# US 5,344,894 A · Polyimide oligomers and blends

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,344,894 A
- Document ID: US5344894A
- Status: Granted
- Kind: A
- Application number: 07/980,109
- Filed: 1992-11-23
- Granted: 1994-09-06
- Earliest claimed: 1983-09-27
- Assignees: The Boeing Company
- Inventors: Hyman R. Lubowitz; Clyde H. Sheppard
- Web page: https://patentgrep.com/patent/US5344894A

## CPC

- C08L 79/08: Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors
- C08G 73/1014: {in the form of (mono)anhydrid}
- C08G 73/1064: {containing sulfur}
- C08G 73/1067: {Wholly aromatic polyimides, i.e. having both tetracarboxylic and diamino moieties aromatically bound}
- C08G 73/1071: {Wholly aromatic polyimides containing oxygen in the form of ether bonds in the main chain}
- C08G 73/14: Polyamide-imides
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS

## Abstract

Polyimide oligomers include (1) linear, monofunctional crosslinking oligomers prepared by condensing a monoanhydride end cap with a diamine that includes alternating ether and "sulfone" (--SO.sub.2 --, --S--, --CO--, --(CF.sub.3).sub.2 C--, or --(CH.sub.3).sub.2 C--) linkages connecting alternating aromatic radicals and with a dianhydride (or dianhydride mixture), particularly the unsaturated, aliphatic dianhydride commonly known as MCTC; (2) linear, mono- or difunctional crosslinking oligomers prepared by condensing an amine end cap with a diamine and a dianhydride; and (3) multidimensional, crosslinking oligomers having an aromatic hub and at least three radiating arms connected to the hub, each arm including a crosslinking end cap at its distal end and at least one imide linkage. Blends, prepregs, and composites can be prepared from the oligomers. Multidimensional oligomers can be prepared using etheranhydride intermediates or etheramine intermediates formed by reacting a suitable hub with nitrophthalic anhydride or aminophenol.

## Claims

### Claim 1

A blend comprising a mixture of a polyimide oligomer and a comparable, noncrosslinking polymer, the oligomer having the formula: ##STR34## wherein E is the residue of an amine end cap selected from the group consisting of: ##STR35## wherein X is: ##STR36## A is the residue of a dianhydride; B is the residue of a diamine;
n=1 or 2;
R.sub.1 =alkyl, alkoxy, aryl, aryloxy, or halogen;
j=0, 1 or 2;
Me=methyl;
G=--SO.sub.2 --, --CH.sub.2 --, --S--, or --O--;
T=methallyl or allyl and
m is an integer selected so that the oligomer possesses thermoplastic properties and has a formula weight of between about 5,000 and about 40,000.

### Claim 2 (depends on 1)

The blend of claim 1 wherein X is: ##STR37## wherein Me, G, R.sub.1, j, and T are as defined in claim 1.

### Claim 3 (depends on 1)

The blend of claim 1 wherein the dianhydride is pyromellitic dianhydride, 5-(2,5-diketotetrahydrofuryl)-3-methylcyclohexene-1,2-dicarbo xylic anhydride, benzophenonetetracarboxylic dianhydride, or mixtures thereof.

### Claim 4 (depends on 3)

The blend of claim 3 wherein the diamine is ##STR38##

### Claim 5 (depends on 1)

The blend of claim 1 wherein X is ##STR39## wherein G is --CH.sub.2 --, j=0, n=2, and said diamine is 4,4'-oxydianiline.

### Claim 6 (depends on 1)

The blend of claim 1 wherein the diamine is: ##STR40## q=--SO.sub.2 --, --CO--, --S--, or --(CF.sub.3).sub.2 C--; Me=methyl;
i=an integer less than 5; and
D=any of --CO--, --SO.sub.2 --, or --(CF.sub.3).sub.2 C--.

### Claim 7 (depends on 1)

The blend of claim 1 wherein the diamine is a phenoxyphenyl sulfone diamine of the formula: ##STR41## wherein m is 0 or 1.

### Claim 8

A blend comprising a mixture of a thermoplastic, polyimide oligomer and a comparable, noncrosslinking polymer, the oligomer being the product formed by reacting under an inert atmosphere a mixture comprising:
(a) two moles of a monoanhydride selected from the group consisting of: ##STR42## wherein Me=methyl;
G=--O--, --SO.sub.2 --, --CH.sub.2 --, or --S--;
T=allyl or methallyl;
R.sub.1 =alkoxy, aryl, alkyl, aryloxy, or halogen; and
j=0, 1, or 2;
(b) n+1 moles of a polyaryl diamine having terminal amino groups, the damine including alternating aryl radicals (--Ar--) connected together by alternating ether (--O--) and electronegative (--L--) linkages, wherein each electronegative linkage (--L--) is selected from the group consisting of --SO.sub.2 --, --S--, --CO--, --(CF.sub.3).sub.2 C--, and --(CH.sub.3).sub.2 C--, so that the diamine has the formula: ##STR43## wherein Ar=an aromatic radical, and
m=a small integer greater than or equal to 0; and
(c) n moles of at least one dianhydride, wherein n=an integer selected so that the oligomer possesses thermoplastic properties and has a formula weight of between about 5,000 and 40,000;
the polymer being prepared from the dianhydride and diamine of the oligomer.

### Claim 9 (depends on 8)

The blend of claim 8 wherein the aromatic radical (--Ar--) is selected from the group consisting of phenyl and substituted phenyl radicals, the substituents being selected from the group consisting of halogen, alkyl groups having 1-4 carbon atoms and alkoxy groups having 1-4 carbon atoms.

### Claim 10 (depends on 9)

The blend of claim 9 wherein --L-- is --SO.sub.2 --.

### Claim 11 (depends on 8)

The blend of claim 8 wherein the oligomer has a formula weight between about 20,000 to 30,000.

### Claim 12 (depends on 8)

The blend of claim 8 wherein the dianhydride is 5-(2,5-diketotetrahydrofuryl)-3-methylcyclohexene-1,2-dicarboxylic anhydride.

### Claim 13 (depends on 8)

The blend of claim 8 wherein the diamine is a phenoxyphenyl sulfone diamine of the formula: ##STR44## wherein m=an integer less than 5.

### Claim 14 (depends on 13)

The blend of claim 13 wherein m is 0 or 1.

### Claim 15 (depends on 8)

The blend of claim 8 wherein the diamine is a phenoxyphenylsulfone diamine selected from the group consisting of: ##STR45## wherein m=an integer such that the diamine has a formula weight between about 2,000 to 10,000, and wherein the diamine is formed by reacting aminophenol, bisphenol A, and 4,4'-dichlorodiphenylsulfone.

### Claim 16 (depends on 15)

The blend of claim 15 wherein the dianhydride is 5-(2,5-diketotetrahydrofuryl)-3-methylcyclohexene-1,2-dicarboxylic anhydride.

### Claim 17 (depends on 15)

The blend of claim 15 wherein the dianhydride is a mixture of 5-(2,5-diketotetrahydrofuryl)-3-methylcyclohexene-1,2-dicarboxylic anhydride and benzophenonetetracarboxylic dianhydride.

### Claim 18

A blend comprising a mixture of a polyimide oligomer and a comparable, noncrosslinking polymer, the oligomer having the formula: ##STR46## wherein E is the residue of an amine end cap selected from the group consisting of: ##STR47## wherein X is selected from the group consisting of: ##STR48## A is the residue of a dianhydride; B is the residue of a diamine;
n=2;
R.sub.1 =alkyl, alkoxy, aryl, aryloxy, or halogen;
j=0, 1, or 2;
Me=methyl;
G=--SO.sub.2 --, --CH.sub.2 --, --S--, or --O--; and
T=methallyl or allyl; and
m is an integer selected so that the oligomer possesses thermoplastic properties and has a formula wight of between about 5,000 and about 40,000.

### Claim 19 (depends on 18)

The blend of claim 18 wherein X is: ##STR49## wherein Me, G, R.sub.1, J, and T are as defined in claim 18.

### Claim 20 (depends on 18)

The blend of claim 18 wherein X is ##STR50## wherein Me and T are defined in claim 18.

### Claim 21 (depends on 18)

A blend as set forth in claim 18 wherein X is ##STR51## wherein G is --CH.sub.2 --, j=0, n=2, and said diamine is 4,4'-oxydianiline.

### Claim 22 (depends on 18)

The blend of claim 18 wherein X is: ##STR52## wherein Me, G, R.sub.1, j, and T are as defined in claim 18.

### Claim 23 (depends on 18)

The blend of claim 18 wherein the dianhydride is pyromellitic dianhydride, 5-(2,5-diketotetrahydrofuryl)-3-methylcyclohexene-1,2-dicarboxylic anhydride, benzophenonetetracarboxylic dianhydride, or mixtures thereof.

### Claim 24 (depends on 23)

The blend of claim 23 wherein the diamine is ##STR53##

### Claim 25 (depends on 18)

The blend of claim 18 wherein the diamine is: ##STR54## q=--SO.sub.2 --, --CO--, --S--, or --(CF.sub.3).sub.2 C--; Me=methyl;
i=an integer less than 5; and
D=any of --CO--, --SO.sub.2 --, or --(CF.sub.3).sub.2 C--.

### Claim 26 (depends on 18)

The blend of claim 18 wherein the diamine is a phenoxyphenyl sulfone diamine of the formula: ##STR55## wherein m is 0 or 1.

### Claim 27 (depends on 18)

A prepreg comprising the blend of claim 18 and a reinforcing additive in fiber of particulate form.

### Claim 28 (depends on 18)

The blend of claim 18 wherein the diamine is ##STR56##

### Claim 29 (depends on 8)

A prepreg comprising the blend of claim 8 and a reinforcing additive in fiber or particulate form.

### Claim 30 (depends on 8)

The blend of claim 8 wherein the monoanhydride is selected from the group consisting of: ##STR57## wherein Me, G, R.sub.1, j, and T are defined in claim 8.

### Claim 31 (depends on 8)

The blend of claim 8 wherein the monohydride is ##STR58## wherein Me and T are defined in claim 8.