Coating agent

Abstract

To provide a coating agent enabling formation of a coat layer which exhibits antibacterial or antiviral effect even when bacteria or viruses adhere thereto together with impurities, and which retains its function upon exposure to water.SOLUTION: A coating agent comprises a modified polyethyleneimine that is a polyethyleneimine having a self-crosslinking group, an antibacterial or antiviral compound, and a liquid medium.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a coating agent. [Background technology]

[0002] One of the main routes of infection is when an infectious disease patient contaminates an object by coughing or talking, or by touching an object, wall, floor, or other surface with contaminated hands, and the infection spreads when a non-infected person touches the contaminated object.

[0003] Contaminated objects can be decontaminated by wiping them with chemicals such as ethanol, but the disinfecting effect of wiping with chemicals generally does not last long, and such cleaning work is time-consuming, making it difficult to keep the objects disinfected.

[0004] BACKGROUND ART Antibacterial or antiviral coatings have been studied in the past to prevent the spread of infection from contaminated objects (see Patent Documents 1 to 5). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-153927 [Patent Document 2] Patent No. 7361965 [Patent Document 3] Patent Publication No. 2021-169494 [Patent Document 4] Japanese Patent Application Laid-Open No. 2011-098976 [Patent Document 5] Japanese Patent Application Laid-Open No. 2009-255500 Summary of the Invention [Problem to be solved by the invention]

[0006] However, body fluids such as saliva contain contaminants such as proteins, and conventional antibacterial or antiviral coating agents tend to have reduced antibacterial or antiviral effects when bacteria or viruses adhere to them in the form of contaminants.Furthermore, conventional antibacterial or antiviral coating agents tend to have reduced antibacterial or antiviral effects when washed with water.

[0007] Therefore, an object of the present invention is to provide a coating agent capable of forming a coating layer that exhibits antibacterial or antiviral effects even when bacteria or viruses are attached in a form containing impurities, and that maintains its functionality even when wetted with water. Another object of the present invention is to provide an antibacterial or antiviral coating layer and a laminate including the coating layer. [Means for solving the problem]

[0008] The present disclosure provides the following [1] to [6].

[0009] [1] A coating agent comprising a modified polyethyleneimine, which is a polyethyleneimine having a self-crosslinking group, an antibacterial or antiviral compound, and a liquid medium. [2] The coating agent according to [1], wherein the polyethyleneimine has at least one nitrogen-containing group selected from an amino group and an imino group, and the modified polyethyleneimine is a reaction product of the polyethyleneimine and a polyfunctional compound having a functional group reactive with the nitrogen-containing group and the self-crosslinking group. [3] The coating agent according to [1] or [2], wherein the polyethyleneimine has a number average molecular weight of 1,000 or more and 150,000 or less. [4] The coating agent according to [2], wherein the reaction product is a reaction product in which the number of moles of ethyleneimine units of the polyethyleneimine relative to the number of moles of the polyfunctional compound is 2 to 2000. [5] An antibacterial or antiviral coating layer comprising a crosslinked product of the coating agent according to any one of [1] to [4]. [6] A laminate comprising a substrate and the antibacterial or antiviral coating layer according to [5] formed on the substrate. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a coating agent capable of forming a coating layer that exhibits antibacterial or antiviral effects even when bacteria or viruses are attached in the form of contaminants and that maintains its functionality even when wetted with water. Furthermore, according to the present invention, it is also possible to provide an antibacterial or antiviral coating layer and a laminate including the coating layer. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 shows the results of an evaluation test of the adsorption and retention properties of copper (II) ions. [Figure 2] FIG. 2 shows the results of an evaluation test of the stable retention characteristics of salazosulfapyridine. [Figure 3] FIG. 3 shows the results of an evaluation test of the retention properties of antiviral compounds. DETAILED DESCRIPTION OF THE INVENTION

[0012] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively.

[0013] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments.

[0014] The coating agent according to the embodiment includes a modified polyethyleneimine, which is a polyethyleneimine having self-crosslinking groups, an antibacterial or antiviral compound, and a liquid medium. The self-crosslinking groups are groups that crosslink between molecules of the polymer polyethyleneimine, and a network structure is formed by reaction between the self-crosslinking groups. At least a portion of the antibacterial or antiviral compound is incorporated into the network structure. Polyethyleneimine itself has antibacterial or antiviral properties, but its coexistence with an antibacterial or antiviral agent can enhance the antibacterial or antiviral effect. Because at least a portion of the antibacterial or antiviral agent is incorporated into the network structure, it does not immediately flow out even when wetted with water, and therefore its function is not significantly reduced by wetting. Furthermore, the antibacterial or antiviral agent incorporated into the network structure can gradually leach out from within the network structure, thereby achieving long-term antibacterial or antiviral effects. Furthermore, because the antibacterial or antiviral agent can gradually seep out from inside the mesh structure, even if bacteria or viruses adhere in a form containing impurities, the antibacterial or antiviral effect can be exerted against the bacteria or viruses in the impurities.

[0015] Modified polyethyleneimine is a compound in which a self-crosslinking group is introduced into polyethyleneimine. The self-crosslinking group introduced into polyethyleneimine may be of one type or two or more types. When the introduced self-crosslinking group is only self-crosslinking group A, two or more self-crosslinking groups A react to crosslink the polyethyleneimine. When the introduced self-crosslinking group is two types, self-crosslinking group A and self-crosslinking group B, reactions may occur between the self-crosslinking groups A, between the self-crosslinking groups B, or between the self-crosslinking groups A and B. From the perspective of ease of production, it is preferable to use only one type of self-crosslinking group.

[0016] The type of reaction between the self-crosslinking groups is arbitrary, but a condensation reaction (esterification, amidation, silylation, etc.) or an addition reaction (urethanization, urea formation, Michael addition, etc.) is preferred. The condensation reaction may occur via hydrolysis, as in the case of a hydrolyzable silyl group (alkoxysilyl group, etc.). Since the reaction between the self-crosslinking groups can occur under mild temperature conditions, such as room temperature, the self-crosslinking group is preferably a hydrolyzable silyl group, and the hydrolyzable silyl group is preferably -SiX n R (3-n) (X is a hydrolyzable group, R is an alkyl group or phenyl group having 1 to 8 carbon atoms, and n is a number from 1 to 3). Examples of the hydrolyzable group include a halogen atom, an alkoxy group, an acyloxy group, an amido group, an amino group, an aminooxy group, a ketoximate group, and a hydride group. Examples of the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, and a cyclohexyl group. It is particularly preferred that n=3 and X is an alkoxy group (such as a methoxy group or an ethoxy group).

[0017] The polyethyleneimine has at least one nitrogen-containing group selected from an amino group and an imino group, and the modified polyethyleneimine may be a reaction product of the polyethyleneimine and a multifunctional compound having a functional group that reacts with the nitrogen-containing group and a self-crosslinking group.

[0018] Examples of functional groups that react with nitrogen-containing groups include (meth)acryloyl groups, glycidyl groups, isocyanurate groups, isocyanate groups, and acid anhydride groups. Examples of polyfunctional compounds include silane compounds such as alkoxysilanes containing at least one functional group selected from (meth)acryloyl groups, glycidyl groups, isocyanurate groups, isocyanate groups, and acid anhydride groups. Examples of alkoxysilanes include ethoxysilane and methoxysilane. When the alkoxysilane is ethoxysilane, the pot life of the coating agent can be extended. Specific examples of polyfunctional compounds include silane compounds such as 3-((meth)acryloyloxy)propyltrialkoxysilane and trialkoxy-(3-glycidyloxypropyl)silane. More specific examples include 3-((meth)acryloyloxy)propyltriethoxysilane and triethoxy-(3-glycidyloxypropyl)silane.

[0019] The method for introducing a self-crosslinking group into polyethyleneimine can be a conventionally known method depending on the self-crosslinking group to be introduced. For example, as shown in the following formula (1), a modified polyethyleneimine having a triethoxysilyl group introduced therein can be obtained by heating 3-(methacryloyloxy)propyltriethoxysilane, a polyfunctional compound having an alkoxysilyl group as a self-crosslinking group, and polyethyleneimine in ethanol at 75°C for 0.5 hours. Note that the branching pattern of polyethyleneimine and the number of modifying groups of the modified polyethyleneimine shown in formula (1) are merely examples and are not limited thereto. Other examples of polyethyleneimine include polyethyleneimine having multiple types of repeating units as shown in the following formula (2) and polyethyleneimine having a partially crosslinked structure as shown in the following formula (3). [ka]

[0020] [ka]

[0021] The polyethyleneimine may be linear or branched. The number-average molecular weight of the polyethyleneimine may be 1,000 or more and 150,000 or less, or 2,000 or more and 30,000 or less. When the number-average molecular weight of the polyethyleneimine is within the above range, the coating agent has excellent crosslinking stability, can maintain antibacterial or antiviral properties for a longer period of time, and is easy to handle during preparation and use of the coating agent.

[0022] The reaction product of a polyfunctional compound and polyethyleneimine may be a reaction product in which the number of moles of ethyleneimine units in polyethyleneimine relative to the number of moles of the polyfunctional compound is 2 to 2000, or may be a reaction product in which this number of moles is 5 to 200, 5 to 100, or 5 to 70. When the number of moles of ethyleneimine units in polyethyleneimine relative to the number of moles of the polyfunctional compound is a reaction product having a value within the above range, antibacterial or antiviral properties can be maintained for a longer period of time.

[0023] The number of moles of ethyleneimine units of polyethyleneimine relative to the number of moles of the polyfunctional compound can be calculated as follows from the number average molecular weight (X) and reaction amount (W parts by mass) of polyethyleneimine, the molecular weight (Y) and reaction amount (Z parts by mass) of the polyfunctional compound, and the molecular weight of ethyleneimine (43.07). Number of moles = (X / 43.07) x (W / X) / (Z / Y) =(W / 43.07) / (Z / Y)

[0024] The calculation of the number of moles of ethyleneimine units of polyethyleneimine relative to the number of moles of a polyfunctional compound is specifically shown below. For example, when 3.1 parts by mass of polyethyleneamine having a number average molecular weight of 10,000 is reacted with 1 part by mass of triethoxy-(3-glycidyloxypropyl)silane, the number of moles of ethyleneimine units of polyethyleneimine relative to the number of moles of triethoxy-(3-glycidyloxypropyl)silane is calculated as follows, using the molecular weight of ethyleneimine: 43.07 and the molecular weight of triethoxy-(3-glycidyloxypropyl)silane: 278.42. Number of moles = (10000 / 43.07) x (3.1 / 10000) / (1 / 278.42) = 20.0

[0025] The content of the modified polyethyleneimine may be 0.01 parts by mass or more and 50 parts by mass or less, 0.05 parts by mass or more and 10 parts by mass or less, or 0.2 parts by mass or more and 5 parts by mass or less, relative to 100 parts by mass of the coating agent.

[0026] The antibacterial or antiviral compound may exhibit at least one of antibacterial properties and antiviral properties, or may exhibit both properties. In the coating agent according to the embodiment, by including the antibacterial or antiviral compound, the coating layer formed by the coating agent exhibits antibacterial properties or antiviral properties. The antibacterial or antiviral compound may include at least one of a compound exhibiting antibacterial properties and a compound exhibiting antiviral properties.

[0027] Compounds that exhibit antibacterial properties include sulfonamide antibacterial agents such as salazosulfapyridine (SASP), metal ions such as copper (II) ions, various antibiotics, and various antifungal agents.

[0028] Compounds that exhibit antiviral properties include ammonium salts with long-chain alkyl groups such as didodecyldimethylammonium chloride (DDDMA), pyridinium salts such as cetylpyridinium chloride (CPC), metal ions such as copper(II) ions, and benzalkonium chloride.

[0029] After the self-crosslinking groups of the modified polyethyleneimine in the coating agent crosslink with each other to form a crosslinked network, the antibacterial or antiviral compound is stably held in the coating layer composed of the crosslinked body of the coating agent by ionic, coordinate, or hydrogen bonds with the polyethylene moiety of the modified polyethyleneimine and / or the crosslinked network part of the modifying group, or by steric hindrance. This steric hindrance refers to a state in which the molecular size (ionic size) of the antibacterial or antiviral compound is larger than the size of the crosslinked network, making the compound physically unable to pass through the crosslinked network.

[0030] The content of the antibacterial or antiviral compound may be 0.01 parts by mass or more and 50 parts by mass or less, 0.1 parts by mass or more and 20 parts by mass or less, or 1 part by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the coating agent.

[0031] The liquid medium can be water, an organic solvent, or a mixture thereof. Examples of organic solvents include lower alcohols such as methanol and ethanol. These can be used alone or in combination. When the liquid medium is a mixture of water and an organic solvent, the pot life of the coating agent can be extended if the concentration of the organic solvent in the mixture is 5 wt% or more, 10 wt% or more, or 15 wt% or more. When the concentration of the organic solvent in the mixture is less than 60 wt%, handling is improved from the perspective of legal regulations. For the reasons mentioned above, when the liquid medium is a mixture of water and an organic solvent, the concentration of the organic solvent in the mixture can be 5 wt% or more but less than 60 wt%, 10 wt% or more but less than 60 wt%, or 15 wt% or more but less than 60 wt%.

[0032] The coating agent according to the embodiment can be produced by dissolving and / or dispersing a modified polyethyleneimine (polyethyleneimine having a self-crosslinking group) and an antibacterial or antiviral compound in a liquid medium. Examples of dispersing machines that can be used include a roller mill, a ball mill, a pebble mill, an attritor, and a sand mill.

[0033] The antibacterial or antiviral coating layer according to the embodiment is composed of a crosslinked product of the coating agent. The antibacterial or antiviral coating layer according to the embodiment is formed by applying the coating agent and then evaporating the volatile components. Here, the volatile components refer to components that evaporate at room temperature and normal pressure (25°C, 1 atm). After the coating agent is applied, the volatile components of the liquid medium and the like evaporate, and the self-crosslinking groups of the modified polyethyleneimine crosslink with each other, generating a crosslinked product, thereby forming the antibacterial or antiviral coating layer. When the antibacterial or antiviral coating layer is formed, a crosslinked network structure of the crosslinked product is formed, and the antibacterial or antiviral compound is stably retained within the crosslinked network structure. As a result, the antibacterial or antiviral effect is exhibited even when bacteria or viruses adhere to the antibacterial or antiviral coating layer in the form of impurities, and the function can be maintained even when wetted with water.

[0034] The antibacterial or antiviral coating layer according to the embodiment may be formed by applying a solution or dispersion obtained by dissolving and / or dispersing modified polyethyleneimine, which is polyethyleneimine having a self-crosslinking group, in a liquid medium to form a coating layer, and then applying a solution or dispersion obtained by dissolving and / or dispersing an antibacterial or antiviral compound in a liquid medium to the coating layer.

[0035] A laminate according to an embodiment includes a substrate and the antibacterial or antiviral coating layer formed on the substrate. By providing the antibacterial or antiviral coating layer on the substrate, the laminate exhibits antibacterial or antiviral effects even when bacteria or viruses are attached in the form of contaminants, and can maintain its functionality even when wet. Examples of substrates include metal materials such as stainless steel, ceramic materials such as tiles, polymer materials such as acrylic resin and polystyrene, and wood. [Example]

[0036] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0037] [Triethoxy-(3-glycidyloxypropyl)silane-modified polyethyleneimine (PEISiG)] The following ethanol solutions of modified polyethyleneimines were prepared:

[0038] (Reference example 1) A 15 wt% ethanol solution of polyethyleneimine with an average molecular weight of 10,000 and a 15 wt% ethanol solution of triethoxy-(3-glycidyloxypropyl)silane (SiG) were mixed in a weight ratio of 3.1:1 and stirred well, and then an addition reaction was carried out at 70°C for 2 hours to obtain an ethanol solution of modified polyethyleneimine (PEISiG10k20), a reaction product in which the number of moles of polyethyleneimine units in the polyethyleneimine relative to the number of moles of SiG was 20.

[0039] (Reference example 2) An ethanol solution of modified polyethyleneimine (PEISiG25k30) was obtained in the same manner as in Reference Example 1, except that a 15 wt% ethanol solution of polyethyleneimine with an average molecular weight of 25,000 was used and SiG and polyethyleneimine were reacted to obtain a modified polyethyleneimine, which is a reaction product in which the number of moles of ethyleneimine units in the polyethyleneimine relative to the number of moles of SiG is 30.

[0040] (Reference example 3) An ethanol solution of modified polyethyleneimine (PEISiG25k40) was obtained in the same manner as in Reference Example 1, except that a 15 wt% ethanol solution of polyethyleneimine with an average molecular weight of 25,000 was used and SiG and polyethyleneimine were reacted to obtain a modified polyethyleneimine, which is a reaction product in which the number of moles of ethyleneimine units in the polyethyleneimine relative to the number of moles of SiG is 40.

[0041] [Water and ethanol resistance evaluation] The ethanol solutions of modified polyethyleneimine obtained in Reference Examples 1 to 3 were each diluted with ethanol to a modified polyethyleneimine concentration of 1 wt% to form coating solutions. 10 μL of each solution was dropped onto the surface of a polystyrene dish, and the solvent was allowed to evaporate, forming transparent, uniform PEISiG coating layers approximately 30 mm in diameter. Water and ethanol were dropped onto portions of the coating layers immediately after solvent evaporation, portions obtained after solvent evaporation at 20°C and subsequent standing at 20°C for 1.5 hours, portions obtained after solvent evaporation at 40°C and subsequent standing at 40°C for 1.5 hours, and portions obtained after solvent evaporation at 15°C and subsequent standing at 15°C for 16 hours. Water and ethanol resistance were evaluated by visually observing the droplet boundaries and using the following evaluation criteria. The results are shown in Table 1. <Evaluation criteria> A: Completely unaffected by water or ethanol B: The film thickness decreases slightly when immersed in water. C: Dissolves quickly when in contact with water

[0042] [Table 1]

[0043] The PEISiG coating layer rapidly dissolved in water immediately after solvent evaporation. However, over time, it self-crosslinked and transformed into a stable coating layer resistant to water and ethanol. This transformation progressed more rapidly at higher temperatures. The water and ethanol resistance of the resulting PEISiG coating layer tended to increase with increasing molecular weight of the raw material polyethyleneimine and the SiG modification rate. In particular, PEISiG 10k20, PEISiG 25k30, and PEISiG 25k40 formed stable crosslinked layers completely resistant to water and ethanol after 1.5 hours at 40°C and 16 hours at 15°C. These results demonstrate that an ethanol solution of modified polyethyleneimine (PEISiG) can self-crosslink to form a stable coating layer at moderate temperatures, such as room temperature, after application to a substrate surface.

[0044] [3-(trimethoxysilyl)propyl methacrylate modified polyethyleneimine (PEISiMA)] (Reference example 4) A 10 wt% ethanol solution of polyethyleneimine (average molecular weight 10,000) and a 6.3 wt% ethanol solution of 3-(trimethoxysilyl)propyl methacrylate (SiMA) were mixed so that the moles of ethyleneimine units in the polyethyleneimine relative to the moles of SiMA were 10, and after stirring well, the mixture was reacted at 75°C for 50 minutes to obtain an ethanol solution of SiMA-modified polyethyleneimine (PEISiMA10k10), a reaction product in which the moles of ethyleneimine units in the polyethyleneimine relative to the moles of SiMA were 10.

[0045] <Water resistance characteristic evaluation test> The ethanol solution of modified polyethyleneimine obtained in Reference Example 4 was diluted with ethanol to a modified polyethyleneimine concentration of 5 wt% to form a coating solution. 10 μL of each solution was dropped onto a polystyrene surface, and the solvent was evaporated to form a transparent, uniform coating layer approximately 30 mm in diameter. Immediately after solvent evaporation, water was dropped onto the coating layer after 12 hours at 20°C following solvent evaporation, and after 2 hours at 40°C following solvent evaporation. The water was then left to stand for 10 seconds before being removed. The water resistance was evaluated by visually observing the drop boundary according to the following evaluation criteria. The results are shown in Table 2. <Evaluation criteria> A: Completely unaffected by water B: The film thickness decreases slightly when immersed in water. C: Dissolves quickly when in contact with water

[0046] [Table 2]

[0047] It was confirmed that a PEISiMA coating layer in which the number of moles of polyethyleneimine units in polyethyleneimine relative to the number of moles of SiMA exceeds a certain level quickly dissolves in water immediately after solvent evaporation, but when left to stand for half a day (12 hours) at room temperature (20°C) or for two hours at 40°C, self-crosslinking proceeds, and the layer changes into a stable coating layer that is resistant to water, similar to the PEISiG coating layers of Reference Examples 1 to 3. From the above, it was demonstrated that an ethanol solution of modified polyethyleneimine (PEISiMA) can self-crosslink under mild temperature conditions, around room temperature, after being applied to the surface of a material, to form a stable coating layer.

[0048] Example 1 [Preparation of silane-modified polyethyleneimine coating layer that retains copper (II) ions and evaluation test of copper (II) ion adsorption and retention properties] The following evaluation test was conducted to investigate the adsorption and retention characteristics of copper (II) ions, which are known to have antibacterial effects, by a triethoxy-(3-glycidyloxypropyl)silane-modified polyethyleneimine (PEISiG) coating layer.

[0049] First, 10 μL of a 5 wt % ethanol solution of PEISiG25k30 prepared in Reference Example 2 was placed in a polystyrene dish with a diameter of 35 mm (bottom area of ​​10 cm). 2The coated dish was placed in the center of a dish and placed on a hot plate at 40°C for 2 hours, forming a coating layer approximately 30 mm in diameter that was completely resistant to both water and ethanol. To examine the adsorption properties of this coating layer for copper(II) ions, which are known to have antibacterial properties, 1.5 mL of 0.5 mM copper(II) sulfate solution was added to a dish with the coated surface washed with water and air-dried, and to an uncoated dish, and the solution was stirred for 20 minutes to ensure that the solution thoroughly contacted the surface. The solution was then collected and mixed with 1.5 mL of water containing 0.4 mg of polyethyleneimine (average molecular weight 10,000) (enough to chelate all of the copper(II) ions in the solution and produce a dark color). The absorbance of the resulting mixture was measured. The remaining percentage of copper(II) ions in the solution was estimated from the absorbance at 270 nm, which was attributed to the copper(II) ions chelated to the lone electron pair of the amino group. The results are shown in Figure 1 (N=3). In FIG. 1, "PEISiG25K" indicates an example, and "uncoated" indicates a comparative example.

[0050] Under uncoated conditions, all copper(II) ions contained in the original copper(II) sulfate solution were recovered (100% retention), confirming that the uncoated polystyrene surface did not adsorb any copper(II) ions. In contrast, the modified polyethyleneimine (PEISiG25k30) coating adsorbed over 90% of the copper(II) ions in the solution (approximately 8% retention), turning blue, indicating chelate stabilization of the copper(II) ions. Furthermore, when copper(II) ions were extracted from a dish containing the modified polyethyleneimine (PEISiG25k30) coating by loading 1.5 mL of water and stirring for 5 minutes, only approximately 5% of the amount contained in the original copper(II) sulfate solution was extracted, indicating that the majority of the copper(II) ions, a highly water-soluble antibacterial component, were stably retained within the modified polyethyleneimine (PEISiG25k30) coating. It is well known that water-soluble polymers form complexes with various metal ions, and in particular, copper (II) ions have a binding constant of 10 20Chelating agents showing high stabilization exceeding mol / L have been reported, suggesting the possibility that a crosslinked layer of water-soluble polymers can provide very strong and stable retention (https: / / www.jstage.jst.go.jp / article / kinoushi / 49 / 0 / 49_21 / _pdf / -char / ja). From the above, it was demonstrated that the coating layer of modified polyethyleneimine (PEISiG25k30) has the effect of adsorbing copper (II) ions in aqueous solution and keeping them on the surface of the coating layer.

[0051] Example 2 [Preparation of a silane-modified polyethyleneimine coating layer that retains salazosulfapyridine and evaluation of the stability of salazosulfapyridine retention] The following evaluation test was carried out to investigate the retention properties of a triethoxy-(3-glycidyloxypropyl)silane-modified polyethyleneimine (PEISiG) coating layer against salazosulfapyridine (SASP), a sulfonamide antibacterial agent.

[0052] First, ethanol solutions containing 5 wt% and 1 wt% PEISiG10k20 and SASP, respectively, were prepared. Under a nitrogen atmosphere, 10 μL of each solution was loaded onto a 35 mm diameter polystyrene dish and spin-coated at 800 rpm. For comparison, a 1.5-fold volume of 1N sodium hydroxide solution was added to the SASP, and ethanol was added to adjust the SASP concentration to 1 wt%. This solution (10 μL) was then coated onto a polystyrene dish in the same manner as above. Each dish was left standing on a hot plate at 40 °C for half a day. After stirring, 1.5 mL of water was added to the coated surface of each dish, and the dish was collected. The dish was then rinsed with another 1.5 mL of water to make a total of 3 mL of solution. 50 μL of 0.01 N sodium hydroxide solution (enough to dissociate all the acid-dissociable groups of the SASP in the solution) was added to obtain an aqueous solution. The absorbance of the resulting aqueous solution was measured, and the SASP elution rate from the coated surface was estimated from the absorbance value at a wavelength of 365 nm. The results are shown in Figure 2 (N=3, vertical axis is logarithmic). In Figure 2, "PEISiG+SASP" indicates the Example, and "SASP" indicates the Comparative Example.

[0053] When SASP was coated alone, all of the coated SASP was eluted from the surface in water, whereas when it was coated with five times the amount of PEISiG, only about 1% of the SASP was eluted. At this coated surface, protons were transferred from the proton donor SASP to the proton acceptor polyethyleneimine, resulting in the formation of negative and positive ions, respectively, through electrostatic attraction. This interaction was suggested to be the mechanism by which SASP remained within the network structure of the PEISiG coating, even when exposed to water. The coating formed from modified polyethyleneimine was shown to have stable retention properties for proton donors such as salazosulfapyridine.

[0054] Example 3 [Production of silane-modified polyethyleneimine coating layer that retains antiviral components and evaluation test of antiviral component retention properties] The following evaluation test was conducted to investigate the retention properties of a 3-(trimethoxysilyl)propyl methacrylate-modified polyethyleneimine (PEISiMA) coating layer against didodecyldimethylammonium chloride (DDDMA), an active ingredient reported to have antiviral properties.

[0055] First, a 0.1 wt% DDDMA ethanol solution, an ethanol solution containing 0.1 wt% DDDMA plus 0.45 wt% polyethyleneimine (PEI, average molecular weight 10,000), and an ethanol solution containing 0.45 wt% PEISiMA10k10 prepared in Reference Example 4 were prepared, and 4 μL of each solution was applied to six wells of a 48-well plate and left at room temperature for half a day. Next, 1 mL of water was added to three of the six wells in each solution condition, shaken for 10 seconds, and then removed to form a coating layer. The antiviral effects of these coating layers were estimated according to the method described in ACS Appl. Bio Mater. 2022, 5, 11, 5174-5180. Specifically, a saliva droplet model containing enveloped viruses was prepared by mixing 0.25 wt% bovine submandibular mucin (confirmed to have virus-protective effects) in Dulbecco's buffer with a medium containing luminescent recombinant Sendai virus in a 4:1 ratio. 2 μL of this mixture was then dropped onto the coated layer prepared above. After the container was capped and left to stand for 1 hour, 10 μL of Dulbecco's buffer was added, and the mixture was recovered. This was then added to the medium of infected cells cultured in a 96-well plate. The following day, luciferase activity was measured in a multiwell plate and normalized by cell number to provide an index of residual virus activity. The results are shown in Figure 3 (N=3, vertical axis is logarithmic). In Figure 3, conditions E and F represent the working example, while conditions A to D and G represent comparative examples.

[0056] DDDMA coating alone exhibited high antiviral activity, reducing residual virus infectivity below the detection limit (~1E+02) (condition A). However, after washing, the surface's antiviral activity was only about one-fifth of that without coating (condition G) (condition B), suggesting that much of the coated DDDMA was lost from the surface by washing. Furthermore, a small amount of residual infectivity was observed in the mixture with non-crosslinked PEI (conditions C and D). Under the non-washing condition, the number of infected cells was reduced to about 60% of the other conditions due to the strong cytotoxicity of PEI introduced with the virus, suggesting that this reduced cell membrane integrity may have affected the estimate of residual infectivity. On the other hand, the mixture with PEISiMA reduced residual virus infectivity below the detection limit, regardless of whether it was washed or not (conditions E and F). This indicates that the DDDMA trapped in the PEISiMA coating layer is not easily lost by washing with water, but is slowly released into the adhering saliva droplets, reaching and inactivating the viruses protected by mucin.

Claims

1. A coating agent comprising a modified polyethyleneimine, which is a polyethyleneimine having self-crosslinking groups, an antibacterial or antiviral compound, and a liquid medium.

2. the polyethyleneimine has at least one nitrogen-containing group selected from an amino group and an imino group, The coating agent according to claim 1 , wherein the modified polyethyleneimine is a reaction product of the polyethyleneimine and a polyfunctional compound having the self-crosslinking group and a functional group reactive with the nitrogen-containing group.

3. 2. The coating agent according to claim 1, wherein the polyethyleneimine has a number average molecular weight of 1,000 or more and 150,000 or less.

4. The reactants are 3. The coating agent according to claim 2, wherein the number of moles of the ethyleneimine unit of the polyethyleneimine relative to the number of moles of the polyfunctional compound is 2 to 2,000.

5. An antibacterial or antiviral coating layer comprising a crosslinked product of the coating agent according to claim 1.

6. A laminate comprising a substrate and the antibacterial or antiviral coating layer according to claim 5 formed on the substrate.

Images