Patent ID: 6579835
Filing Date: 2003-06-17
Classification: C08G,C09D

Abstract:
A process for dry lubrication of rubbers, plastics, metals, and glass materials, comprising applying to said materials a coating of thermally crosslinkable fluorinated polyurethanes, thermally crosslinkable, obtainable from aqueous dispersions of cationic oligourethanes based on branched and thermocrosslinkable (per)fluoropolyethers, said cationic oligourethanes having a number average molecular weight lower than or equal to 9,000, determined by vapour pressure osmometry and formed by the following monomers and macromers:a) aliphatic, cycloaliphatic or aromatic polyisocyanates, having NCO functionality, determined by titration with dibutylamine-HCl according to ASTM D2572, higher than 2; b) bifunctional hydrogenated monomers having the two functions chemically different from each other having the general formula: X0â€”(CR1AR2A)bâ€”Y0â€ƒâ€ƒ(Ib) â€ƒwherein: R1A and R2A, equal to or different from each other, are H, aliphatic radicals from 1 to 10 carbon atoms, b is an integer in the range 1-20, X0=XAH with XA=O, S, Y0 is a salifiable, anionic or cationic function, when in the formula (Ib) X0=OH, b=1, R1A=R2A=H and Y0 is a hydrophilic group having formula â€”CH2Oâ€”(CH2â€”CH2O)nTâ€”CH3â€ƒâ€ƒ(Ib1) wherein nT is an integer in the range 3-20; and one or more of the following compounds:c) bifunctional hydroxylated (per)fluoropolyethers having number average molecular weight in the range 400-3,000; e) monofunctional hydroxyl or carboxylic (per)fluoropolyethers (eÂ°) or monofunctional hydroxyl (per)fluoroalkanes (eâ€²), said compounds (eÂ°) and (eâ€²) having number average molecular weight in the range 300-1,000; and optionally the following compounds: d) hydrogenated monomers with which it is possible to insert a crosslinkable chemical function in the oligourethane, said monomers having formula (Ib), wherein R1A, R2A, b and X0 are as above and Y0 is selected from the following functional groups: â€ƒwherein R1B=H, CH3; Rx is a C1-C5, saturated alkyl; d1) hydrogen-active compounds, able to form with the NCO functions bonds which are stable to hydrolysis but thermolabile, said compounds known as blocking agents of the NCO group.