Antibacterial printing inks and methods of making, antibacterial coating structures and methods of making

Abstract

The application provides an antibacterial printing coating and a preparation method thereof, and an antibacterial coating structure and a preparation method thereof, and belongs to the technical field of combined coatings. The antibacterial printing coating comprises the following components in percentage by weight: 55-80% of a coating main material, 2-10% of an antibacterial additive, and 15-40% of a dispersant; the antibacterial additive comprises a coordination compound containing noble metal and an organic acid, the density of the antibacterial additive is less than the density of the coating main material; the dispersant comprises a polyester-polyamide mixed block high molecular material, the polyester block of the dispersant is dissolved in base oil of the coating main material, and the polyamide block of the dispersant is adsorbed on the surface of the coordination compound containing noble metal of the antibacterial additive. The antibacterial printing coating provided by the application can realize long-acting antibacterial effect at normal temperature and has good antibacterial effect.

Description

Technical Field

[0001] This application relates to the field of composite coating technology, and in particular to an antibacterial printing coating and its preparation method, as well as the structure and preparation method of the antibacterial coating. Background Technology

[0002] Ink and varnish are commonly used printing coatings. Ink is used to print patterns and text onto a substrate through printing or inkjet printing, while varnish is used to enhance the appearance of printed materials, providing gloss, protection, abrasion resistance, and decorative effects.

[0003] Because printed materials often undergo multiple transfers, such as a long time and multiple hands involved in the process from printing to delivery to the customer, people expect printed materials to have antibacterial properties. As a result, antibacterial inks have emerged.

[0004] Antibacterial ink is a type of ink prepared by adding antibacterial agents to ink. Given that the substrates printed with this ink are used at room temperature, and considering the aforementioned requirement for long-lasting antibacterial properties, there is a need for an ink that can provide long-lasting antibacterial protection at room temperature and has a good antibacterial effect. Summary of the Invention

[0005] One object of the present invention is to provide an antibacterial printing coating that can provide long-lasting antibacterial effect at room temperature and has good antibacterial properties.

[0006] In particular, embodiments of the present invention provide an antibacterial printing coating comprising the following components by weight percentage: 55-80% coating base material, 2-10% antibacterial additives and 15-40% dispersant;

[0007] The antibacterial additive includes coordination compounds containing precious metals and organic acids, and the density of the antibacterial additive is less than the density of the main material of the coating.

[0008] The dispersant comprises a polyester-polyamide mixed block polymer material, wherein the polyester block of the dispersant is dissolved in the base oil of the coating body material, and the polyamide block of the dispersant is adsorbed on the surface of the coordination compound containing noble metals of the antibacterial additive.

[0009] Optionally, the dispersant is prepared by copolymerization of fatty acids, lactone compounds, hydroxy acids, lactam compounds, and polyamines.

[0010] Optionally, the antibacterial printing coating is an antibacterial ink, which comprises the following components by weight percentage: 60-78% coating base material, 7-10% antibacterial additives, and 15-25% dispersant.

[0011] Optionally, the antibacterial printing coating is an antibacterial varnish, which comprises the following components by weight percentage: 55-78% coating base material, 2-8% antibacterial additives, and 20-40% dispersant.

[0012] In particular, embodiments of the present invention also provide a method for preparing the antibacterial printing coating described in any of the above claims, comprising the following steps:

[0013] Heat the base oil of the coating material to any value between 40-100℃;

[0014] Add 15-40% by weight of the dispersant to the base oil and stir, then keep warm for 8-15 minutes until the dispersant is completely dissolved.

[0015] Add 2-10% by weight of the antibacterial additive and stir until the antibacterial agent is dispersed to a transparent state to form an antibacterial base oil;

[0016] Mix the other materials in the main coating material with the antibacterial base oil and stir.

[0017] In particular, embodiments of the present invention also provide an antibacterial coating structure, including an ink layer, wherein the material of the ink layer includes the aforementioned antibacterial ink.

[0018] Optionally, the antibacterial coating structure further includes a varnish layer coated on the surface of the ink layer, the material of the varnish layer including the aforementioned antibacterial varnish.

[0019] In particular, embodiments of the present invention also provide a method for preparing the above-mentioned antibacterial coating structure, comprising:

[0020] The antibacterial ink is coated onto the surface of the substrate to be printed to form the ink layer;

[0021] After a preset time, the antibacterial varnish is applied to the ink layer to form the varnish layer, wherein the preset time is 60-90% of the drying time of the ink layer.

[0022] Optionally, the preset time is 70-80% of the drying time of the ink layer.

[0023] According to a first aspect of the invention, the dispersant comprises a polyester block and a polyamide block, wherein the polyamide block portion is firmly adsorbed onto the surface of the noble metal-containing coordination compound of the antibacterial additive, and the polyester portion is readily soluble in the base oil of the ink, with the polymer long chain extending into the base oil. This dispersant can form a protective layer of a certain thickness on the surface of the antibacterial additive particles, reducing the interfacial tension between the two phases, increasing wettability, and improving the dispersion stability of the antibacterial additive particles in the base oil. Furthermore, since the density of the antibacterial additive is less than that of the bulk material of the coating, sedimentation of the antibacterial additive can be avoided during printing, ensuring that the antibacterial additive particles are dispersed by the dispersant while remaining as close as possible to the surface of the entire antibacterial printing coating, thereby maintaining high antibacterial performance.

[0024] Furthermore, considering that the antibacterial additive particles have a relatively high proportion of small-diameter particles, irregular shapes, and are hollow or porous, this embodiment appropriately increased the amount of dispersant, and finally determined the proportion of dispersant to be 15-40%, which resulted in a better dispersion effect.

[0025] According to a second aspect of the present invention, by controlling the heating temperature of the base oil to be between 40-100°C, the dispersion effect of the dispersant can be guaranteed. This is because if the temperature is too low, the viscosity of the base oil will be too high, and too many bubbles will be generated during stirring. If the temperature is too high, the dispersant will decompose, resulting in a lower dispersion effect. Furthermore, if the temperature is too high, the viscosity of the base oil will be low, which will affect the dispersion effect of the antibacterial additive.

[0026] Furthermore, the dispersant is first uniformly dispersed in the base oil, and then the antimicrobial additive is added. That is, the antimicrobial additive is added after the dispersant itself is evenly distributed. Since the dispersant is a multi-block material with high viscosity, adding both the dispersant and the antimicrobial additive to the base oil simultaneously would cause molecular chain entanglement, resulting in poor dispersion of the antimicrobial additive. In other words, by adding the dispersant and antimicrobial additive to the base oil in two steps, the dispersion effect of the antimicrobial additive can be further guaranteed.

[0027] According to a third aspect of the present invention, the antibacterial coating structure includes an ink layer and a varnish layer, both of which contain antibacterial additives. Therefore, the content of antibacterial additives is higher. While the varnish layer continues to provide antibacterial effects, even if some of the antibacterial additives in the varnish layer are consumed due to factors such as friction, the underlying ink layer can still provide antibacterial effects. Furthermore, since the density of the antibacterial additives is set to be less than the density of the coating material, the antibacterial additives in the ink layer and the varnish layer can be located on the upper surface, thereby enhancing the surface antibacterial effect of the structure.

[0028] Furthermore, the component bonding in the ink layer manifests as the dispersant adsorbing some of the antibacterial additives, which are dispersed in the antibacterial ink. Other antibacterial additives tend to accumulate on the surface of the ink layer. These antibacterial additives on the ink layer surface can be adsorbed by excess dispersant in the varnish layer, thus forming a binding force between the ink layer and the varnish layer. This increases the adhesion of the varnish layer to the ink layer. At the same time, the antibacterial additives in the ink layer are partially bound to the varnish layer, resulting in the entire varnish layer having more antibacterial additives and enhancing the antibacterial properties of the antibacterial coating structure.

[0029] According to a fourth aspect of the present invention, applying a varnish layer before the ink layer is semi-dry or more and not completely dry can, on the one hand, prevent small molecule antibacterial additives in the varnish layer from penetrating through the ink layer to the surface of the substrate and reducing the antibacterial effect, and on the other hand, ensure that the dispersant in the varnish layer can effectively adsorb the antibacterial additives in the ink layer, so that the antibacterial coating structure achieves a better antibacterial effect. Attached Figure Description

[0030] Figure 1 A flowchart illustrating a method for preparing an antibacterial printing coating according to an embodiment of the present invention is shown;

[0031] Figure 2 A flowchart illustrating a method for preparing an antibacterial coating structure according to an embodiment of the present invention is shown;

[0032] Figure 3 The diagram shows the dispersion effect of the antibacterial additive in the antibacterial ink according to Embodiment 1 of the present invention;

[0033] Figure 4 The diagram shows the dispersion effect of the antibacterial additive in the antibacterial ink of Comparative Example 6. Detailed Implementation

[0034] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0035] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0036] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0037] In preparing antibacterial inks, the inventors employed an organic acid antibacterial agent containing a coordination compound of a noble metal to achieve long-lasting antibacterial effect at room temperature. The organic acid in this type of antibacterial agent has a bactericidal effect, while the coordination compound containing the noble metal continuously catalyzes the organic acid, enabling long-lasting antibacterial action at room temperature and low concentration. However, when this antibacterial agent was directly dispersed in the ink, it was found that the proportion of the antibacterial agent in the ink was less than 1%, resulting in poor dispersion. To improve the dispersion effect of the antibacterial agent, the inventors added some commonly used alcohols, ketones, and esters as dispersants to the ink, but the dispersion effect was still poor. The inventors also experimented with some polyether-type, polyacrylate-type, and their mixed block polymers as dispersants. The experimental results showed that even after adding dispersants, the proportion of the antibacterial agent in the ink was still less than 1%. To better disperse the antibacterial agent in the ink, this application provides the following embodiments.

[0038] One embodiment of the present invention provides an antibacterial printing coating comprising the following components by weight percentage: 55-80% coating bulk material, 2-10% antibacterial additive, and 15-40% dispersant. Specifically, the weight percentage of the coating bulk material can be, for example, 55%, 65%, 70%, 75%, or 80%, or any other value among 55-80%. The weight percentage of the antibacterial additive can be, for example, 2%, 3%, 5%, 8%, or 10%, or any other value among 2-10%. The weight percentage of the dispersant can be, for example, 15%, 17%, 20%, 25%, or 40%, or any other value among 15-40%.

[0039] The main materials of a coating include base oil, pigments, resin binders, fillers, and additives. Base oils may include mineral oils and / or vegetable oils. Pigments may be organic or inorganic. Resin binders may include colloidal oils and / or resin oils. Fillers may be, for example, nano-calcium carbonate, barium sulfate, or kaolin, and their function is to change the density of the coating's main materials. Additives include abrasion resistant agents and drying agents.

[0040] Antibacterial additives include coordination compounds containing noble metals and organic acids. The density of the antibacterial additive is less than that of the main coating material. The coordination compounds containing noble metals are coordination compounds formed by noble metal ions and organic molecules. Examples of noble metals include silver, gold, copper, zinc, or platinum. Examples of organic molecules include C7H... 15 N3, C6H 13 N3, C8H 17 N3 and other organic molecules containing only C, H, and N elements. This coordination compound containing a noble metal can be, for example, Pt·C7H. 15 N3, Pt·C6H 13 N3, Au·C8H 17 N3, etc. The organic acid may be, for example, citric acid, succinic acid, acetic acid, malic acid, or acetic acid. In some embodiments, the organic acid may be, for example, one or a combination of two of citric acid and malic acid. For example, the organic acid may include 97%–98% citric acid and 0.6%–1% malic acid by weight.

[0041] The dispersant is a polyester-polyamide mixed block polymer material. The polyester block of the dispersant is dissolved in the base oil of the coating material. The polyamide block of the dispersant interacts with the organic ligands in the coordination compound through hydrogen bonds, van der Waals forces or other interactions, thereby binding with the noble metal in the coordination compound.

[0042] In some embodiments, the dispersant is prepared by the following steps:

[0043] Step 1: Add fatty acids, lactone compounds, hydroxy acids and lactam compounds into the reaction vessel in a predetermined ratio, and add an appropriate amount of stannous octoate catalyst.

[0044] Step 2: Inert gas is introduced into the reaction vessel and the reaction vessel is heated to 160℃-200℃ and kept at that temperature for 10h-14h.

[0045] Step 3: Cool the reaction vessel to room temperature and pour the reaction product into an excess of cold methanol or ethanol to precipitate the polymer.

[0046] Step four: Wash the precipitated first polymer with a cold solvent to remove unreacted monomers and catalyst residues;

[0047] Step 5: Dry the washed first polymer in a vacuum drying oven;

[0048] Step 6: Add the first polymer and the polyamine to the reaction vessel in proportion, and add an appropriate amount of toluenesulfonic acid catalyst at the same time.

[0049] Step 7: Heat the reaction vessel to 120℃-160℃ and maintain the temperature for 4-6 hours under a protective gas.

[0050] Step 8: Cool the reaction vessel to room temperature;

[0051] Step nine: Pour the reaction product into a cold solvent to precipitate the second polymer;

[0052] Step 10: Wash the precipitated second polymer with a cold solvent to remove unreacted monomers and catalyst residues;

[0053] Step eleven: The washed second polymer is dried in a vacuum drying oven to finally prepare the dispersant.

[0054] The fatty acids in step one can be, for example, stearic acid, palmitic acid, oleic acid, stearic acid, lauric acid, myristic acid, erucic acid, caprylic acid, or hexanoic acid. The lactone compounds can be, for example, octanolide, caprolactone, methylcaprolactone, or other lactone-substituted derivatives. The hydroxy acids can be, for example, hydroxystearic acid, hydroxyoleic acid, hydroxyhexanoic acid, or hydroxypalmitic acid. The lactam compounds can be, for example, propiolactam, butyrolactam, caprolactam, vinyllactam, or caprolactam-substituted derivatives.

[0055] The heating temperature in step two can be 160℃, 180℃, 190℃ or 200℃, or any other value between 160℃ and 200℃. The heat preservation time can be 10h, 11h, 12h or 14h, or any other value between 10h and 14h.

[0056] The drying temperature in step five can be any value between 40℃ and 60℃, for example, a drying temperature of 40℃, 50℃, or 60℃, and the drying time can be any value between 12h and 24h, for example, a drying time of 12h, 14h, 16h, 18h, 20h, 22h, or 24h.

[0057] The polyamine in step six can be, for example, ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, other polyethylene polyamines, or polypropylene polyamines.

[0058] The heating temperature in step seven can be 120℃, 140℃, 150℃ or 160℃, or any other value between 120℃ and 160℃. The heat preservation time can be 4h, 5h, 5.5h or 6h, or any other value between 4h and 6h.

[0059] The cold solvent in step nine can be ethanol or acetone.

[0060] The drying temperature in step eleven can be any value between 40℃ and 60℃, for example, a drying temperature of 40℃, 50℃, or 60℃, and the drying time can be any value between 24h and 48h, for example, a drying time of 24h, 26h, 30h, 32h, 36h, 40h, or 48h.

[0061] In the above preparation process, fatty acids, lactone compounds, hydroxy acids and lactam compounds copolymerize to generate copolymers containing ester bonds and amide bonds. The copolymers containing ester bonds and amide bonds undergo amidation reaction with polyamines to generate high molecular weight polymers with polyester and polyamide blocks, namely the above dispersant.

[0062] The reaction principle of the above dispersant is shown in the following reaction formulas (1) and (2):

[0063]

[0064] In formulas (1) and (2), R1 is a C6-C17 alkyl or olefinic group, for example, when R1 is CH3(CH2). 16 When R2 is (CH2)5, it is stearic acid. R3 is a C3-C17 alkyl group or its substitute, for example, when R2 is (CH2)5, it is caprolactone. R4 is a C3-C5 alkyl group, for example, when R4 is (CH2)5, it is caprolactam. R5 is H or CH3 alkyl or olefinic group, for example, when R5 is H, it is polyethylenepolyamine. The product of formula (2) is a dispersant, where p and k are polyamide blocks and n and m are polyester blocks.

[0065] The dispersant in this embodiment includes polyester and polyamide blocks. The polyamide block portion can be firmly adsorbed onto the surface of the noble metal-containing coordination compound of the antibacterial additive, while the polyester portion can dissolve well in the base oil of the ink, and the long polymer chains extend into the base oil. This dispersant can form a protective layer of a certain thickness on the surface of the antibacterial additive particles, reducing the interphase tension, increasing wettability, and improving the dispersion stability of the antibacterial additive particles in the base oil. Furthermore, since the density of the antibacterial additive is lower than that of the coating bulk material, sedimentation of the antibacterial additive can be avoided during printing. This ensures that while the antibacterial additive particles are adsorbed and dispersed by the dispersant, the antibacterial additive remains on the surface of the entire antibacterial printing coating as much as possible, thereby maintaining high antibacterial performance.

[0066] Furthermore, considering that the antibacterial additive particles have a relatively high proportion of small-diameter particles, irregular shapes, and are hollow or porous, this embodiment appropriately increased the amount of dispersant, and finally determined the proportion of dispersant to be 15-40%, which resulted in a better dispersion effect.

[0067] In one embodiment, the main material of the coating includes a resin binder, which comprises a resin oil and a gum oil. The resin oil comprises rosin-modified phenolic resin and vegetable oil, and the gum oil comprises rosin-modified phenolic resin, vegetable oil, and a gelling agent. In one embodiment, the rosin-modified phenolic resin comprises the following components by weight percentage: 55.42% rosin, 20.08% octylphenol, 20.10% formaldehyde, 4.21% glycerol, and 0.19% PTS catalyst. The preparation method of this rosin-modified phenolic resin includes:

[0068] Rosin was added to the reaction vessel and the temperature was raised to 150°C. Octylphenol and formaldehyde were then added.

[0069] The addition reaction was carried out at 200-210℃ for 1.5 hours.

[0070] After the addition process is complete, add glycerol and PTS catalyst;

[0071] The esterification reaction was carried out at 250-280℃ for 6-8 hours.

[0072] Sampling and testing of acid value and viscosity; acid value ≤20, rotational viscosity 10000-20000cp, and release 10-18 meet the standards.

[0073] Cool down and discharge the material.

[0074] In this embodiment, the use of rosin-modified phenolic resin with higher viscosity and molecular weight to make resin binder can increase the viscosity of the main coating material, thereby facilitating the stable dispersion of antibacterial additives.

[0075] In one embodiment, the antibacterial printing coating is an antibacterial ink. The antibacterial ink comprises the following components by weight percentage: 60-78% coating bulk material, 7-10% antibacterial additive, and 15-25% dispersant. The weight percentage of the coating bulk material can be, for example, 60%, 65%, 70%, 75%, or 78%, or any value from 60-78%. The weight percentage of the antibacterial additive can be, for example, 7%, 8%, or 10%, or any value from 7-10%. The weight percentage of the dispersant can be, for example, 15%, 17%, 18%, 20%, or 25%, or any value from 15-25%.

[0076] In another embodiment, the antibacterial printing coating is an antibacterial varnish, comprising the following components by weight percentage: 55-78% coating bulk material, 2-8% antibacterial additive, and 20-40% dispersant. The weight percentage of the coating bulk material can be, for example, 55%, 60%, 65%, 70%, or 78%, or any value from 55-78%; the weight percentage of the antibacterial additive can be, for example, 2%, 3%, 5%, or 8%, or any value from 2-8%; the weight percentage of the dispersant can be, for example, 20%, 25%, 30%, 35%, or 40%, or any value from 20-40%.

[0077] Figure 1 A flowchart illustrating a method for preparing an antibacterial printing coating according to an embodiment of the present invention is shown. Figure 1 As shown, one embodiment of the present invention also provides a method for preparing the above-mentioned antibacterial ink, comprising the following steps:

[0078] Step S100: Heat the base oil of the paint body material to any value between 40-100℃;

[0079] Step S200: Add 15-40% by weight of dispersant to the base oil and stir, then keep warm for 8-15 minutes until the dispersant is completely dissolved.

[0080] Step S300: Add 2-10% by weight of antibacterial additive and stir until the antibacterial agent is dispersed to a transparent state to form an antibacterial base oil;

[0081] Step S400: Mix the other materials in the paint base material with the antibacterial primer and stir.

[0082] In step S100, during the heating of the base oil of the coating material, the heating temperature can be, for example, 40°C, 60°C, 80°C, or 100°C. The holding time in step S200 can be, for example, 8 minutes, 10 minutes, 12 minutes, or 15 minutes.

[0083] The base oil in step S100 is mineral oil and / or vegetable oil. Before step S400, there is also a step of preparing color base ink. After kneading, squeezing water, washing, vacuuming, color testing for moisture and rolling, a color base ink with a fineness of less than 5 micrometers is formed. Then, the color base ink, filler and some additives are mixed with antibacterial base oil. The filler here also needs to be rolled to a fineness of less than 5 micrometers.

[0084] In this embodiment, by controlling the heating temperature of the base oil between 40-100℃, the dispersion effect of the dispersant can be guaranteed. This is because if the temperature is too low, the viscosity of the base oil will be too high, and too many bubbles will be generated during stirring. If the temperature is too high, the dispersant will decompose, resulting in a lower dispersion effect. Furthermore, if the temperature is too high, the viscosity of the base oil will be low, which will affect the dispersion effect of the antibacterial additive.

[0085] Furthermore, in this embodiment, the dispersant is first uniformly dispersed in the base oil, and then the antibacterial additive is added. That is, the antibacterial additive is added after the dispersant itself is uniformly distributed. Since the dispersant itself is a multi-block material with high viscosity, if the dispersant and antibacterial additive are added to the base oil at the same time, it will cause molecular chain entanglement, resulting in a poor dispersion effect of the antibacterial additive. In other words, by adding the dispersant and antibacterial additive to the base oil in two steps, this embodiment can further ensure the dispersion effect of the antibacterial additive.

[0086] Some embodiments of the present invention also provide an antibacterial coating structure, which includes an ink layer and a varnish layer coated on the surface of the ink layer. The material of the ink layer includes the antibacterial ink in any of the above embodiments, and the material of the varnish layer includes the antibacterial varnish in any of the above embodiments.

[0087] The antibacterial coating structure of this embodiment includes an ink layer and a varnish layer, both of which contain antibacterial additives. Therefore, the content of antibacterial additives is higher. While the varnish layer continues to provide antibacterial effects, even if some of the antibacterial additives in the varnish layer are consumed due to friction or other factors, the underlying ink layer can still provide antibacterial effects. Furthermore, since the density of the antibacterial additives is set to be lower than that of the main coating material, the antibacterial additives in the ink layer and the varnish layer can be located on the upper surface, thereby enhancing the surface antibacterial effect of the structure.

[0088] Furthermore, in this embodiment, the amount of dispersant added to the ink layer material is insufficient relative to the amount of antibacterial additive, so at least some of the particles in the antibacterial additive in the ink layer are not adsorbed by the dispersant. On the other hand, the amount of dispersant added to the varnish layer material is excessive relative to the amount of antibacterial additive, so at least some of the polyamide blocks of the dispersant in the varnish layer material are not adsorbed by the antibacterial additive particles. Furthermore, since the dispersant is uniformly distributed in the antibacterial ink and antibacterial varnish, and the antibacterial additives, due to their lower density, tend to float on the surface, the component connection in the ink layer is manifested as the dispersant adsorbing some of the antibacterial additives. These antibacterial additives are dispersed in the antibacterial ink, while other antibacterial additives tend to accumulate on the surface of the ink layer. These antibacterial additives on the surface of the ink layer can be adsorbed by excess dispersant in the varnish layer. This creates a binding force between the ink layer and the varnish layer, increasing the adhesion of the varnish layer to the ink layer. At the same time, the antibacterial additives in the ink layer are partially bound to the varnish layer, resulting in the entire varnish layer having more antibacterial additives and enhancing the antibacterial performance of the antibacterial coating structure.

[0089] Figure 2 A flowchart illustrating a method for preparing an antibacterial coating structure according to an embodiment of the present invention is shown. Accordingly, as Figure 2 As shown in the embodiments of this application, a method for preparing the above-mentioned antibacterial coating structure is also provided, the method comprising:

[0090] Step S10: Apply antibacterial ink to the surface of the substrate to be printed to form an ink layer;

[0091] In step S20, after a preset time, an antibacterial varnish is applied to the ink layer to form a varnish layer. The preset time is 60-90% of the drying time of the ink layer, for example, 60%, 85%, or 90% of the drying time of the ink layer. In one embodiment, the preset time in step S20 is 70-80% of the drying time of the ink layer, for example, 70%, 75%, or 80% of the drying time of the ink layer.

[0092] The drying time of the ink layer mentioned in step S20 refers to the time required for the ink layer to dry completely.

[0093] The preparation method of this embodiment involves coating a varnish layer when the ink layer is semi-dry but not completely dry. On the one hand, this can prevent small molecule antibacterial additives in the varnish layer from penetrating through the ink layer to the surface of the substrate and reducing the antibacterial effect. On the other hand, it can also ensure that the dispersant in the varnish layer can effectively adsorb the antibacterial additives in the ink layer, so that the antibacterial coating structure achieves a better antibacterial effect.

[0094] Example 1

[0095] The antibacterial printing coating is an antibacterial ink, comprising the following components by weight percentage: 18% PR57:1 red pigment, 7% 2731 mineral oil, 2% linseed oil, 38% resin binder (of which the resin binder includes 65% gum oil and 35% 218 resin oil), 8% antibacterial additive, 20% dispersant, 2% cobalt naphthenate, and 5% nano-calcium carbonate. The antibacterial additive comprises the following components by weight percentage: 97.6% citric acid, 1.6% Pt·C7H15N3, and 0.8% malic acid.

[0096] The dispersant in this embodiment is prepared through the following steps:

[0097] Add 284.5g of stearic acid, 114.1g of caprolactone, 130.1g of hydroxyhexanoic acid and 113.2g of caprolactam to the reaction vessel, and add 0.1g of stannous octoate.

[0098] Argon gas was introduced into the reaction vessel and the reaction vessel was heated to 180°C and kept at that temperature for 12 hours.

[0099] The reaction vessel was cooled to room temperature, and the reaction product was poured into an excess of cold methanol to precipitate the polymer.

[0100] The precipitated first polymer was washed with cold methanol.

[0101] The washed first polymer was dried in a vacuum drying oven at 50°C for 20 hours.

[0102] The first polymer and 705g of tetraethylenepentamine were added to the reaction vessel, along with 0.7g of toluenesulfonic acid catalyst.

[0103] The reaction vessel was heated to 140°C and kept at that temperature for 6 hours under nitrogen protection.

[0104] Cool the reaction vessel to room temperature;

[0105] The reaction product was poured into a cold solvent, and the second polymer precipitated.

[0106] The precipitated second polymer was washed with acetone to remove unreacted monomers and catalyst residues.

[0107] The washed second polymer was dried in a vacuum drying oven at 50°C for 30 hours to finally prepare the dispersant.

[0108] The resin binder in this embodiment comprises the following components by weight percentage: 23.28% rosin, 8.43% octylphenol, 8.44% formaldehyde, 1.77% glycerol, 0.19% PTS catalyst, 19.89% soybean oil, 37.2% JETA-1 kerosene, and 0.8% aluminum isooctanoate. The corresponding preparation method includes the following steps:

[0109] Rosin was added to the reaction vessel and heated to 150°C. After the rosin dissolved, octylphenol and formaldehyde were added.

[0110] The temperature was raised to 200℃ to carry out the addition reaction for 1.5 hours;

[0111] After the addition process is complete, add glycerol and PTS catalyst;

[0112] The esterification reaction was carried out at 280℃ for 8 hours, followed by vacuuming for 1 hour.

[0113] Cool down to 200℃, add soybean oil and JETA-1 kerosene, stir well, and keep warm for 30 minutes;

[0114] Cool to 170℃, add aluminum isooctanoate and stir for 1 hour to obtain the gum oil in the resin binder.

[0115] The prepared gum oil was tested to have a rotational viscosity of 250,000 mPas, a viscosity of 12, and a yield value of 5,000 mPa.

[0116] The antibacterial ink in this embodiment is prepared by the following method:

[0117] Raw materials shall be supplied in the above weight percentages;

[0118] Dewatering and dispersing: Empty the kneader, open the steam valve, add PR57:1 red pigment to the kneader, keep the kneader temperature below 35℃, keep the speed low, stir for 3-5 minutes, add the gum oil and stir until the water is clear, pour water 5-7 times.

[0119] Cleaning: Start by setting the temperature to 85℃. Pour tap water into the kneader after the water has been poured out. Stop pouring water when the water level is above the ink. Stir for 5 minutes and then pour out the water. Repeat this process three times, keeping the speed low.

[0120] Vacuuming: Start vacuuming when the temperature rises to 60℃, control the temperature not to exceed 85℃-120℃, maintain the pressure at -0.08MPa to -0.1MPa, and control the rotation speed at high speed;

[0121] Moisture content test for color development: After confirming that the color, transparency and moisture content are within acceptable limits, shut off the steam inlet to the condensate.

[0122] Mixing: Slowly add 218 resin oil and linseed oil while stirring at high speed, and stir thoroughly until there are no lumps;

[0123] Rolling: The above-dispersed base ink is fed into a bead mill for rolling, and then rolled by skew rolling to achieve a fineness of ≤5μm;

[0124] Heat mineral oil 2731 to 80°C;

[0125] Add the dispersant to the 2731 mineral oil and stir, then keep warm for 10 minutes until the dispersant is completely dissolved;

[0126] Add the antibacterial additive and stir until the antibacterial agent is dispersed to a transparent state to form an antibacterial base oil;

[0127] The rolled base ink, cobalt naphthenate, and nano calcium carbonate are mixed with the above-mentioned antibacterial base oil and stirred.

[0128] Example 2

[0129] The only difference between Example 2 and Example 1 is that the PR57:1 red pigment in Example 1 is replaced with PY12 yellow pigment, the weight percentage of PY12 yellow pigment is 13%, the weight percentage of 2731 mineral oil is 10%, the weight percentage of linseed oil is 4%, and the color development step is removed.

[0130] Example 3

[0131] The only difference between Example 3 and Example 2 is that the PY12 yellow pigment in Example 2 is replaced with CIPB15:3 blue pigment, with CIPB15:3 blue pigment accounting for 17% by weight, 2731 mineral oil accounting for 8% by weight, and linseed oil accounting for 2% by weight.

[0132] Example 4

[0133] This embodiment uses a dry powder preparation process. The only difference between Example 4 and Example 1 is that the PR57:1 red pigment in Example 1 is replaced with carbon black, the weight percentage of carbon black is 20%, the weight percentage of 2731 mineral oil is 6%, the weight percentage of linseed oil is 1%, and the steps of squeezing water dispersion, washing, vacuuming and color development test for moisture are removed.

[0134] Example 5

[0135] The antibacterial printing coating is an antibacterial varnish, comprising the following components by weight percentage: 25% JETA-1 kerosene, 14% sesame oil, 14% rosin, 2.5% maleic anhydride, 3.2% glycerin, and 0.3% PTS catalyst, 6% antibacterial additive, 28% dispersant, 4% nano-calcium carbonate, 1% MAW-331 wax, 1% MAD-801 cobalt desiccant, and 1% MAD-703 manganese desiccant. The antibacterial additive and dispersant used in this embodiment are the same as those used in Example 1.

[0136] The preparation method of the antibacterial varnish in this embodiment includes the following steps:

[0137] Raw materials shall be supplied according to the above weight percentages;

[0138] Add rosin to the reaction vessel and heat to 160°C until the rosin is completely dissolved.

[0139] Add maleic anhydride, heat to 200℃ and keep warm for 1.5 hours;

[0140] Add glycerol and PTS catalyst;

[0141] Continue heating to 250℃ and hold for 5 hours to produce rosin-based resin.

[0142] When the rosin-based resin is cooled to an acid value ≤25mg / g and a rotational viscosity of 8000mPas, sesame oil and 60% JETA-1 kerosene are added.

[0143] The temperature was controlled at 200℃ and kept at that temperature for 30 minutes. The viscosity, viscosity, and yield value were tested. In this example, the viscosity was 500 mPas, the viscosity was 15, and the yield value was 1800 Pa.

[0144] Add the dispersant and stir, then keep warm for 8 minutes until the dispersant is completely dissolved;

[0145] Add 8% by weight of antibacterial additive and stir until the antibacterial agent is dispersed into a transparent state;

[0146] Cool to 50℃, add nano calcium carbonate, MAW-331 wax, MAD-801 cobalt desiccant and MAD-703 manganese desiccant, and stir at high speed for 30 minutes until uniform;

[0147] The viscosity of the remaining kerosene was adjusted to 7 for qualified filling.

[0148] Comparative Example 1

[0149] The only difference between Comparative Example 1 and Example 1 is that no antibacterial additives and dispersants were added in Comparative Example 1.

[0150] Comparative Example 2

[0151] The only difference between Comparative Example 2 and Example 2 is that no antibacterial additives and dispersants were added in Comparative Example 2.

[0152] Comparative Example 3

[0153] The only difference between Comparative Example 3 and Example 3 is that no antibacterial additives and dispersants were added in Comparative Example 3.

[0154] Comparative Example 4

[0155] The only difference between Comparative Example 4 and Example 4 is that no antibacterial additives and dispersants were added in Comparative Example 4.

[0156] Comparative Example 5

[0157] The only difference between Comparative Example 5 and Example 1 is that the dispersant in Example 1 was replaced with CH-6.

[0158] Comparative Example 6

[0159] The only difference between Comparative Example 6 and Example 1 is that the dispersant in Example 1 was replaced with PEA1:0.8-PCL10.

[0160] Comparative Example 7

[0161] The only difference between Comparative Example 7 and Example 1 is that the antibacterial additive in Example 1 was replaced with NiAgAPO-11 / MCM-41.

[0162] Comparative Example 8

[0163] The only difference between Comparative Example 8 and Example 5 is that no antibacterial additives and dispersants were added in Comparative Example 8.

[0164] Comparative Example 9

[0165] The only difference from Example 1 is that the heating temperature of the mineral oil is 30°C.

[0166] Comparative Example 10

[0167] The only difference from Example 1 is that the heating temperature of the mineral oil is 120°C.

[0168] Comparative Example 11

[0169] The only difference from Example 1 is that the antibacterial additive and dispersant are added to the mineral oil at the same time, stirred until uniform, and kept warm for 10 minutes.

[0170] According to experimental data, the antibacterial ink in Example 1 can maintain long-term antibacterial performance against Staphylococcus aureus ATCC6538 for 12 to 15 months without friction when printed onto the substrate, and the antibacterial rate is greater than 80%.

[0171] Figure 3 A diagram showing the dispersion effect of antibacterial additives in the antibacterial ink according to Embodiment 1 of the present invention is shown. Figure 4 The diagram shows the dispersion effect of the antibacterial additive in the antibacterial ink of Comparative Example 6. It should be noted that, to more clearly observe the dispersion effect of the antibacterial additive, Figure 3 and Figure 4 No colored base ink was added, according to Figure 3 and Figure 4 It can be seen that the antibacterial additive in the antibacterial ink of Example 1 of the present invention can be well dispersed in the main coating material, while the antibacterial additive in Comparative Example 6 cannot be well compatible with the main coating material, indicating that the dispersant in Example 1 has a better dispersion effect.

[0172] Table 1 shows the weight percentage of antibacterial additives effectively dispersed by the dispersants of Examples 1, 5, 6, and 7. According to Table 1, the dispersant of Example 1 can effectively disperse 8% (by weight) of antibacterial additives into the ink system. The commonly used ink dispersant CH-6 in Comparative Example 5 showed poor dispersion of the antibacterial additives, with the weight percentage of antibacterial additives in the ink being less than 1%. The dispersant in Comparative Example 6, containing polyetheramine and polyester segments, also failed to disperse the antibacterial dispersant well, indicating that the polyamide block in the dispersant of this application is a crucial component for ensuring dispersion effectiveness. Based on the data corresponding to Comparative Example 7 in Table 1, the dispersant in this application, including polyester-polyamide mixed block polymer materials, cannot effectively disperse the NiAgAPO-11 / MCM-41 type antibacterial additive. According to the data in Table 1, the dispersant of Example 1 significantly improves the dispersion effect on antibacterial agents containing noble metal coordination compounds and organic acids compared to other dispersants.

[0173] Table 1

[0174]

[0175] The theoretical dosage of dispersant can be determined based on the specific surface area of ​​the antibacterial additive particles. A larger specific surface area requires a greater amount of dispersant. Assuming all antibacterial additive particles are solid, the theoretical dispersant dosage is 10-15% (by weight). However, in practice, antibacterial additives include both solid and hollow particles, thus requiring adjustments to the dispersant dosage. The antibacterial additive in Example 1 consists of nano-sized particles. For antibacterial additives containing some hollow spherical particles, the theoretical dispersant dosage needs to be increased for effective dispersion. Based on orthogonal experimental results of different amounts of dispersant and antibacterial additive (some experimental data are shown in Table 2 below), a dispersant dosage between 15-40% (by weight) yields the best results. Experiments 1 to 7 in Table 2 only changed the weight percentages of the coating's main material and the dispersant; other conditions remained the same as in Example 1.

[0176] The experimental data in Table 2 show that the dispersion effect is poor when the weight percentage of the dispersant is less than 15%. However, the dispersion effect improves as the weight percentage of the dispersant increases. When the weight percentage increases to 15% to 40%, the dispersion effect is relatively stable, remaining at 8%. The dispersion effect weakens when the weight percentage of the dispersant is greater than 40%.

[0177] Table 2

[0178]

[0179] To verify the antibacterial properties of antibacterial inks and varnishes, antibacterial performance tests were conducted on the antibacterial varnish and antibacterial inks of different colors against Staphylococcus aureus ATCC 6538, Escherichia coli 8099, and Candida albicans ATCC 10231.

[0180] The test was conducted according to section 5.2.6 of WS / T650-2019, "Evaluation Methods for Antibacterial and Bacteriostatic Effects," specifically the film-covering test method. The samples were first pretreated, including UV sterilization for 30 minutes. The neutralization solution used was SCDLP, and the culture medium was nutrient agar. The test sample was a 5*5cm square with a thickness of 0.1mm. The contact temperature was 36±1℃, and the RH% was >90%. The inoculum volume was 0.4mL. The covering film was a 4*4cm square PE film with a thickness of 0.01mm.

[0181] The specific results of the antimicrobial performance tests of Examples 1 to 5, Comparative Examples 1 to 4, and Comparative Example 8 against Staphylococcus aureus ATCC 6538 are shown in Table 3 below:

[0182] Table 3

[0183]

[0184]

[0185] The specific results of the antibacterial performance tests of Examples 1 to 5, Comparative Examples 1 to 4, and Comparative Example 8 against Escherichia coli 8099 are shown in Table 4 below:

[0186] Table 4

[0187]

[0188] The specific results of the antimicrobial performance tests of Examples 1 to 5, Comparative Examples 1 to 4, and Comparative Example 8 against Candida albicans ATCC 10231 are shown in Table 5 below:

[0189] Table 5

[0190]

[0191]

[0192] In Tables 3 to 5 above, A represents the logarithmic mean of the recovered colony counts (unit: CFU / sample) for each comparative example after 0 h of inoculation. B represents the logarithmic mean of the recovered colony counts (unit: CFU / sample) for each comparative example after 24 h of inoculation. C represents the logarithmic mean of the recovered colony counts (unit: CFU / sample) for each example after 24 h of inoculation. The antibacterial activity value R = lg(B / C) and the antibacterial rate R' = (BC) / B × 100% for each example in Tables 3 to 5 above are the values ​​of B and C for the corresponding comparative and examples. For example, Example 1 and Comparative Example 1 are corresponding groups. In the formulas for calculating the antibacterial activity value R and antibacterial rate R' of Example 1, B represents B for Comparative Example 1, and C represents C for Example 1.

[0193] According to the data in Tables 3 to 5, Examples 1 to 5 all showed antibacterial effects against Staphylococcus aureus ATCC 6538, Escherichia coli 8099, and Candida albicans ATCC 10231. Among them, the antibacterial rate against Staphylococcus aureus ATCC 6538 and Escherichia coli 8099 was greater than 99.99%, indicating that they had a strong antibacterial effect against Staphylococcus aureus ATCC 6538 and Escherichia coli 8099. Compared with Comparative Examples 1 to 4 and Comparative Example 8 without antibacterial additives and dispersants, the antibacterial performance was significantly improved.

[0194] Table 6 shows the final weight percentage of the antimicrobial additives in the antimicrobial inks of Examples 1 and Comparative Examples 9 to 11.

[0195] Table 6

[0196] Example 1 Comparative Example 9 Comparative Example 10 Comparative Example 11 Antibacterial additive weight percentage 8％ 5％ 3％ 4％

[0197] The data in Table 6 shows that when the heating temperature of the base oil of the main material is too high or too low, the dispersion effect of the antibacterial additive will be significantly affected. Adding the antibacterial additive and the dispersant to the base oil at the same time will also significantly reduce the dispersion effect of the antibacterial additive.

[0198] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An antimicrobial coating structure, characterized by, An ink layer and a varnish layer coated on a surface of the ink layer, a material of the ink layer comprising an antibacterial ink, and a material of the varnish layer comprising an antibacterial varnish; The antibacterial ink comprises components in the following weight percentages: 60-78% of a coating base material, 7-10% of an antibacterial additive, and 15-25% of a dispersant; The antibacterial additive comprises a coordination compound containing noble metal and an organic acid, and the density of the antibacterial additive is less than the density of the coating base material; The dispersant comprises a polyester-polyamide hybrid block high molecular material, the polyester block of the dispersant is dissolved in base oil of the coating base material, and the polyamide block of the dispersant is adsorbed on the surface of the coordination compound containing noble metal of the antibacterial additive; The dispersant is prepared by copolymerization of fatty acid, lactone compound, hydroxy acid, lactam compound, and polyamine; The reaction principle of the dispersant is shown in the following reaction formulas (1) and (2): In the formulas (1) and (2), R1 is C6-C17 alkyl or olefin group, R2 is C3-C7 alkyl or its substitute, R3 is C3-C17 alkyl or olefin group, R4 is C3-C5 alkyl, R5 is H or CH3 alkyl or olefin group, and the product of the formula (2) is the dispersant, in which p and k are polyamide blocks, and n and m are polyester blocks; The antibacterial varnish comprises components in the following weight percentages: 55-78% of a coating base material, 2-8% of an antibacterial additive, and 20-40% of a dispersant.

2. The antimicrobial coating structure according to claim 1, wherein The antibacterial ink or the antibacterial varnish is prepared by the following preparation method: The base oil of the coating base material is heated to any value in the range of 40-100℃; The corresponding weight percentage of the dispersant is added to the base oil and stirred, and the temperature is kept for 8-15 minutes until the dispersant is completely dissolved; The corresponding weight percentage of the antibacterial additive is added and stirred until the antibacterial agent is dispersed to a transparent state to form an antibacterial base oil; Other materials in the coating base material are mixed with the antibacterial base oil and stirred.

3. A method for preparing the antimicrobial coating structure of claim 1, characterized by, Comprises: The antibacterial ink is coated on a surface of a printing substrate to be printed to form the ink layer; The antibacterial varnish is coated on the ink layer after a preset time to form the varnish layer, wherein the preset time is 60-90% of the drying time of the ink layer.

4. The production method according to claim 3, characterized by, The preset time is 70-80% of the drying time of the ink layer.

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