# US 4,377,678 A · Binders for polydiene composite propellants

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- Number: US 4,377,678 A
- Document ID: US4377678A
- Status: Granted
- Kind: A
- Application number: 06/198,957
- Filed: 1980-06-04
- Granted: 1983-03-22
- Earliest claimed: 1978-10-06
- Assignees: Nissan Motor Co., Ltd.; Japan Synthetic Rubber Co., Ltd.
- Inventors: Daizo Fukuma; Shigeru Suzuki; Kensho Shirota; Kunihiro Harada
- Web page: https://patentgrep.com/patent/US4377678A

## CPC

- C08G 18/69: Polymers of conjugated dienes {(hydrogenated polymers of conjugated dienes C08G18/6208)}
- C06B 45/10: the organic component containing a resin
- C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C06B: EXPLOSIVES OR THERMIC COMPOSITIONS (blasting F42D); MANUFACTURE THEREOF; USE OF SINGLE SUBSTANCES AS EXPLOSIVES (compounds in general C01, C07 or C08; {demolition agents based on cementitious or like materials C04B41/0009})

## Abstract

The present invention is a binder for a polydiene composite propellant comprising a small amount of binder and has as its object the production of the binder, which can provide stable physical properties between production lots and has a long pot life, and consists mainly of a polymer which has a predetermined molecular weight between crosslinks and which is obtained by reacting a combination of a polydiene glycol having a hydroxyl group number of 1.8-2.1 and a number average molecular weight of 1,000-5,000, a trifunctional crosslinking agent, a diisocyanate and a bifunctional chain extender. When a diene polymer having a functional group number of not more than 1 is additionally added to the above described combination, the elongation of the binder is improved and the use of a plasticizer can be reduced or eliminated.

## Claims

### Claim 1

A binder for a polydiene composite propellant obtained by reacting a polydiene glycol having a hydroxyl group number of 1.8-2.1 and a number average molecular weight of 1,000-5,000 with a trifunctional crosslinking agent, a diisocyanate and a bifunctional chain extender; said polydiene glycol being obtained by polymerizing butadiene in an organic solvent by using a dilithium compound as a catalyst and treating the resulting polymer with a substance selected from the group consisting of ethylene oxide, propylene oxide, aldehydes and ketones to hydroxylate both terminal groups, and wherein the binder has an average molecular weight between crosslinks from about 7,000 to 15,000.

### Claim 2 (depends on 1)

A binder as claimed in claim 1, wherein the polydiene glycol is polydiene glycol having secondary or tertiary terminal hydroxyl groups.

### Claim 3 (depends on 1, 2)

A binder as claimed in claim 1 or 2, wherein the polydiene glycol is polybutadiene glycol.

### Claim 4

A binder for polydiene composite propellant obtained by reacting a polydiene glycol having a hydroxyl group number of 1.8-2.1 and a number average molecular weight of 1,000-3,500 with a polydiene polymer having a functional group number of not more than 1, a trifunctional crosslinking agent, a diisocyanate and a bifunctional chain extender; said polydiene glycol being produced by polymerizing butadiene in an organic solvent by using a dilithium compound as a catalyst and treating the resulting polymer with a substance selected from the group consisting of ethylene oxide, propylene oxide, aldehydes and ketones to hydroxylate both terminal groups, and wherein the binder has an average molecular weight between crosslinks from about 7,000 to 15,000.

### Claim 5 (depends on 4)

A binder as claimed in claim 4, wherein the polydiene glycol is polybutadiene glycol.