1. A foaming composition comprising a fluororesin and an electrical insulating whisker, wherein the electrical insulating whisker is at least one selected from aluminum borate, magnesium borate and potassium titanate, and the whisker is from 0.1 \u03bcm to 1 \u03bcm in a diameter and further the whisker in the foaming composition is contained in an amount of from 0.1 to 1% by weight.
2. A foaming composition according to claim 1 wherein it is mixed with a foaming agent to create a synthetic resin foam.
3. A foaming composition according to claim 1 wherein the composition is arranged around a central conductor creating a coaxial insulated cable.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A deuterated polyimide, the backbone of which comprises an alternation between:
at least one repeat unit corresponding to the following formula (I):
in which:
Y represents a single bond, \u2014O\u2014, or \u2014CO\u2014; and
at least one repeat unit corresponding to the following formula (II):
in which:
A1 represents a perdeuterated aromatic group comprising from 6 to 10 carbon atoms; and
Z represents a single bond or a group chosen from \u2014O\u2014C6D4\u2014, \u2014CO\u2014C6D4\u2014 and \u2014C6D4\u2014.
2. The deuterated polyimide as claimed in claim 1, in which the repeat unit in accordance with the formula (II) is a repeat unit of following formula (IIa):
in which Z corresponds to the same definition as that given in claim 1.
3. The deuterated polyimide as claimed in claim 1, chosen from the group consisting of the polyimides chosen from:
polyimides comprising a repeat unit of following formula (Ia) and a repeat unit of following formula (IIb):
polyimides comprising a repeat unit of following formula (Ia) and a repeat unit of following formula (IIc):
polyimides comprising a repeat unit of following formula (Ia) and a repeat unit of following formula (IId):
polyimides comprising a repeat unit of following formula (Ib) and a repeat unit of following formula (IIb):
polyimides comprising a repeat unit of following formula (Ib) and a repeat unit of following formula (IId):
polyimides comprising a repeat unit of following formula (Ic) and a repeat unit of following formula (IIb):
polyimides comprising a repeat unit of following formula (Ic) and a repeat unit of following formula (IId):
polyimides comprising a repeat unit of following formula (Ia), a repeat unit of following formula (IIb) and a repeat unit of following formula (IId):
polyimides comprising a repeat unit of following formula (Ic), a repeat unit of following formula (IIb) and a repeat unit of following formula (IId):
4. The deuterated polyimide as claimed in claim 1, additionally comprising a unit corresponding to the following formula (III):
5. The deuterated polyimide as claimed in claim 4, comprising a repeat unit of following formula (Ia), a repeat unit of following formula (IIb) and a repeat unit of following formula (III):
6. A process for the preparation of a deuterated polyimide, the an alternation between:
at least one repeat unit corresponding to the following formula (I):
in which:
\u2014Y represents a single bond, \u2014O\u2014, or \u2014CO\u2014; and
at least one repeat unit corresponding to the following formula (II):
in which:
A1 represents a perdeuterated aromatic group comprising from 6 to 10 carbon atoms; and
Z represents a single bond or a group chosen from \u2014O\u2014C6D4\u2014, \u2014CO\u2014C6D4\u2014 and \u2014C6D4\u2014; said process comprising a stage consisting in treating, by heating at an appropriate temperature, a solution of a poly(amide-acid), the backbone of which comprises an alternation between at least one repeat unit of following formula (IV):
in which Y corresponds to the same definition as that given above; and at least one repeat unit of formula (II):
in which A1 and Z correspond to the same definitions as those given above, the appropriate heating temperature being determined so as to obtain complete imidization of said poly(amide-acid).
7. The preparation process as claimed in claim 6, in which the appropriate heating temperature is a temperature ranging from 80 to 400\xb0 C.
8. The preparation process as claimed in claim 6, in which the poly(amide-acid) solution is prepared by polycondensation, in a solvent, of at least one monomer of following formula (V):
in which Y corresponds to the same definition as that given in claim 6, and of at least one monomer of following formula (VI):
ND2\u2014A1\u2014Z\u2014ND2\u2003\u2003(VI)
in which A1 and Z correspond to the same definitions as those given in claim 6.
9. The preparation process as claimed in claim 6, in which the solvent is a dipolar aprotic solvent chosen from the group consisting of N-methylpyrrolidone (NMP), dimethylformamide (DMF) and dimethylacetamide (DMAC).
10. A film based on a deuterated polyimide, the backbone of which comprises an alternation between:
at least one repeat unit corresponding to the following formula (I):
in which:
Y represents a single bond, \u2014O\u2014, or \u2014CO\u2014; and
at least one repeat unit corresponding to the following formula (II):
in which:
A1 represents a perdeuterated aromatic group comprising from 6 to 10 carbon atoms; and
Z represents a single bond or a group chosen from \u2014O\u2014C6D4\u2014, \u2014CO\u2014C6D4\u2014 and \u2014C6D4\u2014.
11. The deuterated polyimide as claimed in claim 1, in which the repeat unit in accordance with the formula (II) is a repeat unit of following formula (IIa):
in which Z corresponds to the same definition as that given in claim 1.
12. The deuterated polyimide as claimed in claim 1, chosen from the group consisting of the polyimides chosen from:
polyimides comprising a repeat unit of following formula (Ia) and a repeat unit of following formula (IIb):
polyimides comprising a repeat unit of following formula (Ia) and a repeat unit of following formula (IIc):
polyimides comprising a repeat unit of following formula (Ia) and a repeat unit of following formula (IId):
polyimides comprising a repeat unit of following formula (Ib) and a repeat unit of following formula (IIb):
polyimides comprising a repeat unit of following formula (Ib) and a repeat unit of following formula (IId):
polyimides comprising a repeat unit of following formula (Ic) and a repeat unit of following formula (IIb):
polyimides comprising a repeat unit of following formula (Ic) and a repeat unit of following formula (IId):
polyimides comprising a repeat unit of following formula (Ia), a repeat unit of following formula (IIb) and a repeat unit of following formula (IId):
polyimides comprising a repeat unit of following formula (Ic), a repeat unit of following formula (IIb) and a repeat unit of following formula (IId):