Cationic organic silicon as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of organic silicon polymer materials, and provides cationic organic silicon: (Me3SiO0.5) a (R2Me2SiO0.5) b (Me2SiO) c (R2MeSiO) d (MeSiO1.5) e (R2SiO1.5) f (SiO2) g, a being 7-12, b being 0-10, c being 4-30, d being 2-15, e being 4-15 and f being 6-30, aiming at the problems of poor hydrolysis resistance and antibacterial property of the existing organic silicon. G is 30 to 50; r2 is (CH2) n + 1S (CH2) m + 3R1M, and R1 is + N (CH3) 3, + N (C2H5) 3, + N (CH3) 2CH2CH2OH, a pyridine cation or an imidazole cation; m is Cl <->, Br <->, I <-> or BF4 <->; n = 0 or 2; and m = 0-9. And the sterilization effect can be improved by adopting sulfydryl-alkene reaction for preparation.

Description

Technical Field

[0001] This invention belongs to the field of organosilicon polymer materials technology, specifically relating to cationic organosilicon. Background Technology

[0002] There are some reports on cationic organosilicones in the prior art, such as quaternary ammonium salt organosilicones, in which quaternary ammonium salt groups are firmly bonded to the siloxane backbone in the form of side chains via alkyl segments, relying on stable quaternary ammonium salt cations (-N + R3, through strong electrostatic adsorption, inserts into and tears the cell membrane / wall of microorganisms, causing leakage of contents and killing the microorganisms. This is one of the most classic and effective antibacterial mechanisms. Its single cationic head and single hydrophobic chain structure determines that its charge density and membrane-disrupting ability have theoretical limits. Although dual-chain alkyl quaternary ammonium salt organosilicon / gemini quaternary ammonium salt organosilicon has better antibacterial function, its synthesis is complex and costly; its extremely strong hydrophobicity makes its dissolution and dispersion in water exceptionally difficult; it easily forms micelles or precipitates, requiring very strong special emulsification systems or highly polar solvents (such as alcohols) to form stable formulations, which increases the processing difficulty and cost for downstream users. Reactive quaternary ammonium salt organosilicon has alkoxy groups at the molecular ends or side chains, which can form Si-OC bonds on the substrate surface, fixing the quaternary ammonium salt in the coating; however, the Si-OC bonds are easily hydrolyzed and unstable. The aforementioned quaternary ammonium salt organosilicones are small molecule materials, which have the disadvantage of Si-O bonds being susceptible to hydrolysis. Most of them are linear molecules, and linear molecules tend to encapsulate cations, affecting physical adsorption properties and thus impacting antibacterial durability. Even reactive quaternary ammonium salt organosilicones form a "single" network structure on the substrate surface, which also exhibits poor hydrolysis resistance.

[0003] Highly effective antibacterial properties (instantaneous killing): require cationic groups that are easily exposed and readily contact microorganisms. This tends to favor structures with smaller molecular weights and higher mobility, enabling rapid diffusion to the location of microorganisms. Long-lasting antibacterial properties, on the other hand, require molecules to firmly adsorb onto the substrate to form a stable film that is not easily eluted. This tends to favor structures with larger molecular weights and a greater number of adsorption sites. Therefore, how to prepare cationic organosilicones that possess both highly effective antibacterial properties and excellent durability is a problem that needs to be solved. Summary of the Invention

[0004] To address the aforementioned problems of poor hydrolysis resistance and inadequate antibacterial effect, especially long-lasting antibacterial properties, existing cationic organosilicones provide a cationic organosilicon, its preparation method, and its application. This invention uses SH-containing silicone resin and unsaturated olefin cationic compounds as raw materials, employs a mercaptoene reaction to prepare cationic silicone resin, and applies it to an antibacterial coating. Experiments have shown that it can improve both instantaneous bactericidal effect and long-lasting antibacterial performance, while also possessing the advantages of silicone resins such as heat resistance, weather resistance, and hydrolysis resistance.

[0005] This invention is achieved through the following technical solution:

[0006] In a first aspect, the present invention provides a cationic organosilicon with the following structure:

[0007] (Me3SiO 0.5 ) a (R2Me2SiO 0.5 ) b (Me2SiO) c (R2MeSiO) d (MeSiO 1.5 ) e (R2SiO 1.5 ) f (SiO2)g,

[0008] Where a is 7–12, b is 0–10, c is 4–30, d is 2–15, e is 4–15, f is 6–30; g is 30–50; R2 is (CH2). n+1 S(CH2) m+3 R1M, R1 is + N(CH3)3, + N(C2H5)3, + N(CH3)2CH2CH2OH, pyridine cation or imidazole cation; M is Cl － , Br － I － Or BF4 － n = 0 or 2; m = 0 to 9.

[0009] Furthermore, when b is 0, the preferred structure is: (Me3SiO) 0.5 ) a (Me2SiO) c (R2MeSiO) d (MeSiO 1.5 ) e (R2SiO 1.5 ) f (SiO2) g Wherein, a is 8 to 10, c is 8 to 25, more preferably 10 to 20; d is 4 to 12, more preferably 6 to 10; e is 6 to 12, more preferably 8 to 10; f is 10 to 25, more preferably 14 to 20; g is 35 to 45, more preferably 38 to 42.

[0010] When b is not 0, the preferred structure is: (Me3SiO) 0.5 ) a (R2Me2SiO 0.5 ) b (Me2SiO)c (R2MeSiO) d (MeSiO 1.5 ) e (R2SiO 1.5 ) f (SiO2) g Wherein, a is 8 to 10, b is 3 to 8, more preferably 5 to 7; c is 8 to 20, more preferably 10 to 15; d is 4 to 10, more preferably 6 to 8; e is 6 to 13, more preferably 8 to 12; f is 10 to 20, more preferably 13 to 16; g is 35 to 45, more preferably 38 to 42.

[0011] Furthermore, the (CH2) n+1 S(CH2) m+3 R1M, m is 2 to 7, more preferably 4 to 6.

[0012] In a second aspect, the present invention provides a method for preparing cationic organosilicon, comprising the following steps:

[0013] (1) Place the SH-containing silicone resin and solvent in a reaction vessel and start stirring to dissolve;

[0014] (2) Under a protective atmosphere, metered unsaturated olefin cationic compounds and initiators are added dropwise to the reaction vessel, and the reaction is maintained for 0.5 to 2 hours. The solvent is removed to obtain cationic silicone resin.

[0015] The structure of the SH-containing silicone resin is: (Me3SiO) 0.5 ) a (RMe2SiO 0.5 ) b (Me2SiO) c (RMeSiO) d (MeSiO 1.5 ) e (RSiO 1.5 ) f (SiO2) g R = CH2CH2CH2SH or / and CH2SH; a is 7-12, b is 0-10, c is 4-30, d is 2-15, e is 4-15, f is 6-30; g is 30-50;

[0016] The unsaturated olefinic cationic compound is CH2=CH(CH2)mCH2R1M, where m=0~9; R1 is… + N(CH3)3, + N(C2H5)3, + N(CH3)2CH2CH2OH, pyridine cation, imidazole cation, etc.; M is Cl － , Br－ I － BF4 － The amount added is determined by the molar ratio of SH:Vi (mercapto:vinyl) = 1 to 1.05:1;

[0017] The initiator is benzoin dimethyl ether, 2-isopropylthioxanthraquinone, photoinitiator Irgacure 369, or any combination of two, and its addition amount is 0.2% to 3% of the total mass of SH resin and unsaturated anionic monomer.

[0018] In order to shorten the reaction time and optimize the light source selectivity by combining the initiators, the initiators are further composed of benzoin dimethyl ether and 2-isopropylthioxanthrone in a mass ratio of 2:1, which shortens the reaction time to 1 hour.

[0019] Furthermore, the initiator is a mixture of benzoin dimethyl ether and photoinitiator Irgacure 369 in a mass ratio of 1:1, which shortens the reaction time to 0.5 h.

[0020] Furthermore, the preferred structure of the SH-containing silicone resin when b is 0 is: (Me3SiO) 0.5 ) a (Me2SiO) c (RMeSiO) d (MeSiO 1.5 ) e (RSiO 1.5 ) f (SiO2) g R = CH2CH2CH2SH or / and CH2SH; a is 8-10, c is 8-25, more preferably 12-20; d is 4-12, more preferably 6-10; e is 6-12, more preferably 8-10; f is 10-25, more preferably 13-20; g is 35-45, more preferably 30-40.

[0021] When b is not 0, its preferred structure is: (Me3SiO) 0.5 ) a (RMe2SiO 0.5 ) b (Me2SiO) c (RMeSiO) d (MeSiO 1.5 ) e (RSiO 1.5 ) f (SiO2) ga is 8-10, b is 1-8, more preferably 3-7; c is 6-26, more preferably 8-22; d is 2-15, more preferably 5-12; e is 4-15, more preferably 7-12; f is 6-30, more preferably 9-26; g is 30-50, more preferably 33-45.

[0022] Furthermore, in the unsaturated olefinic cationic compound CH2=CH(CH2)mCH2R1M, m is preferably 2 to 8, more preferably 4 to 6.

[0023] Furthermore, the solvent is methanol, ethanol, DMSO, DMF, DMC, etc.

[0024] When the structure of the SH-containing silicone resin is known, it can be prepared using existing synthesis methods. For example, the specific mass of silane monomer to be fed can be determined based on the molar ratio of the units in the structural formula. A certain amount of deionized water, 37wt% concentrated hydrochloric acid, ethanol, and hexamethyldisiloxane are added sequentially to a four-necked flask equipped with a stirrer, condenser, and thermometer. The mixture is stirred and heated. Then, the desired monosilane monomer solution is added to the four-necked flask under rapid stirring. The reaction is stirred at 50–60°C, and the reaction progress can be monitored by sampling until the solution separates into layers and a white viscous product is formed. After standing and separating, the lower layer of resin product is washed with water until neutral, and then dried to obtain the corresponding silicone resin. Alternatively, a stepwise method can be used: first, non-mercaptosilanes are pre-hydrolyzed at low temperature (e.g., 30°C) for 1–2 hours to form oligomers containing Si-OH; then, mercaptosilanes are dissolved in a solvent and slowly added dropwise to the pre-hydrolyzed solution. At this point, the mercaptosilane will undergo co-condensation with the Si-OH on the oligomer, thereby attaching the mercapto segments to the already formed backbone for a more uniform distribution; finally, the temperature is raised to 50-60℃ to promote overall polymerization.

[0025] The third aspect of this invention provides the application of cationic organosilicon as a bactericide and bacteriostatic agent.

[0026] It is prepared into a solution and used as the active ingredient in a bactericide. Its concentration range is 5–20 mg / L, preferably 8–12 mg / L.

[0027] Water, methanol, and ethanol can be used as solvents.

[0028] As an antibacterial coating, it has both immediate bactericidal and long-lasting antibacterial properties.

[0029] It is used to kill various common bacteria such as Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa.

[0030] It can be applied or sprayed onto various solid surfaces, such as glass, ceramics, and plastics, to achieve bactericidal and bacteriostatic effects.

[0031] The present invention has the following beneficial effects: (1) The cationic organosilicon prepared by the present invention has a three-dimensional network silicone resin structure, which allows the cations on the skeleton to spread and be exposed better, increases the physical adsorption with the substrate surface, improves the instantaneous bactericidal effect and long-lasting antibacterial performance, and also has the advantages of silicone resin such as heat resistance, weather resistance and hydrolysis resistance.

[0032] (2) It has strong bactericidal ability and broad-spectrum antibacterial properties; physical adsorption does not damage the substrate surface and has a wide range of applications.

[0033] (3) The synthesis process is highly atom-economical and conforms to the principles of green chemistry; it has high selectivity and efficiency; the reaction rate is fast and the conversion rate is high. It can usually be completed by ultraviolet light irradiation at room temperature or lower temperature, which saves energy and is beneficial to protect heat-sensitive components; it effectively avoids the risk of cross-linking and gelation. Attached Figure Description

[0034] Figure 1 The chemical reaction equation for the ionic silicone resin of this invention is as follows;

[0035] Figure 2 The pyridine salt type silicone resin prepared in Example 5 1 H NMR spectrum. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0037] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0038] I. Preparation of Cationic Silicone Resin

[0039] Example 1

[0040] Take 100 parts by weight (Me3SiO) 0.5 ) 10 (Me2SiO)4(HSCH2CH2CH2MeSiO)2(MeSiO 1.5 )4(HSCH2CH2CH2SiO 1.5 ) 10 (SiO2) 35 33 parts by weight of allyltrimethylammonium chloride, 0.66 parts by weight of benzoin dimethyl ether, and 60 parts by weight of DMSO were mixed and stirred until homogeneous. The mixture was then irradiated with 365nm UV for 1.5 hours to remove the DMSO, yielding a pale yellow solid, which is the quaternary ammonium salt type silicone resin. In this embodiment, the molar ratio of SH in the silicone resin to the double bond in allyltrimethylammonium chloride is 1:1.

[0041] Example 2

[0042] (Me3SiO 0.5 )8(HSCH2CH2CH2Me2SiO 0.5 ) 12 (Me2SiO)5(HSCH2CH2CH2MeSiO)2(MeSiO 1.5 )5(HSCH2CH2CH2SiO 1.5 )6(SiO2) 35 45 parts by weight of allyltrimethylammonium chloride, 0.90 parts by weight of benzoin dimethyl ether, and 60 parts by weight of DMSO were mixed and stirred until homogeneous. The mixture was then irradiated with 365 nm UV for 1.5 hours to remove the DMSO, yielding a pale yellow solid, which is the quaternary ammonium salt type silicone resin. In this embodiment, the molar ratio of SH in the silicone resin to the double bond in allyltrimethylammonium chloride is 1:1.

[0043] Example 3

[0044] (Me3SiO 0.5 )6(Me2SiO)4(HSCH2MeSiO) 15 (MeSiO 1.5 ) 10 (HSCH2SiO 1.5 40-51 parts by weight of 8(SiO2)4, allyltrimethylammonium chloride, 0.90 parts by weight of benzoin dimethyl ether, and 60 parts by weight of DMSO were mixed and stirred until homogeneous. The mixture was then irradiated with 365nm UV for 1.5 hours to remove the DMSO, yielding a pale yellow solid, which is the quaternary ammonium salt type silicone resin. In this embodiment, the molar ratio of SH in the silicone resin to the double bond in the allyltrimethylammonium chloride is 1:1.

[0045] Example 4

[0046] (Me3SiO 0.5 )9(Me2SiO) 15 (HSCH2CH2CH2MeSiO)7(MeSiO 1.5 )8(HSCH2CH2CH2SiO 1.5 )7(SiO2) 35 30 parts by weight of allyltrimethylammonium chloride, 0.60 parts by weight of benzoin dimethyl ether, and 60 parts by weight of DMSO were mixed and stirred until homogeneous. The mixture was then irradiated with 365nm UV for 1.5 hours to remove the DMSO, yielding a pale yellow solid, which is the quaternary ammonium salt type silicone resin. In this embodiment, the molar ratio of SH in the silicone resin to the double bond in allyltrimethylammonium chloride is 1:1.

[0047] Example 5

[0048] Take 100 parts by weight (Me3SiO) 0.5 ) 10 (Me2SiO)4(HSCH2CH2CH2MeSiO)2(MeSiO 1.5 )4(HSCH2CH2CH2SiO 1.5 ) 10 (SiO2) 35 40 parts by weight of allylpyridine chloride, 0.80 parts by weight of benzoin dimethyl ether, and 60 parts by weight of DMSO were mixed and stirred until homogeneous. The mixture was then irradiated with 365nm UV for 1.5 hours to remove the DMSO, yielding a pale yellow solid, which is the pyridine salt type silicone resin. In this embodiment, the molar ratio of SH in the silicone resin to the double bond in the allylpyridine chloride is 1:1.

[0049] Table 1. Structural formulas of cationic silicone resins

[0050]

[0051] II. Antibacterial Test

[0052] Test sample group: The quaternary ammonium salt type silicone resin and pyridinium salt type silicone resin prepared in the examples were respectively prepared into 0.4% and 10% aqueous solutions, and then coated onto glass plates by wire bar coaters, cured at 120°C, and the performance was tested.

[0053] Positive control group: benzalkonium chloride.

[0054] Blank control group: sterile physiological saline.

[0055] Negative material control: Untreated carrier slide of the same material.

[0056] Tested bacterial strains: Staphylococcus aureus ATCC 6538, Escherichia coli 8099 and Pseudomonas aeruginosa ATCC 9027.

[0057] 1. Antibacterial rate:

[0058] Methods: The antibacterial properties of nano-inorganic materials were tested and evaluated according to GB / T 21510-2024. The antibacterial rate was calculated by incubation and counting using the film-coating method.

[0059] 2. Recycling test and coating alcohol wiping resistance test

[0060] Method: Both coatings were wiped simultaneously using the same 75% alcohol and standardized wiping equipment.

[0061] Test point: After each 10 wipes, observe whether the coating peels off or wrinkles, and conduct an antibacterial and bactericidal test. Repeat 10 times.

[0062] 3. Water-soluble

[0063] Method: A certain amount of cationic silicone resin was added to water. After stirring or shaking at 25°C, the homogeneity, emulsion or separation was observed. After standing for 24 hours, the homogeneity, emulsion or separation of the solution was observed.

[0064] Table 2 Test Results

[0065]

[0066]

[0067] Comprehensive experiments show that, compared with commercially available quaternary ammonium salts, the quaternary ammonium salt type silicone resin and pyridinium salt type silicone resin prepared by this invention exhibit significant overall advantages under the same usage conditions: stronger basic bactericidal efficacy; significantly improved durability; coating with low surface energy, antifouling properties, and excellent adhesion; outstanding resistance to organic interference; and more stable performance under polluted conditions.

[0068] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A cationic organosilicon characterized in that, The cationic silicone is a silicone resin chemically bonded with cations on the molecular skeleton, and its structure is as follows: (Me3SiO 0.5 ) a (R2Me2SiO 0.5 ) b (Me2SiO) c (R2MeSiO) d (MeSiO 1.5 ) e (R2SiO 1.5 ) f (SiO2)g, wherein a is 7-12, b is 0-10, c is 4-30, d is 2-15, e is 4-15, f is 6-30, g is 30-50; R2is (CH2) n+1 S(CH2) m+3 R1M, R1is + N(CH3)3, + N(C2H5)3, + N(CH3)2CH2CH2OH, a pyridinium cation or an imidazolium cation; M is Cl － , Br － , I － or BF4 － ; n = 0 or 2; m = 0-9.

2. The cationic silicone according to claim 1, characterized in that, b is 0, the structure is: (Me3SiO 0.5 ) a (Me2SiO) c (R2MeSiO) d (MeSiO 1.5 ) e (R2SiO 1.5 ) f (SiO2) g , wherein a is 8-10, c is 8-25, d is 4-12, e is 6-12, f is 10-25, and g is 35-45; b is not 0, the structure is: (Me3SiO 0.5 ) a (R2Me2SiO 0.5 ) b (Me2SiO) c (R2MeSiO) d (MeSiO 1.5 ) e (R2SiO 1.5 ) f (SiO2) g , wherein a is 8-10, b is 3-8, c is 8-20, d is 4-10, e is 6-13, f is 10-20, and g is 35-45; (CH2) n+1 S(CH2) m+3 R1M, m is 2-7.

3. The method for producing a cationic silicone according to claim 1, characterized by, The method comprises the following steps: (1) Put the SH-containing silicone resin and solvent into a reaction kettle, and start stirring and dissolving; (2) Under a protective atmosphere, measure the unsaturated cationic compound and initiator, and drop them into the reaction kettle, maintain the reaction for 0.5-2 hours, and remove the solvent to obtain the cationic silicone resin; The SH-containing silicone structure is: (Me3SiO 0.5 ) a (RMe2SiO 0.5 ) b (Me2SiO) c (RMeSiO) d (MeSiO 1.5 ) e (RSiO 1.5 ) f (SiO2) g R = CH2CH2CH2SH or / and CH2SH; a is 7-12, b is 0-10, c is 4-30, d is 2-15, e is 4-15, f is 6-30; g is 30-50; The unsaturated olefin cationic compound is CH2=CH(CH2)mCH2R1M, m = 0-9; R1 is + N(CH3)3, + N(C2H5)3, + N(CH3)2CH2CH2OH, pyridinium cation or imidazolium cation; M is Cl － , Br － , I － or BF4 － ; the dropwise addition amount is determined by the molar ratio of mercapto:vinyl = 1- (1.05:1).

4. The preparation method according to claim 3, characterized in that, The initiator is benzoin dimethyl ether, 2-isopropylthioxanthone, photoinitiator Irgacure 369, or any two compounds, and the dropwise amount is 0.2%-3% of the total mass of the SH-containing resin and the unsaturated anionic monomer.

5. The preparation method according to claim 4, characterized in that, The initiator is benzoin dimethyl ether and 2-isopropylthioxanthone compounded according to a mass ratio of 2:1, and the reaction time is shortened to 1 hour; or the initiator is benzoin dimethyl ether and photoinitiator Irgacure 369 compounded according to a mass ratio of 1:1, and the reaction time is shortened to 0.5 hour.

6. The preparation method according to claim 3, characterized in that, The solvent is methanol, ethanol, DMSO, DMF, or DMC.

7. The cationic silicone of claim 1 is used as a bactericide or bacteriostatic agent.

8. Use according to claim 7, characterized in that, The cationic silicone is formulated into a bactericidal solution with a concentration ranging from 5-20 mg / L.

9. Use according to claim 7, characterized in that, The cationic silicone is formulated into a bactericidal solution, applied to the surface of a substrate, and cured to form an antibacterial coating.

10. Use according to any one of claims 7 to 9, characterized in that, It is used for killing Staphylococcus aureus, Escherichia coli, or Pseudomonas aeruginosa.

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