Patent US5069697A successfully refreshed from Google Patents.
US5069697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous ceramic honeycomb filter and method of producing the same
Assignee: NGK Insulators Ltd
•
Filing: 1989-08-03
•
Granted: 1991-12-03
•
Expires: 2009-08-03
Abstract
Abstract A porous ceramic honeycomb filter having a chemical composition consisting of, as main components, 42-56 wt % SiO 2 , 30-45 wt % Al 2 O 3 , and 12-16 wt % MgO and containing cordierite as a main component of a crystalline phase. The porous ceramic honeycomb filter has a porosity of at least 40% and not greater than 55%. The volume of pores having a diameter not larger than 2 μm in the filter is not larger than 0.015 cc/g to thereby improve the collecting time with low pressure loss and high collecting efficiency.
Inventors
- 👤 Kunikazu Hamaguchi
- 👤 Takashi Harada
- 👤 Toshiyuki Hamanaka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:26
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/01; C04B35/16; C04B35/18; C04B35/195; B; B01; B01D; B01D39/00; B01D39/14; B01D39/20; B01D39/2068; B01D39/2072; B01D39/2075; C04B38/00; C04B38/0006; F; F01; F01N; F01N3/00; F01N3/02; F01N3/021; F01N3/022; F01N3/0222; F01N2330/00; F01N2330/06; F02; F02B; F02B3/00; F02B3/06; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y10; Y10S; Y10S55/00; Y10S55/30
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
134 words
A method of producing a porous ceramic honeycomb filter, comprising the steps of: mixing a cordierite raw material consisting essentially of 42-56 wt% SiO 2 , 30-45 wt% Al 2 O 3 , and 12-16 wt% MgO as main components, with a pore forming agent; adjusting a grain size of fine particles of the raw material such that a total amount of particles having a grain size not larger than 2 μm is not more than 35% of the entire wt% of the mixture; adding a plasticizer and a binder to the adjusted raw material to make a batch mixture; extrusion molding the batch mixture to produce a ceramic honeycomb filter; drying the extruded ceramic honeycomb filter; and firing the extruded ceramic honeycomb filter at a firing temperature in a range of 1350°-1440° C.
Claim 2
Independent Claim
134 words
A method of producing a porous ceramic honeycomb filter, comprising the steps of: mixing a cordierite raw material consisting essentially of 42-56 wt% SiO 2 , 30-45 wt% Al 2 O 3 , and 12-16 wt% MgO as main components, with a pore forming agent; adjusting a grain size of fine particles of the raw material such that a total amount of particles having a grain size not larger than 2 μm is not more than 35% of the entire wt% of the mixture; adding a plasticizer and a binder to the adjusted raw material to make a batch mixture; extrusion molding the batch mixture to produce a ceramic honeycomb filter; drying the extruded ceramic honeycomb filter; and firing the extruded ceramic honeycomb filter at a firing temperature in a range of 1350°-1440° C.
Claim 3
Dependent Claim
35 words
The method of claim 1, wherein the total amount of particles having a grain size not larger than 2 μm in the mixture is not more than 15% of the entire wt% of the mixture.
Claim 4
Dependent Claim
93 words
A porous ceramic honeycomb filter produced by the method of claim 1, the ceramic honeycomb filter having a chemical composition consisting essentially of 42-56 wt% SiO 2 , 30-45 wt% Al 2 O 3 , and 12-16 wt% MgO as main components, and cordierite as a main component of a crystalline phase, wherein the ceramic honeycomb filter has a porosity of at least 40% but not greater than 55%, and a volume of pores in the ceramic honeycomb filter having a diameter not larger than 2 μm is not greater than 0.015 cc/g.
Claim 5
Dependent Claim
31 words
The ceramic honeycomb filter of claim 3, wherein the volume of pores in the ceramic honeycomb filter having a diameter not larger than 2 μm is not greater than 0.010 cc/g.
References Cited (Backward Citations)
DE2617491A1
Cited
US4191721A
Cited
US4191720A
Cited
JPS55137022A
Cited
US4407967A
Cited
US4264346A
Cited
US4278544A
Cited
US4283210A
Cited
US4364760A
Cited
US4340403A
Cited
JPS5749009A
Cited
US4432918A
Cited
US4455180A
Cited
JPS5870814A
Cited
US4416675A
Cited
US4417908A
Cited
US4419108A
Cited
JPS58159828A
Cited
JPS6154750A
Cited
US4632683A
Cited
US4704863A
Cited
US4732593A
Cited
JPS6226312A
Cited
US4857089A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-02 | 1995-06-03 | 1995-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-02 | 1999-06-03 | 1999-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-02 | 2003-06-03 | 2003-12-03 | $7700.00 | Window Closed / Lapsed |