Stock material or miscellaneous articles – Composite – Of polycarbonate
Reexamination Certificate
2003-02-03
2004-03-30
Boykin, Terressa (Department: 1711)
Stock material or miscellaneous articles
Composite
Of polycarbonate
C264S176100, C264S219000, C428S411100, C528S196000, C528S198000
Reexamination Certificate
active
06713181
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to thermoplastic molding compositions and more particularly to compositions containing a polymer selected from the group consisting of a polycarbonate, a transparent polycarbonate-polyester-blend, a copolyestercarbonate and a transparent polyester.
SUMMARY OF THE INVENTION
A thermoplastic molding composition is disclosed. The composition that contains a polymer selected from the group consisting of a polycarbonate, a transparent polycarbonate-polyester-blend, a copolyestercarbonate and a transparent polyester and a compound of formula (I)
and one or more compounds of formula (II)
wherein a is 1 to 17, b is 0 to 16, c is 6 to 14, d is 3 to 7, e is 6 to 14, f is 3 to 7, g is 5 to 40 and a+b is 9 to 25 and n is 1 to 10, was found to be especially suitable for co-extrusion applications.
BACKGROUND OF THE INVENTION
Compositions containing polycarbonate are used in many fields. In particular, sheets made from compositions containing polycarbonates are used for roofing or glazing, for example. The compositions containing polycarbonate usually contain additional substances, for example, lubricants (also known as mold-release agents). Carboxylic acid esters, for example, are used as lubricants.
Compositions containing polycarbonate and Guerbet alcohols are known. Guerbet alcohols are the products of the Guerbet reaction and can be prepared by the Guerbet reaction, for example. The self-condensation of alcohols under the influence of sodium or copper at approximately 200° C. and at elevated pressure is known as the Guerbet reaction.
Polycarbonate sheets are known from EP A 0 110 221, for example, and are provided for a large number of applications. The sheets are produced, for example, by extrusion of compositions containing polycarbonate. Co-extrusion with further compositions which contain polycarbonate and which additionally have an elevated content of UV absorbers may optionally be carried out.
A problem that occurs repeatedly in the extrusion of such sheets is the deposition of volatile constituents from the composition on the calibrator (in the case of multi-wall sheets) or on the calender rolls (in the case of solid sheets), which can lead to faults on the surface of the sheets. Volatile constituents are, for example, UV absorbers, mold-release agents and other low molecular weight constituents of the composition.
EP A 0 320 632 describes co-extruded sheets made from polycarbonate-containing compositions which contain a UV absorber and may contain a lubricant. It is disadvantageous that, with a relatively long extrusion time, the surface of the sheets is impaired as a result of evaporations from the melt of the composition, particularly in the co-extrusion.
The increased evaporation of the UV absorber from the melt of the composition leads to the formation of a coating on the calibrator or the calender rolls and, ultimately, to the formation of faults in the surface of the sheet (e.g. white spots, ripples). At the calibrator, polycarbonate abrasion additionally leads to powdery deposits on the polycarbonate sheets.
Esters of Guerbet alcohols in polycarbonates are also known; for example, EP-A 0 390 994 describes polycarbonate-containing compositions which additionally contain particular fatty acid esters of Guerbet alcohols as mold-release agents.
In EP-A 0 390 994, no mention is made of the use of the molding compositions for co-extrusion. In addition, there is no mention that the mold-release agents according to the invention are suitable for co-extrusion applications together with larger amounts of UV absorbers.
The examples of WO 01/62851 and WO 01/25334 describe the use of Lubril J K, which is one of the embodiments of EP-A 0 390 994, in particular polycarbonate-ABS blends. In this case too, there is no mention of co-extrusion.
WO 01/74935 discloses that molding compositions containing esters of fatty acids and Guerbet alcohols and esters of fatty acids and linear alcohols have an improved performance in the coextrusion process.
The object of the present invention is, therefore, to provide compositions containing polycarbonate which do not exhibit the disadvantages of the prior art in the production of sheets by extrusion of those compositions.
DETAILED DESCRIPTION OF THE INVENTION
The object according to the invention is achieved by compositions containing a polymer selected from the group consisting of a polycarbonate, a transparent polycarbonate-polyester-blend, a copolyestercarbonate and a transparent polyester and a compound of formula (I)
and one or more different compounds (a mixture of homologous compounds is preferred) of formula (II)
wherein in the preferred case the homologous compounds of formula (II) are distinguished by different values of n and
wherein the following applies in respect of the compounds according to formula (I) and in respect of the compounds according to formula (II):
a=from 1 to 17,
b=from 0 to 16,
c=from 6 to 14,
d=from 3 to 7,
e=from 6 to 14,
f=from 3 to 7,
g=from 5 to 40 and
a+b=from 9 to 25
and wherein in the compounds according to formula (II) n=from 1 to 10, and wherein the ratio of the amount by weight of the compound according to formula (I) in the composition to the amount by weight of all the compounds according to formula (II) in the composition is preferably from 1:0.001 to 1:1.2.
The sum (I and II) of the amounts by weight of the compounds according to formula (I) and of the compounds according to formula (II) is preferably from 0.02 to 1.0 wt. %, particularly preferably from 0.1 to 0.5 wt. %.
The following preferably applies in respect of the compounds of the general formula I and of the general formula II:
a=from 2 to 14,
b=from 3 to 14,
c=10,
d=5,
e=10,
f=5,
g=from 14 to 16,
n=from 1 to 7,
a+b=from 9 to 25.
The ratio of the amount by weight of the compound according to formula I in the composition according to the invention to the amount by weight of all the compounds according to formula II in the composition according to the invention is from 1:0.001 to 1:1.2, preferably from 1:0.005 to 1:1.
A preferred embodiment of the present invention is given by the mentioned compositions according to the invention in which the amount by weight of the compound according to formula (II) wherein n=1 is from 0.5 to 1.2 times as great as the amount by weight of the compound according to formula (I), and the amount by weight of the compound according to formula (II) wherein n=2 is from 0.2 to 1.2 times as great as the amount by weight of the compound according to formula (I), and the amount by weight of the compound according to formula (II) wherein n=3 is from 0 to 1 times as great as the amount by weight of the compound according to formula (I), and the amount by weight of the compound according to formula (II) wherein n=4 is from 0 to 0.8 times as great as the amount by weight of the compound according to formula (I), and the amount by weight of the compound according to formula (II) wherein n=5 is from 0 to 0.5 times as great as the amount by weight of the compound according to formula (I), and the amount by weight of the compound according to formula (II) wherein n=6 is from 0 to 0.4 times as great as the amount by weight of the compound according to formula (I).
A preferred embodiment of the present invention is also given by the compositions according to the invention wherein the compositions additionally contain from 0.1 to 15 parts by weight of UV absorber. The UV absorber is preferably selected from the group consisting of (bis[2-hydroxy-5-tert-octyl-3-(benzotriazol-2-yl)phenyl]methane), 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-(hexyl)oxy-phenol, 2-cyano-3,3-diphenyl-propenoic acid 2,2-bis[(2-cyano-1-oxo-3,3-diphenyl-2-propenyl)oxy]methyl-1,3-propanediyl ester.
A preferred embodiment of the present invention is also a composition according to the invention wherein the composition
Anders Siegfried
Ebert Wolfgang
Gorny Rüdiger
Nising Wolfgang
Bayer Aktiengesellschaft
Boykin Terressa
Gil Joseph C.
Matz Gary
Preis Aron
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