1. A process for producing a fluoropolymer having two or more units of a repeating unit represented by the following formula (2), which comprises ring-opening polymerization of a fluorinated epoxy compound represented by the following formula (1) in the presence of a trialkylaluminum and a salt having an organic cation as a counter cation:
wherein Q represents a single bond or a bivalent linking group containing no fluorine atom; RF represents a monovalent organic group containing a fluorine atom; and * indicates that the carbon atom marked with * is an asymmetric carbon atom.
2. The process for producing the fluoropolymer according to claim 1, wherein the ring-opening polymerization is a reaction of ring-opening homopolymerization of a fluorinated epoxy compound represented by the formula (1).
3. The process for producing the fluoropolymer according to claim 1 or 2, wherein the fluorinated epoxy compound represented by the formula (1) consists of a compound in which the absolute configuration of the asymmetric carbon atom marked with * is either exclusively S or exclusively R and the absolute configuration of the asymmetric carbon atom marked with * in the repeating unit represented by the following formula (2) is substantially the same as the absolute configuration of the asymmetric carbon atom in the fluorinated epoxy compound represented by the formula (1).
4. The process for producing the fluoropolymer according to claim 1, wherein the trialkylaluminum is triisobutylaluminum and the salt having an organic cation as a counter cation is a cation represented by the following formula (3-1) or the following formula (3-2):
Chem. 3
Ph3P\u2550N\u2550PPh3+\u2003\u2003(3-1)
Chem. 4
Ph3PMe+\u2003\u2003(3-2)
wherein Ph represents a phenyl group and Me represents a methyl group.
5. The process for producing the fluoropolymer according to claim 2, wherein the trialkylaluminum is triisobutylaluminum and the salt having an organic cation as a counter cation is a cation represented by the following formula (3-1) or the following formula (3-2):
Chem. 3
Ph3P\u2550N\u2550PPh3+\u2003\u2003(3-1)
Chem. 4
Ph3PMe+\u2003\u2003(3-2)
wherein Ph represents a phenyl group and Me represents a methyl group.
6. The process for producing the fluoropolymer according to claim 3, wherein the trialkylaluminum is triisobutylaluminum and the salt having an organic cation as a counter cation is a cation represented by the following formula (3-1) or the following formula (3-2):
Chem. 3
Ph3P\u2550N\u2550PPh3+\u2003\u2003(3-1)
Chem. 4
Ph3PMe+\u2003\u2003(3-2)
wherein Ph represents a phenyl group and Me represents a methyl group.
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 catheter assembly for inserting in a fluid filled space in a body, the catheter assembly comprising:
a main body having a first end portion and a second end portion, the first end portion being positionable within the fluid filled space and the second end portion being adapted to extend outward from the fluid filled space when the first end portion is positioned within the fluid filled space; and
a catheter tip connected to the second end portion, the catheter tip comprising:
a housing having a cavity defined therein; and a rotating element positioned within the cavity, wherein the rotating element being connected to the first end portion of the main body such that rotation of the rotating element results in at least one of rotational and linear movement, relative to the housing which has no movement imparted to it, of the first end portion of the main body within the fluid filled space.
2. A catheter assembly in accordance with claim 1, wherein the rotating element is configured to rotate in a single direction.
3. A catheter assembly in accordance with claim 1, wherein the housing comprises:
a cap member; and
a base member coupled to the cap member such that the cavity is defined therebetween.
4. A catheter assembly in accordance with claim 3, wherein the catheter tip further comprises a bearing portion coupled to the base member and to the rotating element, the bearing portion being configured to seal the cavity.
5. A catheter assembly in accordance with claim 1, wherein the rotating element comprises a connecting device for connecting the catheter tip to the second end portion of the main body.
6. A catheter assembly in accordance with claim 1, wherein the rotating element is made of at least one of tungsten, gold, titanium, tantalum, and steel.
7. A catheter assembly in accordance with claim 1, further comprising a sleeve portion to substantially circumscribe at least a portion of the catheter tip and at least a portion of the main body.
8. A shunt system for insertion into a body, the shunt system comprising:
a catheter assembly for inserting in a fluid filled space in the body, the catheter assembly comprising:
a main body having a first end portion and a second end portion, the first end portion being positionable within the fluid filled space and the second end portion being adapted to extend outward from the fluid filled space when the first end portion is positioned within the fluid filled space; and a catheter tip connected to the second end portion, the catheter tip comprising:
a housing having a cavity defined therein; and a rotating element positioned within the cavity, the rotating element being connected to the first end portion of the main body such that rotation of the rotating element results in at least one of rotational and movement of the first end portion of the main body within the fluid filled space relative to the housing which has no movement imparted to it, and
a control valve in fluid communication with the catheter assembly and configured to control the flow of fluid from the fluid filled space.
9. A shunt system in accordance with claim 8, wherein the rotating element is configured to rotate in a single direction.
10. A shunt system in accordance with claim 8, wherein the housing comprises:
a cap member; and
a base member coupled to the cap member such that the cavity is defined therebetween.
11. A shunt system in accordance with claim 10, wherein the catheter tip further comprises a bearing portion coupled to the base member and to the rotating element, the bearing portion being configured to seal the cavity.
12. A shunt system in accordance with claim 8, wherein the rotating element comprises a connecting device for connecting the catheter tip to the second end portion of the main body.
13. A shunt system in accordance with claim 8, wherein the rotating element is made of at least one of tungsten, gold, titanium, tantalum, and steel.
14. A catheter assembly in accordance with claim 1, wherein the rotating element has an upstream surface and a downstream surface, both of the upstream and downstream surfaces being semi-circular in shape.
15. A shunt system in accordance with claim 8, wherein the rotating element has an upstream surface and a downstream surface, both of the upstream and downstream surfaces being semi-circular in shape.