Rough-surfaced interlayer

A thermoplastic interlayer which comprises:

• a) a first air removal surface integrally projecting from the plane of one side of the interlayer in a regular pattern comprising i) or ii) defined below:
• i) a multiplicity of microscopic embossments of substantially identical shape arranged in mutually perpendicular rows;
• ii) a multitude of substantially uninterrupted, parallel narrow linear channels defined by ridges evenly spaced from each other arranged diagonally with respect to a linear edge of the interlayer;
• b) a second air removal surface on the other side of the interlayer which is different from the first air removal surface and comprises a multiplicity of microscopic peaks and valleys of varying heights and depths arranged in an irregular, non-linear pattern;
• the height, R.sub.z, of said embossments, peaks and ridges being less than about 75 microns and the distance S.sub.m, between said embossments, peaks and ridges being less than about 650 microns;
• said interlayer in a prelaminate press-bonded on each side to a layer of glass being capable of transmitting at least 85% of incident light.

A thermoplastic interlayer which comprises:

• a) a first air removal surface comprising a multiplicity of microscopic embossments of substantially identical shape integrally projecting from the plane of one side of the interlayer in a regular pattern of mutually perpendicular rows;
• and
• b) a second air removal surface on the other side of the interlayer which is different from the first air removal surface and comprises a multiplicity of microscopic peaks and valleys of varying heights and depths arranged in an irregular, non-linear pattern;
• the height, R.sub.z, of said embossments and peaks being less than about 75 microns and the average distance S.sub.m, between said embossments and peaks being less than about 300 microns;
• said interlayer in a prelaminate press-bonded on each side to a layer of glass being capable of transmitting at least 85% of incident light.