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US 9,303,120 B2Granted
Cross-linked polycarbonate resin with improved chemical and flame resistance
AssigneeSabic Global Technologies B.V.
InventorsPaul Dean Sybert, Amanda Flores, Peter Johnson, Jean-Francois Morizur, Andrew Frazee, Thomas L. Evans
Life of this patent
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Abstract
Processes for increasing the chemical resistance of a surface of a formed article are disclosed. The formed article is produced from a polymeric composition comprising a photoactive additive containing photoactive groups derived from a monofunctional benzophenone. The surface of the formed article 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.
Claims56
A method for preparing an article that has a high probability of passing a UL94 V1 test, comprising:
- (a) designing a polymeric composition to be exposed to a designed dosage (D) of UV radiation, wherein the polymeric composition comprises:
- (i) a cross-linkable polycarbonate resin having endcaps derived from 4-monohydroxybenzophenone and a weight average molecular weight of 15,000 to 30,000, and
- (ii) optionally one or more polymeric base resins, and
- wherein the polymeric composition has a designed weight percentage of the endcaps derived from 4-monohydroxybenzophenone (HBP), a designed melt flow rate (MF) and a designed weight average molecular weight (MW);
- (b) preparing the cross-linkable polycarbonate resin by interfacial polymerization;
- (c) optionally blending the cross-linkable polycarbonate resin with the optional one or more polymeric base resins to form the polymeric composition;
- (d) forming an article from the polymeric composition;
- and
- (e) exposing the formed article to the designed UV dosage;
- wherein D, HBP, MF, and MW are selected based on an flame performance equation as follows:
- Sqrt(p(FTP)+0.01)=−0.37308+(0.05345×D)+(0.22797×HBP)−(2.06081×10−6×MW)−(0.092440×MF)+(2.81460×10−6×MW×MF)+(0.000583×D2)
- wherein p(FTP) is the probability of a first time pass in a UL94 V1 test at 1.2 mm thickness after UV exposure and after 7 days of aging at 70° C.;
- p(FTP) is 0.7 or greater;
- D is at least 12 J/cm2 of UVA radiation;
- and MF is from 7 to 20 g/10 min measured at 300° C./1.2 kg/360 sec dwell.
12 more elements
A method for preparing an article that has a low delta YI after exposure to unfiltered UV radiation, comprising:
- (a) designing a polymeric composition to be exposed to a designed dosage (D) of unfiltered UV radiation, wherein the polymeric composition comprises:
- (i) a cross-linkable polycarbonate resin having endcaps derived from 4-monohydroxybenzophenone and a weight average molecular weight of 15,000 to 30,000, and
- (ii) optionally one or more polymeric base resins, and
- wherein the polymeric composition has a designed weight percentage of the endcaps derived from 4-monohydroxybenzophenone (HBP), a designed melt flow rate (MF) and a designed weight average molecular weight (MW);
- (b) preparing the cross-linkable polycarbonate resin by interfacial polymerization;
- (c) optionally blending the cross-linkable polycarbonate resin with the optional one or more polymeric base resins to form the polymeric composition;
- (d) forming an article from the polymeric composition;
- and
- (e) exposing the formed article to the designed UV dosage;
- wherein D and MF are selected based on a Delta YI equation as follows:
- Ln(Delta YI)=1.01074+(0.08387×D)−(0.041908×MF)−(0.00077×D2)+(2.41546×10−3×MF2)
- wherein Delta YI is the change in YI after exposure to at least 12 J/cm2 of UVA radiation and at least 0.45 J/cm2 of UVC radiation at 3.2 mm thickness, measured before UV exposure and at least 48 hours after UV exposure;
- wherein the unfiltered UV radiation provides at least 12 J/cm2 of UVA radiation and at least 0.45 J/cm2 of UVC radiation;
- and wherein the delta YI is 15 or less.
11 more elements
A method for preparing an article that has a high percentage of retention of tensile elongation after exposure to acetone at a thickness of 3.2 mm, comprising:
- (a) designing a polymeric composition to be exposed to a designed dosage (D) of unfiltered UV radiation, wherein the polymeric composition comprises:
- (i) a cross-linkable polycarbonate resin having endcaps derived from 4-monohydroxybenzophenone and a weight average molecular weight of 15,000 to 30,000, and
- (ii) optionally one or more polymeric base resins, and
- wherein the polymeric composition has a designed weight percentage of the endcaps derived from 4-monohydroxybenzophenone (HBP), a designed melt flow rate (MF) and a designed weight average molecular weight (MW);
- (b) preparing the cross-linkable polycarbonate resin by interfacial polymerization;
- (c) optionally blending the cross-linkable polycarbonate resin with the optional one or more polymeric base resins to form the polymeric composition;
- (d) forming an article from the polymeric composition;
- and
- (e) exposing the formed article to the designed UV dosage;
- wherein D, HBP, MF, and MW are selected based on a percentage retention of tensile elongation equation as follows:
- Sqrt(ER+1.04)=−29.23264+(0.62157×D)+(1.57655×HBP)+(1.27584×10−3×MW)−(1.63711×10−5×D×MW)−(0.002382 ×D2)
- wherein ER is the percentage retention of tensile elongation after exposure to acetone at a thickness of 3.2 mm;
- wherein the unfiltered UV radiation provides at least 12 J/cm2 of UVA radiation and at least 0.45 J/cm2 of UVC radiation;
- and ER is 85 % or higher.
11 more elements
A method for preparing an article that has a low delta YI after exposure to filtered UV radiation, comprising:
- (a) designing a polymeric composition to be exposed to a designed dosage (D) of filtered UV radiation, wherein the polymeric composition comprises:
- (i) a cross-linkable polycarbonate resin having endcaps derived from 4-monohydroxybenzophenone and a weight average molecular weight of 15,000 to 30,000, and
- (ii) optionally one or more polymeric base resins, and
- wherein the polymeric composition has a designed weight percentage of the endcaps derived from 4-monohydroxybenzophenone (HBP), a designed melt flow rate (MF) and a designed weight average molecular weight (MW);
- (b) preparing the cross-linkable polycarbonate resin by interfacial polymerization;
- (c) optionally blending the cross-linkable polycarbonate resin with the optional one or more polymeric base resins to form the polymeric composition;
- (d) forming an article from the polymeric composition;
- and
- (e) exposing the formed article to the designed UV dosage;
- wherein D and MF are selected based on a Delta YI equation as follows:
- Ln(Delta YI)=0.44154+(0.07712×D)−(0.041908×MF)−(0.00077×D2)+(2.41546×10−3×MF2)
- wherein Delta YI is the change in YI after exposure to at least 12 J/cm2 of UVA radiation and no detectable UVC radiation at 3.2 mm thickness, measured before UV exposure and at least 48 hours after UV exposure;
- wherein the UV radiation is provided by a filtered UV light source that provides at least 12 J/cm2 of UVA radiation and no detectable UVC radiation, as measured using an EIT PowerPuck;
- and wherein the delta YI is 15 or less.
11 more elements
A method for preparing an article that has a high percentage of retention of tensile elongation after exposure to acetone at a thickness of 3.2 mm, comprising:
- (a) designing a polymeric composition to be exposed to a designed dosage (D) of filtered UV radiation, wherein the polymeric composition comprises:
- (i) a cross-linkable polycarbonate resin having endcaps derived from 4-monohydroxybenzophenone and a weight average molecular weight of 15,000 to 30,000, and
- (ii) optionally one or more polymeric base resins, and
- wherein the polymeric composition has a designed weight percentage of the endcaps derived from 4-monohydroxybenzophenone (HBP), a designed melt flow rate (MF) and a designed weight average molecular weight (MW);
- (b) preparing the cross-linkable polycarbonate resin by interfacial polymerization;
- (c) optionally blending the cross-linkable polycarbonate resin with the optional one or more polymeric base resins to form the polymeric composition;
- (d) forming an article from the polymeric composition;
- and
- (e) exposing the formed article to the designed UV dosage;
- wherein D, HBP, MF, and MW are selected based on a percentage retention of tensile elongation equation as follows:
- Sqrt(ER+1.04)=−30.25285+(0.62157×D)+(1.57655×HBP)+(1.27584×10−3×MW)−(1.63711×10−5×D×MW)−(0.002382 ×D2)
- wherein ER is the percentage retention of tensile elongation after exposure to acetone at a thickness of 3.2 mm;
- wherein the UV radiation is provided by a filtered UV light source that provides at least 12 J/cm2 of UVA radiation and no detectable UVC radiation, as measured using an EIT PowerPuck;
- and ER is 85% or higher.
11 more elements
Dependencies are inferred from the claim text.