Polymer mixture having aromatic polycarbonate, styrene I containing copolymer and/or graft polymer and a flame-retardant, articles formed therefrom

• US 5,204,394 A
• Filed: 05/20/1992
• Issued: 04/20/1993
• Est. Priority Date: 09/22/1988
• Status: Expired

• Current Assignee: Sabic Innovative Plastics IP BV (Government of Saudi Arabia)
• Original Assignee: General Electric Company
• Inventors: Pratt, Charles F., Gosens, Johannes C., Savenije, Herman B., Claesen, Christianus A. A.
• Primary Examiner(s): Hoke, Veronica P.
• Application Number:
  US07/887,580
• Time in Patent Office: 335 Days
• Field of Search: 524/125, 524/127
• US Class Current: 524/125
• CPC Class Codes: C08K 5/521 Esters of phosphoric acids, e.g. of H3PO4
• CPC Class Codes: C08L 25/08 Copolymers of styrene C08L29/08, C08L35/06, C08L55/02 take precedence
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 51/04 grafted on to rubbers
• CPC Class Codes: C08L 69/00 Compositions of polycarbonates; Compositions of derivatives of polycarbonates
• CPC Class Codes: C08L 85/00 Compositions of macromolecular compounds obtained by reactions forming a linkage in the main chain of the macromolecule containing atoms other than silicon, sulfur, nitrogen, oxygen and carbon; Compositions of derivatives of such polymers

Abstract

The invention relates to a polymer mixture which comprises an aromatic polycarbonate, a styrene-containing copolymer and/or a styrene-containing graft polymer and a flame-retardant. It has been found that the use of a certain type of flame-retardants, namely oligomeric phosphates leads to a polymer mixture having improved properties. In particular to a polymer mixture having a good combination of flame retardancy, non-juicing characteristics of the flame retardant, good plastifying effect and good heat resistance.

Claims

1. A polymer mixture which comprises an aromatic polycarbonate (A), a styrene-containing copolymer and/or styrene-containing graft copolymer (B) and a phosphate based flame-retardant (C), characterized in that the polymer mixture comprises as flame-retardant an oligomeric phosphate or a blend of oligomeric phosphates with the following formula I:

##STR3## wherein R₁, R₂, R₃, and R₄, each represent an aryl or an alkaryl group chosen independently of each other with the proviso that none of R₁, R₂, R₃ and R₄ are xylyl and wherein X is an arylene group, m₁, m₂, m₃, and m₄, each independently of each other are 0 or 1 and wherein n=1,2,3,4 or 5 or wherein, in case of a blend of phosphates, n has an average value of 1 to 5.

2. A polymer mixture as claimed in claim 1 characterized in that the polymer mixture comprises an oligomeric phosphate of formula 1 or a blend of such phosphates wherein the (average) value of n is greater than 1 but smaller than 3.

3. A polymer mixture as claimed in claim 1, characterized in that the polymer mixture comprises an oligomeric phosphate of formula 1, or a blend of such phosphates wherein the (average) value of n is equal to or greater than 1, but equal to or smaller than 2.

4. A polymer mixture as claimed in claim 1, characterized in that the polymer comprises an oligomeric phosphate of formula 1, or a blend of such phosphates, wherein m₁, m₂, m₃ and m₄ are all equal to 1, R₁, R₂, R₃ and R₄ all represent a phenyl group, X represents a phenylene group and n has an (average) value of 1,2-1,7.

5. A polymer mixture according to claim 1, characterized in that the mixture comprises 5-95% by weight of constituent A and 95-5% by weight of constituent B, calculated with respect to the sum of the quantities of A and B.

6. A polymer mixture according to claim 1, characterized in that the mixture comprises as constituent B a graft copolymer built up from a rubber backbone upon which have been grafted styrene, alphamethylstyrene, a styrene substituted with one or more halogen atoms or with organic groups in its aromatic nucleus, methylmethacrylate or a blend thereof and acrylonitrile, methacrylonitrile, methylmethacrylate, maleic anhydride, N-substituted maleinimide or a blend thereof.

7. A polymer mixture according to claim 1 characterised in that the mixture comprises as constituent B a copolymer of styrene, alpha-methylstyrene, a styrene substituted with one or more halogen atoms or with organic groups in its aromatic nucleus, methylmethacrylate or a blend thereof and acrylonitrile, methacrylonitrile, methylmethacrylate, maleic anhydride, N-substituted maleinimid or a blend thereof.

8. A polymer mixture according to claim 1, characterized in that the mixture comprises as constituent B a graft copolymer built up from a rubber backbone upon which have been grafted styrene, alphamethylstyrene, a styrene substituted with one or more halogen atoms or with organic groups in its aromatic nucleus, methylmethacrylate or a blend thereof and acrylonitrile, methacrylonitrile, methylmethacrylate, maleic anhydride, N-substituted maleinimide or a blend thereof and a copolymer of styrene, alphamethylstyrene, a styrene substituted with one or more halogen atoms or with organic groups in its aromatic nucleus, methylmethacrylate or a blend thereof and acrylonitrile, methacrylonitrile, methylmethacrylate, maleic anhydride, N-substituted maleinimide or a blend thereof.

9. A polymer mixture according to claim 1, 1 characterized in that the mixture comprises 1-25 parts by weight of constituent C per 100 part by weight of A+B.

10. A polymer mixture according to claim 1, characterized in that the mixture comprises 5-20 parts by weight of constituent C per 100 parts by weight of A+B.

11. A polymer mixture as claimed in claim 1, characterised in that the polymer mixture moreover comprises one or more of the following flame retardants (D):

a salt having flame-retarding properties for aromatic polycarbonates and/or

a halogen-containing low-molecular weight compound and/or high-molecular weight polymer and/or

a perfluoroalkane polymer and/or

a metal compound active as a synergist.

12. A polymer mixture as claimed in claim 1, characterized in that the polymer mixture comprises the oligomeric phosphate (C) in combination with a salt having flame-retarding properties for aromatic polycarbonate.

13. A polymer mixture as claimed in claim 1, characterised in that the polymer mixture moreover comprises a perfluoroalkane polymer.

14. Articles formed from the polymer mixture as claimed in claim 1.