Self-lubricated polyacetal molding compositions and molded articles formed thereof
AssigneePolyplastics Co., Ltd.
InventorsKatsunori Takayama, Toshihiko Endo, Osamu Kanoto, Nobuyuki Matsunaga
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Abstract
Self-lubricating polyacetal resin compositions and molded articles (e.g. "wear parts") formed thereof include a polyacetal base resin, and a self-lubricating effective amount of a silica powder in which a silicone polymer (e.g. silicone oil) is absorbed. The silica powder acts as a carrier for the silicone polymer so as to improve the dispersibility of the silicone polymer in the polyacetal base resin as well as to allow greater silicone polymer "loading" of the polyacetal base resin. As a result, improved lubricant dispersibility and sliding characteristics are achieved.
Claims12
A self-lubricating polyacetal resin composition comprising a melt-blend of a polyacetal base resin, and a self-lubricating effective amount of a silica powder having a mean particle diameter of between 5 to 300 .mu.m and in which a silicone polymer is absorbed therein in an amount between 30 to 80% by weight of said silica powder.
A polyacetal resin composition as in claim or 2, wherein the silicone polymer is a silicone
A self-lubricating polyacetal resin molding composition comprising a melt-blend of (A) a polyacetal base resin, (B) a silicone oil, and (C) a powdered silicone-absorbant carrier in which said silicone oil is absorbed, said powdered carrier being a silica powder which is homogeneously dispersed throughout said polyacetal base resin, wherein said silica powder has a mean particle diameter of between 5 to 300 .mu.m and said silicone oil is absorbed in said silica powder in an amount between 30 to 80% by weight of said silica powder.
A method of making a self-lubricated polyacetal molding composition comprising the steps of absorbing a silicone oil within a silica powder carrier therefor, and then melt-blending a self-lubricating effective amount of the silica powder carrier with absorbed silicone oil therein, with a polyacetal base resin, wherein the silica powder has a mean particle diameter of between 5 to 300 .mu.m and the silicone oil is absorbed in the silica powder in an amount between 30 to 80% by weight of the silica powder.
Dependencies are inferred from the claim text.