摘要:
A novel suspension of boric acid comprising a concentrated, finely dispersed suspension of boric acid and a small amount of a soluble borate salt in an aqueous medium and a method of preparing the same.
摘要:
Wood that is especially suited for the manufacture of resonating bodies, is improved according to a process in which small amounts of reactive components of thermosetting polymers are introduced into the wood shortly before or during a heat treatment under pressure.
摘要:
The invention relates to a process for recovering amines from acid amine salt solutions by the addition of bases and evaporating the solution at a pH of 11 to 13 in a kneading drier until a useful solid is obtained as the distillation residue and a device for separating sludges and suspensions into a solid and a plurality of liquid fractions separated according to their boiling point. The low-water-content amine phase separated out by distillation is dehydrated with calcium oxide or potassium hydroxide and then separated into pure amine fractions by rectification. The process described makes it possible to utilise all the secondary flows and completely recycle the amines and the absorption medium (sulphuric acid). The flows for the recycling process are amine-charged washing acids from absorbers obtained from the cleaning of amine-containing exhaust gases, produced for instance in the cold box process for hardening core sand in foundries.
摘要:
A biocidal preservative for cellulose-containing products containing a biocidally effective amount of a polymeric quaternary ammonium borate obtained by simultaneous reaction of (A) at least one member of the group consisting of boric acid and salts and esters thereof and (B) an amine of the formula ##STR1## and (C) ethylene oxide or propylene oxide wherein R.sub.1 is alkyl or alkenyl of 8 to 22 carbon atoms and R.sub.2 is hydrogen, alkyl of 1 to 22 carbon atoms or --CH.sub.2 CH.sub.2 NH.sub.2 or R.sub.1 is alkyl of 1 to 4 carbon atoms and R.sub.2 is --(CH.sub.2 CH.sub.2 O).sub.x --H or --(CH.sub.2 CH.sub.2 CH.sub.2 O).sub.x --H, R.sub.3 is selected from the group consisting of hydrogen, --(CH.sub.2 CH.sub.2 O).sub.x --H, (CH.sub.2 CH.sub.2 CH.sub.2 O).sub.x --H and --CH.sub.2 CH.sub.2 CH.sub.2 NH.sub.2, R.sub.4 and R.sub.6 are individually selected from the group consisting of alkyl of 1 to 4 carbon atoms, --(CH.sub.2 CH.sub.2 O).sub.x --H and --(CH.sub.2 CH.sub.2 CH.sub.2 O).sub.x --H, and R.sub.5 and R.sub.7 are individually --(CH.sub.2 CH.sub.2 O).sub.x --H and --(CH.sub.2 CH.sub.2 CH.sub.2 O).sub.x --H, A is selected from the group consisting of --(CH.sub.2).sub.n, --(CH.sub.2 CH.sub.2 --O--CH.sub.2 CH.sub.2).sub.n -- and --(CH.sub.2 CH.sub.2 --NH--CH.sub.2 CH.sub.2).sub.n --x is an integer from 1 to 55 and n is an integer of 1 to 20, the molar ratio of A:B:C being 1:2 to 20:0.6 to 1.5.
摘要:
A process is described for the modification of wood and wood products by heat treatment in a closed, heatable vessel, wherein the water content of the starting material is controlled to be no higher than 10% by weight.