A kind of baking-free anti-fingerprint coating and preparation method thereof

Abstract

The present invention belongs to the field of fluorine chemical technology, and specifically relates to a baking-free anti-fingerprint coating and a preparation method thereof. A baking-free anti-fingerprint coating is prepared by diluting, coating and drying a mother liquor, and the mother liquor is made of the following components: fluorine-containing silicone, coupling agent, catalyst, lubricant, solvent; wherein the mass of fluorine silicone is 20% of the total mass of the mother liquor, the mass ratio of fluorine silicone, coupling agent and lubricant is 1:0.3-0.8:1, the content of the catalyst in the mother liquor is 300-1000ppm, and the remainder is solvent. The present invention introduces a coupling agent and a catalyst so that the fluorine-containing silicone can cross-link with the substrate at room temperature, so that the fluorine-containing group is close to the surface of the substrate so that the substrate presents a hydrophobic and oleophobic effect, and the use of a lubricant makes the surface of the substrate more smooth. At the same time, the preparation method provided by the present invention also has the advantages of simplicity, low energy consumption, and green environmental protection.

Description

Technical Field

[0001] The invention belongs to the technical field of fluorine chemical industry, and particularly relates to a baking-free anti-fingerprint coating and a preparation method thereof. Background Art

[0002] Anti-fingerprint coatings are widely used in mobile phone cover glass, tempered films and other electronic products because of their unique hydrophobic, oleophobic and self-cleaning properties. The main structure of existing anti-fingerprint coatings is mainly fluorinated silicone. In order to fully demonstrate its performance, high temperature and long-term heating methods have to be adopted in the coating process, and the material of the substrate is restricted. This limits the application field of the coating and increases time and energy costs.

[0003] Therefore, there is an urgent need to develop a new coating that allows fluorinated silicone to exert its effectiveness at room temperature, eliminating the need for heating, achieving "zero waiting", "zero energy consumption" and making the carrier surface smooth and feel better. Summary of the invention

[0004] In view of the problems and shortcomings in the prior art, the object of the present invention is to provide a baking-free anti-fingerprint coating and a preparation method thereof.

[0005] Based on the above purpose, the present invention adopts the following technical solution:

[0006] The invention provides a baking-free anti-fingerprint coating, which is prepared by diluting, coating and drying a mother liquid, wherein the mother liquid is prepared by the following components: fluorinated silicone, a coupling agent, a catalyst, a lubricant and a solvent; the mass of the fluorinated silicone is 20% of the total mass of the mother liquid, the mass ratio of the fluorinated silicone, the coupling agent and the lubricant is 1:0.3-0.8:1, the content of the catalyst in the mother liquid is 300-1000ppm, and the balance is the solvent.

[0007] Preferably, the catalyst is one or more of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, formic acid, acetic acid, and boric acid.

[0008] Preferably, the lubricant is one or more of perfluoropolyether methyl ester, allyl perfluoropolyether, perfluoropolyether oil, and dimethyl silicone oil; the structural formula of the allyl perfluoropolyether is:

[0009] , wherein n is an integer from 4 to 7.

[0010] More preferably, the lubricant is perfluoropolyether oil.

[0011] Preferably, the fluorinated silicone is a fluorinated silicone with an ether bond or an amide bond as a spacer and with multiple methoxy or ethoxy hydrolyzed groups at the end; the fluorinated silicone is preferably a perfluoropolyether silicone with a molecular weight of 800 to 2000.

[0012] The structural formula of the fluorinated siloxane is as follows:

[0013] (a),

[0014] (b),

[0015] Here, n is an integer ≥4.

[0016] Preferably, the coupling agent is one or more of ethyl orthosilicate, trimethoxysilane, triethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, methoxytrimethylsilane, and dimethyldimethoxysilane.

[0017] More preferably, the coupling agent is one or more of tetraethyl orthosilicate, trimethoxysilane and triethoxysilane.

[0018] Preferably, the solvent is one or more of trifluorotrichloroethane, hexafluoroisopropanol, hexafluoropropylene dimer, hexafluoropropylene trimer, perfluorobutyl methyl ether, perfluorobutyl ethyl ether, and perfluorocyclic ether.

[0019] More preferably, the solvent is hexafluoroisopropanol.

[0020] Preferably, the diluent used in the dilution process is one or more of trifluorotrichloroethane, hexafluoropropylene dimer, hexafluoropropylene trimer, perfluorobutyl methyl ether, perfluorobutyl ethyl ether, and perfluorocyclic ether.

[0021] More preferably, the diluent is hexafluoropropylene dimer.

[0022] The present invention also provides a method for preparing the above-mentioned baking-free anti-fingerprint coating, comprising the following steps:

[0023] S1: uniformly mixing fluorinated siloxane, coupling agent, catalyst, lubricant and solvent to obtain a mother solution;

[0024] S2: diluting the mother liquid with a diluent to obtain a coating liquid, applying the coating liquid to the surface of the substrate by immersion or spraying, and waiting for the surface of the substrate to dry to obtain the baking-free anti-fingerprint coating.

[0025] Preferably, the mass fraction of the mother liquid in the coating liquid in step S2 is 0.2wt% to 0.4wt%.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The present invention introduces a coupling agent and a catalyst. When moisture in the air is present, the coupling agent and the fluorinated silicone rapidly capture moisture in the air under the catalysis of the catalyst to form silanol, which then undergoes dehydration condensation with the silanol on the surface of the substrate, so that the fluorinated silicone can undergo a cross-linking reaction with the substrate at room temperature. The fluorinated groups are closely attached to the surface of the substrate, making the substrate hydrophobic and oleophobic. The use of a lubricant makes the surface of the substrate more slippery.

[0028] (2) The present invention adopts a fluorinated siloxane with a hydrolyzable group at the end as a perfluoropolyether siloxane with multiple hydrolyzable groups at the end. The more hydrolyzable groups the perfluoropolyether siloxane contains at the end, the more firmly the fluorinated chain segment is connected to the substrate, and the higher the durability of the coating.

[0029] (3) The preparation method provided by the present invention also has the advantages of being simple, efficient, low energy consumption, pollution-free, and environmentally friendly. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail by way of embodiments below. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] Example 1

[0032] A non-baking anti-fingerprint coating is made of the following raw materials, and the amount of each substance is as follows:

[0033] Fluorosiloxane: 20 g Fluorosiloxane with ether bond as spacer and molecular weight of 1400, having the structure shown in formula (a):

[0034]

[0035] Where n is 6

[0036] Coupling agent: 10g tetraethyl orthosilicate

[0037] Catalyst: 300ppm sulfuric acid

[0038] Lubricant: 20g allyl perfluoropolyether with a molecular weight of 800

[0039] Solvent: 50g perfluorobutyl methyl ether

[0040] Diluent: 50g trichlorotrifluoroethane.

[0041] The preparation steps are as follows:

[0042] S1: 20 g of fluorinated siloxane with an ether bond as a spacer group and a molecular weight of 1400, 10 g of tetraethyl orthosilicate, 20 g of allyl perfluoropolyether with a molecular weight of 800, and 50 g of perfluorobutyl methyl ether were respectively placed in a 100 ml PP bottle, shaken to mix evenly, and then 300 ppm of sulfuric acid was added to the PP bottle to obtain a mother solution;

[0043] S2: Take 0.2g of the mother liquid in a 100ml PP bottle, add 50g of trifluorotrichloroethane, shake and mix evenly to obtain a coating liquid, take a biological glass substrate and put it in the bottle so that the coating liquid covers the glass substrate, take out the glass substrate, and the glass substrate will dry within 10S to obtain a baking-free anti-fingerprint coating.

[0044] Example 2

[0045] A non-baking anti-fingerprint coating is made of the following raw materials, and the amount of each substance is as follows:

[0046] Fluorosiloxane: 20 g Fluorosiloxane with an amide bond as a spacer and a molecular weight of 1700, having a structure as shown in formula (b):

[0047]

[0048] Where n is 8

[0049] Coupling agent: 10g trimethoxysilane

[0050] Catalyst: 300ppm concentrated hydrochloric acid

[0051] Lubricant: 20g perfluoropolyether oil with a molecular weight of 800

[0052] Solvent: 50g hexafluoroisopropanol

[0053] Diluent: 50g perfluorobutyl methyl ether.

[0054] The preparation steps are the same as those in Example 1.

[0055] Example 3

[0056] A non-baking anti-fingerprint coating is made of the following raw materials, and the amount of each substance is as follows:

[0057] Fluorosiloxane: 20 g Fluorosiloxane with a molecular weight of 800 and an ether bond as a spacer group, having a structure as shown in formula (a):

[0058]

[0059] Where n is 3

[0060] Coupling agent: 10g triethoxysilane

[0061] Catalyst: 300ppm formic acid

[0062] Lubricant: 20g perfluoropolyether methyl ester with a molecular weight of 1600

[0063] Solvent: 50g hexafluoropropylene dimer

[0064] Diluent: 20g trifluorotrichloroethane and 30g hexafluoropropylene trimer.

[0065] The preparation steps are as follows:

[0066] S1: 20 g of fluorinated siloxane with an ether bond as a spacer group and a molecular weight of 800, 10 g of triethoxysilane, 20 g of perfluoropolyether methyl ester with a molecular weight of 1600, and 50 g of hexafluoropropylene dimer were placed in a 100 ml PP bottle, shaken to mix evenly, and then 300 ppm of formic acid was added to the PP bottle to obtain a mother solution;

[0067] S2: Take 0.2g of the mother liquid in a 100ml PP bottle, add 20g of trifluorotrichloroethane and 30g of hexafluoropropylene trimer, shake and mix evenly to obtain a coating liquid, take a biological glass substrate and put it in the bottle so that the coating liquid covers the glass substrate, take out the glass substrate, and the glass substrate will dry within 10S to obtain a baking-free anti-fingerprint coating.

[0068] Example 4

[0069] A non-baking anti-fingerprint coating is made of the following raw materials, and the amount of each substance is as follows:

[0070] Fluorosilicone: 20 g Fluorosilicone with a molecular weight of 1700 and an ether bond as a spacer group, having a structure as shown in formula (a):

[0071]

[0072] Where n is 8

[0073] Coupling agent: 6.7g triethoxysilane

[0074] Catalyst: 300ppm sulfuric acid

[0075] Lubricant: 20g perfluoropolyether oil with a molecular weight of 800

[0076] Solvent: 53.3g hexafluoroisopropanol

[0077] Diluent: 50g perfluorobutyl methyl ether.

[0078] The preparation steps are the same as those in Example 1.

[0079] Example 5

[0080] A non-baking anti-fingerprint coating is made of the following raw materials, and the amount of each substance is as follows:

[0081] Fluorosiloxane: 20 g Fluorosiloxane with ether bond as spacer and molecular weight of 1700, having the structure shown in formula (a):

[0082]

[0083] Where n is 8

[0084] Coupling agent: 16g triethoxysilane

[0085] Catalyst: 400ppm sulfuric acid

[0086] Lubricant: 20g perfluoropolyether oil with a molecular weight of 800

[0087] Solvent: 44g trichlorotrifluoroethane

[0088] Diluent: 50g perfluorobutyl methyl ether.

[0089] The preparation steps are the same as those in Example 1.

[0090] Example 6

[0091] A non-baking anti-fingerprint coating is made of the following raw materials, and the amount of each substance is as follows:

[0092] Fluorosiloxane: 20 g Fluorosiloxane with ether bond as spacer and molecular weight of 1700, having the structure shown in formula (a):

[0093]

[0094] Where n is 8

[0095] Coupling agent: 10g trimethoxysilane

[0096] Catalyst: 1000ppm nitric acid

[0097] Lubricant: 20g perfluoropolyether methyl ester with a molecular weight of 1400

[0098] Solvent: 50g trichlorotrifluoroethane

[0099] Diluent: 50g perfluorocyclic ether.

[0100] The preparation steps are the same as those in Example 1.

[0101] Example 7

[0102] A non-baking anti-fingerprint coating is made of the following raw materials, and the amount of each substance is as follows:

[0103] Fluorosiloxane: 20 g Fluorosiloxane with an amide bond as a spacer and a molecular weight of 1700, having a structure as shown in formula (b):

[0104]

[0105] Where n is 8

[0106] Coupling agent: 10g vinyltrimethoxysilane

[0107] Catalyst: 600ppm nitric acid

[0108] Lubricant: 20g perfluoropolyether methyl ester with a molecular weight of 1400

[0109] Solvent: 50g trichlorotrifluoroethane

[0110] Diluent: 20g perfluorocyclic ether and 30g perfluorobutyl methyl ether.

[0111] The preparation steps are as follows:

[0112] S1: 20 g of 1700 molecular weight amide bond spacer fluorinated siloxane, 10 g of vinyl trimethoxy silane, 20 g of 1400 molecular weight perfluoropolyether methyl ester, and 50 g of trichlorotrifluoroethane were placed in a 100 ml PP bottle, shaken to mix evenly, and then 600 ppm of nitric acid was added to the PP bottle to obtain a mother solution;

[0113] S2: Take 0.1g of the mother liquid in a 100ml PP bottle, add 20g of perfluorocyclic ether and 30g of perfluorobutyl methyl ether, shake and mix evenly to obtain a coating liquid, take a biological glass substrate and put it in the bottle so that the coating liquid covers the glass substrate, take out the glass substrate, and the glass substrate can be dried within 10S to obtain a baking-free anti-fingerprint coating.

[0114] Example 8

[0115] A non-baking anti-fingerprint coating is made of the following raw materials, and the amount of each substance is as follows:

[0116] Fluorosiloxane: 20 g Fluorosiloxane with an amide bond as a spacer and a molecular weight of 1700, having a structure as shown in formula (b):

[0117]

[0118] Where n is 8

[0119] Coupling agent: 10g vinyltrimethoxysilane

[0120] Catalyst: 400ppm nitric acid

[0121] Lubricant: 20g allyl perfluoropolyether with a molecular weight of 1400

[0122] Solvent: 50g perfluorocyclic ether

[0123] Diluent: 20g perfluorocyclic ether and 30g perfluorobutyl methyl ether.

[0124] The preparation steps are basically the same as those in Example 7, except that in step S2, 0.15 g of the mother liquor is taken out and dissolved in a diluent.

[0125] Comparative Example 1

[0126] An anti-fingerprint coating is made of the following raw materials, and the amount of each substance is as follows:

[0127] Fluorosiloxane: 20 g Fluorosiloxane with an amide bond as a spacer and a molecular weight of 1500, having a structure as shown in formula (b):

[0128]

[0129] Where n is 7

[0130] Coupling agent: 10g trimethoxysilane

[0131] Catalyst: No addition

[0132] Lubricant: 20g allyl perfluoropolyether with a molecular weight of 1400

[0133] Solvent: 50g hexafluoroisopropanol

[0134] Diluent: 20g perfluorocyclic ether and 30g perfluorobutyl methyl ether.

[0135] The preparation steps are basically the same as those in Example 3, except that no catalyst is added to the mother liquor.

[0136] For the anti-fingerprint coating prepared in Comparative Example 1, when no catalyst is added to the mother solution, the anti-fingerprint coating cannot be cross-linked with the substrate in a short time at room temperature, and then no hydrophobic angle appears on the surface of the substrate.

[0137] Comparative Example 2

[0138] An anti-fingerprint coating is made of the following raw materials, and the amount of each substance is as follows:

[0139] Fluorosiloxane: 20 g Fluorosiloxane with a molecular weight of 1500 and an ether bond as a spacer group, having a structure as shown in formula (a):

[0140]

[0141] Where n is 7

[0142] Coupling agent: 14g trimethoxysilane

[0143] Catalyst: 800ppm formic acid

[0144] Lubricant: No addition

[0145] Solvent: 66g hexafluoroisopropanol

[0146] Diluent: 20g hexafluoropropylene dimer and 30g perfluorobutyl methyl ether.

[0147] The preparation steps are basically the same as those in Example 7, except that no lubricant is added to the mother liquor, and in step S2, 0.15 g of the mother liquor is taken out and added to the diluent.

[0148] For the anti-fingerprint coating prepared in Comparative Example 2, when no lubricant is added to the mother liquid, the surface of the coating formed after the anti-fingerprint coating is catalytically cured by the catalyst is rough and has a large dynamic friction coefficient. If this layer is applied to a touch screen, the feel is extremely poor.

[0149] Comparative Example 3

[0150] An anti-fingerprint coating is made of the following raw materials, and the amount of each substance is as follows:

[0151] Fluorosiloxane: 20 g Fluorosiloxane with an amide bond as a spacer and a molecular weight of 1700, having a structure as shown in formula (b):

[0152]

[0153] Where n is 8

[0154] Coupling agent: No addition

[0155] Catalyst: 400ppm sulfuric acid

[0156] Lubricant: 20g allyl perfluoropolyether with a molecular weight of 1400

[0157] Solvent: 60g hexafluoroisopropanol

[0158] Diluent: 20g perfluorocyclic ether and 30g perfluorobutyl methyl ether.

[0159] The preparation steps are basically the same as those in Example 3, except that no coupling agent is added to the mother liquor.

[0160] For the anti-fingerprint coating prepared in Comparative Example 3, when no coupling agent is added to the mother solution, the anti-fingerprint coating cannot be cross-linked with the substrate in a short time at room temperature, and then no hydrophobic angle appears on the surface of the substrate.

[0161] The baking-free anti-fingerprint coatings prepared in Examples 1 to 8 and the anti-fingerprint coating samples prepared in Comparative Examples 1 to 3 were tested, and the test data results are shown in Table 1.

[0162] Table 1 Anti-fingerprint coating test data table

[0163]

[0164] It can be seen from Example 3 that if the molecular weight of the fluorinated silicone is too low, even in the presence of a coupling agent and a catalyst, the contact angle of the formed coating will not be higher than 110°. Therefore, the fluorinated silicone should have a molecular weight greater than 800. It can be seen from Comparative Examples 1 and 3 that the fluorinated silicone cannot be cured at room temperature to form a hydrophobic coating without adding a catalyst or a coupling agent. It can be seen from Comparative Example 2 that the surface of the sample prepared without adding a lubricant to the coating is rough and has a very poor feel. Therefore, catalysts, coupling agents, and lubricants are indispensable.

Claims

1. A non-baking anti-fingerprint coating, characterized in that: The mother liquor is prepared by diluting, coating and drying, and the mother liquor is made of the following components: fluorinated silicone, coupling agent, catalyst, lubricant and solvent; the mass of the fluorinated silicone is 20% of the total mass of the mother liquor, the mass ratio of the fluorinated silicone, coupling agent and lubricant is 1:0.3-0.8:1, the content of the catalyst in the mother liquor is 300-1000ppm, and the balance is solvent; the catalyst is one or more of sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, formic acid, acetic acid and boric acid; the lubricant is one or more of perfluoropolyether methyl ester, allyl perfluoropolyether, perfluoropolyether oil and dimethyl silicone oil; the structural formula of the fluorinated silicone is formula (a) or formula (b): （a）， (b）， Wherein, n is an integer ≥4; the molecular weight of the fluorinated siloxane is 800-2000; the coupling agent is one or more of tetraethyl orthosilicate, trimethoxysilane, triethoxysilane, vinyltrichlorosilane, vinyltrimethoxysilane, methoxytrimethylsilane, and dimethyldimethoxysilane; the solvent is one or more of trifluorotrichloroethane, hexafluoroisopropanol, hexafluoropropylene dimer, hexafluoropropylene trimer, perfluorobutyl methyl ether, perfluorobutyl ethyl ether, and perfluorocyclic ether.

2. The baking-free anti-fingerprint coating according to claim 1, characterized in that: The allyl perfluoropolyether structural formula is: , wherein n is an integer from 4 to 7.

3. The baking-free anti-fingerprint coating according to claim 1, characterized in that: The diluent used in the dilution process is one or more of trifluorotrichloroethane, hexafluoropropylene dimer, hexafluoropropylene trimer, perfluorobutyl methyl ether, perfluorobutyl ethyl ether, and perfluorocyclic ether.

4. The method for preparing the baking-free anti-fingerprint coating according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: uniformly mixing fluorinated siloxane, coupling agent, catalyst, lubricant and solvent to obtain a mother solution; S2: diluting the mother liquid with a diluent to obtain a coating liquid, applying the coating liquid to the surface of the substrate by immersion or spraying, and waiting for the surface of the substrate to dry to obtain the baking-free anti-fingerprint coating.

5. The method for preparing the baking-free anti-fingerprint coating according to claim 4, characterized in that: In the step S2, the mass fraction of the mother liquid in the coating liquid is 0.2wt% to 0.4wt%.

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