# US 10,370,489 B2 · Polycarbonate composition having improved optical and thermal properties

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- Number: US 10,370,489 B2
- Document ID: US10370489B2
- Status: Granted
- Kind: B2
- Application number: 15/834,607
- Filed: 2017-12-07
- Published: 2018-04-19
- Granted: 2019-08-06
- Earliest claimed: 2010-04-13
- Assignees: Covestro Deutschland AG
- Applicants: Covestro Deutschland AG
- Inventors: Karl-Heinz Köhler; Franky Bruynseels
- Web page: https://patentgrep.com/patent/US10370489B2

## CPC

- C08G 64/06: not containing aliphatic unsaturation
- C08G 64/24: and phenols
- C08L 69/00: Compositions of polycarbonates; Compositions of derivatives of polycarbonates
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

The invention relates to aromatic polycarbonates which comprise dioxydiarylcycloalkane structural units, and which have improved optical and thermal properties. It also relates to an improved process to produce the said polycarbonates from dihydroxydiphenylcycloalkanes, and also to mixtures of these polycarbonates with polymers, with fillers, with dyes and with conventional additives.

## Claims

### Claim 1

Polycarbonate composition comprising at least one polycarbonate component comprising structural units of the general formula (I):
where R1 and R2, independently of one another, are H, halogen, C1-C8-alkyl, C5-C6-cycloalkyl, C6-C10-aryl and C7-C12-arylalkyl, where m is 4 or 5, where R3 and R4 are freely selectable for each X and, independently of one another, are H or C1-C8-alkyl, where X is carbon, characterized in that the sulphur content in the composition is less than 2.0 ppm; characterized in that at least one of the polycarbonate components also comprises diphenols of the formula (III)
where Z is an aromatic or alkylaromatic moiety.

### Claim 2 (depends on 1)

Polycarbonate composition according to claim 1, comprising at least one polycarbonate component comprising structural units of the general formula (II):
where the definition of R1 and R2 is as stated for formula (I).

### Claim 3 (depends on 1)

Polycarbonate composition according to claim 1, characterized in that at least one of the polycarbonate components is a copolymer of 1,1-bis(4-hydroxyphenyl )-3,3,5- trimethylcyclohexane (BPTMC) and bisphenol A, where the molar proportion of BPTMC, based on the total molar amount of bisphenols used, is from 2 to 90 mol % of BPTMC.

### Claim 4 (depends on 1)

Polycarbonate composition according to claim 1, characterized in that the composition comprise from 0 to 5% by weight, based on the total amount of polycarbonate composition, of polymer additives or mixture constituents selected from the group of mould-release agents, flow aids, heat stabilizers, antioxidants, UV absorbers and/or IR absorbers, flame retardants, antistatic agents, dyes and pigments, fillers, thermoplastics or elastomers.

### Claim 5 (depends on 1)

Polycarbonate composition according to claim 1, characterized in that mouldings thereof in a freshly injection-moulded state have a degree of yellowing, measured via the yellowness index (Y.I.), of less than 2.0, and after hot-air aging at 150° C. for a period of 250 hours their Y.I. is smaller than 7.0.

### Claim 6 (depends on 1)

Process for producing polycarbonates according to claim 1 by an interfacial process or a melt transesterification process, characterized in that the sulphur content of the bisphenols used to produce the polycarbonate is less than 1.5 ppm.

### Claim 7 (depends on 6)

Process for producing polycarbonates according to claim 6, characterized in that the sulphur content of the bisphenols used for the production process is less than 1.0 ppm.

### Claim 8 (depends on 1)

A transparent or translucent or opaque or colored molding, obtained from the polycarbonate composition according to claim 1.

### Claim 9 (depends on 1)

Mouldings, extrudates, foils and foil laminates, obtained from polycarbonate compositions according to claim 1.