WO2019233471A1

WO2019233471A1 - Water repellent coating

Info

Publication number: WO2019233471A1
Application number: PCT/CN2019/090292
Authority: WO
Inventors: Qi Chen; Weiwei XUN; Shun RUI
Original assignee: Ppg Coatings (Tianjin) Co., Ltd.
Priority date: 2018-06-06
Filing date: 2019-06-06
Publication date: 2019-12-12
Also published as: TW202000802A; CN108864783A

Abstract

Provided is an UV-moisture dual-curing, water repellent coating composition comprising an acrylate monomer, an isocyanate (meth) acrylate, a fluorine-containing acrylate additive and a solvent. Further provided are a method of coating a substrate comprising with the UV-moisture dual-curing, water repellent coating composition, and the substrate therewith.

Description

WATER REPELLENT COATING

FIELD OF INVENTION

The present invention relates to a dual-curing water repellent coating composition, especially to an UV-moisture dual-curing, water repellent coating composition. The present invention further relates to a method of coating a substrate with the coating composition, and a substrate coated with the coating composition.

BACKGROUND OF INVENTION

Electronic products falling into water without any protection will normally become scrapped, causing losses to users. In order to avoid this loss, it is necessary to impart IPX6 or above water repellent function to electronic products, which is usually realized via the technology of electronic water repellent coating.

Generally, there are two types of electronic water repellent coating technologies:

One is to form coating via vapor deposition technology, e.g., Parylene from HZO and PECVD using fluorine-containing acrylates from P2i. A disadvantage of this type of technology is that the use of vapor deposition results in high equipment and process costs and low yield.

The other one is to selectively applying a solvent-borne water repellent coating with masking techniques, where the coating can be applied through dip coating, spraying, brushing, and the like. This type of technology is widely used because of low cost and high yield. However, with the trend of miniaturization of electronic devices, the structures of electronic components are becoming more and more sophisticated. When selectively applying coating compositions to protect certain areas/components, other areas or components must be masked. This process of masking and demasking usually decreases production efficiency in a great manner.

In order to increase production efficiency, precise dispensing process is chosen to replace the masking techniques. When employing the dispensing process, the viscosity of the coating composition is a crucial factor influencing the speed of the precise dispensing. If the viscosity is too high, the dispensing speed will be lowered, which will slower the running of the dispensing equipment. If the viscosity is too low, the coating will continue to flow after being applied to the desired areas/components, affecting other areas/components.

The object of the present invention is to develop a dual-curing water repellent coating composition with suitable viscosity for use in a precise dispensing equipment to realize rapid and selective coating.

Another object of the present invention is to improve the water repellency of a coating formed from a dual-curing coating composition with the addition of a fluorine-containing additive.

SUMMARY OF INVENTION

In one aspect, the present invention provides a coating composition comprising about 20-60 wt%of an acrylate monomer, about 20-60 wt%of an isocyanate (meth) acrylate, about 0.5-5 wt%of a fluorine-containing acrylate additive and about 10-30 wt%of a solvent, based on the total weight of the coating composition.

In another aspect, the present invention provides a method of coating a substrate comprising applying the coating composition to a substrate by a dispensing process.

In still another aspect, the present invention provides a coated substrate comprising a substrate; and a coating applied onto at least a portion of the substrate, the coating being formed from the coating composition comprising about 20-60 wt%of an acrylate monomer, about 20-60 wt%of an isocyanate (meth) acrylate, about 0.5-5 wt%of a fluorine-containing acrylate additive and about 10-30 wt%of a solvent, based on the total weight of the coating composition.

DRAWINGS

Figure 1 shows a schematic graph of the dispensing areas (shaded) on a substrate.

DETAILED DESCRIPTION

For the purpose of the detailed description as below, it is understood that the present invention may be carried out with various alternations/modifications and step orders, unless clearly indicated to the contrary. Moreover, unless in any operational example or otherwise specified, all numbers representing, e.g., the amount of an ingredient as used in the description and claims should be understood as being modified with the term “about” in any case. Thus, unless noted to be in the contrary, any numerical parameter as described in the following description and the accompanied claims refers to an approximate value varied depending on the desired properties in accordance with the present invention. At the least, it is not intended to limit the application of Doctrine of Equivalents within the scope of claims, and each and every numerical value should be understood in accordance with the number of significant digits as reported by applying ordinary rounding techniques.

Although the numerical ranges and parameters describing a wide range of the present invention involve approximate values, the values as listed in the particular examples are reported as precisely as possible. However, any value contains inherently certain errors resulting necessarily from the standard deviation as found in their respective measurements.

Moreover, it is understood that any numerical range as recited herein is intended to encompass any subrange as included therein. For instance, the range of “1 to 10” is intended to encompass all the subranges between the minimum value of 1 and the maximum value of 10 (inclusive) , that is, such range has a minimum value of 1 or greater and a maximum value of 10 or less.

In the present application, unless otherwise stated, the use of the singular includes the plural, and the plural includes the singular. Moreover, in the present application, unless otherwise stated, the word “or” is intended to mean “and/or” , even if in some cases a phrase “and/or” is literally used. Moreover, in the present application, unless otherwise stated, the word “a” and “an” is used to represent “at least a” . For instance, “a” polymer, “a” coating composition, and the like refers to one or more of any of these items.

In one aspect of the present invention, provided is an UV-moisture dual-curing water repellent coating composition for electronics. The coating composition comprises an acrylate monomer, an isocyanate (meth) acrylate, a fluorine-containing acrylate additive, and a solvent.

The coating composition according to the present invention can be applied to electronics substrates (comprising e.g., metal, plastic and/or glass) via dispersing techniques. As used herein, the term “dispersing” refers to a coating means by which a substrate is selectively coated on certain areas. It is necessary that the composition for use in dispensing techniques has a suitable viscosity. That is to say, the composition product will not block the dispensing equipment or limit the running speed of the equipment on the one hand, and will have adequate flowability but will not flow to undesired areas on the other hand. The coating composition of the present invention may have a viscosity of 15-100 cP, as measured by a DV-C Rotor Viscometer from Brookfield at temperature of 25℃.

As used herein, the term “UV-moisture dual curing” means that the coating composition can be cured by UV radiation followed by moisture curing at room temperature. The moisture curing can function as a complement to the UV curing, which makes that the coating can be fully cured on the areas where UV curing is not sufficient or absent (e.g., due to the restrict of radiation arrangement) .

As used herein, the term "water repellent coating" refers to a coating composition that forms a coating film with hydrophobic property and water permeation resistance after curing. According to the internationally established IEC529 standard, the water repellence of a coating can be scored into 10 grades, with the increasing water repellent performance of IPX0, IPX1, IPX2 ..., and IPX9. Electronic products generally require a water repellence of IPX6 or above, that is, water projected against the enclosure from any direction does not enter the interior of an electronic product. The coating composition according to the present invention forms on a substrate (comprising e.g., metal, plastic, glass, etc. ) a coating having a water repellence of at least IPX6, such as IPX7.

The coating composition according to the present invention may be an environmentally friendly low VOC coating composition. As used herein, the term “VOC (volatile organic compound) ” refers to any organic compound having a boiling point less than or equal to 250℃ (482°F) measured at a standard atmospheric pressure of 101.3 kPa. The term “low VOC” refers to a coating composition having a VOC content of less than 420 g/L (23℃, 101.3 kPa) . The coating composition according to the present invention has a VOC content of less than 420 g/L (calculated without water) .

The acrylate monomer as used in the coating composition of the present invention can comprise any acrylate monomer suitable for use in the present invention, provided that it does not comprise isocyanato and/or fluoro groups. Suitably, the acrylate monomer has a carbon number of between 1 and 20, e.g., 4 to 10 carbon atoms. In some embodiments of the present invention, the acrylate monomer is a monofunctional (meth) acrylate. The monofunctional (meth) acrylate means one acrylate group in one monomer. Examples of the acrylate monomer that can be used in the coating composition of the present invention include but are not limited to methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, and any mixtures thereof.

In some embodiments of the present invention, the acrylate monomer as used in the present invention has urethane group (s) . Suitably, the average number ratio of the urethane groups to the acrylate groups per molecule is about less than 0.6.

Typically, the coating composition according to the present invention comprises at least about 20 wt%, suitably at least about 30 wt%, such as at least about 35 wt%, and up to about 60 wt%, suitably up to about 50 wt%, e.g., up to about 45 wt%of the acrylate monomer, based on the total weight of the coating composition. For example, the coating composition according to the present invention comprises 20-60 wt%, suitably 30-50 wt%, such as 35-45 wt%of the acrylate monomer, based on the total weight of the coating composition. When the amount of the acrylate monomer is less than 20 wt%, the flexibility of the coating formed from the coating composition is deteriorated. When the amount is more than 60 wt%, the coating formed from the coating composition has poor strength, thereby affecting the coating’s protective performance.

The isocyanate (meth) acrylate as used in the coating composition of the present invention can comprise any isocyanate (meth) acrylate suitable for use in the present invention. In some embodiments of the present invention, the isocyanate (meth) acrylate is a monoisocyanate (meth) acrylate prepared from a diisocyanate and a hydroxylalkyl (meth) acrylate monomer in a molar ratio of 1: 1. The monoisocyanate (meth) acrylate useful in the coating composition of the present invention can be either commercially available or prepared by techniques known in the art. The monoisocyanate (meth) acrylate useful in the coating composition of the present invention may be free of fluoro groups.

For example, monoisocyanate (meth) acrylate that can be used in the coating composition of the present invention is prepared from a diisocyanate and a hydroxylalkyl (meth) acrylate monomer. Useful diisocyanates include, but are not limited to, toluene diisocyanate (TDI) , ethyl diisocyanate, propyl diisocyanate, diphenylmethane diisocyanate (DMI) , 1, 5-naphthalene diisocyanate (NDI) , xylylene diisocyanate (XDI) , isophorone diisocyanate (IPDI) , hexamethylene diisocyanate (HDI) , hydrogenated DMI, hydrogenated XDI, oligomeric HDI (e.g., dimer, trimer, etc. ) , oligomeric IPDI (e.g., dimer, trimer, etc. ) , naphthalene diisocyanate, other oligomeric cyanate, and any combination thereof. Useful hydroxylalkyl (meth) acrylates include, but are not limited to, 2-hydroxyethyl acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl acrylate, 3-hydroxypropyl (meth) acrylate, and any combination thereof.

Further examples of monoisocyanate (meth) acrylates that can be used in the coating composition of the present invention can include, but are not limited to, isocyanate ethylacrylate and isocyanate ethyl methacrylate, commercially available from Karenz.

Typically, the coating composition according to the present invention comprises at least about 20 wt%, suitably at least about 30 wt%, such as at least about 35 wt%, and up to about 60 wt%, suitably up to about 50 wt%, e.g., up to about 45 wt%of the isocyanate (meth) acrylate, based on the total weight of the coating composition. For examples, the coating composition according to the present invention comprises 20-60 wt%, suitably 30-50 wt%, such as 35-45 wt%of the isocyanate (meth) acrylate, based on the total weight of the coating composition. When the amount of the isocyanate (meth) acrylate is less than 20 wt%, the water repellent property of the coating will be decreased. When the amount is more than 60 wt%, the coating formed from the coating composition has poor flexibility.

The coating composition of the present invention can comprise a photoinitiator. The photoinitiator can be cleaved to generate a free radical upon exposure to light (UV or visible radiation) , thereby initiating a photopolymerization reaction. Useful photoinitiators include, but are not limited to, benzoin derivatives, benzil ketal derivatives, dialkoxyacetophenones, α-hydroxyalkylphenones, α-aminoalkylphenones, acylphosphine hydrides, esterified oximinoketone compounds, aryl peroxyester compounds, halogenated methyl aromatic ketones, organic sulfur-containing compounds, benzoylformates or the like. Two or more different photoinitiators can be used as needed.

The amount of the photoinitiator can be about 1-10 wt%, e.g., about 3-6 wt%, based on the total weight of the coating composition.

Many commercially available photoinitiators are useful in the present invention. Examples of photoinitiators useful in the present invention include, but are not limited to, IRGACURE 184, 127, 2959, 500, TPO, 2100, 819, 907, 369, 1300, 651 and DAROCUR 1173, MBF, 4265, BP from BASF; JRCure BP from Jiu Ri Chemical., and any combination thereof.

The coating composition of the present invention can further comprise a moisture curing catalyst. The moisture curing catalyst can accelerate the reaction between an isocyanate group and a hydroxyl group and water in the air. Examples of moisture curing catalysts which can be used in the present invention include, but are not limited to, dibutyltin dilaurate, dioctyltin dilaurate, monobutyltin oxide, chloromonobutylstannic acid, dibutyltin acetate, maleic acid dibutyltin, stannous octoate, organic bismuth, and any combination thereof. The moisture-curing catalyst can be about 0.1-1 wt%by weight, e.g., 0.2-0.5 wt%, based on the total weight of the coating composition.

The fluorine-containing acrylate additive as used in the coating composition of the present invention can increase the hydrophobicity of the coating. The fluorine-containing acrylate additive useful in the coating composition of the present invention imparts a hydrophobic effect to the surface coated with the coating composition of the present invention and can be dissolved in a solvent such as an ester, an ether or a ketone solvent. The fluorine-containing acrylate additive useful in the present invention can include at least one of a fluorine-containing alkyl (meth) acrylate, a perfluoropolyether (meth) acrylate, and any combination thereof. The fluorine-containing acrylate additive used in the coating composition of the present invention may be free of isocyanato groups. Suitably, the fluorine-containing alkyl (meth) acrylate useful in the present invention can include perfluorobutyl ethyl (meth) acrylate, perfluorohexylethyl (meth) acrylate, perfluorooctyl ethyl (meth) acrylate, any combination thereof. For example, the perfluoropolyether (meth) acrylate useful in the present invention may include K-type, Y-type, M-type, D-type, Z-type perfluoropolyether acrylates.

Further examples of commercially available fluorine-containing acrylate additives for use in the present invention can include, but are not limited to, DCP-HP from Daikin; KY-1203 from Shin-Etsu; KS75, KS95 from DIC; Fluorolink AD1700, MD700 from Solvay, and any combination thereof.

The amount of the fluorine-containing acrylate additive can be about 0.1-5 wt%, such as about 0.5-2 wt%, based on the total weight of the coating composition.

The solvent used in the coating composition of the present invention can comprise a hydroxyl-free solvent such as ester solvent, ketone solvent or the like. The fluorine-containing acrylate additive decribed above is generally incompatible with the system of the present invention, which is a UV resin system. Thus, at the time of adding a fluorine-containing acrylate additive to improve the hydrophobic property of the UV system of the present invention, it is necessary to introduce the solvent. The solvent is intended to improve the compatibility of the fluorine-containing acrylate additive, influence the viscosity and the application properties of the coating. Suitable solvents include, but are not limited to, methyl acetate, ethyl acetate, butyl acetate, methyl ethyl ketone, and a mixture of any two or more of the foregoing. The amount of the solvent can be 10-30 wt%, such as 15-25 wt%, based on the total weight of the coating composition.

In some embodiments of the present invention, the weight ratio of the solvent to the fluorine-containing acrylate additive is about 8-30, suitably 10-20, such as 10-15.

The coating composition according to the present invention may have a viscosity of about 15-100 cP, such as 30-80 cP, as determined by a DV-C Rotor Viscometer from Brookfield at 25℃. Within this viscosity range, the coating composition can be applied with a precise, selective dispensing process without employing masking techniques, which increases production efficiency.

The coating compositions of the present invention can be applied to substrates of various electronic devices and components, including for example, metallic or non-metallic substrates. Metal substrates include, but are not limited to, tin, steel (including electrogalvanized steel, cold rolled steel, hot-dip galvanized steel, etc. ) , aluminum, aluminum alloy, zinc-aluminum alloy, zinc-aluminum coated steel and aluminized steel. Non-metallic substrates include glass, polymers, plastics, e.g., polyesters, polyolefins, polyamides, cellulose, polystyrene, polyacrylic acid, polyethylene naphthalate, polypropylene, polyethylene, nylon, EVOH, polylactic acid, other "green" polymer substrates, polyethylene terephthalate (PET) , polycarbonate, polycarbonate propylene butadiene styrene (PC/ABS) , polyamide, and the like.

The substrate can also include a metallized plastic substrate. As used herein, "metallized plastic substrate" refers to a substrate formed from both plastic and metal. For example, the metallized plastic substrate can comprise a plastic material comprising a metallic material incorporated into the plastic material and/or coated on at least a portion of the plastic material.

The coating composition is particularly useful when at least partially coated on a consumer electronic product. For example, the coating composition of the present invention can be applied to a mainboard of a smartphone, a tablet and a laptop, as well as other electronic components to provide water repellent protection. Based on the above, the present invention further provides electronic products or electronic components having a surface at least partially coated with the coating composition as described herein. It should be understood that the consumer electronic products can be formed from any of the foregoing materials, such as metallized plastic.

The coating composition of the present invention can be applied by various means such as spraying, dip coating, roller coating, brushing, dispensing, or the like, suitably precise dispensing. For example, referring to Figure 1, the coating composition of the present invention can be precisely applied on a substrate of 9 cm*6 cm via dispensing technique (in any shape or size) , and the shaded portions represent areas coated with the composition of the present invention by precise dispensing.

The coating composition of the present invention forms a coating after curing. When fully cured, the coating formed from the coating composition of the present invention can have a film thickness of about from 1 micron to 100 microns, or from 5 microns to 75 microns, or from 25 microns to 50 microns.

The following numbered clauses summarizes some aspects of the invention:

1. A coating composition comprising about 20-60 wt%of an acrylate monomer, about 20-60 wt%of an isocyanate (meth) acrylate, about 0.5-5 wt%of a fluorine-containing acrylate additive and about 10-30 wt%of a solvent, based on the total weight of the coating composition.

2. The coating composition according to clause 1, wherein the composition has a viscosity in the range of from 15 to 100 cP.

3. The coating composition according to clause 1 or 2, wherein the acrylate monomer comprises a monofunctional (meth) acrylate having 1 to 20 carbon atoms.

4. The coating composition according to clause 3, wherein the acrylate monomer comprises methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, and/or tetrahydrofurfuryl (meth) acrylate.

5. The coating composition according to any one of the preceding clauses, wherein the acrylate monomer contains urethane group (s) .

6. The coating composition according to any one of the preceding clauses, wherein the isocyanate (meth) acrylate is a monoisocyanate (meth) acrylate prepared from a diisocyanate and a hydroxylalkyl (meth) acrylate monomer in a molar ratio of 1: 1.

7. The coating composition according to clause 6, wherein the diisocyanate comprises toluene diisocyanate (TDI) , ethyl diisocyanate, propyl diisocyanate, diphenylmethane diisocyanate (DMI) , 1, 5-naphthalene diisocyanate (NDI) , xylylene diisocyanate (XDI) , isophorone diisocyanate (IPDI) , hexamethylene diisocyanate (HDI) , hydrogenated DMI, hydrogenated XDI, oligomeric HDI, oligomeric IPDI, and/or naphthalene diisocyanate.

8. The coating composition according to clause 6 or 7, wherein the hydroxylalkyl (meth) acrylate monomer comprises 2-hydroxyethyl acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl acrylate, and/or 3-hydroxypropyl (meth) acrylate.

9. The coating composition according to any one of the preceding clauses, wherein the fluorine-containing acrylate additive comprises fluorine-containing alkyl alcohol (meth) acrylate, and/or perfluoropolyether alcohol ester (meth) acrylate.

10. The coating composition according to any one of the preceding clauses, wherein the solvent comprises a hydroxyl-free ester solvent and/or ketone solvent.

11. The coating composition according to any one of the preceding clauses, wherein the weight ratio of the solvent to the fluorine-containing acrylate additive is about 8-30.

12. The coating composition according to any one of the preceding clauses, further comprising a moisture curing catalyst and a photoinitiator.

13. A method of coating a substrate comprising applying the coating composition according to any one of the preceding clauses to a substrate by a dispensing process.

14. The method according to clause 13, wherein the substrate comprises plastic substrates, metal substrates, and/or glass.

15. A coated substrate, comprising:

(a) a substrate;

(b) a coating applied onto at least a portion of the substrate, the coating being formed from the coating composition according to any one of the preceding clauses.

16. The coated substrate according to clause 15, wherein the substrate comprises plastic substrates, metal substrates, and/or glass.

17. The coated substrate according to clause 15 or 16, wherein the substrate has been coated using a method according to clause 13 or 14.

Example

The invention is further illustrated by the following examples, which are not to be construed as limiting the invention. All parts and percentages in the following examples and throughout the specification are by weight unless otherwise indicated.

I Preparation of the coating compositions

The coating compositions of the Examples 1-6 and of the Comparative Examples 1-4 were prepared in accordance with the components and their amount as listed in Tables 1 and 2.

Table 1. Examples of the coating compositions of the present invention

Table 2. Comparative Examples of the Coating Compositions

A. Isocyanate ethylacrylate from Karenz;

B. Butyl (meth) acrylate from Sigma-Aldrich;

C. Perfluorohexylethyl (meth) acrylate from Chemour;

D. Fluorolink AD1700 from Solvay;

E. α-Hydroxyalkylphenones from Sigma-Aldrich;

F. Dibutyltin dilaurate from Sigma-Aldrich;

G. Butyl acetate from Sigma-Aldrich.

II. Process of forming a coating

The different components of A-G were added sequentially into a 1L three-necked flask under the protection of nitrogen atmosphere, and well stirred to obtain the wet sample of the coating. Then, the wet sample of the coating was applied to the glass substrate via dispensing process, followed by UV curing for 1 minute (UV wavelength of 365 nm, UV energy of 800-1200 mJ/cm ²) . Afterwards, the glass substrate coated with the wet sample of the coating was left to stand in the air at room temperature for moisture curing for 2-3 days to obtain the coated substrate.

III. Performance tests

The following performance tests were conducted on the coating composition of the present invention, the comparative compositions, as well as the substrates coated with the coating composition of the Examples 1-6 and those coated with the coating composition of the Comparative Examples 1-4. The results are shown in Tables 3-4 below.

1. Compatibility test

The compatibility was evaluated by visual inspection of the coating composition for delamination or obvious droplets.

Excellent: completely clear and transparent;

Good: uniform, milky white, turbid, without delamination or droplets;

Poor: with delamination or obvious droplets;

-: not evaluated.

2. Viscosity

The viscosity was determined by a DV-C Rotor Viscometer from Brookfield at room temperature (e.g., 25℃) . A suitable rotor (such as, No. 3 rotor) was selected according to the viscosity of the sample to be tested, and the coating composition was poured into the test container until the conical surface of the rotor was completely inserted into the liquid. Then the motor was turned on with the speed set to 100 rpm and the drum adjusted to the centre, the data was recorded when stable. The average value of continuous two measurements were taken as the measured viscosity (the error does not exceed ± 5%of the average value) .

3. Flexibility of the coating

A mandrel having a diameter of 0.3 cm was placed on an iron plate coated with the coating compositions, which was bent 180 degrees in 1 second, and then observed under a 10x microscope for crack.

4. Hydrophobic property

The hydrophobic property of the coatings was evaluated by the static contact angle of water, which was measured using a contact angle measuring device from Bioscience Inc. One microliter of water was dropped to the surface of the coatings to determine the water drop angle. The larger the angle measured, the better the hydrophobic property.

5. Water repellent performance

Water repellence was evaluated by the water vapor transmission rate of the coatings. The coating was prepared into a 20 μm thick film and tested by a W3-031 water vapor transmission rate tester from Labthink with weight loss method. The test conditions were 38℃°and 90%relative humidity. The lower the water vapor transmission rate, the better the water repellent performance of the coatings.

6. Dispensing speed

The dispensing speed was evaluated by the time taken to complete the dispensing in the set areas (shaded portion) as shown in FIG. 1. The dispensing equipment used was from Nordson with the valve models of SC-280 and S400.

Table 3. Test results of the coating compositions of Examples 1-6

Table 4. Test results of the coating compositions of the Comparative Examples 1-4

It can be seen that the application efficiency, compatibility, water repellence and hydrophobic property as well as flexibility of the coating compositions of Examples 1-6 are all better than those of the Comparative Examples 1-4. The products of the Examples 1-6 have good compatibility and improved hydrophobicity by the addition of suitable fluorine-containing acrylate additives and specific solvents. At the same time, the specific combination of the resin system (i.e., the acrylate monomer and the isocyanate (meth) acrylate) and the fluorine-containing acrylate additive, together with the balance between the amounts of these components, imparts a suitable viscosity and excellent water repellence/resistance to the coating product.

The present invention has been described by means of embodiments. It is understood that those embodiments are intended to be illustrative, rather than limitative. In accordance with the above teachings, numerous modifications and variations may be made to the present invention. Thus, it is recognized that the present invention may be carried out within the scope as defined by the appended claims.

Claims

A coating composition comprising about 20-60 wt%of an acrylate monomer, about 20-60 wt%of an isocyanate (meth) acrylate, about 0.5-5 wt%of a fluorine-containing acrylate additive and about 10-30 wt%of a solvent, based on the total weight of the coating composition.
The coating composition according to claim 1, wherein the composition has a viscosity in the range of from 15 to 100 cP.
The coating composition according to claim 1 or 2, wherein the acrylate monomer comprises a monofunctional (meth) acrylate having 1 to 20 carbon atoms.
The coating composition according to claim 3, wherein the acrylate monomer comprises methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isobornyl (meth) acrylate, and/or tetrahydrofurfuryl (meth) acrylate.
The coating composition according to claim 1 or 2, wherein the acrylate monomer contains urethane group (s) .
The coating composition according to claim 1 or 2, wherein the isocyanate (meth) acrylate is a monoisocyanate (meth) acrylate prepared from a diisocyanate and a hydroxylalkyl (meth) acrylate monomer in a molar ratio of 1: 1.
The coating composition according to claim 6, wherein the diisocyanate comprises toluene diisocyanate (TDI) , ethyl diisocyanate, propyl diisocyanate, diphenylmethane diisocyanate (DMI) , 1, 5-naphthalene diisocyanate (NDI) , xylylene diisocyanate (XDI) , isophorone diisocyanate (IPDI) , hexamethylene diisocyanate (HDI) , hydrogenated DMI, hydrogenated XDI, oligomeric HDI, oligomeric IPDI, and/or naphthalene diisocyanate.
The coating composition according to claim 6, wherein the hydroxylalkyl (meth) acrylate monomer comprises 2-hydroxyethyl acrylate, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl acrylate, and/or 3-hydroxypropyl (meth) acrylate.
The coating composition according to claim 1 or 2, wherein the fluorine-containing acrylate additive comprises fluorine-containing alkyl (meth) acrylate, and/or perfluoropolyether (meth) acrylate.
The coating composition according to claim 1 or 2, wherein the solvent comprises a hydroxyl-free ester solvent and/or ketone solvent.
The coating composition according to claim 1 or 2, wherein the weight ratio of the solvent to the fluorine-containing acrylate additive is about 8-30.
The coating composition according to claim 1 or 2, further comprising a moisture curing catalyst and a photoinitiator.
A method of coating a substrate comprising applying the coating composition of any of claims 1-12 to a substrate by a dispensing process.
The method according to claim 13, wherein the substrate comprises plastic substrates, metal substrates, and/or glass.
A coated substrate, comprising:

(a) a substrate;

(b) a coating applied onto at least a portion of the substrate, the coating being formed from the coating composition comprising about 20-60 wt%of an acrylate monomer, about 20-60 wt%of an isocyanate (meth) acrylate, about 0.5-5 wt%of a fluorine-containing acrylate additive and about 10-30 wt%of a solvent, based on the total weight of the coating composition.
The coated substrate according to claim 15, wherein the substrate comprises plastic substrates, metal substrates, and/or glass.