Insulating tape for covering, and method for producing structure
To provide an insulating tape for covering, in which a polyimide film and a fluorinated resin film are laminated with excellent adhesion, and a method for producing a structure, which comprises covering a conductor with such an insulating tape for covering, followed by thermal treatment. The insulating tape for covering, comprises a polyimide film and a fluorinated resin film directly laminated on one or both surfaces of the polyimide film, wherein the fluorinated resin film contains a fluorinated copolymer (A) which has a melting point of from 220 to 320° C. and can be melt-molded and which has at least one type of functional groups selected from the group consisting of carbonyl group-containing groups, hydroxy groups, epoxy groups and isocyanate groups.
1. A method for producing a structure, comprising:
covering the surface of a conductor with an insulating tape to form a covering layer; and
thermally treating the conductor covered with the covering layer at a temperature of at least the melting point of the fluorinated copolymer (A) to obtain a structure,
wherein the insulating tape comprises a polyimide film and a fluorinated resin film directly laminated on one or both surfaces of the polyimide film,
wherein the fluorinated resin film comprises a fluorinated copolymer (A) which has a melting point of from 220 to 320° C. and can be melt-molded, and the fluorinated copolymer (A) comprises at least one functional group selected from the group consisting of carbonyl group-containing groups, hydroxy groups, epoxy groups and isocyanate groups.
2. The method for producing a structure according to claim 1 , wherein the thermal treatment is conducted at a temperature of at least the melting point of the fluorinated copolymer (A) and lower than 400° C.
3. The method for producing a structure according to claim 1 , wherein the structure is an electric cable.
4. The method for producing a structure according to claim 1 , wherein the melting point of the fluorinated copolymer (A) is from 260 to 320° C.
5. The method for producing a structure according to claim 1 , wherein the fluorinated copolymer (A) comprises a carbonyl group-containing group, wherein the carbonyl group-containing group is at least one selected from the group consisting of groups containing a carbonyl group between carbon atoms of a hydrocarbon group, carbonate groups, carboxy groups, haloformyl groups, alkoxycarbonyl groups and acid anhydride residual groups.
6. The method for producing a structure according to claim 1 , wherein a content of the functional groups is from 10 to 60,000 groups to 1×10 6 carbon atoms in the main chain of the fluorinated copolymer (A).
7. The method for producing a structure according to claim 1 , wherein the fluorinated copolymer (A) has a melt flow rate of from 0.5 to 15 g/10 min., as measured at 372° C. under a load of 49N.
8. The method for producing a structure according to claim 1 , wherein the fluorinated copolymer (A) has a melt flow rate of from 0.5 to 25 g/10 min., as measured at 297° C. under a load of 49N.
9. The method for producing a structure according to claim 1 , wherein the fluorinated copolymer (A) is a tetrafluoroethylene/perfluoro(alkyl vinyl ether) copolymer (PFA) or a tetrafluoroethylene/ethylene copolymer (ETFE).