A preservative for polycarboxylate water-reducing agent containing a preservative monomer and a bactericidal monomer and a preparation method thereof

Abstract

The application belongs to the field of building materials, and particularly relates to a preservative for polycarboxylate water reducing agent containing a preservative monomer and a bactericidal monomer and a preparation method thereof. According to weight parts, the preservative for polycarboxylate water reducing agent comprises 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 a modified isothiazolinone compound, and the preservative monomer is a dihydric alcohol. The preservative for polycarboxylate water reducing agent prepared by using the dihydric alcohol and the bactericidal monomer has wide antibacterial effect, good dissolving performance and safety and environmental protection characteristics.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building materials, in particular to a kind of containing anticorrosive monomer and bactericidal monomer's polycarboxylate water-reducing agent preservative and its preparation method. BACKGROUND

[0002] At present, polycarboxylate water-reducing agent often needs to add a certain amount of preservative to prolong its service life and stability during use. However, the preservatives in the prior art have the following defects: (1) harmful substance release: some traditional preservatives contain harmful substances, such as formaldehyde, benzene and other volatile organic compounds, which may be released into the environment, posing potential risks to human health. (2) reduce water-reducing effect: certain preservatives may interact with polycarboxylate molecules at high concentrations, resulting in impaired performance of water-reducing agent and reduced water-reducing effect. (3) influence on cement gel: some preservatives may react with cement gel, resulting in slower hardening speed or prolonged setting time of cement, affecting the process performance of concrete. (4) environmental pollution problem: certain preservatives may produce pollutants during production and use, causing negative impact on the environment.

[0003] In view of the defects of polycarboxylate water-reducing agent when using preservatives, some improvement measures have been taken: (1) use environmentally friendly inorganic salts or organic substances as alternative preservatives, which 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 water-reducing agent. (2) improve the compatibility between water-reducing agent and preservative by improving the structure and synthesis method of polycarboxylate molecules, and reduce their interaction. For example, some studies have improved the interaction between polycarboxylate molecules and preservatives by adjusting the side chain structure and length of polycarboxylate molecules, thereby improving the water-reducing effect. (3) find preservatives that do not have adverse reactions with cement gel. For example, some studies have shown that using specific organic acid preservatives, such as benzoic acid, propionic acid, etc., can reduce their influence on cement gel. (4) pay more attention to environmental friendliness and sustainability when selecting preservatives. For example, choose preservatives that are biodegradable and have less impact on the environment. In addition, by improving the production process, reduce or avoid the emission of harmful substances to reduce environmental pollution.

[0004] Therefore, more environmentally friendly preservatives are needed in the future. SUMMARY

[0005] To solve the problems raised in the background art, the present application provides a kind of containing anticorrosive monomer and bactericidal monomer's polycarboxylate water-reducing agent preservative and its preparation method.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] A polycarboxylic acid water reducing agent preservative containing a preservative monomer and a bactericidal monomer, by weight fraction, comprising 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 a modified isothiazolinone compound, the preservative monomer is a dihydric alcohol, and the structure formula is as follows:

[0008]

[0009] In which R2 is one of CH3(CH2)5-, (CH2)6-, CH3-.

[0010] Preferably, the stabilizer is at least one of propylene glycol, propylene glycol fatty acid ester, D-mannitol, propylene glycol alginate, chitin, polyglycerol ricinoleate.

[0011] Preferably, the preparation method of the modified isothiazolinone compound comprises the following steps by weight fraction:

[0012] Step (1), 4-6 parts of isothiazolinone compound, 5-7 parts of acid anhydride are added to a four-necked flask with stirring device, thermometer and condenser, 100-180 parts of dimethylbenzene are put in under nitrogen protection, slowly heated to 100-150 DEG C, and reacted for 6-8 h to obtain a crude product;

[0013] Step (2), the obtained crude product is ground and washed with 30-50 parts of dimethylbenzene for 3-5 times,

[0014] Vacuum drying to obtain a modified isothiazolinone compound.

[0015] Preferably, the structure formula of the isothiazolinone is as follows:

[0016]

[0017] In which R1 is one of H, Ph, Bn, Et, Me.

[0018] Preferably, the acid anhydride is any one of maleic anhydride, phthalic anhydride, oxalic anhydride.

[0019] Preferably, the slow heating in step (1) is to 100-150 DEG C.

[0020] Preferably, the vacuum drying time in step (2) is 18-36 h.

[0021] A preparation method of a polycarboxylic acid water reducing agent preservative containing a preservative monomer and a bactericidal monomer, characterized in that, by weight fraction, comprising the following steps:

[0022] Step (1), the preservative monomer and the bactericidal monomer are added into 10-30 parts by weight of water, and stirred uniformly to obtain a mixture;

[0023] Step (2), the stabilizer is added into the mixture, and the remaining water is added, and stirred for 10-30 min, to obtain the polycarboxylate water reducing agent preservative.

[0024] The polycarboxylate water reducing agent preservative has the following beneficial effects:

[0025] (1) The dihydric alcohol substance as the preservative monomer contains hydroxyl groups, which can effectively reduce the surface tension of the system, and contains nitro groups, which can effectively adsorb microorganisms with negative charges in the system, and can significantly inhibit the growth of microorganisms, thereby playing a preservative and bactericidal effect.

[0026] (2) The bactericidal monomer prepared in the present application introduces carboxyl groups on the isothiazolinone molecular structure by N substitution, which enhances the bonding degree between molecules, and has good water solubility, so that the prepared preservative has increased bacteriostatic activity and improved solubility, and the preservative effect is improved.

[0027] (3) The dihydric alcohol and the bactericidal monomer are used together with other preservative active components, which enhances the antimicrobial effect and expands the range of microbial growth inhibition, and is non-irritating and safe and environmentally friendly. DETAILED DESCRIPTION

[0028] Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application, and are not intended to limit the protection scope of the present application.

[0029] Example 1:

[0030] (1) Preparation of bactericidal monomer: 4 parts of benzisothiazolinone and 5 parts of maleic anhydride are added into a four-mouthed baking pan with stirring device, thermometer and condenser under nitrogen protection, 100 parts of toluene is added, and slowly heated to 120℃, and reacted for 6h to obtain a crude product. The obtained crude product is ground and washed with 30 parts of xylene for 4 times, and vacuum dried for 24h to obtain the reaction product.

[0031] (2) Preparation of polycarboxylate water reducing agent preservative: 1 part by weight of preservative monomer and 0.5 parts by weight of bactericidal monomer are weighed and added into 20 parts by weight of water, and stirred uniformly, then 1 part by weight of propylene glycol and 50 parts by weight of water are added and stirred for 20 min to obtain the polycarboxylate water reducing agent preservative.

[0032] The structure of the preservative monomer used is as follows:

[0033]

[0034] The procedure of Examples 2-8 was the same as that of Example 1, and the reagents and condition parameters used were as follows:

[0035] Table 1 Preparation of bactericidal monomers

[0036]

[0037] Table 2 Preparation of preservatives for polycarboxylate water reducing agents

[0038]

[0039] The structure of the preservative monomer used in Example 2 is as follows:

[0040]

[0041] The structure of the preservative monomer used in Example 3 is as follows:

[0042]

[0043] The structure of the preservative monomer used in Example 4 is as follows:

[0044]

[0045] The structure of the preservative monomer used in Example 5 is as follows:

[0046]

[0047] The structure of the preservative monomer used in Example 6 is as follows:

[0048]

[0049] The structure of the preservative monomer used in Example 7 is as follows:

[0050]

[0051] The structure of the preservative monomer used in Example 8 is as follows:

[0052]

[0053] Comparative Example 1

[0054] Unlike Example 1, thiazole was used instead of the benzisothiazolinone of Example 1.

[0055] Comparative Example 2

[0056] Unlike Example 1, benzyl alcohol was used instead of the preservative monomer of Example 1.

[0057] The bacteriostatic activity of the prepared sample was determined by filter paper method. Staphylococcus aureus, Bacillus subtilis and Escherichia coli were used as test objects in the experiment process, which were purchased from Shanghai Center for Bio-Organism Preservation. The specific test method was as follows: Staphylococcus aureus, Bacillus subtilis and Escherichia coli were activated in advance, and then were mixed with sterile water to prepare a bacterial suspension. Then, the bacterial suspension was mixed with beef extract peptone culture medium (peptone 1%, beef extract 0.3%, NaCl 0.5%, glucose 1%, pH 6.5-7) uniformly, and 5 mL of the mixture was taken in a 9 mm diameter culture dish. 5 μL of preservative with a concentration of 1000 μg / mL of polycarboxylate superplasticizer was coated on a 5 mm filter paper sheet, and dried. Each group had 3 parallel experiments. The dried filter paper sheet was placed on the surface of the culture medium, and was pressed by sterile forceps. Then, the filter paper sheet was cultured in a 30°C incubator for 18 h. The diameter of the bacteriostatic circle was measured by cross method, and the transparency of the bacteriostatic circle was observed. The test results are shown in Table 3.

[0058] Table 3 Bacteriostatic activity test of preservative

[0059]

[0060] “+” represents the degree of bacteriostatic circle, and the more, the more obvious the bacteriostasis.

[0061] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent of the present application. It should be noted that, for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are all within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1.A preservative for polycarboxylate superplasticizer containing a preservative monomer and a bactericidal monomer, comprising the following raw materials in parts by weight: 1-15 parts of a preservative 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 a modified isothiazolinone compound, the preservative monomer is a dihydric alcohol, and the structure of the dihydric alcohol is as follows: wherein R2 is one of CH3(CH2)5- and CH3-; the stabilizer is at least one of propylene glycol, propylene glycol fatty acid ester, D-mannitol, propylene glycol alginate, chitin, and polyglycerol ricinoleate; and the modified isothiazolinone compound is prepared by the following steps in parts by weight: step (1) : adding 4-6 parts of an isothiazolinone compound and 5-7 parts of an anhydride into a four-necked flask with a stirring device, a thermometer, and a condenser tube, adding 100-180 parts of dimethylbenzene under nitrogen protection, slowly heating to 100-150 DEG C, and reacting for 6-8 hours to obtain a crude product; step (2) : grinding the crude product, washing it with 30-50 parts of dimethylbenzene for 3-5 times, and vacuum drying to obtain the modified isothiazolinone compound; wherein the isothiazolinone compound has the following structure: wherein R1 is one of H, Ph, Bn, Et, and Me; and the anhydride is any one of maleic anhydride, phthalic anhydride, and oxalic anhydride; wherein the slowly heating in step (1) is to 100-150 DEG C; and the vacuum drying time in step (2) is 18-36 hours; and the preservative for polycarboxylate superplasticizer is prepared by the following steps in parts by weight: step (1) : adding the preservative monomer and the bactericidal monomer into 10-30 parts of water, stirring to obtain a mixture; and step (2) : adding the stabilizer into the mixture, adding the remaining water, and stirring for 10-30 minutes to obtain the preservative for polycarboxylate superplasticizer. ， ​ ​ characterized in that ​ ​ ​ 2. The preservative for polycarboxylate water reducer containing a preservative monomer and a bactericidal monomer according to claim 1, characterized in that, ​ ， ​ 3. The preservative for polycarboxylate water reducer containing a preservative monomer and a bactericidal monomer according to claim 1, characterized in that, ​ 4. The preservative for polycarboxylate water reducer containing a preservative monomer and a bactericidal monomer according to claim 1, characterized in that, ​ 5. The preservative for polycarboxylate water reducer containing a preservative monomer and a bactericidal monomer according to claim 1, characterized in that, ​ 6. A method for producing a preservative for polycarboxylate water reducing agents containing a preservative monomer and a bactericidal monomer according to any one of claims 1 to 5, characterized by, ​ ​ ​

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