Nonwoven products bonded with binder emulsions of copolymers of vinyl acetate/ethylene/incompatible comonomer/latent crosslinking comonomer
US4975320A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 1989 |
| Grant date | Dec 4, 1990 |
| Priority date | — |
| Expiry date | Feb 1, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/60
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A two stage polymerization process for preparing a vinyl acetate/ethylene emulsion copolymer containing a monomer which is normally incompatible with vinyl acetate. In the first stage the vinyl acetate and ethylene and, optionally, an active crosslinking comonomer and/or latent crosslinking comonomer are free radical polymerized in the presence of a stabilizing system to yield a first stage polymer emulsion. When the free vinyl acetate monomer content of the first stage emulsion is less than about 5%, the second stage polymerization begins by adding the incompatible monomer. Preferably, there is no cessation of the addition of the free radical source during the transition from the first stage to the second stage polymerization. No additional stabilizing system is added to the reaction in the second stage. Vinyl acetate/ethylene/incompatible comonomer/latent crosslinking comonomer copolymers prepared by the two stage polymerization process are suitably used as binders for making nonwoven products.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.