摘要:
Polyisocyanurate foams are prepared from reacting partially etherified methylolmelamines either alone or in mixture with polyoxyalkylene polyether polyols with polyisocyanates. Improved friability and flame retardancy are obtained.
摘要:
Haloalkoxymethylmelamine adduct is prepared by reacting hexamethoxymethylmelamine with a halogenated alcohol. Dispersions of this adduct in a polyol produce a polyurethane product which displays improved flame retardancy.
摘要:
Aminoplast resin is prepared by reacting urea or melamine with formaldehyde in the presence of a stabilizer compound. Dispersions of the resin in a polyol reacted with a polyisocyanate produce polyurethane products having low flammability properties.
摘要:
Liquid carbodiimide-modified organic polyisocyanates are prepared by reacting a crude polymethylene polyphenylene polyisocyanate containing no more than 70 weight percent diphenylmethane diisocyanate with an isomer mixture of 40 to 100 weight percent 4,4'-, 0 to 50 weight percent 2,4- and 0 to 10 weight percent 2,2'-diphenylmethane diisocyanate and having an average functionality of 2.1 to 2.7 and a free NCO content of at least 30 percent weight percent in the presence of an effective amount of carbodimidization catalyst. Polyisocyanurate-polyurethane foams prepared by reacting the modified polyisocyanates and polyols selected from the group consisting of diethylene glycol and ethylene oxide adducts of trimethylolpropane, trimethylolethane, glycerine, pentaerythritol, .alpha.-methylglucoside, sucrose, toluene diamine and methylene dianiline in the presence of trimerization catalysts exhibit improved compression strengths and K-factors with low friability and smoke density.
摘要:
A stable isocyanurate-modified polyisocyanate prepared by trimerizing an organic polyisocyanate mixture of 45 to 70 percent by weight of diphenylmethane diisocyanate having an isomer mixture of 40 to 100 weight percent, 4,4'-, 0 to 50 weight percent 2,4-, and 0 to 10 weight percent 2,2'-diphenylmethane diisocyanate and from 30 to 55 percent by weight polymethylene polyphenylene polyisocyanate with an isocyanurate content of 20 to 33 percent by weight. Polyurethane isocyanurate foams prepared from the reaction of these isocyanates with active hydrogen compounds selected from the group consisting of diethylene glycol and ethylene oxide adducts of trimethylolpropane, trimethylolethane, and glycerine exhibit good K- factors, low friability and low smoke density.
摘要:
Polyisocyanurate-polyurethane foams are prepared by reacting an organic polyisocyanate with oxyethylated aromatic amines and diols having equivalent weights from 31 to 100 and at an isocyanate index of 150 to 500 in the presence of a trimerization catalyst and a blowing agent.
摘要:
Polyisocyanurate polymers are prepared by polymerization of polyisocyanates in organic solvents employing trimerization catalysts. The polyisocyanates are reacted with monofunctional active hydrogen compounds prior to polymerization or subsequent to the polymerization. These polymers may be dispersed in polyols for the preparation of cellular and non-cellular polyurethane products having improved physical properties.
摘要:
Polyisocyanurate polymers are prepared by polymerization of polyisocyanates in organic solvents employing trimerization catalysts. The polyisocyanates are reacted with halogenated alcohols subsequent to polymerization. These polymers may be dispersed in polyols for the preparation of cellular and non-cellular polyurethane products having improved flame retardant physical properties.
摘要:
Enhanced load-bearing properties for flexible polyurethane foam can be achieved by employing a hydroxyl compound-modified benzyl ether-containing resole polyol as part of the polyol component (5 to 25 weight percent based on polyol) in the preparation of the foam.
摘要:
Polyisocyanurate polymers containing pendant urea groups are prepared by polymerization of polyisocyanates in organic solvents employing appropriate trimerization catalysts and then end-capping the polyisocyanurate polymer with ammonia or ammonium hydroxide. These end-capped polyisocyanurate polymers which contain pendant urea groups are dispersed in polyols to yield fine particulate dispersions. Cellular and non-cellular urethane products prepared using these dispersions displayed improved physical properties.