Abstract: Substantially insoluble bismaleimide compositions consisting essentially of bismaleimides of the formula ##STR1## where R.sub.1 and R.sub.2 are independently hydrogen, methyl, ethyl or halogenated methyl. The phenyl groups may be substituted. The compositions, having a solubility in acetone of less than about 5% by wt., are useful as melt processable resins for high temperature resistant laminates.

Abstract: Polyimide laminates are prepared from solutions of maleimide resins comprising a mixture of maleimides and maleamic acids, e.g., greater than about 45% bismaleimide and up to about 40% bis-maleamic acid and a stabilizing amount of polyamine. The bismaleimide is preferably derived from 2,2-bis[4-(4-aminophenoxy)phenyl] propane.

Abstract: Soluble maleimide resins comprise a mixture of maleimides and maleamic acids, e.g. greater than about 45% bismaleimide and up to about 40% bis-maleamic acid. Such resins are soluble in solvents such as acetone, methyl ethyl ketone and toluene. Stable resin solutions comprise a minor amount of polyamine.

Abstract: Solutions of maleimide resins comprising a mixture of bismaleimides and low but solubilizing amounts of maleamic acids are provided at high solids levels, e.g. at least about 50%. Such solutions which comprise common solvents such as acetone, methyl ethyl ketone and toluene are useful in preparing laminates based on bismaleimide resins.

Abstract: This invention relates to an improved foamable resole resin composition comprising a resole resin, a blowing agent and a surfactant wherein said improvement comprises incorporating a particular resole resin catalyzed with alkaline earth metal hydroxides and neutralized with oxalic acid or its acid salts providing inert insoluble oxalate salts dispersed in said resole. Said salts are sized controlled and stabilized in an aqueous resole resin solution having about 60 to 99% resole resin by weight. Methods for preparing and foaming said compositions are disclosed.

Abstract: This invention relates to an improved foamable resole resin composition comprising a resole resin, a blowing agent and a surfactant wherein said improvement comprises incorporation dispersed metal powders in said composition providing a foamable resole composition curable to a non-corrosive foam. Methods for preparing, foaming and curing said non-corrosive foams are disclosed.

Abstract: This invention relates to an improved foamable resole resin composition comprising a resole resin, a blowing agent and a surfactant wherein said improvement comprises incorporation dispersed calcium oxide particles in said composition providing a foamable resole composition curable to a non-corrosive foam. Methods for preparing, foaming and curing said noncorrosive foams are disclosed.

Abstract: This invention relates to industrial laminates which can be cold punchable and are flame resistant. The laminates are prepared from paper impregnated with a composition comprising a phenol-formaldehyde resole resin and a vinyl chloride interpolymer.

Abstract: The invention relates to a resin binder composition comprising, in combination, a resole resin and a metal salt curing accelerator providing a binder composition that has an improved cure rate in electrical grade laminates without adversely affecting electrical properties. The binder composition provides low viscosity for impregnation and accelerated curing rates for advancing the impregnated substrate prior to laminating and final curing.

Abstract: The invention relates to a binder composition comprising a low molecular weight resole resin in combination with boron compounds wherein said boron compounds are present in from about 1 to 30 parts per 100 parts by resole resin solids, said composition having a pH of about 2-6 and said resole having a viscosity of from about 5 to 5000 cps. Said binder provides laminates having superior electrical and flame retardant properties.

Abstract: The invention relates to a binder composition comprising a low molecular weight resole resin in combination with boron compounds wherein said boron compounds are present in from about 1 to 30 parts per 100 parts by resole resin solids, said composition having a pH of about 2-6 and said resole having a viscosity of from about 5 to 5000 cps. Said binder provides laminates having superior electrical and flame retardant properties.

Abstract: The invention relates to a resin binder composition comprising, in combination, a resole resin and a metal salt curing accelerator providing a binder composition that has an improved cure rate in electrical grade laminates without adversely affecting electrical properties. The binder composition provides low viscosity for impregnation and accelerated curing rates for advancing the impregnated substrate prior to laminating and final curing.