.

[0039] In the step (1), the fermentation temperature and time are 30° C. and 48 h respectively, the temperature and time of the heating sterilization are 150° C. and 30 min respectively, the rotation speed of the centrifugal separation is 800 r / min, and the temperature and time of the drying are 80° C. and 2 h respectively.

[0040] The mass ratio of the powder, catechins, distilled water and sodium hydroxide solution in step (2) is 5:5:3:2, the mass fraction of the sodium hydroxide solution in step (2) and step (3) is 40%, and the insulation temperature and time are 85° C. and 2.5 h, respectively.

[0041] The volume ratio of the total volume of the formaldehyde aqueous solution in step (3) to the distilled water in step (2) is 1:5, the volume ratio of the total volume of the formaldehyde aqueous solution to the sodium hydroxide solution is 20:2, and the mass fraction of the formaldehyde aqueous solution is 40%.

[0042] The temperature and time of heating and heat preservation in the step (3) are 95° C. and 90 min respectively, the time of constant temperature stirring is 20 min, and the viscosity is 3 Pa·s.

[0043] The peptone was purchased from Guangdong Mingtong Biotechnology Co., Ltd., CAS No.: 73049-73-7.

[0044] Comparative Example 1 On the basis of Example 2, the white rot fungi were removed and replaced with Bacillus subtilis of equal mass, and other conditions were consistent with Example 2.

[0045] Comparative Example 2 On the basis of Example 2, Bacillus subtilis was removed and replaced with white rot fungi of equal mass, and other conditions were consistent with Example 2.

[0046] Comparative Example 3 On the basis of Example 2, catechin was replaced by phenol of equal mass, and other conditions were consistent with Example 2.

[0047] Comparative Example 4 On the basis of Example 2, an environmentally friendly waterproof adhesive for furniture wood panels is provided, and the environmentally friendly waterproof adhesive for furniture wood panels comprises the following raw materials: biomass lignin, phenolic compounds, and formaldehyde aqueous solution, and the phenolic compound is catechin.

[0048] A method for preparing an environmentally friendly waterproof adhesive for furniture wood boards, the method comprising the following steps: (1) Biomass lignin, catechins, distilled water and 2 / 3 of sodium hydroxide solution were stirred and mixed, then heated and kept warm, and then 1 / 3 of sodium hydroxide solution was added and stirred for 3 minutes; (2) Then, 1 / 2 of the formaldehyde aqueous solution is added, and the mixture is heated and kept warm. Then, the sodium hydroxide solution and the remaining formaldehyde aqueous solution are added and stirred at a constant temperature. The viscosity is measured using a viscometer. The mixture is cooled to room temperature and then discharged to obtain an environmentally friendly waterproof adhesive for furniture wood panels.

[0049] In the step (1), the mass ratio of biomass lignin, catechins, distilled water and sodium hydroxide solution is 5:5:2.5:1.5, the mass fraction of sodium hydroxide solution in the steps (2) and (3) is 37%, and the insulation temperature and time are 83° C. and 2 h, respectively.

[0050] The volume ratio of the total volume of the formaldehyde aqueous solution in step (2) to the distilled water in step (1) is 1:4.5, the volume ratio of the total volume of the formaldehyde aqueous solution to the sodium hydroxide solution is 20:1.5, and the mass fraction of the formaldehyde aqueous solution is 40%.

[0051] The temperature and time of heating and heat preservation in the step (2) are 92° C. and 75 min respectively, the time of constant temperature stirring is 18 min, and the viscosity is 2 Pa·s.

[0052] Performance Testing The adhesives prepared in Examples 1-3 and Comparative Examples 1-4 were used as samples, and the adhesive prepared according to the preparation method of Example 2 of Patent CN115572575B was used as a control group. The samples and the control group were used for bonding poplar wood boards, and relevant performance tests were performed. The test results of bonding strength, first-class water boiling and second-class water boiling were based on the standards GB / T9846-2015 and GB / T17657-2013. The test results are shown in Table 1.

[0053] Table 1 Test results Sample Bonding strength / MPa A type of boiling Second type of boiling Example 1 1.54 Three times qualified without opening the layer No opening after five passes Example 2 1.56 Three times qualified without opening the layer No opening after five passes Example 3 1.55 Three times qualified without opening the layer No opening after five passes Comparative Example 1 1.23 First pass, second opening Second pass and third opening Comparative Example 2 1.25 First pass, second opening Second pass and third opening Comparative Example 3 1.32 Second pass and third opening Three times qualified and four times opened Comparative Example 4 1.12 Pass once with slight delamination Second pass with slight delamination Control group 1.35 Second pass and third opening Three times qualified and four times opened From Table 1, it can be seen that the bonding strength of Examples 1-3 is greater than that of Comparative Examples 1-4 and the control group, and the effects of the first and second water boiling of the examples are better than those of Comparative Examples 1-4 and the control group. Comparative Example 1-2 removes white rot fungi or Bacillus subtilis, which has a poor effect on the degradation of lignin, and its active sites are reduced, which has never reduced the bonding strength, and also reduced the dense cross-linked network structure; Comparative Example 3 uses phenol to replace catechins, and the introduction of phenolic hydroxyl groups is reduced, resulting in a reduction in active sites, which leads to a decrease in the performance of Comparative Example 3; Comparative Example 4 performs a fermentation step, lignin is not degraded, the steric hindrance of the molecular structure is large, and the combination with formaldehyde is reduced, thereby reducing the performance of the adhesive.

[0054] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. Environmentally friendly waterproof adhesive for furniture wood panels, characterized in that: The environmentally friendly waterproof adhesive for furniture wood board comprises the following raw materials: biomass lignin, phenolic compounds, and formaldehyde aqueous solution, wherein the phenolic compound is catechin.

2. The method for preparing the environmentally friendly waterproof adhesive for furniture wood board according to claim 1, characterized in that: The preparation method of the environmentally friendly waterproof adhesive for furniture wood panels comprises the following steps: (1) mixing biomass lignin and liquid culture solution into a mixed solution, adding composite bacteria for aerobic fermentation, heating and sterilizing to obtain a fermentation solution and centrifuging, removing the supernatant, and drying the solid to form a powder; (2) stirring and mixing the powder, catechins, distilled water and 2 / 3 of the sodium hydroxide solution, then heating and keeping the temperature, and then adding 1 / 3 of the sodium hydroxide solution and stirring for 2-4 minutes; (3) Then, 1 / 2 of the formaldehyde aqueous solution is added, and the mixture is heated and kept warm. Then, the sodium hydroxide solution and the remaining formaldehyde aqueous solution are added and stirred at a constant temperature. The viscosity is measured using a viscometer. The mixture is cooled to room temperature and then discharged to obtain an environmentally friendly waterproof adhesive for furniture wood panels.

3. The method for preparing the environmentally friendly waterproof adhesive for furniture wood board according to claim 2, characterized in that: The biomass lignin in step (1) is agricultural waste straw, cotton stalks, and sulfonate lignin remaining as a byproduct of industry and papermaking industry. The mass ratio of the biomass lignin to the liquid culture medium is 1-5:15-20.

4. The method for preparing an environmentally friendly waterproof adhesive for furniture wood panels according to claim 2, characterized in that: In the step (1), the liquid culture solution is composed of peptone, sodium acetate and distilled water in a mass ratio of 7-9:0.5-1:50-60, and the composite bacteria accounts for 3-5wt% of the mass of the mixed solution, wherein the composite bacteria is composed of white rot fungi and Bacillus subtilis in a mass ratio of 1:

1.

5. The method for preparing an environmentally friendly waterproof adhesive for furniture wood panels according to claim 2, characterized in that: In the step (1), the fermentation temperature and time are 25-30°C and 24-48h respectively, the temperature and time of the heating sterilization are 140-150°C and 20-30min respectively, the rotation speed of the centrifugal separation is 500-800r / min, and the temperature and time of the drying are 70-80°C and 1-2h respectively.

6. The method for preparing the environmentally friendly waterproof adhesive for furniture wood board according to claim 2, characterized in that: The mass ratio of the powder, catechins, distilled water and sodium hydroxide solution in step (2) is 5:5:2-3:1-2, the mass fraction of the sodium hydroxide solution in step (2) and step (3) is 35-40%, and the insulation temperature and time are 80-85° C. and 2-2.5 h, respectively.

7. The method for preparing an environmentally friendly waterproof adhesive for furniture wood panels according to claim 2, characterized in that: The volume ratio of the total volume of the formaldehyde aqueous solution in step (3) to the distilled water in step (2) is 1:4-5, the volume ratio of the total volume of the formaldehyde aqueous solution to the sodium hydroxide solution is 20:1-2, and the mass fraction of the formaldehyde aqueous solution is 40%.

8. The method for preparing an environmentally friendly waterproof adhesive for furniture wood panels according to claim 2, characterized in that: The temperature and time of heating and heat preservation in the step (3) are 90-95° C. and 60-90 min respectively, the time of constant temperature stirring is 15-20 min, and the viscosity is 2-3 Pa·s.