Flame retardant polypropylene resin composition
The present invention provides a polypropylene resin composition including a polypropylene resin having a melt flow rate of 4-18 g/10 minutes, a flame retardant additive having a low melting point, an antimony oxide, a UV stabilizer, a silane coupling agent, and titanium dioxide as a light-blocking agent. The resin composition of the invention produces products exhibiting excellent flame retarding properties, stability against weather, and maintainability of physical/mechanical properties as shown by maintaining the original flame retarding properties after long periods of outdoor exposure and hydrothermal dipping treatments.
1. A flame retardant polypropylene resin composition comprising:
40-86% by weight of polypropylene resin with a melt flow rate of 4-18 g/10 minutes;
9-16% by weight of a halogen-containing flame retardant additive having a melting point of 95° C. to 120° C.;
4-15% by weight of an antimony oxide in the form of white granules;
0.2-3.0% by weight of an ultraviolet stabilizer, wherein the ultraviolet stabilizer comprises a mixture of a HALS ultraviolet stabilizer with a molecular weight of more than 2,000 and a UV absorber, wherein the ratio of HALS ultraviolet stabilizer to the UV absorber, ranges from 1:15 to 15:1;
0.1-5% by weight of a silane coupling agent; and
0.2-5% by weight titanium dioxide.
2. The flame-retardant polypropylene resin composition according to claim 1 wherein the polypropylene resin is a polypropylene homopolymer or a crystalline polypropylene copolymer.
3. The flame retardant polypropylene resin composition according to claim 1 wherein the halogen-containing flame retardant additive is tetrabromobisphenol A bis-(dibromopropylether), tetrabromodimethylsulfone dipropylether, or a mixture thereof.
4. The flame-retardant polypropylene resin composition according to claim 1 wherein the antimony oxide is antimony trioxide, antimony pentaoxide, or a mixture thereof.
5. The flame-retardant polypropylene resin composition according to claim 1 wherein the silane coupling agent is vinyl trimethoxy silane, vinyl triethoxy silane, 3-aminopropyl triethoxy silane, N-(2-aminoethyl)-3-aminopropyltrimethoxy silane, 3-glycydoxypropyl trimethoxy silane, 3-chloropropyl trimethoxy silane, 3-methacryloxypropyl trimethoxy silane, or 3-mercaptopropyltrimethoxy silane.