| 摘要 |
#CMT# #/CMT# Size for mineral fibers comprises a phenolic resin, urea and a crosslinking catalyst comprising ammonium sulfamate and ammonium sulfate. #CMT# : #/CMT# An independent claim is also included for a heat or sound insulation product based on mineral fibers, especially glass fibers or rock wool, where the fibers are coated with a size as above. #CMT#USE : #/CMT# The size is useful for making heat or sound insulation materials with a thermal conductivity of less than 40 mW/m.K (claimed). #CMT#ADVANTAGE : #/CMT# The size has a low crosslinking temperature and a long pregelling time. #CMT#POLYMERS : #/CMT# Preferred Binder: The catalyst is present in an amount of 2.6-4.2% by weight of resin solids and urea. The molar ratio of ammonium sulfamate to ammonium sulfate is 0.4-0.6. The resin is produced by reacting phenol and formaldehyde in the presence of a basic catalyst, the formaldehyde/phenol molar ratio being 2.3-4.2. The reasin has a free phenol content of 2 wt.% or less and a free formaldehyde content of 10 wt.% or less. The urea content is 20-45% by weight of resin plus urea. The size can also contain 0-2 wt.% of an amino silane and 4-15 wt.% of an oil. #CMT#EXAMPLE : #/CMT# A mixture of 63 parts by weight (pbw) of phenol-formaldehyde resin and 37 pbw urea was diluted to 30% solids with water. A size prepared by adding 2.1 pbw ammonium sulfamate and 2.1 pbw ammonium sulfate had a crosslinking temperature of 145[deg] C and a pregelling time of 4700 seconds. The corresponding values for a size containg 4.2 pbw ammonium sulfamate were 145[deg] C and 3500 seconds. |
