Thermoplastic compositions with low dielectric constant and high stiffness and the shaped article therefore
View Patent ↗A thermoplastic composition includes: from 48.9 wt % to 93.9 wt % of a thermoplastic resin component including polypropylene, polypropylene copolymer, blends thereof or combinations thereof; from 5 wt % to 50 wt % glass fiber; from 1 wt % to 30 wt % impact modifier; and from 0.1 wt % to 10 wt % of a polyolefin-siloxane copolymer. The thermoplastic composition has a dielectric constant (Dk) of less than 2.8 at from 1-5 gigahertz (GHz) and a dissipation factor (Df) of less than 0.003 at from 1-5 GHz, the combined weight percent value of all components does not exceed 100 wt %, and all weight percent values are based on the total weight of the composition. Articles including the thermoplastic composition—and in particular telecommunications devices including the thermoplastic composition—are also described.
1. A thermoplastic composition comprising:
from 48.9 wt % to 93.9 wt % of a thermoplastic resin component comprising polypropylene, polypropylene copolymer, or combinations thereof;
from 5 wt % to 50 wt % glass fiber, wherein the glass fiber is sized so as to be compatible with the thermoplastic resin component;
from 1 wt % to 30 wt % impact modifier; and
from 0.1 wt % to 10 wt % of a polyolefin-siloxane copolymer,
wherein
the thermoplastic composition has a dielectric constant (Dk) of less than 2.8 at from 1-5 gigahertz (GHz) and a dissipation factor (Df) of less than 0.003 at from 1-5 GHz,
the combined weight percent value of all components does not exceed 100 wt %, and
all weight percent values are based on the total weight of the composition.
2. The thermoplastic composition of claim 1 , wherein the composition comprises 65 wt % to 85 wt % of the thermoplastic resin component.
3. The thermoplastic composition of claim 1 , wherein the composition comprises from 5 wt % to 15 wt % impact modifier.
4. The thermoplastic composition of claim 1 , wherein the impact modifier is selected from the group consisting of: styrene-ethylene/butylene-styrene (SEBS); syndiotactic polystyrene (SPS); styrene-ethylene-propylene-styrene (SEPS); and combinations thereof.
5. The thermoplastic composition of claim 1 , wherein the impact modifier is a low flow SEBS compound having a melt flow index less than 1 gram per 10 minute (g/10 min) at 230 degrees Celsius (° C.) and 5 kilograms (kg).
6. The thermoplastic composition of claim 1 , wherein the composition comprises from 1 wt % to 5 wt % polyolefin-siloxane copolymer.
7. The thermoplastic composition of claim 1 , wherein the composition further comprises from greater than 0 wt % to 0.5 wt % of a β-nucleating agent for polypropylene.
8. The thermoplastic composition of claim 7 , wherein the composition comprises from 0.1 wt % to 0.2 wt % of the β-nucleating agent for polypropylene.
9. The thermoplastic composition of claim 1 , wherein the composition has a heat deflection temperature (HDT) that is from 10% to 100% greater than a substantially identical reference composition that does not include the polyolefin-siloxane copolymer, wherein HDT is determined in accordance with ASTM D648 or ISO 75 using a 1.82 or 1.8 megapascal (MPa) load and a 3.2 millimeter (mm) or 80 mm×10 mm×4 mm specimen.
10. The thermoplastic composition of claim 1 , wherein the composition has a notched Izod impact strength that is from 5% to 100% greater than a substantially identical reference composition that does not include the polyolefin-siloxane copolymer, wherein notched Izod impact strength is determined in accordance with ASTM D256 or ISO 180.
11. The thermoplastic composition of claim 1 , wherein the composition has a flexural strength that is from 40% to 100% greater than a substantially identical reference composition that does not include the polyolefin-siloxane copolymer, wherein flexural strength is determined in accordance with ASTM D790.
12. The thermoplastic composition of claim 1 , wherein the composition has a tensile strength that is from 20% to 80% greater than a substantially identical reference composition that does not include the polyolefin-siloxane copolymer, wherein tensile strength is determined in accordance with ASTM D638.
13. The thermoplastic composition of claim 1 , wherein the composition has a tensile elongation that is from 40% to 100% greater than a substantially identical reference composition that does not include the polyolefin-siloxane copolymer, wherein tensile elongation is determined in accordance with ASTM D638.
14. An article comprising the thermoplastic composition of claim 1 , wherein the article is a telecommunications device.
15. A thermoplastic composition comprising:
from 65 wt % to 85 wt % of a thermoplastic resin component comprising polypropylene, polypropylene copolymer, or combinations thereof;
from 5 wt % to 50 wt % glass fiber;
from 1 wt % to 30 wt % impact modifier; and
from 0.1 wt % to 10 wt % of a polyolefin-siloxane copolymer,
wherein
the thermoplastic composition has a dielectric constant (Dk) of less than 2.8 at from 1-5 gigahertz (GHz) and a dissipation factor (Df) of less than 0.003 at from 1-5 GHz,
the combined weight percent value of all components does not exceed 100 wt %, and
all weight percent values are based on the total weight of the composition.
16. A thermoplastic composition comprising:
from 48.9 wt % to 93.9 wt % of a thermoplastic resin component comprising polypropylene, polypropylene copolymer, or combinations thereof;
from 5 wt % to 50 wt % glass fiber;
from 1 wt % to 30 wt % impact modifier;
from 0.1 wt % to 10 wt % of a polyolefin-siloxane copolymer; and
from 0.1 wt % to 0.2 wt % of a β-nucleating agent for polypropylene,
wherein
the thermoplastic composition has a dielectric constant (Dk) of less than 2.8 at from 1-5 gigahertz (GHz) and a dissipation factor (Df) of less than 0.003 at from 1-5 GHz,
the combined weight percent value of all components does not exceed 100 wt %, and
all weight percent values are based on the total weight of the composition.