Barrier sealant of phenylene oxetane and cationic initiator
This invention relates to cationically curable sealants that provide low moisture permeability and good adhesive strength after cure. The composition consists essentially of an electrophoretic device containing an oxetane compound and a photoinitiating system comprising and photoinitiator and optionally a photosensitizer.
1. An electrophoretic device sealed with a barrier sealant in which the barrier sealant comprises a cationic initiator and an oxetane compound selected from the group consisting of;
2. The electrophoretic device in accordance with claim 1 , wherein the cationic initiator is selected from the group consisting of diaryliodonium salts, triarylsulfonium salts benzylsulfonium salts, phenacylsulfonium salts, N-benzylpyridinium salts, N-benzylpyrazinium salts, N-benzylammonium salts, phosphonium salts, hydrazinium salts, and ammonium borate salts.
3. The electrophoretic device in accordance with claim 2 , wherein the cationic initiator is selected from the group consisting of diaryliodonium salts and triarylsulfonium salts.
4. An electrophoretic device sealed with a barrier sealant in which the barrier sealant consists essentially of
(a) an oxetane compound;
(b) a cationic initiator,
(c) one or more fillers, and
(d) one or more adhesion promoters, or one or more epoxy resins;
wherein said oxetane compound has the structure:
in which
R 7 , R 8 , R 9 , R 10 , and R 11 are independently selected from the group consisting of hydrogen, alkyl, haloalkyl, alkoxy, aryloxy, aryl, alkyloyl and aryloyl groups;
n is 0, 1, 2, 3, or 4;
Z is a cationically reactive functionality selected from the group consisting of
hydroxyl
—OH
vinyl ether
—O—CH═CH—R 12
aliphatic epoxy
glycidyl ether
cycloaliphatic epoxy
in which
R 12 is independently selected from the group consisting of hydrogen, alkyl, haloalkyl, alkoxy, aryloxy, aryl, alkyloyl and aryloyl groups; and
R 13 is a linking group selected from the group consisting of alkyl, haloalkyl, aryl, ether, thio-ether, ester, thio-ester, silane, carbonate, and ketone.
5. The electrophoretic device in accordance with claim 4 , wherein the cationic initiator is selected from the group consisting of diaryliodonium salts, triarylsulfonium salts benzylsulfonium salts, phenacylsulfonium salts, N-benzylpyridinium salts, N-benzyl-pryazinium salts, N-benzylammonium salts, phosphonium salts, hydrazinium salts, and ammonium borate salts.
6. The electrophoretic device in accordance with claim 5 , wherein the cationic initiator is selected from the group consisting of diaryliodonium salts and triarylsulfonium salts.
7. The electrophoretic device in accordance with claim 4 , wherein the one or more fillers are selected from the group consisting of ground quartz, fused silica, amorphous silica, talc, glass beads, graphite, carbon black, alumina, clays, mica, vermiculite, aluminum nitride, boron nitride; silver, copper, gold, tin, tin/lead alloys, poly(tetrachloroethylene), poly(chlorotriflouroethylene), poly(vinylidene chloride), CaO, BaO, Na 2 SO 4 , CaSO 4 , MgSO 4 , zeolites, silica gel, P 2 O 5 , CaCl 2 , and Al 2 O 3 .
8. The electrophoretic device in accordance with claim 4 in which adhesion promoter is not present, and one or more epoxy resins are present and are selected from the group consisting of bisphenol F diglycidyl ether, resorcinol diglycidyl ether, novolac glycidyl ethers, and halogenated glycidyl ethers.
9. The electrophoretic device in accordance with claim 4 in which epoxy resin is not present, and one or more adhesion promoters are present and the promoter is a silane.