Polycarbonates with alkylphenyl end groups, their preparation and their use

• US 4,269,964 A
• Filed: 09/14/1979
• Issued: 05/26/1981
• Est. Priority Date: 09/27/1978
• Status: Expired due to Term

• Current Assignee: Bayer AG
• Original Assignee: Bayer AG
• Inventors: Freitag, Dieter, Burkhardt, Claus, Nouvertne, Werner, Kleiner, Frank
• Primary Examiner(s): Taylor, Hosea E.
• Assistant Examiner(s): Yarbrough, Amelia B.
• Application Number:
  US06/075,439
• Time in Patent Office: 620 Days
• Field of Search: 528/126, 528/128, 528/171, 528/174, 528/196, 528/198, 528/204
• US Class Current: 528/126
• CPC Class Codes: C08G 64/14 containing a chain-terminating or -crosslinking agent

Abstract

This development is concerned with aromatic thermoplastic polycarbonates with special chain terminators which give the polymers enhanced hydrolysis resistance and impact toughness. These chain terminators are alkyl substituted monohydroxy phenyls in which each phenyl is substituted by one alkyl group having 8 or 9 carbon atoms and about 47 to 89% of its hydrogen atoms trisubstituted on carbon atoms with up to about 20% of the substituents in the ortho position and the balance at the para position. This development is also concerned with a process for synthesizing such polymers by using such chain terminators as reactants in generically known synthesis methods for polycarbonates.

Claims

1. A thermoplastic aromatic polycarbonate with a molecular weight Mw (weight average) of about 10,000 to 200,000, which is based on at least one diphenol and, if appropriate, a branching agent, characterized in that it is also based on at least one phenolic chain stopper of the general formula ##STR3## in which R represents a branched alkyl radical consisting of 8 or 9 C atoms, and, in the alkyl radical, the proportion of CH₃ protons is between about 47% and 89% and the proportion of the sum of the CH and CH₂ protons is between about 53% and 11%, and wherein R can be in the o-position or p-position relative to the OH group, the upper limit of the ortho proportion being about 20%.

2. A polycarbonate according to claim 1 characterized by a molecular weight Mw of about 20,000 to 80,000.

3. A polycarbonate according to claim 1, characterized in that it is based on a diphenol of the general formula

4. A polycarbonate according to claim 3 characterized in that the diphenol is selected from hydroquinone, resorcinol, dihydroxydiphenyls, bis-(hydroxyphenyl)-alkanes, bis-(hydroxyphenyl)-cycloalkanes, bis-(hydroxyphenyl) sulphides, bis-(hydroxyphenyl) ethers, bis-(hydroxyphenyl) ketones, bis-(hydroxyphenyl) sulphoxides bis-(hydroxyphenyl) sulphones and α

,α

'"'"'-bis-(hydroxyphenyl)-diisopropylbenzenes, and their nuclear-alkylated and nuclear-halogenated compounds.

5. A polycarbonate according to any of claims 1, 2 or 3 characterized in that it is based on, as a branching agent, a compound containing 3 or more functional groups in the molecule, the said compound being present in an amount of about 0.05 to 2 mol percent, relative to the content of diphenol.

6. A polycarbonate according to any of claims 1, 2 or 3, characterized in that the chain stopper is selected from 2-(3,5-dimethylheptyl)-phenol, 4-(3,5-dimethylheptyl)-phenol, 4-(1,1,3,3-tetramethyl-butyl)-phenol and mixtures thereof.

7. In the phase boundary process for the preparation of a thermoplastic aromatic polycarbonate with a molecular weight Mw of at least about 10,000 the improvement wherein at least one diphenol, optionally a branching agent and about 0.1 mol % to 8 mol %, relative to the amount of diphenol, of a phenolic chain stopper of the formula (I), given in claim 1, are reacted.

8. A process according to claim 7, characterized in that the diphenol is employed in the form of a mono- and/or bis-chlorocarbonic acid ester thereof.

9. A process according to claim 7 or 8, characterized in that the reaction is effected at from about 0°

to 40°

C.

10. A process according to claim 7 or 8, characterized in that the organic phase of the reaction medium is methylene chloride, chlorobenzene or a mixture thereof.

11. A process according to claim 7 or 8, characterized in that the reaction is effected in the presence, as a catalyst, of a tertiary amine.

12. A process according to claim 11, characterized in that the catalyst is employed in an amount of about 0.05 to 10 mol % relative to the amount of diphenol.

13. A process according to claim 7 or 8, characterized in that about 0.1 to 5 mol % of phenolic chain stopper is employed, relative to the amount of diphenol.

14. A polycarbonate prepared by the process of claim 7 or 8.