Hardener for epoxy resins
OwnerJohn Shomerinventor
Life of this patent
Estimating the term…
Abstract
A hardener for epoxy resins is disclosed the use of which imparts improved resistance in the resins to aging on exposure to ultraviolet radiation. The hardener comprises (a) at least one amine selected from the group consisting of trimethylhexamethylenediamine and isophoronediamine and (b) at least one inorganic salt which contains nitrate ion.
Claims23
A hardener for epoxy resins, to increase resistance in the resins to aging on exposure to ultraviolet radiation, which comprises:
- (a) at least one amine selected from the group consisting of trimethylhexamethylenediamine and isophoronediamine;
- and
- (b) at least one inorganic nitrate salt selected from the group consisting of ammonium, lithium, sodium, potassium, magnesium, calcium, strontium, barium and aluminum nitrate.
In a method for curing epoxy resins to obtain a product having resistance to aging on exposure to ultraviolet radiation using a hardener which comprises at least one amine selected from the group consisting of trimethylhexamethylenediamine and isophoronediamine, together with a phenolic accelerator, in the presence of a solvent medium, the improvement which comprises replacing at least 90% of the phenolic accelerator by at least one dissolved inorganic nitrate salt selected from the group consisting of ammonium, lithium, sodium, potassium, magnesium, calcium, strontium, barium and aluminum nitrates, and using at least one solvent medium selected from the group consisting of monohydric alcohols containing 1 to 10 carbon atoms in the molecule, polyhydric alcohols containing 2 to 10 carbon atoms and 2 to 4 hydroxy groups in the molecule, poly-(C2 to C5-alkylene) glycols and phenyl- C1 to C4 monohydric alcohols.
Dependencies are inferred from the claim text.