Corrosive substance in laminate and some coppers (6,4)
I believe the answer is:
formic acid
'corrosive substance' is the definition.
'laminate and some coppers' is the wordplay.
'laminate' becomes 'formica' (Formica is an example).
'and' says to put letters next to each other.
'some coppers' becomes 'cid' (Criminal Investigation Department).
'formica'+'cid'='FORMIC ACID'
'in' is the link.
(Other definitions for formic acid that I've seen before include "Tannery chemical" , "Substance emitted by some ants" .)