Process for producing polishing pads comprising a fully impregnated non-woven batt

DETAILED DESCRIPTION OF THE INVENTION "Bulk density" as used herein means and refers to the density of the material including air space.
"Actual density" as used herein means and refers to the density of the material not including air space, i.
e.
specific gravity.
The fibrous nonwoven mass useful in the practice of the invention is typically a needled fibrous batt formed of natural and synthetic fibers such as wool, polyester, polypropylene, rayon, nylon and the like and blends thereof.
Preferably, the fibers have a denier of between 1 and 5 and a length which is suitable for carding which is typically 1 to 6 inches and, more preferably, 11/2 to 3 inches.
The needled fibrous batts are typically 0.
125 to 0.
50 cm in thickness with a density of about 0.
1 to 0.
5 gm/cm.
sup.
3 and, more preferably, a thickness of 0.
08 to 0.
3 cm with a density of 0.
1 to 0.
4 gm/cm.
sup.
3.
Most preferably, the fibers are synthetic fibers.
Additionally, the batts are characterized as "saturating batts" which have high integrity due to the needle punching operation, as opposed to lightly bonded batts having few needle punches with little or no integrity.
The polymeric resins useful in the practice of the invention are preferably those polymeric resins which are capable of solubilization, dispersion, or emulsification in water and subsequent coagulation from the water system with a coagulating agent and preferably an ionic coagulation agent.
A polymer system which can be useful is one which is synthesized from acrylic monomers such as the alkyl acrylates and methylacrylates, acrylonitrile, methacrylonitrile and other well-known acrylic monomers.
These acrylic monomers may be polymerized by emulsion polymerization to form a latex or by other free radical polymerization mechanisms and subsequently solubilized or emulsified in water.
The emulsification or solubilization system must be such that when the emulsion is contacted with concentrated acid or base, the polymer coagulates from the aqueous system and is rendered substantially insoluble