Halogen-free crosslinked resin composition and insulated wire and cable using the same
A halogen-free crosslinked resin composition includes a base polymer including as a main component (a) an ethylene vinyl acetate copolymer and (b) an acid modified polyolefin resin having a differential scanning calorimetry glass transition temperature Tg of not higher than −55 degrees Celsius in a mass ratio (a):(b) of 70:30 to 100:0, the base polymer including 50 to 70% by mass of vinyl acetate, 0.5 to 10 parts by mass of a silicone rubber with respect to 100 parts by mass of the base polymer, and 100 to 250 parts by mass of a metal hydroxide with respect to 100 parts by mass of the base polymer.
1. A halogen-free crosslinked resin composition, consisting of:
a base polymer including as a main component (a) an ethylene vinyl acetate copolymer and (b) an acid modified polyolefin resin having a differential scanning calorimetry glass transition temperature Tg of not higher than −55 degrees Celsius in a mass ratio (a):(b) of 70:30 to 90:10, the base polymer including 50 to 70% by mass of vinyl acetate;
0.5 to 10 parts by mass of a silicone rubber with respect to 100 parts by mass of the base polymer; and
100 to 250 parts by mass of a metal hydroxide with respect to 100 parts by mass of the base polymer,
wherein the acid modified polyolefin resin has a melting point of not more than 90 degrees Celsius.
2. The halogen-free crosslinked resin composition, according to claim 1 , wherein the ethylene vinyl acetate copolymer comprises two or more kinds of ethylene vinyl acetate copolymers which are different in melt mass flow rate, and
wherein 5% to 20% by mass of the ethylene vinyl acetate copolymer has a melt mass flow rate of not less than 15 g/10 min.
3. The halogen-free crosslinked resin composition, according to claim 1 , wherein 5% to 20% by mass of the ethylene vinyl acetate copolymer has a melt mass flow rate of not less than 15 g/10 min.
4. The halogen-free crosslinked resin composition, according to claim 1 , wherein the ethylene vinyl acetate copolymer comprises two or more kinds of ethylene vinyl acetate copolymers which are different in melt mass flow rate, and
wherein 5% to 15% by mass of the ethylene vinyl acetate copolymer has a melt mass flow rate of not less than 15 g/10 min.
5. The halogen-free crosslinked resin composition, according to claim 1 , wherein the ethylene vinyl acetate copolymer comprises two or more kinds of ethylene vinyl acetate copolymers which are different in melt mass flow rate, and
wherein 5% to 10% by mass of the ethylene vinyl acetate copolymer has a melt mass flow rate of not less than 15 g/10 min.
6. The halogen-free crosslinked resin composition, according to claim 1 , wherein the acid modified polyolefin resin comprises an acid modified compound of at least one of ultra-low density polyethylene, ethylene methyl acrylate copolymer, ethylene ethyl acrylate copolymer, ethylene-butene-1 copolymer, ethylene-hexene-1 copolymer, and ethylene-octene-1 copolymer.
7. The halogen-free crosslinked resin composition, according to claim 6 , wherein an acid that is used in the acid modified polyolefin resin comprises one of maleic acid, maleic anhydride, and fumaric acid.
8. The halogen-free crosslinked resin composition, according to claim 1 , wherein an acid that is used in the acid modified polyolefin resin comprises one of maleic acid, maleic anhydride, and fumaric acid.
9. The halogen-free crosslinked resin composition, according to claim 1 , wherein the silicone rubber is in a range from 0.5 to 7.5 parts by mass with respect to 100 parts by mass of the base polymer.
10. The halogen-free crosslinked resin composition, according to claim 1 , wherein the silicone rubber is in a range from 0.5 to 5 parts by mass with respect to 100 parts by mass of the base polymer.
11. The halogen-free crosslinked resin composition, according to claim 10 , wherein the mass ratio (a):(b) is in a range from 80:20 to 90:10.
12. The halogen-free crosslinked resin composition, according to claim 1 , wherein the silicone rubber comprises one of dimethyl polysiloxane, methyl vinyl polysiloxane, and methyl phenyl polysiloxane.
13. The halogen-free crosslinked resin composition, according to claim 1 , wherein the metal hydroxide is in a range from 100 to 150 parts by mass of with respect to 100 parts by mass of the base polymer.
14. The halogen-free crosslinked resin composition, according to claim 1 , wherein the mass ratio (a):(b) is in a range from 80:20 to 90:10.
15. An insulated wire covered with an insulating layer comprising the halogen-free crosslinked resin composition according to claim 1 .
16. An insulated wire covered with an insulating layer comprising the halogen-free crosslinked resin composition according to claim 2 .
17. A cable comprising the insulated wire according to claim 15 .
18. A cable comprising the insulated wire according to claim 16 .
19. A cable covered with a sheath comprising the halogen-free crosslinked resin composition according to claim 1 .
20. A cable covered with a sheath comprising the halogen-free crosslinked resin composition according to claim 2 .