Views:0 Author:Site Editor Publish Time: 2020-11-23 Origin:Site
Development of blister packaging materials for adhesives
At present, aluminum foil coating adhesive is mainly composed of one - component and two - component adhesive. Glue is mainly composed of natural glue or synthetic glue and acrylic acid composition, because it is mainly elastomer, plus viscosity additives and organic solvents mixed with emulsion, with strong thermal solubility, strong adhesion and other characteristics.
As health requirements increase for pharmaceutical packaging materials, the use of newly produced single-component adhesives is gradually decreasing, and mainly two-component polyurethane coatings. The main mechanism of the adhesives is the master agent and the fixative agent, which usually contain many active hydrogens, such as hydroxyl, amino hydrogen and other substances solidified composite isocyanate vinegar. The addition reaction occurs automatically when it comes into contact with the active hydrogen of the main molecule of the chemical reagent, forming an ammonium structure. The main stabilizer molecules are multiplied until the product is produced with the three-dimensional conformation of the cross-linked structure branch chain, high temperature resistance, superior erosion characteristics of the branch chain structure, because the polyurethane tsuen containing a large number of polar molecules, the dipole moment is large, has a great affinity for bonding materials, at the same time, a lot of materials have bonding effect.
The isocyanate in curing agent is a very active reactive material. In addition to the main reaction with hydrogen molecules, it can also react with hydrogen molecules on the viscous surface to form chemical bonds, which is the bridge of adhesive molecular viscosity and produces greater adhesiveness. Because of the adhesiveness of these adhesives, it has been widely used in the composite process of aluminum foil coatings with adhesives and various plastic films.
Application solvent adhesive development direction in the future, it also belongs to the basic bicomponent poly ester, hydrogen is different, the main agent and curing agent at room temperature, high viscosity, but there are still a liquidity, belong to the semi-solid materials, when used, the main agent and solid agent mixture ratio to isolate heating container, good temperature control, low viscosity, then through which has the function of the heating roller to the dielectric material, after besmear is need not heating dry, because of its itself without any solvent, made out of glue and another matrix directly. Using solvent-free adhesives does not create exhaust emissions problems and does not require the installation of large heating, drying and air removal devices. So now we have a lot of this adhesive.