Method for electrical insulation and insulated electrical conductor
An electrically conductive material may be electrically insulated with a curable composition that includes a curable compound, such as an unsaturated polyester resin, and a functionalized poly(arylene ether) resin. After curing, the composition exhibits increased flexural strength, increased impact strength, and improved tensile properties relative to currently employed insulation materials.
1 . A method of insulating an electrically conductive material, comprising:
applying to the electrically conductive material a curable composition comprising
a functionalized poly(arylene ether); and
a curable compound selected from olefinically unsaturated monomers, unsaturated polyester resins, epoxy resins, polyester/epoxy copolymers, unsaturated esterimide resins, curable silicones, and combinations thereof.
2 . The method of claim 1 , wherein said applying comprises using an application technique selected from dip and bake, dip and spin, vacuum/pressure impregnation, roll through, trickle application, and total encapsulation.
3 . The method of claim 1 , wherein the functionalized poly(arylene ether) comprises a capped poly(arylene ether) having the formula
Q(J-K) y
wherein Q is the residuum of a monohydric, dihydric, or polyhydric phenol; y is 1 to 100; J has the formula
wherein R 1 and R 3 are each independently selected from the group consisting of hydrogen, halogen, primary or secondary C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C2-C 12 alkynyl, C 1 -C 12 aminoalkyl, C 1 -C 12 hydroxyalkyl, phenyl, C 1 -C 12 haloalkyl, C 1 -C 12 hydrocarbyloxy, and C 2 -C 12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms; R 2 and R 4 are each independently selected from the group consisting of halogen, primary or secondary C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C2-C 12 alkynyl, C 1 -C 12 aminoalkyl, C 1 -C 12 hydroxyalkyl, phenyl, C 1 -C 12 haloalkyl, C 1 -C 12 hydrocarbyloxy, and C 2 -C 12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms; m is 1 to about 200; and K is a capping group selected from the group consisting of
wherein R 5 is C 1 -C 12 hydrocarbyl optionally substituted with one or two carboxylic acid groups, R 6 -R 8 are each independently hydrogen, C 1 -C 18 hydrocarbyl optionally substituted with one or two carboxylic acid groups, C 2 -C 18 hydrocarbyloxycarbonyl, nitrile, formyl, carboxylic acid, imidate, and thiocarboxylic acid; R 9 -R 13 are each independently selected from the group consisting of hydrogen, halogen, C 1 -C 12 alkyl, hydroxy, carboxylic acid, and amino; and wherein Y is a divalent group selected from the group consisting of
wherein R 14 and R 15 are each independently selected from the group consisting of hydrogen and C 1 -C 12 alkyl.
4 . The method of claim 1 , wherein the functionalized poly(arylene ether) comprises a dicapped poly(arylene ether) having the structure
wherein each occurrence of Q 2 is independently selected from hydrogen, halogen, primary or secondary C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 3 -C 12 alkenylalkyl, C 2 -C 12 alkynyl, C 3 -C 12 alkynylalkyl, C 1 -C 12 aminoalkyl, C 1 -C 12 hydroxyalkyl, phenyl, C 1 -C 12 haloalkyl, C 1 -C 12 hydrocarbyloxy, and C 2 -C 12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms; and wherein each occurrence of Q 1 is independently selected from halogen, primary or secondary C 1 -C 12 alkyl, C 2 -C 12 alkenyl, C 3 -C 12 alkenylalkyl, C 2 -C 12 alkynyl, C 3 -C 12 alkynylalkyl, C 1 -C 12 aminoalkyl, C 1 -C 12 hydroxyalkyl, phenyl, C 1 -C 12 haloalkyl, C 1 -C 12 hydrocarbyloxy, and C 2 -C 12 halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms; each occurrence of R 16 is independently hydrogen or methyl; each occurrence of x is independently 1 to about 100; z is 0 or 1; and Y has a structure selected from
wherein each occurrence of R 17 , R 18 , and R 19 is independently selected from hydrogen and C 1 -C 12 hydrocarbyl.
5 . The method of claim 1 , wherein the functionalized poly(arylene ether) comprises a ring-functionalized poly(arylene ether) comprising repeating structural units of the formula
wherein each L 1 -L 4 is independently hydrogen, a C 1 -C 12 alkyl group, an alkenyl group, or an alkynyl group; wherein the alkenyl group is represented by
wherein L 5 -L 7 are independently hydrogen or methyl, and a is 0, 1, 2, 3, or 4; wherein the alkynyl group is represented by
wherein L 8 is hydrogen, methyl, or ethyl, and b is 0, 1, 2, 3, or 4; and wherein about 0.02 mole percent to about 25 mole percent of the total L 1 -L 4 substituents in the ring-functionalized poly(arylene ether) are alkenyl and/or alkynyl groups.
6 . The curable composition of claim 1 , wherein the functionalized poly(arylene ether) resin comprises at least one terminal functional group selected from carboxylic acid, glycidyl ether, vinyl ether, and anhydride.
7 . The method of claim 1 , wherein the functionalized poly(arylene ether) resin has an intrinsic viscosity of about 0.03 to about 0.6 deciliter per gram measured at 25° C. in chloroform.
8 . The method of claim 1 , wherein the functionalized poly(arylene ether) resin has an intrinsic viscosity of about 0.06 to about 0.3 deciliter per gram measured at 25° C. in chloroform.
9 . The method of claim 1 , wherein the curable composition comprises about 1 to about 50 weight percent of the functionalized poly(arylene ether), based on the total weight of the curable composition.
10 . The method of claim 1 , wherein the curable composition comprises an olefinically unsaturated monomer selected from acryloyl monomers, alkenyl aromatic monomers, allylic monomers, vinyl ethers, maleimides, and mixtures thereof.
11 . The method of claim 1 , wherein the curable compound comprises an olefinically unsaturated monomer comprising an alkenyl aromatic monomer and an acryloyl monomer comprising at least two acryloyl moieties.
12 . The method of claim 1 , wherein the curable compound comprises an unsaturated polyester resin.
13 . The method of claim 12 , wherein the curable composition further comprises a curable compound selected from styrene, vinyl toluene, t-butyl styrene, p-methyl styrene, alpha-methyl styrene, diallyl phthalate, diallyl isophthalate, diallyl maleate, triallyl isocyanurate, triallyl cyanurate, dibutyl maleate, dicyclopentyloxyethyl methacrylate, meta-diisopropenylbenzene, and combinations thereof.
14 . The method of claim 1 , wherein the curable compound comprises an epoxy resin.
15 . The method of claim 1 , wherein the curable compound comprises a polyester/epoxy copolymer.
16 . The method of claim 1 , wherein the curable compound comprises an unsaturated esterimide resin.
17 . The method of claim 1 , wherein the curable compound comprises a curable silicone resin.
18 . The method of claim 1 , wherein the curable composition comprises about 50 to about 99 weight percent of the curable compound, based on the total weight of the curable composition.
19 . The method of claim 1 , wherein the curable composition further comprises a cure catalyst.
20 . The method of claim 1 , wherein the curable composition further comprises an additive selected from mineral fillers, thixotropes, UV tracers, flame retardants, and combinations thereof.
21 . The method of claim 1 , wherein the curable composition exhibits an unnotched Izod impact strength of about 220 to about 275 joules per meter after curing.
22 . The method of claim 1 , wherein the curable composition exhibits a tensile strength of about 58 to about 65 megapascals after curing.
23 . The method of claim 1 , wherein the curable composition exhibits a tensile elongation at break of about 2.5 to about 3.6 percent after curing.
24 . A method of insulating an electrically conductive material, comprising:
applying to the electrically conductive material a curable composition comprising
about 5 to about 50 weight percent of a (meth)acrylate-capped poly(arylene ether) having an intrinsic viscosity of about 0.06 to about 0.3 deciliter/gram in chloroform at 25° C.; and
about 50 to about 95 weight percent of a curable compound comprising an alkenyl aromatic monomer and an acryloyl monomer comprising at least two acryloyl moieties.
25 . A method of insulating an electrically conductive material, comprising:
applying to the electrically conductive material a curable composition comprising
about 5 to about 40 weight percent of a (meth)acrylate-capped poly(arylene ether) having an intrinsic viscosity of about 0.06 to about 0.3 deciliter/gram in chloroform at 25° C.; and
about 60 to about 95 weight percent of an unsaturated polyester resin.
26 . An electrical insulation varnish, comprising the cured product of a curable composition comprising
a functionalized poly(arylene ether); and
a curable compound selected from olefinically unsaturated monomers, unsaturated polyester resins, epoxy resins, polyester/epoxy copolymers, unsaturated esterimide resins, curable silicones, and combinations thereof.
27 . An electrical conductor, comprising:
an electrically conductive material; and
an electrically insulating material contacting said electrically conductive material, said electrically insulating material comprising the reaction product of a curable composition comprising
a functionalized poly(arylene ether); and
a curable compound selected from olefinically unsaturated monomers, unsaturated polyester resins, epoxy resins, polyester/epoxy copolymers, unsaturated esterimide resins, curable silicones, and combinations thereof.