POLYCARBONATE

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Indian Patent Application No. 202011051626, filed on November 26, 2020, the contents of which are incorporated by reference herein in their entirety.

BACKGROUND

[0001] Polycarbonates, copolymers thereof, and blends formed therefrom are useful in the manufacture of articles and components for a wide range of applications, from automotive parts to electronic appliances. Because of their broad use, particularly in automotive, lighting and consumer electronics industries, it is desirable to provide polycarbonates having a specific combination of properties. It would be particularly advantageous to provide a polycarbonate having good mechanical strength, low moisture uptake, and low birefringence. It would be a further advantage to provide a polycarbonate having improved flow, which can facilitate the manufacture of thin molded parts such as lenses.

SUMMARY

[0002] A poly(oxyalkylcarbonate) comprises oxyalkylaryl repeating units derived from a bis(substituted or unsubstituted 4-hydroxyalkoxyaryl)- or bis(substituted or unsubstituted 4- hydroxy(poly(alkoxyaryl))-substituted ring system, wherein the ring system is a substituted or unsubstituted 2-hydrocarbyl-isoindolin-l-one, a substituted cyclohexylidene, or an unsubstituted cyclohexylidene when the 4-hydroxyalkoxyaryl or the 4-hydroxy(poly(alkoxyaryl) groups are substituted.

[0003] A method of making the poly (oxy alky lcarbonate) comprises contacting an aromatic dihydroxy compound corresponding to the repeating units of formula (I), (II), or a combination thereof and, optionally, an aromatic dihydroxy compound not including an oxyalkylene linking group, with a carbonate precursor under conditions effective to provide the poly (oxy alky lcarbonate) .

[0004] A method for the manufacture of the poly(oxyalkylcarbonate) is disclosed.

[0005] A composition comprises the poly (oxy alky lcarbonate).

[0006] An article comprises the poly(oxyalkylcarbonate) or the composition. [0007] The above described and other features are exemplified by the following detailed description, examples, and claims.

DETAILED DESCRIPTION

[0008] The present inventors have unexpectedly found that a polycarbonate having a particularly desirable combination of properties can be prepared from specific monomers that provide an oxyalkylene linking group in the repeating unit structure (hereinafter referred to as a “poly (oxy alky lcarbonate)”). The poly(oxyalkylcarbonate) can exhibit one or more of reduced glass transition temperature, reduced refractive index, reduced stress optic coefficient, reduced entanglement molecular weight, reduced modulus, and increased brittle fracture stress, each as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present (i.e., a polycarbonate having repeating units that are identical except that the oxyalkylene linking group is omitted).

[0009] Accordingly, an aspect is a poly(oxyalkylcarbonate) having an oxyalkylene linking group. “Polycarbonate” and “poly(oxyalkylcarbonate)” as used herein means a homopolymer or copolymer. In particular, a poly(oxyalkylcarbonate) comprises oxyalkylaryl repeating units derived from a bis(substituted or unsubstituted 4-hydroxyalkoxyaryl)- or bis(substituted or unsubstituted 4-hydroxy(poly(alkoxyaryl))-substituted ring system. As used herein the terms “(substituted or unsubstituted 4-hydroxyalkoxyaryl)” and “(substituted or unsubstituted 4-hydroxy(poly(alkoxyaryl)) refer to the alkoxy and/or the aryl groups in the repeating unit being substituted or unsubstituted. Possible substituents are described below. In an aspect, preferred substituents include halogen or hydrocarbyl, more preferably halogen, Ci- ₆ alkyl, or Ci- ₆ alkyloxy.

[0010] Further in the repeat units, the ring system is a substituted or unsubstituted 2- hydrocarbyl-isoindolin-l-one, a substituted cyclohexylidene, or an unsubstituted cyclohexylidene when a 4-hydroxyalkoxyaryl or 4-hydroxy(poly(alkoxyaryl) group is substituted. Possible substituents are described below. Preferred substituents include halogen or hydrocarbyl, more preferably halogen, Ci- ₆ alkyl, or Ci- ₆ alkyloxy.

[0011] In an aspect, the oxyalkylaryl units are derived from a 3,3-(bis(substituted or unsubstituted 4-hydroxyalkoxyaryl))-2-hydrocarbyl-isoindolin-l-one that is further substituted or unsubstituted; a 3,3-(bis(substituted or unsubstituted 4-hydroxy(polyalkoxy))aryl)-2- hydrocarbyl-isoindolin-l-one; a l,l-(bis(substituted or unsubstituted 4-hydroxy(alkoxy))aryl)- hydrocarbyl substituted cyclohexylidene that is further substituted or unsubstituted; a 1,1- (substituted or unsubstituted bis(4-hydroxy(polyalkoxy))aryl)-hydrocarbyl-substituted cyclohexylidene; a 1,1 -(substituted bis(4-hydroxy(alkoxy))aryl)-unsubstituted cyclohexylidene; a 1,1 -(substituted bis(4-hydroxy(polyalkoxy))aryl)-unsubstituted cyclohexylidene; or a combination thereof. Possible substituents are described below. Preferred substituents include halogen or hydrocarbyl, more preferably halogen, Ci- ₆ alkyl, or Ci- ₆ alkyloxy.

[0012] In an aspect, the poly (oxy alky lcarbonate) comprises repeating units of the formula (I), (II), or a combination thereof.

[0013] In each of the foregoing formulas, it will be understood that the represents a point of attachment to the other units of the poly (oxy alky lcarbonate) or to an end group. In the foregoing formulas, R ^a and R ^b are independently at each occurrence a halogen, C1-3 alkoxy, or Ci-3 alkyl; R ¹ is independently at each occurrence a halogen, C _M alkoxy, or C1-4 alkyl; R ² is independently at each occurrence a C1-4 alkyl; R ³ is a Ci-12 alkyl, or phenyl optionally substituted with 1 to 5 Ci-6 alkyl; L is a C2-12 linear or branched alkylene or alkylidene; n is independently at each occurrence 1 to 10, or 1 to 8, or 1 to 6, or 1 to 4, or 1 to 2 or 1; j is 0 or 1 to 4; and p and q are independently at each occurrence 0 or 1 to 4, preferably 0 or 1; and m is 0 to 10 when at least one of p and q is 1 to 4, or 1 to 10 when both p and q are 0.

[0014] In an aspect, p and q are each 0, or p and q is each 1 and R ^a and R ^b are each a methyl group disposed meta to the bond with oxygen on each arylene group. In an aspect, R ¹ is independently at each occurrence a C1-3 alkyl, or C1-3 alkoxy. In an aspect, m is 1 to 5, preferably 1 to 3, preferably 3. In an aspect, R ² is independently at each occurrence methyl. In an aspect, R ³ is Ci-12 alkyl, or phenyl optionally substituted with 1 to 5 Ci-6 alkyl, preferably Ci-6 alkyl, or phenyl optionally substituted with 1 to 5 Ci-6 alkyl, more preferably methyl or phenyl. In an aspect L is a C2-6 linear alkylene, for example ethylene, propylene, butylene, preferably ethylene. In an aspect, L is a C3-12 branched alkylene or alkylidene. In an aspect, L is ethylene (i.e., a C2 alkylene). In an aspect, n is 1 to 4, or 1 to 2, or 1.

[0015] In an aspect in Formulas (I) and (II), p and q are each 0, or p and q is each 1 and R ^a and R ^b are each a methyl disposed meta to the bond with oxygen on each arylene ring; j is zero or 1, and R ¹ is C1-3 alkyl; m is 1 to 3, preferably 3; R ² is methyl; R ³ is Ci- ₆ alkyl, or phenyl optionally substituted with 1 to 5 Ci- ₆ alkyls, more preferably methyl or phenyl; L is a C2-6 linear alkylene or a C3-12 branched alkylene or alkylidene, preferably ethylene; and n is 1 to 4, or 1 to 2, or 1.

[0016] For example, in a specific aspect in Formula (I), p and q are each 0 or p and q is each 1 and R ^a and R ^b are each a methyl disposed meta to the bond to oxygen on each arylene ring; L is a C2-6 linear alkylene or a C3-8 branched alkylidene, preferably ethylene; and n is 1 or 2, preferably 1.

[0017] In a specific aspect in Formula (I), p and q are each 0; m is 1 to 10, preferably 1 to 3; R ² is a C1-3 alkyl, preferably methyl; L is a C2-6 linear alkylene or a C3-8 branched alkylidene, preferably ethylene; and n is 1 or 2, preferably 1. When p and q are 0, m is 3, R ² is methyl, the R ² groups are at the 3,3,5 positions on the cyclohexane ring, L is ethylene and n is 1, the poly(oxyalkylcarbonate) comprises, consists essentially of, or consists of repeating units according to formula (la)

[0018] In another specific aspect in Formula (I), p and q are 1 and R ^a and R ^b are each Ci- 3 alkyl, preferably methyl meta to the oxygen bond of the aryl ring; m is 0 to 3; R ² is C1-3 alkyl, preferably methyl; L is an ethylene group and n is 1. When p and q are 1, R ^a and R ^b are each methyl meta to the oxygen bond of the aryl ring, m is 0, L is an ethylene group and n is 1, the poly(oxyalkylcarbonate) comprises, consists essentially of, or consists of repeating units according to formula (lb) [0019] In a specific aspect in Formula (II), p and q are each 0, or p and q is each 1 and R ^a and R ^b are each methyl disposed meta to the bond to oxygen on each arylene ring; m is 1 to 3,

R ¹ is Ci-3 alkyl, preferably methyl; R ³ is independently at each occurrence Ci- ₆ alkyl or phenyl, preferably methyl or phenyl. L is a C2-6 linear alkylene or a C3-8 branched alkylidene, preferably ethylene; and n is 1 or 2, preferably 1. In as aspect, when R ³ is phenyl, p and q are 0, j is 0, L is ethylene and n is 1, the poly(oxyalkylcarbonate) can comprise, consist essentially of, or consist of repeating units according to formula (Ila)

[0020] The poly(oxyalkylcarbonate) can be a homopoly(oxyalkylcarbonate) of repeating units of formula (I) or formula (II), preferably of repeating units of formula (la), formula (lb), or formula (Ila).

[0021] Alternatively, the poly(oxyalkylcarbonate) can be a copolymer comprising repeating units different from the repeating units of formula (I) or formula (II). In an aspect, the poly(oxyalkylcarbonate) is a copolymer comprising repeating units different from the repeating units of formula (la), formula (lb), or formula (Ila). For example, the poly(oxyalkylcarbonate) can further comprise oxyalkylaryl repeating units of formula (III) wherein R ^a , R ^b , p, q and n are as defined above in formula (I) or formula (II. In an aspect in Formula (III), p and q are each 0, or p and q is each 1 and R ^a and R ^b are each a methyl) disposed meta to the bond with oxygen on each arylene ring; L is a C _2-6 linear alkylene or a C _3-12 branched alkylene or alkylidene, preferably ethylene; and n is 1 to 4, or 1 to 2, or 1. For example, in a specific aspect in Formula (III), p and q are each 0, or p and q is each 1 and R ^a and R ^b are each a methyl disposed meta to the bond to oxygen on each arylene ring; L is a C2-6 linear alkylene or a C3-8 branched alkylidene, preferably ethylene; and n is 1 or 2, preferably 1. When p and q are 0, L is ethylene and n is 1, the copolycarbonate can further comprise repeating units according to formula (Ilia) (Ilia).

[0022] The relative amounts of different oxyalkylcarbonate units in the copolycarbonates can be varied depending on the desired characteristics of the polymer. When only oxyalkylcarbonate-containing units are present in the copolymer, the poly(oxyalkylcarbonate) can include repeating units of formula (I), (II), or a combination thereof, preferably repeating units of formula (la), (lb), (Ila), or a combination thereof, in an amount of 1 to 99 mole percent, or 5 to 99 mole percent, or 10 to 99 mole percent, or 20 to 99 mole percent, or 30 to 99 mole percent, or 40 to 99 mole percent, or 50 to 99 mole percent. In another aspect, the poly(oxyalkylcarbonate) can include repeating units of formula (I), (II), or a combination thereof, preferably repeating units of formula (la), (lb), (Ila), or a combination thereof, in an amount of 1 to 95 mole percent, or 1 to 90 mole percent, or 1 to 80 mole percent, or 1 to 70 mole percent, or 1 to 60 mole percent, or 1 to 50 mole percent, with the remaining units being of formula (III), preferably of formula (Ilia), each based on the total moles of repeating units of the poly (oxyalkylcarbonate), which totals 100 mole percent. In another aspect, the poly (oxyalkylcarbonate) can comprise repeating units of formula (I), (II), or a combination thereof, preferably repeating units of formula (la), (lb), (Ila), or a combination thereof in an amount of 5 to 95 mole percent, or 10 to 90 mole percent, or 20 to 80 mole percent, or 30 to 70 mole percent, with the remaining units being of formula (III), preferably of formula (Ilia), each based on the total moles of repeating units of the poly (oxyalkylcarbonate), which totals 100 mole percent.

[0023] Alternatively, or in addition to repeating units of formula (III), preferably units of formula (Ilia), the copolycarbonate can further comprise carbonate repeating units wherein no oxyalkylene linking group is present. These can be repeating structural carbonate units of formula (IV) wherein represents a point of attachment to the other units of the copolycarbonate or an end group, and R ⁴ does not contain an oxyalkylene linker group. Furthermore, at least 60 percent of the total number of R ⁴ groups are aromatic, or each R ⁴ group contains at least one C6-30 aromatic group. Preferably, each R ⁴ can be derived from an aromatic dihydroxy compound not having an oxyalkylene linker group, such as an aromatic dihydroxy compound of formula (V) or a bisphenol of formula (5).

In formula (V), each R ^h is independently a halogen atom, for example bromine, a CMO hydrocarbyl group such as a Ci-io alkyl, a halogen-substituted Ci-io alkyl, a C6-10 aryl, or a halogen-substituted C _6-i o aryl, and n is 0 to 4.

[0024] In formula (VI), R ^a and R ^b are each independently a halogen, Ci-12 alkoxy, or Ci- 12 alkyl, and p and q are each independently 0 or 1 to 4, such that when p or q is less than 4, the valence of each carbon of the ring is filled by hydrogen. In an aspect, p and q is each 0, or p and q is each 1, and R ^a and R ^b are each a C1-3 alkyl, preferably methyl, disposed meta to the hydroxy group on each arylene group. X ^a is a bridging group connecting the two hydroxy-substituted aromatic groups, where the bridging group and the hydroxy substituent of each Ce arylene group are disposed ortho, meta, or para (preferably para) to each other on the Ce arylene group, for example, a single bond, -0-, -S-, -S(O)-, -S(0) ₂ -, -C(O)-, or a C _MS organic group, which can be cyclic or acyclic, aromatic or non-aromatic, and can further comprise heteroatoms such as halogens, oxygen, nitrogen, sulfur, silicon, or phosphorous. For example, X ^a can be a substituted or unsubstituted C3-18 cycloalky lidene; a Ci-25 alkylidene of the formula -C(R ^c )(R ^d ) - wherein R ^c and R ^d are each independently hydrogen, Ci-12 alkyl, Ci-12 cycloalkyl, C7-12 arylalkyl, Ci-12 heteroalkyl, or cyclic C7-12 heteroarylalkyl; or a group of the formula -C(=R ^e )- wherein R ^e is a divalent Ci-12 hydrocarbon group.

[0025] Examples of bisphenol compounds include 4,4'-dihydroxybiphenyl, 1,6- dihydroxynaphthalene, 2,6-dihydroxynaphthalene, bis(4-hydroxyphenyl)methane, bis(4- hydroxyphenyl)diphenylmethane, bis(4-hydroxyphenyl)-l-naphthylmethane, l,2-bis(4- hydroxyphenyl)ethane, l,l-bis(4-hydroxyphenyl)-l-phenylethane, 2-(4-hydroxyphenyl)-2-(3- hydroxyphenyl)propane, bis(4-hydroxyphenyl)phenylmethane, 2,2-bis(4-hydroxy-3- bromophenyl)propane, 1,1 -bis (hydroxyphenyl)cyclopentane, l,l-bis(4- hydroxyphenyl)cyclohexane, 1 , 1 -bis(4-hydroxyphenyl)isobutene, 1 , 1 -bis(4- hydroxyphenyl)cyclododecane, trans-2,3-bis(4-hydroxyphenyl)-2-butene, 2,2-bis(4- hydroxyphenyl)adamantane, alpha, alpha' -bis(4-hydroxyphenyl)toluene, bis(4- hydroxyphenyl)acetonitrile, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 2,2-bis(3-ethyl-4- hydroxyphenyl)propane, 2,2-bis(3-n-propyl-4-hydroxyphenyl)propane, 2,2-bis(3-isopropyl-4- hydroxyphenyl)propane, 2,2-bis(3-sec-butyl-4-hydroxyphenyl)propane, 2,2-bis(3-t-butyl-4- hydroxyphenyl)propane, 2,2-bis(3-cyclohexyl-4-hydroxyphenyl)propane, 2,2-bis(3-allyl-4- hydroxyphenyl)propane, 2,2-bis(3-methoxy-4-hydroxyphenyl)propane, 2,2-bis(4- hydroxyphenyl)hexafluoropropane, l,l-dichloro-2,2-bis(4-hydroxyphenyl)ethylene, 1,1- dibromo-2,2-bis(4-hydroxyphenyl)ethylene, l,l-dichloro-2,2-bis(5-phenoxy-4- hydroxyphenyl)ethylene, 4,4'-dihydroxybenzophenone, 3,3-bis(4-hydroxyphenyl)-2-butanone,

1.6-bis(4-hydroxyphenyl)-l,6-hexanedione, ethylene glycol bis(4-hydroxyphenyl)ether, bis(4- hydroxyphenyl)ether, bis(4-hydroxyphenyl)sulfide, bis(4-hydroxyphenyl) sulfoxide, bis(4- hydroxyphenyl)sulfone, 9,9-bis(4-hydroxyphenyl)fluorene, 2,7-dihydroxypyrene, 6,6'- dihydroxy-3,3,3',3'- tetramethylspiro(bis)indane ("spirobiindane bisphenol"), 3,3-bis(4- hydroxyphenyl)phthalimide, 2,6-dihydroxydibenzo-p-dioxin, 2,6-dihydroxythianthrene, 2,7- dihydroxyphenoxathin, 2,7-dihydroxy-9, 10-dimethylphenazine, 3,6-dihydroxydibenzofuran,

3.6-dihydroxydibenzothiophene, and 2,7-dihydroxycarbazole; resorcinol, substituted resorcinol compounds such as 5-methyl resorcinol, 5-ethyl resorcinol, 5-propyl resorcinol, 5-butyl resorcinol, 5-t-butyl resorcinol, 5-phenyl resorcinol, 5-cumyl resorcinol, 2,4,5,6-tetrafluoro resorcinol, 2,4,5,6-tetrabromo resorcinol, or the like; catechol; hydroquinone; substituted hydroquinones such as 2-methyl hydroquinone, 2-ethyl hydroquinone, 2-propyl hydroquinone, 2-butyl hydroquinone, 2-t-butyl hydroquinone, 2-phenyl hydroquinone, 2-cumyl hydroquinone,

2.3.5.6-tetramethyl hydroquinone, 2,3,5,6-tetra-t-butyl hydroquinone, 2,3,5,6-tetrafluoro hydroquinone, 2,3,5,6-tetrabromo hydroquinone, or the like.

[0026] In an aspect, the polycarbonate is a copolycarbonate further comprising repeating units derived from 2,2-bis(4-hydroxyphenyl) propane (bisphenol A), l,l-bis(4-hydroxy-3- methylphenyl)cyclohexane, 2-phenyl-3,3’-bis(4-hydroxyphenyl) phthalimidine, 4,4'-(3,3,5- trimethylcyclohexane-l,l-diyl)diphenol (also known as isophorone bisphenol or bisphenol TMC), or a combination thereof.

[0027] In an aspect where the copolycarbonates contain oxyalkylcarbonate units of formula (I), (II), or a combination thereof, and optionally units of formula (III), together with carbonate units of formula (IV), the relative amounts of each type of unit is adjusted to obtain the desired properties. With respect to the total amount of oxyalkylcarbonate units, the amount of units of formula (I), (II), or a combination thereof, preferably of formulas (la), (lb), (Ila), or a combination thereof, can vary widely, from 1 to 100 mole percent, with the optional units of formula (III), preferably formula (Ilia), providing the remainder of the oxyalkylcarbonate units, i.e., 0 to 99 mole percent, each based on the total moles of oxyalkylcarbonate units, which totals 100 mole percent. The amount of units of formula (I), (II), or a combination thereof, preferably of formulas (la), (lb), (Ila), or a combination thereof, can be from 1 to 99 mole percent, 10 to 99 mole percent, 20 to 99 mole percent, 30 to 99 mole percent, 40 to 95 mole percent, 50 to 95 mole percent, 1 to 95 mole percent, 1 to 90 mole percent, 1 to 80 mole percent, 1 to 70 mole percent, 1 to 60 mole percent, 1 to 50 mole percent, 5 to 95 mole percent, 10 to 90 mole percent, 20 to 80 mole percent, or 30 to 70 mole percent, with the units of formula (III), preferably formula (Ilia), providing the remainder of the oxyalkylcarbonate units, each based on the total moles of oxyalkylcarbonate units, which totals 100 mole percent.

[0028] Further in this aspect where the copolycarbonates contain oxyalkylcarbonate units of formula (I), (II), or a combination thereof, and optionally units of formula (III), together with carbonate units of formula (IV), the total amount of oxyalkylcarbonate units (the total of the amount of units of formula (I), (II), or a combination thereof and optionally formula (III), preferably the total amount of formulas (la), (lb), (Ila), or a combination thereof and optionally formula (Ilia), can vary widely, from 1 to 99 mole percent, with the carbonate units of formula (IV) providing the remainder of the carbonate units, i.e., 1 to 99 mole percent, each based on the total of the total of the oxyalkylcarbonate units and non-oxyalkylcarbonate carbonate units in the copolymer, which totals 100 mole percent. For example, the total amount of oxyalkylcarbonate units can be can be from 1 to 99 mole percent, 10 to 99 mole percent, 20 to 99 mole percent, 30 to 99 mole percent, 40 to 95 mole percent, 50 to 95 mole percent, 1 to 95 mole percent, 1 to 90 mole percent, 1 to 80 mole percent, 1 to 70 mole percent, 1 to 60 mole percent, 1 to 50 mole percent, 5 to 95 mole percent, 10 to 90 mole percent, 20 to 80 mole percent, or 30 to 70 mole percent, with the units of formula (IV), preferably bisphenol A, l,l-bis(4-hydroxy-3- methylphenyl)cyclohexane, 2-phenyl-3,3’-bis(4-hydroxyphenyl) phthalimidine4,4'-(3,3,5- trimethylcyclohexane-l,l-diyl)diphenol, or a combination thereof providing the remainder of the carbonate units, each based on the total moles of oxyalkylcarbonate and carbonate units, which totals 100 mole percent.

[0029] The poly(oxyalkylcarbonate) can provide one or more advantageous properties. The poly (oxyalkylcarbonate) can have a reduced glass transition temperature as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present. Glass transition temperature can be determined, for example, by differential scanning calorimetry. The poly(oxyalkylcarbonate) can have a reduced refractive index as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present. The poly(oxyalkylcarbonate) can have a reduced stress optic coefficient as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present. The poly(oxyalkylcarbonate) can have a reduced entanglement molecular weight as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present. The poly(oxyalkylcarbonate) can have a reduced modulus as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present. The poly (oxy alky lcarbonate) can have an increased brittle fracture stress as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present.

[0030] The poly(oxyalkylcarbonate) can exhibit one, two, three, four, five, or all of the foregoing properties. Where the poly(oxyalkylcarbonate) is described as having a “reduced” property relative to the reference polycarbonate (i.e., the polycarbonate of the same composition except that the oxyalkylene linking group is not present), it will be understood that the recited property can be reduced by at least 5%, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, relative to the reference polycarbonate. Where the poly(oxyalkylcarbonate) is described as having an “increased” property relative to the reference polycarbonate (i.e., the polycarbonate of the same composition except that the oxyalkylene linking group is not present), it will be understood that the recited property can be increased by at least 5%, or at least 10%, or at least 20%, or at least 30%, or at least 40%, or at least 50%, relative to the reference polycarbonate.

[0031] For example, the glass transition temperature that is reduced by at least 10%, or at least 15% as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present. For example, refractive index can be reduced by at least 0.75%, or at least 1% as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present. For example, stress optic coefficient can be reduced by at least 20%, or at least 25% as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present. For example, entanglement molecular weight can be reduced by at least 5%, or at least 10% as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present. For example, modulus can be reduced by at least 5%, or at least 10%, or at least 15% as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present. For example, brittle fracture stress can be increased by at least 10%, or at least 15% as compared to a polycarbonate of the same composition except that the oxyalkylene linking group is not present.

[0032] In an aspect, when the poly(oxyalkylcarbonate) comprises repeating units according to formula (I), particularly when in formula (I) p and q are each 0, m is 3, R ² is methyl, wherein R ² groups are at the 3,3,5 positions on the cyclohexane ring, the polycarbonate can have one or more of a glass transition temperature of less than 215°C, or 150 to 200°C, or 165 to 200°C, a refractive index of less than or equal to 1.55, or 1.53 to 1.55, a stress optic coefficient of less than 25, or 0.1 to 20, or 0.1 to 5, an entanglement molecular weight of less than 2800 g/mol, or 2000 to 2750 g/mol, a modulus of less than or equal to 2.5 GPa, or 1.9 to 2.4 GPa and a brittle fracture stress of greater than or equal to 75 MPa, or 75 to 130 MPa, or 90 to 130 MPa.

[0033] In an aspect, when the poly (oxy alky lcarbonate) comprises repeating units according to formula (II), the polycarbonate can have one or more of a glass transition temperature of less than 260°C, or 180 to 255°C, a refractive index of less than or equal to 1.62, or 1.55 to 1.62, a stress optic coefficient of less than 50, or 1 to 48, an entanglement molecular weight of less than 3000 g/mol, or 2000 to 2900 g/mol, a modulus of less than or equal to 2.8 GPa, or 1.9 to 2.8 GPa and a brittle fracture stress of greater than or equal to 80 MPa, or 80 to 100 MPa.

[0034] The poly(oxyalkylcarbonate) can be made from an aromatic dihydroxy compound containing an oxyalkylene linking group corresponding to the repeating units of formula (I) or (II), for example, aromatic dihydroxy compounds according to formula (Ic) or (lie). wherein the variables are as defined in formulas (I) and (II).

[0035] One or more aromatic dihydroxy compound containing an oxyalkylene linking group, optionally together with a dihydroxy compound of formula (V), (VI), or a combination can be contacted with a carbonate precursor under conditions effective to provide the polycarbonate. The polycarbonates can be manufactured by methods such as interfacial polymerization and melt polymerization, which are known, and are described, for example, in WO 2013/175448 A1 and WO 2014/072923 Al. An end-capping agent (also referred to as a chain stopper agent or chain terminating agent) can be included during polymerization to provide end groups, for example monocyclic phenols such as phenol, p-cyanophenol, and Ci-22 alkyl-substituted phenols such as p-cumyl-phenol, resorcinol monobenzoate, and p-and tertiary- butyl phenol, monoethers of diphenols, such as p-methoxyphenol, monoesters of diphenols such as resorcinol monobenzoate, functionalized chlorides of aliphatic monocarboxylic acids such as acryloyl chloride and methacryoyl chloride, and mono-chloroformates such as phenyl chloroformate, alkyl-substituted phenyl chloroformates, p-cumyl phenyl chloroformate, and toluene chloroformate. Combinations of different end groups can be used.

[0036] Exemplary carbonate precursors for forming the polycarbonate can include a carbonyl halide such as carbonyl bromide or carbonyl chloride (phosgene) a bishaloformate of a dihydroxy compound (e.g., the bischloroformate of bisphenol A, hydroquinone ethylene glycol, neopentyl glycol, or the like), and diaryl carbonates. A combination thereof can also be used. The diaryl carbonate ester can be diphenyl carbonate, or an activated diphenyl carbonate having electron-withdrawing substituents on the each aryl, such as bis(4-nitrophenyl)carbonate, bis(2- chlorophenyl)carbonate, bis(4-chlorophenyl)carbonate, bis(methyl salicyl)carbonate, bis(4- methylcarboxylphenyl) carbonate, bis(2-acetylphenyl) carboxylate, bis(4-acetylphenyl) carboxylate, or a combination thereof.

[0037] When interfacial polymerization is used, the polymerization can be conducted in the presence of an interfacial catalyst. Among tertiary amines that can be used as catalysts in interfacial polymerization are aliphatic tertiary amines such as triethylamine and tributylamine, cycloaliphatic tertiary amines such as N,N-diethyl-cyclohexylamine, and aromatic tertiary amines such as N,N-dimethylaniline. Among the phase transfer catalysts that can be used are catalysts of the formula (R ³ )4Q ⁺ X, wherein each R ³ is the same or different, and is a Ci-io alkyl; Q is a nitrogen or phosphorus atom; and X is a halogen atom or a Ci-s alkoxy or Ce-is aryloxy. Exemplary phase transfer catalysts include (CH3(CH2)3)4NX, (CH3(CH2)3)4PX,

(CH ₃ (CH ₂ )5)4NX, (CH ₃ (CH ₂ )6)4NX, (CH ₃ (CH ₂ ) )4NX, CH3(CH ₃ (CH ₂ )3)3NX, and CH3(CH3(CH2)2)3NX, wherein X is CT, Br , a Ci-s alkoxy or a Ce-is aryloxy. An effective amount of a phase transfer catalyst can be 0.1 to 10 wt%, or 0.5 to 2 wt%, each based on the weight of dihydroxy compound in the phosgenation mixture.

[0038] Alternatively, melt processes can be used to make the polycarbonates. In the melt polymerization process, polycarbonates can generally be prepared by co-reacting, in a molten state, a dihydroxy reactant as described above and a diaryl carbonate ester as described above in the presence of a transesterification catalyst. Conditions for melt process are described, for example, in WO2013/027165 and the references cited therein. Catalysts used in the melt polymerization can include an alpha catalyst and a beta catalyst. Alpha catalysts can comprise a source of alkali or alkaline earth ions and are typically more thermally stable and less volatile than beta catalysts. Beta catalysts are typically volatile and degrade at elevated temperatures, and can comprise a transesterification catalyst of the formula (R ³ )4Q ⁺ X as described above.

Beta catalysts are therefore preferred for use at early low-temperature polymerization stages. The alpha catalyst can be used in an amount sufficient to provide 1 x 10 ² to 1 x 10 ⁸ moles, preferably, 1 x 10 ⁴ to 1 x 10 ⁷ moles of metal per mole of the dihydroxy compounds used. The amount of beta catalyst (e.g., organic ammonium or phosphonium salts) can be 1 x 10 ² to 1 x 10 ⁵ , preferably 1 x 10 ³ to 1 x 10 ⁴ moles per total mole of the dihydroxy compounds in the reaction mixture. Quenching of the transesterification catalysts and any reactive catalysts residues with an acidic compound after polymerization is completed can also be useful in some melt polymerization processes. Among the many quenchers that can be used are alkyl sulfonic esters of the formula R ⁸ S03R ⁹ wherein R ⁸ is hydrogen, Ci-12 alkyl, C6-18 aryl, or C7-19 alkylaryl, and R ⁹ is Ci-12 alkyl, C6-18 aryl, or C7-19 alkylaryl (e.g., benzene sulfonate, p-toluene sulfonate, methylbenzene sulfonate, ethylbenzene sulfonate, n-butyl benzenesulfonate, octyl benzenesulfonate and phenyl benzenesulfonate, methyl p-toluenesulfonate, ethyl p- toluenesulfonate, n-butyl p-toluene sulfonate, octyl p-toluenesulfonate and phenyl p- toluenesulfonate, in particular alkyl tosylates such as n-butyl tosylate).

[0039] An end-capping agent (also referred to as a chain stopper agent or chain terminating agent) can be included during polymerization to provide end groups. The end capping agent (and thus end groups) are selected based on the desired properties of the polycarbonates. Exemplary end-capping agents are exemplified by monocyclic phenols such as phenol and Ci-22 alkyl-substituted phenols such as p-cumyl-phenol, resorcinol monobenzoate, and p-and tertiary-butyl phenol, monoethers of diphenols, such as p-methoxyphenol, and alkyl- substituted phenols with branched chain alkyl substituents having 8 to 9 carbon atoms, 4- substituted-2-hydroxybenzophenones and their derivatives, aryl salicylates, monoesters of diphenols such as resorcinol monobenzoate, 2-(2-hydroxyaryl)-benzotriazoles and their derivatives, 2-(2-hydroxyaryl)-l,3,5-triazines and their derivatives, mono-carboxylic acid chlorides such as benzoyl chloride, Ci-22 alkyl-substituted benzoyl chloride, toluoyl chloride, bromobenzoyl chloride, cinnamoyl chloride, and 4-nadimidobenzoyl chloride, polycyclic, mono-carboxylic acid chlorides such as trimellitic anhydride chloride, and naphthoyl chloride, functionalized chlorides of aliphatic monocarboxylic acids, such as acryloyl chloride and methacryoyl chloride, and mono-chloroformates such as phenyl chloroformate, alkyl-substituted phenyl chloroformates, p-cumyl phenyl chloroformate, and toluene chloroformate.

Combinations of different end groups can be used.

[0040] The poly(oxyalkylcarbonate) can be useful for forming a composition comprising the poly (oxy alky lcarbonate). For example, the composition can comprise the poly(oxyalkylcarbonate) (i.e., including repeating units according to formulas (I), (II), or a combination thereof), and a polymer different from the poly (oxy alky lcarbonate) of the present disclosure. In an aspect, the poly(oxyalkylcarbonate) can be present in an amount of 1 to 99 weight percent, and the polymer different from the poly(oxyalkylcarbonate) can be present in an amount of 1 to 99 weight percent, each based on the total weight of the composition.

[0041] The polymer different from the poly (oxy alky lcarbonate) can include, for example, polyacetals (e.g., polyoxyethylene and polyoxymethylene), poly(Ci- ₆ alkyl)acrylates, polyacrylamides, polyamides, (e.g., aliphatic polyamides, polyphthalamides, and polyaramides), polyamideimides, polyanhydrides, polyarylates, polyarylene ethers (e.g., polyphenylene ethers), polyarylene sulfides (e.g., polyphenylene sulfides), polyarylene sulfones (e.g., polyphenylene sulfones), polybenzothiazoles, polybenzoxazoles, polycarbonates (including polycarbonate copolymers such as polycarbonate-siloxanes, polycarbonate-esters, and polycarbonate-ester- siloxanes, provided that any polycarbonate is different in composition from the poly(oxyalkylcarbonate) of the present disclosure), polyesters (e.g., polyethylene terephthalates, polybutylene terephthalates, polyarylates, and polyester copolymers such as polyester-ethers), polyetheretherketones, polyetherimides (including copolymers such as polyetherimide-siloxane copolymers), polyetherketoneketones, polyetherketones, polyethersulfones, polyimides (including copolymers such as polyimide-siloxane copolymers), poly(Ci- ₆ alkyl)methacrylates, polymethacrylamides, polynorbomenes (including copolymers containing norbomenyl units), polyolefins (e.g., polyethylenes, polypropylenes, polytetrafluoroethylenes, and their copolymers, for example ethylene- alpha-olefin copolymers), polyoxadiazoles, polyoxymethylenes, polyphthalides, polysilazanes, polysiloxanes, polystyrenes (including copolymers such as acrylonitrile-butadiene-styrene (ABS) and methyl methacrylate -butadiene-styrene (MBS)), polysulfides, polysulfonamides, polysulfonates, polysulfones, polythioesters, polytriazines, polyureas, polyurethanes, polyvinyl alcohols, polyvinyl esters, polyvinyl ethers, polyvinyl halides, polyvinyl ketones, polyvinyl thioethers, polyvinylidene fluorides, or the like, or a combination thereof. In some aspects, the polymer different from the poly(oxyalkylcarbonate) can comprise a polycarbonate (not including repeating units according to formulas (I) or (II)), a polyetherimide, a polyimide, a polysulfone, a polyethersulfone, a polyphenylene sulfone, a polyarylene ether, a polyetherether ketone, a polyamide, or a combination thereof. In an aspect, the poly(oxyalkylcarbonate) can be blended with a polycarbonate of repeating units derived from bisphenol A, l,l-bis(4-hydroxy-3-methylphenyl)cyclohexane, 2 -phenyl-3, 3 ’-bis(4- hydroxyphenyl) phthalimidine, or 4,4'-(3,3,5-trimethylcyclohexane-l,l-diyl)diphenol.

[0042] The composition can optionally further comprise an additive composition comprising one or more additives. The one or more additives can be selected to achieve a desired property, with the proviso that the additive(s) are also selected so as to not significantly adversely affect a desired property of the composition. The additive composition or individual additives can be mixed at a suitable time during the mixing of the components for forming the composition. The additive can be soluble or non-soluble in polycarbonate. The additive composition can include an impact modifier, flow modifier, filler (e.g., a particulate polytetrafluoroethylene (PTFE), glass, carbon, mineral, or metal), reinforcing agent (e.g., glass fibers), antioxidant, heat stabilizer, light stabilizer, ultraviolet (UV) light stabilizer, UV absorbing additive, plasticizer, lubricant, release agent (such as a mold release agent), antistatic agent, anti-fog agent, antimicrobial agent, colorant (e.g, a dye or pigment), surface effect additive, radiation stabilizer, flame retardant, anti-drip agent (e.g., a PTFE-encapsulated styrene- acrylonitrile copolymer (TSAN)), or a combination thereof. For example, a combination of a heat stabilizer, mold release agent, and ultraviolet light stabilizer can be used. In general, the additives are used in the amounts generally known to be effective. For example, the total amount of the additive composition (other than any impact modifier, filler, or reinforcing agent) can be 0.001 to 10.0 wt%, or 0.01 to 5 wt%, each based on the total weight of the polymer in the composition.

[0043] The composition can be manufactured by various methods known in the art. For example, powdered polycarbonate, and other optional components are first blended, optionally with any fillers, in a high speed mixer or by hand mixing. The blend is then fed into the throat of a twin-screw extruder via a hopper. Alternatively, at least one of the components can be incorporated into the composition by feeding it directly into the extruder at the throat or downstream through a sidestuffer, or by being compounded into a masterbatch with a desired polymer and fed into the extruder. The extruder is generally operated at a temperature higher than that necessary to cause the composition to flow. The extrudate can be immediately quenched in a water bath and pelletized. The pellets so prepared can be one-fourth inch long or less as desired. Such pellets can be used for subsequent molding, shaping, or forming.

[0044] Shaped, formed, or molded articles comprising the poly(oxyalkylcarbonate) or the polycarbonate composition are also provided. The poly(oxyalkylcarbonate) or the polycarbonate composition can be molded into useful shaped articles by a variety of methods, such as injection molding, extrusion, rotational molding, blow molding and thermoforming. Some examples of articles include computer and business machine housings such as housings for monitors, handheld electronic device housings such as housings for cell phones, electrical connectors, and components of lighting fixtures, ornaments, home appliances, roofs, greenhouses, sun rooms, swimming pool enclosures, and the like. Additional exemplary articles include a plug, a plug housing, a switch, an electrical conductor, a connector, an electric board, a lamp holder, a lamp cover, a lamp bezel, a reflector, a signal indicator, glazing, a lens, a lens holder, a waveguide element, a collimator, a light emitting diode, a diffuser sheet, a safety pane, a film, a film laminate, a safety goggle, and a visor. The poly(oxyalkylcarbonate) and composition can be especially useful for articles such as a lens, an automotive part, an optical article, a dielectric film, a viewing screen, or a display.

[0045] This disclosure is further illustrated by the following examples, which are non limiting.

EXAMPLES

[0046] Materials referred to in the following examples are described in Table 1.

Table 1

[0047] The ethoxylated monomers of Table 1 can be prepared using techniques that are generally known. For example, BPA can be converted to BPA-Et through reaction with ethylene carbonate in the presence of triethylamine at 105°C for 24 hours to provide BPA-Et in a yield of 40-45%, or in the presence of potassium iodide at 150°C for 4 hours to provide BPA- Et in a yield of greater than 90%. Alternatively, BPA can be converted to BPA-Et through reaction with ethylene glycol in the presence of sodium carbonate, urea, and zinc oxide at a temperature of 175°C for 2 hours, to provide BPA-Et in a yield of 85-90%. Alternatively still, BPA can be converted to BPA-Et through reaction with ethylene oxide in the presence of triethylamine and acetone at a temperature of 130°C for less than 1 hour to provide BPA-Et in a yield of greater than 95%. DMBPC-Et, PPPBP-Et and BPI-Et can be prepared using similar methods.

[0048] The properties of polymers made with ethoxylated monomers were compared to the non-ethoxylated versions using quantum mechanical computations. The properties were modelled based on homopolymer structures (i.e., 100% of the given monomer structure) and SO SO random block copolymer (i.e., a copolymer having randomly placed blocks) structures with BPA.

[0049] The results of the calculations are shown in Tables 2 and 3 for the homopolymers and copolymers, respectively. Specifically, calculated glass transition temperature (Tg, °C), refractive index (RI), stress optic coefficient (SOC), entanglement molecular weight (M _E , Daltons (DA)), modulus (GPa) and brittle fracture stress (MPa) are reported for each composition.

Table 2. Homopolymers

Table 3. Copolymers [0050] It can be seen from the computational data that the addition of the ethoxy spacer in the polycarbonate structure decreases the Tg for both homopolymers and copolymers. Unexpectedly, despite lowering the Tg, mechanical properties were generally improved, and the stress optic coefficient (and therefore the inherent birefringence) was also lowered for each sample. To further tailor properties to suit a desired application, it is expected that various combinations of the above components can be prepared as copolymers, terpolymers, and the like.

[0051] In a particularly advantageous feature, it was noted that the mechanical properties for polymers prepared from DMBPC-Et were improved. For example, a 50:50 copolymer of DMBPC-BPA (E10) is generally brittle, with a brittle fracture stress of 88 MPa. The ethoxylated version (Ell) provided a 50:50 copolymer with a brittle fracture stress of 110 MPa, which is similar to the BPA homopolymer, having a brittle fracture stress of 109 MPa.

[0052] Thus, the present inventors have unexpectedly found that incorporation of a “soft” alkyl group (e.g., an ethoxy group) can lead to an improved property profile for various polycarbonate structures, including both homopolymers and copolymers. Without wishing to be bound by theory, it is believed that addition of the ethoxy group can decrease chain stiffness, thereby impacting properties including mechanical strength, moisture uptake and birefringence. Further, due to a drop in the Tg, the polymer flow increases significantly, allowing for molding of very thin parts such as lenses. So, a significant improvement is provided by the present disclosure.

[0053] The compositions, methods, and articles can alternatively comprise, consist of, or consist essentially of, any appropriate materials, steps, or components herein disclosed. The compositions, methods, and articles can additionally, or alternatively, be formulated so as to be devoid, or substantially free, of any materials (or species), steps, or components, that are otherwise not necessary to the achievement of the function or objectives of the compositions, methods, and articles.

[0054] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. “Combinations” is inclusive of blends, mixtures, alloys, reaction products, and the like. The terms “first,” “second,” and the like, do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The terms “a” and “an” and “the” do not denote a limitation of quantity, and are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. “Or” means “and/or” unless clearly stated otherwise. Reference throughout the specification to “an aspect” means that a particular element described in connection with the aspect is included in at least one aspect described herein, and may or may not be present in other aspects. The term “combination thereof’ as used herein includes one or more of the listed elements, and is open, allowing the presence of one or more like elements not named. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various aspects.

[0055] Unless specified to the contrary herein, all test standards are the most recent standard in effect as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

[0056] Unless defined otherwise, technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art to which this application belongs. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.

[0057] Compounds are described using standard nomenclature. For example, any position not substituted by any indicated group is understood to have its valency filled by a bond as indicated, or a hydrogen atom. A dash that is not between two letters or symbols is used to indicate a point of attachment for a substituent. For example, -CHO is attached through carbon of the carbonyl group.

[0058] As used herein, the term “hydrocarbyl”, whether used by itself, or as a prefix, suffix, or fragment of another term, refers to a residue that contains only carbon and hydrogen. The residue can be aliphatic or aromatic, straight-chain, cyclic, bicyclic, branched, saturated, or unsaturated. It can also contain combinations of aliphatic, aromatic, straight chain, cyclic, bicyclic, branched, saturated, and unsaturated hydrocarbon moieties. However, when the hydrocarbyl residue is described as substituted, it may, optionally, contain heteroatoms over and above the carbon and hydrogen members of the substituent residue. Thus, when specifically described as substituted, the hydrocarbyl residue can also contain one or more carbonyl groups, amino groups, hydroxyl groups, or the like, or it can contain heteroatoms within the backbone of the hydrocarbyl residue. The term "alkyl" means a branched or straight chain, saturated aliphatic hydrocarbon group, e.g., methyl, ethyl, n-propyl, i-propyl, n-butyl, s-butyl, t-butyl, n- pentyl, s-pentyl, and n- and s-hexyl. “Alkenyl” means a straight or branched chain, monovalent hydrocarbon group having at least one carbon-carbon double bond (e.g., ethenyl (-HC=CH2)). “Alkoxy” means an alkyl group that is linked via an oxygen (i.e., alkyl-O-), for example methoxy, ethoxy, and sec-butyloxy groups. "Alkylene" means a straight or branched chain, saturated, divalent aliphatic hydrocarbon group (e.g., methylene (-CH ₂ -) or, propylene (-(CH ₂ ) ₃ - )). “Cycloalky lene” means a divalent cyclic alkylene group, -C _n Fh _n-x , wherein x is the number of hydrogens replaced by cyclization(s). “Cycloalkenyl” means a monovalent group having one or more rings and one or more carbon-carbon double bonds in the ring, wherein ah ring members are carbon (e.g., cyclopentyl and cyclohexyl). "Aryl" means an aromatic hydrocarbon group containing the specified number of carbon atoms, such as phenyl, tropone, indanyl, or naphthyl. “Arylene” means a divalent aryl group. “Alkylarylene” means an arylene group substituted with an alkyl group. “Arylalkylene” means an alkylene group substituted with an aryl group (e.g., benzyl). The prefix "halo" means a group or compound including one more of a fluoro, chloro, bromo, or iodo substituent. A combination of different halo atoms (e.g., bromo and fluoro), or only chloro atoms can be present. The prefix “hetero” means that the compound or group includes at least one ring member that is a heteroatom (e.g., 1, 2, or 3 heteroatom(s)), wherein the heteroatom(s) is each independently N, O, S, Si, or P. “Substituted” means that the compound or group is substituted with at least one (e.g., 1, 2, 3, or 4) substituents that can each independently be a C _1-9 alkoxy, a C _1-9 haloalkoxy, a nitro (-NO ₂ ), a cyano (-CN), a Ci-6 alkyl sulfonyl (-S(=0) ₂ -alkyl), a C _6-12 aryl sulfonyl (-S(=0) ₂ -aryl), a thiol (-SH), a thiocyano (-SCN), a tosyl (CH3C6H4SO2-), a C3-12 cycloalkyl, a C2-12 alkenyl, a C5-12 cycloalkenyl, a C6-12 aryl, a C7- ₁₃ arylalkylene, a C _4-12 heterocycloalkyl, and a C _3-12 heteroaryl instead of hydrogen, provided that the substituted atom’s normal valence is not exceeded. The number of carbon atoms indicated in a group is exclusive of any substituents. For example -CH ₂ CH ₂ CN is a C ₂ alkyl group substituted with a nitrile.

[0059] While particular aspects have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace ah such alternatives, modifications variations, improvements, and substantial equivalents.