Preparation of glass/plastic laminates having improved optical quality

DETAILED DESCRIPTION In accordance with the present invention, a process is provided for controlling optical defects in glass/plastic laminates induced by particulate contaminants during the preparation of the laminates wherein heat and pressure are applied to a coverplate and a receiving glass to bond elements of the laminate.
The process comprises forming a composite structure having exterior surfaces comprised of the outboard surfaces of a receiving glass and an abrasion resistant polymeric film with an adhesive material therebetween for bonding the elements of the laminate together.
A soft plastic film is releasably adhered to the outboard surface of the abrasion resistant polymeric film.
In the bonding step a coverplate is positioned over the composite structure, and sufficient heat and pressure are applied to the coverplate and the receiving glass to bond the elements of the composite structure and permit deformation of the soft plastic film to entrap particulate contaminants present between the outboard surface of the abrasion resistant polymeric film and the coverplate in the soft plastic film while maintaining the optical integrity of the surface of the abrasion resistant polymeric film.
It has been found that optical defects due to the presence of particulate contaminants on the surface of the abrasion resistant polymeric film surface are substantially eliminated by using the process of this invention.
As heat and pressure are applied in bonding the polymeric film to the receiving glass, the particles become embedded in the soft plastic film.
When the soft plastic film is removed, the optical integrity of the abrasion resistant polymeric film is found to be undisturbed.
In carrying out the process of this invention, a soft plastic film is releasably adhered to the outboard surface of an abrasion resistant polymeric film.
As disclosed more fully later herein, the soft plastic film may first be adhered to the abrasion resistant polymeric film surface, or it may be applied later in a coating operation