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:
Sound-damping and energy-absorbing flexible PUR foams are produced by reacting organic and/or modified organic polyisocyanates (a) with a polyetherol mixture (b) and, if desired, further compounds (c) bearing hydrogen atoms which are reactive toward isocyanates, in the presence of water and/or other blowing agents (d), catalysts (e) and, if desired, further auxiliaries and additives (f).
摘要:
Polyurethane foams are produced by reactinga) organic and/or modified organic diisocyanates and/or polyisocyanates withb) at least one relatively high molecular weight compound containing at least two reactive hydrogen atoms,c) at least one compound containing from three to eight, preferably from three to six, reactive hydrogen atoms andd) low molecular weight chain extenders and/or crosslinkers containing at least two reactive hydrogen atomsin the presence ofe) blowing agentsf) catalysts and, if desired,g) further auxiliaries and additives,wherein (c) are ethylene oxide-rich adducts having an ethylene oxide content of more than 50% by weight and an OH number of from 200 to 800 mg KOH/g and (d) are polyfunctional chain extenders and/or crosslinkers having an OH number of more than 700 mg KOH/g.The polyurethane foam produced by this process can be used as upholstery material.
摘要:
A process for preparing a homogeneous polyol component which is stable to separation and consists of at least one compound of relatively high molecular weight having at least two reactive hydrogen atoms and low-molecular-weight chain extenders and/or crosslinkers and, if desired, of blowing agents, catalysts and other auxiliaries and/or additives comprises the addition to this component of at least one amine and at least one organic and/or modified organic isocyanate; the invention also provides the corresponding polyol component which is stable to separation.The use of this polyol component for preparing PUR, in particular compact or foamed PUR, is also described.
摘要:
Process for producing flexible polyurethane foams in particular molded flexible polyurethane foams, by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reactive toward isocyanate groups, wherein the component b) comprises b1a) at least one polyether alcohol having an end block of ethylene oxide units which has been added on by means of DMC catalysis and makes up not more than 10% by weight of the weight of the alkylene oxide added on by means of DMC catalysis, and/or b1b) at least one polyether alcohol comprising a terminal mixture of ethylene oxide and propylene oxide which has been added on by means of DMC catalysis and has an ethylene oxide content in the mixture of at least 25% by weight, and also b2a) at least one polyether alcohol or comprising exclusively propylene oxide units, and/or b2b) at least one graft polyether alcohol.
摘要:
Process for producing flexible polyurethane foams in particular molded flexible polyurethane foams, by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reactive toward isocyanate groups, wherein the component b) or comprises b1a) at least one polyether alcohol having an end block of ethylene oxide units which has been added on by means of DMC catalysis and makes up not more than 10% by weight of the weight of the alkylene oxide added on by means of DMC catalysis, and/or b1b) at least one polyether alcohol comprising a terminal mixture of ethylene oxide and propylene oxide which has been added on by means of DMC catalysis and has a n ethylene oxide content in the mixture of at least 25% by weight, and also b2a) at least one polyether alcohol or comprising exclusively propylene oxide units. and/or b2b) at least one graft polyether alcohol.
摘要:
Polyester-polyether block copolymers can be prepared by catalytic addition of alkylene oxides onto H-functional initiator substances, using polyester alcohols as H-functional initiator substances and multimetal cyanide compounds as catalysts.
摘要:
In a process for preparing polyether alcohols by catalytic addition of at least two alkylene oxides onto H-functional initiator substances, at least one multimetal cyanide compound is used as catalyst and the addition of the alkylene oxides onto the initiator substance includes incorporation of at least one oxyalkylene block during whose formation at least two alkylene oxides are metered in together and the ratio of the alkylene oxides to one another in the mixture is changed during the joint introduction.