# US 4,395,934 A · Wear reducer

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- Number: US 4,395,934 A
- Document ID: US4395934A
- Status: Granted
- Kind: A
- Application number: 06/356,880
- Filed: 1982-03-10
- Granted: 1983-08-02
- Earliest claimed: 1980-04-21
- Assignees: The United States of America as represented by the Secretary of the Army
- Inventors: Sydney Axelrod; Walter Brenner; Barry A. Rugg
- Web page: https://patentgrep.com/patent/US4395934A

## CPC

- F42B 5/24: for cleaning; for cooling; for lubricating {; for wear reducing}
- C06B 23/04: for cooling the explosion gases {including antifouling and flash suppressing agents}
- F42B: EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION (explosive compositions C06B; fuzes F42C; blasting F42D)
- 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

An improved ammunition propellant composition and method for reducing gun mber wear, erosion, flash and cook-off through use of an additive comprising a mixture of a super water absorbent starch modified polyacrylonitrile which has been subjected to alkaline saponification and water. The wear reducing additive is preferably formed into sheets which can be used with propellants selected from the group consisting of bagged propelling charges and cartridge cased propellants.

## Claims

### Claim 1

A method for reducing gun member thermal erosion and wear through use of coolant additive with a propellant charge for reducing propellant flame temperature comprising the steps of preparing a sheet comprising a highly water adsorbent starch-acrylonitrile copolymer which has been subjected to alkaline saponification and a major amount of absorbed water; and disposing said sheet around the ammunition propellant charge to reduce erosion by formation of a laminar cooling layer of gas adjacent to the gun member upon firing of said charge.

### Claim 2 (depends on 1)

The method of claim 1 wherein the water absorbed within said sheet contains ethylene glycol antifreeze to prevent freezing of the water at low temperature.

### Claim 3 (depends on 1)

The method of claim 1 wherein the coolant additive sheet is disposed around said propellant charge within a conventional cartridge case.

### Claim 4 (depends on 1)

The method of claim 1 wherein the coolant additive sheet is disposed around said propellant charge within a propellant bagged charge.

### Claim 5 (depends on 1)

The method of claim 1 wherein the additive sheet consists essentially of no more than 10% by weight copolymer and the balance absorbed water.