Biodegradable low melt hot melt adhesive and prodn. from gluten glue - by adjusting water content and opt. adding plasticiser, etc. and use for bonding material, esp. wood, paper, cardboard or foamed plastics

摘要

Hot melt adhesives (I) is based on glutin glue (II), which is made meltable by adjusting its water content, and opt. also contains plasticiser (III) and other usual additives (IV). The bonding process is also claimed. Pref. (I) contains 40-80 wt.% (II) and 20-40% water, together with 0.1-70% (III) and 0.01-45% (IV) w.r.t. (II) + water. (IV) may include 0.01-2% wetting agent, 0.01-5% colourant and/or 0.01-1% microbiocide. (I) may be in the form of a soft gum; particles; esp. with a dia. of 1-10 mm; crumb; bars, esp. for use in adhesive guns; sheet, esp. film; or particles covered with a release agent powder, pref. highly disperse SiO2. It melts at 50-95, esp. 60-70 deg.C and the melt viscosity is generally higher than that of liq. adhesives, esp. 25000-100000 mPa.s. The viscosity can be reduced after melting by adding water. (I) is kept in a moisture-proof package. USE/ADVANTAGE - (I) is used as low melt hot melt adhesive for bonding porous materials, esp. wood, paper, cardboard or foamed plastics (claimed). It is useful e.g. in the prodn. of packaging. The constituents of (I) are not harmful when the bonded articles are recycled and are easily degraded in sewage plant.