Production of super-smooth articles
AssigneeThe United States of America as represented by the Department of Energy
InventorDavid V. Duchane
Life of this patent
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Abstract
Super-smooth rounded or formed articles made of thermoplastic materials including various poly(methyl methacrylate) or acrylonitrile-butadiene-styrene copolymers are produced by immersing the articles into a bath, the composition of which is slowly changed with time. The starting composition of the bath is made up of at least one solvent for the polymer and a diluent made up of at least one nonsolvent for the polymer and optional materials which are soluble in the bath. The resulting extremely smooth articles are useful as mandrels for laser fusion and should be useful for a wide variety of other purposes, for example lenses.
Claims12
A method of smoothing the surface of an article comprising a first material selected from the group consisting of poly(methyl methacrylate) and acrylonitrile-butadiene-styrene polymers, said method comprising:
- (a) immersing at least a portion of said article into a bath consisting essentially of (1) at least one solvent for said first material and (2) a diluent consisting essentially of at least one nonsolvent for said first material and optional accessory material which is soluble in said bath;
- and
- (b) slowly removing said solvent from said bath by diluting said bath with said diluent, wherein said nonsolvent is a mixture of water and a water-soluble polymer having a molecular weight within the range from about 2000 to about 20,000, wherein said at least one solvent is selected from the group consisting of ketones and esters which show some significant mutual solubility with water, and wherein the rate of dilution of said bath is such that it results in extraction of said solvent from said first material on a molecular scale, rather than on a massive scale.
Dependencies are inferred from the claim text.