A preservative for polycarboxylate superplasticizer containing an isothiazolinone composition and its preparation method

Abstract

This invention belongs to the field of building materials, specifically relating to a preservative for polycarboxylate superplasticizers containing an isothiazolinone composition and its preparation method. The invention comprises, by weight, the following raw materials: 1-15 parts of preservative monomer, 0.5-2.0 parts of bactericidal monomer, 1-2 parts of stabilizer, and 50-90 parts of water. The bactericidal monomer is an isothiazolinone composition, including isothiazolinone derivatives and isothiazolinone quaternary ammonium salts; the preservative monomer is an organic bromine compound. This invention, using organic bromine compounds and isothiazolinone derivatives, provides a preservative for polycarboxylate superplasticizers that exhibits excellent antibacterial properties and tolerance, and can be widely applied in various fields.

Description

Technical Field

[0001] This invention relates to the field of building materials, specifically to a preservative for polycarboxylate superplasticizers containing isothiazolinone compositions and its preparation method. Background Technology

[0002] Currently, polycarboxylate superplasticizers often require the addition of a certain amount of preservatives during use to extend their service life and stability. However, existing preservatives have the following drawbacks: (1) Release of harmful substances: Some traditional preservatives contain harmful substances, such as formaldehyde, benzene, and other volatile organic compounds, which may be released into the environment, posing a potential risk to human health. (2) Reduced water-reducing effect: Some preservatives may interact with polycarboxylate molecules at high concentrations, resulting in impaired performance of the superplasticizer and reduced water-reducing effect. (3) Impact on cement gel: Some preservatives may react with cement gel, causing slower hardening speed or prolonged setting time of cement, affecting the process performance of concrete. (4) Environmental pollution problems: Some preservatives generate pollutants during production and use, causing negative impacts on the environment.

[0003] To address the shortcomings of using preservatives in polycarboxylate superplasticizers, several improvements have been made: (1) Environmentally friendly inorganic salts or organic compounds are used as alternative preservatives. These alternatives are safer and do not produce harmful volatile organic compounds. For example, some studies have proposed using potassium chloride or other harmless salts as preservatives for polycarboxylate superplasticizers. (2) The compatibility between superplasticizers and preservatives is improved by modifying the structure and synthesis methods of polycarboxylate molecules, thereby reducing their interaction. For example, some studies have improved the interaction between polycarboxylate molecules and preservatives by adjusting the side chain structure and length, thus improving the water-reducing effect. (3) Preservatives that do not react adversely with cement gels are sought. For example, some studies have shown that using specific organic acid preservatives, such as benzoic acid and propionic acid, can reduce their impact on cement gels. (4) Environmental friendliness and sustainability are given more attention when selecting preservatives. For example, preservatives with good biodegradability and less environmental impact are selected. In addition, environmental pollution can be reduced by improving production processes and reducing or avoiding the emission of harmful substances.

[0004] Therefore, more environmentally friendly preservatives are needed in the future. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a preservative for polycarboxylate superplasticizers containing an isothiazolinone composition and a method for preparing the same.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A preservative for polycarboxylate superplasticizers containing an isothiazolinone composition, comprising, by weight, the following raw materials: 1-15 parts preservative monomer, 0.5-2.0 parts bactericidal monomer, 1-2 parts stabilizer, and 50-90 parts water; wherein the bactericidal monomer is an isothiazolinone composition, comprising isothiazolinone derivatives and isothiazolinone quaternary ammonium salts; and the preservative monomer is an organic bromine compound with the following structural formula:

[0008]

[0009] Where M is One of them.

[0010] Preferably, the structural formula of the isothiazolinone derivative is as follows:

[0011]

[0012] In the formula, R1 is CH3COO-, One of them.

[0013] Preferably, the structural formula of the isothiazolinone quaternary ammonium salt is as follows:

[0014]

[0015] In the formula, n is a positive integer from 5 to 10, and R2 is an alkyl group with 1 to 5 carbon atoms.

[0016] Preferably, the stabilizer is at least one selected from propylene glycol, propylene glycol fatty acid ester, D-mannitol, propylene glycol alginate, chitosan, and polyglycerol ricinoleate.

[0017] A method for preparing a preservative for a polycarboxylate superplasticizer containing an isothiazolinone composition, comprising the following steps by weight:

[0018] Step (1): Add the preservative monomer and the bactericidal monomer to 10-30 parts by weight of water, stir evenly to obtain a mixture;

[0019] Step (2): Add the stabilizer to the mixture, add the remaining water, and stir to obtain the preservative for the polycarboxylate superplasticizer.

[0020] Preferably, the stirring time in step (2) is 10 to 30 minutes.

[0021] The beneficial effects of this invention are as follows:

[0022] (1) This invention uses organic bromine substances as preservative monomers, which hydrolyze in water to release HO-Br, which can form relatively stable hydrogen-halogen bonds with microorganisms, thus preventing the erosion of mold and other microorganisms under complex environmental conditions and preventing the sample from becoming moldy and deteriorating.

[0023] (2) The present invention uses isothiazolinone derivatives and isothiazolinone quaternary ammonium salts as preservative monomers. The activity of their heterocyclic structures can effectively destroy the structure of bacteria. Combined with the functional characteristics of isothiazolinone and quaternary ammonium salts, it has strong antiseptic and bactericidal properties.

[0024] (3) The present invention uses organic bromine and isothiazolinone composition as preservative active components to enhance the antimicrobial effect, prevent the preservative and bactericidal effect from decreasing after long-term use, expand the range of inhibition of microbial growth, and enhance the drug resistance and tolerance of the preservative.

[0025] (4) The preservative for polycarboxylate superplasticizer prepared in this invention has strong practicality. Detailed Implementation

[0026] Those skilled in the art should understand that these embodiments are merely for explaining the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0027] Example 1:

[0028] Weigh 1 part by weight of preservative monomer and 0.7 parts by weight of bactericide monomer, add them to 25 parts by weight of water and stir evenly. Then add 1 part by weight of propylene glycol and 60 parts by weight of water and stir for 15 minutes to obtain the preservative for polycarboxylate superplasticizer.

[0029] The anti-corrosion monomer is:

[0030]

[0031] bactericidal monomers are

[0032]

[0033] The steps in Examples 2-8 are the same as in Example 1, and the reagents and conditions used are as follows:

[0034] Table 1 Experimental parameters

[0035]

[0036] The bactericidal monomer used in Example 2 is:

[0037]

[0038] The anti-corrosion monomer is

[0039]

[0040] The bactericidal monomer used in Example 3 is:

[0041] The anti-corrosion monomer is

[0042]

[0043] The bactericidal monomer used in Example 4 is:

[0044]

[0045] The anti-corrosion monomer is

[0046]

[0047] The bactericidal monomer used in Example 5 is:

[0048]

[0049] The anti-corrosion monomer is

[0050]

[0051] The bactericidal monomer used in Example 6 is:

[0052]

[0053] The anti-corrosion monomer is

[0054]

[0055] The bactericidal monomer used in Example 7 is:

[0056]

[0057] The anti-corrosion monomer is

[0058] The bactericidal monomer used in Example 8 is:

[0059]

[0060] The anti-corrosion monomer is

[0061]

[0062] Comparative Example 1

[0063] Unlike Example 1, methyl benzoate (bromine-free) was used instead of the bactericidal monomer.

[0064] Comparative Example 2

[0065] Unlike Example 1, benzyl alcohol was used instead of the preservative monomer.

[0066] The minimum inhibitory concentration (MIC) method was used to evaluate the preservative and antibacterial properties of the prepared samples. Bacillus subtilis, Escherichia coli, and Aspergillus niger were used as test subjects in the experiment, all purchased from the Shanghai Preservation Biotechnology Center. The MCI was determined using the tube dilution method: 10 mL of peptone beef broth medium (1% peptone, 0.3% beef extract, 0.5% NaCl, 1% glucose, pH 6.5–7) was injected into a 20 mL test tube. After autoclaving, different concentrations of polycarboxylate preservative were added, and 1% bacterial suspension was inoculated under aseptic conditions. The culture was then incubated at 37°C on a water-soluble shaker for 24 h. The tube with the lowest concentration of preservative was selected from the tubes showing sterile growth.

[0067] The test results are shown in Table 2.

[0068] Table 2. Tests on the preservative and antibacterial properties of preservatives.

[0069]

[0070] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A preservative for polycarboxylate water reducing agent containing an isothiazolinone composition, characterized by, The product comprises, by weight, the following raw materials: 1-15 parts preservative monomer, 0.5-2.0 parts bactericidal monomer, 1-2 parts stabilizer, and 50-90 parts water; wherein the bactericidal monomer is an isothiazolinone composition, which includes isothiazolinone derivatives and isothiazolinone quaternary ammonium salts; and the preservative monomer is an organic bromine compound with the following structural formula: ， wherein M is , or one of The structural formula of the isothiazolinone derivative is as follows: ， wherein R1is CH3COO-, or one of the following: The structural formula of the isothiazolinone quaternary ammonium salt is as follows: ， In the formula, n is a positive integer from 5 to 10, and R2 is an alkyl group with 1 to 5 carbon atoms.

2. The preservative for a polycarboxylate superplasticizer containing an isothiazolinone composition according to claim 1, characterized in that, The stabilizer is at least one of propylene glycol, propylene glycol fatty acid ester, D-mannitol, propylene glycol alginate, chitin, and polyglycerol ricinoleate.

3. A method for preparing a preservative for a polycarboxylate superplasticizer containing an isothiazolinone composition as described in claim 1 or 2, characterized in that, By weight, the following steps are included: Step (1): Add the preservative monomer and the bactericidal monomer to 10-30 parts by weight of water, stir evenly to obtain a mixture; Step (2): Add the stabilizer to the mixture, add the remaining water, and stir to obtain the preservative for the polycarboxylate superplasticizer.

4. The method for preparing a preservative for a polycarboxylate superplasticizer containing an isothiazolinone composition according to claim 3, characterized in that, The stirring time in step (2) is 10 to 30 minutes.

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