There are many kinds of epoxy resin curing agents. As an important anti-corrosion coating, epoxy resin coatings mostly use room temperature and low temperature curing agents. Commonly used polyamides, amines and amine adducts, isomeric acid curing agents, etc. Wait, how much do you know about it? Do you know what common epoxy resin curing agents are?
1. Polyamide curing agent is a commonly used variety of epoxy resin coating curing agent, which is formed by polycondensation of dimer and unsaturated polyamine of vegetable oil. Polyamide-cured epoxy resin coatings have good bonding strength to metals and non-metals, good construction performance, less toxicity to humans, and the coating can be used for a longer construction time after preparation (6,-.,.,8h), The coating film has good water resistance, but the chemical resistance is slightly worse than the polyamine curing agent. It takes 30 minutes (at room temperature) for the induction period when preparing the coating.
2. Polyamine curing agents include aliphatic amines, aromatic amines, alicyclic amines and tertiary amines, and amine adduct curing agents.
(1) Aromatic amine curing agents mainly include m-phenylenediamine, m-xylylenediamine, etc. The benzene ring structure cured product has good temperature resistance and corrosion resistance, and is mainly used for heating curing process or as modified amine curing Raw materials.
(2) Tertiary amines mainly include triethylamine, triethanolamine, N,N-dimethylaniline, N,N-dimethylbenzylamine and 2,4, 6-tris(dimethylaminomethyl)phenol (COMP), etc. . The molecular structure does not contain active H atoms and is a catalytic curing agent, so it is mainly used as an accelerator for epoxy curing agents to accelerate curing.
(3) Epoxy resin manufacturers tell everyone that aliphatic amines such as ethylenediamine, diethylenetriamine, triethyleneamine, and tetraethylenepentamine, etc. These curing agents can be cured at room temperature, but are more toxic In particular, the LD50 of ethylenediamine is 620mg/kg, and the vapor pressure is as high as 1466.5Pa. After contact and inhalation, the construction workers may cause skin allergies, dizziness, chest tightness, and other nervous system and liver diseases. In severe cases, it may cause acute poisoning or even death. The use of such curing agents should be strictly controlled.
(4) Alicyclic amines, that is, cyclic aliphatic polyamines, such as isophorone diamine, 4,4'-diaminodicyclohexane methane, etc., suitable for high solids and solvent-free coatings, coating after curing The film has a light color, good gloss, and good chemical resistance. It does not require a construction induction curing period, but the toughness of the coating is poor. Curing requires heating or adding accelerator to cure at room temperature.
(5) Aliphatic amine and aromatic amine curing agents are toxic and easy to whiten. Using amine epoxy resin adduct curing agents can effectively improve their performance. Commonly used amine adduct curing agents include ethylenediamine-epoxy adducts, Mannich base curing agents, etc.
(6) The warp group of the epoxy resin of the polymer day and the polyisone neodymium acid can be cross-linked and cured at room temperature and low temperature. The epoxy resin coating cured by polyisoneonic acid has excellent water resistance, solvent resistance, chemical resistance and flexibility.
(7) The amine adduct curing agent phenol amino alcohol curing agent using cashew nutshell oil as raw material, developed and produced by Cardolite in the United States. After the aromatic side chain aromatic compound is combined with the amine, the simpler reaction product of phenol and amine It has better flexibility, and at the same time can be cured in a low temperature and humid environment. This type of curing agent is suitable for high solids and solvent-free heavy-duty coatings.