Coinitiators
Type II photoinitiators require a coinitiator that can readily allow hydrogen atoms to be abstracted or undergo an electron/proton transfer. These coinitiators are usually in the form of an alcohol, amine, or thiol. The absorption of UV light, by a Type II photoinitiator, causes an excited electron state in the photoinitiator. That excited state will abstract a hydrogen or undergo an electron/proton transfer, depending upon the type of coinitiator, yielding the desired radicals.
Hexaarylbiimidazoles (HABI) split into two lophyl radicals, like a Norrish type I reaction. However, the two lophyl radicals are very stable and unreactive, requiring a “coinitiator" to function as a chain transfer agent or hydrogen donor to efficiently initiate polymerization. Primary and secondary amines, such as N-Phenylglycine, as well as thiols are typically used as coinitiators with the HABI molecules. Tertiary amines are not as effective with HABIs.
Hampford Research specializes in the manufacture of high purity photoinitiators, coinitiators, and sensitizers for all photoactive applications.
| Product Name | Function | CAS Number | HRI Prod. # |
|---|---|---|---|
| Ethyl-4-dimethylamino benzoate (EDAB) | Coinitiator, tertiary amine | 10287-53-3 | FP5170 |
| N-Phenylglycine (NPG) | N-Phenylglycine (NPG) | 103-01-5 | FP5360 |
| N-Phenylglycine (NPG) LTM | Coinitiator, secondary amine, low trace metals | 103-01-5 | FP5385 |
Dyes & Sensitizers
Sensitization is the process of energy transfer between a sensitizer and an initiator. This is commonly used in systems to capture light energy, outside the range of the photoinitiator, and channel it to the photoinitiator. It is especially useful in pigmented systems where the absorption or reflection from the pigment is often much stronger than that of the initiator itself, thus inhibiting polymerization. A sensitizer or sensitizing dye is added to absorb energy at wavelengths outside those absorbed or reflected by pigments and the initiator. That absorbed energy is then transferred to the initiator.
Hampford Research is a leading provider of sensitizing dyes, custom laser dyes, near infrared dyes, and blends for multiple dye applications. Our unique synthesis and purification methodology assures customers of consistent quality and performance.
| Product Name | Function | CAS Number | HRI Prod. # |
|---|---|---|---|
| JAW | Holographic dye, 490-500nm, sensitizer, sensitizing dye | 125594-50-5 | FP5200 |
| SD-184 | Holographic dye, 530-540nm, sensitizer, sensitizing dye | 154482-35-6 | FP5432 |
| TMISQ DYE | Holographic dye, 630-640nm, sensitizer, sensitizing dye | 12243-46-8 | FP5490 |
| IR 775 Tosylate | Infrared dye, 770-780nm, sensitizer, sensitizing dye | 205744-92-9 | FP5194 |
| IR 813 Tosylate | Infrared dye, 810-820nm, sensitizer, sensitizing dye | 134127-48-3 | FP5192 |
| 9-Phenylacridine | Photoinitiator type II, sensitizer, sensitizing dye | 602-56-2 | FP5400 |
| Dibromochalcone | Photoinitiator, sensitizer, sensitizing dye | 611-91-6 | FP5080 |
| BFBK | Sensitizer, sensitizing dye, 410-420nm | 24293-93-4 | FP5059 |