Adhesion of silicone rubber to thermoplastics

US11945981B1 · kind B1 · utility

Assignee

• Dow Silicones Corporation · US

Inventors

• Florian Ludwig GEYER · Ludwigshafen, DE
• Michael Backer · Mainz, DE

Key dates

• Filing date: Mar 29, 2022
• Grant date: Apr 2, 2024
• Expiry date: Mar 29, 2042

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C08G77/20
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

There is provided an adhesion mediator composition for use in the adhesion of silicone elastomers made from hydrosilylation curable silicone rubber compositions to thermoplastic substrates, especially polyolefin substrates. There is also provided a process for adhering silicone elastomers to thermoplastic substrates using the adhesion mediator composition. The adhesion mediator composition comprises: (i) a trialkoxysilane; (ii) a platinum group metal based hydrosilylation reaction catalyst; (iii) an alkoxy titanium compound; (iv) a tetraalkoxysilane; and (v): either (a′) a polyorganosiloxane containing at least two unsaturated groups; or (b′) a mixture of two or more polyorganosiloxanes containing at least two unsaturated groups. The method comprises the steps of: (a) optionally, activating a thermoplastic substrate surface; (b) treating the optionally activated thermoplastic substrate surface with the adhesion mediator composition; (c) applying a hydrosilylation curable silicone rubber composition on to the treated surface resulting from step (b); and (d) curing the hydrosilylation curable silicone rubber composition.