Cyanate resin blends and radomes including them

Patent metadata

Field	Value
Publication number	US-9914803-B2
Application number	US-201414314059-A
Country	US
Kind code	B2
Filing date	Jun 25, 2014
Priority date	Jun 28, 2013
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

Certain embodiments are directed to cyanate resin blends comprising, for example, a mixture of a cyanate monomer and a cyanate oligomer. The resin blends are effective to provide a dielectric constant of less than 2.7, a glass transition temperature of at least 150° C. and a moisture absorption of less than 1.5%. Radomes using the resin are also described.

First claim

The invention claimed is:

1. A prepreg comprising a plurality of plies coupled to each other, in which at least one of the plurality of plies comprises a substrate and a resin blend comprising 31-70 weight percent of a cyanate monomer and 70-30 weight percent of a cyanate ester oligomer to provide a cured resin comprising a dielectric constant of less than 2.7, a glass transition temperature of at least 150° C. and a moisture absorption of less than 1.5%, wherein the monomer is a compound of formulae (I)-(IX)

or mixtures of two or more cyanate monomers, wherein at least one of R 1 and R 2 is —CN and the other of R 1 and R 2 is selected from hydrogen, —CN, —COOH, a hydrocarbon group comprising 1 to 6 carbon atoms, a hydrocarbonyl group comprising 1 to 6 carbon atoms, a halohydrocarbon group comprising 1 to 6 carbon atoms, a halohydrocarbonyl group comprising 1 to 6 carbon atoms and phenyl, and wherein R 3 and R 4 , when present, are independently selected from hydrogen, —CN, —COOH, a hydrocarbon group comprising 1 to 6 carbon atoms, a hydrocarbonyl group comprising 1 to 6 carbon atoms, a halohydrocarbon group comprising 1 to 6 carbon atoms, a halohydrocarbonyl group comprising 1 to 6 carbon atoms and phenyl
wherein the oligomer is a cyanate ester oligomer comprising two or more monomeric units each selected from a compound having the formula (I)-(IX); and
wherein the oligomer is not a polymerization product of a compound of formula III, a compound of formula IV, or a mixture of a compound of formula III and a compound of formula IV.

2. The prepreg of claim 1 , further comprising at least one phenol added to the resin blend.

3. The prepreg of claim 2 , further comprising at least one metal catalyst added to the resin blend.

4. The prepreg of claim 1 , in which the substrate comprises one or more of a woven fabric, a non-woven fabric, a ceramic, a plastic, a glass, a fiberglass, a nylon, a polyester, a polyethersulfone, an aramid, a polyethylene, a polypropylene, a polyolefin, a polyimide, a polyamide, a polyamide-imide, a polyphenylene sulfide, a carbon, a carbon black, a graphite, a diamond, a polybenzimidazole, a polybenzoxazole or a halocarbon.

5. The prepreg of claim 1 , in which the cyanate monomer comprises a bisphenol dicyanate group and the cyanate ester oligomer comprises a diphenylcyanate group.

6. The prepreg of claim 1 , wherein the resin blend comprises the cyanate monomer in an amount within the range of 50 wt. % to 70 wt. %, and the oligomer in an amount within the range of 30 wt % to 50 wt. %.

7. The prepreg of claim 1 , wherein the cyanate monomer comprises a compound having the formula (V) or a compound having the formula (VI), and the oligomer comprises at least one monomeric unit selected from a compound having the formula (V)-(VI).

Assignees

• Saint Gobain Performance Plastics Corp

Inventors

• Cheon Kapsoo
• Demers Marie J
• Padwal Ajay

Classifications

• Y10T442/60

  Nonwoven fabric [i.e., nonwoven strand or fiber material] · CPC title

• Y10T442/30

  Woven fabric [i.e., woven strand or strip material] · CPC title

• C08K5/13

  Phenols; Phenolates · CPC title

• B32B27/42

  comprising condensation resins of aldehydes, e.g. with phenols, ureas or melamines · CPC title

• C08J2379/04

  Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors · CPC title