Intumescent water-based fireproof coating for steel structure

Abstract

The invention relates to an intumescent water-based steel structure fireproof coating, and belongs to the technical field of steel structure fire prevention. The intumescent water-based fireproof coating for the steel structure is characterized by comprising a component A and a component B. The component A comprises the following components in percentage by weight: 35-50% of water-based silicone acrylic emulsion, 20-30% of ammonium polyphosphate, 20-30% of aluminosilicate polymer, 1-5% of titanium dioxide, 0.05-0.15% of aluminum silicate fiber and the balance of water. The component B is a boron phenolic aldehyde alcohol solution, and the content of boron phenolic aldehyde is 20-30%. The ratio of the component A to the component B is 10: 1. According to the invention, four flame-retardant elements of phosphorus, nitrogen, silicon and boron are optimized, so that the fire resistance and product safety of the fireproof coating are improved.

Description

Technical Field

[0001] The present invention relates to an intumescent waterborne steel structure fireproof coating, belonging to the technical field of steel structure fire protection. Background Art

[0002] The intumescent waterborne steel structure fireproof coating is a common type of thin fireproof coating for steel structures. Ammonium polyphosphate, pentaerythritol and melamine form an intumescent char layer through the thermal reaction of the three, hindering the transmission of oxygen and heat, and realizing the fireproof function. It is a commonly used intumescent flame retardant system at present. However, pentaerythritol belongs to inflammable and explosive dangerous goods, and melamine will release toxic cyanide at high temperature, affecting the safety of the product. Chinese Patent CN112322167A discloses an intumescent waterborne steel structure fireproof coating, which uses modified ammonium polyphosphate, triazine-based charring agent and expandable graphite to replace the traditional ammonium polyphosphate, pentaerythritol and melamine, and can improve the flame retardancy and heat resistance of the fireproof coating. However, the triazine-based charring agent has a high price, high requirements for the types of fillers, and low applicability. Summary of the Invention

[0003] In view of the above problems, the present invention provides an intumescent waterborne steel structure fireproof coating, which includes two components, namely component A and component B. The weight percentage composition of component A is: 35-50% waterborne silicone-acrylic emulsion, 20-30% ammonium polyphosphate, 20-30% aluminosilicate polymer, 1-5% titanium dioxide, 0.05-0.15% aluminum silicate fiber, and the balance is water. Component B is a boron phenolic alcohol solution. The ratio of component A to component B is 10:1.

[0004] Specifically, the solid content of the waterborne silicone-acrylic emulsion is 40-45%. The aluminosilicate polymer is prepared from slag powder and potassium silicate aqueous solution in a ratio of 2:1. The slag powder is 400 mesh. The potassium silicate aqueous solution has a Baume degree of 40 and a modulus of 3.3. The titanium dioxide is rutile type with a particle size of 45 microns. The aluminum silicate fiber has a diameter of 5-10 microns and a length of 5 mm. For the boron phenolic alcohol solution, the boron phenolic content is 20-30%.

[0005] Preparation method: Weigh aqueous silicon-acrylic emulsion, ammonium polyphosphate, slag powder, potassium silicate aqueous solution, titanium dioxide, aluminum silicate fiber, water, boron phenolic aldehyde and alcohol according to weight percentages. Mechanically stir the aqueous silicon-acrylic emulsion at 300 - 500 rpm, and successively add ammonium polyphosphate, slag powder, potassium silicate aqueous solution, titanium dioxide, water, and aluminum silicate fiber during the stirring process. Stir at 800 - 1000 rpm for 20 - 40 min to prepare Component A of the fireproof coating. Use a magnetic heating stirrer to stir alcohol at 50 °C and 600 rpm, add boron phenolic aldehyde powder, and magnetically stir for 120 min to prepare Component B of the fireproof coating. Add Component B to Component A in proportion, stir at 100 - 200 rpm for 5 - 10 minutes to obtain the fireproof coating, and then apply it on the surface of the steel structure to form a fireproof coating.

[0006] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The aluminosilicate polymer is a polymer formed by the sol-gel reaction of slag powder and potassium silicate aqueous solution. This type of polymer is a three-dimensional network structure formed by connecting silicon-oxygen tetrahedrons and aluminum-oxygen tetrahedrons through sharing oxygen atoms. Under the action of high temperature, dehydration reaction occurs on the surface of the aluminosilicate polymer, hydroxyl groups are removed, and a denser amorphous structure is formed, thereby effectively preventing heat transfer and playing a good heat insulation role. At the same time, the two raw materials of slag powder and potassium silicate aqueous solution have low prices, and the slag powder belongs to the utilization of solid waste, with significant social benefits.

[0007] (2) Boron phenolic aldehyde can undergo a cross-linking reaction with silicon-acrylic, and form a three-dimensional cross-linked structure containing silicon-boron bonds by means of covalent bonds and hydrogen bonds. After heating, silicon elements promote the formation of silicon oxide glass with high heat insulation at high temperature, effectively blocking heat transfer; boron elements generate an expandable borate glassy protective layer on the surface of the material, which can both insulate heat and isolate oxygen. At the same time, the phosphorus and nitrogen elements decomposed from ammonium polyphosphate promote the dehydration and carbonization of the coating surface, forming a dense carbonized layer. The four elements of silicon, boron, phosphorus, and nitrogen synergistically enhance the flame retardancy and fire resistance of the material through various flame retardant mechanisms such as gas-phase dilution and condensed-phase barrier.

[0008] (3) Aluminum silicate fiber is a high-temperature resistant fiber. Compared with carbon fiber, zirconia fiber, and basalt fiber, aluminum silicate fiber not only has a low price but also has higher toughness. When the silicon-acrylic fireproof coating expands upon heating, the internal molecular structure of the coating changes and gradually forms a carbonized layer. Due to its high toughness, aluminum silicate fiber can be closely intertwined with the carbonized layer, preventing the generation and expansion of microcracks inside the carbonized layer, enhancing the crack resistance of the carbonized layer, greatly improving the integrity and stability of the carbonized layer, and significantly improving the fireproof and heat insulation effect. Specific embodiments

[0009] The following embodiments are only for explaining the technical solutions recorded in the claims, and are not intended to limit the protection scope of the claims.

[0010] Embodiment 1 An intumescent waterborne steel structure fireproof coating comprises two components, namely component A and component B. The weight percentage composition of component A is as follows: 35% waterborne silicon-acrylic emulsion, 30% ammonium polyphosphate, 30% aluminosilicate polymer, 1% titanium dioxide, 0.05% aluminum silicate fiber, and the balance is water. Component B is a boron phenolic alcohol solution. The ratio of component A to component B is 10:1.

[0011] Among them, the solid content of the waterborne silicon-acrylic emulsion is 40%. The aluminosilicate polymer is prepared from slag powder and potassium silicate aqueous solution in a ratio of 2:1. The slag powder is 400 mesh. The potassium silicate aqueous solution has a Baume degree of 40 and a modulus of 3.3. The titanium dioxide is of rutile type with a particle size of 45 microns. The aluminum silicate fiber has a diameter of 5 microns and a length of 5 mm. For the boron phenolic alcohol solution, the boron phenolic content is 20%.

[0012] Embodiment 2 An intumescent waterborne steel structure fireproof coating comprises two components, namely component A and component B. The weight percentage composition of component A is as follows: 50% waterborne silicon-acrylic emulsion, 20% ammonium polyphosphate, 20% aluminosilicate polymer, 5% titanium dioxide, 0.15% aluminum silicate fiber. Component B is a boron phenolic alcohol solution. The ratio of component A to component B is 10:1.

[0013] Among them, the solid content of the waterborne silicon-acrylic emulsion is 45%. The aluminosilicate polymer is prepared from slag powder and potassium silicate aqueous solution in a ratio of 2:1. The slag powder is 400 mesh. The potassium silicate aqueous solution has a Baume degree of 40 and a modulus of 3.3. The titanium dioxide is of rutile type with a particle size of 45 microns. The aluminum silicate fiber has a diameter of 10 microns and a length of 5 mm. For the boron phenolic alcohol solution, the boron phenolic content is 30%.

[0014] Embodiment 3 An intumescent waterborne steel structure fireproof coating comprises two components, namely component A and component B. The weight percentage composition of component A is as follows: 40% waterborne silicon-acrylic emulsion, 25% ammonium polyphosphate, 25% aluminosilicate polymer, 3% titanium dioxide, 0.1% aluminum silicate fiber. Component B is a boron phenolic alcohol solution. The ratio of component A to component B is 10:1.

[0015] Among them, the solid content of the waterborne silicon-acrylic emulsion is 42%. The aluminosilicate polymer is prepared from slag powder and potassium silicate aqueous solution in a ratio of 2:1. The slag powder is 400 mesh. The potassium silicate aqueous solution has a Baume degree of 40 and a modulus of 3.3. The titanium dioxide is of rutile type with a particle size of 45 microns. The aluminum silicate fiber has a diameter of 8 microns and a length of 5 mm. For the boron phenolic alcohol solution, the boron phenolic content is 25%.

[0016] Example 4 An intumescent waterborne steel structure fireproof coating, which includes two components, component A and component B. The weight percentage composition of component A is: 45% waterborne silicon-acrylic emulsion, 28% ammonium polyphosphate, 22% aluminosilicate polymer, 2% titanium dioxide, 0.12% aluminum silicate fiber. Component B is a boron phenolic aldehyde alcohol solution. The ratio of component A to component B is 10:1.

[0017] Among them, the solid content of the waterborne silicon-acrylic emulsion is 43%. The aluminosilicate polymer is prepared from slag powder and potassium silicate aqueous solution in a ratio of 2:1. The slag powder is 400 mesh. The potassium silicate aqueous solution has a Baume degree of 40 and a modulus of 3.3. The titanium dioxide is rutile type with a particle size of 45 microns. The aluminum silicate fiber has a diameter of 6 microns and a length of 5 mm. For the boron phenolic aldehyde alcohol solution, the boron phenolic aldehyde content is 27%.

[0018] The preparation method of the intumescent waterborne fireproof coatings in Examples 1-4 is as follows: Weigh the waterborne silicon-acrylic emulsion, ammonium polyphosphate, slag powder, potassium silicate aqueous solution, titanium dioxide, aluminum silicate fiber, water, boron phenolic aldehyde and alcohol according to the weight percentage. Mechanically stir the waterborne silicon-acrylic emulsion at 300 - 500 rpm, and successively add ammonium polyphosphate, slag powder, potassium silicate aqueous solution, titanium dioxide, water, and aluminum silicate fiber during the stirring process, then stir at 800 - 1000 rpm for 20 - 40 min to prepare component A of the fireproof coating. Use a magnetic heating stirrer to stir the alcohol at 50 °C and 600 rpm, add boron phenolic aldehyde powder, and magnetically stir for 120 min to prepare component B of the fireproof coating. Add component B to component A according to the ratio, stir at 100 - 200 rpm for 5 - 10 minutes to obtain the fireproof coating, and then apply it on the surface of the steel structure to form a fireproof coating.

[0019] Comparative Example 1 An intumescent waterborne steel structure fireproof coating, with the weight percentage composition: 43% waterborne emulsion, 28% ammonium polyphosphate, 10% pentaerythritol, 10% melamine, 7% titanium dioxide, and the other 2%.

[0020] Comparative Example 2 An intumescent waterborne steel structure fireproof coating, with the weight percentage composition: 25% waterborne emulsion, 25% ammonium polyphosphate, 10% pentaerythritol, 7.5% melamine, and the other 32.5%.

[0021] Take a number of identical galvanized steel substrates, apply Examples 1-4 and Comparative Examples 1-2 to the surface of the galvanized steel substrates, and after curing at room temperature for four weeks, test the fire resistance performance of the fireproof coating using an alcohol blowtorch and measure the temperature of the backfire surface of the galvanized steel using a thermocouple. Stop the test when the backfire surface temperature remains stable, and the results of the stable backfire surface temperature are shown in Table 1. It can be seen that the backfire surface temperature of the present invention (Examples 1-4) is lower than that of the market products (Comparative Examples 1-2), indicating that the present invention has excellent fire resistance performance.

[0022] Table 1 Flame test performance of intumescent waterborne steel structure fireproof coatings Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Back fire surface temperature 207℃ 219℃ 163℃ 165℃ 166℃ 159℃ The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An intumescent waterborne steel structure fireproof coating, characterized in that, It includes two components, namely component A and component B. The weight percentage composition of component A is as follows: 35-50% water-based silicone-acrylic emulsion, 20-30% ammonium polyphosphate, 20-30% aluminosilicate polymer, 1-5% titanium dioxide, 0.05-0.15% aluminosilicate fiber, and the balance is water. Component B is a boron phenolic alcohol solution. The ratio of component A to component B is 10:

1.

2. The intumescent waterborne steel structure fireproof coating according to claim 1, characterized in that, The solid content of the water-based silicone-acrylic emulsion is 40-45%.

3. The intumescent waterborne steel structure fireproof coating according to claim 1, wherein, The aluminosilicate polymer is prepared from slag powder and potassium silicate aqueous solution in a ratio of 2:

1. The slag powder is 400 mesh. The potassium silicate aqueous solution has a Baume degree of 40 and a modulus of 3.

3.

4. The intumescent waterborne steel structure fireproof coating according to claim 1, characterized in that The titanium dioxide is of rutile type with a particle size of 45 microns.

5. The intumescent waterborne steel structure fireproof coating according to claim 1, wherein, The aluminosilicate fiber has a diameter of 5-10 microns and a length of 5 mm.

6. The intumescent waterborne steel structure fireproof coating according to claim 1, characterized in that For the boron phenolic alcohol solution, the boron phenolic content is 20-30%.