Ramp for polyoxmethylene resin hard disk drive
AssigneeAsahi Kasei Chemicals Corporation
InventorMitsuhiro Horio
Life of this patent
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Abstract
A ramp for a polyoxymethylene hard resin disk drive, which has an outgas level of not more than 20 μg/g. The ramp for a polyoxymethylene resin hard disk drive comprises the steps of providing an extruder, melt kneading a polyoxymethylene resin with a colorant while degassing through one or more vents under a reduced pressure of −0.06 Mpa or less to prepare polyoxymethylene resin pellets, and injection molding the polyoxymethylene resin pellets, washing the molding with a solvent, and drying the molding.
Claims9
A ramp for a hard disk drive having an outgas level of 20 μg/g or less, the ramp being produced by the steps:
- forming a polyoxymethylene resin pellet by melt-kneading a polyoxymethylene resin with a colorant using an extruder while degassing under a reduced pressure of −0.06 MPa or less from one or more vents of the extruder;
- injection molding the formed polyoxymethylene resin pellet;
- solvent washing the molded article;
- and
- drying the washed molded article,
- wherein the polyoxymethylene resin has a composition comprising a hindered phenol of 0.05 to 0.5% by weight, a formaldehyde reactive nitrogen-containing polymer of 0.01 to 0.5% by weight and a fatty acid salt of an alkaline earth metal of 0.01 to 0.5% by weight, relative to a polyoxymethylene copolymer,
- wherein the colorant is at least one member selected from the group consisting of titanium oxide, a composite metal oxide, iron oxide, carbon black, calcium carbonate, wollastonite and ultrafine particles of carbon, and
- wherein an amount of chloride ion adhering to a surface of a polyacetal resin obtained by the melt-kneading step is 1 μg/g or less.
Dependencies are inferred from the claim text.