VARNISH COMPOSITIONS FOR ELECTRICAL INSULATION AND METHOD OF USING THE SAME

• US 20100080892A1
• Filed: 09/30/2008
• Published: 04/01/2010
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: SHPP Global Technologies BV (Government of Saudi Arabia)
• Original Assignee: Sabic Innovative Plastics IP BV (Government of Saudi Arabia)
• Inventors: O'Brien, Michael J., Irwin, Patricia Chapman, Lu, Qiwei
• Granted Patent: US 8,092,722 B2
• Time in Patent Office: Days
• US Class Current: 427/104
• CPC Class Codes: C08F 212/06 Hydrocarbons
• CPC Class Codes: C08F 283/08 on to polyphenylene oxides
• CPC Class Codes: C08F 287/00 Macromolecular compounds obtained by polymerising monomers on to block polymers
• CPC Class Codes: C08F 290/062 Polyethers
• CPC Class Codes: C08G 65/485 Polyphenylene oxides
• CPC Class Codes: C08L 2666/02 Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• CPC Class Codes: C08L 53/00 Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
• CPC Class Codes: C08L 53/02 of vinyl-aromatic monomers and conjugated dienes
• CPC Class Codes: C08L 65/02 Polyphenylenes
• CPC Class Codes: C08L 67/06 Unsaturated polyesters
• CPC Class Codes: C08L 71/12 Polyphenylene oxides
• CPC Class Codes: H01B 3/425 Non-saturated polyesters derived from polycarboxylic acids and polyhydroxy compounds, in which at least one of the two components contains aliphatic unsaturation
• CPC Class Codes: H01B 3/427 Polyethers
• CPC Class Codes: H01B 3/441 from alkenes
• CPC Class Codes: H01B 3/442 from aromatic vinyl compounds
• CPC Class Codes: H02K 3/30 Windings characterised by the insulating material
• CPC Class Codes: H02K 3/44 Protection against moisture or chemical attack; Windings specially adapted for operation in liquid or gas

Abstract

A varnish composition for producing an electrically insulative thermoset coating is disclosed. The varnish composition comprises a functionalized poly(phenylene ether), an unsaturated polyester, and/or a vinylester resin. The varnish composition further comprises a reactive liquid monomer and a block copolymer comprising a poly(olefin) block, or a poly(diolefin) block, and at least one terminal poly(alkenyl aromatic) block comprising repeat units derived from an alkenyl aromatic monomer. When cured, the polymers and reactive liquid monomer forms an electrically insulative thermoset that provides superior crack resistance.

Claims

1. A curable composition comprising:

a functionalized poly(phenylene ether), an unsaturated polyester, and/or a vinylester resin;

a reactive liquid monomer, and

a block copolymer comprising a poly(olefin) block comprising repeat units derived from a C₂-C₄ olefinic monomer or a poly(diolefin) block comprising repeat units derived from a C₄-C₆ diolefinic monomer and at least one terminal poly(alkenyl aromatic) block comprising repeat units derived from an alkenyl aromatic monomer.

2. The curable composition of claim 1 wherein the poly(alkenyl aromatic) block is greater than or equal to 10 wt. % by weight of the block copolymer.

3. The curable composition of claim 1 wherein the block copolymer is a triblock copolymer having three blocks of at least two different monomeric compositions.

4. The curable composition of claim 1 wherein the block copolymer is a linear triblock copolymer comprising two terminal poly(alkenyl aromatic) blocks and an internal poly(olefin) block.

5. The curable composition of claim 1 wherein the curable composition comprises a functionalized poly(phenylene ether) comprising at least one aliphatic unsaturated group and exhibiting an intrinsic viscosity of about 0.06 to about 0.25 deciliter per gram, measured in chloroform at 25°

C., and wherein the block copolymer meets at least one of the following requirements;

a viscosity at 25 wt. % in toluene of greater than or equal to 5000 centipoise at 25°

C. or weight average molecular weight of 50,000 to 200,000.

6. The curable composition of claim 1 wherein the block copolymer comprises a poly(olefin) block comprising repeat units derived from ethylene, isopropene, or butene or comprises a poly(diolefin) block comprising repeat units of butadiene.

7. The curable composition of claim 1, wherein the block copolymer is used in an amount of greater than 1 weight percent to 10 weight percent, based on the total weight of functionalized poly(phenylene ether), unsaturated polyester resin and/or vinylester resin, and wherein composition is crack free, based on specified hex nut cracking testing.

8. The curable composition of claim 1 wherein the block copolymer comprises a poly(acrylic) block derived from methacrylic C₁-C₆ ester monomers and a poly(styrene) block derived from styrene monomer, each of said poly(acrylic) block and poly(styrene) blocks located at a terminal end of the block copolymer.

9. The curable composition of claim 8 wherein the block copolymer comprises a poly(styrene)-block-poly(1,4-butadiene)-block-poly(methyl methacrylate) copolymer.

10. The curable composition of claim 1, wherein the functionalized poly(phenylene ether) is present and is terminally capped with a group containing aliphatic unsaturation.

11. The curable composition of claim 10, wherein the functionalized poly(phenylene ether) is a bifunctionalized capped poly(phenylene ether) having methacryloyl end groups.

12. The curable composition of claim 1, wherein the functionalized poly(phenylene ether) is present and is a capped poly(phenylene ether) having the structure:

wherein each occurrence of Q¹ and Q² is independently halogen, unsubstituted or substituted C₁-C₁₂ hydrocarbyl with the proviso that the hydrocarbyl group is not tertiary hydrocarbyl, C₁-C₁₂ hydrocarbylthio, C₁-C₁₂ hydrocarbyloxy, or C₂-C₁₂ halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms;

each occurrence of Q³ and Q⁴ is independently hydrogen, halogen, unsubstituted or substituted C₁-C₁₂ hydrocarbyl with the proviso that the hydrocarbyl group is not tertiary hydrocarbyl, C₁-C₁₂ hydrocarbylthio, C₁-C₁₂ hydrocarbyloxy, or C₂-C₁₂ halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms;

p is 1 to about 100;

R¹ is C₁-C₁₂ hydrocarbylene;

n is 0 or 1; and

R² and R³ and R⁴ are each independently hydrogen or C₁-C₁₈ hydrocarbyl.

13. The curable composition of claim 12, wherein the functionalized poly(phenylene ether) is a capped poly(phenylene ether) having the structure:

wherein Q⁵ and Q⁶ are each independently methyl or di-n-butylaminomethyl; and

s is 1 to about 20.

14. The curable composition of claim 12, wherein the functionalized poly(phenylene ether) is a capped poly(phenylene ether) having the structure:

wherein each occurrence of Q1 and Q2 is independently halogen, unsubstituted or substituted C₁-C₁₂ hydrocarbyl with the proviso that the hydrocarbyl group is not tertiary hydrocarbyl, C₁-C₁₂ hydrocarbylthio, C₁-C₁₂ hydrocarbyloxy, or C₂-C₁₂ halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms;

each occurrence of Q³ and Q⁴ is independently hydrogen, halogen, unsubstituted or substituted C₁-C₁₂ hydrocarbyl with the proviso that the hydrocarbyl group is not tertiary hydrocarbyl, C₁-C₁₂ hydrocarbylthio, C₁-C₁₂ hydrocarbyloxy, or C₂-C₁₂ halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms;

each occurrence of x and y is independently 0 to about 100 with the proviso that the sum of x and y is 2 to about 100;

each occurrence of R¹ is independently C₁-C₁₂ hydrocarbylene;

each occurrence of n is independently 0 or 1;

each occurrence of R²-R⁴ is independently hydrogen or C₁-C₁₈ hydrocarbyl; and

L has the structure;

wherein each occurrence of Q³ is, as defined above, independently hydrogen, halogen, unsubstituted or substituted C₁-C₁₂ hydrocarbyl with the proviso that the hydrocarbyl group is not tertiary hydrocarbyl, C₁-C₁₂ hydrocarbylthio, C₁-C₁₂ hydrocarbyloxy, or C₂-C₁₂ halohydrocarbyloxy wherein at least two carbon atoms separate the halogen and oxygen atoms;

z is 0 or 1; and

X¹ has a structure selected from the group consisting of

wherein each occurrence of R⁵ is independently selected from the group consisting of hydrogen and C₁-C₁₂ hydrocarbyl and each occurrence of R⁶ and R⁷ is independently selected from the group consisting of hydrogen, C₁-C₁₂ hydrocarbyl, and C₁-C₆ hydrocarbylene wherein R⁶ and R⁷ collectively form a C₄-C₁₂ alkylene.

15. The curable composition of claim 14, wherein the functionalized poly(phenylene ether) is a capped poly(phenylene ether) having the structure

wherein each occurrence of Q⁵ and Q⁶ is independently methyl or di-n-butylaminomethyl;

and each occurrence of x and y is independently 0 to about 100 with the proviso that the sum of x and y is 2 to about 100.

16. The curable composition of claim 1, wherein the unsaturated polyester resin is present and is obtained by reaction of at least one polyhydric alcohol with at least one polybasic acid comprising an unsaturated polybasic acid, wherein the unsaturated polybasic acid is selected from the group consisting of maleic acid, fumaric acid, itaconic acid, citraconic acid, chloromaleic acid, dimeric methacrylic acid, nadic acid, tetrahydrophthalic acid, endo-methylenetetrahydrophthalic acid, hexachloro-endo-methylenetetrahydrophthalic acid, halogenated phthalic acids, and their corresponding esters and anhydrides.

17. The curable composition of claim 1 wherein the vinylester resin is based on the reaction product of a bisphenol, an epoxy, and a monocarboxylic acid.

18. The curable composition of claim 16 wherein the polyhydric alcohol is selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, glycerol, triethylene glycol, pentanediol, hexylene glycol, bisphenol A, hydrogenated bisphenol A, bisphenol A-alkylene oxide adducts, and tetrabromobisphenol alkylene oxide adducts.

19. The curable composition of claim 1, wherein the reactive liquid monomer is selected from the group consisting of vinyl toluene, styrene, t-butyl styrenes, dibromostyrenes, and combinations thereof.

20. The curable composition of claim 1, wherein a mixture of both a functionalized poly(phenylene ether) and an unsaturated polyester or vinyl ester resin is present, and the ratio of the total amount of functionalized poly(phenylene ether) and unsaturated polyester resin or vinylester resin to the reactive liquid monomer is about 2:

1 to about 1;

5 by weight.

22. A method for electrically insulating a motor using a varnish composition comprising:

applying a varnish composition according to claim 1 to a motor component; and

curing the varnish composition to form an electrically insulative thermoset coating over the motor component.

21. A curable composition for electrically insulating a motor comprising:

10 to 45 weight percent of a functionalized poly(phenylene ether) having the structure;

wherein each occurrence of Q⁵ and Q⁶ is independently methyl or di-n-butylaminomethyl and herein n is a number providing an intrinsic viscosity of about 0.06 to 0.25 deciliter per gram, measured in chloroform at 25°

C.;

30 to 50 weight percent of unsaturated polyester resin;

2 to 8 weight percent of a linear triblock copolymer comprising a total of 10 to 50 wt. %, based on the triblock copolymer, of two terminal poly(styrene) blocks and an internal block that is a poly(olefin) block, wherein the linear triblock copolymer has a viscosity at 25 wt. % in toluene of greater than or equal to 5000 centipoise at 25°

C., and wherein the internal block comprises repeat units derived from an C₁-C₄ diolefinic monomer;

20 to 70 weight percent of reactive liquid monomer comprising vinyl toluene, styrene, t-butyl styrene, dibromostyrene, or combinations comprising at least one of the foregoing monomers; and

1 to 30 weight percent of a multifunctional acrylate crosslinking agent;

wherein all weight percents are based on the total weight of the composition, unless otherwise specified; and

wherein a thermoset obtained by curing the curable composition has a glass transition temperature of about 100°

C. to about 165°

C.