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 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 to 4000 Da; and a second diacrylate, II,
where p=2-6.
2. The composition of claim 1 wherein the weight ratio of diacrylate I to diacrylate II is in the range of 30:70 to 90:10, and further comprising 0.5 to 10 pph of a polymer including a repeat unit represented by the formula III
where q=1-2 and X=F or H.
3. The composition of claim 1 or claim 2 further comprising 0.5 to 5 pph of a soluble free-radical initiator.
4. The composition of claim 2 wherein the molecular weight of diacrylate I is in the range of 1000-2000, k=0, p=4, and the weight ratio of diacrylate I to diacrylate II is in the range of 40:60 to 80:20, while polymer including a repeat unit represented by the formula III, where q=1 and X=F, is present at a concentration of 7 pph.
5. The composition of claim 2 wherein the molecular weight of diacrylate I is in the range of 1000-2000, k=1 or 2, p=4 and the weight ratio of diacrylate I to diacrylate II is in the range of 60:40 to 90:10, while polymer including a repeat unit represented by the formula III, where q=1 and X=F, is present at a concentration of 7 pph.