摘要:
The present invention provides a method of recovering a fluorinated acid surfactant or salt thereof from adsorbent particles to which said fluorinated acid surfactant has been adsorbed. The method comprises mixing adsorbent particles having adsorbed fluorinated acid surfactant or salt thereof with an alcohol and optionally an acid. The mixture is generally heated to cause esterification of the fluorinated acid surfactant or salt thereof with the alcohol so as to form an ester derivative of the fluorinated acid surfactant, distilling the mixture to form a distillate comprising the ester derivative, separating the ester derivative from the distillate and optionally feeding the remainder of the distillate back into the mixture.
摘要:
Non-free flowable, non-dusting molding powders with a bulk density of more than 450 g/l are obtained when a suspension polymer of tetrafluoroethylene with a content of 0.01 to 1% by weight of units of at least one perfluoro(alkyl-vinyl) ether is ground to a particle diameter of 10 to 50 .mu.m and agglomerated in water.
摘要:
Crosslinkable, fluorine-containing copolymers, comprising:(a) 15 to 70 mol % of copolymerized units of a vinyl ester of the formula ##STR1## in which R.sup.1, R.sup.2 and R.sup.3 are branched or straight-chain alkyl radicals or cycloalkyl radicals, at most one of these radicals is hydrogen and at least one of these radicals is a methyl group, and where, furthermore, the entire acyl radical of the vinyl ester contains at least 9 and at most 28 carbon atoms,(b) 5 to 50 mol % of copolymerized units of a hydroxyalkyl vinyl ether of the formulaCH.sub.2 .dbd.CH--O--R.sup.4 --OH in which R.sup.4 OH is a branched or straight-chain hydroxy-alkyl group having 1 to 6 carbon atoms, and(c) copolymerized units of tertrafluoroethylene in an amount which makes up the sum of components (a) plus (b) plus (c) to 100, but with the proviso that at least 10 mol % of copolymerized units of tetrafluoroethylene are present in the copolymer.From these, highly weather-resistant surface-coating compositions are obtained on addition of crosslinking agents, solvents and conventional additives.
摘要:
Crosslinkable fluorine-containing copolymers comprising copolymerized units of(a) a vinyl ester of a heavily branched carboxylic acid,(b) a vinyl ester of a short-chain carboxylic acid and(c) of a fluoroolefin, the vinyl ester groups of component (b) having been converted into OH groups by solvolysis of the copolymer. The copolymers are suitable for coating purposes of any type, in particular as binders in surface-coating systems for industrial surface-coatings.
摘要:
A protective colloid-free plastics dispersion yielding after drying a polymer film which under the influence of moisture has no or little tendency to whitening contains polymer particles having a bimodal size distribution, that is, on the one hand relatively coarse particles and on the other hand relatively fine particles. The polymer component consists of at least 10 weight % of particles having an average diameter of less than 0.2 .mu.m and of 90 weight % at most of particles having an average diameter of more than 0.25 .mu.m, and the ratio of average grain size of coarse to fine polymer is at least 2:1. The plastics dispersion is suitable especially as binder dispersion in plasters and gloss paints.