Anti-fouling silicone rubber for shower nozzle and preparation method of anti-fouling silicone rubber

Abstract

The invention discloses anti-fouling silicone rubber for a shower nozzle and a preparation method. The silicone rubber is prepared from the modified monomer with the hydrophilic group, the epoxy polysiloxane, the vinyl-terminated polydimethylsiloxane and the polyhexamethylene biguanide hydrochloride, and the obtained silicone rubber is good in hydrophilicity, so that dirt, bacteria and the like are not easy to adhere to the surface of the silicone rubber, and therefore, the silicone rubber is good in anti-fouling performance and good in antibacterial effect; not only can the shower comfort be improved, but also the service life can be prolonged, and good application value is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of silicone rubber, and in particular to an anti-fouling silicone rubber for a shower head and a preparation method thereof. Background Art

[0002] Silicone rubber has excellent high temperature resistance and can maintain stable physical properties in high temperature environments. This is especially important when the shower is used in a hot water environment, which can prevent the material from deforming or being damaged at high temperatures. At the same time, silicone rubber also has good low temperature resistance and can maintain its elasticity and performance in cold environments, ensuring the normal operation of the shower under different temperature conditions. Silicone rubber has excellent elasticity and flexibility, and can adapt to the pressure changes of the water flow, so that the water flow is sprayed more evenly and improves the shower experience. Its softness allows the outlet part to flexibly adjust the direction of the water flow to meet the needs of different users. Silicone rubber has good weather resistance. During long-term use, it is not easy to age or degrade due to factors such as light and temperature changes, which prolongs the service life of the shower. Silicone rubber is not easy to degrade under the action of ozone generated by corona discharge, and its physical properties only change slightly under light conditions such as ultraviolet rays, ensuring the long-term stability of the shower outlet. Silicone rubber has good corrosion resistance to many chemicals and is not easy to react with chemical components in water, ensuring the long-term performance of the shower outlet. Silicone rubber is non-toxic and odorless, has no adverse effects on the human body, and does not release harmful substances during use, meeting the requirements of health and environmental protection. The excellent properties of silicone rubber make it an ideal material for showerhead outlets, providing a better user experience and longer service life.

[0003] Hard water contains higher concentrations of minerals such as calcium and magnesium, which exist in a dissolved state in the water. When water passes through the shower head, as the water temperature rises or the water evaporates, these minerals will gradually precipitate and deposit in the water outlet and internal pipes of the shower head to form scale. Other dissolved substances in the water, such as iron and aluminum, will also crystallize and deposit on the shower head under certain conditions, further aggravating the scaling phenomenon. When hot water is used, the increase in water temperature will accelerate the precipitation and crystallization process of minerals, making it easier for scale to form and accumulate on the shower head. During use, frequent changes in water temperature will also lead to accelerated scale formation, because temperature changes will change the solubility and stability of dissolved substances in the water, prompting more minerals to deposit. Impurities such as dust and bacteria in the air may also adhere to the shower head and mix with scale to further block the nozzle hole. If the surface of the material of the shower head is not smooth enough or has a certain adsorption capacity, it will be easier to adsorb scale and impurities, leading to scaling. The nozzle has a small aperture or a complex internal structure, which can easily generate eddies and dead corners when water flows through, making it easier for scale to deposit in these areas.

[0004] Patent CN116462807A relates to the field of silica gel technology, in particular to a formula of silica gel and its preparation method, as well as its application in showerhead water outlet nets and showerheads. The silica gel formula includes the following components by mass: 40 to 70 parts of vinyl polysiloxane, 1 to 5 parts of borneol ester containing reactive groups, 1 to 4 parts of fluorine-containing acrylates, and 0.1 to 0.5 parts of platinum catalysts. Borneol ester has an antibacterial effect. By chemically reacting with vinyl polysiloxane under the action of a platinum catalyst, the borneol ester is grafted onto the polysiloxane molecular chain, thereby giving the polysiloxane an antibacterial function. After the fluorine-containing acrylate reacts with vinyl polysiloxane, it is directly grafted onto the polysiloxane molecular chain, making the antifouling performance of silica gel more durable. Vinyl polysiloxane is the main raw material for preparing silica gel. The present invention prepares silica gel by using raw materials with antibacterial and antifouling functions, thereby producing a silica gel product with durable antibacterial and antifouling properties.

[0005] Patent CN110423472A relates to the field of silicone rubber technology, and specifically to an anti-fouling silicone rubber and a preparation method thereof. The anti-fouling composition of the invention includes an anti-fouling agent A and / or an anti-fouling agent B; the anti-fouling silicone rubber is composed of a masterbatch and an anti-fouling composition. By introducing hydroxyl fluorosilicone oil and vinyl fluorosilicone oil, and compounding nano-scale polytetrafluoroethylene powder with micron-scale polytetrafluoroethylene powder, the polytetrafluoroethylene powder is fully infiltrated with fluorosilicone oil. This process improves the uniformity of dispersion of polytetrafluoroethylene powder in the layered structure of mica powder, thereby effectively reducing the surface energy of silicone rubber and improving its oil resistance and barrier properties. As a result, the anti-fouling performance is significantly enhanced, the anti-fouling effect is long-lasting, the residual oil and color stains are reduced, and the whiteness of the product is improved. At the same time, this method avoids the occurrence of swelling, does not limit the physical properties of the masterbatch, and has a wide range of applicability.

[0006] The introduction of low surface energy substances such as fluorine can significantly improve the anti-fouling properties of silicone rubber. However, fluorine-containing substances pose a certain threat to human health, so it is necessary to develop a safer anti-fouling silicone rubber. Summary of the invention

[0007] In view of the above-mentioned defects in the prior art, the technical problem to be solved by the present invention is to provide an anti-fouling silicone rubber for a shower head and a preparation method thereof.

[0008] Scaling of shower heads can bring many hazards, including affecting the user experience, such as causing poor water flow, clogging the shower head, and reducing shower comfort; shortening the life of the equipment, due to corrosion and wear of the shower head and pipes by scale; endangering health, breeding bacteria and microorganisms, and possibly causing skin and respiratory problems. Therefore, the present invention provides a silicone rubber for a shower head, which is obtained by introducing hydrophilic groups and antibacterial monomers. Due to its good hydrophilicity, the surface will preferentially bind water to form a hydration layer, thereby preventing the adhesion of microorganisms and other pollutants, thereby achieving anti-fouling properties, not only reducing scale but also reducing the growth of bacteria. The introduced antibacterial monomers are not only highly hydrophilic but also have positively charged guanidine groups. These positively charged guanidine groups can electrostatically adsorb with the negatively charged microbial surface (such as bacteria, viruses, etc.), thereby firmly binding to the microbial surface to prevent it from dividing and reproducing. Through its cationic properties, it can achieve multiple effects such as destroying cell membranes, inhibiting nucleic acid synthesis, and forming thin films, achieving a broad-spectrum, high-efficiency, and low-toxic antibacterial effect.

[0009] The silicone rubber is prepared by modifying a monomer having a hydrophilic group with epoxy polysiloxane, terminal vinyl polydimethylsiloxane and polyhexamethylene biguanide hydrochloride. The various monomers can interpenetrate to form a network polymer during polymerization, so that the hydrophilic groups are aggregated in large quantities, thereby greatly improving the hydrophilicity. The amino groups are covalently bonded to the polyhexamethylene biguanide hydrochloride, thereby introducing antibacterial groups into the silicone rubber. The silicone rubber finally obtained has good hydrophilicity and is not easy to adhere to dirt and bacteria on the surface. Therefore, it has good anti-fouling performance and good antibacterial effect. It can not only improve the comfort of showering, but also prolong the service life and has good application value.

[0010] To achieve the above object, the present invention provides a method for preparing anti-fouling silicone rubber for a shower head, comprising the following steps:

[0011] S1, adding a modifier, ethyltrimethoxysilane and triethylchlorosilane to a solvent, adding dilute hydrochloric acid to adjust the pH to 1-2, adding water and heating to hydrolyze, after the reaction is completed, reducing pressure and concentrating to remove the solvent, dialyzing and mixing with hexamethyldisilazane and a solvent, stirring at 110-120° C. for 4-6 hours, and then concentrating to remove the solvent to obtain a modified monomer;

[0012] S2, adding vinyl-terminated polydimethylsiloxane to a solvent and vinyl alcohol, adding a catalyst and heating to 80-100° C., then adding 1,2-epoxy-5-hexene-3-ol, reacting for 6-10 hours and post-treating to obtain epoxy polysiloxane;

[0013] S3. Mix the modified monomer and epoxy polysiloxane in a solvent, then add terminal vinyl polydimethylsiloxane and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, stir evenly for polymerization, then add methanol solution of polyhexamethylene biguanide hydrochloride, stir for 1 to 2 hours, remove the solvent, add to an open mill for open refining, and after curing and molding in a mold, obtain the anti-fouling silicone rubber for shower heads.

[0014] Furthermore, the mass ratio of the modifier to ethyltrimethoxysilane, triethylsilyl chloride, solvent, and hexamethyldisilazane is 1:2-3:0.5-1.5:5-15:0.8-1.2.

[0015] Furthermore, the temperature range of the heating in step S1 is 70-85°C.

[0016] Furthermore, the mass ratio of the vinyl-terminated polydimethylsiloxane to the solvent, vinyl alcohol, catalyst, and 1,2-epoxy-5-hexene-3-ol is 1:1~2:0.1~0.2:0.005~0.01:0.2~0.3.

[0017] Furthermore, the catalyst is a platinum catalyst, and the mass content of platinum is 1000ppm-2000ppm.

[0018] Furthermore, the mass ratio of the modified monomer to the epoxy polysiloxane, the solvent, the vinyl-terminated polydimethylsiloxane, the 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and the methanol solution of polyhexamethylene biguanide hydrochloride is 1:0.2~0.5:4~6:3~4:0.1~0.15:1~2.

[0019] Furthermore, the methanol solution of polyhexamethylene biguanide hydrochloride is a methanol solution containing 5-10 wt % of polyhexamethylene biguanide hydrochloride.

[0020] Furthermore, the modified monomer is one of 3-aminopropyltriethoxysilane, 3-triethoxysilylpropane-1,1-diamine and 2-(triethoxysilyl)-ethylamine.

[0021] The present invention also provides an anti-fouling silicone rubber for a shower head, which is prepared by the above method.

[0022] Beneficial effects of the present invention:

[0023] The present invention prepares silicone rubber by modifying a modified monomer having a hydrophilic group with epoxy polysiloxane, vinyl-terminated polydimethylsiloxane and polyhexamethylene biguanide hydrochloride. The various monomers can interpenetrate to form a network polymer during polymerization, so that the hydrophilic groups are aggregated in large quantities, thereby greatly improving the hydrophilicity. The amino groups are covalently bonded to the polyhexamethylene biguanide hydrochloride, thereby introducing antibacterial groups into the silicone rubber. The silicone rubber finally obtained has good hydrophilicity and is not easy to adhere to dirt and bacteria on the surface. Therefore, the silicone rubber has good anti-fouling performance and good antibacterial effect, can not only improve the shower comfort, but also can prolong the service life, and has good application value. DETAILED DESCRIPTION

[0024] 3-Triethoxysilylpropane-1,1-diamine, CAS No.: 149493-42-5, the structure is as follows: ;

[0025] 1,2-epoxy-5-hexen-3-ol, CAS No.: 24058-61-5, the structure is as follows: ;

[0026] Vinyl-terminated polydimethylsiloxane, Mw=2000.

[0027] Custer catalyst, mass content of platinum: 2000 ppm, purchased from Hubei Langbowan Biomedicine Co., Ltd.

[0028] Example 1

[0029] A method for preparing anti-fouling silicone rubber for a shower head comprises the following steps, measured in parts by weight:

[0030] S1. Add 1 part of 3-aminopropyltriethoxysilane, 2.5 parts of ethyltrimethoxysilane and 1.1 parts of triethylchlorosilane to 10 parts of isopropanol, add 1 mol / L dilute hydrochloric acid to adjust the pH to 2, add 2 parts of water and heat to 74°C for hydrolysis, concentrate under reduced pressure after 3 hours, remove the solvent, dialyze, mix with 1 part of hexamethyldisilazane and 3 parts of toluene, stir at 115°C for 6 hours, and then concentrate to remove the solvent to obtain a modified monomer;

[0031] S2, adding 1 part of vinyl-terminated polydimethylsiloxane to 1 part of toluene and 0.1 part of vinyl alcohol, adding 0.006 parts of Custer catalyst and heating to 90° C., then adding 0.3 parts of 1,2-epoxy-5-hexene-3-ol, reacting for 8 hours and then concentrating under reduced pressure to remove the solvent to obtain epoxy polysiloxane;

[0032] S3. Mix 1 part of modified monomer and 0.3 part of epoxy polysiloxane in 5 parts of toluene, then add 3 parts of vinyl-terminated polydimethylsiloxane and 0.1 part of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, stir evenly and polymerize, then add 1 part of 10wt% methanol solution of polyhexamethylene biguanide hydrochloride, stir for 2 hours, remove the solvent and grind on an open mill, and after curing and molding in a mold, you can get the anti-fouling silicone rubber for shower heads.

[0033] Example 2

[0034] It is basically the same as Example 1, the only difference being that 3-aminopropyltriethoxysilane is replaced by 2-(triethoxysilyl)-ethylamine.

[0035] Example 3

[0036] The method is substantially the same as Example 1, except that 3-aminopropyltriethoxysilane is replaced by 3-triethoxysilylpropane-1,1-diamine.

[0037] Comparative Example 1

[0038] A method for preparing anti-fouling silicone rubber for a shower head comprises the following steps, measured in parts by weight:

[0039] S1. Add 1 part of 3-aminopropyltriethoxysilane, 2.5 parts of ethyltrimethoxysilane and 1.1 parts of triethylchlorosilane to 10 parts of isopropanol, add 1 mol / L dilute hydrochloric acid to adjust the pH to 2, add 2 parts of water and heat to 74°C for hydrolysis, concentrate under reduced pressure after 3 hours, remove the solvent, dialyze, mix with 1 part of hexamethyldisilazane and 3 parts of toluene, stir at 115°C for 6 hours, and then concentrate to remove the solvent to obtain a modified monomer;

[0040] S2, adding 1 part of vinyl-terminated polydimethylsiloxane to 1 part of toluene and 0.1 part of vinyl alcohol, adding 0.006 parts of Custer catalyst and heating to 90° C., then adding 0.3 parts of 1,2-epoxy-5-hexene-3-ol, reacting for 8 hours and then concentrating under reduced pressure to remove the solvent to obtain epoxy polysiloxane;

[0041] S3. Mix 1 part of modified monomer and 0.3 part of epoxy polysiloxane in 5 parts of toluene, then add 3 parts of vinyl-terminated polydimethylsiloxane and 0.1 part of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, stir evenly and polymerize, then perform refining on an open mill, and cure and shape in a mold to obtain anti-fouling silicone rubber for shower heads.

[0042] Comparative Example 2

[0043] A method for preparing anti-fouling silicone rubber for a shower head comprises the following steps, measured in parts by weight:

[0044] S1, adding 1 part of vinyl-terminated polydimethylsiloxane to 1 part of toluene and 0.1 part of vinyl alcohol, adding 0.006 parts of Custer catalyst and heating to 90°C, then adding 0.3 parts of 1,2-epoxy-5-hexene-3-ol, reacting for 8 hours and then concentrating under reduced pressure to remove the solvent to obtain epoxy polysiloxane;

[0045] S2. Mix 1 part of 3-aminopropyltriethoxysilane and 0.3 parts of epoxy polysiloxane in 5 parts of toluene, then add 3 parts of vinyl-terminated polydimethylsiloxane and 0.1 parts of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, stir evenly for polymerization, then add 1 part of 10wt% methanol solution of polyhexamethylene biguanide hydrochloride, stir for 2 hours, remove the solvent, and add to an open mill for curing to obtain anti-fouling silicone rubber for shower heads.

[0046] Test Example 1

[0047] The samples for testing were prepared by the preparation methods of the antifouling silicone rubber of the embodiment and the control example. A mold with a length, width and thickness of 50 mm×50 mm×10 mm was used for curing and molding. The water contact angle of the obtained samples was tested by a contact angle meter, and the antibacterial performance of silicone rubber was tested with reference to the method in GB / T 31402-2015 "Test Method for Antibacterial Performance of Plastic Surfaces". The specific results are shown in Table 1.

[0048] Table 1 Water contact angle and antibacterial test results of silicone rubber

[0049] As can be seen from Table 1, compared with the control example, the embodiment has better hydrophilicity and higher antibacterial property. This is because the hydrophilic surface can preferentially bind water to form a hydration layer to prevent the adhesion of microorganisms and other pollutants, thereby achieving antifouling, which can not only reduce scale but also reduce the growth of bacteria. Therefore, hydrophilicity has a positive effect on antibacterial property, and the higher the hydrophilicity, the better the antibacterial property. Compared with Examples 1 and 2, the modifier in Example 3 has more hydrophilic amino groups, and the number of hydrophilic groups in the interpenetrating network formed during polymerization is greater, resulting in better hydrophilicity and therefore better antibacterial property.

[0050] Compared with Control Example 1, Example 1 is different from Control Example 1 in that polyhexamethylene biguanide hydrochloride is added in the preparation of Example 1, and the positively charged guanidine group therein can be electrostatically adsorbed to the negatively charged surface of microorganisms (such as bacteria, viruses, etc.), thereby firmly binding to the surface of microorganisms to prevent them from dividing and reproducing. This cationic property can achieve a broad-spectrum, high-efficiency, low-toxic antibacterial effect through multiple mechanisms such as destroying cell membranes, inhibiting nucleic acid synthesis, and forming thin films. Therefore, the antibacterial property of the embodiment is stronger.

[0051] Compared with Example 1 and Control Example 2, no modified monomer was prepared in Control Example 2. Therefore, not only is the network structure formed during polymerization more loose, but the number of hydrophilic groups is also significantly lower, the hydrophilicity is weaker, and the antibacterial property is therefore poorer.

[0052] Test Example 2

[0053] The samples for testing were prepared by the preparation methods of the anti-fouling silicone rubber of the embodiment and the comparative example. During the curing and molding, a mold with a length, width and thickness of 50 mm×50 mm×10 mm was used.

[0054] The anti-fouling performance of the samples was tested with reference to the method in GB / T17657-2013 "Test methods for physical and chemical properties of wood-based panels and veneered wood-based panels". The specific results are shown in Table 2.

[0055] Table 2 Anti-fouling performance test results of silicone rubber

[0056] As can be seen from Table 2, the silicone rubber in the embodiment has good antifouling properties, which may be due to the hydrophilic surface being able to form a stable water film, which can effectively reduce the direct contact between pollutants and the coating surface, so the surface is not easily contaminated after cleaning, and the antifouling performance of Example 3 is better than that of Examples 1-2, which may be due to the fact that the modifier in Example 3 has more hydrophilic amino groups, so the number of hydrophilic groups in the interpenetrating network formed during polymerization is more, resulting in better hydrophilicity, and thus better antifouling properties. In the embodiment, a modified monomer having a hydrophilic group is prepared with epoxy polysiloxane, vinyl-terminated polydimethylsiloxane and polyhexamethylene biguanide hydrochloride, and a variety of monomers can interpenetrate to form a network polymer during polymerization, so that a large number of hydrophilic groups are aggregated, thereby greatly improving the hydrophilicity, and the amino group is covalently bonded to the polyhexamethylene biguanide hydrochloride, thereby introducing an antibacterial group into the silicone rubber, and the silicone rubber finally obtained has good hydrophilicity, so that the surface is not easy to adhere to dirt and bacteria, etc., resulting in good antifouling properties.

[0057] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A method for preparing anti-fouling silicone rubber for a shower head, characterized in that: The steps include: S1, adding a modifier, ethyltrimethoxysilane and triethylchlorosilane to a solvent, adding dilute hydrochloric acid to adjust the pH to 1-2, adding water and heating to hydrolyze, after the reaction is completed, reducing pressure and concentrating to remove the solvent, dialyzing and mixing with hexamethyldisilazane and a solvent, stirring at 110-120° C. for 4-6 hours, and then concentrating to remove the solvent to obtain a modified monomer; S2, adding vinyl-terminated polydimethylsiloxane to a solvent and vinyl alcohol, adding a catalyst and heating to 80-100° C., then adding 1,2-epoxy-5-hexene-3-ol, reacting for 6-10 hours and post-treating to obtain epoxy polysiloxane; S3. Mix the modified monomer and epoxy polysiloxane in a solvent, then add terminal vinyl polydimethylsiloxane and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, stir evenly for polymerization, then add methanol solution of polyhexamethylene biguanide hydrochloride, stir for 1 to 2 hours, remove the solvent, add to an open mill for open refining, and after curing and molding in a mold, obtain the anti-fouling silicone rubber for shower heads.

2. The method for preparing the anti-fouling silicone rubber for a shower head according to claim 1, characterized in that: The mass ratio of the modifier to ethyltrimethoxysilane, triethylsilyl chloride, solvent and hexamethyldisilazane is 1:2-3:0.5-1.5:5-15:0.8-1.

2.

3. The method for preparing the anti-fouling silicone rubber for a shower head according to claim 1, characterized in that: The temperature range of the heating in step S1 is 70-85°C.

4. The method for preparing the anti-fouling silicone rubber for a shower head according to claim 1, characterized in that: The mass ratio of the vinyl-terminated polydimethylsiloxane to the solvent, vinyl alcohol, catalyst and 1,2-epoxy-5-hexene-3-ol is 1:1-2:0.1-0.2:0.005-0.01:0.2-0.

3.

5. The method for preparing the anti-fouling silicone rubber for a shower head according to claim 1, characterized in that: The catalyst is a platinum catalyst, and the mass content of platinum is 1000ppm-2000ppm.

6. The method for preparing the anti-fouling silicone rubber for a shower head according to claim 1, characterized in that: The mass ratio of the modified monomer to epoxy polysiloxane, solvent, vinyl-terminated polydimethylsiloxane, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and methanol solution of polyhexamethylene biguanide hydrochloride is 1:0.2-0.5:4-6:3-4:0.1-0.15:1-2.

7. The method for preparing the anti-fouling silicone rubber for a shower head according to claim 1, characterized in that: The methanol solution of polyhexamethylene biguanide hydrochloride is a methanol solution containing 5-10 wt % of polyhexamethylene biguanide hydrochloride.

8. The method for preparing the anti-fouling silicone rubber for a shower head according to claim 1, characterized in that: The modified monomer is one of 3-aminopropyltriethoxysilane, 3-triethoxysilylpropane-1,1-diamine and 2-(triethoxysilyl)-ethylamine. 9.An anti-fouling silicone rubber for a shower head, characterized in that: Prepared by the method according to any one of claims 1 to 8.

10. Use of the anti-fouling silicone rubber according to claim 9 in the field of sanitary ware.

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