COMPOSITION TECHNICAL FIELD

The present disclosure relates to a preparation method of a coating composition having a durable easy -cleaning effect and a durable antimicrobial function.

BACKGROUND ART

With the continuous improvement in the living standards, hygiene and health conditions of various facilities are drawing increasing attentions. How to keep various facilities clean for a long time and provide an effective antimicrobial function is a new challenge presented to the modern life. At present, it is required in fields like industrial transportation, construction and decoration, electronics and electric power, household appliances, kitchen and toilet facilities and the like to use easy-cleaning and antimicrobial coatings. These fields now have a high demand of having long-lasting, easy-cleaning and antimicrobial coatings.

CN105482536 (ZHOU Zhiwei et al.) discloses a transparent and antimicrobial hydrophilic paint comprising the following components: at least one of silicate salt or sol, nanometer oxide dispersions, alkali metal phosphates, inorganic antimicrobial agents, inhibitors, humectants, and solvents. In that invention, the antimicrobial effect was achieved by adding nano-copper or nano-silver into the paint; yet, the antimicrobial durability was not tested.

US2012204762 (Albert Philipp et al.) discloses an aqueous silane system for bare corrosion protection and corrosion protection of metals. In that invention, bare corrosion protection of metal substrates is greatly improved by adding a metal salt into a silane and sol-gel system. However, its easy-cleaning feature and antimicrobial performances of the coating were not mentioned, and were not tested either.

SUMMARY

The present disclosure is intended to provide a preparation method of a durable easy-cleaning and antimicrobial coating composition to allow coated articles prepared by the method to have an easy- cleaning effect and an antimicrobial function that are both relatively enduring. According to one aspect of the present disclosure, the present disclosure provides a preparation method of a durable easy-cleaning and antimicrobial coating composition, comprising steps of:

1) adding an acid into an alcohol -water solution comprising at least one orthosilicate and at least one fluorinated polyether silane compound to perform hydrolysis and co-condensation at a temperature of 20 to 80°C, so as to form a reaction mixture i;

2) placing the reaction mixture i at room temperature to perform aging for 12 to 72 h, so as to form a reaction mixture ii;

3) adding an acid into an aqueous solution comprising at least one high-valence metal salt to adjust the pH of the solution to a range of 1-4, and then mixing the solution with the reaction mixture ii, so as to form a reaction mixture iii, wherein the high-valence metal salt is one or more selected from the group consisting of aluminum salts (in an oxidation state of 3+), chromium salts (in an oxidation state of 3+), cerium salts (in an oxidation state of 3+ or 4+), zirconium salts (in an oxidation state of 4+), and vanadium salts (in an oxidation state of 5+); and

4) adding at least one inorganic antimicrobial agent into the reaction mixture iii to form a coating composition, wherein the inorganic antimicrobial agent is one or more selected from the group consisting of silver salts (in an oxidation state of 1+), copper salts (in an oxidation state of 2+), and zinc salts (in an oxidation state of 2+).

According to another aspect of the present disclosure, the present disclosure provides a coated article prepared according to the preparation method of the coating composition, comprising a substrate and a dry coating applied on the substrate, wherein the dry coating comprises a coating obtained by drying the coating composition obtained by the preparation method applied onto the substrate surface.

According to another aspect of the present disclosure, the present disclosure provides a preparation method of the coated article, comprising steps of: applying the coating composition obtained according to the preparation method onto at least part of a surface of the substrate to form a liquid film layer of the wet coating composition on the at least part of the surface of the substrate, and drying the liquid film of the wet coating composition to obtain a dry coating attached to the surface of the substrate. DESCRIPTION OF THE PREFERRED EMBODIMENTS

It should be appreciated that those skilled in the art, in light of the teachings of the present application, may be able to envisage other various embodiments and make modifications thereof without departing from the scope or essences of the disclosure. Therefore, the present disclosure is not limited to the following particular embodiments .

All figures for denoting quantities and physicochemical properties used in the description and claims are to be understood as modified by the term "about" in all situations, unless indicated otherwise.

Therefore, unless stated on the contrary, parameters in numerical values listed in the description and in the attached claims are all approximate values; and those of skill in the art are capable of seeking to obtain desired properties by taking advantage of contents of the teachings disclosed herein, and changing these approximate values appropriately. A numerical range represented by end points includes all figures within the range, and any range within the range; for example, the range of 1, 2, 3, 4 and 5 includes 1, 1.1, 1.3, 1.5, 2, 2.75, 3, 3.80, 4, 5, and the like. Preparation method of coating compositions

The preparation method of a durable easy-cleaning and antimicrobial coating composition as provided herein includes steps of:

1) adding an acid into an alcohol -water solution comprising at least one orthosilicate and at least one fluorinated polyether silane compound to perform hydrolysis and co-condensation at a temperature of 20 to 80°C, so as to form a reaction mixture i;

2) placing the reaction mixture i at room temperature to perform aging for 12 to 72 h, so as to form a reaction mixture ii;

3) adding an acid into an aqueous solution comprising at least one high-valence metal salt to adjust the pH of the solution to a range of 1-4, and then mixing the solution with the reaction mixture ii, so as to form a reaction mixture iii, wherein the high-valence metal salt is one or more selected from the group consisting of aluminum salts (in an oxidation state of 3+), chromium salts (in an oxidation state of 3+), cerium salts (in an oxidation state of 3+ or 4+), zirconium salts (in an oxidation state of 4+), and vanadium salts (in an oxidation state of 5+); and 4) adding at least one inorganic antimicrobial agent into the reaction mixture iii to form a coating composition, wherein the inorganic antimicrobial agent is one or more selected from the group consisting of silver salts (in an oxidation state of 1+), copper salts (in an oxidation state of 2+), and zinc salts (in an oxidation state of 2+).

The orthosilicate content is 1-10 wt% based on the total weight of the coating composition as 100 wt%. If the orthosilicate content is lower than 1 wt%, it may not be easy to form a coating of a desired thickness on the substrate, and the coated article obtained thereby may have poor abrasion resistance, salt-fog resistance, or high-temperature and high-humidity resistance; and if the orthosilicate content is higher than 10 wt%, the coated article obtained thereby may have evident defects in the appearance.

The orthosilicate can be represented by a general formula I:

Si(OR) ₄ (I) where R represents a hydrogen atom or CI -4 alkyl, and R, which may be identical or different, is one or more selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, i-butyl, and t-butyl.

The content of the fluorinated polyether silane compound is 0.05-5 wt% based on the total weight of the coating composition as 100 wt%. If the content of the fluorinated polyether silane compound is lower than 0.05 wt%, the coated article obtained thereby may have poor easy-cleaning performance; and if the content of the fluorinated polyether silane compound is higher than 5 wt%, the coated article obtained thereby may have evident defects in the appearance.

The fluorinated polyether silane compound can be represented by a general formula II:

Rf-[Q-CR ₂ -Si(OR) ₃ -a(R ¹ )a]b (II) wherein a is an integer and 0 < a < l ; b is an integer and 2 < b < 4; R _f represents a multivalent polyfluoropolyether chain segment; Q represents an organic bivalent linking group; R ¹ represents C I -8 alkyl; R represents a hydrogen atom or CI -4 alkyl, and R, which may be identical or different, is one or more selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, i-butyl, and t-butyl.

The polyfluoropolyether chain segment includes a perfluorinated repeating unit, being one or more selected from the group consisting of: -(C _n F2 _n O)-, -(CF(Z)O)-, -(CF(Z)C _n F2nO)-, -(C _n F2nCF(Z)0)-, and -

(CF2CF(Z)0)-, wherein n is an integer and 1 < n < 12; and Z represents perfluoroalkyl, oxygen- substituted perfluoroalkyl, perfluoroalkoxy, or oxygen-substituted perfluoroalkoxy having a linear, branched or cyclic structure and comprising 1 to 9 carbon atoms and 0 to 4 oxygen atoms.

A ratio by weight of the orthosilicate to the fluorinated polyether silane compound is from 2: 1 to 25 : 1. When the ratio by weight of the orthosilicate to the fluorinated polyether silane compound is lower than 2: 1, the coated article obtained thereby may have evident defects in the appearance; and when the ratio by weight of the orthosilicate to the fluorinated polyether silane compound is higher than 25 : 1, the coated article obtained thereby may have poor easy-cleaning performance.

The acid is an inorganic acid or an organic acid, where the inorganic acid is one or more selected from the group consisting of hydrochloric acid, nitric acid and phosphoric acid; and the organic acid is one or more selected from the group consisting of formic acid and acetic acid.

The content of the high-valence metal salt is 0.2-5 wt% based on the total weight of the coating composition as 100 wt%. When the content of the high-valence metal salt is lower than 0.2 wt%, the coated article obtained thereby may have poor abrasion resistance, salt-fog resistance or high- temperature, and high-humidity resistance; and when the content of the high-valence metal salt is higher than 5 wt%, a problem may arise that the high-valence metal salt is dissolved incompletely or the concentration thereof is too high.

The high-valence metal salt is at least one metal salt selected from the group consisting of nitrate or acetate, and the high-valence metal salt is one or more selected from the group consisting of aluminum nitrate, chromium nitrate, cerium nitrate, zirconium nitrate, vanadium nitrate, aluminum acetate, chromium acetate, cerium acetate and zirconium acetate.

The content of the inorganic antimicrobial agent is 0.05-5 wt% based on the total weight of the coating composition as 100 wt%. When the content of the inorganic antimicrobial agent is lower than 0.05 wt%, the coated article obtained thereby may have poor antimicrobial performance; and when the content of the inorganic antimicrobial agent is higher than 5 wt%, the problem of the inorganic antimicrobial agent not being able to dissolve completely or the concentration thereof is too high may arise.

The inorganic antimicrobial agent is at least one metal salt selected from the group consisting of nitrate or sulphate, and the inorganic antimicrobial agent is one or more selected from the group consisting of silver nitrate, copper nitrate, zinc nitrate, copper sulfate, and zinc sulfate. The coating composition has a pH value less than or equal to 4. When the coating composition has a pH value higher than 4, the coated article obtained thereby may have poor abrasion resistance, salt-fog resistance, or poor high-temperature and high-humidity resistance.

The coating composition of the present disclosure may also further comprise additives. The additives includes one or more of detergents, surfactants, leveling agents, colorants, brighteners, light stabilizers, flavors, dyes, pigments, and organic polymer binders. The surfactant is a non-ionic surfactant that can improve wettability of the coating composition on a substrate surface. The non-ionic surfactant may be one or more selected from the group consisting of polyoxyethylene non-ionic surfactants, polyhydric alcohol non-ionic surfactants, alkylolamide non-ionic surfactants, fluorocarbon non-ionic surfactants, organosilicon non-ionic surfactants, and modified organosilicon non-ionic surfactants.

The content of the non-ionic surfactant is 0.01-2 wt%, preferably 0.01-1 wt%, and particularly preferably 0.05-0.5 wt% based on the total weight of the coating composition as 100 wt%. If the content of the non-ionic surfactant is higher than 2 wt%, the coated article obtained thereby may have poor appearance, abrasion resistance, salt-fog resistance or poor high-temperature and high-humidity resistance.

Coating compositions

The coating composition provided herein is a coating composition obtained according to the preparation method of the coating composition.

With regard to the description of the preparation method of the coating composition, details can be seen in the section of "Preparation method of coating compositions" in the description of this disclosure.

Coated articles

The coated article provided here includes a substrate and a dry coating applied on the substrate, wherein the dry coating includes a coating obtained by drying the coating composition applied onto the substrate surface. The substrate is one or more selected from the group consisting of ceramic tile substrates, glass substrates, stone substrates and metal substrates. The "ceramic tiles" as described here or in the claims are applicable to porcelain materials prepared from fire-resistant clays, tile materials, concrete, ceramics, marbles, limestones, and other stone materials or slate. The ceramic tile substrate is one or more selected from the group consisting of vitrified tiles, glazed tiles, rustic tiles, microlites, polished tiles, granite-simulating tiles, and marble-simulating tiles. The stone substrate is one or more selected from the group consisting of marble, granite, and artificial stone. The metal substrate is one or more selected from the group consisting of stainless steel, cold rolled steel, galvanized steel, chromized steel, phosphated steel, iron, aluminum, titanium, magnesium, copper, zinc, and alloys comprising the above metals.

With regard to the description of the coating composition, details can be seen in the sections of

"Preparation method of coating compositions" and "Coating compositions" in the description of this disclosure.

The dry coating may have any appropriate thickness as required, and the thickness of the dry coating may be from 50 nm to 10 um, or from 100 nm to 5 um, or from 200 nm to 1 um.

Preparation method of coated articles

The preparation method of a coated article provided herein includes steps of: applying the coating composition provided in the present disclosure onto at least part of a surface of the substrate to form a liquid film layer of the wet coating composition on the at least part of the surface of the substrate, and drying the liquid film of the wet coating composition to obtain a dry coating attached to the surface of the substrate.

With regard to the description of the coating composition, the substrate, and the coated article, details can be seen in the sections of "Preparation method of coating compositions," "Coating compositions", and "Coated articles" in the description of this disclosure.

The coating composition can be applied onto the substrate surface by methods known in the prior art; and the methods are preferably one or more of blade coating, wipe coating, brush coating, dip coating, and spray coating. The antiskid liquid can be dried by an appropriate drying method known in the prior art. The drying process can be performed in a room temperature or higher temperature condition. For example, the temperature may be from 40 to 200°C, or from 60 to 180°C, or from 80 to 150°C.

The present disclosure provides multiple preferred embodiments of the preparation method of a durable, easy-cleaning and antimicrobial coating composition. Preferred embodiment 1 is a preparation method of a durable, easy-cleaning and antimicrobial coating composition, including steps of:

1) adding an acid into an alcohol-water solution comprising at least one orthosilicate and at least one fluorinated polyether silane compound to perform hydrolysis and co-condensation at a temperature of 20 to 80°C, so as to form a reaction mixture i;

2) placing the reaction mixture i at room temperature to perform aging for 12 to 72 h, so as to form a reaction mixture ii;

3) adding an acid into an aqueous solution comprising at least one high-valence metal salt to adjust the pH of the solution to a range of 1-4, and then mixing the solution with the reaction mixture ii, so as to form a reaction mixture iii, wherein the high-valence metal salt is one or more selected from the group consisting of aluminum salts (in an oxidation state of 3+), chromium salts (in an oxidation state of 3+), cerium salts (in an oxidation state of 3+ or 4+), zirconium salts (in an oxidation state of 4+), and vanadium salts (in an oxidation state of 5+); and

4) adding at least one inorganic antimicrobial agent into the reaction mixture iii to form a coating composition, wherein the inorganic antimicrobial agent is one or more selected from the group consisting of silver salts (in an oxidation state of 1+), copper salts (in an oxidation state of 2+), and zinc salts (in an oxidation state of 2+).

Preferred embodiment 2 is the preparation method of preferred embodiment 1, wherein the orthosilicate content is 1- 10 wt% based on the total weight of the coating composition as 100 wt%.

Preferred embodiment 3 is the preparation method of preferred embodiment 1, wherein the orthosilicate can be represented by a general formula I:

Si(OR) ₄ (I) wherein R represents a hydrogen atom or C I -4 alkyl, and R, which may be identical or different, is one or more selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, i-butyl, and t-butyl.

Preferred embodiment 4 is the preparation method of preferred embodiment 1, wherein the content of the fluorinated polyether silane compound is 0.05-5 wt% based on the total weight of the coating composition as 100 wt%. Preferred embodiment 5 is the preparation method of preferred embodiment 1, wherein the fluorinated polyether silane compound can be represented by a general formula II:

wherein a is an integer and 0 < a < l; b is an integer and 2 < b < 4; Rf represents a multivalent polyfluoropolyether chain segment; Q represents an organic bivalent linking group; R ¹ represents CI -8 alkyl; R represents a hydrogen atom or CI -4 alkyl, and R, which may be identical or different, is one or more selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, i-butyl, and t-butyl.

Preferred embodiment 6 is the preparation method of preferred embodiment 5, wherein the polyfluoropolyether chain segment includes a perfluorinated repeating unit, being one or more selected from the group consisting of: -(C _n F _2n O)-, -(CF(Z)O)-, -(CF(Z)C _n F _2n O)-, -(C _n F _2n CF(Z)0)-, and - (CF2CF(Z)0)-, where n is an integer and 1 < n < 12; and Z represents perfluoroalkyl, oxygen-substituted perfluoroalkyl, perfluoroalkoxy, or oxygen-substituted perfluoroalkoxy having a linear, branched, or cyclic structure and comprising 1 to 9 carbon atoms and 0 to 4 oxygen atoms.

Preferred embodiment 7 is the preparation method of preferred embodiment 1, wherein a ratio by weight of the orthosilicate to the fluorinated polyether silane compound is from 2: 1 to 25: 1.

Preferred embodiment 8 is the preparation method of preferred embodiment 1, wherein the acid is an inorganic acid or an organic acid, wherein the inorganic acid is one or more selected from the group consisting of hydrochloric acid, nitric acid, and phosphoric acid; and the organic acid is one or more selected from the group consisting of formic acid and acetic acid.

Preferred embodiment 9 is the preparation method of preferred embodiment 1, wherein the content of the high- valence metal salt is 0.2-5 wt% based on the total weight of the coating composition as 100 wt%.

Preferred embodiment 10 is the preparation method of preferred embodiment 1, wherein the high- valence metal salt is at least one metal salt selected from the group consisting of nitrate or acetate; and the high- valence metal salt is one or more selected from the group consisting of aluminum nitrate, chromium nitrate, cerium nitrate, zirconium nitrate, vanadium nitrate, aluminum acetate, chromium acetate, cerium acetate, and zirconium acetate. Preferred embodiment 11 is the preparation method of preferred embodiment 1, wherein the content of the inorganic antimicrobial agent is 0.05-5 wt% based on the total weight of the coating composition as 100 wt%.

Preferred embodiment 12 is the preparation method of preferred embodiment 1, wherein the inorganic antimicrobial agent is at least one metal salt selected from the group consisting of nitrate or sulphate; and the inorganic antimicrobial agent is one or more selected from the group consisting of silver nitrate, copper nitrate, zinc nitrate, copper sulfate, and zinc sulfate.

Preferred embodiment 13 is the preparation method of preferred embodiment 1, wherein the coating composition has a pH value less than or equal to 4.

Preferred embodiment 14 is the preparation method of preferred embodiment 1, wherein the coating composition further comprises 0.01-2 wt% additives based on the total weight of the coating composition as 100 wt%; and the additives includes one or more of detergents, surfactants, leveling agents, colorants, brighteners, light stabilizers, flavors, dyes, pigments, and organic polymer binders.

Preferred embodiment 15 is a coated article, including a substrate and a dry coating applied on the substrate, wherein the dry coating includes a coating obtained by drying the coating composition obtained by the preparation method according to the preferred embodiments 1 to 14 applied onto the substrate surface.

Preferred embodiment 16 is the coated article of preferred embodiment 15, wherein the substrate is one or more selected from the group consisting of ceramic tile substrates, glass substrates, stone substrates, and metal substrates.

Preferred embodiment 17 is the coated article of preferred embodiment 16, wherein the ceramic tile substrate is one or more selected from the group consisting of vitrified tiles, glazed tiles, rustic tiles, microlites, polished tiles, granite -simulating tiles, and marble-simulating tiles.

Preferred embodiment 18 is the coated article of preferred embodiment 16, wherein the stone substrate is one or more selected from the group consisting of marble, granite, and artificial stone.

Preferred embodiment 19 is the coated article of preferred embodiment 16, wherein the metal substrate is one or more selected from the group consisting of stainless steel, cold rolled steel, galvanized steel, chromized steel, phosphated steel, iron, aluminum, titanium, magnesium, copper, zinc, and alloys comprising the above metals. Preferred embodiment 20 is a preparation method of a coated article, including steps of: applying the coating composition obtained by the preparation method according to the preferred embodiments 1 to 14 onto at least part of a surface of the substrate to form a liquid film layer of the wet coating composition on the at least part of the surface of the substrate; and drying the liquid film of the wet coating composition to obtain a dry coating attached to the surface of the substrate.

Preferred embodiment 21 is the preparation method of preferred embodiment 20, wherein the coating composition is applied onto the surface of the substrate by the following methods: blade coating, wipe coating, brush coating, dip coating, and spray coating.

Examples

Examples and Comparative examples provided hereinafter facilitate understanding of the present disclosure, and should not be understood to limit the scope of the present invention. All parts and percentages are based on weight unless indicated otherwise.

Raw materials employed in Examples and Comparative examples of the present disclosure are shown in Table 1 below.

Table 1. Raw materials employed in Examples and Comparative examples

Sinopharm Chemical Reagent

Aluminum nitrate nonahydrate A1(N0 ₃ ) ₃ 9H ₂ 0, purity >= 99.0 wt%

Co., Ltd.

Chromium nitrate nonahydrate Cr(N0 ₃ ) ₃ 9H ₂ 0, purity >= 99.0 wt% Shanghai Zhanyun Chemical

Cerium nitrate hexahydrate Ce(N0 ₃ ) ₃ 6H ₂ 0, purity >= 99.0 wt% Co., Ltd.

Shanghai Dibo Biotech Co.,

Zirconium nitrate pentahydrate Zr(N0 ₃ ) ₄ 5H ₂ 0, purity >= 99.9 wt%

Ltd

Suzhou DongHua Vanadium

Vanadium nitrate V0 ₂ N0 ₃ , purity = 50-52 wt%

and Silicon Co., Ltd.

Chengdu Aikeda Chemical

Aluminum acetate Al(CH ₃ COO) ₃ , purity >= 99.0 wt%

Reagent Co., Ltd.

Shanghai Aladdin Bio-Chem

Silver nitrate AgN0 ₃ , purity >= 99.8 wt%

Technology Co., Ltd.

Copper nitrate trihydrate Cu(N0 ₃ ) ₂ 3H ₂ 0, purity >= 99.0 wt%

Sinopharm Chemical Reagent

Zinc nitrate hexahydrate Zn(N0 ₃ ) ₂ 6H ₂ 0, purity >= 99.0 wt%

Co., Ltd.

Copper sulfate pentahydrate CuS0 ₄ 5H ₂ 0, purity >= 99.0 wt%

Shandong Xiya Chemical

Zinc sulfate heptahydrate ZnS0 ₄ 7H ₂ 0, purity >= 99.0 wt%

Industry Co., Ltd.

Deionized water Deionized water (DI H ₂ 0) Home-made in 3M

Alkyl polyglucoside surfactant, TRITON™ Dow Chemical Co.

Non-ionic surfactant

BG-10, 70 wt% aqueous solution (Dow Chemical Company)

Shanghai Bohao Building

Vitrified tiles 200 mm ^χ 200 mm ^χ 10 mm

Material Co., Ltd.

Shanghai Yangguang

Granite 200 mm ^χ 150 mm ^χ 15 mm

Decorative Material Co., Ltd.

Shanghai Jinqia Trade Co.,

Glass 180 mm ^χ 100 mm ^χ 3 mm

Ltd.

304 stainless steel 100 mm x 50 mm ^χ 1 mm Suzhou Hengqiang Stainless

439 stainless steel 100mm x 50mm ^χ 1mm Steel Material Co., Ltd.

Southwest Aluminum

6061 aluminum alloy 100mm x 50mm ^χ 1mm

Company

In the present disclosure, the easy-cleaning performance of coated articles provided in Examples and

Comparative examples are evaluated through the contact angle tests; and the antimicrobial performance of coated articles provided in Examples and Comparative examples are evaluated through tests of the antimicrobial ratio. On this basis, in the present disclosure, abrasion resistance of coated articles provided in

Examples and Comparative examples are evaluated through the observed changes in the contact angle and in the antimicrobial ratio before and after the wet grinding test; salt-fog resistance of coated articles provided in Examples and Comparative examples are evaluated through the observed changes in the contact angle and in the antimicrobial ratio before and after the salt-fog test; and high-temperature and high- humidity resistance of coated articles provided in Examples and Comparative examples are evaluated through the observed changes in the contact angle and in the antimicrobial ratio before and after the high- temperature and high-humidity test.

Contact angle test

The easy-cleaning performance of the coated articles herein will be shown through the contact angle tests.

The instrument for performing the contact angle tests is a Kruss DSA100 automatic contact angle tester commercially available from Kruss Corporation.

5 of water drop is quantitatively injected onto a surface of the coated article, and the water drop is tested for the contact angle after its shape no longer changes. Five different regions are selected randomly on the surface of the coated article; the above experiment is repeated to obtain five numerical values of the water contact angle which are then averaged. If the averaged water contact angle is less than 90°, it indicates that the surface of the coated article has a hydrophilic effect, and a lower numerical value indicates better hydrophilicity of the surface; and if the averaged water contact angle is greater than or equal to 90°, it indicates that the surface of the coated article has a hydrophobic effect, and a higher numerical value indicates better hydrophobicity of the surface.

5 of hexadecane drop is quantitatively injected onto a surface of the coated article, and the hexadecane drop is tested for the contact angle after its shape no longer changes. Five different regions are selected randomly on the surface of the coated article; and the above experiment is repeated to obtain five numerical values of the hexadecane contact angle which are then averaged. If the averaged hexadecane contact angle is less than 60°, it indicates that the surface of the coated article has an oleophilic effect, and a lower numerical value indicates better oleophilicity of the surface; and if the averaged hexadecane contact angle is greater than or equal to 60°, it indicates that the surface of the coated article has an oleophobic effect, and a higher numerical value indicates better oleophobicity of the surface. If the averaged water contact angle measured on the surface of the coated article is greater than or equal to 110°, and at the same time the averaged hexadecane contact angle is greater than or equal to 60°, it indicates that the coated article has good easy-cleaning performance.

Test results of the easy-cleaning performance of coated articles provided in Examples and Comparative examples of the present disclosure are listed in Table 3.

Test of antimicrobial ratio

The antimicrobial performance of the coated articles herein is shown through tests of the antimicrobial ratio.

Test organisms for testing the antimicrobial ratio are Escherichia coli (a gram-negative bacterium) and Staphylococcus aureus (a gram -positive bacterium).

Tests of the antimicrobial ratio are performed according to JIS Z 2801-2010. Control products (not including the substrate of the same material as the coating composition) and coated articles are respectively clipped into a size with an area of about 50 mm χ 50 mm (three samples each), and sterilization is performed thereon. Several milliliters of bacterium liquid are added dropwise onto each sample surface to maintain the viable count on each sample surface at about 10 ⁵ . The sample surface with the bacterium liquid added dropwise thereon is covered with a plastic film; and then all samples are placed into a sterile plate, which is placed into a constant-temperature incubator at 36±1°C to culture the samples for 24 h. The viable count is obtained beside the flame within the sterile chamber; and the antimicrobial ratio of each sample is calculated according to the following formula:

antimicrobial ratio = [(A-B)/A] * 100%

wherein A represents the average viable count on each sample surface of the control products after 24 h; and B represents the average viable count on each sample surface of the coated articles after 24 h.

Antimicrobial ratios of three samples each of the control products and the coated articles are averaged respectively.

If the averaged antimicrobial ratio measured on the surface of the coated article is greater than or equal to 99%, it indicates that the coated article has good antimicrobial performance.

Test results of the antimicrobial performance of coated articles provided in Examples and Comparative examples of the present disclosure are listed in Table 3. Wet grinding test

The abrasion resistance of the coated articles herein is shown through changes in the contact angle and in the antimicrobial ratio before and after the wet grinding test.

The instrument for performing the wet grinding tests is Sheen Wet Abrasion Scrub Tester REF 903 commercially available from Sheen Corporation.

Under a condition of 1 kg load, surface friction is performed on the coated article with a friction material which is a sponge scouring pad (Brand Miaojie) for dedicated use in non-stick pans, commercially available from Miaojie Corporation, and the friction medium is water. When the number of friction cycles (one friction cycle refers to one back-and-forth friction) reaches 20,000 times, the test is stopped; and the water contact angle, the hexadecane contact angle, and the antimicrobial ratio on the surface of the coated article are remeasured.

The water contact angle and the hexadecane contact angle obtained by measurement on the surface of the coated article after the wet grinding test are compared with those before the wet grinding test respectively. If the losses in the water contact angle and in the hexadecane contact angle are both less than or equal to 10%, it indicates that, with regard to the easy-cleaning performance, the coated article has good abrasion resistance and is labelled as V; and if the loss in either contact angle is greater than 10%, it indicates that, with regard to the easy-cleaning performance, the coated article does not have good abrasion resistance and is labelled as x.

If the antimicrobial ratio obtained by measurement on the surface of the coated article after the wet grinding test is still greater than or equal to 90%, it indicates that, with regard to the antimicrobial performance, the coated article has good abrasion resistance and is labelled as V; and if the antimicrobial ratio is less than 90%, it indicates that, with regard to the antimicrobial performance, the coated article does not have good abrasion resistance and is labelled as x.

Test results of the abrasion resistance of coated articles provided in Examples and Comparative examples of the present disclosure are listed in Table 3. Salt-fog test

The salt-fog resistance of coated articles herein is shown through changes in the contact angle and in the antimicrobial ratio before and after the salt-fog test.

The instrument for performing the salt-fog tests is Q-Fog SF-1 600L commercially available from Q-Lab Corporation.

The salt-fog test is performed according to ASTM B 117-07. The coated article is placed into a salt- fog chamber with a temperature in the exposed zone thereof being constant within a range of 35 ± 2°C. A 5 ± 1 wt% sodium chloride solution is sprayed, and drips have a pH value maintained within a range of 6.5-7.2. By the time of 1000 h, the test is stopped. The coated article is taken out, cleaned with deionized water, and then measured for the water contact angle, the hexadecane contact angle, and the antimicrobial ratio on the surface thereof.

The water contact angle and the hexadecane contact angle obtained by measurement on the surface of the coated article after the salt-fog test are compared with those before the salt-fog test respectively. If the losses in the water contact angle and in the hexadecane contact angle are both less than or equal to 10%, it indicates that, with regard to the easy-cleaning performance, the coated article has good salt-fog resistance and is labelled as V; and if the loss in either contact angle is greater than 10%, it indicates that, with regard to the easy-cleaning performance, the coated article does not have good salt-fog resistance and is labelled as x.

If the antimicrobial ratio obtained by measurement on the surface of the coated article after the salt- fog test is still greater than or equal to 90%, it indicates that, with regard to the antimicrobial

performance, the coated article has good salt-fog resistance and is labelled as V; and if the antimicrobial ratio is less than 90%, it indicates that, with regard to the antimicrobial performance, the coated article does not have good salt-fog resistance and is labelled as x.

Test results of the salt-fog resistance of coated articles provided in Examples and Comparative examples of the present disclosure are listed in Table 3. High-temperature and high-humidity test

The high-temperature and high-humidity resistance of coated articles herein is shown through changes in the contact angle and in the antimicrobial ratio before and after the high-temperature and high- humidity test.

The instrument for performing the high-temperature and high-humidity test is C7-340 commercially available from Votsch Industrietechnik Corporation.

The high-temperature and high-humidity test is performed according to GB/T 2423.3-2006. The coated article is placed into a test chamber at a temperature constant within a range of 85 ± 2°C and a relative humidity constant within a range of 85 ± 3 RH%. By the time of 1000 h, the test is stopped. The coated article is taken out, cleaned with deionized water, and then measured for the water contact angle, the hexadecane contact angle, and the antimicrobial ratio on the surface thereof.

The water contact angle and the hexadecane contact angle obtained by measurement on the surface of the coated article after the high-temperature and high-humidity test are compared with those before the high-temperature and high-humidity test respectively. If the losses in the water contact angle and in the hexadecane contact angle are both less than or equal to 10%, it indicates that, with regard to the easy- cleaning performance, the coated article has good high-temperature and high-humidity resistance and is labelled as V; and if the loss in either contact angle is greater than 10%, it indicates that, with regard to the easy -cleaning performance, the coated article does not have good high-temperature and high-humidity resistance and is labelled as x.

If the antimicrobial ratio obtained by measurement on the surface of the coated article after the high- temperature and high-humidity test is still greater than or equal to 90%, it indicates that, with regard to the antimicrobial performance, the coated article has good high-temperature and high-humidity resistance and is labelled as V; and if the antimicrobial ratio is less than 90%, it indicates that, with regard to the antimicrobial performance, the coated article does not have good high-temperature and high-humidity resistance and is labelled as x.

Test results of the high-temperature and high-humidity resistance of coated articles provided in Examples and Comparative examples of the present disclosure are listed in Table 3. Preparation of coating compositions

Example 1

88.15 g of i-propanol, 7.60 g of deionized water, 1.00 g of tetraethyl orthosilicate, and 0.05 g of a fluorinated polyether silane compound (ECC-1000) were successively added into a 250-mL three-mouth flask, and mechanical stirring was switched on; the mixture was stirred for 30 min, and adjusted to pH 2-3 with dilute nitric acid added dropwise;

the resulting mixture was heated up to 80°C, stirred for 2 h under a condensation reflux condition, then cooled to room temperature and stopped from stirring, and aged for 12 h at room temperature;

mechanical stirring was switched on again, and 2.04 g of an aqueous solution (adjusted to pH 2-3 with dilute nitric acid) of 10 wt% aluminum nitrate was added dropwise into the three-mouth flask;

this mixture was stirred for 1 h at room temperature, and 0.05 g of solid silver nitrate was added therein; and

stirring was further performed for 30 min at room temperature to obtain a slightly cloudy colorless coating composition.

Examples 2 to 6

Coating compositions of Examples 2 to 6 were prepared by the same method as Example 1 ; types and contents of ingredients included in the coating compositions are listed in Table 2.

Comparative example 1

70.20 g of n-butanol, 7.60 g of deionized water, and 4.00 g of tetraethyl orthosilicate were successively added into a 250-mL three-mouth flask, and mechanical stirring was switched on;

the mixture was stirred for 30 min, and adjusted to pH 3-4 with dilute nitric acid added dropwise;

the resulting mixture was heated up to 40°C, further stirred for 2 h, then cooled to room temperature and stopped from stirring, and aged for 24 h at room temperature;

mechanical stirring was switched on again, and 16.00 g of an aqueous solution (adjusted to pH 3-4 with dilute nitric acid) of 10 wt% zirconium nitrate was added dropwise into the three-mouth flask;

this mixture was stirred for 1 h at room temperature, and 0.50 g of solid silver nitrate was added therein; and stirring was further performed for 30 min at room temperature to obtain a colorless clear transparent coating composition.

Comparative example 2

30.30 g of i-propanol, 29.70 g of deionized water, 5.00 g of tetraethyl orthosilicate, and 0.50 g of a fluorinated polyether silane compound (ECC-1000) were successively added into a 250-mL three-mouth flask, and mechanical stirring was switched on;

the mixture was stirred for 30 min, and adjusted to pH 1-2 with concentrated hydrochloric acid added dropwise;

the resulting mixture was heated up to 30°C, further stirred for 3h, and then cooled to room temperature, and 25.00 g of an aqueous solution (adjusted to pH 1-2 with concentrated hydrochloric acid) of 10 wt% aluminum nitrate was added dropwise into the three-mouth flask;

this mixture was stirred for 1 h at room temperature, and 2.50 g of solid copper sulfate pentahydrate was added therein; and

stirring was further performed for 30 min at room temperature, and 5.00 g of an aqueous solution of 10 wt% TRITON BG-10 surfactant was added therein; and

stirring was further performed for 10 min at room temperature to obtain a slightly cloudy blue coating composition. Comparative example 3

41.85 g of i-propanol, 18.36 g of deionized water, 6.00 g of tetraethyl orthosilicate, and 1.00 g of 1H,1H,2H,2H- perfluorooctyl triethoxy silane (F 8261) were successively added into a 250-mL three- mouth flask, and mechanical stirring was switched on;

the mixture was stirred for 30 min, and adjusted to pH 1-2 with concentrated hydrochloric acid added dropwise;

the resulting mixture was heated up to 50°C, further stirred for 1 h, then cooled to room temperature and stopped from stirring, and aged for 48 h at room temperature; mechanical stirring was switched on again, and 30.00 g of an aqueous solution (adjusted to pH 2-3 with concentrated hydrochloric acid) of 10 wt% aluminum nitrate was added dropwise into the three-mouth flask;

this mixture was stirred for 1 h at room temperature, and 1.29 g of solid copper nitrate trihydrate was added therein; and

stirring was further performed for 30 min at room temperature to obtain a blue clear transparent coating composition.

Comparative example 4

A product Novec™ 1720 commercially available from 3M was used as a coating composition and denoted as Comparative example 4.

Table 2. Formulae of coating compositions

Note: ⁽¹⁾ in Example 4, a ratio by weight of tetraethyl orthosilicate to tetramethyl orthosilicate is 6:4.

Preparation and performance test of coated articles

Example 7

A coated article was prepared by a blade coating method, including steps as follows:

a vitrified tile (200 mm 200 mm 10 mm) was used as a substrate of the coated article. A surface of the vitrified tile was first cleaned with a cleanser essence (brand White Cat, commercially available from Shanghai Hutchison White Cat Co., Ltd.), subsequently rinsed with deionized water, and then blown dry with compressed air;

10 g of the coating composition obtained from Example 1 was filtered twice through a 200-mesh filter screen;

a coil bar of an automatic blade coater (K303 Multicoater, commercially available from RK Print Coat Instruments Corporation) was placed on one end of the vitrified tile, and 5 g of the coating composition filtered off was dropped uniformly with a dropper into a gap between the coil bar and the vitrified tile; at room temperature, the coating composition was blade coated with the automatic blade coater on the surface of the vitrified tile;

in the blade coating process, the wet-film thickness of the coating composition was about 12 μτη, which was denoted as T-12, as shown in Table 3; and

after the blade coated vitrified tile was heated and dried for 3 h in an 80°C oven, it was taken out and cooled to room temperature to obtain the coated article.

The easy-cleaning performance, antimicrobial performance, abrasion resistance, salt-fog resistance and high-temperature and high-humidity resistance of the coated article obtained were tested, and test results are listed in Table 3.

Example 8

A coated article was prepared by the same method as Example 7; the substrate type of the coated article, blade coating conditions and thermal treatment conditions are listed in Table 3. As shown in Table 3, if the wet-film thickness in the blade coating process is 1.5 um, it is denoted as T- 1.5; if the wet-film thickness of the coating composition in the blade coating process is 3 um, it is denoted as T-3; if the wet-film thickness of the coating composition in the blade coating process is 6 um, it is denoted as T-6; and if the wet-film thickness of the coating composition in the blade coating process is 12 um, it is denoted as T-12.

The easy-cleaning performance, antimicrobial performance, abrasion resistance, salt-fog resistance, and high -temperature and high-humidity resistance of the coated article obtained were tested; and the test results are listed in Table 3. Example 9

A coated article was prepared by a dip coating method, including steps as follows:

glass (180 mm 100 mm 3 mm) was used as a substrate of the coated article. A surface of the glass was first cleaned with a cleanser essence (brand White Cat, commercially available from Shanghai Hutchison White Cat Co., Ltd.), subsequently rinsed with deionized water, and then blown dry with compressed air;

200 g of the coating composition obtained from Example 3 was poured into a 400-mL stainless steel tank (150 mm χ 150 mm χ 20 mm);

at room temperature, an automatic dip coater (SKVDX2S-500, commercially available from KSV NIMA Corporation) subjected the glass to dip coating in the coating composition;

in the dip coating process, the dip speed was 300 mm/min, the dip time was 1 min, and the pull speed was 300 mm/min, with details listed in Table 3; and

after the dip coated glass was heated and dried for 1 h in a 100°C oven, it was taken out and cooled to room temperature to obtain the coated article.

The easy-cleaning performance, antimicrobial performance, abrasion resistance, salt-fog resistance, and high -temperature and high-humidity resistance of the coated article obtained were tested; and the test results are listed in Table 3. Examples 10 to 11

Coated articles were prepared by the same method as Example 9; the substrate types of the coated articles, blade coating conditions and thermal treatment conditions are listed in Table 3.

The easy-cleaning performance, antimicrobial performance, abrasion resistance, salt-fog resistance, and high-temperature and high-humidity resistance of the coated articles obtained were tested; and the test results are listed in Table 3.

Example 12

A coated article was prepared by wipe coating, including steps as follows:

439 stainless steel (100 mm 50 mm 1 mm) was used as a substrate of the coated article. A surface of the 439 stainless steel was first cleaned with a cleanser essence (brand White Cat, commercially available from Shanghai Hutchison White Cat Co., Ltd.), subsequently rinsed with deionized water, and then blown dry with compressed air;

a spunbonded polypropylene nonwoven cloth commercially available from 3M Corporation was clipped into 50 mm χ 20 mm strips. 6 g of the coating composition obtained from Example 6 was drawn by a dropper, 3 g of which was then dropped onto one end of the 439 stainless steel and the other 3 g was dropped onto the middle of the 304 stainless steel. The nonwoven cloth was pressed by hand to perform uniform coating from one end with the coating composition to the other end without the coating composition on the 439 stainless steel; and

after the wipe coated 439 stainless steel was heated and dried for 5 min in a 180°C oven, it was taken out and cooled to room temperature to obtain the coated article.

The easy-cleaning performance, antimicrobial performance, abrasion resistance, salt-fog resistance, and high -temperature and high-humidity resistance of the coated article obtained were tested; and the test results are listed in Table 3. Comparative examples 5 to 8

Coated articles were prepared by the same method as Example 9 to serve as Comparative examples 5 to 8; the substrate types of the coated articles, dip coating conditions and thermal treatment conditions are listed in Table 3.

The easy-cleaning performance, antimicrobial performance, abrasion resistance, salt-fog resistance, and high -temperature and high-humidity resistance of the coated articles obtained were tested; and the test results are listed in Table 3.

Table 3. Preparation and performance test of coated articles

As can be seen from Table 3, the averaged water contact angles obtained by measurement on the surfaces of the coated articles provided according to Examples 7 to 12 are all greater than 110°; and at the same time the averaged hexadecane contact angles are all greater than 60°; these coated articles therefore had good easy-cleaning performance. The averaged antimicrobial ratios obtained by measurement on the surfaces of the coated articles provided according to Examples 7 to 12 are all greater than 99%, and thus these coated articles had good antimicrobial performance. After the wet grinding test, the salt-fog test, and the high-temperature and high-humidity test, losses in the water contact angle and in the hexadecane contact angle obtained by measurement on the surfaces of the coated articles provided according to Examples 7 to 12, as compared with those before the tests, are both less than or equal to 10%, and thus these coated articles exhibited very durable, easy-cleaning performance. After the wet grinding test, the salt-fog test, and the high-temperature and high-humidity test, the antimicrobial ratios obtained by measurement on the surfaces of the coated articles provided according to Examples 7 to 12 are still greater than or equal to 90%, and thus these coated articles exhibit quite durable antimicrobial performance.

Although the above particular embodiments comprise a great many concrete details for the purpose of illustration through examples, it is to be understand by those of ordinary skill in the art that, many variations, modifications, replacements and changes to these details shall all fall within the scope of the present invention as claimed in the claims. Therefore, the disclosure as described in the particular embodiments does not pose any limitation to the present invention as claimed in the claims. The proper scope of the present invention should be defined by the claims and proper legal equivalents thereof. All references referred to are incorporated herein by reference in their entireties.