Novolac resin, bisphenol Cresol, phenol

The epoxy novolac resins are synthesized by reaction of phenolic or cresol novolacs with epichlorohydrin in the same fashion as the bisphenol A resins. The number of epoxy groups per molecule is dependent on the number of hydroxyls in the phenol novolac molecule and to the extent to which they are reacted. Complete epoxidation can be accomplished, but this will lead to steric factors, which could limit the useful size of the cured polymer. Thus, selective epoxidation is often practiced.9... 

Epoxy resins based on glycidylation of bisphenols, cresol and phenol novolacs, polycarboxylic acids, polyols, amines, and aminophenols have been long known. Epoxidized linear and cyclic olefins have also been used as specialty epoxy resins. More recently, glycidylated heterocycles have been introduced, initially as specialty resins promising improved resistance to weathering. One heterocycle in particular, the hydantoin ring, has become of particular interest as an epoxy substrate (J ). 

Others include brominated bisphenol A resins which impart fire resistance, epoxy phenol novolac (EPN) resins, bisphenol F epoxy (DGEBF) resins, epoxy cresol novolac (ECN) resins, cycloaliphatic epoxy resins, and tetraglycidyl-4,4 -diaminodiphenylmethane (TGDDM). 

The primary resins used in this market are the radiation-curable epoxy acrylates, accounting for 60% of the resins used. A small amoimt of cycloaliphatic epoxies are also used in UV-curable inks and resists. Phenol and cresol epoxy no-volacs, and bisphenol A based epoxies are used in thermally cured formulations. The epoxy novolacs are used where higher heat resistance is needed such as in solder masks. Both free-radical and cationic-curable UV inks and colored base coats have grown rapidly because of the needs for higher line speeds, faster cleanup or line turnaround, less energy consumption, less capital for a new hne, and fewer emissions. 

Diglycidyl ethers of bisphenol A (DGEBA or Bis A epoxies) Diglycidyl ethers of bisphenol F (DGEBF or Bis F epoxies) -low-molecular-weight epoxy coatings Epoxy phenol or cresol novolac multifunctional resins... 

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