Optically transparent water-resistant protective film composition based on double network structure

Abstract

The present invention relates to an optically transparent, water-resistant protective film composition based on a dual-network structure. Specifically, the present invention relates to a liquid, optically transparent / clear protective film composition that can be applied to various substrate surfaces requiring transparent film protection after UV curing. It is particularly suitable for use in high-humidity or underwater environments. Even after prolonged exposure to water, it maintains good adhesion to the substrate surface and isolates the substrate from contact and damage by water molecules. For example, it can be used for external screens of electronic display products and external screens made of silicate-based light-transmitting materials in humid / aquatic environments.

Description

Technical Field

[0001] The invention relates to the technical field of transparent optical protective film preparation, in particular to an optical water-resistant protective film composition based on a double network structure. Background Art

[0002] Displays and display devices have been widely used in the consumer market, generating a trillion-level market capacity, such as in organic light-emitting diodes (OLEDs) and liquid crystal displays (LCDs).

[0003] To protect components in displays or display devices, flexible protective films are typically applied and laminated to the surface of these components. These films must meet numerous requirements, including high visible light transmittance, low haze, good adhesion, high and low temperature resistance, and water / moisture resistance. This is particularly true in harsh environments, high humidity environments, or underwater environments, where high and low temperature transitions and water can severely impact the adhesive properties of the film.

[0004] Currently, most optically transparent adhesives have a high bonding effect in a dry state, but fail in a wet environment due to hydration or swelling. Current research on adhesives in wet environments, such as surface drainage structures, hydrophobic adjustment, and water displacement, has been proposed. However, these adhesives often require special texturing, making practical application difficult. Furthermore, these methods have strict temperature requirements and are not suitable for a wide temperature range. Therefore, the design of optically transparent adhesives that can operate over a wide temperature range in high humidity or underwater environments remains a huge challenge. Summary of the Invention

[0005] The object of the present invention is to provide an optically transparent water-resistant protective film composition based on a double network structure. After UV curing, the transparent protective film can still maintain excellent bonding properties in a high humidity / underwater environment, and its light transmittance and fog will not change significantly, thereby solving the problems raised in the above-mentioned background technology.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] An optically transparent water-resistant protective film composition based on a double network structure, comprising the following components in parts by weight:

[0008] 3 to 9 parts by weight of a monomer having a phenoxy group that can be cured by light radiation;

[0009] 5 to 10 parts by weight of a monomer having an olefin group and a thiourea group that can be cured by light radiation;

[0010] 2 to 8 parts by weight of a silane monomer having a (meth)acryloyloxy group that can be cured by light radiation;

[0011] 5 to 12 parts by weight of a monomer having an imidazolate group that can be cured by light radiation;

[0012] 3 to 7 parts by weight of a bisacrylamide monomer capable of photocuring;

[0013] 10 to 20 parts by weight of an acryloxy hard monomer capable of light radiation curing;

[0014] 40 to 65 parts by weight of a urethane oligomer having a (meth)acryloyloxy group that is capable of being cured by light radiation;

[0015] 15 to 30 parts by weight of an epoxy oligomer having a (meth)acryloyloxy group that can be cured by radiation;

[0016] 0 to 30 parts by weight of a solvent;

[0017] 3 to 9 parts by weight of ultraviolet light initiator.

[0018] Preferably, the photo-curable monomer having a phenoxy group is selected from any one of ethylene glycol phenyl ether acrylate, 2-phenoxyethyl methacrylate, 3-(2-bromophenoxy)ethyl acrylate, and 2-phenoxyethyl acrylate.

[0019] Preferably, the monomer having an olefin group and a thiourea group that can be cured by photoradiation is selected from any one of N-allylthiourea, N-propylene N'-2-hydroxyethylthiourea, 4-(3-allylthiourea)benzoic acid, 4-propylenethioaminourea, 1-allyl-3-(pyridin-2-yl)thiourea, and 1-allyl-3-(pyridin-4-yl)thiourea.

[0020] Preferably, the silane monomer having a (meth)acryloyloxy group that can be cured by light radiation is selected from one of γ-methacryloxypropyltriisopropoxysilane, γ-methacryloxypropylmethyldimethoxysilane and 3-methacryloxypropyltrimethyloxysilane.

[0021] Preferably, the monomer having an imidazolium salt group that can be cured by photoradiation is selected from one of 1-vinyl-3-butylimidazolium bromide, 1-allyl-3-vinylimidazolium chloride, 1-allyl-3-vinylimidazolium bromide and 1-vinyl-3-butylimidazolium chloride.

[0022] Preferably, the bisacrylamide-based monomer capable of photo-radiation curing is selected from one of N,N'-methylenebisacrylamide, hexamethylenebisacrylamide, N,N'-vinylbisacrylamide and N,N'-vinylbisacrylamide.

[0023] Preferably, the acryloxy hard monomer capable of being cured by light radiation refers to a monomer homopolymer whose glass transition temperature is above room temperature.

[0024] As a further preferred embodiment, the photo-curable acryloxy hard monomer is selected from methyl (meth)acrylate, isobornyl (meth)acrylate, stearyl methyl acrylate, trimethylolpropane formal acrylate, and ethoxylated bisphenol A dimethacrylate.

[0025] Preferably, the average functionality of the photo-curable urethane oligomer having a (meth)acryloyloxy group is 2, where the “average functionality” refers to the average number of (meth)acryloyloxy groups on each macromolecular chain.

[0026] As a further preferred embodiment, the photo-curable urethane oligomer having a (meth)acryloyloxy group has a viscosity of about 2,000 to about 40,000 cps (at 60° C.).

[0027] As a further preferred embodiment, the radiation-curable urethane oligomer having a (meth)acryloyloxy group is selected from at least one of CN2920, CN8010NS, CN8887NS, CN8888NS, CN9023, CN9014NS, and CN9001NS sold by Sartomer Chemical Co., Ltd., and YC2521, YC3100, and YC3165 sold by Shanghai Yinchang New Materials Co., Ltd. In actual production, these manufacturers and products are not limited, and a wider range of selections can be made based on requirements.

[0028] Preferably, the average functionality of the photo-curable epoxy oligomer having a (meth)acryloyloxy group is greater than or equal to 2 and less than or equal to 4. Here, the "average functionality" refers to the average number of (meth)acryloyloxy groups on each macromolecular chain.

[0029] As a further preferred embodiment, the viscosity of the epoxy oligomer having a (meth)acryloyloxy group that can be cured by radiation is about 1000 to about 5000 (at 60° C.) or about 15000 to about 40000 cps (at 25° C.).

[0030] As a further preferred embodiment, the radiation-curable epoxy oligomer having a (meth)acryloyloxy group is selected from at least one of CN104NS, CN104A80NS, and CNUVE151NS sold by Satrmoner Company, Inc., and YC1181 and YC3390 sold by Shanghai Yinchang New Materials Co., Ltd. In actual production, these manufacturers and products are not limited, and a wider range of options can be selected based on requirements.

[0031] Preferably, the solvent is a solvent well known in the art that can dissolve the composition and ensure uniform mixing of the composition.

[0032] As a further preferred embodiment, the solvent is selected from but not limited to one of ethanol, butanone, ethyl acetate, tetrahydrofuran, and pentanedione.

[0033] Preferably, the UV initiator is a well-known one in the art, effective in the wavelength range of 200 to 400 nm, and capable of initiating a photo-radical polymerization reaction capable of photo-curing. Typically, the UV initiator may be a benzyl ketal, a hydroxy ketone, an amino ketone, an acylphosphine peroxide, or the like.

[0034] As a further preferred embodiment, the ultraviolet light initiator is selected from but not limited to 2-hydroxy-2-methyl-1-phenyl-1-propanone, diphenyl (2,4,6-triphenylbenzoyl) -phosphine oxide, 2-benzyl-dimethylamino-1-(4-morpholinylphenyl) -butan-1-one, benzoin dimethyl ketal dimethoxyacetophenone, α-hydroxybenzyl phenyl ketone, 1-hydroxy-1-methylethyl phenyl ketone, oligo-2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl) ) acetone, benzophenone, methyl o-benzyl benzoate, methyl benzoyl formate, 2-diethoxyacetophenone, 2,2-di-sec-butoxyacetophenone, p-phenylbenzophenone, 2-isopropylthioxanthone, 2-methylanthrone, 2-ethylanthrone, 2-chloroanthrone, 1,2-benzanthrone, benzoyl ether, benzoin ether, benzoin methyl ether, benzoin isopropyl ether, α-phenylbenzoin, thioxanthone, diethylthioxanthone, 1,5-acetonaphthone, 1-hydroxycyclohexyl phenyl ketone, and combinations thereof.

[0035] The optically transparent, water-resistant protective film composition based on a dual-network structure described herein can be prepared by mixing and then cured to form a film using methods commonly used in the art. The following provides a method for preparing the composition. In actual use, this method is not limiting, and those skilled in the art may adjust it based on common methods in the art or actual needs.

[0036] In a light-proof environment, a monomer having a phenoxy group, a monomer having an olefin group and a thiourea group, a silane monomer having a (meth)acryloyloxy group, a monomer having an imidazole salt group, a bisacrylamide monomer, an acryloxy hard monomer and a solvent in accordance with weight parts are mixed at 200 rpm for more than 20 minutes at room temperature by magnetic stirring, and then a (meth)acryloyloxy carbamate polymer and a (meth)acryloyloxy epoxy polymer are added to the mixed system, and the mixture is heated to 60±5°C and mixed at 200 rpm for more than 30 minutes, and then the stirring is maintained and the temperature is lowered to room temperature, and an ultraviolet light initiator is added to the mixed system, and the mixture is mixed at 300 rpm for more than 10 minutes and stored in the dark to prepare an optically transparent water-resistant protective film composition based on a double network.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. Based on the double network structure of the cured polymer film, the imidazolium salt group and the benzene tetracarboxylic acid group form an ionic network structure, which gives the protective film good elasticity and efficient energy dissipation, thereby ensuring a firm bond on the substrate surface.

[0039] 2. Based on the double-network structure of the cured polymer film, the thiourea group, siloxane group and acrylamide group form a cross-linked network structure, which gives the protective film good water repellency and swelling / dissolution resistance, thereby ensuring that in a high humidity / water environment, water molecules cannot come into contact with the substrate and cause damage.

[0040] 3. The dual network structure can form a microphase separation structure based on the "opposite repulsion" of the molecular structure, thereby ensuring that the respective network structures will not affect each other. DETAILED DESCRIPTION

[0041] The following examples are provided to further illustrate the present invention. The examples are merely illustrative of the present invention and should not be considered as limiting the scope of the present invention as defined by the claims.

[0042] The dual-network structure is considered a key innovation for enhancing the adhesion of organic polymers, particularly for long-lasting adhesion in high-humidity / underwater environments. By constructing a sacrificial network through ionic bonding, the polymer material possesses excellent elastic deformation and efficient energy dissipation, key factors for achieving excellent adhesion. Furthermore, the strongly cross-linked structure creates a reinforcing network, imparting high strength and toughness to the polymer material, extending its service life. Therefore, the application of the dual-network structure in the field of optically transparent protective films holds significant potential.

[0043] <Specific test experiments and conditions>

[0044] Test 1: UV radiation curing

[0045] At room temperature, the radiation power of the ultraviolet light covering the 200-400nm band is 100mW / cm 2 The adhesive composition coated between two layers of polycarbonate films with a thickness of 50 μm was irradiated with an ultraviolet light source for 30 seconds.

[0046] Test 2: Transmittance test

[0047] Using the above-mentioned test 1 method, the adhesive cured in the polycarbonate film was peeled off (the thickness was controlled to be about 40 μm), and the transmittance of the adhesive was measured using a WGT-S transmittance / fog meter.

[0048] Test 3: Peel force test

[0049] The adhesive composition was coated on a glass substrate with a width of 25 mm and covered with polycarbonate (thickness controlled to be 20 μm). The peeling force of the adhesive composition at a sample width of 25 mm was tested according to GB / T2791-1995.

[0050] Test 4: Constant temperature and humidity test

[0051] An adhesive composition cured between two polycarbonate films with a controlled thickness of 50 μm was placed in a constant temperature and humidity test chamber at 80° C. and 95% humidity for 240 hours, and then Tests 2 and 3 were completed.

[0052] Test 5: High and low temperature impact test

[0053] Take the adhesive composition cured between two layers of polycarbonate film with a controlled thickness of 50 μm, use a constant temperature and humidity test chamber, under 40% humidity conditions, cycle 120 times at 0°C (30 min) -100°C (30 min), and then complete Test 2 and Test 3.

[0054] <Raw Materials Used>

[0055] The raw materials used in the examples and comparative examples are shown in Table 1. The specific implementation is not limited to the substances in Table 1, and corresponding chemicals can be selected according to the above. Other chemicals used in the examples are all chemically pure commercially available chemical reagents.

[0056] Table 1

[0057]

[0058]

[0059] Example 1

[0060] According to the composition in Table 2, an optically transparent water-resistant protective film composition 1 based on a double network structure was prepared.

[0061] Table 2

[0062]

[0063]

[0064] Example 2

[0065] According to the composition in Table 3, an optically transparent water-resistant protective film composition 2 based on a double network structure was prepared.

[0066] Table 3

[0067]

[0068] Example 3

[0069] According to the composition in Table 4, an optically transparent water-resistant protective film composition 3 based on a double network structure was prepared.

[0070] Table 4

[0071]

[0072]

[0073] Example 4

[0074] According to the composition in Table 5, an optically transparent water-resistant protective film composition 4 based on a double network structure was prepared.

[0075] Table 5

[0076]

[0077] Example 5

[0078] According to the composition in Table 6, an optically transparent water-resistant protective film composition 5 based on a double network structure was prepared.

[0079] Table 6

[0080]

[0081]

[0082] Example 6

[0083] According to the composition in Table 7, an optically transparent water-resistant protective film composition 6 based on a double network structure was prepared.

[0084] Table 6

[0085]

[0086] Comparative Example 1

[0087] According to the composition in Table 8, a comparative protective film composition 1 was prepared.

[0088] Table 8

[0089]

[0090] Comparative Example 2

[0091] According to the composition in Table 9, a comparative protective film composition 2 was prepared.

[0092] Table 9

[0093]

[0094] The performance test results of the embodiments and comparative examples are summarized in Table 10 below.

[0095] Table 10

[0096]

[0097] As shown in Table 10, compared to the comparative example, the optically transparent, water-resistant protective film based on the dual-network structure prepared in the examples of the present invention adheres excellently to the substrate surface. Even in high-humidity environments, its transmittance and adhesion remain essentially stable, while the comparative example exhibits significant decreases. Furthermore, the examples can withstand high- and low-temperature cycling tests, significantly outperforming the comparative example.

Claims

1. An optically transparent water-resistant protective film composition based on a double network structure, characterized in that: In parts by weight, it comprises the following components: 3 to 9 parts by weight of a photo-curable monomer having a phenoxy group; 5 to 10 parts by weight of a monomer having an olefin group and a thiourea group that can be cured by radiation; 2 to 8 parts by weight of a silane monomer having a (meth)acryloyloxy group that can be cured by light radiation; 5 to 12 parts by weight of a monomer having an imidazolium salt group that can be cured by light radiation; 3 to 7 parts by weight of a bisacrylamide monomer capable of photocuring; 10 to 20 parts by weight of an acryloxy hard monomer capable of light radiation curing; 40 to 65 parts by weight of a photo-curable urethane oligomer having a (meth)acryloyloxy group; 15 to 30 parts by weight of a light-curable epoxy oligomer having a (meth)acryloyloxy group; 0 to 30 parts by weight of a solvent; 3 to 9 parts by weight of a UV initiator; The photo-curable monomer having a phenoxy group is selected from any one of ethylene glycol phenyl ether acrylate, 2-phenoxyethyl methacrylate, 3-(2-bromophenoxy)ethyl acrylate, and 2-phenoxyethyl acrylate; The monomer having an imidazolium salt group capable of being cured by light radiation is selected from 1-vinyl-3-butylimidazolium bromide, 1-allyl-3-vinylimidazolium chloride, 1-allyl-3-vinylimidazolium bromide and 1-vinyl-3-butylimidazolium chloride.

2. The composition according to claim 1, wherein The monomer having an olefin group and a thiourea group and capable of being cured by light radiation is selected from any one of N-allylthiourea, N-propylene N'-2-hydroxyethylthiourea, 4-(3-allylthiourea)benzoic acid, 4-propylenethiosemicarbazide, 1-allyl-3-(pyridin-2-yl)thiourea, and 1-allyl-3-(pyridin-4-yl)thiourea.

3. The composition according to claim 1, wherein The silane monomer having a (meth)acryloyloxy group and capable of being cured by light radiation is selected from one of γ-methacryloxypropyltriisopropoxysilane, γ-methacryloxypropylmethyldimethoxysilane and 3-methacryloxypropyltrimethyloxysilane.

4. The composition according to claim 1, wherein The bisacrylamide-based monomer capable of being cured by light radiation is selected from one of N,N'-methylenebisacrylamide, hexamethylenebisacrylamide and N,N'-vinylbisacrylamide.

5. The composition according to claim 1, wherein The photo-curable acryloxy hard monomer is selected from methyl (meth)acrylate, isobornyl (meth)acrylate, trimethylolpropane formal acrylate, and ethoxylated bisphenol A dimethacrylate.

6. The composition according to claim 1, wherein The average functionality of the photo-curable urethane oligomer having a (meth)acryloyloxy group is 2.

7. The composition according to claim 1, wherein The viscosity of the photo-curable urethane oligomer having a (meth)acryloyloxy group is 2000~40000 cps when tested at 60°C.

8. The composition according to claim 1, wherein The average functionality of the epoxy oligomer having a (meth)acryloyloxy group that can be cured by photoradiation is greater than or equal to 2 and less than or equal to 4.

9. The composition according to claim 1, wherein The viscosity of the epoxy oligomer having a (meth)acryloyloxy group that can be cured by light radiation is 1000-5000 cps when tested at 60°C or 15000-40000 cps when tested at 25°C.

10. The composition according to claim 1, wherein The ultraviolet light initiator is selected from any one of benzil ketals, hydroxy ketones, amino ketones and acylphosphine peroxides.

11. The composition according to claim 1, wherein The UV photoinitiator is selected from 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-benzyl-dimethylamino-1-(4-morpholinylphenyl)-butan-1-one, benzoin dimethyl ketal dimethoxyacetophenone, α-hydroxybenzyl phenyl ketone, 1-hydroxy-1-methylethyl phenyl ketone, oligo-2-hydroxy-2-methyl-1-(4-(1-methylvinyl)phenyl)propanone, benzophenone, methyl-benzyl benzoate, methyl benzoyl formate, 2-diethoxyacetophenone, 2,2-di-sec-butoxyacetophenone, p-phenylbenzophenone, 2-isopropylthioxanthone, 2-ethylanthrone, 2-chloroanthrone, 1 , any one of 2-benzanthrone, benzoin ether, benzoin methyl ether, benzoin isopropyl ether, α-phenyl benzoin, thioxanthone, diethylthioxanthone, 1-acetonaphthone, 1-hydroxycyclohexyl phenyl ketone and their combinations.

Images