One-component polyurethane adhesive:
One-component polyurethane adhesives are also single-package polyurethane adhesives. Compared with two-component polyurethane adhesives, its advantages are: there is no need to take samples like two-component or multi-component adhesives and use them after preparation. Therefore, there is no need for metering calculations and no external crosslinking agent when used.
One-component polyurethane adhesives can be divided into two categories: reactive and non-reactive according to the type of reaction.
Reactive one-component polyurethane adhesives include: ordinary moisture-curing adhesives, reactive hot melt adhesives, heat-reactive-curing adhesives, foaming one-component glues, one-component polyurethane foam caulking adhesives, and silicone-terminated wet Curing polyurethane glue, polyisocyanate adhesive.
Non-reactive polyurethane adhesives include: solvent volatilization, thermoplastic hot melt adhesives.
According to the curing method, it can be divided into: moisture curing type, solvent volatilization type, hot melt adhesive type, radiation curing type, thermal (and moist heat) curing type, etc., of which moisture curing polyurethane adhesive is the most important one-component polyurethane adhesive Product type (the best drier for this type of one-component adhesive: Sinocat®DMDEE-Bis(morpholinoethyl)ether).
Two-component polyurethane adhesive:
Two-component polyurethane adhesive is the most important category of polyurethane adhesives. It has a wide range of uses and a large amount. It usually consists of two components, A and B (or called A and B, main agent and curing agent). , The two components are packaged separately and can be prepared in a certain proportion before use. The first component (main agent) can be a hydroxyl component, and the second component (curing agent) can be a component containing free isocyanate groups. Some main agents are NCO-terminated polyurethane prepolymers, and the curing agent is low-molecular-weight polyols or polyamines. The first component and the second component are mixed in a certain proportion to produce a polyurethane film with good elasticity, toughness, heat resistance, low temperature resistance and medium resistance.
Two-component polyurethane adhesives have the following characteristics:
(1) It is a reactive adhesive. After the two components are mixed, a chemical reaction occurs to produce a cured product.
(2) During preparation, the raw material composition and molecular weight of the two components can be adjusted to make it have a suitable viscosity at room temperature, and can be made into a two-component adhesive with high weekly content or solvent-free.
(3) Generally, it can be cured at room temperature, and the curing speed can be adjusted by selecting the raw materials for preparing the adhesive or adding a catalyst. Heat can be used to accelerate curing.
(4) The amount of the two components can be adjusted within a certain range, and there is generally a certain tolerance.
