Optically clear adhesives using semi- interpenetrating polymer networks
Provided are semi -interpenetrating optically clear adhesives, methods of use, and methods of manufacture. An example semi-interpenetrating optically clear adhesive comprises a transparent polymer network comprised of at least two or more interpenetrating polymer networks, wherein at least one polymer network is a thermoset material and at least one other polymer network is a thermoplastic material, yielding an optically clear adhesive with a transparency above 80% and an elastic toughness above 1 MJ/m 3 .
1. A method of manufacturing a semi-interpenetrating optically clear adhesive comprising:
providing a monomer mixture comprising thermoplastic-forming monomers and thermoset-forming monomers, the thermoset-forming monomers comprising one or more multifunctional thiol(s) and one or more multifunctional comonomer(s), the one or more multifun-ctional thiol(s) and the one or more mult fun ctional comonomen(s) provided in off-stoichiometric ratios;
dispensing the monomer mixture on a display module;
curing the thermoset-forming monomers to form a thermoset network of polysulfide thermoset polymers;
curing the thermoplastic-forming monomers to form a thermoplastic network;
wherein the curing the thermoplastic-forming monomers is performed after the curing of the thermoset-forming monomers;
wherein the thermoplastic network semi-interpenetrates the thermoset network to produce the semi-interpenetrating optically clear adhesive
where the optically clear adhesive comprises a Young's Modulus less than 100 MPa in order to serve as a buffer layer for mechanical stresses between two layers of the display module.
2. The method of claim 1 , wherein the monomer mixture undergoes two orthogonal reactions to form one or more thermoset networks, and after which another reaction to form one or more thermoplastic networks.
3. The method of claim 1 , wherein the monomer mixture comprises one or more thermoplastic polymers solvated into the liquid monomer mixture.
4. The method of claim 1 , wherein the monomer mixture is dispensed directly between a display module and a cover lens.