A heat-resistant composition useful as a flame retardant, a flame retardant composition containing the same, and a flame-retardant resin composition are provided. The composition contains 20 to 50 parts by mass of a specific melamine salt as component (A), 50 to 80 parts by mass of a specific piperazine salt as component (B), and 1 to 50 parts by mass of a phosphoric ester compound having a specific structure as component (C), wherein the sum of the components (A) and (B) is 100 parts by mass.
Facile synthetic routes for fused metallaaromatic compounds have been developed by CH activation strategy of designed alkyl-bridged diphenol derivatives. The developed reactions provide benzo- and benzofuran-fused iridaoxabenzenes with fully delocalized π-conjugated systems.
The invention provides a polypropylene molded article characterised in that the content of hexane and/or heptane therein is less than 5 ppm and the content of 2,4-dimethyl-heptene-1 therein is less than 5 ppm. It has a greatly lowered level of odor and hence is suitable for food packaging.
Pure tungsten oxyphenolate complexes as DCPD polymerization catalysts
申请人:HERCULES INCORPORATED
公开号:EP0480447A2
公开(公告)日:1992-04-15
This invention relates to a two component catalyst system for polymerization of metathesis polymerizable cycloolefins, comprising
(a) a tungsten compound of the formula WOX4-x(OAr)x wherein X represents chlorine, bromine or fluorine, Ar represents a hindered phenyl ring having 1-5 substituents and x = 1, 2 or 3; and
(b) an activator compound that preferably is triphenyltin hydride or trialkyltin hydride, preferably a tributyltin hydride.
Among the preferred molecules or groups that are substituted on the phenyl ring of the tungsten compound include chlorine, bromine, phenyl, methoxy and isopropyl. Ar may also represent a multisubstituted phenyl group such as 2,4-dichloro-6-methyl phenyl.
Tungsten-imido catalysts for ring-opening metathesis polymerization of cycloolefins
申请人:HERCULES INCORPORATED
公开号:EP0534388A1
公开(公告)日:1993-03-31
This invention relates to a two component catalyst system for the polymerization of metathesis polymerizable polycyclic cycloolefins, comprising (a) a tungsten-imido compound having the formula W(NR¹)X4-x(OR²)x·Ly wherein x=O, 1, 2, 3 or 4; y=O or 1; R¹ and R² are alkyl, phenyl, phenyl-substituted phenyl, phenylalkyl or halogen-substituted derivatives of alkyl, phenyl, phenyl-substituted phenyl or phenylalkyl; X=Br or Cl; where alkyl has 1 to 8 carbon atoms, phenyl substituted phenyl has 12-18 carbon atoms and phenylalkyl has 7 to 20 carbon atoms; and L is a donor ligand; and (b) an activator compound.
The catalyst system is used to prepare thermoset molded articles having low levels of residual monomer.