A photocuring coating solution, its preparation method and application

Abstract

The present invention provides a photocurable coating liquid, a preparation method thereof and an application. The photocurable coating liquid includes an acrylate oligomer, a polycarbonate-modified acrylate oligomer, an active diluent monomer, a photoinitiator and a vinylsilane. The cured coating of the photocurable coating liquid of the present invention has the characteristics of high hardness, good abrasion resistance, high adhesion, excellent chemical resistance, excellent aging resistance and surface antistatic property.

Description

Technical Field

[0001] The present invention belongs to the technical field of photocurable coating liquids, and particularly relates to a photocurable coating liquid, a preparation method thereof, and an application thereof. Background Art

[0002] Optical films are thin film materials with high transparency and high reflectivity, light weight, good thermal stability, and good mechanical and optical properties. They can be used to manufacture various optical devices and improve the performance of optical instruments, and have been widely used in fields such as liquid crystal TVs, displays, laptop computers and other electronic products, as well as in-mold decoration of control panels in household appliances, medical devices, and vehicle navigation. Optical films are usually made of plastic films. Due to the low surface hardness and poor wear resistance of plastic films, they are easily scratched during the preparation process, which affects the decorative and optical properties. Treating the surface of plastic film materials can improve the wear resistance of plastic films. Currently, the treatment of the hardness and wear resistance of optical films is to add a coating liquid on the surface. After photocuring or dual curing of heat and light, the improvement of hardness and wear resistance is achieved. Usually, inorganic nanoparticles are introduced into the coating liquid to improve wear resistance and hardness, and fluorine-containing and silicon-containing groups are introduced to improve the smoothness and stain resistance of the coating.

[0003] CN114854234A discloses a high-transparency and high-wear-resistant hard coating and a preparation method thereof. The high-transparency and high-wear-resistant hard coating includes a substrate, a hardening resin layer, a high-refractive-index resin layer, and a low-refractive-index resin layer from bottom to top. The hardening resin layer contains the following components in percentage: 20-40% of an organic resin, 5-15% of inorganic particles, 1-5% of a photoinitiator, 1-5% of a thermal initiator, and 35-73% of an organic solvent. The high-refractive-index resin layer contains the following components in percentage: 10-20% of an organic resin, 1-5% of a photoinitiator, 1-5% of a thermal initiator, and 70-88% of an organic solvent. The low-refractive-index resin layer contains the following components in percentage: 10-20% of an organic resin, 3-8% of inorganic particles, 1-5% of a photoinitiator, 1-5% of a thermal initiator, 1-5% of a leveling agent, and 37-84% of an organic solvent. The inorganic particles are modified hollow silica nanoparticles. This technical solution improves the wear resistance and hardness performance of the product by adding surface-functionalized modified hollow silica nanoparticles to the hardening resin layer and the low-refractive-index resin layer. However, the dispersion of nanomaterials requires special equipment, and the degree of dispersion directly affects the stability of the coating and the thickness of the coating, which will indirectly affect the refractive index of the coating and the light transmittance. Uneven dispersion will lead to a decrease in transparency, and the preparation conditions require high standards.

[0004] CN111454648A discloses a high-strength flexible transparent wear-resistant hardening coating on the surface of a folding screen and a preparation method thereof. The high-strength flexible transparent wear-resistant hardening coating on the surface of the folding screen mobile phone comprises a UV-curable hardening liquid, and the UV-curable hardening liquid comprises: naphthalene ring-type polyethylene glycol acrylate, a diluent, a photoinitiator, and octavinyl-POSS, which are uniformly mixed. The mass ratio of naphthalene ring-type polyethylene glycol acrylate, the diluent, the photoinitiator, and octavinyl-POSS is 1:0.5-2:0.01-0.1:0.005-0.1. The high-strength flexible transparent wear-resistant hardening coating on the surface of the folding screen provided by this technical solution has the characteristics of combining rigidity and flexibility, realizing the combination of good hardness and flexibility, and having good wear resistance. However, the cost of the octavinyl-POSS used is high.

[0005] Therefore, it is necessary to develop a photo-curable coating liquid whose cured coating has the characteristics of high hardness and high wear resistance. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a photo-curable coating liquid, a preparation method thereof, and an application. The cured coating of the photo-curable coating liquid has the characteristics of high hardness, good wear resistance, high adhesion, excellent chemical resistance, excellent aging resistance, and surface antistatic property.

[0007] To achieve this purpose, the present invention adopts the following technical solutions:

[0008] In the first aspect, the present invention provides a photo-curable coating liquid, which comprises an acrylate oligomer, a polycarbonate-modified acrylate oligomer, an active diluent monomer, a photoinitiator, and a vinyl silane;

[0009] The preparation raw materials of the acrylate oligomer include an isocyanate, a polyester polyol, a hydroxyl-type acrylic resin, and a hydroxyl-type chain transfer agent.

[0010] In the present invention, the acrylate oligomer and the polycarbonate-modified acrylate oligomer can form a relatively high crosslinking density through photo-curing, making each molecular structure more compact. The polycarbonate-modified acrylate oligomer has a large number of polar ester bonds, which are easy to form hydrogen bonds with other polar groups in the system, further enhancing the internal cohesion within the coating formed by the photo-curable coating liquid. Therefore, the resistance to external stress damage is stronger, endowing the coating with excellent chemical resistance and hardness.

[0011] In the present invention, the acrylate oligomer and the polycarbonate-modified acrylate oligomer form an interpenetrating polymer network structure with a flexible structure and a rigid structure, enabling the coating formed by the photocurable coating solution to have high hardness, excellent adhesion, and excellent wear resistance. The wear resistance of the coating refers to the resistance of the coating to mechanical friction, meaning the degree to which the material resists peeling from the matrix under the condition of mechanical friction force. In fact, it is the comprehensive effect of the hardness, flexibility, adhesion, and cohesion of the coating. The polycarbonate chain segment in the polycarbonate-modified acrylate oligomer and the chain segment formed by the polyester polyol in the acrylate oligomer are both flexible structures, which can absorb the stress caused by the shrinkage of functional groups and the attraction of chemical bonds during the curing process, thereby playing a certain role in improving the shrinkage rate of the coating. At the same time, the alternating arrangement of ester groups and benzene rings in the polycarbonate structure helps to hinder the sliding and deformation of molecular chains, thereby improving its toughness. Wear resistance is closely related to toughness, and wear resistance is greatly affected by toughness. The addition of the polycarbonate-modified acrylate oligomer helps to improve the wear resistance of the coating formed by the photocurable coating solution.

[0012] In the present invention, the vinyl silane is grafted onto the polymer structure of the photocurable coating through a double bond, improving the surface antistatic property, wear resistance, and aging resistance of the coating formed by the photocurable coating solution. The vinyl silane is grafted onto the polymer structure through a double bond, and the other end is a siloxane structure, which can form a single-molecule conductive layer, avoiding the accumulation of charges in the polymer structure and improving the antistatic performance; in addition, the bond energy of the silicon-oxygen bond is 452 l kJ / mol, which can endow the coating with a certain aging resistance on the surface of the coating formed by the photocurable coating; the vinyl silane reduces the surface energy of the surface of the coating formed by the photocurable coating, and the friction coefficient of the coating is significantly reduced, thereby further improving the wear resistance of the coating.

[0013] In the present invention, the hydroxyl-terminated chain transfer agent introduces hydroxyl groups at the ends of the acrylate oligomer chains, improving the hydroxyl distribution, reducing the viscosity of the photocurable coating solution, and increasing the hardness of the coating.

[0014] Preferably, the isocyanate includes aromatic isocyanates.

[0015] In the present invention, the aromatic isocyanate has high activity and high hardness, and can increase the hardness of the coating formed by the photocurable coating solution.

[0016] Preferably, the aromatic isocyanate includes any one or a combination of at least two of toluene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, dimethylbiphenyl diisocyanate, or polymethylene polyphenyl isocyanate.

[0017] Preferably, the polyester polyol includes any one or a combination of at least two of Suzhou Hanhai P1010, Suzhou Hanhai P1011, Suzhou Hanhai P1020, Suzhou Hanhai P1030, Suzhou Hanhai P1040, or Suzhou Hanhai P1050.

[0018] Preferably, the hydroxyl group-containing acrylic resin includes any one or a combination of at least two of hydroxyethyl acrylate, hydroxyethyl methacrylate, β-hydroxyethyl acrylate, or β-hydroxyethyl methacrylate.

[0019] Preferably, the hydroxyl group-containing chain transfer agent includes any one or a combination of at least two of mercaptoethanol, mercaptopropanol, or 2-hydroxyethyl mercaptopropionate.

[0020] Preferably, the raw materials for preparing the acrylate oligomer include the following components in parts by weight: 40-70 parts of isocyanate (such as 42 parts, 45 parts, 48 parts, 50 parts, 52 parts, 55 parts, 60 parts, 65 parts, or 68 parts, etc.), 20-40 parts of polyester polyol (such as 22 parts, 24 parts, 26 parts, 28 parts, 30 parts, 32 parts, 34 parts, 36 parts, or 38 parts, etc.), 5-15 parts of hydroxyl group-containing acrylic resin (such as 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, or 14 parts, etc.), and 0.5-1.5 parts of hydroxyl group-containing chain transfer agent (such as 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts, or 1.4 parts, etc.).

[0021] In the present invention, if the weight fraction of the hydroxyl group-containing chain transfer agent is too large, the molecular weight of the polymer formed after photocuring of the photocurable coating liquid is small, and the mechanical properties will deteriorate significantly, even affecting the degree of photocuring, resulting in a decrease in chemical resistance and hardness; if the weight fraction of the hydroxyl group-containing chain transfer agent is too small, the molecular weight distribution of the polymer formed after photocuring of the photocurable coating liquid is too wide, and the formed coating loses uniformity and controllability.

[0022] Preferably, the raw materials for preparing the polycarbonate-modified acrylate oligomer include polycarbonate diol, acrylate compounds, and a catalyst.

[0023] Preferably, the polycarbonate diol includes any one or a combination of at least two of Ube UH-50, Ube UH-100, Ube UH-200, Ube UH-300, Ube PH-50, Ube PH-100, Ube PH-200, or Ube PH-300 of Japan.

[0024] Preferably, the acrylate compounds include any one or a combination of at least two of acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, octyl acrylate, or phenyl acrylate.

[0025] Preferably, the raw materials for preparing the polycarbonate-modified acrylate oligomer include the following components in parts by weight: 40-60 parts of polycarbonate diol (such as 42 parts, 44 parts, 46 parts, 48 parts, 50 parts, 52 parts, 54 parts, 56 parts or 58 parts, etc.), 50-70 parts of acrylate compound (such as 52 parts, 54 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 66 parts or 68 parts, etc.) and 0.5-1.5 parts of catalyst (such as 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, 1.1 parts, 1.2 parts, 1.3 parts or 1.4 parts, etc.).

[0026] In the present invention, if the weight fraction of the polycarbonate diol is too large, the density of the photocurable groups in the photocurable coating solution is low, and the degree of photocuring will decrease, resulting in a decrease in chemical resistance and hardness; if the weight fraction of the polycarbonate diol is too small, the content of flexible groups in the photocurable coating solution is small, and the flexibility will decrease significantly.

[0027] Preferably, the catalyst includes tetrabutyl titanate.

[0028] Preferably, the active diluent monomer includes a monofunctional diluent monomer and / or a polyfunctional diluent monomer.

[0029] Preferably, the monofunctional diluent monomer includes any one or a combination of at least two of isobornyl acrylate, isobornyl methacrylate, octadecyl methacrylate, butyl acrylate, isooctyl acrylate, isodecyl acrylate, isodecyl methacrylate, lauryl acrylate, lauryl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl acrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, styrene, isodecyl acrylate, vinyl acetate, dicyclopentenyloxyethyl methacrylate, N-vinylpyrrolidone or 4-tert-butylcyclohexyl acrylate.

[0030] Preferably, the polyfunctional diluent monomer includes any one or a combination of at least two of diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, ethylene glycol phthalate diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, propoxylated neopentyl glycol diacrylate, dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, tricyclodecane dimethanol diacrylate or dipropylene glycol diacrylate.

[0031] Preferably, the photoinitiator is a cleavage-type photoinitiator.

[0032] Preferably, the photoinitiator includes any one or a combination of at least two of photoinitiator 184, photoinitiator 1173, or photoinitiator 651.

[0033] Preferably, the vinyl silane includes any one or a combination of at least two of vinyltrimethoxysilane, vinyltriethoxysilane, or vinyltriisopropoxysilane.

[0034] Preferably, the photocurable coating solution includes the following components by weight: 30-50 parts (such as 32 parts, 34 parts, 36 parts, 38 parts, 40 parts, 42 parts, 44 parts, 46 parts, or 48 parts, etc.) of acrylate oligomer, 20-50 parts (such as 22 parts, 25 parts, 28 parts, 30 parts, 32 parts, 35 parts, 38 parts, 40 parts, 45 parts, or 48 parts, etc.) of polycarbonate-modified acrylate oligomer, 40-60 parts (such as 42 parts, 44 parts, 46 parts, 48 parts, 50 parts, 52 parts, 54 parts, 56 parts, or 58 parts, etc.) of reactive diluent monomer, 3-8 parts (such as 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, or 7.5 parts, etc.) of photoinitiator, and 1-3 parts (such as 1.1 parts, 1.2 parts, 1.3 parts, 1.5 parts, 1.8 parts, 2.0 parts, 2.2 parts, 2.5 parts, or 2.9 parts, etc.) of vinyl silane.

[0035] In the present invention, if the weight fraction of the acrylate oligomer is too large, the brittleness of the coating formed after photocuring of the photocurable coating solution will be too large, the flexibility will decrease, and the impact resistance will decrease; if the weight fraction is too small, the aging resistance of the coating formed after photocuring of the photocurable coating solution will significantly decrease.

[0036] In a second aspect, the present invention provides a method for preparing the photocurable coating solution as described in the first aspect, and the preparation method includes the following steps: mixing the acrylate oligomer, polycarbonate-modified acrylate oligomer, reactive diluent monomer, photoinitiator, and vinyl silane to obtain the photocurable coating solution.

[0037] In a third aspect, the present invention provides an application of the photocurable coating solution as described in the first aspect in an optical film.

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] The photocurable coating liquid prepared by compounding acrylate oligomer, polycarbonate-modified acrylate oligomer, reactive diluent monomer, photoinitiator and vinyl silane has a cured coating with the characteristics of high hardness, good abrasion resistance, high adhesion, excellent chemical resistance, excellent aging resistance and surface antistatic property. The adhesion of the coating formed by the photocurable coating liquid is 3-5B level, the number of times of abrasion resistance by steel wool is 35-50 times, the hardness is 2-4H, and the surface resistance is 9×10 7 Ω - 3.1×10 8 Ω. Preferably, the adhesion is 5B level, the number of times of abrasion resistance by steel wool is 44-50 times, the hardness is 4H, and the surface resistance is 1.1×10 8 Ω - 1.4×10 8 Ω. Specific Embodiments

[0040] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0041] Example 1

[0042] This example provides a photocurable coating liquid and its preparation method. The photocurable coating liquid includes the following components by weight: 40 parts of acrylate oligomer, 40 parts of polycarbonate-modified acrylate oligomer, 40 parts of 1,6-hexanediol diacrylate, 20 parts of butyl acrylate, 2 parts of initiator 184, 1 part of initiator 1173 and 1 part of vinyltriethoxysilane.

[0043] Preparation of the acrylate oligomer: Add 30 parts by weight of polyester polyol (Suzhou Hanhai P1010) to a flask, stir and heat to 45°C, slowly add 55 parts by weight of isocyanate (toluene diisocyanate), react at 80°C for 2.5 h, then add 10 parts by weight of hydroxyl-type acrylic resin (hydroxyethyl acrylate) and 1 part by weight of hydroxyl-type chain transfer agent (mercaptoethanol), and continue to react at a constant temperature for 1 h to obtain the acrylate oligomer.

[0044] Preparation of the polycarbonate-modified acrylate oligomer: Add 50 parts by weight of polycarbonate diol (Ube PH-200, Japan), 60 parts by weight of acrylate compound (methacrylic acid), and 50 parts by weight of toluene, heat to 55°C, stir at a stirring speed of 1000 revolutions per minute until the solution is mixed evenly, add 1 part by weight of catalyst (tetrabutyl titanate), then raise the temperature to 80°C, and react at a constant temperature for 6 h to obtain the polycarbonate-modified acrylate oligomer.

[0045] The preparation method of the photocurable coating liquid is as follows: Mix 40 parts by weight of the above acrylate oligomer, 40 parts by weight of the above polycarbonate-modified acrylate oligomer, 40 parts by weight of 1,6-hexanediol diacrylate, 20 parts by weight of butyl acrylate, 2 parts by weight of initiator 184, 1 part by weight of initiator 1173, and 1 part by weight of vinyltriethoxysilane evenly to obtain the photocurable coating liquid.

[0046] Example 2

[0047] This example provides a photocurable coating liquid and its preparation method. The photocurable coating liquid includes the following components in parts by weight: 30 parts of the above acrylate oligomer, 20 parts of the above polycarbonate-modified acrylate oligomer, 40 parts of 1,3-butanediol dimethacrylate, 5 parts of initiator 651, and 2 parts of vinyltrimethoxysilane.

[0048] Preparation of the acrylate oligomer: Add 40 parts by weight of polyester polyol (Suzhou Hanhai P1040) to a flask, stir and heat to 45 °C, slowly add 60 parts by weight of isocyanate (p-phenylene diisocyanate), and react at 80 °C for 2 h; then add 15 parts by weight of hydroxy-type acrylic resin (2-hydroxyethyl methacrylate) and 0.5 part by weight of hydroxy-type chain transfer agent (3-mercaptopropanol), and continue to keep the temperature for reaction for 1 h to obtain the acrylate oligomer.

[0049] Preparation of the polycarbonate-modified acrylate oligomer: Add 60 parts by weight of polycarbonate diol (Ube PH-300, Japan), 50 parts by weight of acrylate compound (ethyl acrylate), and 50 parts by weight of toluene, heat to 55 °C, stir at a stirring speed of 1000 revolutions per minute until the solution is mixed evenly, add 1.5 parts by weight of catalyst tetrabutyl titanate, then raise the temperature to 80 °C, and keep the temperature for reaction for 6 h to obtain the polycarbonate-modified acrylate oligomer.

[0050] The preparation method of the photocurable coating liquid is as follows: Mix 30 parts by weight of the above acrylate oligomer, 20 parts by weight of the above polycarbonate-modified acrylate oligomer, 40 parts by weight of 1,3-butanediol dimethacrylate, 5 parts by weight of initiator 651, and 2 parts by weight of vinyltrimethoxysilane evenly to obtain the photocurable coating liquid.

[0051] Example 3

[0052] This example provides a photocurable coating liquid and its preparation method. The photocurable coating liquid includes the following components in parts by weight: 50 parts of the above acrylate oligomer, 50 parts of the above polycarbonate-modified acrylate oligomer, 30 parts of diethylene glycol diacrylate, 20 parts of isooctyl acrylate, 4 parts of initiator 651, 4 parts of photoinitiator 1173, and 3 parts of vinyltriisopropoxysilane.

[0053] Preparation of the acrylate oligomer: Add 30 parts by weight of polyester polyol (Suzhou Hanhai P1050) to a flask, stir and heat to 45 °C, slowly add 50 parts by weight of isocyanate (dimethylbiphenyl diisocyanate), and react at 80 °C for 3 h; then add 5 parts by weight of hydroxyl-type acrylic resin (2-hydroxyethyl acrylate) and 1.5 parts by weight of hydroxyl-type chain transfer agent (2-hydroxyethyl mercaptopropionate), and continue to react under insulation for 1 h to obtain the acrylate oligomer.

[0054] Preparation of the polycarbonate-modified acrylate oligomer: Add 40 parts by weight of polycarbonate diol (Ube UH-100, Japan), 70 parts by weight of acrylate compound (octyl acrylate), and 50 parts by weight of toluene, heat to 55 °C, stir at a stirring speed of 1000 revolutions per minute until the solution is mixed evenly, add 0.5 part by weight of catalyst (tetrabutyl titanate), then raise the temperature to 80 °C, and react under insulation for 6 h to obtain the polycarbonate-modified acrylate oligomer.

[0055] The preparation method of the photocurable coating liquid is as follows: Mix 50 parts by weight of the above acrylate oligomer, 50 parts by weight of the above polycarbonate-modified acrylate oligomer, 30 parts by weight of diethylene glycol diacrylate, 20 parts by weight of isooctyl acrylate, 4 parts by weight of initiator 651, 4 parts by weight of photoinitiator 1173, and 3 parts by weight of vinyltriisopropoxysilane evenly to obtain the photocurable coating liquid.

[0056] Example 4

[0057] This example provides a photocurable coating liquid and its preparation method. The difference from Example 1 is only that the weight fraction of the polycarbonate-modified acrylate oligomer is adjusted to 15 parts, and the others are the same as in Example 1.

[0058] Example 5

[0059] This example provides a photocurable coating liquid and its preparation method. The difference from Example 1 is only that the weight fraction of the polycarbonate-modified acrylate oligomer is adjusted to 55 parts, and the others are the same as in Example 1.

[0060] Example 6

[0061] This example provides a photocurable coating liquid and its preparation method. The difference from Example 1 is only that the weight fraction of vinyltriethoxysilane is adjusted to 0.2 parts, and the others are the same as in Example 1.

[0062] Example 7

[0063] This embodiment provides a photocurable coating liquid and a preparation method thereof. The difference from Embodiment 1 is only that the weight part of vinyltriethoxysilane is adjusted to 3.5 parts, and the others are the same as those in Embodiment 1.

[0064] Example 8

[0065] This embodiment provides a photocurable coating liquid and a preparation method thereof. The difference from Embodiment 1 is only that in the preparation of the acrylate oligomer, toluene diisocyanate is replaced with hexamethylene diisocyanate of the same mass, and the others are the same as those in Embodiment 1.

[0066] Example 9

[0067] This embodiment provides a photocurable coating liquid and a preparation method thereof. The difference from Embodiment 1 is only that the weight part of the polycarbonate diol is adjusted to 65 parts, and the others are the same as those in Embodiment 1.

[0068] Example 10

[0069] This embodiment provides a photocurable coating liquid and a preparation method thereof. The difference from Embodiment 1 is only that the weight part of the polycarbonate diol is adjusted to 35 parts, and the others are the same as those in Embodiment 1.

[0070] Comparative Example 1

[0071] This comparative example provides a photocurable coating liquid and a preparation method thereof. The difference from Embodiment 1 is only that in the preparation of the acrylate oligomer, no hydroxyl group-containing chain transfer agent (mercaptoethanol) is added, and the others are the same as those in Embodiment 1.

[0072] Comparative Example 2

[0073] This comparative example provides a photocurable coating liquid and a preparation method thereof. The difference from Embodiment 1 is only that in the preparation of the acrylate oligomer, the polyester polyol (Suzhou Hanhai P1010) is replaced with ethylene glycol of the same mass, and the others are the same as those in Embodiment 1.

[0074] Comparative Example 3

[0075] This comparative example provides a photocurable coating liquid and a preparation method thereof. The difference from Embodiment 1 is only that 40 parts by weight of the polycarbonate-modified acrylate oligomer in the photocurable coating liquid is replaced with 18.2 parts by weight of polycarbonate diol (Ube PH-200, Japan) and 21.8 parts by weight of acrylate compound (methacrylic acid), and the others are the same as those in Embodiment 1.

[0076] Comparative Example 4

[0077] This comparative example provides a photocurable coating solution and a preparation method thereof. The difference from Example 1 is only that the photocurable coating solution does not contain vinyltriethoxysilane, and the others are the same as in Example 1.

[0078] The photocurable coating solutions provided in the examples and comparative examples were coated on one surface of an optical grade polyethylene terephthalate film with a thickness of 125 μm (manufacturer: Toyobo Co., Ltd., Japan, trade name: A4300), and the coating weight was controlled at 10 ± 2 gsm. The formed coating was dried at 90 °C for 2 minutes, and then cured by ultraviolet irradiation with a light amount of 400 mJ / cm 2 to form a coating, and the following performance tests were carried out.

[0079] (1) Adhesion: Determined with reference to GB / T 1720-1979 (1989) "Method for Determining Adhesion of Paint Films".

[0080] (2) Flexibility: Determined with reference to GB / T 1731-1993 "Method for Determining Flexibility of Paint Films".

[0081] (3) Resistance to steel wool abrasion: Under a load of 500 gf / cm 2 in a wear-resistant instrument, use 0000# steel wool to rub back and forth on the surface of the hard coating, and record the maximum number of friction times without scratches.

[0082] (4) Pencil hardness: Test the hardness of the cured coating by the pencil method with reference to GB / T 6739-2006.

[0083] (5) Surface resistance: Determined with reference to GB / T 1410-2006 (IEC 60093) "Test Methods for Volume Resistivity and Surface Resistivity of Solid Insulating Materials".

[0084] (6) Resistance to MEK rubbing: Under a load of 500 gf / cm 2 in a wear-resistant instrument, use a cotton cloth dipped in MEK to rub back and forth on the surface of the hard coating, and collect the maximum number of times the coating is not damaged.

[0085] (7) Aging resistance test: The light irradiance is 0.83 W / m 2 / nm, the blackboard temperature under light is 70 °C, the light exposure duration is 8 h; the blackboard temperature under condensation is 50 °C, the condensation duration is 4 h, and the cycle is carried out. Record the aging resistance test result when ΔE ≥ 0.5 before and after light exposure or the minimum duration when the coating shows powdering.

[0086] The test results are shown in Table 1.

[0087] Table 1

[0088]

[0089] According to the test results in Table 1, the adhesion of the coatings formed by the photocurable coating liquids provided in Examples 1-10 is 3-5B level, the number of times of resistance to steel wool abrasion is 35-50 times, the hardness is 2-4H, and the surface resistance is 9×10 7 Ω - 3.1×10 8 Ω. The adhesion of the coatings formed by the photocurable coating liquids provided in Examples 1-3 is 5B level, the number of times of resistance to steel wool abrasion is 44-50 times, the hardness is 4H, and the surface resistance is 1.1×10 8 Ω - 1.4×10 8 Ω. The coatings cured from the photocurable coating liquids of the present invention have the characteristics of high hardness, good wear resistance, high adhesion, excellent chemical resistance, excellent aging resistance and surface antistatic property.

[0090] Compared with Example 1, if the weight fraction of the polycarbonate-modified acrylate oligomer is too small (Example 4), the hardness of the coating formed by the photocurable coating liquid will decrease, and the brittleness will increase, resulting in a slight deterioration in the resistance to steel wool wiping; if the weight fraction of the polycarbonate-modified acrylate oligomer is too large (Example 5), the aging resistance of the coating formed by the photocurable coating liquid will decrease significantly, indicating that the photocurable coating liquid prepared with the weight fraction of the polycarbonate-modified acrylate oligomer within a specific range has better performance.

[0091] Compared with Example 1, if the weight fraction of vinyltriethoxysilane is too small (Example 6), the aging resistance and conductivity of the coating formed by the photocurable coating liquid will decrease; if the weight fraction of vinyltriethoxysilane is too large (Example 7), the adhesion of the coating will decrease, indicating that the photocurable coating liquid prepared with the weight fraction of vinyltriethoxysilane within a specific range has better performance.

[0092] Compared with Example 1, if toluene diisocyanate is replaced with hexamethylene diisocyanate (Example 8), the number of times of resistance to steel wool abrasion will decrease, the wear resistance will decrease, the hardness will decrease, the number of times of resistance to methyl ethyl ketone wiping will decrease, and the aging resistance will decrease, indicating that the use of aromatic isocyanate as the isocyanate results in better performance of the prepared photocurable coating liquid.

[0093] Compared with Example 1, if the weight fraction of polycarbonate diol in the preparation of the polycarbonate-modified acrylate oligomer is too large (Example 9), the resistance to methyl ethyl ketone wiping and the hardness of the coating formed by the photocurable coating liquid will decrease due to the decrease in the density of photocuring groups; if the weight fraction of polycarbonate diol in the preparation of the polycarbonate-modified acrylate oligomer is too small (Example 10), the content of flexible groups after photocuring will be small, and the flexibility will decrease significantly, indicating that the photocurable coating liquid prepared with the weight fraction of polycarbonate diol within a specific range has better performance.

[0094] Compared with Example 1, if no hydroxyl type chain transfer agent is added in the preparation of the acrylate oligomer (Comparative Example 1), the viscosity of the prepared photocurable coating liquid is high, uneven, the number of times of resistance to steel wool abrasion decreases, and the abrasion resistance, flexibility, hardness and aging resistance of the formed coating all decrease.

[0095] Compared with Example 1, if the polyester polyol is replaced with ethylene glycol (Comparative Example 2), the number of times of resistance to steel wool abrasion, adhesion, flexibility, abrasion resistance, resistance to methyl ethyl ketone wiping, hardness and aging resistance all decrease.

[0096] Compared with Example 1, if the polycarbonate diol and the acrylate compound are not esterified and directly mixed with other components in the photocurable coating liquid (Comparative Example 3), the flexibility of the coating formed by the prepared photocurable coating liquid is poor, the adhesion decreases, and the abrasion resistance, chemical resistance and aging resistance all decrease significantly.

[0097] Compared with Example 1, if vinyltriethoxysilane is not included in the photocurable coating liquid (Comparative Example 4), the abrasion resistance is poor and the hardness decreases significantly, the surface resistance is high, the antistatic performance is poor, and the aging resistance decreases.

[0098] The applicant declares that the present invention uses the above embodiments to illustrate a photocurable coating liquid and its preparation method and application, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent replacement of each raw material of the product of the present invention, the addition of auxiliary components, the selection of specific methods, etc. all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A photocurable coating liquid, characterized in that, The photocurable coating solution comprises the following components in parts by weight: 30 - 50 parts of acrylate oligomer, 20 - 50 parts of polycarbonate-modified acrylate oligomer, 40 - 60 parts of reactive diluent monomer, 3 - 8 parts of photoinitiator, and 1 - 3 parts of vinylsilane; The raw materials for preparing the acrylate oligomer include isocyanate, polyester polyol, hydroxy-type acrylic resin, and hydroxy-type chain transfer agent; The raw materials for preparing the polycarbonate-modified acrylate oligomer include polycarbonate diol, acrylate compound, and catalyst.

2. The photocuring coating liquid according to claim 1, wherein The isocyanate includes aromatic isocyanate.

3. The photocurable coating liquid according to claim 2, wherein, The aromatic isocyanate includes any one or a combination of at least two of toluene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, dimethylbiphenyl diisocyanate, or polymethylene polyphenyl isocyanate.

4. The photocurable coating liquid according to claim 1, characterized in that The hydroxy-type acrylic resin includes hydroxyethyl acrylate and / or hydroxyethyl methacrylate.

5. The photocurable coating liquid according to claim 1, characterized in that, The hydroxy-type chain transfer agent includes any one or a combination of at least two of mercaptoethanol, mercaptopropanol, or 2-hydroxyethyl mercaptopropionate.

6. The photocuring coating liquid according to claim 1, wherein The raw materials for preparing the acrylate oligomer include the following components in parts by weight: 40 - 70 parts of isocyanate, 20 - 40 parts of polyester polyol, 5 - 15 parts of hydroxy-type acrylic resin, and 0.5 - 1.5 parts of hydroxy-type chain transfer agent.

7. The photocuring coating liquid according to claim 1, wherein The acrylate compound includes any one or a combination of at least two of acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, octyl acrylate, phenyl acrylate, etc.

8. The photocurable coating liquid according to claim 1, wherein The raw materials for preparing the polycarbonate-modified acrylate oligomer include the following components in parts by weight: 40 - 60 parts of polycarbonate diol, 50 - 70 parts of acrylate compound, and 0.5 - 1.5 parts of catalyst.

9. The photocurable coating liquid according to claim 1, wherein The reactive diluent monomer includes monofunctional diluent monomer and / or polyfunctional diluent monomer.

10. The photocurable coating liquid according to claim 9, wherein The monofunctional diluent monomer includes any one or a combination of at least two of isobornyl acrylate, isobornyl methacrylate, stearyl methacrylate, butyl acrylate, isooctyl acrylate, isodecyl acrylate, isodecyl methacrylate, lauryl acrylate, lauryl methacrylate, glycidyl methacrylate, tetrahydrofurfuryl acrylate, 2-phenoxyethyl acrylate, 2-phenoxyethyl methacrylate, styrene, vinyl acetate, dicyclopentenyloxyethyl methacrylate, N-vinylpyrrolidone, or 4-tert-butylcyclohexyl acrylate.

11. The photocurable coating liquid according to claim 9, wherein The polyfunctional diluent monomer includes any one or a combination of at least two of diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, ethylene glycol phthalate diacrylate, 1,3-butanediol dimethacrylate, 1,4-butanediol diacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, propoxylated neopentyl glycol diacrylate, dipropylene glycol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, tricyclodecane dimethanol diacrylate, or dipropylene glycol diacrylate.

12. The photocuring coating liquid according to claim 1, wherein The photoinitiator is a cleavage-type photoinitiator.

13. The photocurable coating liquid according to claim 1, characterized in that, The photoinitiator includes any one or a combination of at least two of photoinitiator 184, photoinitiator 1173, or photoinitiator 651.

14. The photocurable coating liquid according to claim 1, characterized in that, The vinylsilane includes any one or a combination of at least two of vinyltrimethoxysilane, vinyltriethoxysilane, or vinyltriisopropoxysilane.

15. A method for preparing a photocurable coating liquid according to any one of claims 1-14, characterized in that, The preparation method includes the following steps: mixing an acrylate oligomer, a polycarbonate-modified acrylate oligomer, an active diluent monomer, a photoinitiator, and a vinylsilane to obtain the photocurable coating liquid.

16. Use of the photocurable coating liquid according to any one of claims 1-14 in an optical film.

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