FLUOROPOLYMER COMPOSITION

Abstract

The invention pertains to a fluoropolymer composition suitable for adhering a fluoropolymer coating onto a surface, in particular onto a metal surface, said composition comprising: at least one fluoropolymer [polymer (A)]; at least one aromatic polycondensation polymer [polymer (P)]; a solvent mixture [mixture (M)] comprising dimethylsulfoxide (DMSO) and at least one solvent selected from the group consisting of diesters of formula (I.sub.de) and ester-amide of formula (I.sub.ea):

R.sup.1OOCA.sub.deCOOR.sup.2 (I.sub.de)

R.sup.1OOCA.sub.eaCONR.sup.3R.sup.4 (I.sub.ea)

wherein: R.sup.1 and R.sup.2, equal to or different from each other, are independently selected from the group consisting of C.sub.1-C.sub.20 hydrocarbon groups; R.sup.3 and R.sup.4, equal to or different from each other, are independently selected from the group consisting of hydrogen, C.sub.1-C.sub.36 hydrocarbon groups, possibly substituted, being understood that R.sup.3 and R.sup.4 might be part of a cyclic moiety including the nitrogen atom to which they are bound, said cyclic moiety being possibly substituted and/or possibly comprising one or more than one additional heteroatom, and mixtures thereof; A.sub.de and A.sub.ea, equal to or different from each other, are independently a linear or branched divalent alkylene group,
and to a method for coating a surface, specifically a metal surface, with a fluoropolymer, using said fluoropolymer composition.

Claims

1-12. (canceled)

13. A fluoropolymer composition comprising: at least one polymer (A) wherein polymer (A) is a fluoropolymer; at least one aromatic polycondensation polymer (P); and a solvent mixture (M) comprising dimethylsulfoxide (DMSO) and at least one solvent selected from the group consisting of diesters of formula (I.sub.de) and ester-amides of formula (I.sub.ea):
R.sup.1OOCA.sub.deCOOR.sup.2 (I.sub.de)
R.sup.1OOCA.sub.eaCONR.sup.3R.sup.4 (I.sub.ea) wherein: R.sup.1 and R.sup.2, equal to or different from each other, are independently selected from the group consisting of C.sub.1-C.sub.20 hydrocarbon groups; R.sup.3 and R.sup.4, equal to or different from each other, are independently selected from the group consisting of hydrogen, optionally substituted C.sub.1-C.sub.36 hydrocarbon groups, or R.sup.3 and R.sup.4 form an optionally substituted cyclic moiety including the nitrogen atom to which they are bound, optionally comprising one or more than one additional heteroatom, and mixtures thereof; and A.sub.de and A.sub.ea, equal to or different from each other, are independently a linear or branched divalent alkylene group.

14. The fluoropolymer composition of claim 13, wherein mixture (M) comprises, in addition to DMSO: (i) at least one diester of formula (I.sub.de) and at least one diester of formula (I.sub.de), optionally in combination with at least one diester of formula (II.sub.de); or (ii) at least one esteramide of formula (I.sub.ea) and at least one esteramide of formula (I.sub.ea), optionally in combination with at least one esteramide of formula (II.sub.ea); or (iii) combinations of (i) and (ii), wherein: (I.sub.de) is R.sup.1OOCA.sub.MGCOOR.sup.2 (I.sub.ea) is R.sup.1OOCA.sub.MGCONR.sup.3R.sup.4 (I.sub.de) is R.sup.1OOCA.sub.ESCOOR.sup.2 (I.sub.ea) is R.sup.1OOCA.sub.ESCONR.sup.3R.sup.4; (II.sub.ea) is R.sup.1OOC(CH.sub.2).sub.4CONR.sup.3R.sup.4; and (II.sub.de) is R.sup.1OOC(CH.sub.2).sub.4COOR.sup.1, wherein: A.sub.MG is of formula CH(CH.sub.3)CH.sub.2CH.sub.2 or CH.sub.2CH.sub.2CH(CH.sub.3), A.sub.ES is of formula CH(C.sub.2H.sub.5)CH.sub.2, or CH.sub.2CH(C.sub.2H.sub.5); R.sup.1 and R.sup.2, equal to or different from each other, are independently selected from the group consisting of C.sub.1-C.sub.2o alkyl, C.sub.1-C.sub.20 aryl, C.sub.1-C.sub.20 alkyaryl, and C.sub.1-C.sub.20 arylalkyl groups; and R.sup.3 and R.sup.4, equal to or different from each other, are selected from the group consisting of C.sub.1-C.sub.20 alkyl, C.sub.1-C.sub.20 aryl, C.sub.1-C.sub.20 alkyaryl, and C.sub.1-C.sub.20 arylalkyl groups, all said groups optionally comprising one or more than one substituent, optionally having one or more than one heteroatom, or R.sup.3 and R.sup.4 form a cyclic moiety including the nitrogen atom to which they are bound, said cyclic moiety optionally comprising one or more than one heteroatom.

15. The fluoropolymer composition of claim 13, wherein mixture (M) comprises, in addition to DMSO: (k) at least one diester of formula (III.sup.4.sub.de), at least one diester of formula (III.sup.3.sub.de), and at least one diester of formula (III.sup.2.sub.de); (kk) at least one esteramide of formula (III.sup.4.sub.ea), at least one esteramide of formula (III.sup.3.sub.ea), and at least one esteramide of formula (III.sup.2.sub.ea); or (kkk) combinations of (k) and (kk), wherein: (III.sup.4.sub.de) is R.sup.1OOC(CH.sub.2).sub.4COOR.sup.2 (III.sup.3.sub.de) is R.sup.1OOC(CH.sub.2).sub.3COOR.sup.2 (III.sup.2.sub.de) is R.sup.1OOC(CH.sub.2).sub.2COOR.sup.2 (III.sup.4.sub.ea) is R.sup.1OOC(CH.sub.2).sub.4CONR.sup.3R.sup.4 (III.sup.3.sub.ea) is R.sup.1OOC(CH.sub.2).sub.3CONR.sup.3R.sup.4 (III.sup.2.sub.ea) is R.sup.1OOC(CH.sub.2).sub.2CONR.sup.3R.sup.4 wherein: R.sup.1 and R.sup.2, equal to or different from each other, are independently selected from C.sub.1-C.sub.20 alkyl, C.sub.1-C.sub.20 aryl, C.sub.1-C.sub.20 alkyaryl, and C.sub.1-C.sub.20 arylalkyl groups; and R.sup.3 and R.sup.4, equal to or different from each other, are selected from the group consisting of C.sub.1-C.sub.20 alkyl, C.sub.1-C.sub.20 aryl, C.sub.1-C.sub.20 alkyaryl, and C.sub.1-C.sub.20 arylalkyl groups, all said groups optionally comprising one or more than one substituent, optionally having one or more than one heteroatom, or R.sup.3 and R.sup.4 form a cyclic moiety including the nitrogen atom to which they are bound, said cyclic moiety optionally comprising one or more than one heteroatom.

16. The fluoropolymer composition of claim 13, wherein polymer (A) is a per(halo)fluoropolymer selected from the group consisting of copolymers of tetrafluoroethylene (TFE) with at least one per(halo)fluoromonomer different from TFE, said per(halo)fluoromonomer being selected from the group consisting of: C.sub.3-C.sub.8 perfluoroolefins; C.sub.2-C.sub.6 perhalofluoroolefins comprising at least one halogen different from fluorine; per(halo)fluoroalkylvinylethers complying with general formula CF.sub.2CFOR.sub.f1 in which R.sub.f1 is a C.sub.1-C.sub.6 per(halo)fluoroalkyl, optionally comprising one or more than one halogen atom different from F; per(halo)fluoro-oxyalkylvinylethers complying with general formula CF.sub.2CFOX01, in which X.sub.01 is a C.sub.1-C.sub.12 per(halo)fluorooxyalkyl optionally comprising halogen atoms different from F, having one or more ether groups; per(halo)fluoro-methoxy-alkylvinylethers complying with general formula CF.sub.2CFOCF.sub.2OR.sub.f2 in which R.sub.f2 is a C.sub.1-C.sub.6 per(halo)fluoroalkyl, optionally comprising halogen atoms different from F, or a C.sub.1-C.sub.6 per(halo)fluorooxyalkyl, optionally comprising halogen atoms different from F, having one or more ether groups; per(halo)fluorodioxoles of formula: ##STR00027## wherein each of R.sub.f3, R.sub.f4, R.sub.f5, R.sub.f6, equal of different each other, is independently a fluorine atom, a C.sub.1-C.sub.6 per(halo)fluoroalkyl group, optionally comprising one or more oxygen atom, optionally comprising halogen atoms different from F.

17. The fluoropolymer composition of claim 16, wherein the per(halo)fluoromonomer is selected from the group consisting of: a hexafluoropropene (HFP); a chlorotrifluoroethylene; a per(halo)fluoroalkylvinylethers complying with general formula CF.sub.2CFOR.sub.f1 in which R.sub.f1 is selected from CF.sub.3, C.sub.2F.sub.5, and C.sub.3F.sub.7; a per(halo)fluoro-oxyalkylvinylether complying with general formula CF.sub.2CFOX.sub.01, in which X.sub.01 is a perfluoro-2-propoxy-propyl group; a per(halo)fluoro-methoxy-alkylvinylether complying with general formula CF.sub.2CFOCF.sub.2OR.sub.f2 in which R.sub.f2 is selected from CF.sub.3, C.sub.2F.sub.5, C.sub.3F.sub.7 and C.sub.2F.sub.5OCF.sub.3; per(halo)fluorodioxoles of formula: ##STR00028## wherein each of R.sub.f3, R.sub.f4, R.sub.f5, R.sub.f6, equal of different each other, is independently selected from a fluorine atom, CF.sub.3, C.sub.2F.sub.5, C.sub.3F.sub.7, OCF.sub.3, and OCF.sub.2CF.sub.2OCF.sub.3.

18. The fluoropolymer composition of claim 17, wherein R.sub.f3 and R.sub.f4 are each independently fluorine atoms and R.sub.f5 and R.sub.f6 are each independently CF.sub.3.

19. The fluoropolymer composition of claim 17, wherein R.sub.f3, R.sub.f5 and R.sub.f6 are each independently fluorine atoms and R.sub.f4 is are each independently OCF.sub.3.

20. The fluoropolymer composition of claim 16, wherein polymer (A) is selected from the group consisting of TFE copolymers comprising recurring units derived from hexafluoropropylene (HFP) and optionally from at least one perfluoroalkylvinylether complying with general formula CF.sub.2CFOR.sub.f1 in which R.sub.f1 is a C.sub.1-C.sub.6 perfluoroalkyl.

21. The fluoropolymer composition of claim 16, wherein polymer (A) is selected from the group consisting of TFE copolymers comprising recurring units derived from at least one per(halo)fluoroalkylvinylether complying with general formula CF.sub.2CFOR.sub.f1 in which R.sub.f1 is a C.sub.1-C.sub.6 per(halo)fluoroalkyl, optionally comprising one or more than one halogen atom different from F; and optionally further comprising recurring units derived from at least one C.sub.3-C.sub.8 perfluoroolefins.

22. The fluoropolymer composition of claim 13, wherein polymer (P) is a mixture of at least one polyamideimide (PAI) and at least one aromatic sulfone polymer (SP), wherein said polyamideimide (PAI) comprises more than 50% moles of recurring units (R.sub.PAI), wherein recurring units (R.sub.PAI) are recurring units comprising at least one aromatic ring, at least one imide group in its imide form or its amic acid form or a mixture thereof, and at least one amide group which is not included in the amic acid form of the imide group, said recurring units (R.sub.PAI) being selected from the group consisting of: ##STR00029## wherein: Ar is a trivalent aromatic group; R is a divalent aromatic group; and wherein said aromatic sulfone polymer (SP) comprises at least 50% moles of recurring units (R.sub.SP), wherein recurring units (R.sub.SP) are recurring units comprising at least one group of formula (SP):
ArSO.sub.2Ar(SP) wherein Ar and Ar, equal to or different from each other, are aromatic groups.

23. The fluoropolymer composition of claim 22, Ar is a trivalent aromatic group selected from the group consisting of: ##STR00030## and corresponding optionally substituted structures, wherein X is selected from O, C(O), CH.sub.2, C(CF.sub.3).sub.2, and (CF.sub.2).sub.n, and n is an integer from 1 to 5; R is a divalent aromatic group selected from the group consisting of: ##STR00031## and corresponding optionally substituted structures, wherein Y is selected from O, S, SO.sub.2, CH.sub.2, C(O), C(CF.sub.3).sub.2, and (CF.sub.2).sub.n, and n is an integer from 0 to 5.

24. The fluoropolymer composition of claim 22, wherein the aromatic sulfone polymer (SP) is a polyethersulfone polymer comprising recurring units (jjj) and, optionally, recurring units (jj): ##STR00032##

25. A process for manufacturing the fluoropolymer composition according to claim 13, comprising mixing polymer (A), polymer (P), and mixture (M).

26. A method for coating a surface, the method comprising coating the composition according to claim 13 onto said surface, so as to obtain a wet coating layer on said surface.

27. The method of claim 26, said method further comprising drying the wet coating layer at temperatures ranging from room temperature to about 200 C., so as to obtain a dried coating layer on said surface.

28. The method of claim 27, further comprising coating the dried coating layer with an additional layer of a fluoropolymer, so as to provide an outer fluoropolymer layer assembled onto the dried coating layer on the surface.

29. A fluoropolymer composition comprising: (a) at least one polymer (A), wherein polymer (A) is a per(halo)fluoropolymer selected from the group consisting of copolymers of tetrafluoroethylene (TFE) with at least one per(halo)fluoromonomer different from TFE, said per(halo)fluoromonomer being selected from the group consisting of: C.sub.3-C.sub.8 perfluoroolefins; C.sub.2-C.sub.6 perhalofluoroolefins comprising at least one halogen different from fluorine; per(halo)fluoroalkylvinylethers complying with general formula CF.sub.2CFOR.sub.f1 in which R.sub.f1 is a C.sub.1-C.sub.6 per(halo)fluoroalkyl, optionally comprising one or more than one halogen atom different from F; per(halo)fluoro-oxyalkylvinylethers complying with general formula CF.sub.2CFOX.sub.01, in which X.sub.01 is a C.sub.1-C.sub.12 per(halo)fluorooxyalkyl optionally comprising halogen atoms different from F, having one or more ether groups; per(halo)fluoro-methoxy-alkylvinylethers complying with general formula CF.sub.2CFOCF.sub.2OR.sub.f2 in which R.sub.f2 is a C.sub.1-C.sub.6 per(halo)fluoroalkyl, optionally comprising halogen atoms different from F, or a C.sub.1-C.sub.6 per(halo)fluorooxyalkyl, optionally comprising halogen atoms different from F, having one or more ether groups; per(halo)fluorodioxoles of formula: ##STR00033## wherein each of R.sub.f3, R.sub.f4, R.sub.f5, R.sub.f6, equal of different each other, is independently a fluorine atom, a C.sub.1-C.sub.6 per(halo)fluoroalkyl group, optionally comprising one or more oxygen atom, optionally comprising halogen atoms different from F; (b) at least one aromatic polycondensation polymer (P), wherein polymer (P) is a mixture of at least one polyamideimide (PAI) and at least one aromatic sulfone polymer (SP), wherein said polyamideimide (PAI) comprises more than 50% moles of recurring units (R.sub.PAI), wherein recurring units (R.sub.PAI) are recurring units comprising at least one aromatic ring, at least one imide group in its imide form or its amic acid form or a mixture thereof, and at least one amide group which is not included in the amic acid form of the imide group, said recurring units (R.sub.PAI) being selected from the group consisting of: ##STR00034## wherein Ar is a trivalent aromatic group and R is a divalent aromatic group; and wherein said aromatic sulfone polymer (SP) comprises at least 50% moles of recurring units (R.sub.SP), wherein recurring units (R.sub.SP) are recurring units comprising at least one group of formula (SP):
ArSO.sub.2Ar(SP) wherein Ar and Ar, equal to or different from each other, are aromatic groups; and (c) a solvent mixture (M) comprising dimethylsulfoxide (DMSO) and at least one solvent selected from the group consisting of diesters of formula (I.sub.de) and ester-amides of formula (I.sub.ea):
R.sup.1OOCA.sub.deCOOR.sup.2 (I.sub.de)
R.sup.1OOCA.sub.eaCONR.sup.3R.sup.4 (I.sub.ea) wherein: R.sup.1 and R.sup.2, equal to or different from each other, are independently selected from the group consisting of C.sub.1-C.sub.20 hydrocarbon groups; R.sup.3 and R.sup.4, equal to or different from each other, are independently selected from the group consisting of hydrogen, optionally substituted C.sub.1-C.sub.36 hydrocarbon groups or R.sup.3 and R.sup.4 form an optionally substituted cyclic moiety including the nitrogen atom to which they are bound, optionally comprising one or more than one additional heteroatom, and mixtures thereof; A.sub.de and A.sub.ea, equal to or different from each other, are independently a linear or branched divalent alkylene group.

30. A method for coating a surface, the method comprising coating the composition according to claim 29 onto said surface, so as to obtain a wet coating layer on said surface.

31. The method of claim 30, said method further comprising drying the wet coating layer at temperatures ranging from room temperature to about 200 C., so as to obtain a dried coating layer on said surface.

32. The method of claim 31, further comprising coating the dried coating layer with an additional layer of a fluoropolymer, so as to provide an outer fluoropolymer layer assembled onto the dried coating layer on the surface.

Description

GENERAL PROCEDURE FOR THE MANUFACTURE OF THE COMPOSITION

[0238] The solvent mixture (M) comprising DMSO and at least one of the diesters of formula (I.sub.de) and ester-amide of formula (I.sub.ea) is prepared by blending and shaking the ingredients in a bottle at a temperature comprised between 20 and 35 C.

[0239] The aromatic polycondensation polymer(s) (P) is/are added at room temperature and solubilised in the solvent mixture through agitation on a bottle roller at a temperature comprised between 20 C. and 90 C. Once complete dissolution of said polymer(s) (P) was achieved, the fluoropolymer (A) was added to the resulting transparent solution, and the bottle is agitated on a bottle roller for additional 10 minutes. Following similar procedure (addition, followed by 10 minutes blending), the other ingredients were added in the following order: [0240] pigment; [0241] optional further solvent; [0242] surfactant; [0243] defoamer/deareator; [0244] optional rheology modifier.

[0245] The resulting mixture was finally homogeneized and milled in a glass beads blender, by adding an amount of glass beads equal to the volume of the obtained mixture, and blending the resulting dispersion in a Dispermat CV3 mixer for 10 minutes. Appropriate homogeneization was checked by evaluation on grind gauge grooves so as to detect, if any, presence of aggregates/particles with dimension higher than 5 m. In case any particle(s)/aggregate(s) of dimension higher than 5 m was/were detected, additional grinding for 10 minutes was performed. Formulation was considered completed and well-dispersed only when after the composition was distributed with a scraper in the grooves of the grind gauge, no detected scratches or film discontinuities above 5 m were detected.

General Coating Procedure

[0246] The formulation prepared as above detailed was applied on carbon steel substrates (square panels) via spray coating using a gun with a die of 1.2 mm and air pressure of 2.5 bar.

[0247] On the wet primer a layer of HYFLON(R) PFA powder (a tetrafluoroethylene/perfluoropropylvinylether copolymer commercially available from Solvay Specialty Polymers Italy, SPA) has been applied as top coat via electrostatic powder coating and then the assembly is treated in oven at 380 C. for 20 minutes. The thickness of the complete coating (primer+top coat) was comprised between 50 and 100 m.

[0248] Evaluation of Adhesion Properties (Including Initial Adhesion and after 60 Days of Water Vapour Exposure)

[0249] Adhesion performances of the coatings onto the substrate were determined via the cross cut test. The coating was cut making two incision lines of about 20 mm crossing each other in the middle with an angle of about 60. The coating in proximity of the cross point was scratched: if a continuous polymer film was detached from the substrate, the adhesion was qualified as poor. If, on the contrary, it was not possible to peel the coating, the adhesion was quoted as good.

[0250] This test for assessing adhesion was performed on at least 3 coated panels shortly after completion of the coating procedure (about 1 hour) and on at least additional 3 coated panels, after having exposed the same to water vapour for 60 days. To this aim, the coated side of the panels to be submitted to the test was contacted with water vapour generated by a water bath maintained at 85 C., suspending horizontally the panels at about 3 cm from the free surface of hot water.

[0251] Details of the compositions manufactured and obtained results are provided in the following table.

[0252] In this table: [0253] the ester-amide (EA) is an ester-amide of formula MeOC(O)CH(Me)CH.sub.2CH.sub.2C(O)NMe.sub.2 with Me=methyl, commercially available from Rhodia under trade name POLAR CLEAN(R); [0254] the diester (DE) is a mixture of diesters comprising essentially (more than 80 wt %) of dimethyl ethylsuccinate and dimethyl 2-methylglutarate, commercially available from Rhodia under trade name RHODIASOLV IRIS; [0255] MFA P6010 stands for HYFLON MFA P6010, which is a TFE/MVE copolymer commercially available from Solvay Specialty Polymers Italy SpA; [0256] VW10200RP PES stands for Virantage VW10200RP PES, which is a hydroxyl-functionalized PES with a molecular weight of about 45000, commercially available from Solvay Specialty Polymers USA, LLC; [0257] PAI A110 stands for Torlon PAI A110, which is a polyamideimide commercially available from Solvay Specialty Polymers USA, LLC; [0258] 30C 965 Shepherd is a black pigment commercially available as DYNAMIX BLACK 30C.sub.965 from Shepherd Color Company; [0259] BYK-431 is a Liquid Rheology Control Additive made consisting of a solution of a high molecular urea modified medium polar polyamide, commercially available from BYK; [0260] Airex 931 stands for TEGO Airex 931, which is a deaerator/defoaming agent for solvent-based coating systems, based on a fluorinated silicone commercially available from Evonik Tego Chemie GmbH; [0261] 15-S-5 stands for Tergitol 15-S-5, which is a secondary Alcohol Ethoxylate surfactant commercially available from Dow.

TABLE-US-00001 TABLE 1 Ex. 1C Ex. 2 Ex. 3 (wt (wt (wt Material parts) parts) parts) Solvent N-methylpyrrolidone 52.3 mixture (M) Ester-amide (EA) 36 Diester (DE) 36 Diacetonalcohol 18.3 Ethyl Acetate 1.4 1.3 1.3 DMSO 36 36 Polymer (P1) VW10200RP PES 6.6 6.3 6.3 Polymer (P2) PAI Al10 2 1.9 1.9 Polymer (A) MFA P6010 9.4 9 9 Pigment 30C 965 7 6.7 6.7 Rheology BYK-431 0.5 0.5 0.5 modifier Defoamer Airex 931 0.2 0.2 0.2 Surfactant 15-S-5 2.3 2.3 2.3 Cross cut test Initial adhesion good good good Adhesion after 60 gg vapour exposure good good good

[0262] Data provided herein above well demonstrate that solvent mixture (M) can be successfully used for manufacturing primer compositions providing outstanding adhesion behaviour, comparable to traditional primer compositions formulated with NMP solvent.