Processes for enhancing flame retardance and chemical resistance of polymers
AssigneeSabic Innovative Plastic IP B.V.
InventorsJean-Francois Morizur, Paul Dean Sybert
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Abstract
Processes for increasing the chemical resistance of a surface of a formed product are disclosed. The formed product is produced from a polymeric composition comprising a photoactive additive containing photoactive groups derived from a dihydroxybenzophenone. The surface of the formed product is then exposed to ultraviolet light to cause crosslinking of the photoactive additive and produce a crosslinked surface. The crosslinking enhances the chemical resistance of the surface. Various means for controlling the depth of the crosslinking are also discussed.
Claims22
A product having a crosslinked surface with a delta YI value of 12 or less at 3.2 mm thickness measured at least 48 hours after UV exposure to a dosage of about 36 J/cm2 of UVA radiation and no detectable UVC radiation, as measured using an EIT PowerPuck, wherein the crosslinked surface is formed by:
- (a) molding the product from a polymeric composition comprising:
- (i) a photoactive additive that is a cross-linkable polycarbonate resin containing a photoactive group derived from a dihydroxybenzophenone;
- and
- (ii) optionally one or more polymeric base resins, and
- (b) exposing the surface of the formed product to an effective dosage of ultraviolet radiation to cause crosslinking on a surface of the product.
A method for increasing the chemical resistance of a surface of a product, comprising:
- (a) molding a product from a polymeric composition comprising:
- (i) a photoactive additive that is a cross-linkable polycarbonate resin containing a photoactive group derived from a dihydroxybenzophenone;
- and
- (ii) optionally one or more polymeric base resins, and
- (b) exposing the surface of the formed product to an effective dosage of ultraviolet radiation to cause crosslinking on a surface of the product, increasing the chemical resistance of the product;
- wherein the crosslinked surface has a delta YI value of 12 or less at 3.2 mm thickness measured at least 48 hours after UV exposure to a dosage of about 36 J/cm2 of UVA radiation and no detectable UVC radiation, as measured using an EIT PowerPuck.
Dependencies are inferred from the claim text.