Photo base generators

WPBG-300

Cas : 1801263-71-7

high oil solubility

Plastics manufacturing

Photocurable

  • Shows high stability (pot life) in monomer.
  • Generates a strong base, biguanide (pKbH=31.8), upon irradiation.
  • Can be exposed with sensitizer at 365 nm and longer wavelength.
  • Can be employed with cross-linking agents such as thiol or anhydride.
Molecular formula
Chemical name 1,2-Dicyclohexyl-4,4,5,5-tetramethylbiguanidium n-butyltriphenylborate
CAS RN® 1801263-71-7
Molecular weight 621.75

Physical characteristics

Color
Appearance
white
powder
Melting point/freezing point 115℃
Solubilities

water : slightly soluble.
acetone, 1-methyl-2-pyrrolidone : freely soluble.
methanol, PGMEA (1-methoxy-2-propyl acetate) : soluble

TG-DTA weight loss from 203℃
Solubility (g/solv. 100 g)
  • NMP29
  • GBL41
  • PGMEA5
  • Acetone46
  • Ethyl lactate8
  • PGME7
  • Methanol4
  • H2O<0.5

UV(0.02 mg/mL in CH3CN)

Absorption spectrum of WPBG-345

Absorption maximum
197 nm(ε=79000) 254 nm(ε=14000) 365 nm(ε=0)

※When used in combination with a sensitizer, it shows photosensitivity even in the long wavelength region.

Related laws and regulations

TSCA Not Listed
EINECS Not Listed
REACH Not Listed

Packaging

  • 5g

Mechanism of base generation

Base generation mechanism

Example of Use 1Anionic UV curing of epoxy oligomer × polyfunctional thiol

Example using epoxy oligomer and polyfunctional thiol

Conditions

Preparation Mix 1-5 parts of WPBG 300, 0.2-1 part of 2-isopropylthioxanthone (0.2 equivalent amount to WPBG), and 100 parts of jER®828 (epoxy equivalent of 185, Product of Mitsubishi Chemical Corporation), and heat or use a diluent to promote dissolution. Mix 70 parts of KarenzMT®PE1 (SH equivalent of 138.5, Product of Showa Denko K.K.) at room temperature.
Stability of composition as pot life (period in which the viscosity does not exceed the twice of the initial viscosity) 1 month (10°C), 1 week (25°C), and 3 days (40°C)
Exposure Irradiation for 10 seconds (Illuminance: 5mW/cm2 (254 nm), 100 mW/cm2 (365 nm), and 261 mW/cm2 (405 nm))

Example of Use 2Anionic UV curing of epoxy oligomer × acid anhydride

Example using an epoxy oligomer and an anhydride

Conditions

Preparation Mix 3-10 parts of WPBG-300, 0.6-2 parts of 2-isopropylthioxanthone (0.2 equivalent amount to WPBG), and 100 parts of jER®828 (epoxy equivalent of 185, Product of Mitsubishi Chemical Corporation), and heat or use a diluent to dissolve.
Mix 50 parts of methyl-5-norbornene-2,3-dicarboxylic anhydride (Product of FUJIFILM Wako Pure Chemical Corporation) at room temperature.
Stability of composition as pot life (period in which the viscosity does not exceed the twice of the initial viscosity) 1 month (10°C), 1 week (25°C), and 3 days (40°C)
Exposure Irradiation for 10 seconds (Illuminance: 5mW/cm2 (254 nm), 100 mW/cm2 (365 nm), and 261 mW/cm2 (405 nm))

Example of Use 3Anionic UV curing of episulfide

Anionic UV Curing of Episulfide

Conditions

Preparation Mix 1-5 parts of WPBG-300 and 0.2-1 part of 2-isopropylthioxanthone (0.2 equivalent amount to WPBG) in 20 parts of γ-butyrolactone and mix hydrogenated bisphenol A type episulphide (episulphide equivalent of 220).
Stability of composition as pot life (period in which the viscosity does not exceed the twice of the initial viscosity) 1 month (10°C), 1 week (25°C), and 3 days (40°C)
Exposure Irradiation for 10 seconds (Illuminance: 5mW/cm2 (254 nm), 100 mW/cm2 (365 nm), and 261 mW/cm2 (405 nm))