Patent Application
20230374243
This invention relates to foamable thermoplastic compositions, thermoplastic foams, foaming methods, and systems and articles made from same, including foam articles, such as panels, boards, sheets, blocks, beams and other formed articles, comprising a thermoplastic foam comprising polyethylenefuranoate (PEF) and having a surface covered by a sheet, mat, film, scrim or like surface covering, and to the uses of such articles in devices, systems and methods that require or benefit from relatively lightweight and relatively strong foam forms, and especially to environmentally advantageous and sustainable lightweight and relatively strong foam forms.
While foams are used in a wide variety of applications, it is a desirable but difficult-to-achieve goal in many applications for the foam material to be environmentally friendly while at the same time possessing excellent performance properties and being cost effective to produce. Environmental considerations include not only of the recyclability and sustainability of the polymeric resin that forms the structure of the foam but also the low environmental impact of blowing agents used to form the foam, such as the Global Warming Potential (GWP) and Ozone Depletion Potential (ODP) of the blowing agent.
Foams based on certain thermoplastic resins, including polyester resins, have been investigated for potential advantage from the perspective of being recyclable and/or sustainably sourced. However, difficulties have been encountered in connection with the development of such materials. For example, it has been a challenge to develop polyester resins that are truly recyclable, can be produced from sustainable sources, and which are compatible with blowing agents that are able, in combination with the thermoplastic, to produce foams with good performance properties. In many applications the performance properties that are considered highly desirable include the production of high-quality closed cell foam that are low density (and therefore have a low weight in use) and at the same time having relatively high mechanical integrity and strength.
Many important applications exist which would benefit from the use of covered or faced foam forms in which the foam portion is made from a renewable and sustainable material that is relatively lightweight (i.e., has a density that is relatively low) and has a strength that is relatively high. Such applications include, for example, use in transportation devices, such as cars, trucks, rail cars, boats, ships, aircraft and the like, since in all such applications the use of lightweight and relatively strong materials can be beneficial. Other examples include sporting equipment, such as skis, snowboards, skateboards and the like, as well as stationary building structures, including for example, as roof and floor underlayment, and as components of walls, in buildings and homes.
Packaging applications can also benefit from foams which are provided by the present invention.
Another important example of an application which would benefit from a relatively lightweight and relatively high strength covered or faced foam made from renewable and sustainable material is in blades, foils and the like used as fluid energy transfer devices. Examples of such fluid energy transfer devices include the blades used on wind generators. Other types of fluid energy transfer devices include vortex, tidal, oceans current oscillating hydrofoils and kites which recover air or water kinetic energy from fixed or mobile devices located in air or water.
An example of one type of wind generator is schematically illustrated in
The nacelle in many wind generators sits atop a tower that can be 120 meters off the ground for ground-based generators or and potentially even higher, and for off-shore application can be 150 meters, and potentially even higher, above the water surface for offshore generators, and for this and other reasons it is often critical to construct the various components of the wind turbine blades from materials that are relatively light in weight and at the same time sufficiently strong to withstand the forces to which the blades will be exposed. It is therefore highly important in such uses that the lightest weight material be used that can provide the necessary strength properties since this will not only improve the efficiency of operation of the wind turbine but can benefit the cost of construction and maintenance of the wind generator. While thermoplastic foams formed from polyethylene terephthalate (PET) have been used in wind turbine blades, applicants have come to appreciate that several important disadvantages are associated with the use of such materials in such applications. For example, PET is not a sustainable material. In addition, certain portions of the wind turbine blade use higher density materials, such as balsa wood, instead of PET foam because PET foams do not provide sufficient strength to meet the needs in those areas of the wind turbine blade.
With particular reference to
With respect to
Because of these requirements of the spar caps used in rotor blades, it has heretofore been common to not generally use PET foam for these portions of the blade and to instead form the spar caps from other materials considered to have better strength properties, such as balsa wood which has been surface reinforced with facing or glass fiber reinforced laminate or carbon fiber reinforced laminate.
Whether the core material is in the shell or is in the shear web or is in the spar caps of the wind turbine blade, the core is typically sandwiched between two or more face sheets that are made of a few layers glass fibers adhered with epoxy resin. The facings, after being rigidized, provide longitudinal stiffness and strength, whereas the core provides out-of-plane strength and stiffness. The face sheets carry most of the bending and in-plane loads, while the core mostly carries the shear load.
With respect to the selection of thermoplastic resin, EP 3,231,836 acknowledges that while there has been interest in thermoplastic resins, in particularly polyester-based resins, this interest has encountered difficulty in development, including difficulty in identifying suitable foaming grades of such resins. Moreover, while EP 3,231,836 notes that certain polyethylene terephthalate (PET) resins, including recycled versions of PET, can be melt-extruded with a suitable physical and/or chemical blowing agent to yield closed-cell foams with the potential for low density and good mechanical properties, it is not disclosed that any such resins are at once are able to produce foams with good environmental properties and good performance properties, and are also able to be formed from sustainable sources. The '836 application identifies several possible polyester resins to be used in the formation of open-celled foams, including polyethylene terephthalate, poly butylene terephthalate, poly cyclohexane terephthalate, polyethylene naphthalate, polyethylene furanoate or a mixture of two or more of these. While the use of polyester materials to make foams that have essentially no closed cells, as required by EP '836, may be beneficial for some applications, a disadvantage of such structures is that in general open cell foams will exhibit relatively poor mechanical strength properties.
CN 108484959 discloses that making foam products based on 2,5-furan dimethyl copolyester is problematic because of an asserted problem of dissolution of foaming agent into the polyester and proposes the use of a combination of a liquid blowing agent and a gaseous blowing agent and a particular process involving sequential use of these different classes of blowing agent.
US 2020/0308363 and US 2020/0308396 each disclose the production of amorphous polyester copolymers that comprise starting with a recycled polyester, of which only PET is exemplified, as the main component and then proceeding through a series of processing steps to achieve an amorphous co-polymer, that is, as copolymer having no crystallinity. A wide variety of different classes of blowing agent are mentioned for use with such amorphous polymers.
With respect to blowing agents, the use generally of halogenated olefin blowing agents, including hydrofluoroolefins (HFOs) and hydrochlorofluorolefins (HCFOs), is also known, as disclosed for example in US 2009/0305876, which is assigned to the assignee of the present invention, and which is incorporated herein by reference. While the '876 application discloses the use of HFO and HFCO blowing agents with various thermoplastic materials to form foams, including PET, there is no disclosure or suggestion to use any of such blowing agents with any other type of polyester resin.
Applicants have come to appreciate that one or more unexpected advantages can be achieved in connection with the formation of thermoplastic foams, and in particular extruded thermoplastic foams, by using a polyester resin as disclosed herein in combination with a blowing agent comprising one of more hydrohaloolefin as disclosed herein.
Applicants have come to appreciate that one or more unexpected advantages can be achieved in connection with the formation of foam articles and members, including covered or faced thermoplastic foams, in which the foam is based on PEF, and preferably such PEF foams that are formed using a blowing agent comprising one of more hydrohaloolefin as disclosed herein. The articles as disclosed herein overcome one or more of the deficiencies of prior art foam article, including those deficiencies describe above, and provide significant and unexpected advantages over prior art foam articles and members, as described in more detail hereinafter.
The present invention includes foam articles comprising: a thermoplastic, closed-cell foam and having at least a first foam surface and being any of Foams 1-4 as defined hereinafter; and
a material different than said thermoplastic, closed-cell foam attached to and/or integral with at least a portion of said first foam surface. For the purposes of convenience, foam articles in accordance with this paragraph are referred to herein as Foam Article 1.
For the purposes of convenience, but not necessarily by way of limitation, the material of the present invention that is different than said thermoplastic, closed-cell foam and which attached to and/or integral with at least a portion of said first foam surface is sometimes referred to herein as a “facing.”
The present invention also includes foam articles comprising:
a thermoplastic, closed-cell foam having at least a first surface; and
a material different than said thermoplastic, closed-cell foam attached to and/or integral with at least a portion of said first foam surface, wherein said thermoplastic, closed-cell foam comprises thermoplastic polymer cell walls comprising at least about 0.5% by weight of ethylene furanoate moieties and optionally one or more co-monomer moieties. For the purposes of convenience, foam articles in accordance with this paragraph are referred to herein as Foam Article 2.
The present invention also includes foam articles comprising:
For the purposes of convenience, foam articles in accordance with this paragraph are referred to herein as Foam Article 3A.
The present invention also includes foam articles comprising:
For the purposes of convenience, foam articles in accordance with this paragraph are referred to herein as Foam Article 3B.
As used herein, the relative foam density (RFD) means the density of the foamed polymer divided by the density of the polymer before expansion, which for simplification purposes herein has been taken as 1.43 g/cc. Thus, for purposes as used herein, the RFD is equal to the density of the foam in g/cc divided by 1.43.
The present invention also includes foam articles comprising:
For the purposes of convenience, foam articles in accordance with this paragraph are referred to herein as Foam Article 3C.
The present invention also includes foam articles comprising:
For the purposes of convenience, foam articles in accordance with this paragraph are referred to herein as Foam Article 3D.
The present invention also includes foam articles comprising:
For the purposes of convenience, foam articles in accordance with this paragraph are referred to herein as Foam Article 3E.
The present invention also provides wind turbine blades comprising a blade shell and a foam article of the present invention, including a foam article selected from each of Foam Articles 1-3 within said blade shell. For the purposes of convenience, methods in accordance with this paragraph are referred to herein as Wind Turbine Blade 1.
The present invention also provides a transportation vehicle comprising a vehicle body and a foam article of the present invention, including a foam article selected from each of Foam Articles 1-3 within said vehicle body. For the purposes of convenience, methods in accordance with this paragraph are referred to herein as Vehicle 1.
The present invention also provides stationary building structures comprising a structural component and a foam article of the present invention, including a foam article selected from each of Foam Articles 1-3, within or otherwise attached to said vehicle body. For the purposes of convenience, methods in accordance with this paragraph are referred to herein as Stationary Building Structure 1.
The present invention also provides sporting equipment article comprising a foam article of the present invention, including a foam article selected from each of Foam Articles 1-3, within or otherwise attached to said sporting equipment article vehicle body. For the purposes of convenience, methods in accordance with this paragraph are referred to herein as Sporting Equipment Article 1.
The present invention also provides sporting equipment article comprising a foam article of the present invention, including a foam article selected from each of Foam Articles 1-3, within or otherwise attached to said sporting equipment article vehicle body. For the purposes of convenience, methods in accordance with this paragraph are referred to herein as Packaging 1.
Poly (ethylene furanoate)
The present invention relates to foams and foam articles that comprise cell walls comprising PEF moieties.
The PEF which forms the cells walls of the foams and foam articles of the present invention can be PEF homopolymer or PEF copolymer, and particularly PEF:PET copolymer.
PEF homopolymer is a known material that is known to be formed by either: (a) esterification and polycondensation of FDCA with MEG; or (b) transesterification and polycondensation of FDME with MEG as illustrated below for example:
A detailed description of such known esterification and polycondensation synthesis methods is provided in GB Patent 621971 (Drewitt, J. G. N., and Lincocoln, J., entitled “Improvements in Polymers”), which is incorporated herein by reference. A detailed description of such know transesterification and polycondensation synthesis methods is provided in Gandini, A., Silvestre, A. J.
D., Neto, C. P., Sousa, A. F., and Gomes, M. (2009), “The furan counterpart of poly(ethylene terephthalate): an alternative material based on renewable resources.”, J. Polym. Sci. Polym. Chem. 47, 295-298. doi: 10.1002/pola.23130, which is incorporated herein by reference.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1A.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1B.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1C.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1D.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1E.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1F.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1G.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1H.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1I.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1J.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1K.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 1L.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 2A.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 2B.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 2C.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 2D.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 2E.
The present invention includes low-density, thermoplastic foam comprising:
Reference will be made at various locations herein to a numbered foam (e.g., Foam 1) or to group of numbered foams that have been defined herein, and such reference means each of such numbered systems, including each system having a number within the group, including any suffixed numbered system. For example, reference to Foam 1 includes a separate reference to each of Foams 1A, 1B, 1C, 1D, etc., and reference to Foams 1-2 is understood to include a separate reference to each of Foams 1A, 1B, 1C, 1D, etc., and each of foams 2A, 2B, 2C, 2D, etc. Further, this convention is used throughout the present specification for other defined materials, including Blowing Agents.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 3.
The present invention includes low-density, thermoplastic foam comprising:
For the purposes of convenience, foams in accordance with this paragraph are referred to herein as Foam 4.
The foams of the present invention, including each of Foams 1-4, are formed from either PEF homopolymers, PEF copolymers, or a combination/mixture of these.
The foams of the present invention, including each of Foams 1-4, may be formed in preferred embodiments from PEF homopolymer in which the polymer has at least 99.5% by weight, or at least 99.9% of by weight, of ethylene furanoate moieties.
It is contemplated that the foams of the present invention, including each of Foams 1-4, may be formed in preferred embodiments from PEF copolymer in which the polymer, including PEF copolymer, has from about 60% to about 99% by weight of ethylene furanoate moieties, or from about 70% to about 99% by weight of ethylene furanoate moieties, or from about 80% to about 99% by weight of ethylene furanoate moieties, or from about 90% to about 99% by weight of ethylene furanoate moieties or from about 95% to about 99.5% by weight of ethylene furanoate moieties.
It is contemplated that the foams of the present invention, including each of Foams 1-4, may be formed in preferred embodiments from PEF copolymer in which the polymer, including PEF copolymer, has from about 40% to about 1% by weight of ethylene furanoate moieties, or from about 30% to about 1% by weight of ethylene furanoate moieties, or from about 20% to about 1% by weight of ethylene furanoate moieties, or from about 10% to about 1% by weight of ethylene furanoate moieties, or from about 5% to about 1% by weight of ethylene furanoate moieties, or from about 5% to about 0.5% by weight of ethylene furanoate moieties.
It is contemplated that the foams of the present invention, including each of Foams 1-4, may be formed in preferred embodiments from PEF copolymer in which the polymer, including PEF copolymer, has from about 40% to about 1% by mole of ethylene furanoate moieties, or from about 30% to about 1% by mole of ethylene furanoate moieties, or from about 20% to about 1% by mole of ethylene furanoate moieties, or from about 10% to about 1% by mole of ethylene furanoate moieties, or from about 5% to about 1% by mole of ethylene furanoate moieties, or from about 5% to about 0.5% by mole of ethylene furanoate moieties.
It is contemplated that the foams of the present invention, including each of Foams 1-4, may be formed in preferred embodiments from PEF copolymer in which the polymer, including PEF copolymer, has from about 40% to about 1% by mole of ethylene furanoate moieties and from about 60% to about 99% by mole of ethylene terephthalate moieties, or from about 30% to about 1% by mole of ethylene furanoate moieties and from about 70% to about 99% by mole of ethylene terephthalate moieties, or from about 20% to about 1% by mole of ethylene furanoate moieties and from about 80% to about 99% by mole of ethylene terephthalate moieties, or from about 10% to about 1% by mole of ethylene furanoate moieties and from about 90% to about 99% by mole of ethylene terephthalate moieties, or from about 5% to about 1% by mole of ethylene furanoate moieties and from about 95% to about 99% by mole of ethylene terephthalate moieties, or from about 5% to about 0.5% by mole of ethylene furanoate moieties and from about 95% to about 99.5% by mole of ethylene terephthalate moieties.
For those embodiments of the present invention involving PEF copolymers, it is contemplated that those skilled in the art will be able, in view of the teachings contained herein, to select the type and amount of co-polymeric materials to be used within each of the ranges described herein to achieve the desired enhancement/modification of the polymer without undue experimentation.
For those embodiments of the present invention involving the use of PEF homopolymer or PEF copolymer, it is contemplated that such material may be formed with a wide variety of molecular weights and physical properties within the scope of the present invention. In preferred embodiments, the foams, including each of Foams 1-4, are formed from PEF having the ranges of characteristics identified in Table 1 below, which are measured as described in the Examples hereof:
In general, it is contemplated that those skilled in the art will be able to formulate PEF polymers within the range of properties described above without undue experimentation in view of the teachings contained herein. In preferred embodiments, however, PEF (including PEF homopolymer and PEF copolymer) having these properties is achieved using one or more of the synthesis methods described above, in combination with a variety of known supplemental processing techniques, including by treatment with chain extenders, such as PMDA (and alternatives and supplements to PMDA, such as ADR, pentaerythritol (hereinafter referred to as “PENTA”) and talc as described in the present examples, and others) and/or SSP processing. It is believed that, in view of the disclosures contained herein, including the polymer synthesis described in the Examples below, a person skilled in the art will be able to produce PEF polymers within the range of characteristics described in the table above and elsewhere herein, including the use of methods to enhance crystallization of polymers, including. Such processing conditions include methods of increasing crystallization as described herein, and such methods as are disclosed in the Examples hereof.
An example of the process for chain extension treatment of polyesters is provided in the article “Recycled poly(ethylene terephthalate) chain extension by a reactive extrusion process,” Firas Awaja, Fugen Daver, Edward Kosior, 16 Aug. 2004, available at https://doi.org/10,1002/pen,20155, which is incorporated herein by reference. As explained in US 1009/0264545, which is incorporated herein by reference, chain extenders generally are typically compounds that are at least di-functional with respect to reactive groups which can react with end groups or functional groups in the polyester to extend the length of the polymer chains. In certain cases, as disclosed herein, such a treatment can advantageously increases the average molecular weight of the polyester to improve its melt strength and/or other important properties. The degree of chain extension achieved is related, at least in part, to the structure and functionalities of the compounds used. Various compounds are useful as chain extenders. Non-limiting examples of chain extenders include trimellitic anhydride, pyromellitic dianhydride (hereinafter referred to as PMDA), trimellitic acid, haloformyl derivatives thereof, or compounds containing multi-functional epoxy (e.g., glycidyl), or oxazoline functional groups. Nanocomposite material such as finely dispersed nanoclay may optionally be used for controlling viscosity. Commercial chain extenders include CESA-Extend from Clariant, Joncryl from BASF, or Lotader from Arkema. The amount of chain extender can vary depending on the type and molecular weight of the polyester components. The amount of chain extender used to treat the polymer can vary widely, and in preferred embodiments ranges from about 0.1 to about 5 wt. %, or preferably from about 0.1 to about 1.5 wt. %. Examples of chain extenders are also described in U.S. Pat. No. 4,219,527, which is incorporated herein by reference.
An example of the process for SSP processing of poly(ethylene furanoate) is provided in the article “Solid-State Polymerization of Poly(ethylene furanoate) Biobased Polyester, I: Effect of Catalyst Type on Molecular Weight Increase,” Nejib Kasmi, Mustapha Majdoub, George Z. Papageorgiou, Dimitris S. Achilias, and Dimitrios N. Bikiaris, which is incorporated herein by reference.
The PEF thermoplastic polymers which are especially advantageous for making foams, including Foams 1-4 and FC1-FC11, and foam articles, including Foam Articles 1-4, of the present invention are identified in the following Thermoplastic Polymer Table (Table 2A), wherein all numerical values in the table are understood to be preceded by the word “about.”
The PEF thermoplastic polymers which are especially advantageous for making, including Foams 1-4 and FC1-FC11, and foam articles, including Foam Articles 1-4, also include those materials identified in the following Thermoplastic Polymer Table (Table 21B), wherein all numerical values in the table are understood to be preceded by the word “about.”
The PEF thermoplastic polymers which are especially advantageous for making, including Foams 1-4 and FC1-FC11, and foam articles, including Foam Articles 1-4, of the present invention also include those materials identified in the following Thermoplastic Polymer Table (Table 2C), wherein all numerical values in the table are understood to be preceded by the word “about.”
For the purposes of definition of terms used herein, it is to be noted that reference will be made at various locations herein to the thermoplastic polymers identified in the first column in each of rows in the TPP table above, and reference to each of these numbers is a reference to a thermoplastic polymer as defined in the corresponding columns of that row. Reference to a group of TPPs that have been defined in the table above by reference to a TPP number means separately and individually each such numbered TPP, including each TPP having the indicated number, including any such number that has a suffix. So for example, reference to TPP1 is a separate and independent reference to TPP1A, TPP1B, TPP1C, TPP1D and TPP1E. Reference to TPP1-TPP2 is a separate and independent reference to TPP1A, TPP1B, TPP1C, TPP1D, TTP1E, TPP2A, TPP2B, TPP2C, TPP2D and TPP1E. This use convention is used for the Foamable Composition Table and the Foam Table below as well.
As explained in detail herein, the present invention includes, but is not limited to, applicant's discovery that a select group of blowing agents are capable of providing foamable PEF foamable compositions and PEF foams and foam articles, including Foam Articles 1-4, having a difficult-to-achieve and surprising combination of physical properties, including low density as well as good mechanical strength properties.
The blowing agent used in accordance with the present invention preferably comprises one or more hydrohaloolefins having three or four carbon atoms. For the purposes of convenience, a blowing agent in accordance with this paragraph is sometimes referred to herein as Blowing Agent 1A.
The blowing agent used in accordance with the present invention preferably consists essentially of one or more hydrohaloolefins having three or four carbon atoms. For the purposes of convenience, a blowing agent in accordance with this paragraph is sometimes referred to herein as Blowing Agent 1B.
The blowing agent used in accordance with the present invention preferably consists essentially of one or more hydrohaloolefins having three or four carbon atoms. For the purposes of convenience, a blowing agent in accordance with this paragraph is sometimes referred to herein as Blowing Agent 1C.
The blowing agent used in accordance with of the present invention preferably comprises one or more of 1234ze, 1234yf, 1336mzz, 1233zd and 1224ydf (referred to hereinafter for convenience as Blowing Agent 2A); or comprises one or more of trans1234ze, 1336mzz, trans1233zd and cis1224yd (referred to hereinafter for convenience as Blowing Agent 3A); or comprises one or more of trans1234ze, trans1336mzz, trans1233zd and cis1224yd (referred to hereinafter for convenience as Blowing Agent 4A); or comprises one or more of trans1234ze and trans1336mzz (referred to hereinafter for convenience as Blowing Agent 5A); or comprises trans1234ze (referred to hereinafter for convenience as Blowing Agent 6A); or comprises trans1336mzz (referred to hereinafter for convenience as Blowing Agent 7A); or comprises cis1336mzz (referred to hereinafter for convenience as Blowing Agent 8A); or comprises 1234yf(referred to hereinafter for convenience as Blowing Agent 9A); or comprises 1224yd (referred to hereinafter for convenience as Blowing Agent 10A); or comprises trans1233zd(referred to hereinafter for convenience as Blowing Agent 11A).
The blowing agent used in accordance with of the present invention preferably consists essentially of one or more of 1234ze, 1234yf, 1336mzz, 1233zd and 1224ydf (referred to hereinafter for convenience as Blowing Agent 2B); or consists essentially of one or more of trans1234ze, 1336mzz, trans1233zd and cis1224yd (referred to hereinafter for convenience as Blowing Agent 3B); or consists essentially of one or more of trans1234ze, trans1336mzz, trans1233zd and cis1224yd (referred to hereinafter for convenience as Blowing Agent 4B); or consists essentially of one or more of trans1234ze and trans1336mzz (referred to hereinafter for convenience as Blowing Agent 5B); or consists essentially of trans1234ze (referred to hereinafter for convenience as Blowing Agent 6B); or consists essentially of trans1336mzz (referred to hereinafter for convenience as Blowing Agent 7B); or consists essentially of cis1336mzz (referred to hereinafter for convenience as Blowing Agent 8B); or consists essentially of 1234yf(referred to hereinafter for convenience as Blowing Agent 9B); or consists essentially of 1224yd (referred to hereinafter for convenience as Blowing Agent 10B); or consists essentially of trans1233zd(referred to hereinafter for convenience as Blowing Agent 11B).
The blowing agent used in accordance with of the present invention preferably consists of one or more of 1234ze, 1234yf, 1336mzz, 1233zd and 1224ydf (referred to hereinafter for convenience as Blowing Agent 2B); or consists of one or more of trans1234ze, 1336mzz, trans1233zd and cis1224yd (referred to hereinafter for convenience as Blowing Agent 3B); or consists of one or more of trans1234ze, trans1336mzz, trans1233zd and cis1224yd (referred to hereinafter for convenience as Blowing Agent 4B); or consists of one or more of trans1234ze and trans1336mzz (referred to hereinafter for convenience as Blowing Agent 5B); or consists of trans1234ze (referred to hereinafter for convenience as Blowing Agent 6B); or consists of trans1336mzz (referred to hereinafter for convenience as Blowing Agent 7B); or consists of cis1336mzz (referred to hereinafter for convenience as Blowing Agent 8B); or consists of 1234yf(referred to hereinafter for convenience as Blowing Agent 9B); or consists of 1224yd (referred to hereinafter for convenience as Blowing Agent 10B); or consists of trans1233zd(referred to hereinafter for convenience as Blowing Agent 11B).
It is thus contemplated that the blowing agent of the present invention, including each of Blowing Agents 1-11, can include, in addition to each of the above-identified blowing agent(s), co-blowing agent including in one or more of the optional potential co-blowing agents as described below. In preferred embodiments, the present foamable compositions, foams, and foaming methods include a blowing agent as described according described herein, wherein the indicated blowing agent (including the compound or group of compound(s) specifically identified in each of Blowing Agent 1-11) is present in an amount, based upon the total weight of all blowing agent present, of at least about 50% by weight, or preferably at least about 60% by weight, preferably at least about 70% by weight, or preferably at least about 80% by weight, or preferably at least about 90% by weight, or preferably at least about 95% by weight, or preferably at least about 99% by weight, based on the total of all blowing agent components.
It is contemplated and understood that blowing agent of the present invention, including each of Blowing Agents 1-11, can include one or more co-blowing agents which are not included in the indicated selection, provided that such co-blowing agent in the amount used does not interfere with or negate the ability to achieve relatively low-density foams as described herein, including each of Foams 1-4, and preferably further does not interfere with or negate the ability to achieve foam with mechanical strengths properties as described herein. It is contemplated, therefore, that given the teachings contained herein a person of skill in the art will be able to select, by way of example, one or more of the following potential co-blowing agents for use with a particular application without undue experimentation: one or more saturated hydrocarbons or hydrofluorocarbons (HFCs), particularly C4-C6 hydrocarbons or C1-C4 HFCs, that are known in the art. Examples of such HFC co-blowing agents include, but are not limited to, one or a combination of difluoromethane (HFC-32), fluoroethane (HFC-161), difluoroethane (HFC-152), trifluoroethane (HFC-143), tetrafluoroethane (HFC-134), pentafluoroethane (HFC-125), pentafluoropropane (HFC-245), hexafluoropropane (HFC-236), heptafluoropropane (HFC-227ea), pentafluorobutane (HFC-365), hexafluorobutane (HFC-356) and all isomers of all such HFC's. With respect to hydrocarbons, the present blowing agent compositions also may include in certain preferred embodiments, for example, iso, normal and/or cyclopentane and butane and/or isobutane. Other materials, such as water, CO2, CFCs (such as trichlorofluoromethane (CFC-11) and dichlorodifluoromethane (CFC-12)), hydrochlorocarbons (HCCs such as dichloroethylene (preferably trans-dichloroethylene), ethyl chloride and chloropropane), HCFCs, C1-C5 alcohols (such as, for example, ethanol and/or propanol and/or butanol), C1-C4 aldehydes, C1-C4 ketones, C1-C4 ethers (including ethers (such as dimethyl ether and diethyl ether), diethers (such as dimethoxy methane and diethoxy methane)), and methyl formate, organic acids (such as but not limited to formic acid), including combinations of any of these may be included, although such components are not necessarily preferred in many embodiments due to negative environmental impact.
The foams of the present invention, including each of Foams 1-4, or foam made from PEF polymer of the present invention, including Thermoplastic Polymer TPP1A-TPP22E, or any of the foams described in Examples 1-22, may generally be formed from a foamable composition of the present invention. In general, the foamable compositions of the present invention may be formed by combining a PEF polymer of the present invention, including each of Thermoplastic Polymer TPP1A-TPP22E, with a blowing agent of the present invention, including each of Blowing Agents 1-11.
Foamable compositions that are included within the present invention and which provide particular advantage in connection with forming the foams of the present invention, are described in the following Foamable Composition Table (Table 3A and Table 3B), in which all numerical values in the table are understood to be preceded by the word “about” and in which the following terms used in the table have the following meanings:
It is contemplated that any one or more of a variety of known techniques for forming a thermoplastic foam can be used in view of the disclosures contained herein to form a foam of the present invention, including each of Foams 1-4, all such techniques and all foams and foamed articles, including Foamed Articles 1-3 formed thereby are within the broad scope of the present invention. For clarity, it will be noted that definition of the foams in the Table below all begin with only the letter F, in contrast to the foams defined by the paragraphs in the summary above, which begin with the capitalized phrase Foamable Composition.
In general, the forming step involves first introducing into a PEF polymer of the present invention, including each of TPP1-TPP22, a blowing agent of the present invention, including each of Blowing Agents 1-31, to form a foamable PEF composition comprising PEF and blowing agent. One example of a preferred method for forming a foamable PEF composition of the present invention is to plasticize the PEF, preferably comprising heating the PEF to its melt temperature, preferably above its melt temperature, and thereafter exposing the PEF melt to the blowing agent under conditions effective to incorporate (preferably by solubilizing) the desired amount of blowing agent into the polymer melt.
In preferred embodiments, the foaming methods of the present invention comprise providing a foamable composition of the present invention, including each of FC1-FC13 and foaming the provided foamable composition. In preferred embodiments, the foaming methods of the present invention comprising providing a foamable composition of the present invention, including each of FC1-FC13, and extruding the provided foamable composition to form a foam of the present invention and then forming a foam article of the present invention, including each of Foam Articles 1-4.
Foaming processes of the present invention can include batch, semi-batch, continuous processes, and combinations of two or more of these. Batch processes generally involve preparation of at least one portion of the foamable polymer composition, including each of FC1-FC13, in a storable state and then using that portion of foamable polymer composition at some future point in time to prepare a foam. Semi-batch process involves preparing at least a portion of a foamable polymer composition, including each of FC1-FC13, and intermittently expanding that foamable polymer composition into a foam including each of Foams 1-4 and each of foams F1-F8, all in a single process. For example, U.S. Pat. No. 4,323,528, herein incorporated by reference, discloses a process for making thermoplastic foams via an accumulating extrusion process. The present invention thus includes processes that comprises: 1) mixing PEF thermoplastic polymer, including each of TPP1-TPP22, and a blowing agent of the present invention, including each of Blowing Agents 1-31, under conditions to form a foamable PEF composition; 2) extruding the foamable PEF composition, including each of FC1-FC13, into a holding zone maintained at a temperature and pressure which does not allow the foamable composition to foam, where the holding zone preferably comprises a die defining an orifice opening into a zone of lower pressure at which the foamable polymer composition, including each of FC1-FC13, foams and an openable gate closing the die orifice; 3) periodically opening the gate while substantially concurrently applying mechanical pressure by means of a movable ram on the foamable polymer composition, including each of FC1-FC13, to eject it from the holding zone through the die orifice into the zone of lower pressure, and 4) allowing the ejected foamable polymer composition to expand, under the influence of the blowing agent, to form the foam, including each of Foams 1-4 and each of foams F1-F8.
The present invention also can use continuous processes for forming the foam. By way of example such a continuous process involves forming a foamable PEF composition, including each of FC1-FC13, and then expanding that foamable PEF composition without substantial interruption. For example, a foamable PEF composition, including each of FC1-FC13, may be prepared in an extruder by heating the selected PEF polymer resin, including each of TPP1-TPP22, to form a PEF melt, incorporating into the PEF melt a blowing agent of the present invention, including each of Blowing Agents 1-11, preferably by solubilizing the blowing agent into the PEF melt, at an initial pressure to form a foamable PEF composition comprising a substantially homogeneous combination of PEF and blowing agent, including each of FC1-FC13, and then extruding that foamable PEF composition through a die into a zone at a selected foaming pressure and allowing the foamable PEF composition to expand into a foam, including each of Foams 1-4 and each of foams F1-F8 described below, under the influence of the blowing agent. Optionally, the foamable PEF composition which comprises the PEF polymer, including each of FC1-FC13, and the incorporated blowing agent, including each of Blowing Agents 1-11, may be cooled prior to extruding the composition through the die to enhance certain desired properties of the resulting foam, including each of Foams 1-6 and each of foams F1-F8.
The methods can be carried out, by way of example, using extrusion equipment of the general type disclosed in
The foamable polymer compositions of the present invention, including each of FC1-FC13, may optionally contain additional additives such as nucleating agents, cell-controlling agents, glass and carbon fibers, dyes, pigments, fillers, antioxidants, extrusion aids, stabilizing agents, antistatic agents, fire retardants, IR attenuating agents and thermally insulating additives. Nucleating agents include, among others, materials such as talc, calcium carbonate, sodium benzoate, and chemical blowing agents such azodicarbonamide or sodium bicarbonate and citric acid. IR attenuating agents and thermally insulating additives can include carbon black, graphite, silicon dioxide, metal flake or powder, among others. Flame retardants can include, among others, brominated materials such as hexabromocyclodecane and polybrominated biphenyl ether. Each of the above-noted additional optional additives can be introduced into the foam at various times and that various locations in the process according to known techniques, and all such additives and methods of addition or within the broad scope of the present invention.
In preferred embodiments, the foams of the present invention are formed in a commercial extrusion apparatus and have the properties as indicated in the following Table 4, with the values being measured as described in the Examples hereof:
20-300
Foams that are included within the present invention and which provide particular advantage are described in the following Table 5, and in which all numerical values in the table are understood to be preceded by the word “about” and in which the designation NR means “not required.”
The foams of the present invention have wide utility. The present foams, including each of Foams 1-4 and foams F1-F8, have unexpected advantage in applications requiring low density and/or good compression and/or tensile and/or shear properties, and/or long-term stability, and/or sustainable sourcing, and/or being made from recycled material and being recyclable. In particular, the present foams, including each of Foams 1-6 and each of foams F1-F8, have unexpected advantage in: wind energy applications (wind turbine blades (shear webs, shells, cores, and root); marine applications (hulls, decks, superstructures, bulkheads, stringers, and interiors); industrial low weight applications; automotive and transport applications (interior and exterior of cars, trucks, trains, aircraft, and spacecraft).
PEF:PET copolymers can be formed by any means to those known to those skilled in the art, including but not limited to those procedures described in the Examples hereof.
The foams of the present invention, including each of Foam 1-4, are formed from either PEF homopolymers, PEF copolymers, PEF:PET copolymers or a combination/mixture of these.
The foams, including each of Foam 1-4, may be formed in preferred embodiments from PEF homopolymer in which the polymer has at least 99.5% by weight, or at least 99.9% of by weight, of ethylene furanoate moieties.
It is contemplated that the foams of the present invention, including each of Foam 1-3, may be formed in preferred embodiments from PEF copolymer in which the polymer, including PEF copolymer that has from about 0.5% to about 99% by weight of ethylene furanoate moieties. The invention includes foams, including each of Foam 1-3, wherein the thermoplastic polymer consists essentially of the components as described in the following table:
The foams of the present invention, including each of Foams 1-3, can comprise closed cell walls comprising each of the thermoplastic polymers of the present invention, including each of TMP1-TMP12 describe in the table above.
For those embodiments of the present invention involving PEF copolymers, it is contemplated that those skilled in the art will be able, in view of the teachings contained herein, to select the type in an amount of co-polymeric materials to be used within each of the ranges described herein to achieve the desired enhancement/modification of the polymer without undue experimentation.
It is contemplated that the TMPs of the present invention may be formed with a variety of physical properties, including the following ranges of polymer characteristics, which are measured as described in the Examples hereof:
In general, it is contemplated that those skilled in the art will be able to formulate PEF polymers within the range of properties described above without undue experimentation in view of the teachings contained herein. In preferred embodiments, however, PEF polymer according to the present invention (including PEF:PET copolymers of the present invention), having these properties is achieved using one or more of the synthesis methods described above, in combination with a variety of known supplemental processing techniques, including by treatment with chain extenders, such as PMDA, and/or SSP processing.
An example of the process for chain extension treatment of polyesters is provided in the article “Recycled poly(ethylene terephthalate) chain extension by a reactive extrusion process,” Firas Awaja, Fugen Daver, Edward Kosior, 16 Aug. 2004, available at https://doi.org/10,1002/pen.20155, which is incorporated herein by reference. As explained in US 1009/0264545, which is incorporated herein by reference, chain extenders generally are typically compounds that are at least di-functional with respect to reactive groups which can react with end groups or functional groups in the polyester to extend the length of the polymer chains. In certain cases, as disclosed herein, such a treatment can advantageously increase the average molecular weight of the polyester to improve its melt strength and/or other important properties. The degree of chain extension achieved is related, at least in part, to the structure and functionalities of the compounds used. Various compounds are useful as chain extenders. Non-limiting examples of chain extenders include trimellitic anhydride, pyromellitic dianhydride (PMDA), trimellitic acid, haloformyl derivatives thereof, or compounds containing multi-functional epoxy (e.g., glycidyl), or oxazoline functional groups. Nanocomposite material such as finely dispersed nanoclay may optionally be used for controlling viscosity. Commercial chain extenders include CESA-Extend from Clariant, Joncryl from BASF, or Lotader from Arkema. The amount of chain extender can vary depending on the type and molecular weight of the polyester components. The amount of chain extender used to treat the polymer can vary widely, and in preferred embodiments ranges from about 0.1 to about 5 wt. %, or preferably from about 0.1 to about 1.5 wt. %. Examples of chain extenders are also described in U.S. Pat. No. 4,219,527, which is incorporated herein by reference.
An example of the process for SSP processing of poly(ethylene furanoate) is provided in the article “Solid-State Polymerization of Poly(ethylene furanoate) Biobased Polyester, I: Effect of Catalyst Type on Molecular Weight Increase,” Nejib Kasmi, Mustapha Majdoub, George Z. Papageorgiou, Dimitris S. Achilias, and Dimitrios N. Bikiaris, which is incorporated herein by reference.
As explained in detail herein, the present invention involves applicant's discovery that a select group of blowing agents are capable of providing foamable PEF compositions, including each of Foamable Composition 1, and PEF foams, including Foams 1-3, having a difficult to achieve a surprising combination of physical properties, including low density as well as good mechanical strengths properties.
The foams of the present invention are thermoplastic foams, and generally it is contemplated that any one or more of a variety of known techniques for forming a thermoplastic foam can be used in view of the disclosures contained herein, and all such techniques and all foams formed thereby or within the broad scope of the present invention.
Foam Articles
The foams and foam articles of the present invention have wide utility. The present foam articles, including each of Foam Articles 1-3, have unexpected advantage, especially in applications requiring low density and/or good compression and/or tensile and/or shear properties, and/or long-term stability, and/or sustainable sourcing, and/or being made from recycled material and being recyclable. In particular, the present foam articles, including each of Foam Articles 1-3, have unexpected advantage in: wind energy applications (wind turbine blades (shear webs, shells, cores, and nacelles); marine applications (hulls, decks, superstructures, bulkheads, stringers, and interiors); industrial low weight applications; automotive and transport applications (interior and exterior of cars, trucks, trains, aircraft, and spacecraft); stationary building structure; and sporting equipment.
As described above, the foam articles of the present invention, including each of Foam Articles 1-3, generally comprise a foam which has a facing on at least a portion of the surface thereof. As used herein, reference to a numbered foam article or group of numbered foam articles that have been defined herein means each of such numbered foam articles, including each foam article having a number within the group, including any suffixed number. For example, reference to Foam Article 3 includes reference to each of Foam Articles 3A, 3B, 3C and 3D.
The size and shape of the foam used in the present foam articles can vary widely within the scope of the present invention depending on the use that will be made of the article, and all such sizes and shapes are within the scope of the present invention. In many applications, the foam article will be in the form of a three dimensional form in which the length and/or width are much larger in dimension than the thickness. In other applications, the form of the article can be characterized as a block, slab, panel or the like, or as a particular shape such as I-beam, U-shaped or other specific shape.
For convenience of illustration but not by way of limitation,
The connecting/integrating film, layer or region 3 can be any material and in any thickness needed to attach or integrate the facing 3 to the core 1. Furthermore, while the film or layer 3 is shown as generally as being between the facing 2 and the core 1, it will be understood and appreciated by those skilled in the art that the connecting layer or film generally extends into each of the foam core 1 and the facing 2. In certain preferred embodiments, the film or layer 3 can comprise adhesive material, such as an epoxy adhesive, which bonds the core 1 and the facing sheet 2 together. Other adhesive resins which may be used to bond the facing to the foam include polyurethane, vinyl ester, polyester, cyanate esters, urethane-acrylates, bismaleimides, polyimides, silicones, phenolics, polypropenes, caprolactams and combinations of any two or more of these. In general, the processing of forming the foam articles of the present invention involves steps which provide a strong chemical and/or physical bond between facing 2 and the foam 1, and all such steps are within the scope of the present invention.
In preferred embodiments, the facing 2 comprises a plurality of inter-bonded sheets or mats which can be the same or different and are bound to one another by appropriate means, including inter-bonding layers of adhesive or resin or inter-bonding regions formed by material integration (e.g., melting together to form an integrated region). In such embodiments, it is contemplated that the number of inter-bonded sheets that make-up the facing 2 can vary widely, and in preferred embodiments the facing comprises from 2 to 10 inter-bonded sheets, and even more preferably from about 3 to about 5 inter-bonded sheets.
While it is understood that the dimensions of the present foam articles, including each of Foam Articles 1-3, can vary widely, in preferred embodiments involving the use in connections with wind turbine applications, the face sheet can vary from about 0.1 mm to about 3 mm, or from about 0.4 mm to about 1.5 mm. Furthermore, it is generally understood that the relative thickness of the foam compared to the face sheet can vary over a wide range depending on the particular application, and that those skilled in the art will be able to make appropriate selections in view of the teachings contained herein, and that in general the face sheet thickness will be less than the thickness of the foam.
Preferred materials which are used to form the foam articles of the present invention, including each of Foam Articles 1-3, are described in additional detail below.
Facings
The foam articles of the present invention include a facing that can have a wide variety of dimensions, and the dimensions used will depending upon the particular needs of the application in which the foam article will be used, and articles having all such dimensions are within the scope of the present invention.
The materials which form the facing material may also vary widely depending on the particular use intended for the foam article, and again all such materials are within the scope of present invention. For example, the facing used in the present foam articles, including each of Foam Articles 1-3, comprises one or more fibrous sheets or mats wherein the fibrous portion can be formed from a wide variety of materials, including for example, glass fibers (preferably impregnated with resin and/or polymers), other natural fibers (such as cellulose and other plant derived materials), mineral fibers (such as quartz), metal fibers or films, carbon fibers (preferably impregnated with or reinforced with one or more polymers, including thermoplastic polymer and/or thermoset polymers), synthetic fibers, such as polyesters (including fibers comprising furan-based polyesters, as disclosed for example in US 2015/0111450, which is incorporated herein by reference), polyethylenes, aramids, Kevlars, and any and all combinations of these.
Particular Uses
The foam articles of the present invention have wide utility. The present foam articles, including each of Foam Articles 1-3, have unexpected advantage in applications requiring low density and/or good compression and/or tensile and/or shear properties, and/or long-term stability, and/or sustainable sourcing, and/or being made from recycled material and being recyclable. In particular, the present foam articles, including each of Foam Articles 1-3, have unexpected advantage in: fluid energy transfer components, such as for example in wind and water energy transfer applications (e.g., wind turbine blades (shear webs, shells, cores, and nacelles) for transferring wind energy from fixed or mobile devices located in air, and vortex, tidal, oceans current oscillating hydrofoils and kites which recover water kinetic energy from fixed or mobile devices located in water); marine applications (hulls, decks, superstructures, bulkheads, stringers, and interiors); industrial low weight applications; automotive and transport applications (interior and exterior of cars, trucks, trains, aircraft, and spacecraft); and packaging applications.
With particular reference to
The following Foam Use Table includes an identification of some of the preferred uses for some of the preferred articles of the present invention, wherein the column heading “Foam Article Number” refers to the Foam Article as identified above and the column heading Particular Foam refers to the Foams identified above.
Without limiting the full scope of the present invention, Applicants have conducted a series of experiments using batch process laboratory equipment for the purposes of demonstrating the utility of the PEF homopolymers and the PEF-based copolymers of the present invention and to compare the performance of the inventive foams made in accordance with the present invention to foams made from PET. It will be appreciated by those skilled in the art that scaling up such laboratory tests to commercial grade extrusion will generally result in a substantial increase in many of the strength values reported herein for reasons that are inherent in commercial processes and testing. By way of non-limiting example of these scale-up factors, commercial extruded foams are generally stronger in the extrusion direction because of the impact of being forced under pressure through an extrusion die, the common use of roll stacks, and the testing of strength being done in the extrusion direction. Extruded commercial foam is also generally formed by seaming sections of foam together, and the presence of these seams tends to strengthen the foam overall. As a result of these and potentially other factors, the strength results reported in these examples will generally be lower than the results that a person skilled in the art would expected when the foaming process is carried out on a commercial extruder. Nevertheless, the results reported herein are understood by those skilled in the art to be generally reflective on a foam to foam comparative basis of results to be expected when the process is scaled up to commercial extrusion.
These test utilized herein involved the synthesis of a series of reference PET polymers covering a range of physical properties, including molecular weights, crystallinities, melting points, glass transition and decomposition temperatures, followed by foaming under a wide range of processing conditions, including melt temperatures, melt times pre-foaming pressures and temperatures. Applicants also synthesized a series of PEF polymers (including homopolymers and copolymers) covering a range of physical properties and foaming them under a similarly wide range of processing conditions.
Polymer Formation
A series of polymers were synthesized generally in accordance with the procedures described in Synthesis Examples 1-3 below. The polymers produced in accordance with the present invention included homopolymers of PEF and copolymers of PEF with PET in various mole ratios. Homopolymers of PET were also produced for comparison purposes.
A wide variety of synthesis parameters were used for each type of polymer in order to produce a series of polymers having a variety of polymer physical properties, including Glass Transition Temperature (Tg), Melt Temperature (Tm), Decomposition Temperature (Td), Crystallinity (Cr) and Molecular Weight. These polymers were then used to produce PEF foams in accordance with the present invention and PET foams for comparison purposes. The polymers thus produced are identified in the following Table PFEx.
The series of PEF foams and reference PET foams were prepared using the highly preferred 1234ze(E) of the present invention as the blowing agent. Representative methods for forming the foams are reported in Foam Formation Examples 1-3 below. The foams included foam densities that are grouped for convenience into the following ranges: (1) in the low density range of 0.060 g/cc up to 0.115 g/cc; (2) in a medium density range of greater than 0.115 g/cc up to 0.170 g/cc and (3) in a high density region of greater than 0.170 g/cc up to 0.250 g/cc. A consistent set of processing conditions for a given range of comparable polymer properties were utilized. The details of each of these sets of experimental results are explained in the examples and tables which follow.
For each polymer, a unique and narrow range of melting and pre-foaming temperatures were identified for the foaming experiments. The foams thus produced throughout the Examples in this application, were tested to determine the density of foam using a method which corresponds generally to ASTM D71, except that hexane is used for displacement instead of water. In order to facilitate comparison of the densities of the foam produced in these examples. In addition, each of the foams produced in these examples was tested to determine tensile strength (hereinafter referred to as TS) and compressive strength (hereinafter referred to as CS) and the sum of TS and CS (hereinafter referred to as TS+CS). The tensile strength and compressive strength measurements were based on the guidelines provided in ASTM C297 and ISO 844, respectively, with the measurement in each case in the direction of depressurizing.
A series of foams were produced using the polymers described in Table PFEx above using foam processes which generally comprised placing approximately 1 gram of the polymer (as indicated in the following Table FFEx below) in a glass container, which was then loaded into a 60 cc volume autoclave and dried under vacuum for six (6) hours at an elevated temperature in the range of 130° C. to 150° C. The dried polymer was then cooled to room temperature. For each case in Table FFEx below, the blowing agent consisted of 1234ze(E). The blowing agent was pumped into the autoclave containing the dried polymer, and then the autoclave was heated to bring the polymer to a melt state. The PET/blowing agent mixture was maintained in the melt state at the melt state pressure and temperature for about a period (designated below as the “Melt Time”, MTime) as indicated in the table (either 60 minutes or 15 minutes). The temperature (MTemp) and pressure (MP) of the melt/blowing agent were then reduced over a period of about 5-15 minutes to pre-foaming temperature (PFT) and pre-foaming pressure (PFP), as indicated in Table FFEx. The autoclave was then maintained at about this temperature and pressure for a period of about 30 minutes to ensure that the amount of blowing agent incorporated into the melt under such conditions reached equilibrium. The temperature and pressure in the autoclave were then reduced rapidly (over a period of about 10 seconds for the pressure reduction and about 1-10 minutes for the temperature reduction using chilled water) to ambient conditions (approximately 22° C. and 1 atmosphere) and foaming occurred. The conditions used, including the amount of the blowing agent and the melt temperature and pressure, were determined after several tests, based on the ability to form acceptable foams with density values in the range of about 0.06 to 0.115 grams per cubic centimeter (g/cc) which are referred to for convenience in the tables below as low density foams, or in the range of greater than 0.115 to 0.250 g/cc, which are referred to for convenience in the tables below as high density foams.
Representative methods for forming the foams are reported in Foam Formation Examples 1-3 below, in which all foams used 1234ze(E) as the sole blowing agent. In addition, Foam Formation Example 4 reports a series of foams made from PEF:PET copolymer and blowing agent 1233zd and 1336mzz, in addition to the preferred blowing agent 1234ze(E′). These foams were prepared using the same general procedures as disclosed in Foam Formation Examples 1-3. While the foams made using 1234ze(E) were found to be unexpectedly superior to foams blown with other blowing agents other than 1234zd(E), acceptable foams were made and have substantial utility when the blowing agent comprises, or consists essentially of or consists of 1233zd(E) or 1336mzz(Z), as also revealed by the data reported in Foam Formation Example 3. Applicants have surprisingly found that the foams of the present invention have superior strength characteristics, especially as measured by the value of the combined tensile strength and compressive strength, which combination also reflects superior shear strength properties. In particular, the following charts show the trend line data for the combined value of the tensile strength and the compressive strength as a function of foam density in each of the low density region (see
As shown in
As shown in
As described in the present specification above, including the Examples, the foams of the present invention provide important and unexpected advantages in connection with many uses. These advantages include the ability to achieve: (1) a superior strength for a given density; (2) reduced density, and hence a weight advantage, for a foam with the same density as previously used PET foam; and (3) a combination of superior strength and reduced density. Based on the average values illustrated in
A wind turbine generator having a configuration of the general type illustrated in
A wind turbine generator having a configuration as described in Comparative Example 1 is constructed, except that the high density PET foam and/or the low density PET foam of Comparative Example 1 is replaced with foam of the present invention based on any one of Foams 1-4. For this example, the high density PET foam and/or the low density PET foam of Comparative Example 1 is replaced by foam made from preferred PEF homopolymer foam blown with 1234ze as represented by the PEF Replacement Tables above and the trend lines in
Many other advantageous options for replacing PET foam with foams of the present invention are possible, and several of these options (together with option described in this example above, which is identified below as Option 1), are exemplified in the following table:
As can be seen from the options shown in the table above, the extent of weight reduction in the blade weight ranges from 2.5% to 3.95%, and for any given case those skilled in the art may select an option that does not provide the highest weight reduction in order to satisfy other requirements. For example, for those cases in which the highest priority is to eliminate any foam that is sourced from petroleum products, then option 3 would be selected since it relies on 100% PEF homopolymer which can be sourced 100% from non-petroleum products. Alternatively, for those cases in which cost is a primary consideration, then it is expected that Option 4 may be of interest because it is expected that PEFPET copolymer may be available at a lower cost than PEF homopolymer. Many other advantageous combinations and options will be understood by those skilled in the art to be available for any particular replacement case in view of the teachings and examples contained herein.
A wind turbine generator having a configuration as described in Example 1A is constructed, except that the PET foam core material of Comparative Example 1A is replaced with a PEF polymer foam of the present invention blown with a blowing agent consisting of HFO-1336mzz, including as reported in Form Formation Example 4. Acceptable results are observed.
A wind turbine generator having a configuration as described in Example 1A is constructed, except that the PET foam core material of Comparative Example 1A is replaced with a PEF polymer foam of the present invention blown with a blowing agent consisting of HFO-1336mzz, including as reported in Form Formation Example 4. Acceptable results are observed.
A wind turbine generator having a configuration as described in Example 1A is constructed, except that the PET foam core material of Comparative Example 1A is replaced with a PEF polymer foam of the present invention blown with a blowing agent consisting of HFO-1224yd. Acceptable results are observed.
A wind turbine generator having a configuration as described in Example 1 is constructed, except that the PET foam core material of Comparative Example 1 is replaced with a foam of the present invention made from PEF polymer using ADR additive as described in Foam Formation Example 5. Acceptable results are observed.
A wind turbine generator having a configuration as described in Example 1 is constructed, except that the PET foam core material of Comparative Example 1 is replaced with a foam of the present invention made from PEF polymer using PENTA additive as described in Foam Formation Example 5. Acceptable results are observed.
A wind turbine generator having a configuration as described in Example 1 is constructed, except that the PET foam core material of Comparative Example 1 is replaced with a foam of the present invention made from PEF polymer using PMDA plus talc additive as described in Foam Formation Example 5. Acceptable results are observed.
A wind turbine generator having a configuration as described in Comparative Example 1 is made, except that the PET foam core is replaced with a PEF homopolymer foam of the present invention, including each of Foams 1-4, or foam made from PEF copolymer of the present invention, including Thermoplastic Polymer TPP1A-TPP22E. The preferred homopolymeric foams of the present invention, as represented by the PEF Replacement Tables above, show on average an approximate 1.3 times higher tensile strength+compressive strength at about the same densities comparable to the density of the PET foam of Comparative Example 1. The preferred PEF homopolymeric foams of the present invention are believed to have a shear strength advantage over PET foams at about this density. In particular, shear strength is approximately the average of the tensile and compressive strength, and therefore the shear strength of the present copolymer foams have, on average, a shear strength that is about 1.3 times higher than that of the PET foam at a foam density of about 0.1 g/cc. This 1.3 times advantage in shear strength is an unexpected and highly advantageous result, at least in part, because it enables the core foam thickness to be reduced by about 30 relative percent, as long as the flexural rigidity of the foam core is still acceptable, which is expected to be the case. This is indicated by the following calculations described in Chapter 3 of the Introduction to Sandwich Structures, Student Edition, 1995, Dan Zenkert.
τc=Tx/d
where:
Tx is the direct load in newtons (per width of the beam, which is 1 cm in this case), causing bending of the beam (in this case the blade);
d is thickness of the core foam+skin, which is approximately equal to thickness of the core foam (in cm);
A wind turbine generator having a configuration as described in Comparative Example 1 is made, except that the combinations of PEF homopolymer and PEFPET copolymer of the present invention as described in Example 1 are used but for the purpose of increasing power output of the wind turbine instead of weight reduction. As illustrated in Example 1A above, use of various combinations of PEF homopolymers and/or PEFPET copolymers of the present invention allows a blade weight reduction in the range of 2.5% to about 4% of the blade weight. A weight reduction of 2.5% to 4% is expected to provide the blades to regain the 2.5% to 4% weight loss, but this time, with at least 1.1% to 1.8% longer blades, leading to from 2.4% to 3.8% more power. The power data used for these calculations are shown in
In another option, advantage may also be achieved by using the same density of PEF or PETPEF foam of the present as was used in the PET foam invention but because of the increased strength of the present foam, it may be possible to improve blade design in various ways to achieve power improvements.
A wind turbine generator having a configuration as described in each of Example 3A is constructed, except that the PET foam core material of Comparative Example 1 is replaced with a PEF polymer foam of the present invention blown with a blowing agent consisting of HFO-1336mzz, including as reported in Form Formation Example 4. Acceptable results are observed.
A wind turbine generator having a configuration as described in each of Example 3A is constructed, except that the PET foam core material of Comparative Example 1 is replaced with a PEF polymer foam of the present invention blown with a blowing agent consisting of HFO-1336mzz, including as reported in Form Formation Example 4. Acceptable results are observed.
A wind turbine generator having a configuration as described in each of Example 3A is constructed, except that the PET foam core material of Comparative Example 1 is replaced with a PEF polymer foam of the present invention blown with a blowing agent consisting of HFO-1224yd. Acceptable results are observed.
A wind turbine generator having a configuration as described in each of Example 3A is constructed, except that the PET foam core material of Comparative Example 1 is replaced with a PEF polymer foam of the present invention made from PEF polymer using ADR additive as described in Foam Formation Example 5. Acceptable results are observed.
A wind turbine generator having a configuration as described in each of Example 3A is constructed, except that the PET foam core material of Comparative Example 1 is replaced with a PEF polymer foam of the present invention made from PEF polymer using PENTA additive as described in Foam Formation Example 5. Acceptable results are observed.
A wind turbine generator having a configuration as described in each of Example 3A is constructed, except that the PET foam core material of Comparative Example 1 is replaced with a PEF polymer foam of the present invention made from PEF polymer using PMDA plus talc additive as described in Foam Formation Example 5. Acceptable results are observed.
An aircraft includes in one or more locations which require structural foam, including preferably at least a portion of one or more of the wing, fuselage, tail, doors, bulkheads, interiors and/or superstructures, contain at least one foam article of the present invention, including on or more of each of Foam Articles 1-3. The aircraft achieves: (1) a lighter foam weight than previously used structural foam articles, preferably a weight that is at least about 2% less than the weight of the previously used foam; (2) an advantage in size and/or performance compared to using the same foam weight as previously used structural foam; and/or (3) a combination of (1) and (2).
An automobile includes in one or more locations which require structural foam, including preferably at least a portion of one or more of the side panels, floor panels, roof panels, engine compartments, battery compartments interiors and/or superstructures, contain at least one foam article of the present invention, including on or more of each of Foam Articles 1-3. The automobile achieves: (1) a lighter foam weight than previously used structural foam articles, preferably a weight that is at least about 2% less than the weight of the previously used foam; (2) an advantage in size and/or performance compared to using the same foam weight as previously used structural foam; and/or (3) a combination of (1) and (2).
A railway car includes in one or more locations which require structural foam, including preferably at least a portion of one or more of the side panels, floor panels, roof panels and superstructures, contain at least one foam article of the present invention, including on or more of each of Foam Articles 1-3. The railway car achieves: (1) a lighter foam weight than previously used structural foam articles, preferably a weight that is at least about 2% less than the weight of the previously used foam; (2) an advantage in size and/or performance compared to using the same foam weight as previously used structural foam; and/or (3) a combination of (1) and (2).
A building structure that includes in one or more locations which require structural foam, including preferably at least a portion of one or more of the wall panels, floor structure and roof structure and other structures in the building, contain at least one foam article of the present invention, including on or more of each of Foam Articles 1-3. The building achieves: (1) a lighter foam weight than previously used structural foam articles, preferably a weight that is at least about 2% less than the weight of the previously used foam; (2) an advantage in size and/or performance compared to using the same foam weight as previously used structural foam; and/or (3) a combination of (1) and (2).
Packaging, preferably in the form of boxes, inserts, separators, envelops and the like, that includes in one or more locations which require structural foam, contains at least one foam article of the present invention, including on or more of each of Foam Articles 1-3. The building achieves: (1) a lighter foam weight than previously used structural foam articles, preferably a weight that is at least about 2% less than the weight of the previously used foam; (2) an advantage in size and/or performance compared to using the same foam weight as previously used structural foam; and/or (3) a combination of (1) and (2).
A sporting good, including preferably a tennis racket, a skate board, a water or snow ski, and the like, that includes in one or more locations which require structural foam, contains at least one foam article of the present invention, including on or more of each of Foam Articles 1-3. The sporting good achieves: (1) a lighter foam weight than previously used structural foam articles, preferably a weight that is at least about 2% less than the weight of the previously used foam; (2) an advantage in size and/or performance compared to using the same foam weight as previously used structural foam; and/or (3) a combination of (1) and (2).
A PEF homopolymer having a molecular weight of 41.2 kg/mol1 was formed by esterification and polycondensation of 75 grams of 2,5-furandicarboxylic acid (FDCA) with 55 grams of mono-ethylene glycol (EG). The reactants were added to a 500-mL cylindrical steel reactor equipped with an overhead stirrer and a distillation/condensation apparatus. After pulling vacuum and back filling with nitrogen, 0.228 gram of titanium (IV) isopropoxide catalyst was added to the flask. The flask was then lowered into a 180° C. salt bath and overhead mixing was started at 200 rpm under a nitrogen atmosphere. After 2.5 hours, the bath temperature was increased to 220° C. After 30 minutes at this temperature under nitrogen, vacuum was started. After 40 minutes under vacuum, the temperature was increased to 250° C. and was continued for 1 hour. Under a stream of nitrogen, PMDA (0.5732 g) was slowly added over the span of about 5 minutes. An additional 30 minutes of mixing at temperature were allowed before stopping the reaction. To perform SSP, an aliquot of the product was ground and heated at 180° C. under vacuum for 3 days on a rotary evaporator to produce the PEF homopolymer with a molecular weight of 41 kg/mole.
1 Throughout these examples, molecular weight as determined and referenced herein refers to molecular weight determination by diffusion ordered nuclear magnetic resonance spectroscopy (DOSY NMR) as per the description contained in “Application of 1 H DOSY NMR in Measurement of Polystyrene Molecular Weights,” VNU Journal of Science: Natural Sciences and Technology, Vol. 36, No. 2 (2020) 16-21 Jun. 2020, Nam et a, except for differences in the solvents used. The reference above used 3 mg of polystyrene and 0.5 ml of deuterated chloroform. For these examples, NMR measurements were made with the dissolved portion of 2-3 mg of polymer in a 0.6 ml mixture of 50 vol % deuterated chloroform+50 vol % trifluoroacetic acid.
A 75 kg/mol PEF homopolymer was formed by esterification and polycondensation of 350 grams of 2,5-furandicarboxylic acid (FDCA) with 279 grams of mono-ethylene glycol (EG). The reactants were added to a 1-liter cylindrical steel reactor equipped with an overhead stirrer and a distillation/condensation apparatus. After pulling vacuum and back filling with nitrogen, 0.228 gram of titanium (IV) isopropoxide catalyst was added to the flask. The flask was then lowered into a 180° C. salt bath and overhead mixing was started at 200 rpm under a nitrogen atmosphere. After 2.5 hours, the bath temperature was increased to 220° C. After 30 minutes at this temperature under nitrogen, vacuum was started. After 40 minutes under vacuum, the temperature was increased to 230° C. and was continued for 1 hour. Under a stream of nitrogen, PMDA (2.73 g-0.7% by weight) was slowly added over the span of about 5 minutes. An additional 30 minutes of mixing at temperature were allowed before stopping the reaction. To perform SSP, an aliquot (30 g) of the product was ground and heated at 180° C. under vacuum for 3 days on a rotary evaporator to produce the PEF homopolymer with a molecular weight of 75 kg/mole.
A 96,078 g/mol MW polymer is made by combining 75 grams of 2,5-furandicarboxylic acid (FDCA) with 55 grams of mono-ethylene glycol (EG). The reactants were added to a 500-mL cylindrical steel reactor equipped with an overhead stirrer and a distillation/condensation apparatus. After pulling vacuum and back filling with nitrogen, 0.228 gram of titanium (IV) isopropoxide catalyst was added to the flask. The flask was then lowered into a 180° C. salt bath and overhead mixing was started at 200 rpm under a nitrogen atmosphere. After 2.5 hours, the bath temperature was increased to 220° C. After 30 minutes at this temperature under nitrogen, vacuum was started. After 40 minutes under vacuum, the temperature was increased to 250° C. and was continued for 1 hour. Under a stream of nitrogen, PMDA (0.5732 g) was slowly added over the span of about 5 minutes. An additional 30 minutes of mixing at temperature were allowed before stopping the reaction. To perform SSP, an aliquot of the product was ground and heated at 180° C. under vacuum for 3 days on a rotary evaporator to produce the PEF homopolymer as reported below. The product was removed from the vessel. Gamma-valerolactone was added to dissolve the polymer that was remaining in the reactor and on the impeller. The mixture was stirred for several hours at 190° C. The gamma-valerolactone was distilled from the polymer under vacuum resulting in a solid. To perform SSP, an aliquot of the product was ground and heated at 180° C. under vacuum for 3 days on a rotary evaporator to produce the PEF homopolymer with a molecular weight of 96,078.
A block copolymer of PET9:PEF1 (9:1 mole ratio) was prepared with a target molecular of about 117,900 g/mol with PET and PEF blocks of 4,4 respectively. In particular, PEF was first prepared by adding 498 grams of FDCA (2.7 moles) and 417 grams of EG (6.72 moles) to a 1000 mL cylindrical glass reactor equipped with an overhead stirrer and a distillation/condensation apparatus which was immersed in a 190° C. salt bath. After purging with nitrogen, 0.414 grams of Ti (IV) isopropoxide catalyst were added to the flask and overhead mixing was started at 200 rpm under N2 atmosphere. After 2.5 hours, the bath temperature was increased to 220° C. After 30 minutes at this temperature under N2, vacuum was started. After 40 minutes under vacuum, the temperature was increased to 240° C. and was continued for 2 hours before stopping the reaction, and PEF was produced.
PEF Oligomers were prepared by adding 109 grams of EG and 0.45 grams of sodium carbonate to a 500 ml cylindrical reactor equipped with a reflux condenser and an overhead stirrer. The mixture was heated until boiling in at salt bath at 230° C. An aliquot of PEF (160 grams) from the above step was added. The mixture was allowed to react under reflux for 2 hours until the reaction was stopped. The resulting mixture are the PEF oligomers.
PET Oligomers were prepared by adding, 103 grams of EG and 0.45 gram of sodium carbonate to a 500 ml cylindrical reactor equipped with a condenser and an overhead stirrer. The mixture was heated in at salt bath at 230° C. Then 160 grams of commercially available recycled PET flake were added. The mixture was allowed to react under reflux for 2 hours until the reaction was stopped. The result was a PET oligomer mixture.
The co-polymer was made by quickly adding 12.0 grams of the PEF oligomers and 111.7 grams of the PET oligomers to a 500 mL cylindrical steel reactor equipped with an overhead stirrer and a distillation/condensation apparatus that was immersed in a 220° C. salt bath, followed by adding 0.9083 grams of Ti(IV) isopropoxide. Shortly thereafter (<2 min), vacuum was applied to remove EG. After 40 minutes, the temperature was increased to 270° C., and the contents of the reactor were allowed to remain under vacuum for 40 minutes. Under a N2 atmosphere, 0.483 gram of PMDA was slowly added. An additional 30 minutes of mixing at temperature were allowed before stopping the reaction. Solid state polymerization was conducted by grinding an aliquot (30g) of the above product and then heating at 180° C. under vacuum for 3 days on a rotary evaporator to produce the PET9:PEF1 copolymer with a PET molecular weight of 117.9 kg/mole.
Three (3) block copolymers of PET9:PEF1 (9:1 mole ratio) and one (1) block copolymer of PET19:PEF1 (19:1 mole ratio) were prepared with target molecular weights of from about 10 to about 69 kg/mol for the PET portion of the copolymer using the additives and polymer formation procedures generally as described in Synthesis Examples 1-3, except that PMDA+talc, the chain extender ADR-4468 (hereinafter referred to as “ADR”)2 and PENTA were used to replace PMDA alone.
The PET:PEF copolymers thus produced were tested using the measurement protocols as described above and found to have the characteristics reported in Table SyEx3 below:
2 ADR 4468 is a trade name for 2,3-Epoxypropyl methacrylate chain extender sold by BASF under the Joncryl family of trademarks.
Four (4) PET homopolymers were prepared by polycondensation yielding polymer products having a range of molecular size from about 80 kg/mol to about of 96 kg/mol using the procedures describe in Synthesis Example 1 above an variations thereof to achieve the polymer with a molecular weight as indicted in SyEx4 below.
The PET polymers are designated herein as PETC1, PETC2, PETC3 and PETC and were tested and found to have the characteristics as reported in Table SyEx4 below:
As noted from the table above, each of the PET homopolymers was produced utilizing the preferred high crystallinity aspects of the present invention.
In a series of runs, 1 gram of each PET polymer (as indicated in the Table SyEx4 above) in a glass container was loaded into a 60 cc volume autoclave and then dried under vacuum for six (6) hours at an elevated temperature in the range of 130° C. to 150° C. The dried polymer was then cooled to room temperature. For each case, the blowing agent was 1234ze(E) was then pumped into the autoclave containing the dried polymer, and then the autoclave was heated to bring the polymer to a melt state, for which the temperatures, pressures and times are listed in Table FFeX—Low Density Foams and Table FFeX-High Density Foams above. After the indicated melt time, the temperature and pressure of the melt/blowing agent were then reduced over a period of about 5-15 minutes to pre-foaming temperature and pre-foaming pressure, as indicted in tables above. The autoclave was then maintained at about this temperature and pressure for a period of about 30 minutes to ensure that the amount of blowing agent incorporated into the melt under such conditions reached equilibrium. The conditions used, including the amount of the blowing agent and the melt temperature and pressure, were determined after several tests, based on the ability to form acceptable foams with RFD values in the range of about 0.05 to about 0.25. The temperature and pressure in the autoclave were then reduced rapidly (over a period of about 10 seconds for the pressure reduction and about 1-10 minutes for the temperature reduction using chilled water) to ambient conditions (approximately 22° C. and 1 atmosphere) and foaming occurred.
The PET foams thus produced have the properties identified in Table FFeX-Low Density Foams and Table FFeX-High Density Foams above.
One foam was made using PEF2 and four foams were made using PEF2 identified in Table FFeX—Low Density Foams and Table FFeX—High Density Foams above and, as described herein, using foaming processes that were designed using the same criteria as described in SyExC 1 above. The foams thus produced were tested and found to have the properties as reported in in Table FFeX—Low Density Foams and Table FFeX-High Density Foams above and as shown in Table FFEx2 below.
Six (6) foams were made from PET9PEF1-EX3A using foaming processes that were designed using the same criteria as described in Comparative Example 1. The foams thus produced were tested and found to have the properties as reported in Table E3B below:
A series of foams were made using PET9:PEF1 using foaming processes that were designed using the same criteria as described in Foam Synthesis Examples 1-3. The foams thus produced were tested and found to have the properties as reported in Table FFEx 4 below.
As revealed by the data in Table FFEx4 above and the other examples presented herein, applicants have surprisingly found that PEF:PET foams according to the present invention generally possess superior strength characteristics when the blowing agent comprises, or consists essentially of or consists of 1234ze(E) in comparison to other blowing agents, including 1233zd and 1336, as revealed by the data in the table above. Nevertheless, acceptable foams were made and have substantial utility when the blowing agent comprises, or consists essentially of or consists of 1233zd(E) or 1336mzz(Z), as also revealed by the data above.
Foams were made from PET9PEF1 as described above in Synthesis Example 4 above using foaming processes that were designed using the same criteria as described in Foam Formation Examples 1-3. The foams thus produced were tested and found to have the properties as reported in Table FFEx5 below:
As revealed by the data in Table FFEx4 above, applicants have surprisingly found that PET:PEF foams according to the present invention generally possess superior strength characteristics when the preferred blowing agent comprises, or consists essentially of or consists of 1234ze(E) is used with a variety of polymerization additives.
This application is related to, claims the priority benefit of and incorporates by reference U.S. Provisional Application 63/343,990, filed May 19, 2022 and also claims the priority benefit of U.S. application Ser. No. 18/113,605 filed Feb. 23, 2023.
| Number | Date | Country | |
|---|---|---|---|
| 63343990 | May 2022 | US | |
| 63312855 | Feb 2022 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 18113605 | Feb 2023 | US |
| Child | 18199885 | US |
