摘要:
The invention relates to a process for the production of rigid to semirigid polyurethane foams having an increased proportion of open cells and reduced shrinkage using recyclate polyols. The invention furthermore relates to the rigid to semirigid polyurethane foams produced by this process.
摘要:
In a process for producing rigid polyurethane foams by reactinga) polyisocyanatesb) compounds containing at least two hydrogen atoms capable of reacting with isocyanate groups, in the presence ofc) catalysts,d) blowing agents and, if desired,e) further auxiliaries and/or additives,the component b) comprises at least one recycled polyol which is formed by glycolysis of polyurethanes.
摘要:
A process for recycling plastic waste containing a mixture of polyurethanes and other plastics, comprises reacting the plastic waste with an alcohol mixture comprising at least one low-molecular-weight, at least difunctional alcohol and at least one polyether-polyol, and then separating the resultant glycolysis polyol mechanically from the other plastic waste.
摘要:
In a process for reducing the primary amine content of a composition comprising at least one polyol, in which a composition comprising at least one polyol is admixed with at least one isocyanate which contains only secondary and/or tertiary, aliphatically bound isocyanate groups, isocyanate is added in an amount of up to 5% by weight, based on the total composition, and a polyol preparation is obtained.
摘要:
The invention relates to a process for the preparation of recyclate polyols by reacting rigid polyurethane foam with short-chain hydroxyl-containing compounds, which comprises adding at least one epoxidized native fatty oil to the reaction mixture after glycolysis at a temperature from 10.degree. to 80.degree. C. below the glycolysis temperature.
摘要:
A process for the preparation of recyclate polyols obtained by glycolysis of polyurethanes and/or polyurea-polyurethanes comprises metering in monofunctional and/or difunctional glycidyl ethers over the entire course of the reaction; the low-amine recyclate polyols obtained in this way are used for the preparation of cellular or noncellular polyurethanes.