US 12,478,501 B2
High-blasting-volume waterborne polyurethane condom and preparation method therefor
Jiabing Dai, Gansu (CN); Linlin Feng, Gansu (CN); Bin Liu, Gansu (CN); and Liang Chen, Gansu (CN)
Assigned to Reckitt Benckiser Health Limited, (GB)
Appl. No. 18/245,764
Filed by RECKITT BENCKISER HEALTH LIMITED, Berkshire (GB)
PCT Filed Sep. 16, 2021, PCT No. PCT/CN2021/118733
§ 371(c)(1), (2) Date Mar. 17, 2023,
PCT Pub. No. WO2022/057856, PCT Pub. Date Mar. 24, 2022.
Claims priority of application No. 202010996806.6 (CN), filed on Sep. 21, 2020.
Prior Publication US 2023/0390104 A1, Dec. 7, 2023
Int. Cl. B29C 41/14 (2006.01); A61F 6/04 (2006.01); B29C 41/46 (2006.01); B29K 75/00 (2006.01)
CPC A61F 6/04 (2013.01) [B29C 41/14 (2013.01); B29C 41/46 (2013.01); B29K 2075/00 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A method for preparing a waterborne polyurethane condom having a high burst volume, characterized in that the method comprises at least the steps of:
providing a waterborne polyurethane;
dipping into the waterborne polyurethane and then drying, and repeating the process of dipping into the waterborne polyurethane and then drying N times so as to obtain a waterborne polyurethane film;
rolling up an end of the waterborne polyurethane film and then drying;
dipping into a releasing agent, followed by drying, mold releasing, and electrical inspection, to obtain a waterborne polyurethane condom;
wherein N is equal to 1-5, the waterborne polyurethane is an anionic waterborne polyurethane, and the waterborne polyurethane has a 100% tensile modulus of less than or equal to 2.0 MPa and an elongation at break of greater than or equal to 650%; and
wherein the drying after rolling up an end of the waterborne polyurethane film is drying for formation, the drying after dipping into the waterborne polyurethane is drying for fixing, and the duration of the drying for fixing and the duration of the drying for formation satisfy tform=90·Φ−8·(N+2)·tfix, where tform is the duration of the drying for formation in minutes, tfix is the duration of the drying for fixing in minutes, N is the number of repeated dipping, Φ=2.7−0.015·T, and T is the temperature of the drying for fixing and the drying for formation in ° C.