Low shrinkage, low optical absorbance, low refractive index adhesive composition
View Patent ↗This invention is directed to fluorinated acrylate compositions, which are suitable for use as low shrinkage, low absorbance refractive index matching adhesives for use in “pig-tailing” polymeric integrated waveguides to optical fiber bundles.
1. A cross-linked composition comprising cross-linked monomer units of a first acrylate diradical, Ia,
wherein m and n are integers, k=0-2, the molecular weight is in the range of 1000-4000 Da, and the wavy bonds indicate a radical; and, a second acrylate diradical, IIa,
wherein p=2-6 and the wavy bonds indicate a radical.
2. An article comprising a first shaped moiety having a first surface, a second shaped moiety having a second surface, each of said first surface and said second surface consisting essentially of a fluorinated organic polymer, silica, or silicon; and a composition disposed between and bonding together said first surface and said second surface, said composition comprising cross-linked monomer units of a first acrylate diradical, Ia,
wherein m and n are integers, k=0-2, the molecular weight is in the range of 1000-4000 Da, and the wavy bonds indicate a radical; and, a second acrylate diradical, IIa,
wherein p=2-6 and the wavy bonds indicate a radical.
3. The shaped article of claim 2 wherein said shaped moieties are capable of transmitting light through said surfaces.
4. The shaped article of claim 2 wherein said first surface consists essentially of a fluorinated organic polymer and said second surface consists essentially of silica.
5. A method for effecting bonding the method comprising
positioning a first shaped article having a first surface proximate to a second shaped article having a second surface such that said first surface is separated from said second surface by a gap 0.1 to 100 micrometers across, each of said first surface and said second surface independently consisting essentially of silica, silicon, or a fluorinated organic polymer;
causing to reside in said gap a liquid composition in such manner that both said first surface and said second surface are contacted with said composition, said liquid composition comprising
a first diacrylate, I,
wherein m and n are integers, k=0-2, and the molecular weight is in the range of 1000-4000 Da;
and a second diacrylate, II,
where p=2-6
causing free radicals to be introduced into said composition in such manner as to cause a cross-linking reaction to occur;
allowing the free-radical induced cross-linking reaction to take place until said liquid composition has become clear, hard, glassy, non-flowing and rigid.
6. The method of claim 5 wherein said liquid composition further comprises 0.5 to 5 pph of a soluble free-radical initiator.
7. The method of claim 5 wherein said shaped articles are capable of transmitting light through said surfaces.
8. The method of claim 5 wherein said first surface consists essentially of a fluorinated organic polymer and said second surface consists essentially of silica.