Late to this one, but I just discovered an alternative way of doing it:
On your template,
Associates
And on your component.ts, you can use serializeUrl to convert the route into a string, which can be used with window.open()
navigateAssociates() {
const url = this.router.serializeUrl(
this.router.createUrlTree(['/page1'])
);
window.open(url, '_blank');
}