Abstract: Disclosed herein is a method for producing polyurethane or polyisocyanurate foams. The method involves reacting a composition (Z1) with at least one polyisocyanate, and occurs in the presence of at least one nucleating agent and a blowing agent, in which the nucleating agent and the blowing agent are mixed to obtain a composition (Z2) that is added to the composition (Z1) before it is reacted with the at least one polyisocyanate. The composition (Z1) contains (i) 100 parts by mass of a composition (ZP) including at least one polyol and at least one catalyst that catalyzes formation of a urethane, urea or isocyanuarate bond, and (ii) from 0.05 to 10 parts by mass of a surfactant TD having an HLB value below 6 and no silicon atom.

Abstract: The present invention relates to a method for manufacturing a composite element comprising a single- or multi-part core and an envelope which are in a force fit combination with each other, at least comprising providing a single- or multi-part core of an evacuable organic material; at least partly enveloping the core with an envelope to obtain a composite element precursor; and treating the composite element precursor for a period leading to an at least partial softening of the evacuable organic material and of the envelope surface apposing the core. The present invention further relates to composite elements obtained or obtainable by a method of the present invention and also to the method of using a composite element of the present invention as a vacuum insulation panel or as a thermal insulation material.

Abstract: The present invention relates to a method for manufacturing a composite element comprising a single- or multi-part core and an envelope which are in a force fit combination with each other, at least comprising providing a single- or multi-part core of an evacuable organic material; at least partly enveloping the core with an envelope to obtain a composite element precursor; and treating the composite element precursor for a period leading to an at least partial softening of the evacuable organic material and of the envelope surface apposing the core. The present invention further relates to composite elements obtained or obtainable by a method of the present invention and also to the method of using a composite element of the present invention as a vacuum insulation panel or as a thermal insulation material.

Abstract: The invention relates to rigid polyurethane foams which can be produced by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reacted toward isocyanate groups in the presence of c) blowing agents, wherein the polyisocyanate a) used is a mixture of diphenylmethane diisocyanate and polyphenylenepolymethylene polyisocyanates comprising a1) 30-35% by weight of diphenylmethane diisocyanate, a2) 21-28% by weight of polyphenylenepolymethylene polyisocyanate having three aromatic rings, a3) 8-13% by weight of polyphenylenepolymethylene polyisocyanate having four aromatic rings, a4) 24-41% by weight of polyphenylenepolymethylene polyisocyanate having five or more aromatic rings, where the percentages by weight of the components a1) to a4) are based on the total weight of the components a1) to a4) and add up to 100% by weight.

Abstract: The present invention relates to a method of producing polyurethane or polyisocyanurate foams which comprises the step of reacting a composition (Z1), comprising a composition (ZP) at least comprising a polyol and a catalyst that catalyzes the formation of a urethane, urea or isocyanurate bond, and a surfactant TD having an HLB value below 10 and no silicon atom, wherein the sum total of surfactants TD in the composition comprises from 0.

Abstract: The invention relates to a xerogel comprising from 30 to 90% by weight of a monomer component (a1) composed of at least one polyfunctional isocyanate and from 10 to 70% by weight of a monomer component (a2) composed of at least one polyfunctional aromatic amine, at least one of which is selected from 4,4?-diaminodiphenylmethane, 2,4?-diaminodiphenylmethane, 2,2?-dIamino-diphenylmethane and oligomeric diaminodiphenylmethane, where the sum of the % by weight of monomer components (a1) and (a2) adds up to 100% by weight and where the monomer components are present in polymeric form in the xerogel and the volume-weighted mean pore diameter of the xerogel is at most 5 ?m. The invention further relates to a process for preparing xerogels, to the xerogels thus obtainable and to the use of the xerogels as an insulating material and in vacuum insulation panels.

Abstract: The invention relates to thermal insulation elements comprising a) a covering layer having a thickness of from 0.2 to 1.0 mm, b) at least one vacuum insulation panel located on a), c) a further thermal insulation material, d) a further covering layer.

Abstract: The invention relates to a xerogel comprising from 30 to 90% by weight of a monomer component (a1) composed of at least one polyfunctional isocyanate and from 10 to 70% by weight of a monomer component (a2) composed of at least one polyfunctional aromatic amine, at least one of which is selected from 4,4?-diaminodiphenylmethane, 2,4?-diaminodiphenylmethane, 2,2?-diaminodiphenylmethane and oligomeric diaminodiphenylmethane, where the sum of the % by weight of monomer components (a1) and (a2) adds up to 100% by weight and where the monomer components are present in polymeric form in the xerogel and the volume-weighted mean pore diameter of the xerogel is at most 5 ?m, The invention further relates to a process for preparing xerogels, to the xerogels thus obtainable and to the use of the xerogels as an insulating material and in vacuum insulation panels.

Abstract: The invention relates to rigid polyurethane foams which can be produced by reacting a) polyisocyanates with b) compounds having at least two hydrogen atoms which are reacted toward isocyanate groups in the presence of c) blowing agents, ?wherein the polyisocyanate a) used is a mixture of diphenylmethane diisocyanate and polyphenylenepolymethylene polyisocyanates comprising a1) 30-35% by weight of diphenylmethane diisocyanate, a2) 21-28% by weight of polyphenylenepolymethylene polyisocyanate having three aromatic rings, a3) 8-13% by weight of polyphenylenepolymethylene polyisocyanate having four aromatic rings, a4) 24-41% by weight of polyphenylenepolymethylene polyisocyanate having five or more aromatic rings, where the percentages by weight of the components a1) to a4) are based on the total weight of the components a1) to a4) and add up to 100% by weight.

Abstract: Storage-stable, blowing agent-containing halogen-free emulsions for producing rigid foams based on isocyanate comprise a) compounds containing hydrogen atoms which are reactive toward isocyanate groups, b) water, c) physically acting, halogen-free blowing agents and, if desired, d) auxiliaries and/or additives which are customary in polyurethane chemistry, wherein the component a) comprises polyether alcohols having a functionality of greater than 1.5 and a hydroxyl number of from 10 to 100 mg KOH/g in an amount of from 0.2% by mass to 80% by mass, based on the mass of the component a), and the halogen-free, physically acting blowing agents c) used are hydrocarbons having from 3 to 10 carbon atoms.

Abstract: A process for producing rigid polyurethane foams with reduced density by reactinga) organic and/or modified organic polyisocyanates withb) at least one higher-molecular-weight compound having at least two reactive hydrogen atoms and, if desired,c) low-molecular-weight chain extenders and/or crosslinkers in the presence ofd) blowing agents,e) catalysts and, if desired,f) other auxiliaries and/or additives,is described, which comprises using, as blowing agent (d), a mixture of cyclopentane with at least one compound which is homogeneously miscible with cyclopentane selected from the class consisting of the alkanes and/or alkenes having 3 or 4 carbon atoms in the molecule and with the carbon dioxide produced from water and isocyanate, and using, as higher-molecular-weight compound (b) having at least two reactive hydrogen atoms, polyethers which contain aromatics and nitrogen.The use of the rigid foams produced in this way as insulating material is also described.

Abstract: Blowing agent-containing emulsions comprisea) compounds containing hydrogen atoms which are reactive toward isocyanates,b) blowing agents,c) catalysts, auxiliaries and/or additives which are customary in polyurethane chemistry, wherein the blowing agents b) are present as an emulsion in the components a) and c), and polyester alcohols having the following structure are used as emulsification aids: ##STR1## where m=0-15n=0-1o=0-15p=0-1q=0-15r=0-1s=0-15t=0-1u=0-10v=0-15x=1-5y=1-4 or mixtures of 1-3 where r+n.noteq.0z=0-3z.sub.i =0.1-3R.sub.1 is an aliphatic structure without OH groups, based on the structure of polyhydric alcohols, preferably ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol and dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,3-butanediol, trimethylolpropane, trimethylol ethane, glycerol, pentaerythritol, where these substances can also be used as any mixture with one another in the esterification and R.sub.

Abstract: In a process for producing rigid polyurethane foams having improved heat distortion resistance and reduced thermal conductivity by reactinga) polyisocyanates withb) compounds containing hydrogen atoms reactive toward isocyanates, in the presence ofc) water, and, if desired,d) physically acting blowing agents ande) catalysts and known auxiliaries and/or additives, the compounds b) containing hydrogen atoms reactive toward isocyanates are a polyol mixture comprisingb1) a polyol which can be prepared by addition of ethylene oxide and/or propylene oxide onto a hexitol or a hexitol mixture, with the total hexitol content of the polyol mixture being from 15 to 30% by weight, based on the polyol mixture, andb2) a polyol which can be prepared by addition of ethylene oxide and/or propylene oxide onto one or more aromatic amines, with the total amine content of the polyol mixture being from 1 to 10% by weight, based on the polyol mixture, and the amount of the polyol mixture in the component b) is from 60 to 100 parts

Abstract: In a process for producing open-celled rigid foams by reactinga) polyisocyanates withb) compounds containing hydrogen atoms which are reactive toward isocyanates, in the presence ofc) water,d) if desired, organic compounds acting as physical blowing agents,e) catalysts, auxiliaries and/or additives,the compounds containing reactive hydrogen atoms used are substances having the structure I: ##STR1## where m is 0-15n is 0-1o is 0-15p is 0-1q is 0-15r is 0-1s is 0-15t is 0-1u is 0-10v is 0-15x is 1-5y is 1-4 or mixtures of 1-3 where r+n.noteq.0z is 0-3z.sub.i is 0.1-3R.sub.1 is an aliphatic structure without OH groups based on the structure of polyhydric alcohols, preferably ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol and dipropylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, 1,3-butanediol, trimethylolpropane, trimethylolethane, glycerol, pentaerythritol, where these substances can also be used in the esterification as any mixture among one another and R.sub.

Abstract: An anti-lock brake control system comprises at least two micro-computers and at least two input/output circuits which monitor one another as well as functions of other components of the anti-lock brake control system. If faulty voltages appear within the anti-lock brake control system or if false values in transmitted signals occur, the anti-lock brake control system will be dependably shut down. By integrating a plurality of monitoring functions in the input/output circuits as well as by building redundancies into the anti-lock brake control system, a high level of safety is achieved, in spite of the small number of necessary components and the small production cost associated therewith.

Abstract: A circuit has circuit amplifiers (T1, T2) and inductive loads (MV1, MV2) with the circuit amplifiers being controlled by control signals provided by a microcomputer (MC). The circuit accomplishes this control while monitoring a load circuit, comprised of the circuit amplifiers and the loads, and terminates control of the circuit amplifiers, without assistance of the controlling microcomputer, upon occurrence of incorrect voltages in the load circuit. Thus, the circuit of this invention allows particularly fast termination of control of the load circuit upon the appearances of critical voltages and also allows the monitoring of the load circuits by the microcomputer in a particularly uncomplicated manner.