Anti-cracking quick-drying indoor wall surface repairing coating and construction method thereof

Abstract

The invention discloses an anti-cracking quick-drying indoor wall surface repairing coating and a construction method thereof, a repairing material adopts a double-gel system of beta-semi-hydrated gypsum and sulphoaluminate cement, and the component ratio is gt; meanwhile, the ratio of the composite fibers is innovatively adopted, the repairing material forms an effective three-dimensional network structure, the technical problem that the quick-drying property and the crack resistance of an existing repairing material cannot be achieved at the same time is solved, the specific surface area of the nanometer silica fume is larger than or equal to 150,000 m < 2 > / kg, and the problems of micropore filling and shrinkage compensation are solved at the same time through the synergistic effect of the nanometer silica fume and the magnesium oxide expanding agent; the organic silicon water repellent is adopted for modification, so that the bonding strength on a wet base plane is improved, and the anti-alkali requirement of the wall surface of the toilet is met.

Description

Technical Field

[0001] This invention relates to the field of architectural coatings technology, and in particular to a crack-resistant, fast-drying interior wall repair coating and its application method. Background Technology

[0002] Before painting interior walls with latex paint, the wall surface usually needs to be repaired to make it ready for painting. Currently, the commonly used repair process involves multiple steps: removing hollow areas → adding a bonding agent → roughing and leveling with plaster → leveling with putty. This process has the following shortcomings:

[0003] 1. Single-layer application thickness > 5mm is prone to cracking;

[0004] 2. The repair material used had a fineness of only 200 mesh, resulting in uneven gloss on the topcoat;

[0005] 3. The required hardening time is greater than 2 hours, resulting in a long construction period;

[0006] 4. The repair materials have poor water resistance, resulting in a high rate of efflorescence in the bathroom area.

[0007] Currently, the various types of repair agents available have good performance parameters in one of the three aspects of quick drying, crack resistance, and fineness, and there are very few wall repair agents that have all the necessary properties. Summary of the Invention

[0008] In order to overcome the problems existing in the background art, the present invention provides a crack-resistant and fast-drying interior wall repair coating and its construction method.

[0009] The technical solution adopted by this invention to solve its technical problem is:

[0010] A crack-resistant, quick-drying interior wall repair coating is made from the following raw material components:

[0011] 50-58 parts by weight of β-hemihydrate gypsum;

[0012] 12-15 parts by weight of sulfoaluminate cement;

[0013] 18-22 parts by weight of heavy calcium carbonate powder;

[0014] 4-5 parts by weight of redispersible latex powder;

[0015] 0.5 parts by weight of composite fiber;

[0016] 0.8 parts by weight of magnesium oxide expanding agent;

[0017] 2 parts by weight of nano silica fume;

[0018] 0.4 parts by weight of organosilicon water-repellent agent;

[0019] 0.08-0.12 parts by weight of composite retarder;

[0020] 0.3 parts by weight of polycarboxylate superplasticizer;

[0021] 0.5 parts by weight of fumed silica.

[0022] Furthermore, the composite fiber is composed of polypropylene fibers with a diameter of 3 mm and glass fibers with a diameter of 50 μm, with a weight ratio of polypropylene fibers to glass fibers of 2:1. The use of two different fiber specifications results in strong bond strength while maintaining high elastic modulus, impact resistance, tensile strength, and flexural strength, significantly improving the overall crack resistance of the repaired surface. The glass fiber is preferably alkali-resistant, characterized by good alkali resistance, effectively resisting the erosion of high-alkali substances in cement, and possessing strong design flexibility and easy molding characteristics, making it a novel, green, and environmentally friendly reinforcing material.

[0023] Furthermore, the composite retarder is made of tartaric acid and borax, with a weight ratio of tartaric acid to borax of 3:1 and a mixing reaction time of 18-20 min. The complex formed by the two has good retarding and stabilizing effects.

[0024] Furthermore, the redispersible latex powder is a vinyl acetate / ethylene copolymer.

[0025] Furthermore, the specific surface area of ​​the β-hemihydrate gypsum is ≥400 m². 2 / kg, the specific surface area of ​​the nano-silica fume is ≥150000m² 2 / kg.

[0026] Furthermore, the preparation method of the above-mentioned crack-resistant and quick-drying interior wall repair coating specifically includes the following steps:

[0027] 1) Composite fiber pretreatment: First, mix polypropylene fiber, glass fiber and heavy calcium carbonate powder evenly;

[0028] 2) Main mixing: Mix the pretreated components from step 1) with other raw material components and stir for 25 minutes at 35 rpm in a double helical conical mixer;

[0029] 3) Sieving: After passing through a 325-mesh vibrating sieve, the repair coating is made.

[0030] Furthermore, this invention also discloses a method for applying the above-mentioned crack-resistant and quick-drying interior wall repair coating, specifically including the following steps:

[0031] S1 Base surface treatment: Remove the hollow layer on the wall surface and apply epoxy interface agent;

[0032] S2 Repair Coating Application: Apply this repair coating by scraping at an ambient temperature of 15-35℃, with a thickness of 3-13mm.

[0033] S3 Hardening Control: 20-30 minutes after step S2 is completed, polish the surface with 240-grit sandpaper until the surface roughness Ra≤12μm;

[0034] S4 Coating: 60 minutes after step S3 is completed, apply water-based epoxy primer by roller, and wait another two hours before applying the topcoat.

[0035] Furthermore, in step S1, the epoxy interface agent is a two-component epoxy interface agent, with the ratio of component A to component B being 3:1.

[0036] Furthermore, in step S4, the solid content of the water-based epoxy sealing primer applied by roller is ≥45%.

[0037] The beneficial effects of this invention are as follows: The repair material of this invention adopts a dual-cementing system of β-hemihydrate gypsum and sulfoaluminate cement, with the component accounting for more than 50%. Simultaneously, it innovatively employs a composite fiber ratio, wherein the weight ratio of polypropylene fiber to glass microfiber is 2:1. The repair material forms an effective three-dimensional network structure, solving the technical problem that existing repair materials cannot simultaneously achieve fast drying and crack resistance. The nano-silica fume used has a specific surface area ≥150,000 m². 2 The synergistic effect of / kg and magnesium oxide expanding agent simultaneously solves the problems of micropore filling and shrinkage compensation. Modification with an organosilicon water-repellent agent increases adhesion strength on damp substrates by 40%, meeting the anti-alkali reaction requirements for bathroom walls.

[0038] This repair material preparation method employs a pre-mixing technique involving composite fibers and heavy calcium carbonate powder, which solves the technical problem of fiber clumping and achieves uniform fiber dispersion. After vibratory sieving using a 325-mesh sieve in step 3), the repair material exhibits uniform fineness, resulting in a smooth wall surface after sanding, high compatibility with topcoat, and excellent paint finish.

[0039] By using organosilicon hydrophobic agents to block capillary channels and sulfoaluminate cement to provide an alkaline buffer, a dual-effect synergistic effect is achieved to inhibit salting out.

[0040] This invention achieves a synergistic effect of 325-mesh fineness and rapid, stable final setting by using a core formulation system of compounded high-activity β-gypsum, sulfoaluminate cement, composite fiber, and magnesium oxide expansion agent, with nano-silica fume filling. It also solves the technical problem of existing repair materials in maintaining and balancing the three aspects of "fast drying, crack resistance, and fineness". Furthermore, the surface modification with organosilicon water-repellent agent significantly improves the bonding strength on damp substrates and meets the requirements for anti-alkali reaction on bathroom walls. Detailed Implementation

[0041] The following embodiments of the present invention further illustrate the invention. It should be noted that these descriptions of embodiments are intended to aid in understanding the invention but do not constitute a limitation thereof. The technical features involved in the various embodiments can be combined with each other as long as they do not conflict with each other.

[0042] In a first aspect, the present invention provides a crack-resistant and quick-drying interior wall repair coating, which is made from the following raw material components: 50-58 parts by weight of β-hemihydrate gypsum; 12-15 parts by weight of sulfoaluminate cement; 18-22 parts by weight of heavy calcium carbonate powder; 4-5 parts by weight of redispersible latex powder; 0.5 parts by weight of composite fiber; 0.8 parts by weight of magnesium oxide expanding agent; 2 parts by weight of nano silica fume; 0.4 parts by weight of organosilicon water-repellent agent; 0.08-0.12 parts by weight of composite retarder; 0.3 parts by weight of polycarboxylate superplasticizer; and 0.5 parts by weight of fumed silica.

[0043] Furthermore, the composite fiber is composed of polypropylene fibers with a diameter of 3 mm and glass fibers with a diameter of 50 μm, wherein the weight ratio of polypropylene fibers to glass fibers is 2:1.

[0044] Furthermore, the composite retarder is made of tartaric acid and borax, with a weight ratio of tartaric acid to borax of 3:1, and the mixing reaction time is controlled at 18-20 min.

[0045] Furthermore, the redispersible latex powder is a vinyl acetate / ethylene copolymer.

[0046] Furthermore, the specific surface area of ​​the β-hemihydrate gypsum is ≥400 m². 2 / kg, the specific surface area of ​​the nano-silica fume is ≥150000m² 2 / kg.

[0047] Secondly, the present invention provides a method for preparing the crack-resistant and quick-drying interior wall repair coating described in the first aspect, specifically comprising the following steps:

[0048] 1) Composite fiber pretreatment: First, mix polypropylene fiber, glass fiber and heavy calcium carbonate powder evenly;

[0049] 2) Main mixing: Mix the pretreated components from step 1) with other raw material components and stir for 25 minutes at 35 rpm in a double helical conical mixer;

[0050] 3) Sieving: After passing through a 325-mesh vibrating sieve, the repair coating is made.

[0051] Example 1

[0052] This invention provides a crack-resistant, fast-drying interior wall repair coating, made from the following raw materials: 50-58 parts by weight of β-hemihydrate gypsum; 12-15 parts by weight of sulfoaluminate cement; 18-22 parts by weight of heavy calcium carbonate powder; 4-5 parts by weight of redispersible latex powder; 0.5 parts by weight of composite fiber; 0.8 parts by weight of magnesium oxide expanding agent; 2 parts by weight of nano silica fume; 0.4 parts by weight of organosilicon water-repellent agent; 0.08-0.12 parts by weight of composite retarder; 0.3 parts by weight of polycarboxylate superplasticizer; and 0.5 parts by weight of fumed silica.

[0053] Furthermore, the composite fiber is composed of polypropylene fibers with a diameter of 3 mm and glass fibers with a diameter of 50 μm, wherein the weight ratio of polypropylene fibers to glass fibers is 2:1.

[0054] Furthermore, the composite retarder is made of tartaric acid and borax, with a weight ratio of tartaric acid to borax of 3:1 and a mixing reaction time of 18-20 min.

[0055] Furthermore, the redispersible latex powder is a vinyl acetate / ethylene copolymer.

[0056] Furthermore, the specific surface area of ​​the β-hemihydrate gypsum is ≥400 m². 2 / kg, the specific surface area of ​​the nano-silica fume is ≥150000m² 2 / kg.

[0057] The preparation method of the above-mentioned crack-resistant and quick-drying interior wall repair coating specifically includes the following steps:

[0058] 1) Composite fiber pretreatment: First, mix polypropylene fiber, glass fiber and heavy calcium carbonate powder evenly;

[0059] 2) Main mixing: Mix the pretreated components from step 1) with other raw material components and stir for 25 minutes at 35 rpm in a double helical conical mixer;

[0060] 3) Sieving: After passing through a 325-mesh vibrating sieve, the repair coating is made.

[0061] Example 2

[0062] This invention provides a crack-resistant, quick-drying interior wall repair coating, made from the following raw materials: 50 parts by weight of β-hemihydrate gypsum; 12 parts by weight of sulfoaluminate cement; 18 parts by weight of heavy calcium carbonate powder; 4 parts by weight of redispersible latex powder; 0.5 parts by weight of composite fiber; 0.8 parts by weight of magnesium oxide expanding agent; 2 parts by weight of nano silica fume; 0.4 parts by weight of organosilicon water-repellent agent; 0.08 parts by weight of composite retarder; 0.3 parts by weight of polycarboxylate superplasticizer; and 0.5 parts by weight of fumed silica.

[0063] Furthermore, the composite fiber is composed of polypropylene fibers with a diameter of 3 mm and alkali-resistant glass fibers with a diameter of 50 μm, wherein the weight ratio of polypropylene fibers to glass fibers is 2:1.

[0064] Furthermore, the composite retarder is made of tartaric acid and borax, with a weight ratio of tartaric acid to borax of 3:1, and the mixing reaction time is controlled at 18-20 min.

[0065] Furthermore, the redispersible latex powder is a vinyl acetate / ethylene copolymer.

[0066] Furthermore, the specific surface area of ​​the β-hemihydrate gypsum is ≥400 m². 2 / kg, the specific surface area of ​​the nano-silica fume is ≥150000m² 2 / kg.

[0067] The above raw materials are prepared into a crack-resistant, fast-drying interior wall repair coating. The specific preparation method includes the following steps:

[0068] 1) Composite fiber pretreatment: First, mix polypropylene fiber, glass fiber and heavy calcium carbonate powder evenly;

[0069] 2) Main mixing: Mix the pretreated components from step 1) with other raw material components and stir for 25 minutes at 35 rpm in a double helical conical mixer;

[0070] 3) Sieving: After passing through a 325-mesh vibrating sieve, the repair coating is made.

[0071] Example 3

[0072] This invention provides a crack-resistant, fast-drying interior wall repair coating, made from the following raw materials: 55 parts by weight of β-hemihydrate gypsum; 13 parts by weight of sulfoaluminate cement; 20 parts by weight of heavy calcium carbonate powder; 4.6 parts by weight of redispersible latex powder; 0.5 parts by weight of composite fiber; 0.8 parts by weight of magnesium oxide expanding agent; 2 parts by weight of nano silica fume; 0.4 parts by weight of organosilicon water-repellent agent; 0.1 parts by weight of composite retarder; 0.3 parts by weight of polycarboxylate superplasticizer; and 0.5 parts by weight of fumed silica.

[0073] The composite fiber is composed of polypropylene fibers with a diameter of 3 mm and glass fibers with a diameter of 50 μm, and the weight ratio of polypropylene fibers to glass fibers is 2:1.

[0074] The composite retarder is made of tartaric acid and borax, with a weight ratio of tartaric acid to borax of 3:1, and the mixing reaction time is controlled at 18-20 min.

[0075] The redispersible latex powder is a vinyl acetate / ethylene copolymer.

[0076] The specific surface area of ​​the β-hemihydrate gypsum is ≥400m². 2 / kg, the specific surface area of ​​the nano-silica fume is ≥150000m² 2 / kg.

[0077] The above raw materials are prepared into a crack-resistant, fast-drying interior wall repair coating. The specific preparation method includes the following steps:

[0078] 1) Composite fiber pretreatment: First, mix polypropylene fiber, glass fiber and heavy calcium carbonate powder evenly;

[0079] 2) Main mixing: Mix the pretreated components from step 1) with other raw material components and stir for 25 minutes at 35 rpm in a double helix conical mixer;

[0080] 3) Sieving: After passing through a 325-mesh vibrating sieve, the repair coating is made.

[0081] Example 4

[0082] This invention provides a crack-resistant, fast-drying interior wall repair coating, made from the following raw materials: 58 parts by weight of β-hemihydrate gypsum; 15 parts by weight of sulfoaluminate cement; 22 parts by weight of heavy calcium carbonate powder; 5 parts by weight of redispersible latex powder; 0.5 parts by weight of composite fiber; 0.8 parts by weight of magnesium oxide expanding agent; 2 parts by weight of nano silica fume; 0.4 parts by weight of organosilicon water-repellent agent; 0.12 parts by weight of composite retarder; 0.3 parts by weight of polycarboxylate superplasticizer; and 0.5 parts by weight of fumed silica.

[0083] Furthermore, the composite fiber is composed of polypropylene fibers with a diameter of 3 mm and glass fibers with a diameter of 50 μm, wherein the weight ratio of polypropylene fibers to glass fibers is 2:1.

[0084] Furthermore, the composite retarder is made of tartaric acid and borax, with a weight ratio of tartaric acid to borax of 3:1, and the mixing reaction time is controlled at 18-20 min.

[0085] Furthermore, the redispersible latex powder is a vinyl acetate / ethylene copolymer.

[0086] Furthermore, the specific surface area of ​​the β-hemihydrate gypsum is ≥400 m². 2 / kg, the specific surface area of ​​the nano-silica fume is ≥150000m² 2 / kg.

[0087] The above raw materials are prepared into a crack-resistant, fast-drying interior wall repair coating. The specific preparation method includes the following steps:

[0088] 1) Composite fiber pretreatment: First, mix polypropylene fiber, glass fiber and heavy calcium carbonate powder evenly;

[0089] 2) Main mixing: Mix the pretreated components from step 1) with other raw material components and stir for 25 minutes at 35 rpm in a double helix conical mixer;

[0090] 3) Sieving: After passing through a 325-mesh vibrating sieve, the repair coating is made.

[0091] Example 5

[0092] This invention provides the application of the crack-resistant, quick-drying interior wall repair coatings prepared in Examples 1-4 above for wall repair. The specific application includes the following steps:

[0093] S1 Base surface treatment: Remove the hollow layer on the wall surface and apply epoxy interface agent;

[0094] S2 Repair Coating Scraping: The crack-resistant and fast-drying interior wall repair coatings prepared in Examples 1-4 were applied to different interior wall surfaces. The repair coatings were scraped at an ambient temperature of 15-35℃, with a scraping thickness of 3-13mm.

[0095] S3 hardening control: After 20-30 minutes, polish with 240-grit sandpaper until the surface roughness Ra≤12μm;

[0096] S4 Coating: 60 minutes after step S3 is completed, apply water-based epoxy primer by roller, and wait another two hours before applying the topcoat.

[0097] In step S1, the epoxy interface agent is a two-component epoxy interface agent, with the ratio of component A to component B being 3:1.

[0098] In step S1, the solid content of the water-based epoxy sealing primer applied by roller is ≥45%.

[0099] In addition, traditional plaster was used to repair the walls in other selected areas, while unrepaired areas were left for comparative testing.

[0100] Example 6

[0101] For effect testing, actual tests were conducted on different wall areas that had been repaired in Example 5. The test results are as follows:

[0102] Crack resistance test: On different repair areas of the wall, after being exposed to hot air at 50°C for 24 hours, the walls repaired with the crack-resistant and quick-drying indoor wall repair coatings prepared in Examples 1-4 showed no cracks, while the walls repaired with traditional gypsum produced cracks.

[0103] Quick-drying test: The test method of JC / T 1025 standard was used for testing. The walls repaired by the crack-resistant quick-drying indoor wall repair coatings prepared in Examples 1-4 reached the condition of being sandable after 20-30 minutes of final setting, and reached the condition of being able to apply primer after 60 minutes of sanding. The gypsum repaired walls in the control area reached the condition of being able to apply primer after 24 hours.

[0104] Water resistance test: The anti-cracking and quick-drying indoor wall repair coatings prepared in Examples 1-4 showed an efflorescence inhibition area of ​​>95% on the repaired walls, and no powdering area was observed in the 7-day saturated Ca(OH)2 immersion test; while the gypsum-repaired walls showed an efflorescence area of ​​>28%, and powdering area was observed in the 7-day saturated Ca(OH)2 immersion test.

[0105] Topcoat compatibility test: Compared with the unrepaired area, the difference in 60° gloss of the wall surface repaired by the crack-resistant and fast-drying interior wall repair coatings prepared in Examples 1-4 is ≤3%.

Claims

1. A crack-resistant, quick-drying interior wall repair coating, characterized in that, Made from the following raw material components: 50-58 parts by weight of β-hemihydrate gypsum; 12-15 parts by weight of sulfoaluminate cement; 18-22 parts by weight of heavy calcium carbonate powder; 4-5 parts by weight of redispersible latex powder; 0.5 parts by weight of composite fiber; 0.8 parts by weight of magnesium oxide expanding agent; 2 parts by weight of nano silica fume; 0.4 parts by weight of organosilicon water-repellent agent; 0.08-0.12 parts by weight of composite retarder; 0.3 parts by weight of polycarboxylate superplasticizer; 0.5 parts by weight of fumed silica.

2. The crack-resistant, quick-drying interior wall repair coating according to claim 1, characterized in that, The composite fiber is composed of polypropylene fibers with a diameter of 3 mm and glass fibers with a diameter of 50 μm, and the weight ratio of polypropylene fibers to glass fibers is 2:

1.

3. The crack-resistant, quick-drying interior wall repair coating according to claim 2, characterized in that, The composite retarder is made of tartaric acid and borax, with a weight ratio of tartaric acid to borax of 3:

1.

4. The crack-resistant, quick-drying interior wall repair coating according to claim 2, characterized in that, The redispersible latex powder is a vinyl acetate / ethylene copolymer.

5. The crack-resistant, quick-drying interior wall repair coating according to claim 2, characterized in that, The specific surface area of ​​the β-hemihydrate gypsum is ≥400m². 2 / kg, the specific surface area of ​​the nano-silica fume is ≥150000m² 2 / kg.

6. A method for preparing a crack-resistant, quick-drying interior wall repair coating according to any one of claims 2 to 5, characterized in that, The preparation method specifically includes the following steps: 1) Composite fiber pretreatment: First, mix polypropylene fiber, glass fiber and heavy calcium carbonate powder evenly; 2) Main mixing: Mix the pretreated components from step 1) with other raw material components and stir for 25 minutes at 35 rpm in a double helix conical mixer; 3) Sieving: After passing through a 325-mesh vibrating sieve, the repair coating is made.

7. The application method of the repair coating prepared according to the method for preparing a crack-resistant and quick-drying interior wall repair coating as described in claim 6, characterized in that, Includes the following steps: S1 Base surface treatment: Remove the hollow layer on the wall surface and apply epoxy interface agent; S2 Repair Coating Application: Apply this repair coating by scraping at an ambient temperature of 15-35℃, with a thickness of 3-13mm. S3 Hardening Control: 20-30 minutes after step S2 is completed, polish the surface with 240-grit sandpaper until the surface roughness Ra≤12μm; S4 Coating: 60 minutes after step S3 is completed, apply water-based epoxy primer by roller, and wait another two hours before applying the topcoat.

8. The construction method of the crack-resistant and quick-drying interior wall repair coating according to claim 7, characterized in that, In step S1, the epoxy interface agent is a two-component epoxy interface agent, with the ratio of component A to component B being 3:

1.

9. The construction method of the crack-resistant and quick-drying interior wall repair coating according to claim 7, characterized in that, In step S4, the solid content of the water-based epoxy sealing primer applied by roller is ≥45%.