Curable fluoroelastomer compositions
阅读说明：本技术 可固化含氟弹性体组合物 (Curable fluoroelastomer compositions ) 是由 朴志英 福士达夫 米格尔·A·格拉 凯坦·P·亚里瓦拉 克劳斯·辛策 于 2019-02-13 设计创作，主要内容包括：本发明公开了一种可固化组合物,该可固化组合物包含氟化无定形含氟聚合物和由下式表示的氟化磺酰胺交联剂。(A curable composition comprising a fluorinated amorphous fluoropolymer and a fluorinated sulfonamide crosslinker represented by the formula is disclosed.)
1. A curable composition comprising an amorphous fluoropolymer, wherein the partially fluorinated amorphous fluoropolymer,
optionally organicAn accelerator(s) for the accelerator(s),
an acid acceptor; and
a crosslinking agent of the formula:
R2(NH-SO2R1)xwherein
R1Is a non-fluorinated or a fluorinated group,
R2is a fluorinated or non-fluorinated group; and is
The subscript x is a number of from 2 to 8,
provided that when R is1When being fluorinated, R2Is fluorinated.
2. The curable composition of claim 1, wherein R1Is a perfluorinated radical Rf 1。
3. The curable composition of claim 1, wherein Rf 1Is C2-C6A perfluoroalkyl group.
4. The curable composition of claim 1, wherein Rf 1Is a perfluoroether group.
5. The curable composition of claim 4, wherein Rf 1Is a perfluoroether group of the formula:
F-Rf 3-O-Rf 4-(Rf 5)q- (V)
wherein
Rf 3Represents a perfluoroalkylene group, Rf 4Represents a perfluoroalkyleneoxy group, Rf 5Represents a perfluoroalkylene group, and q is 0 or 1.
6. The curable composition of claim 1, wherein the crosslinker is of formula Rh 2(NH-SO2Rf 1)x，
Wherein R ish 2Is a (hetero) hydrocarbyl group, and Rf 1Is perfluoroalkyl or perfluoroether group.
7. The curable composition of claim 6, wherein Rh 2Is C with a valence of x2-C30Aliphatic, alicyclic, aromatic or alkyl-substituted aromatic hydrocarbon radicals.
8. The curable composition of claim 1, wherein Rh 2Derived from a polyamine.
9. The curable composition of claim 1, wherein the crosslinker is of formula
Rf 3(Y-NH-SO2R1)x，
Wherein
Rf 3Represents a perfluoroalkylene group, and represents a perfluoroalkyl group,
y is a (hetero) hydrocarbyl group including an alkylidene, arylidene or heteroalkylidene and a heteroaromatylidene, and preferably an alkylidene having 1 to 4 carbons; and is
Subscript x is 2 to 8.
10. The curable composition of claim 1, wherein the crosslinker is of formula
[F-Rf 3-O-Rf 4-(Rf 5)q]-(Y-NH-SO2R1)xWherein
[F-Rf 3-O-Rf 4-(Rf 5)q]Having a structure from Rf 3、Rf 4Or Rf 5A valence x obtained by extracting two or more F atoms from any one of the groups,
Rf 3represents a perfluoroalkylene group, and represents a perfluoroalkyl group,
Rf 4represents a perfluoroalkyleneoxy group and a perfluoroalkyleneoxy group,
Rf 5represents a perfluoroalkylene group and q is 0 or 1.
11. The composition of claim 1, wherein both R1 and R2 of the crosslinker are non-fluorinated and can be represented by the formula:
Rh 2(NH-SO2Rh 1)x，IV
wherein
Rh 1Is a (hetero) hydrocarbyl group, and Rh 2Is a (hetero) hydrocarbyl group.
12. The composition of claim 11 wherein Rh2 is a C2-C30 aliphatic, alicyclic, aromatic, or alkyl-substituted aromatic hydrocarbyl group.
13. The composition of claim 11 wherein Rh1 is a C2-C30 aliphatic, alicyclic, aromatic, or alkyl-substituted aromatic hydrocarbyl group.
14. The curable composition of claim 1 wherein the amorphous fluoropolymer is partially fluorinated.
15. The curable composition of any one of the preceding claims, wherein the amorphous fluoropolymer is derived from vinylidene fluoride.
16. The curable composition of any one of the preceding claims, wherein the amorphous fluoropolymer comprises at least one of carbon-carbon double bonds or units capable of forming carbon-carbon double bonds along the amorphous fluoropolymer chain.
17. The curable composition of any one of the preceding claims, wherein the amorphous fluoropolymer is a copolymer of: (i) hexafluoropropylene, tetrafluoroethylene, and vinylidene fluoride; (ii) hexafluoropropylene and vinylidene fluoride; (iii) vinylidene fluoride and perfluoromethyl vinyl ether; (iv) vinylidene fluoride, tetrafluoroethylene, and perfluoromethyl vinyl ether; (v) (vii) vinylidene fluoride, tetrafluoroethylene, and propylene, or (vi) ethylene, tetrafluoroethylene, and perfluoromethyl vinyl ether, and (vii) blends thereof.
18. The curable composition of any one of the preceding claims, wherein the fluoropolymer comprises: from 10 to 50 mol% of recurring units derived from tetrafluoroethylene; 15 to 40 mol% of recurring units derived from hexafluoropropylene; 25 to 59 mole% of recurring units derived from vinylidene fluoride; 1 to 20 mol% of recurring units derived from chlorotrifluoroethylene; and optionally e.one or more repeating units derived from a fluorinated monomer other than tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, and chlorotrifluoroethylene.
19. The curable partially fluorinated polymer composition of any one of the preceding claims, wherein the partially fluorinated amorphous fluoropolymer comprises: (i) adjacent copolymerized units of VDF and HFP; (ii) (ii) copolymerized units of VDF and a fluorinated comonomer having an acidic hydrogen atom; (iii) copolymerized units of TFE and a fluorinated comonomer having an acidic hydrogen atom; and (iv) combinations thereof.
20. The curable partially fluorinated polymer composition of claim 8, wherein the fluorinated comonomer having an acidic hydrogen atom is selected from the group consisting of: trifluoroethylene; vinyl fluoride; 3,3, 3-trifluoropropene-1; pentafluoropropene; and 2,3,3, 3-tetrafluoropropene.
21. The curable partially fluorinated polymer composition of any one of the preceding claims, wherein the partially fluorinated amorphous fluoropolymer is derived from: (i) vinylidene fluoride, tetrafluoroethylene, and propylene; (ii) vinylidene fluoride, tetrafluoroethylene, ethylene, and perfluoroalkyl vinyl ethers such as perfluoro (methyl vinyl ether); (iii) vinylidene fluoride and hexafluoropropylene; (iv) hexafluoropropylene, tetrafluoroethylene, and vinylidene fluoride; (v) hexafluoropropylene and vinylidene fluoride; (vi) vinylidene fluoride and perfluoroalkyl vinyl ethers; (vii) vinylidene fluoride, tetrafluoroethylene, and perfluoroalkyl vinyl ether; (viii) vinylidene fluoride, perfluoroalkyl vinyl ether, hydropentafluoroethylene and optionally tetrafluoroethylene; (ix) tetrafluoroethylene, propylene and 3,3, 3-trifluoropropene; (x) Tetrafluoroethylene and propylene; (xi) Ethylene, tetrafluoroethylene, and a perfluoroalkyl vinyl ether, and optionally 3,3, 3-trifluoropropene; (xii) Vinylidene fluoride, tetrafluoroethylene, and perfluoroalkyl allyl ether; (xiii) Vinylidene fluoride and perfluoroalkyl allyl ethers; (xiv) Vinylidene fluoride, tetrafluoroethylene, and perfluoroalkylallylether; (xv) Vinylidene fluoride and perfluoroalkylallyl ethers; (xvi) Vinylidene fluoride, tetrafluoroethylene, and perfluoroalkylallylether; (xv) Vinylidene fluoride and perfluoroalkylallyl ethers; and (xvi) combinations thereof.
22. The curable composition of any one of the preceding claims, wherein the organic isThe compound comprises: c3-C6Symmetric tetraalkylammonium salts, asymmetric tetraalkylammonium salts, wherein the total number of alkyl carbons is between 8 and 24; and benzyltrialkylammonium salts in which the total number of alkyl carbons is between 7 and 19, (e.g., tetrabutylammonium bromide, tetrabutylammonium chloride, benzyltributylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium hydrogen sulfate, and tetrabutylammonium hydroxide, phenyltrimethylammonium chloride, tetrapentylammonium chloride, tetrapropylammonium bromide, tetrahexylammonium chloride, and tetraheptylammonium tetramethylammonium bromide); season
23. The curable composition according to any one of the preceding claims, further comprising a secondary crosslinking agent selected from the group consisting of polyol compounds, polythiol compounds, polyamine compounds, amidine compounds, bisaminophenol compounds, and oxime compounds.
24. A molded article comprising a cured composition according to any one of claims 1 to 23.
25. A method of making a shaped article, the method comprising the steps of:
providing a curable composition according to any one of claims 1 to 23,
heating the composition to a temperature sufficient to cure the composition; and
recovering the shaped article.
Background
Fluoropolymers are a commercially important class of materials, including, for example, crosslinked and uncrosslinked fluorocarbon elastomers, as well as semi-crystalline or glassy fluorocarbon plastics.
Fluorocarbon elastomers, particularly copolymers of vinylidene fluoride with other ethylenically unsaturated halogenated and non-halogenated monomers (such as hexafluoropropylene), have particular utility in high temperature applications, such as seals, gaskets, and liners. See, for example, R.A. Brullo, "fluoroelastomer rubbers for Automotive Applications", Automotive Elastomers and designs, 6.1985, "future of fluoroelastomer-sealed automobiles", Material engineering, 10.1988 (R.A. Brullo, "Fluoroelastomer rubber for Automotive Applications," Automotive Elastomer rubber&Design, June 1985, "Fluoroelastomer Seal Up automatic Future," Materials Engineering, October1988), and W.M. Grootaert et al, "Fluorocarbon Elastomers", Kirk-Othmer, Encyclopedia of Chemical Technology, Vol.8, page 990 (4 th edition, John Willi-Giraffe Press 1993) (W.M. Grootaert, et al, "Fluorocarbon Elastomers," Kirk-Othmer, Encyclopedia of Chemical Technology, Vol.8, pp.990-1005(4thed.,John Wiley&Sons,1993))。
Disclosure of Invention
There is a need for new curing systems that identify partially fluorinated amorphous fluoropolymers. In one aspect, a curable partially fluorinated polymer is disclosed comprising:
(i) a partially fluorinated amorphous fluoropolymer, wherein the partially fluorinated amorphous fluoropolymer contains carbon-carbon double bonds or is capable of forming carbon-carbon double bonds along the partially fluorinated amorphous fluoropolymer; and
(ii) a curing agent comprising a sulfonamide compound of the formula:
R2(NH-SO2R1)x， I
wherein
R1Is a non-fluorinated or a fluorinated group,
R2is a fluorinated or non-fluorinated group; and is
The subscript x is a number of from 2 to 8,
provided that when R is1When being fluorinated, R2Is fluorinated. It will be understood that formula I will include its corresponding salt.
In another aspect, an article comprising the cured composition described above is disclosed.
In yet another aspect, a method of making a partially fluorinated elastomer is disclosed that includes curing the curable partially fluorinated polymer composition disclosed above.
As used herein, "alkyl" and "alkylidene" refer to the monovalent and divalent residues remaining after removal of one and two hydrogen atoms, respectively, from a straight or branched chain hydrocarbon having from 1 to 20 carbon atoms. Examples of "alkyl" as used herein include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, n-pentyl, isobutyl, tert-butyl, isopropyl, n-octyl, n-heptyl, ethylhexyl, cyclopentyl, cyclohexyl, cycloheptyl, adamantyl, norbornyl, and the like. Unless otherwise specified, an alkyl group can be monovalent or polyvalent.
As used herein, the term "heteroalkyl" includes straight-chain, branched, and cyclic alkyl groups having one or more heteroatoms independently selected from S, O and N, including both unsubstituted and substituted alkyl groups. Unless otherwise indicated, heteroalkyl groups typically contain from 1 to 20 carbon atoms. "heteroalkyl" is a subset of "hetero (hetero) hydrocarbyl" described below. Examples of "heteroalkyl," as used herein, include, but are not limited to, methoxy, ethoxy, propoxy, 3, 6-dioxaheptyl, 3- (trimethylsilyl) -propyl, 4-dimethylaminobutyl, and the like. Unless otherwise specified, heteroalkyl groups may be monovalent or multivalent.
"aryl" and "arylidene" means the residue of an aromatic compound having 5 to 12 ring atoms (monocyclic as well as polycyclic and fused rings) after removal of one and two hydrogen atoms, respectivelyMonovalent and divalent residues, and include substituted aromatic groups such as lower alkaryl and aralkyl, lower alkoxy, N-di (lower alkyl) amino, nitro, cyano, halogen, and lower alkyl carboxylate, wherein "lower" means C1To C4。
Unless otherwise specified, alkyl, aryl and heteroaryl groups may be monovalent or polyvalent.
As used herein, "(hetero) hydrocarbyl" includes hydrocarbyl alkyl and aryl groups, as well as heterohydrocarbyl heteroalkyl and heteroaryl groups. The heterohydrocarbyl group may optionally contain one or more catenary (in-chain) functional groups including ester, amide, urea, carbamate, and carbonate functional groups. Unless otherwise indicated, the non-polymeric (hetero) hydrocarbyl groups typically contain 1 to 60 carbon atoms. As used herein, some examples of such (hetero) hydrocarbyl groups include, but are not limited to, methoxy, ethoxy, propoxy, 4-diphenylaminobutyl, 2- (2' -phenoxyethoxy) ethyl, 3, 6-dioxaheptyl, 3, 6-dioxahexyl-6-phenyl (in addition to those "alkyl", "heteroalkyl", "aryl" and "heteroaryl" groups described above).
Detailed Description
In the present disclosure, it has been found that partially fluorinated amorphous fluoropolymers can be cured with fluorinated sulfonamide compounds.
Fluorine-containing polymer
The amorphous fluoropolymers of the present disclosure are partially fluorinated polymers. As disclosed herein, an amorphous partially fluorinated polymer is a polymer comprising at least one carbon-hydrogen bond and at least one carbon-fluorine bond in the polymer backbone. In one embodiment, the amorphous partially fluorinated polymer is a highly fluorinated polymer wherein at least 60%, 70%, 80% or even 90% of the polymer backbone comprises C-F bonds.
The amorphous fluoropolymers of the present disclosure also contain carbon-carbon double bonds and/or are capable of forming carbon-carbon double bonds along the polymer chain. In one embodiment, the partially fluorinated amorphous fluoropolymer contains carbon-carbon double bonds along the backbone of the partially fluorinated amorphous fluoropolymer or is capable of forming carbon-carbon double bonds along the backbone of the partially fluorinated amorphous fluoropolymer. In another embodiment, the partially fluorinated amorphous fluoropolymer contains carbon-carbon double bonds, or is capable of forming carbon-carbon double bonds in pendant groups other than the backbone of the partially fluorinated amorphous fluoropolymer.
The fluoropolymer being capable of forming carbon-carbon double bonds means that the fluoropolymer comprises units capable of forming double bonds. Such units include, for example, two adjacent carbons along the polymer backbone or pendant side chain, where a hydrogen is attached to the first carbon and a leaving group is attached to the second carbon. During the elimination reaction (e.g., thermal reaction and/or use of an acid or base), the leaving group and hydrogen leave, forming a double bond between the two carbon atoms. Exemplary leaving groups include: fluoride, alkoxide, hydroxide, tosylate, methanesulfonic acid, amine, ammonium, sulfide, sulfonium, sulfoxide, sulfone, and combinations thereof. Those fluoropolymers capable of forming carbon-carbon bonds typically have a structure of-CH-CX-wherein X is a leaving group such that when treated with a base, the desired degree of unsaturation will be provided. In many embodiments, the polymer has a-CH-CF-in the backbone, which can be dehydrofluorinated.
Amorphous fluoropolymers contain a plurality of these groups (carbon-carbon double bonds or groups capable of forming double bonds) to achieve adequate cure. Typically, this means at least 0.1 mol%, 0.5 mol%, 1 mol%, 2 mol% or even 5 mol%; up to 7 mol%, 10 mol%, 15 mol% or even 20 mol% (i.e. the number of moles of these carbon-carbon double bonds or precursors thereof per mole of polymer).
In one embodiment, the amorphous partially fluorinated polymer is derived from at least one hydrogen-containing monomer, such as vinylidene fluoride.
In one embodiment, the amorphous fluoropolymer comprises: adjacent copolymerized units of vinylidene fluoride (VDF) and Hexafluoropropylene (HFP); copolymerized units of VDF (or tetrafluoroethylene) and a fluorinated comonomer capable of delivering acidic hydrogen atoms to the polymer backbone, such as trifluoroethylene; vinyl fluoride; 3,3, 3-trifluoropropene-1; pentafluoropropenes (e.g., 2-hydropentafluoropropene and 1-hydropentafluoropropene); 2,3,3, 3-tetrafluoropropene; and combinations thereof.
In some embodiments, a small amount (e.g., less than 10, 5,2, or even 1 weight percent) of additional monomer may be added, so long as the amorphous fluoropolymer is capable of being cured using the curing agent disclosed herein.
In one embodiment, the amorphous fluoropolymer is additionally derived from hydrogen-containing monomers comprising: pentafluoropropene (e.g., 2-hydrogenated pentafluoropropene), propylene, ethylene, isobutylene, and combinations thereof.
In one embodiment, the amorphous fluoropolymer is additionally derived from a perfluorinated monomer. Exemplary perfluorinated monomers include: hexafluoropropylene; tetrafluoroethylene; chlorotrifluoroethylene; perfluoro (alkyl vinyl ether), such as perfluoromethyl vinyl ether, CF2＝CFOCFCF2CF2OCF3、CF2＝CFOCF2OCF2CF2CF3、CF2＝CFOCF2OCF2CF3、CF2＝CFOCF2OCF3And CF2＝CFOCF2OC3F7Perfluoro (alkylallyl ether) such as perfluoromethylallyl ether, perfluoro (alkoxyallyl ether) such as perfluoro-4, 8-dioxa-1-nonene (i.e., CF)2＝CFCF2O(CF2)3OCF3) (ii) a And combinations thereof.
Exemplary types of polymers include those comprising interpolymerized units derived from: (i) vinylidene fluoride, tetrafluoroethylene, and propylene; (ii) vinylidene fluoride, tetrafluoroethylene, ethylene, and perfluoroalkyl vinyl ethers such as perfluoro (methyl vinyl ether); (iii) vinylidene fluoride and hexafluoropropylene; (iv) hexafluoropropylene, tetrafluoroethylene, and vinylidene fluoride; (v) hexafluoropropylene and vinylidene fluoride, (vi) vinylidene fluoride and perfluoroalkyl vinyl ethers; (vii) (viii) vinylidene fluoride, tetrafluoroethylene, and perfluoroalkyl vinyl ether, (viii) vinylidene fluoride, perfluoroalkyl vinyl ether, hydropentafluoroethylene, and optionally tetrafluoroethylene; (ix) tetrafluoroethylene, propylene and 3,3, 3-trifluoropropene; (x) Tetrafluoroethylene and propylene; (xi) Ethylene, tetrafluoroethylene, and a perfluoroalkyl vinyl ether, and optionally 3,3, 3-trifluoropropene; (xii) Vinylidene fluoride, tetrafluoroethylene, and perfluoroalkyl allyl ether, (xiii) vinylidene fluoride, and perfluoroalkyl allyl ether; (xiv) Ethylene, tetrafluoroethylene, and a perfluoroalkyl vinyl ether, and optionally 3,3, 3-trifluoropropene; (xv) (xvi) vinylidene fluoride, tetrafluoroethylene, and perfluoroalkyl allyl ether, (xvi) vinylidene fluoride, and perfluoroalkyl allyl ether; (xvii) Vinylidene fluoride, tetrafluoroethylene, and perfluoroalkylallyl ether, (xviii) vinylidene fluoride, and perfluoroalkylallyl ether; (xiv) Vinylidene fluoride, tetrafluoroethylene, and perfluoroalkylallyl ether, (xv) vinylidene fluoride, and perfluoroalkylallyl ether; and (xvi) combinations thereof.
Advantageously, by using the curing agents disclosed herein, the amorphous fluoropolymers of the present disclosure can be cured without the need for side bromine, iodine, or nitrile cure sites along the polymer backbone. In general, iodine and bromine containing cure site monomers that polymerize to fluoropolymers and/or chain ends can be quite expensive.
The amorphous fluoropolymers of the present disclosure are substantially free of iodine, bromine, and nitrile groups, wherein the amorphous fluoropolymer comprises less than 0.1, 0.05, 0.01, or even 0.005 mole%, relative to the total polymer.
In one embodiment, the amorphous fluoropolymer of the present disclosure is a non-grafted polymer, that is, it does not contain pendant groups including vinyl, allyl, acrylate, amido, sulfonate, pyridine, carboxylate, sterically hindered silanes (which are aliphatic or aromatic tri-ethers or triesters). In one embodiment, the amorphous fluoropolymer does not contain monophenol grafts.
The amorphous fluoropolymers described above may be blended with one or more additional crystalline fluoropolymers. With the curing compounds of the present invention, the crystalline fluoropolymer can be cured into a matrix of amorphous fluoropolymer.
Commercially available vinylidene fluoride-containing fluoropolymers include those fluoropolymers such as: such as those sold under the trade designation "THV" (e.g., "THV 200", "THV 400", "THVG", "THV 610" or "THV 800") by 3M/Dyneon corporation of st paul, Minn; "KYNAR" (e.g., "KYNAR 740") sold by Atofina, Philadelphia, Pa.); "HYLAR" (e.g., "HYLAR 700") sold by Ausimont of Morisdun, N.J.); and "FLUOREL" marketed by 3M/Dyneon (e.g., "FLUOREL FC-2178").
Useful fluoropolymers also include copolymers of HFP, TFE, and VDF (i.e., THV). These polymers can have, for example, in the range of at least about 2 wt%, 10 wt%, or 20 wt% up to 30 wt%, 40 wt%, or even 50 wt% VDF monomeric units, and in the range of at least about 5 wt%, 10 wt%, or 15 wt% up to about 20 wt%, 25 wt%, or even 30 wt% HFP monomeric units, with the remaining weight of the polymer being TFE monomeric units. Examples of commercially available THV polymers include those sold by the 3M/Dyneon company under the trade designations "3M/DYNEON THV 2030 GFLUOROTHERMOPLASTIC", "3M/DYNEON THV 220 FLUOROTHERMOPLASTIC", "3M/DYNEON THV340C FLUOROTHERMOPLASTIC", "3M/DYNEON THV 415 FLUOROTHERMOPLASTIC", "3M/DYNEON THV 500A FLUOROTHERMOPLASTIC", "3M/DYNEON V610G FLUOROTHERMOPLASTIC" or "3M/DYNEON THV 810G FLUOROTHERMOPLASTIC".
Useful fluoropolymers also include copolymers of ethylene, TFE and HFP. These polymers can have, for example, in the range of at least about 2 wt%, 10 wt%, or 20 wt% up to 30 wt%, 40 wt%, or even 50 wt% ethylene monomer units, and in the range of at least about 5 wt%, 10 wt%, or 15 wt% up to about 20 wt%, 25 wt%, or even 30 wt% HFP monomer units, with the remaining weight of the polymer being TFE monomer units. Such polymers are sold, for example, by the 3M/Dyneon company under the trade name "3M/DYNEON FLUOROTHERMOPLASTIC HTE" (e.g., "3M/DYNEON FLUOROTHERMOPLASTIC HTE X1510" or "3M/DYNEON FLUOROTHERMOPLASTIC X1705").
Useful fluoropolymers also include copolymers of tetrafluoroethylene and propylene (TFE/P). These polymers can have, for example, in the range of at least about 20, 30, or 40 to at most about 50, 65, or even 80 weight percent TFE monomer units, with the remaining weight of the polymer being propylene monomer units. Such polymers are commercially available, for example, from 3M/Dyneon under the trade designation "AFLAS" (e.g., "AFLAS TFE ELASTOMER FA 100H", "AFLAS TFE ELASTOMER FA 150C", "AFLAS TFE ELASTOMER FA 150L", or "AFLAS TFE ELASTOMER FA 150P") or "VITON" (e.g., "VITON VTR-7480" or "VITONVTR-7512") from E.I. DuPont de Nemours & Company, Wilmington, Del., Wilmington, Del., Wilmington, Del.
Useful fluoropolymers also include copolymers of ethylene and TFE (i.e., "ETFE"). These polymers can have, for example, in the range of at least about 20, 30, or 40 to at most about 50, 65, or even 80 weight percent TFE monomer units, with the remaining weight of the polymer being propylene monomer units. Such polymers are commercially available, for example, from the 3M/DYNEON company under the trade designations "3M/DYNEON FLUOROTHERPOSTIC ET 6210J", "3M/DYNEON FLUOROTHERPOSTIC ET 6235" or "3M/DYNEON FLUOROTHERPOSTIC ET 6240J".
VDF-containing fluoropolymers may be prepared using emulsion polymerization techniques such as those described in U.S. Pat. No. 4,338,237(Sulzbach et al) or U.S. Pat. No. 5,285,002(Grootaert) or U.S. Pat. No. 20060029812 (lacing et al), the disclosures of which are incorporated herein by reference.
The curable composition also includes a fluorinated sulfonamide curing agent represented by the formula:
R2(NH-SO2R1)x， I
wherein
R1Is a fluorinated or non-fluorinated group,
R2is a fluorinated or non-fluorinated group;
subscript x is 2 to 8; and is
Provided that when R is1When being fluorinated, R2Is fluorinated.
In some embodiments, R1Is a perfluorinated group (designated as R)f 1) And R is2Is fluorinated (designated as R)f 2) Or non-fluorinated (designated as R)h 2). Such embodiments may be represented by:
Rh 2(NH-SO2Rf 1)xII, or
Rf 2(NH-SO2Rf 1)x， III
In some embodiments, R1And R2Both are non-fluorinated and can be represented by the formula:
Rh 2(NH-SO2Rh 1)x， IV
wherein
Rf 1Is a perfluorinated group;
Rf 2is a fluorinated group, and
Rh 2are non-fluorinated groups.
Rf 1The groups may comprise linear, branched, or cyclic monovalent fluorinated groups, or any combination thereof. Rf 1The group may optionally contain one or more catenary oxygen atoms on the carbon-carbon chain, thereby forming a carbon-oxygen-carbon chain (i.e., an alkylene oxide subunit group). Perfluorinated groups are generally preferred, but hydrogen or chlorine atoms may also be present as substituents, provided that no more than one atom is present for every two carbon atoms.
It is further preferred that any R isf 1The groups all contain at least about 40 weight percent fluorine, more preferably at least about 50 weight percent fluorine. Monovalent Rf 1The terminal part of the group is generally perfluorinated, preferably containing at least three fluorine atoms, e.g. CF3-、CF3CF2-、CF3CF2CF2-、(CF3)2N-、(CF3)2CF-、SF5CF2-. In certain embodiments, a monovalent perfluoroalkyl group (i.e., represented by formula C)nF2n+1Those represented by-) are preferred Rf 1Groups wherein n-3 to 5 are more preferred, and wherein n-4 is most preferred.
In some embodiments, Rf1 may comprise fluoroethers or fluoropolyethers. Perfluoroalkyloxy (R) groups are usefulf 1) Corresponding to the following formula:
F-Rf 3-O-Rf 4-(Rf 5)q- (V)
wherein
Rf 3Represents a perfluoroalkylene group, and represents a perfluoroalkyl group,
Rf 4represents a perfluoroalkyleneoxy group consisting of perfluoroalkyleneoxy groups having 1,2, 3 or 4 carbon atoms or a mixture of such perfluoroalkyleneoxy groups,
Rf 5represents a perfluoroalkylene group and q is 0 or 1.
The perfluoroalkylidene radical R in the formula (IV)f 3And Rf 5May be straight or branched chain and may contain 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. A typical monovalent perfluoroalkyl group is CF3-CF2-CF2-, and a typical divalent perfluoroalkylene group is-CF2-CF2-CF2-、-CF2-or-CF (CF)3) -. Perfluoroalkyleneoxy radical Rf 4Examples of (a) include: -CF2-CF2-O-、-CF(CF3)-CF2-O-、-CF2-CF(CF3)-O-、-CF2-CF2-CF2-O-、-CF2-O-、-CF(CF3) -O and-CF2-CF2-CF2-CF2-O-, which may be repeated, for example, 3 to 30 times.
Perfluoroalkyleneoxy radical Rf 4May or may not be composed of the same perfluoroalkoxy subunitA mixture of identical perfluoroalkoxy subunits. When the perfluoroalkoxy subunits are comprised of different perfluoroalkoxy units, they may be present in a random configuration, an alternating configuration, or they may be present as blocks. Typical examples of perfluorinated poly (oxyalkylene) groups include:
-[CF2-CF2-O]r-；-[CF(CF3)-CF2-O]s-；-[CF2CF2-O]r-[CF2O]t-、-[CF2CF2CF2CF2-O]uand- [ CF2-CF2-O]r-[CF(CF3)-CF2-O]s-; wherein each of r, s, t and u is an integer of 1 to 50, preferably 2 to 25. The preferred perfluorooxyalkyl radical corresponding to formula (V) is CF3-CF2-CF2-O-[CF(CF3)-CF2O]s-CF(CF3)CF2-, where s is an integer from 1 to 50.
In some embodiments, R1May be non-fluorinated (R)h 1) And is selected from the group consisting of monovalent (hetero) hydrocarbyl groups including aliphatic, alicyclic, aromatic, or alkyl-substituted aromatic groups having from 2 to 30 carbon atoms and optionally zero to four catenary heteroatoms of oxygen, nitrogen, or sulfur; i.e., a heterohydrocarbyl group.
In some embodiments, R2May be non-fluorinated (R)h 2) And is selected from divalent and polyvalent (hetero) hydrocarbyl groups including aliphatic, alicyclic, aromatic or alkyl-substituted aromatic groups having from 2 to 30 carbon atoms and optionally zero to four catenary heteroatoms of oxygen, nitrogen or sulfur; i.e., a heterohydrocarbyl group.
In some embodiments, R2The group may be fluorinated and is designated Rf 2. There should be at least one non-fluorinated carbon between the fluorinated carbon and the nitrogen atom; for example-CF2-CH2-NH-。Rf 2The groups are divalent or multivalent, and may comprise pendant multivalent fluorinated groups that are linear, branched, or cyclic, or any combination thereof. Rf 2The group may optionally contain one or more catenary oxygen atoms on the carbon-carbon chain, thereby forming a carbon-oxygen-carbon chain (i.e., an alkylene oxide subunit group). Perfluorinated groups are generally preferred, but hydrogen or chlorine atoms may also be present as substituents, provided that no more than one atom is present for every two carbon atoms.
In some embodiments, Rf 2The group can be a fluorinated alkylidene group to produce a compound of the formula:
Rf 3(Y-NH-SO2R1)x，
wherein
Rf 3Represents a perfluoroalkylene group, and represents a perfluoroalkyl group,
y is a (hetero) hydrocarbyl group including an alkylidene, arylidene or heteroalkylidene and heteroarylidene group, and preferably an alkylidene group having 1 to 4 carbons; and is
Subscript x is 2 to 8.
Rf 2The group may also be a fluorinated ether or fluorinated polyether group to yield a compound of the formula:
[F-Rf 3-O-Rf 4-(Rf 5)q-(Y-NH-SO2R1)xwherein
[F-Rf 3-O-Rf 4-(Rf 5)q]Having a structure from Rf 3、Rf 4Or Rf 5A valence x obtained by extracting two or more F atoms from any one of the groups, and
Rf 3、Rf 4、Rf 5subscripts q, Y and R1As hereinbefore defined.
Fluorinated sulfonamides of formula I can be prepared by reaction of sulfonyl halide compounds with diamines or polyamines:
R1SO2-X+R2(NH2)x→I，
wherein R is1Is a fluorinated or non-fluorinated group andand may be designated as R abovef 1；
Wherein R is2Can be a fluorinated group or a non-fluorinated group, and is a non-polymeric organic group having a valence x, and x is two to eight.
In some embodiments, R2Can be selected from monovalent and polyvalent (hetero) hydrocarbyl groups including aliphatic, alicyclic, aromatic or alkyl-substituted aromatic groups having from 1 to 30 carbon atoms and optionally zero to four catenary heteroatoms of oxygen, nitrogen or sulfur.
In some embodiments, R2The group may be fluorinated, as described above, designated as Rf 2。
Useful compounds of the formula R2(NH2)xThe (hetero) hydrocarbyl amines represented include aliphatic polyamines and aromatic polyamines. Aliphatic amines, aromatic amines, cycloaliphatic amines, and oligomeric diamines and polyamines are all considered useful in the practice of the present invention. Representative of the useful classes of diamines or polyamines are 4,4' -methylenedianiline, 3, 9-bis (3-aminopropyl) -2,4,8, 10-tetraoxaspiro [5,5]]Undecane, and polyoxyethylene diamine. Useful diamines include N-methyl-1, 3-propanediamine; n-ethyl-1, 2-ethylenediamine; 2- (2-aminoethylamino) ethanol; pentaethylenehexamine; ethylene diamine; n-methylethanolamine; and 1, 3-propanediamine.
Examples of useful polyamines include polyamines having at least three amino groups, wherein at least one of the three amino groups is a primary amino group and the remainder can be primary amino groups, secondary amino groups, or combinations thereof. Examples include H2N(CH2CH2NH)1-10H、H2N(CH2CH2CH2CH2NH)1-10H、H2N(CH2CH2CH2CH2CH2CH2NH)1-10H、H2N(CH2)3NHCH2CH＝CHCH2NH(CH2)3NH.2、H2N(CH2)4NH(CH2)3NH2、H2N(CH2)3NH(CH2)4NH(CH2)3NH2、H2N(CH2)3NH(CH2)2NH(CH2)3NH2、H2N(CH2)2NH(CH2)3NH(CH2)2NH2、H2N(CH2)3NH(CH2)2NH2、C6H5NH(CH2)2NH(CH2)2NH2And N (CH)2CH2NH2)3，
Other useful diamines or polyamines are 4,4' -methylenedianiline, 3, 9-bis (3-aminopropyl) -2,4,8, 10-tetraoxaspiro [5,5] undecane, and polyoxyethylenediamines. Many diamines and polyamines (such as those just mentioned) are commercially available, for example, those available from Huntsman chemistry (Houston Chemical, Houston, TX) in Houston, texas.
The amount of curing agent used should be sufficient to cause the amorphous fluoropolymer to cure as indicated by the increase in torque on the rotorless rheometer. For example, at least 0.5 parts to 20 parts of crosslinking agent per 100 parts of amorphous fluoropolymer is used. If too little curative is used, the amorphous fluoropolymer will not cure. For example, no more than 20, 15, 10, or even 8 millimoles of curative are used per 100 parts of amorphous fluoropolymer. If too much curative is used, the amorphous fluoropolymer may become brittle.
One of the sulfonamide compounds of formula I or blends thereof, including any combination of sulfonamide compounds of formulae II, and IV, can be used.
In addition to the sulfonamide crosslinker of formula I, the curable composition may optionally comprise a second optional crosslinker. Examples of the optional crosslinking agent include polyol compounds, polythiol compounds, polyamine compounds, amidine compounds, bisaminophenol compounds, oxime compounds, and the like. In some embodiments, the second crosslinking agent can comprise a non-fluorinated hydrocarbyl sulfonamide similar to formula I.
In general, depending on the type of polymer, examples are not limited to the selection of a specific combination of sulfonamide of formula I with secondary crosslinker and/or crosslinking facilitator, but typical examples are shown below. For example, for vinylidene fluoride systems (binary systems or ternary systems), polyol compounds, polyamine compounds, polythiophene compounds are preferable. For the tetrafluoroethylene-propylene-vinylidene fluoride-based fluororubber (ternary) system, a polyol compound, a polyamine compound, a polythiol compound, or the like is preferable.
Examples of preferred polyol compounds include 2, 2-bis (4-hydroxyphenyl) hexafluoropropane, 4 '-dihydroxydiphenylsulfone, 4' -diisopropylidenediphenol, and the like.
Examples of preferred polythiol compounds include 2-dibutylamino-4, 6-dimercapto-s-triazine, 2,4, 6-trimercapto-s-triazine, and the like.
Examples of preferred polyamine compounds include hexamethylene diamine carbamate, N '-diphenylene allyl-1, 6-hexamethylene diamine, 4' -methylene bis (cyclohexylamine) carbonate, and the like.
Examples of preferred amidine compounds include p-toluenesulfonate salt of 1, 8-diazabicyclo [5.4.0] undec-7-ene, and the like.
Examples of preferred bisaminophenol compounds include 2, 2-bis (3-amino-4-hydroxyphenyl)) -hexafluoropropane, 2-bis [ 3-amino-4- (N-phenylamino) phenyl ] hexafluoropropane and the like.
In some embodiments, the combination of sulfonamides of formulas I-IV can be with formula Rf[(A)zSO2NR(M1/2)]2Such as described in US5086123 (Guenthner et al), which is incorporated herein by reference.
In some embodiments, the combination of sulfonamides of formulas I-IV may be with a compound of formula Z-Q-Rf-O-(Rfo)Rf-Q-Z, as described in US 5384374, US 5266650(Guerra et al), each of which is incorporated herein by reference.
If an optional second crosslinker is used, the molar ratio of sulfonamide crosslinker of formula I to second crosslinker can be from 5:1 to 1: 1.
The curable composition may further comprise an acid acceptor comprising an organic acid acceptor, an inorganic acid acceptor, or a blend thereof. Examples of inorganic acceptors include magnesium oxide, lead oxide, calcium hydroxide, dibasic lead phosphate, zinc oxide, barium carbonate, strontium hydroxide, calcium carbonate, hydrotalcite, and the like. Organic acceptors include amines, epoxides, sodium stearate, and magnesium oxalate. Particularly suitable acid acceptors include calcium hydroxide, magnesium oxide, and zinc oxide. Blends of acid acceptors may also be used. The amount of acid acceptor will generally depend on the nature of the acid acceptor used.
If the presence of extractable metal compounds is not desired (such as in semiconductor applications), the use of inorganic acid acceptors should be minimized, and preferably these should not be used at all. For example, the hardening composition having a formulation that does not use an inorganic acid acceptor is particularly useful for a sealing material and gasket for manufacturing semiconductor elements, a sealing material that comes into contact with water, hot water, or the like, and a sealing material for high-temperature areas such as automotive applications.
Examples of preferred acid acceptors commonly used include zinc oxide, calcium hydroxide, calcium carbonate, magnesium oxide, hydrotalcite, silicon dioxide (silica), lead oxide, and the like. These compounds are generally used in order to bond to HF and other acids. These acids may be generated at high temperatures encountered during hardening when molding a molded article using the fluoropolymer composition, or at temperatures at which the function of the fluoropolymer, etc., is exhibited.
In one embodiment, at least 0.5 parts, 1 part, 2 parts, 3 parts, or even 4 parts of acid acceptor is used per 100 parts of amorphous fluoropolymer. In one embodiment, no more than 10, 7, or even 5 parts of acid acceptor are used per 100 parts of amorphous fluoropolymer.
The curable composition may also contain an organic compoundCompound, organicThe compound is added to the composition as a phase transfer catalyst to assist in crosslinking the amorphous fluoropolymer, and/or mayFor generating double bonds on the fluoropolymer by dehydrofluorination. Such organic compoundsThe compound comprises quaternary ammonium hydroxide or salt thereof, quaternary phosphoniumHydroxides or salts thereof and ternary sulfonium hydroxides or salts thereof.
In short,
Briefly, sulfonium compounds are sulfur-containing organic compounds in which at least one sulfur atom is covalently bonded by means of a carbon-sulfur covalent bond to three organic moieties having from 1 to 20 carbon atoms and associated with an anion. The organic moieties may be the same or different. The sulfonium compounds may have more than one relatively positive sulfur atom, e.g., [ (C)6H5)2S+(CH2)4S+(C6H5)2]2Cl-And the two carbon-sulfur covalent bonds may be between carbon atoms of the divalent organic moiety, i.e., the sulfur atom may be a heteroatom in a cyclic structure.
A number of organic compounds useful in the present invention are described
Exemplary organic CompoundsThe compound comprises: c3-C6Symmetric tetraalkylammonium salts, asymmetric tetraalkylammonium salts, wherein the total number of alkyl carbons is between 8 and 24; and benzyltrialkylammonium salts in which the total number of alkyl carbons is between 7 and 19, (e.g., tetrabutylammonium bromide, tetrabutylammonium chloride, benzyltributylammonium chloride, benzyltriethylammonium chloride, tetrabutylammonium hydrogen sulfate, and tetrabutylammonium hydroxide, phenyltrimethylammonium chloride, tetrapentylammonium chloride, tetrapropylammonium bromide, tetrahexylammonium chloride, and tetraheptylammonium tetramethylammonium bromide); seasonSalts, such as tetrabutylSalt, tetraphenyl chlorideBenzyl triphenyl chlorideTributylallyl chlorideTributylbenzyl chloride
In one embodiment, organic
In addition to the above components, the fluoropolymer composition may also contain various additives. Examples of the additives include a crosslinking aid and/or a crosslinking promoting aid which are favorably combined with a crosslinking agent and/or a crosslinking promoter used, a filler such as carbon black, spangle, silica, diatomaceous earth, a silicate compound (clay, talc, wollastonite, etc.), calcium carbonate, titanium oxide, precipitated barium sulfate, alumina, mica, iron oxide, chromium oxide, a fluoropolymer filler, etc., a plasticizer, a lubricant (graphite, molybdenum disulfide, etc.), a mold release agent (fatty acid ester, fatty acid amide, fatty acid metal, low molecular weight polyethylene, etc.), a coloring agent (cyanine green, etc.), and a processing aid which is commonly used when compounding a fluoropolymer composition, and the like. However, these additives are preferably sufficiently stable under the intended use conditions.
In addition, carbon black can be used to achieve a balance between fluoropolymer composition properties such as tensile stress, tensile strength, elongation, hardness, abrasion resistance, conductivity, processability, and the like. Preferred examples include MT carbon blacks (medium thermal blacks) with product numbers N-991, N-990, N-908 and N-907; FEF N-550; and large diameter furnace black, etc. If carbon black is used, the amount is preferably about 0.1 parts by mass to about 70 parts by mass (phr), based on 100 parts by mass of the total amount of the polymer containing a fluorinated olefin unit and the additional polymer. This range is particularly preferred for the case where large particle furnace black is used.
The curable amorphous fluoropolymer composition may be prepared as follows: the amorphous fluoropolymer, curative, along with other components (e.g., acid acceptor, hardener, plasticizer, etc.) are mixed in conventional rubber processing equipment,Compound and/or additional additives) to provide a solid mixture, i.e., a solid polymer comprising additional ingredients, also referred to in the art as a "compound. This method of mixing ingredients to produce such solid polymer compositions comprising other ingredients is commonly referred to as "compounding". Such equipment includes rubber mills, internal mixers (e.g., banbury mixers), and mixing extruders. The temperature of the mixture during mixing typically does not rise above about 120 c. During mixing, the components and additives are uniformly distributed throughout the resulting fluorinated polymer "compound" or polymer sheet. The "compound" may then be extruded or pressed into a mold (e.g., a cavity or transfer mold) and subsequently oven cured. In an alternative embodiment, curing may be carried out in an autoclave.
Curing is typically accomplished by heat treating the curable amorphous fluoropolymer composition. Heat treatment is conducted at an effective temperature and for an effective time to produce a cured fluoroelastomer. The optimum conditions can be tested by examining the mechanical and physical properties of the cured fluoroelastomer. Curing is typically carried out at a temperature greater than 120 ℃ or greater than 150 ℃. Typical curing conditions include curing at a temperature between 160 ℃ and 210 ℃ or between 160 ℃ and 190 ℃. Typical cure cycles include 3 to 90 minutes. Curing is preferably carried out under pressure. For example, a pressure of 10 bar to 100 bar may be applied. A post cure cycle may be applied to ensure that the curing process is fully completed. The post-curing may be carried out at a temperature between 170 ℃ and 250 ℃ for a time of 1 to 24 hours.
The partially fluorinated amorphous fluoropolymer in the curable composition has a mooney viscosity determined according to ASTM D1646-06 type a by MV 2000 instrument (available from alpha technologies, Ohio, USA) using a large rotor (ML 1+10) at 121 ℃. Upon curing, using the curatives disclosed herein, the amorphous fluoropolymer becomes an elastomer, becomes a nonflowable fluoropolymer, and has an infinite viscosity (and thus no measurable mooney viscosity).
The above curable compositions may be compounded or mixed in one or more steps, and the mixture may then be processed and shaped, for example, by extrusion (e.g., in the form of a hose or hose liner) or molding (e.g., in the form of an O-ring). The shaped article can then be heated to cure the composition and form a cured elastomeric article.
In some embodiments, the desired amounts of conventional additive adjuvants or ingredients can be added to the uncured composition and intimately blended or compounded by employing any of the usual rubber mixing devices such as a banbury mixer, roll mill, or any other convenient mixing device. The temperature of the mixture on the mill does not typically rise above about 120 c. During milling, the components and adjuvants are uniformly distributed throughout the gum. The curing process typically includes extruding or pressing the compounded mixture into a mold (e.g., a cavity or transfer mold), and subsequent oven curing. The compounded mixture is typically pressed (press cured) at a temperature of from about 95 ℃ to about 230 ℃, preferably from about 150 ℃ to about 205 ℃, for a period of from 1 minute to 15 hours, typically from 5 minutes to 30 minutes. Typically, a pressure of between about 700kPa and about 20,600kPa is applied to the compounded mixture in the mold. The mold may first be coated with a release agent such as silicone oil and pre-baked. The molded vulcanizate is then post-cured (oven cured) typically at a temperature typically between about 150 ℃ and about 315 ℃ for a period of time from about 2 hours to 50 hours or more, depending on the cross-sectional thickness of the article.
The compositions of the present invention are useful in forming seals, O-rings, and gaskets. The cured fluorocarbon elastomer mixture has excellent low temperature flexibility while maintaining the desired physical properties of conventional compounded and cured compositions, such as tensile strength and elongation. Particularly useful articles that can be made from the fluorocarbon elastomer compositions of the present invention are particularly useful as seals, gaskets, and mold parts in automotive, chemical processing, semiconductor, aerospace, and petroleum industry applications, among others.
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