The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 19, 1992
Filed:
Feb. 26, 1991
NGK Insulators, Ltd., , JP;
NGK Adrec Co., Ltd., , JP;
Abstract
A filter for aluminum hot melt comprises alumina aggregate particles and an inorganic binder in an amount of 5 to 20 parts by weight bound to 100 parts by weight of said alumina aggregate particles. The inorganic binder is composed to 15 wt % to 80 wt % of B.sub.2 O.sub.3, 2 wt % to 60 wt % of Al.sub.2 O.sub.3, 0 wt % to 30 wt % of CaO and 5 wt % to 50 wt % of MgO, and the presence of a highly crystalline binder in the filter yields better properties such as an increase in chemical durability and a lower thermal expansion coefficient where the crystallinity is defined by a peak height of 9Al.sub.2 O.sub.3 -2B.sub.2 O.sub.3 at 2.theta.=16.5.degree. being not less than 30% of a peak-height of .alpha.-Al.sub.2 O.sub.3 at 2.theta.=43.4.degree. when measured by powder X-ray diffractometry and is obtained by a cooling rate of less than 70.degree. C./hr.