CN115386288B - Water-based antiviral varnish and preparation method thereof - Google Patents

Abstract

The invention discloses a water-based antiviral varnish and a preparation method thereof, belonging to the technical field of varnish. The water-based antiviral varnish has excellent antiviral function by adding the compound antiviral agent with antiviral effect, not only has high antiviral rate and good broad-spectrum antibacterial property, but also has better high temperature resistance and weather resistance, no irritation and more environmental protection because the main component of the water-based antiviral varnish is an inorganic substance. Meanwhile, the compound antiviral agent adopts nano silicon dioxide as a carrier, and an amino acid stabilizer and a potassium salt are added, so that the poor dispersibility and stability caused by agglomeration of nano silver can be avoided, and the antiviral property is improved.

Description

Water-based antiviral varnish and preparation method thereof

Technical Field

The invention relates to the technical field of varnish, in particular to aqueous antiviral varnish and an improvement of a preparation method thereof.

Background

Paper products and plastic film products are widely used as decorative films, but because the paper products and plastic film products have poor scratch resistance, abrasion resistance and chemical resistance, a layer of varnish is usually coated on the surface of the paper products and plastic film products to improve the surface performance of the paper products and plastic films. Meanwhile, the varnish can also make paper products and plastic film products obtain different gloss so as to meet different requirements of users on the gloss. However, with the improvement of living standard, people's demand for safe and healthy home is higher and higher, and a decorative film with better antiviral function is urgently needed, and in the prior art, the antiviral property is usually obtained by adding organic antiviral components such as guanidines, thiazoles, and quinolinones into varnish, or the antiviral function is obtained by adding inorganic antiviral agents such as inorganic metal particles such as nano silver and zinc. However, the organic antiviral component has low antiviral rate, poor broad-spectrum antibacterial property, no high temperature resistance and no environmental protection. The inorganic antiviral agent has the defects of easy oxidation, poor dispersibility, unstable system and the like, and is easy to cause varnish discoloration and large color difference.

It is seen that improvements and enhancements to the prior art are needed.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide the aqueous antiviral varnish and the preparation method thereof, and aims to overcome the defects of low antiviral rate, poor dispersibility and stability and easiness in generating color difference of the existing aqueous antiviral varnish.

In order to achieve the purpose, the invention adopts the following technical scheme:

the water-based antiviral varnish comprises water-based polyurethane emulsion and a compound antiviral agent, wherein the compound antiviral agent comprises nano silver, nano silicon dioxide, a reducing agent, amino acid, potassium salt and alkyl dimethyl benzyl ammonium chloride.

In the aqueous antiviral varnish, the compound antiviral agent comprises the following components in parts by weight: 100 parts of 0.5wt% nano silver solution, 3 to 4 parts of nano silicon dioxide, 0.19 to 0.21 part of reducing agent, 0.95 to 1.05 parts of amino acid, 0.76 to 0.84 part of potassium salt and 0.19 to 0.21 part of alkyl dimethyl benzyl ammonium chloride.

In the water-based antiviral varnish, the particle size of the nano silicon dioxide is 500-900 nm.

In the aqueous antiviral varnish, the amino acid is serine or glycine.

In the aqueous antiviral varnish, the potassium salt is potassium citrate or potassium acetate.

In the aqueous antiviral varnish, the aqueous polyurethane emulsion comprises: an aqueous polyurethane resin composition, polycarbodiimide, polyisocyanate and a diluent; the mass ratio of the aqueous polyurethane resin composition, the polycarbodiimide, the polyisocyanate, the diluent and the compound antiviral agent is 90-100: 3-5: 1-15: 5-10.

In the aqueous antiviral varnish, the aqueous polyurethane resin composition comprises the following components in parts by weight: 90 to 95 portions of polyurethane resin, 1 to 3 portions of anti-scraping agent, 0.1 to 1 portion of defoaming agent, 0.1 to 1 portion of wetting agent and 0.1 to 0.5 portion of pH regulator.

In the water-based antiviral varnish, the anti-scraping agent is one of surface modified nano aluminum oxide, surface modified nano silicon dioxide or PTEF wax.

In the water-based antiviral varnish, the defoaming agent is one of a polymer defoaming agent, a mineral oil defoaming agent, an organic silicon defoaming agent and a polyether siloxane emulsion defoaming agent.

In the water-based antiviral varnish, the wetting agent is one of a modified acrylic wetting and leveling agent, a polyether modified polydimethylsiloxane wetting and leveling agent and a nonionic polyurethane association type wetting agent.

A method for preparing an aqueous antiviral varnish for preparing the aqueous antiviral varnish as described above, wherein the method comprises the steps of:

step S1: taking 0.5wt% of nano silver solution, potassium salt and amino acid, stirring, adding nano silicon dioxide after uniformly mixing, stirring for 2 hours, dropwise adding a reducing agent, continuously stirring for 1 hour, adding alkyl dimethyl benzyl ammonium chloride, continuously stirring, and uniformly mixing to obtain a compound antiviral agent;

step S2: adding polyurethane resin into a reaction container, stirring, sequentially adding an anti-scraping agent, a defoaming agent, a wetting agent and a pH regulator, continuously stirring, adding polycarbodiimide after uniformly mixing, continuously stirring, adding polyisocyanate after uniformly mixing, continuously stirring, adding a compound antiviral agent after uniformly mixing, continuously stirring, adding a diluent after uniformly mixing to adjust the viscosity, and uniformly stirring to obtain the aqueous antiviral varnish.

Has the beneficial effects that:

the invention provides a water-based antiviral varnish, which can be prepared by adding a compound antiviral agent into a water-based polyurethane emulsion to obtain a varnish with excellent antiviral properties. The compound antiviral agent takes the nano silicon dioxide as a carrier of the nano silver, and simultaneously adds the amino acid and the sylvite, so that the nano silver can be prevented from agglomerating, and can be well and stably dispersed in the aqueous polyurethane emulsion, thereby greatly improving the antiviral rate of the varnish, simultaneously solving the problems of varnish color difference and color change caused by agglomeration of the nano silver, and improving the appearance effect of a varnish product; in addition, as the main material of the compound antiviral agent is inorganic, the compound antiviral agent can improve the high-temperature resistance processability and weather resistance of the varnish, has fine and smooth hand feeling, is nonirritating and is more environment-friendly.

The invention also provides a preparation method of the water-based antiviral varnish, which has the advantages of simple steps, wide raw material sources, low cost, wide application in industrial production and strong practicability.

Detailed Description

The present invention provides an aqueous antiviral varnish and a preparation method thereof, and in order to make the purpose, technical scheme and effect of the present invention clearer and clearer, the present invention is further described in detail by the following examples. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the invention.

According to the aqueous antiviral varnish and the preparation method thereof provided by the preferred embodiment of the invention, the varnish comprises aqueous polyurethane emulsion and a compound antiviral agent uniformly dispersed in the aqueous polyurethane emulsion, and the varnish has better antiviral property by adding the compound antiviral agent into the aqueous polyurethane emulsion. The compound antiviral agent comprises nano silver, nano silicon dioxide, a reducing agent, amino acid, sylvite and alkyl dimethyl benzyl ammonium chloride. The nano silver has excellent antiviral effect, can kill bacteria and viruses, and has high antiviral rate and good broad-spectrum antibacterial property.

In order to improve the antiviral rate, nano silver with smaller particle size is generally adopted, for example, nano silver with particle size of 5-10 nm is adopted in the application, however, the smaller the particle size of nano silver is, the more easily the nano silver is agglomerated, and further the dispersibility of the nano silver in the aqueous polyurethane emulsion is reduced, so that not only is the antiviral rate reduced, but also the varnish is easily subjected to color difference. In contrast, the nano silicon dioxide is added into the compound antiviral agent, and the nano silicon dioxide with mesoporous/high specific surface area is used as a carrier of the nano silver, so that the agglomeration of the nano silver can be avoided, the nano silver can be uniformly dispersed in the aqueous polyurethane emulsion, and the antiviral rate of the varnish can be greatly improved. Preferably, the particle size of the nano-silica is 500-900 nm, the nano-silica has a porous structure and a huge specific surface area, and silicon hydroxyl on the surface of the nano-silica is easy to functionalize due to good hydrophilicity of the nano-silica, so that the agglomeration of particles can be prevented, and the stable adsorption and loading of nano-silver are facilitated. Meanwhile, the nano silicon dioxide with the particle size of 500-900 nm is adopted, and the particle size of the nano silicon dioxide is close to that of polyurethane resin, so that the appearance performances of the varnish and a finished product, such as glossiness, color difference and the like, are not influenced, and meanwhile, the chemical stability, high temperature resistance and coating anti-adhesion of the varnish can be improved.

Because the nano silver is easy to oxidize and loses antiviral effect, the reducing agent is added into the compound antiviral agent of the components to keep the nano silver in a zero valence state, so that the varnish has better antibacterial and antivirus effects. The reducing agent is sodium sulfite or potassium sodium tartrate, preferably sodium sulfite.

However, since both nano silver and nano silica are inorganic particles, they are easily precipitated in a polymer material, and thus the stability of the varnish is poor. In contrast, the compound antiviral agent containing the components is added with amino acid, and the amino group and the carboxyl group of the amino acid are used for acting with the groups in the varnish, so that inorganic particles are prevented from settling, and the stability of the system is improved. The amino acid is serine or glycine, preferably serine, and the serine contains hydroxyl besides amino and carboxyl, so that the amino acid has better group affinity, can act with a curing agent in the varnish, and enables a water-based antiviral varnish system to be more stable.

In addition, as the polarity of the nano silicon dioxide influences the stability of the system, the adsorption and the association of nano silver and amino acid are more compact as the polarity is larger, and the system is more unstable as the polarity is smaller, so that the antiviral rate is easily influenced and the chromatic aberration is easily caused. In contrast, in the complex antiviral agent containing the above components, the polarity of the nano-silica is improved by adding a potassium salt. The potassium salt is potassium citrate or potassium acetate, and metal ions of the added potassium salt can be attached to the nano silicon dioxide, so that the polarity of the nano silicon dioxide is increased, the adsorption of the nano silicon dioxide on nano silver is promoted, the combination of the nano silicon dioxide and amino acid is enhanced, the dispersity and stability of the nano silicon dioxide in the aqueous polyurethane emulsion are improved, and the antiviral effect of the varnish is greatly improved.

In the compound antiviral agent, alkyl dimethyl benzyl ammonium chloride is added as a dispersing agent, wherein the alkyl dimethyl benzyl ammonium chloride can be one of dodecyl dimethyl benzyl ammonium chloride, tetradecyl dimethyl benzyl ammonium chloride or octadecyl dimethyl benzyl ammonium chloride, so that the nano silicon dioxide can be well dispersed in a system, and in addition, the compound antiviral agent also has broad-spectrum antibacterial property, and the antiviral effect of the varnish can be improved.

In a preferred embodiment, the compound antiviral agent comprises, by weight, 100 parts of 0.5wt% nano silver solution, 3 to 4 parts of nano silicon dioxide, 0.19 to 0.21 part of reducing agent, 0.95 to 1.05 part of amino acid, 0.76 to 0.84 part of potassium salt, and 0.19 to 0.21 part of alkyl dimethyl benzyl ammonium chloride. The compound antiviral agent prepared according to the proportion has high antiviral rate and good dispersibility and stability in aqueous polyurethane emulsion.

In a preferred embodiment, the aqueous polyurethane emulsion comprises: an aqueous polyurethane resin composition, polycarbodiimide, polyisocyanate and a diluent; the mass ratio of the waterborne polyurethane resin composition, the polycarbodiimide, the polyisocyanate, the diluent and the compound antiviral agent is 90-100: 3-5: 1-15: 5-10, the waterborne polyurethane resin composition has high antiviral rate and good dispersibility and stability, and color difference cannot be generated after the waterborne polyurethane resin composition is coated and scraped.

The main component of the aqueous polyurethane resin composition is polyurethane resin, the polyurethane resin is self-extinction organic silicon modified polyurethane resin containing hydroxyl and carboxyl, the hydroxyl can be subjected to crosslinking curing reaction with isocyanate groups (NCO) in polyisocyanate to form a stable crosslinking structure, and the carboxyl can be crosslinked with amino in polycarbodiimide to avoid hydrolysis; the polycarbodiimide is an anti-hydrolysis agent, so that polyurethane resin can be prevented from being hydrolyzed, and a system is stable; preferably, the polycarbodiimide is the polycarbodiimide with the grade of SV-02 provided by CARBODILITE company, and has better hydrolysis resistance; the polyisocyanate is a curing agent which contains NCO groups capable of crosslinking with hydroxyl groups in the polyurethane resin and can cure and mold the polyurethane resin; preferably, the polyisocyanate is hydrophilic aliphatic polyisocyanate, more preferably, the polyisocyanate is hydrophilic aliphatic polyisocyanate with the NCO content of 10-20%, and high-content NCO can react with hydroxyl in polyurethane resin and also can react with hydroxyl in amino acid, so that the compound antiviral agent is dispersed in the aqueous polyurethane emulsion more uniformly and stably. More preferably, the polyisocyanate is an aqueous aliphatic polyisocyanate curing agent available from Asahi Kasei corporation under the brand number WT30-100, which has a better curing effect and an effect of promoting system stabilization. The diluent is deionized water or alcohol.

In a preferred embodiment, the aqueous polyurethane resin composition comprises 90 to 95 parts by weight of polyurethane resin, 1 to 3 parts by weight of anti-scraping agent, 0.1 to 1 part by weight of defoaming agent, 0.1 to 1 part by weight of wetting agent and 0.1 to 0.5 part by weight of pH regulator. The polyurethane resin is preferably self-extinction organic silicon modified waterborne polyurethane resin, the solid content of the polyurethane resin is preferably 35-45%, the particle size range of the polyurethane resin is preferably 400-800 nm, the glossiness of the polyurethane resin is preferably 1-7 degrees, and the polyurethane resin has a good appearance effect; more preferably, the polyurethane resin is self-extinction organic silicon modified waterborne polyurethane resin with the solid content of 35-40%, the particle size range of 500-600 nm and the glossiness of 1-4 degrees, and the particle size range of the self-extinction organic silicon modified waterborne polyurethane resin is matched with that of the nano silicon dioxide, so that the nano silicon dioxide has better dispersity and stability, and the color difference caused by sedimentation can be avoided; the anti-scraping agent is one of surface modified nano aluminum oxide, surface modified nano silicon dioxide or PTEF wax, preferably PTEF wax with the particle size of 3-5 mu m, and has better anti-scraping effect; the defoaming agent is one of a polymer defoaming agent, a mineral oil defoaming agent, a silicone defoaming agent and a polyether siloxane emulsion defoaming agent, preferably the polyether siloxane emulsion defoaming agent, and more preferably the polyether siloxane emulsion defoaming agent with the trade name of BYK 1719 provided by Bik chemical company; the wetting agent is one of a modified acrylic wetting and leveling agent, a polyether modified polydimethylsiloxane wetting and leveling agent and a nonionic polyurethane associated wetting agent, can improve the adhesion and the fluidity of varnish on the surface of a product, and is preferably a nonionic polyurethane associated wetting agent, more preferably a nonionic polyurethane associated wetting agent with the trade name of 810 provided by EVONIK company, and has the effect of wetting and leveling; the pH regulator is one of sodium oxysulfide, ammonia water and organic ammonia, preferably organic ammonia pH regulator, and the organic ammonia regulator is Alpamine N41 organic ammonia regulator produced by Arkema company.

The water-based antiviral varnish has excellent antiviral function by adding the compound antiviral agent with antiviral effect, not only has high antiviral rate and good broad-spectrum antibacterial property, but also has better high temperature resistance and weather resistance, no irritation and more environmental protection due to the inorganic antiviral agent. Meanwhile, the composite antiviral agent adopts nano silicon dioxide as a carrier, so that poor dispersity and stability of nano silver caused by agglomeration can be avoided, and the adsorbability of the nano silicon dioxide to the nano silver and the stability of the nano silicon dioxide in a system are improved by adding amino acid and sylvite, so that the antiviral property is improved.

The invention also provides a preparation method of the water-based antiviral varnish, which is used for preparing the water-based antiviral varnish, and the method comprises the following steps:

step S1: taking 0.5wt% of nano silver solution, sylvite and amino acid according to the proportion, stirring, adding nano silicon dioxide after uniformly mixing, stirring for 2-3 h, dropwise adding a reducing agent, continuously stirring for 1h, adding alkyl dimethyl benzyl ammonium chloride, and uniformly stirring to obtain the compound antiviral agent.

Step S2: taking polyurethane resin according to a ratio, putting the polyurethane resin into a reaction container, stirring, sequentially adding an anti-scraping agent, an antifoaming agent, a wetting agent and a pH regulator, stirring and uniformly mixing, adding polycarbodiimide, continuously stirring at the stirring speed of 300-500 rpm for 10min, adding polyisocyanate, continuously stirring, adding a compound antiviral agent after uniformly mixing, continuously stirring, adding a diluent after uniformly mixing to adjust the viscosity, continuously stirring, and uniformly mixing to obtain the aqueous antiviral varnish.

The preparation method of the water-based antiviral varnish has simple steps, and the water-based antiviral varnish can be obtained by uniformly stirring.

To further illustrate the aqueous antiviral varnish and the preparation method thereof provided by the present invention, the following examples are provided.

Example 1

A preferred water-based antiviral varnish comprises the following components in parts by weight: 95 parts of aqueous polyurethane resin composition, 4 parts of polycarbodiimide, 4 parts of polyisocyanate, 10 parts of deionized water and 8 parts of compound antiviral agent. Wherein the polycarbodiimide is the polycarbodiimide with the mark of SV-02 provided by CARBODILITE corporation; the polyisocyanate is hydrophilic aliphatic polyisocyanate with NCO content of 20%;

the aqueous polyurethane resin composition comprises the following components in parts by weight: 93 parts of polyurethane resin, 2 parts of PTEF wax scratch resistant agent with the particle size of 3-5 mu m, 0.6 part of polyether siloxane emulsion defoaming agent with the model number of BYK 1719 provided by Picker chemical company, 0.6 part of nonionic polyurethane associated wetting agent with the model number of 810 provided by EVONIK company and 0.3 part of Alpamine N41 organic ammonia pH regulator produced by Arkema company. Wherein the polyurethane resin is self-extinction organic silicon modified waterborne polyurethane resin, the solid content of the polyurethane resin is 40%, the particle size range of the polyurethane resin is 500-600 nm, and the glossiness of the polyurethane resin is 3-4 degrees.

The compound antiviral agent comprises the following components in parts by weight: 100 parts of 0.5wt% nano silver solution, 4 parts of nano silicon dioxide, 0.2 part of sodium sulfite, 1 part of serine, 0.8 part of potassium citrate and 0.2 part of dodecyl dimethyl benzyl ammonium chloride.

A preparation method of water-based antiviral varnish comprises the following steps:

step S1: taking 0.5wt% of nano silver solution, amino acid and potassium citrate according to the proportion, stirring, adding nano silicon dioxide after uniformly mixing, stirring for 2h, dropwise adding sodium sulfite, continuously stirring for 1h, adding dodecyl dimethyl benzyl ammonium chloride, and uniformly stirring to obtain the compound antiviral agent.

Step S2: and (2) taking polyurethane resin according to a ratio, putting the polyurethane resin into a reaction container, stirring, sequentially adding an anti-scraping agent, a defoaming agent, a wetting agent and a pH regulator, uniformly stirring, adding polycarbodiimide, continuously stirring at the stirring speed of 300rpm for 10min, adding polyisocyanate, continuously stirring, uniformly mixing, adding a compound antiviral agent, continuously stirring, uniformly mixing, adding deionized water to adjust the viscosity, continuously stirring, and uniformly mixing to obtain the aqueous antiviral varnish.

Example 2

An aqueous antiviral varnish comprises the following components in parts by weight: 100 parts of waterborne polyurethane resin composition, 5 parts of polycarbodiimide, 5 parts of polyisocyanate, 15 parts of deionized water and 10 parts of compound antiviral agent. Wherein the polyisocyanate is hydrophilic aliphatic polyisocyanate with NCO content of 10%;

the aqueous polyurethane resin composition comprises the following components in parts by weight: 90 parts of polyurethane resin, 1 part of surface modified nano aluminum oxide, 0.1 part of polymer defoaming agent, 0.1 part of modified acrylic wetting and leveling agent and 0.1 part of sodium oxide. Wherein the polyurethane resin is self-extinction organic silicon modified waterborne polyurethane resin, the solid content of the polyurethane resin is 35 percent, the particle size range of the polyurethane resin is 400-500 nm, and the glossiness of the polyurethane resin is 5-7 degrees.

The compound antiviral agent comprises the following components in parts by weight: 100 parts of 0.5wt% nano silver solution, 3.5 parts of nano silicon dioxide, 0.19 part of sodium sulfite, 0.95 part of serine, 0.76 part of potassium citrate and 0.19 part of tetradecyl dimethyl benzyl ammonium chloride.

Example 3

An aqueous antiviral varnish comprises the following components in parts by weight: 90 parts of aqueous polyurethane resin composition, 3 parts of polycarbodiimide, 3 parts of polyisocyanate, 1 part of alcohol and 5 parts of compound antiviral agent. Wherein the polyisocyanate is hydrophilic aliphatic polyisocyanate with NCO content of 15%.

The waterborne polyurethane resin composition comprises the following components in parts by weight: 95 parts of polyurethane resin, 3 parts of surface modified nano silicon dioxide, 1 part of mineral oil defoaming agent, 1 part of polyether modified polydimethylsiloxane wetting agent and 0.5 part of ammonia water. The polyurethane resin is self-extinction organic silicon modified waterborne polyurethane resin, the solid content of the polyurethane resin is 45%, and the particle size range of the polyurethane resin is 700-800 nm.

The compound antiviral agent comprises the following components in parts by weight: 100 parts of 0.5wt% nano silver solution, 4 parts of nano silicon dioxide, 0.21 part of sodium sulfite, 1.05 parts of serine, 0.84 part of potassium citrate and 0.21 part of octadecyl dimethyl benzyl ammonium chloride.

Example 4

The water-based antiviral varnish comprises the following components in parts by weight: 92 parts of aqueous polyurethane resin composition, 4.5 parts of polycarbodiimide, 3.5 parts of polyisocyanate, 12 parts of alcohol and 7 parts of compound antiviral agent. The polyisocyanate is hydrophilic aliphatic polyisocyanate with NCO content of 12%.

The aqueous polyurethane resin composition comprises the following components in parts by weight: 92 parts of polyurethane resin, 1 part of PTEF wax with the particle size of 3-5 mu m, 0.7 part of organic silicon defoamer, 0.7 part of nonionic polyurethane association type wetting and leveling agent and 0.3 part of organic ammonia pH regulator. Wherein the polyurethane resin is self-extinction organic silicon modified waterborne polyurethane resin, the solid content of the polyurethane resin is 42 percent, the particle size range of the polyurethane resin is 600-700 nm, and the glossiness of the polyurethane resin is 2-3 degrees.

The compound antiviral agent comprises the following components in parts by weight: 100 parts of 0.5wt% nano silver solution, 3.7 parts of nano silicon dioxide, 0.19 part of sodium potassium tartrate, 1.05 parts of glycine, 0.76 part of potassium acetate and 0.21 part of dodecyl dimethyl benzyl ammonium chloride.

In examples 1 to 4, the particle size of the nano silver is 5 to 10nm, and the particle size of the nano silica is 500 to 900nm; examples 2-4 were prepared in the same manner as in example 1.

Comparative example 1

A varnish having substantially the same composition and preparation as in example 1 except that: the composite antiviral agent is replaced by nano silver in the same weight part.

Comparative example 2

A varnish having substantially the same composition and preparation method as in example 1, except that no nanosilica is added to the complex antiviral agent.

Comparative example 3

A varnish having substantially the same composition and preparation method as in example 1, except that no serine is added to the complex antiviral agent.

Comparative example 4

A varnish having substantially the same composition and preparation as in example 1, except that no potassium citrate is added to the complex antiviral agent.

Performance test

The varnishes prepared in examples 1 to 4 and comparative examples 1 to 4 were subjected to tests for the antiviral rate, the varnish appearance, the color difference and the light fastness performance, wherein the test for the antiviral rate was carried out according to ISO 21702-2019 "determination of antiviral properties of plastics and other nonporous surfaces", wherein the virus type is influenza virus H3N2; the color difference test is carried out in accordance with DIN 53236 "test for pigmented materials," [ measurement and evaluation conditions ] for determining the color difference of paints, such as paints, and plastics; the test of the color fastness to light was carried out in accordance with DIN EN ISO 4892-2-2013 method for exposing plastics to light in the laboratory. Specific test results are shown in table 1.

TABLE 1 varnish Property test results

As can be seen from table 1, the aqueous antiviral varnish prepared in examples 1 to 4 has a high antiviral rate, no discoloration, small color difference, and good weather resistance, because the nano-silica is used as the carrier of the nano-silver, and the combined action of the reducing agent, the amino acid, and the potassium salt is combined, the aggregation of the nano-silver can be avoided, the nano-silver can be uniformly dispersed in the system, the antiviral rate is greatly improved, and the problem of large color difference can not occur because the nano-silica is not aggregated. In contrast, in comparative example 1, nano silver was used as an antiviral agent, and although the amount of nano silver added was greater than the amount of nano silver in examples 1 to 4, the color change was severe and the color difference was large due to the easy agglomeration of the nano silver, and the nano silver was easily oxidized due to the absence of a reducing agent, so that the antiviral rate was only 31.2%.

In addition, as shown in comparative examples 2-4, when the composite antiviral agent is not supported by nano-silica, or no amino acid or potassium salt is added, the antiviral rate is affected, and discoloration and color difference are easily caused, which are mainly caused by agglomeration of nano-silver, and poor dispersibility and stability in the system. Therefore, the complex antiviral agent has excellent antiviral rate and stability as a result of the combined action of a plurality of components.

In conclusion, the aqueous antiviral varnish disclosed by the invention has an excellent antiviral function by adding the compound antiviral agent, is high in antiviral rate and good in broad-spectrum antibacterial property, and has better high temperature resistance and weather resistance, no irritation and environmental friendliness due to the fact that the aqueous antiviral varnish is an inorganic antiviral agent. The composite antiviral agent takes the nano silicon dioxide as a carrier of the nano silver, and the amino acid and the sylvite modifier are added simultaneously, so that the nano silver can be prevented from agglomerating, the nano silver can be well and stably dispersed in the aqueous polyurethane emulsion, the antiviral rate of the varnish is further greatly improved, the problems of varnish color difference and color change caused by agglomeration of the nano silver are solved, and the appearance effect of a varnish product is improved.

It should be understood that equivalents and modifications of the technical solution and inventive concept thereof may occur to those skilled in the art, and all such modifications and alterations should fall within the scope of the appended claims.

Claims (7)

1. The water-based antiviral varnish comprises water-based polyurethane emulsion and is characterized by also comprising a compound antiviral agent, wherein the compound antiviral agent comprises the following components in parts by weight: 100 parts of 0.5wt% nano silver solution, 3 to 4 parts of nano silicon dioxide, 0.19 to 0.21 part of reducing agent, 0.95 to 1.05 parts of amino acid, 0.76 to 0.84 part of potassium salt and 0.19 to 0.21 part of alkyl dimethyl benzyl ammonium chloride; the potassium salt is potassium citrate or potassium acetate; the particle size of the nano silicon dioxide is 500-900 nm.

2. The aqueous antiviral varnish of claim 1, wherein the amino acid is serine or glycine.

3. The aqueous antiviral varnish according to claim 1, wherein the aqueous polyurethane emulsion comprises: an aqueous polyurethane resin composition, polycarbodiimide, polyisocyanate and a diluent; the mass ratio of the aqueous polyurethane resin composition, the polycarbodiimide, the polyisocyanate, the diluent and the compound antiviral agent is 90-100: 3-5: 1-15: 5-10.

4. The aqueous antiviral varnish according to claim 3, wherein the aqueous polyurethane resin composition comprises, in parts by weight: 90 to 95 portions of polyurethane resin, 1 to 3 portions of anti-scraping agent, 0.1 to 1 portion of defoaming agent, 0.1 to 1 portion of wetting agent and 0.1 to 0.5 portion of pH regulator.

5. The aqueous antiviral varnish of claim 4, wherein the scratch resistant agent is one of surface modified nano alumina, surface modified nano silica or PTEF wax.

6. The aqueous antiviral varnish according to claim 4, wherein the antifoaming agent is one of a mineral oil-based antifoaming agent and a silicone-based antifoaming agent.

7. A process for preparing an aqueous antiviral varnish for use in the preparation of an aqueous antiviral varnish according to any one of claims 4 to 6, wherein the process comprises the steps of:

step S1: taking 0.5wt% of nano silver solution, potassium salt and amino acid, stirring, adding nano silicon dioxide after uniformly mixing, stirring for 2 hours, dropwise adding a reducing agent, continuously stirring for 1 hour, adding alkyl dimethyl benzyl ammonium chloride, continuously stirring, and uniformly mixing to obtain a compound antiviral agent;

step S2: adding polyurethane resin into a reaction container, stirring, sequentially adding an anti-scraping agent, a defoaming agent, a wetting agent and a pH regulator, continuously stirring, adding polycarbodiimide after uniformly mixing, continuously stirring, adding polyisocyanate after uniformly mixing, continuously stirring, adding a compound antiviral agent after uniformly mixing, continuously stirring, adding a diluent after uniformly mixing to adjust the viscosity, and uniformly stirring to obtain the aqueous antiviral varnish.