Method for producing organyloxysilane-terminated polymers

A process for preparing a mixture (M), comprising:

• providing silane-terminated polymers (SP1) of the general formula (I)
• Y1—[O—C(═O)—NH—(CR12)b—SiRa(OR2)3-a]x (I),
• optionally silane-terminated polymers (SP2) of the general formula (II)
• Y2—[O—C(═O)—NH—(CR12)b—SiRa(OR2)3-a]z (II)
• and hydroxy-functional polymers (SP3) of the general formula (III)
• Y2—[O—C(═O)—NH—(CR12)b—SiRa(OR2)3-a]z-z1(OH)z1 (III)
• wherein Y1 is an x-valent polymer radical having a numerical average molar mass Mn of at least 2000 g/mol;
• wherein Y2 is a z-valent oligomer or polymer radical having at least 3 identical repeating units which contain at least 2 carbon atoms and at least 1 heteroatom;
• wherein R may be identical or different and is a monovalent, optionally substituted hydrocarbon radical;
• wherein R1 may be identical or different and is hydrogen atom or a monovalent, optionally substituted hydrocarbon radical;
• wherein R2 may be identical or different and is hydrogen atom or a monovalent, optionally substituted hydrocarbon radical;
• wherein x is an integer from 2 to 50;
• wherein z is an integer from 1 to 50;
• wherein z1 is less than or equal to z and is an integer from 1 to 50,
• wherein a may be identical or different and is 0, 1 or 2;
• and
• wherein b may be identical or different and is an integer from 1 to 10;
• wherein, in a first process step, at least one polymer (HP1) of the general formula (IV)
• Y1—[OH]x (IV)
• reacts with at least one isocyanate-functional silane (S) of the general formula (V)
• O═C═N—(CR12)b—SiRa(OR2)3-a (V)
• to give silane-terminated polymers (SP1);
• wherein the isocyanate-functional silane (S) of the general formula (V) is used in an amount such that there are at least 1.1 isocyanate groups of the isocyanate-functional silane (S) of the general formula (V) to each hydroxyl group in the compounds (HP1) of the general formula (IV);
• wherein in a subsequent second process step, all unreacted isocyanate groups of the isocyanate-functional silane (S) of the general formula (V) are reacted with at least one oligomer or polymer (HP2) of the general formula (VI)
• Y2(OH)z (VI),
• and the compound (HP2) of the general formula (VI) is used in an amount such that there are at least 1.1 hydroxyl groups in the compounds (HP2) of the general formula (IV) to each isocyanate group still present in the reaction mixture after the first process step;
• and
• wherein either z and z1 in the general formulae (II), (III) and (VI) possess a value of 1, there are silane-terminated polymers (SP2) of the general formula (II) in the mixture (M), and the polymers (SP3) likewise present in the mixture (M) correspond to the polymers (HP2) used in the second reaction step, or z in the general formulae (II), (III) and (VI) possesses a value of more than 1, Y2 is a z-valent oligomer or polymer radical having a numerical average molar mass Mn of at most 1500 g/mol, and the mixture (M) comprises hydroxy-functional polymers (SP3) in which z1 is less than z.