Low-dust high-strength gypsum-based putty and preparation method thereof

Abstract

The present application relates to a kind of low-dust high-strength gypsum-based putty and its preparation method, it includes the following weight parts components: beta-desulfurization gypsum powder, white sand, calcium powder, composite dust control component, glue powder, water retaining agent, auxiliary agent;The composite dust control component includes: polyether, alkyl sulfate, alkaline inorganic;Wherein the weight ratio of polyether, alkyl sulfate, alkaline inorganic is: polyether:alkyl sulfate:alkaline inorganic=1~3:2~5:5~8;The polyether is polyethylene oxide;The alkyl sulfate is dodecyl sulfate;The alkaline inorganic is calcium hydroxide.The present application solves the environmental impact of large dust in the construction site of gypsum-based putty, and solves the engineering quality problems such as cracking, low strength, powder falling, etc.

Description

Technical Field

[0001] This invention relates to the field of gypsum-based mixed mortar technology, and in particular to a low-dust, high-strength gypsum-based putty and its preparation method. Background Technology

[0002] The current market demands increasingly stringent requirements for construction site environmental management and construction product quality management. Gypsum-based putty is a widely used leveling material for interior walls, and its quality directly impacts the construction site environment and construction quality. However, existing gypsum-based putty commonly suffers from problems such as dust generation during mixing, cracking after application, low strength, and powdering, all of which seriously affect project quality. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a low-dust, high-strength gypsum-based putty and its preparation method, thereby solving the environmental impact of high dust levels on construction sites caused by gypsum-based putty, as well as engineering quality problems such as cracking, low strength, and powdering during construction.

[0004] To solve the above problems, the present invention is achieved through the following technical solution:

[0005] The first objective of this invention is:

[0006] A low-dust, high-strength gypsum-based putty is provided, comprising the following components in parts by weight:

[0007] 280–600 parts β-desulfurized gypsum powder, 120–300 parts ordinary white sand, 100–400 parts calcium powder,

[0008] The composite dust-suppressing component consists of 5-30 parts, the adhesive powder consists of 5-30 parts, the water-retaining agent consists of 1-4 parts, and the additives consist of 2-5 parts.

[0009] The composite dust-suppressing components include: polyether, alkyl sulfate, and alkaline inorganic substances;

[0010] The weight ratio of the polyether, alkyl sulfate, and basic inorganic substance is as follows:

[0011] Polyether:alkyl sulfate:basic inorganic compound = 1-3:2-5:5-8;

[0012] The polyether is polyethylene oxide (PEO);

[0013] The alkyl sulfate mentioned is dodecyl sulfate;

[0014] The alkaline inorganic substance mentioned is calcium hydroxide (Ca(OH)2).

[0015] A preferred embodiment of the low-dust, high-strength gypsum-based putty of the present invention is as follows:

[0016] The aforementioned low-dust, high-strength gypsum-based putty comprises the following components in parts by weight:

[0017] 400-500 parts of β-desulfurized gypsum powder, 180-240 parts of ordinary white sand, 200-400 parts of calcium powder, 10-20 parts of composite dust suppressant, 8-18 parts of adhesive powder, 2-3 parts of water-retaining agent, and 3-4 parts of additives.

[0018] The composite dust-suppressing components include: polyether, alkyl sulfate, and alkaline inorganic substances;

[0019] The weight ratio of the polyether, alkyl sulfate, and basic inorganic substance is as follows:

[0020] Polyether:alkyl sulfate:basic inorganic compound = 1-3:2-5:5-8;

[0021] The polyether is polyethylene oxide (PEO);

[0022] The alkyl sulfate mentioned is dodecyl sulfate;

[0023] The alkaline inorganic substance mentioned is calcium hydroxide (Ca(OH)2).

[0024] The low-dust, high-strength gypsum-based putty of the present invention is further optimized as follows:

[0025] The percentage of the composite dust-suppressing component in the total weight of the low-dust, high-strength gypsum-based putty shall not exceed 3%.

[0026] The low-dust, high-strength gypsum-based putty of the present invention is further optimized as follows:

[0027] The polyether is polyethylene oxide (PEO) with a relative molecular mass of 10. 5 ~10 7 Between; and / or

[0028] The alkyl sulfate is one or a combination of sodium dodecyl sulfate, potassium dodecyl sulfate, and ammonium dodecyl sulfate; and / or

[0029] The β-desulfurized gypsum powder comprises the following components by weight percentage:

[0030] The content of soluble anhydrous gypsum AⅢ is less than 5%, the content of hemihydrate gypsum HH is more than 85%, the residual dihydrate gypsum DH is less than 4%, the attached water should be <1%, and the rest are impurities.

[0031] The purity of β-desulfurized gypsum powder should be >90%; (purity refers to the CaSO4 content in β-desulfurized gypsum powder)

[0032] The initial setting time should be between 4 and 30 minutes, and the final setting time should be between 5 and 30 minutes.

[0033] The flexural strength should be >3 MPa, and the compressive strength should be >6 MPa; and / or

[0034] The adhesive powder is a redispersible latex powder based on vinyl acetate and ethylene copolymer; and / or

[0035] The viscosity of the water-retaining agent should be between 60,000 and 80,000 mPa·s; and / or

[0036] The additives include protein-based high-efficiency gypsum retarder; and / or

[0037] The sieve residue of the aforementioned ordinary white sand is strictly controlled so that the percentage of stone powder content is less than 2%.

[0038] The second objective of this invention is:

[0039] A method for preparing the aforementioned low-dust, high-strength gypsum-based putty is provided:

[0040] β-desulfurized gypsum powder, ordinary white sand, calcium powder, composite dust suppressant, adhesive powder, water retainer and additives are added to a dry powder mixer in a certain proportion and mixed evenly to prepare low dust and high strength gypsum-based putty.

[0041] The composite dust suppression component mentioned above includes the following preparation steps:

[0042] S1. Put the alkaline inorganic material into a dry powder mixing mixer at a temperature of 23±2℃ and a relative humidity of 90%, start the machine for pretreatment for 400 seconds to allow a certain amount of water to be adsorbed on its surface.

[0043] S2. Add the alkyl sulfate to the mixer and mix for 400 seconds to allow the hydrophilic groups in the alkyl sulfate to adsorb onto the water adsorbed on the surface of the alkaline inorganic material. Then add the polyether and mix for 400 seconds to allow it to adsorb onto the head groups of the alkyl sulfate.

[0044] S3. Place the above-mixed components into a 60℃ constant temperature drying oven and dry until the moisture content by mass percentage is ≤1% to prepare the composite dust suppression component.

[0045] The low-dust, high-strength gypsum-based putty prepared by this invention produces less dust when mixed with water and exhibits excellent workability after mixing. Furthermore, this invention meets the limits for hazardous substances in putty within the hazardous substances content of base coat plaster type B in GB / T 28627-2012 and GB18582-2020 standards for hazardous substances in wall coatings for building construction.

[0046] This invention has significant implications for construction site environmental management and the protection of construction workers, and it also solves problems such as cracking and low strength that are prone to occur during construction. Detailed Implementation

[0047] To make the application, technical solution, and advantages of this invention clearer, the invention is described in detail with reference to specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. Any simple modifications to the preparation method of this invention based on the inventive concept are within the scope of protection of this invention.

[0048] Example 1

[0049] A method for preparing low-dust, high-strength gypsum-based putty:

[0050] β-desulfurized gypsum powder, ordinary white sand, calcium powder, composite dust suppressant, adhesive powder, water retainer and additives are added to a dry powder mixer in a certain proportion and mixed evenly to prepare low dust and high strength gypsum-based putty.

[0051] The composite dust suppression component mentioned above includes the following preparation steps:

[0052] S1. Put the alkaline inorganic material into a dry powder mixing mixer at a temperature of 23±2℃ and a relative humidity of 90%, start the machine for pretreatment for 400 seconds to allow a certain amount of water to be adsorbed on its surface.

[0053] S2. Add the alkyl sulfate to the mixer and mix for 400 seconds to allow the hydrophilic groups in the alkyl sulfate to adsorb onto the water adsorbed on the surface of the alkaline inorganic substance (Ca(OH)2). Then add the polyether [polyethylene oxide (PEO)] and mix for 400 seconds to allow it to adsorb onto the head groups of the alkyl sulfate.

[0054] S3. Place the above-mixed components into a 60℃ constant temperature drying oven and dry until the moisture content by mass percentage is ≤1% to prepare the composite dust suppression component.

[0055] Its specific composition is detailed in the table below (parts by weight):

[0056]

[0057] In experimental groups 1 through 3, the alkyl sulfate was sodium dodecyl sulfate.

[0058] In experimental groups 4 to 6, the alkyl sulfate was potassium dodecyl sulfate.

[0059] Dust concentration test: The test was conducted using the Beidouxing portable dust concentration detector HBD5SPM4210-DS-A03.

[0060] Standard tensile bond strength test: The test shall be conducted according to Type B of GB / T 28627-2012.

[0061] Flexural / compressive strength test: The test shall be conducted according to Type B of GB / T 28627-2012.

[0062] The test results of the examples are shown in the table below:

[0063] 1# 2.85 0.85 2.82 5.91 2# 2.69 0.83 2.88 6.11 3# 2.42 0.87 2.96 5.98 4# 2.84 0.91 2.78 5.68 5# 2.79 0.88 2.71 5.82 6# 2.65 0.80 2.73 5.78

[0064] Comparative Examples 1-3 are set below, and their preparation methods are the same as those of the Examples, except that the composite dust-suppressing component in the Examples is not used.

[0065] Its specific composition is detailed in the table below (parts by weight):

[0066] β-Desulfurized Gypsum Powder 450 450 450 Ordinary white sand 200 200 200 Calcium powder 323.5 323.5 323.5 Sodium dodecyl sulfate 15 10 5 Polyethylene / 5 5 <![CDATA[Ca(OH)2]]> / / 5 glue powder 6 6 6 Water-retaining agent 2.5 2.5 2.5 Additives 3 3 3

[0067] The test results for the comparative model are shown in the table below:

[0068] 1# 80.21 0.52 2.06 4.15 2# 78.95 0.47 2.15 4.21 3# 75.54 0.49 2.23 4.26

[0069] Comparative analysis revealed that the low-dust, high-strength gypsum-based putty provided by this invention has a much lower dust concentration during mixing than conventional gypsum-based putty, resulting in significant improvements in worker protection and the construction site environment.

[0070] In summary, the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any changes, modifications, and evolutions made by those skilled in the art without departing from the scope of the present invention based on the disclosed technical content shall be considered equivalent embodiments of the present invention. Furthermore, any changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention shall still fall within the protection scope of the present invention.

[0071] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0072] Experimental methods not specified in this invention are generally performed under conventional conditions or as recommended by the manufacturer.

[0073] Unless otherwise stated, the various optimized technical solutions in this invention can be combined with each other.

[0074] Unless otherwise stated, percentages and parts are weight percentages and weight parts.

[0075] Experimental methods not specified in the instructions and examples are generally performed under standard conditions or as recommended by the manufacturer.

[0076] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as are familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be used in the methods of this invention.

Claims

1. A low-dust, high-strength gypsum-based putty, characterized in that: It comprises the following components in parts by weight: 280–600 parts β-desulfurized gypsum powder, 120–300 parts ordinary white sand, 100–400 parts calcium powder, The composite dust-suppressing component consists of 5-30 parts, the adhesive powder consists of 5-30 parts, the water-retaining agent consists of 1-4 parts, and the additives consist of 2-5 parts. The composite dust-suppressing components include: polyether, alkyl sulfate, and alkaline inorganic substances; The weight ratio of the polyether, alkyl sulfate, and basic inorganic substance is as follows: Polyether:alkyl sulfate:basic inorganic compound = 1-3:2-5:5-8; The polyether is polyethylene oxide; The alkyl sulfate mentioned is dodecyl sulfate; The alkaline inorganic substance mentioned is calcium hydroxide; The composite dust suppression component mentioned above includes the following preparation steps: S1. Put the alkaline inorganic material into a dry powder mixing mixer at a temperature of 23±2℃ and a relative humidity of 90%, start the machine for pretreatment for 400 seconds to allow a certain amount of water to be adsorbed on its surface. S2. Add the alkyl sulfate to the mixer and mix for 400 seconds to allow the hydrophilic groups of the alkyl sulfate to adsorb onto the water adsorbed on the surface of the alkaline inorganic material. Then add the polyether and mix for 400 seconds to allow it to adsorb onto the head groups of the alkyl sulfate. S3. Place the above-mixed components into a 60℃ constant temperature drying oven and dry until the moisture content by mass percentage is ≤1% to prepare the composite dust suppression component.

2. The low-dust, high-strength gypsum-based putty according to claim 1, characterized in that: It comprises the following components in parts by weight: 400-500 parts of β-desulfurized gypsum powder, 180-240 parts of ordinary white sand, 200-400 parts of calcium powder, 10-20 parts of composite dust suppressant, 8-18 parts of adhesive powder, 2-3 parts of water-retaining agent, and 3-4 parts of additives. The composite dust-suppressing components include: polyether, alkyl sulfate, and alkaline inorganic substances; The weight ratio of the polyether, alkyl sulfate, and basic inorganic substance is as follows: Polyether:alkyl sulfate:basic inorganic compound = 1-3:2-5:5-8; The polyether is polyethylene oxide; The alkyl sulfate mentioned is dodecyl sulfate; The alkaline inorganic substance mentioned is calcium hydroxide.

3. The low-dust, high-strength gypsum-based putty according to claim 1, characterized in that: The percentage of the composite dust-suppressing component in the total weight of the low-dust, high-strength gypsum-based putty shall not exceed 3%.

4. The low-dust, high-strength gypsum-based putty according to claim 1, characterized in that: The polyether is polyethylene oxide with a relative molecular mass of 10. 5 ~10 7 Between; and / or The alkyl sulfate is one or a combination of sodium dodecyl sulfate, potassium dodecyl sulfate, and ammonium dodecyl sulfate; and / or The β-desulfurized gypsum powder comprises the following components by weight percentage: The content of soluble anhydrous gypsum AⅢ is less than 5%, the content of hemihydrate gypsum HH is more than 85%, the residual dihydrate gypsum DH is less than 4%, the attached water should be less than 1%, and the rest is impurities. The purity of β-desulfurized gypsum powder should be >90%; The initial setting time should be between 4 and 30 minutes, and the final setting time should be between 5 and 30 minutes. The flexural strength should be >3 MPa, and the compressive strength should be >6 MPa; and / or The adhesive powder is a redispersible latex powder based on vinyl acetate and ethylene copolymer; and / or The viscosity of the water-retaining agent should be between 60,000 and 80,000 mPa·s; and / or The aforementioned additive is a protein-based high-efficiency gypsum retarder; and / or The sieve residue of the aforementioned ordinary white sand is strictly controlled so that the percentage of stone powder content is less than 2%.

5. A method for preparing the low-dust, high-strength gypsum-based putty according to claim 1, characterized in that: β-desulfurized gypsum powder, ordinary white sand, calcium powder, composite dust suppressant, adhesive powder, water-retaining agent, and additives are added to a dry powder mixer in a certain proportion and mixed evenly to prepare low-dust, high-strength gypsum-based putty.

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