摘要:
The instant invention is directed to a process for dissociating cellular and non-cellular polyurethane resins into re-usable starting products for the isocyanate polyaddition process, wherein the polyurethane is reacted with associates of lactams and adduct-formers having at least two Zerewitinoff-active hydrogen atoms at from 150.degree. to 250.degree. C., optionally at elevated pressure, the improvement wherein from 35 to 1000 parts, by weight, based on 100 parts, by weight, of the polyurethane, of an associate mixture of:(a) from 4 to 50 parts, by weight, of a lactam or azalactam, based on 100 parts, by weight, of polyurethane; and a mixture of:(b) water and/or a compound having a molecular weight of from 62 to 200 having at least two Zerewitinoff-active hydrogen atoms; and(c) a polyhydroxyl compound having a molecular weight of from 300 to 6000; is used, and the proportion by weight of components (b) to (c) is from 1:10 to 10:1, and wherein said component (a) is used in a quantity such that said 35 to 1000 parts comprises from 4 to 50 parts of component (a).
摘要:
A process is provided for the production of synthetic polyurethane plastics, particularly foam plastics, containing biuret groups by reacting polyisocyanates, polyhydroxyl and/or polycarboxyl compounds, flame inhibitors and, if desired, blowing agents, emulsifiers, activators and other additives which is characterized by using as the polyisocyanate solutions in monomeric polyisocyanates of from about 1 per cent to 85 per cent of polyisocyanates containing biuret groups and having the formula: ##EQU1## in which R is an aromatic, araliphatic or cycloaliphatic radical which may, if desired, be substituted andn is an integer from 0 to 5, wherein the proportion of biuret-polyisocyanates having more than three isocyanate groups is at least 20 per cent by weight based on the total quantity of biuret-polyisocyanates, and the solutions contain from about 0.03 per cent to about 5 per cent by weight of chemically combined emulsifiers.
摘要:
The present invention relates to stable solutions of urea diisocyanates in diisocyanates which are free from urea groups which solutions are prepared by a process which comprises reacting in the absence of a solvent at a temperature from about -20.degree.C to about 80.degree.C an organic diisocyanate with a bis-secondary diamine such that the NCO/NH-ratio is from 2.5 : 1 to 20 : 1. The solutions of the invention are well-suited for use as isocyanate component for the preparation of polyurethane resins by the isocyanate polyaddition process.
摘要:
In data transmitting systems, an apparatus for synchronizing the frame clock in units/nodes. The apparatus has a phase detector and a voltage controlled oscillator. At least one input of the phase detector is supplied with an incoming clock signal and another input is supplied with an output signal of the voltage controlled oscillator. The output signal of the voltage controlled oscillator is conducted over a divider, which is connected to a frame clock phase detector for setting its division factor. The frame clock phase detector is supplied with an input frame clock, the output of the variable divider, and at least one output of an output divider. The at least one output of the output divider divides the output signal of the controlled oscillator into the output frame clock. The frame clock phase detector is configured for the output of a pulse that temporarily raises or lowers the division factor of the divider when the phase difference between input and output clock deviates from a prescribable quantity.
摘要:
A method and an arrangement for controlling modulated lasers are provided, in which an input signal of a laser is modulated by a pilot signal. The combined signal that is emitted is then utilized to control the laser. In order to substantially prevent individual spectral lines of the input signal from affecting the pilot signal, a pilot signal is selected with a frequency spectrum that is spread substantially uniformly in the spectral range of the input signal. Versions of this method are also known by the term “spread spectrum modulation”.
摘要:
A compound adapted to be used to advantage as a catalyst for making carbodiimide foams is prepared by a process whereinA. a phosphetane oxide or phosphetane sulphide of the general Formulae I and II: ##EQU1## wherein X represents a C.sub.1 -C.sub.18 alkyl, C.sub.2 -C.sub.18 alkenyl, C.sub.6 -C.sub.14 aryl, C.sub.7 -C.sub.20 aralkyl, C.sub.1 -C.sub.18 alkoxy or C.sub.6 -C.sub.14 aroxy group andR.sup.1 to R.sup.6 represent hydrogen and/or C.sub.1 -C.sub.4 alkyl groups and is reacted withB. a mono-, di- and/or polyhydric alcohol having a molecular weight of about 32 to about 250, a protonic acid which has a pH of between 1 and 8 in N/10 aqueous solution, a metal salt or an acid chloride.
摘要:
A processor (PR) is connected to the output of a phase comparator (PK) in a phase-locked loop. The processor (PR) calculates the phase shift of an input signal (f.sub.E) within an observation time span (for example, .DELTA.t=0-T) from the phase difference (.DELTA..phi.) at the output of the phase comparator (PK) and the parameters of the phase-locked loop (FT1, PK, FI, VCO, FT2).
摘要翻译:处理器(PR)在锁相环中连接到相位比较器(PK)的输出端。 处理器(PR)在相位比较器(PK)的输出处的相位差(DELTA phi)中计算观测时间间隔内的输入信号(fE)的相移(例如,DELTA t = 0-T) 以及锁相环(FT1,PK,FI,VCO,FT2)的参数。
摘要:
Isocyanate-based foams are produced by the reaction of polyisocyanates with compounds with molecular weights of from 400 to 10,000 and having at least two hydrogen atoms active towards isocyanates in the presence of hydrocarbons which are vaporizable under the foaming conditions as blowing agents. The active hydrogen component is a mixture of a) one or more nitrogen-free polyethers having at least two hydrogen atoms active towards isocyanates and containing oxyethylene residues, and b) one or more polyethers having at least two hydrogen atoms active towards isocyanates and containing no oxyethylene groups.
摘要:
A compound adapted to be used to advantage as a catalyst for making carbodiimide foams is prepared by a process wherein(a) a phosphetane oxide or phosphetane sulphide of the general Formulae I and II: ##STR1## wherein X represents a C.sub.1 -C.sub.18 alkyl, C.sub.2 -C.sub.18 alkenyl, C.sub.6 -C.sub.14 aryl, C.sub.7 -C.sub.20 aralkyl, C.sub.1 -C.sub.18 alkoxy or C.sub.6 -C.sub.14 aroxy group andR.sup.1 to R.sup.6 represent hydrogen and/or C.sub.1 -C.sub.4 alkyl groups and is reacted with(b) a mono-, di- and/or polyhydric alcohol having a molecular weight of about 32 to about 250, a protonic acid which has a pH of between 1 and 8 in N/10 aqueous solution, a metal salt or an acid chloride.
摘要:
A cylinder head for an internal combustion engine has at least one receptacle socket, penetrating a coolant chamber, for a spark plug and/or an injection valve. At one end, the socket rests tightly, with a frustoconical seating face, against a corresponding seating face of a seat embodied on a lower cylinder head wall, and at its other end the socket is retained in the associated cylinder head wall and is pressed axially against the seat. In order to attain particularly intensive cooling in the vicinity of the nozzle of the injection valve and/or the spark plug, the seating face on the respective socket is embodied as a female cone, and the associated seating face on the respective seat is embodied as a male cone, and the associated end faces of the respective socket are open toward the coolant chamber.