The United States of America As Represented by the Administrator of the

The United States of America As Represented by the United States

George M Fohlen

John A Parker

Devendra Kumar

Bappalige N Achar

Indra K Varma

4-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g. hexakis amino or trisaminophenoxy-trisphenoxy-cyclotriphosphazenes), selection of molar proportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yields and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.

Aromatic cyclotriphosphazenes

Aminophenoxycyclotriphosphazenes such as hexakis(4-aminophenoxy)cyclotriphosphazene and tris(4-aminophenoxy)-tris phenoxyclyclotriphosphazene are used as curing agents for epoxy resins. These 1,2-epoxy resins are selected from di- or polyepoxide-containing organic moieties of the formula (CH.sub.2 --CHO--CH.sub.2).sub.m --W--R--W--(CH.sub.2 CH--CH.sub.2 O).sub.m where R is diphenyldimethylmethane, diphenylmethane, bis(dibromophenyl)dimethylmethane, or ##STR1## W is a nitrogen or oxygen atom; and m is 1 when W is oxygen and 2 when W is nitrogen. The resins are cured thermally in stages at between about 110.degree. to 135.degree. C. for between about 1 and 10 min, then at between about 175.degree. to 185.degree. C. for between about 0.5 to 10 hr and post-cured at between about 215.degree. and 235.degree. C. for between abut 0.1 and 2 hr. These resins are useful for making fire-resistant elevated temperature stable composites, laminates (e.g. graphite fiber or fiberglass), molded parts, and adhesives and structures, usually for aircraft secondary structures and for spacecraft construction.

Aminophenoxycyclotriphosphazene cured epoxy resins and the composites,

Imide-linked bisphthalonitrile compounds are prepared by combining a dicyano aromatic diamine and an organic dianhydride to produce an amic acid linked bisphthalonitrile copound. The amic acid linked bisphthalonitrile compound is dehydrocyclized to produce the imide-linked bisphthalonitrile compounds. The imide-linked bisphthalonitrile compounds may be polymerized to produce a phthalocyanine polymer by heating the imide-linked bisphthalonitrile compound, either alone or in the presence of a metal powder or a metal salt. These compounds are useful in the coating, laminating and molding arts. The polymers are useful in composite matrix resins where increased fire resistance, toughness and resistance to moisture are required, particularly as secondary structures in aircraft and spacecraft.

Process for preparing phthalocyanine polymer from imide containing

4-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g. hexakis amino or trisaminophenoxy-trisphenoxy-cyclotriphosphazenes), selection of molar proportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yeilds and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.

Fire and heat resistant laminating resins based on maleimido substituted

Novel amine terminated bisaspartimides, especially 4,4'-bis{N.sup.2 -[4-(4-aminophenoxy)phenyl]aspartimido} diphenylmethane are prepared by a Michael-type reaction of an aromatic bismaleimide and an aromatic diamine in an aprotic solvent. These bisaspartimides are thermally polymerized to yield tough, resinous polymers cross-linked through --NH-- groups. Such polymers are useful in applications requiring materials with resistance to change at elevated temperatures, e.g., as lightweight laminates with graphite cloth, molding material prepregs, adhesives and insulating material.

Amine terminated bisaspartimide polymer

Novel amine terminated bisaspartimides, especially 4,4'-bis{N.sup.2 -[4-(4-aminophenoxy)phenyl]aspartimido}diphenylmethane are prepared by a Michael-type reaction of an aromatic bismaleimide and an aromatic diamine in an aprotic solvent. These bisaspartimides are thermally polymerized to yield tough, resinous polymers cross-linked through --NH-- groups. Such polymers are useful in applications requiring materials with resistance to change at elevated temperatures, e.g., as lightweight laminates with graphite cloth, molding material prepregs, adhesives and insulating material.

Laminate comprising fibers embedded in cured amine terminated bis-imide

Maleimido substituted aromatic cyclotriphosphazenes

Metal, preferably divalent copper, cobalt or nickel, phthalocyanine tetraamines are used as curing agents for epoxides. The resulting copolymers have high thermal and chemical resistance and are homogeneous. They are useful as binders for laminates, e.g. graphite cloth laminate.

Metal (II) 4,4',4',4''-phthalocyanine tetraamines as curing agents for

Metal 4, 4', 4', 4''-tetracarboxylic phthalocyanines (MPTC) are prepared by reaction of trimellitic anhydride, a salt or hydroxide of the desired metal (or the metal in powdered form), urea and a catalyst. A purer form of MPTC is prepared than heretofore. These tetracarboxylic acids are then polymerized by heat to sheet polymers which have superior heat and oxidation resistance. The metal is preferably a divalent metal having an atomic radius close to 1.35.ANG..

Metal phthalocyanine intermediates for the preparation of polymers

Method of forming 4,4',4',4''-tetraamino phthalocyanines by reducing 4,4',4',4''-tetranitro phthalocyanines, polymerization of the metal tetraamino phthalocyanines with a tetracarboxylic dianhydride (preferably aromatic) or copolymerization with a tetracarboxylic dianhydride and a diamine (preferably also aromatic) to produce amic acids which are then dehydrocyclized to imides. Thermally and oxidatively stable polymers result which form tough, flexible films, etc.

Phthalocyanine polymers

Cured polymers of bis- and tris-imides derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, and addition polymers of such imides, including a variant in which a mono-imide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride prior to curing are disclosed and claimed. Such polymers are flame resistant. Also disclosed are an improved method of producing tris(m-aminophenyl) phosphine oxides from the nitro analogues by reduction with hydrazine hydrate using palladized charcoal or Raney nickel as the catalyst and fiber-reinforced cured resin composites.

Phosphorus-containing imide resins

The invention relates to metal, primarily divalent metal such as divalent copper, cobalt and nickel, 4,4',4', 4'' phthalocyanine tetracarboxylic acids and to polymers prepared by heating the same, and to a method of preparing the tetracarboxylic acids. A method is provided for preparing the aforesaid tetracarboxylic acids in purer form than heretofore. Upon heating these acids decarboxylate and produce polymers. These polymers have diphenyl (conjugated) types of linkage; they are thermally and oxidatively stable and useful as sheet polymers for various purposes such as heat shielding. The monomeric tetracarboxylic acid is shown in FIG. 1, the polymer in FIG. 2 and thermal resistance in FIG. 3. The monomeric tetracarboxylic acids are prepared in purer form than heretofore, the resulting polymers are more stable thermally and oxidatively than metal phthalocyanine polymers and monomers heretofore made.

Metal phthalocyanine polymers

Flame-resistant reinforced bodies are disclosed which are composed of reinforcing fibers, filaments or fabrics in a cured body of bis- and tris-imide resins derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, or of addition polymers of such imides, including a variant in which a mono-imide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride.

Phosphine oxide-containing polyimide resins modified by elastomers, having improved mechanical properties and particularly useful in the production of fiber or fabric-reinforced composites or laminates.

Elastomer-modified phosphorus-containing imide resins

Bis- and tris-imides derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, and addition polymers of such imides, including a variant in which a mono-imide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride. Such monomers or their oligomers may be used to impregnate fibers and fabrics which when cured, are flame resistant. Also an improved method of producing tris(m-aminophenyl) phosphine oxides from the nitro analogues by reduction with hydrazine hydrate using palladized charcoal or Raney nickel as the catalyst.

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Millbrae, CA, United States of America

George M Fohlen