Reinforced waterproof coating material for building and preparation method of reinforced waterproof coating material

Abstract

The invention provides a reinforced waterproof coating material for buildings. The reinforced waterproof coating material comprises the following components in parts by mass: 30-60 parts of modified polyurethane emulsion; 10 to 25 parts of Portland cement; 3-8 parts of nano silicon dioxide; 5-9 parts of short carbon fiber shreds; 5 to 10 parts of flame-retardant expanded graphite; 10 to 15 parts of water-borne epoxy resin; 0.5 to 1.5 parts of a polycarboxylic acid water reducing agent; 0.3 to 0.8 part of a defoaming agent; 0.5 to 2 parts of a thickening agent; 20 to 30 parts of water; the compressive strength of the material is larger than 25 MPa, the material is waterproof at 0.6 MPa / 2 h, and the combustion performance is A2 level.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, in particular to a reinforced waterproof coating material for construction and a preparation method thereof. Background Art

[0002] Existing waterproofing materials have the following defects: 1. Polyurethane materials have good flexibility but low compressive strength (<15MPa); 2. Cement-based materials have high strength but are prone to cracking (elongation <20%); 3. Traditional materials lack structural reinforcement; 4. Poor bonding at the organic / inorganic interface leads to insufficient durability.

[0003] For example, the polyurethane coating disclosed in CN201510288XXX.2 has an elongation at break of ≥300% (GB / T528), but its compressive strength is only 12-15 MPa (GB / T17671), which cannot meet the needs of structural reinforcement; the cement-based permeable crystallization material described in CN201820735XXX.5 has a compressive strength of up to 30 MPa, but its elongation at break is less than 5% (JC / T984), and its dynamic crack tracking ability is poor. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a reinforced waterproof coating material for construction and a preparation method thereof in view of the shortcomings of the above-mentioned prior art.

[0005] The technical solution of the present invention to solve the above technical problems is: a reinforced waterproof coating material for construction, comprising the following components by mass: 30-60 parts of modified polyurethane emulsion 10-25 parts of Portland cement 3-8 parts of nano silicon dioxide 5-9 pieces of carbon fiber chopped strands 5-10 parts flame retardant expanded graphite 10-15 parts water-based epoxy resin 0.5-1.5 parts of polycarboxylate water reducer 0.3-0.8 parts of defoaming agent Thickener 0.5-2 parts 20-30 parts water.

[0006] The technical solution further defined in the present invention is: Preferably, the modified polyurethane emulsion is a silicone-modified water-based polyurethane with a solid content of 40-45%, a glass transition temperature (Tg) of -30°C to -10°C, and a tensile strength of ≥8 MPa.

[0007] Preferably, the nano-silica has a particle size of 10-30 nm, is surface-treated with silane coupling agent KH550 or KH560, has a specific surface area of ≥200 m² / g, and a coefficient of variation of its dispersion uniformity in the cement matrix of ≤15%.

[0008] Preferably, the carbon fiber chopped strands have a length of 1-5 mm and a diameter of 5-15 μm, and their surface is oxidized by nitric acid to increase the oxygen content to 8-12 wt%.

[0009] Preferably, the particle size of the flame retardant expanded graphite is 50-200 mesh, the expansion ratio is ≥150 ml / g, and the interfacial contact angle with the polyurethane emulsion is ≤30°.

[0010] Preferably, the defoaming agent is a polyether-modified silicone defoaming agent with a dynamic surface tension of ≤25 mN / m and a stability of ≥95% in the pH range of 8-12.

[0011] Preferably, the thickener is a compound system of hydroxyethyl cellulose and a hydrophobically modified polyurethane associative thickener, the mass ratio of the two is 1:0.5-1.2, and the thixotropic index of the solution is ≥3.5.

[0012] The present invention also provides a method for preparing a reinforced waterproof coating material for construction, which specifically comprises the following steps: a. Premix silicate cement, nano-silica and carbon fiber chopped strands in a dry environment at 500-800 rpm for 10-15 minutes. b. Stirring the modified polyurethane emulsion, waterborne epoxy resin and water at 50-60°C and 1200-1500 rpm to emulsify to form a composite emulsion; c. Add the mixture from step a to the emulsion from step b three times, with an interval of 5 minutes between each addition, and simultaneously add the flame retardant expanded graphite during the second addition; d. Finally, add water reducer, defoamer and thickener, and disperse at a high speed of 2000-3000 rpm for 20-30 minutes under vacuum degree -0.08~-0.1MPa and temperature 40±2℃; e is ground by a three-roll mill to a fineness of ≤50μm to obtain the finished product.

[0013] The beneficial effects of the present invention are: The present invention boasts a compressive strength of >25MPa, impermeability at 0.6MPa / 2h, and A2-grade combustion performance. By combining a modified polyurethane continuous phase with a Portland cement dispersed phase to form a system, the system can precisely control the formation of an interpenetrating network structure. Nanosilica and carbon fibers enhance network strength. The addition of flame-retardant expanded graphite, which expands upon exposure to fire to form a dense 2-3mm carbon layer, reduces the peak heat release rate by 65%, and maintains a contact angle of ≤30° between the flame-retardant expanded graphite and the polyurethane interface, ensuring uniform dispersion. DETAILED DESCRIPTION Example

[0014] This embodiment provides a reinforced waterproof coating material for construction, which comprises the following components in parts by mass: 30 parts of modified polyurethane emulsion 10 parts of Portland cement 3 parts of nano silicon dioxide 5 pieces of carbon fiber chopped strands 5 parts flame retardant expanded graphite 10 parts water-based epoxy resin 0.5 parts of polycarboxylate water reducer 0.3 parts of defoaming agent 0.5 parts thickener 20 parts water.

[0015] The modified polyurethane emulsion is a water-based polyurethane modified with silicone, with a solid content of 40%, a glass transition temperature (Tg) of -30°C to -10°C, and a tensile strength of ≥8MPa; the nano-silica particle size is 30nm, surface treated with silane coupling agent KH550 or KH560, with a specific surface area of ≥200m² / g, and a coefficient of variation of its dispersion uniformity in the cement matrix of ≤15%; the carbon fiber chopped strands are 4mm long and 10μm in diameter, and the surface is treated with nitric acid oxidation to increase the oxygen content to 8-12wt%; the flame-retardant expanded graphite has a particle size of 100 mesh, an expansion ratio of ≥150ml / g, and an interfacial contact angle with the polyurethane emulsion of ≤30°; the defoamer is a polyether-modified silicone defoamer with a dynamic surface tension of ≤25mN / m and a pH of 1. The stability within the range of 8-12 is ≥95%; the thickener is a compound system of hydroxyethyl cellulose and hydrophobically modified polyurethane associative thickener, the mass ratio of the two is 1:0.7, and the solution thixotropic index is ≥3.5.

[0016] The product prepared in this embodiment has a compressive strength of 26 MPa (GB / T17671), a bonding strength of 2.8 MPa (JC / T984), a water-tightness of 0.6 MPa / 2h without leakage (GB / T16777), and an elongation of 280% (GB / T528). Example

[0017] This embodiment provides a reinforced waterproof coating material for construction, which comprises the following components in parts by mass: 50 parts of modified polyurethane emulsion 20 parts of Portland cement 5 parts of nano silicon dioxide 7 pieces of carbon fiber chopped strands 8 parts flame retardant expanded graphite 13 parts water-based epoxy resin 1 part polycarboxylate water reducer 0.3-0.85 parts of defoaming agent 1 part thickener 25 parts water.

[0018] The modified polyurethane emulsion is a water-based polyurethane modified with silicone, with a solid content of 40%, a glass transition temperature (Tg) of -30°C to -10°C, and a tensile strength of ≥8MPa; the nano-silica particle size is 30nm, surface treated with silane coupling agent KH550 or KH560, with a specific surface area of ≥200m² / g, and a coefficient of variation of its dispersion uniformity in the cement matrix of ≤15%; the carbon fiber chopped strands are 4mm long and 10μm in diameter, and the surface is treated with nitric acid oxidation to increase the oxygen content to 8-12wt%; the flame-retardant expanded graphite has a particle size of 100 mesh, an expansion ratio of ≥150ml / g, and an interfacial contact angle with the polyurethane emulsion of ≤30°; the defoamer is a polyether-modified silicone defoamer with a dynamic surface tension of ≤25mN / m and a pH of 1. The stability within the range of 8-12 is ≥95%; the thickener is a compound system of hydroxyethyl cellulose and hydrophobically modified polyurethane associative thickener, the mass ratio of the two is 1:0.7, and the solution thixotropic index is ≥3.5.

[0019] This embodiment also provides a method for preparing a reinforced waterproof coating material for construction, which specifically includes the following steps: a. Premix silicate cement, nano-silica and carbon fiber chopped strands in a dry environment at 800 rpm for 10 minutes. b. Stirring the modified polyurethane emulsion, waterborne epoxy resin and water at 50°C and 1500 rpm to emulsify the emulsion to form a composite emulsion; c. Add the mixture from step a to the emulsion from step b three times, with an interval of 5 minutes between each addition, and simultaneously add the flame retardant expanded graphite during the second addition; d. Finally, add water reducer, defoamer and thickener, and disperse at 3000 rpm for 20 minutes under vacuum degree -0.08 MPa and temperature 40°C; e is ground by a three-roll mill to a fineness of ≤50μm to obtain the finished product.

[0020] The product prepared in this embodiment has a compressive strength of 28 MPa (GB / T17671), a bonding strength of 2.9 MPa (JC / T984), a water impermeability of 0.6 MPa / 2h without leakage (GB / T16777), and an elongation of 290% (GB / T528). Example

[0021] This embodiment provides a reinforced waterproof coating material for construction, which comprises the following components in parts by mass: 60 parts of modified polyurethane emulsion 25 parts of Portland cement 8 parts of nano silicon dioxide 9 pieces of carbon fiber chopped strands 10 parts flame retardant expanded graphite 15 parts water-based epoxy resin 1.5 parts polycarboxylate water reducer 0.8 parts of defoaming agent 2 parts thickener 30 parts water.

[0022] The modified polyurethane emulsion is a water-based polyurethane modified with silicone, with a solid content of 45%, a glass transition temperature (Tg) of -30°C to -10°C, and a tensile strength of ≥8MPa; the nano-silica particle size is 30nm, surface-treated with silane coupling agent KH550 or KH560, with a specific surface area of ≥200m² / g, and a coefficient of variation of its dispersion uniformity in the cement matrix of ≤15%; the carbon fiber chopped strands are 4mm long and 15μm in diameter, and the surface is treated with nitric acid oxidation to increase the oxygen content to 8-12wt%; the flame-retardant expanded graphite has a particle size of 100 mesh, an expansion ratio of ≥150ml / g, and an interfacial contact angle with the polyurethane emulsion of ≤30°; the defoamer is a polyether-modified silicone defoamer with a dynamic surface tension of ≤25mN / m and a pH of 1. The stability within the range of 8-12 is ≥95%; the thickener is a compound system of hydroxyethyl cellulose and hydrophobically modified polyurethane associative thickener, the mass ratio of the two is 1:0.7, and the solution thixotropic index is ≥3.5.

[0023] The product prepared in this embodiment has a compressive strength of 30 MPa (GB / T17671), a bonding strength of 2.9 MPa (JC / T984), a water impermeability of 0.7 MPa / 2h without leakage (GB / T16777), and an elongation of 300% (GB / T528).

[0024] In addition to the above embodiments, the present invention may also have other implementations. Any technical solution formed by equivalent replacement or equivalent transformation falls within the protection scope of the present invention.

Claims

1. A reinforced waterproof coating material for construction, characterized in that: The following components are included in parts by mass: 30-60 parts of modified polyurethane emulsion 10-25 parts of Portland cement 3-8 parts of nano silicon dioxide 5-9 pieces of carbon fiber chopped strands 5-10 parts flame retardant expanded graphite 10-15 parts water-based epoxy resin 0.5-1.5 parts of polycarboxylate water reducer 0.3-0.8 parts of defoaming agent Thickener 0.5-2 parts 20-30 parts water.

2. A reinforced waterproof coating material for construction according to claim 1, characterized in that: The modified polyurethane emulsion is a water-based polyurethane modified with organic silicon, has a solid content of 40-45%, a glass transition temperature (Tg) of -30°C to -10°C, and a tensile strength of ≥8MPa.

3. A reinforced waterproof coating material for construction according to claim 1, characterized in that: The nano-silicon dioxide has a particle size of 10-30 nm, is surface-treated with silane coupling agent KH550 or KH560, has a specific surface area of ≥200 m² / g, and has a coefficient of variation of dispersion uniformity of ≤15% in the cement matrix.

4. A reinforced waterproof coating material for construction according to claim 1, characterized in that: The carbon fiber chopped strands have a length of 1-5 mm and a diameter of 5-15 μm, and their surfaces are oxidized by nitric acid to increase the oxygen content to 8-12 wt%.

5. A reinforced waterproof coating material for construction according to claim 1, characterized in that: The particle size of the flame retardant expanded graphite is 50-200 meshes, the expansion ratio is ≥150 ml / g, and the interface contact angle with the polyurethane emulsion is ≤30°.

6. A reinforced waterproof coating material for construction according to claim 1, characterized in that: The defoaming agent is a polyether-modified silicone defoaming agent with a dynamic surface tension of ≤25 mN / m and a stability of ≥95% within a pH range of 8-12.

7. A reinforced waterproof coating material for construction according to claim 1, characterized in that: The thickener is a compound system of hydroxyethyl cellulose and a hydrophobically modified polyurethane associative thickener, the mass ratio of the two is 1:0.5-1.2, and the solution thixotropic index is ≥3.

5.

8. The method for preparing a reinforced waterproof coating material for construction according to any one of claims 1 to 7, characterized in that: The specific steps include: a. Premix silicate cement, nano-silica and carbon fiber chopped strands in a dry environment at 500-800 rpm for 10-15 minutes. b. Stirring the modified polyurethane emulsion, waterborne epoxy resin and water at 50-60°C and 1200-1500 rpm to emulsify to form a composite emulsion; c. Add the mixture from step a to the emulsion from step b three times, with an interval of 5 minutes between each addition, and simultaneously add the flame retardant expanded graphite during the second addition; d. Finally, add water reducer, defoamer and thickener, and disperse at a high speed of 2000-3000 rpm for 20-30 minutes under vacuum degree -0.08~-0.1MPa and temperature 40±2℃; e is ground by a three-roll mill to a fineness of ≤50μm to obtain the finished product.