3M Innovative Properties Company

Dyneon Gmbh

Ralph Kaulbach

Friedrich Kloos

Thomas J Blong

Denis Duchesne

Gernot Loehr

Albert Killich

Ludwig Mayer

Tilman C Zipplies

Erik Peters

Klaus Hintzer

Gernot L&ouml;hr

Lisa P Chen

Georg Burkard

Herbert Strasser

Peter Stamprech

Harald Kaspar

Werner Schwertfeger

William D Coggio

Allan T Worm

Helmut Traunspurger

Gernot Löhr

A tetrafluoroethylene/hexafluoropropylene copolymer with high drawability is provided. Also provided is a process employing the polymer and an article coated with the polymer.

Tetrafluoroethylene/hexafluoropropylene copolymers with higher drawability

The invention relates to high purity fluoropolymers and processes for making such materials. These polymers are particularly suited for applications in the semiconductor industry. The process comprises removal of unstable polymer end groups by fluorination and removal of heavy metal impurities by extraction with an aqueous acid medium.

High purity fluoropolymers

The present invention provides a method of making a fluoropolymer through emulsion polymerization of one or more fluorinated monomers in an aqueous phase in the presence of a fluorinated surfactant. At least part of the fluorinated surfactant is added to the aqueous phase as an aqueous mixture with at least one organic liquid that is not miscible with water and that is selected from halogenated and non-halogenated organic liquids, the mixture having droplets having an average droplet diameter of not more than 1000 nm and the mixture being added to the aqueous phase in such an amount that the total amount of the fluorinated surfactant is not more than 1% by weight based on the weight of the aqueous phase and the total amount of said organic liquid is not more than 1% by weight based on the weight of said aqueous phase. The invention allows for an improvement of the efficiency of an aqueous emulsion polymerization process. In particular, the polymerization time can be reduced and the polymer yield may be improved.

Aqueous emulsion polymerization process for producing fluoropolymers

A fluoropolymer having a melting point of at least 160&#xb0; C. is provided wherein the fluoropolymer is derived from tetrafluoroethylene as the major component, one or more perfluoro vinyl ethers as the minor component, the perfluoro vinyl ether having the formula CF&#x2550;CFO(CF)ORwherein n is from 2 to 6 and Ris a perfluoroalkyl group having 1 to 6 carbon atoms, and optionally a perfluoro alkyl vinyl ether having from 1 to 5 carbon atoms in the alkyl radical.

Fluoropolymers from tetrafluoroethylene and perfluoro(alkoxyalkyl vinyl) ether

The invention provides a fluorothermoplastic composition comprising interpolymerized units derived from about 94 to about 97.5 mole percent (mol %) tetrafluoroethylene (TFE), about 2 to about 3 mol % perfluoro (propyl vinyl ether) (PPVE), and about 0.5 to about 3 mol % hexafluoropropylene (HFP). The invention also provides a fluorothermoplastic composition comprising interpolymerized units derived from about 94 to about 97 mol % TFE, about 0.75 to about 3 mol % PPVE, and about 1.5 to about 3.5 mol % HFP. These fluorothermoplastic compositions have a flex life that fits the equation:log(flex life cycles)&#x2267;0.71+4.0*(MFI),a method of making fluorothermoplastic compositions, a method of improving stress crack resistance, and fluorothermoplastic articles.

Fluoropolymers resistant to stress cracking

The present invention provides a fluoropolymer that is melt-processible and thermoplastic and that has a melting point between 100&#xb0; C. and 320&#xb0; C. The fluoropolymer is derived from (a) one or more gaseous fluorinated monomers, (b) one or more modifiers selected from (i) olefins having a bromine or iodine atom bonded to a carbon of the double bond of the olefin, (ii) olefins corresponding to formula (I):XC&#x2550;CX&#x2014;R&#x2014;Br&#x2003;&#x2003;(I)wherein each Xindependently represents hydrogen, fluorine, bromine, chlorine or iodine, Ris a perfluoroalkylene group, typically having 1 to 8 carbon atoms, a perfluorooxyalkylene group or a perfluoropolyether group and (iii) mixtures thereof; and (c) optionally one or more comonomers selected from non-gaseous fluorinated monomers and non-fluorinated monomers. The resulting fluoropolymer has long chain branches. The invention further provides a method for making these polymers.

Melt-processible thermoplastic fluoropolymers having improved processing characteristics and method of producing same

Provided is a co-curable blend comprising (a) a fluoroplastic comprising (i) bromine atoms, iodine atoms, and combinations thereof, and (ii) units derived from a fluorinated monomer, and a peroxide curable fluoroelastomer gum. The invention also provides a composition comprising a fluoroplastic comprising (i) bromine atoms, iodine atoms, and combinations thereof and (ii) units derived from a fluorinated monomer, peroxide curable fluoroelastomer gum, a peroxide curative, and optionally a coagent. The fluoroplastic has an MFI no greater than 5 g/10 min., and/or an average particle size greater than 100 nm. The invention also provides a method of making a fluoropolymer blend and cured articles.

Co-curable blends featuring bromine-and iodine-containing fluoroplastic polymers

A low-molecular-weight copolymer of tetrafluoroethylene with units of perfluoro alkyl vinyl ethers having a melt index of &gE;30 suitable as a mixing component with a higher-molecular-weight copolymer of the same monomers for producing moldings in injection molding or by extrusion.

Mixtures of thermoplastic fluoropolymers

In preparing a fluorinated thermoplastic with good flex life, high thermal conductivity and low average spherolite diameter from tetrafluoroethylene and perfluoro n-alkyl vinyl ether, perfluoro 2-propoxyalkyl vinyl ether is additionally incorporated into the fluorinated thermoplastic. A semicrystalline, thermoplastically processable copolymer is prepared, made from units of the tetrafluoroethylene, from 2 to 10% by weight of units of perfluoro n-propyl vinyl ether and from 0.1 to 6% by weight of units of perfluoro 2-propoxypropyl vinyl ether. The novel copolymer preferably contains fewer than 70 unstable end groups per 10 carbon atoms, has thermal conductivity of at least 0.19 W/mK at 23&deg; C. and has a smooth surface with an average spherolite diameter of <5 &mgr;m. The novel terpolymer is suitable for extrusion of hose, in particular for heat exchangers, and also for ultrahigh-purity applications.

Perfluoro copolymers of tetrafluoroethylene and perflouro alkyl vinyl ethers

Provided is a melt-processible perfluorinated polymer composition comprising (a) a melt-processible perfluoropolymer comprising (i) from 80 to 98% by weight of repeating units derived from tetrafluoroethylene, (ii) from 2 to 20% by weight of repeating units derived from hexafluoropropylene, and (iii) from 0 to 5% by weight of repeating units derived from further comonomers other than tetrafluoroethylene and hexafluoropropylene, and wherein the proportion by weight of the repeating units derived from hexafluoropropylene units is greater than that of the repeating units of said further comonomers, and (b) from 0.01 to 5% by weight, based on perfluoropolymer (a), of a high-molecular-weight perfluorinated polymer with a melting point at least 20&deg; C. above that of the fluoropolymer (a). Also provided are processes for making and using such melt-processable compositions.

Growing community of inventors

Emmerting, Germany

Ralph Kaulbach