Claims
- 1. Vulcanizable compositions of fluoroelastomers based on vinylidene fluoride having improved processability and improved chemical stability, comprising, as a processing coadjuvant, a mono- or di-hydroxypolyfluoroether, the hydroxy group being present at one end of the polyether chain in the case of the mono-hydroxypolyfluoroether and the two hydroxy groups being present at the opposite ends of the polyfluoroether chain in the case of the di-hydroxypolyfluoroether, said mono- or di-hydroxypolyfluoroether having no other functional groups beside the hydroxy group at the end or ends of the polyfluoroether chain, and having a mean molecular weight ranging from 400 to 10,000 for the mono-hydroxypolyfluoroether and ranging from 2,500 to 10,000 for the di-hydroxypolyfluoroether, wherein the mono-hydroxypolyfluoroether comprises repeating fluoropolyoxylalkylene units selected from the units;
- (1) C.sub.3 F.sub.6 O and CFXO whre X=F or CF.sub.3 and said units are statistically distributed along the fluoropolyoxylalkylene chain,
- (2) C.sub.3 F.sub.6 O or
- (3) CH.sub.2 CF.sub.2 CF.sub.2 O, and wherein the di-hydroxypolyfluoroether comprises fluoropolyoxyalkylene units;
- (4) C.sub.2 F.sub.4 O and CF.sub.2 O and said units are statistically distributed along the fluoropolyoxyalkylene chain,
- (5) C.sub.3 F.sub.6 O, C.sub.2 F.sub.4 O and CFXO where X=--F or --CF.sub.3 and said units are statically distributed along the fluoropolyoxyalkylene chain,
- (6) CH.sub.2 --CF.sub.2 --CF.sub.2 --O-- and said units within the fluoropolyoxyalkylene chain are linked to one another in the following manner, --(O--CF.sub.2 --CF.sub.2 CH.sub.2).sub.p --O--R.sub.f --O--(CH.sub.2 --CF.sub.2 --CF.sub.2 --O).sub.q --, wherein R.sub.f is a fluoroalkylene group, and p and q are integers, or
- (7) ##STR6## and said units are linked to one another inside the fluoropolyoxyalkylene chain in the following manner ##STR7## wherein R.sub.f is a fluoroalkylene group, z is 0 or 1, and a and b are integers, said mono- or di- hydroxypolyfluoroethers being used in an amount from 0.5 to 15 parts by weight per 100 parts of fluoroelastomers.
- 2. The vulcanizable compositions of claim 1, wherein the monohydroxypolyfluoroether having the fluoropolyoxyalkylene units (1) are selected from those having the following formula: ##STR8## where the radicals D and E are equal to or different from each other and are selected from H, --CH.sub.3 and --CF.sub.3, and m' and n' are positive integers such that the m'n' ratio ranges from 1 to 20.
- 3. The vulcanizable compositions of claim 1, wherein the monohydroxypolyfluoroether having the fluoropolyoxyalkylene units (2) are selected from those having the following formula: ##STR9## where r' is an integer and Z is the same as defined in claim 2.
- 4. The vulcanizable compositions of claim 1, wherein the monohydroxypolyfluoroether having the fluoropolyoxyalkylene units (3) are selected from those having the following formula:
- F(CH.sub.2 CF.sub.2 CF.sub.2 O).sub.a'--CH.sub.2 --CF.sub.2 --Z--H
- where s' is an integer, and z is the same as defined in claim 2.
- 5. The vulcanizable compositions of claim 1, wherein the dihydroxypolyfluoroethers having the fluoropolyoxyalkylene units (4) are selected from those having the following formula:
- HZ--CF.sub.2 O (C.sub.2 F.sub.4 O).sub.m (CF.sub.2 O).sub.n CF.sub.2 --ZH
- where Z is the same as defined in claim 13, m and n are integers, and the m/n ratio ranges from 0.5 to 1.5, with the oxyfluoroalkylene units being statistically distributed along the claim.
- 6. The vulcanizable compositions of claim 1, wherein the dihydroxypolyfluoroethers having the fluoropolyoxyalkylene units in (5) are selected from the compounds having the following formula:
- HZ--CF.sub.2 --(C.sub.3 F.sub.6 O).sub.r (C.sub.2 F.sub.4 O).sub.s (CFXO).sub.t --CF.sub.2 --ZH,
- wherein X is --F or --CF.sub.3, the indexes r, s, t are integers, and Z is the same as defined in claim 2.
- 7. The vulcanizable compositions of claim 1, wherein the dihydroxypolyfluoroethers having the fluoropolyoxyalkylene units (6) are selected from the compounds having the formula:
- HZ--CF.sub.2 CH.sub.2 (OCF.sub.2 CF.sub.2 CF.sub.2).sub.p --OR.sub.f --O--(CH.sub.2 CF.sub.2 CF.sub.2 O).sub.q CH.sub.2 CF.sub.2 --ZH
- where R.sub.f is a fluoroalkylene group and Z is the same as defined in claim 13, and p and q are integers.
- 8. The vulcanizable compositions of claim 1, wherein the dihydroxypolyfluoroethers having the fluoropolyoxyalkylene units in (7) are selected from the compounds having the formula: ##STR10## where A is a group comprising the end group --OH, n is an integer equal to or higher than 1 and a and b are integers.
- 9. The vulcanizable compositions of claim 1, wherein the fluoroelastomer is a copolymer of vinylidene fluoride, perfluoropropene or a blend of both with tetrafluoroethylene.
- 10. The vulcanizable compositions of claim 1, comprising polyfluoroethers not containing functional groups, corresponding to the mono- and di-hydroxypolyfluoroethers, as indicated in claim 1, in an amount ranging from 0.5 to 4 parts by weight per 100 parts of fluoroelastomer.
Priority Claims (1)
Number |
Date |
Country |
Kind |
22865 A/85 |
Nov 1985 |
ITX |
|
Parent Case Info
This application is a continuation of application Ser. No. 928,407, filed Nov. 10, 1986, now abandoned.
US Referenced Citations (6)
Continuations (1)
|
Number |
Date |
Country |
Parent |
928407 |
Nov 1986 |
|