Polyformals and copolyformals with reduced water absorption, production and use thereof
View Patent ↗A thermoplastic molding composition comprising a linear (co)polyformal is disclosed. The (co)polyformal corresponds to formulae (Ia) or (Ib), in which A independently denotes hydrogen or phenyl, —O-D-O— and —O-E-O— independently denote a diphenolate residue, in which -E- and -D- independently denote an aromatic radical having 6 to 40 C atoms, wherein at least one of —O-D-O— and —O-E-O— denotes 1,1-bis(4-hydroxyphenyl)cyclohexane residue. The composition is characterized in its restricted water absorption. Also disclosed is a process for the preparation of the composition.
1. A thermoplastic molding composition comprising a linear (co)polyformal corresponding to formulae (1a) or (1b),
in which A independently denotes hydrogen or phenyl, —O-D-O— and —O-E-O— independently denote a diphenolate residue, in which -E- and -D-independently denote an aromatic radical having 6 to 40 C atoms, wherein at least one of —O-D-O— and —O-E-O— denotes 1,1-bis(4-hydroxyphenyl)cyclohexane residue,
k and o independently denote 1 to 4000, m denotes a fraction z/o and n a fraction (o-z)/o, wherein z denotes numbers between 1 and o,
and wherein said 1,1-bis(4-hydroxyphenyl)cyclohexane residue is 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane.
2. A molding composition according to claim 1 wherein in formula (1a) or (1b) A denotes hydrogen.
3. A molded article comprising the thermoplastic molding composition of claim 1 .
4. A molded article for medical application comprising the thermoplastic molding composition of claim 1 .
5. An optical data storage medium comprising the composition of claim 1 .
6. A process for the production of the molding composition of claim 1 comprising reacting at least one bisphenol with methylene chloride in a homogeneous solution in a suitable high-boiling solvent in the presence of a base, at temperatures of 30 to 160° C.