Siliconstabilizers for flame retardant polyurethane- resp. polyioscyanurate rigid foams

Abstract

The invention relates to a process for producing rigid polyurethane or polyisocyanurate foams by reacting an isocyanate with a polyol in the presence of urethane and / or isocyanurate catalysts, water, optionally further blowing agents, optionally flame retardants and optionally further additives (e.g. fillers, emulsifiers, purely organic stabilizers and surfactants, viscosity reducers, dyes, antioxidants, UV stabilizers, antistatics) using foam stabilizers of the general formula (I) R-Si(CH3)2-O-[-Si(CH3)2-O-]n-[-Si(CH3)R- O-]m-Si(CH3)2-R, where R=-(CH2)x-O-(CH2-CHR'-O )y- R''. -27- Claims: 1. A process for producing rigid polyurethane or polyisocyanurate foams by reacting an isocyanate with a polyol in the presence of foam stabilizers, urethane and / or isocyanurate catalysts, water, optionally further blowing agents, optionally flame retardants and optionally further additives, wherein one or more compounds of the general formula (I) R-Si(CH3)2-O-[-Si(CH3)2-O-]n-Si(CH3)R1-O-]m Si(CH3)2-R2 where the substituents and indices have the following meanings: R, R1, R2 are identical or different and are each -(CH2)x-O-(CH2-CHR'-O) y-R'', R' = H, -CH3, -CH2CH3, phenyl, R'' = H, alkyl, acyl, n+m+2 = 10 to 45, m = 0 to 4, x = 3 to 10, y = 1 to 19, are used as foam stabilizers. 2. The process for producing rigid polyurethane or polyisocyanurate foams as claimed in claim 1, wherein at least 50% of the radicals R' are H. -28- 3. The process for producing rigid polyurethane or polyisocyanurate foams as claimed in claim 1 and / or 2, wherein R'' = H. 4. The process for producing rigid polyurethane or polyisocyanurate foams as claimed in at least one of claims 1 to 3, wherein m = 0 to 2. 5. The process for producing rigid polyurethane or polyisocyanurate foams - as claimed in at least one of claims 1 to 4, wherein n+m+2 = 10 to 40. 6. The process for producing rigid polyurethane or polyisocyanurate foams as claimed in at least one of claims 1 to 5.

Description

technical field [0001] The present invention relates to the development of rigid polyurethane or polyisocyanurate foams which offer particularly advantageous application properties, such as low thermal conductivity and good surface quality, as well as the formulations on which they are based. Background technique [0002] In the production of rigid polyurethane and polyisocyanurate foams, cell stabilizing additives are used to ensure a fine-celled, homogeneous foam structure which is low in defects and therefore critical to the application properties of the rigid foams , especially thermal insulation capacity, has a significant positive effect. Surfactants based on polyether-modified siloxanes are particularly effective and thus represent the preferred class of foam stabilizers. [0003] Since there are many different rigid foam formulations for different applications, in which the foam stabilizers have to meet individual requirements, polyether siloxanes with different str...

AI Technical Summary

Problems solved by technology

However, especially at high levels, these flame retardants have a detrimental effect on the physical properties of the foam, especially in terms of thermal conductivity and compressive strength

Images