Method for producing electric wire, method for producing molded artile, and method for producing resin material containing modified fluororesin
A method for producing an electric wire or a molded article with improved abrasion resistance is described. The method uses a fluororesin via electron beam irradiation in air at a temperature where the fluororesin does not melt. A method for producing a resin material containing a modified fluororesin is also described.
1. A method for producing an electric wire comprising a conductor and an insulating layer containing a fluororesin and covering a surface of the conductor, the method comprising:
irradiating an electron beam to the insulating layer to modify at least part of the fluororesin, thereby forming an insulating layer containing a modified fluororesin,
wherein
the fluororesin
has a crystalline melting point prior to the electron beam irradiation Ta of at least 260° C.,
contains either one or both of a structural unit (a) having a carbonyl group-containing group and a main chain terminal group (a′) having a carbonyl group-containing group, and a structural unit (b) based on a perfluoromonomer which does not contain the structural unit (a), and
does not contain a structural unit based on a hydrocarbon monomer except for the structural unit (a); and
said irradiating is conducted at an irradiation dose of less than 30 kGy at a temperature of less than Ta in air.
2. The method according to claim 1 , wherein
the fluororesin is a copolymer comprising a structural unit (a1) based on a hydrocarbon monomer having either one or both of a carboxyl group and an acid anhydride group, a structural unit (b1) based on tetrafluoroethylene, and a structural unit (b2) based on a perfluoromonomer which is not tetrafluoroethylene, and
based on a total molar amount of the structural unit (a1), the structural unit (b1) and the structural unit (b2), the structural unit (a1) is from 0.01 to 5 mol %, the structural unit (b1) is from 50 to 99.89 mol %, and the structural unit (b2) is from 0.1 to 49.99 mol %.
3. A method for producing a molded article, the method comprising:
irradiating an electron beam to a molded article containing a fluororesin, to modify at least part of the fluororesin, thereby obtaining a molded article containing a modified fluororesin,
wherein
the fluororesin
has a crystalline melting point prior to the electron beam irradiation Ta of at least 260° C.,
contains either one or both of a structural unit (a) having a carbonyl group-containing group and a main chain terminal group (a′) having a carbonyl group-containing group, and a structural unit (b) based on a perfluorotnonomer which does not contain the structural unit (a), and
does not contain a structural unit based on a hydrocarbon monomer except for the structural unit (a); and
said irradiating is conducted at an irradiation dose of less than 30 kGy at a temperature of less than Ta in air.
4. The method according to claim 3 , wherein
the fluororesin is a copolymer comprising a structural unit (a1) based on a hydrocarbon monomer having either one or both of a carboxyl group and an acid anhydride group, a structural unit (b1) based on tetrafluoroethylene, and a structural (b2) based on a perfluoromonomer which is not tetrafluoroethylene, and
based on a total molar amount of the structural unit (a1), the structural unit (b1) and the structural unit (b2), the structural unit (a1) is from 0.01 to 5 mol %, the structural unit (b1) is from 50 to 99.89 mol %, and the structural unit (b2) is from 0.1 to 49.99 mol %.
5. A method for producing a resin material containing a modified fluororesin, the method comprising:
irradiating an electron beam to a resin material containing a fluororesin, to modify at least part of the fluororesin, thereby obtaining the resin material containing the modified fluororesin,
wherein
the fluororesin
has a crystalline melting point prior to the electron beam irradiation Ta of at least 260° C.,
contains either one or both of a structural unit (a) having a carbonyl group-containing group and a main chain terminal group (a′) having a carbonyl group-containing group, and a structural unit (h) based on a perfluoromononier which does not contain the structural unit (a), and
does not contain a structural unit based on a hydrocarbon monomer except for the structural unit (a); and
said irradiating is conducted at an irradiation dose of less than 30 kGy at a temperature of less than Ta in air.
6. The method according to claim 5 , wherein
the fluororesin is a copolymer comprising a structural unit (a1) based on a hydrocarbon monomer having either one or both of a carboxyl group and an acid anhydride group, a structural unit (b1) based on tetrafluoroethylene, and a structural unit (b2) based on a perfluoromonomer which is not tetrafluoroethylene, and
based on a total molar amount of the structural unit (a1), the structural unit (b1) and the structural unit (b2), the structural unit (a1) is from 0.01 to 5 mol %, the structural unit (b1) is from 50 to 99.89 mol %, and the structural unit (b2) is from 0.1 to 49.99 mol %.
7. A process for producing a molded article, the method comprising:
molding a resin material containing a modified fluororesin obtained by the method according to claim 6 , thereby obtaining the molded article.
8. The method according to claim 1 , wherein said irradiating satisfies 0.5≤Mb/Ma<1.2, where Ma represents a melt flow rate by g10 min of the fluororesin prior to the electron beam irradiation, and Mb represents a melt flow rate by g/10 min of the modified fluororesin after the electron beam irradiation.
9. The method according to claim 1 , wherein said irradiating satisfies 1≤Tb−Ta<6.5, where Tb is a crystalline melting point by ° C. of the modified fluororesin after the electron beam irradiation.
10. The method according to claim 1 , wherein said irradiating satisfies
0.5≤Mb/Ma<1.2, where Ma represents a melt flow rate by g/10 min of the fluororesin prior to the electron beam irradiation, and Mb represents a melt flow rate by g/10 min of the modified fluororesin after the electron beam irradiation; and
1≤Tb−Ta<6.5, where Tb is a crystalline melting point by ° C. of the modified fluororesin after the electron beam irradiation.
11. The method according to claim 1 , wherein said irradiating is conducted at a temperature of at most (Ta−5)° C.
12. The method according to claim 3 , wherein said irradiating satisfies 0.5≤Mb/Ma<1.2, where Ma represents a melt flow rate by g/10 min of the fluororesin prior to the electron beam irradiation, and Mb represents a melt flow rate by g/10 min of the modified fluororesin after the electron beam irradiation.
13. The method according to claim 3 , wherein said irradiating satisfies 1≤Tb−Ta<6.5 where Tb is a crystalline melting point by ° C. of the modified fluororesin after the electron beam irradiation.
14. The method according to claim 3 , wherein said irradiating satisfies
0. 5≤Mb/Ma<1.2, where Ma represents a melt flow rate by g/10 min of the fluororesin prior to the electron beam irradiation, and Mb represents a melt flow rate by g/10 min of the modified fluororesin after the electron beam irradiation; and
1≤Tb−Ta<6.5, where Tb is a crystalline melting point by ° C. of the modified fluororesin after the electron beam irradiation.
15. The method according to claim 3 , wherein said irradiating is conducted at a temperature of at most (Ta−5)° C.
16. The method according to claim 5 , wherein said irradiating satisfies 0.5≤Mb/Ma<1.2, where Ma represents a melt flow rate by g/10 min of the fluororesin prior to the electron beam irradiation, and Mb represents a melt flow rate by g/10 min of the modified fluororesin after the electron beam irradiation.
17. The method according to claim 5 , wherein said irradiating satisfies 1≤Tb−Ta<6.5, where Tb is a crystalline melting point by ° C. of the modified fluororesin after the electron beam irradiation.
18. The method according to claim 5 , wherein said irradiating satisfies
0. 5≤Mb/Ma<1.2, where Ma represents a melt flow rate by g/10 min of the fluororesin prior to the electron beam irradiation, and Mb represents a melt flow rate by g/10 min of the modified fluororesin after the electron beam irradiation; and
1≤Tb−Ta<6.5, where Tb is a crystalline melting point by ° C. of the modified fluororesin after the electron beam irradiation.
19. The method according to claim 5 , wherein said irradiating is conducted at a temperature of at most (Ta−5)° C.