Epoxy-functional radiation-curable composition containing an epoxy-functional siloxane oligomer for enhanced film retention and adhesion during solvent development

Patent metadata

Field	Value
Publication number	US-9354518-B2
Application number	US-201214119950-A
Country	US
Kind code	B2
Filing date	May 23, 2012
Priority date	May 25, 2011
Publication date	May 31, 2016
Grant date	May 31, 2016

Abstract

The present invention provides a silicone composition that includes an epoxy-functional organopolysiloxane resin and an epoxy-functional organosiloxane oligomer, and a method of preparing optical waveguides using the silicon composition. The present invention also provides a cured silicon composition, and an optical waveguide that includes the cured silicon composition.

First claim

We claim:

1. A curable silicone composition, comprising:
(A) an epoxy-functional organopolysiloxane resin having the average unit formula
(R 1 R 2 R 3 SiO 1/2 ) a (R 4 R 5 SiO 2/2 ) b (R 6 SiO 3/2 ) c (SiO 4/2 ) d   (I)

wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are organic groups independently selected from C 1-6 monovalent aliphatic hydrocarbon groups, C 6-10 monovalent aromatic hydrocarbon groups, and monovalent epoxy-substituted organic groups, 0≦a<0.4, 0<b<0.5, 0<c<1, 0≦d<0.4, 0.1≦b/c≦0.3, a+b+c+d=1, the resin has a number-average molecular weight of at least about 2000, at least about 15 mol % of the organic groups are C 6 to C 10 monovalent aromatic hydrocarbon groups, and about 2 to about 50 mol % of siloxane units have epoxy-substituted organic groups;
(B) an epoxy-functional organosiloxane oligomer having an average of at least two epoxy-substituted organic groups per molecule and a molecular weight not greater than about 1500;
(C) a cationic photoinitiator; and
(D) optionally, an organic solvent
wherein the epoxy-functional organosiloxane oligomer has a formula selected from
R 8 R 7 2 SiO(R 7 2 SiO) m SiR 7 2 R 8   (II),

and R 9 Si(OSiR 7 2 R 8 ) 3   (IV),

wherein R 7 is C 1-8 alkyl, R 8 is an epoxy-substituted organic group, R 9 is R 7 or —OSiR 7 2 R 8 , m is 0 or a positive integer, and n is from 3 to 10.

2. The curable silicone composition of claim 1 , wherein the epoxy-functional organosiloxane oligomer has the formula:
R 8 R 7 2 SiO(R 7 2 SiO) m SiR 7 2 R 8   (II)

wherein m is 0 and R 8 is 3,4-epoxycyclohexylethyl.

3. The curable silicone composition of claim 1 , further comprising a photosensitizer.

4. A cured composition obtained by curing the curable silicone composition of claim 1 .

5. The cured composition of claim 4 , wherein the cured composition is flexible.

6. The cured composition of claim 4 , wherein the cured composition is a light-transmitting component of an optical waveguide.

7. An optical waveguide, comprising the cured composition of claim 4 .

8. The cured composition of claim 4 , wherein the curable silicone composition is cured using radiation.

9. The cured composition of claim 4 , wherein the curable silicone composition is cured using UV light.

10. The cured composition of claim 4 , wherein the curable silicone composition is cured using heat.

11. A method of preparing a flexible planar optical waveguide assembly, comprising the steps of:
(i) applying a first silicone composition to a surface of a substrate to form a first silicone film, the first silicone composition comprising
(A) an epoxy-functional organopolysiloxane resin having the average unit formula
(R 1 R 2 R 3 SiO 1/2 ) a (R 4 R 5 SiO 2/2 ) b (R 6 SiO 3/2 ) c (SiO 4/2 ) d   (I)

wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are organic groups independently selected from C 1-6 monovalent aliphatic hydrocarbon groups, C 6-10 monovalent aromatic hydrocarbon groups, and monovalent epoxy-substituted organic groups, 0≦a<0.4, 0<b<0.5, 0<c<1, 0≦d<0.4, 0.1≦b/c≦0.3, a+b+c+d=1, the resin has a number-average molecular weight of at least about 2000, at least about 15 mol % of the organic groups are C 6 to C 10 monovalent aromatic hydrocarbon groups, and about 2 to about 50 mol % of siloxane units have epoxy-substituted organic groups,
(B) an epoxy-functional organosiloxane oligomer having an average of at least two epoxy-substituted organic groups per molecule and a molecular weight not greater than about 1500,
(C) a cationic photoinitiator, and
(D) optionally, an organic solvent; and

(ii) exposing at least one selected region of the first silicone film to radiation having a wavelength of from about 150 to about 800 nm to produce a partially exposed film having at least one exposed region and at least one non-exposed region;
(iii) removing the non-exposed region of the partially exposed film with a developing solvent to form a patterned film;
(iv) heating the patterned film for an amount of time sufficient to form at least one silicone core having a refractive index of from about 1.45 to about 1.60 at about 23° C. for light having a wavelength of about 589 nm; wherein the substrate has a refractive index less than the refractive index of the silicone core;
(v) optionally covering the substrate and the silicone core with a second silicone composition to form a second silicone film; and
(vi) optionally curing the second silicone film to form a clad layer, wherein the clad layer has a refractive index less than the refractive index of the silicone core.

12. The method of claim 11 , further comprising, subsequent to exposing step (ii) and prior to removing step (iii):
(ii-2) heating the partially exposed film for an amount of time such that the exposed region is substantially insoluble in a developing solvent and the non-exposed region is soluble in the developing solvent.

13. The method of claim 11 , wherein the second silicone composition comprises:
(A) an epoxy-functional organopolysiloxane resin having the average unit formula
(R 1 R 2 R 3 SiO 1/2 ) a (R 4 R 5 SiO 2/2 ) b (R 6 SiO 3/2 ) c (SiO 4/2 ) d   (I)

wherein R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 are organic groups independently selected from C 1-6 monovalent aliphatic hydrocarbon groups, C 6-10 monovalent aromatic hydrocarbon groups, and monovalent epoxy-substituted organic groups, 0≦a<0.4, 0<b<0.5, 0<c<1, 0≦d<0.4, 0.1≦b/c≦0.3, a+b+c+d=1, the resin has a number-average molecular weight of at least about 2000, at least about 15 mol % of the organic groups are C 6 to C 10 monovalent aromatic hydrocarbon groups, and about 2 to about 50 mol % of siloxane units have epoxy-substituted organic groups;
(B) an epoxy-functional organosiloxane oligomer having an average of at least two epoxy-substituted organic groups per molecule and a molecular weight not greater than about 1500;
(C) a cationic photoinitiator; and
(D) an organic solvent.

14. The method of claim 11 , wherein the optional steps of covering and curing are performed.

15. A flexible planar optical waveguide assembly prepared according to the method of claim 11 .

16. The method of claim 11 , further comprising (v) covering the substrate and the silicone core with a second silicone composition to form a second silicone film and (vi) curing the second silicone film to form a clad layer, wherein the clad layer has a refractive index less than the refractive index of the silicone core.

17. A method of preparing a flexible planar optical waveguide assembly, comprising the steps of:
(i) applying a first silicone composition to a surface of a substrate to form a first silicone film;
(ii) curing the first silicone film to form a lower clad layer;
(iii) applying a second silicone composition to the lower clad layer to form a second silicone film;
(iv) exposing at least one selected region of the second silicone film to radiation having a wavelength of from about 150 to about 800 nm to produce a partially exposed film having at least one exposed region and at least one non-exposed region;
(v) removing the non-exposed region of the partially exposed film with a developing solvent to form a patterned film;
(vi) heating the patterned film for an amount of time sufficient to form at least one silicone core having a refractive index of from about 1.45 to about 1.60 at about 23° C. for light having a wavelength of 589 nm; wherein the lower clad layer has a refractive index less than the refractive index of the silicone core;
(vii) optionally covering the lower clad layer

Assignees

• Bujalski Duane Raymond
• Degroot Jr Jon Vierling
• Deshazer David J
• Glover Shedric Oneal
• Hueston Karen L
• Ladouce John
• Dow Corning

Inventors

• Bujalski Duane Raymond
• Degroot Jr Jon Vierling
• Deshazer David J
• Glover Shedric Oneal
• Hueston Karen L
• Ladouce John

Classifications

• G02F1/0063

  Optical properties, e.g. absorption, reflection or birefringence (materials for non-linear optics G02F1/355) · CPC title

• G02F2202/023

  curable · CPC title

• C09D183/06

  containing silicon bound to oxygen-containing groups (C09D183/12 takes precedence) · CPC title

• G03F7/0757 Primary

  Macromolecular compounds containing Si-O, Si-C or Si-N bonds (G03F7/0752 takes precedence) · CPC title

• G03C1/00

  Photosensitive materials (photosensitive materials for multicolour processes G03C7/00; for diffusion transfer processes G03C8/00; photosensitive glass C03C4/04) · CPC title