US 12,214,564 B2
Optical assembly with encapsulated multilayer optical film and methods of making same
Gregg A. Ambur, San Clemente, CA (US); Douglas S. Dunn, Woodbury, MN (US); Henry A. Kostalik, IV, Minneapolis, MN (US); Christopher S. DeGraw, Inver Grove Heights, MN (US); Thomas P. Klun, Lakeland, MN (US); Benjamin R. Coonce, South St. Paul, MN (US); Richard J. Pokorny, Maplewood, MN (US); Chunjie Zhang, Shoreview, MN (US); Laurent Froissard, Cottage Grove, MN (US); and Joseph S. Warner, Hudson, WI (US)
Assigned to 3M Innovative Properties Company, St. Paul, MN (US)
Appl. No. 17/780,560
Filed by 3M INNOVATIVE PROPERTIES COMPANY, St. Paul, MN (US)
PCT Filed Dec. 1, 2020, PCT No. PCT/IB2020/061319
§ 371(c)(1), (2) Date May 27, 2022,
PCT Pub. No. WO2021/111291, PCT Pub. Date Jun. 10, 2021.
Claims priority of provisional application 63/198,987, filed on Nov. 30, 2020.
Claims priority of provisional application 62/944,906, filed on Dec. 6, 2019.
Prior Publication US 2022/0410511 A1, Dec. 29, 2022
Int. Cl. B29D 11/00 (2006.01); B29K 75/00 (2006.01); B29K 83/00 (2006.01); B29K 105/00 (2006.01); B29K 105/16 (2006.01); B29K 509/02 (2006.01); G02B 5/30 (2006.01)
CPC B29D 11/0073 (2013.01) [B29D 11/0048 (2013.01); B29D 11/00644 (2013.01); G02B 5/305 (2013.01); B29D 11/00932 (2013.01); B29K 2075/00 (2013.01); B29K 2083/00 (2013.01); B29K 2105/0002 (2013.01); B29K 2105/162 (2013.01); B29K 2509/02 (2013.01)] 12 Claims
OG exemplary drawing
 
1. A method of making a shaped optical assembly including an encapsulated multilayer optical film, the method comprising:
i) forming an optical assembly blank by:
a) providing a female thermoforming mold having an internal mold cavity defined by a curved concave platen and a curved convex platen opposite the curved concave platen, wherein the curved convex platen and the curved concave platen are separable when the female thermoforming mold is open, separated by a first gap when the internal mold cavity is being injected with a molten resin, and separated by a second gap smaller than the first gap when the female thermoforming mold is closed;
b) opening the female thermoforming mold and positioning a multilayer optical film preform in contact with the curved convex platen, wherein the multilayer optical film preform has a curvature identical to that of the curved convex platen;
c) positioning a first hard coat film preform with a hard-coat in contact with the curved concave platen, wherein the first hard coat film preform has a curvature identical to that of the curved concave platen, the first hard coat film preform comprising a first (co) polymeric substrate having two opposed major surfaces and an at least partially cured hard coat layer on at least one of the opposed major surfaces, the at least partially cured hard coat layer being formed by at least partially curing a curable hard coat composition comprising:
A. 70 to 96 weight percent of at least one urethane (meth)acrylate compound having an average (meth)acrylate functionality of 2 to 9.58, based on the total weight of components A to D,
B. 2 to 20 weight percent of at least one (meth)acrylate monomer having a (meth)acrylate functionality of 1 to 2, based on the total weight of components A to D, optionally wherein the (meth)acrylate monomer does not comprise a urethane (meth)acrylate compound or a silicone (meth)acrylate,
C. an optional 0.5 to 2 weight percent of at least one silicone (meth)acrylate based on the total weight of components A to D,
D. an optional effective amount of at least one photoinitiator,
E. an optional plurality of inorganic nanoparticles and
F. optionally, at least one solvent;
d) injecting a first flowable material into the internal mold cavity while the curved concave platen and the curved convex platen are maintained separated by the first gap;
e) closing the female thermoforming mold to achieve the second gap and cooling the mold while maintaining the second gap in order to solidify the first flowable material and form the optical assembly blank;
ii) opening the female thermoforming mold and positioning the optical assembly blank in contact with the curved concave platen;
iii) positioning a second hard coat film preform in contact with the curved convex platen, wherein the second hard coat film preform has a curvature identical to that of the curved convex platen, the second hard coat film preform comprising a second (co) polymeric substrate having two opposed major surfaces and an at least partially cured hard coat layer on at least one of the opposed major surfaces, the at least partially cured hard coat layer being formed by at least partially curing a curable hard coat composition identical to the curable hard-coat composition of step (c);
iv) injecting a second flowable material into the internal mold cavity while the curved concave platen and the curved convex platen are maintained separated by the first gap;
v) partially closing the female thermoforming mold to achieve a third gap positioned between the first gap and the second gap and cooling the mold while maintaining the third gap in order to solidify the second flowable material and obtain the shaped optical assembly, wherein the multilayer optical film is encapsulated by the first and second flowable materials.