Waterborne polyurethane adhesive is a kind of high-grade adhesive, with excellent flexibility, impact resistance, chemical resistance and wear resistance, the most important is its low temperature resistance.It has adsorption and chemical bonding effect on many kinds of materials. It can not only bond porous materials, but also bond smooth surface materials. It is widely used.

Polyurethane adhesives have strong adhesion, most water based polyurethane adhesives do not contain NCO group, but there are ammonia ester bond urea bond ether bond ionic bond, so the adhesion of a variety of substrates is strong, good affinity, because waterborne polyurethane contains carboxyl hydroxyl and other active groups, under appropriate conditions can form crosslinking, improve adhesion.The viscosity of waterborne polyurethane is generally adjusted by water-soluble thickener and water, which is easy to operate and easy to clean up the residual glue. Can be mixed with a variety of water-based resins, conducive to improve performance and reduce costs, but pay attention to ionic properties and acid alkaline, to prevent condensation.

In addition to the added polymer thickener, the main factors affecting the viscosity of waterborne polyurethane adhesives are ion charge particle size and so on.The viscosity of water-based adhesives is lower than that of solvent-based adhesives with the same solid content.Due to the poor volatility of water than organic solvents, waterborne polyurethane adhesives dry slowly, and due to the large surface tension of water, the wetting ability of surface hydrophobic substrate is poor, when most of the water is not volatilized into the air from the adhesive layer or absorbed by porous substrate heating and drying, it is not easy to get a continuous adhesive layer.Because most water based polyurethane adhesives are made of hydrophilic polyurethane as the main solid component, and sometimes also contain water-soluble polymer thickener adhesives, after drying the film, if there is not a certain degree of crosslinking, the water resistance is not good.In recent years, a great deal of research has been carried out and great progress has been made on problems such as slow drying speed of waterborne polyurethane adhesives, poor wettability of non-polar substrates, low initial viscosity and poor water resistance.The results show that if the solid content is increased to more than 50%, the drying speed is similar to that of common solvent-based polyurethane adhesive at the drying temperature of 40~60.Blends with other emulsions (such as EVA acrylate emulsion, etc.) to form interpenetrating network or graft structure, which can improve the initial viscosity and bonding performance, and reduce the cost. Crosslinking method can improve water resistance and heat resistance.Polyurethane adhesives have the advantages of adjustable softness and hardness, low temperature resistance, good flexibility, high bonding strength and so on. They can bond a variety of materials, such as metal and non-metal, and are more and more widely used. But the whole polyurethane adhesives industry is still based on solvent-based.

Polyurethane adhesive curing at room temperature is usually slower, complete curing sometimes up to several days, such as the use of multi-component compounding can significantly shorten the curing time at room temperature, more convenient and applicable.The high temperature resistance of polyurethane adhesive is far less than its low temperature resistance, such as used in food packaging composite film, it needs to have cooking resistance.The introduction of nano-particles can significantly improve its heat resistance, tensile strength, shear strength, peel strength, etc., but the addition of nano-materials should be appropriate, too much may destroy the ordered arrangement of the hard segments in some macromolecules, so as to reduce the mechanical properties.At very low temperature, general polymer materials are transformed into glass state and become brittle, while polyurethane adhesive can maintain high peel strength even below -250, and its shear strength increases greatly with the decrease of temperature.Polyurethane adhesive middle divorced cyanate ester monomer has great toxicity, can be used as hydroxyl-terminated multivariate epoxy compound with the isocyanate polyurethane prepolymer was prepared epoxy polyurethane, again with the mixture of polyurethane adhesives, polyamine compounds the adhesive as the excellent properties of epoxy resin and polyurethane, and almost do not contain swim divorced cyanate ester monomer, high solids content.Polyurethane adhesives are developing towards water-based and solvent-free environmental protection adhesives.

The water based adhesive series has become a hot product of Sinograce Chemical.Sinograce Chemical's adhesive binder is commonly praised in the market due to good materials, fine workmanship, reliable quality, and favorable price.As for customer service management, Sinograce Chemical insists on combining standardized service with personalized service, so as to fulfill different needs of customers. This enables us to build a good corporate image.This is our email sales@sinogracechem.com, welcome to consult.