HIGH MELTING PTFE POLYMERS FOR MELT-PROCESSING

• US 20130172477A1
• Filed: 07/15/2011
• Published: 07/04/2013
• Est. Priority Date: 07/23/2010
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Hintzer, Klaus, Kaspar, Harald, Mayer, Ludwig, Zipplies, Tilman C.
• Granted Patent: US 9,175,113 B2
• Time in Patent Office: Days
• US Class Current: 524/544
• CPC Class Codes: C08F 16/24 Monomers containing halogen
• CPC Class Codes: C08F 2/16 Aqueous medium
• CPC Class Codes: C08F 214/262 with fluorinated vinyl ethers
• CPC Class Codes: C09D 127/18 Homopolymers or copolymers of tetrafluoroethene

Abstract

Provided are a tetrafluoroethylene copolymers having a melting point of at least 317° C., a melt flow index (MFI) at 372° C. and a 5 kg load (MFI 372/5) of from about 0.60 g/10 min up to about 15 g/10 min. Also provided are methods of forming a shaped article using the copolymers described above, shaped articles made with those copolymers and compositions containing such copolymers.

Claims

1. A tetrafluoroethylene copolymer comprising repeating units derived from tetrafluoroethene (TFE) and having a melting point of at least 317°

C., a melt flow index (MFI) at 372°

C. and a 5 kg load (MFI 372/5) of from about 0.60 g/10 min up to about 15 g/10 min, and comprising from 0.12 to 1.40% by weight based on the weight of the copolymer of units derived from one or more perfluorinated comonomers and wherein the perfluorinated comonomers comprise one or more perfluorinated alkyl vinyl or alkyl allyl ether wherein the alkyl group of vinyl or allyl ether is interrupted by at least one oxygen atom.

2. The copolymer of claim 1 wherein the perfluorinated alkyl vinyl or alkyl allyl ether corresponds to the general formula

CF₂═

CF—

(CF₂)_n—

O—

Rf 

 

(I),

or

CF₂═

CF—

(CF₂)_n′

—

O—

Rf′

—

O—

(CF₂)_m—

CF═

CF₂ 

 

(II),

wherein

n represents either 1 or 0,

n′ and

m represent, independently from each other either 1 or 0,

Rf represents a linear or branched, cyclic or acyclic perfluorinated alkyl residue containing at least one catenary oxygen atom and containing up to 8 carbon atoms, and

Rf′

represents a linear, branched, cyclic or acyclic perfluorinated alkylene unit that may or may not contain one or more catenary oxygen atoms and that has up to 8 carbon atoms.

3. The copolymer of either one of claim 1 having an elongation at break of at least 10%.

4. The copolymer of claim 1 having a tensile strength at break of at least 10 MPa.

5. The copolymer of claim 1 having a melting point of at least 319°

C. or at least 321°

C.

6. The copolymer of claim 1 wherein the perfluorinated comonomer is selected from CF₂═

CF—

(CF₂)_n—

O—

Rf and wherein Rf represents a linear or branched perfluorinated alkyl residue containing one catenary oxygen and up to 6 carbon atoms and wherein the copolymer has an MFI (372/5) between 0.60 and 5 g/10 min.

7. The copolymer of claim 1 wherein the perfluorinated comonomer is selected from CF₂═

CF—

(CF₂)_n—

O—

Rf and wherein Rf represents a linear or branched perfluorinated alkyl residue containing one catenary oxygen and up to 6 carbon atoms and wherein the copolymer has an MFI (372/5) between 0.60 and 5 g/10 min and wherein the amount of the perfluorinated comonomer is from about 0.2 to about 1.4% by weight based on the weight of the polymer, preferably from about 0.4 up to about 1.0% by weight based on the weight of the copolymer.

8. The copolymer according to claim 1 wherein the perfluorinated comonomer is selected from CF₂═

CF—

(CF₂)_n—

O—

Rf and wherein Rf represents a linear or branched perfluorinated alkyl residue containing at least two catenary oxygen atoms and up to 6 carbon atoms.

9. The copolymer of claim 8 having an MFI (372/5) between 0.8 and 12.0 g/min and wherein the amount of perfluorinated comonomer is from about 0.12% by weight to about 1.40 by weight, preferably from about 0.20 up to about 1.0% by weight, more preferably up to about 0.9% by weight based on the weight of the copolymer.

10. The copolymer according to claim 1 wherein the perfluorinated comonomer has the formula CF₂═

CF—

(CF₂)_n′

—

O—

Rf′

—

O—

(CF₂)_m—

CF═

CF₂.

11. The copolymer according to claim 1 comprising up to 30% by weight of the units derived from chlorotrifluoroethene (CTFE).

12. Method of making a shaped article comprising:

providing a composition comprising a copolymer according to claim 1, subjecting the composition to melt-processing selected from melt extrusion, melt spinning, injection molding and melt blowing.

13. A shaped article comprising the polymer according to claim 1.

14. A composition comprising an aqueous dispersion of the polymer according to claim 1.

15. A method of making tetrafluoroethene copolymers that are melt-processable and have an elongation at break of at least 20% and a tensile strength at break of at least 10 MPa and a melting point of at least 317°

C., or at least 319°

C., or at least 321°

C., and an MFI (375/5) of from about 1 to about 15 g/10 min comprising;

polymerising TFE in an aqueous medium in the presence of an effective amount of a perfluorinated comonomer to provide a copolymer as defined in claim 1.