Silicon-free low-foaming medical device cleaning surfactant, cleaning agent and preparation method thereof

Abstract

This invention discloses a silicone-free, low-foaming surfactant and cleaning agent for cleaning medical devices, and their preparation method, relating to the field of medical device cleaning technology. The technical solution involves using citric acid, lauryl glycol ether, and octylphenol polyoxyethylene ether-6 as reaction substrates, and obtaining the surfactant by adding (Boc)₂O and reacting under solvent-free conditions in an electromagnetic grinder. This invention uses citric acid, lauryl glycol ether, and octylphenol polyoxyethylene ether-6 as reaction substrates, and obtains the silicone-free, low-foaming surfactant for cleaning medical devices by adding (Boc)₂O and reacting under solvent-free conditions in an electromagnetic grinder. The entire process employs a mechanochemical method, and the reaction can be completed without harsh conditions such as high temperature and high pressure, resulting in low cost, simple process, and minimal pollution.

Description

Technical Field

[0001] This invention relates to the field of medical device cleaning technology, specifically to a silicone-free, low-foaming surfactant, cleaning agent, and preparation method for cleaning medical devices. Background Technology

[0002] The quality of medical device cleaning directly impacts medical safety, especially for precision or implantable devices such as laparoscopes and orthopedic implants, which require extremely high levels of surface cleanliness. Residual contaminants can not only cause postoperative infections and tissue rejection reactions, but also interfere with subsequent disinfection and sterilization, such as hindering the penetration of high-temperature steam, reducing the contact efficiency of chemical disinfectants, and even causing irreversible damage to the optical performance of precision components such as endoscope lenses. Therefore, medical device cleaning agents must simultaneously meet three core requirements: "low residue," "low foam," and "highly effective decontamination."

[0003] Regarding component compatibility, while traditional silicone-containing cleaning agents have a certain defoaming effect, they easily form difficult-to-remove silicone film residues on the surface of instruments after cleaning, posing a medical safety hazard. Therefore, silicone-free cleaning has become an important development direction for medical device cleaning agents. At the same time, the foam problem during the cleaning process also urgently needs to be solved: excessive foam can cause misjudgment of liquid level sensors in equipment such as ultrasonic cleaners and fully automatic cleaning and sterilizing machines, insufficient spray pressure, or overflow of cleaning fluid, resulting in interruption of the cleaning process or incomplete cleaning, affecting clinical work efficiency and cleaning quality.

[0004] In the field of surfactant synthesis, existing technologies largely rely on solution-phase synthesis methods, requiring the use of large amounts of organic solvents to dissolve reactants and catalysts. However, most organic solvents are toxic, flammable, or explosive, posing serious safety risks to the production process and causing environmental pollution and energy consumption in solvent production, purification, and recycling. Although solvent recovery systems have been gradually adopted, they cannot fundamentally solve the safety and environmental hazards posed by organic solvents. Developing green and sustainable synthesis technologies has become an urgent need for the industry.

[0005] Therefore, there is an urgent need to develop medical device cleaning agents that combine high-efficiency decontamination, low residue, and low foaming properties, which is of great significance for improving medical safety and promoting the green upgrading of cleaning technology. Summary of the Invention

[0006] The technical problem to be solved by this invention is to overcome the shortcomings of the prior art and provide a silicone-free, low-foaming surfactant for cleaning medical devices, a cleaning agent and its preparation method. Citric acid, lauryl glycol ether and octylphenol polyoxyethylene ether-6 are used as reaction substrates. By adding (Boc)2O, the reaction is carried out under solvent-free conditions in an electromagnetic mill to obtain the silicone-free, low-foaming surfactant for cleaning medical devices. The entire process adopts a mechanochemical method, and the reaction can be completed without harsh conditions such as high temperature and high pressure. It is low in cost, simple in process and low in pollution.

[0007] The technical solution of this invention is as follows: In a first aspect, the present invention provides a method for preparing a silicone-free, low-foaming surfactant for cleaning medical devices, using citric acid, lauryl glycol ether, and octylphenol polyoxyethylene ether-6 as reaction substrates, and obtaining the surfactant by adding (Boc)2O and reacting under solvent-free conditions in an electromagnetic mill.

[0008] Preferably, the molar ratio of citric acid, lauryl glycol ether and octylphenol polyoxyethylene ether-6 is 1:(1-2):(1-2).

[0009] Preferably, the molar ratio of (Boc)₂O to citric acid is (2-3):1.

[0010] Preferably, the steel rod used as the grinding medium in the electromagnetic grinding machine has a diameter of 0.3-0.5 mm and a length of 5-10 mm.

[0011] Preferably, the electromagnetic frequency is 30-50Hz and the reaction time is 3-5h.

[0012] Preferably, during the reaction, each raw material is placed in a reaction vessel, which is a flat-bottomed flask, a reaction vessel, or a glass pressure-resistant tube.

[0013] Secondly, the present invention provides a silicone-free, low-foaming surfactant for cleaning medical devices, which is prepared by the above-described method for preparing a silicone-free, low-foaming surfactant for cleaning medical devices.

[0014] Thirdly, the present invention provides a silicone-free, low-foaming cleaning agent for medical devices, comprising the following components in parts by weight: 5-10 parts of the above-mentioned silicone-free, low-foaming surfactant for medical device cleaning, 4-5 parts of organic acid, 10-15 parts of organic solvent, 7-12 parts of polyvinyl alcohol ether, 3-5 parts of potassium hydroxide, 3-5 parts of organic salt, 1-3 parts of additives, 0.1-0.3 parts of polyether-modified silicone-free defoamer, and deionized water to make up to 100 parts.

[0015] Preferably, the organic acid is prepared by mixing ethylenediaminetetraacetic acid and citric acid in a mass ratio of (2-4):1; the organic solvent is prepared by mixing propylene glycol and anhydrous ethanol in a volume ratio of (3-5):1; the organic salt is prepared by mixing sodium citrate and sodium polyacrylate in a mass ratio of (2-3):1; and the additive is Tween-80.

[0016] Fourthly, the present invention provides a method for preparing the above-mentioned silicone-free, low-foaming cleaning agent for medical devices, comprising the following steps: S1 premixes the above-mentioned silicone-free low-foaming medical device cleaning surfactant, polyvinyl alcohol ether, and organic solvent under nitrogen protection conditions. S2 After thoroughly mixing the organic acid with deionized water, potassium hydroxide is added in three portions, and the mixture is sheared and stirred to keep the resulting solution below 35°C. S3. The solution obtained in step S1 and the solution obtained in step S2 are sheared and stirred at 800-1000 rpm at 38°C for 15-20 min. Add organic salt to S4 and mix by shearing and stirring. Add additives to S5 and mix by shearing and stirring. Add polyether-modified silicone-free defoamer to S6 and mix by shearing and stirring; S7 After filtering the solution obtained in step S6, fill it into a container to obtain a silicone-free, low-foaming cleaning agent for medical devices.

[0017] Compared with the prior art, the present invention has the following advantages: 1. This invention employs a mechanochemical method to synthesize surfactants under solvent-free conditions using an electromagnetic mill. This completely eliminates the toxic and flammable organic solvents required for traditional solution-phase synthesis, avoiding the safety risks and environmental pollution associated with solvent use from the outset. Furthermore, it eliminates the need for additional solvent recovery equipment, reducing energy consumption and overall production costs. The surfactant synthesis reaction is driven by mechanical energy rather than thermal energy, requiring no harsh conditions such as high temperature or high pressure. Efficient reactions can be achieved simply by adjusting easily operable parameters such as electromagnetic frequency and milling time. The process is simple, highly reproducible, and suitable for large-scale industrial production, solving the problems of high equipment requirements and operational difficulties associated with traditional synthesis processes.

[0018] 2. The cleaning agent of the present invention does not contain siloxane components, which fundamentally avoids the interference of residues with the disinfection and sterilization effect, as well as damage to the optical performance of precision instruments. It is especially suitable for precision or implantable medical devices with extremely high requirements for surface cleanliness, such as laparoscopes and orthopedic implants, which significantly reduce medical risks.

[0019] 3. The surfactant synthesized in this invention produces extremely low foam when used in cleaning agents. This prevents problems such as misjudgment of liquid level sensors, insufficient spray pressure, or overflow of cleaning liquid in ultrasonic cleaners, fully automatic cleaning and sterilizing equipment, ensuring that the cleaning equipment operates stably according to the preset program, avoiding interruption of the cleaning process or incomplete cleaning, and improving the efficiency and quality of clinical cleaning work.

[0020] 4. The cleaning agent of the present invention has a strong ability to remove complex stains on the surface of medical devices through the synergistic effect of surfactants and components such as organic acids, organic solvents, and polyvinyl alcohol ethers. The stain removal rate can reach more than 82%, and the removal rate of Example 1 is as high as 96.8%, which can quickly achieve deep cleaning of medical devices.

[0021] 5. The components in the cleaning agent formulation of the present invention have good compatibility. After a 60-day room temperature standing test, the system remains uniform and stable with no impurities generated, and the cleaning ability does not significantly decrease. Compared with systems using conventional surfactants, the cleaning agent of the present invention can maintain excellent performance after long-term storage, has a longer service life, and reduces the waste of usage costs caused by product deterioration. Attached Figure Description

[0022] Figure 1 These are foam quantity test charts of the cleaning agents in Examples 1-3 and Comparative Examples 1-3 of the present invention. Detailed Implementation

[0023] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of this invention will be clearly and completely described below in conjunction with the embodiments of this invention.

[0024] The preparation method of the silicone-free, low-foaming surfactant used in the following examples is as follows: Add 1 mmol citric acid, 1.5 mmol lauryl glycol ether, 1.5 mmol octylphenol polyoxyethylene ether-6, 2 mmol (Boc)₂O, and 5 g steel rod (0.4 mm in diameter and 8 mm in length) to a 10 mL glass pressure-resistant tube (capable of withstanding 6 atmospheres). Tightly cap the glass tube and place it in an electromagnetic grinder. React at 50 Hz for 3 hours. Monitor the reaction progress. After the reaction is complete, rinse the glass tube and steel rod with ethyl acetate. Extract three times with water to remove water-soluble impurities. Transfer the organic phase to a round-bottom flask, remove the solvent under vacuum, and obtain the surfactant. The reaction process is as follows: .

[0025] Among them, product 1 1 H NMR, 13 The C NMR data are as follows: 1 H NMR (300 MHz, δ ppm): 4.20 (t, 6 H), 3.63 (t, 6 H), 3.35 (t, 6 H), 2.73 (s, 4 H), 1.55-1.37 (m, 6 H), 1.36-1.21 (m, 6 H), 0.94-0.78 (m, 9H). 13 CNMR (100 MHz, δ ppm): 173.1, 170.9, 72.8, 71.0, 70.1, 69.3, 66.9, 67.5, 42.4,27.3, 10.4. Product 2 1 H NMR, 13 The C NMR data are as follows: 1 H NMR (300 MHz, δ ppm): 7.54 (d, 6 H), 6.78 (d, 6 H), 4.31 (t, 6 H), 4.20 (t, 6 H), 3.77 (t, 6 H), 3.63 (t, 6 H), 3.52 (s, 60 H), 2.73 (s, 4 H),1.36 (s, 6 H), 0.91 (s, 45 H). 13 C NMR (100 MHz, δ ppm): 173.1, 170.9, 156.3,141.6, 125.6, 114.0, 72.8, 70.4, 70.1, 70.0, 69.3, 67.5, 66.9, 57.3, 42.4,38.5, 32.8, 30.4, 29.7. Example 1 The silicone-free, low-foaming cleaning agent for medical devices in this embodiment comprises the following components in parts by weight: 10 parts silicone-free, low-foaming surfactant for medical device cleaning, 4 parts organic acid, 10 parts organic solvent, 7 parts polyvinyl alcohol propylene ether C-201, 3 parts potassium hydroxide, 3 parts organic salt, 1 part additive, 0.1 parts polyether-modified silicone-free defoamer, and deionized water to a total of 100 parts. The organic acid is prepared by mixing ethylenediaminetetraacetic acid and citric acid in a mass ratio of 4:1; the organic solvent is prepared by mixing propylene glycol and anhydrous ethanol in a volume ratio of 5:1; the organic salt is prepared by mixing sodium citrate and sodium polyacrylate in a mass ratio of 3:1; and the additive is Tween-80.

[0026] The preparation method of the silicone-free, low-foaming cleaning agent for medical devices in this embodiment includes the following steps: S1 is prepared by premixing a non-silicone low-foaming medical device cleaning surfactant, polyvinyl alcohol propylene ether C-201, and an organic solvent at 38°C for 30 min under nitrogen protection. S2 After thoroughly mixing the organic acid with deionized water, potassium hydroxide is added in three portions, and the mixture is sheared and stirred at 800 rpm for 15 minutes. The final solution must be kept below 35°C. S3 The solution obtained in step S1 and the solution obtained in step S2 are sheared and stirred at 800 rpm at 38°C for 20 min. Add organic salt to S4 and mix at a high speed of 800 rpm for 15 minutes using a shearing and stirring motion. Add additives to S5 and mix at high speed (800 rpm) for 15 minutes using shearing and stirring. Add polyether-modified silicone-free defoamer to S6 and mix at a high speed of 800 rpm for 60 minutes using high-speed shearing and stirring. S7. After passing the solution obtained in step S6 through an 8μm filter membrane, it is filled into a container to obtain a silicone-free, low-foaming cleaning agent for medical devices.

[0027] Example 2 The silicone-free, low-foaming cleaning agent for medical devices in this embodiment comprises the following components in parts by weight: 5 parts silicone-free, low-foaming surfactant for medical device cleaning, 4 parts organic acid, 15 parts organic solvent, 8 parts polyvinyl alcohol propylene ether C-201, 5 parts potassium hydroxide, 5 parts organic salt, 3 parts additives, 0.1 parts polyether-modified silicone-free defoamer, and deionized water to a total of 100 parts. The organic acid is prepared by mixing ethylenediaminetetraacetic acid and citric acid in a mass ratio of 2:1; the organic solvent is prepared by mixing propylene glycol and anhydrous ethanol in a volume ratio of 3:1; the organic salt is prepared by mixing sodium citrate and sodium polyacrylate in a mass ratio of 2:1; and the additive is Tween-80.

[0028] The preparation method of the silicone-free, low-foaming cleaning agent for medical devices in this embodiment includes the following steps: S1 is prepared by premixing a non-silicone low-foaming medical device cleaning surfactant, polyvinyl alcohol propylene ether C-201, and an organic solvent at 38°C for 40 minutes under nitrogen protection. S2 After thoroughly mixing the organic acid with deionized water, potassium hydroxide is added in three portions, and the mixture is sheared and stirred at 1000 rpm for 15 minutes. The final solution must be kept below 35°C. S3 The solution obtained in step S1 and the solution obtained in step S2 are sheared and stirred at 1000 rpm at 38°C for 15 min. Add organic salt to S4 and mix at a high speed of 1000 rpm for 15 minutes using a shearing and stirring motion. Add the additive to S5 and mix at a high speed of 1000 rpm for 15 minutes using high-speed shearing and stirring. Add polyether-modified silicone-free defoamer to S6 and mix at a high speed of 1000 rpm for 60 minutes using high-speed shearing and stirring. S7. After passing the solution obtained in step S6 through an 8μm filter membrane, it is filled into a container to obtain a silicone-free, low-foaming cleaning agent for medical devices.

[0029] Example 3 The silicone-free, low-foaming cleaning agent for medical devices in this embodiment comprises the following components in parts by weight: 6 parts silicone-free, low-foaming surfactant for medical device cleaning, 5 parts organic acid, 11 parts organic solvent, 12 parts polyvinyl alcohol propylene ether C-201, 5 parts potassium hydroxide, 3 parts organic salt, 1 part additive, 0.3 parts polyether-modified silicone-free defoamer, and deionized water to a total of 100 parts. The organic acid is prepared by mixing ethylenediaminetetraacetic acid and citric acid in a mass ratio of 3:1; the organic solvent is prepared by mixing propylene glycol and anhydrous ethanol in a volume ratio of 4:1; the organic salt is prepared by mixing sodium citrate and sodium polyacrylate in a mass ratio of 2.5:1; and the additive is Tween-80.

[0030] The preparation method of the silicone-free, low-foaming cleaning agent for medical devices in this embodiment includes the following steps: S1 is prepared by premixing a non-silicone low-foaming medical device cleaning surfactant, polyvinyl alcohol propylene ether C-201, and an organic solvent at 38°C for 30 min under nitrogen protection. S2 After thoroughly mixing the organic acid with deionized water, potassium hydroxide is added in three portions, and the mixture is sheared and stirred at 900 rpm for 15 minutes. The final solution must be kept below 35°C. S3 The solution obtained in step S1 and the solution obtained in step S2 are sheared and stirred at 900 rpm at 38°C for 18 min. Add organic salt to S4 and mix at a high speed of 900 rpm for 15 minutes using shearing and stirring. Add the additive to S5 and mix at a high speed of 900 rpm for 15 minutes using high-speed shearing and stirring. Add polyether-modified silicone-free defoamer to S6 and mix at a high speed of 900 rpm for 60 minutes using high-speed shearing and stirring. S7. After passing the solution obtained in step S6 through an 8μm filter membrane, it is filled into a container to obtain a silicone-free, low-foaming cleaning agent for medical devices.

[0031] Comparative Example 1 The difference from Example 1 is that triethanolamine is used instead of Tween-80.

[0032] Comparative Example 2 The difference from Example 2 is that the amount of organic solvent added is 5 parts.

[0033] Comparative Example 3 The difference from Example 1 is that AES is used instead of the silicone-free, low-foaming surfactant for cleaning medical devices in Example 1.

[0034] Test Example 1: Stain Removal Ability Test The detergency of the cleaning agents used in Examples 1-3 and Comparative Examples 1-3 was tested using the following methods: (1) Testing equipment Stain simulation board: STF load test card (49mm×99mm×0.34mm); Cleaning power tester: Heat collection and constant temperature magnetic stirrer (temperature 45℃, frequency 600r / min).

[0035] (2) Testing process Test piece pretreatment: Fix the STF load test card to be cleaned onto the spring clip.

[0036] Pretreatment of the thermally heated magnetic stirrer: Add 1200mL of deionized water to the working chamber of the thermally heated magnetic stirrer, then turn on the heating and stirring functions and heat the deionized water in the working chamber to 45℃.

[0037] Cleaning solution pretreatment: Add 4 mL of cleaning agent to the working chamber of the heat-collecting constant-temperature magnetic stirrer, then keep heating and stirring for 2 minutes to allow the cleaning agent to fully diffuse in the deionized water and form a uniform mixture.

[0038] Cleaning test: Place the spring clip with the STF load detection card in the working chamber of the heat-collecting constant temperature magnetic stirrer and perform a cleaning test for 15 minutes.

[0039] Post-processing: Remove the spring clip holding the STF load test card from the working chamber of the heat-collecting constant-temperature magnetic stirrer; then, detach the STF load test card from the spring clip; finally, place the cleaned STF load test card into an oven and dry it at a temperature of 60°C for 20 minutes.

[0040] (3) Evaluation indicators Stain removal rate = (initial stain weight - residual stain weight) / initial stain weight × 100%.

[0041] The results of the detergency test are shown in Table 1: Table 1. Determination ability test results of the cleaning agents in Examples 1-3 and Comparative Examples 1-3

[0042] As shown in Table 1, the cleaning agent of Example 1 achieved a stain removal rate of 96.8%, which is higher than that of Comparative Example 1. This is because Tween-80, as a nonionic surfactant, has excellent solubilizing, emulsifying, and dispersing properties. It can synergistically work with surfactants and organic acids used in the cleaning of silicone-free, low-foaming medical devices, significantly improving the solubility and removal efficiency of stains in the cleaning solution. Triethanolamine, on the other hand, is a commonly used additive whose main function is to adjust the pH value and enhance alkaline cleaning. Its solubilizing and emulsifying abilities are far weaker than those of Tween-80, and it cannot effectively assist surfactants in dispersing complex stains (such as protein and oil contaminants) on the surface of medical devices, resulting in an initial cleaning rate that decreased from 96.8% to 84.6%.

[0043] Although organic solvents do not directly participate in stain removal, they can disrupt the adhesion between stains and the surface of medical devices through "solventization" (e.g., dissolving the hydrophobic groups of grease stains) and enhance the penetration ability of surfactants at the stain interface. In Example 2, 15 parts of organic solvent can fully encapsulate the stain particles, assisting the surfactant to penetrate quickly; while in Comparative Example 2, only 5 parts of organic solvent were added, resulting in insufficient solvation and difficulty for the surfactant to effectively contact the interior of the stain, causing the cleaning rate to drop from 88.5% to 82.1%.

[0044] The silicone-free, low-foaming surfactant for cleaning medical devices of this invention is synthesized through the synergistic polymerization of citric acid, lauryl glycol ether, and octylphenol polyoxyethylene ether-6. It combines the low-foaming properties, high penetration, and carboxyl chelating ability of nonionic surfactants, and can simultaneously remove proteins, greases, and inorganic contaminants. In contrast, AES (sodium fatty alcohol polyoxyethylene ether sulfate) is a traditional anionic surfactant. Although it has a certain detergency, it produces a lot of foam (which can easily lead to equipment failure) and has weak chelating and dispersing ability for complex mixed stains. It cannot meet the high-precision cleaning requirements of medical devices, and therefore the initial detergency rate is reduced from 96.8% to 80.1%.

[0045] Test Example 2: Foam Quantity Test The foaming volume of the cleaning agents in Examples 1-3 and Comparative Examples 1-3 was tested using the following methods: The test was conducted using a fully automated foam volume analyzer manufactured by SITA GmbH, Germany. The test results are as follows: Figure 1 As shown, the amount of foam in the cleaning agents of Examples 1-3 is much lower than that in Comparative Examples 1-3. When used in mechanical cleaning methods such as spray cleaning machines, pulsed vacuum cleaning machines, and ultrasonic cleaning machines, the lower amount of foam can greatly extend the service life of the circulating pump in the cleaning equipment.

[0046] Test Example 3: Residual Content Test The residual amount of the cleaning agents in Examples 1-3 and Comparative Examples 1-3 was tested, and the test method is as follows: The Xinhua brand Rapid-M-320 fully automatic cleaning and disinfection machine was used for testing. During the cleaning phase, the cleaning agent was added at a ratio of 1:300 to water. After the cleaning phase, rinsing phases 1 and 2 were run. After rinsing phase 2, water samples were taken for TOC residue testing. The test results are shown in Table 2. Table 2 TOC values ​​of cleaning agents in Examples 1-3 and Comparative Examples 1-3

[0047] As shown in Table 2, the TOC values ​​of the cleaning agents in Examples 1-3 are all around 3 mg / L, while the TOC values ​​of the cleaning agents in Comparative Examples 1-3 are all around 8 mg / L. The comparison shows that the residual amount of the cleaning agents in Examples 1-3 is much lower than that in Comparative Examples 1-3, proving that the surfactant of the present invention has the advantages of being easier to rinse and having lower residual amount when used in cleaning agents.

[0048] Test Example 4 Stability Test The stability of the cleaning agents in Examples 1-3 and Comparative Examples 1-3 was tested using the following methods: (1) Sample preparation Sample vials: Brand new and clean 100mL PP sample vials; Filling: The cleaning agent is quantitatively filled into the PP sample bottle; after filling, the appearance of the cleaning agent in the PP sample bottle is inspected, including two aspects: first, to determine whether there are impurities in the cleaning agent, and second, to confirm whether the cleaning agent system is homogeneous and stable; after confirming that the cleaning agent meets the conditions of "no impurities" and "homogeneous and stable system", the PP sample bottle is capped and sealed to complete the sample sealing.

[0049] (2) Testing process Test method: The cleaning agent that has been filled (i.e., the cleaning agent filled into PP sample bottles and sealed) is placed in a storage environment that meets the following conditions: ambient temperature is room temperature, the environment is cool and dry, and the storage location is inside a fume hood; under the above environmental conditions, the cleaning agent is allowed to stand for 60 days.

[0050] Post-processing: After the cleaning agent has completed 60 days of settling, remove the PP sample bottle and take out the cleaning agent inside. Two indicators of the removed cleaning agent are retested: the appearance of the cleaning agent and the cleaning agent's detergency. The method for retesting the detergency is consistent with the method used in Test Example 1.

[0051] The stability test results are shown in Table 3: Table 3. Stability test results of the cleaning agents in Examples 1-3 and Comparative Examples 1-3

[0052] As shown in Table 3, Examples 1-2 all have good stability, but in Example 3, the stability decreased due to the increased amount of polyvinyl alcohol ether.

[0053] Triethanolamine is highly alkaline and may undergo a slow neutralization reaction with organic acids in the cleaning agent during long-term storage, leading to pH fluctuations in the system and affecting the critical micelle concentration (CMC) of the surfactant, thus weakening its detergency activity. Tween-80, on the other hand, is chemically stable and has good compatibility with the components in the system, maintaining its synergistic detergency effect even after storage. Therefore, the detergency rate decrease after the stability test of Comparative Example 1 (3.5%) was much greater than that of Example 1 (1.1%). Since both triethanolamine and Tween-80 are water-soluble additives and have no incompatibilities with other components in the cleaning agent (such as polyvinyl alcohol ether and organic solvents), they do not cause system stratification, precipitation, or impurity formation. Therefore, both maintain a uniform and stable appearance.

[0054] Organic solvents have a stabilizing effect on surfactants: propylene glycol and anhydrous ethanol can reduce the probability of aggregation between surfactant molecules, maintain their uniform dispersion in the system, and prevent crystallization or precipitation during long-term storage. In Comparative Example 2, the organic solvent content was insufficient, which could not effectively stabilize the surfactant, resulting in the aggregation of some surfactant molecules after 60 days, an increase in the critical micelle concentration, and a decrease in detergency activity. Therefore, the decrease in detergency rate after stabilization (3.6%) was much higher than that in Example 2 (1%). In addition, even with a reduction in the amount of organic solvent added, it could still form a homogeneous mixture with other components (surfactant, polyvinyl alcohol ether, deionized water), without phase separation or impurity generation, thus maintaining a stable appearance.

[0055] AES is prone to hydrolysis in alkaline systems, and the content of active ingredients decreases after long-term storage, leading to a further reduction in detergency. AES molecules have strong intermolecular forces and are prone to aggregation after long-term standing, resulting in reduced system transparency. In contrast, the surfactant of this invention contains polyoxyethylene ether chains and ester groups in its molecular structure, which has better compatibility with polyvinyl alcohol ethers and organic solvents, and can maintain uniform dispersion for a long time without aggregation or sedimentation.

[0056] In summary, this invention provides a silicone-free, low-foaming cleaning agent for medical devices, prepared through a specific process using surfactants, organic solvents, organic acids, polyvinyl alcohol ethers, potassium hydroxide, organic salts, additives, polyether-modified silicone-free defoamers, and deionized water as raw material components. This cleaning agent achieves a stain removal rate of over 85% on STF load test cards. Through the synergistic effect of the aforementioned raw material components, this invention achieves a breakthrough in the cleaning agent's high-efficiency decontamination and safe, environmentally friendly performance.

Claims

1. A method for preparing a surfactant for cleaning silicone-free, low-foaming medical devices, characterized in that, A surfactant was obtained by reacting citric acid, lauryl glycol ether, and octylphenol polyoxyethylene ether-6 as reaction substrates with the addition of (Boc)2O under solvent-free conditions in an electromagnetic mill.

2. The method for preparing the surfactant for cleaning silicone-free, low-foaming medical devices as described in claim 1, characterized in that, The molar ratio of citric acid, lauryl glycol ether and octylphenol polyoxyethylene ether-6 is 1:(1-2):(1-2).

3. The method for preparing the surfactant for cleaning silicone-free, low-foaming medical devices as described in claim 1, characterized in that, The molar ratio of (Boc)₂O to citric acid is (2-3):

1.

4. The method for preparing the surfactant for cleaning silicone-free, low-foaming medical devices as described in claim 1, characterized in that, The steel rods used as grinding media in the electromagnetic grinding machine have a diameter of 0.3-0.5 mm and a length of 5-10 mm.

5. The method for preparing the surfactant for cleaning silicone-free, low-foaming medical devices as described in claim 1, characterized in that, During the reaction, the electromagnetic frequency is 30-50Hz, and the reaction time is 3-5h.

6. The method for preparing the surfactant for cleaning silicone-free, low-foaming medical devices as described in claim 1, characterized in that, During the reaction, each raw material is placed into a reaction vessel, which can be a flat-bottomed flask, a reaction vessel, or a glass pressure-resistant tube.

7. A silicone-free, low-foaming surfactant for cleaning medical devices, characterized in that, It is prepared by the method for preparing a silicone-free, low-foaming surfactant for cleaning medical devices as described in any one of claims 1-6.

8. A silicone-free, low-foaming cleaning agent for medical devices, characterized in that, The product comprises the following components in parts by weight: 5-10 parts of the silicone-free, low-foaming medical device cleaning surfactant as described in claim 7, 4-5 parts of organic acid, 10-15 parts of organic solvent, 7-12 parts of polyvinyl alcohol ether, 3-5 parts of potassium hydroxide, 3-5 parts of organic salt, 1-3 parts of additives, 0.1-0.3 parts of polyether-modified silicone-free defoamer, and deionized water to make up to 100 parts.

9. The silicone-free, low-foaming cleaning agent for medical devices as described in claim 8, characterized in that, The organic acid is prepared by mixing ethylenediaminetetraacetic acid and citric acid in a mass ratio of (2-4):1; the organic solvent is prepared by mixing propylene glycol and anhydrous ethanol in a volume ratio of (3-5):1; the organic salt is prepared by mixing sodium citrate and sodium polyacrylate in a mass ratio of (2-3):1; and the additive is Tween-80.

10. The method for preparing the silicone-free, low-foaming cleaning agent for medical devices as described in claim 8, characterized in that, Includes the following steps: S1 Under nitrogen protection, the surfactant, polyvinyl alcohol ether and organic solvent for cleaning silicone-free low-foaming medical devices as described in claim 7 are premixed. S2 After thoroughly mixing the organic acid with deionized water, potassium hydroxide is added in three portions, and the mixture is sheared and stirred to keep the resulting solution below 35°C. S3. The solution obtained in step S1 and the solution obtained in step S2 are sheared and stirred at 800-1000 rpm at 38°C for 15-20 min. Add organic salt to S4 and mix by shearing and stirring. Add additives to S5 and mix by shearing and stirring. Add polyether-modified silicone-free defoamer to S6 and mix by shearing and stirring; S7 After filtering the solution obtained in step S6, fill it into a container to obtain a silicone-free, low-foaming cleaning agent for medical devices.

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