Room temperature-curing silicone-polyester binder
The present invention is directed to binder based on an alkoxy- and/or silanol-functional polysiloxane A), one or more dicarboxylic or polycarboxylic acids B), one or more di- or polyols C), one or more di- or polyisocyanates and one or more aminosilanes D1) or one or more isocyanatosilanes D2), the constituents A) to D1) or D2) being present condensed with one another in the binder.
1. A process for preparing binders, based on an alkoxy- and/or silanol-functional polysiloxane A), one or more dicarboxylic or polycarboxylic acids B), one or more di- or polyols C), one or more di- or polyisocyanates and one or more aminosilanes D1) or one or more isocyanatosilanes D2), the constituents A) to D1) or D2) being present condensed with one another in the binder, comprising the following steps:
where in a first step an alkoxy- and/or silanol-functional polysiloxane A), one or more dicarboxylic or polycarboxylic acids B) and one or more diols or polyols C) are reacted with one another to form a silicone-polyester hybrid resin, and
in a second step the silicone-polyester hybrid resin obtained in the first step is reacted with one or more di- or polyisocyanates and one or more aminosilanes D1) or one or more isocyanatosilanes D2).
2. The process according to claim 1 , wherein aromatic, aliphatic or cycloaliphatic dicarboxylic or polycarboxylic acids and their derivatives are used as component B).
3. The process according to claim 1 wherein ethylene glycol, propanediol s, butane-1,4-diol, hexane-1,6-diol, neopentyl glycol, trimethylolpropane, pentaerythritol, ditrimethylolpropane, perhydrobisphenol A, dimethylolcyclohexane and 3(4),8(9)-dihydroxymethyltricyclo[5.2.1.02,6]decane (TCD Alcohol DM) are used as diols or polyols C).
4. The process according to claim 1 , wherein component A) comprises non-linear, branched, alkoxy-functional and/or silanol-functional polysiloxanes of the general formula 1,
in which R 1 independently at each occurrence are alkyl, aryl or alkoxy groups, hydroxyl or -OSi(R 3 ) 3 -groups, where R 3 independently at each occurrence may be alkyl, aryl or alkoxy groups, hydroxyl or -OSi(R 3 ) 3 -groups, and where R 2 independently at each occurrence may be hydrogen, alkyl groups or aryl groups, and n is >1.
5. The process according to claim 1 , wherein an esterification catalyst is used in the polycondensation reaction of components A) to D1) or D2).
6. A binders coating compositions according to the process of claim 1 .
7. The binders according to the process of claim 1 , wherein they are 1-component coatings.