摘要:
This invention relates to a continuous or discontinuous process for the removal of catalytic quantities of lead ions from aqueous formose solutions by cationic electro-deposition. The process is preferably carried out with a constant current and in at least three stages, with lower current densities being maintained during the first and last stage than in the middle stages.
摘要:
In a construction material comprising a flexible carrier substrate impregnated or coated with a water-hardening resin, the resin contains as an additive polyether polysiloxane polyurethanes of the formula ##STR1## in which R.sup.1 is lower alkyl,m is the average number of siloxane groups in the range from 5 to 25,R is ##STR2## in which X is lower alkylene,Y is an aliphatic, cycloaliphatic, aromatic or araliphatic moiety, which is unsubstituted or substituted by further ##STR3## Z is a polyether moiety based on ethylene oxide units propylene oxide units, or both with the average number of ethylene oxide and propylene oxide units being in the range fro 10 to 100 andR.sup.2 is lower alkyl.
摘要:
The present invention is directed to an improved process for the direct preparation of polyurethane powders in a finely divided form by the reaction of polyisocyanates and isocyanate reactive compounds in a carrier phase, using interface active compounds, the improvement wherein the interface active compound used consists of at least one polymer of a urethane of (i) a long chain alkyl isocyanate and (ii) a hydroxyalkyl-acrylic or -metacrylic acid ester.
摘要:
The present invention is directed to aqueous solutions or dispersions of cationically modified polyurethanes, characterized in that the dissolved or dispersed polyurethanes(i) contain about 2 to 200 milliequivalents of incorporated ammonium groups per 100 g of solids content,(ii) contain 0 to about 25% by weight of ethylene oxide units within terminal or lateral polyether chains and(iii) contain at least 1.3% by weight, calculated as SiO.sub.3 (molecular weight=76), of built-in structural units corresponding to the formula ##STR1## wherein R', R" and R"' may be the same or different and represent hydrogen or alkyl groups containing 1 to 4 carbon atoms,the total quantity of hydrophilic structural units (i) and (ii) being sufficient to ensure the solubility or dispersibility of the polyurethanes in water and the solutions or dispersions having a pH value of 3 to 6. The present invention is also directed to a process for the preparation of these storage stable aqueous solutions or dispersions and to their use as coating compounds or for the preparation of coating compositions for any substrates.
摘要:
This invention relates to storage stable resin reaction mixtures obtained by mixing at least one organic polyisocyanate, at least one organic compound containing at least two epoxide groups, at least one alkylating agent that inhibits the reaction of the polyisocyanate and epoxide components, and optional auxiliary agents and additives. The present invention further relates to a process for the preparation of such reaction mixtures and to their use.
摘要:
Liquid crystalline bis-chlorocarbonic acid esters are 4-hydroxybenzoic acid-(4'-hydroxyphenyl) esters corresponding to the following formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 denote, independently of one another, hydrogen, a halogen atom or a C.sub.1 to C.sub.6 alkyl group. Preparation of (I) and liquid crystalline N-alkyl polyurethanes and polycarbonates prepared form (I) are other invention embodiments.
摘要:
Novel polyurethanes are prepared by reacting(a) an organic diisocyanate of formula ##STR1## wherein M represents --CH.dbd.CH--; --N.dbd.N--; --CH.dbd.N--; ##STR2## or and where R.sub.1 through R.sub.4 may be the same or different and represent hydrogen, halogen, CN, CF.sub.3 or saturated aliphatic C.sub.1 -C.sub.12 alkyl residues which may be interrupted by ether hydrogen atoms with(b) compounds of molecular weights of from between 400 and 10,000 and which contain at least two active hydrogen atoms reactive toward isocyanate groups.
摘要:
The present invention relates to a process for the production of aliphatic and/or cycloaliphatic diisocyanates which are color stable to heat, which is characterized in that a diisocyanate with aliphatically-and/or cycloaliphatically-bound isocyanate groups is heated in the presence of about 0.1 to 3% by weight, based on the diisocyanate, of at least one compound which is soluble in the diisocyanate and contains at least 3% by weight of structural units corresponding to the formula: ##STR1## for up to about 5 hours at a temperature of about 100.degree. to 220.degree. C. and the diisocyanate which has been treated in this way is subsequently purified by distillation.The present invention also relates to the use of the products of the present process for the production of modified polyisocyanates having improved coloration.
摘要:
The invention relates to new cyclic ethers which are substituted in the .alpha.-position by an isocyanide-dichloride group, of the formula ##STR1## in which R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and n have the meaning indicated in the description, and to a process for their preparation.
摘要:
The instant invention relates to an improved process for the preparation of low molecular weight polyalcohols by the catalytic hydrogenation of a mixture of different low molecular weight hydroxy aldehydes, hydroxy ketones and optionally also polyhydric alcohols such as is formed from the autocondensation of formaldehyde (such a mixture will hereinafter be referred to as "formose"). The invention also relates to the use of these polyalcohols for the production of polyurethane resins.