Hydrophobic fireproof coating for wood material and preparation method and application of hydrophobic fireproof coating

Abstract

The invention discloses a hydrophobic fireproof coating for a wood material as well as a preparation method and application of the hydrophobic fireproof coating. The hydrophobic fireproof coating is prepared from the following components: a sodium silicate solution, a hydroxyl-containing toughening agent, a dispersing agent, an amino-containing silane coupling agent and a curing agent, the mass ratio of the total mass of the sodium silicate solution, the hydroxyl-containing toughening agent and the dispersing agent to the total mass of the amino-containing silane coupling agent and the curing agent is (40-50): (7-10): (1-4). According to the hydrophobic fireproof coating disclosed by the invention, the sodium silicate solution is taken as a raw material, the hydroxyl-containing toughening agent and the amino-containing silane coupling agent are taken as modifiers, and a C-O-Si-OH--NH2 cross-linked network structure is formed through an inorganic-organic hybridization strategy, so that a wood material is endowed with hydrophobic and fireproof functions, and the surface contact angle of the wood material reaches 85 degrees, and the hardness reaches 5H, LOIt; the coating has the advantages of high toughness, high hydrophobicity, high hardness, high flame retardance and the like, and can be used for coating furniture wood products.

Description

Technical Field

[0001] The invention belongs to the technical field of wood materials, and in particular relates to a hydrophobic fire-retardant coating for wood materials and a preparation method and application thereof. Background Art

[0002] With the continuous progress of science and technology and economy, environmental protection, green and recyclable concepts have become the main theme of economic and social development. As a result, wood products are favored by the market and widely used in home furnishing, construction and other fields. Since wood products are exposed to the air for a long time, their surfaces will be affected by various adverse factors such as temperature, humidity, acid and alkali, and decaying fungi. If they are in these environments for a long time, wood products will be corroded and oxidized, resulting in surface damage, flammability, reduced strength and other problems, thereby reducing their service life.

[0003] Applying paint on the surface of wood products can not only ensure the structural integrity of wood and reduce the impact of various adverse factors, but also beautify wood products, maximize resource utilization and extend their service life. In recent years, with the rise of the domestic sustainable development model, consumers' environmental awareness has been continuously improved, and non-toxic and green water-based paints have accounted for an increasing proportion of the paint market for wood household products. Water-based paints are divided into organic water-based paints and inorganic water-based paints. Organic water-based paints, such as water-based polyurethane varnishes and water-based acrylic varnishes, have the disadvantages of poor flame retardancy and poor high temperature resistance; inorganic water-based paints, such as sodium silicate paints, have the disadvantages of poor water resistance and poor coating toughness. Therefore, how to obtain a highly hydrophobic, high hardness, and highly flame-retardant hydrophobic fire-retardant paint is of great significance for the wide application of water-based paints in the fields of home and construction. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a hydrophobic fire-retardant coating for wood materials with high hydrophobicity, high hardness and high flame retardancy, and a preparation method and application thereof.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions.

[0006] A hydrophobic fireproof coating for wood materials, the hydrophobic fireproof coating comprising the following components: sodium silicate solution, a hydroxyl-containing toughening agent, a dispersant, an amino-containing silane coupling agent and a curing agent; the mass ratio of the total mass of the sodium silicate solution, the hydroxyl-containing toughening agent and the dispersant, and the total mass of the amino-containing silane coupling agent and the curing agent is 40-50:7-10:1-4.

[0007] In the above-mentioned hydrophobic fire retardant coating, preferably, the mass ratio of the hydroxyl-containing toughening agent to the dispersant is 5:4.

[0008] In the above-mentioned hydrophobic fire-retardant coating, preferably, the mass ratio of the amino-containing silane coupling agent to the curing agent is 1:9.

[0009] In the above-mentioned hydrophobic fire-retardant coating, preferably, the hydroxyl-containing toughening agent is polyvinyl alcohol, and the polyvinyl alcohol is implemented in the form of a polyvinyl alcohol solution, and the mass percentage concentration of the polyvinyl alcohol solution is 10%; the amino-containing silane coupling agent is amino di-terminated polydimethylsiloxane.

[0010] The hydrophobic fire retardant coating mentioned above is preferably such that the mass percentage concentration of the sodium silicate solution is 35% to 40%, and the modulus of the sodium silicate solution is 3.3M to 3.4M.

[0011] In the above-mentioned hydrophobic fire retardant coating, preferably, the dispersant is at least one of Triton X-100 solution, OP-10 emulsifier and dodecyl dimethyl betaine, and the mass percentage concentration of the Triton X-100 solution is 20%; the curing agent is at least one of ethyl acetate, acetic acid, citric acid and maleic acid.

[0012] As a general technical concept, the present invention also provides a method for preparing the hydrophobic fire retardant coating of the above-mentioned wood material, comprising the following steps:

[0013] (1) mixing a hydroxyl-containing toughening agent and a dispersant to obtain a mixed solution A;

[0014] (2) mixing an amino-containing silane coupling agent and a curing agent to obtain a mixed solution B;

[0015] (3) Mixing the mixed solution A obtained in step (1) and the sodium silicate solution, stirring, adding the mixed solution B obtained in step (2), stirring again, and obtaining a hydrophobic fire retardant coating for wood materials.

[0016] The preparation method of the present invention premixes a hydroxyl-containing toughening agent and a dispersant to improve the subsequent compatibility with a sodium silicate solution, and then adds a mixed solution of an amino-containing silane coupling agent and a curing agent to form a fully mixed and uniform mixture, thereby ultimately improving the overall stability of the hydrophobic fire retardant coating system and reducing phase separation and precipitation phenomena.

[0017] In the above preparation method, preferably, in step (3), the stirring time is 1 min to 5 min, the stirring temperature is 40° C., the re-stirring time is 1.5 h, and the re-stirring temperature is 40° C.

[0018] As a general technical concept, the present invention also provides an application of the hydrophobic fire retardant coating for wood materials mentioned above or the hydrophobic fire retardant coating for wood materials prepared by the above preparation method in wood materials.

[0019] The above application preferably includes the following steps: applying a hydrophobic fire-retardant coating of a wood material on the surface of the wood material; the wood material is any one of solid wood, artificial board and integrated wood, and the solid wood is poplar.

[0020] Compared with the prior art, the advantages of the present invention are:

[0021] The invention provides a hydrophobic fireproof coating for wood materials, which uses sodium silicate solution as a raw material, a hydroxyl-containing toughening agent and an amino-containing silane coupling agent as a modifier, and forms a CO-Si-OH--NH2 cross-linked network structure through an "inorganic-organic hybridization" strategy, thereby giving the wood material a hydrophobic and fireproof function, so that the surface contact angle of the wood material reaches 85°, the hardness reaches 5H, and the LOI>95%, and has the advantages of high toughness, high hydrophobicity, high hardness and high flame retardancy. The hydrophobic fireproof coating of the invention uses low-priced raw materials, abundant output, is green and non-toxic, is conducive to reducing environmental pollution, and can be used for the finishing of furniture wood products. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a diagram of the bonding mechanism between the hydrophobic fire retardant coating and the wood material in Example 2 of the present invention.

[0023] Figure 2 These are flame retardant effect diagrams of the wooden material coated with hydrophobic fire retardant coating in Example 2 of the present invention and the wooden material coated with water-based varnish in Comparative Example 2. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby. The materials and instruments used in the following embodiments are all commercially available.

[0025] Embodiment 1:

[0026] The invention discloses a hydrophobic fireproof coating for wood materials, which is composed of the following components: sodium silicate solution, polyvinyl alcohol solution, Triton X-100, amino diblocked polydimethylsiloxane and ethyl acetate; wherein the mass ratio of the total mass of the sodium silicate solution, the polyvinyl alcohol solution and the Triton X-100 solution to the total mass of the amino diblocked polydimethylsiloxane and ethyl acetate is 20:4:1; the mass percentage concentration of the sodium silicate solution is 35%, and its modulus is 3.3M-3.4M; the mass ratio of the polyvinyl alcohol solution to the Triton X-100 solution is 5:4, the mass percentage concentration of the polyvinyl alcohol solution is 10%, and the mass percentage concentration of the Triton X-100 solution is 20%, that is, the molar ratio of the polyvinyl alcohol in the polyvinyl alcohol solution to the Triton X-100 in the Triton X-100 solution is 0.003:0.1; and the mass ratio of the amino diblocked polydimethylsiloxane to the ethyl acetate is 1:9.

[0027] A method for preparing a hydrophobic fire retardant coating for a wood material of the present embodiment, adding the hydrophobic fire retardant coating for the wood material according to the dosage, comprises the following steps:

[0028] (1) The polyvinyl alcohol solution and the Triton X-100 solution were mixed to obtain a mixed solution A.

[0029] (2) Mix aminopropyl di-terminated polydimethylsiloxane (2NH2-PDMS) and ethyl acetate to obtain a mixed solution B.

[0030] (3) Add the mixed solution A obtained in step (1) to the sodium silicate solution, place in a water bath, and stir at 40° C. for 1 min; then, add the mixed solution B, stir at 40° C. for 1.5 h, and obtain a hydrophobic fire retardant coating.

[0031] Embodiment 2:

[0032] An application of the hydrophobic fire retardant coating for wood materials of the present invention to wood materials comprises the following steps:

[0033] (1) The poplar wood is polished with 240-grit sandpaper to obtain a treated wooden material.

[0034] (2) The hydrophobic fire retardant coating prepared in Example 1 is applied to the surface of the treated wooden material and dried at room temperature for seven days to obtain a wooden material coated with the hydrophobic fire retardant coating.

[0035] Figure 1 This is a diagram showing the bonding mechanism between the hydrophobic fire retardant coating and the wood material in Example 2 of the present invention. Figure 1 It can be seen that the sodium silicate solution was modified by polyvinyl alcohol and aminopropyl dicapped polydimethylsiloxane (2NH2-PDMS) to form a network cross-linked structure (CO-Si-OH--NH2), which gave the wood flame retardancy and hydrophobicity.

[0036] Comparative Example 1:

[0037] A method for coating a wood material using a sodium silicate solution comprises the following steps:

[0038] (1) The poplar wood is polished with 240-grit sandpaper to obtain a processed wood product material.

[0039] (2) A sodium silicate solution (the mass percentage concentration of the solution is 35%) is applied to the surface of the treated wooden material, and the wooden material is dried at room temperature for seven days to obtain a sodium silicate coated wooden material.

[0040] Comparative Example 2:

[0041] A method for finishing a wood material using a water-based varnish comprises the following steps:

[0042] (1) The poplar wood is polished with 240-grit sandpaper to obtain a processed wood product material.

[0043] (2) The treated wooden material surface is coated with water-based varnish and dried at room temperature for seven days to obtain a wooden material coated with water-based varnish. In Comparative Example 2, the water-based varnish used is purchased from a varnish company in Fujian, and the solid content of the water-based varnish is 39.7%.

[0044] The hydrophobic fire retardant coating prepared in Example 1, the sodium silicate solution in Comparative Example 1, and the water-based varnish in Comparative Example 2 were respectively coated on a polytetrafluoroethylene plate or cardboard, and placed in an oven at 50°C for rapid drying until the coating was surface dry (finger touch method: touch the surface of the coating lightly with your finger, if you feel no paint sticking to your finger, it is surface dry) and solidified into a film to test the thermal stability of the coating. The performance test was performed on the wooden material coated with hydrophobic fire retardant coating in Example 2, the wooden material coated with sodium silicate in Comparative Example 1, and the wooden material coated with water-based varnish in Comparative Example 2, that is, the adhesion, hardness and wear resistance of the coated wood film were tested according to the national standards GB / T 4893.4-2013, GB / T 6739-2006 "Determination of film hardness by pencil method for paint and varnish", and GB / T 15036.1-2018 "Inspection and test methods for solid wood flooring", and the coating thermogravimetric and contact angle were tested by NETZSCH STA2500 tester and JGW-360B contact angle tester, and the results are shown in Table 1. In Table 1, the uncoated material is poplar wood that is not coated with any coating.

[0045] Table 1 Performance test results of different coatings

[0046]

[0047] It can be seen from Table 1 that compared with uncoated materials and water-based varnishes, the hydrophobic fire-retardant coating of the present invention can give wood materials excellent properties. Specifically, the hardness of the wood material after coating with water-based varnish is 6B, the wear resistance (mass loss g / r) is 0.15, the contact angle is 61°, the LOI value is 23%, and the 600°C pyrolysis residue is 18.20%. The hardness of the wood material after coating with the hydrophobic fire-retardant coating is 5H, the wear resistance (mass loss g / r) is 0.11, the contact angle is 85°, the LOI value>95%, and the 600°C pyrolysis residue is 97.15%. It can be seen that compared with the wood material coated with water-based varnish, the wear resistance and flame retardancy of the wood material coated with the hydrophobic fire-retardant coating are significantly improved, which shows that the hydrophobic fire-retardant coating of the present invention has obvious advantages in home flame retardancy and fire prevention.

[0048] Figure 2 These are flame retardant effect diagrams of the wooden material coated with hydrophobic fire retardant coating in Example 2 of the present invention and the wooden material coated with water-based varnish in Comparative Example 2. Figure 2In the example, "uncoated" refers to the poplar wood that is not coated with any coating, "varnish coated" refers to the wood material coated with water-based varnish in Comparative Example 2, and "flame retardant coated" refers to the wood material coated with hydrophobic fire retardant coating in Example 2. Figure 2 It can be seen that the ignition time of uncoated materials, wooden materials coated with water-based varnish, and wooden materials coated with hydrophobic fire-retardant coating are 13s, 4s, and 48s, respectively. That is to say, compared with uncoated materials and wooden materials coated with water-based varnish, the ignition time of wooden materials coated with hydrophobic fire-retardant coating is extended by more than 30s, and the flame retardant effect is significantly improved.

[0049] In addition, the toughness of the hydrophobic fire retardant coating prepared in Example 2 was tested. According to the national standard GB / T1731-2020 paint film and putty film flexibility determination method, the coated tinplate sheet was placed on the shaft rod, and then the toughness of the paint film was tested by a certain deformation and the performance of the paint film under different conditions was recorded, such as whether it was broken and the degree of cracks. The specific test process is: the hydrophobic fire retardant coating prepared in Example 1 is coated on the tinplate sheet, and after drying, it is placed on the shaft rod for testing. When the radius of curvature of the shaft rod is 5mm, the coating does not break. It can be seen that the hydrophobic fire retardant coating of the present invention has the advantage of high toughness.

[0050] The above 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 above in the preferred embodiment, it is not used to limit the present invention. Any technician familiar with the art can make many possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention, still fall within the scope of protection of the technical solution of the present invention.

Claims

1. A hydrophobic fire retardant coating for wood materials, characterized in that: The hydrophobic fire-retardant coating is composed of the following components: sodium silicate solution, a hydroxyl-containing toughening agent, a dispersant, an amino-containing silane coupling agent and a curing agent; the mass ratio of the total mass of the sodium silicate solution, the hydroxyl-containing toughening agent and the dispersant, and the total mass of the amino-containing silane coupling agent and the curing agent is 40-50:7-10:1-4.

2. The hydrophobic fire retardant coating for wood materials according to claim 1, characterized in that: The mass ratio of the hydroxyl-containing toughening agent to the dispersant is 5:

4.

3. The hydrophobic fire retardant coating for wood materials according to claim 2, characterized in that: The mass ratio of the amino-containing silane coupling agent to the curing agent is 1:

9.

4. The hydrophobic fire retardant coating for wood materials according to claim 3, characterized in that: The hydroxyl-containing toughening agent is polyvinyl alcohol, which is implemented in the form of polyvinyl alcohol solution, and the mass percentage concentration of the polyvinyl alcohol solution is 10%; the amino-containing silane coupling agent is amino double-terminated polydimethylsiloxane.

5. The hydrophobic fire retardant coating for wood materials according to any one of claims 1 to 4, characterized in that: The mass percentage concentration of the sodium silicate solution is 35% to 40%, and the modulus of the sodium silicate solution is 3.3M to 3.4M.

6. The hydrophobic fire retardant coating for wood materials according to any one of claims 1 to 4, characterized in that: The dispersant is at least one of a Triton X-100 solution, an OP-10 emulsifier and dodecyl dimethyl betaine, and the mass percentage concentration of the Triton X-100 solution is 20%; the curing agent is at least one of ethyl acetate, acetic acid, citric acid and maleic acid.

7. A method for preparing a hydrophobic fire retardant coating for wood materials as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: (1) mixing a hydroxyl-containing toughening agent and a dispersant to obtain a mixed solution A; (2) mixing an amino-containing silane coupling agent and a curing agent to obtain a mixed solution B; (3) Mixing the mixed solution A obtained in step (1) and the sodium silicate solution, stirring, adding the mixed solution B obtained in step (2), stirring again, and obtaining a hydrophobic fire retardant coating for wood materials.

8. The method for preparing a hydrophobic fire retardant coating for wood materials according to claim 7, characterized in that: In step (3), the stirring time is 1 min to 5 min, the stirring temperature is 40°C, the re-stirring time is 1.5 h, and the re-stirring temperature is 40°C.

9. Use of the hydrophobic fire retardant coating for wood materials according to any one of claims 1 to 6 or the hydrophobic fire retardant coating for wood materials prepared by the preparation method according to claim 7 or 8 in wood materials.

10. The use according to claim 9, characterized in that: The following steps are involved: The hydrophobic fireproof coating of the wood material is coated on the surface of the wood material; the wood material is any one of solid wood, artificial board and integrated wood, and the solid wood is poplar.

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