Antibacterial UV printing ink, photocuring method thereof and printed matter

Abstract

The invention relates to antibacterial UV printing ink, a photocuring method thereof and a printed matter, nano-silver is adopted as an antibacterial agent in the antibacterial UV printing ink, the particle size of the nano-silver is 5-10 nm, the mass ratio of the nano-silver in the UV printing ink is 2.8%-3.5%, and the photocuring temperature of the antibacterial UV printing ink is 95-120 DEG C. The smaller the particle size of the nano-silver is, the larger the specific surface area of the nano-silver is, and the more the chance of contact with bacteria is, so that the nano-silver has higher bactericidal performance, however, the too small or too large particle size of the nano-silver may cause the increase of the viscosity of the ink, and the fluidity and the printing effect of the ink are affected. And the photocuring temperature of the antibacterial UV ink is controlled to be 95-120 DEG C, so that the antibacterial property and the printing quality of the ink can be ensured at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of UV ink, in particular to an antibacterial UV ink and a light curing method and printed matter thereof. Background Art

[0002] Antibacterial UV ink is an ink with special functions. It can cure quickly under ultraviolet light and has excellent antibacterial and environmental protection properties. By adding antibacterial agents to UV inks, antibacterial UV inks can give printed products bactericidal or antibacterial functions. At present, antibacterial UV inks have been used in the actual production of some printing companies. Regarding the photocuring technology of antibacterial UV inks, in the prior art, Duan Huawei et al. used UV varnish as the dispersion matrix of the antibacterial agent. Through experiments, it was found that the curing temperature of UV varnish only needs to be 90-120°C, and it was explained that at this temperature, Huake-108 mildew inhibitor can stably exert its high-efficiency bactericidal performance in UV varnish. In the article "How to Match Photocurable Ink, Coating Photoinitiator, Pigment and Light Source", Yang Yongyuan introduced how to select the best composite photoinitiator and their maximum absorption wavelength, and match them with the maximum UV light source emission wavelength and the minimum absorption wavelength of the pigment as much as possible, so as to make full use of the energy of the UV light source to increase the UV light curing speed. Hu Shicheng and others have developed a UV-curing antibacterial and stain-resistant clear coating by using special photoinitiators and antibacterial agents, specially treated hard fillers and a reasonably matched formula system. It can be quickly dried with just one roller coating, and has antibacterial and stain-resistant properties. It can meet the production requirements of wooden floors and home improvement companies with a high degree of mechanized construction, which not only ensures the coating effect but also saves coating costs.

[0003] Based on the research status of the above scholars, it can be seen that at present, in the field of photocuring of antibacterial UV inks, researchers mainly adapt to ultraviolet light curing by studying and analyzing the composition ratio of antibacterial UV inks and the selection of antibacterial agent types to obtain good printed products.

[0004] However, there are still many problems in actual production: the viscosity of antibacterial UV ink causes problems such as lighter printing color, enlarged dots, and uneven ink transfer; the poor drying performance of the ink layer causes scratches, poor glossiness of the ink layer, insufficient tensile strength, and color loss due to over-oiling; the antibacterial performance of the antibacterial agent decreases due to ultraviolet radiation during the light curing process. There are problems such as reduced ink printing quality and reduced antibacterial performance.

[0005] Patent CN107778970A discloses an antibacterial UV ink, in which the antibacterial agent is nanosilver, and the particle size of the nanosilver is 18-23 nm. However, the problem that the UV ink printing performance is reduced and the antibacterial performance cannot be achieved at the same time still exists. Summary of the invention

[0006] Based on this, it is necessary to provide an antibacterial UV ink and a photocuring method and printed product thereof that can ensure antibacterial performance and ink printing quality.

[0007] In a first aspect, the present application provides an antibacterial UV ink, in which nanosilver is used as an antibacterial agent, the particle size of the nanosilver is 5-10 nm, the mass proportion of the nanosilver in the UV ink is 2.8%-3.5%, and the light curing temperature of the antibacterial UV ink is 95°C-120°C.

[0008] In one of the embodiments, the mass proportion of the nanosilver in the UV ink is 3%-3.3%.

[0009] In one embodiment, the viscosity of the antibacterial UV ink during use is 25-35s.

[0010] In one embodiment, the antibacterial UV ink includes the following components in parts by weight: 20% colorant, 8% photoinitiator, 40% synthetic resin oil, 20% paste ink, 2% ink additive, 3% antibacterial agent, and 7% other additives.

[0011] In one embodiment, the synthetic resin oil is acrylic resin;

[0012] And / or, the photoinitiator is benzoin ethyl ether;

[0013] And / or, the paste ink is paste ink;

[0014] and / or, other additives are dispersant 2.6%, wax 2%, leveling agent 3%;

[0015] And / or, the ink auxiliary agent is a stabilizer.

[0016] In one embodiment, the antibacterial UV ink is diluted by adding a diluent when in use, the diluent is an aqueous diluent, and the ratio of the antibacterial UV ink to the diluent is less than or equal to 2:1.

[0017] In one embodiment, the diluent includes the following components in parts by weight: 80% water, 10% ethanol, 8% glycol ether, and 2% surfactant.

[0018] In a second aspect, the present application provides a method for photocuring the antibacterial UV ink as described in any of the above embodiments, comprising the following steps:

[0019] Dilute the UV varnish with a diluent and apply it on the surface of the printed matter that needs to be cured;

[0020] Use a UV curing machine to irradiate the printed matter coated with UV varnish with ultraviolet light to cure it into a film, and control the curing temperature to 95℃-120℃.

[0021] In one embodiment, the initial drying property of the antibacterial UV ink is 18-25 microns, and the thorough drying time is 40-45 seconds.

[0022] In a third aspect, the present application provides a printed matter, wherein the surface of the printed matter has a film layer formed by curing the antibacterial UV ink as described in any of the above embodiments.

[0023] The above-mentioned antibacterial UV ink adopts nanosilver as an antibacterial agent, the particle size of the nanosilver is 5~10nm, and the mass proportion of the nanosilver in the UV ink is 2.8%-3.5%. The smaller the particle size of the nanosilver, the larger its specific surface area, and the more opportunities it has to contact with bacteria, thereby showing stronger bactericidal performance. Nanosilver with a small particle size also has a higher surface energy, making it easier for it to interact with the negative charge on the surface of bacteria, thereby enhancing the bactericidal effect, and further improving the antibacterial effect. However, too small or too large a particle size of nanosilver may increase the viscosity of the ink, affecting the fluidity and printing effect of the ink. The present application sets the particle size of the nanosilver to 5~10nm, and controls the light curing temperature of the antibacterial UV ink to 95℃-120℃, so that both the antibacterial performance and the printing quality of the ink can be ensured. DETAILED DESCRIPTION

[0024] In order to facilitate the understanding of the present invention, in order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below. In the following description, many specific details are set forth so as to fully understand the present invention, and preferred embodiments of the present invention are given. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood. The present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited to the specific embodiments disclosed below. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art belonging to the technical field of the present invention. The terms used herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0025] In a first aspect, the present application provides an antibacterial UV ink, in which nanosilver is used as an antibacterial agent, the particle size of the nanosilver is 5-10 nm, the mass proportion of the nanosilver in the UV ink is 2.8%-3.5%, and the light curing temperature of the antibacterial UV ink is 95°C-120°C.

[0026] The above-mentioned antibacterial UV ink adopts nanosilver as an antibacterial agent, the particle size of the nanosilver is 5~10nm, and the mass proportion of the nanosilver in the UV ink is 2.8%-3.5%. The smaller the particle size of the nanosilver, the larger its specific surface area, and the more opportunities it has to contact with bacteria, thereby showing stronger bactericidal performance. Nanosilver with a small particle size also has a higher surface energy, which makes it easier for it to interact with the negative charge on the surface of bacteria, thereby enhancing the bactericidal effect, and further improving the antibacterial effect. However, too small or too large a particle size of nanosilver may increase the viscosity of the ink, affecting the fluidity and printing effect of the ink. The present application can ensure both the antibacterial performance and the printing quality of the ink by setting the particle size of the nanosilver to 5~10nm, and combined with controlling the light curing temperature of the antibacterial UV ink to 95℃-120℃, so that the printing quality and antibacterial effect of the antibacterial UV ink can be better ensured.

[0027] In one embodiment, the mass proportion of the nanosilver in the UV ink is 3%-3.5%. Preferably, the mass proportion of the nanosilver in the UV ink is 3.4%. In this way, the applicant has found that when the light curing temperature is controlled at 95°C-120°C, it has a good antibacterial effect and can ensure the printing quality. The antibacterial rate can reach more than 96%.

[0028] In one embodiment, the viscosity of the antibacterial UV ink during use is 25-35s. Thus, the antibacterial UV ink with the above viscosity is used to further improve the printing quality. For another example, the above viscosity is confirmed according to GB / T 13217.4 "Test Method for Viscosity of Liquid Ink". For another example, the antibacterial UV ink includes the following components in parts by weight: 20% colorant, 8% photoinitiator, 40% synthetic resin oil, 20% paste ink, 2% ink additive, 3% antibacterial agent, and 7% other additives. The synthetic resin oil is acrylic resin; and / or, the photoinitiator is benzoin ethyl ether; for example, other additives include dispersants, waxes, and leveling agents; for example, other additives include: dispersants 2.6%, waxes 2%, leveling agents 3%, and the content of the antibacterial agent is 3.4%; for example, the ink additive is a stabilizer; for example, the stabilizer includes hydroquinone, p-methoxyphenol, etc.; for example, the dispersant includes but is not limited to silicates, aluminum oxide, etc., for example, the leveling agent includes but is not limited to oily silicone leveling agents, epoxy acrylic acid water-based leveling agents, etc. For example, when the antibacterial UV ink is used, a diluent is added for dilution, and the diluent is an aqueous diluent, and the ratio of the antibacterial UV ink to the diluent is less than or equal to 2:1. For example, the diluent includes the following components by mass: 80% water, 10% ethanol, 8% glycol ether, and 2% surfactant. In this way, it can better ensure that the viscosity is 25-35s during use, thereby ensuring the printing quality.

[0029] The above-mentioned antibacterial UV ink adopts nanosilver as an antibacterial agent, the particle size of the nanosilver is 5~10nm, and the mass proportion of the nanosilver in the UV ink is 2.8%-3.5%. The smaller the particle size of the nanosilver, the larger its specific surface area, and the more opportunities it has to contact with bacteria, thereby showing stronger bactericidal performance. Nanosilver with a small particle size also has a higher surface energy, which makes it easier for it to interact with the negative charge on the surface of bacteria, thereby enhancing the bactericidal effect, and further improving the antibacterial effect. However, too small or too large a particle size of nanosilver may increase the viscosity of the ink, affecting the fluidity and printing effect of the ink. The present application can ensure both the antibacterial performance and the printing quality of the ink by setting the particle size of the nanosilver to 5~10nm, and combined with controlling the light curing temperature of the antibacterial UV ink to 95℃-120℃, so that the printing quality and antibacterial effect of the antibacterial UV ink can be better ensured.

[0030] In a second aspect, the present application provides a method for photocuring the antibacterial UV ink as described in any of the above embodiments, comprising the following steps:

[0031] Dilute the UV varnish with a diluent and apply it on the surface of the printed matter that needs to be cured;

[0032] Use a UV curing machine to irradiate the printed matter coated with UV varnish with ultraviolet light to cure it into a film, and control the curing temperature to 95℃-120℃.

[0033] It should be noted that the quality of initial drying directly affects the subsequent processing and stacking of printed products. If the initial drying is not good, the printed products may stick together during stacking or subsequent processing, affecting the printing quality. The length of the thorough drying time has an important impact on printing efficiency. If the thorough drying time is too long, the printing cycle will be extended and production efficiency will be reduced. At the same time, the thorough drying time is also one of the important indicators for evaluating the drying performance of ink. For example, the initial drying of the antibacterial UV ink is 18-25 microns, and the thorough drying time is 40-45s. It was found through experiments that at room temperature of 25°C, when the initial drying of the antibacterial UV ink is 18-25 microns and the thorough drying time is 40-45s, the printed product dries quickly and the film gloss is better. For example, ultraviolet irradiation uses ultraviolet light with a wavelength of 300nm for 0.8~2.3s.

[0034] In a third aspect, the present application provides a printed matter, wherein the surface of the printed matter has a film layer formed by curing the antibacterial UV ink as described in any of the above embodiments.

[0035] The present application will be further described below in conjunction with specific embodiments. Specific embodiments

[0036] The present application first prepares an antibacterial UV ink and adds nanosilver to the UV ink, wherein the antibacterial UV ink includes the following components in parts by weight: 20% colorant, 8% photoinitiator, 40% synthetic resin oil, 20% paste ink, 2% ink additive, 3% antibacterial agent, and 7% other additives.

[0037] 1. Explore the relationship between the performance of antibacterial agents in antibacterial UV inks and the light curing temperature

[0038] Studies have shown that the stability of antimicrobial agents in the dispersion matrix is ​​also an important factor affecting the use of antimicrobial agents. The applicant uses UV varnish as the dispersion matrix of antimicrobial agent nanosilver, and nanosilver accounts for 3.4% in UV ink.

[0039] The curing of UV varnish is through the action of ultraviolet light, the photosensitive substances in the system undergo chemical reactions to produce active fragments, which trigger the polymerization and cross-linking of active monomers or oligomers in the system, thereby curing. Therefore, the curing temperature will have a certain impact on the performance of the antibacterial agent. The applicant used the group control experiment method to add a nano-silver antibacterial agent with a total mass ratio of 3.4% to 900g UV ink, took three groups of 100*100mm packaging materials, and carried out light curing experiments at 6 different temperatures. The prepared bacterial solution was used for the cured packaging material to explore the relationship between the curing temperature and the bacterial survival rate. After the experiment, the following data was obtained:

[0040] Table 1 Bacterial survival rate and curing temperature of antibacterial UV ink

[0041] As shown in Table 1, when the curing temperature is between 95-130°C, the antibacterial rate can reach more than 96%. However, the applicant has found that when the temperature exceeds 120°C, the quality of the printed matter decreases, so the curing temperature is best kept at 95-120°C.

[0042] 2. Explore the relationship between UV ink viscosity and light curing quality

[0043] According to GB / T 13217.4 "Test Method for Viscosity of Liquid Inks", the general viscosity should be controlled at 25-35s. It should be noted that the Zahn cup viscosity technique in GB / T 13217.4-2020 uses the time for the ink to stop flowing into the measuring cup as the viscosity, so seconds (s) are used as the unit. This application study took 4 groups of 100*100mm packaging materials at a temperature of 110°, and used 4 groups of antibacterial UV inks and diluents in different proportions. The viscosity of each group of antibacterial UV inks was tested 3 times and the average value was taken to obtain the optimal viscosity value. The diluent uses a special aqueous diluent, which includes the following components in the following mass percentages: 80% water, 10% ethanol, 8% ethylene glycol ether, and 2% surfactant. The viscosity tested after different dilutions is as follows:

[0044] Table 2. Viscosity of antibacterial UV ink

[0045] According to Table 2 above, it can be found that when the proportion of diluent increases, the viscosity of antibacterial ink decreases significantly. The applicant found that when the ratio of ink to diluent gradually approaches or is less than 2:1, it does not meet the printing standard, and the antibacterial performance decreases at this time, and the curing effect is poor. Therefore, the appropriate dilution ratio of ink to diluent is greater than 2:1. It is best to control the ink: diluent in the range of 5:1 to 2:1 in this application.

[0046] 3. Relationship between drying performance and light curing quality of antibacterial UV ink

[0047] Through experiments, it was found that at room temperature of 25°C, when the initial drying of the antibacterial UV ink is 18-25 microns and the thorough drying time is 40-45s, the printed product dries quickly and the film gloss is better.

[0048] 4. Add 3% nanosilver to the antibacterial UV ink, use the ink: diluent at a ratio of 2:1 to control the viscosity, and solidify it into a film on a 100*100mm packaging material at a temperature of 110°. The results of the subsequent tests are shown in Table 4.

[0049] Table 4 Test results

[0050] It can be seen from the above table that the use of the UV antibacterial ink of the present application meets the printing quality and antibacterial requirements, and can simultaneously ensure both antibacterial performance and ink printing quality.

[0051] The above-mentioned antibacterial UV ink adopts nanosilver as an antibacterial agent, the particle size of the nanosilver is 5~10nm, and the mass proportion of the nanosilver in the UV ink is 2.8%-3.5%. The smaller the particle size of the nanosilver, the larger its specific surface area, and the more opportunities it has to contact with bacteria, thereby showing stronger bactericidal performance. Nanosilver with a small particle size also has a higher surface energy, which makes it easier for it to interact with the negative charge on the surface of bacteria, thereby enhancing the bactericidal effect, and further improving the antibacterial effect. However, too small or too large a particle size of nanosilver may increase the viscosity of the ink, affecting the fluidity and printing effect of the ink. The present application can ensure both the antibacterial performance and the printing quality of the ink by setting the particle size of the nanosilver to 5~10nm, and combined with controlling the light curing temperature of the antibacterial UV ink to 95℃-120℃, so that the printing quality and antibacterial effect of the antibacterial UV ink can be better ensured.

[0052] This application studies and updates the photocuring technology of antibacterial UV inks, and uses existing printing equipment to explore the effects of factors such as the viscosity, curing time and temperature, drying performance, and amount of antibacterial agent on photocuring. By improving the production process and equipment parameters, the antibacterial ink is printed on paper to ensure good antibacterial effects while achieving better printing effects, thereby improving the production efficiency and yield rate of the product. Compared with existing photocuring technology, in addition to studying the effects of the performance of the antibacterial UV ink itself on the photocuring technology, this application also studies the effects of the curing parameters of ultraviolet light on the antibacterial properties of the antibacterial UV ink. The photocuring conditions determined by this application are universal and have a certain reference value for the photocuring technology of inks in the printing industry.

[0053] The technical features of the above-described embodiments can be combined arbitrarily. In order to make the description concise, all possible combinations of the technical features in the above-described embodiments are not described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. It should be noted that "in one embodiment", "for example", "for example", etc. in this application are intended to illustrate the present application, rather than to limit the present application. The above-described embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present invention, several variations and improvements can be made, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. An antibacterial UV ink, characterized in that: Nanosilver is used as an antibacterial agent in the antibacterial UV ink. The particle size of the nanosilver is 5-10 nm, the mass proportion of the nanosilver in the UV ink is 2.8%-3.5%, and the light curing temperature of the antibacterial UV ink is 95°C-120°C.

2. The antibacterial UV ink according to claim 1, characterized in that: The mass proportion of the nano silver in the UV ink is 3%-3.3%.

3. The antibacterial UV ink according to claim 1, characterized in that: The viscosity of the antibacterial UV ink when used is 25-35s.

4. The antibacterial UV ink according to claim 1, characterized in that: The antibacterial UV ink comprises the following components in parts by weight: 20% colorant, 8% photoinitiator, 40% synthetic resin oil, 20% paste ink, 2% ink additive, 3.2%-3.5% antibacterial agent, and 6.5%-6.8% other additives.

5. The antibacterial UV ink according to claim 4, characterized in that: The synthetic resin oil is acrylic resin; And / or, the photoinitiator is benzoin ethyl ether; And / or, other additives include dispersants, waxes, and leveling agents; preferably, other additives include: dispersants 2.6%, waxes 2%, leveling agents 3%, and the content of the antibacterial agent is 3.4%; And / or, the ink auxiliary agent is a stabilizer.

6. The antibacterial UV ink according to claim 4, characterized in that: The antibacterial UV ink is diluted by adding a diluent when in use, the diluent is an aqueous diluent, and the ratio of the antibacterial UV ink to the diluent is less than or equal to 2:

1.

7. The antibacterial UV ink according to claim 6, characterized in that: The diluent comprises the following components in parts by weight: 80% water, 10% ethanol, 8% glycol ether, and 2% surfactant.

8. A method for photocuring the antibacterial UV ink as claimed in any one of claims 1 to 7, characterized in that: The steps include: Dilute the UV varnish with a diluent and apply it on the surface of the printed matter that needs to be cured; Use a UV curing machine to irradiate the printed matter coated with UV varnish with ultraviolet light to cure it into a film, and control the curing temperature to 95℃-120℃.

9. The light curing method according to claim 8, characterized in that: The initial drying property of the antibacterial UV ink is 18-25 microns, and the thorough drying time is 40-45 seconds.

10. A printed matter, characterized in that: The printed product surface has a film layer formed by curing the antibacterial UV ink as described in any one of claims 1 to 7.

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