Method for the production of hydroxyalkyl polysiloxanes
View Patent ↗The invention relates to a method for the production of hydroxyalkyl polysiloxanes of general formula (V) (SiO 4/2 ) k (R 1 2 SiO 3/2 ) m (R 1 2 SiO 2/2 ) p (R 1 3 SiO 1/2 ) q [O 1/2 SiR 3 2 —(CR 4 2 ) b —OH] 5 [O 1/2 H] t (V), wherein organosiloxanes of general formula (VI) (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 (VI) containing silanol are made to react with compounds having at least one unit of general formula (IV) [O—(CR 4 2 ) b —SiR 3 2 ] n —(IV).
1. A process for preparing hydroxyalkylpolysiloxanes of the formula V
(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 3 2 —(CR 4 2 ) b —OH] s [O 1/2 H] t (V),
in which silanol-containing organosiloxanes of the formula VI
(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 (VI)
are reacted with compounds comprising at least one unit of the formula IV
—[O—(CR 4 2 ) b —SiR 3 2 ) n — (IV)
where
R 1 , R 3 , R 4 are each a hydrogen atom or a monovalent C 1 -C 20 -hydrocarbon radical or C 1 -C 15 -hydrocarbonoxy radical which may be unsubstituted or substituted by —CN, —NCO, —NR x 2 , —COOH, —COOR x , halogen, acryl, epoxy, —SH, —OH or —CONR x 2 , in which one or more nonadjacent methylene units may be replaced by —O—, —CO—, —COO—, —OCO—, or —OCOO—, —S—or —Nr x — groups and in which one or more nonadjacent methine units may be replaced by —N═, —N═N— or —P═ groups,
R x is hydrogen or a C 1 -C 10 -hydrocarbon radical which may be unsubstituted or substituted by —CN or halogen,
b is at least 2,
s is at least 1,
r is at least 1,
n is at least 2,
s+t=r and
k+m+p+q is at least 2.
2. The process as claimed in claim 1 , in which R 1 is methyl, ethyl, phenyl, vinyl or triflouropropyl.
3. The process as claimed in claim 2 , in which R 4 is hydrogen.
4. The process as claimed in claim 3 , in which R 3 is a methyl radical.
5. The process as claimed in claim 1 , in which a linear organosiloxane of the formula VI in which k and m are each 0, p is greater or equal to 1, q is 0 or 1 and r is 1 or 2 is used.
6. The process as claimed in claim 1 , in which results in which 5%<k+m<90%, based on the sum of k, m, p, q, s and t, are prepared.
7. The process as claimed in claim 1 , in which the reaction temperature is from 0° C. to 160° C.
8. The process as claimed in claim 7 , in which a catalyst which is an inorganic or organic Lewis acid or Lewis base is used.
9. The process as claimed in claim 8 , in which the catalyst is selected from among carboxylic acids, partly esterified carboxylic acids, unesterified and partly esterified monophosphoric, oligophosphoric and polyphosphoric acids, alkylammonium hydroxides, ammonium alkoxides, alkylammonium fluorides and amine bases.