Polymer-related chemicals

WPBG-345

Photo base generators

優れた溶解性

Plastics manufacturing

Photocurable

  • Shows high stability (pot life) in various compositions (epoxy × thiol and epoxy × acid anhydride).
  • Generates a strong base, biguanide (pKbH =31.8), upon irradiation.
  • Can be exposed with sensitizer at 365 nm and longer wavelength.
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Chemical name (Z)-{[Bis(dimethylamino)methylidene]amino}-N-cyclohexyl(cyclohexylamino)methaniminium tetrakis(3-fluorophenyl)borate
CAS RN® 2073916-67-1
Molecular weight 713.70

Physical characteristics

Color
Appearance
nearly white
crystals
Melting point/freezing point 138℃
Solubilities

water, diisopropyl ether : practically insoluble,or insoluble.
ethyl acetate : freely soluble. no data available

TG-DTA weight loss from 231℃
Solubility (g/solv. 100 g)
  • NMP62
  • GBL81
  • PGMEA55
  • Acetone107
  • Ethyl lactate31
  • PGME44
  • Methanol3
  • H2O<0.5

UV(0.02 mg/mL in CH3CN)

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Absorption maximum
197 nm(ε=118000) 254 nm(ε=15500) 365 nm(ε=15)

※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

Stability of compositions as pot life

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●Possible to use sensitizer in order to irradiate @365 nm and longer wavelength.
●higher stability of pot-life than WPBG-300.

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

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Conditions

Preparation Mix 3-10 parts of WPBG-345, 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 promote dissolution. Mix 70 parts of KarenzMT®PE1 (SH equivalent of 138.5, Product of Showa Denko K.K.) at room temperature.
Stability of components as pot life (period in which the viscosity does not exceed the twice of the initial viscosity) 2 month or more (10°C), 3 weeks (25°C), and 3 days (40°C)
Exposure Irradiation for 10 seconds (Illuminance: 5mW/cm2 (254 nm), 100 mW/cm22 (365 nm), and 261 mW/cm2 (405 nm))

Example of Use 2Patterning by epoxy oligomer × carboxylic acid

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Conditions

Preparation Mix 1-10 parts of WPBG-345, 0.2-2 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 64 parts of Joncryl®682 (OH equivalent of 138, Product of BASF Japan Ltd.) into 300 parts of γ-butyrolactone.
Film-forming Polycarbonate, film thickness: 10-20 μm
Exposure Optional (Illuminance: 5mW/cm2 (254 nm), 100 mW/cm2 (365 nm), and 261 mW/cm2 (405 nm))
Post-exposure bake 150°C/10 minutes
Development 1 wt% Na2CO3, Immerse for 1 minute → rinse with water.

Photo sensitizer effective for borate-type photo base generators (PBG)

WPBG-300 and WPBG-345 can generate alkyl biguanide under a wide range of wavelength by used with photo sensitizers such as thioxanthone which can be absorbed in long-wavelength (Fig.1). Since photodegradability of PBG changes depending on the type of photo sensitizer, it is necessary to select the optimal sensitizer by taking into consideration the light source, coloration after curing and other conditions.

イメージ Fig.1 Structural formulas for WPBG-300and WPBG-345

Fig.2 shows the photo-decomposition rate when WPBG-345 is used combined with different photo sensitizers.
2-Ethylanthraquinone and 1-Chloroanthraquinone show high photo sensitizing effect and contribute to improvement of photodegradability of WPBG-345.

イメージ Fig.2 Change of photodegradability of WPBG-345 depending on different photo sensitizers

To use 2-Ethylanthraquinone as a photo sensitizer for epoxy oligomer/multifunctional thiol makes the curing time shorter than to use 2-Isopropylthioxanthone. Similarly, to use 2-Ethylanthraquinone for WPBG-300 makes the photodegradability improved.

イメージ Fig.3 Anionic UV curing of epoxy oligomer and polyfunctional thiol

Mix 3-10 parts of WPBG-345, 0.2-1 parts of sensitizer, 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. Irradiate for 10 seconds (Illuminance: 5mW/cm2 (254 nm), 100 mW/cm2 (365 nm), and 261 mW/cm2 (405 nm)), and heat at 120℃.