Impact resistant composite article
View Patent ↗An impact resistant composite article has two or more layers of ballistic fabric and ionomer layers disposed between the fabric layers. The ionomer is highly neutralized so that it has essentially no melt flow. A process also for making such a composite article that involves deposition of an aqueous colloid of the ionomer onto the fabric, followed by drying.
1. An impact resistant composite article comprising one or more stacks layered together, each stack comprising two or more fibrous layers with a non-melt-processable ionomer disposed between at least two of the fibrous layers in which the non-melt-processable ionomer is at least 85% neutralized based on the total number of equivalents of carboxylic acid moieties in the ionomer and has a zero melt flow index at 190° C. melt flow test of ASTM D1238, and wherein
(i) the weight fraction of solid ionomer in the multilayer composite article is between 5 and 16%, and
(ii) the ionomer is neutralized with an ion selected from the group consisting of sodium, potassium, lithium, beryllium, magnesium, calcium, strontium, barium, tin, lead, aluminum, titanium, tantalum, cerium and combinations thereof.
2. The composite article of claim 1 in which the ionomer comprises between 5 mole % and 15 mole % of acid comonomer.
3. The composite article of claim 2 in which the ionomer comprises between 8 mole % and 12 mole % of acid comonomer.
4. The composite article of claim 1 in which the ionomer is at least 95% neutralized based on the total number of equivalents of carboxylic acid moieties.
5. The composite article of claim 1 in which the ionomer is at least 100% neutralized based on the total number of equivalents of carboxylic acid moieties.
6. The composite article of claim 1 in which the ionomer is in the form of a coating partially covering the fibers in at least some of the fibrous layers.
7. The composite article of claim 1 in which the ionomer forms a discrete layer between at least two of the fibrous layers.
8. The composite article of claim 7 in which the fibrous layers comprise fiber bundles and at least half of the thickness of any bundle the bundle remains un-impregnated by ionomer.
9. The composite article of claim 1 in which at least some of the fibrous layers comprise nonwoven fabrics.
10. The composite article of claim 1 in which at least one of the fibrous layers is a woven fabric.
11. The composite article of claim 1 in which at least one stack comprises at least one pair of adjacent fibrous layers of different composition.
12. The composite article of claim 11 in which the fibrous layer comprises poly (p-phenylene terephthalamide).
13. The composite article of claim 1 in which the fibrous layer is at least partially coated with a water repellant material.
14. The composite article of claim 13 in which the water repellant material comprises a material that is at least partially fluorinated.
15. The composite article of claim 14 in which the fluorinated material is a partially fluorinated acrylate copolymer or a partially fluorinated methacrylate copolymer.
16. The composite article of claim 1 in which the ionomer further comprises up to 30% dry weight of a material selected from the group consisting of a plasticizer, a surfactant, and a mixture or combination thereof.
17. The composite article of claim 16 in which the plasticizer is a long chain fatty acid.
18. The composite article of claim 16 in which the plasticizer is 1-decanol.
19. An impact resistant composite article comprising one or more stacks layered together, each stack comprising two or more fibrous layers with a non-melt-processable ionomer disposed between at least two of the fibrous layers in which the non-melt-processable ionomer is at least 100% neutralized based on the total number of equivalents of carboxylic acid moieties in the ionomer and has a zero melt flow index at 190° C. melt flow test of ASTM D1238, and wherein
(i) the weight fraction of solid ionomer in the multilayer composite article is between 5 and 16% and the weight fraction of fiber is between 84 and 95%, and
(ii) the ionomer is neutralized with an ion selected from the group consisting of sodium, potassium, lithium, beryllium, magnesium, calcium, strontium, barium, tin, lead, aluminum, titanium, tantalum, cerium and combinations thereof.