Optical waveguides derived from a combination of poly(perfluorocyclobutanes) and polymeric cyanates
View Patent ↗The present invention is directed to optical waveguides or waveguide systems, comprising at least (a) a first material which is a poly(perfluorocyclobutane), and in direct contact to this material, (b) a second material which is a polycyanate resin made from at least one aromatic difunctional cyanate of formula (I) wherein R 1 to R 8 are independently from each other hydrogen, optionally substituted C 1 -C 10 alkyl, C 3 -C 8 cycloalkyl, C 1 -C 10 alkoxy, halogen, phenyl or phenoxy, the alkyl or aryl groups being unfluorinated, partly fluorinated or fully fluorinated with the proviso that (I) carries at least 1 fluorine atom, and Z is a chemical bond, SO 2 , CF 2 CH 2 , CHF, CH(CH 3 ), isopropylene, hexafluoroisopropylene, n- or iso-C 1 -C 10 alkylene which may be partly or fully fluorinated, O, NR 9 whereby R 9 is hydrogen or C 1 -C 10 alkyl, N═N, CH═CH, C(O)O, CH═N, CH═N—N═CH, alkyloxyalkylene having 1 to 8 carbon atoms, S, or Si(CH 3 ) 2 optionally in mixture with other components. Preferably, both the first and the second materials are in the form of a thin layer, the layers directly adhered to each other. Either the waveguide can be made from the first material and at least one of the buffer layer and the cladding layer can be made from the second material, or vice versa.
1. An optical waveguide system or waveguide structure comprising at least
(a) a first material selected from poly(perfluorocyclobutanes); which is in direct contact with
(b) a second material selected from polycyanate resins (co)polymerized from at least one difunctional cyanate of formula (I);
wherein
R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , and R 8 are independently selected from hydrogen, halogen, C 1 -C 10 alkyl groups, C 3 -C 8 cycloalkyl groups, C 1 -C 10 alkoxy groups, phenyl groups, and phenoxy groups;
Z is selected from a chemical bond, SO 2 , CF 2 CH 2 , CHF, CH(CH 3 ), isopropylene, hexafluoroisopropylene, n-C 1 -C 10 alkylene groups (optionally substituted with at least one fluorine), iso-C 1 -C 10 alkylene groups (optionally substituted with at least one fluorine), O, NR 9 , N═N, CH═CH, C(O)O, CH═N, CH═N—N═CH, alkyloxyalkylene groups (having 1 to 8 carbon atoms), S, and Si(CH 3 ) 2 ;
R 9 is selected from hydrogen and C 1 -C 10 alkyl groups; and
wherein said at least one difunctional cyanate is substituted with at least one fluorine atom.
2. An optical waveguide system or waveguide structure as claimed in claim 1 , wherein the polycyanate resin has been copolymerized from at least one dicyanate of formula I, and at least one difunctional cyanate of formula II:
N≡C—O—R 10 —O—C≡N (II)
wherein
R 10 is C(R′) 2 —R″—C(R′) 2 ,
R′ is independently selected from hydrogen, fluorine, alkyl groups and alkenyl groups, and
R″ is selected from non-aromatic hydrocarbon groups and arylenic structures,
wherein the difunctional cyanate of formula II comprises at least one fluorine atom.
3. An optical waveguide system or waveguide structure as claimed in claim 2 , wherein the alkyl or alkenyl group of R′ is fluorinated.
4. An optical waveguide system or waveguide structure as claimed in claim 2 , wherein the polycyanate resin has been copolymerized from at least one dicyanate of formula I, at least one difunctional cyanate of formula II, and at least one of the following compounds:
(i) monocyanates having formula IIIa or IIIb:
R—O—R 11 IIIb,
wherein R 1 to R 5 are as previously defined for the dicyanate of formula I, R is N≡C— and R 11 is a straight, branched, or cyclic non-aromatic hydrocarbon radical or a non-aromatic hydrocarbon radical comprising a cyclic structure;
(ii) phenols having either formula IIIa above or formula IIIc:
wherein Z and R 1 to R 8 are as defined above for formula I and R is hydrogen;
(iii) monoalcohols having formula IIIb wherein R 11 is as defined above, and wherein R is hydrogen,
(iv) non-aromatic dihydroxy compounds having formula Vd
R—O—R 10 —O—R Vd
wherein R is hydrogen and R 10 is as defined for the dicyanates of formula IV above, and
(v) glycidylethers of formulas IIIa to IIIc wherein R is glycidyl, the other radicals being as defined above.
5. An optical waveguide system or waveguide structure as claimed in any of one of claim 2 , 3 , 4 , or 1 , wherein both the first and the second materials are in the form of a thin layer, the layers directly adhered to each other.
6. An optical waveguide system or waveguide structure according to claim 5 , wherein either the waveguide is made of the first material and at least one of a buffer layer and a cladding layer is made of the second material, or the waveguide is made of the second material and at least one of a buffer layer and a cladding layer is made of the first material.
7. The optical waveguide system or waveguide structure of claim 1 , wherein the alkyl groups included in formula (I) are selected from unfluorinated alkyl groups, fully fluorinated alkyl groups, and alkyl groups comprising at least one fluorine atom.
8. The optical waveguide system or waveguide structure of claim 1 , wherein the alkyl groups included in formula (I) are fully fluorinated.
9. The optical waveguide system or waveguide structure of claim 1 , wherein the aryl groups included in formula (I) are selected from unfluorinated aryl groups, fully fluorinated aryl groups, and aryl groups comprising at least one fluorine atom.
10. The optical waveguide system or waveguide structure of claim 1 , wherein the aryl groups included in formula (I) are fully fluorinated.