Photo base generators (WPBG series)
A Photo base generator is a compound which generates organic base such as amines upon irradiation of light in the UV range. The generated organic base accelerates an anionic UV curing of epoxy resin, sol-gel method, etc.
Characteristics of anionic polymerization
- Can be used in air. (No disturbance of curing)
- Can conduct delay cure. (Anion of active species is not deactivated)
- Can be used on metal wiring. (Hardly causes metallic corrosion)
Active Species | Example of Reaction | Inhibition | Delay cure | Metallic Corrosion |
---|---|---|---|---|
Radical | O2 | Non | Non | |
Cationic | H2O | Yes | Yes | |
Anionic | Non | Yes | Non |
Different reactions utilizing bases
Organic bases are able to initiate different curing reactions by utilizing their nucleophilicity and basicity. Bases are also available for purposes other than curing agents. For example, as a catalyst for depolymerization and neutralizer for acidic systems.
WPBG-300
CAS RN® : 1801263-71-7
- Can be employed with cross-linking agents such as thiol or anhydride.
- Generates a strong base biguanide (pKbH=31.8) and radical upon irradiation.
- Can be exposed with sensitizer at 365 nm and longer wavelength.
WPBG-345
CAS RN® : 2073916-67-1
- Shows high stability (pot life) in various compositions.
- Generates a strong base biguanide (pKbH=31.8) and radical upon irradiation.
- Can be exposed with sensitizer at 365 nm and longer wavelength.
WPBG-266
CAS RN® : 1632211-89-2
- Is optimal as catalyst for sol-gel method
- Generates a strong base biguanide (pKbH=31.8) and radical in high quantum yield upon irradiation.
- Shows high solubility to various solvents
- Was co-developed with Dr. Koji Arimitsu, Professor, Tokyo University of Science.
WPBG-018
CAS RN® : 1228312-05-7
- Light absorption in long-wavelength region, and has excellent solubility.
- Generates a weak base diethylamine upon irradiation.