摘要:
A process for the preparation of foamed plastics materials based on polyisocyanate polyaddition products by the reaction of isocyanates with isocyanate-reactive compounds in the presence of catalysts and, optionally, auxiliaries and/or additives, wherein i) isocyanates having isocyanurate and/or biuret structures are used, the isocyanate-reactive compounds used are ii) at least one diol and/or polyol having a molecular weight of from 400 to 8000 and containing at least 50% of primary hydroxyl groups based on all of the hydroxyl groups present in the compound, iii) at least one compound having at least one primary amine group, and diols and/or triols having molecular weights of less than 400 are optionally used as chain-extending and/or crosslinking agents, the reaction being carried out in the presence of iv) at least one tertiary amine acting as catalyst and/or v) at least one metal salt acting as catalyst and vi) water.
摘要:
The invention relates to graft polyols with a bimodal particle size distribution and a total solid content of between 5 and 65 wt. %. Said polyols contain small particles with a particle diameter of between 0.05 and 0.7 μm and large particles with a particle diameter of between 0.4 and 5.0 μm, whereby the peaks of the large and small particles measured during a representation according to the light-scattering analysis method do not overlap. The total solid content with the defined particle sizes consists of a volumetric fraction of between 5 and 45% small particles and a volumetric fraction of between 95 and 55% large particles, said volumetric fractions totalling 100%. The invention also relates to a method for producing graft polyols of this type and to the use thereof for producing polyurethanes.
摘要:
The present invention relates to a process for the production of flexible polyurethane foams by reaction of a) at least one compound having at least two isocyanate-reactive hydrogen atoms, with b) polyisocyanates, wherein the compund used as said compound having at least two isocyanate-reactive hydrogen atoms a) comprises at least one block polyoxypropylene/polyoxyethylene/polyol having a hydroxyl value of from 25 to 45 mg KOH/g and a content of terminally bound ethylene oxide units of from 15 to 17 wt %, based on the total amount of the alkylene oxide, obtained by attachment of ethylene oxide and propylene oxide to an initiator having an average functionality of 3.
摘要:
Silver halide emulsions with tabular grains showing increased aspect ratio are produced by adding to the precipitiation vessel a compound of the formula I: ##STR1## in which R.sub.1 means H or optionally substituted alkyl, aralkyl or cycloalkylR.sub.2 means H or optionally substituted alkyl, aryl or aralkyl or a polymer chainR.sub.3 means H, OH, alkyl, aryl, aralkyl, halogen, NHR.sub.4, O--CO--R.sub.4, O--CO--NHR.sub.4 or an optionally substituted oxazoline ringR.sub.4 means optionally substituted or alkyl, aralkyl or arylm means 2 or 3,n means 2 to 10,000,or a compound of the formula II ##STR2## in which R.sub.1, R.sub.3, n and m have the meaning stated above and may be identical or different andR.sub.5 means optionally substituted alkene, arylene, aralkene or a polyaddition, polycondensation or polymerisation chain.
摘要:
The invention relates to a process for detecting the position and direction of movement and for detecting the dynamic characteristic values of remote-controlled displacements of an adjustable object. According to the invention a signal is detected and evaluated which is solely made up of a system-characteristic signal or the overlapping of several system-characteristic signals. The aim is to achieve a high dissolution of the aforesaid values which are to be detected without using additional sensor or transmitter elements whilst incurring only small production costs.
摘要:
Novel herbicidal fluorobenzothiazolyloxyacetamides of the formula ##STR1## in which R.sup.1 represents hydrogen or an optionally substituted radical from the group consisting of alkyl, alkenyl, alkinyl and aralkyl,R.sup.2 represents an optionally substituted radical from the group consisting of alkyl, alkenyl, alkinyl, cycloalkyl, cycloalkenyl, aralkyl, aryl, alkoxy, alkenyloxy or alkinyloxy, orR.sup.1 and R.sup.2, together with the nitrogen atom to which they are bonded, form an optionally substituted, saturated or unsaturated nitrogen heterocycle which can contain further heteroatoms and to which a benzo group can be fused.
摘要:
The sensitivity/fog ratio can be improved by using photographic silver halide emulsions containing gelatine which has a cysteine content of less than 10 ppm and a gold number of .gtoreq.23 .mu.mol/g.
摘要:
In combination with oil formers of the alkylphenol type, 3-anilinopyrazolones show absorption maxima displaced by about 8 to 12 nm towards longer wavelengths and a blue secondary absorption further displaced towards the UV range and, hence, a reduced yellow secondary density.