Truly permanent adhesive inside patching of tear in pants?

Somehow a pair of Dockers-style pants got snagged and it created about a 3 - 4 inch straight tear. The pants are fairly new, would otherwise have a lot of life in them. Any recommendations for a strong adhesive or adhesive patch for patching from the inside?

I know it wouldn't be invisible but it isn't that critical, just looking for a solid repair that will hold up to being sat on and machine washing. The tear is on the back of one leg perpendicular to the leg below the seat area so it wouldn't be constantly being stretched while sitting.

Any such thing exist?

Thanks

 

There are iron on patches that work pretty well. Just do it on the inside where it can't be seen.

 

I've patched some embroidered ones.. what I've learned: pressing cloth over it protects your patch from any heat damage and also your iron from glue. Set the iron on the hottest temp and remember to not use steam cause it will affect the glue.

 

I'm hard on work clothes and have used the iron on patches fairly often. In high stress areas it can be helpful to sew part or all of the perimeter of the patch.