摘要:
Fluorinated oligourethanes, having number average molecular weight lower than or equal to 9,000, having a branched structure, formed of the following monomers and macromers: a) aliphatic, cycloaliphatic or aromatic polyisocyanates, b) heterofunctional hydrogenated monomers having general formula: X0—(CR1AR2A)b—Y0 (Ib) one or more of the following compounds: c) bifunctional hydroxyl (per)fluoropolyethers (PFPE diols) having number average molecular weight in the range 400-3,000, e) monofunctional hydroxyl (per)fluoropolyethers or monofunctional hydroxyl (per)fluoroalkanes (e′), having number average molecular weight in the range 300-1,000, and optionally the following compounds: d) heterofunctional monomers, dI) hydrogen-active compounds, capable to form bonds with the NCO functions stable at the hydrolysis but weak at heat.
摘要:
Compositions comprising anionic ionomeric polyurethanes crosslinkable in a wide temperature range, said composition comprising the following components: I) an aqueous dispersion of a linear crosslinkable ionomeric polyurethane, containing carboxylic groups and having a perfluoropolyether structure; II) a crosslinking agent, the ratio between the equivalents of the functional groups of the crosslinking agent and of the carboxylic groups of component I) being at least 0.7 up to 1.5, preferably 0.9–1.2, said crosslinking agent being dispersible or soluble in the dispersion component I).
摘要:
Formulations formed by aqueous dispersions of cationic ionomer fluorinated polyurethanes based on (per)fluoropolyethers, having end groups constituted by —NCO groups reacted with hydrogenactive compounds to give covalent bonds stable to water but thermolabile, usable for the surface hydro- and oil-repellent treatment of textiles.
摘要:
Use for the paper sizing of aqueous polyurethane dispersions from (per)fluoropolyethers obtainable by reaction among the following compounds: a) (per)fluoropolyether diols having a number average molecular weight from 400 to 5,000; b) diisocyanates having formula: OCN—R—NCO (VIa) wherein R is an aliphatic, cycloaliphatic bifunctional radical; or an aromatic bifunctional radical; c) diols containing one carboxylic function and optionally one or both the following components: d) hydrazine and/or aliphatic diamines; e) monofunctional hydroxylic (per)fluoropolyethers having a number average molecular weight in the range 300-1,000.
摘要:
Use of fluorinated polyurethanes thermally crosslinkable for obtaining coatings having an improved friction coefficient for the dry lubrication of rubbers, plastics, metals, glass, said polyurethanes obtainable from aqueous dispersions of cationic oligourethanes having a molecular weight≦9,000, formed by: a) polyisocyanates, having NCO functionality higher than 2, b) bifunctional hydrogenated monomers, c) bifunctional hydroxylated (per)fluoropolyethers, e) monofunctional hydroxyl or carboxylic (per)fluoropolyethers or monofunctional hydroxyl (per)fluoroalkanes optionally: d) hydrogenated monomers by which it is possible to insert a crosslinkable chemical function in the oligourethane; dI) hydrogen-active compounds, able to form with the NCO functions thermolabile bonds.
摘要:
Perfluoropolyethereal compounds having polycarbonate structure, and general formula: ##STR1## wherein c is an integer comprised between 0 and 10, preferably between 0 and 3,n is an integer from 2 to 1,000, extremes included,Rf is a poly-fluorooxyalkylenic chain, having number average molecular weight (Mn) comprised between 500 and 10,000.
摘要:
A process for separating, or enriching, non-functional, monofunctional and bifunctional species in a mixture of perfluoropolyoxyalkylenes of the general formula:Z--O--Rf--YwhereRf=a perfluoropolyoxyalkylene chain comprising one or more monomeric units of formula ##STR1## --CFXO-- (X=F, CF.sub.3), and optionally also units (--CF.sub.2 CF.sub.2 O--); andZ, Y, like or different from each other, are non-functional groups or functional groups containing --OH,which consists in subjecting said mixture of perfluoropolyoxyalkylenes to column chromatography using, as eluents, non-polar fluorinated solvents, either alone or in admixture with polar solvents.
摘要:
Fluorinated polymers having thermoplastic elastomeric properties comprising in the macromolecule perfluoropolyoxyalkylene sequences of formula:--CF.sub.2 O--(CF.sub.2 CF.sub.2 O).sub.m --(CF.sub.2 O).sub.n --CF.sub.2 --(I)where m/n=0.2+5, are obtained through polycondensation with suitable perfluoropolyoxyalkylene condensation monomers corresponding to formula (I), functionalized with suitable reactive groups and having a functionality at least equal to 1.97, preferably at least equal to 1.99.Such polymers are characterized by an average molecular weight at least 50%, preferably at least 100%, higher than that of the corresponding polymers obtained starting from perfluoropolyoxyalkylenes corresponding to formula (I) having a functionality not higher than 1.96.
摘要:
The present invention concerns a textile support for bituminous membranes, particularly for waterproofing roof surfaces of buildings, characterised by a high dimensional stability. The support comprises at least two layers (1, 2) of non-woven polyester or polymeric material in general and a plurality of longitudinal reinforcing filaments (3). The reinforcing filaments (3), preferably of glass, have been treated in advance with a size which allows the formation of stable chemical bonds, not strongly influenced by temperature.
摘要:
1) Disclosed herein are new fluorine-containing compounds having polyacetalic structure, of general formula:[Rf.sub.m --CH.sub.2 O(CH.sub.2 O).sub.c --CH.sub.2 --.brket close-st..sub.n (I)where:Rf=a perfluorooxyalkylene chain having Mn from 500 to 5,000;m=4-25;c=1-10;n=2-100.2) A process for preparing them which comprises carrying out the polycondensation of diols having formula:HORfOH (II)with formaldehyde, in mass or in the presence of solvents, in an acid medium. The compounds of formula (I) can be oligomeric compounds (polymerization degree x.sub.n from 2 to about 20) or polymeric compounds (x.sub.n from about 20 to about 100). They exhibit a high stability to heat and to chemical agents, and Tg values slightly different from the ones of the diols utilized for preparing them.
摘要翻译:1)本文公开了具有以下通式的具有聚缩醛结构的新的含氟化合物:[Rfm-CH2O(CH2O)c-CH2- + 548n(I))其中:Rf =具有+ E的全氟氧化烯链,ovs M + EE n从500到5,000; m = 4-25; c = 1-10; n = 2-100。 2)一种制备它们的方法,其包括在酸性介质中,以质量或在溶剂存在下,将具有式:HORFOH(II)的二醇与甲醛缩聚。 式(I)化合物可以是低聚化合物(聚合度+ E,ovs x + EE n从2至约20)或聚合化合物(+ E,ovs x + EE n约20至约100)。 它们对热和化学试剂表现出高稳定性,并且Tg值与用于制备它们的二醇的那些略有不同。