# US 11,079,208 B2 · Masking material and use of the material to mask a target and ammunition for disseminating such masking material > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,208 B2 - Document ID: US11079208B2 - Status: Granted - Kind: B2 - Application number: 16/758,171 - Filed: 2018-09-14 - Published: 2020-10-01 - Granted: 2021-08-03 - Earliest claimed: 2017-10-23 - Assignees: Mecar, SociéTé Anonyme - Applicants: Mecar, SociéTé Anonyme - Inventors: Nicolas Perrot - Web page: https://patentgrep.com/patent/US11079208B2 ## CPC - F41H 9/06: Apparatus for generating artificial fog or smoke screens ({for producing special effects on stages A63J5/00}; smoke-pot projectors, e.g. arranged on vehicles, F42B5/155) - F42B 12/70: for dispensing radar chaff or infrared material (radar-reflector targets, active targets transmitting infrared radiation F41J2/00; radar-reflecting surfaces H01Q15/14) - F41H 3/00: Camouflage, i.e. means or methods for concealment or disguise (for vessels B63G8/34, B63G13/02 {; sound camouflage, i.e. simulating gun fire noise, F41A33/04; dummy or decoy targets F41J; chaff per se F41J2/00; ammunition for dispensing chaff F42B5/15, F42B12/70; radar absorbing fabrics H01Q17/005}) - F42B 12/48: smoke-producing {, e.g. infrared clouds} - F42B 33/00: Manufacture of ammunition; Dismantling of ammunition; Apparatus therefor (F42B5/188 takes precedence; manufacturing processes for hollow charges F42B1/036; manufacture of blasting cartridge initiators F42B3/195) - F41H: ARMOUR; ARMOURED TURRETS; ARMOURED OR ARMED VEHICLES; MEANS OF ATTACK OR DEFENCE, e.g. CAMOUFLAGE, IN GENERAL - F42B: EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION (explosive compositions C06B; fuzes F42C; blasting F42D) ## Abstract Disclosed is a masking material intended to be disseminated by an ammunition or a launcher to create a cloud that masks a target with respect to electromagnetic radiation in a given wavelengths range. This material contains at least one aluminium oxyhydroxide, such as boehmite or pseudoboehmite. Also disclosed is an ammunition enabling the dissemination of such masking material and the use of aluminium oxyhydroxide, such as boehmite or pseudoboehmite as a masking material that can be disseminated by an ammunition. ## Claims ### Claim 1 A method of masking a target with respect to electromagnetic radiation in a range of given wavelengths, comprising: providing aluminium oxyhydroxide as a masking material; and disseminating the masking material by an ammunition or launcher. ### Claim 2 (depends on 1) The method according to claim 1, wherein the aluminium oxyhydroxide is used in powdered form, whether or not compressed, with a granulometry of between 1 and 100 micrometres, with at least 90% of particles (G1,G2) of the masking material (3) having an average diameter of between 25 and 35 micrometres. ### Claim 3 (depends on 2) The method according to claim 2, wherein the aluminium oxyhydroxide is disseminated by means of an explosive ammunition comprising aluminium oxyhydroxide powder, whether or not in compressed form. ### Claim 4 (depends on 1) The method according to claim 1, wherein the range of given wavelengths comprises infrared wavelengths from 8 to 14 micrometres, infrared wavelengths from 3 to 5 micrometres, and visible wavelengths. ### Claim 5 (depends on 1) The method according to claim 1, wherein the aluminium oxyhydroxide is disseminated as a cloud. ### Claim 6 Masking ammunition, comprising: a shell containing a masking material (3); and a pyrotechnical dissemination charge (4) that can be activated by a rocket (5), wherein the masking material (3) is configured to create a cloud ensuring masking of a target with respect to electromagnetic radiation in a given wavelengths range, said masking material (3) comprising at least one aluminium oxyhydroxide. ### Claim 7 (depends on 6) The masking ammunition according to claim 6, wherein the pyrotechnical dissemination charge (4) is composed of at least one explosive material arranged in a dissemination rod (6) closed off at an end of the rod (6a) furthest from the rocket (5), the dissemination rod (6) extending axially through the masking material (3) and along the axis of the ammunition. ### Claim 8 (depends on 7) The masking ammunition according to claim 7, wherein the dissemination rod (6) is a metallic rod. ### Claim 9 (depends on 7) The masking ammunition according to claim 7, wherein the masking material (3) is contained in the shell (2) by a base (14) that ensures that the shell (2) is closed off at a rear of the shell, and wherein a length of the dissemination rod (6) is such that there remains an axial distance (D) between the rod (6) and the base (14). ### Claim 10 (depends on 9) The masking ammunition according to claim 9, wherein the axial distance (D) between the rod (6) and the base (14) is at least equal to half of an internal diameter (d) of the shell (2). ### Claim 11 (depends on 7) The masking ammunition according to claim 7, wherein the explosive material of the pyrotechnic dissemination charge (4) comprises pellets of an explosive combining hexogen and wax or of a composite explosive. ### Claim 12 (depends on 11) The masking ammunition according to claim 11, wherein a quantity of explosive of the dissemination charge (4) is sufficient to ensure bursting of the rod (6) and the shell (2). ### Claim 13 (depends on 6) The masking ammunition according to claim 6, wherein the masking material (3) comprises at least one bloc compressed directly inside the shell (2) and around the dissemination rod (6). ### Claim 14 (depends on 13) The masking ammunition according to claim 13, wherein the masking material (3) is compressed inside the shell (2) without use of a binding agent.