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EP-4735527-A1 - POLYCARBONATE COMPOSITION

EP4735527A1EP 4735527 A1EP4735527 A1EP 4735527A1EP-4735527-A1

Abstract

The present invention relates to a polycarbonate composition comprising the following components, relative to the total weight of the composition， A) 90-99 wt.% of an aromatic polycarbonate, B) 0.2-0.8 wt.% of a sulfonated polyester, C) 0.5-3.5 wt.% of a core-shell impact modifier selected from the group consisting of methyl methacrylate-butadiene-styrene (MBS), acrylonitrile-butadiene-styrene (ABS), silicone-acrylate rubber based impact modifiers and combinations thereof, and D) 0.2-0.5 wt.% of polytetrafluoroethylene. The present invention also relates to a shaped article made from the composition. The polycarbonate composition according to the present invention has a good combination of flame retardancy and impact strength.

Inventors

  • HUANG, ZHENYU
  • HUANG, CHENGLONG

Assignees

  • Covestro Deutschland AG

Dates

Publication Date
20260506
Application Date
20240626

Claims (13)

  1. 1. A polycarbonate composition comprising the following components, relative to the total weight of the composition: A) 90-99 wt.% of one or more aromatic polycarbonate, B) 0.2-0.8 wt.% of one or more sulfonated polyester, C) 0.5-3.5 wt.% of one or more core-shell impact modifier selected from the group consisting of methyl methacrylate-butadiene-styrene, acrylonitrile-butadiene-styrene, silicone-acrylate rubber based impact modifiers and combinations thereof, and D) 0.2-0.5 wt.% of polytetrafluoroethylene.
  2. 2. The polycarbonate composition according to claim 1, wherein the sulfonated polyester is obtained by a reaction of 35-45 mole % of isophthalic acid, 2-6 mole % of 5-(sodiosulfo)-isophthalic acid, 15-30 mole % of 1, 4-cyclohexanedimethanol, and 25-45 mole % of diethyleneglycol, relative to the total mole number of isophthalic acid, 5-(sodiosulfo)-isophthalic acid, 1, 4-cyclohexanedimethanol and diethyleneglycol.
  3. 3. The polycarbonate composition according to claim 1 or 2, wherein methyl methacrylate-butadiene- styrene is contained and the methyl methacrylate-butadiene-styrene comprises 10 wt.% to 35 wt.% of units derived from methyl methacrylate, 5 wt.% to 20 wt.% of units derived from styrene, and 60 wt.% to 85 wt.% of units derived butadiene, based on the weight of methyl methacrylate-butadiene-styrene.
  4. 4. The polycarbonate composition according to any of claims 1-3, wherein methyl methacrylate- butadiene-styrene is present in an amount ranging from 0.5 wt. % to 3.5 wt. %, preferably from 1 wt. % to 2.5 wt. %, relative to the total weight of the polycarbonate composition.
  5. 5. The polycarbonate composition according to any of claims 1-4, wherein acrylonitrile-butadiene- styrene is contained and the acrylonitrile-butadiene-styrene comprises 5 wt.% to 20 wt.% of units derived from acrylonitrile, 20 wt.% to 55 wt.% of units derived from styrene, and 75 wt.% to 30 wt.% of units derived butadiene, based on the weight of acrylonitrile-butadiene-styrene.
  6. 6. The polycarbonate composition according to any of claims 1-5, wherein acrylonitrile-butadiene- styrene is present in an amount ranging from 0.5 wt. % to 3.5 wt. %, preferably from 1 wt. % to 2.5 wt. %, relative to the total weight of the polycarbonate composition.
  7. 7. The polycarbonate composition according to any of claims 1-6, wherein the silicone-acrylate rubber based impact modifier is selected from (Ci-Cs)-alkyl (meth)acrylates-grafted silicone-(Ci-Cs) alkyl acrylate rubber.
  8. 8. The polycarbonate composition according to claim 7, wherein the silicone-acrylate rubber based impact modifier is a methyl methacrylate-grafted silicone-butyl acrylate rubber.
  9. 9. The polycarbonate composition according to any of claims 1-8, wherein silicone-acrylate rubber based impact modifier is present in the composition according to the present invention in an amount ranging from 0.5 wt. % to 3.5 wt. %, preferably from 1 wt. % to 2.5 wt. %, relative to the total weight of the polycarbonate composition.
  10. 10. The polycarbonate composition according to any of claims 1-9, wherein polytetrafluoroethylene is present in an amount ranging from 0.2 wt.% to 0.4 wt.%, relative to the total weight of the polycarbonate composition.
  11. 11. Composition according to any of Claims 1-10, comprising, relative to the total weight of the composition: A) 93-98 wt.% of an aromatic polycarbonate based on bisphenol A, B) 0.2-0.7 wt. % of a sulfonated polyester obtained by a reaction of 35-45 mole % of isophthalic acid, 2-6 mole % of 5-(sodiosulfo)-isophthalic acid, 15-30 mole % of 1, 4-cyclohexanedimethanol, and 25-45 mole % of diethyleneglycol, relative to the total mole number of isophthalic acid, 5-(sodiosulfo)- isophthalic acid, 1, 4-cyclohexanedimethanol and diethyleneglycol, C) 0.5-3 wt.% of a core-shell impact modifier selected from the group consisting of acrylonitrile-butadiene-styrene, methyl methacrylate-butadiene-styrene and methyl methacrylate-grafted silicone-butyl acrylate rubber, and D) 0.2-0.4 wt.% of polytetrafluoroethylene.
  12. 12. Composition according to any of claims 1-11, wherein the total amount of components A)-D) as defined above is from 95 wt.% to 100 wt.%, preferably from 97 wt.% to 100 wt.%, more preferably from 97 wt.% to 99.5 wt.%, based on the total weight of the composition.
  13. 13. A shaped article made from the composition according to any of claims 1 to 12.

Description

POLYCARBONATE COMPOSITION TECHNICAL FIELD The present invention relates to a polycarbonate (PC) composition with good flame retardancy and impact strength. In particular, the present invention relates to a polycarbonate composition and a shaped article made from the same. BACKGROUND ART It is known in the art that polycarbonate compositions can achieve good flame-retardant performance by loading enough amount of traditionally flame-retardant agents such as potassium perfluorobutane sulfonate. For example, the usage of any of a variety of salts, notably perfluoroalkane sulfonate salts, of alkali metal or alkaline earth metal as a flame retardant for polycarbonate has been disclosed in U.S. Pat. Nos. 3,775, 367; 46060,469,833; 4,626,563; 4,626,563; and 4,649,168. In most flame retardant PC compositions, potassium perfluorobutane sulfonate has been proved to be the most efficient flame retardant agent so far. Very small amount (usually less than 0.2 wt% is used) of potassium perfluorobutane sulfonate is needed for PC compositions to achieve a flame-retardency level of UL94 VO at a thickness of 1.5 mm. It has been shown that potassium perfluorobutane sulfonate does not affect the mechanical and thermal properties of polycarbonate compositions. With such a small loading of potassium perfluorobutane sulfonate in polycarbonate compositions, optical properties, colorability, and surface quality will also not be affected. However, since potassium perfluorobutane sulfonate contains fluorine, some potential environmental contamination might occur during manufacturing and following applications of polycarbonate compositions containing potassium perfluorobutane sulfonate. Considering that, potassium perfluorobutane sulfonate has been banned according to the Blue Angel and is also on the list of SVHC (Substances of Very High Concern) of REACH. In the US, several states are drafting the bills to restrict the use of PF AS that includes potassium perfluorobutane sulfonate. In addition, since 2020 it is required by REACH (registration, evaluation, authorization and restriction of chemicals) regulation in the European Union that the loading of potassium perfluorobutane sulfonate in polymer blends should be less than 1000 ppm by weight. Therefore, we can see that there are higher requirements than before on the plastic housing materials for electronics& electrical (EE) applications targeting high flame retardant level and good toughness that is able to meet strict regulations and pass functional tests. In most cases, a flame retardancy level of UL94 V0 at a thickness of 1.5 mm needs to be achieved and some impact tests such as ball drop test has to be passed. Therefore, there is a need for polycarbonate compositions which can be used to prepare articles with a good combination of flame retardancy and impact strength. SUMMARY OF THE INVENTION One object of the present application is thus to provide a polycarbonate composition which can be used to prepare articles having a good combination of flame retardancy and impact strength. Another object of the present application is to provide an article which has a good combination of flame retardancy and impact strength. In a first aspect, the present invention provides a polycarbonate composition comprising the following components, relative to the total weight of the composition: A) 90-99 wt.% of at least one aromatic polycarbonate, B) 0.2-0.8 wt.% of at least one sulfonated polyester, C) 0.5-3.5 wt.% of at least one core-shell impact modifier selected from the group consisting of methyl methacrylate-butadiene-styrene (MBS), acrylonitrile-butadiene-styrene (ABS), silicone-acrylate rubber based impact modifiers and combinations thereof, and D) 0.2-0.5 wt.% of polytetrafluoroethylene. The inventors have unexpectedly discovered that the composition according to the present invention, comprising a small amount of sulfonated polyester in combination with of a core-shell impact modifier selected from the group consisting of methyl methacrylate-butadiene-styrene (MBS), acrylonitrile- butadiene-styrene (ABS), silicone-acrylate rubber based impact modifiers and combinations thereof, can be used to prepare articles having a good combination of flame retardancy and impact strength. For example, the articles prepared with the composition according to the present invention have an 2 2 impact strength more than 54 kJ/m at 0 °C and more than 58 kJ/m at 23 °C as determined according to ISO 180/A:2000. Meanwhile, the articles prepared with the composition according to the present invention have a flame retardancy of V0 at a thickness of 1.5 mm as measured according to UL94: 2015. In a second aspect, the present invention provides a shaped article made from a polycarbonate composition according to the first aspect of the present invention. In a third aspect, the present invention provides a process for preparing the shaped article mentioned above, comprising injection moulding, extrusion moulding, b