Patent Application
20250051529
Peroxide initiated crosslinking, functionalization, and rheology modification is widely used in olefin-based polymer applications. The reaction characteristics (for example, efficiency, curing speed, and reaction selectivity) are crucial factors that can largely affect the polymer formulation, part processing, and part performance. For example, an olefin-based polymer with an improved rate and effectiveness of crosslinking can help customers to reduce the cycle time of part manufacturing and/or minimize the usage of costly curing additives in the formulation. There is a need for olefin-based polymer compositions that can be crosslinked at improved (faster) crosslinking rates and improved crosslinking efficiencies (higher degrees of crosslinking). Specifically, there remains a need for new olefin-based polymer compositions and crosslinking process of the same, that result in high crosslinking rates and efficiencies and also provide for good mechanical properties for the crosslinked compositions and parts. These needs have been met by the following invention.
A process to form a crosslinked composition, the process comprising thermally treating a composition that comprises the following components:
A composition that comprises the following components:
Compositions containing olefin/silane interpolymers have been discovered that provide the following distinctive features, and related benefits: a) improved curing effectiveness under low peroxide loading, which allows for a reduction in peroxide loading for cost saving and reduced peroxide side-reactions; b) improved curing rate, which allows for a reduction in cycle time, an increase in the throughput of manufactured parts, and a reduction in the variable cost in equipment; c) selective formation of chemical bonding with the silicon hydride (Si—H) functional groups, which allows for the design of distinctive polymer network microstructures with tailored properties; and d) good mechanical properties for the resulting crosslinked compositions and parts.
Processes to effectively cure these compositions have also been discovered. Also, it has been discovered that the silicon hydride functional groups can readily react with peroxide to form a sufficiently crosslinked interpolymer, without the need for an additional cure catalyst. It has also been discovered that even a small fraction (for example, ≤5.0 wt %) of the incorporated silane comonomer greatly improves the crosslinking effectiveness of the composition, as compared to the crosslinking of ethylene-based polymers using conventional crosslinking methods.
As discussed, in a first aspect, a process to form a crosslinked composition is provided, which comprises thermally treating a composition that comprises the following components:
The above process may comprise a combination of two or more embodiments, as described herein. Each component a, b, c, and d may comprise a combination of two or more embodiments, as described herein.
Also provided, in a second aspect, is a composition that comprises the following components:
The above composition may comprise a combination of two or more embodiments, as described herein. Each component a, b, c, and d may comprise a combination of two or more embodiments, as described herein.
The following embodiments apply to both the first aspect and the second aspect of the invention, unless stated otherwise.
In one embodiment, or a combination of two or more embodiments, each described herein, the olefin/silane interpolymer of component a is an ethylene/silane copolymer, an ethylene/alpha-olefin/silane interpolymer, or an ethylene/alpha-olefin/silane terpolymer. In one embodiment, or a combination of two or more embodiments, each described herein, the olefin/silane interpolymer of component a is an olefin/silane interpolymer formed in the presence of a bis-biphenyl-phenoxy metal complex.
In one embodiment, or a combination of two or more embodiments, each described herein, the composition comprises only one olefin/silane interpolymer for component a, or only one ethylene/alpha-olefin/silane interpolymer, or only one ethylene/alpha-olefin/silane terpolymer. In one embodiment, or a combination of two or more embodiments, each described herein, the composition comprises two or more olefin/silane interpolymers for component a, or two or more ethylene/alpha-olefin/silane interpolymers, or two or more ethylene/alpha-olefin/silane terpolymers.
In one embodiment, or a combination of two or more embodiments, each described herein, the interpolymer of component a comprises, in polymerized form, ≥0.10 wt %, or ≥0.20 wt %, or ≥0.30 wt %, or ≥0.40 wt %, or ≥0.50 wt %, or ≥0.60 wt %, or ≥0.70 wt %, or ≥0.80 wt %, or ≥0.90 wt %, or ≥1.0 wt %, or ≥1.5 wt %, or ≥2.0 wt % of the silane, based on the weight of the interpolymer. In one embodiment, or a combination of two or more embodiments, each described herein, the interpolymer of component a comprises, in polymerized form, ≤40 wt %, or ≤30 wt %, or ≤20 wt %, or ≤10 wt %, or ≤8.0 wt %, or ≤6.0 wt %, or ≤5.0 wt %, or ≤4.0 wt % of the silane, based on the weight of the interpolymer.
In one embodiment, or a combination of two or more embodiments, each described herein, the interpolymer of component a has a molecular weight distribution (MWD, defined as the ratio of the weight average (Mw) and the number average (Mn) molecular weights of the polymer, Mw/Mn) ≥1.5, or ≥1.6, or ≥1.7, or ≥1.8, or ≥1.9. In one embodiment, or a combination of two or more embodiments, each described herein, the interpolymer of component a has a molecular weight distribution MWD ≤5.0, or ≤4.5, or ≤4.0, or ≤3.5, or ≤3.0, or ≤2.9, or ≤2.8, or ≤2.7, or ≤2.6, or ≤2.5, or ≤2.4, or ≤2.3.
In one embodiment, or a combination of two or more embodiments, each described herein, the silane is derived from a silane monomer selected from Formula 1:
A-(SiBC—O)x—Si-EFH (Formula 1),
where A is an alkenyl group, B is a hydrocarbyl group or hydrogen, C is a hydrocarbyl group or hydrogen, and where B and C may be the same or different;
In one embodiment, or a combination of two or more embodiments, each described herein, Formula 1 is selected from the following compounds s1) through s16) below:
In one embodiment, or a combination of two or more embodiments, each described herein, the composition has a mole ratio of “the active oxygen atom in component b” to component a ≥0.5, or ≥0.7, or ≥1.0, or ≥1.5, or ≥2.0, or ≥2.5, or ≥3.0, or ≥3.5, or ≥4.0. In one embodiment, or a combination of two or more embodiments, each described herein, the composition has a mole ratio of “the active oxygen atom in component b” to component a ≤30, or ≤25, or ≤20, or ≤15, or ≤12, or ≤10, or ≤7.5, or ≤5.5.
In one embodiment, or a combination of two or more embodiments, each described herein, the composition has a mole ratio component c to “the active oxygen atom in component b″ ≥0, or ≥0.01, or ≥0.05, or ≥0.10, or ≥0.15, or ≥0.20. In one embodiment, or a combination of two or more embodiments, each described herein, the composition has a mole ratio component c to “the active oxygen atom in component b” ≤10.00, or ≤7.50, or ≤5.00, or ≤2.50, or ≤1.00, or ≤0.75, or ≤0.50.
In one embodiment, or a combination of two or more embodiments, each described herein, the composition further comprises an ethylene/alpha-olefin interpolymer, or an ethylene/alpha-olefin copolymer.
In one embodiment, or a combination of two or more embodiments, each described herein, the composition comprises only one peroxide for component b. In one embodiment, or a combination of two or more embodiments, each described herein, the composition comprises two or more peroxides for component b. In one embodiment, or a combination of two or more embodiments, each described herein, the composition comprises two or more crosslinking coagents for component c.
In one embodiment, or a combination of two or more embodiments, each described herein, the composition is thermally treated at a temperature ≥120° C., or ≥130° C., or ≥140° C., or ≥150° C. In one embodiment, or a combination of two or more embodiments, each described herein the composition is thermally treated at a temperature ≤200° C., or ≤195° C., or ≤190° C., or ≤185° C., or 180° C.
Also is provided a crosslinked composition formed by an inventive process as described herein, or from an inventive composition as described herein.
Also provided is an article comprising at least one component formed from a composition of any one embodiment, or a combination of two or more embodiments, each described herein. In one embodiment, or a combination of two or more embodiments, each described herein, the article is a film. In one embodiment, or a combination of two or more embodiments, each described herein, the article is a solar cell module, an encapsulant film, a cable, a footwear component, an automotive part, a window profile, a tire, a weatherstrip, a tube, a belt, a hose, or a roofing membrane.
A silane monomer, as used herein, comprises at least one Si—H group. In one embodiment, the silane monomer is selected from Formula 1, as discussed above.
Some examples of silane monomers include hexenylsilane, allylsilane, vinylsilane, octenylsilane, hexenyldimethylsilane, octenyldimethylsilane, vinyldimethylsilane, vinyldiethylsilane, vinyldi(n-butyl)silane, vinylmethyloctadecylsilane, vinyidiphenylsilane, vinyldibenzylsilane, allyldimethylsilane, allyldiethylsilane, allyldi(n-butyl)silane, allylmethyloctadecylsilane, allyldiphenylsilane, bishexenylsilane, and allyidibenzylsilane. Mixtures of the foregoing alkenylsilanes may also be used.
More specific examples of silane monomers include the following: (5-hexenyl-dimethylsilane (HDMS), 7-octenyldimethylsilane (ODMS), allyldimethylsilane (ADMS), 3-butenyldimethylsilane, 1-(but-3-en-1-yl)-1,1,3,3-tetramethyldisiloxane (BuMMH), 1-(hex-5-en-1-yl)-1,1,3,3-tetramethyldisiloxane (HexMMH), (2-bicyclo[2.2.1]hept-5-en-2-yl)ethyl)-dimethylsilane (NorDMS), and 1-(2-bicyclo[2.2.1]hept-5-en-2-yl)ethyl)-1,1,3,3-tetramethyldisiloxane (NorMMH). Mixtures of the foregoing alkenylsilanes may also be used.
As noted above, the composition comprises a peroxide. As used herein, a peroxide contains at least one oxygen-oxygen bond (O—O). Peroxides include, but are not limited to, dialkyl, diaryl, dialkaryl, and diaralkyl peroxide having the same or differing respective alkyl, aryl, alkaryl, and aralkyl moieties, and dialkyl, diaryl, dialkaryl, and diaralkyl peroxide having the same respective alkyl, aryl, alkaryl, and aralkyl moieties.
Exemplary organic peroxides include dicumyl peroxide (“DCP”), tert-butyl peroxybenzoate, di-tert-amyl peroxide (“DTAP”), bis(t-butyl-peroxy isopropyl) benzene (“BIPB”), isopropylcumyl t-butyl peroxide, t-butylcumylperoxide, di-t-butyl peroxide; 2,5-bis(t-butylperoxy)-2,5-dimethylhexane, 2,5-bis(t-butylperoxy)-2,5-dimethylhexyne-3,1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, isopropylcumyl cumylperoxide, butyl 4,4-di(tert-butylperoxy)valerate, di(isopropylcumyl) peroxide, 1,1-di-(tert-butylperoxy)cyclohexane (“Luperox 331”), 1,1-di-(tert-amylperoxy)cyclohexane (“Luperox 531”); tert-butylperoxyacetate (“TBPA”), tert-amyl peroxyacetate (“TAPA”), 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (“Luperox 101”), tert-Butylperoxy-2-ethylhexyl carbonate (“TBEC”), and mixtures of two or more thereof.
In one or more embodiments, the peroxide may be a cyclic peroxide. An example of a cyclic peroxide is represented by the following Formula 2:
wherein R1-R6 are each independently hydrogen or an inertly-substituted or unsubstituted C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl, C7-C20 aralkyl, or C7-C20 alkaryl. Representative of the inert-substituents included in R1-R6 are hydroxyl, C1-C20 alkoxy, linear or branched C1-C20 alkyl, C6-C20 aryloxy, halogen, ester, carboxyl, nitrile, and amido. In one or more embodiments, R1-R6 are each independently lower alkyls, including, for example, a C1-C10 alkyl or a C1-C4 alkyl.
A number of cyclic peroxides are commercially available, for example, under the tradename TRIGONOX, such as 3,6,9-triethyl-3,6,9-trimethyl-1,4,7-triperoxonane. Examples of cyclic peroxides include those derived from acetone, methylamyl ketone, methylheptyl ketone, methylhexyl ketone, methylpropyl ketone, methylbutyl ketone, diethyl ketone, methylethyl ketone, methyloctyl ketone, methylnonyl ketone, methyldecyl ketone, methylundecyl ketone, and combinations thereof, among others. The cyclic peroxides can be used alone or in combination with one another. The peroxide can be liquid, solid, or paste.
As used herein, a “crosslinking coagent” is a compound that promotes crosslinking; for example, by helping to establish a higher concentration of reactive sites and/or helping to reduce the chance of deleterious radical side reactions. Crosslinking coagents include, but are not limited to, triallyl cyanurate (TAC), triallyl phosphate (TAP), triallyl isocyanurate (TAIC), 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane (Vinyl D4), 2,4,6-trimethyl-2,4,6-trivinyl-1,3,5,2,4,6-trioxatrisilinane (Vinyl D3), 2,4,6,8,10-pentamethyl-2,4,6,8,10-pentavinyl-1,3,5,7,9,2,4,6,8,10-pentaoxapentasilecane (Vinyl D5), dipentaerythritolpenta-acrylate and trimethylolpropane triacrylate, triallyl trimellitate, N,N,N′,N′,N″,N″-hexaallyl-1,3,5-triazine-2,4,6-triamine, triallyl orthoformate, pentaerythritol triallyl ether, triallyl citrate; triallyl aconitate, trimethylolpropane triacrylate, trimethylolpropane trimethylacrylate, ethoxylated bisphenol A dimethacrylate, 1,6-hexanediol diacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, tris(2-hydroxyethyl) isocyanurate triacrylate, propoxylated glyceryl triacrylate, a polybutadiene having at least 50 wt % 1,2-vinyl content, trivinyl cyclohexane, certain dicarbonyl species, e.g., 1,3-diacetylbenzene (DAB), and mixtures of any two or more thereof.
An inventive composition may comprise further additives. Additives include, but are not limited to, UV stabilizer, antioxidants, fillers, scorch retardants, tackifiers, waxes, compatibilizers, adhesion promoters, plasticizers (for example, oils), blocking agents, antiblocking agents, anti-static agents, release agents, anti-cling additives, colorants, dyes, pigments, and combination thereof.
Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percents are based on weight, and all test methods are current as of the filing date of this disclosure.
The term “composition,” as used herein, includes a mixture of materials, which comprise the composition, as well as reaction products and decomposition products formed from the materials of the composition. Any reaction product or decomposition product is typically present in trace or residual amounts.
The term “polymer,” as used herein, refers to a polymeric compound prepared by polymerizing monomers, whether of the same or a different type. The generic term polymer thus, includes the term homopolymer (employed to refer to polymers prepared from only one type of monomer, with the understanding that trace amounts of impurities can be incorporated into the polymer structure), and the term interpolymer as defined hereinafter. Trace amounts of impurities, such as catalyst residues, can be incorporated into and/or within the polymer. Typically, a polymer is stabilized with very low amounts (“ppm” amounts) of one or more stabilizers.
The term “interpolymer,” as used herein, refers to polymer prepared by the polymerization of at least two different types of monomers. The term interpolymer thus includes the term copolymer (employed to refer to polymers prepared from two different types of monomers) and polymers prepared from more than two different types of monomers.
The term “olefin-based polymer,” as used herein, refers to a polymer that comprises, in polymerized form, at least 50 wt % or a majority weight percent of an olefin, such as ethylene or propylene (based on the weight of the polymer), and optionally may comprise one or more comonomers.
The term “propylene-based polymer,” as used herein, refers to a polymer that comprises, in polymerized form, at least 50 wt % or a majority weight percent of propylene (based on the weight of the polymer), and optionally may comprise one or more comonomers.
The term “ethylene-based polymer,” as used herein, refers to a polymer that comprises, in polymerized form, at least 50 wt % or a majority weight percent of ethylene (based on the weight of the polymer), and optionally may comprise one or more comonomers.
The term “ethylene/alpha-olefin interpolymer,” as used herein, refers to a random interpolymer that comprises, in polymerized form, at least 50 wt % or a majority weight percent of ethylene (based on the weight of the interpolymer), and an alpha-olefin.
The term, “ethylene/alpha-olefin copolymer,” as used herein, refers to a random copolymer that comprises, in polymerized form, at least 50 wt % or a majority weight percent of ethylene (based on the weight of the copolymer), and an alpha-olefin, as the only two monomer types.
The term “olefin/silane interpolymer,” as used herein, refers to a random interpolymer that comprises, in polymerized form, at least 50 wt % or a majority weight percent of an olefin (based on the weight of the interpolymer), and a silane monomer. As used herein, the interpolymer comprises at least one Si—H group, and the phrase “at least one Si—H group” refers to a type of “Si—H” group. It is understood in the art that the interpolymer would contain a multiple number of these groups. The olefin/silane interpolymer is formed by the copolymerization (for example, using a bis-biphenyl-phenoxy metal complex) of at least the olefin and the silane monomer. An example of a silane monomer is depicted in Formula 1, as described above.
The term “ethylene/silane interpolymer,” as used herein, refers to a random interpolymer that comprises, in polymerized form, at least 50 wt % or a majority weight percent of ethylene (based on the weight of the interpolymer), and a silane monomer. As used herein, the interpolymer comprises at least one Si—H group, and the phrase “at least one Si—H group,” as discussed above. The ethylene/silane interpolymer is formed by the copolymerization of at least the ethylene and the silane monomer.
The term “ethylene/alpha-olefin/silane interpolymer,” as used herein, refers to a random interpolymer that comprises, in polymerized form, at least 50 wt % or a majority weight percent of ethylene (based on the weight of the interpolymer), an alpha-olefin and a silane monomer. As used herein, these interpolymer comprises at least one Si—H group, as discussed above. The ethylene/silane interpolymer is formed by the copolymerization of at least the ethylene, the alpha-olefin and the silane monomer.
The term “ethylene/alpha-olefin/silane terpolymer,” as used herein, refers to a random terpolymer that comprises, in polymerized form, at least 50 wt % or a majority weight percent of ethylene (based on the weight of the terpolymer), an alpha-olefin and a silane monomer as the only three monomer types. As used herein, the terpolymer comprises at least one Si—H group, as discussed above. The ethylene/silane terpolymer is formed by the copolymerization of the ethylene, the alpha-olefin and the silane monomer.
The phrase “a majority weight percent,” as used herein, in reference to a polymer (or interpolymer, or terpolymer or copolymer), refers to the amount of monomer present in the greatest amount in the polymer.
The terms “hydrocarbon group,” “hydrocarbyl group,” and similar terms, as used herein, refer to a chemical group containing only carbon and hydrogen atoms.
The term “crosslinked composition,” as used herein, refers to a composition that has a network structure due to the formation of chemical bonds between polymer chains. The degree of formation of this network structure is indicated by the increase in the “MH-ML” value as discussed herein.
The terms “thermally treating,” “thermal treatment,” and similar terms, as used herein, in reference to a composition comprising an olefin/silane interpolymer, refer to the application of heat to the composition. Heat may be applied by electrical means (for example, a heating coil) and/or by radiation and/or by hot oil and/or by mechanical shearing. Note, the temperature at which the thermal treatment takes place, refers to the temperature of the composition (for example, the melt temperature of the composition).
The term “bis-biphenyl-phenoxy metal complex,” as used herein, refers to complexes such as those disclosed in WO2012/027448. Examples of such complexes include but are not limited to “PE CAT 1” and “PE CAT 2” as seen below in the experimental section. Specifically, the term “bis-biphenyl-phenoxy metal complex,” as used herein, refers to a chemical structure comprising a metal or metal ion that is bonded and/or coordinated to one or more, and preferably two, biphenyl-phenoxy ligands. In one embodiment, the chemical structure comprises a metal that is bonded to two, biphenyl-phenoxy ligands, via an oxygen atom of each respective biphenyl-phenoxy ligand. The metal complex is typically rendered catalytically active by the use of one or more cocatalysts.
For example, see Formula D1 below:
With respect to the term “ratio,” as used herein, a value of X is understood to be X:1 (or X to 1). For example, a ratio of at least 2.0 is understood to be 2.0:1.0 (or 2.0 to 1.0).
The term “alkenyl group,” as used herein, refers to an organic chemical group that contains at least one carbon-carbon double bond (C=C). In a preferred embodiment, the alkenyl group is an example of a hydrocarbon group containing at least one carbon-carbon double bond, or containing only one carbon-carbon double bond.
The term “active oxygen atom,” as used herein, refers to the oxygen atoms present as one of two covalently bonded oxygen atoms in the organic peroxide. For example, a mono-functional peroxide has two active oxygen atoms. Oxygen atoms present in the organic peroxide that are not covalently bonded to another oxygen atom are not considered active oxygen atoms. As used herein, “mono-functional peroxides” denote peroxides having a single pair of covalently bonded oxygen atoms (e.g., having a structure R—O—O—R). As used herein, “di-functional peroxides” denote peroxides having two pairs of covalently bonded oxygen atoms (e.g., having a structure R—O—O—R—O—O—R). In an embodiment, the organic peroxide is a mono-functional peroxide.
The mole ratio of the active oxygen atom to polymer is calculated according to the equation below. The mole of polymer is calculated based on Mn of the polymer.
The terms “comprising,” “including,” “having,” and their derivatives, are not intended to exclude the presence of any additional component, step or procedure, whether the same is specifically disclosed. In order to avoid any doubt, all compositions claimed through use of the term “comprising” may include any additional additive, adjuvant, or compound, whether polymeric or otherwise, unless stated to the contrary. In contrast, the term, “consisting essentially of” excludes from the scope of any succeeding recitation, any other component, step or procedure, excepting those that are not essential to operability. The term “consisting of” excludes any component, step or procedure, not specifically delineated or listed.
The chromatographic system consisted of a PolymerChar GPC-IR (Valencia, Spain) high temperature GPC chromatograph, equipped with an internal IR5 infra-red detector (IR5). The autosampler oven compartment was set at 1600 Celsius, and the column compartment was set at 1500 Celsius. The columns were four AGILENT “Mixed A” 30 cm, 20-micron linear mixed-bed columns. The chromatographic solvent was 1,2,4-trichloro-benzene, which contained 200 ppm of butylated hydroxytoluene (BHT). The solvent source was nitrogen sparged. The injection volume used was 200 microliters, and the flow rate was 1.0 milliliters/minute.
Calibration of the GPC column set was performed with 21 narrow molecular weight distribution polystyrene standards, with molecular weights ranging from 580 to 8,400,000, and which were arranged in six “cocktail” mixtures, with at least a decade of separation between individual molecular weights. The standards were purchased from Agilent Technologies. The polystyrene standards were prepared at “0.025 grams in 50 milliliters” of solvent, for molecular weights equal to, or greater than, 1,000,000, and at “0.05 grams in 50 milliliters” of solvent, for molecular weights less than 1,000,000. The polystyrene standards were dissolved at 80 degrees Celsius, with gentle agitation, for 30 minutes. The polystyrene standard peak molecular weights were converted to polyethylene molecular weights using Equation 1 (as described in Williams and Ward, J. Polym. Sci., Polym. Let., 6, 621 (1968)):
Mpolyethylene=A×(Mpolystyrene)B (EQ1), where M is the molecular weight, A has a value of 0.4315 and B is equal to 1.0.
A fifth order polynomial was used to fit the respective polyethylene-equivalent calibration points. A small adjustment to A (from approximately 0.375 to 0.445) was made to correct for column resolution and band-broadening effects, such that linear homopolymer polyethylene standard is obtained at 120,000 Mw. The total plate count of the GPC column set was performed with decane (prepared at “0.04 g in 50 milliliters” of TCB, and dissolved for 20 minutes with gentle agitation.) The plate count (Equation 2) and symmetry (Equation 3) were measured on a 200 microliter injection according to the following equations:
where RV is the retention volume in milliliters, the peak width is in milliliters, the peak max is the maximum height of the peak, and ½ height is ½ height of the peak maximum; and
where RV the retention volume in milliliters, and the peak width is in milliliters, Peak max is the maximum position of the peak, one tenth height is 1/10 height of the peak maximum, and where rear peak refers to the peak tail at later retention volumes than the peak max, and where front peak refers to the peak front at earlier retention volumes than the peak max. The plate count for the chromatographic system should be greater than 18,000, and symmetry should be between 0.98 and 1.22.
Samples were prepared in a semi-automatic manner with the PolymerChar “Instrument Control” Software, wherein the samples were weight-targeted at 2 mg/ml, and the solvent (contained 200 ppm BHT) was added to a pre nitrogen-sparged, septa-capped vial, via the PolymerChar high temperature autosampler. The samples were dissolved for two hours at 1600 Celsius under “low speed” shaking.
The calculations of Mn(GPC), Mw(GPC), and Mz(GPC) were based on GPC results using the internal IR5 detector (measurement channel) of the PolymerChar GPC-IR chromatograph according to Equations 4-6, using PolymerChar GPCOne™ software, the baseline-subtracted IR chromatogram at each equally-spaced data collection point (i), and the polyethylene equivalent molecular weight obtained from the narrow standard calibration curve for the point (i) from Equation 1. Equations 4-6 are as follows:
In order to monitor the deviations over time, a flowrate marker (decane) was introduced into each sample, via a micropump controlled with the PolymerChar GPC-IR system. This flowrate marker (FM) was used to linearly correct the pump flowrate (Flowrate(nominal)) for each sample, by RV alignment of the respective decane peak within the sample (RV(FM Sample)), to that of the decane peak within the narrow standards calibration (RV(FM Calibrated)). Any changes in the time of the decane marker peak were then assumed to be related to a linear-shift in flowrate (Flowrate(effective)) for the entire run. To facilitate the highest accuracy of a RV measurement of the flow marker peak, a least-squares fitting routine was used to fit the peak of the flow marker concentration chromatogram to a quadratic equation. The first derivative of the quadratic equation was then used to solve for the true peak position. After calibrating the system, based on a flow marker peak, the effective flowrate (with respect to the narrow standards calibration) was calculated as Equation 7: Flowrate(effective)=Flowrate(nominal)*(RV(FM Calibrated)/RV(FM Sample)) (EQ7). Processing of the flow marker peak was done via the PolymerChar GPCOne™ Software. Acceptable flowrate correction is such that the effective flowrate should be within +/−0.7% of the nominal flowrate.
The melt index I2 of an ethylene-based polymer is measured in accordance with ASTM D-1238, condition 190° C./2.16 kg (melt index 110 at 190° C./10.0 kg). The I10/I2 was calculated from the ratio of 110 to the 12. The melt flow rate MFR of a propylene-based polymer is measured in accordance with ASTM D-1238, condition 230° C./2.16 kg.
ASTM D4703 was used to make a polymer plaque for density analysis. ASTM D792, Method B, was used to measure the density of each polymer.
For 13C NMR experiments, samples were dissolved, in 10 mm NMR tubes, in tetrachloroethane-d2 (with or without 0.025 M Cr(acac)3). The concentration was approximately 300 mg/2.8 mL. Each tube was then heated in a heating block set at 110° C. The sample tube was repeatedly vortexed and heated to achieve a homogeneous flowing fluid. The 13C NMR spectrum was taken on a BRUKER AVANCE 600 MHz spectrometer, equipped with a 10 mm C/H DUAL cryoprobe. The following acquisition parameters were used: 60 seconds relaxation delay, 90 degree pulse of 12.0 ρs, 256 scans. The spectrum was centered at 100 ppm, with a spectral width of 250 ppm. All measurements were taken without sample spinning at 110° C. The 13C NMR spectrum was referenced to “74.5 ppm” for the resonance peak of the solvent. For a sample with Cr, the data was taken with a “7 seconds relaxation delay” and 1024 scans. The “mol % octene (or other alpha-olefin)” was calculated based on the CH/CH3 carbons associated with octene (or other alpha-olefin) versus the integration of CH2 associated with ethylene units.
For 1H NMR experiments, each sample was dissolved, in 8 mm NMR tubes, in tetrachloroethane-d2 (with or without 0.001 M Cr(acac)3). The concentration was approximately 100 mg/1.8 mL. Each tube was then heated in a heating block set at 110° C. The sample tube was repeatedly vortexed and heated to achieve a homogeneous flowing fluid. The 1H NMR spectrum was taken on a BRUKER AVANCE 600 MHz spectrometer, equipped with a 10 mm C/H DUAL cryoprobe. A standard single pulse 1H NMR experiment was performed. The following acquisition parameters were used: 70 seconds relaxation delay, 90 degree pulse of 17.2 ρs, 32 scans. The spectrum was centered at 1.3 ppm, with a spectral width of 20 ppm. All measurements were taken, without sample spinning, at 110° C. The 1H NMR spectrum was referenced to “5.99 ppm” for the resonance peak of the solvent (residual protonated tetrachloroethane). For a sample with Cr, the data was taken with a “16 seconds relaxation delay” and 128 scans. The “mol % silane (silane monomer)” was calculated based on the integration of SiMe proton resonances, versus the integration of CH2 protons associated with ethylene units and CH3 protons associated with octene units.
The evaluation of the peroxide reaction to the olefin/silane interpolymer was evaluated through Moving Die Rheometer testing (MDR), as follows. Crosslinking characteristics of the samples were measured using an Alpha Technologies Moving Die Rheometer (MDR) 2000 E, according to ASTM D5289, with amplitude of the oscillation of 0.5 deg of arc. The MDR was run for 30 minutes at 180° C. The “Torque vs Time” profile was generated over the given interval. The minimum torque (ML) maximum torque (MH) exerted by the MDR during the testing interval are reported in dNm. The difference between MH and ML is indicative of the extent of crosslinking, with the greater the difference reflecting a greater extent of crosslinking. The time it takes for torque to reach 90% of MH (t90) is reported in minutes. The time required for the increase of X (tsX) points from minimum torque is recorded in minutes. The ts1 values are indicative of the time required for the crosslinking process to begin. A shorter time indicates crosslinking initiates faster.
Differential Scanning Calorimetry (DSC) is used to measure Tm, Tc, Tg and crystallinity in ethylene-based (PE) polymer samples and propylene-based (PP) polymer samples. Each sample (0.5 g) was compression molded into a film, at 5000 psi, 190° C., for two minutes. About 5 to 8 mg of film sample was weighed and placed in a DSC pan. The lid was crimped on the pan to ensure a closed atmosphere. Unless otherwise stated, the sample pan was placed in a DSC cell, and then heated, at a rate of 10° C./min, to a temperature of 180° C. for PE (230° C. for PP). The sample was kept at this temperature for three minutes. Then the sample was cooled at a rate of 10° C./min to −90° C. for PE (−60° C. for PP), and kept isothermally at that temperature for three minutes. The sample was next heated at a rate of 10° C./min, until complete melting (second heat). Unless otherwise stated, melting point (Tm) and the glass transition temperature (Tg) of each polymer were determined from the second heat curve, and the crystallization temperature (Tc) was determined from the first cooling curve. The respective peak temperatures for the Tm and the Tc were recorded. The percent crystallinity can be calculated by dividing the heat of fusion (Hf), determined from the second heat curve, by a theoretical heat of fusion of 292 J/g for PE (165 J/g for PP), and multiplying this quantity by 100 (for example, % cryst.=(Hf/292 J/g)×100 (for PE)). In DSC measurements, it is common that multiple Tm peaks are observed, and here, the highest temperature peak as the Tm of the polymer is recorded.
Tensile properties were measured according to ASTM D412 using a Zwick Roell Z010 device. Dumbbells (type 5A) were cut from cured plates (t95+3 min, 180° C.). Tear strength was measured according to ASTM D624 type-T on a Zwick Roell Z010 device. Test specimens were cut from cured plates (t95+3 min, 180° C.).
Compression set was measured at 100° C. for 22 h as described in ASTM D395 (25% deflection method B). Test specimens have been cured at 180° C. for t90+10 minutes under standard pressure. Additional one set of samples was measured according to PV3307 from the quality requirements of VW TL 52704-B. The samples were compressed with a deflection of 50% for 22 h at 100° C. Before opening the compression set setup the samples were let to cool for additional 2 h at RT.
Shore A type hardness was measured according to ASTM D2240 using a 3 layer ply of cured plates (t95+3 min, 180° C.).
Cured plates were aged in hot air for 72 h or 168 h (EPDM Design Study) and 94 h (Blend Ratio Study) respectively at 125° C. according to ASTM D573.
The interpolymers SiH-POE D, SiH-POE E, and POE D were each prepared in a one-gallon polymerization reactor that was hydraulically full, and operated at steady state conditions. The solvent was ISOPAR-E, supplied by the ExxonMobil Chemical Company. The 5-hexenyldimethylsilane (HDMS), supplied by Gelest was used as a termonomer, and was purified over AZ-300 alumina supplied by UOP Honeywell prior to use. HDMS was fed to the reactor as a 22 wt % solution in ISOPAR-E. The reactor temperature was measured at or near the exit of the reactor. The interpolymer was isolated and pelletized. Polymerization conditions are listed in Table 1B-1D, and catalysts and co-catalysts are listed in Table 1A. The polymer properties of each ethylene/octene/silane terpolymer (SiH-POE) and the ethylene/octene copolymer (POE) are shown in Tables 2A and 2B.
Polymer compositions (weight parts per hundred resin/rubber-phr) and curing properties are listed in Table 3. The mechanical properties of these compositions are listed in Table 4. For each composition in Table 3, the compounds were mixed in a Banbury™ BR 1600 internal rubber mixer equipped with a pair of tangential two wing rotors using a standard “upside-down” mixing procedure, adding the EPDM last. The 1.6 Liter mixing chamber was filled to a filling level of 75%. The rotor speed was kept constant at 45 rpm during the mixing cycle. The mixer body temperature was 60° C., the compounds were mixed for 240 s, and the melt temperature was controlled to be below 110° C. After the mixing was complete the compound was collected and then pressed into a sheet at 90° C.
The curing properties of the compositions were measured via the MDR method described above. The physical properties of the compositions were measured from vulcanized sheets, cured in a compression molder (for tensile, compression set testing, and temperature retraction). Samples from the uncured blankets were cut, heated, and cured in a compression molder to make test specimens in accordance with ASTM D3182, using a PHI (100 ton press). The desired mold (6 in×6 in, or compression buttons) was placed on a platen. The sample (uncured blanket) was cut slightly smaller than the dimensions of the individual mold cavity. The mill direction was marked, and the sample was labeled. The mold was spray brushed with a dilute solution of silicone. The samples were in a preheated mold, with care being taken to place properly for mill direction. The platens were closed. The “normal” operating pressure was 100 tons, or as shown on the gauge as 200,000 pounds. When cure time ended, the samples were removed, and immediately placed in water to stop the curing. Samples were conditioned for 24 hours at room temperature, prior to testing. For vulcanization, the samples were under minimum compression pressure of 3.5 MPa (500 psi) at 180° C. using t95 data plus 3 minutes for plaques, and using t95 data plus 15 minutes for compression set buttons.
Inventive Examples 1 and 2 (IE-1 and IE-2) represent the inventive composition of the present application. Comparative Examples 1-3 (CE-1 to CE-3) represent conventional compositions, with CE-1 and CE-1 being conventional POE (ethylene/1-octene copolymer) compositions and CE-3 being a conventional EPDM composition.
Surprisingly, the crosslinked inventive compositions, in comparison to conventional crosslinked compositions, showed relatively high curing levels and fast curing, along with improved or good mechanical properties such as high temperature compression set resistance and excellent low temperature flexibility. With CE-1 and CE-2, conventional crosslinked POE compositions showed good mechanical properties but had poor crosslinking properties. With CE-3, conventional crosslinked EPDM composition showed good curing properties but had poor mechanical properties. Thus, the present application is inventive over the state of the art in that it provides a composition that allows for relatively high curing levels and fast curing while also providing for good mechanical properties.
This application claims the benefit of priority to U.S. Provisional Application No. 63/265,635, filed on Dec. 17, 2021.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/081850 | 12/16/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63265635 | Dec 2021 | US |
