Preservative for polycarboxylate superplasticizer containing isothiazolinone composition, and preparation method for preservative

Abstract

The present invention belongs to the field of building materials, and particularly relates to a preservative for a polycarboxylate superplasticizer containing an isothiazolinone composition, and a preparation method for the preservative. The present invention comprises the following raw materials in parts by weight: 1-15 parts of an anti-corrosion monomer, 0.5-2.0 parts of a bactericidal monomer, 1-2 parts of a stabilizer and 50-90 parts of water, wherein the bactericidal monomer is an isothiazolinone composition and comprises an isothiazolinone derivative and an isothiazolinone quaternary ammonium salt; and the anti-corrosion monomer is organic bromine. The present invention employs the preservative for a polycarboxylate superplasticizer, in which an organic bromine substance and an isothiazolinone derivative are used in cooperation. The preservative has excellent antimicrobial performance and tolerance, and can be widely applied to various fields.

Description

A preservative for polycarboxylate water-reducing agent containing isothiazolinone composition and preparation method thereof

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to the Chinese patent application with application number 202311801252.X filed with the Chinese Patent Office on December 26, 2023, entitled "A preservative for polycarboxylic acid water-reducing agent containing an isothiazolinone composition and its preparation method", the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present invention relates to the field of building materials, in particular to a preservative for a polycarboxylate water-reducing agent containing an isothiazolinone composition and a preparation method thereof. Background Art

[0004] At present, during the use of polycarboxylic acid water reducers, a certain amount of preservatives are often added to extend their service life and stability. However, the preservatives in the prior art have the following defects: (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: Certain preservatives will interact with polycarboxylic acid molecules at high concentrations, resulting in impaired performance of the water reducer and reduced water-reducing effect. (3) Impact on cement gel: Some preservatives may react with cement gel, resulting in a slower hardening rate of cement or a longer setting time, affecting the process performance of concrete. (4) Environmental pollution problems: Certain preservatives will produce pollutants during production and use, which will have a negative impact on the environment.

[0005] In response to the defects of polycarboxylic acid water reducers when using preservatives, some improvement measures have been taken: (1) Use environmentally friendly inorganic salts or organic substances as alternative preservatives. These alternatives are safer and do not produce harmful volatile organic compounds. For example, some studies have proposed the use of potassium chloride or other harmless salts as preservatives for polycarboxylic acid water reducers. (2) Improve the compatibility between water reducers and preservatives by improving the structure and synthesis method of polycarboxylic acid molecules and reduce the interaction between them. For example, some studies have improved the interaction between polycarboxylic acid molecules and preservatives by adjusting the side chain structure and length of polycarboxylic acid molecules, thereby improving the water reduction effect. (3) Find preservatives that will not react adversely with cement gel. For example, some studies have shown that the use of specific organic acid preservatives, such as benzoic acid and propionic acid, can reduce their impact on cement gel. (4) When selecting preservatives, pay more attention to environmental friendliness and sustainability. For example, choose preservatives that have good biodegradability and less impact on the environment. In addition, by improving production processes, the emission of harmful substances can be reduced or avoided to reduce environmental pollution.

[0006] Therefore, more environmentally friendly preservatives will be needed in the future.

[0007] Summary of the Invention

[0008] In order to solve the problems raised in the above background technology, the present invention provides a preservative for polycarboxylate water-reducing agent containing an isothiazolinone composition and a preparation method thereof.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A preservative for a polycarboxylate water-reducing agent containing an isothiazolinone composition comprises the following raw materials, measured by weight: 1 to 15 parts of an antiseptic monomer, 0.5 to 2.0 parts of a bactericidal monomer, 1 to 2 parts of a stabilizer, and 50 to 90 parts of water. The bactericidal monomer is an isothiazolinone composition comprising an isothiazolinone derivative and an isothiazolinone quaternary ammonium salt. The antiseptic monomer is an organic bromine, and its structural formula is as follows:

[0011] Where M is One of them.

[0012] Preferably, the structural formula of the isothiazolinone derivative is as follows:

[0013] Wherein, R1 is CH3COO-, One of them.

[0014] Preferably, the structural formula of the isothiazolinone quaternary ammonium salt is as follows:

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

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

[0017] A method for preparing a preservative for a polycarboxylate water-reducing agent containing an isothiazolinone composition comprises the following steps, calculated by weight:

[0018] Step (1), adding the antiseptic monomer and the bactericidal monomer to 10 to 30 parts by weight of water, stirring evenly to obtain a mixture;

[0019] Step (2): adding the stabilizer to the mixture, adding the remaining water, and stirring to obtain the preservative for the polycarboxylate water-reducing agent.

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

[0021] The beneficial effects of the present invention are:

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

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

[0024] (3) The present invention adopts organic bromine and isothiazolinone combination antiseptic active components to enhance the antimicrobial effect, prevent the antiseptic and bactericidal effect from decreasing after long-term use of the preservative, expand the scope of inhibiting microbial growth, and enhance the drug resistance and tolerance of the preservative.

[0025] (4) The preservative for polycarboxylic acid water-reducing agent prepared by the present invention has strong practicality. DETAILED DESCRIPTION

[0026] It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0027] Embodiment 1:

[0028] 1 part by weight of antiseptic monomer and 0.7 part by weight of bactericidal monomer were weighed, added to 25 parts by weight of water and stirred evenly, and then 1 part by weight of propylene glycol and 60 parts by weight of water were added and stirred for 15 minutes to obtain a preservative for polycarboxylate water reducer.

[0029] The anticorrosion monomers are:

[0030] The bactericidal monomer is

[0031] The steps of Examples 2 to 8 are the same as those of Example 1. The reagents and conditions used are as follows: Table 1 Experimental parameters

[0032] The bactericidal monomer used in Example 2 is:

[0033] The anticorrosive monomer is

[0034] The bactericidal monomer used in Example 3 is:

[0035] The anticorrosive monomer is

[0036] The bactericidal monomer used in Example 4 is:

[0037] The anticorrosive monomer is

[0038] The bactericidal monomer used in Example 5 is:

[0039] The anticorrosive monomer is

[0040] The bactericidal monomer used in Example 6 is:

[0041] The anticorrosive monomer is

[0042] The bactericidal monomer used in Example 7 is:

[0043] The anticorrosive monomer is

[0044] The bactericidal monomer used in Example 8 is:

[0045] The anticorrosive monomer is

[0046] Comparative Example 1

[0047] The difference from Example 1 is that methyl benzoate (containing no bromine) is used instead of the bactericidal monomer.

[0048] Comparative Example 2

[0049] The difference from Example 1 is that benzyl alcohol is used instead of the antiseptic monomer.

[0050] The minimum inhibitory concentration (MIC) method was used to evaluate the antiseptic and antibacterial properties of the prepared samples. Bacillus subtilis, Escherichia coli, and Aspergillus niger, all purchased from the Shanghai Collection Biotechnology Center, were used as test subjects. The MCI was determined using the test tube dilution method: 10 mL of peptone beef broth (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, various concentrations of polycarboxylic acid admixtures were added as a preservative. Under sterile conditions, the tube was inoculated with 1% of the bacterial suspension and incubated in a water-shaking incubator at 37°C for 24 hours. The tube with the lowest concentration of the culture medium was identified from the test tubes showing sterile growth.

[0051] The test results are shown in Table 2.

[0052] Table 2 Antiseptic and antibacterial performance test of preservatives

[0053] The above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended claims.

Claims

1. A preservative for polycarboxylate water reducer containing an isothiazolinone composition, characterized in that, By weight parts, it includes the following raw materials: 1 to 15 parts of an anti-corrosion monomer, 0.5 to 2.0 parts of a bactericidal monomer, 1 to 2 parts of a stabilizer, and 50 to 90 parts of water. The bactericidal monomer is an isothiazolinone composition, and the isothiazolinone composition includes an isothiazolinone derivative and an isothiazolinone quaternary ammonium salt; the anti-corrosion monomer is an organic bromine type, and its structural formula is as follows: where M is One of them.

2. The preservative for polycarboxylate water reducer containing an isothiazolinone composition according to claim 1, characterized in that, The structural formula of the isothiazolinone derivative is as follows: In the formula, R1 is CH3COO-, One of them.

3. A preservative for polycarboxylate water reducer containing isothiazolinone composition according to claim 1, characterized in that, 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.

4. The preservative for polycarboxylate water reducer 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.

5. A preparation method of a preservative for polycarboxylate water reducing agent containing an isothiazolinone composition as described in claim 1 or 2, characterized in that, By mass parts, it includes the following steps: Step (1): Add the anti-corrosion monomer and the bactericidal monomer to 10 to 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 anti-corrosion agent for polycarboxylate water reducer.

6. The preparation method of a preservative for polycarboxylate water reducer containing an isothiazolinone composition according to claim 3, characterized in that, The stirring time in step (2) is 10 to 30 minutes.

Images