| 摘要 |
PURPOSE:To restrain the generation of formaldehyde odor, by dispersing PVA powder into a phenolic foam prepared from a resol-type phenol/formaldehyde resin. CONSTITUTION:Polyvinyl alcohol powder is dispersed into a phenolic foam prepared from a resol-type phenol formaldehyde resin, a foaming agent, and a curing agent as main components. The resol-type phenol formaldehyde resin to be used preferably has a viscosity at 25 deg.C of 1,000-20,000 and a solid content of 70-90%. The less the free formaldehyde component, the less will be the generation of formaldehyde odor when preparing a phenolic foam. As a foaming agent, a saturated hydrocarbon, a fluorocarbon, etc. having a boiling point of about -40-100 deg.C is used.
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