Coating or plastic compositions which are rendered porous by some specific step performed for this purpose.
(1) Note. This subclass does not include porous compositions in which the porosity is due solely to the use of naturally occurring porous ingredients, which compositions are classified on some other basis.
SEE OR SEARCH THIS CLASS, SUBCLASS:
40, 41, 601+, and 672+, for other pore forming within this class.
SEE OR SEARCH CLASS
51, Abrasive Tool Making Process, Material, or Composition,
296, for an abrasive tool making process including a pore forming step, or for a porous abrading composition.
216, Etching a Substrate: Processes,
56, for the use of etching in the formation of a porous or perforated article. 264, Plastic and Nonmetallic Article Shaping or Treating: Processes,
41+, for processes of molding which include the step of pore forming in situ.
366, Agitating,
3+, for mortar mixing processes including the step of incorporating air or gas.
419, Powder Metallurgy Processes,
2, for processes of making porous products from particulate material which include metal particles with heat.
428, Stock Material or Miscellaneous Articles,
304.4+, for a stock material product of at least two components, in which one of the components is either porous or cellular and subclass 613 for porous metallic stock.
521, Synthetic Resins or Natural Rubbers, appropriate subclass for a cellular or pore containing synthetic resin or natural rubber.
