Process for making pressure-sensitive adhesive and duct tape
US11560498B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 14, 2019 |
| Grant date | Jan 24, 2023 |
| Priority date | — |
| Expiry date | Nov 24, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09J2423/00
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A continuous process for making a pressure-sensitive adhesive is disclosed. A mixture comprising natural rubber having a Mooney viscosity of 85 to 100, a tackifier, a filler, and 0.1 to 5 wt. % of an added C12-C24 fatty acid based on the amount of mixture is masticated in a first section of a single- or twin-screw extruder. Mastication of the mixture continues in at least one subsequent extruder section in the presence of additional tackifier. The product is a homogeneous, reduced-viscosity pressure-sensitive adhesive. The minor proportion of added C12-C24 fatty acid aids mastication of the rubber and enables high throughput without addition of peptizers. Duct tapes made from the adhesives display improved adhesion to steel, better adhesion bond strength, and enhanced seven-day clean removability from even difficult substrates such as marble or ceramic tile.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.