摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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.
摘要:
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 by mass per 100 parts by mass of the component b).
摘要:
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.
摘要:
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.1 can therefore also be a mixture of the corresponding structures,R.sub.2 is the radical of a polycarboxylic acid without COOH groups, eg. adipic acid, terephthalic acid, o-phthalic acid,R.sub.3 is an alcohol radical like R.sub.1.
摘要翻译:含发泡剂的乳液包括a)含有对异氰酸酯具有反应性的氢原子的化合物,b)发泡剂,c)在聚氨酯化学中常用的催化剂,助剂和/或添加剂,其中发泡剂b)作为乳液存在 在组分a)和c)中,具有以下结构的聚酯醇用作乳化助剂:其中m = 0-15n = 0-1 o = 0-15 p = 0-1 q = 0-15 r = 0-1 s = 0-15 t = 0-1 u = 0-10 v = 0-15 x = 1-5 y = 1-4或1-3的混合,其中r + n NOTEQUAL 0 z = 0-3 zi = 0.1-3 R1是不含OH基团的脂肪族结构,基于多元醇的结构,优选乙二醇,二甘醇,三甘醇,1,2-丙二醇和二丙二醇,1,4-丁二醇, 6-己二醇,新戊二醇,1,3-丁二醇,三羟甲基丙烷,三羟甲基乙烷,甘油,季戊四醇,其中这些物质也可以作为彼此在酯化中的任何混合物使用,因此, 因此是相应结构的混合物,R2是不含COOH基团的多元羧酸的基团,例如。 己二酸,对苯二甲酸,邻苯二甲酸,R3是如R1的醇基。
摘要:
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.
摘要:
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.1 can therefore also be a mixture of the corresponding structures,R.sub.2 is the radical of a polycarboxylic acid without COOH groups, eg. adipic acid, terephthalic acid, o-phthalic acid,R.sub.3 is an alcohol radical like R.sub.1.
摘要:
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 μm, 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.