US 12,351,683 B2
Method for producing organyloxysilane-terminated polymers
Volker Stanjek, Ampfing (DE); and Lars Zander, Altötting (DE)
Assigned to Wacker Chemie AG, Munich (DE)
Appl. No. 17/778,863
Filed by Wacker Chemie AG, Munich (DE)
PCT Filed Dec. 13, 2019, PCT No. PCT/EP2019/085139
§ 371(c)(1), (2) Date May 23, 2022,
PCT Pub. No. WO2021/115621, PCT Pub. Date Jun. 17, 2021.
Prior Publication US 2022/0396665 A1, Dec. 15, 2022
Int. Cl. C08G 65/336 (2006.01)
CPC C08G 65/336 (2013.01) [C08G 2650/04 (2013.01)] 8 Claims
 
1. A process for preparing silane-terminated polymers (SP) of the formula (I)
Y—[O—C(—O)—NH—(CR12)b—SiRa(OR2)3-a]x  (I),
characterized in that
in a 1st process step at least one polymer (OHP) of the formula (II)
Y—[OH]x   (II)
is reacted with at least one isocyanate-functional silane (IS) of the formula (III)
O═C═N—(CR12)b—SiRa(OR2)3-a   (III)
with the proviso that the at least one isocyanate-functional silane (IS) is used in an amount such that there are at least 1.05 isocyanate groups in the at least one isocyanate-functional silane (IS) to each hydroxyl group in the at least one polymer (OHP),
where
Y is an x-valent polymer radical,
R may be identical or different and is a monovalent, optionally substituted hydrocarbon radical,
R1 may be identical or different and is hydrogen atom or a monovalent, optionally substituted hydrocarbon radical,
R2 may be identical or different and is hydrogen atom or a monovalent, optionally substituted hydrocarbon radical,
x is an integer from 1 to 50,
a may be identical or different and is 0, 1 or 2, and
b may be identical or different and is an integer from 1 to 10,
subsequently in a 2nd process step the unreacted isocyanate groups of the silanes (IS)” with “unreacted isocyanate groups of the at least one isocyanate-functional silane (IS) are reacted, in the reaction mixture obtained in the 1st process step, with at least one alcohol (A) of the formula (IV)
R3OH   (IV),
where
R3 is a hydrocarbon radical having 1 to 4 carbon atoms, and a carbamatosilane (CS) is formed,
and subsequently in a 3rd process step the reaction mixture obtained in the 2nd process step is passed through an evaporation unit (VD) in which the reaction mixture in a layer thickness of not more than 5 cm is exposed to a pressure of at most 80 mbar and temperatures of at most 200° C., wherein the carbamatosilane (CS) formed in the 2nd process step, of the formula (V)
R30—C(═O)—NH—(CR12)b-SiRa(OR2)3-a   (V),
in which all the variables have the definition stated above, is at least partly evaporated and removed.