Fluorinated thermoplastic elastomers

Patent metadata

Field	Value
Publication number	US-11760820-B2
Application number	US-201816606621-A
Country	US
Kind code	B2
Filing date	Apr 16, 2018
Priority date	Apr 18, 2017
Publication date	Sep 19, 2023
Grant date	Sep 19, 2023

Abstract

The invention pertains to novel fluorinated thermoplastic elastomers, including PCTFE-like plastomeric blocks, contributing substantially to the improvement of sealing performances upon increasing temperature of the fluorinated thermoplastic elastomers comprising the same.

First claim

The invention claimed is:

1. A fluorinated thermoplastic elastomer [polymer (F-TPE)] consisting of:
at least one elastomeric block (A) consisting of a sequence of recurring units, said sequence consisting of recurring units derived from at least one fluorinated monomer and optionally recurring units derived from at least one bis-olefin [bisolefin (OF)] of formula:
R A R B C═CR C -T-CR D ═CR E R F

wherein R A , R B , R C , R D , R E and R F , equal to or different from each other, are selected from the group consisting of H, F, Cl, C 1 -C 5 alkyl groups and C 1 -C 5 (per)fluoroalkyl groups, and T is a linear or branched C 1 -C 18 alkylene or cycloalkylene group, optionally comprising one or more than one ethereal oxygen atom,
said block (A) possessing a glass transition temperature of less than 25° C., as determined according to ASTM D3418,

wherein the fluorinated monomer of elastomeric block (A) is selected from the group consisting of:
(a) C 2 -C 8 perfluoroolefins;
(b) hydrogen-containing C 2 -C 8 fluoroolefins;
(c) C 2 -C 8 chloro- and/or bromo-containing fluoroolefins; and
(d) (per)fluorodioxoles of formula:

wherein each of R f3 , R f4 , R f5 and R f6 , equal to or different from each other, is independently a fluorine atom, a C 1 -C 6 perfluoro(oxy)alkyl group, optionally comprising one or more oxygen atoms, and

at least one thermoplastic block (B) consisting of a sequence of recurring units, said sequence of recurring units having at least 99% of moles derived from chlorotrifluoroethylene, and
wherein the fluorinated thermoplastic elastomer is a block copolymer comprising a central block (A) having two ends, connected at each end to a side block (B), thus forming a (B)-(A)-(B) structure, and
wherein the weight ratio between blocks (A) and blocks (B) in the fluorinated thermoplastic elastomer is comprised between 95:5 and 10:90.

2. The fluorinated thermoplastic elastomer of claim 1 , which comprises:
at least one elastomeric block (A) selected from the group consisting of:
(1) vinylidene fluoride (VDF)-based elastomeric blocks (A VDF ) consisting of a sequence of recurring units, said sequence comprising recurring units derived from VDF and recurring units derived from at least one fluorinated monomer different from VDF; and
(2) tetrafluoroethylene (TFE)-based elastomeric blocks (A TFE ) consisting of a sequence of recurring units, said sequence comprising recurring units derived from TFE and recurring units derived from at least one fluorinated monomer different from TFE; and

at least one thermoplastic block (B) consisting of a sequence of recurring units, said sequence of recurring units having at least 99% of moles derived from chlorotrifluoroethylene.

3. The fluorinated thermoplastic elastomer of claim 2 , which comprises:
at least one elastomeric block (A) selected from the group consisting of:
(1) vinylidene fluoride (VDF)-based elastomeric blocks (A VDF ) consisting of a sequence of recurring units, said sequence comprising recurring units derived from VDF and recurring units derived from at least one fluorinated monomer different from VDF, said fluorinated monomer different from VDF being selected from the group consisting of:
(a) C 2 -C 8 perfluoroolefins;
(b) hydrogen-containing C 2 -C 8 fluoroolefins different from VDF;
(c) C 2 -C 8 chloro- and/or bromo-containing fluoroolefins; and
(d) perfluorooxyalkylvinylethers of formula:

wherein each of R f3 , R f4 , R f5 and R f6 , equal to or different from each other, is independently a fluorine atom or a C 1 -C 6 perfluoro(oxy)alkyl group, optionally comprising one or more oxygen atoms; and

(2) tetrafluoroethylene (TFE)-based elastomeric blocks (AWE) consisting of a sequence of recurring units, said sequence comprising recurring units derived from TFE and recurring units derived from at least one fluorinated monomer different from TFE, said fluorinated monomer different from TFE being selected from the group consisting of those of classes (b), (c), (d), and (e) as defined above; and

at least one thermoplastic block (B) consisting of a sequence of recurring units, said sequence of recurring units having at least 99% of moles derived from chlorotrifluoroethylene.

4. The fluorinated thermoplastic elastomer of claim 3 , which consists of:
at least one elastomeric block (A) selected from the group consisting of:
(1) vinylidene fluoride (VDF)-based elastomeric blocks (A VDF ) consisting of a sequence of recurring units, said sequence comprising recurring units derived from VDF and recurring units derived from at least one fluorinated monomer different from VDF, said fluorinated monomer different from VDF being selected from the group consisting of:
(a) tetrafluoroethylene (TFE), hexafluoropropylene (HFP);
(b) vinyl fluoride, trifluoroethylene (TrFE), hexafluoroisobutylene (HFIB), perfluoroalkyl ethylenes of formula CH 2 ═CH—R f1 , wherein R f1 is a C 1 -C 6 perfluoroalkyl group;
(c) chlorotrifluoroethylene (CTFE); and
(d) perfluoromethoxyalkylvinylethers of formula:

wherein each of R f3 , R f4 , R f5 and R f6 , equal to or different from each other, is independently —F, —CF 3 , —C 2 F 5 , —C 3 F 7 , —OCF 3 or —OCF 2 CF 2 OCF 3 ; and

(2) tetrafluoroethylene (TFE)-based elastomeric blocks (AWE) consisting of a sequence of recurring units, said sequence comprising recurring units derived from TFE and recurring units derived from at least one fluorinated monomer different from TFE, said fluorinated monomer being selected from the group consisting of those of classes (b), (c), (d), and (e) as defined above; and

at least one thermoplastic block (B) consisting of a sequence of recurring units, said sequence of recurring units having at least 99% of moles derived from chlorotrifluoroethylene.

5. The fluorinated thermoplastic elastomer of claim 1 , wherein the fluorinated monomer of elastomeric block (A) is selected from the group consisting of:
(a) tetrafluoroethylene (TFE), hexafluoropropylene (HFP), perfluoroisobutylene;
(b) vinylidene fluoride (VDF), vinyl fluoride, trifluoroethylene (TrFE), hexafluoroisobutylene (HFIB), perfluoroalkyl ethylenes of formula CH 2 ═CH—R f1 , wherein R f1 is a C 1 -C 6 perfluoroalkyl group;
(c) chlorotrifluoroethylene (CTFE); and
(d) (per)fluorodioxoles of formula:

wherein each of R f3 , R f4 , R f5 and R f6 , equal to or different from each other, is independently —F, —CF 3 , —C 2 F 5 , —C 3 F 7 , —OCF 3 or —OCF 2 CF 2 OCF 3 .

6. The fluorinated thermoplastic elastomer of claim 1 , wherein the weight ratio between blocks (A) and blocks (B) in the fluorinated thermoplastic elastomer is comprised between 50:50 and 85:15.

7. A method for manufacturing the fluorinated thermoplastic elastomer of claim 1 , said method comprising the following sequential steps:
(a) emulsion-polymerizing at least one fluorinated monomer, and optionally at least one bis-olefin (OF), in an aqueous medium in the presence of a radical initiator and of an iodinated chain transfer agent, thereby providing a pre-polymer consisting of at least one block (A) containing one or more iodinated end groups dispersed in an aqueous medium; a

Assignees

• Solvay Specialty Polymers It

Inventors

• Carella Serena
• Brinati Giulio

Classifications

• C08F293/005 Primary

  using free radical "living" or "controlled" polymerisation, e.g. using a complexing agent · CPC title

• C08F214/26 Primary

  Tetrafluoroethene · CPC title

• C08L53/00

  Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers · CPC title

• C08F214/262

  with fluorinated vinyl ethers · CPC title

• C08F214/24

  Trifluorochloroethene · CPC title