Bactericidal coating as well as preparation method and application thereof

Abstract

The invention discloses a bactericidal coating as well as a preparation method and application thereof. The preparation method comprises the following steps: mixing epoxy resin and benzoxazine resin, applying the mixture to the surface of a matrix, carrying out curing and laser irradiation treatment, packaging the generated porous graphene by using the epoxy resin, and carrying out curing treatment to obtain the bactericidal coating. The sterilization coating prepared by the invention can realize efficient sterilization under the condition of applying voltage or infrared light source irradiation; meanwhile, the bactericidal coating provided by the invention avoids the addition of chemical bactericides, and has stronger bactericidal durability.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional coatings, and in particular relates to a bactericidal coating and a preparation method and application thereof. Background Art

[0002] In today's society, the hazards caused by microbial contamination are becoming increasingly prominent, posing a serious threat to human health. For example, in the medical field, bacterial infections of medical devices occur frequently; in daily life, the surface of objects can easily become the source of pathogen transmission, and bacteria breed in high-frequency contact areas in crowded places, and traditional cleaning methods are difficult to completely sterilize and the effects are short-lived. In this situation, bactericidal coatings are of great significance. At present, the application of bactericidal coatings in medical devices, food packaging, public facilities and other fields is becoming more and more extensive. Among them, polymer bactericidal coatings occupy a place in the antibacterial field. Polymer bactericidal coatings are mainly based on polymers as the matrix material, and antibacterial agents with bactericidal functions (such as metal ions, quaternary ammonium salts, natural antibacterial substances, etc.) are introduced into them, thereby giving the substrate surface bactericidal and antibacterial capabilities. Epoxy resin is a commonly used coating film-forming material. The coating prepared by it has good film-forming and adhesion properties and can be firmly covered on the surfaces of various objects. However, its shortcomings cannot be ignored. The antibacterial durability of traditional polymer bactericidal coatings is limited. As time goes by and the frequency of use increases, the antibacterial agent will gradually be lost, resulting in a decrease in the bactericidal effect. Some antibacterial agents have biotoxicity risks and may cause potential harm to the ecological environment. Moreover, when faced with a complex and changeable microbial environment, their bactericidal specificity is insufficient.

[0003] In comparison, electrothermal / photothermal sterilization shows significant advantages due to the physical thermal effect: it sterilizes by heating through the Joule heat / photothermal conversion effect of electrothermal / photothermal fillers (such as graphene), directly avoiding the use of chemical antibacterial agents, and can achieve long-term and stable bactericidal performance. Due to the poor dispersibility of the filler, it is usually necessary to add a higher filler amount to the epoxy resin to achieve the construction of a continuous functional network. This often leads to problems such as poor coating processability, decreased mechanical properties and increased costs. Although assembling the filler into a three-dimensional porous structure and then compounding it with epoxy resin solves the above-mentioned dispersion problem, the construction of the three-dimensional porous structure of the filler is cumbersome, including the synthesis and reduction of graphene oxide and the construction of the three-dimensional structure, which involves the use of a large amount of non-recyclable solvents as well as high temperature and inert atmosphere. Therefore, there is an urgent need to develop an efficient electrothermal / photothermal sterilization coating with a simple preparation method. Summary of the Invention

[0004] The main purpose of the present invention is to provide a bactericidal coating and its preparation method and application to overcome the shortcomings of the prior art.

[0005] To achieve the aforementioned object of the invention, the technical solutions adopted by the present invention include:

[0006] An embodiment of the present invention provides a method for preparing a bactericidal coating, which comprises:

[0007] Epoxy resin and benzoxazine resin are mixed and applied to the surface of a substrate for curing and laser irradiation. The generated porous graphene is then encapsulated with epoxy resin and cured to obtain a bactericidal coating.

[0008] The embodiment of the present invention further provides a bactericidal coating prepared by the aforementioned preparation method, wherein the bactericidal coating has a bactericidal rate of ≥95% against Escherichia coli and Staphylococcus aureus.

[0009] The embodiments of the present invention further provide uses of the aforementioned bactericidal coating in the fields of medical devices, food packaging or public facilities.

[0010] An embodiment of the present invention further provides a sterilization method for a sterilizing coating, which comprises:

[0011] Providing the aforementioned bactericidal coating;

[0012] Furthermore, voltage is applied to the bactericidal coating or light is irradiated to achieve sterilization.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The bactericidal coating prepared by the present invention avoids the use of chemical bactericides and achieves efficient and long-lasting sterilization through electric heating and / or photothermal methods, with low energy consumption, economical and environmentally friendly;

[0015] (2) The preparation method of the bactericidal coating provided by the present invention not only solves the problem of poor dispersibility of functional fillers, but also the constructed three-dimensional graphene network does not require traditional multiple steps and harsh conditions such as high temperature and inert atmosphere. The process is simple and the conditions are mild. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is an SEM photograph of the three-dimensional porous graphene on the surface of the laser-treated pre-coating layer in Example 1 of the present invention;

[0018] Figure 2 This is the XRD pattern of the laser-treated pre-coating surface in Example 1 of the present invention;

[0019] Figure 3This is a graph showing the surface temperature of the coating prepared in Example 1 of the present invention changing with time under different applied voltages;

[0020] Figure 4 The coatings prepared in Example 1 and Comparative Example 1 of the present invention were irradiated with near-infrared light (intensity 0.5 W / cm 2 ) surface temperature versus time. DETAILED DESCRIPTION

[0021] In view of the shortcomings of the prior art, the inventors of this case, after long-term research and extensive practice, have proposed the technical solution of the present invention. The technical solution of the present invention will be clearly and completely described below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making any creative effort shall fall within the scope of protection of the present invention.

[0022] The mechanism of action of the bactericidal coating in the present invention is that the polybenzoxazine resin has a high carbonization rate and can be directly converted into three-dimensional porous graphene through the photothermal effect under the action of laser. The epoxy resin has a low carbonization rate, and the laser action easily causes it to directly decompose or even burn, forming a dark but insulating or poorly conductive char layer, and it is impossible to obtain a continuous, porous, highly conductive graphene network. A certain proportion of benzoxazine resin is introduced into the epoxy resin. On the basis of not affecting the coating processing and mechanical properties, the polybenzoxazine resin can be converted into porous graphene by laser action, and a functional network is constructed on the coating surface. Epoxy resin is further filled into the graphene network to ensure the mechanical stability of the coating surface. Under applied voltage and / or light, due to the excellent electrical conductivity and light absorption properties of porous graphene, the coating surface can generate high temperature by electric heating and / or photothermal heating, denaturing microbial proteins and destroying nucleic acids, thereby achieving the purpose of sterilization.

[0023] Specifically, as one aspect of the technical solution of the present invention, a method for preparing a bactericidal coating includes:

[0024] Epoxy resin and benzoxazine resin are mixed and applied to the surface of a substrate for curing and laser irradiation. The generated porous graphene is then encapsulated with epoxy resin and cured to obtain a bactericidal coating.

[0025] In some preferred embodiments, the preparation method specifically comprises: mixing an epoxy resin precursor and a benzoxazine resin and heating the mixture to above the melting point of the benzoxazine resin, and then adding an epoxy resin curing agent to obtain a mixture; wherein the epoxy resin comprises an epoxy resin precursor and an epoxy resin curing agent.

[0026] Furthermore, the mass ratio of the epoxy resin precursor to the epoxy resin curing agent is 100:28-125.

[0027] Furthermore, the mass ratio of the epoxy resin precursor to the benzoxazine resin is 9:1 to 7:3.

[0028] Furthermore, the epoxy resin precursor includes any one or more combinations of bisphenol A epoxy resin, bisphenol F epoxy resin, and alicyclic epoxy resin, but is not limited thereto.

[0029] Furthermore, the epoxy resin curing agent includes polyamine and / or acid anhydride compound, but is not limited thereto.

[0030] Furthermore, the benzoxazine resin includes any one or more combinations of bisphenol A benzoxazine resin, bisphenol F benzoxazine resin, MDA benzoxazine resin, DOPO benzoxazine resin, and phenol aniline benzoxazine resin, but is not limited thereto.

[0031] In some preferred embodiments, the preparation method specifically comprises:

[0032] applying the mixture to a substrate surface for curing, and then irradiating the cured surface with a laser to obtain porous graphene;

[0033] Epoxy resin is filled into the structure of the porous graphene and cured to obtain a bactericidal coating, wherein the mass ratio of the epoxy resin to the porous graphene is 3:1 to 9:1, and the mass ratio of the epoxy resin precursor to the epoxy resin curing agent in the epoxy resin is 100:28 to 125.

[0034] Furthermore, the curing temperature is 80-210° C., and the curing time is more than 4 hours.

[0035] Furthermore, the laser is a 10.6 μm infrared laser; the power of the laser is 5 to 20 W.

[0036] Furthermore, the laser speed used in the irradiation treatment is 0.1 to 0.6 m / s, and the number of treatments is 1 to 3 times.

[0037] Furthermore, the epoxy resin includes an epoxy resin precursor and an epoxy resin curing agent.

[0038] Furthermore, the substrate includes a glass substrate and / or a metal substrate, but is not limited thereto.

[0039] The present invention mainly involves uniformly blending a mixture of epoxy resin and benzoxazine resin at a temperature at or above the melting point of the benzoxazine monomer, coating the mixture, cross-linking and curing the mixture, directly converting the mixture into three-dimensional porous graphene by laser irradiation, and finally encapsulating and curing the mixture with epoxy resin to obtain a sterilization coating.

[0040] In some preferred embodiments, the preparation method specifically comprises the following steps:

[0041] Step 1: Mix epoxy resin precursor and benzoxazine resin in a certain proportion;

[0042] Step 2: heating the blend to or above the melting point of the benzoxazine resin and stirring, and then adding the epoxy resin curing agent to achieve uniform blending;

[0043] Step 3: Apply the blend to the surface of the substrate, raise the temperature above the curing temperature, and cross-link and cure;

[0044] Step 4: Using laser to irradiate the cured epoxy resin / benzoxazine resin, the resin is directly converted into three-dimensional porous graphene;

[0045] Step 5: Fill the epoxy resin into the three-dimensional porous graphene structure for encapsulation, heat it to above the curing temperature, cross-link and cure it to obtain a sterilization coating.

[0046] In some preferred embodiments, the preparation method specifically includes: performing laser processing on the resin surface by adjusting laser processing parameters.

[0047] Another aspect of the embodiments of the present invention further provides a bactericidal coating prepared by the aforementioned preparation method, wherein the bactericidal coating has a bactericidal rate of ≥95% against Escherichia coli and Staphylococcus aureus.

[0048] Another aspect of the embodiments of the present invention further provides the use of the aforementioned sterilization coating in the fields of medical devices, food packaging or public facilities.

[0049] Another aspect of the embodiments of the present invention further provides a method for sterilizing a bactericidal coating, comprising:

[0050] Providing the aforementioned bactericidal coating;

[0051] Furthermore, voltage is applied to the bactericidal coating or light is irradiated to achieve sterilization.

[0052] In some preferred embodiments, the coating of the present invention is sterilized by applying voltage to generate electric thermal sterilization and / or by irradiating light to generate photothermal sterilization.

[0053] Furthermore, the applied voltage is 4 to 13 V, and the voltage application time is 5 to 15 minutes.

[0054] Furthermore, the light source used for the illumination is near infrared light, and the illumination intensity is 0.3 to 2.5 W / cm 2 The irradiation time is 4 to 20 minutes.

[0055] The technical solution of the present invention is further described in detail below in conjunction with several preferred embodiments and the accompanying drawings. This embodiment is implemented on the premise of the technical solution of the invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0056] Unless otherwise specified, the experimental materials used in the following examples can be purchased from conventional biochemical reagent companies.

[0057] Example 1

[0058] (1) Bisphenol A epoxy resin E51 and bisphenol A benzoxazine resin were mixed in a mass ratio of 8:2, heated to 90°C, and stirred for 20 minutes;

[0059] (2) adding 4,4′-diaminodiphenyl sulfone (DDS, 35% of the mass of the epoxy resin) and stirring to degas to obtain a mixture;

[0060] (3) applying the above mixture to the surface of a stainless steel substrate, curing at 80°C for 2 h, 120°C for 2 h, 180°C for 4 h, and 200°C for 2 h to form a pre-coating layer;

[0061] (4) using a CO2 laser with a wavelength of 10.6 μm, a power of 8 W, a scanning rate of 0.3 m / s, and repeating once to generate a three-dimensional porous graphene structure on the surface of the pre-coating layer;

[0062] (5) Fill E51 / DDS into three-dimensional porous graphene (DDS is 35% of the mass of E51, and the mass ratio of E51 / DDS to three-dimensional porous graphene is 5:1), and cure according to the process in (3) to obtain the corresponding bactericidal coating.

[0063] Figure 1 This is an SEM photo of the pre-coating layer after laser treatment, showing a three-dimensional porous structure; Figure 2 This is the XRD pattern of the pre-coating layer after laser treatment, and its characteristic peaks are the same as those of graphene.

[0064] Figure 3 The surface temperature of the prepared coating changes with time under different applied voltages. As can be seen from the figure, under the applied voltage, the temperature of the coating surface gradually increases due to the electrothermal effect and reaches the equilibrium temperature around 30 seconds.

[0065] Figure 4The surface temperature of the prepared coating changes with time under near infrared light irradiation. 2 ) irradiation, the surface temperature of the coating gradually increases due to the photothermal effect.

[0066] When the applied voltage is 6V and the action time is 8min, the sterilization rate is 99%; at 0.5W / cm 2 Under near-infrared irradiation, the irradiation time is 7 minutes and the sterilization rate is 99.9%.

[0067] Bactericidal test test method: The antibacterial ability of the sample was evaluated by colony technique. The experimental bacteria included Escherichia coli and Staphylococcus aureus. The bacteria were inoculated into a conical flask containing LB broth and cultured at 37°C for 18 hours. Then, the culture solution was taken and diluted with phosphate-buffered saline (PBS) to a concentration of 108 CFU / mL. 200 μL of the diluted bacterial solution was extracted with a pipette and added dropwise to the surface of the sample, and reacted for a certain period of time with / without applied voltage and with / without near-infrared radiation. After the end, it was immersed in PBS buffer (20 mL) and ultrasonically treated for 5 minutes. Finally, 200 μL of the bacterial solution was spread on an LB plate for culture (37°C, 24 hours) and counted.

[0068] Example 2

[0069] (1) Bisphenol A epoxy resin E51 and bisphenol A benzoxazine resin were mixed in a mass ratio of 7:3, heated to 90°C, and stirred for 20 minutes;

[0070] (2) adding 4,4'-diaminodiphenyl sulfone (DDS, 35% of the mass of the epoxy resin) and stirring to degas to obtain a mixture;

[0071] (3) applying the above mixture to the surface of a stainless steel substrate, curing at 80°C for 2 h, 120°C for 2 h, 180°C for 4 h, and 200°C for 2 h to form a pre-coating layer;

[0072] (4) using a CO2 laser with a wavelength of 10.6 μm, a power of 5 W, a scanning rate of 0.3 m / s, and repeating once to generate a three-dimensional porous graphene structure on the surface of the pre-coating layer;

[0073] (5) Fill E51 / DDS into three-dimensional porous graphene (DDS is 35% of the mass of E51, and the mass ratio of E51 / DDS to three-dimensional porous graphene is 5:1), and cure according to the process in (3) to obtain the corresponding bactericidal coating.

[0074] The sterilization test method is the same as that in Example 1. When the applied voltage is 5V and the action time is 10min, the sterilization rate is 98%. 2 Under near-infrared irradiation, the irradiation time is 6 minutes and the sterilization rate is 99.2%.

[0075] Example 3

[0076] (1) Bisphenol A type epoxy resin E51 was mixed with bisphenol A type benzoxazine resin at a mass ratio of 9:1, heated to 90°C, and stirred for 20 min;

[0077] (2) 4,4'-diaminodiphenyl sulfone (DDS, 35% of the mass of the epoxy resin) was added, and the mixture was stirred and degassed;

[0078] (3) The above mixture was coated on the surface of a stainless steel substrate, cured at 80°C for 2 h, at 120°C for 2 h, at 180°C for 4 h, and at 200°C for 2 h to form a pre-coating layer;

[0079] (4) A CO2 laser with a wavelength of 10.6 μm was used for processing, with a power of 10 W and a scanning speed of 0.4 m / s, repeated 3 times, to generate a three-dimensional porous graphene structure on the surface of the pre-coating layer;

[0080] (5) E51 / DDS was filled into the three-dimensional porous graphene (DDS was 35% of the mass of E51, and the mass ratio of E51 / DDS to the three-dimensional porous graphene was 5:1), and cured according to the process in (3) to obtain the corresponding sterilization coating.

[0081] The sterilization test method was the same as in Example 1. The sterilization rate was 97% at an applied voltage of 6 V and an action time of 10 min, and the sterilization rate was 99.9% at 1.5 W / cm 2 Under near-infrared irradiation, the sterilization rate was 98.9% at an irradiation time of 6 min.

[0082] Example 4

[0083] (1) Bisphenol A type epoxy resin E44 was mixed with phenol-aniline type benzoxazine resin at a mass ratio of 8:2, heated to 100°C, and stirred for 20 min;

[0084] (2) 4,4'-diaminodiphenyl methane (DDM, 28% of the mass of the epoxy resin) was added, and the mixture was stirred and degassed;

[0085] (3) The above mixture was coated on the surface of a stainless steel substrate, cured at 100°C for 2 h, at 150°C for 4 h, and at 200°C for 2 h to form a pre-coating layer;

[0086] (4) A CO2 laser with a wavelength of 10.6 μm was used for processing, with a power of 6 W and a scanning speed of 0.1 m / s, repeated 1 time, to generate a three-dimensional porous graphene structure on the surface of the pre-coating layer;

[0087] (5) Fill E44 / DDM into three-dimensional porous graphene (DDM is 28% of the mass of E44, and the mass ratio of E44 / DDM to three-dimensional porous graphene is 5:1), and cure according to the process in (3) to obtain the corresponding bactericidal coating.

[0088] The sterilization test method is the same as that in Example 1. When the applied voltage is 4V and the action time is 15min, the sterilization rate is 97.5%. 2 Under near-infrared irradiation, the irradiation time was 20 minutes and the sterilization rate was 98.2%.

[0089] Example 5

[0090] (1) Bisphenol A epoxy resin E44 and DOPO benzoxazine resin were mixed in a mass ratio of 9:1, heated to 110°C, and stirred for 20 minutes;

[0091] (2) adding 4,4′-diaminodiphenylmethane (DDM, 28% of the mass of the epoxy resin) and stirring to degas to obtain a mixture;

[0092] (3) applying the above mixture to the surface of a stainless steel substrate, curing at 100°C for 2 h, 150°C for 4 h, and 200°C for 2 h to form a pre-coating layer;

[0093] (4) using a CO2 laser with a wavelength of 10.6 μm, a power of 10 W, a scanning rate of 0.4 m / s, and repeating twice to generate a three-dimensional porous graphene structure on the pre-coating surface;

[0094] (5) Fill E44 / DDM into three-dimensional porous graphene (DDM is 28% of the mass of E44, and the mass ratio of E44 / DDM to three-dimensional porous graphene is 5:1), and cure according to the process in (3) to obtain the corresponding bactericidal coating.

[0095] The sterilization test method is the same as that in Example 1. When the applied voltage is 8V and the action time is 10min, the sterilization rate is 99.1%. 2 Under near-infrared irradiation, the irradiation time is 15 minutes and the sterilization rate is 99.5%.

[0096] Example 6

[0097] (1) Bisphenol F epoxy resin and MDA benzoxazine resin were mixed in a mass ratio of 8:2, heated to 120°C, and stirred for 20 minutes;

[0098] (2) adding polyetheramine (D230, 28% of the mass of the epoxy resin) and stirring to degas to obtain a mixture;

[0099] (3) applying the above mixture to the surface of a stainless steel substrate, curing at 120°C for 2 h, 150°C for 2 h, and 210°C for 2 h to form a pre-coating layer;

[0100] (4) using a CO2 laser with a wavelength of 10.6 μm, a power of 20 W, a scanning rate of 0.6 m / s, and repeating once to generate a three-dimensional porous graphene structure on the pre-coating surface;

[0101] (5) Filling bisphenol F epoxy resin / polyetheramine D230 into three-dimensional porous graphene (D230 is 28% of the mass of bisphenol F epoxy resin, and the mass ratio of bisphenol F epoxy resin / polyetheramine D230 to three-dimensional porous graphene is 5:1), and curing is carried out according to the process in (3) to obtain the corresponding bactericidal coating.

[0102] The sterilization test method is the same as that in Example 1. When the applied voltage is 6V and the action time is 10min, the sterilization rate is 99.1%. 2 Under near-infrared irradiation, the irradiation time is 10 minutes and the sterilization rate is 99.6%.

[0103] Example 7

[0104] (1) Bisphenol F epoxy resin and benzoxazine resin (bisphenol A and MDA mass ratio 1:1) were mixed in a mass ratio of 8:2, heated to 120 °C, and stirred for 20 min;

[0105] (2) adding polyetheramine (D230, 28% of the mass of the epoxy resin) and stirring to degas to obtain a mixture;

[0106] (3) applying the above mixture to the surface of a stainless steel substrate, curing at 120°C for 2 h, 150°C for 2 h, and 210°C for 2 h to form a pre-coating layer;

[0107] (4) using a CO2 laser with a wavelength of 10.6 μm, a power of 18 W, a scanning rate of 0.5 m / s, and repeating once to generate a three-dimensional porous graphene structure on the pre-coating surface;

[0108] (5) Filling bisphenol F epoxy resin / polyetheramine D230 into three-dimensional porous graphene (D230 is 28% of the mass of bisphenol F epoxy resin, and the mass ratio of bisphenol F epoxy resin / polyetheramine D230 to three-dimensional porous graphene is 5:1), and curing is carried out according to the process in (3) to obtain the corresponding bactericidal coating.

[0109] The sterilization test method is the same as that in Example 1. The sterilization rate is 99.0% when the applied voltage is 7V and the action time is 10min. 2 Under near-infrared irradiation, the irradiation time is 8 minutes and the sterilization rate is 99.3%.

[0110] Example 8

[0111] (1) Mix alicyclic epoxy resin TDE-85 and bisphenol F-type benzoxazine resin in a mass ratio of 9:1, heat to 90°C, and stir for 20 minutes;

[0112] (2) adding methyltetrahydrobenzoic anhydride (MTHPA, 125% of the mass of the epoxy resin) and stirring to degas to obtain a mixture;

[0113] (3) applying the above mixture to the surface of the glass substrate, curing at 80°C for 2 hours, 120°C for 3 hours, and 200°C for 1 hour to form a pre-coating layer;

[0114] (4) using a CO2 laser with a wavelength of 10.6 μm, a power of 10 W, a scanning rate of 0.4 m / s, and repeating once to generate a three-dimensional porous graphene structure on the pre-coating surface;

[0115] (5) The alicyclic epoxy resin TDE-85 / MTHPA is filled into the three-dimensional porous graphene (MTHPA is 125% of the mass of TDE-85, and the mass ratio of TDE-85 / MTHPA to the three-dimensional porous graphene is 5:1), and the curing is carried out according to the process in (3) to obtain the corresponding bactericidal coating.

[0116] The sterilization test method is the same as that in Example 1. When the applied voltage is 13V and the action time is 15min, the sterilization rate is 95.6%. 2 Under near-infrared irradiation, the irradiation time was 12 minutes and the sterilization rate was 96.3%.

[0117] Example 9

[0118] The difference between this embodiment and the example is that the laser treatment is repeated twice.

[0119] The sterilization test method is the same as that in Example 1. When the applied voltage is 13V and the action time is 10min, the sterilization rate is 96.9%. 2 Under near-infrared irradiation, the irradiation time is 8 minutes and the sterilization rate is 97.5%.

[0120] Example 10

[0121] The difference between this embodiment and the example is that the laser treatment is repeated three times.

[0122] When the applied voltage is 13V and the action time is 5min, the sterilization rate is 99.2%; at 2.5W / cm 2 Under near-infrared irradiation, the irradiation time is 4 minutes and the sterilization rate is 99.3%.

[0123] Comparative Example 1

[0124] The difference from Example 1 is that no laser treatment is used. Since there is no porous graphene structure in the coating, Figure 4 As shown, under near-infrared light irradiation (0.5W / cm 2 ), the equilibrium temperature of the coating surface was significantly lower than that of Example 1, and the sterilization rate was 38%. Since it is not conductive, electric heat sterilization cannot be performed.

[0125] Comparative Example 2

[0126] The difference from Example 1 is that the epoxy resin coating is laser treated without adding benzoxazine resin. Due to the low carbonization rate of epoxy resin, a dark but insulating or poorly conductive char layer forms on the surface under laser treatment, and a continuous, porous, and highly conductive graphene network cannot be obtained.

[0127] Comparative Example 3

[0128] The difference from Example 1 is that the ratio of epoxy resin to benzoxazine resin is 95:5. Since the content of polybenzoxazine resin in the coating is too low, a continuous porous graphene structure cannot be formed on the surface.

[0129] Comparative Example 4

[0130] The difference from Example 1 is that the ratio of epoxy resin to benzoxazine resin is 6:4. Too high a content of benzoxazine resin increases the viscosity of the mixture, making processing difficult, and increases the brittleness of the cured pre-coating layer, making it prone to cracking.

[0131] Comparative Example 5

[0132] The difference from Example 1 is that the laser power is 2 W. The laser power is too low to achieve carbonization of the polybenzoxazine resin, and no porous graphene structure is formed on the surface. The sterilization effect is the same as that of Comparative Example 1.

[0133] Comparative Example 6

[0134] The difference from Example 1 is that the laser power is 25 W. The laser power is too high, resulting in severe ablation of the coating under the action of the laser and damage.

[0135] In addition, the inventors of this case also referred to the aforementioned embodiments and conducted experiments using other raw materials, process operations, and process conditions described in this specification, and obtained relatively ideal results.

[0136] It should be understood that the technical solution of the present invention is not limited to the above-mentioned specific implementation cases. Any technical variations made according to the technical solution of the present invention without departing from the scope of protection of the purpose of the present invention and the claims shall fall within the scope of protection of the present invention.

Claims

1. A method for preparing a bactericidal coating, characterized in that: include: Epoxy resin and benzoxazine resin are mixed and applied to the surface of a substrate for curing and laser irradiation. The generated porous graphene is then encapsulated with epoxy resin and cured to obtain a bactericidal coating.

2. The preparation method according to claim 1, characterized in that Specifically include: An epoxy resin precursor and a benzoxazine resin are mixed and heated to above the melting point of the benzoxazine resin, and then an epoxy resin curing agent is added to obtain a mixture; wherein the epoxy resin comprises an epoxy resin precursor and an epoxy resin curing agent; Preferably, the mass ratio of the epoxy resin precursor to the epoxy resin curing agent is 100:28-125; Preferably, the mass ratio of the epoxy resin precursor to the benzoxazine resin is 9:1 to 7:

3.

3. The preparation method according to claim 2, wherein: The epoxy resin precursor includes any one or more combinations of bisphenol A epoxy resin, bisphenol F epoxy resin, and alicyclic epoxy resin; and / or, the epoxy resin curing agent comprises a polyamine and / or an acid anhydride compound; And / or, the benzoxazine resin includes any one or more combinations of bisphenol A benzoxazine resin, bisphenol F benzoxazine resin, MDA benzoxazine resin, DOPO benzoxazine resin, and phenol aniline benzoxazine resin.

4. The preparation method according to claim 2, characterized in that Specifically include: applying the mixture to a substrate surface for curing, and then irradiating the cured surface with a laser to obtain porous graphene; Epoxy resin is filled into the structure of the porous graphene and cured to obtain a bactericidal coating, wherein the mass ratio of the epoxy resin to the porous graphene is 3:1 to 9:1, and the mass ratio of the epoxy resin precursor to the epoxy resin curing agent in the epoxy resin is 28 to 125:

100.

5. The preparation method according to claim 4, characterized in that: The curing temperature is 80-210° C., and the curing time is more than 4 hours.

6. The preparation method according to claim 4, characterized in that: The laser is a 10.6 μm infrared laser; the power of the laser is 5 to 20 W; And / or, the laser speed used in the irradiation treatment is 0.1-0.6 m / s, and the number of treatments is 1-3 times.

7. The preparation method according to claim 4, characterized in that: The epoxy resin includes an epoxy resin precursor and an epoxy resin curing agent; And / or, the substrate includes a glass substrate and / or a metal substrate.

8. The bactericidal coating prepared by the method according to any one of claims 1 to 7, characterized in that: The sterilization rate of the bactericidal coating on Escherichia coli and Staphylococcus aureus is ≥95%.

9. Use of the bactericidal coating according to claim 8 in the fields of medical devices, food packaging or public facilities.

10. A method for sterilizing a bactericidal coating, characterized in that: include: Providing the bactericidal coating according to claim 8; and applying voltage or irradiating light to the bactericidal coating to achieve sterilization; Preferably, the applied voltage is 4 to 13 V, and the applied voltage time is 5 to 15 minutes; preferably, the light source used for the illumination is near-infrared light, and the illumination intensity is 0.3 to 2.5 W / cm 2 The irradiation time is 4 to 20 minutes.

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