Block co-condensates of polysiloxanes and dihydroxydiphenylcycloalkane-based n (CO)polycarbonates
The present invention relates to block cocondensates of polysiloxanes and dihydroxydiarylcycloalkane-based (co)polycarbonates and also to a process for preparing such block cocondensates. The invention further relates to the use of these block cocondensates for producing mouldings and extrudates.
1. A block cocondensate comprising
(A) 1-80 wt % of structural units of the general formula (1), based on the total weight of the block cocondensate,
in which
R 1 and R 2 independently of one another are hydrogen, halogen, C 1 -C 8 alkyl, C 5 -C 6 cycloalkyl, phenyl or C 7 -C 12 aralkyl,
R 3 and R 4 for each X are individually selectable and independently of one another are hydrogen or C 1 -C 6 alkyl, and
n is an integer from 4 to 7,
X is carbon,
with the proviso that on at least one atom X R 3 and R 4 are C 1 -C 6 alkyl;
(B) siloxane blocks of the general formula (2)
where
R 5 is H,
R 6 and R 7 are each methyl,
V is O,
W is a single bond,
Y is isopropylidene,
m is an average number of repeat units from 2 to 5,
o is an average number of repeat units from 10 to 100,
q is 0, and
p is 0 or 1; and the product of m times o is a number between 15 and 200, and
(C) homopolycarbonate blocks which contain no structural units of the formula (1) and have a number-average molecular weight M n of at least 2000 g/mol.
2. The block cocondensate according to claim 1 , wherein the homopolycarbonate blocks derive from a homopolycarbonate obtained by the melt transesterification process.
3. The block cocondensate according to claim 1 , wherein the homopolycarbonate blocks (C) are based on bisphenol A.
4. The block cocondensate according to claim 1 , comprising copolycarbonate blocks which contain the structural units of the general formula (1).
5. The block cocondensate according to claim 4 , wherein the copolycarbonate blocks further have structural units which derive from a diphenol of the formula (3)
in which
R 8 and R 9 independently of one another are H, C 1 -C 18 alkyl, C 1 -C 18 alkoxy, halogen or optionally substituted aryl or aralkyl, and
Z is a single bond, —CO—, —O—, C 1 to C 6 alkylene, C 2 to C 5 alkylidene, is a C 5 to C 6 cycloalkylidene radical which may be substituted one or more times by C 1 to C 4 alkyl, or is C 6 to C 12 arylene, which may be fused to a further aromatic ring containing heteroatoms.
6. The block cocondensate according to claim 4 , wherein the copolycarbonate blocks further have structural units which derive from bisphenol A.
7. The block cocondensate according to claim 1 , wherein the fraction of the siloxane blocks of the formula (2) in the block cocondensate is 0.5 to 20.0 wt %, based on the total weight of the block cocondensate.
8. Process for preparing the block cocondensate according to claim 1 , comprising the reaction of
(a) a (co)polycarbonate comprising structural units of the general formula (1)
(b) a hydroxyaryl-terminated polysiloxane of the formula (2b)
where R 5 , R 6 , R 7 , V, W, Y, o, p, q and m have the same definition as in formula (2) according to claim 1 ;
(c) and a homopolycarbonate
in the melt.
9. The process according to claim 8 , wherein the homopolycarbonate has been prepared by the melt transesterification process.
10. The process according to claim 8 , wherein the homopolycarbonate has a number-average molecular weight of at least 2000 g/mol, and an OH end group content of 300 to 900 ppm.
11. The process according to claim 8 , wherein components (a) to (c) are present in the following amounts in the melt:
(a) 20 to 94.5 wt % of the (co)polycarbonate,
(b) 0.5 to 20 wt % of the hydroxyaryl-terminated polysiloxane, and
(c) 5 to 79.5 wt % of the homopolycarbonate,
based in each case on the total weight of the melt.
12. The process according to claim 8 , wherein the homopolycarbonate is based on bisphenol A and the copolycarbonate is based on bisphenol A and bisphenol TMC.
13. The block cocondensate according to claim 1 , obtained by reacting
(a) a (co)polycarbonate comprising structural units of the general formula (1)
in which
R 1 and R 2 independently of one another are hydrogen, halogen, C 1 -C 8 alkyl, C 5 -C 6 cycloalkyl, phenyl or C 7 -C 12 aralkyl,
R 3 and R 4 for each X are individually selectable and independently of one another are hydrogen or C 1 -C 6 alkyl, and
n is an integer from 4 to 7,
X is carbon,
with the proviso that on at least one atom X R 3 and R 4 are C 1 -C 6 alkyl;
(b) a hydroxyaryl-terminated polysiloxane of the formula (2b)
R 5 is H,
R 6 and R 7 are each methyl,
V is O,
W is a single bond,
Y is isopropylidene,
m is an average number of repeat units from 2 to 5,
o is an average number of repeat units from 10 to 100,
q is 0, and
p is 0 or 1; and the product of m times o is a number between 15 and 200; and
(c) and a homopolycarbonate which contains no structural units of the formula (1) and has a number-average molecular weight M n of at least 2000 g/mol in the melt.
14. A method comprising utilizing the block cocondensates according to claim 1 for producing mouldings and extrudates.
15. A moulding or extrudate comprising a block cocondensate according to claim 1 .