Two-component urethane resin adhesive for polymer lithium ion battery flexible package film

Abstract

The invention provides a two-component urethane resin adhesive for a polymer lithium ion battery flexible package film, and aims to provide an adhesive which has the advantages of high bonding strength, stripping resistance, excellent barrier property, impact resistance, high bonding compatibility with a nonmetallic film or an aluminum foil, resistance to swelling, dissolving, permeation and absorption of electrolyte organic solvents and high-volatility substances, resistance to strong acid and strong alkali and difficulty in breaking a molecular chain after becoming dry and hard. The two-component urethane resin adhesive consists of components, wherein a first component (A) is an emulsion waterborne Poly Urethane (PU) performed polymer which is obtained by compounding polyester and isocyanate/benzene ring-containing polyether in the mass ratio 75/25-55/45 and adding an aid for reacting; a second component (B) is a composition consisting of glycidyl ether epoxy resin with the epoxy resin 0.25-0.45 and a melamine-formaldehyde resin additional crosslinking agent; the weight ratio of the first component to the second component is 10/1-10/2; and a certain amount of additional crosslinking agent is added into a PU emulsion in a certain mass ratio.

Description

technical field [0001] The invention relates to a two-component polyurethane resin adhesive used for the bonding layer of polymer lithium ion battery packaging film. Background technique [0002] In the prior art, the adhesives used in the flexible packaging industry include one-component polyurethane adhesives, two-component polyurethane adhesives, acrylic adhesives, solvent-free adhesives, alcohol-soluble, water-soluble polyurethane adhesives, etc. . At present, most of the water-based polyurethane properties such as water resistance, solvent resistance, heat resistance and adhesion still need to be improved, so the modification of water-based polyurethane has become a hot spot in this field in recent years. But so far, no breakthrough has been made in replacing two-component solvent-based polyurethane adhesives with two-component water-based polyurethane adhesives at home and abroad. [0003] The disadvantages of water-soluble polyurethane adhesives currently used for b...

AI Technical Summary

Problems solved by technology

[0005] (2) Slow drying speed

Because the volatility of water is worse than that of organic solvents, the drying speed of water-soluble polyurethane adhesives is slow, and because the surface tension of water is about 7.3×10-4N / cm, which is 3 times that of ordinary organic solvents, it is difficult for surface hydrophobic groups. The wetting ability of the material is poor. When most of the moisture is not evaporated from the adhesive layer, volatilized into the air or absorbed by the porous substrate and then dried suddenly, it is difficult to obtain a continuous adhesive layer.

[0006] (3) Poor water resistance and heat resistance

The disadvantages of these hot-melt agent-coated adhesive bonding layers are that they cannot effectively block the penetration of battery contents, do not have the properties of anti-strong acid and alkali, high corrosion resistance, organic solvents and high volatile substances, and cannot effectively resist The swelling, dissolution, penetration, absorption and electrochemical reaction of the electrolyte in the battery