These materials, characterized by a combination of cycloaliphatic and siloxane structures, have outstanding weathering characteristics, controlled release and coefficient of friction and excellent electrical properties. They can be cured either by cationic UV photoinitiators or conventional epoxy hardeners. In cationic UV-cure systems the cycloaliphatic epoxy silicones combine the properties of reactive diluents with surfactant properties. The release properties can be employed to make parting layers for multilayer films. If high levels of epoxy functional silicones are used in UV cure formulations, cationic photoinitiators with hydrophobic substitution are preferred.
Difunctional Siloxanes
| Product Code | Structure | Name | Molecular Weight | BP/mm (MP) (°C) | Density D420 | Refractive Index nD20 | Comments | CAS |
|---|---|---|---|---|---|---|---|---|
| SIB1092.0 |  | bis[2-(3,4-epoxycyclohexyl)ethyl]-tetramethyldisiloxane | 382.69 | (-34) | 0.998 | 1.4758 | flashpoint: 200 °C viscosity: 40 cSt UV-initiated polymerization with weak acid donors | [18724-32-8 TSCA |
Epoxycyclohexylethyl-Terminated Polydimethylsiloxanes, CAS: [102782-98-9], TSCA
| Product Code | Viscosity (cSt) | Molecular Weight | Epoxy (eq/kg) | Refractive Index | Density |
|---|---|---|---|---|---|
| DMS-EC13 | 25-35 | 900-1,000 | 1.9-2.0 | 1.433 | 0.99 |
| DMS-EC17 | 60-80 | 3,200-3,600 | 0.5-0.7 | 1.412 | 0.98 |
| DMS-EC31 | 800-1,200 | 40,000 | 0.04-0.06 | 1.410 | 0.98 |
(Epoxycyclohexylethylmethylsiloxane)-Dimethylsiloxane Copolymers, CAS: [67762-95-2], TSCA
| Product Code | Viscosity (cSt) | Molecular Weight | Epoxy (eq/kg) | Refractive Index | Density |
|---|---|---|---|---|---|
| ECMS-127 | 500-1,200 | 12,000-15,000 | 1-2 | 1.407 | 0.98 |
| ECMS-227 | 650-800 | 18,000-20,000 | 2-3 | 1.407 | 0.98 |
| ECMS-327 | 350-850 | 18,000-20,000 | 3-4 | 1.409 | 0.99 |
| ECMS-924 | 300-450 | 10,000-12,000 | 8-10 | 1.421 | 0.97 |
(2-3% Epoxycyclohexylethylmethylsiloxane)(10-15% Methoxypolyalkyleneoxymethylsiloxane)-(Dimethylsiloxane) Terpolymer, CAS: [69669-36-9], TSCA
| Product Code | Viscosity (cSt) | Molecular Weight | Epoxy (eq/kg) | Refractive Index | Density |
|---|---|---|---|---|---|
| EBP-234 | 4,000-5,000 | 25,000-36,000 | 0.75-0.80 | 1.445 | 1.03 |
(Epoxypropoxypropylmethylsiloxane)-(Dimethylsiloxane) Copolymer, CAS: [68440-71-7], TSCA
| Product Code | Viscosity (cSt) | Molecular Weight | Epoxy (eq/kg) | Refractive Index | Density |
|---|---|---|---|---|---|
| EMS-622 | 200-300 | 7,000-9,000 | 5-7 | 1.412 | 0.99 |
Gelest offers cationic and long-wavelength UV initiators that are hydrophobic and soluble in silicone systems.
Photoinitiators
| Product Code | Structure | Name | Molecular Weight | BP/mm (MP) (°C) | Density D420 | Refractive Index nD20 | Comments | CAS |
|---|---|---|---|---|---|---|---|---|
| OMAN076 |  | (thophenoxyphenyl)diphenylsulfoniumhexafluoroantimonate bis(bis(dip[henysulfonium)diphenylthio)ether hexafluoroantimonate blend, 50% in propylene carbonate | 607.28 | (145) | 4.10 | -- | amber liquid UV initiator for cationic polyerizations (e.g. cycloaliphatic epoxides) | [71449-78-0]/[89452-37-9] TSCA |
| OMAN071 |  | p-(octyloxyphenyl)phenyliodonium-hexafluoroantimonate | 645.07 | (57-58) | -- | -- | -- | [121239-74-5] TSCA |
| OMBO037 |  | (p-isopropylphenyl)(p-methylphenyl)-iodonium tetrakis(pentafluorophenyl)borate | 1,015.7 | 120-133 | -- | -- | UV max: 235nm UV initiator for cycloaliphatic epoxide-functionalized silicones | [178233-72-2] TSCA |
| OMTI014 |  | bis(2,6-difluoro-3-(1-hydropyrrol-1-yl)phenyl)titanocene | 534.4 | (160-170) | -- | -- | color: orange-yellow soluble: acetone, methylethylketone, >hexanediol diacrylate, toluene visible (blue-green) light and UV photoinitiator long wavelength photoinitiator with Al- (488nm) and FD Nd/YAG- (532nm) lasers store <5 °C | [12051-32-3] TSCA |