公开(公告)号：US20230364851A1

公开(公告)日：2023-11-16

申请号：US18246064

申请日：2021-10-26

Applicant: 3M INNOVATIVE PROPERTIES COMPANY

Inventor： Anthony F. Schultz ,  Ta-Hua Yu ,  Duane D. Fansler ,  Karl J.L. Geisler ,  Bruce R. Broyles ,  Bhaskar V. Velamakanni ,  THomas J. Metzler ,  Jonathan E. Janoski ,  Richard J. Pokomy ,  Mark T. Gibson ,  Ahmed S. Abuelyaman

IPC: B29C51/14

CPC classification number: B29C51/14 ,  B29K2033/12

Abstract: A method of thermoforming is described. The method comprises providing a multilayer polymer film comprising at least one first thermoplastic polymer layer having a glass transition temperature (Tg) greater than 60° C. and at least one second polymer layer; and thermoforming the multilayer polymer film into a three-dimensional shape. The second polymer layer can be characterized by one or more properties selected from i) a Tg ranging from 20 to 70° C.; ii) a molecular weight between crosslinks of no greater than 20,000 g/mole; and iii) sufficient crosslinking such that the second polymer layer lacks a thermal melt or softening transition at a temperature up to the decomposition temperature of the second polymer layer. Also described are multilayer films and articles, such as orthodontic aligner and retainer trays.