UV/thermal-radical curing "For ( Meth ) acrylate systems"

It is possible to improve the reactivity and sensitivity of radical polymerization systems using unsaturated compounds such as ( meth ) acrylic resin.
Resonac's thiols feature a secondary SH group, which stabilizes the mixture compared to conventional thiols and is suitable for one-component compositions due to the extended shelf life. 

Improved sensitivity

Improved sensitivity

Reduction of oxygen inhibition

Polymerization of acrylates is easily affected by oxygen, and generated peroxide radicals stops the polymerization.
Thiols donate hydrogen to peroxide radicals, it becomes thiyl radicals themselves and acthelate the polymerization.
In other words, the problem of oxygen inhibition of acrylic photopolymerization can be solved by adding thiols.

Reduction of oxygen inhibition

IR-Imaging

Curing condition: Exposure 1/cm2

  • Under the air atmosphere ( PE1 0wt%, 5wt%, 10wt% )
  • Under the Nitrogen atmosphere ( PE1 0wt% )

IR-Imaging

Measurement : Microscopic ATR imagery method(Ge)
range of measurement: 70 μmx70 μm

It measured the wave length of 1408 cm-1 which the double bond has it and expressed the intensity in color.

スクロールできます
amount of PE1 / composition 0wt% ( N2 )
PE1 / U-15HA / TMPTA / Irg184 = 0/47.5/47.5/5
0wt% ( Air )
PE1 / U-15HA / TMPTA / Irg184 = 0/47.5/47.5/5
5wt% ( Air )
PE1 / U-15HA / TMPTA / Irg184 = 5/45/45/5
10wt% ( Air )
PE1 / U-15HA / TMPTA / Irg184 = 10/42.5/42.5/5
Sticky ×
IR-imaging 0wt%(N2下) 0wt%(Air) 5wt%(Air) 10wt%(Air)

low IR-Imaging high

Deep curability

Effect of chain transfer ability

  • Deep curability
  • Deep curability2
    Monomer: BisA type acrylate 100phr
    Thiol: KarenzMT PE1 2phr
    Photo initiator: Irgacure184 2phr

Improved stability

Improved stability for acrylic system

The mercapto group and the double bond cause an addition reaction, but the secondary thiol suppresses the contact between the mercapto group and the double bond due to steric hindrance.
Therefore, the composition using the secondary thiol has improved stability as compared with it using the primary thiol.

Improved stability

※Dipentaerythritol hexaacrylate

Reduction of curing shrinkage

Evaluation

Reduction of curing shrinkage Fill the mold with the composition.
Light source: High pressure mercury lamp
Illuminance: 150mW/cm2、1J/cm2.

  • Reduction of curing shrinkage

    Composition

    Trimethylolpropane triacrylate: 100phr
    Irgacure184: 2phr
  • Reduction of curing shrinkage

    Composition

    Trimethylolpropane triacrylate:90phr
    KarenzMT PE1: 10phr
    Irgacure184: 2phr

Improved adhesion (Stress relaxation)

  • Glass
  • Stainless
  • PET

※ The information contained herein is based upon data considered true and accurate. However, Resonac Corporation accepts no responsibility or risk which may result from the handling and use of products or for infringement of any patent.