Method for producing organosilicon compounds having amino groups
The object of the invention is therefore to provide a method for the preparation of amino-functional polyorganosiloxanes, in which (A) organosiloxanes containing Si—OH groups are reacted with (B) at least stoichiometric amounts of monoalkoxy(aminoalkyl) silanes with respect to the Si—OH groups, wherein catalytically active additives selected from acid, base or metal-organic compound are used in amounts of less than 0.1 ppm acid, less than 30 ppm base and less than 0.4% metal-organic compound.
1. A method for producing aminofunctional polyorganosiloxanes of general formula I
(SiO 4/2 ) k (R 1 SiO 3/2 ) m (R 1 2 SiO 2/2 ) p (R 1 3 SiO 1/2 ) q [O 1/2 SiR 1 2 —R—NR 2 R 3 ] s [O 1/2 H] t (I),
which comprises reacting
(A) organosiloxanes which contain Si—OH groups, of general formula (II)
(SiO 4/2 ) k (R 1 SiO 3/2 ) m (R 1 2 SiO 2/2 ) p (R 1 3 SiO 1/2 ) q [O 1/2 H] r (II),
with
(B) at least a stoichiometric amount of a monoalkoxy(aminoalkyl)silane, based on the Si—OH groups, of general formula (III)
R 2 R 3 N—R—SiR 1 2 (OR 4 ) (III),
while utilizing less than 0.01 ppm of acid, less than 30 ppm of base and less than 0.4% of organometallic compound, wherein
R is an unsubstituted or halogen-substituted alkylene radical of 2 to 12 carbon atoms,
R x is hydrogen, an unsubstituted C 1 -C 10 hydrocarbyl radical or a C 1 -C 10 hydrocarbyl radical substituted with substituents selected from —CN and halogen,
R 1 is a hydrogen atom or a C 1 -C 20 hydrocarbyl or C 1 -C 15 hydrocarbyloxy radical which is bonded Si—C and is unsubstituted or substituted with substituents selected from —CN, NR x 2 , COOH, COOR x , -halogen, -acryloyl, -epoxy, —SH, —OH and —CONR x 2 and in each of which one or more mutually nonadjacent methylene units at a time may be replaced by groups —O—, —CO—, —COO—, —OCO— or —OCOO—, —S—, or NR x and in each of which one or more mutually nonadjacent methine units may be replaced by groups —N═, —N═N—, or —P═,
R 2 and R 3 are each hydrogen or unbranched, branched or cyclic saturated or unsaturated alkyl of 1 to 12 carbon atoms or aryl or aralkyl where individual nonadjacent methylene units may be replaced by nitrogen atoms or oxygen atoms,
R 4 is linear or branched alkyl of 1 to 8 carbon atoms where nonadjacent methylene units may be replaced by oxygens,
s is not less than 1,
r is not less than 1,
s+t is equal to the value of r, and
k+m+p+q is not less than 2,
and s:t is not less than 10.
2. The method as claimed in claim 1 , wherein R 1 is a straight-chain, branched or cyclic C 1 -C 6 alkyl radical.
3. The method as claimed in claim 2 , wherein R 2 and R 3 are each hydrogen.
4. The method as claimed in claim 3 , wherein R 4 is alkyl of 1 to 5 carbon atoms.
5. The method as claimed in claim 4 , wherein less than 0.01 ppm of acid is present.
6. The method as claimed in claim 5 , conducted at temperatures of 50° C. to 150° C.
7. The method as claimed in claim 6 , wherein said monoalkoxy(aminoalkyl)silane (B) is used in a molar amount of not less than 1.2 and not more than 10 equivalents based on Si—OH units present in said organosiloxane (A).
8. The method as claimed in claim 1 , wherein R 2 and R 3 are each hydrogen.
9. The method as claimed in claim 1 , wherein R 4 is alkyl of 1 to 5 carbon atoms.
10. The method as claimed in claim 1 , wherein less than 0.01 ppm of acid is present.
11. The method as claimed in claim 1 , conducted at temperatures of 50° C. to 150° C.
12. The method as claimed in claim 1 , wherein said monoalkoxy(aminoalkyl)silane (B) is used in a molar amount of not less than 1.2 and not more than 10 equivalents based on Si—OH units present in said organosiloxane (A).
13. The method as claimed in claim 1 , wherein the reacting is conducted without catalysts.