An aluminum template release agent with adsorption and migration capabilities and its preparation method

Abstract

The present invention discloses a demoulding agent for aluminum formwork with adsorption and migration capabilities and a preparation method thereof. The demoulding agent for aluminum formwork, by mass parts, comprises the following raw materials: 5-25 parts of an isolation and lubricating material, 3-10 parts of a film-forming material, 0.1-2 parts of an antifoaming agent, 1-5 parts of an emulsifier, 1-3 parts of a stabilizer, 1-2 parts of an auxiliary material, 0.1-0.8 parts of an external admixture, 1-3 parts of an adsorption and migration material, and 65-79 parts of water; wherein: the auxiliary material is a mixture of dodecanol, sodium dodecyl sulfate, hydrophobically modified polyacrylamide and alkyl glucoside; the adsorption and migration material is a mixture of fine pulp powder, fine kapok powder and polyacrylamide. The demoulding agent for aluminum formwork of the present invention has adsorption and migration capabilities, avoids the formation of water streaks and color differences on the concrete surface, has good dispersion performance and stability performance, excellent demoulding performance, is environmentally friendly and green, and at the same time, the preparation method is simple and has a wide application prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of concrete release agents, and particularly relates to an aluminum formwork release agent with adsorption and migration capabilities and a preparation method thereof. Technical Background

[0002] With the development of society, there are more and more infrastructure construction projects, and construction enterprises have also developed rapidly. Concrete is widely used in various fields due to its good performance and high functionality, and different functional concretes are constantly being developed. In recent years, aluminum alloy formwork has been widely used in the high-rise building field and environmental protection project construction in many countries around the world. It conforms to the dimensions and formwork matching of building standardization regulations and can be reused continuously, meeting the requirements of today's new environmentally friendly and green building standard construction design. However, aluminum alloy formwork also has some problems. Due to the problems of its raw materials, concrete will bring substances that cause differences in the apparent color of concrete, such as oil and unburned carbon in fly ash, colored substances and light substances in aggregates. These substances will float to the surface of the concrete or remain at the formwork-concrete boundary after pouring and vibration. After demolding, a series of phenomena such as water patterns, color marks, and color differences are likely to appear on the concrete surface, seriously affecting the appearance. Currently, the uneven color and large color difference of the pores on the surface of aluminum formwork concrete have become urgent problems to be solved in engineering construction. Summary of the Invention

[0003] The purpose of the present invention is to provide an aluminum formwork release agent with adsorption and migration capabilities and a preparation method thereof. This aluminum formwork release agent has adsorption and migration capabilities, avoids the formation of water patterns and color differences on the concrete surface, has good dispersion and stability, excellent demolding performance, is environmentally friendly and green, and has broad application prospects.

[0004] To achieve the above purpose, the present invention provides the following solutions:

[0005] The present invention provides an aluminum formwork release agent with adsorption and migration capabilities, which includes the following raw materials by mass parts: 5 - 25 parts of isolation and lubrication material, 3 - 10 parts of film-forming material, 0.1 - 2 parts of defoaming agent, 1 - 5 parts of emulsifier, 1 - 3 parts of stabilizer, 1 - 2 parts of auxiliary material, 0.1 - 0.8 parts of external admixture, 1 - 3 parts of adsorption and migration material, and 65 - 79 parts of water; wherein:

[0006] The auxiliary material is a mixture of dodecanol, sodium dodecyl sulfate, hydrophobically modified polyacrylamide, and alkyl glycoside;

[0007] The adsorption and migration material is a mixture of fine pulp powder, fine kapok powder, and polyacrylamide.

[0008] According to the above scheme, in the auxiliary materials, the mass ratio of dodecanol, sodium dodecyl sulfate, hydrophobically modified polyacrylamide to alkyl polyglycoside is 1:(1 - 2):(0.4 - 0.7):(0.2 - 0.5).

[0009] According to the above scheme, in the adsorption and migration materials, the mass ratio of pulp fines, kapok fines to polyacrylamide is (2.5 - 3):(1.5 - 2):1.

[0010] According to the above scheme, the isolation and lubrication material is waste oil, and the waste oil is waste mineral oil or waste animal and vegetable oil. The waste oil can be reused, saving resources and achieving the actual effect of green and low - carbon.

[0011] According to the above scheme, the film - forming material is a mixture of acrylic - acrylate copolymer and hydroxypropyl methylcellulose. Preferably, the mass ratio of the two is (1 - 2):1. The acrylic - acrylate copolymer can form a film quickly, and will form a transparent and bright film after drying, and has anti - corrosion performance; hydroxypropyl methylcellulose has excellent film - forming properties, and will become a colorless, transparent and tough film after drying, with good moisture resistance. The combination of the two can play a better role.

[0012] According to the above scheme, the emulsifier is fatty alcohol polyoxyethylene ether (AEO - 9). Fatty alcohol polyoxyethylene ether (AEO - 9) is an important type of non - ionic surfactant. The ether bond in the molecule is not easily destroyed by acids and alkalis, so it has high stability, good water solubility, resistance to electrolytes, is easy to biodegradable, has small foam, and can be used in combination with different types of surfactants; at the same time, AEO - 9 has certain adsorption properties.

[0013] According to the above scheme, the defoamer is branched - chain alkyl alcohol polyether. This defoamer is a type of surfactant containing hydrophilic and hydrophobic parts. The hydrophilic part is a polyether chain composed of repeating ethylene oxide (EO) or propylene oxide (PO) units, and the hydrophobic part is a linear long alkyl chain (mainly C16 - C22). The polyether defoamer shows better water solubility and compatibility with other admixtures.

[0014] According to the above scheme, the stabilizer is polyanionic cellulose. Polyanionic cellulose (PAC) has good stability, salt tolerance and strong antibacterial properties.

[0015] According to the above scheme, the external admixture is polydimethylsiloxane. Its incorporation into the release agent can significantly inhibit the mutual adhesion between the metal aluminum formwork and the concrete, reduce the adhesion force between the two, facilitate the demoulding of the aluminum formwork and reduce the adhesion amount of the concrete paste, and improve the appearance of the concrete components to a certain extent.

[0016] According to the above scheme, the auxiliary materials are dodecanol, sodium dodecyl sulfate, hydrophobically modified polyacrylamide, and alkyl polyglycoside; medium-chain fatty alcohols such as dodecanol are often used as additives as cosolvents, splitting at different solubilization sites. When mixed with surfactants, on the one hand, it can enhance the viscoelasticity and adsorption capacity at the interface, and on the other hand, it can enhance the stability of the dispersion system; sodium dodecyl sulfate is an anionic surfactant, often used in combination with other components, with good emulsifying ability and stability in aqueous solutions with a wide pH range; hydrophobically modified polyacrylamide (HMP) can form hydrophobic microdomains in aqueous solutions, providing association sites for the self-assembly of fatty alcohols; alkyl polyglycoside has good compatibility, can be compounded with various ionic and non-ionic surfactants to produce a synergistic effect, has good compatibility with the skin, significantly improves the mildness of the formulation, is non-toxic, non-irritating, and easily biodegradable.

[0017] According to the above scheme, the adsorption and migration materials are fine pulp powder, kapok fine powder, and polyacrylamide. Preferably, the fineness of both the fine pulp powder and the kapok fine powder is between 200 and 300 mesh. As adsorption and migration materials, after the fine pulp powder and the kapok fine powder are added to water, they can effectively form irregular grid structures and migration channels layer by layer, effectively adsorbing light substances and carbon powder that overflow to the formwork boundary due to vibration and migrating them from the concrete-release agent interface to the release agent-formwork interface; polyacrylamide, as an adsorbent, can dissolve in water in any proportion, has a certain adsorption effect, can effectively adsorb light substances and carbon powder in the concrete and aggregate them together. On the other hand, the polyacrylamide aqueous solution can also effectively adjust the viscosity of the release agent.

[0018] The present invention provides a novel aluminum formwork release agent with adsorption and migration capabilities, wherein:

[0019] The adsorption and migration capabilities in the present invention are specifically divided into adsorption and migration capabilities. The adsorption refers to the adsorption of impurities such as light substances and carbon powder in the concrete, mainly achieved through fine pulp powder, kapok fine powder, polyacrylamide, and emulsifier, and the impurities are adsorbed together through the adsorption; the migration ability refers to the migration of substances from the release agent-concrete slurry interface to the release agent-formwork interface. Among them, the fine pulp powder and the kapok fine powder can effectively form irregular grid structures and migration channels layer by layer after film formation, and can migrate the impurities adsorbed in the previous adsorption step. The two functions cooperate with each other, having good adsorption and migration capabilities, effectively reducing the color difference of the concrete, and improving the consistency of the concrete surface color.

[0020] However, the pulp fines and kapok fines in the adsorption and migration material of the present invention are solid powders, and it is still difficult to disperse them evenly even with the assistance of an emulsifier. Therefore, the present invention also effectively improves their dispersibility and stability with the assistance of auxiliary materials. At the same time, the auxiliary materials are also beneficial to reducing the adhesion between the concrete interface and the aluminum formwork, ensuring the integrity and cleanliness of the demoulding surface. Together with a branched-chain alkyl alcohol polyether defoaming agent, a stabilizer, an isolation and lubricating material, a film-forming material and an emulsifier, a new type of aluminum formwork demoulding agent with adsorption and migration ability, good dispersion performance, stable performance, excellent demoulding performance, environmental protection and greenness is obtained.

[0021] Provided is a preparation method of the above-mentioned new type of aluminum formwork demoulding agent with adsorption and migration ability, comprising the following steps:

[0022] 1) Mix an isolation and lubricating material, a film-forming material, an emulsifier, an external admixture material, an auxiliary material and water in sequence and then stir and emulsify them;

[0023] 2) After stopping stirring, add the adsorption and migration material, then continue stirring, and sequentially add an auxiliary defoaming agent and a stabilizer during the stirring process, and control the pH value of the system to be 7-9 until the slurry becomes a uniform liquid state, and then stop stirring to obtain the demoulding agent.

[0024] According to the above solution, in the step 1), stir and emulsify for 1-1.5 h.

[0025] The present invention has the following beneficial effects:

[0026] 1. The present invention provides an aluminum formwork demoulding agent with adsorption and migration ability. The adsorption and migration are realized through the adsorption and migration material and the emulsifier, effectively reducing the color difference of the concrete and improving the consistency of the surface color of the concrete. By using the auxiliary material and its synergistic effect with the emulsifier, the dispersibility and stability of the solution are greatly improved, making the solid powders such as pulp fines and kapok fines in the adsorption and migration material disperse more evenly with the emulsion system. Together with the defoaming agent, the stabilizer, the isolation and lubricating material and the film-forming material, the obtained demoulding agent has adsorption and migration ability, avoiding the formation of water streaks and color differences on the concrete surface, having good dispersion performance and stable performance, excellent demoulding performance, environmental protection and greenness, and having a wide application prospect.

[0027] 2. The present invention provides a preparation method of a new type of aluminum formwork demoulding agent. First, mix an isolation and lubricating material, a film-forming material, an emulsifier, an external admixture material, an auxiliary material and water for emulsification, and each component is dispersed evenly. Then, after stopping stirring, add the adsorption and migration material, which is beneficial to the uniform dispersion of the adsorption and migration material. Finally, add the auxiliary defoaming agent and the stabilizer, and the preparation method is simple. The obtained demoulding agent is uniform and stable, which is beneficial to industrial production. Specific embodiments

[0028] The present invention will be further described in detail below in conjunction with specific embodiments, but it should not be understood that the scope of the present invention is limited to the following examples.

[0029] In the following examples, a preparation method of a novel aluminum formwork release agent with adsorption and migration ability includes the following steps:

[0030] (1) Mix the isolation and lubrication material, film-forming material, emulsifier, external admixture, auxiliary material and water in sequence and then stir and emulsify. Stop stirring after 1 - 1.5 h.

[0031] (2) After stopping stirring, add the adsorption and migration material, and then continue stirring. During the stirring process, add the defoamer and stabilizer in sequence, and then continue stirring. Control the pH value of the system until the slurry becomes a uniform liquid state, and then stop stirring to obtain the release agent. The pH value of the release agent is controlled between 7 and 9.

[0032] The particle sizes of the pulp fine powder and kapok fine powder are 200 - 300 mesh.

[0033] Example 1

[0034] A novel aluminum formwork release agent with adsorption and migration ability includes the following components in parts by weight:

[0035] Isolation and lubrication material: 23 parts of waste mineral oil;

[0036] Film-forming material 6.9 parts, which is a mixture of acrylic acid - acrylate copolymer and hydroxypropyl methylcellulose, and the mass ratio of the two is 1.5:1;

[0037] Emulsifier: 4.0 parts of fatty alcohol polyoxyethylene ether;

[0038] Defoamer: 0.2 parts of branched-chain alkyl alcohol polyether;

[0039] Stabilizer: 1.9 parts of polyanionic cellulose;

[0040] Auxiliary material 1.7 parts, which is a mixture of dodecanol, sodium dodecyl sulfate, hydrophobically modified polyacrylamide and alkyl glycoside, and the mass ratio is 1:1.5:0.5:0.3;

[0041] External admixture: 0.4 parts of polydimethylsiloxane;

[0042] Adsorption and migration material 2.0 parts, which is a mixture of pulp fine powder, kapok fine powder and polyacrylamide, and the mass ratio is 2.5:2:1;

[0043] 68 parts of deionized water.

[0044] Example 2

[0045] A novel aluminum formwork release agent with adsorption and migration ability, comprising the following components in parts by weight:

[0046] Isolation and lubrication material: 21 parts of waste vegetable oil;

[0047] Film-forming material 6.6 parts, which is a mixture of acrylic acid-acrylate copolymer and hydroxypropyl methylcellulose, and the mass ratio of the two is 1.8:1;

[0048] Emulsifier: 3.7 parts of fatty alcohol polyoxyethylene ether;

[0049] Defoamer: 0.4 part of branched-chain alkyl alcohol polyether;

[0050] Stabilizer: 1.5 parts of polyanionic cellulose;

[0051] Auxiliary material 1.8 parts, which is a mixture of dodecanol, sodium dodecyl sulfate, hydrophobically modified polyacrylamide and alkyl glycoside, and the mass ratio is 1:1.7:0.6:0.5;

[0052] External admixture: 0.5 part of polydimethylsiloxane;

[0053] Adsorption and migration material 2.5 parts, which is a mixture of pulp fine powder, kapok fine powder and polyacrylamide, and the mass ratio is 2.8:1.6:1;

[0054] 71 parts of deionized water.

[0055] Example 3

[0056] A novel aluminum formwork release agent with adsorption and migration ability, comprising the following components in parts by weight:

[0057] Isolation and lubrication material: 19 parts of waste vegetable oil;

[0058] Film-forming material 7.6 parts, which is a mixture of acrylic acid-acrylate copolymer and hydroxypropyl methylcellulose, and the mass ratio of the two is 2:1;

[0059] Emulsifier: 3.5 parts of fatty alcohol polyoxyethylene ether;

[0060] Defoamer: 0.3 part of branched-chain alkyl alcohol polyether;

[0061] Stabilizer: 2.0 parts of polyanionic cellulose;

[0062] Auxiliary material 2.0 parts, which is a mixture of dodecanol, sodium dodecyl sulfate, hydrophobically modified polyacrylamide and alkyl glycoside, and the mass ratio is 1:1.9:0.7:0.5;

[0063] External admixture: 0.6 part of polydimethylsiloxane;

[0064] 2.0 parts of adsorption migration material, which is a mixture of pulp fine powder, kapok fine powder and polyacrylamide, with a mass ratio of 3:1.8:1;

[0065] 66 parts of deionized water.

[0066] Comparative Example 1

[0067] Aluminum formwork commonly uses water-based release agent A, which is often used in industrial construction and has good working performance.

[0068] Comparative Example 2

[0069] Based on Example 3, the emulsifier was replaced with dodecylphenol polyoxyethylene ether in the same mass fraction, and the other components and preparation process remained unchanged.

[0070] Comparative Example 3

[0071] Based on Example 3, no auxiliary materials are added, and other components and preparation processes remain unchanged.

[0072] Comparative Example 4

[0073] Based on Example 3, no adsorption migration material is added, and other components and preparation process remain unchanged.

[0074] Release agent performance test

[0075] The release agents of Examples 1-3 and Comparative Examples 1-4 were used to conduct relevant tests on C40 strength grade concrete in accordance with "Release Agents for Concrete Products" (JC / T 949-2005). The tests were conducted using aluminum templates. The test results are shown in Table 1 below.

[0076] Table 1. Release agent performance test results

[0077]

[0078] The demoulding concrete specimens were photographed with a high-resolution SLR camera for sample retention. All specimens were photographed under the same conditions (same lighting, same distance, same area, same shooting parameters, same area, etc.). The concrete color difference was then analyzed using Matlab software. The color consistency of the concrete was evaluated by the average grayscale standard deviation of the concrete surface. The larger the standard deviation, the greater the difference in the overall apparent color of the concrete. The specific evaluation results are shown in Table 2:

[0079] Table 2. Concrete specimen surface color consistency evaluation results

[0080] Category Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Standard deviation of gray scale 7.8 6.6 5.3 13.4 9.5 8.7 11.7

[0081] As can be seen from Table 1 and Table 2, the release agent for aluminum formwork of the present invention has excellent performance, good dispersibility, stable performance and a significant effect of reducing the color difference on the concrete surface, which is significantly better than the currently used release agent for aluminum formwork. Among them, the auxiliary materials play a role in improving the dispersibility and stability of the emulsion, making the components more evenly dispersed; the adsorption and migration materials play a role in adsorbing the impurities on the concrete surface and migrating them to the formwork surface, reducing the color difference on the concrete surface. The components of the release agent cooperate with each other to make the utility of the release agent reach the optimal level.

[0082] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A demoulding agent for aluminum templates with adsorption and migration capabilities, characterized in that, By mass parts, it includes the following raw materials: 5-25 parts of isolation lubricating material, 3-10 parts of film-forming material, 0.1-2 parts of defoaming agent, 1-5 parts of emulsifier, 1-3 parts of stabilizer, 1-2 parts of auxiliary material, 0.1-0.8 parts of external admixture, 1-3 parts of adsorption and migration material, and 65-79 parts of water; wherein: The auxiliary material is a mixture of dodecanol, sodium dodecyl sulfate, hydrophobically modified polyacrylamide and alkyl glucoside; The adsorption and migration material is a mixture of fine pulp powder, fine kapok powder and polyacrylamide; The film-forming material is a mixture of acrylic-acrylate copolymer and hydroxypropyl methylcellulose; The isolation lubricating material is waste oil; the emulsifier is fatty alcohol polyoxyethylene ether; the defoaming agent is branched alkyl alcohol polyether; the stabilizer is polyanionic cellulose; the external admixture is polydimethylsiloxane.

2. The aluminum formwork release agent according to claim 1, characterized in that, In the auxiliary material, the mass ratio of dodecanol, sodium dodecyl sulfate, hydrophobically modified polyacrylamide and alkyl glucoside is 1:(1-2):(0.4-0.7):(0.2-0.5).

3. The aluminum formwork release agent according to claim 1, wherein In the adsorption and migration material, the mass ratio of fine pulp powder, fine kapok powder and polyacrylamide is (2.5-3):(1.5-2):

1.

4. The aluminum formwork release agent according to claim 1, wherein In the film-forming material, the mass ratio of acrylic-acrylate copolymer and hydroxypropyl methylcellulose is (1-2):

1.

5. A method for preparing an aluminum template release agent with adsorption and migration ability according to any one of claims 1-4, characterized in that, It includes the following steps: 1) Mix the isolation lubricating material, film-forming material, emulsifier, external admixture, auxiliary material and water in sequence and then stir and emulsify; 2) After the stirring stops, add the adsorption and migration material, then continue stirring, and sequentially add the defoaming agent and stabilizer during the stirring process, and control the pH value of the system to be 7-9 until the slurry becomes a uniform liquid state, and stop stirring to obtain the mold release agent.

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