Workshop repairing putty

Abstract

The invention provides workshop repairing putty which comprises white latex, bamboo powder and 35-45 wt% of modified white latex, and the white latex comprises PVAc emulsion and 1-5% of nano SiO2; the surface modified bamboo powder is treated by a silane coupling agent, and the water content of the surface modified bamboo powder is less than or equal to 3%; 15-25 wt% of an inorganic filler comprising a compound system of heavy calcium powder and talcum powder; the preparation method comprises the following steps: uniformly stirring the raw materials in a stirring bin, putting the raw materials into a storage tank body, storing and sealing the raw materials through the storage tank body, and extruding the raw materials through an extrusion piece in the storage tank body when in use; according to the invention, the VOC emission problem of the existing traditional solvent type putty and the defect that wood flour is easy to mildew can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of workshop putty production, in particular to a workshop repair putty. Background Art

[0002] The existing workshop repair putty in the prior art is prepared by mixing and stirring PU paint, talcum powder and colorant (for facilitating the repair of bamboo defects). Since there is no document for the putty preparation materials, there is a color difference between the repaired color and the bamboo.

[0003] Traditional workshop repair putties mostly adopt solvent-based epoxy resin or nitrocellulose systems, which have the following defects: Solvent-based putties contain high VOC, which is harmful to the health of workers; The existing wood powder-based putties do not solve the problems of easy water absorption and poor dispersibility of bamboo powder, resulting in easy cracking and low adhesion of the putties; Traditional putties lack comprehensive properties such as crack resistance and water resistance. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to provide a workshop repair putty that can solve the VOC emission problem of existing traditional solvent-based putties and the defect of easy mildew of wood powder.

[0005] The present invention is achieved by the following method: A workshop repair putty, comprising white emulsion and bamboo powder, 35-45 wt% of modified white emulsion, the white emulsion comprising PVAc emulsion and 1-5% nano-SiO 2 ; 25-35 wt% of surface-modified bamboo powder, which is treated with a silane coupling agent and has a water content ≤ 3%; 15-25 wt% of inorganic fillers, comprising a compound system of heavy calcium powder and talcum powder; 0.5-1.5 wt% of functional additives, and then stirred evenly in a stirring bin, put into a storage tank body, stored and sealed through the storage tank body, and extruded through an extrusion part in the storage tank body during use.

[0006] Further, the modified white emulsion is an environment-friendly white emulsion with polyvinyl formal as the main body, and 5-10% of nano-SiO 2 .

[0007] Further, the modified bamboo powder is prepared by treating bamboo powder with 2% NaOH solution.

[0008] Further, the storage tank body includes a tank body with an open upper surface. A gantry is erected at the left and right ends of the upper surface of the tank body. Strip-shaped grooves are formed on the inner sides of the two vertical plates of the gantry. A synchronous motor is arranged in the strip-shaped groove. The output end of the synchronous motor is connected with a screw rod. A lifting block is spirally sleeved on the screw rod. A switchable cover for opening and closing the tank body is erected between the lifting blocks at the left and right ends. A sealing ring is arranged on the lower surface of the switchable cover. A first multi-stage telescopic cylinder is embedded in the middle of the upper part of the switchable cover. The end of the telescopic rod of the first multi-stage telescopic cylinder is provided with a pressing plate. Rubber scraping plates are arranged on the left and right sides of the pressing plate. The middle part of the lower surface of the tank body is connected with a discharge pipe. A second multi-stage telescopic cylinder is embedded in the right end of the discharge pipe. The end of the telescopic rod of the second multi-stage telescopic cylinder is provided with a switchable plate for opening and closing the discharge pipe.

[0009] The beneficial effects of the present invention are as follows: The present invention adopts an aqueous white emulsion system with a VOC content < 5 g / L (120 - 150 g / L for traditional nitro putty), meeting the environmental protection standard of GB 30982-2020 "Limit of Hazardous Substances in Wall Coatings for Building Use"; it avoids the use of formaldehyde-based adhesives; bamboo powder replaces 30% of inorganic fillers (the proportion of calcium carbonate in the traditional formula exceeds 50%), reducing the consumption of non-renewable resources; the renewable characteristics of bamboo reduce carbon emissions (the production energy consumption is reduced by 40% compared with calcium carbonate powder); after the bamboo powder is modified by alkali treatment + silane coupling agent, the interfacial bonding force between the fiber and the white emulsion is enhanced, and the three-stage particle size filler system (bamboo powder 45μm / calcium carbonate 15μm / talc 5μm) achieves a porosity < 8%; it is stored in a tank and is not prone to excessive drying and has a long persistence. The strength of the putty after formulation can meet the requirements, and small batches have been tested and qualified; the water absorption rate ≤ 2.5% (5.6% for traditional white emulsion putty), suitable for humid workshop environments; after adding 0.5% of mold inhibitor, there is no mildew through the 28-day damp heat test (40°C / 95%RH). Description of the Drawings

[0010] Figure 1 It is a schematic structural diagram of the first state of the storage tank body.

[0011] Figure 2 It is a schematic structural diagram of the second state of the storage tank body. Detailed Embodiments

[0012] The present invention will be further described below with reference to the drawings.

[0013] Embodiment: Modified white emulsion (PVAc + 8% nano-SiO 2 ): 40 parts adopt an aqueous white emulsion system with a VOC emission lower than 5 g / L, superior to solvent-based epoxy putty;

[0014] - Bamboo powder treated with silane coupling agent (80 - 120 mesh, water content ≤ 3%): 30 parts

[0015] - Heavy calcium powder (800 mesh): 18 parts

[0016] - Talc powder (1250 mesh): 10 parts

[0017] - Fumed silica (thixotropic agent): 1 part

[0018] - Organosilicon defoamer: 0.2 part.

[0019] Alkali treatment: Soak bamboo powder in 2% NaOH solution for 2 hours, wash with water until neutral, dry. Alkali treatment + silane coupling agent modification significantly improves the interfacial bonding strength of fibers and reduces the water absorption rate; Hydrophobic modification: Spray the surface of bamboo powder with KH-550 silane coupling agent ethanol solution (concentration 5%), and dry at 80 °C. Disperse nano-SiO 2 in PVAc emulsion, and add 1% calcium carbonate to adjust the pH to 8.5.

[0020] Premixing: Stir the modified white latex and dibutyl phthalate (plasticizer) at 50 °C for 5 minutes;

[0021] Gradient feeding: Add bamboo powder and heavy calcium powder in sequence (disperse at high speed of 1200 rpm for 5 minutes), then add talc powder and additives (homogenize at low speed of 400 rpm for 10 minutes); Dense packing is achieved for bamboo powder (45 μm), heavy calcium (15 μm), and talc powder (5 μm), and the compressive strength is increased by 90% compared with the traditional formula;

[0022] Vacuum degassing: Treat at a vacuum degree of 0.08 MPa for 15 minutes, then fill and seal.

[0023] It can be proved by experimental data. Please refer to the following table:

[0024] Dimension This patent White emulsion + calcium carbonate Bamboo charcoal putty Core material Modified bamboo powder + white emulsion Unmodified bamboo powder Bamboo charcoal powder + fine soil Environmental protection Zero formaldehyde, VOC < 5 g / L Risk of formaldehyde-containing glue Environmentally friendly but low in strength Strength Compressive strength of 18.7 MPa 9.8 MPa 7.5 MPa Construction scenario Workshop repair Wood filling Wall repair

[0025] As can be seen from the above table, using the water-based white latex system, the VOC content < 5 g / L (120 - 150 g / L for traditional nitro putty), which meets the environmental protection standard of GB 30982-2020 "Limit of Hazardous Substances in Wall Coatings for Building Use". After the bamboo powder is modified by alkali treatment + silane coupling agent, the interfacial bonding strength between the fiber and the white latex is enhanced (SEM shows that a dense coating layer is formed on the fiber surface). The three-stage particle size filler system (bamboo powder 45 μm / heavy calcium 15 μm / talc 5 μm) achieves a porosity < 8% (the porosity of the traditional formula is 15 - 20%), and the compressive strength is greater than that of the putty in the prior art.

[0026] Please refer to Figure 1 and Figure 2As shown in the figure, the present invention provides an embodiment: The storage tank body 1 includes a tank body 11 with an open upper surface. At the left and right ends of the upper surface of the tank body 11, a gantry 12 is erected. Strip-shaped grooves 13 are formed on the inner sides of the two vertical plates of the gantry 12. A synchronous motor 14 is arranged in the strip-shaped groove 13. The output end of the synchronous motor 14 is connected to a screw rod 15. A lifting block 16 is spirally sleeved on the screw rod 15. A separable cover 17 for opening and closing the tank body 11 is erected between the lifting blocks 16 at the left and right ends. A sealing ring 18 is arranged on the lower surface of the separable cover 17. A first multi-stage telescopic cylinder 19 is embedded in the middle of the upper part of the separable cover 17. The end of the telescopic rod of the first multi-stage telescopic cylinder 19 is provided with a pressing plate 2. Rubber scraping plates 21 are arranged on the left and right sides of the pressing plate 2. The middle part of the lower surface of the tank body 11 is connected to a discharge pipe 22. A second multi-stage telescopic cylinder 23 is embedded in the right end of the discharge pipe 22. The end of the telescopic rod of the second multi-stage telescopic cylinder 23 is provided with a separable plate 24 for opening and closing the discharge pipe 22. After the putty is made, it is placed in the tank body 11. The synchronous motor 14 drives the screw rod 15 to rotate, so that the lifting block 16 moves up and down, and the tank body 11 can be covered and sealed through the separable cover 17. When in use, the first multi-stage telescopic cylinder 19 drives the pressing plate 2 to press downwards, and then the second multi-stage telescopic cylinder 23 can drive the separable plate 24 to move left and right, so as to extrude and use the putty, ensuring the sealing performance and facilitating timely use.

[0027] In the present invention, the multi-stage telescopic cylinder and the synchronous motor are both prior arts, and those skilled in the art have been able to clearly understand them, so no detailed description will be given here.

[0028] The above are only the preferred embodiments of the present invention. All equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope covered by the present invention.

Claims

1. A workshop repair putty, characterized in that: The invention comprises white latex and bamboo powder, 35-45wt% of modified white latex, wherein the white latex comprises PVAc emulsion and 1-5% of nano-SiO2; 25-35wt% of surface modified bamboo powder which is treated with a silane coupling agent and has a water content of ≤3%; 15-25wt% of inorganic filler, comprising a compound system of heavy calcium powder and talcum powder; and 0.5-1.5wt% of functional additives. The mixture is then stirred evenly in a stirring bin, put into a storage tank, stored and sealed in the storage tank, and extruded through an extrusion piece in the storage tank when in use.

2. A workshop repair putty according to claim 1, characterized in that: The modified white latex adopts environmentally friendly white latex with polyvinyl formal as main component and 5-10% of nano-SiO2 is added.

3. A workshop repair putty according to claim 1, characterized in that: The modified bamboo powder is prepared by alkali treating the bamboo powder with a 2% NaOH solution.

4. A workshop repair putty according to claim 1, characterized in that: The storage tank body includes a tank body with an open upper surface, a gantry is mounted on the left and right ends of the upper surface of the tank body, the inner sides of the two vertical plates of the gantry are provided with strip grooves, a synchronous motor is arranged in the strip groove, the output end of the synchronous motor is connected with a screw, a lifting block is arranged on the spiral sleeve of the screw, an openable and closable cover for opening the tank body is mounted between the left and right lifting blocks, a sealing ring is arranged on the lower surface of the openable and closable cover, a first multi-section telescopic cylinder is embedded in the middle part of the openable and closable cover, an extrusion plate is arranged at the end of the telescopic rod of the first multi-section telescopic cylinder, rubber scrapers are arranged on the left and right sides of the extrusion plate, a discharge pipe is connected to the middle part of the lower surface of the tank body, a second multi-section telescopic cylinder is embedded in the right end of the discharge pipe, and an openable and closable plate for opening and closing the discharge pipe is arranged at the end of the telescopic rod of the second multi-section telescopic cylinder.

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