SEALANT RESIN COMPOSITION FOR FLEXIBLE GRAPHITE PLATE IMPREGNATION
A sealant configured to saturate and seal a graphite plate, such as a type of graphite plate that may be used in a hydrogen (H 2 ) fuel cell, wherein the sealant may be one or more, or a mixture, of ethoxylated monomers. In some embodiments herein the sealant does not have an acid or a surfactant. Also disclosed is a graphite sheet impregnated with a sealant.
1 . A sealant configured to saturate and seal a graphite plate for use in a hydrogen (H 2 ) fuel cell, wherein the sealant comprises one or more ethoxylated [meth]acrylate monomers.
2 . The sealant of claim 1 that comprises 70-95% by weight of triethylene glycol dimethacrylate monomer.
3 . The sealant of claim 1 that comprises a [meth]acrylate-based monomer.
4 . The sealant of claim 1 , that includes a trifunctional monomer.
5 . The sealant of claim 1 , wherein the sealant has a viscosity at 22° C. from 8-20 centipoise (cP).
6 . The sealant of claim 1 , wherein the sealant is configured to be washed with water to remove it from the graphite plate surface prior to curing.
7 . The sealant of claim 1 that has a cured hardness of up to 90 Shore D.
8 . The sealant of claim 1 , wherein the extractables in a cured graphite plate impregnated with the sealant are <3% by weight.
9 . The sealant of claim 1 that provides a flexural strength of impregnated graphite plates at 95° C. of a <30% drop from RT strength.
10 . The sealant of claim 1 that does not include a surfactant.
11 . The sealant of claim 1 that can be cured by (a) E-beam radiation or, (b) heating.
12 . The sealant of claim 1 that is further includes a radical initiator and that is configured to be cured by heating.
13 . The sealant of claim 12 that has a cure profile of <100 minutes at a temperature of <100° C.
14 . The sealant of claim 13 , wherein the thermal cure profile is generated at atmospheric pressure.
15 . The sealant of claim 1 that has a gel time in a 90° C. water bath of from 1.5 minutes to 3 minutes.
16 . The sealant of claim 1 that has an activated resin stability of no curing up to 1 week at 40° C.
17 . The sealant of claim 12 that is configured to cure in 10 minutes or less, or less than 45 minutes, after being impregnated in a graphite sheet and the graphite sheet is immersed in water at a temperature of 80° C.-95° C.
18 . The sealant of claim 17 , wherein the cure time is determined by a solvent extraction test.
19 . The sealant of claim 1 that comprises a plurality of ethoxylated [meth] acrylate monomers.
20 . The sealant of claim 12 that includes 0.15%-0.35% by weight of radical initiator.