BALLISTIC-RESISTANT COMPOSITE WITH BLOCKED ISOCYANATE
A ballistic-resistant composite includes at least one layer that has a network of ballistic fibers and a resin matrix. The resin matrix includes blocked isocyanate that is composed of isocyanate bonded with a blocking agent. The resin matrix is cross-linkable by heating to a temperature that causes the isocyanate to liberate from the blocking agent and the liberated isocyanate to reactively cause cross-linking of the resin matrix.
1 . A ballistic-resistant composite comprising:
at least one layer including a network of ballistic fibers and a resin matrix, the resin matrix including blocked isocyanate composed of isocyanate bonded with a blocking agent, the resin matrix being cross-linkable by heating to a temperature that causes the isocyanate to liberate from the blocking agent and the liberated isocyanate to reactively cause cross-linking of the resin matrix.
2 . The ballistic-resistant composite as recited in claim 1 , wherein the resin matrix includes polyurethane.
3 . The ballistic-resistant composite as recited in claim 1 , wherein the resin matrix includes, by weight, from 0.2% to 25% of the blocked isocyanate.
4 . The ballistic-resistant composite as recited in claim 1 , wherein the resin matrix includes, by weight, from 2% to 18% of the blocked isocyanate.
5 . The ballistic-resistant composite as recited in claim 1 , wherein the resin matrix includes, by weight, from 8% to 12% of the blocked isocyanate.
6 . The ballistic-resistant composite as recited in claim 1 , wherein the deblocking temperature is from 120° C. to 140° C.
7 . The ballistic-resistant composite as recited in claim 1 , wherein the blocking agent is selected from the group consisting of phenol, nonyl phenol, β-dicarbonyl compounds, methylethylketoxime, alcohols, ε-caprolactam, amides, imidazoles, pyrazoles, and combinations thereof.
8 . The ballistic-resistant composite as recited in claim 1 , wherein the resin matrix further includes a deblocking catalyst.
9 . The ballistic-resistant composite as recited in claim 1 , wherein the network of ballistic fibers is selected from the group consisting of ultra-high molecular weight polyethylene fibers, aramid fibers, copolymer aramid fibers, and combinations thereof.
10 . The ballistic-resistant composite as recited in claim 9 , wherein the resin matrix is a polyurethane selected from the group consisting of polyether-based urethane, polyester-based urethane, polycaprolactone-based urethane, and combinations thereof.
11 . The ballistic-resistant composite as recited in claim 1 , wherein the at least one layer includes two of the layers laminated together.
12 . A ballistic-resistant composite comprising:
at least one layer including a network of ultra-high molecular weight polyethylene (UHMWPE) fibers and a polyurethane resin matrix, the polyurethane resin matrix including blocked isocyanate composed of isocyanate bonded with a blocking agent, the blocked isocyanate having a deblocking temperature from 120° C. to 140° C. at which the isocyanate liberates from the blocking agent.
13 . The ballistic-resistant composite as recited in claim 12 , wherein the polyurethane resin matrix includes, by weight, from 2% to 18% of the blocked isocyanate.
14 . The ballistic-resistant composite as recited in claim 13 , wherein the blocking agent is selected from the group consisting of phenol, nonyl phenol, β-dicarbonyl compounds, methylethylketoxime, alcohols, ε-caprolactam, amides, imidazoles, pyrazoles, and combinations thereof.
15 . The ballistic-resistant composite as recited in claim 14 , wherein the polyurethane resin matrix is a polyurethane selected from the group consisting of polyether-based urethane, polyester-based urethane, polycaprolactone-based urethane, and combinations thereof.
16 . The ballistic-resistant composite as recited in claim 15 , wherein the polyurethane resin matrix further includes a deblocking catalyst.
17 . A method of forming a ballistic-resistant article, the method comprising:
providing at least one layer that includes a network of ballistic fibers and a resin matrix, the resin matrix includes blocked isocyanate composed of isocyanate bonded with a blocking agent, the resin matrix being cross-linkable by heating to a deblocking temperature that liberates the isocyanate from the blocking agent, the liberated isocyanate being reactive to cause cross-linking of the resin matrix; and heating the at least one layer to at least the deblocking temperature to cause the resin matrix to cross-link.
18 . The method as recited in claim 17 , including compressing the at least one layer during the heating.
19 . The method as recited in claim 17 , wherein the deblocking temperature is from 120° C. to 140° C.