Fluid plasticizers containing fluorinated organic compounds for use in curable fluoropolymer and fluoroelastomer compositions, and methods for improving the processability and low temperature use properties of such compositions - Patents.com

Abstract

Described herein are curable fluorine-containing compositions and fluoroelastomer compositions that incorporate a fluid plasticizer comprising at least one at least partially fluorinated organic compound into the composition, thereby reducing the viscosity of the fluoroelastomer, improving processability, and lowering the minimum use temperature, and that can reduce the viscosity and improve processability of the fluoroelastomer formed from the curable fluorine-containing polymer compared to the fluoroelastomer formed from the same curable fluorine-containing polymer that does not contain at least one at least partially fluorinated organic compound, and / or can achieve a minimum use temperature of the fluoroelastomer formed from the curable fluorine-containing polymer that is lower than the minimum use temperature of the fluoroelastomer formed from the same curable fluorine-containing polymer that does not contain at least one at least partially fluorinated organic compound.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This U.S. non-provisional patent application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 63 / 383,663, filed November 14, 2022, entitled "Fluid Plasticizers Including Fluorinated Organic Compounds for Use in Curable Fluoropolymer Compositions, and Methods for Improving Processability and Low Temperature Use Properties of Such Compositions," the entire disclosure of which is incorporated herein by reference.

[0003] Background of the Invention FIELD OF THE INVENTION The present invention relates to the field of improving the processability and / or low temperature use properties of fluoroelastomer compositions, and in particular to improving the processability and low temperature use of perfluoroelastomer compositions. [Background technology]

[0004] 2. Description of Related Art Each class of elastomer has its own characteristic glass transition value (Tg). If such an elastomer does not have a Tg value as low as desired for a particular end use, compounders may add, for example, processing oils or organic compounds known in the art to lower the Tg. These materials penetrate the elastomer structure, revealing mobile polymer segments, thereby allowing molecular mobility at lower temperatures. However, this technique has proven to have little benefit with fluoroelastomers (a class of polymers known as FKMs under the ASTM rubber system), particularly perfluoroelastomers (known as FFKMs). With such materials, the Tg can rarely be altered by the use of additives such as those useful for other elastomers, and such materials are also known to have processability challenges.

[0005] Attempts have been made to make FKM materials more processable by using additives that can reduce the hardness and / or modulus, potentially resulting in a decrease in the Tg of the FKM by about 1° C. to about 3° C. However, such additives can affect processability or other material properties, including physical or elastomeric properties, associated with the FKM or FFKM.

[0006] Finding a suitable solution for improving processability and adjusting the Tg of FKM / FFKM in fluoroelastomer technology has proven difficult. Previous attempts to use plasticizers known to be useful in other elastomers have not solved this problem for FKM and FFKM, which are typically used in end-use applications involving harsh chemicals or plasma materials with high levels of chemical resistance, and also in high-temperature and / or high-process processing environments. Such end-use applications may also be carried out at temperatures that exceed the useful operating temperatures of other rubber plasticizers.

[0007] One approach used in the art to improve the processing of FFKM involves the addition of various oils, such as mineral oil, vegetable-derived oil, or perfluoropolyether fluids as described in U.S. Patent No. 10,023,722. While such materials are beneficial, they have limited impact on the ability to use FFKM at lower temperatures or modify viscosity for processability. As a result, FKM / FFKM is difficult to process, requiring compounding, extrusion, and then heating in a mold. Thus, to date, there exists a need in the art for improved processability of FKM / FFKM that may further improve the low temperature properties of such materials in more extreme service environments, including when processed at processing temperatures and conditions typically associated with the use of such highly chemically and plasma resistant materials. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] U.S. Patent No. 10,023,722 Summary of the Invention [Means for solving the problem]

[0009] A brief summary of the invention The present invention provides herein a curable fluorine-containing composition comprising a curable fluorine-containing polymer; and at least one fluid plasticizer comprising at least one at least partially fluorinated organic compound, wherein the at least one at least partially fluorinated organic compound is capable of reducing the viscosity and improving the processability of the fluoroelastomer formed from the curable fluorine-containing polymer compared to a fluoroelastomer formed from the same curable fluorine-containing polymer that does not comprise the at least one at least partially fluorinated organic compound; and / or the at least one at least partially fluorinated organic compound is capable of achieving a minimum use temperature of the fluoroelastomer formed from the curable fluorine-containing polymer that is lower than the minimum use temperature of the fluoroelastomer formed from the same curable fluorine-containing polymer that does not comprise the at least one at least partially fluorinated organic compound.

[0010] In one embodiment, the composition further comprises at least one curing agent capable of curing the fluorine-containing polymer. The curable fluorine-containing polymer may be selected from the group consisting of at least partially fluorinated curable fluoropolymers (which can form FKM), perfluorinated curable fluoropolymers (which can form FFKM), at least partially fluorinated curable copolymers of tetrafluoroethylene and propylene (which can form FEPM), or at least partially fluorinated curable silicon-containing polymers (which can form FVMQ).

[0011] In further embodiments, the curable fluorine-containing polymer is a curable perfluorinated polymer (which can form an FFKM). In such embodiments, the curable perfluorinated polymer can be a copolymer of tetrafluoroethylene, a perfluoroalkyl vinyl ether, and at least one cure site monomer, where the at least one cure site monomer has cure sites comprising halogen atoms or nitrile groups.

[0012] Furthermore, in another embodiment, the curable fluorine-containing polymer may be a curable fluoropolymer that is at least partially fluorinated and includes vinylidene fluoride monomers along its backbone. In such an embodiment, the curable fluoropolymer may further include hexafluoropropylene and tetrafluoroethylene as comonomers with vinylidene fluoride.

[0013] The at least one at least partially fluorinated organic compound may be selected from alkoxyfluoroalkanes, alkoxyfluoroalkenes, alkenoxyfluoroalkanes, alkenoxyfluoroalkenes, alkoxyperfluoroalkanes, alkoxyperfluoroalkenes, alkenoxyperfluoroalkanes, alkenoxyperfluoroalkenes, and combinations and mixtures thereof.

[0014] The at least one at least partially fluorinated organic compound is a compound according to formula (A): (R af )(R b ) y -OR c (A) (In the formula, R af may be a fluorinated alkane or alkene group of 4 to 20 carbon atoms, which may be branched or straight chain, and which may contain from about 4 to about 41 fluorine atoms; R b may be an alkane of about 2 to 5 carbon atoms; y may be 0 or 1. When y is 1, R b is R af or at the end of R af Even if it is within the carbon chain of R af may be pendant from the carbon chain of R c may be an alkane or alkene group of 2 to 7 carbon atoms, and may optionally have 1 to about 3 fluorine atoms on the carbon atoms of the alkane or alkene group. may be.

[0015] In one embodiment, R a and R b may have a total of 4 to about 15 carbon atoms. Ra may also be perfluorinated.

[0016] OR c The group is (R af )(R b ) y The OR may have pendant alkoxy or alkenoxy groups on the carbon chain. c may be an alkoxy group having about 2 to about 5 carbon atoms.

[0017] In embodiments herein, the at least one at least partially fluorinated organic compound may be selected from methoxydecafluoroheptane and its isomers; ethoxy-nonafluorobutene ether or ethoxy-nonafluoroisobutyl ether isomers; ethoxy-trifluoromethylhexane and its isomers and derivatives; and mixtures and combinations thereof. In another embodiment, the at least one at least partially fluorinated organic compound may be 3-ethoxy-1,1,1,2,3,4,5,5,6,6,6-dodecafluoromethylhexane.

[0018] The at least one at least partially fluorinated organic compound may be present in the composition in an amount of about 1 to about 20 parts by weight per 100 parts of the at least one curable fluorine-containing polymer, or in an amount of about 3 to about 15 parts by weight per 100 parts of the at least one curable fluorine-containing polymer.

[0019] The composition may further comprise one or more additives or fillers different from the at least one fluid plasticizer comprising at least one at least partially fluorinated organic compound, and the one or more additives or fillers may be present in the composition in an amount of up to about 95 parts by weight per 100 parts of the curable fluorine-containing polymer. In one embodiment, the curable fluorine-containing composition is an additive manufacturing composition for use in printing fluorine-containing elastomeric articles.

[0020] The present invention also includes a cured fluoroelastomer composition comprising an at least partially cured fluoroelastomer; and at least one at least partially fluorinated organic compound in a matrix of the fluoroelastomer, the at least one at least partially fluorinated organic compound incorporated into the matrix of the fluoroelastomer in a fluid plasticizer, wherein the fluoroelastomer in the composition has reduced viscosity and improved processability compared to a fluoroelastomer that is the same as the fluoroelastomer in the composition but does not contain the at least one at least partially fluorinated organic compound; and / or the fluoroelastomer in the composition has a minimum use temperature that is lower than the minimum use temperature of a fluoroelastomer that is the same as the fluoroelastomer in the composition but does not contain the at least one at least partially fluorinated organic compound.

[0021] In one embodiment, the Tg of the fluoroelastomer in the composition, measured in °C, is at least about 30% lower than the Tg of a fluoroelastomer that is the same as the fluoroelastomer in the composition but that does not include the at least one at least partially fluorinated organic compound.

[0022] In a further embodiment, the minimum torque value (ML) of the fluoroelastomer in the composition, measured in pounds-inches, is at least about 50% less than the minimum torque value of a fluoroelastomer that is the same as the fluoroelastomer in the composition but does not include the at least one at least partially fluorinated organic compound.

[0023] The fluoroelastomer in the composition may be selected from cured at least partially fluorinated elastomers, cured perfluoroelastomers, cured at least partially fluorinated tetrafluoroethylene-propylene fluoroelastomers, and cured at least partially fluorinated fluorosilicones. The fluoroelastomer in the composition may also be a perfluoroelastomer.

[0024] The at least one at least partially fluorinated organic compound in the composition may be selected from alkoxyfluoroalkanes, alkoxyfluoroalkenes, alkenoxyfluoroalkanes, alkenoxyfluoroalkenes, alkoxyperfluoroalkanes, alkoxyperfluoroalkenes, alkenoxyperfluoroalkanes, alkenoxyperfluoroalkenes, and combinations and mixtures thereof.

[0025] In another embodiment of the fluoroelastomer composition, the at least one at least partially fluorinated organic compound is a compound according to formula (A): (R af )(R b ) y -OR c (A) (In the formula, R af R may be a fluorinated alkane or alkene group of 4 to 20 carbon atoms, the fluorinated alkane or alkene group may be branched or straight chain, and the fluorinated alkane or alkene group may contain from about 4 to about 41 fluorine atoms. b may be an alkane of about 2 to 5 carbon atoms; y may be 0 or 1. When y is 1, R b is R af or at the end of R af or in the carbon chain of R af R c may be an alkane or alkene group of 2 to 7 carbon atoms, optionally having 1 to about 3 fluorine atoms on the carbon atoms of the alkane or alkene group. may be.

[0026] In one embodiment, R a and R b R has a total of 4 to about 15 carbon atoms. a may be perfluorinated. OR c The group is (R af )(R b ) y The OR may have pendant alkoxy or alkenoxy groups on the carbon chain. c may be an alkoxy group having about 2 to about 5 carbon atoms.

[0027] In another embodiment, the at least one at least partially fluorinated organic compound may be selected from methoxydecafluoroheptane and its isomers; ethoxy-nonafluorobutene ether or ethoxy-nonafluoroisobutyl ether isomers; ethoxy-trifluoromethylhexane and its isomers and derivatives; and mixtures and combinations thereof. In another embodiment, the at least one at least partially fluorinated organic compound is 3-ethoxy-1,1,1,2,3,4,5,5,6,6,6-dodecafluoromethylhexane.

[0028] In still further embodiments, the at least one at least partially fluorinated organic compound may be present in the fluoroelastomer composition in an amount of from about 1 to about 20 parts by weight per 100 parts of fluoroelastomer. The at least one at least partially fluorinated organic compound may be present in the fluoroelastomer composition in an amount of from about 3 to about 15 parts by weight per 100 parts of fluoroelastomer.

[0029] The fluoroelastomer composition may further comprise one or more additives or fillers different from the at least one at least partially fluorinated organic compound, the one or more additives or fillers being present in the composition in an amount of up to about 95 parts by weight per 100 parts of fluoroelastomer.

[0030] The present invention also includes a method for improving the viscosity and processability of a fluoroelastomer by providing the matrix of the fluoroelastomer with at least one at least partially fluorinated organic compound, wherein the at least one at least partially fluorinated organic compound is at least partially incorporated into the matrix of the fluoroelastomer in a fluid plasticizer.

[0031] In the method, before curing the curable fluorine-containing polymer composition to form the fluoroelastomer, at least one at least partially fluorinated organic compound may be provided to the fluoroelastomer by incorporating a fluid plasticizer into the composition comprising the curable fluorine-containing polymer. In one embodiment, the method may further include introducing the composition into an additive manufacturing process before curing the curable fluorine-containing polymer composition to form the fluoroelastomer.

[0032] Additionally, the at least one at least partially fluorinated organic compound may be provided to the curable fluorine-containing polymer in an amount of about 1 to about 20 parts by weight per 100 parts by weight of the curable fluorine-containing polymer.

[0033] The present invention further includes a method for reducing the minimum use temperature of a fluoroelastomer by providing at least one at least partially fluorinated organic compound in the matrix of the fluoroelastomer, wherein the at least one at least partially fluorinated organic compound is at least partially incorporated into the matrix of the fluoroelastomer in a fluid plasticizer. In the method, the Tg of the fluoroelastomer is also reduced by the at least one at least partially fluorinated organic compound. In a further embodiment of the method, the at least one at least partially fluorinated organic compound may be provided to the fluoroelastomer by incorporating a fluid plasticizer into a composition comprising a curable fluorine-containing polymer before curing the curable fluorine-containing polymer composition to form the fluoroelastomer.

[0034] The present invention further includes a method for reducing the viscosity and improving the processability of a composition comprising a first curable fluorine-containing polymer having a Mooney viscosity (ML 1+10 @ 121°C) of about 30 to about 160, or a molded article formed from the composition, comprising incorporating into the composition at least one second curable fluorine-containing polymer having a Mooney viscosity (ML 1+10 @ 121°C) of about 10 to about 45, wherein the Mooney viscosity of the second curable fluorine-containing polymer is selected to be lower than the Mooney viscosity of the first curable fluorine-containing polymer. One or more plasticizers may be incorporated into the composition, and the composition may be introduced into an additive manufacturing process.

[0035] In one embodiment, the first fluorine-containing polymer and the second fluorine-containing polymer may be blended, alloyed, or copolymerized. The composition may further include at least one fluid plasticizer having at least one at least partially fluorinated organic compound described above, and the composition may be introduced into an additive manufacturing process. One or more additional plasticizers different from the at least one fluid plasticizer may be used in such an embodiment.

[0036] A brief description of some of the figures of the drawing The foregoing summary of the invention and the following detailed description of the preferred embodiments will be better understood when read in conjunction with the accompanying drawings. For the purpose of illustration, there is shown in the drawings an embodiment which is presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. [Brief explanation of the drawings]

[0037] [Figure 1] FIG. 1 is a graphical representation of the thermogravimetric analysis (TGA) of control Sample A of Examples 1 and 3, and inventive Samples A1, A2, and A3.

[0038] [Figure 2]FIG. 2 is a graphical representation of the differential scanning calorimetry analysis of Control Sample A of Examples 1 and 3, and Inventive Samples A1, A2, and A3.

[0039] [Figure 3] FIG. 3 is a graphical representation of low temperature O-ring leakage testing of control samples A, B, and C of Examples 1 and 2, and inventive samples A1, A2, and A3, and B1, B2, and B3, and C1, C2, and C3.

[0040] [Figure 4] FIG. 4 is a graphical representation of the RPA analysis of sample compounds 1, 3, 6 and 8 of Example 4 showing the increase in torque (ML) measured in dN-m over time at 100° C.

[0041] [Figure 5] FIG. 5 is a graphical representation of the ML and post-print shrinkage (%) at 100° C. for each of Compounds 1, 3, 6 and 8 of Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0042] Detailed Description of the Invention The present invention provides herein a method for improving the processability of fluorine-containing curable polymers to form elastomers and curable compositions, as well as the resulting elastomers with enhanced processability. The elastomers formed from the fluorine-containing curable polymers are preferably fluoroelastomers, which may be various types of perfluorinated or at least partially fluorinated elastomers. In one embodiment, the present invention includes compositions containing such fluoroelastomers with improved processability, as well as novel fluorinated organic compounds that act as plasticizers for the curable fluoropolymers in the curable fluoropolymer compositions and / or the resulting cured fluoroelastomers, in some embodiments as high-performance plasticizers. Such plasticizers, which comprise at least partially or fully fluorinated organic compounds, can be used to substantially improve processability, enabling these materials to be processed using more traditional thermal processing techniques, such as injection molding, and to enhance the ability to incorporate fluoroelastomers into three-dimensional printing applications.

[0043] To date, attempts to develop 3D printed parts made from fluoroelastomers have been difficult due to the processability issues inherent in such curable fluoropolymer materials and the resulting cured elastomers. Efforts have focused on modifying 3D printing equipment to facilitate extrusion by controlling the timing and cure cycle, adding conventional processing aids, and / or modifying printhead design or conditions. The present invention instead provides an improvement by substantially increasing the processability of the curable fluoropolymer itself and the resulting elastomer, making 3D printing easier.

[0044] In another embodiment, the processability of curable fluoropolymers for three-dimensional printing is improved by the use of curable fluoropolymers that are blended to reduce the Mooney viscosity of the curable fluoropolymer for printing.

[0045] In addition to enhancing the processability of curable fluoropolymer compositions, the present invention further demonstrates a method for improving the low-temperature use of fluoroelastomers formed from such compositions by modifying the Tg of the fluoroelastomer.Thus, the present invention provides a composition and a fluoroelastomer obtained after curing at a reduced low-temperature processing range that is significantly lower than that currently achieved using the same curable fluoropolymer but without the fluid plasticizer described herein, comprising at least one fluorinated organic compound, that exhibits a high level of chemical and plasma resistance without substantially affecting the beneficial properties associated with the use of the resulting fluoroelastomer and the articles formed therefrom, which are known.

[0046] Improvements may be realized both before and / or after curing of the elastomer and may be indicated by a decrease in viscosity, a decrease in Tg, a decrease in hardness, and / or an average decrease in TR10 value of the elastomer. Addition of a fluid plasticizer, such as the plasticizers described herein, to an at least partially cured elastomer after curing, such as by immersion in a liquid plasticizer, may also be realized. The fluid plasticizers herein, including at least partially fluorinated organic compounds used herein, offer significant advantages and act as plasticizers for fluoroelastomer materials, in preferred embodiments, as high performance plasticizers for fluoroelastomer materials.

[0047] In embodiments herein, the compositions comprise at least one fluid plasticizer comprising at least one at least partially fluorinated organic compound and are in the form of specialty or formulated fluids, a class of fluids typically used as heat transfer fluids or as replacements for chlorofluorocarbons because they have lower ozone depletion potential (ODP) and lower global warming potential (DWP). Such fluids are used as solvents for various materials in heat transfer applications.

[0048] In evaluating such fluids for other end uses, applicants have unexpectedly discovered that such fluorinated organic compounds can not only reduce the viscosity of fluoroelastomers, but also substantially improve their processability, as well as enhance the low temperature processing temperature range of the fluoroelastomers. Such specialty fluids and tailored heat transfer fluids are therefore useful in the invention herein.

[0049] Preferred specialty or tailored fluids are fluid compounds (in this case, they are predominantly liquid fluids) that contain one or more at least partially fluorinated organic compounds that can reduce the viscosity and improve the processability of the fluoroelastomers described herein and / or reduce the useful use temperature of the fluoroelastomers by lowering their Tg.

[0050] In one embodiment of the present disclosure, at least partially fluorinated organic compounds are provided in fluid form to act as fluid plasticizers. They may be the only compounds in the fluid plasticizer, or the fluid plasticizer may incorporate one or more of the at least partially fluorinated organic compounds and / or other additives. The at least partially fluorinated organic compounds are selected from alkoxyfluoroalkanes, alkoxyfluoroalkenes, alkenoxyfluoroalkanes, alkenoxyfluoroalkenes, alkoxyperfluoroalkanes, alkoxyperfluoroalkenes, alkenoxyperfluoroalkanes, alkenoxyperfluoroalkenes, and combinations and mixtures thereof.

[0051] In other embodiments herein, preferred fluorinated organic compounds have one or more functional groups thereon, such as alkoxy groups, for example, those of formula (A): (R af )(R b ) y -OR c (A) (In the formula, R afis a fluorinated alkane group of 4 to 20 carbon atoms which may be branched or straight chain and which may contain from about 4 to about 41 fluorine atoms; R b is an alkane of about 2 to 5 carbon atoms. In formula (A), y can be 0 or 1. When y is 1, R b is R af or either end or both ends of the backbone or R af It is a pendant from the branched R af It may be incorporated into the chain. R c is an alkane or alkene group of 2 to 7 carbon atoms, optionally containing 1 to about 3 fluorine atoms on the carbon atoms. af and R b are a total of about 4 to about 15 carbon atoms in the chain, which may be straight or branched, each mostly fluorinated and, in some embodiments, perfluorinated. OR c The group is (R a f)(R b ) y or may be attached to the backbone as a pendant alkoxy or alkenoxy group. c The group is an alkoxy group of about 2 to about 5 carbon atoms in length. The alkoxy group may be non-fluorinated or partially fluorinated, although in some embodiments herein, it is preferred that the alkoxy group is non-fluorinated. Optionally, an at least partially fluorinated alkene is present in the backbone (R a f)(R b ) y and / or the alkenoxy group may be used in OR c (R af )(R b ) yHowever, in some embodiments herein, unsaturated bonds are not preferred to avoid possible interference with the reaction with functional groups involved in the curing of the curable fluoropolymer in the composition.

[0052] The at least partially fluorinated organic compounds in the fluid plasticizers herein, which act as plasticizers for the fluoroelastomers formed therefrom, including those described above in Formula (A), are preferably provided as fluid plasticizers having a liquid density of about 1.4 to about 2.0 g / ml and a wide liquid use range, from a low freezing point of about -150°C to a boiling point of about 275°C. Furthermore, such fluid plasticizers preferably have an absolute viscosity of about 0.40 cP to about 4.7 cP, preferably about 0.6 cP to about 2.0 cP. While the molecular weight of such materials can vary depending on the at least partially fluorinated organic compound in the fluid plasticizer, the fluorinated compounds preferably have an atomic molecular weight of about 150 g / mol to about 600 g / mol, more preferably about 200 g / mol to about 540 g / mol.

[0053] As used herein, it is preferred that the fluid plasticizer at least partially, substantially, or completely penetrates the curable fluoropolymer, soaking into the polymer structure, and upon curing or thermoforming, the plasticizer fluid can be substantially or completely baked out of the formed article.

[0054] Additional functional groups that facilitate fluid penetration into the curable fluoropolymer are optional and can be incorporated into the at least partially fluorinated organic compound structure, if desired, to tailor the final properties of the final product, for example, to increase the consistency of the blend or to compatibilize the blend materials, using standard functionalization techniques known or to be developed in the curing, blending and / or compatibilization arts.

[0055] Examples of suitable fluorinated organic compounds for use in the fluid plasticizers herein are specialty fluids and conditioned liquid heating fluids that are at least partially fluorinated organic compounds including methoxydecafluoroheptane and its isomers; ethoxy-nonafluorobutene ether and ethoxy-nonafluoroisobutyl ether isomers; ethoxy-trifluoromethylhexane, including 3-ethoxy-1,1,1,2,3,4,5,5,6,6,6-dodecafluoromethylhexane, and similar compounds, and mixtures and combinations thereof.

[0056] Fluids containing the preferred fluorinated organic compounds herein that are commercially available and useful in the compositions and methods herein include, for example, 3M Fluorinated Organic Compounds from Minnesota, Mining and Manufacturing Corporation. TM Heat transfer fluids include commercially available ones such as Novec TM 700, 7100, 7200, 7300, 7500 and 7700, as well as 649 and 774, with the preferred material being Novec TM 7200, 7300, 7500 and 7700, and also Fluorinert TM These include FC-3284, FC-72, FC-77, FC-84, FC-770, FC-3283, FC-40, and FC-43, with FC-84, FC-770, and FC-3283 being preferred. Others are available from Solvay Corporation as Galden® HT heat transfer fluids HT270, HT230, HT200, HT170, HT135, HT110, HT80, HT70, and HT55, with HT55 through HT135 being preferred. Also available are Opteon® HT from Chemours. TM and Vertrel TM are also available and useful herein, and Opteon TM The SF-10 is preferred.

[0057] Fluid plasticizers comprising one or more of the at least partially fluorinated fluid organic compounds herein may be added to the compositions described together with the curable fluoropolymer and any additives either before, during, or after the curing of the curable polymer, i.e., they may also be added to the cured fluoroelastomer by immersing or dipping the at least partially, substantially, or fully cured fluoroelastomer. The addition of a fluid plasticizer before or during curing provides the benefit of improved processability. However, the other benefits of the present invention mentioned herein may be realized either before, during, and / or after the curing of the curable fluoropolymer.

[0058] The fluid plasticizer having an at least partially fluorinated organic compound is preferably added to the compositions herein after at least partial curing to provide from about 1 to about 20 parts by weight, preferably from about 3 to about 15 parts by weight, of the at least partially fluorinated organic compound per 100 parts by weight of the curable fluoropolymer or fluoroelastomer. In either case, the uncured or cured fluoroelastomer may be formed and / or subjected to thermoforming or other heat treatment, and the at least partially fluorinated organic compound may preferably be baked out and removed from the elastomeric article during or after processing.

[0059] The compositions described herein comprise one or more curable fluoropolymers, which may be one or more at least partially fluorinated curable polymers, including partially fluorinated fluoropolymers and fully fluorinated perfluoropolymers. Such materials may be cured using one or more of the various curing agents described further below to form cured fluoroelastomer materials and articles, including perfluoroelastomer materials and articles, or such curing agents may not be included in the compositions herein if the curable polymer is curable by radiation.

[0060] Initially, in the composition herein, the curable fluoropolymer, such as the curable perfluoropolymer, is in an uncured state. The fluid plasticizer is preferably incorporated into the uncured polymer before the initiation of crosslinking of the polymer or before any substantial crosslinking of the polymer in order to better incorporate the plasticizer into the polymer matrix. If rheological properties such as material flow are important in the intended final application of the resulting elastomer, for example, three-dimensional printing, it is preferable to incorporate the plasticizer into the uncured polymer before crosslinking. In such final applications, it is also important to incorporate the plasticizer into the at least partially fluorinated polymer before subjecting it to a flow process, such as before any three-dimensional printing.

[0061] The curable fluoropolymers herein may be any suitable curable fluoropolymer, including compositions that, when cured, may be used in other end uses, including those used in harsh environments such as those encountered in oil field industrial use, petrochemical processing, or semiconductor manufacturing, medical, electronics, and clean environments, and / or may also include those used to form coatings or other elastomeric articles.

[0062] An elastomeric material (e.g., a cured or crosslinked fluoropolymer herein) is elastomeric because it can be compressed and substantially retain its original shape. As used herein, "compression set" refers to the tendency of an elastomeric material to remain distorted and not return to its original shape after a deforming compressive load is removed. The compression set value is expressed as the percentage of the original deflection that the material cannot recover. For example, a compression set value of 0% indicates that the material completely returns to its original shape after the deforming compressive load is removed. Conversely, a compression set value of 100% indicates that the material does not recover at all from the applied deforming compressive load. A compression set value of 30% indicates that 70% of the original deflection has been recovered. A higher compression set value generally indicates the potential for seal leakage.

[0063] The curable fluoropolymers used herein can have varying degrees of fluorination. They may be radiation crosslinkable, but are preferably crosslinkable (curable) by a cure system in which a curing agent is added that is capable of reacting with the functional groups of the cure site monomers to form an elastomeric material.

[0064] Curable fluoropolymer materials in embodiments herein include those classified by the standard rubber family definitions provided by ASTM International in ASTM Standard D1418-22, which includes FKM, FFKM, FEPM, and FVMQ curable polymers.

[0065] Standard FKM and FEPM polymers from such elastomer systems typically have at least two monomers, one of which is fluorinated, and in the case of FKM, preferably all of the monomers are fluorinated to some extent. Such polymers also preferably have at least one cure site monomer for use in vulcanization.

[0066] In the case of FEPM polymers, at least one monomer is a fluorinated olefin, such as tetrafluoroethylene, and the other monomer is at least one non-fluorinated olefin, such as propylene, which has a reactive hydrogen-containing group as the reactive group of the polymer so that propylene can be the cure site monomer. Such materials are commercially available, for example, from Asahi Glass under the trademark Aflas®.

[0067] In most FKMs, the at least two comonomers forming the polymer chain preferably include vinylidene fluoride and hexafluoropropylene or similar fluorinated olefins, but may also include a variety of other monomers, all known in the art or to be developed. The fluoroelastomer composition may also include at least one curing agent capable of undergoing a crosslinking reaction with the functional groups in the cure site or comonomer of the curable fluoropolymer used to form the fluoroelastomer.

[0068] With respect to the FKM and FEPM materials herein, the polymer may contain one or more cure site monomers, or may contain only one cure site monomer. When more than one cure site monomer is present, each may have the same or different cure sites. The terms "uncured" or "curable" refer to fluoropolymers for use in the compositions herein that have not yet been subjected to any substantial degree of crosslinking reaction, such that the material is not yet sufficiently cured for its intended end application.

[0069] Each cure site is curable by a curative (also known as a crosslinker or curing agent). Such cure site monomers may contain, for example, halogenated materials such as Br or I in the cure site functional groups, and may contain functional groups that can be cured using a peroxide cure system. By "peroxide cure system" we mean a peroxide curative and any associated co-curatives that act to form crosslinks that cure the curable polymer to form an elastomer or vulcanizate. Such systems are known in the art.

[0070] While at least two of the monomers in an FKM may be hexafluoropropylene (HFP) and vinylidene fluoride (VF2), other typical monomers may be used in addition to these two to form various fluoropolymers known in the art, and the cure site monomers and cure systems may vary.

[0071] In addition to at least one curing agent, if desired, co-curing agents and / or curing accelerators may be present in compositions containing such curable fluoropolymers, where indicated. The compositions herein may contain a single curable fluoropolymer or a combination of at least two curable fluoropolymers, for example, in the form of a polymer blend, graft composition, or alloy, depending on the desired final properties. Curable fluoropolymers for use in the compositions herein may optionally contain additional such polymers in blend-like or graft / copolymer compositions. Furthermore, the polymer backbone may contain various types of cure site monomers along the chain to provide one or more different functional groups for crosslinking. In embodiments herein, one of such groups may be curable by a curing agent, such as, for example, a peroxide cure system or a nitrile-containing curative. The compositions may also contain curing agents and co-curing agents and / or accelerators to assist the crosslinking reaction, as used in the art to cure such fluoroelastomers.

[0072] Other cure sites and cure systems may be provided with the same or different cure site monomers. For example, a cure site may be provided that reacts with a bisphenyl-based cure system to create crosslinks; for example, a cure site with a nitrogen-containing reactive group may be used. Such a cure site may be the sole cure site of the curable polymer, or the curable polymer may also or instead have peroxide-curable functional groups, such as the halogen-functional cure sites described above.

[0073] Various curing agents (also referred to herein as crosslinkers or curing agents) are referred to herein and may be used with a wide variety of curable fluoropolymers depending on their reactive cure sites as is known in the art.

[0074] The fluoroelastomer compositions described herein may preferably comprise any suitable standard curable fluoroelastomer fluoropolymer (FKM) that can be cured to form a fluoroelastomer using the cure system described herein and one or more other curing agents. Examples of suitable curable FKM fluoropolymers include those sold under the trade name Tecnoflon® PL958 by Solvay Solexis, SpA, Italy, or other similar fluoropolymers that, when used in the compositions herein, are preferably curable by a peroxide cure system. Other sources of such materials include, among others, Daikin Industries, Japan; 3M Corporation, Minnesota; and EI DuPont de Nemours & Company, Inc., Delaware. Such FKM polymers are not fully fluorinated in the polymer backbone.

[0075] One or more curable fluoropolymers may be present in such compositions. Such polymers are themselves formed by polymerizing or copolymerizing one or more fluorinated monomers. Various techniques known in the art (direct polymerization, emulsion polymerization, and / or free radical initiated polymerization, latex polymerization, etc.) can be used to form such polymers. Each such curable fluoropolymer, when used in a blend or combination, may have the same cure site thereon or different cure sites thereon. When different cure sites of different polymers are used in a blend, the curing agent that reacts to cure such cure sites should be selected to crosslink the curable fluoropolymer in order to crosslink the polymers used.

[0076] The fluoropolymers herein may be formed by polymerizing two or more monomers, one of which is at least partially fluorinated, although equally, all or some of the monomers may be fully fluorinated (perfluorinated) monomers. For example, hexafluoropropylene (HFP) and vinylidene fluoride (VF2) may be combined with tetrafluoroethylene (TFE) or one or more perfluoroalkyl vinyl ethers (PAVE), or similar monomers, along with at least one monomer that is a cure site monomer that enables curing, i.e., at least one fluoropolymeric cure site monomer.

[0077] In a preferred embodiment of the present invention, at least one curable fluoropolymer is a curable perfluoropolymer that can be used to form perfluoroelastomers, particularly for end applications that require performance in harsh environments such as chemical or plasma environments, oil well environments, and clean manufacturing.The compositions of the present invention, whether curable fluoropolymer compositions or perfluoropolymer compositions, can be used and / or cured to form a single fluoro- or perfluoroelastomer, or when two or more are used, can contain only one fluoro- or perfluoropolymer, or two or more of such fluoro- or perfluoropolymers in the composition to form a perfluoroelastomer blend composition.Additional curable fluoropolymers can be blended with the curable perfluoropolymer to create a partially fluorinated blended fluoroelastomer.

[0078] As used in this application, "perfluoroelastomer" or "cured perfluoroelastomer," unless otherwise indicated, includes any cured fluoroelastomer material or composition formed by curing a curable perfluoropolymer, for example, a curable fluoropolymer that is a preferred curable perfluoropolymer in the curable compositions described further herein.

[0079] "Curable perfluoropolymers" (sometimes referred to in the art as "perfluoroelastomers" or more appropriately "perfluoroelastomer gums") suitable for use in forming cured perfluoroelastomers are polymers that are substantially fully fluorinated, preferably fully perfluorinated in their polymer backbones. Based on this disclosure, it is understood that some residual hydrogen may be present in some perfluoroelastomers within the crosslinks of those materials due to the use of hydrogen as part of the functional crosslinking groups. The cured material, e.g., perfluoroelastomer, is a crosslinked polymer structure.

[0080] Two or more curable fluoro- or perfluoropolymers, and preferably at least one optional curing agent (curing agent), may be combined in a composition herein, which is then cured to form the resulting crosslinked cured fluoroelastomer composition, and preferably the perfluoroelastomer composition described herein.

[0081] As used herein, when the curable fluorine-containing elastomer composition is a perfluoropolymer composition curable with FKMS, the curable perfluoropolymer may be a blended or combined composition formed from two or more such curable polymers. The curable perfluoropolymer used in the perfluoroelastomer composition herein to form a cured perfluoroelastomer upon curing is formed by polymerizing one or more perfluorinated monomers, more preferably two or more perfluorinated monomers. One of such perfluorinated monomers is preferably a perfluorinated cure site monomer having a cure site as described above, i.e., a functional group that enables curing. The functional group may be or contain a reactive group that may or may not be perfluorinated, and if not fully fluorinated, such reactive group is preferably present in a polymer portion that is not in the polymer backbone.

[0082] Such curable perfluoropolymer materials are also commonly referred to as FFKM in accordance with the standardized rubber definition of the American Standard Test Methods (ASTM) and as described herein above in ASTM standard D1418-22, which in relevant part is incorporated herein by reference.

[0083] As described herein, the present invention includes curable fluorine-containing polymers and compositions comprising such fluorine-containing polymers, which may be curable perfluoroelastomers. The present invention also includes cured compositions herein and molded or otherwise formed articles from such compositions, which, due to the inclusion of the plasticizers herein, have improved processability and lower glass transition temperatures for low temperature end applications.

[0084] When curable perfluoropolymer is used in the composition of the present invention, preferably there is at least one, but may be two or more curable perfluoropolymers, preferably perfluoro-copolymers.For curable perfluoropolymer, at least one monomer is preferably TFE, which may be present in various amounts.In the blend of two or more curable perfluoropolymers, one perfluoropolymer may have a higher content of tetrafluoroethylene (TFE) compared to the other.

[0085] In addition to TFE, other suitable comonomers in perfluorinated polymers may include other ethylenically unsaturated fluoromonomers, such as HFP or other perfluorinated olefin monomers and / or one or more perfluoroalkyl vinyl ethers (PAVEs), which contain alkyl or alkoxy groups that may be linear or branched, and may also contain ether bonds.Preferred PAVEs for use herein include, for example, perfluoromethyl vinyl ether (PMVE), perfluoroethyl vinyl ether (PEVE), perfluoropropyl vinyl ether (PPVE), perfluoromethoxy vinyl ether, and other similar compounds, and particularly preferred PAVEs are PMVE, PEVE, and PPVE.PAVEs may be used alone or in combination with the PAVE types within the scope of the curable perfluoropolymers described above.

[0086] Suitable preferred perfluoropolymers are copolymers of TFE, at least one PAVE, and at least one perfluorinated cure site monomer that incorporates cure sites or functional groups that allow for crosslinking of the curable polymer.

[0087] The cure site monomers in such curable perfluoropolymers may be of the various types described herein. Preferred cure sites may include those with nitrogen-containing groups, carboxyl groups, alkylcarbonyl groups, or halogenated groups, for example, with iodine or bromine, as well as other cure sites known in the art that may also be used. More than one type of cure site monomer may be present in a given curable perfluoropolymer. In a blend of different perfluoropolymers, each may have the same cure site monomer or different cure site monomers.

[0088] The present disclosure herein provides fluoropolymers, including perfluoropolymers, that are curable by radiation or by using one or more of a variety of preferred curing agents (also referred to herein as crosslinking agents, curing agents) that are capable of curing cure sites provided in the curable fluoropolymers and / or perfluoropolymers herein.

[0089] Listed below are exemplary cure site monomers for use in the curable fluoropolymers or curable perfluoropolymers described herein for use in the compositions herein, most of which are PAVE-based structures and have reactive sites.These monomers are merely examples and are not intended to be limiting.Polymers can be various, but examples of structures that can be used include the following structure (A): CF2=CFO(CF2CF(CF3)O) m (CF2) n -X 1 (A) (wherein m may be 0, or m and n may be various integers from 1 to 5). 1 may be a nitrogen-containing group, such as nitrile or cyano. However, a carboxyl group, an alkoxycarbonyl group, or a halogenated end group may also be X 1 It may also be used as

[0090] The compounds according to formula (A) may be used alone or in various optional combinations thereof.

[0091] Further examples of cure site monomers according to formula (A) include the following formulas (1)-(17): CY2=CY(CF2) n -X 2 (1) (wherein Y is H or F, and n is an integer from 1 to about 8). CF2=CFCF2R f 2 -X 2 (2) (In the formula, R f 2 is (-CF2) n -, -(OCF2) n -, and n is 0 or an integer from 1 to about 5. CF2=CFCF2(OCF(CF3)CF2) m (OCH2CF2CF2) n OCH2CF2-X 2 (3) (wherein m is 0 or an integer of 1 to about 5, and n is 0 or an integer of 1 to about 5). CF2=CFCF2(OCH2CF2CF2) m (OCF(CF3)CF2) n OCF(CF2)-X 2 (4) (wherein m is 0 or an integer of 1 to about 5, and n is 0 or an integer of 1 to about 5). CF2=CF(OCF2CF(CF3)) m O(CF2) n -X 2 (5) (wherein m is 0 or an integer of 1 to about 5, and n is an integer of 1 to about 8). CF2=CF(OCF2CF(CF3)) m -X 2 (6) (wherein m is an integer of 1 to about 5) CF2=CFOCF2(CF(CF3)OCF2) n CF(-X2 )CF3(7) (wherein n is an integer from 1 to about 4) CF2=CFO(CF2) n OCF(CF3)-X 2 (8) (wherein n is an integer of 2 to about 5) CF2=CFO(CF2) n -(C6H4)-X 2 (9) (wherein n is an integer from 1 to about 6) CF2=CF(OCF2CF(CF3)) n OCF2CF(CF3)-X 2 (10) (wherein n is an integer of 1 to about 2) CH2=CFCF2O(CF(CF3)CF2O) n CF(CF3)-X 2 (11) (wherein n is 0 or an integer from 1 to about 5) CF2=CFO(CF2CF(CF3)O) m (CF2) n =X 2 (12) (wherein m is 0 or an integer of 1 to about 4, and n is an integer of 1 to about 5). CH2=CFCF2OCF(CF3)OCF(CF3)-X 2 (13) CH2=CFCF2OCH2CF2-X 2 (14) CF2=CFO(CF2CF(CF3)O) m CF2CF(CF3)-X 2 (15) (wherein m is an integer greater than 0) CF2=CFOCF(CF3)CF2O(CF2) n -X 2 (16) wherein n is an integer of at least 1. CF2=CFOCF2OCF2CF(CF3))OCF2-X 2 (17) (In the formula, X 2may be a monomeric reactive site subunit, such as a nitrile (-CN), a carboxyl (-COOH), an alkoxycarbonyl group (-COOR, where R is an alkyl group of 1 to about 10 carbon atoms, which may be fluorinated or perfluorinated), a halogen or alkylated halogen group (I or Br, CHI, etc.).

[0092] In the curable perfluoropolymers for use in the compositions herein, TFE may be present as a comonomer in a mole percentage of about 40 to about 95 mole percent in the perfluoropolymer compound. Other comonomers, many of which are known in the art, such as perfluorinated PAVE monomers, may also be used herein. The various PAVEs described above may be used in the curable polymers for use in the compositions herein and may be incorporated with TFE in a mole percentage of about 5 to 60 mole percent in the perfluoropolymer compound. Each cure site monomer may be present in an amount of about 0.1 to about 6 mole percent, although if more than one is used, they may be present in a total amount of up to about 10 mole percent. Optionally, each cure site monomer may be present in an amount of about 0.2 to 5.0 mole percent, or 0.5 to about 2.0 mole percent.

[0093] Suitable perfluoropolymers are commercially available from Daikin Industries, Ltd. and are described in U.S. Patent Nos. 6,518,366 and 6,878,778, and U.S. Patent Application Publication No. 2008-0287627, each of which is incorporated herein in relevant part with respect to the perfluoropolymers described therein.Another perfluoropolymer for use in preferred embodiments herein is the commercially available perfluoroelastomer known as PFK-65 or PFK-100, as well as those that comprise at least two cure site monomers, as described in International Publication No. WO00 / 29479A1, which is incorporated herein in relevant part with respect to such perfluoroelastomers.

[0094] In some embodiments herein, there may be two curable fluoropolymers in the blend, such as those described above, which may be used with a second curable fluoropolymer or curable perfluoropolymer used herein that may be the same or different from those described above, and such second curable polymer may, but need not, have the same content of TFE or PAVE.

[0095] In one embodiment, perfluoropolymers can be used in fluoroplastic materials, such as fluoroplastics. Fluoroplastic particles can be provided in a variety of forms and using a variety of techniques. Fluoroplastics, such as PTFE, and their copolymers (FEP and PFA type polymers), core-shell, or other modified fluoropolymers, in a variety of sizes (microparticles, nanoparticles, etc.), each alone or in combination, can be incorporated into the material by mechanical means or chemical processing and / or polymerization. Known or to-be-developed techniques, such as those described in U.S. Pat. Nos. 4,713,418 and 7,476,711 (each of which is incorporated herein by reference for such techniques), and other techniques, such as those described in U.S. Pat. No. 7,019,083, also incorporated herein by reference for the use of fluoroplastic particles, can be used. Suitable commercially available polymers are available from 3M Corporation, St. Paul, Minnesota.

[0096] Examples of other perfluoropolymers and the resulting elastomers formed therefrom using cure site monomers such as those described above can be found in U.S. Pat. Nos. 6,518,366, 6,878,778, and U.S. Patent Application Publication No. 2008-0287627, and U.S. Pat. No. 7,019,083, each of which is incorporated herein in relevant part with respect to the perfluoropolymers described therein, as well as the resulting elastomers and methods of forming the same.

[0097] Uncured perfluoropolymers are also available under the name Dyneon®, marketed by 3M Corporation, St. Paul, Minnesota. TM The perfluoropolymer may be one of those available from Daikin Industries, Ltd., Osaka, Japan, under the name Daiel-Perfluor®, and other similar polymers. Other suitable materials are also available from Solvay Solexis, Italy, Asahi Glass, Japan, and W.L. Gore. Other examples of suitable perfluoropolymers and blends thereof can be found, for example, in U.S. Pat. Nos. 9,018,309 and 9,365,712, which are incorporated herein by reference with respect to suitable perfluoropolymers and blends thereof.

[0098] Perfluoropolymers for use in the compositions claimed herein may be synthesized using any known or to be developed polymerization technique for forming fluorine-containing elastomers using polymerization, including, for example, emulsion polymerization, latex polymerization, chain-initiated polymerization, batch polymerization, etc. Preferably, the polymerization is carried out so that reactive cure sites are located at either one or both ends of the polymer backbone and / or pendant from the main polymer backbone.

[0099] The uncured perfluoropolymer may be cured by any method, including the use of radiation curing, but preferably includes at least one curing agent (also referred to herein as a crosslinker, curing agent and / or cure system) for use with the various curable fluorine-containing curable fluoropolymers and perfluoropolymers in the compositions herein, which may be selected for use at the various cure sites described herein and which should be capable of curing (i.e., capable of reacting with and crosslinking) or otherwise undergoing a curing reaction to form crosslinks with the cure site or functional groups of the cure site monomers of the various uncured perfluoropolymers in the composition, resulting in an elastomeric material which may be in the form of a molded or printed article.

[0100] Suitable crosslinking or curing agents are those that form bridges having an oxazole, thiazole, imidazole, or triazine ring. Such compounds, as well as other curing agents including amidoximes, tetraamines, and amidrazones, can be used to crosslink in the present invention.

[0101] For nitrogen-containing curing sites, preferred curing agents are bisphenyl-based curing agents, including bisaminophenols and their salts, and their derivatives and their combinations; bisaminothiophenols, parabenzoquinonedioxime (PBQD), and also the salts of various such compounds can be used.Examples of suitable curing agents can be found in, for example, US Patent No. 7,521,510B2, US Patent No. 7,247,749B2 and US Patent No. 7,514,506B2, each of which is incorporated herein in its relevant part for the list of various curing agents for cyano-containing perfluoropolymers.In addition, perfluoropolymers can be cured using radiation curing technology.

[0102] Further preferred curing agents for cure sites having cyano group cure sites are curing agents having aromatic amines having at least two crosslinkable groups according to the following formulas (I) and (II), or combinations thereof, which form benzimidazole bridge structures upon curing. These curing agents are known in the art and are discussed by specific examples in relevant portions in U.S. Patent Nos. 6,878,778 and 6,855,774, which are incorporated herein in their entireties. [ka] In the formula, R 1 are the same or different in each group according to formula (II), NH2, NHR 2 , OH, SH, or monovalent organic groups or other organic groups such as alkyl, alkoxy, aryl, aryloxy, aralkyl, and aralkyloxy groups of from about 1 to about 10 carbon atoms, non-aryl type groups can be branched or straight chain and substituted or unsubstituted; R 2 may be -NH, -OH, -SH, or monovalent or other organic groups, such as aliphatic hydrocarbon groups, phenyl and benzyl groups, or alkyl, alkoxy, aryl, aryloxy, aralkyl, and aralkyloxy groups, each group having from about 1 to about 10 carbon atoms; non-aryl-type groups may be branched or straight-chain, and substituted or unsubstituted. Suitable monovalent or other organic groups, such as alkyl and alkoxy (or perfluorinated versions thereof), may have from 1 to 6 carbon atoms; examples of suitable aryl-type groups include phenyl and benzyl groups. Examples include -CF3, -C2F5, -CH2F, -CH2CF3, or -CH2C2F5, a phenyl group, a benzyl group; or a phenyl or benzyl group in which 1 to about 5 of the hydrogen atoms have been replaced by fluorine atoms, e.g., -CF5, -CH2C6F5, where the group is -CF3 or other lower perfluoroalkyl group, or a phenyl or benzyl group in which 1 to 5 hydrogen atoms have been replaced by CF3, e.g., CH 5-n (CF3) n, -CH2C6H 5-n (CF3) n (wherein n is 1 to about 5), etc. The hydrogen atom may be further substituted with a phenyl or benzyl group.

[0103] The structure having formula (I) or (II) incorporated into the organic amine should contain at least two such groups of formula (I) or (II) so as to provide at least two crosslinking reactive groups. Also useful herein are curing agents having formulas (III), (IV), and (V) shown below. [ka] In the formula, R 3 R may be SO, O, or CO, or an organic or alkylene-type group having from about 1 to about 10 carbon atoms, branched or straight chain, saturated or unsaturated, and branched or straight chain (for non-aryl-type groups), such as an alkyl, alkoxy, aryl, aralkyl, or aralkoxy group of 1 to 6 carbon atoms, or perfluorinated versions of such groups, or a single bond. 4 is a reactive side group, such as shown below: [ka] [ka] (In the formula, R f 1 is a perfluoroalkyl or perfluoroalkoxy group of about 1 to about 10 carbon atoms, which may be a straight or branched chain group and / or saturated or unsaturated and / or substituted or unsubstituted); and [ka] (wherein n is an integer of about 1 to about 10).

[0104] A single curing agent or combinations thereof may be selected from any of the curing agents herein within the scope of the present invention depending on the cure site to be crosslinked. For good heat resistance, oxazole, imidazole, thiazole and triazine ring-forming crosslinkers are useful, which are listed below and have formulas (I), (II), (III), (IV) and (V), specifically formula (II) (wherein R 1 are the same or different, and each is -NH2, -NHR 2 , -OH or -SH, and R 2 is a monovalent organic group, preferably not hydrogen; 3 is —SO—, —O—, —CO—, and an alkylene group of 1 to about 6 carbon atoms, a perfluoroalkylene group of 1 to about 10 carbon atoms, or a single bond; R 4 is as described below; formula (IV) (wherein R f 1 is a perfluoroalkylene group of 1 to about 10 carbon atoms), and compounds of the formulae discussed further below with respect to formula (V) (where n is an integer from 1 to about 10).

[0105] Exemplary curing agents based on the above preferred formula include those having at least two functional groups, such as those represented by the following structural formulas (VI), (VII), or (VIII): [ka] (In the formula, R 5 represents a saturated or unsaturated, branched or straight chain, substituted or unsubstituted group, such as alkyl, alkoxy, aryl, SO, O, CO, or similar group that is perfluorinated in terms of carbon atoms, preferably from about 1 to about 10 carbon atoms; [ka] (In the formula, R 1 is as defined elsewhere herein, and R 6may be O, SO, CO, or an optionally perfluorinated organic group of about 1 to about 10 carbon atoms, such as alkyl, alkoxy, aryl, aryloxy, aralkyl, and aralkyloxy; non-aryl type groups may be branched or straight chain and substituted or unsubstituted, or may have a single bond or alkylene linkage. Examples include:

[0106] In one embodiment of the present disclosure, compounds containing at least two chemical groups having crosslinking reactive groups as in formula (I) or (II) may be used to increase heat resistance and stabilize aromatic ring systems. For groups such as those in (I) or (II) having two to three such groups, it is preferable to have at least two for each group (I) or (II), since having fewer groups may not result in sufficient crosslinking. Such combinations are known and are described in U.S. Pat. Nos. 9,018,309 B2 and 9,365,712 B2, which are incorporated herein in relevant part.

[0107] Other cross-linking agents include compounds having two cross-linkable reactive groups represented by formula (II), which are shown below in formula (VIII). [ka] In the formula, R 1 is as above, and R 6 is —SO—, —O—, —CO—, an alkylene group of 1 to about 6 carbon atoms, a perfluoroalkylene group of 1 to about 10 carbon atoms, a single bond, or a group represented by formula (IX): [ka] This formula may result in easier synthesis in some cases. Examples of alkylene groups of 1 to about 6 carbon atoms include methylene, ethylene, propylene, butylene, pentylene, hexylene, etc. Examples of perfluoroalkylene groups of 1 to about 10 carbon atoms include: [ka] These compounds are known as examples of bisaminophenyl compounds. A preferred compound according to this structure is represented by formula (X): [ka] (In the formula, R 7 are the same or different in each case, and each R 7 is hydrogen, an alkyl group of 1 to about 10 carbon atoms; a partially fluorinated or perfluorinated alkyl group of 1 to 10 carbon atoms; a phenyl group; a benzyl group; or a phenyl or benzyl group in which 1 to about 5 hydrogen atoms have been replaced by fluorine or a lower alkyl or perfluoroalkyl group, e.g., CF3). Includes:

[0108] Non-limiting examples of curing agents include 2,2-bis(2,4-diaminophenylhexafluoropropane, 2,2-bis[3-amino-4-(N-methylamino)phenyl]hexafluoropropane, 2,2-bis[3-amino-4-(N-ethylamino)phenyl]hexafluoropropane, 2,2-bis[3-amino-4-(N-propylamino)phenyl]hexafluoropropane, 2,2-bis[3-amino-4-(N-phenylamino)phenyl]hexafluoropropane, 2,2-bis[3-amino-4-(N-perfluorophenylamino)phenyl]hexafluoropropane, 2,2-bis[3-amino-4(N-benzylamino)phenyl]hexafluoropropane, and similar compounds. Of these, preferred Due to their excellent heat resistance, 2,2-bis[3-amino-4(N-methylamino)phenyl]hexafluoropropane, 2,2-bis[3-amino-4-(N-ethylamino)phenyl]hexafluoropropane, 2,2-bis[3-amino-4-(N-propylamino)phenyl]hexafluoropropane, and 2,2-bis[3-amino-4-(N-phenylamino)phenyl]hexafluoropropane are preferred. Also, due to their heat resistance, tetra-amines such as 4,4'-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]bis[N1-phenyl-1,2-benzenediamine] or 2,2-bis[3-amino-4-(N-phenylaminophenyl)]hexafluoropropane are preferred.

[0109] Other suitable curing agents include oxazole, imidazole, thiazole, and triazine ring-forming curing agents, amidoxime and amidrazone crosslinkers known in the art or to be developed, and in particular bisaminophenols, bisaminophenol AF, and combinations thereof; bisaminothiophenols; bisamidines; bisamidoximes; bisamidrazones; monoamidines; monoamidoximes and monoamidrazones, examples of which are set forth, for example, in U.S. Pat. Nos. 7,247,749 and 7,521,510, which are incorporated herein by reference in relevant part, including the curing agents and co-curing agents and accelerators therein. In some embodiments herein, bisamidoxime, bisamidrazone, bisaminophenol, bisaminothiophenol, or bisdiaminophenyl curing agents are suitable for reacting with nitrile or cyano groups, carboxyl groups, and / or alkoxycarbonyl groups in the perfluoropolymer to form perfluoroelastomers having oxazole rings, thiazole rings, imidazole rings, or triazine rings as crosslinks in the resulting cured articles formed from the compositions herein.

[0110] When more than one cure site monomer is used, each monomer of each of the curable perfluoropolymers is preferably present in an amount of from about 0.1 to about 10 mole percent.

[0111] When at least one curing agent is used, it may be present in various amounts suitable for curing the cure site monomers of the curable perfluoropolymer in the composition, for example, a total amount of from about 0.2 parts by weight to about 10 parts by weight per 100 parts by weight of perfluoropolymer in the composition, and each may be present in an amount of from about 0.1 to about 6 parts by weight per 100 parts by weight of perfluoropolymer in the composition, or preferably from about 0.1 to about 2 parts by weight per 100 parts by weight of perfluoropolymer in the composition.

[0112] One cure site in at least one cure site monomer in the perfluoropolymer may be a nitrogen-containing cure site, a peroxide-curable cure site, or a cure site capable of forming a triazine ring. When a halogenated cure site is used, peroxide curing agents and co-curing agents well known in the art can also be used. Other suitable curing agents include those listed above.

[0113] Regarding the curable at least partially or fully fluorinated silicon-containing polymer, at least partially fluorinated thermosetting silicon-containing polymers may be used, including various at least partially fluorinated silicon-containing homopolymers and copolymers curable to form fluorosilicones (which are elastomers and are also called fluorosilicone rubbers or fluorosilicone rubbers). Curable at least partially fluorinated silicones are generally polymers that incorporate at least silicon, fluorine, and may contain oxygen and / or hydrogen in their chemical structure. Curable thermosetting silicon fluoride-containing polymers that can be used to form fluorosilicones (elastomers) include polymers having a backbone classified as FVMQ (fluorosilicone) in ASTM D1418-17 according to the Standard Rubber System Definition provided by ASTM International. However, fluorosilicones that are not readily classified by ASTM D1418-22 can also be used, provided they exhibit the useful additive manufacturing printability characteristics described herein.

[0114] As used herein, "curing" with respect to fluorosilicon-containing polymers is meant to encompass any method that results in the requisite elastomeric silicone structure by vulcanization, chemical crosslinking, catalytic crosslinking, etc. After curing, at least some thermally cured, particularly fluorinated, silicon-containing polymers form fluorosilicone elastomers.

[0115] In the uncured state, silicones are typically liquids or viscous gels. Curable at least partially fluorinated silicon-containing polymers that form fluorosilicone rubbers can be cured using a variety of cure systems, including catalytic cure systems, which typically use platinum-based catalysts, condensation cure systems, peroxide cure systems, and oxime cure systems.

[0116] In platinum-catalyzed curing, crosslinks are formed using functional at least partially fluorinated silicone polymers, such as vinyl-functional silicones and hydride-functional silicones, through a crosslink-forming addition reaction. Such reactions are typical curing routes in the art because they do not produce by-products.

[0117] Condensation systems typically involve crosslinking materials that are activated in some way. A typical one-component system utilizes at least partially fluorinated functional silicon-containing polymers that undergo hydrolysis when exposed to water at room temperature, with the hydrolyzable groups (hydroxyl or silanol groups) initiating the curing reaction. Once initiated, the hydrolysis reaction continues until curing is complete and can be carried out at room temperature. Crosslinking materials include condensation systems containing functional silanes with active oxygen-containing groups, such as alkoxy, acetoxy, ester, enoxy, or oxime silanes, e.g., methyltrimethoxysilane, methyltriacetoxysilane, and similar materials, where the silane or other reactant is at least partially fluorinated. Such substituents and / or functional groups can be similarly catalyzed, if desired, using organometallic catalysts, e.g., tetraalkoxytitanates, chelating titanates, and tin catalysts (e.g., dibutyltin dilaurate and acetoxytin).

[0118] In two-component condensation, the crosslinking material and optional catalyst are held in one container, while the curable silicon-containing polymer composition (free of these materials) is held in another container, and curing is initiated upon mixing of the materials in the two containers.

[0119] Other silicone cure systems for forming silicone elastomers include peroxide cure systems that can crosslink via silicone reactive sites that form Si-R-Si bonds between silicone chains.

[0120] Preferably, the curable at least partially fluorinated silicon-containing polymer used herein is one or more of at least partially fluorinated polysiloxanes, polyalkylsiloxanes, polydialkylsiloxanes, polyarylsiloxanes, polyaralkylsiloxanes, and blends, alloys, or copolymers of these materials. Furthermore, such thermally cured at least partially fluorinated silicon-containing polymers may have one or more hydrogen atoms in the backbone substituted with one or more groups, or one or more silicon-bonded groups on the silicon atoms, each of which may be further functionalized or further substituted, and preferably, such groups (or groups further substituted or functionalized thereon) contain fluorine. Such substituted or functionalized groups may be branched and / or straight chain groups and include, but are not limited to, hydroxyl, alkyl, alkenyl, alkynyl, aryl, alkoxy, alkenoxy, alkynoxy, aryloxy, arylalkyl, arylalkoxy, arylalkenoxy, vinyl, carboxyl, carbonyl, halogen, heterocycle, each of which may be partially fluorinated or perfluorinated, provided that the resulting silicon-containing polymer remains at least partially fluorinated along the polymer backbone and / or is at least partially fluorinated at one or more branch groups attached to the polymer backbone.

[0121] The compositions comprising at least one partially fluorinated silicone-containing polymer herein may include curing agents, cure initiators, crosslinkers, such as hydrolysis crosslinkers, cure catalysts, such as organic peroxides, and other cure system components known or to be developed in the art, as described above.Additives and / or modifiers may also be incorporated into the compositions comprising the at least partially fluorinated silicone-containing polymer, including, but not limited to, siloxane additives, ultra-high molecular weight siloxane additives, clarifiers, processing aids, stabilizers, thixotropic agents, rheological agents, compatibilizers, colorants, such as pigments and dyes, fillers, such as carbon black, quartz, silica, pyrogenic silica, carbon nanotubes, glass fibers, and optional coupling agents, aramid fibers, olefin fibers, carbon fibers, UV absorbers, UV stabilizers, lubricants, such as waxes, fatty acids, and other rheological agents. Included are additives, flame retardants, polyols, amides, fluoropolymers, fluorinated or perfluorinated polymer additives, nanosilica particles (i.e., silicon dioxide nanoparticles), polysiloxanes, antiblocking aids such as silica and talc, optional brighteners, dispersants, wetting agents, compatibilizers, and any other suitable additives and / or modifiers for the at least partially fluorinated silicon-containing polymer that provide the desired composition properties, provided that preferably such additives are selected so as not to block, prevent, or substantially interfere with the use of the at least one fluid plasticizer described herein.

[0122] Preferred additives for use in the curable, heat-cured, at least partially fluorinated silicon-containing polymer compositions herein include curing agents, such as peroxide curing agents typically incorporated at about 0.01 to about 5.5 parts per 100 parts of curable at least partially fluorinated silicon-containing polymer, or, in other systems, platinum catalysts in an amount of about 0.0005 to about 0.005 parts per 100 parts of curable at least partially fluorinated silicon-containing polymer. Other preferred additives can vary, but typically include colorants and pigments, such as white (titanium oxide), yellow (iron oxide or azo), blue (phthalocyanine GS or ultramarine), and / or green (phthalocyanine BS), individually in an amount of up to about 1.0 part per 100 parts of curable at least partially fluorinated silicon-containing polymer, or combined in an amount of up to about 1.5 parts per 100 parts of curable at least partially fluorinated silicon-containing polymer.

[0123] Such additives, other than any particular cure system, are optional and may be incorporated in a total amount of up to about 50% by weight.

[0124] Depending on the cure system used, the degree of the relevant curing agent can be adjusted for the system. Therefore, cure systems are known in the art for FVMQ systems, and the same systems described above can be used herein. Preferred examples of heat-curable fluorosilicones for use within the scope of the present invention include commercially available silicones, such as, but not limited to, Silastic available from Dow Chemical. TM FSR, e.g. Silastic TM FL 60-9201;Momentive TMExamples include fluorosilicones FF160 and FF170; two-component silicones with platinum cure systems, including Wacker Chemical Corporation's ElastoSil® R 901 / 40 CN. Such systems can be used and combined as recommended by their manufacturers. Other fluorosilicones that meet similar standards and capabilities may be used herein.

[0125] The cured fluoroelastomers, perfluoroelastomers and / or cured fluorosilicones formed from the curable fluoroelastomer compositions, including the perfluoroelastomer compositions described herein, may be cured and molded to form shaped articles using known techniques for molding shaped articles, including sealing members such as O-rings, seals, gaskets, inserts, etc.; however, other shapes and methods of formation known in the art or to be developed are contemplated herein, as such compositions, in view of the improved processability herein, may be processed using previously unfavorable methods of processing fluoropolymers and perfluoropolymers, including curable fluoropolymers containing silicon.

[0126] The compositions herein can be used in additive manufacturing as "ink" compositions to print articles, such as those described above, or various types of other articles based on pre-programmed designs and using known three-dimensional printing equipment or the specially designed printing equipment described in applicant's U.S. Patent Application No. 2021 / 0395405A1 herein, to create a wide variety of useful end products.

[0127] Furthermore, due to the enhanced processability provided by the plasticizers herein, the compositions may be processed using other types of methods not previously considered for traditional FKM / FFKM / FEPM and / or FVMQ processing, including injection molding, extrusion, film forming, transfer molding, and extruded sheets and parts, as well as three-dimensionally engineered articles for mass production or small-scale design. The use of these types of plasticizers may be used to enable the use of transfer or injection molding to more easily manufacture large parts, such as oilfield packing elements, and to improve the low-temperature properties of the elastomer, for example, with respect to FKM, FFKM, or FEPM. In such uses, if desired, the plasticizer may be removed (e.g., by baking out) after the packer is installed in the well.

[0128] Molded or thermoformed articles can also be used in oilfield, energy, semiconductor, and other end-use applications where high chemical or plasma resistance is required. For example, parts formed from the material can be bonded to surfaces to form bonded seals. Such bonded seals can be used to form pre-bonded doors, gates, and slit valve doors, for example, for use in semiconductor processing and other end-use applications. Replacement seals can be easily reprinted or remolded for custom projects or quick turnaround on replacement parts. Surfaces to which such molded articles, e.g., seals, can be bonded include polymeric surfaces as well as metal and metal alloy surfaces. In one embodiment, the present invention includes a gate or slit valve door, formed from, for example, stainless steel or aluminum, with an O-ring seal mated to a groove in the door configured to receive the seal. Bonding may be achieved using a bonding composition or with an adhesive.

[0129] Other end uses include medical devices, implants or artificial tissue applications, more easily moldable parts for dielectrics and other equipment, protective coatings for use in tools, electronics and building materials, base materials for use in integration into QTC composites or directly forming gaskets and other parts for radio frequency interference (RFI) and / or electromagnetic interference (EMI) shielding, aircraft seals or parts, and fluid handling end uses, and similar applications for fluoroelastomers, including FKM, FFKM, FEPM, and FVMQ. Reducing viscosity can also be used to enhance the processability of such materials in three-dimensional printing end uses.

[0130] The curable elastomeric compositions herein, when blends are used, are first prepared by combining at least one curable fluoro- or perfluoropolymer described elsewhere herein, e.g., by combining a first and a second perfluoropolymer with a plasticizer described herein.

[0131] When more than one polymer is used, the polymers may be first combined using typical rubber processing equipment, such as an open roll, a Banbury mixer, a kneader, etc., and other additives may also be preblended. The composition may also be prepared using an internal mixer method. Preferably, a typical mixer, such as a two-rotor mixer, is typically used to combine the fluoropolymer and other materials described. Preferably, in this method, especially for perfluoropolymers, the polymers are mixed at room temperature or at an elevated temperature of about 30°C to about 100°C or about 50 to about 250°C, depending on the type of mixer and the design and polymer being processed.

[0132] Other additives are not required, but may be added if desired to modify certain properties. Examples of such additives include curing accelerators in the form of micropowders, pellets, fibers, and nanopowders, co-curing agents, co-agents, processing aids, other plasticizers, fillers such as silica, the fluoropolymers described above, such as TFE, fluorinated copolymers, core-shell modified fluoropolymers, fluorographite, silica, barium sulfate, carbon, carbon black, nanodiamonds, microdiamonds, fluorocarbons, clay, talc, metal fillers (titanium oxide, aluminum oxide, yttrium oxide, silicon oxide, zirconium oxide), metal carbides (silicon carbide, aluminum carbide), metal nitrides (silicon nitride, aluminum nitride), etc. Examples of fillers include inorganic fillers (aluminum fluoride, fluorocarbons), colorants, organic dyes and / or pigments, such as azo, isoindolinone, quinacridone, diketopyrrolopyrrole, anthraquinone, and the like, imide fillers (e.g., polyimides, polyamide-imides, and polyetherimides), ketone plastics (e.g., polyarylene ketones such as PEEK, PEK, and PEKK), polyarylates, polysulfones, polyethersulfones, polyphenylene sulfides, polyoxybenzoates, and the like, which may be used in varying amounts as known in the art and / or for different properties. All fillers herein may be used alone or in combination of two or more such fillers and additives.

[0133] In some embodiments herein, any additives capable of curing the cure site of at least one cure site monomer and any curatives, including any cure accelerators, co-curatives, co-agents, etc., are added after other fillers and / or additives have been incorporated into the fluoro- or perfluoropolymer and blended before the addition of the novel plasticizers herein.

[0134] The compositions herein may be highly filled, if desired, or may be formed without fillers or additives other than the novel fluid plasticizer, and any curing agent and associated co-curing agent and / or accelerator. Optional additional fillers, such as those described above, may be used in a total amount of up to about 95 parts by weight, up to about 100 parts by weight, or up to about 150 parts by weight per 100 parts by weight of the combined curable perfluoropolymer in the composition, and may be more or less, especially if higher levels of filler are required.

[0135] After the curable fluoro- or perfluoropolymer is combined with the optional additives, including any optional curing agents, and, if already added, the fluid plasticizers herein, the curable fluoro- or perfluoropolymer in the elastomeric or perfluoroelastomer composition is cured to form the cured fluoroelastomer or perfluoroelastomer article described herein.

[0136] The curable composition is preferably cured at a temperature and for a time traditionally used to form the desired crosslinks, depending on the curing method or system, cure site, and / or curing agent selected. The temperature should be sufficient to allow the curing reaction to proceed until the curable fluoro- or perfluoropolymer in the composition is substantially cured, preferably at least 90% or more. Preferred curing temperatures and times for preferred curable perfluoropolymer compositions are, for example, about 150°C to about 250°C and about 5 to about 40 minutes. After curing, an optional post-cure step may be used. Acceptable post-cure temperatures and times for the most preferred perfluoropolymers described herein are, for example, about 200°C to about 320°C and about 5 to about 48 hours.

[0137] During curing, the curable compositions described herein may be formed into shaped articles by applying heat and pressure to a mold while simultaneously curing. The combined curable fluoro- and perfluoropolymers may be formed into preforms, such as extrusion ropes or other shapes, useful for forming shaped articles while curing, including in a mold with a groove shaped to receive the preform. Such compositions may also be cured using other heat treatment methods in view of the addition of the fluid plasticizers herein. Optional post-curing and bakeout may also be preferably carried out under air, nitrogen, or vacuum. Alternatively, the curable compositions may be formed into shaped articles or three-dimensionally printed articles using other molding or processing methods.

[0138] In end uses, applications, and other examples where improved processability is required, such as additive manufacturing processes or industrial coatings, the viscosity of curable fluorine-containing polymers known to have high viscosity and be difficult to process, as described above, can be reduced to improve processability, with such materials exhibiting Mooney viscosity (ML 1+10@121°C) values ​​of about 30 to about 160 or higher. Similarly, molded articles formed from such materials, such as preforms or molded article parts formed from the compositions, also face processability and viscosity challenges. To improve processability and reduce viscosity in such materials, the fluorine-containing polymers having higher Mooney viscosity as described above may be incorporated into the fluorine-containing polymer composition with one or more further curable fluorine-containing polymers having low Mooney viscosity (ML 1+10@121°C) of about 10 to about 45. When combining a lower Mooney viscosity curable fluorine-containing polymer with a higher Mooney viscosity polymer, it is preferable that the second polymer added be selected to have a lower Mooney viscosity than the first polymer used, in order to reduce the Mooney viscosity of the first polymer used. Many fluoroelastomers and perfluoroelastomers, as well as their compound forms, have sufficiently high Mooney viscosities that it is important for them to have improved processability for use in flow-related end applications.

[0139] Suitable low or lower Mooney viscosity polymers may be blended, alloyed, or copolymerized with the base high or higher viscosity fluorine-containing polymer using roll mills and preform extruders known in the art. Functionalization of either or both polymers to compatibilize or alloy them together, or grafting or other copolymerization of lower viscosity fluorine-containing polymers with higher viscosity fluorine-containing polymers, may also be carried out within the scope of the present invention using techniques known in the art.

[0140] The low or lower viscosity curable fluorine-containing polymer may be present in the composition in a weight percentage of about 5 to about 95 weight percent, or about 10 to about 90 weight percent, or about 20 to about 80 weight percent, or about 25 to about 75 weight percent, or about 40 to about 60 weight percent, or about 50 weight percent, based on 100 parts by weight of the total fluorine-containing polymer, each range incorporating all integer and decimal weight percentage values ​​within the recited range. The amount of the lower viscosity curable fluorine-containing polymer can be adjusted depending on the higher viscosity curable viscous polymer and the intended end use of the composition, and in some preferred embodiments is about 10 to about 20 weight percent of the weight of all combined curable fluorine-containing polymers in the composition.

[0141] While the use of a combination of high and low Mooney viscosity fluorine-containing polymers in a composition may in some cases sufficiently improve processability, it is also within the scope of the present invention to further introduce into such a composition at least one fluid plasticizer having at least one at least partially fluorinated organic compound and / or to incorporate additional plasticizers different from the fluid plasticizers herein.

[0142] The composition may also include various curing agents, cure systems, and additives described above with respect to the curable fluorine-containing polymer compositions herein, and the fluorine-containing polymer in the composition may be partially or substantially fluorinated or perfluorinated. Such compositions having a combination of high and low Mooney viscosity fluorine-containing polymers and / or further incorporating the fluid plasticizers herein may be used in end applications and applications in demanding environments where processability and low viscosity are important, including those listed above with respect to the previous embodiments, and in additive manufacturing and coating applications where fluorinated or perfluorinated materials are used.

[0143] The invention will now be described with reference to the following non-limiting examples. [Example]

[0144] Example 1 Three filled and mixed curable perfluoropolymer compositions were prepared herein and were formulated with a fluid plasticizer having at least a partially fluorinated organic compound in the form of a commercially available product, Novec TM Control samples were prepared from each of the filled and mixed curable perfluoropolymer compositions using Novec 7500. TM Each control sample, A, B, and C, was prepared without the inclusion of Novec 7500. TM The curable perfluoropolymer in Control Sample A was Tecnoflon® from Solvay Specialty Polymers. TM The curable perfluoropolymer for Control Sample B was Dai-el PFR-95HT perfluoropolymer manufactured by Daikin Industries, Inc. TM The curable perfluoropolymer for Control Sample C was Tecnoflon® from Solvay Specialty Polymers. TM It was PFR LT.

[0145] Control Sample A further contained a total of 26 parts per 100 parts of curable perfluoropolymer of various fillers and curatives: N990 carbon black, N962 carbon black, organosilicone lubricant, and peroxide curative.

[0146] Control Sample B contained 15.9 parts total of filler and curing agent per 100 parts by weight of curable perfluoropolymer: silicon carbide nanoparticles and tetraamine curing agent, 4,4′-[2,2,2-trifluoro-l-(trifluoromethyl)ethylidene]bis[N1-phenyl-1,2-benzenediamine].

[0147] Control Sample C contained 39 parts by weight of filler, curative and co-curative per 100 parts by weight of curable perfluoropolymer: PTFE powder, AerosilTM It contained R 972 silica, a peroxide curing agent, and triallyl isocyanurate (TAIC).

[0148] The same control samples A, B, and C were then evaluated as base formulations. Each control sample contained varying amounts of Novec per 100 parts of the premixed control sample composition. TM 7500 was added to each control sample composition A, B or C for each of the inventive samples A1, A2, A3, B1, B2, B3, C1, C2 and C3. TM The amount of 7500 is shown in Table A below.

[0149] Control Sample A and inventive samples A1, A2, and A3 were cured for 10 minutes at 320° F. Control Sample B and inventive samples B1, B2, and B3 were cured for 30 minutes at 360° F. Control Sample C and inventive samples C1, C2, and C3 were cured for 8 minutes at 300° F. Each sample was compression cured without post-cure.

[0150] To prepare Sample C, uncured Tecnoflon® PFR-LT (having a Mooney viscosity of 25 (ML 1+10 @ 121°C)) was added to the mixer and mixed for 1 minute. 15 g of Novec® 7500 plasticizer was added dropwise over approximately 15-20 minutes and mixed for 2 minutes. The mixed compound was banded with a CW Brabender Type 6 Model 60433 mill (16-inch mill) with the nip set to a 1.58 mm setting, the compound was cut, and the blend was allowed to blend for 1 minute. The compound was pig-rolled five times, and the mill setting was changed to 7.93 mm. The compound was sheeted to a final thickness of 7.93 mm. The nip was again closed to have a nip point of 1.58 mm, the compound was blended for 1 minute, rolled 5 times, the mill setting was again changed to 7.93 mm, and the compound was sheeted to a final thickness of 7.93 mm. The same procedure was used to blend various levels of Novec TM7500 samples were prepared, and samples A and B were prepared. [Table A]

[0151] As shown in Table A, 15 phr of Novec as a fluid plasticizer having a fluorinated organic compound. TM The inventive samples using 7500 showed a 64% reduction in ML (lb-in) compared to control Sample A (Sample A3), a 79% reduction in ML (lb-in) compared to control Sample B (Sample B3), and a 52% reduction in ML (lb-in) compared to control Sample C (Sample C3). This is a substantial reduction in ML torque indicating a substantial reduction in the viscosity of the control compound when fed with the inventive compound, indicating superplasticizer behavior.

[0152] The same samples also showed a significant reduction in hardness, again demonstrating superplasticizer behavior as shown in Table B below. [Table B] [Table C]

[0153] Example 2 Control samples A, B and C were evaluated for compound shrinkage temperature (TR10) and glass transition temperature (Tg) to compare Novec to inventive samples A1, A2 and A3, B1, B2 and B3 from Example 1, and C1, C2 and C3. TM The effect of adding Novec 7500 to the fluid plasticizer was determined. The results are shown in Table C above. As can be seen, the fluid plasticizer Novec TMAn increase of 7500 parts per hundred represents an improvement of approximately 1.5°C in TR10 from Control Sample A for each additional part per hundred parts added, and an improvement of approximately 1.8°C in Tg for each part per hundred parts added. Control Sample B showed an increase of approximately 1.3°C in TR10 for each part of fluorinated organic compound added to the fluid plasticizer, and an improvement of approximately 1.4°C in Tg for each part added. A similar effect was seen in Control Sample C, where the TR10 improved by 0.85°C and the Tg improved by approximately 1.0°C for each part per hundred of fluorinated organic compound. The results indicate that fluid plasticizers with fluorinated organic compounds can provide lower minimum use temperatures than the respective control samples and exhibit high-performance low-temperature plasticizer effects.

[0154] To further illustrate this improvement, low-temperature O-ring leak tests were performed on control samples A, B, and C, and on each of inventive samples A1, A2, and A3; B1, B2, and B3; and C1, C2, and C3. The leak tests were performed as described in R. Campbell, "Improved Low Temperature Seals for Oil and Gas Applications," Rubber World, pp. 44-52 (August 2022). Suitable leak tests include those described in SAE Technical Paper Series 2001-01-2974 and variations of that test used in the seal industry, in which seals are tested in compression and using low-pressure nitrogen. See Campbell, "Improved Low Temperature Seals for Oil and Gas Applications," Rubber World, pp. 44-52 (August 2022).

[0155] The results are shown in the graphical representation of Figure 3, where improvements in Tg and TR10 result in a lower effective use temperature before leakage during testing. The low temperature leak test showed that low temperature leakage was observed with 15 phr of Novec TMIt was further revealed that the addition of 7500 (Sample A3) resulted in an 18.1°C shift from the value of Control Sample A, the addition of 15 phr (Sample C3) resulted in a 9.4°C shift from the value of Control Sample C; and the addition of 15 phr (Sample B3) resulted in a 16°C shift from Control Sample B.

[0156] Example 3 Samples were subjected to TGA analysis and analyzed by Novec TM 7500 was shown to be baked out from Samples A1, A2 and A3 of Example 1 between 200° C. and 300° C. See FIG.

[0157] Differential scanning calorimetry (DSC) analysis was also performed on control sample A and inventive samples A1, A2, and A3, as shown in Figure 2. The DSC scans showed that Novec TM Each of inventive samples A1, A2, and A3 demonstrates a shift in Tg from control sample A in terms of increasing 7500 content, which is consistent with the data from Example 2 and Table C.

[0158] Example 4 Compounds were prepared to demonstrate torque (ML) improvements using a Rubber Processing Analyzer (RPA) for high Mooney viscosity fluorine-containing polymers alone and in various combinations with the fluid plasticizers described herein, and for low Mooney viscosity polymers alone and with the plasticizers described herein. Various combinations of such polymers, both in combination with and without the plasticizer, also demonstrated changes in processability.

[0159] The compositions are shown below in Table D. Ten compounds (Compounds 1-10) were prepared using three different fluoroelastomer polymers: Tecnoflon TM VPL 75545 (having a Mooney viscosity (ML 1+10 @ 121°C) of 32); Tecnoflon with a Mooney viscosity of 25 TM VPL 45535, and Viton, also Mooney viscosity 25 TMThe compounds were prepared using a Diak GLT 200S. Additives typically used in fluoroelastomer compounds, including PTFE and silica, were incorporated into Sample Compounds 1-8, and various curing agents were used. TM Varox 7 TM DBPH or Varox TM 130XL in Compounds 1 to 8. One of two fluid plasticizers containing organic fluoride compounds (Novec TM 7500) has a lower molecular weight than the other (Fomblin M60).

[0160] Fluoroelastomer compositions were prepared in a similar manner. TM For compounding with VPL 45535, 100g of polymer was weighed out, warmed in a mill, formed into strips that fit into the mixer, added to the mixer and mixed for 1 minute. TM PTFE was added to the mixture in an amount of 30 g and mixed for 3 minutes. TM R972, Varox manufactured by R.T. Vanderbilt Company TM DBPH (2,5-dimethyl-2,5-(t-butylperoxy)hexane) (1 gram), and Diak from Chemours Company TM A premix of 7 (triallyl isocyanurate) (5 grams) was added to the first mix and mixed for 5 minutes. The compound mix was added dropwise to a Tite CW Brabender Type 6 Model 60433 mill and formed into a sheet. This was cut, blended for 3 minutes, pigrolled 4 times, and formed into a sheet. This was cut into strips and extruded at 140°F, which were used to make seals or parts by compression molding and introduced into additive manufacturing processes.

[0161] Sample compounds 1, 3, 6, and 8 were analyzed by RPA to evaluate torque (ML) in compounds with lower Mooney viscosities of 32 and 25 to compare the effect of using plasticizer in compounds of various Mooney viscosities. As shown in Figure 4, the ML in each of the plasticizer-free compounds (compounds 1 and 6) was reduced by the incorporation of plasticizer (compounds 3 and 8), regardless of the starting Mooney viscosity of the fluorine-containing elastomer used.

[0162] Parts formed from the compounds were tested for torque, interlayer adhesion, and post-printing shrinkage. As shown in Figure 5, torque ML was measured at 100°C for four samples before and after the articles were printed (showing the change after cure), and the post-cure shrinkage percentage is also shown for Compounds 1, 3, 6, and 8. Shrinkage and torque were lowest when using the lower viscosity polymers of Compounds 6 and 8, with very little shrinkage. The highest shrinkage difference and torque were seen when using the higher viscosity polymer without plasticizer of Compound 1. [Table D]

[0163] To evaluate processability and print quality, sample compounds 1-10 were introduced into an additive printing manufacturing process and samples were printed. All compounds were printable, but compounds 1 and 2, which had somewhat higher Mooney viscosities and did not contain plasticizers, were of poor quality. Compounds 3-5 each printed better than compounds 1 and 2 due to the use of plasticizers, but some blistering occurred due to the higher viscosity and thermal contact. All lower Mooney viscosity compounds 6-10 demonstrated good processability and printability and did not exhibit print blister defects. Those with plasticizers performed best.

[0164] The data show that parts formed using additive printing of FKM curable polymers with Mooney viscosities above 30 without plasticizers can experience shrinkage after cure of approximately 67±9%, similar to Compound 1. The addition of a low molecular weight plasticizer in Compound 3 of the examples herein reduced shrinkage by 17%, to 50±6%. A study of Compound 6, using a low Mooney viscosity FKM curable polymer with a Mooney viscosity of 25, demonstrated a similar level of shrinkage after cure to Compound 3 at 54±5% alone. However, when a high molecular weight plasticizer was added in Compound 8, shrinkage was only 6±1% after cure, a 48% reduction due to the use of the plasticizer. This is demonstrated in Figure 5. In supporting examples, the use of a plasticizer can substantially or significantly reduce the Mooney viscosity of fluoropolymer compounds for use in flow or coating applications, such as additive printing or coating. Theoretically, because viscosity is directly proportional to induced stress, the polymer chains will experience less induced stress. The reduced stress on the polymer chains reduces strain, and when the chains relax and return to their original coiled state, they will relax to a lesser extent compared to higher viscosity compounds. This results in less shrinkage in the final cured article.

[0165] Those skilled in the art will recognize that modifications may be made to the above-described embodiments without departing from the broad inventive concept thereof. It is understood, therefore, that the invention is not limited to the particular embodiments disclosed, but is intended to cover modifications within the spirit and scope of the invention as defined by the appended claims.

Claims

1. at least one curable fluorine-containing polymer; at least one fluid plasticizer comprising at least one at least partially fluorinated organic compound; A curable fluorine-containing composition comprising: the at least one at least partially fluorinated organic compound is capable of reducing the viscosity and improving the processability of a fluoroelastomer formed from the curable fluorine-containing polymer in the composition compared to a fluoroelastomer formed from the same curable fluorine-containing polymer without the at least one at least partially fluorinated organic compound; and / or A curable fluorine-containing composition, wherein said at least one at least partially fluorinated organic compound is capable of achieving a minimum use temperature of a fluoroelastomer formed from said curable fluorine-containing polymer that is lower than a minimum use temperature of a fluoroelastomer formed from the same curable fluorine-containing polymer that does not contain said at least one at least partially fluorinated organic compound.

2. 10. The curable fluorine-containing composition of claim 1, further comprising at least one curing agent capable of curing said at least one curable fluorine-containing polymer.

3. 2. The curable fluorine-containing composition according to claim 1, wherein the at least one curable fluorine-containing polymer is selected from the group consisting of at least partially fluorinated fluoropolymers, perfluorinated fluoropolymers, at least partially fluorinated copolymers of tetrafluoroethylene and propylene, and at least partially fluorinated silicone-containing polymers.

4. 4. The curable fluorine-containing composition of claim 3, wherein said at least one curable fluorine-containing polymer is a curable perfluorinated polymer.

5. 5. The curable fluorine-containing composition of claim 4, wherein the curable perfluorinated polymer is a copolymer of tetrafluoroethylene, a perfluoroalkyl vinyl ether, and at least one cure site monomer, the at least one cure site monomer having a cure site comprising a halogen atom or a nitrile group.

6. 4. The curable fluorine-containing composition of claim 3, wherein said at least one curable fluorine-containing polymer is an at least partially fluorinated polymer comprising vinylidene fluoride monomers along its backbone.

7. 7. The curable fluorine-containing composition of claim 6, wherein said at least partially fluorinated polymer further comprises hexafluoropropylene and tetrafluoroethylene as comonomers with said vinylidene fluoride.

8. 2. The curable fluorine-containing composition of claim 1, wherein the at least one at least partially fluorinated organic compound is selected from alkoxyfluoroalkanes, alkoxyfluoroalkenes, alkenoxyfluoroalkanes, alkenoxyfluoroalkenes, alkoxyperfluoroalkanes, alkoxyperfluoroalkenes, alkenoxyperfluoroalkanes, alkenoxyperfluoroalkenes, and combinations and mixtures thereof.

9. The at least one at least partially fluorinated organic compound is a compound according to formula (A): (R ａｆ )(R ｂ ) ｙ -O-R ｃ (A) (In the formula, R ａｆ is a fluorinated alkane or alkene group of from about 4 to about 20 carbon atoms, said fluorinated alkane or alkene group being branched or straight chain, said fluorinated alkane or alkene group containing from about 4 to about 41 fluorine atoms; R ｂ is an alkane of about 2 to about 5 carbon atoms; y is 0 or 1; When y is 1, R ｂ is R ａｆ or at the end of R ａｆ or in the carbon chain of R ａｆ hanging from the carbon chain of R ｃ is an alkane or alkene group of about 2 to about 7 carbon atoms, optionally having 1 to about 3 fluorine atoms on said carbon atoms of said alkane or alkene group.

2. The curable fluorine-containing composition according to claim 1, wherein

10. R ａｆ and R ｂ The curable fluorine-containing composition of claim 9, wherein a total of from about 4 to about 15 carbon atoms.

11. R ａｆ 10. The curable fluorine-containing composition of claim 9, wherein is perfluorinated.

12. The O-R ｃ The group is (R ａｆ ) (R ｂ ) ｙ 10. The curable fluorine-containing composition of claim 9, wherein the pendant alkoxy or alkenoxy groups are on a carbon chain of

13. O-R ｃ The curable fluorine-containing composition of claim 9, wherein is an alkoxy group having from about 2 to about 5 carbon atoms.

14. 2. The curable fluorine-containing composition of claim 1, wherein the at least one at least partially fluorinated organic compound is selected from methoxydecafluoroheptane and its isomers; ethoxy-nonafluorobutene ether and ethoxy-nonafluoroisobutyl ether isomers; ethoxy-trifluoromethylhexane and its isomers and derivatives; and mixtures and combinations thereof.

15. 15. The curable fluorine-containing composition of claim 14, wherein said at least one at least partially fluorinated organic compound is 3-ethoxy-1,1,1,2,3,4,5,5,6,6,6-dodecafluoromethylhexane.

16. 2. The curable fluorine-containing composition of claim 1, wherein said at least one at least partially fluorinated organic compound is present in said composition in an amount of from about 1 to about 20 parts by weight per 100 parts of said at least one curable fluorine-containing polymer.

17. 17. The curable fluorine-containing composition of claim 16, wherein said at least one at least partially fluorinated organic compound is present in said composition in an amount of from about 3 to about 15 parts by weight per 100 parts of said at least one curable fluorine-containing polymer.

18. 2. The curable fluorine-containing composition of claim 1, further comprising one or more additives or fillers different from said fluid plasticizer comprising said at least one at least partially fluorinated organic compound, said one or more additives or fillers being present in said composition in an amount of up to about 95 parts by weight per 100 parts of said curable fluorine-containing polymer.

19. 10. The curable fluorine-containing composition of claim 1, wherein the curable fluorine-containing composition is an additive manufacturing composition for use in printing fluorine-containing elastomeric articles.

20. an at least partially cured fluoroelastomer; at least one at least partially fluorinated organic compound in a matrix of said fluoroelastomer, said at least one at least partially fluorinated organic compound being incorporated into said matrix of said fluoroelastomer in a fluid plasticizer; 1. A cured fluoroelastomer composition comprising: the fluoroelastomer in the composition has reduced viscosity and improved processability compared to a fluoroelastomer identical to the fluoroelastomer in the composition but free of the at least one at least partially fluorinated organic compound; and / or A cured fluoroelastomer composition, wherein the minimum use temperature of said fluoroelastomer in said composition is lower than the minimum use temperature of a fluoroelastomer that is the same as said fluoroelastomer in said composition but that does not contain said at least one at least partially fluorinated organic compound.

21. 21. The fluoroelastomer composition of claim 20, wherein the Tg of said fluoroelastomer in said composition, measured in ° C., is at least about 30% lower than the Tg of a fluoroelastomer that is the same as said fluoroelastomer in said composition but does not include said at least one at least partially fluorinated organic compound.

22. 21. The fluoroelastomer composition of claim 20, wherein the minimum torque value (ML) of the fluoroelastomer in said composition is at least about 50% lower, measured in pounds-inches, than the minimum torque value of a fluoroelastomer identical to said fluoroelastomer in said composition but not including said at least one at least partially fluorinated organic compound.

23. 21. The fluoroelastomer composition of claim 20, wherein said fluoroelastomer is selected from cured at least partially fluorinated elastomers, cured perfluoroelastomers, cured at least partially fluorinated tetrafluoroethylene-propylene fluoroelastomers, and cured at least partially fluorinated fluorosilicones.

24. 24. The fluoroelastomer composition of claim 23, wherein said fluoroelastomer is a perfluoroelastomer.

25. 21. The fluoroelastomer composition of claim 20, wherein said at least one at least partially fluorinated organic compound is selected from alkoxyfluoroalkanes, alkoxyfluoroalkenes, alkenoxyfluoroalkanes, alkenoxyfluoroalkenes, alkoxyperfluoroalkanes, alkoxyperfluoroalkenes, alkenoxyperfluoroalkanes, alkenoxyperfluoroalkenes, and combinations and mixtures thereof.

26. The at least one at least partially fluorinated organic compound is a compound according to formula (A): (R ａｆ )(R ｂ ) ｙ -O-R ｃ (A) (In the formula, R ａｆ is a fluorinated alkane or alkene group of from about 4 to about 20 carbon atoms, said fluorinated alkane or alkene group being branched or straight chain, said fluorinated alkane or alkene group containing from about 4 to about 41 fluorine atoms; R ｂ is an alkane of about 2 to about 5 carbon atoms; y is 0 or 1; When y is 1, R ｂ is R ａｆ or at the end of R ａｆ or in the carbon chain of R ａｆ hanging from the carbon chain of R ｃ is an alkane or alkene group of about 2 to about 7 carbon atoms, optionally having about 1 to about 3 fluorine atoms on said carbon atoms of said alkane or alkene group.

21. The fluoroelastomer composition of claim 20, wherein:

27. R ａｆ and R ｂ The fluoroelastomer composition of claim 26, wherein a total of from about 4 to about 15 carbon atoms.

28. R ａｆ 27. The fluoroelastomer composition of claim 26, wherein is perfluorinated.

29. The O-R ｃ The group is (R ａｆ ) (R ｂ ) ｙ 27. The fluoroelastomer composition of claim 26, wherein the pendant alkoxy or alkenoxy groups are on the carbon chain of

30. O-R ｃ The fluoroelastomer composition of claim 26, wherein is an alkoxy group having from about 2 to about 5 carbon atoms.

31. 21. The fluoroelastomer composition of claim 20, wherein said at least one at least partially fluorinated organic compound is selected from methoxydecafluoroheptane and its isomers; ethoxy-nonafluorobutene ether and ethoxy-nonafluoroisobutyl ether isomers; ethoxy-trifluoromethylhexane, and its isomers and derivatives; and mixtures and combinations thereof.

32. The fluoroelastomer composition of claim 31, wherein said at least one at least partially fluorinated organic compound is 3-ethoxy-1,1,1,2,3,4,5,5,6,6,6-dodecafluoromethylhexane.

33. 21. The fluoroelastomer composition of claim 20, wherein said at least one at least partially fluorinated organic compound is present in said fluoroelastomer composition in an amount of from about 1 to about 20 parts by weight per 100 parts of said fluoroelastomer.

34. 34. The fluoroelastomer composition of claim 33, wherein said at least one at least partially fluorinated organic compound is present in said fluoroelastomer composition in an amount of from about 3 to about 15 parts by weight per 100 parts of said fluoroelastomer.

35. 21. The fluoroelastomer composition of claim 20, further comprising one or more additives or fillers different from said at least one at least partially fluorinated organic compound, said one or more additives or fillers being present in said composition in an amount up to about 95 parts by weight per 100 parts of said fluoroelastomer.

36. 1. A method for improving the viscosity and processability of a fluoroelastomer by providing the matrix of the fluoroelastomer with at least one at least partially fluorinated organic compound, wherein the at least one at least partially fluorinated organic compound is at least partially incorporated into the matrix of the fluoroelastomer in a fluid plasticizer.

37. 37. The method of claim 36, wherein the at least one at least partially fluorinated organic compound is provided to the fluoroelastomer by incorporating the fluid plasticizer into a composition comprising a curable fluorine-containing polymer prior to curing the curable fluorine-containing polymer composition to form the fluoroelastomer.

38. 38. The method of claim 37, further comprising introducing the curable fluorine-containing polymer composition into an additive manufacturing process prior to curing the composition to form the fluoroelastomer.

39. 37. The method of claim 36, wherein the at least one at least partially fluorinated organic compound is provided to the curable fluorine-containing polymer in an amount of about 1 to about 20 parts by weight per 100 parts by weight of the curable fluorine-containing polymer.

40. 1. A method for reducing the minimum use temperature of a fluoroelastomer by providing at least one at least partially fluorinated organic compound in a matrix of said fluoroelastomer, wherein said at least one at least partially fluorinated organic compound is at least partially incorporated into said matrix of said fluoroelastomer in a fluid plasticizer.

41. 41. The method of claim 40, wherein the Tg of said fluoroelastomer is also lowered by said at least one at least partially fluorinated organic compound.

42. 41. The method of claim 40, wherein the at least one at least partially fluorinated organic compound is provided to the fluoroelastomer by incorporating the fluid plasticizer into a composition comprising a curable fluorine-containing polymer prior to curing the curable fluorine-containing polymer composition to form the fluoroelastomer.

43. 1. A method for reducing the viscosity and improving the processability of a composition comprising a first curable fluorine-containing polymer having a Mooney viscosity (ML 1+10 @ 121°C) of about 30 to about 160, or a molded article formed from said composition, comprising:

1. A method comprising incorporating into said composition at least one second curable fluorine-containing polymer having a Mooney viscosity (ML 1+10 @ 121°C) of from about 10 to about 45, wherein said Mooney viscosity of said second curable fluorine-containing polymer is selected to be lower than said Mooney viscosity of said first curable fluorine-containing polymer.

44. 44. The method of claim 43, wherein the first fluorine-containing polymer and the second fluorine-containing polymer are blended, alloyed, or copolymerized.

45. 44. The method of claim 43, wherein the composition further comprises at least one fluid plasticizer having at least one at least partially fluorinated organic compound.

46. 46. ​​The method of claim 45, wherein the composition is introduced into an additive manufacturing process.

47. 46. ​​The method of claim 45, further comprising one or more additional plasticizers different from the at least one fluid plasticizer.

48. 44. The method of claim 43, further comprising one or more additional plasticizers.

49. 44. The method of claim 43, wherein the composition is introduced into an additive manufacturing process.

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