Nano base-free protective film material as well as preparation method and application thereof

Abstract

The invention provides a nanometer base-free protective film material and a preparation method of the nanometer base-free protective film material. Comprising 40%-70% of a main prepolymer, 20%-50% of a reactive diluent, 1%-5% of a photoinitiator, 2%-4% of a defoaming agent, 1%-2% of a flatting agent, 1%-2% of a light curing accelerator, 1%-2% of an antioxidant polymerization inhibitor and 1%-2% of an anti-shrinkage agent. The protective film material can completely cover the surface of a base material with low surface tension, has good adhesion to the base material after film formation, moderate stripping force and high film strength, can be completely stripped from the base material, has no residual glue and no shrinkage cavity, and can completely and effectively protect an object with low surface tension.

Description

Technical Field

[0001] The present invention relates to the technical field of protective films, and more specifically, to a nanometer baseless protective film material and a preparation method and application thereof. Background Art

[0002] With the development and progress of society, people have more and more requirements for the surface performance of objects. In order to obtain a better surface state of objects and meet more functional requirements, many industries will coat the surface of objects with a layer of AF anti-fingerprint coating, so that it has the characteristics of anti-fingerprint, anti-oil, anti-dust, wear-resistant, scratch-resistant, high penetration, etc., especially in 3C electronics, national defense and military industries. However, after the AF anti-fingerprint coating is plated, the object will inevitably encounter dirt, scratches, etc. during the turnover process, which will cause defects to the product. The existing practice on the market is to cover the surface of the object with a layer of plastic film to protect the surface of the object from intrusion, but the film has the disadvantages of high production cost, complex construction process, and difficulty in transportation and protection. In addition, general plastic films need to go through a series of processes such as coating, coiling, splitting, plate-loading, die-cutting, and film-sticking. Each process will have defects and waste, and the protective film after die-cutting can only be used for a single fixed product. In addition, the surface tension of the object surface coated with AF anti-fingerprint coating is low, and general resin materials have hydrophobic, oleophobic or shrinkage pores on the surface of the coating, which is difficult to cover comprehensively. Summary of the invention

[0003] Based on the above-mentioned technical problems existing in the prior art, the present invention provides a nano-base-free protective film material, which can completely cover the surface of a substrate with low surface tension, and has good adhesion to the substrate after film formation, moderate peeling force, high film strength, and can be completely peeled off from the substrate without residual glue or shrinkage holes, and can completely and effectively protect objects with low surface tension.

[0004] In order to achieve the above object, the technical solution of the present invention is as follows:

[0005] A nanometer baseless protective film, the raw materials of which include the following components by mass percentage:

[0006]

[0007] The main prepolymer includes a difunctional polyurethane acrylate prepolymer and a fluorine-modified polyurethane acrylate prepolymer; and the active diluent includes acrylate and fluorine-modified acrylate.

[0008] In some embodiments, the mass ratio of the difunctional polyurethane acrylate prepolymer to the fluorine-modified polyurethane acrylate is (30-50): (15-30), wherein the number average molecular weight of the polyurethane acrylate prepolymer is 3000-5000, and the number average molecular weight of the fluorine-modified polyurethane acrylate prepolymer is 3000-10000.

[0009] In some embodiments, the raw materials of the fluorine-modified polyurethane acrylate include the following components by mass percentage:

[0010]

[0011]

[0012] In some embodiments, the preparation method of the fluorine-modified polyurethane acrylate prepolymer is as follows:

[0013] The polyfluoro alcohol is added into the polyurethane prepolymer, and the temperature is raised to 50-80° C. for reaction; then the acrylate prepolymer and the catalyst are added for reaction to obtain the fluorine-modified polyurethane acrylate prepolymer.

[0014] In some embodiments, the polyurethane prepolymer is a polymer obtained by reacting polyisocyanate with polyether or polyester polyol.

[0015] In some embodiments, the number average molecular weight of the polyurethane prepolymer is 1,000-10,000.

[0016] In some embodiments, the catalyst is an organotin catalyst or an organozinc catalyst.

[0017] In some embodiments, the mass ratio of the acrylate to the fluorine-modified acrylate is (10-20):(5-10).

[0018] In some embodiments, the fluorine-modified acrylate is at least one of perfluoroacrylate, hexafluorobutyl methacrylate, hexafluorobutyl acrylate, trifluoroethyl methacrylate, and heptafluorobutyl acrylate.

[0019] In some embodiments, the acrylate is at least one of o-phenylphenoxyethyl acrylate, tetrahydrofurfuryl acrylate, hydroxyethyl methacrylate, isobornyl acrylate, and tripropylene glycol diacrylate.

[0020] In some embodiments, the photoinitiator is at least one of diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, and 2-isopropylthioxanthone.

[0021] In some embodiments, the defoaming agent is a polysiloxane defoaming agent, preferably a Foamex N defoaming agent and / or a LeAd243 defoaming agent.

[0022] In some embodiments, the leveling agent is a polyether-modified siloxane leveling agent, preferably LeAd152S.

[0023] In some embodiments, the photocuring accelerator is a reactive tertiary amine co-initiator, preferably Changxing 6420.

[0024] In some embodiments, the antioxidant inhibitor is a difunctional polyether amine modified acrylate, preferably LuCure5186.

[0025] In some embodiments, the anti-cratering agent is a fluorine-modified polyether siloxane auxiliary agent, preferably SN-2260.

[0026] The present invention also provides a method for preparing the nano-base-free protective film material of any of the above embodiments, the method comprising the following steps:

[0027] The main prepolymer, active diluent, photoinitiator, defoamer, leveling agent, photocuring accelerator, antioxidant inhibitor and anti-cratering agent are mixed uniformly and then subjected to degassing treatment to obtain the protective film material.

[0028] The present invention also provides the use of the nano-base-free protective film material of any of the above embodiments as a protective film for low surface tension objects, wherein the surface tension of the object is below 20 mN / m and the water drop angle on the surface is above 110°.

[0029] In some embodiments, the surface tension of the object is 10-20 mN / m, and the water drop angle on the surface is 110°-120°.

[0030] In some embodiments, the object includes, but is not limited to, an AF anti-fingerprint coating.

[0031] In some embodiments, the application method is: cover the protective film material on the surface of the substrate, and then irradiate with UV light at an intensity of 3500-4000 mj / cm 2 Curing under conditions.

[0032] In some embodiments, the curing time is 5-10 seconds.

[0033] In some embodiments, the protective film material is covered on the surface of the object by screen printing, spraying, rolling or dispensing, and then photocured to obtain a nano-based free protective film.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] The present invention adopts bifunctional polyurethane acrylate prepolymer and fluorine-modified polyurethane acrylate prepolymer as main materials, acrylate and fluorine-modified acrylate as active diluents, and combines other raw materials according to a specific component ratio, so that the obtained nano base-free protective film has good adhesion on the surface of an object with low surface tension and does not have shrinkage holes. The protective film has high strength, good toughness, and moderate peeling force, and can be completely peeled off from the substrate without residual glue.

[0036] The baseless protective film of the present invention can completely cover the surface of an object with a surface tension below 20 mN / m and a water drop angle above 110°, thereby effectively protecting the surface of the object.

[0037] In addition, the base-free protective film of the present invention has low curing energy, fast curing speed and excellent surface drying effect. DETAILED DESCRIPTION

[0038] Many specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without violating the connotation of the present invention, so the present invention is not limited to the specific implementation disclosed below.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0040] Example 1

[0041] Preparation of fluorine-modified polyurethane acrylate prepolymer: Take 50 parts of polyurethane prepolymer, add 20 parts of octafluoropentanol, stir and heat to 60°C, and react for 4 hours; then add 30 parts of acrylate prepolymer and 1 part of dibutyltin dilaurate, continue to react at 60°C for 5 hours to obtain fluorine-modified polyurethane acrylate prepolymer.

[0042] Preparation of nano base-free protective film material: Take 45 parts of difunctional polyurethane acrylate prepolymer, add 20 parts of fluorine-modified polyurethane acrylate prepolymer prepared in this embodiment, and stir evenly; then add 20 parts of isobornyl acrylate, 5 parts of tripropylene glycol diacrylate and 5 parts of hexafluorobutyl methacrylate, and stir evenly; then add 4 parts of diphenyl-(2,4,6-trimethylbenzoyl)phosphine, 2 parts of reactive tertiary amine co-initiator Changxing 6420, 1 part of difunctional polyether amine modified acrylate LuCure5186, 1 part of polyether modified siloxane leveling agent LeAd152S, 2 parts of polysiloxane defoamer LeAd243 and 1 part of anti-shrinkage crater agent SN-2260 in sequence, stir evenly and put into a vacuum degasser for degassing to obtain a nano base-free protective film material;

[0043] The obtained nano-base-free protective film material was printed on the surface of the substrate coated with the AF anti-fingerprint coating by a screen printer. The surface tension of the substrate was 10-20 mN / m, and the water drop angle was 110°-120°. The substrate was clamped to the adjusted high-speed dispensing machine with a special fixture, and the irregular surface and narrow side were dispensing by piezoelectric valve control. After the coating was completed, LED cold light source UV light (light intensity 3500-4000 mj / cm 2 ) is irradiated for 5-10s to obtain a nano-base-free protective film coating; the thickness of the protective film is 20-40μm.

[0044] Example 2

[0045] Preparation of fluorine-modified polyurethane acrylate prepolymer: Take 40 parts of polyurethane prepolymer, add 30 parts of hexafluoroisopropanol, stir and heat to 80°C, and react for 5 hours; then add 50 parts of acrylate prepolymer and 1 part of dibutyltin dilaurate, continue to react at 80°C for 4 hours to obtain fluorine-modified polyurethane acrylate prepolymer.

[0046] Preparation of nano base-free protective film material: Take 55 parts of difunctional polyurethane acrylate prepolymer, add 10 parts of fluorine-modified polyurethane acrylate prepolymer prepared in this embodiment, and stir evenly; then add 15 parts of tetrahydrofurfuryl acrylate, 10 parts of o-phenylphenoxyethyl acrylate and 10 parts of trifluoroethyl methacrylate, and stir evenly; then add 5 parts of 2-isopropylthioxanthone, 1 part of reactive tertiary amine co-initiator Changxing 6420, 1 part of difunctional polyether amine-modified acrylate LuCure5186, 1 part of polyether-modified siloxane leveling agent LeAd152S, 2 parts of polysiloxane defoamer Foamex N and 2 parts of anti-shrinkage crater agent SN-2260 in sequence, stir evenly and put into a vacuum degassing machine for degassing treatment to obtain a nano base-free protective film material;

[0047] The obtained nano-base-free protective film material was printed on the surface of the substrate coated with the AF anti-fingerprint coating by a screen printer. The surface tension of the substrate was 10-20 mN / m, and the water drop angle was 110°-120°. The substrate was clamped to the adjusted high-speed dispensing machine with a special fixture, and the irregular surface and narrow side were dispensing by piezoelectric valve control. After the coating was completed, LED cold light source UV light (light intensity 3500-4000 mj / cm 2 ) is irradiated for 5-10s to obtain a nano-base-free protective film coating with a thickness of 20-40μm.

[0048] Comparative Example 1

[0049] The difference between this comparative example and Example 1 is that the main prepolymer is a mixture of a difunctional polyurethane acrylate prepolymer and a multifunctional polyurethane acrylate prepolymer, and the amount of each component used is the same as that of Example 1.

[0050] Comparative Example 2

[0051] The difference between this comparative example and Example 1 is that the reactive diluent is acrylate, and the amount of each component used is the same as that of Example 1.

[0052] Comparative Example 3

[0053] The difference between this comparative example and Example 1 is that the nano-base-free protective film is coated on the surface of a general irregular substrate without an AF anti-fingerprint coating.

[0054] The protective film coatings obtained in Examples 1-2 and Comparative Examples 1-3 were tested for relevant properties, and the testing method was as follows:

[0055] 1. Surface appearance: observe the surface state of the protective film coating;

[0056] 2. Surface drying effect: Touch the surface of the protective film coating with your fingers to observe whether it is smooth, sticky, etc.;

[0057] 3. Anti-adhesion: Fold and slide the protective film coatings against each other. If there is no blocking feeling and it is relatively smooth, the anti-adhesion is OK;

[0058] 4. Film hardness: Use pencil hardness tester or finger pressure method. This application uses finger pressure method, that is, use finger to press and observe the depth of fingerprint;

[0059] 5. Peelability: Peel off the protective film coating from the substrate, record the feel when peeling, and then observe the substrate surface with the naked eye under the irradiation of a three-wavelength lamp;

[0060] 6. Elongation at break: Use a tensile testing machine to test the elongation at break of the peeled base-free protective film coating;

[0061] 7. Fracture strength: The peeled base-free protective film coating is tested for fracture strength using a tensile testing machine;

[0062] 8. Peeling force: The base-free protective film coating after coating is peeled off using a tensile testing machine.

[0063] The test results are shown in Table 1 below:

[0064] Table 1 Performance test results of nano base-free protective film coatings of Examples 1-2 and Comparative Examples 1-3

[0065]

[0066] It can be concluded from Table 1 that the nano base-free protective film provided by the present invention has good adhesion to the low surface substrate coated with the AF anti-fingerprint coating, moderate peeling force, high film strength, good toughness, can be completely peeled off from the substrate, and has no residual glue.

[0067] The present invention uses bifunctional polyurethane acrylate prepolymer and fluorine-modified polyurethane acrylate prepolymer as the main resin, and a combination of acrylate and fluorine-modified acrylate as the diluent. According to different proportions, the baseless protective film material can be adjusted to be coated on different low surface tension substrates, and can balance the film hardness and elongation, strippability and other properties. According to tests, the baseless protective film material of the present invention can be perfectly coated on a substrate with a water drop angle of 110°-120° after being coated with the AF anti-fingerprint coating.

[0068] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A nanometer baseless protective film material, characterized in that: The raw materials include the following components by mass percentage: The main prepolymer includes a difunctional polyurethane acrylate prepolymer and a fluorine-modified polyurethane acrylate prepolymer; and the active diluent includes acrylate and fluorine-modified acrylate.

2. The nano-based non-base protective film material according to claim 1, characterized in that: The mass ratio of the bifunctional polyurethane acrylate prepolymer to the fluorine-modified polyurethane acrylate prepolymer is (30-50): (15-30); wherein the molecular weight of the polyurethane acrylate prepolymer is 3000-5000, and the molecular weight of the fluorine-modified polyurethane acrylate prepolymer is 3000-10000.

3. The nano-base-free protective film material according to claim 1, characterized in that: The mass ratio of the acrylic ester to the fluorine-modified acrylic ester is (10-20):(5-10).

4. The nano-base-free protective film material according to claim 1, characterized in that: The raw materials of the fluorine-modified polyurethane acrylate prepolymer include the following components by mass percentage:

5. The nano-base-free protective film material according to claim 4, characterized in that: The preparation method of the fluorine-modified polyurethane acrylate prepolymer is as follows: The polyfluoro alcohol is added into the polyurethane prepolymer, and the temperature is raised to 50-80° C. for reaction; then the acrylate prepolymer and the catalyst are added for reaction to obtain the fluorine-modified polyurethane acrylate prepolymer.

6. The nanometer baseless protective film material according to claim 5, characterized in that: The polyurethane prepolymer is a polymer obtained by reacting polyisocyanate with polyether or polyester polyol.

7. The nano-base-free protective film material according to claim 1, characterized in that: The fluorine-modified acrylate is at least one of perfluoroacrylate, hexafluorobutyl methacrylate, hexafluorobutyl acrylate, trifluoroethyl methacrylate, and heptafluorobutyl acrylate; and / or the acrylate is at least one of o-phenylphenoxyethyl acrylate, tetrahydrofurfuryl acrylate, hydroxyethyl methacrylate, isobornyl acrylate, and tripropylene glycol diacrylate.

8. The method for preparing the nano-based non-base protective film material according to any one of claims 1 to 7, characterized in that: The following steps are involved: The main prepolymer, active diluent, photoinitiator, defoamer, leveling agent, photocuring accelerator, antioxidant inhibitor and anti-cratering agent are mixed evenly to obtain the protective film.

9. Use of the nanometer baseless protective film material according to any one of claims 1 to 7 as a protective film for low surface tension objects, wherein the surface tension of the object is below 20 mN / m and the water drop angle is above 110°.

10. The use according to claim 9, characterized in that: The application method is: cover the protective film material on the surface of the substrate, and then expose it to UV light at an intensity of 3500-4000mj / cm 2 Curing under conditions.

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