CN116283035A - Powdery air entraining agent for gypsum mortar and synthetic method thereof - Google Patents

Abstract

The invention belongs to the technical field of air-entraining agents, and in particular relates to a powdery air-entraining agent for gypsum mortar and a synthesis method thereof. The components of the powdery air-entraining agent include liquid air-entraining agent, anti-caking agent and anti-sticking agent; the components of the liquid air-entraining agent include foaming agent, stabilizer, dispersion leveling agent, wetting agent , rheology modifier, calcium and magnesium ion complexing agent and water; the powdery air-entraining agent can effectively solve the problem of application in gypsum mortar, and the air-entraining agent can show excellent Foaming performance, strong resistance to hard water, lower surface tension of water, and excellent foam stability, and the foam is fine and not easy to break. When applied to gypsum mortar, it can maintain the same state as the initial mixing mortar for 2 to 3 hours. Consistency in construction, and no irritating smell, in addition, the air-entraining agent has a unique wetting and dispersing ability, which can quickly disperse powder and save mixing time.

Description

A kind of powdery air-entraining agent for gypsum mortar and its synthesis method

technical field

The invention belongs to the technical field of air-entraining agents, and in particular relates to a powdery air-entraining agent for gypsum mortar and a synthesis method thereof.

Background technique

Industrial by-product gypsum refers to the by-product or waste residue mainly composed of calcium sulfate produced by chemical reactions in industrial production, also known as chemical gypsum or industrial waste gypsum, mainly including desulfurization gypsum, phosphogypsum, citrate gypsum, fluorine gypsum, salt Gypsum, monosodium glutamate gypsum, copper gypsum, titanium gypsum, etc. With the development of economy and industry, the output of by-product gypsum is increasing. In addition, the country's strict environmental protection policies and the requirements for carbon neutrality and carbon peaking have also formulated relevant policies for the recycling of gypsum from industrial solid waste. The comprehensive utilization of gypsum and its development in building materials have been paid more and more attention. As an air-hardening cementitious material, gypsum itself is widely used in building materials with the advantages of micro-expansion, sound absorption, and light weight. Among them, plastering and bonding materials mainly composed of gypsum occupy a high proportion in building construction. The plastering gypsum mortar used for leveling the interior walls faces problems such as poor construction, sagging on the wall, sticking trowels and scrapers, and stickiness in the barrel after mixing, which seriously affects the construction efficiency of workers and the efficiency of mechanical spraying. efficiency.

In order to solve the application problem of this kind of gypsum, the conventional technical idea is to add surfactants, introduce air bubbles to reduce the viscosity of gypsum, thereby improving the workability of gypsum mortar. Traditional air-entraining agents on the market rarely have powder and are all Single-component materials, conventional powder air-entraining agents have many problems when applied to gypsum mortar. First, common air-entraining agents have a pungent smell, which has an adverse effect on the human respiratory tract, and workers have a strong unpleasant feeling after use; The second is that the foaming ability is very strong, but the foam stability is poor, and it is easy to cause foam collapse and rupture. When it is stirred in gypsum mortar for a few minutes, the bubbles burst, resulting in internal honeycomb holes in the gypsum mortar, and slag becomes sticky. "Tofu residue" seriously affects the use of gypsum mortar; third, too many air bubbles are introduced, which seriously reduces the strength of gypsum mortar, resulting in engineering quality problems such as pulverization and powder loss of gypsum mortar.

Contents of the invention

In view of the above problems, the object of the present invention is to provide a powdery air-entraining agent for gypsum mortar and its synthesis method.

Technical content of the present invention is as follows:

The invention provides a powdery air-entraining agent for gypsum mortar, the components of the powdery air-entraining agent include a liquid air-entraining agent, an anticaking agent and an antisticking agent;

The components of the liquid air-entraining agent include foaming agent, stabilizer, dispersion leveling agent, wetting agent, rheology modifier, calcium and magnesium ion complexing agent and water;

In terms of mass fraction, in the liquid air-entraining agent, the foaming agent accounts for 20%-35%, the stabilizer accounts for 1%-5%, the dispersing and leveling agent accounts for 1%-5%, and the wetting agent accounts for 2%-5%. 4%, rheology modifiers accounted for 2% to 5%, calcium and magnesium ion complexing agents accounted for 0.5% to 2.0%, and water accounted for 45% to 75%;

Among the powdery air-entraining agents, the liquid air-entraining agent accounts for 90-95%, the anti-caking agent accounts for 2-5%, and the anti-sticking agent accounts for 3-5%;

The foaming agent includes more than one of sodium α-olefin sulfonate, fatty alcohol polyoxyethylene ether (AEO-9), alkyl glucoside (APG), and cocamide propyl ammonium oxide (CAO-30);

The stabilizer includes more than one of guar gum, xanthan gum, Wenlun gum or modified polysaccharide compounds;

The modified polysaccharides include but are not limited to more than one of carboxymethyl cellulose, carboxymethyl starch, carboxymethyl pachyranan, fucoidan, amino-modified cellulose, and amino-modified starch. The modified polysaccharide compound can be a compound obtained by chemical modification, physical modification or graft copolymerization of natural polysaccharides;

The dispersion leveling agent includes more than one of sodium salt dispersant, ammonium salt dispersant, melamine dispersant or naphthalene sulfonate;

The sodium salt dispersant includes but is not limited to polycarboxylate sodium salt dispersant, acrylic acid sodium salt dispersant, etc., and the corresponding sodium salt dispersant can be selected according to actual needs;

The ammonium salt dispersant includes but is not limited to polyacrylic acid ammonium salt dispersant, and the corresponding ammonium salt dispersant can be selected according to actual needs;

Described melamine dispersion agent comprises melamine;

The naphthalenesulfonate includes but is not limited to alkylnaphthalenesulfonate, and the corresponding naphthalenesulfonate dispersant can be selected according to actual needs;

The wetting agent includes more than one of acrylic acid-hydroxypropyl acrylate copolymer, phosphonocarboxylic acid copolymer, and polyoxyalkylene alkyl ethers;

The rheology modifier includes more than one of associative alkali-swellable thickener, lithium magnesium silicate, and modified attapulgite;

The calcium and magnesium ion complexing agent includes more than one of ethylenediaminetetramethylenephosphonic acid EDTMPA, hexamethylenediaminetetramethylenephosphonic acid HDTMPA, and aminotrimethylenephosphonic acid ATMP;

The anti-caking agent includes more than one of heavy calcium carbonate, talcum powder, and metakaolin;

The anti-sticking agent includes more than one of 4A zeolite powder and fumed silica.

The present invention also provides a synthesis process for the powdery air-entraining agent for gypsum mortar, comprising the steps of:

1) Preparation of liquid air-entraining agent: start stirring, add foaming agent, stabilizer, dispersing and leveling agent, wetting agent, rheology modifier, calcium and magnesium ion complexing agent and water in sequence, mix and stir evenly to obtain a liquid air-entraining agent;

2) Preparation of powder air-entraining agent: adding anti-caking agent and anti-sticking agent to the liquid air-entraining agent, carrying out high-temperature spray drying, so that the liquid air-entraining agent is atomized into powder air-entraining agent;

The conditions of the high temperature spray drying are: under the vacuum condition of -0.1～-0.2MPa, the inlet temperature is 150～180°C, the feed rate is 0.3～0.5L/h, and the air intake flow rate is 300～400L/h, The outlet temperature is 70-90°C.

The beneficial effects of the present invention are as follows:

The powdery air-entraining agent for gypsum mortar of the present invention can effectively solve the problem of application in gypsum mortar, the air-entraining agent can exhibit excellent foaming performance under the condition of relatively high calcium ion concentration, and has strong resistance to hard water , reduces the surface tension of water, and exhibits excellent foam stability, and the foam is fine and not easy to break. When applied to gypsum mortar, it can maintain the same state as the initial mixing mortar for 2 to 3 hours to maintain the consistency of construction without stimulation. Non-toxic odor, it will not have adverse effects on workers' production or construction site workers. In addition, the air-entraining agent has a unique wetting and dispersing ability, which can quickly disperse the powder, save mixing time, and evenly disperse. The impact on the strength of gypsum Therefore, the powdery air-entraining agent of the present invention has great promotion and application value, and can exert great value in the application of gypsum mortar.

Description of drawings

Fig. 1 is the SEM scanning picture of the gypsum mortar doped with the air-entraining agent of Example 1.

Detailed ways

The present invention will be described in further detail below through specific examples of implementation and description of the accompanying drawings. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the protection scope of the present invention. After reading the present invention, those skilled in the art Modifications to various equivalent forms of the present invention fall within the scope of the appended claims of this application.

Unless otherwise specified, all raw materials and reagents of the present invention are raw materials and reagents in the conventional market.

The powdery air-entraining agent of the present invention, its component comprises liquid air-entraining agent, anticaking agent and antisticking agent;

The components of the liquid air-entraining agent include foaming agent, stabilizer, dispersion leveling agent, wetting agent, rheology modifier, calcium and magnesium ion complexing agent and water;

In terms of mass fraction, in the liquid air-entraining agent, the foaming agent accounts for 20%-35%, the stabilizer accounts for 1%-5%, the dispersing and leveling agent accounts for 1%-5%, and the wetting agent accounts for 2%-5%. 4%, rheology modifiers accounted for 2% to 5%, calcium and magnesium ion complexing agents accounted for 0.5% to 2.0%, and water accounted for 45% to 75%;

Among the powdery air-entraining agents, the liquid air-entraining agent accounts for 90-95%, the anti-caking agent accounts for 2-5%, and the anti-sticking agent accounts for 3-5%;

The sodium salt dispersant includes but is not limited to polycarboxylate sodium salt dispersant, acrylic acid sodium salt dispersant, etc., and the corresponding sodium salt dispersant can be selected according to actual needs;

The ammonium salt dispersant includes but is not limited to polyacrylic acid ammonium salt dispersant, and the corresponding ammonium salt dispersant can be selected according to actual needs;

Described melamine dispersion agent comprises melamine;

The naphthalenesulfonate includes but is not limited to alkylnaphthalenesulfonate, and the corresponding naphthalenesulfonate dispersant can be selected according to actual needs;

The modified polysaccharides include but are not limited to more than one of carboxymethyl cellulose, carboxymethyl starch, carboxymethyl pachyranan, fucoidan, amino-modified cellulose, and amino-modified starch. The modified polysaccharide compound can be a compound obtained by chemical modification, physical modification or graft copolymerization of natural polysaccharides;

The specific raw materials of the associative alkali-swellable thickener are not limited, and can be selected according to actual needs.

Example 1

A kind of synthesis process of powdery air-entraining agent for gypsum mortar

1) Preparation of liquid air-entraining agent: start stirring, add 30% foaming agent sodium α-olefin sulfonate, 2% stabilizer modified polysaccharide compound (carboxymethyl cellulose, carboxymethyl pachymansin mass ratio 1:1) ), 3% sodium salt dispersant, 3% wetting agent acrylic acid-hydroxypropyl acrylate copolymer, 4% rheology modifier magnesium lithium silicate, 1% calcium and magnesium ion complexing agent ethylenediamine tetramethylene phosphonic acid EDTMPA and 57% water are mixed and stirred evenly to obtain a liquid air-entraining agent;

2) Preparation of powder air-entraining agent: add 3% anti-caking agent ground calcium carbonate and 4% anti-sticking agent fumed silica to 93% liquid air-entraining agent, carry out high-temperature spray drying, so that the liquid air-entraining agent is atomized into powder air-entraining agent;

The conditions for the high-temperature spray drying are: under the vacuum condition of -0.15MPa, the inlet temperature is 165°C, the feed rate is 0.4L/h, the inlet air flow rate is 350L/h, and the outlet temperature is 80°C.

Example 2

A kind of synthesis process of powdery air-entraining agent for gypsum mortar

1) Preparation of liquid air-entraining agent: start stirring, add 20% foaming agent fatty alcohol polyoxyethylene ether (AEO-9), 1% stabilizer (guar gum, Wenlun gum mass ratio 1:1), 1 % Dispersion and leveling agent ammonium salt dispersant, 2% wetting agent phosphonocarboxylic acid copolymer, 2% rheology modifier associative alkali swelling thickener, 0.5% calcium and magnesium ion complexing agent hexamethylene diamine tetra Methylenephosphonic acid HDTMPA and 3.5% water were mixed and stirred evenly to obtain a liquid air-entraining agent;

2) Preparation of powdered air-entraining agent: add 2% anti-caking agent talcum powder and 3% anti-sticking agent fumed silica to 95% liquid air-entraining agent, carry out high-temperature spray drying, so that the liquid air-entraining agent is atomized into powder air-entraining agent Aerosol;

The conditions for the high-temperature spray drying are: under the vacuum condition of -0.2MPa, the inlet temperature is 180°C, the feed rate is 0.5L/h, the inlet air flow rate is 400L/h, and the outlet temperature is 90°C.

Example 3

A kind of synthesis process of powdery air-entraining agent for gypsum mortar

1) Preparation of liquid air-entraining agent: start stirring, add 35% foaming agent alkyl glucoside (APG), 5% stabilizer (xanthan gum, carboxymethyl starch mass ratio 1:1), 5% dispersion flow Leveling agent melamine dispersant, 4% wetting agent polyoxyalkylene alkyl ether, 5% rheology modifier modified attapulgite, 2.0% calcium and magnesium ion complexing agent aminotrimethylene phosphonic acid ATMP and 45.5% water, Mix and stir evenly to obtain a liquid air-entraining agent;

2) Preparation of powder air-entraining agent: add 5% anti-caking agent metakaolin and 5% anti-sticking agent 4A zeolite powder to 90% liquid air-entraining agent, carry out high-temperature spray drying, so that the liquid air-entraining agent is atomized into powder air-entraining agent agent;

The conditions for the high-temperature spray drying are: under the vacuum condition of -0.1MPa, the inlet temperature is 150°C, the feed rate is 0.3L/h, the inlet air flow rate is 300L/h, and the outlet temperature is 70°C.

Example 4

A kind of synthesis process of powdery air-entraining agent for gypsum mortar

1) Preparation of liquid air-entraining agent: start stirring, add 28% foaming agent cocamidopropyl ammonium oxide (CAO-30), 3% stabilizer (fucoidan, amino-modified cellulose mass ratio 1:1) ), 2% dispersing and leveling agent naphthalene sulfonate, 2% wetting agent acrylic acid-hydroxypropyl acrylate copolymer, 3% rheology modifier modified attapulgite, 1.2% calcium and magnesium ion complexing agent ethylene glycol Amine tetramethylene phosphonic acid EDTMPA and 60.8% water were mixed and stirred evenly to obtain a liquid air-entraining agent;

2) Preparation of powder air-entraining agent: add 3% anti-caking agent talc powder and 5% anti-sticking agent A zeolite powder to 92% liquid air-entraining agent, carry out high-temperature spray drying, so that the liquid air-entraining agent is atomized into powder air-entraining agent agent;

The conditions for the high-temperature spray drying are: under the vacuum condition of -0.2MPa, the inlet temperature is 170°C, the feed rate is 0.4L/h, the inlet air flow rate is 380L/h, and the outlet temperature is 75°C.

Comparative example 1

The air-entraining agent is sodium lauryl sulfate air-entraining agent.

Comparative example 2

The air-entraining agent is rosin type air-entraining agent.

The air-entraining agents of Examples and Comparative Examples were added to different gypsum mortars in different amounts to make lightweight gypsum plastering mortars (the basic formula is shown in Table 1, and two kinds of gypsum from Shandong desulfurization gypsum and Anhui phosphogypsum were used for comparison. ), and add water to stir, wherein the content of each group of air-entraining agents is as shown in Table 2

Table 1 Comparative formula of light gypsum mortar foundation in the market

The wet density of mortar after various embodiments and comparative examples are stirred and mixed with the content of different air-entraining agents is as follows:

Table 2 The wet density of gypsum mortar with different air-entraining agents in each group

It can be seen from Table 2 that, compared with the blank group, after the addition of Examples 1 to 4, the wet density of the mortar can be significantly reduced, the coating rate of construction can be improved, and the labor intensity can be reduced. The wet densities of the samples did not change, indicating that the air-entraining agent has a better foam stabilizing effect, while the wet density of Comparative Example 1-2 increased significantly, indicating that the foam burst and the foam stabilization was poor. The concentration of calcium ions in gypsum mortar, the prepared air-entraining agent can show excellent foaming performance under the condition of high calcium ion concentration, strong resistance to hard water, reduce the surface tension of water, and show excellent foam stability , and the foam is fine and not easy to break. It can be applied to gypsum mortar for 2 to 3 hours to maintain the same state as the initial mixing mortar to maintain the consistency of construction, and there is no pungent smell. It will not have adverse effects on workers' production or construction. .

Table 3 mechanical performance test performance test results

As can be seen from Table 3, the air-entraining agent prepared by the present invention is added in the gypsum mortar, and the thermal conductivity is obviously reduced, which can provide a certain thermal insulation effect; in addition, the compressive strength and flexural strength are improved to a certain extent, which can reach the level of gypsum mortar. performance index, while the intensity of Comparative Example 1-2 is obviously reduced. From the air-entraining agent efficiency and strength data, the powdered air-entraining agent prepared by the present invention can also achieve foam stabilization while bringing corresponding air-entraining effects. It can be seen that it has higher surface activity and foaming performance , showing good foam stability.

As can be seen from Figure 1, it is the SEM microstructure diagram of the gypsum mortar doped with the air-entraining agent prepared in Example 1. It can be seen that there are a large number of circular pores with a diameter of about 100-200 μm. It can be seen that due to the existence of pores, It helps to reduce the dry apparent density and thermal conductivity of gypsum mortar, so that gypsum mortar has excellent construction performance, thermal insulation effect and excellent strength.

Claims (10)

1. A powdery air-entraining agent for gypsum mortar, characterized in that, the components of the powdery air-entraining agent include liquid air-entraining agent, anti-caking agent and anti-sticking agent; The components of the liquid air-entraining agent include foaming agent, stabilizer, dispersion leveling agent, wetting agent, rheology modifier, calcium and magnesium ion complexing agent and water. 2. The powdery air-entraining agent for gypsum mortar according to claim 1, characterized in that, in terms of mass fraction, in the liquid air-entraining agent, foaming agent accounts for 20% to 35%, stabilizer accounts for 1% to 5%, dispersing leveling agent 1% to 5%, wetting agent 2% to 4%, rheology modifier 2% to 5%, calcium and magnesium ion complexing agent 0.5% to 2.0% % and water accounted for 45% to 75%; in the powdery air-entraining agent, the liquid air-entraining agent accounted for 90-95%, the anti-caking agent accounted for 2-5%, and the anti-sticking agent accounted for 3-5%. 3. The powdery air-entraining agent for gypsum mortar according to claim 1 or 2, characterized in that, the foaming agent comprises sodium α-olefin sulfonate, fatty alcohol polyoxyethylene ether AEO-9, alkanes More than one of glucoside APG and cocamidopropyl ammonium oxide CAO-30. 4. the powdery air-entraining agent for gypsum mortar according to claim 1 or 2, is characterized in that, described stabilizing agent comprises a kind of of guar gum, xanthan gum, Wenlun gum or modified polysaccharide compound above; The modified polysaccharide includes but not limited to one or more of carboxymethyl cellulose, carboxymethyl starch, carboxymethyl pachyman, fucoidan, amino-modified cellulose, and amino-modified starch. 5. the powdery air-entraining agent for gypsum mortar according to claim 1 and 2, is characterized in that, described dispersion leveling agent comprises sodium salt dispersant, ammonium salt dispersant, melamine dispersant or naphthalenesulfonate more than one. 6. The powdery air-entraining agent for gypsum mortar according to claim 1 or 2, wherein the wetting agent comprises acrylic acid-hydroxypropyl acrylate copolymer, phosphonocarboxylic acid copolymer, polyoxygen One or more dilute alkyl ethers. 7. The powdery air-entraining agent for gypsum mortar according to claim 1 or 2, wherein the rheology modifier comprises an associative alkali-swellable thickener, lithium magnesium silicate, modified More than one kind of attapulgite. 8. The powdery air-entraining agent for gypsum mortar according to claim 1 or 2, wherein the calcium and magnesium ion complexing agent comprises ethylenediaminetetramethylenephosphonic acid EDTMPA, hexamethylenediaminetetramethyl One or more kinds of phosphonic acid HDTMPA and ATMP of aminotrimethylene phosphonic acid. 9. the powdery air-entraining agent for gypsum mortar according to claim 1 or 2, is characterized in that, described anticaking agent comprises more than one of ground calcium carbonate, talcum powder, metakaolin; The anti-sticking agent includes more than one of 4A zeolite powder and fumed silica. 10. A synthetic process for the powdery air-entraining agent for gypsum mortar described in any one of claims 1 to 9, characterized in that it comprises the steps of: 1) Preparation of liquid air-entraining agent: start stirring, add foaming agent, stabilizer, dispersing and leveling agent, wetting agent, rheology modifier, calcium and magnesium ion complexing agent and water in sequence, mix and stir evenly to obtain a liquid air-entraining agent; 2) Preparation of powder air-entraining agent: adding anti-caking agent and anti-sticking agent to the liquid air-entraining agent, carrying out high-temperature spray drying, so that the liquid air-entraining agent is atomized into powder air-entraining agent; The conditions for the high temperature spray drying are: under the vacuum condition of -0.1～-0.2MPa, the inlet temperature is 150～180°C, the feed rate is 0.3～0.5L/h, and the air intake flow rate is 300～400L/h, The outlet temperature is 70-90°C.

Images