Concrete release agent and preparation method thereof

Abstract

The invention relates to the technical field of concrete admixtures, in particular to a concrete release agent and a preparation method thereof.Soybean oil is subjected to epoxidation treatment and matched with alkylol amine, OP-7, Span80, water-based acrylic resin, hydrophobic nano-silica, waste glass powder, a defoaming agent and a preservative, and the concrete release agent with good isolation performance and good anti-corrosion performance is prepared. The concrete release agent is smooth in surface, reusable and stable in storage.

Description

Technical Field

[0001] This invention relates to the field of concrete admixtures, and in particular to a concrete release agent and its preparation method. Background Technology

[0002] Release agents are functional chemicals used to form a release film between two surfaces. They are widely used in the production and manufacturing of concrete, shape memory polymers, metal-based shape memory alloys, electromagnetic rheological materials, and self-healing materials.

[0003] A large amount of concrete is used in the construction process. Concrete has good fluidity and high compressive strength, but it requires molds or templates to be set up during its molding process. Once the concrete has reached its initial strength, the molds and templates will be removed. However, concrete often adheres to the surface of the molds and templates. In addition, concrete is prone to tensile damage, so surface defects are easily generated during the demolding process.

[0004] Applying release agents to the surface of molds and formwork is a common measure in engineering to improve the surface quality of concrete after demolding. Initially, release agents such as waste engine oil were used, which easily led to contamination and blackening of the concrete surface. Later, the engineering industry often used synthetic release agents to improve the demolding quality. However, some commercially available release agents use hydrophobic substances such as silicone oil and paraffin wax, which are not only expensive but also easily contaminate the formwork and concrete surface. In recent years, water-based release agents using acrylic resin, vegetable oil, etc. have been developed. However, their reusability is low and they are not suitable for long-term storage.

[0005] Release agents often contain fillers for lubrication and filling. Commonly used fillers include talc powder and quartz powder. Industrial solid waste recycling is a way to achieve sustainable development of building materials. Existing technology CN119799405A discloses a high-performance anti-mildew release agent for concrete, which uses water glass, waste glass powder and flake graphite as reinforcing materials to achieve isolation and lubrication. However, it still uses silicone oil as the matrix component and requires the addition of components such as polyisobutylene-modified silica. Furthermore, flake graphite must be added, and the release agent cannot be recycled. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a concrete release agent. By epoxidizing soybean oil and combining it with alkanolamine, OP-7, Span80, water-based acrylic resin, hydrophobic nano silica, waste glass powder, defoamer, and preservative, a concrete release agent with good isolation properties, smooth surface, reusability, and stable storage is prepared.

[0007] Specifically, the concrete release agent of the present invention is composed of the following raw materials in parts by weight: 30-38 parts modified soybean oil, 1-5 parts alkanolamine, 0.5-3 parts nonylphenol polyoxyethylene ether OP-7, 0.1-2 parts Span80, 0.1-5 parts water-based acrylic resin, 1-3 parts hydrophobic nano silica, 1-3 parts waste glass powder, 0.1-0.4 parts defoamer, 0.1-0.5 parts preservative, and 50-60 parts water.

[0008] Preferably, the concrete release agent is composed of the following raw materials in parts by weight: 33-36 parts modified soybean oil, 2-4 parts alkanolamine, 1-2 parts nonylphenol polyoxyethylene ether OP-7, 0.1-1 parts Span80, 1-3 parts water-based acrylic resin, 2-3 parts hydrophobic nano silica, 2-3 parts waste glass powder, 0.1-0.3 parts defoamer, 0.2-0.5 parts preservative, and 52-55 parts water.

[0009] Preferably, the concrete release agent is composed of the following raw materials in parts by weight: 35 parts modified soybean oil, 3 parts alkanolamine, 1.5 parts nonylphenol polyoxyethylene ether OP-7, 0.5 parts Span80, 2 parts water-based acrylic resin, 2 parts hydrophobic nano silica, 2 parts waste glass powder, 0.2 parts defoamer, 0.3 parts preservative, and 53.5 parts water.

[0010] Preferably, the modified soybean oil preparation process is as follows: organic acid and hydrogen peroxide are mixed at a mass ratio of 1:(3-4) to obtain peroxy acid. Refined soybean oil is slowly added to the peroxy acid, and the mass ratio of refined soybean oil to peroxy acid is 1:(6-10). The mixture is stirred slowly under controlled temperature, cooled, neutralized, and allowed to stand to separate the aqueous phase. The oil phase is washed until neutral and then removed by vacuum distillation to remove water and low-boiling substances, thus obtaining the modified soybean oil.

[0011] This invention utilizes the epoxidation reaction between the carbon-carbon double bonds in the soybean oil molecular chain and peroxy acids to transform the double bonds into more stable epoxy groups. Epoxy groups are more stable than double bonds and are less susceptible to heat or oxygen attack, which can reduce the formation of coking and oxidation products. Furthermore, the epoxy groups increase the polarity of the molecules, making them easier to spread and adhere to polar mold surfaces (such as metals), forming a more uniform and dense film. In addition, the epoxy structure itself has a certain degree of lubricity, which can further improve the surface quality of the demolded concrete.

[0012] Preferably, the organic acid is formic acid or acetic acid.

[0013] Preferably, the temperature is controlled at 50-70℃.

[0014] Preferably, the alkanolamine is at least one of triethanolamine, diethanolamine, and triisopropanolamine. Alkanolamines act as a bridge between hydrophilic (amine) and hydrophobic (long-chain alkyl) groups, helping modified soybean oil form a stable emulsion in water. This maintains the weakly alkaline pH (8-10) of the release agent system, preventing acid corrosion of the mold and enhancing the anti-corrosion effect.

[0015] This invention adds water-based acrylic resin to form a continuous, dense polymer film on the mold surface, improving the mechanical strength of the release agent film, reducing film damage during demolding, preventing resin products from sticking to the mold, improving surface smoothness after spraying, and avoiding oil spots or streaks. OP-7 is nonylphenol polyoxyethylene ether, a nonionic emulsifier. Through its hydrophilic ethoxy chain (EO=7) and hydrophobic nonylphenol groups, it stabilizes the oil-water interface, reduces surface tension, helps the release agent penetrate into the mold micropores, and is less prone to precipitation in water containing calcium / magnesium ions. The combination of sorbitan monooleate Span 80 and OP-7 can adjust the HLB value to suit different oil systems. The long-chain oleic acid groups provide auxiliary lubrication, reduce demolding friction, and inhibit foam formation during emulsion stirring.

[0016] This invention adds waste glass powder as a filler to achieve waste recycling and promote the effectiveness of waste glass. However, adding waste glass powder alone in the modified soybean oil system of this invention is not very effective, as the glass powder is prone to sedimentation. After extensive testing, this invention combines it with hydrophobic nano-silica, which can fill the release agent film layer together with waste glass powder. This not only improves scratch resistance but also forms a three-dimensional network structure, preventing particle sedimentation and reducing the surface energy of the film layer, further reducing adhesion to concrete components. The effect is better than using organic thickeners.

[0017] Preferably, the defoamer is an organosilicone defoamer. It eliminates bubbles generated by stirring / spraying by disrupting the foam film structure through low surface tension silicone oil, and the silicone oil particles dispersed in the system continuously inhibit foam regeneration.

[0018] Preferably, the preservative is sodium benzoate. It can disrupt bacterial / mold cell membranes, preventing the release agent from spoiling and deteriorating.

[0019] Preferably, the water is at least one of deionized water, distilled water, and tap water.

[0020] This invention also relates to a method for preparing the above-mentioned concrete release agent, specifically comprising the following steps:

[0021] 1) Weigh each ingredient according to its weight.

[0022] 2) Mix all ingredients thoroughly.

[0023] Preferably, the preparation method of the present invention uses mechanical stirring for high-speed mixing, and the mixing order of each raw material is not strictly limited, as long as homogeneity is achieved. Detailed Implementation

[0024] To characterize the technical effect of the present invention, a release agent was prepared, sprayed onto a steel template, used for the steam curing of tunnel segments, and the release effect of the tunnel segments was judged.

[0025] During the experiment, the modified soybean oil preparation process was as follows: acetic acid and hydrogen peroxide were mixed at a mass ratio of 1:3 to obtain peroxyacid. Refined soybean oil was slowly added to the peroxyacid at a mass ratio of 1:8. The mixture was stirred slowly at 60℃, cooled, neutralized, and allowed to stand to separate the aqueous phase. The oil phase was washed until neutral and then removed by vacuum distillation to remove water and low-boiling substances, thus obtaining the modified soybean oil.

[0026] Example 1 The release agent is composed of the following raw materials in parts by weight: 34 parts modified soybean oil, 4 parts triethanolamine, 1 part OP-7, 0.6 parts Span80, 1.5 parts water-based acrylic resin, 3 parts hydrophobic nano silica, 2 parts waste glass powder, 0.2 parts organosilicon defoamer, 0.2 parts sodium benzoate, and 53.5 parts water.

[0027] Tests showed that the concrete adhesion content was 1.1 g / m³. 2 There are 5 air bubbles, and the release agent can be recycled 17 times.

[0028] Example 2 The release agent is composed of the following raw materials in parts by weight: 35 parts modified soybean oil, 3 parts triethanolamine, 1.5 parts OP-7, 0.5 parts Span80, 2 parts water-based acrylic resin, 2 parts hydrophobic nano silica, 2 parts waste glass powder, 0.2 parts organosilicon defoamer, 0.3 parts sodium benzoate, and 53.5 parts water.

[0029] Tests showed that the concrete adhesion content was 0.9 g / m³. 2 There were 2 air bubbles, and the release agent was recycled 19 times.

[0030] Comparative Example 1 The release agent is composed of the following raw materials in parts by weight: 35 parts soybean oil, 1.5 parts OP-7, 0.5 parts Span80, 2 parts water-based acrylic resin, 2 parts hydrophobic nano silica, 2 parts waste glass powder, 0.2 parts organosilicon defoamer, 0.3 parts sodium benzoate, and 53.5 parts water.

[0031] The concrete adhesion content was measured at 5.2 g / m³. 2 There were 21 air bubbles, and the release agent was recycled twice.

[0032] Comparative Example 2 The release agent is composed of the following raw materials in parts by weight: 36 parts modified soybean oil, 2.5 parts OP-7, 1.5 parts Span80, 2 parts water-based acrylic resin, 2 parts hydrophobic nano silica, 2 parts waste glass powder, 0.2 parts organosilicon defoamer, 0.3 parts sodium benzoate, and 53.5 parts water.

[0033] Tests showed that the concrete adhesion content was 3.4 g / m³. 2 There are 15 air bubbles, and the release agent can be recycled 5 times.

[0034] Comparative Example 3 The release agent is composed of the following raw materials in parts by weight: 35 parts modified soybean oil, 3 parts triethanolamine, 1.5 parts OP-7, 0.5 parts Span80, 2 parts water-based acrylic resin, 4 parts waste glass powder, 0.2 parts organosilicon defoamer, 0.3 parts sodium benzoate, and 53.5 parts water.

[0035] The concrete adhesion content was measured at 2.6 g / m³. 2 There are 12 air bubbles, and the release agent can be recycled 8 times.

[0036] Comparative Example 4 The release agent is composed of the following raw materials in parts by weight: 35 parts modified soybean oil, 3 parts triethanolamine, 1.5 parts OP-7, 0.5 parts Span80, 2 parts water-based acrylic resin, 3.8 parts waste glass powder, 0.2 parts sodium carboxymethyl cellulose, 0.2 parts organosilicon defoamer, 0.3 parts sodium benzoate, and 53.5 parts water.

[0037] Tests showed that the concrete adhesion content was 1.8 g / m³. 2 There were 9 air bubbles, and the release agent was recycled 13 times.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A concrete release agent, characterized in that, It is composed of the following raw materials in parts by weight: 30-38 parts modified soybean oil, 1-5 parts alkanolamine, 0.5-3 parts nonylphenol polyoxyethylene ether OP-7, 0.1-2 parts Span80, 0.1-5 parts waterborne acrylic resin, 1-3 parts hydrophobic nano silica, 1-3 parts waste glass powder, 0.1-0.4 parts defoamer, 0.1-0.5 parts preservative, and 50-60 parts water.

2. The concrete release agent according to claim 1, characterized in that, It is composed of the following raw materials in parts by weight: 33-36 parts modified soybean oil, 2-4 parts alkanolamine, 1-2 parts nonylphenol polyoxyethylene ether OP-7, 0.1-1 parts Span80, 1-3 parts water-based acrylic resin, 2-3 parts hydrophobic nano silica, 2-3 parts waste glass powder, 0.1-0.3 parts defoamer, 0.2-0.5 parts preservative, and 52-55 parts water.

3. The concrete release agent according to claim 1, characterized in that, It is composed of the following raw materials in parts by weight: 35 parts modified soybean oil, 3 parts alkanolamine, 1.5 parts nonylphenol polyoxyethylene ether OP-7, 0.5 parts Span80, 2 parts water-based acrylic resin, 2 parts hydrophobic nano silica, 2 parts waste glass powder, 0.2 parts defoamer, 0.3 parts preservative, and 53.5 parts water.

4. The concrete release agent according to claim 1, characterized in that, The modified soybean oil preparation process is as follows: organic acid and hydrogen peroxide are mixed at a mass ratio of 1:(3-4) to obtain peroxy acid. Refined soybean oil is slowly added to the peroxy acid, and the mass ratio of refined soybean oil to peroxy acid is 1:(6-10). The mixture is stirred slowly under controlled temperature, cooled, neutralized, and allowed to stand to separate the aqueous phase. The oil phase is washed until neutral and then removed by vacuum distillation to remove water and low-boiling substances, thus obtaining the modified soybean oil.

5. The concrete release agent according to claim 4, characterized in that, The organic acid is formic acid or acetic acid, and the temperature is controlled at 50-70℃.

6. The concrete release agent according to claim 1, characterized in that, The alkanolamine is at least one of triethanolamine, diethanolamine, and triisopropanolamine.

7. The concrete release agent according to claim 1, characterized in that, The defoamer is an organosilicone defoamer.

8. The concrete release agent according to claim 1, characterized in that, The preservative is sodium benzoate.

9. The concrete release agent according to claim 1, characterized in that, The water is at least one of deionized water, distilled water, or tap water.

10. The method for preparing the concrete release agent according to any one of claims 1-9, characterized in that, Includes the following steps: 1) Weigh each ingredient according to its weight. 2) Mix all ingredients thoroughly.