UV photocuring OCA optical adhesive film and preparation method thereof

Abstract

The invention discloses a UV photocuring OCA optical adhesive film and a preparation method thereof, and relates to the technical field of adhesive materials, the UV photocuring OCA optical adhesive film sequentially comprises a light release film layer, an optical colloid layer and a heavy release film layer from top to bottom; the optical colloid layer is prepared from the following raw materials in parts by weight: 25 to 35 parts of allylated hyperbranched polyphenyl ether, 8 to 12 parts of a soft monomer, 5 to 8 parts of a hard monomer, 4 to 6 parts of other functional monomers, 0.5 to 1 part of a photoinitiator, 0.5 to 0.8 part of an antioxidant and 0.8 to 1.2 parts of a defoaming agent. The UV photocuring OCA optical adhesive film is good in adhesive property, excellent in aging resistance and high temperature resistance and good in environmental protection performance, the release layer is easy to strip, and no trace and no pollution are generated after the release layer is stripped.

Description

Technical Field

[0001] The invention relates to the technical field of adhesive materials, and in particular to a UV light-cured OCA optical adhesive film and a preparation method thereof. Background Art

[0002] As the application of electronic and electrical products with LCD screens such as mobile phones and computers becomes more and more popular, the use of OCA optical adhesive films in LCD touch screens is becoming more and more widespread, and the amount used is also increasing. OCA optical adhesive film is a baseless double-sided laminating tape made by curing OCA optical adhesive. It has the characteristics of colorless transparency, high light transmittance, and high adhesive strength. It is widely used in display touch modules in mobile phones, tablets, smart watches, car central control, notebooks and other products.

[0003] The structure of OCA optical adhesive film is generally divided into three layers, the middle one is the optical colloid layer without substrate, and the upper and lower layers are optical release film layers. Existing OCA optical adhesive films have more or less poor adhesion and peeling properties, insufficient aging resistance, poor high temperature resistance, and poor environmental performance. During long-term use, the adhesive layer is prone to swelling, mechanical properties and light transmittance decrease, which in turn leads to technical problems such as reduced reliability and durability of corresponding equipment.

[0004] In order to solve the above problems, the Chinese invention patent with authorization announcement number CN107245304B discloses an OCA optical adhesive film, which includes a first release film layer, a soft adhesive layer, a first hard adhesive layer and a second release film layer in contact with each other in sequence, or includes a first release film layer, a second hard adhesive layer, a soft adhesive layer, a first hard adhesive layer and a second release film layer in contact with each other in sequence; the Shore hardness of the soft adhesive layer is 5 to 50A, and the thickness is 50 to 200 μm; the Shore hardness of the first and second hard adhesive layers are both 15 to 50D, and the thickness is both 50 to 150 μm. The invention designs the adhesive layer of the OCA optical adhesive film into a multi-layer structure with different hardnesses, so that the OCA optical adhesive film has suitable hardness and elasticity, thereby making it show good filling properties. Moreover, since the adhesive layer of the OCA optical adhesive film provided by the invention is a multi-layer structure, each adhesive layer is relatively thin, thereby reducing the difficulty of curing the adhesive layer during the production of the adhesive film. However, the OCA optical adhesive film still has more or less technical defects such as high temperature resistance and heat aging resistance need to be further improved, and adhesion and peeling performance need to be further improved.

[0005] It can be seen that the art still needs an OCA optical adhesive film with good bonding performance, excellent aging resistance, high temperature resistance, good environmental performance, easy peeling of the release layer, no traces after peeling, and no pollution, and a preparation method thereof. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a UV light-cured OCA optical adhesive film with good bonding performance, excellent aging resistance and high temperature resistance, good environmental performance, easy peeling of the release layer, no traces after peeling, and no pollution, and a preparation method thereof.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a UV light-cured OCA optical adhesive film, which includes a light release film layer, an optical colloid layer and a heavy release film layer from top to bottom; the optical colloid layer is made of the following raw materials in parts by weight: 25-35 parts of allylated hyperbranched polyphenylene ether, 8-12 parts of soft monomers, 5-8 parts of hard monomers, 4-6 parts of other functional monomers, 0.5-1 parts of photoinitiator, 0.5-0.8 parts of antioxidant, and 0.8-1.2 parts of defoaming agent.

[0008] Preferably, the thickness of the light release film layer is 50 microns or 75 microns; the thickness of the heavy release film layer is 75 microns or 100 microns; and the thickness of the optical colloid layer is 75-250 microns.

[0009] Preferably, there is no special requirement for the source of the allylated hyperbranched polyphenylene ether. In one embodiment of the present invention, the allylated hyperbranched polyphenylene ether is prepared according to the method of Example 6 of Chinese invention patent with authorization announcement number CN101717503B.

[0010] Preferably, the soft monomer is at least one of ethyl acrylate, butyl acrylate and isooctyl acrylate.

[0011] Preferably, the hard monomer is a mixture of methyl methacrylate, styrene and acrylonitrile in a mass ratio of (1-3):1:(1-2).

[0012] Preferably, the other functional monomers are at least two of N-vinyloxazolidinone, 1,3-dihydro-1-(1-methylethynyl)-2H-benzimidazol-2-one, bis(1-alkenyl-1-imidazole)methanone, tricyclo[5.2.1.02,6]dec-8-yl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, and allyl succinimidyl carbonate.

[0013] Preferably, the antioxidant is at least one of antioxidant 1010 and antioxidant 168.

[0014] Preferably, the photoinitiator is at least one of benzoin dimethyl ether, benzoin ethyl ether and benzoin isopropyl ether.

[0015] Preferably, the defoaming agent is one or more of tributyl phosphate, defoaming agent Deqian 3100, and defoaming agent BYK088.

[0016] Preferably, the light release film layer is made of a PET base film with a release agent coated on the surface; the heavy release film layer is a PET release film layer; the ratio of the release force of the release surface of the heavy release film layer to that of the light release film layer is (2-4):1.

[0017] Preferably, the release agent comprises the following components in parts by weight: 5-8 parts of 80# microcrystalline wax, 35-45 parts of hydroxyfluorosilicone oil, 3-6 parts of inorganic functional filler, 0.8-1.2 parts of catalyst, 2-4 parts of dimethylbiphenyl diisocyanate, 0.5-0.8 parts of leveling agent, and 20-35 parts of solvent.

[0018] Preferably, the hydroxy fluorosilicone oil is SiSB®OF 9020 hydroxy fluorosilicone oil, provided by Nanjing Sisbo Silicone Co., Ltd.

[0019] Preferably, the inorganic functional filler is at least one of talc and kaolin; the particle size of the inorganic functional filler is 1000-1500 mesh.

[0020] Preferably, the catalyst is at least one of dibutyltin dilaurate DY-12 and organic bismuth DY-20.

[0021] Preferably, the leveling agent is at least one of leveling agent WynCoat®6077 and leveling agent WynCoat®SL 3310.

[0022] Preferably, the solvent is any one of diethyl ether, chloroform and toluene.

[0023] Another object of the present invention is to provide a method for preparing the UV light-curable OCA optical adhesive film, comprising the following steps:

[0024] Step S1, preparation of a light release film layer: after uniformly mixing the components of the release agent according to weight, uniformly coating the mixture on the PET base film, and then drying the mixture at 100-120° C. for 3-5 hours to obtain a light release film layer;

[0025] Step S2, preparation of optical adhesive: after mixing the raw materials of the optical colloid layer uniformly according to weight parts, evacuate and remove bubbles to obtain the optical adhesive;

[0026] Step S3, preparation of optical adhesive film: evenly coating the optical adhesive on the light release film layer, and then laminating the heavy release film layer on the surface of the optical adhesive, and after curing, obtaining a UV light-cured OCA optical adhesive film.

[0027] Preferably, the curing in step S3 is carried out under ultraviolet light with a wavelength of 365 nm and a light intensity of 20-110 mW / cm for 2-3 hours.

[0028] Due to the application of the above technical solution, the present invention has the following beneficial effects:

[0029] (1) The method for preparing the UV light-curing OCA optical adhesive film disclosed in the present invention has simple process, convenient operation and control, high preparation efficiency and finished product qualification rate, low energy consumption, low equipment dependence and labor intensity, is suitable for continuous large-scale production, and has high promotion and application value.

[0030] (2) The UV light-cured OCA optical adhesive film disclosed in the present invention, the optical colloid layer comprises the following raw materials in parts by weight: 25-35 parts of allylated hyperbranched polyphenylene ether, 8-12 parts of soft monomer, 5-8 parts of hard monomer, 4-6 parts of other functional monomers, 0.5-1 parts of photoinitiator, 0.5-0.8 parts of antioxidant, and 0.8-1.2 parts of defoamer. Through the mutual cooperation between the raw materials, the product has good bonding performance, excellent aging resistance and high temperature resistance. Since no volatile toxic and harmful organic solvents are added, the product has good environmental performance during production and use.

[0031] (3) In the UV light-cured OCA optical adhesive film disclosed in the present invention, the other functional monomers are at least two of N-vinyl oxazolidinone, 1,3-dihydro-1-(1-methylethynyl)-2H-benzimidazol-2-one, bis(1-alkenyl-1-imidazole)methanone, tricyclo[5.2.1.02,6]dec-8-yl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, and allyl succinimidyl carbonate. The addition of these functional monomers can simultaneously introduce at least two of oxazolidinone, benzimidazolone, bisimidazolyl ketone, tricyclo[5.2.1.02,6]dec-8-yl ester, amphoteric organic ion salt, and succinimidyl carbonate into the formed film. Under the multiple effects of electronic effect, steric effect, and conjugation effect on structures such as hyperbranched polyphenylene ether, the manufactured product has better aging resistance and high temperature resistance, better peeling performance, and no trace or pollution after the release layer is peeled off.

[0032] (4) The UV light-cured OCA optical adhesive film disclosed in the present invention, the release agent comprises the following components in parts by weight: 5-8 parts of 80# microcrystalline wax, 35-45 parts of hydroxy fluorosilicone oil, 3-6 parts of inorganic functional filler, 0.8-1.2 parts of catalyst, 2-4 parts of dimethyl biphenyl diisocyanate, 0.5-0.8 parts of leveling agent, and 20-35 parts of solvent. Through the mutual cooperation and joint action of the components, the prepared release film exhibits a light and stable release force, is easy to peel off, and leaves no trace or pollution after peeling. DETAILED DESCRIPTION

[0033] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0034] Embodiment 1: A UV light-cured OCA optical adhesive film comprises, from top to bottom, a light release film layer, an optical colloid layer and a heavy release film layer; the optical colloid layer comprises the following raw materials in parts by weight: 25 parts of allylated hyperbranched polyphenylene ether, 8 parts of soft monomers, 5 parts of hard monomers, 4 parts of other functional monomers, 0.5 parts of photoinitiator, 0.5 parts of antioxidant, and 0.8 parts of defoaming agent.

[0035] The thickness of the light release film layer is 50 microns; the thickness of the heavy release film layer is 75 microns; the thickness of the optical colloid layer is 100 microns; the allylated hyperbranched polyphenylene ether is made according to the method of Example 6 of the Chinese invention patent with authorization announcement number CN101717503B; the soft monomer is ethyl acrylate; the hard monomer is methyl methacrylate, styrene, and acrylonitrile mixed in a mass ratio of 1:1:1.

[0036] The other functional monomers are N-vinyl oxazolidinone, 1,3-dihydro-1-(1-methylethynyl)-2H-benzimidazol-2-one, bis(1-alkenyl-1-imidazole)methanone, tricyclo[5.2.1.02,6]dec-8-yl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, and allyl succinimidyl carbonate, which are mixed in a mass ratio of 1:2:3:2:2:1.

[0037] The antioxidant is antioxidant 1010; the photoinitiator is dimethyl benzoate; the defoaming agent is tributyl phosphate; the light release film layer is made of a PET base film coated with a release agent on the surface; the heavy release film layer is a PET release film layer; the release force ratio of the release surface of the heavy release film layer to that of the light release film layer is 2:1.

[0038] The release agent comprises the following components in parts by mass: 5 parts of 80# microcrystalline wax, 35 parts of hydroxyfluorosilicone oil, 3 parts of inorganic functional filler, 0.8 parts of catalyst, 2 parts of dimethylbiphenyl diisocyanate, 0.5 parts of leveling agent, and 20 parts of solvent; the hydroxyfluorosilicone oil is SiSB®OF 9020 hydroxyfluorosilicone oil, provided by Nanjing Sisbo Silicone Co., Ltd.; the inorganic functional filler is talcum powder; the particle size of the inorganic functional filler is 1000 mesh; the catalyst is dibutyltin dilaurate DY-12; the leveling agent is leveling agent WynCoat®6077; and the solvent is ether.

[0039] A method for preparing the UV light-curable OCA optical adhesive film comprises the following steps:

[0040] Step S1, preparation of a light release film layer: after uniformly mixing the components of the release agent according to parts by weight, uniformly coating the mixture on a PET base film, and then drying the mixture at 100° C. for 3 hours to obtain a light release film layer;

[0041] Step S2, preparation of optical adhesive: after mixing the raw materials of the optical colloid layer uniformly according to weight parts, evacuate and remove bubbles to obtain the optical adhesive;

[0042] Step S3, preparation of optical adhesive film: evenly apply the optical adhesive on the light release film layer, and then overlap the heavy release film layer on the surface of the optical adhesive. After curing, a UV light-cured OCA optical adhesive film is obtained; the curing is carried out under ultraviolet light with a wavelength of 365nm and a light intensity of 60mW / cm for 2 hours.

[0043] Embodiment 2: A UV light-cured OCA optical adhesive film comprises, from top to bottom, a light release film layer, an optical colloid layer and a heavy release film layer; the optical colloid layer is made of the following raw materials in parts by weight: 27 parts of allylated hyperbranched polyphenylene ether, 9 parts of soft monomers, 6 parts of hard monomers, 4.5 parts of other functional monomers, 0.6 parts of photoinitiator, 0.6 parts of antioxidant, and 0.9 parts of defoaming agent.

[0044] The thickness of the light release film layer is 50 microns; the thickness of the heavy release film layer is 75 microns; the thickness of the optical colloid layer is 100 microns; the allylated hyperbranched polyphenylene ether is made according to the method of Example 6 of the Chinese invention patent with authorization announcement number CN101717503B; the soft monomer is butyl acrylate; the hard monomer is methyl methacrylate, styrene, and acrylonitrile mixed in a mass ratio of 1.5:1:1.2.

[0045] The other functional monomers are N-vinyl oxazolidinone, 1,3-dihydro-1-(1-methylethynyl)-2H-benzimidazol-2-one, bis(1-alkenyl-1-imidazole)methanone, tricyclo[5.2.1.02,6]dec-8-yl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, and allyl succinimidyl carbonate, which are mixed in a mass ratio of 1:2:3:3:1:1; the antioxidant is antioxidant 168; the photoinitiator is benzoin ethyl ether; and the defoamer is defoamer Deqian 3100.

[0046] The light release film layer is made of a PET base film with a release agent coated on the surface; the heavy release film layer is a PET release film layer; the release force ratio of the release surface of the heavy release film layer to the light release film layer is 2.5:1.

[0047] The release agent comprises the following components in parts by mass: 6 parts of 80# microcrystalline wax, 37 parts of hydroxyfluorosilicone oil, 4 parts of inorganic functional filler, 0.9 parts of catalyst, 2.5 parts of dimethylbiphenyl diisocyanate, 0.6 parts of leveling agent, and 25 parts of solvent; the hydroxyfluorosilicone oil is SiSB®OF 9020 hydroxyfluorosilicone oil, provided by Nanjing Sisbo Organic Silicone Co., Ltd.; the inorganic functional filler is kaolin; the particle size of the inorganic functional filler is 1200 mesh; the catalyst is organic bismuth DY-20; the leveling agent is leveling agent WynCoat®SL 3310; and the solvent is chloroform.

[0048] A method for preparing the UV light-curable OCA optical adhesive film comprises the following steps:

[0049] Step S1, preparation of a light release film layer: after uniformly mixing the components of the release agent according to parts by weight, uniformly coating the mixture on the PET base film, and then drying the mixture at 105° C. for 3.5 hours to obtain a light release film layer;

[0050] Step S2, preparation of optical adhesive: after mixing the raw materials of the optical colloid layer uniformly according to weight parts, evacuate and remove bubbles to obtain the optical adhesive;

[0051] Step S3, preparation of optical adhesive film: evenly apply the optical adhesive on the light release film layer, and then overlap the heavy release film layer on the surface of the optical adhesive. After curing, a UV light-cured OCA optical adhesive film is obtained; the curing is carried out under ultraviolet light with a wavelength of 365nm and a light intensity of 60mW / cm for 2.3 hours.

[0052] Embodiment 3: A UV light-cured OCA optical adhesive film comprises, from top to bottom, a light release film layer, an optical colloid layer and a heavy release film layer; the optical colloid layer is made of the following raw materials in parts by weight: 30 parts of allylated hyperbranched polyphenylene ether, 10 parts of soft monomers, 6.5 parts of hard monomers, 5 parts of other functional monomers, 0.75 parts of photoinitiator, 0.65 parts of antioxidant, and 1 part of defoaming agent.

[0053] The thickness of the light release film layer is 50 microns; the thickness of the heavy release film layer is 75 microns; the thickness of the optical colloid layer is 100 microns; the allylated hyperbranched polyphenylene ether is made according to the method of Example 6 of the Chinese invention patent with authorization announcement number CN101717503B; the soft monomer is isooctyl acrylate; the hard monomer is methyl methacrylate, styrene, and acrylonitrile mixed in a mass ratio of 2:1:1.5.

[0054] The other functional monomers are N-vinyl oxazolidinone, 1,3-dihydro-1-(1-methylethynyl)-2H-benzimidazol-2-one, bis(1-alkenyl-1-imidazole)methanone, tricyclo[5.2.1.02,6]dec-8-yl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, and allyl succinimidyl carbonate, which are mixed in a mass ratio of 2:3:1:2:4:1.

[0055] The antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 1:2; the photoinitiator is benzoin isopropyl ether; and the defoamer is defoamer BYK088.

[0056] The light release film layer is made of a PET base film with a release agent coated on the surface; the heavy release film layer is a PET release film layer; the release force ratio of the release surface of the heavy release film layer to the light release film layer is 3:1.

[0057] The release agent comprises the following components in parts by mass: 6.5 parts of 80# microcrystalline wax, 40 parts of hydroxyfluorosilicone oil, 4.5 parts of inorganic functional filler, 1 part of catalyst, 3 parts of dimethylbiphenyl diisocyanate, 0.65 parts of leveling agent, and 28 parts of solvent; the hydroxyfluorosilicone oil is SiSB®OF 9020 hydroxyfluorosilicone oil, provided by Nanjing Sisbo Silicone Co., Ltd.; the inorganic functional filler is talcum powder; the particle size of the inorganic functional filler is 1300 mesh; the catalyst is dibutyltin dilaurate DY-12; the leveling agent is leveling agent WynCoat®SL 3310; and the solvent is toluene.

[0058] A method for preparing the UV light-curable OCA optical adhesive film comprises the following steps:

[0059] Step S1, preparation of a light release film layer: after uniformly mixing the components of the release agent according to parts by weight, uniformly coating the mixture on the PET base film, and then drying the mixture at 110° C. for 4 hours to obtain a light release film layer;

[0060] Step S2, preparation of optical adhesive: after mixing the raw materials of the optical colloid layer uniformly according to weight parts, evacuate and remove bubbles to obtain the optical adhesive;

[0061] Step S3, preparation of optical adhesive film: evenly apply the optical adhesive on the light release film layer, and then overlap the heavy release film layer on the surface of the optical adhesive. After curing, a UV light-cured OCA optical adhesive film is obtained; the curing is carried out under ultraviolet light with a wavelength of 365nm and a light intensity of 60mW / cm for 2.5 hours.

[0062] Embodiment 4: A UV light-cured OCA optical adhesive film comprises, from top to bottom, a light release film layer, an optical colloid layer and a heavy release film layer; the optical colloid layer comprises the following raw materials in parts by weight: 33 parts of allylated hyperbranched polyphenylene ether, 11 parts of soft monomers, 7.5 parts of hard monomers, 5.5 parts of other functional monomers, 0.9 parts of photoinitiator, 0.75 parts of antioxidant, and 1.1 parts of defoaming agent.

[0063] The thickness of the light release film layer is 50 microns; the thickness of the heavy release film layer is 75 microns; the thickness of the optical colloid layer is 100 microns; the allylated hyperbranched polyphenylene ether is made according to the method of Example 6 of the Chinese invention patent with authorization announcement number CN101717503B; the soft monomer is a mixture of ethyl acrylate, butyl acrylate, and isooctyl acrylate in a mass ratio of 1:2:3; the hard monomer is a mixture of methyl methacrylate, styrene, and acrylonitrile in a mass ratio of 2.5:1:1.8.

[0064] The other functional monomers are N-vinyl oxazolidinone, 1,3-dihydro-1-(1-methylethynyl)-2H-benzimidazol-2-one, bis(1-alkenyl-1-imidazole)methanone, methacrylate tricyclo[5.2.1.02,6]dec-8-yl ester, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, allyl succinimide The amino carbonates are mixed in a mass ratio of 1:1:1:1:1:1; the antioxidant is a mixture of antioxidant 1010 and antioxidant 168 in a mass ratio of 3:5; the photoinitiator is a mixture of benzoin dimethyl ether, benzoin ethyl ether and benzoin isopropyl ether in a mass ratio of 1:2:3; the defoamer is a mixture of tributyl phosphate, defoamer Deqian 3100 and defoamer BYK088 in a mass ratio of 2:1:1.

[0065] The light release film layer is made of a PET base film with a release agent coated on the surface; the heavy release film layer is a PET release film layer; the release force ratio of the release surface of the heavy release film layer to the light release film layer is 3.5:1.

[0066] The release agent comprises the following components in parts by mass: 7.5 parts of 80# microcrystalline wax, 43 parts of hydroxyfluorosilicone oil, 5.5 parts of inorganic functional filler, 1.1 parts of catalyst, 3.5 parts of dimethylbiphenyl diisocyanate, 0.75 parts of leveling agent, and 33 parts of solvent; the hydroxyfluorosilicone oil is SiSB®OF 9020 hydroxyfluorosilicone oil, provided by Nanjing Sisbo Silicone Co., Ltd.; the inorganic functional filler is talcum powder and kaolin mixed in a mass ratio of 1:3; the particle size of the inorganic functional filler is 1400 mesh; the catalyst is dibutyltin dilaurate DY-12 and organic bismuth DY-20 mixed in a mass ratio of 1:2; the leveling agent is a leveling agent WynCoat®6077 and a leveling agent WynCoat®SL 3310 mixed in a mass ratio of 3:5; the solvent is ether.

[0067] A method for preparing the UV light-curable OCA optical adhesive film comprises the following steps:

[0068] Step S1, preparation of a light release film layer: after uniformly mixing the components of the release agent according to parts by weight, uniformly coating the mixture on a PET base film, and then drying the mixture at 115° C. for 4.5 hours to obtain a light release film layer;

[0069] Step S2, preparation of optical adhesive: after mixing the raw materials of the optical colloid layer uniformly according to weight parts, evacuate and remove bubbles to obtain the optical adhesive;

[0070] Step S3, preparation of optical adhesive film: evenly apply the optical adhesive on the light release film layer, and then overlap the heavy release film layer on the surface of the optical adhesive. After curing, a UV light-cured OCA optical adhesive film is obtained; the curing is carried out under ultraviolet light with a wavelength of 365nm and a light intensity of 60mW / cm for 2.8 hours.

[0071] Embodiment 5: A UV light-cured OCA optical adhesive film comprises, from top to bottom, a light release film layer, an optical colloid layer and a heavy release film layer; the optical colloid layer is made of the following raw materials in parts by weight: 35 parts of allylated hyperbranched polyphenylene ether, 12 parts of soft monomers, 8 parts of hard monomers, 6 parts of other functional monomers, 1 part of photoinitiator, 0.8 parts of antioxidant, and 1.2 parts of defoaming agent.

[0072] The thickness of the light release film layer is 50 microns; the thickness of the heavy release film layer is 75 microns; the thickness of the optical colloid layer is 100 microns; the allylated hyperbranched polyphenylene ether is made according to the method of Example 6 of the Chinese invention patent with authorization announcement number CN101717503B; the soft monomer is ethyl acrylate; the hard monomer is a mixture of methyl methacrylate, styrene and acrylonitrile in a mass ratio of 3:1:2.

[0073] The other functional monomers are N-vinyl oxazolidinone, 1,3-dihydro-1-(1-methylethynyl)-2H-benzimidazol-2-one, bis(1-alkenyl-1-imidazole)methanone, tricyclo[5.2.1.02,6]dec-8-yl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, and allyl succinimidyl carbonate, which are mixed in a mass ratio of 1:2:1:2:3:1; the antioxidant is antioxidant 1010; the photoinitiator is benzoin ethyl ether; and the defoamer is defoamer Deqian 3100.

[0074] The light release film layer is made of a PET base film with a release agent coated on the surface; the heavy release film layer is a PET release film layer; the release force ratio of the release surface of the heavy release film layer to the light release film layer is 4:1.

[0075] The release agent comprises the following components in parts by mass: 8 parts of 80# microcrystalline wax, 45 parts of hydroxyfluorosilicone oil, 6 parts of inorganic functional filler, 1.2 parts of catalyst, 4 parts of dimethylbiphenyl diisocyanate, 0.8 parts of leveling agent, and 35 parts of solvent; the hydroxyfluorosilicone oil is SiSB®OF 9020 hydroxyfluorosilicone oil, provided by Nanjing Sisbo Organic Silicone Co., Ltd.; the inorganic functional filler is kaolin; the particle size of the inorganic functional filler is 1500 mesh; the catalyst is dibutyltin dilaurate DY-12; the leveling agent is leveling agent WynCoat®6077; and the solvent is chloroform.

[0076] A method for preparing the UV light-curable OCA optical adhesive film comprises the following steps:

[0077] Step S1, preparation of a light release film layer: after uniformly mixing the components of the release agent according to parts by weight, uniformly coating the mixture on the PET base film, and then drying the mixture at 120° C. for 5 hours to obtain a light release film layer;

[0078] Step S2, preparation of optical adhesive: after mixing the raw materials of the optical colloid layer uniformly according to weight parts, evacuate and remove bubbles to obtain the optical adhesive;

[0079] Step S3, preparation of optical adhesive film: evenly apply the optical adhesive on the light release film layer, and then overlap the heavy release film layer on the surface of the optical adhesive. After curing, a UV light-cured OCA optical adhesive film is obtained; the curing is carried out under ultraviolet light with a wavelength of 365nm and a light intensity of 60mW / cm for 3 hours.

[0080] Comparative Example: A UV light-cured OCA optical adhesive film and a preparation method thereof are substantially the same as those in Example 1, except that no other functional monomers and dimethylbiphenyl diisocyanate are added.

[0081] In order to further illustrate the beneficial technical effects of the UV light-curing OCA optical adhesive films involved in each embodiment of the present invention, the UV light-curing OCA optical adhesive films involved in Examples 1-5 and Comparative Examples 1-2 were tested for relevant performances, and the test methods are as follows:

[0082] (1) Peel strength: Refer to GB / T 2792-2014 to measure the 180° peel strength of stainless steel plates;

[0083] (2) Whether there is residual adhesive: Tear off the release film layer of the optical adhesive film, stick it to the steel plate, press it back and forth naturally with a 2kg roller, let it stand for 20 minutes, and gently tear off the film to see if there is any residual adhesive on the adhesive material;

[0084] (3) Heat aging resistance: The optical film was baked at 80°C for 100 hours. After cooling to room temperature, the 180° peel strength was measured according to method (1). The 180° peel strength retention rate was calculated. The larger the value, the better the heat aging resistance.

[0085] (4) High temperature resistance: Place each test sample in an aging oven at 200°C for 1 hour, then test the peel strength according to the method in (1) and calculate the peel strength retention rate. The larger the value, the better the high temperature resistance.

[0086] (5) Release force of light release film: TESA7475 standard tape, peeled at 300 mm / min and 180°C.

[0087]

[0088] As can be seen from Table 1, the UV light-cured OCA optical adhesive film involved in the embodiment of the present invention has better aging resistance and high temperature resistance than the comparative product, the release film layer is easy to peel off, and there is no residual adhesive after peeling. The addition of other functional monomers and dimethyl diphenyl diisocyanate is beneficial to improving the above properties.

[0089] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A UV light-curable OCA optical adhesive film, characterized in that: The optical colloid layer comprises a light release film layer, an optical colloid layer and a heavy release film layer from top to bottom; the optical colloid layer comprises the following raw materials in parts by weight: 25-35 parts of allylated hyperbranched polyphenylene ether, 8-12 parts of soft monomer, 5-8 parts of hard monomer, 4-6 parts of other functional monomers, 0.5-1 parts of photoinitiator, 0.5-0.8 parts of antioxidant, and 0.8-1.2 parts of defoaming agent; The soft monomer is at least one of ethyl acrylate, butyl acrylate and isooctyl acrylate; the hard monomer is methyl methacrylate, styrene and acrylonitrile mixed in a mass ratio of (1-3):1:(1-2).

2. The UV light-curable OCA optical adhesive film according to claim 1, characterized in that: The thickness of the light release film layer is 50 micrometers or 75 micrometers; the thickness of the heavy release film layer is 75 micrometers or 100 micrometers; the thickness of the optical colloid layer is 75-250 micrometers.

3. The UV light-curable OCA optical adhesive film according to claim 1, characterized in that: The other functional monomers are at least two of N-vinyl oxazolidinone, 1,3-dihydro-1-(1-methylethynyl)-2H-benzimidazol-2-one, bis(1-alkenyl-1-imidazole)methanone, tricyclo[5.2.1.02,6]dec-8-yl methacrylate, 3-[N,N-dimethyl-[2-(2-methylprop-2-enoyloxy)ethyl]ammonium]propane-1-sulfonic acid inner salt, and allyl succinimidyl carbonate.

4. The UV light-curable OCA optical adhesive film according to claim 1, characterized in that: The antioxidant is at least one of antioxidant 1010 and antioxidant 168; the photoinitiator is at least one of benzoin dimethyl ether, benzoin ethyl ether, and benzoin isopropyl ether; the defoamer is one or more of tributyl phosphate, defoamer Deqian 3100, and defoamer BYK088.

5. The UV light-curable OCA optical adhesive film according to claim 1, characterized in that: The light release film layer is made of a PET base film with a release agent coated on the surface; the heavy release film layer is a PET release film layer; the ratio of the release force of the release surface of the heavy release film layer to that of the light release film layer is (2-4):

1.

6. The UV light-curable OCA optical adhesive film according to claim 5, characterized in that: The release agent comprises the following components in parts by mass: 5-8 parts of 80# microcrystalline wax, 35-45 parts of hydroxyfluorosilicone oil, 3-6 parts of inorganic functional filler, 0.8-1.2 parts of catalyst, 2-4 parts of dimethylbiphenyl diisocyanate, 0.5-0.8 parts of leveling agent and 20-35 parts of solvent.

7. The UV light-curable OCA optical adhesive film according to claim 6, characterized in that: The hydroxy fluorosilicone oil is SiSB®OF 9020 hydroxy fluorosilicone oil; the inorganic functional filler is at least one of talc and kaolin; the particle size of the inorganic functional filler is 1000-1500 mesh; the catalyst is at least one of dibutyltin dilaurate DY-12 and organic bismuth DY-20; the leveling agent is at least one of leveling agent WynCoat®6077 and leveling agent WynCoat®SL 3310; the solvent is any one of ether, chloroform and toluene.

8. A method for preparing the UV light-curable OCA optical adhesive film according to any one of claims 1 to 7, characterized in that: The steps include: Step S1, preparation of a light release film layer: after uniformly mixing the components of the release agent according to weight, uniformly coating the mixture on the PET base film, and then drying the mixture at 100-120° C. for 3-5 hours to obtain a light release film layer; Step S2, preparation of optical adhesive: after mixing the raw materials of the optical colloid layer uniformly according to weight parts, evacuate and remove bubbles to obtain the optical adhesive; Step S3, preparation of optical adhesive film: evenly coating the optical adhesive on the light release film layer, and then laminating the heavy release film layer on the surface of the optical adhesive, and after curing, obtaining a UV light-cured OCA optical adhesive film.

9. A method for preparing the UV light-curable OCA optical adhesive film according to claim 8, characterized in that: The curing in step S3 is carried out under the irradiation of ultraviolet light with a wavelength of 365 nm and a light intensity of 20-110 mW / cm for 2-3 hours.

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