US4677026A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resin composition for sealing electronic parts, and hydration-resistant magnesia powder and process for preparation thereof
Assignee: Ube Corp
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Filing: 1986-07-14
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Granted: 1987-06-30
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Expires: 2006-07-14
Abstract
Abstract Disclosed is a resin composition for sealing electronic parts, which comprises a thermosetting resin and, incorporated therein, high-purity magnesium oxide. A hydration-resistant magnesia powder having the particle surfaces covered with a continuous and uniform coating of silica is advantageously used as the magnesium oxide. This hydration-resistant magnesia powder is prepared by introducing a heated vapor of an organic silicate compound into a reactor of a fluidized bed of magnesia powder heated at 100° to 600° C. so that the concentration of the organic silicate compound is 1 to 20 mole %, and precipitating a coating of silica on the surfaces of magnesia particles by thermal decomposition and/or hydrolysis of the organic silicate compound on the surfaces of magnesia particles.
Inventors
- 👤 Toshikazu Hamamoto
- 👤 Motojirou Aoi
- 👤 Kozaburo Yoshida
- 👤 Yasuhiko Toda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:10
CPC Classifications
C; C08; C08K; C08K3/00; C08K3/18; C08K3/20; C08K3/22; C01; C01F; C01F5/00; C01F5/02; C08K9/00; C08K9/02; C09; C09C; C09C1/00; C09C1/02; C09C1/028; H; H01; H01B; H01B3/00; H01B3/02; H01B3/10; H01B3/18; H01B3/30; H01B3/40; H01B7/00; H01B7/17; H01B7/28; H01B7/282; H01B7/29; C01P; C01P2004/00; C01P2004/80; C01P2004/82; C01P2004/84; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2982; Y10T428/2991; Y10T428/2993
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
21 words
A hydration-resistant magnesia powder consisting of particles of magnesia having the surface covered with a continuous and uniform coating of silica.
Claim 2
Dependent Claim
21 words
A hydration-resistant magnesia powder consisting of particles of magnesia having the surface covered with a continuous and uniform coating of silica.
Claim 3
Dependent Claim
80 words
A process for the preparation of a hydration-resistant magnesia powder, which comprises introducing a heated vapor of an organic silicate compound into a reactor of a fluidized bed of magnesia powder heated at 100° to 600° C. so that the concentration of the organic silicate compound is 1 to 20 mole %, and precipitating a coating of silica on the surfaces of magnesia particles by thermal decomposition and/or hydrolysis of the organic silicate compound on the surfaces of magnesia particles.
Claim 4
Dependent Claim
80 words
A process for the preparation of a hydration-resistant magnesia powder, which comprises introducing a heated vapor of an organic silicate compound into a reactor of a fluidized bed of magnesia powder heated at 100° to 600° C. so that the concentration of the organic silicate compound is 1 to 20 mole %, and precipitating a coating of silica on the surfaces of magnesia particles by thermal decomposition and/or hydrolysis of the organic silicate compound on the surfaces of magnesia particles.
Claim 5
Dependent Claim
19 words
A process according to claim 2, wherein the temperature of the fluidized bed reactor is 350° to 450° C.
Claim 6
Dependent Claim
24 words
A process according to claim 2, wherein the concentration of the heated vapor of the organic silicate compound is 4 to 8 mole %.
Claim 7
Dependent Claim
19 words
A process according to claim 2, wherein steam is supplied together with the vapor of the organic silicate compound.
Claim 8
Dependent Claim
25 words
A process according to claim 5, wherein steam is supplied in an amount of 0.1 to 20.0 moles per mole of the organic silicate compound.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |