Fluoropolymer compositions comprising a copolymer of vinylidene fluoride and trifluoroethylene and a fluorinated elastomer

Abstract

The present invention pertains to a fluoropolymer composition comprising a copolymer of vinylidene fluoride (VDF) and trifluoroethylene (TrFE), to a process for the manufacture of said fluoropolymer composition and to uses of said fluoropolymer composition in various applications, in particular to uses of fluoropolymer films obtainable therefrom in electrical or electronic devices.

Claims

1. A composition (C) comprising: (A) from 90% to 99% by weight of at least one polymer (F), wherein polymer (F) is a fluoropolymer comprising: from 40% to 82% by moles of recurring units derived from vinylidene fluoride (VDF), from 19% to 40% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from trifluoroethylene (TrFE), and from 1% to 15% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from at least one (per)fluorinated monomer different from VDF and TrFE, wherein the recurring units derived from vinylidene fluoride (VDF) are the complement to 100% by moles of total recurring units, and (B) from 1% to 10% by weight of at least one elastomer (F), wherein elastomer (F) is a (per)fluoroelastomer, wherein the composition (C) has a higher resistivity compared to the resistivity value of a composition comprising only the fluoropolymer.

2. The composition (C) according to claim 1, wherein polymer (F) comprises: from 55% to 83% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from vinylidene fluoride (VDF), and from 19% to 40% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from trifluoroethylene (TrFE).

3. The composition (C) according to claim 2, wherein polymer (F) comprises: from 60% to 81% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from vinylidene fluoride (VDF), and from 19% to 40% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from trifluoroethylene (TrFE).

4. The composition (C) according to claim 1, wherein polymer (F) comprises one or more chain branches comprising end groups of formulae —CF.sub.2H and/or —CF.sub.2CH.sub.3 in an amount of at least 30 mmoles per Kg of vinylidene fluoride (VDF) recurring units.

5. The composition (C) according to claim 1, wherein elastomer (F) is a VDF-based copolymer, wherein VDF is copolymerized with at least one monomer selected from the group consisting of: (a′) C.sub.2-C.sub.8 perfluoroolefins; (b′) hydrogen-containing C.sub.2-C.sub.8 olefins; (c′) C.sub.2-C.sub.8 chloro- and/or bromo- and/or iodo-fluoroolefins; (d′) (per)fluoroalkylvinylethers (PAVE) of formula CF.sub.2═CFOR.sub.f1, wherein R.sub.f1 is a C.sub.1-C.sub.6 (per)fluoroalkyl group; (e′) (per)fluorooxyalkylvinylethers of formula CF.sub.2═CFOX.sub.0, wherein X.sub.0 is a C.sub.1-C.sub.6 oxyalkyl group or a C.sub.1-C.sub.12 (per)fluorooxyalkyl group comprising one or more catenary oxygen atoms; (f′) (per)fluorodioxoles of formula: ##STR00014## wherein each of R.sub.f3, R.sub.f4, R.sub.f5, R.sub.f6, equal to or different from each other, is independently a fluorine atom, or a C.sub.1-C.sub.6 fluoro- or per(halo)fluoroalkyl group, optionally comprising one or more oxygen atoms; (g′) (per)fluoromethoxyvinylethers of formula CFX.sub.2═CX.sub.2OCF.sub.2OR″.sub.f, wherein R″.sub.f is selected from C.sub.1-C.sub.6 linear or branched (per)fluoroalkyl groups, C.sub.5-C.sub.6 cyclic (per)fluoroalkyl groups, and C.sub.2-C.sub.6 linear or branched (per)fluorooxyalkyl groups comprising from 1 to 3 catenary oxygen atoms, and X.sub.2 is F or H; and (h′) C.sub.2-C.sub.8 non-fluorinated olefins (O1).

6. The composition (C) according to claim 1, wherein elastomer (F) has a glass transition temperature (T.sub.g) below 10° C.

7. The composition (C) according to claim 6, wherein elastomer (F) has a glass transition temperature (T.sub.g) below 5° C.

8. The composition (C) according to claim 1, said composition (C) further comprising one or more additives selected from the group consisting of crosslinking agents and crosslinking initiators.

9. The composition (C) according to claim 1, said composition (C) further comprising a liquid medium (L).

10. A fluoropolymer film (F) comprising the composition (C) according to claim 1.

11. An electrical or electronic device comprising at least one film (F) according to claim 10.

12. A process for the manufacture of a film (F) comprising the composition (C) according to claim 1, said process comprising processing the composition (C) into a film.

13. The process according to claim 12, said process comprising: applying the composition (C) onto at least one surface of a substrate thereby providing a wet film, and drying the wet film thereby providing the fluoropolymer film (F).

14. The composition (C) according to claim 1, wherein said composition (C) comprises: (A) from 95% to 98.5% by weight of at least one polymer (F), and (B) from 1.5% to 5% by weight of at least one elastomer (F).

15. The composition (C) according to claim 1, wherein polymer (F) comprises: from 56% by moles to 77% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from vinylidene fluoride (VDF), from 19% to 40% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from trifluoroethylene (TrFE), and from 4% to 10% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from at least one (per)fluorinated monomer different from VDF and TrFE.

16. A composition (C) comprising: (A) from 90% to 99% by weight of at least one polymer (F), wherein polymer (F) is a fluoropolymer comprising: recurring units derived from vinylidene fluoride (VDF), from 19% to 40% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from trifluoroethylene (TrFE), and optionally, from 1% to 15% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from at least one (per)fluorinated monomer different from VDF and TrFE, wherein the recurring units derived from vinylidene fluoride (VDF) are the complement to 100% by moles of total recurring units, and (B) from 1% to 10% by weight of at least one elastomer (F), wherein elastomer (F) is a (per)fluoroelastomer, wherein the composition (C) has a higher resistivity compared to the resistivity value of a composition comprising only the fluoropolymer, and wherein polymer (F) comprises 0.01% to 10% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from at least one hydrogenated monomer selected from the group consisting of (meth)acrylic monomers of formula (I): ##STR00015## wherein each of R.sub.A, R.sub.B and R.sub.C, equal to or different from each other, is independently a hydrogen atom or a C.sub.1-C.sub.3 hydrocarbon group, and R.sub.X is a hydrogen atom or a C.sub.1-C.sub.5 hydrocarbon group comprising at least one hydroxyl group.

17. The composition (C) according to claim 16, wherein polymer (F) comprises from 0.03% to 6% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from at least one (meth)acrylic monomer of formula (I).

18. A composition (C) comprising: (A) from 90% to 99% by weight of at least one polymer (F), wherein polymer (F) is a fluoropolymer comprising: recurring units derived from vinylidene fluoride (VDF), from 19% to 40% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from trifluoroethylene (TrFE), and optionally, from 1% to 15% by moles, with respect to the total amount by moles of recurring units of said polymer (F), of recurring units derived from at least one (per)fluorinated monomer different from VDF and TrFE, wherein the recurring units derived from vinylidene fluoride (VDF) are the complement to 100% by moles of total recurring units, and (B) from 1% to 10% by weight of at least one elastomer (F), wherein elastomer (F) is a (per)fluoroelastomer, wherein the composition (C) has a higher resistivity compared to the resistivity value of a composition comprising only the fluoropolymer, wherein polymer (F) comprises one or more chain branches comprising end groups of formulae —CF.sub.2H and/or —CF.sub.2CH.sub.3.

Description

EXAMPLE 1

(1) A fluoropolymer film was manufactured according to general procedure using a composition containing the polymer (F-1) and 3% by weight, with respect to the total weight of said composition, of the fluoroelastomer (F-a).

EXAMPLE 2

(2) The same procedure as detailed under Example 1 was followed except that a fluoroelastomer (F-b) was used in place of the fluoroelastomer (F-a).

EXAMPLE 3

(3) The same procedure as detailed under Example 1 was followed except that a fluoroelastomer (F-c) was used in place of the fluoroelastomer (F-a).

EXAMPLE 4

(4) The same procedure as detailed under Example 1 was followed except that a fluoroelastomer (F-d) was used in place of the fluoroelastomer (F-a).

EXAMPLE 5

(5) The same procedure as detailed under Example 1 was followed except that a polymer (F-2) was used in place of the polymer (F-1).

EXAMPLE 6

(6) The same procedure as detailed under Example 1 was followed except that a polymer (F-3) was used in place of the polymer (F-1).

EXAMPLE 7

(7) The same procedure as detailed under Example 1 was followed except that a polymer (F-4) was used in place of the polymer (F-1).

COMPARATIVE EXAMPLE 1

(8) The same procedure under Example 1 was followed but using a composition containing only the polymer (F-1).

COMPARATIVE EXAMPLE 2

(9) The same procedure under Example 1 was followed but using a composition wherein the fluoroelastomer (F-a) was replaced by PMMA in an amount of 3% by weight, with respect to the total weight of said composition.

COMPARATIVE EXAMPLE 3

(10) The same procedure under Example 1 was followed but using a composition wherein the fluoroelastomer (F-a) was replaced by PMMA in an amount of 6% by weight, with respect to the total weight of said composition.

COMPARATIVE EXAMPLE 4

(11) The same procedure under Example 1 was followed but using a composition containing only the polymer (F-2).

COMPARATIVE EXAMPLE 5

(12) The same procedure under Example 1 was followed but using a composition containing only the polymer (F-3).

COMPARATIVE EXAMPLE 6

(13) The same procedure under Example 1 was followed but using a composition containing only the polymer (F-4).

(14) As shown in Table 1 hereinbelow, each of the fluoropolymer films obtained according to any of Examples 1 to 4 according to the invention is advantageously endowed with a high dielectric constant value close to the dielectric constant value of the fluoropolymers film made of the pure polymer (F-1) according to Comparative Example 1.

(15) Each of the fluoropolymer films obtained according to any of Examples 1 to 4 according to the invention is also advantageously endowed with a higher dielectric constant value as compared to the dielectric constant value of the fluoropolymer films obtained according to any of Comparative Examples 2 and 3.

(16) Also, as shown in Table 1 hereinbelow, each of the fluoropolymer films obtained according to any of Examples 1 to 4 according to the invention is advantageously endowed with a high resistivity value close to the resistivity value of the fluoropolymer films obtained according to any of Comparative Examples 2 and 3.

(17) Each of the fluoropolymer films obtained according to any of Examples 1 to 4 according to the invention is also advantageously endowed with a higher resistivity value as compared to the resistivity value of the fluoropolymer film made of the pure polymer (F-1) according to Comparative Example 1.

(18) Further, as shown in Table 1 hereinbelow, each of the fluoropolymer films obtained according to any of Examples 5 to 7 according to the invention is advantageously endowed with a high dielectric constant value close to the dielectric constant value of the fluoropolymers film made of the pure polymer (F-2), polymer (F-3) and polymer (F-4), respectively, according to Comparative Examples 4 to 6, respectively.

(19) Each of the fluoropolymer films obtained according to any of Examples 5 to 7 according to the invention is also advantageously endowed with a higher resistivity value as compared to the resistivity value of the fluoropolymer film made of the pure polymer (F-2), polymer (F-3) and polymer (F-4), respectively, according to Comparative Examples 4 to 6, respectively.

(20) TABLE-US-00001 TABLE 1 Electrical Resistivity Dielectric constant (8000 ms, bias 33 V/μm) (110 Hz) [Ω .Math. cm] Ex. 1 26.67 1.15 .Math. 10.sup.12 Ex. 2 27.80 1.06 .Math. 10.sup.12 Ex. 3 27.20 1.06 .Math. 10.sup.12 Ex. 4 27.51 1.54 .Math. 10.sup.12 C. Ex. 1 28.89 5.26 .Math. 10.sup.11 C. Ex. 2 23.12 2.11 .Math. 10.sup.12 C. Ex. 3 19.83 2.53 .Math. 10.sup.12 Ex. 5 11.21 1.04 .Math. 10.sup.13 C. Ex. 4 11.72 8.26 .Math. 10.sup.11 Ex. 6 27.02 2.14 .Math. 10.sup.11 C. Ex. 5 28.62 6.47 .Math. 10.sup.10 Ex. 7 11.11 6.02 .Math. 10.sup.12 C. Ex. 6 11.91 1.04 .Math. 10.sup.11

(21) The composition (C) according to the present invention may be advantageously used in a process for the manufacture of fluoropolymer films thereby providing for homogeneous fluoropolymer films advantageously endowed with a high dielectric constant and a low leakage current while exhibiting good mechanical properties to be suitably used in various applications including electrical or electronic devices.